Rice Husk Ash to Stabilize Heavy Metals Contained in Municipal Solid Waste Incineration Fly Ash: First Results by Applying New Pre-treatment Technology

PubMed Central

Benassi, Laura; Franchi, Federica; Catina, Daniele; Cioffi, Flavio; Rodella, Nicola; Borgese, Laura; Pasquali, Michela; Depero, Laura E.; Bontempi, Elza

2015-01-01

A new technology was recently developed for municipal solid waste incineration (MSWI) fly ash stabilization, based on the employment of all waste and byproduct materials. In particular, the proposed method is based on the use of amorphous silica contained in rice husk ash (RHA), an agricultural byproduct material (COSMOS-RICE project). The obtained final inert can be applied in several applications to produce “green composites”. In this work, for the first time, a process for pre-treatment of rice husk, before its use in the stabilization of heavy metals, based on the employment of Instant Pressure Drop technology (DIC) was tested. The aim of this work is to verify the influence of the pre-treatment on the efficiency on heavy metals stabilization in the COSMOS-RICE technology. DIC technique is based on a thermomechanical effect induced by an abrupt transition from high steam pressure to a vacuum, to produce changes in the material. Two different DIC pre-treatments were selected and thermal annealing at different temperatures were performed on rice husk. The resulting RHAs were employed to obtain COSMOS-RICE samples, and the stabilization procedure was tested on the MSWI fly ash. In the frame of this work, some thermal treatments were also realized in O2-limiting conditions, to test the effect of charcoal obtained from RHA on the stabilization procedure. The results of this work show that the application of DIC technology into existing treatment cycles of some waste materials should be investigated in more details to offer the possibility to stabilize and reuse waste. PMID:28793605

Fluidized bed coal combustion reactor

NASA Technical Reports Server (NTRS)

Moynihan, P. I.; Young, D. L. (Inventor)

1981-01-01

A fluidized bed coal reactor includes a combination nozzle-injector ash-removal unit formed by a grid of closely spaced open channels, each containing a worm screw conveyor, which function as continuous ash removal troughs. A pressurized air-coal mixture is introduced below the unit and is injected through the elongated nozzles formed by the spaces between the channels. The ash build-up in the troughs protects the worm screw conveyors as does the cooling action of the injected mixture. The ash layer and the pressure from the injectors support a fluidized flame combustion zone above the grid which heats water in boiler tubes disposed within and/or above the combustion zone and/or within the walls of the reactor.

Volcanic Ash fall Impact on Vegetation, Colima 2005

NASA Astrophysics Data System (ADS)

Garcia, M. G.; Martin, A.; Fonseca, R.; Nieto, A.; Radillo, R.; Armienta, M.

2007-05-01

An ash sampling network was established arround Colima Volcano in 2005. Ash fall was sampled on the North, Northeast, East, Southeast, South, Southwest and West of the volcano. Samples were analyzed for ash components, geochemistry and leachates. Ash fall ocurred on April (12), May (10, 23), June (2, 6, 9, 10, 12, 14), July (27), September (27), October (23) and November (24). Most of the ash is made of andesitic dome-lithics but shows diferences in crystal, juvenile material and lithic content. In May, some samples contained grey and dark pumice (scoria). Texture varies from phi >4 to phi 0. Leachate concentration were low: SO4 (7.33-54.19) Cl- (2.29-4.97) and F- (0.16-0.37). During 2005, Colima Volcano's ash fall rotted some of the guava and peach fruits and had a drying effect on spearment and epazote plants. Even these small ash amounts could have hindered sugar cane and agave growth.

Physical-durable performance of concrete incorporating high loss on ignition-fly ash

NASA Astrophysics Data System (ADS)

Huynh, Trong-Phuoc; Ngo, Si-Huy; Hwang, Chao-Lung

2018-04-01

This study investigates the feasibility of using raw fly ash with a high loss on ignition in concrete. The fly ash-free concrete samples were prepared with different water-to-binder (w/b) ratios of 0.35, 0.40, and 0.45, whereas the fly ash concrete samples were prepared with a constant w/b of 0.40 and with various fly ash contents (10%, 20%, and 30%) as a cement substitution. The physical properties and durability performance of the concretes were evaluated through fresh concrete properties, compressive strength, strength efficiency of cement, ultrasonic pulse velocity, and resistance to sulfate attack. Test results show that the w/b ratio affected the concrete properties significantly. The incorporation of fly ash increased the workability and reduced the unit weight of fresh concrete. In addition, the fly ash concrete samples containing up to 20% fly ash exhibited an improved strength at long-term ages. Further, all of the fly ash concrete samples showed a good durability performance with ultrasonic pulse velocity value of greater than 4100 m/s and a comparable sulfate resistance to the no-fly ash concrete.

Rheological Variations in Lahars Expected to Flow Along the Sides of Sakurajima and Ontake Volcanoes, Japan

NASA Astrophysics Data System (ADS)

Kurokawa, A. K.; Ishibashi, H.

2016-12-01

Volcanic ash is known to accumulate on the ground surface around volcano after eruptions. Once the ash gains weight and mixes with water to a critical point, the mixture of volcanic ash and water runs down a side of volcano causing severe damage to the ambient environment. The flow is referred to as lahar that is widely observed all over the world and it occasionally generates seismic signals [Walsh et al., 2016; Ogiso and Yomogida, 2015]. Sometimes it happens just after an eruption [Nakayama and Kuroda, 2003] whereas a large debris flow, which occurred about 30 years after the latest eruption due to heavy rainfall is also reported [Ogiso and Yomogida, 2015]. Thus when the lahar starts flowing is a key. In order to understand flow characteristics of lahar, it is important to focus on the rheology. However, little is known about the rheological property although the experimental condition can be controlled at atmospheric pressure and ambient temperature. This is an advantage when compared with magma and rock, which need to reach high-pressure and/or high-temperature conditions to be measured. Based on the background, we have performed basic rheological measurements using mixtures of water and volcanic ashes collected at Sakurajima and Ontake volcanoes in Japan. The first important point of our findings is that the two types of mixtures show non-linear characteristics differently. For instance, the viscosity variation strongly depends on the water content in the case of Sakurajima sample while the viscosity fluctuates within a certain definite range of shear rate using Ontake sample. Since these non-linear characteristics are related to structural changes in the flow, our results indicate that the flow of lahar is time-variable and complicated. In this presentation, we report the non-linear rheology in detail and go into the relation to temporal changes in the flow.

Deposition and immersion-mode nucleation of ice by three distinct samples of volcanic ash

NASA Astrophysics Data System (ADS)

Schill, G. P.; Genareau, K.; Tolbert, M. A.

2015-07-01

Ice nucleation of volcanic ash controls both ash aggregation and cloud glaciation, which affect atmospheric transport and global climate. Previously, it has been suggested that there is one characteristic ice nucleation efficiency for all volcanic ash, regardless of its composition, when accounting for surface area; however, this claim is derived from data from only two volcanic eruptions. In this work, we have studied the depositional and immersion freezing efficiency of three distinct samples of volcanic ash using Raman microscopy coupled to an environmental cell. Ash from the Fuego (basaltic ash, Guatemala), Soufrière Hills (andesitic ash, Montserrat), and Taupo (Oruanui eruption, rhyolitic ash, New Zealand) volcanoes were chosen to represent different geographical locations and silica content. All ash samples were quantitatively analyzed for both percent crystallinity and mineralogy using X-ray diffraction. In the present study, we find that all three samples of volcanic ash are excellent depositional ice nuclei, nucleating ice from 225 to 235 K at ice saturation ratios of 1.05 ± 0.01, comparable to the mineral dust proxy kaolinite. Since depositional ice nucleation will be more important at colder temperatures, fine volcanic ash may represent a global source of cold-cloud ice nuclei. For immersion freezing relevant to mixed-phase clouds, however, only the Oruanui ash exhibited appreciable heterogeneous ice nucleation activity. Similar to recent studies on mineral dust, we suggest that the mineralogy of volcanic ash may dictate its ice nucleation activity in the immersion mode.

Sintering of MSW fly ash for reuse as a concrete aggregate.

PubMed

Mangialardi, T

2001-10-12

The sintering process of municipal solid waste (MSW) fly ash was investigated in order to manufacture sintered products for reuse as concrete aggregates. Four types of fly ash resulting from different Italian MSW incineration plants were tested in this study. A modification of the chemical composition of MSW fly ash--through a preliminary four-stage washing treatment of this material with water--was attempted to improve the chemical and mechanical characteristics of sintered products.The sintering treatment of untreated or washed fly ash was performed on cylindrical compact specimens (15 mm in diameter and 20mm in height) at different compact pressures, sintering temperatures and times.The sintering process of untreated MSW fly ashes proved to be ineffective for manufacturing sintered products for reuse as a construction material, because of the adverse chemical characteristics of these fly ashes in terms of sulfate, chloride, and vitrifying oxide contents.A preliminary washing treatment of MSW fly ash with water greatly improved the chemical and mechanical characteristics of sintered products and, for all the types of fly ash tested, the sintered products satisfied the Italian requirements for normal weight aggregates for use in concretes having a specified strength not greater than 12 and 15N/mm(2), when measured on cylindrical and cubic specimens, respectively.A compact pressure of 28 N/mm(2), a sintering temperature of 1140 degrees C, and a sintering time of 60 min were the best operating conditions for manufacturing sintered products of washed MSW fly ash.

Arsenic Speciation of Solvent-Extracted Leachate from New and Weathered CCA-Treated Wood

PubMed Central

KHAN, BERNINE I.; SOLO - GABRIELE, HELENA M.; DUBEY, BRAJESH K.; TOWNSEND, TIMOTHY G.; CAI, YONG

2009-01-01

For the past 60 yr, chromate-copper-arsenate (CCA) has been used to pressure-treat millions of cubic meters of wood in the United States for the construction of many outdoor structures. Leaching of arsenic from these structures is a possible health concern as there exists the potential for soil and groundwater contamination. While previous studies have focused on total arsenic concentrations leaching from CCA-treated wood, information pertaining to the speciation of arsenic leached is limited. Since arsenic toxicity is dependent upon speciation, the objective of this study was to identify and quantify arsenic species leaching from new and weathered CCA-treated wood and CCA-treated wood ash. Solvent-extraction experiments were carried out by subjecting the treated wood and the ash to solvents of varying pH values, solvents defined in the EPA’s Synthetic Precipitation Leaching Procedure (SPLP) and Toxicity Characteristic Leaching Procedure (TCLP), rainwater, deionized water, and seawater. The generated leachates were analyzed for inorganic As(III) and As(V) and the organoarsenic species, monomethylarsonic acid (MMAA) and dimethylarsinic acid (DMAA), using high-performance liquid chromatography followed by hydride generation and atomic fluorescence spectrometry (HPLC–HG-AFS). Only the inorganic species were detected in any of the wood leachates; no organoarsenic species were found. Inorganic As(V) was the major detectable species leaching from both new and weathered wood. The weathered wood leached relatively more overall arsenic and was attributed to increased inorganic As(III) leaching. The greater presence of As(III) in the weathered wood samples as compared to the new wood samples may be due to natural chemical and biological transformations during the weathering process. CCA-treated wood ash leached more arsenic than unburned wood using the SPLP and TCLP, and ash samples leached more inorganic As(III) than the unburned counterparts. Increased leaching was due to higher concentrations of arsenic within the ash and to the conversion of some As(V) to As(III) during combustion. PMID:15461159

Hydrothermal carbonization of rice husk for fuel upgrading

NASA Astrophysics Data System (ADS)

Suteerawattananonda, N.; Kongkaew, N.; Patumsawad, S.

2018-01-01

The biomass is popularly used as renewable energy. In Thailand rice is the most consume agricultural products. Agricultural residues from rice husk can be an energy resource. However, alkali and alkali earth materials (AAEMs) in biomass ash are the causes of corrosion and erosion problem in the heat exchanger equipment, while the acidity of ash affects the slagging agglomeration problem. Reduction of alkali and alkali earth materials can minimize the problem. In order to challenge the reduction of alkali and alkali earth materials in biomass ash, hydrothermal carbonization process was selected. Thai rice husk was used as sample to compare the result of treatment. The rice husk was heated under the condition of different temperature ranged from 180°C to 250°C, at operate pressure ranges from 12 bar to 42 bar with residence holding reaction time 1 hour. The results of proximate analysis show that the percentage by mass of fixed carbon are increased 2 times, but volatile matter is decreased by 40% and ash content is decreased by 11% due to the increment of temperature. Meanwhile, the X-Ray fluorescence (XRF) analysis results show the decreasing of alkali and alkali earth materials are reduced.

Trace element partitioning in ashes from boilers firing pure wood or mixtures of solid waste with respect to fuel composition, chlorine content and temperature

DOE Office of Scientific and Technical Information (OSTI.GOV)

Saqib, Naeem, E-mail: naeem.saqib@oru.se; Bäckström, Mattias, E-mail: mattias.backstrom@oru.se

Highlights: • Different solids waste incineration is discussed in grate fired and fluidized bed boilers. • We explained waste composition, temperature and chlorine effects on metal partitioning. • Excessive chlorine content can change oxide to chloride equilibrium partitioning the trace elements in fly ash. • Volatility increases with temperature due to increase in vapor pressure of metals and compounds. • In Fluidized bed boiler, most metals find themselves in fly ash, especially for wood incineration. - Abstract: Trace element partitioning in solid waste (household waste, industrial waste, waste wood chips and waste mixtures) incineration residues was investigated. Samples of flymore » ash and bottom ash were collected from six incineration facilities across Sweden including two grate fired and four fluidized bed incinerators, to have a variation in the input fuel composition (from pure biofuel to mixture of waste) and different temperature boiler conditions. As trace element concentrations in the input waste at the same facilities have already been analyzed, the present study focuses on the concentration of trace elements in the waste fuel, their distribution in the incineration residues with respect to chlorine content of waste and combustion temperature. Results indicate that Zn, Cu and Pb are dominating trace elements in the waste fuel. Highly volatile elements mercury and cadmium are mainly found in fly ash in all cases; 2/3 of lead also end up in fly ash while Zn, As and Sb show a large variation in distribution with most of them residing in the fly ash. Lithophilic elements such as copper and chromium are mainly found in bottom ash from grate fired facilities while partition mostly into fly ash from fluidized bed incinerators, especially for plants fuelled by waste wood or ordinary wood chips. There is no specific correlation between input concentration of an element in the waste fuel and fraction partitioned to fly ash. Temperature and chlorine content have significant effects on partitioning characteristics by increasing the formation and vaporization of highly volatile metal chlorides. Zinc and cadmium concentrations in fly ash increase with the incineration temperature.« less

Experimental constraints on phreatic eruption processes at Whakaari (White Island volcano)

NASA Astrophysics Data System (ADS)

Mayer, Klaus; Scheu, Bettina; Gilg, H. Albert; Heap, Michael J.; Kennedy, Ben M.; Lavallée, Yan; Letham-Brake, Mark; Dingwell, Donald B.

2015-09-01

Vigorous hydrothermal activity interspersed by sequences of phreatic and phreatomagmatic eruptions occur at Whakaari (White Island volcano), New Zealand. Here, we investigate the influence of sample type (hydrothermally altered cemented ash tuffs and unconsolidated ash/lapilli) and fragmentation mechanism (steam flashing versus gas expansion) on fragmentation and ejection velocities as well as on particle-size and shape. Our rapid decompression experiments show that fragmentation and ejection speeds of two ash tuffs, cemented by alunite and amorphous opal, increase with increasing porosity and that both are significantly enhanced in the presence of steam flashing. Ejection speeds of unconsolidated samples are higher than ejection speeds of cemented tuffs, as less energy is consumed by fragmentation. Fragmentation dominated by steam flashing results in increased fragmentation energy and a higher proportion of fine particles. Particle shape analyses before and after fragmentation reveal that both steam flashing and pure gas expansion produce platy or bladed particles from fracturing parallel to the decompression front. Neither fragmentation mechanisms nor sample type show a significant influence on the shape. Our results emphasize that, under identical pressure and temperature conditions, eruptions accompanied by the process of liquid water flashing to steam are significantly more violent than those driven simply by gas expansion. Therefore, phase changes during decompression and cementation are both important considerations for hazard assessment and modeling of eruptions in hydrothermally active environments.

DOE Office of Scientific and Technical Information (OSTI.GOV)

M. Mercedes Maroto-Valer; John M. Andresen; Yinzhi Zhang

This research program focused on the development of fly ash derived sorbents to capture CO{sub 2} from power plant flue gas emissions. The fly ash derived sorbents developed represent an affordable alternative to existing methods using specialized activated carbons and molecular sieves, that tend to be very expensive and hinder the viability of the CO{sub 2} sorption process due to economic constraints. Under Task 1 'Procurement and characterization of a suite of fly ashes', 10 fly ash samples, named FAS-1 to -10, were collected from different combustors with different feedstocks, including bituminous coal, PRB coal and biomass. These samples presentedmore » a wide range of LOI value from 0.66-84.0%, and different burn-off profiles. The samples also spanned a wide range of total specific surface area and pore volume. These variations reflect the difference in the feedstock, types of combustors, collection hopper, and the beneficiation technologies the different fly ashes underwent. Under Task 2 'Preparation of fly ash derived sorbents', the fly ash samples were activated by steam. Nitrogen adsorption isotherms were used to characterize the resultant activated samples. The cost-saving one-step activation process applied was successfully used to increase the surface area and pore volume of all the fly ash samples. The activated samples present very different surface areas and pore volumes due to the range in physical and chemical properties of their precursors. Furthermore, one activated fly ash sample, FAS-4, was loaded with amine-containing chemicals (MEA, DEA, AMP, and MDEA). The impregnation significantly decreased the surface area and pore volume of the parent activated fly ash sample. Under Task 3 'Capture of CO{sub 2} by fly ash derived sorbents', sample FAS-10 and its deashed counterpart before and after impregnation of chemical PEI were used for the CO{sub 2} adsorption at different temperatures. The sample FAS-10 exhibited a CO{sub 2} adsorption capacity of 17.5mg/g at 30 C, and decreases to 10.25mg/g at 75 C, while those for de-ashed counterpart are 43.5mg/g and 22.0 mg/g at 30 C and 75 C, respectively. After loading PEI, the CO{sub 2} adsorption capacity increased to 93.6 mg/g at 75 C for de-ashed sample and 62.1 mg/g at 75 C for raw fly ash sample. The activated fly ash, FAS-4, and its chemical loaded counterparts were tested for CO{sub 2} capture capacity. The activated carbon exhibited a CO{sub 2} adsorption capacity of 40.3mg/g at 30 C that decreased to 18.5mg/g at 70 C and 7.7mg/g at 120 C. The CO{sub 2} adsorption capacity profiles changed significantly after impregnation. For the MEA loaded sample the capacity increased to 68.6mg/g at 30 C. The loading of MDEA and DEA initially decreased the CO{sub 2} adsorption capacity at 30 C compared to the parent sample but increased to 40.6 and 37.1mg/g, respectively, when the temperature increased to 70 C. The loading of AMP decrease the CO{sub 2} adsorption capacity compared to the parent sample under all the studied temperatures. Under Task 4 'Comparison of the CO{sub 2} capture by fly ash derived sorbents with commercial sorbents', the CO{sub 2} adsorption capacities of selected activated fly ash carbons were compared to commercial activated carbons. The CO{sub 2} adsorption capacity of fly ash derived activated carbon, FAS-4, and its chemical loaded counterpart presented CO{sub 2} capture capacities close to 7 wt%, which are comparable to, and even better than, the published values of 3-4%.« less

Physical and hydrologic properties of outcrop samples from a nonwelded to welded tuff transition, Yucca Mountain, Nevada

USGS Publications Warehouse

Rautman, C.A.; Flint, L.E.; Flint, A.L.; Istok, J.D.

1995-01-01

Quantitative material-property data are needed to describe lateral and vertical spatial variability of physical and hydrologic properties and to model ground-water flow and radionuclide transport at the potential Yucca Mountain nuclear-waste repository site in Nevada. As part of ongoing site characterization studies of Yucca Mountain directed toward this understanding of spatial variability, laboratory measurements of porosity, bull* and particle density, saturated hydraulic conductivity, and sorptivity have been obtained for a set of outcrop samples that form a systematic,two dimensional grid that covers a large exposure of the basal Tiva Canyon Tuff of the Paintbrush Group of Miocene age at Yucca Mountain. The samples form a detailed vertical grid roughly parallel to the transport direction of the parent ash flows, and they exhibit material-property varia- tions in an interval of major lithologic change overlying a potential nuclear-waste repository at Yucca Mountain. The observed changes in hydrologic properties were systematic and consistent with the changes expected for the nonwelded to welded transition at the base of a major ash-flow sequence. Porosity, saturated hydraulic conductivity, and sorptivity decreased upward from the base of the Tiva Canyon Tuff, indicating the progressive compaction of ash- rich volcanic debris and the onset of welding with increased overburden pressure from the accumulating ash-flow sheet. The rate of decrease in the values of these material properties varied with vertical position within the transition interval. In contrast, bulk-density values increased upward, a change that also is consistent with progressive compaction and the onset of welding. Particle-density values remained almost constant throughout the transition interval, probably indicating compositional (chemical) homogeneity.

Characterization of fly ash from low-sulfur and high-sulfur coal sources: Partitioning of carbon and trace elements with particle size

USGS Publications Warehouse

Hower, J.C.; Trimble, A.S.; Eble, C.F.; Palmer, C.A.; Kolker, A.

1999-01-01

Fly ash samples were collected in November and December of 1994, from generating units at a Kentucky power station using high- and low-sulfur feed coals. The samples are part of a two-year study of the coal and coal combustion byproducts from the power station. The ashes were wet screened at 100, 200, 325, and 500 mesh (150, 75, 42, and 25 ??m, respectively). The size fractions were then dried, weighed, split for petrographic and chemical analysis, and analyzed for ash yield and carbon content. The low-sulfur "heavy side" and "light side" ashes each have a similar size distribution in the November samples. In contrast, the December fly ashes showed the trend observed in later months, the light-side ash being finer (over 20 % more ash in the -500 mesh [-25 ??m] fraction) than the heavy-side ash. Carbon tended to be concentrated in the coarse fractions in the December samples. The dominance of the -325 mesh (-42 ??m) fractions in the overall size analysis implies, though, that carbon in the fine sizes may be an important consideration in the utilization of the fly ash. Element partitioning follows several patterns. Volatile elements, such as Zn and As, are enriched in the finer sizes, particularly in fly ashes collected at cooler, light-side electrostatic precipitator (ESP) temperatures. The latter trend is a function of precipitation at the cooler-ESP temperatures and of increasing concentration with the increased surface area of the finest fraction. Mercury concentrations are higher in high-carbon fly ashes, suggesting Hg adsorption on the fly ash carbon. Ni and Cr are associated, in part, with the spinel minerals in the fly ash. Copyright ?? 1999 Taylor & Francis.

Comparison of heterogeneous photolytic reduction of Hg(II) in the coal fly ashes and synthetic aerosols

NASA Astrophysics Data System (ADS)

Tong, Yindong; Eichhorst, Terry; Olson, Michael R.; Rutter, Andrew P.; Shafer, Martin M.; Wang, Xuejun; Schauer, James J.

2014-03-01

In this study, we examined the heterogeneous reduction of Hg(II) on the coal fly ash samples and synthetic aerosols under different light conditions in a controlled laboratory reactor. Three types of coal fly ashes were studied: a high carbon fly ash from a stoker boiler, a low carbon/low sulfate fly ash from a pulverized coal combustor burning low sulfur coal, and a high sulfate fly ash from a pulverized coal combustor burning high sulfur coal. The rate of Hg(II) reduction on the three diverse fly ash samples was found to be relatively fast with an average half-life of 1.6 h under clear sky atmospheric conditions (under the irradiance of 1000 W/m2). The reduction rate in the low sulfate/low carbon fly ash was approximately 1.5 times faster than with the other coal fly ash samples. Synthetic aerosols made of carbon black and levoglucosan produced Hg(II) reduction rates similar to coal fly ashes. However, aerosols composed of adipic acid resulted in reduction rates that were 3-5 times faster. The sensitivity of adipic acid reduction to light source wavelength was found to be greater than for the coal fly ash and other synthetic aerosols. Aerosols made from the water extracts of coal fly ash samples produced reduction rates equal to or slightly higher than with the native fly ash suggesting that the soluble components of fly ash play a significant role in the reduction mechanism. The measured reduction rates are likely important in the chemical processing of mercury in power plant plumes and potentially in the atmosphere and should be considered for incorporation in atmospheric transport models that are used to understand the fate of atmospheric mercury.

The use of shale ash in dry mix construction materials

NASA Astrophysics Data System (ADS)

Gulbe, L.; Setina, J.; Juhnevica, I.

2017-10-01

The research was made to determine the use of shale ash usage in dry mix construction materials by replacing part of cement amount. Cement mortar ZM produced by SIA Sakret and two types of shale ashes from Narva Power plant (cyclone ash and electrostatic precipitator ash) were used. Fresh mortar properties, hardened mortar bulk density, thermal conductivity (λ10, dry) (table value) were tested in mortar ZM samples and mortar samples in which 20% of the amount of cement was replaced by ash. Compressive strenght, frost resistance and resistance to sulphate salt solutions were checked. It was stated that the use of electrostatic precipitator ash had a little change of the material properties, but the cyclone ash significantly reduced the mechanical strength of the material.

Simulating intracrater ash recycling during mid-intensity explosive activity: high temperature laboratory experiments on natural basaltic ash

NASA Astrophysics Data System (ADS)

D'Oriano, Claudia; Pompilio, Massimo; Bertagnini, Antonella; Cioni, Raffaello; Pichavant, Michel

2010-05-01

Direct observations of mid-intensity eruptions, in which a huge amount of ash is generated, indicate that ash recycling is quite common. The recognition of juvenile vs. recycled fragments is not straightforward, and no unequivocal, widely accepted criteria exist to support this. The presence of recycled glassy fragments can hide primary magmatic information, introducing bias in the interpretations of the ongoing magmatic and volcanic activity. High temperature experiments were performed at atmospheric pressure on natural samples to investigate the effects of reheating on morphology, texture and composition of volcanic ash. Experiments simulate the transformation of juvenile glassy fragments that, falling into the crater or in the upper part of the conduit, are recycled by following explosions. Textural and compositional modifications obtained in laboratory are compared with similar features observed in natural samples in order to identify some main general criteria to be used for the discrimination of recycled material. Experiments were carried out on tephra produced during Strombolian activity, fire fountains and continuous ash emission at Etna, Stromboli and Vesuvius. Coarse glassy clasts were crushed in a nylon mortar in order to create an artificial ash, and then sieved to select the size interval of 1-0.71 mm. Ash shards were put in a sealed or open quartz tube, in order to prevent or to reproduce effects of air oxidation. The tube was suspended in a HT furnace at INGV-Pisa and kept at different temperatures (up to to 1110°C) for increasing time (0.5-12 hours). Preliminary experiments were also performed under gas flux conditions. Optical and electron microscope observations indicate that high temperature and exposure to the air induce large modifications on clast surface, ranging from change in color, to incipient plastic deformation till complete sintering. Significant change in color of clasts is strictly related to the presence of air, irrespective of temperature while sintering is favored by the high temperature and low fO2. Re-heating promotes nucleation and growth of crystals in the groundmass and associated change of glass composition, sometimes accompanied by growth and coalescence of vesicles in the size of 10-50 µm and cracking of the external surface.

Proximate nutritional composition of CELSS crops grown at different CO2 partial pressures

NASA Technical Reports Server (NTRS)

Wheeler, R. M.; Mackowiak, C. L.; Sager, J. C.; Knott, W. M.; Berry, W. L.

1994-01-01

Two Controlled Ecological Life Support System (CELSS) candidate crops, soybean (Glycine max) and potato (Solanum tuberosum), were grown hydroponically in controlled environments maintained at carbon dioxide (CO2) partial pressures ranging from 0.05 to 1.00 kPa (500 to 10,000 ppm at 101 kPa atmospheric pressure). Plants were harvested at maturity (90 days for soybean and 105 days for potato) and all tissues analyzed for proximate nutritional composition (i.e. protein, fat, carbohydrate, crude fiber, and ash content). Soybean seed ash and crude fiber were higher and carbohydrate was lower than values reported for field-grown seed. Potato tubers showed little difference from field-grown tubers. Crude fiber of soybean stems and leaves increased with increased CO2, as did soybean leaf protein (total nitrogen). Potato leaf and stem (combined) protein levels also increased with increased CO2, while leaf and stem carbohydrates decreased. Values for leaf and stem protein and ash were higher than values generally reported for field-grown plants for both species. Results suggest that CO2 partial pressure should have little influence on proximate composition of potato tubers or soybean seed, but that high ash and protein levels might be expected from leaves and stems of crops grown in controlled environments of a CELSS.

Evaluation of the Biotoxicity of Tree Wood Ashes in Zebrafish Embryos.

PubMed

Consigli, Veronica; Guarienti, Michela; Bilo, Fabjola; Benassi, Laura; Depero, Laura E; Bontempi, Elza; Presta, Marco

2016-10-01

Ashes derived from biomass combustion and used as soil fertilizers can generate negative environmental and human health risks, related to leaching of heavy metals and other putative toxic elements. Tree wood ash composition may vary depending on geographical location and surrounding industrial processes. In this study, we evaluated the biotoxicity of lixiviated tree wood ash samples from trees of the Ash (Fraxinus), Cherry (Pronus), Hazel (Corylus), and Black locust (Robinia) genus collected in an industrialized region in Northern Italy. Elemental chemical analysis of the samples was performed by total reflection X-ray fluorescence technique and their biotoxicity was assessed in zebrafish (Danio rerio) embryos. Ashes from Ash, Cherry, and Hazel trees, but not Black locust trees, had a high concentration of heavy metals and other putative toxic elements. Accordingly, a dose-dependent increase in mortality rate and morphological and teratogenic defects was observed in zebrafish embryos treated with lixiviated Ash, Cherry, and Hazel tree wood samples, whereas the toxicity of Black locust tree wood ashes was negligible. In conclusion, lixiviated wood ashes from different plants show a different content of toxic elements that correlate with their biotoxic effects on zebrafish embryos. Tree wood ashes derived from biomass combustion may represent a potential risk for the environment and human health.

Trace and major element pollution originating from coal ash suspension and transport processes.

PubMed

Popovic, A; Djordjevic, D; Polic, P

2001-04-01

Coal ash obtained by coal combustion in the "Nikola Tesla A" power plant in Obrenovac, near Belgrade, Yugoslavia, is mixed with water of the Sava river and transported to the dump. In order to assess pollution caused by leaching of some minor and major elements during ash transport through the pipeline, two sets of samples (six samples each) were subjected to a modified sequential extraction. The first set consisted of coal ash samples taken immediately after combustion, while the second set was obtained by extraction with river water, imitating the processes that occur in the pipeline. Samples were extracted consecutively with distilled water and a 1 M solution of KCl, pH 7, and the differences in extractability were compared in order to predict potential pollution. Considering concentrations of seven trace elements as well as five major elements in extracts from a total of 12 samples, it can be concluded that lead and cadmium do not present an environmental threat during and immediately after ash transport to the dump. Portions of zinc, nickel and chromium are released during the ash transport, and arsenic and manganese are released continuously. Copper and iron do not present an environmental threat due to element leaching during and immediately after the coal ash suspension and transport. On the contrary, these elements, as well as chromium, become concentrated during coal ash transport. Adsorbed portions of calcium, magnesium and potassium are also leached during coal ash transport.

Polished sample preparing and backscattered electron imaging and of fly ash-cement paste

NASA Astrophysics Data System (ADS)

Feng, Shuxia; Li, Yanqi

2018-03-01

In recent decades, the technology of backscattered electron imaging and image analysis was applied in more and more study of mixed cement paste because of its special advantages. Test accuracy of this technology is affected by polished sample preparation and image acquisition. In our work, effects of two factors in polished sample preparing and backscattered electron imaging were investigated. The results showed that increasing smoothing pressure could improve the flatness of polished surface and then help to eliminate interference of morphology on grey level distribution of backscattered electron images; increasing accelerating voltage was beneficial to increase gray difference among different phases in backscattered electron images.

Investigation of mineral transformations and ash deposition during staged combustion. Quarterly technical progress report, April 1, 1997--June 30, 1997

DOE Office of Scientific and Technical Information (OSTI.GOV)

Harb, J.N.

This report describes work performed in the fifteenth quarter of a fundamental study to examine the effect of staged combustion on ash formation and deposition. Efforts this quarter included addition of a new cyclone for improved particle sampling and modification of the existing sampling probe. Particulate samples were collected under a variety of experimental conditions for both coals under investigation. Deposits formed from the Black Thunder coal were also collected. Particle size and composition from the Pittsburgh No. 8 ash samples support previously reported results. In addition, the authors ability to distinguish char/ash associations has been refined and applied tomore » a variety of ash samples from this coal. The results show a clear difference between the behavior of included and excluded pyrite, and provide insight into the extent of pyrite oxidation. Ash samples from the Black Thunder coal have also been collected and analyzed. Results indicate a significant difference in the particle size of {open_quotes}unclassifiable{close_quotes} particles for ash formed during staged combustion. A difference in composition also appears to be present and is currently under investigation. Finally, deposits were collected under staged conditions for the Black Thunder coal. Specifically, two deposits were formed under similar conditions and allowed to mature under either reducing or oxidizing conditions in natural gas. Differences between the samples due to curing were noted. In addition, both deposits showed skeletal ash structures which resulted from in-situ burnout of the char after deposition.« less

Ambient airborne solids concentrations including volcanic ash at Hanford, Washington sampling sites subsequent to the Mount St. Helens eruption

NASA Technical Reports Server (NTRS)

Sehmel, G. A.

1982-01-01

Airborne solids concentrations were measured on a near daily basis at two Hanford, Washington sites after the eruption of Mount St. Helens on May 18, 1980. These sites are about 211 km east of Mount St. Helens. Collected airborne solids included resuspended volcanic ash plus normal ambient solids. Average airborne solids concentrations were greater at the Hanford meteorological station sampling site which is 24 km northwest of the Horn Rapids dam sampling site. These increased concentrations reflect the sampling site proximity to greater ash fallout depths. Both sites are in low ash fallout areas although the Hanford meteorological station site is closer to the greater ash fallout areas. Airborne solids concentrations were decreased by rain, but airborne solids concentrations rapidly increased as surfaces dried. Airborne concentrations tended to become nearly the same at both sampling sites only for July 12 and 13.

Optoelectronic system of online measurements of unburned carbon in coal fly ash

NASA Astrophysics Data System (ADS)

Golas, Janusz; Jankowski, Henryk; Niewczas, Bogdan; Piechna, Janusz; Skiba, Antoni; Szkutnik, Wojciech; Szkutnik, Zdzislaw P.; Wartak, Ryszarda; Worek, Cezary

2001-08-01

Carbon-in-ash level is an important consideration for combustion efficiency as well as ash marketing. The optoelectronic analyzing system for on-line determination and monitoring of the u burned carbon content of ash samples is presented. The apparatus operates on the principle that carbon content is proportional to the reflectance of IR light. Ash samples are collected iso kinetically from the flue gas duct and placed in a sample tube with a flat glass bottom. The same is then exposed to a light. The reflectance intensity is used by the system's computer to determine residual carbon content from correlation curves. The sample is then air purged back to the duct or to the attached sample canister to enable laboratory check analysis. The total cycle time takes between 5 and 10 minutes. Real time result of carbon content with accuracy 0.3-0.7 percent are reported and can be used for boiler controlling.

Characteristics of fly ashes from full-scale coal-fired power plants and their relationship to mercury adsorption

USGS Publications Warehouse

Lu, Y.; Rostam-Abadi, M.; Chang, R.; Richardson, C.; Paradis, J.

2007-01-01

Nine fly ash samples were collected from the particulate collection devices (baghouse or electrostatic precipitator) of four full-scale pulverized coal (PC) utility boilers burning eastern bituminous coals (EB-PC ashes) and three cyclone utility boilers burning either Powder River Basin (PRB) coals or PRB blends,(PRB-CYC ashes). As-received fly ash samples were mechanically sieved to obtain six size fractions. Unburned carbon (UBC) content, mercury content, and Brunauer-Emmett-Teller (BET)-N2 surface areas of as-received fly ashes and their size fractions were measured. In addition, UBC particles were examined by scanning electron microscopy, high-resolution transmission microscopy, and thermogravimetry to obtain information on their surface morphology, structure, and oxidation reactivity. It was found that the UBC particles contained amorphous carbon, ribbon-shaped graphitic carbon, and highly ordered graphite structures. The mercury contents of the UBCs (Hg/UBC, in ppm) in raw ash samples were comparable to those of the UBC-enriched samples, indicating that mercury was mainly adsorbed on the UBC in fly ash. The UBC content decreased with a decreasing particle size range for all nine ashes. There was no correlation between the mercury and UBC contents of different size fractions of as-received ashes. The mercury content of the UBCs in each size fraction, however, generally increased with a decreasing particle size for the nine ashes. The mercury contents and surface areas of the UBCs in the PRB-CYC ashes were about 8 and 3 times higher than UBCs in the EB-PC ashes, respectively. It appeared that both the particle size and surface area of UBC could contribute to mercury capture. The particle size of the UBC in PRB-CYC ash and thus the external mass transfer was found to be the major factor impacting the mercury adsorption. Both the particle size and surface reactivity of the UBC in EB-PC ash, which generally had a lower carbon oxidation reactivity than the PRB-PC ashes, appeared to be important for the mercury adsorption. ?? 2007 American Chemical Society.

Volcanic Ash Retrievals Using ORAC and Satellite Measurements in the Visible and IR

NASA Astrophysics Data System (ADS)

Mcgarragh, Gregory R.; Thomas, Gareth E.; Povey, Adam C.; Poulsen, Caroline A.; Grainger, Roy G.

2015-11-01

The Optimal Retrieval of Aerosol and Cloud (ORAC) is a generalized optimal estimation system that uses visible to infrared measurements from a wide range of instruments including AATSR, AVHRR, MODIS and SEVIRI. Recently, support to retrieve volcanic ash has been added for which it retrieves optical thickness, effective radius and cloud top pressure. In this proceeding we discuss the implementation of the volcanic ash retrieval in ORAC including the retrieval methodology, forward model, sources of uncertainty and the discrimination of ash from aerosol and cloud. Results are presented that are consistent with a well know eruption from both AATSR and MODIS while results of a full SEVIRI retrieval of ash, aerosol and cloud properties relative to the ash is are discussed.

On the removal of hexavalent chromium from a Class F fly ash.

PubMed

Huggins, F E; Rezaee, M; Honaker, R Q; Hower, J C

2016-05-01

Coarse and fine samples of a Class F fly ash obtained from commercial combustion of Illinois bituminous coal have been exposed to two long-term leaching tests designed to simulate conditions in waste impoundments. ICP-AES analysis indicated that the coarse and fine fly ash samples contained 135 and 171mg/kg Cr, respectively. Measurements by XAFS spectroscopy showed that the ash samples originally contained 5 and 8% of the chromium, respectively, in the hexavalent oxidation state, Cr(VI). After exposure to water for more than four months, the percentage of chromium as Cr(VI) in the fly-ash decreased significantly for the coarse and fine fly-ash in both tests. Combining the XAFS data with ICP-AES data on the concentration of chromium in the leachates indicated that, after the nineteen-week-long, more aggressive, kinetic test on the coarse fly ash, approximately 60% of the Cr(VI) had been leached, 20% had been reduced to Cr(III) and retained in the ash, and 20% remained as Cr(VI) in the ash. In contrast, during the six-month-long baseline test, very little Cr was actually leached from either the coarse or the fine fly-ash (<0.1mg/kg); rather, about 66% and 20%, respectively, of the original Cr(VI) in the coarse and fine fly-ash was retained in the ash in that form, while the remainder, 34% and 80%, respectively, was reduced and retained in the ash as Cr(III). The results are interpreted as indicating that Cr(VI) present in Class F fly-ash can be reduced to Cr(III) when in contact with water and that such chemical reduction can compete with physical removal of Cr(VI) from the ash by aqueous leaching. Copyright © 2016 Elsevier Ltd. All rights reserved.

Characteristics of ash and particle emissions during bubbling fluidised bed combustion of three types of residual forest biomass.

PubMed

Ribeiro, João Peres; Vicente, Estela Domingos; Alves, Célia; Querol, Xavier; Amato, Fulvio; Tarelho, Luís A C

2017-04-01

Combustion of residual forest biomass (RFB) derived from eucalypt (Eucalyptus globulus), pine (Pinus pinaster) and golden wattle (Acacia longifolia) was evaluated in a pilot-scale bubbling fluidised bed reactor (BFBR). During the combustion experiments, monitoring of temperature, pressure and exhaust gas composition has been made. Ash samples were collected at several locations along the furnace and flue gas treatment devices (cyclone and bag filter) after each combustion experiment and were analysed for their unburnt carbon content and chemical composition. Total suspended particles (TSP) in the combustion flue gas were evaluated at the inlet and outlet of cyclone and baghouse filter and further analysed for organic and elemental carbon, carbonates and 57 chemical elements. High particulate matter collection efficiencies in the range of 94-99% were observed for the baghouse, while removal rates of only 1.4-17% were registered for the cyclone. Due to the sand bed, Si was the major element in bottom ashes. Fly ashes, in particular those from eucalypt combustion, were especially rich in CaO, followed by relevant amounts of SiO 2 , MgO and K 2 O. Ash characteristics varied among experiments, showing that their inorganic composition strongly depends on both the biomass composition and combustion conditions. Inorganic constituents accounted for TSP mass fractions up to 40 wt%. Elemental carbon, organic matter and carbonates contributed to TSP mass fractions in the ranges 0.58-44%, 0.79-78% and 0.01-1.7%, respectively.

Monotonic aspects of the mechanical behaviour of bottom ash from municipal solid waste incineration and its potential use for road construction.

PubMed

Becquart, Frederic; Bernard, Fabrice; Abriak, Nor Edine; Zentar, Rachid

2009-04-01

Municipal solid waste incineration (MSWI) bottom ash is an atypical granular material because it may include industrial by-products that result from the incineration of domestic waste. The prospects for the beneficial use of this particular material mainly lie in the field of road construction, as a substitute for the traditional natural aggregates. However, its mechanical properties are still little known, particularly in term of stiffness and deformability, characteristics that are essential to the construction of a durable roadway. The purpose of this paper is to describe better the mechanical behaviour of this recycled material. In order to reach this objective, a large experimental campaign is presented. The first part of this paper presents and comments in detail on the results obtained from static monotonic tests. Oedometric and triaxial shear tests were performed on MSWI bottom ash both before and after treatment with a specific hydraulic binder. These tests allow specification of the mechanical characteristics of the MSWI bottom ash, such as the initial Young's modulus, Poisson's ratio, the compressibility index, the friction angle, and the contracting or dilating behaviour of the material. The results reveal a mechanical behaviour similar to that of initially dense standard materials (sands, unbound granular materials) and a dependence on the applied average pressure, characteristic of the mechanical behaviour of granular media. More laboratory data on other samples of MSWI bottom ash are required to ensure that this comparison is statistically valid.

Leaching characteristics of fly ash from thermal power plants of Soma and Tuncbilek, Turkey.

PubMed

Baba, Alper; Kaya, Abidin

2004-02-01

Use of lignite in power generation has led to increasing environmental problems associated not only with gaseous emissions but also with the disposal of ash residues. In particular, use of low quality coal with high ash content results in huge quantities of fly ash to be disposed of. The main problem related to fly ash disposal is the heavy metal content of the residue. In this regard, experimental results of numerous studies indicate that toxic trace metals may leach when fly ash contacts water. In this study, fly ash samples obtained from thermal power plants, namely Soma and Tunçbilek, located at the west part of Turkey, were subjected to toxicity tests such as European Committee for standardization (CEN) and toxicity characteristic leaching (TCLP) procedures of the U.S. Environmental Protection Agency (U.S. EPA). The geochemical composition of the tested ash samples from the power plant show variations depending on the coal burned in the plants. Furthermore, the CEN and TCLP extraction results showed variations such that the ash samples were classified as 'toxic waste' based on TCLP result whereas they were classified as 'non-toxic' wastes based on CEN results, indicating test results are pH dependent.

Simultaneous determination of V, Ni and Fe in fuel fly ash using solid sampling high resolution continuum source graphite furnace atomic absorption spectrometry.

PubMed

Cárdenas Valdivia, A; Vereda Alonso, E; López Guerrero, M M; Gonzalez-Rodriguez, J; Cano Pavón, J M; García de Torres, A

2018-03-01

A green and simple method has been proposed in this work for the simultaneous determination of V, Ni and Fe in fuel ash samples by solid sampling high resolution continuum source graphite furnace atomic absorption spectrometry (SS HR CS GFAAS). The application of fast programs in combination with direct solid sampling allows eliminating pretreatment steps, involving minimal manipulation of sample. Iridium treated platforms were applied throughout the present study, enabling the use of aqueous standards for calibration. Correlation coefficients for the calibration curves were typically better than 0.9931. The concentrations found in the fuel ash samples analysed ranged from 0.66% to 4.2% for V, 0.23-0.7% for Ni and 0.10-0.60% for Fe. Precision (%RSD) were 5.2%, 10.0% and 9.8% for V, Ni and Fe, respectively, obtained as the average of the %RSD of six replicates of each fuel ash sample. The optimum conditions established were applied to the determination of the target analytes in fuel ash samples. In order to test the accuracy and applicability of the proposed method in the analysis of samples, five ash samples from the combustion of fuel in power stations, were analysed. The method accuracy was evaluated by comparing the results obtained using the proposed method with the results obtained by ICP OES previous acid digestion. The results showed good agreement between them. The goal of this work has been to develop a fast and simple methodology that permits the use of aqueous standards for straightforward calibration and the simultaneous determination of V, Ni and Fe in fuel ash samples by direct SS HR CS GFAAS. Copyright © 2017 Elsevier B.V. All rights reserved.

Effects of volcanic ash on the forest canopy insects of Montserrat, West Indies.

PubMed

Marske, Katharine A; Ivie, Michael A; Hilton, Geoff M

2007-08-01

The impact of ash deposition levels on canopy arthropods was studied on the West Indian island of Montserrat, the site of an ongoing volcanic eruption since 1995. Many of the island's natural habitats have been buried by volcanic debris, and remaining forests regularly receive volcanic ash deposition. To test the effect of ash on canopy arthropods, four study sites were sampled over a 15-mo period. Arthropod samples were obtained using canopy fogging, and ash samples were taken from leaf surfaces. Volcanic ash has had a significant negative impact on canopy arthropod populations, but the decline is not shared equally by all taxa present, and total population variation is within the variance attributed to other aboitic and biotic factors. The affected populations do not differ greatly from those of the neighboring island of St. Kitts, which has not been subject to recent volcanic activity. This indicates that observed effects on Montserrat's arthropod fauna have a short-term acute response to recent ash deposition rather than a chronic depression caused by repeated exposure to ash over the last decade.

Eco-friendly fly ash utilization: potential for land application

DOE Office of Scientific and Technical Information (OSTI.GOV)

Malik, A.; Thapliyal, A.

2009-07-01

The increase in demand for power in domestic, agricultural, and industrial sectors has increased the pressure on coal combustion and aggravated the problem of fly ash generation/disposal. Consequently the research targeting effective utilization of fly ash has also gained momentum. Fly ash has proved to be an economical substitute for expensive adsorbents as well as a suitable raw material for brick manufacturing, zeolite synthesis, etc. Fly ash is a reservoir of essential minerals but is deficient in nitrogen and phosphorus. By amending fly ash with soil and/or various organic materials (sewage sludge, bioprocess materials) as well as microbial inoculants likemore » mycorrhizae, enhanced plant growth can be realized. Based on the sound results of large scale studies, fly ash utilization has grown into prominent discipline supported by various internationally renowned organizations. This paper reviews attempts directed toward various utilization of fly ash, with an emphasis on land application of organic/microbial inoculants amended fly ash.« less

Group-V atoms exchange due to exposure of InP surface to AsH3(+PH3) revealed by x-ray CTR scattering

NASA Astrophysics Data System (ADS)

Tabuchi, M.; Yamada, N.; Fujibayashi, K.; Takeda, Y.; Kamei, H.

1996-05-01

We conducted x-ray crystal truncation rod (CTR) measurements using synchro-tron radiation to analyze the As atom distribution in InP to the order of 1 ML. The InP samples which were only exposed to AsH3(+PH3) and capped by InP were investigated to study the effect of the purge sequence. The purge sequence is unavoidable to grow heteroepitaxial layers by OMVPE and is considered to affect largely the structure of the interface. From the results of the measurement and the computer simulation, the distribution of P and As atoms of the order of 1 ML was discussed as functions of the exposing time. It was shown that the number of As atoms contained in the samples saturated when the AsH3-exposure time is longer than 10 s. Comparing the profiles of AsH3-exposed samples with that of (AsH3 + PH3)-exposed samples, it was found that the As distribution in the buffer layer was suppressed in (AsH3 + PH3)-exposed samples. In order to obtain the sharp interfaces, the AsH3-exposure time must be shorter than 0.5 s.

Ion Beam Analyses Of Bark And Wood In Environmental Studies

NASA Astrophysics Data System (ADS)

Lill, J.-O.; Saarela, K.-E.; Harju, L.; Rajander, J.; Lindroos, A.; Heselius, S.-J.

2011-06-01

A large number of wood and bark samples have been analysed utilizing particle-induced X-ray emission (PIXE) and particle-induced gamma-ray emission (PIGE) techniques. Samples of common tree species like Scots Pine, Norway Spruce and birch were collected from a large number of sites in Southern and Southwestern Finland. Some of the samples were from a heavily polluted area in the vicinity of a copper-nickel smelter. The samples were dry ashed at 550 °C for the removal of the organic matrix in order to increase the analytical sensitivity of the method. The sensitivity was enhanced by a factor of 50 for wood and slightly less for bark. The ashed samples were pressed into pellets and irradiated as thick targets with a millimetre-sized proton beam. By including the ashing procedure in the method, the statistical dispersion due to elemental heterogeneities in wood material could be reduced. As a by-product, information about the elemental composition of ashes was obtained. By comparing the concentration of an element in bark ash to the concentration in wood ash of the same tree useful information from environmental point of view was obtained. The obtained ratio of the ashes was used to distinguish between elemental contributions from anthropogenic atmospheric sources and natural geochemical sources, like soil and bedrock.

Effect of antecedent-hydrological conditions on rainfall triggering of debris flows in ash-fall pyroclastic mantled slopes of Campania (southern Italy)

USGS Publications Warehouse

Napolitano, E.; Fusco, F; Baum, Rex L.; Godt, Jonathan W.; De Vita, P.

2016-01-01

Mountainous areas surrounding the Campanian Plain and the Somma-Vesuvius volcano (southern Italy) are among the most risky areas of Italy due to the repeated occurrence of rainfallinduced debris flows along ash-fall pyroclastic soil-mantled slopes. In this geomorphological framework, rainfall patterns, hydrological processes taking place within multi-layered ash-fall pyroclastic deposits and soil antecedent moisture status are the principal factors to be taken into account to assess triggering rainfall conditions and the related hazard. This paper presents the outcomes of an experimental study based on integrated analyses consisting of the reconstruction of physical models of landslides, in situ hydrological monitoring, and hydrological and slope stability modeling, carried out on four representative source areas of debris flows that occurred in May 1998 in the Sarno Mountain Range. The hydrological monitoring was carried out during 2011 using nests of tensiometers and Watermark pressure head sensors and also through a rainfall and air temperature recording station. Time series of measured pressure head were used to calibrate a hydrological numerical model of the pyroclastic soil mantle for 2011, which was re-run for a 12-year period beginning in 2000, given the availability of rainfall and air temperature monitoring data. Such an approach allowed us to reconstruct the regime of pressure head at a daily time scale for a long period, which is representative of about 11 hydrologic years with different meteorological conditions. Based on this simulated time series, average winter and summer hydrological conditions were chosen to carry out hydrological and stability modeling of sample slopes and to identify Intensity- Duration rainfall thresholds by a deterministic approach. Among principal results, the opposing winter and summer antecedent pressure head (soil moisture) conditions were found to exert a significant control on intensity and duration of rainfall triggering events. Going from winter to summer conditions requires a strong increase of intensity and/or duration to induce landslides. The results identify an approach to account for different hazard conditions related to seasonality of hydrological processes inside the ash-fall pyroclastic soil mantle. Moreover, they highlight another important factor of uncertainty that potentially affects rainfall thresholds triggering shallow landslides reconstructed by empirical approaches.

Gypsum treated fly ash as a liner for waste disposal facilities

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sivapullaiah, Puvvadi V., E-mail: siva@civil.iisc.ernet.in; Baig, M. Arif Ali, E-mail: reach2arif@gmail.com

2011-02-15

Fly ash has potential application in the construction of base liners for waste containment facilities. While most of the fly ashes improve in the strength with curing, the ranges of permeabilities they attain may often not meet the basic requirement of a liner material. An attempt has been made in the present context to reduce the hydraulic conductivity by adding lime content up to 10% to two selected samples of class F fly ashes. The use of gypsum, which is known to accelerate the unconfined compressive strength by increasing the lime reactivity, has been investigated in further improving the hydraulicmore » conductivity. Hydraulic conductivities of the compacted specimens have been determined in the laboratory using the falling head method. It has been observed that the addition of gypsum reduces the hydraulic conductivity of the lime treated fly ashes. The reduction in the hydraulic conductivity of the samples containing gypsum is significantly more for samples with high amounts of lime contents (as high as 1000 times) than those fly ashes with lower amounts of lime. However there is a relatively more increase in the strengths of the samples with the inclusion of gypsum to the fly ashes at lower lime contents. This is due to the fact that excess lime added to fly ash is not effectively converted into pozzolanic compounds. Even the presence of gypsum is observed not to activate these reactions with excess lime. On the other hand the higher amount of lime in the presence of sulphate is observed to produce more cementitious compounds which block the pores in the fly ash. The consequent reduction in the hydraulic conductivity of fly ash would be beneficial in reducing the leachability of trace elements present in the fly ash when used as a base liner.« less

40 CFR 240.211-3 - Recommended procedures: Operations.

Code of Federal Regulations, 2011 CFR

2011-07-01

... every 60 minutes and as changes are made. (5) Weights of bottom ash, grate siftings, and fly ash.... (10) Gross calorific value of daily representative samples of bottom ash, grate siftings, and fly ash...

EU landfill waste acceptance criteria and EU Hazardous Waste Directive compliance testing of incinerated sewage sludge ash.

PubMed

Donatello, S; Tyrer, M; Cheeseman, C R

2010-01-01

A hazardous waste assessment has been completed on ash samples obtained from seven sewage sludge incinerators operating in the UK, using the methods recommended in the EU Hazardous Waste Directive. Using these methods, the assumed speciation of zinc (Zn) ultimately determines if the samples are hazardous due to ecotoxicity hazard. Leaching test results showed that two of the seven sewage sludge ash samples would require disposal in a hazardous waste landfill because they exceed EU landfill waste acceptance criteria for stabilised non-reactive hazardous waste cells for soluble selenium (Se). Because Zn cannot be proven to exist predominantly as a phosphate or oxide in the ashes, it is recommended they be considered as non-hazardous waste. However leaching test results demonstrate that these ashes cannot be considered as inert waste, and this has significant implications for the management, disposal and re-use of sewage sludge ash.

Possibilities of municipal solid waste incinerator fly ash utilisation.

PubMed

Hartmann, Silvie; Koval, Lukáš; Škrobánková, Hana; Matýsek, Dalibor; Winter, Franz; Purgar, Amon

2015-08-01

Properties of the waste treatment residual fly ash generated from municipal solid waste incinerator fly ash were investigated in this study. Six different mortar blends with the addition of the municipal solid waste incinerator fly ash were evaluated. The Portland cement replacement levels of the municipal solid waste incinerator fly ash used were 25%, 30% and 50%. Both, raw and washed municipal solid waste incinerator fly ash samples were examined. According to the mineralogical composition measurements, a 22.6% increase in the pozzolanic/hydraulic properties was observed for the washed municipal solid waste incinerator fly ash sample. The maximum replacement level of 25% for the washed municipal solid waste incinerator fly ash in mortar blends was established in order to preserve the compressive strength properties. Moreover, the leaching characteristics of the crushed mortar blend was analysed in order to examine the immobilisation of its hazardous contents. © The Author(s) 2015.

Modification of hydraulic conductivity in granular soils using waste materials.

PubMed

Akbulut, S; Saglamer, A

2004-01-01

This paper evaluates the use of waste products such as silica fume and fly ash in modification of the granular soils in order to remove some environmental problems and create new useful findings in the field of engineering. It is known that silica fume and fly ash, as well as clay material, are used in geotechnical engineering because of their pozzolanic reactivity and fineness to improve the soil properties needed with respect to engineering purposes. The main objective of this research project was to investigate the use of these materials in geotechnical engineering and to improve the hydraulic properties of soils by means of grouting. For this reason, firstly, suitable grouts in suspension forms were prepared by using silica fume, fly ash, clay and cement in different percentages. The properties of these cement-based grouts were then determined to obtain the desired optimum values for grouting. After that, these grouts were penetrated into the soil samples under pressure. The experimental work indicates that these waste materials and clay improved the physical properties and the fluidity of the cement-based grouts and they also decreased the hydraulic conductivity of the grouted soil samples by sealing the voids of the soil. The results of this study have important findings concerning the use of these materials in soil treatment and the improvement of hydraulic conductivity of the soils.

Environmental chamber measurements of mercury flux from coal utilization by-products

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pekney, Natalie J.; Martello, Donald; Schroeder, Karl

2009-05-01

An environmental chamber was constructed to measure the mercury flux from coal utilization by-product (CUB) samples. Samples of fly ash, FGD gypsum, and wallboard made from FGD gypsum were tested under both dark and illuminated conditions with or without the addition of water to the sample. Mercury releases varied widely, with 7- day experiment averages ranging from -6.8 to 73 ng/m(2) h for the fly ash samples and -5.2 to 335 ng/m(2) h for the FGD/wallboard samples. Initial mercury content, fly ash type, and light exposure had no observable consistent effects on the mercury flux. For the fly ash samples,more » the effect of a mercury control technology was to decrease the emission. For three of the four pairs of FGD gypsum and wallboard samples, the wallboard sample released less (or absorbed more) mercury than the gypsum.« less

Environmental chamber measurements of mercury flux from coal utilization by-products

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pekney, N.J.; Martello, D.V.; Schroeder, K.T.

2009-05-01

An environmental chamber was constructed to measure the mercury flux from coal utilization by-product (CUB) samples. Samples of fly ash, FGD gypsum, and wallboard made from FGD gypsum were tested under both dark and illuminated conditions with or without the addition of water to the sample. Mercury releases varied widely, with 7-day experiment averages ranging from -6.8 to 73 ng/m2 h for the fly ash samples and -5.2 to 335 ng/m2 h for the FGD/wallboard samples. Initial mercury content, fly ash type, and light exposure had no observable consistent effects on the mercury flux. For the fly ash samples, themore » effect of a mercury control technology was to decrease the emission. For three of the four pairs of FGD gypsum and wallboard samples, the wallboard sample released less (or absorbed more) mercury than the gypsum.« less

Properties and Leachability of Self-Compacting Concrete Incorporated with Fly Ash and Bottom Ash

NASA Astrophysics Data System (ADS)

Kadir, Aeslina Abdul; Ikhmal Haqeem Hassan, Mohd; Jamaluddin, Norwati; Bakri Abdullah, Mohd Mustafa Al

2016-06-01

The process of combustion in coal-fired power plant generates ashes, namely fly ash and bottom ash. Besides, coal ash produced from coal combustion contains heavy metals within their compositions. These metals are toxic to the environment as well as to human health. Fortunately, treatment methods are available for these ashes, and the use of fly ash and bottom ash in the concrete mix is one of the few. Therefore, an experimental program was carried out to study the properties and determine the leachability of selfcompacting concrete incorporated with fly ash and bottom ash. For experimental study, self-compacting concrete was produced with fly ash as a replacement for Ordinary Portland Cement and bottom ash as a replacement for sand with the ratios of 10%, 20%, and 30% respectively. The fresh properties tests conducted were slump flow, t500, sieve segregation and J-ring. Meanwhile for the hardened properties, density, compressive strength and water absorption test were performed. The samples were then crushed to be extracted using Toxicity Characteristic Leaching Procedure and heavy metals content within the samples were identified accordingly using Atomic Absorption Spectrometry. The results demonstrated that both fresh and hardened properties were qualified to categorize as self-compacting concrete. Improvements in compressive strength were observed, and densities for all the samples were identified as a normal weight concrete with ranges between 2000 kg/m3 to 2600 kg/m3. Other than that, it was found that incorporation up to 30% of the ashes was safe as the leached heavy metals concentration did not exceed the regulatory levels, except for arsenic. In conclusion, this study will serve as a reference which suggests that fly ash and bottom ash are widely applicable in concrete technology, and its incorporation in self-compacting concrete constitutes a potential means of adding value to appropriate mix and design.

Firing system modification to alter ash properties for reduction of deposition and slagging under low NOx firing conditions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hart, D.; Lewis, R.; Tobiasz, R.

1998-07-01

The composition and properties of ash formed during coal firing have a major impact on boiler performance. Higher ash content in the coal can mean higher costs associated with coal handling, transportation, ash removal and ash disposal along with higher costs due to the increased ash content's deleterious effects on pulverizing, combustion and heat transfer. ABB C-E Services, Inc. has conducted research what might be done to minimize the adverse effects of ash on boiler performance for many years. Recently, ABB C-E Services has studied the effects of firing system modifications on ash composition and properties and the effect thesemore » firing system modifications have on overall furnace performance. The subject of this paper is the impact of the installation of the CFS{trademark} yaw angles were varied and particle samples were collected at the waterwalls for the different yaw angles tested. These ash samples were analyzed for ash composition. The results showed that with a larger CFS{trademark} yaw angle (the air stream directed more towards the boiler walls) the base/acid ratio, iron content and sulfur content of the particle samples collected at the waterwall were reduced. This effect is due to several contributing factors: (1) an oxidizing environment produced by injecting more air toward the walls; and (2) an aerodynamic change which impacts the particle combustion time/temperature history.« less

Firing system modification to alter ash properties for reduction of deposition and slagging under low NOx firing conditions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hart, D.; Lewis, R.; Tobiasz, R.

1998-12-31

The composition and properties of ash formed during coal firing have a major impact on boiler performance. Higher ash content in the coal can mean higher costs associated with coal handling, transportation, ash removal and ash disposal along with higher costs due to the increased ash content`s deleterious effects on pulverizing, combustion and heat transfer. ABB C-E Services, Inc. has conducted research for many years on what might be done to minimize the adverse effects of ash on boiler performance. Recently, ABB C-E Services has studied the effects of firing system modifications on ash composition and properties and the effectmore » these firing system modifications have on overall furnace performance. The subject of this paper is the impact of the installation of the CFS Concentric Firing System on the propensity for boiler wall ash deposition. For this study, CFS yaw angles were varied and particle samples were collected at the waterwalls for the different yaw angles tested. These ash samples were analyzed for ash composition. The results showed that with a larger CFS yaw angle (the air stream directed more towards the boiler walls) the base/acid ratio, iron content and sulfur content of the particle samples collected at the waterwall were reduced. This effect is due to several contributing factors: (1) an oxidizing environment produced by injecting more air toward the walls; and (2) an aerodynamic change which impacts the particle combustion time/temperature history.« less

Characterization of fine volcanic ash from explosive eruption from Sakurajima volcano, South Japan

NASA Astrophysics Data System (ADS)

Nanayama, F.; Furukawa, R.; Ishizuka, Y.; Yamamoto, T.; Geshi, N.; Oishi, M.

2013-12-01

Explosive volcanic eruptions can affect infrastructure and ecosystem by their dispersion of the volcanic particle. Characterization of volcanic particle expelled by explosive eruption is crucial for evaluating for quantitative hazard assessment by future volcanic eruption. Especially for fine volcanic ash less than 64 micron in diameter, it can disperse vast area from the source volcano and be easily remobilized by surface wind and precipitation after the deposition. As fine volcanic ash is not preserved well at the earth surface and in strata except for enormously large scale volcanic eruption. In order to quantify quantitative characteristics of fine volcanic ash particle, we sampled volcanic ash directly falling from the eruption cloud from Showa crater, the most active vent of Sakurajima volcano, just before landing on ground. We newly adopted high precision digital microscope and particle grain size analyzer to develop hazard evaluation method of fine volcanic ash particle. Field survey was performed 5 sequential days in January, 2013 to take tamper-proof volcanic ash samples directly obtained from the eruption cloud of the Sakurajima volcano using disposable paper dishes and plastic pails. Samples were taken twice a day with time-stamp in 40 localities from 2.5 km to 43 km distant from the volcano. Japan Meteorological Agency reported 16 explosive eruptions of vulcanian style occurred during our survey and we took 140 samples of volcanic ash. Grain size distribution of volcanic ash was measured by particle grain size analyzer (Mophologi G3S) detecting each grain with parameters of particle diameter (0.3 micron - 1 mm), perimeter, length, area, circularity, convexity, solidity, and intensity. Component of volcanic ash was analyzed by CCD optical microscope (VHX-2000) which can take high resolution optical image with magnifying power of 100-2500. We discriminated each volcanic ash particle by color, texture of surface, and internal structure. Grain size distributions of volcanic ash from Sakurajima volcano have basically characteristics of unimodal and gaussian. Mode of distributions are 150 - 200 micron at 5 km and 70-80 micron at 20 km respectively from the Showa crater. Mode and deviation of the grain size distribution are function of distance from the source. Fine volcanic ash less than 1 micron in diameter is few and exists in every samples. Component of volcanic ash samples are dark-colored dense glass shard (ca. 50%), light-colored dense glass shard (10%), variously colored and vesiculated glass shard (10%), free crystal (20%), lithic fragment (10%), and altered fragment (less than 5%) which are mostly having similar ratio in every location suggesting single source process of the eruption. We also found fine volcanic ash samples less than 10 micron are frequently aggregated. The present study includes the result of "Research and Development of Margin Assessment Methodology of Decay Heat Removal Function against External Hazards" entrusted to Japan Atomic Energy Agency by the Ministry of Education, Culture, Sports, Science and Technology of Japan (MEXT).

HIGH PRESSURE COAL COMBUSTON KINETICS PROJECT

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stefano Orsino

As part of the U.S. Department of Energy (DoE) initiative to improve the efficiency of coal-fired power plants and reduce the pollution generated by these facilities, DOE has funded the High-Pressure Coal Combustion Kinetics (HPCCK) Projects. A series of laboratory experiments were conducted on selected pulverized coals at elevated pressures with the specific goals to provide new data for pressurized coal combustion that will help extend to high pressure and validate models for burnout, pollutant formation, and generate samples of solid combustion products for analyses to fill crucial gaps in knowledge of char morphology and fly ash formation. Two seriesmore » of high-pressure coal combustion experiments were performed using SRI's pressurized radiant coal flow reactor. The first series of tests characterized the near burner flame zone (NBFZ). Three coals were tested, two high volatile bituminous (Pittsburgh No.8 and Illinois No.6), and one sub-bituminous (Powder River Basin), at pressures of 1, 2, and 3 MPa (10, 20, and 30 atm). The second series of experiments, which covered high-pressure burnout (HPBO) conditions, utilized a range of substantially longer combustion residence times to produce char burnout levels from 50% to 100%. The same three coals were tested at 1, 2, and 3 MPa, as well as at 0.2 MPa. Tests were also conducted on Pittsburgh No.8 coal in CO2 entrainment gas at 0.2, 1, and 2 MPa to begin establishing a database of experiments relevant to carbon sequestration techniques. The HPBO test series included use of an impactor-type particle sampler to measure the particle size distribution of fly ash produced under complete burnout conditions. The collected data have been interpreted with the help of CFD and detailed kinetics simulation to extend and validate devolatilization, char combustion and pollutant model at elevated pressure. A global NOX production sub-model has been proposed. The submodel reproduces the performance of the detailed chemical reaction mechanism for the NBFZ tests.« less

Formation of Humic Substances in Weathered MSWI Bottom Ash

PubMed Central

Zhang, Haixia; Shimaoka, Takayuki

2013-01-01

The study aimed at evaluating the humic substances (HSs) content from municipal solid waste incinerator (MSWI) bottom ash and its variation with time and the effect of temperature on HSs formation. The process suggested by IHSS was applied to extract HSs from two different bottom ash samples, and the extracted efficiency with NaOH and Na4P2O7 was compared. MSWI bottom ash samples were incubated at 37°C and 50°C for 1 year. HSs and nonhumic substances were extracted from the bottom ash sample with different incubated period by 0.1 M NaOH/Na4P2O7. Results show that the rate of humic acid formation increased originally with incubation time, reached a maximum at 12th week under 37°C and at 18th week under 50°C, and then decreased with time. More humic acid in MSWI bottom ash was formed under 50°C incubated condition compared with that incubated under 37°C. Also, the elemental compositions of HSs extracted from bottom ash are reported. PMID:23844394

Distribution of arsenic and mercury in lime spray dryer ash

DOE Office of Scientific and Technical Information (OSTI.GOV)

Panuwat Taerakul; Ping Sun; Danold W. Golightly

The partitioning of As and Hg in various components of lime spray dryer (LSD) ash samples from a coal-fired boiler was characterized to better understand the form and fate of these elements in flue gas desulfurization byproducts. LSD ash samples, collected from the McCracken Power Plant on the Ohio State University campus, were separated by a 140-mesh (106 {mu}m) sieve into two fractions: a fly-ash-/unburned-carbon-enriched fraction (> 106 {mu}m) and a calcium-enriched fraction (< 106 {mu}m). Unburned carbon and fly ash in the material > 106 {mu}m were subsequently separated by density using a lithium heteropolytungstate solution. The concentrations ofmore » As and Hg were significant in all fractions. The level of As was consistently greater in the calcium-enriched fraction, while Hg was evenly distributed in all components of LSD ash. Specific surface area was an important factor controlling the distribution of Hg in the different components of LSD ash, but not for As. Comparing the LSD ash data to samples collected from the economizer suggests that As was effectively captured by fly ash at 600{sup o}C, while Hg was not. Leaching tests demonstrated that As and Hg were more stable in the calcium-enriched fraction than in the fly-ash- or carbon-enriched fractions, potentially because of the greater pH of the leachate and subsequently greater stability of small amounts of calcium solids containing trace elements in these fractions. 37 refs., 8 figs., 2 tabs.« less

Inhalational and dermal exposures during spray application of biocides.

PubMed

Berger-Preiss, Edith; Boehncke, Andrea; Könnecker, Gustav; Mangelsdorf, Inge; Holthenrich, Dagmar; Koch, Wolfgang

2005-01-01

Data on inhalational and potential dermal exposures during spray application of liquid biocidal products were generated. On the one hand, model experiments with different spraying devices using fluorescent tracers were carried out to investigate the influence of parameters relevant to the exposure (e.g. spraying equipment, nozzle size, direction of application). On the other hand, measurements were performed at selected workplaces (during disinfection operations in food and feed areas; pest control operations for private, public and veterinary hygiene; wood protection and antifouling applications) after application of biocidal products such as Empire 20, Responsar SC, Omexan-forte, Actellic, Perma-forte; Fendona SC, Pyrethrum mist; CBM 8, Aldekol Des 03, TAD CID, Basileum, Basilit. The measurements taken in the model rooms demonstrated dependence of the inhalation exposure on the type of spraying device used, in the following order: "spraying with low pressure" < "airless spraying" < "fogging" indicating that the particle diameter of the released spray droplets is the most important parameter. In addition inhalation exposure was lowest when the spraying direction was downward. Also for the potential dermal exposure, the spraying direction was of particular importance: overhead spraying caused the highest contamination of body surfaces. The data of inhalational and potential dermal exposures gained through workplace measurements showed considerable variation. During spraying procedures with low-pressure equipments, dose rates of active substances inhaled by the operators ranged from 7 to 230 microg active substance (a.s.)/h. An increase in inhaled dose rates (6-33 mg a.s./h) was observed after use of high application volumes/time unit during wood protection applications indoors. Spraying in the veterinary sector using medium-pressure sprayers led to inhaled dose rates between 2 and 24mga.s./h. The highest inhaled dose rates were measured during fogging (114 mg a.s./h) and after-high-pressure applications in the antifouling sector (110-300 mg a.s./h). The potential dermal exposure of spray operators was lowest (dose rates from 0.2 to 7 mg a.s./h) in the areas of food and feed disinfection and private and public hygiene during spraying with low-pressure devices. During fogging, wood protection and antifouling applications, high-potential dermal exposures of the operators were determined. Dermal dose rates varied between 100 and 34,000 mg a.s./h.

Heterogeneous Ice Nucleation by Soufriere Hills Volcanic Ash Immersed in Water Droplets.

PubMed

Mangan, T P; Atkinson, J D; Neuberg, J W; O'Sullivan, D; Wilson, T W; Whale, T F; Neve, L; Umo, N S; Malkin, T L; Murray, B J

2017-01-01

Fine particles of ash emitted during volcanic eruptions may sporadically influence cloud properties on a regional or global scale as well as influencing the dynamics of volcanic clouds and the subsequent dispersion of volcanic aerosol and gases. It has been shown that volcanic ash can trigger ice nucleation, but ash from relatively few volcanoes has been studied for its ice nucleating ability. In this study we quantify the efficiency with which ash from the Soufriere Hills volcano on Montserrat nucleates ice when immersed in supercooled water droplets. Using an ash sample from the 11th February 2010 eruption, we report ice nucleating efficiencies from 246 to 265 K. This wide range of temperatures was achieved using two separate droplet freezing instruments, one employing nanolitre droplets, the other using microlitre droplets. Soufriere Hills volcanic ash was significantly more efficient than all other ash samples that have been previously examined. At present the reasons for these differences are not understood, but may be related to mineralogy, amorphous content and surface chemistry.

Heterogeneous Ice Nucleation by Soufriere Hills Volcanic Ash Immersed in Water Droplets

PubMed Central

Atkinson, J. D.; Neuberg, J. W.; O’Sullivan, D.; Wilson, T. W.; Whale, T. F.; Neve, L.; Umo, N. S.; Malkin, T. L.; Murray, B. J.

2017-01-01

Fine particles of ash emitted during volcanic eruptions may sporadically influence cloud properties on a regional or global scale as well as influencing the dynamics of volcanic clouds and the subsequent dispersion of volcanic aerosol and gases. It has been shown that volcanic ash can trigger ice nucleation, but ash from relatively few volcanoes has been studied for its ice nucleating ability. In this study we quantify the efficiency with which ash from the Soufriere Hills volcano on Montserrat nucleates ice when immersed in supercooled water droplets. Using an ash sample from the 11th February 2010 eruption, we report ice nucleating efficiencies from 246 to 265 K. This wide range of temperatures was achieved using two separate droplet freezing instruments, one employing nanolitre droplets, the other using microlitre droplets. Soufriere Hills volcanic ash was significantly more efficient than all other ash samples that have been previously examined. At present the reasons for these differences are not understood, but may be related to mineralogy, amorphous content and surface chemistry. PMID:28056077

Sinabung Volcanic Ash Utilization As The Additive for Paving Block Quality A and B

NASA Astrophysics Data System (ADS)

Sembiring, I. S.; Hastuty, I. P.

2017-03-01

Paving block is one of the building materials used as the top layer of the road structure besides asphalt and concrete. Paving block is made of mixed materials such as portland cement or other adhesive materials, water and aggregate. In this research, the material used as the additive of cement and concrete is volcanic ash from Mount Sinabung, it is based on the results of the material testing, Sinabung ash contains 74.3% silica (SiO2). The purpose of this research aims to analyze the behavior of the paving blocks quality A and B with and without a mixture of Sinabung ash, to analyze the workability of fresh concrete using Sinabung ash as an additive in concrete, and to compare the test results of paving blocks with and without using Sinabung ash. The samples that we made consist of four variations of the concrete mix to experiment a mixture of normal sample without additive, samples which are mixed with the addition of Sinabung ash 5%, 10%, 15%, 20% and 25% of the volume of concrete/m3. Each variation consists of 10 samples of the concrete with 28 days curing time period. We will do the compressive strength and water absorption test to the samples to determine whether the samples are in accordance with the type needed. According to the test result, paving blocks with Sinabung ash and curing time reach quality A at 0%, 5% and 10% mixture with the compressive strength of each 50.14 MPa, 46.20 MPa and 1.49Mpa, and reach quality B at 15%, 20 %,25% mixture with curing time and 0%, 5%, 10%, 15%, 20% and 25% mixture without curing time. According to the absorption values we got from the test which are 6.66%, 6.73%, 6.88%, 7.03%, 7.09% and 7.16%, the entire sample have average absorption exceeding SNI standardization which is above 6% and reach quality C. Based on compressive strength and absorption data obtained Sinabung ash can’t fully replace cement as the binder because of the low CaO content.

The Complex Refractive Index of Volcanic Ash Aerosol Retrieved From Spectral Mass Extinction

NASA Astrophysics Data System (ADS)

Reed, Benjamin E.; Peters, Daniel M.; McPheat, Robert; Grainger, R. G.

2018-01-01

The complex refractive indices of eight volcanic ash samples, chosen to have a representative range of SiO2 contents, were retrieved from simultaneous measurements of their spectral mass extinction coefficient and size distribution. The mass extinction coefficients, at 0.33-19 μm, were measured using two optical systems: a Fourier transform spectrometer in the infrared and two diffraction grating spectrometers covering visible and ultraviolet wavelengths. The particle size distribution was measured using a scanning mobility particle sizer and an optical particle counter; values for the effective radius of ash particles measured in this study varied from 0.574 to 1.16 μm. Verification retrievals on high-purity silica aerosol demonstrated that the Rayleigh continuous distribution of ellipsoids (CDEs) scattering model significantly outperformed Mie theory in retrieving the complex refractive index, when compared to literature values. Assuming the silica particles provided a good analogue of volcanic ash, the CDE scattering model was applied to retrieve the complex refractive index of the eight ash samples. The Lorentz formulation of the complex refractive index was used within the retrievals as a convenient way to ensure consistency with the Kramers-Kronig relation. The short-wavelength limit of the electric susceptibility was constrained by using independently measured reference values of the complex refractive index of the ash samples at a visible wavelength. The retrieved values of the complex refractive indices of the ash samples showed considerable variation, highlighting the importance of using accurate refractive index data in ash cloud radiative transfer models.

The in vitro respiratory toxicity of cristobalite-bearing volcanic ash.

PubMed

Damby, David E; Murphy, Fiona A; Horwell, Claire J; Raftis, Jennifer; Donaldson, Kenneth

2016-02-01

Ash from dome-forming volcanoes poses a unique hazard to millions of people worldwide due to an abundance of respirable cristobalite, a crystalline silica polymorph. Crystalline silica is an established respiratory hazard in other mixed dusts, but its toxicity strongly depends on sample provenance. Previous studies suggest that cristobalite-bearing volcanic ash is not as bio-reactive as may be expected for a dust containing crystalline silica. We systematically address the hazard posed by volcanic cristobalite by analysing a range of dome-related ash samples, and interpret the crystalline silica hazard according to the mineralogical nature of volcanic cristobalite. Samples are sourced from five well-characterized dome-forming volcanoes that span a range of magmatic compositions, specifically selecting samples rich in cristobalite (up to 16wt%). Isolated respirable fractions are used to investigate the in vitro response of THP-1 macrophages and A549 type II epithelial cells in cytotoxicity, cellular stress, and pro-inflammatory assays associated with crystalline silica toxicity. Dome-related ash is minimally reactive in vitro for a range of source compositions and cristobalite contents. Cristobalite-based toxicity is not evident in the assays employed, supporting the notion that crystalline silica provenance influences reactivity. Macrophages experienced minimal ash-induced cytotoxicity and intracellular reduction of glutathione; however, production of IL-1β, IL-6 and IL-8 were sample-dependent. Lung epithelial cells experienced moderate apoptosis, sample-dependent reduction of glutathione, and minimal cytokine production. We suggest that protracted interaction between particles and epithelial cells may never arise due to effective clearance by macrophages. However, volcanic ash has the propensity to incite a low, but significant, and sample-dependent response; the effect of this response in vivo is unknown and prolonged exposure may yet pose a hazard. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

Generation of volcanic ash: a textural study of ash produced in various laboratory experiments

NASA Astrophysics Data System (ADS)

Lavallée, Yan; Kueppers, Ulrich; Dingwell, Donald B.

2010-05-01

In volcanology, ash is commonly understood as a fragment of a bubble wall that gets disrupted during explosive eruptions. Most volcanic ashes are indeed the product of explosive eruptions, but the true definition is however that of a particle size being inferior to 2 mm. The term does not hold any information about its genesis. During fragmentation, particles of all sizes in various amounts are generated. In nature, fragmentation is a brittle response of the material (whether a rock or magma) caused by changes in 1) strain rate and 2) temperature, and/or 3) chemical composition. Here we used different experimental techniques to produce ash and study their physical characteristics. The effects of strain rate were investigated by deforming volcanic rocks and magma (pure silicate melt and crystal-bearing magma) at different temperatures and stresses in a uniaxial compression apparatus. Failure of pure silicate melts is spontaneous and generates more ash particles than fragmentation of crystal-bearing melts. In the latter, the abundance of generated ash correlates positively with the strain rate. We complemented this investigation with a study of particles generated during rapid decompression of porous rocks, using a fragmentation apparatus. Products of decompression experiments at different initial applied pore pressure show that the amount of ash generated by bubble burst increase with the initial applied pressure and the open porosity. The effects of temperature were investigated by dropping pure silicate melts and crystal-bearing magma at 900 and 1100°C in water at room temperature. Quenching of the material is accompanied by rapid contraction and near instantaneous fragmentation. Pure silicate melts respond more violently to the interaction with water and completely fragmented into small particles, including a variety of ash morphologies and surface textures. Crystal-bearing magmas however fragmented only very partially when in contact with water and produced a few ash particles (< 0.05 g). The morphology and surface textures of the experimentally generated ash particles were imaged through scanning electron microscopy, and the observations will be discussed in terms of fragmentation processes.

Characterization of Briquette from the Corncob Charcoal and Sago Stem Alloys

NASA Astrophysics Data System (ADS)

Lestari, Lina; Inda Variani, Viska; Nyoman Sudiana, I.; Purnama Sari, Dewi; Ode Sitti Ilmawati, Wa; Sahaluddin Hasan, Erzam

2017-05-01

The briquettes fabricated from charcoal of corncob (zea mays,L) and sago stem (metroxilon sago rottb) have been produced and characterized. The samples were prepared step by step carefully. The charcoal powder filtered by strainer with mesh size of 70-80 to get the homogeneous particle size. Briquettes are made by mixing corncob charcoal powder, sago stem charcoal and sago adhesive with a mass ratio of 4:5:1, 4.5: 4.5: 1, 5:4:1. The materials are mixed with hot water and stirred to get homogeneous blend. Then they are compacted by pressure of 34.66kg/cm2, 69.32kg/cm2, and 103.98kg/cm2 to form a cylindrical shape with diameter of 4 cm. The cylindrical briquettes then were dried at temperature of 60°C for 48 hours. After dried, the samples where then characterized their density and water, ash, volatile matter, fixed carbon contents. The burning rate, combustion temperature, and ignition time were also determined. The experimental results show that the briquettes have average densities from 0.602 to 0.717gr/cm3. The density increase with the increasing of forming pressure. The increasing of pressure also result in the decreasing of moisture content from 2.669% to 0.842%. The ash content is found from 3.459% to 8.766%. Volatile matter and fixed carbon are varies from 13.658% and 21.168% and 67.667% to 80.758% respectively. The lowest burning rate is 0.0898gr/s and the optimum burning temperature is 499.2°C with the lowest ignition time of 1.58 minutes. These briquette’s parameters agree wit the quality standard of industrial briquette.

The bioreactivity of the sub-10 μm component of volcanic ash: Soufrière Hills volcano, Montserrat.

PubMed

Jones, Timothy; Bérubé, Kelly

2011-10-30

With the recent eruption of the Icelandic volcano Eyafallajökull and resulting ash cloud over much of Europe there was considerable concern about possible respiratory hazards. Volcanic ash can contain minerals that are known human respiratory health hazards such as cristobalite. Short-term ash exposures can cause skin sores, respiratory and ocular irritations and exacerbation of pre-existing lung conditions such as asthma. Long-term occupational level exposures to crystalline silicon dioxide can cause lung inflammation, oedema, fibrosis and cancer. The potential health effects would be dependent on factors including mineralogy, surface chemistry, size, and levels and duration of exposure. Bulk ash from the Soufrière Hills volcano was sourced and inhalable (<2.5 μm) ash samples prepared and physicochemically characterised. The fine ash samples were tested for bioreactivity by SDS-PAGE which determined the strength of binding between mineral grains and lung proteins. Selected proteins bound tightly to cristobalite, and bound loosely to other ash components. A positive correlation was seen between the amount of SiO(2) in the sample and the strength of the binding. The strength of binding is a function of the mineral's bioreactivity, and therefore, a potential geo-biomarker of respiratory risk. Copyright © 2011 Elsevier B.V. All rights reserved.

Design and fabrication of advanced materials from Illinois coal wastes. Quarterly report, 1 March 1995--31 May 1995

DOE Office of Scientific and Technical Information (OSTI.GOV)

Malhotra, V.M.; Wright, M.A.

1995-12-31

The main goal of this project is to develop a bench-scale procedure to design and fabricate advanced brake and structural composite materials from Illinois coal combustion residues. Scanning electron microscopy (SEM), differential scanning calorimetry (DSC), differential thermal analysis (DTA), and transmission-Fourier transform infrared (FTIR) were conducted on PCC fly ash (Baldwin), FBC fly ash (ADM unit1-6), FBC fly ash (S.I. coal), FBC spent bed ash (ADM unit1-6), bottom ash, and scrubber sludge (CWLP) residues to characterize their geometrical shapes, mineral phases, and thermal stability. Our spectroscopic results indicate that the scrubber sludge is mainly composed of a gypsum-like phase whosemore » lattice structure is different from the lattice structure of conventional gypsum, and sludge does not contain hannebachite (CaSO{sub 3}0.5H{sub 2}O) phase. In the second and third quarters the focus of research has been on developing protocols for the formation of advanced brake composites and structural composites. Our attempts to fabricate brake frictional shoes, in the form of 1.25 inch disks, from PCC fly ash, FBC spent bed ash, scrubber sludge, coal char, iron particles, and coal tar were successful. Based on the experience gained and microscopic analyses, we have now upscaled our procedures to fabricate 2.5 inch diameter disks from coal combustion residues. The SEM and Young`s modulus analyses of brake composites fabricated at 400 psi < Pressure < 2200 psi suggest pressure has a strong influence on the particle packing and the filling of interstices in our composites.« less

Aluminum-fly ash metal matrix composites for automotive parts. [Reports for October 1 to December 1998, and January 31 to March 31, 1999

DOE Office of Scientific and Technical Information (OSTI.GOV)

Weiss, David; Purgert, Robert; Rhudy, Richard

1999-04-21

Some highlights are: (1) Material development, process development, and part validation are occurring simultaneously on a fast track schedule. (2) Prior project activity has resulted in a program emphasis on three components--manifolds, mounting brackets, and motor mounts; and three casting techniques--squeeze casting, pressure die casting, and sand casting. (3) With the project focus, it appears possible to offer manifolds and mounting brackets for automotive qualification testing on a schedule in line with the PNGV Year 2004 goal. (4) Through an iterative process of fly ash treatment, MMC ingot preparation, foundry process refinement, and parts production, both foundries (Eck Industries andmore » Thompson Aluminum Casting Company) are addressing the pre-competitive issues of: (a) Optimum castability with fly ash shapes and sizes; (b) Best mechanical properties derived from fly ash shapes and sizes; (c) Effective fly ash classification processes; (d) Mechanical properties resulting from various casting processes and fly ash formulations. Eck and TAC continued experiments with batch ingot provided by both Eck and the University of Wisconsin at Milwaukee. Castings were run that contained varying amounts of fly ash and different size fractions. Components were cast using cenosphere material to ascertain the effects of squeeze casting and to determine whether the pressure would break the cenospheres. Test parts are currently being machined into substandard test bars for mechanical testing. Also, the affect of heat treatments on ashalloy are being studied through comparison to two lots, one heat treated and one in the ''as cast'' condition.« less

Aluminum-fly ash metal matrix composites for automotive parts. [Reports for October 1 to December 31, 1999, and January 1 - to March 31, 2000

DOE Office of Scientific and Technical Information (OSTI.GOV)

Weiss, David; Purgert, Robert; Rhudy, Richard

2000-04-21

The highlights of this report are: (1) fly ash classified by less than 100 microns in size was mixed into a 300 lb melt of alloy 535 without the need of a magnesium additive; (2) a vibratory feeder fitted with a sieve was used as the means to minimize particle clustering while introducing fly ash into the aluminum alloy 535 melt; and (3) the industrial-size field test was successful in that sand mold castings and permanent mold castings of tensile bars, K mold bars, and ingots were made from aluminum alloy 535-fly ash mix. Use of aluminum alloy 535 containingmore » 7% magnesium precluded the need to introduce additional magnesium into the melt. The third round of sand mold castings as well as permanent mold castings produced components and ingots of alloy 535 instead of alloy 356. The ingots will be remelted and cast into parts to assess the improvement of flyash distribution which occurs through reheating and the solidification wetting process. Microstructure analysis continues on sand and permanent mold castings to study particle distribution in the components. A prototype sand cast intake manifold casting was found to be pressure tight which is a major performance requirement for this part. Another heat of pressure die cast brackets of A380-classified fly ash will be made to examine their strength and fly ash distribution. Ingots of A356-fly ash have been made at Eck for remelting at Thompson Aluminum for squeeze casting into motor mounts.« less

Predicting Water Quality Problems Associated with Coal Fly Ash Disposal Facilities Using a Trace Element Partitioning Study

NASA Astrophysics Data System (ADS)

Bhattacharyya, S.; Donahoe, R. J.; Graham, E. Y.

2006-12-01

For much of the U.S., coal-fired power plants are the most important source of electricity for domestic and industrial use. Large quantities of fly ash and other coal combustion by-products are produced every year, the majority of which is impounded in lagoons and landfills located throughout the country. Many older fly ash disposal facilities are unlined and have been closed for decades. Fly ash often contains high concentrations of toxic trace elements such as arsenic, boron, chromium, molybdenum, nickel, selenium, lead, strontium and vanadium. Trace elements present in coal fly ash are of potential concern due to their toxicity, high mobility in the environment and low drinking water MCL values. Concern about the potential release of these toxic elements into the environment due to leaching of fly ash by acid rain, groundwater or acid mine drainage has prompted the EPA to develop national standards under the subtitle D of the Resource Conservation and Recovery Act (RCRA) to regulate ash disposal in landfills and surface impoundments. An attempt is made to predict the leaching of toxic elements into the environment by studying trace element partitioning in coal fly ash. A seven step sequential chemical extraction procedure (SCEP) modified from Filgueiras et al. (2002) is used to determine the trace element partitioning in seven coal fly ash samples collected directly from electric power plants. Five fly ash samples were derived from Eastern Bituminous coal, one derived from Western Sub-bituminous coal and the other derived from Northern Lignite. The sequential chemical extraction procedure gives valuable information on the association of trace elements: 1) soluble fraction, 2) exchangeable fraction, 3) acid soluble fraction, 4) easily reducible fraction, 5) moderately reducible fraction, 6) poorly reducible fraction and 7) oxidizable organics/sulfide fraction. The trace element partitioning varies with the composition of coal fly ash which is influenced by the type of coal burned. Preliminary studies show that in some fly ash samples, significant amounts of As, B, Mo, Se, Sr and V are associated with the soluble and exchangeable fraction, and thus would be highly mobile in the environment. Lead, on the other hand, is mainly associated with the amorphous Fe and Mn oxide fractions and would be highly immobile in oxidizing conditions, but mobile in reducing conditions. Ni and Cr show different associations in different fly ash samples. In most fly ash samples, significant amounts of the trace elements are associated with more stable fractions that do not threaten the environment. The study of trace element partitioning in coal fly ash thus helps us to predict their leaching behavior under various conditions.

Identification of organically associated trace elements in wood and coal by inductively coupled plasma mass spectrometry.

PubMed

Richaud, R; Lazaro, M J; Lachas, H; Miller, B B; Herod, A A; Dugwell, D R; Kandiyoti, R

2000-01-01

1-Methyl-2-pyrrolidinone (NMP) was used to extract samples of wood (forest residue) and coal; the extracts were analysed by inductively coupled plasma mass spectrometry (ICP-MS) using two different sample preparation methods, in order to identify trace elements associated with the organic part of the samples. A sample of fly ash was similarly extracted and analysed in order to assess the behaviour of the mineral matter contained within the wood and coal samples. 32% of the biomass was extracted at the higher temperature and 12% at room temperature while only 12% of the coal was extracted at the higher temperature and 3% at room temperature. Less than 2% of the ash dissolved at the higher temperature. Size exclusion chromatograms of the extracts indicated the presence of significant amounts of large molecular mass materials (>1000 mu) in the biomass and coal extracts but not in the ash extract. Trace element analyses were carried out using ICP-MS on the acid digests prepared by 'wet ashing' and microwave extraction. Sixteen elements (As, Ba, Be, Cd, Co, Cr, Cu, Ga, Mn, Mo, Ni, Pb, Sb, Se, V and Zn) were quantified, in the samples before extraction, in the extracts and in the residues. Concentrations of trace elements in the original biomass sample were lower than in the coal sample while the concentrations in the ash sample were the highest. The major trace elements in the NMP extracts were Ba, Cu, Mn and Zn from the forest residue; Ba, Cu, Mn, Pb and Zn from the coal; Cu and Zn from the ash. These elements are believed to be associated with the organic extracts from the forest residue and coal, and also from the ash. Be and Sb were not quantified in the extracts because they were present at too low concentrations; up to 40% of Mn was extracted from the biomass sample at 202 degrees C, while Se was totally extracted from the ash sample. For the forest residue, approximately 7% (at room temperature) and 45% (at 202 degrees C) of the total trace elements studied were in the extract; for the coal, approximately 8% (at room temperature) and 23% (at 202 degrees C) were in the extract. For the ash, only 1.4% of the trace elements were extracted at 202 degrees C, comprising 25% of Cd but less than 1% of Pb. Copyright 2000 John Wiley & Sons, Ltd.

The analysis of mechanical properties of non autoclaved aerated concrete with the substitution of fly ash and bottom ash

NASA Astrophysics Data System (ADS)

Karolina, R.; Muhammad, F.

2018-02-01

Based on PP. No.85 of 1999 on the management of hazardous and toxic (B3), fly ash and bottom ash wastes are categorized into B3 waste because there are heavy metal oxide contents that can pollute the environment. One form of environmental rescue that can be applied is to utilize waste fly ash and bottom ash in the manufacture of concrete. In this research, fly ash and bottom ash waste are used as substitution of cement and fine aggregate to make lightweight concrete. The purpose of this research is to know the mechanical properties of non-autoclaved aerated lightweight concrete (NAAC) with FA and BA substitution to cement and fine aggregate which is expected to improve the quality of concrete. The NAAC lightweight concrete in this study is divided into 4 categories: normal NAAC lightweight concrete, NAAC lightweight NAAC substituted concrete with FA, NAAC lightweight concrete substituted with BA, and NAAC combined light weight from FA and BA with variations of 10%, 20% And 30%. The test specimen used in cylindrical shape, which was tested at the age of 28 days, amounted to 90 pieces and consisted of 10 variations. Each variation amounted to 9 samples. Based on the test results with FA and BA substitutions of 10%, 20%, and 30%, the highest compressive strength was achieved in samples with FA 30% of 12.687 MPa, maximum tensile strength achieved in samples with FA 30% of 1,540 MPa, The highest absorption was achieved in normal NAAC of 5.66%. Based on the weight of the contents of all samples, samples can be categorized in lightweight concrete, since the weight of the contents is less than 1900 kg / m3.

Spatial trends in S and Cl in ash leachates of the May 18th, 1980 eruption of Mt. St Helens

NASA Astrophysics Data System (ADS)

Ayris, Paul M.; Delmelle, Pierre; Durant, Adam J.; Damby, David E.; Maters, Elena C.

2014-05-01

It has long been known that surficial deposits of salts and acids on volcanic ash particles derive from interactions of ash with sulphur and halide species within the eruption plume and volcanic cloud. These compounds are mobilised as ash particles are wetted, and beneficial or detrimental environmental and health impacts may be induced where the most concentrated solutions are produced. However, limited mechanistic understanding of gas-ash interactions currently precludes prediction of the spatial distribution or variation in leachate chemistry and concentration following an eruption. Sampling and leachate analysis of freshly-fallen ash therefore offers the sole method by which such variations can be observed. Previous ash leachate studies often involve a limited number of ash samples, and utilise a 'one-dimensional' analysis that considers variation in terms of absolute distance from the source volcano. Here, we demonstrate that extensive sampling and a 'two-dimensional' analysis can uncover more complex spatial trends. We compiled over 358 leachate compositions from the May 18th 1980 eruption of Mt. St. Helens. Of the water-extracted leachates, only 95 compositions from ash sampled at 45 localities between 35 and 1129 km from the volcano are sufficiently documented to be retrospectively comparable. To consider the effects of intra-deposit variability, we calculated average concentrations of leachate data within 11×22 km grid cells across the region, and defined a data quality parameter to reflect confidence in the derived values. To investigate any dependence of leachate composition on the grain size distribution, we generated an interpolated map of geometric specific surface area variation across the deposit, normalising ash leachate data to the calculated specific surface area at the corresponding sampling location. The data treatment identifies S and Cl enrichments in proximal blast deposits; relatively constant Cl concentrations across the ashfall deposits; and a core region of depleted S concentrations in ashfall deposits between 240 and 400 km from the volcano, coinciding with the distal thickening of the deposit attributed to particle aggregation and enhanced fallout. Blast deposit enrichments can be attributed to pre-eruptive uptake of SO2 and HCl gases within the cryptodome, while ashfall deposit trends could reflect differences in the rates of HCl and SO2 uptake by ash, modified by in-plume aggregation processes. However, to validate and interpret such trends with greater confidence would have required a greater spatial density and temporal resolution of sampling, with comprehensive characterisation of the recovered ash and the surrounding deposit. In the future, rigorous study and sampling of equivalent extent to that in the aftermath of the historic Mt. St. Helens eruption is likely required to extend insight into processes affecting the spatial distribution of leachate chemistry.

Coal hydrogenation and deashing in ebullated bed catalytic reactor

DOEpatents

Huibers, Derk T. A.; Johanson, Edwin S.

1983-01-01

An improved process for hydrogenation of coal containing ash with agglomeration and removal of ash from an ebullated bed catalytic reactor to produce deashed hydrocarbon liquid and gas products. In the process, a flowable coal-oil slurry is reacted with hydrogen in an ebullated catalyst bed reaction zone at elevated temperature and pressure conditions. The upward velocity and viscosity of the reactor liquid are controlled so that a substantial portion of the ash released from the coal is agglomerated to form larger particles in the upper portion of the reactor above the catalyst bed, from which the agglomerated ash is separately withdrawn along with adhering reaction zone liquid. The resulting hydrogenated hydrocarbon effluent material product is phase separated to remove vapor fractions, after which any ash remaining in the liquid fraction can be removed to produce substantially ash-free coal-derived liquid products.

Design and fabrication of advanced materials from Illinois coal wastes. Quarterly report, 1 December 1994--28 February 1995

DOE Office of Scientific and Technical Information (OSTI.GOV)

Malhotra, V.M.; Wright, M.A.

1995-12-31

The main goal of this project is to develop a bench-scale procedure to design and fabricate advanced brake and structural composite materials from Illinois coal combustion residues. During the first two quarters of the project, the thrust of the work directed towards characterizing the various coal combustion residues and FGD residue, i.e., scrubber sludge. Scanning electron microscopy (SEM), differential scanning calorimetry (DSC), differential thermal analysis (DTA), and transmission-Fourier transform infrared (FTIR) were conducted on PCC fly ash (Baldwin), FBC fly ash (ADK unit l-6), FBC fly ash (S.I. coal), FBC spent bed ash (ADM, unit l-6), bottom ash, and scrubbermore » sludge (CWLP) residues to characterize their geometrical shapes, mineral phases, and thermal stability. Our spectroscopic results indicate that the scrubber sludge is mainly composed of a gypsum-like phase whose lattice structure is different from the lattice structure of conventional gypsum, and sludge does not contain hannebachite (CaSO{sub 3}.0.5H{sub 2}O) phase. Our attempts to fabricate brake frictional shoes, in the form of 1.25 inch disks, from PCC fly ash, FBC spent bed ash, scrubber sludge, coal char, iron particles, and coal tar were successful. Based on the experience gained and microscopic analyses, we have now upscaled our procedures to fabricate 2.5 inch diameter disk,- from coal combustion residues. This has been achieved. The SEM and Young`s modulus analyses of brake composites fabricated at 400 psi < Pressure < 2200 psi suggest pressure has a strong influence on the particle packing and the filling of interstices in our composites. Also, these results along with mechanical behavior of the fabricated disks lead us to believe that the combination of surface altered PCC fly ash and scrubber sludge particles, together ed ash particles are ideal for our composite materials.« less

Survival of emerald ash borer in chips

Treesearch

Deborah G. McCullough; Therese M. Poland; David L. Cappaert

2005-01-01

The ability of emerald ash borer (EAB), Agrilus planipennis Fairmaire, to survive following chipping or grinding of infested ash trees remains a critical question for regulatory officials. In October 2002, we felled eight infested ash trees and sampled sections of the trunk and large branches from each tree to estimate EAB density.

Conditioning of carbonaceous material prior to physical beneficiation

DOEpatents

Warzinski, Robert P.; Ruether, John A.

1987-01-01

A carbonaceous material such as coal is conditioned by contact with a supercritical fluid prior to physical beneficiation. The solid feed material is contacted with an organic supercritical fluid such as cyclohexane or methanol at temperatures slightly above the critical temperature and pressures of 1 to 4 times the critical pressure. A minor solute fraction is extracted into critical phase and separated from the solid residuum. The residuum is then processed by physical separation such as by froth flotation or specific gravity separation to recover a substantial fraction thereof with reduced ash content. The solute in supercritical phase can be released by pressure reduction and recombined with the low-ash, carbonaceous material.

Environmentally-Friendly Dense and Porous Geopolymers Using Fly Ash and Rice Husk Ash as Raw Materials

PubMed Central

Ziegler, Daniele; Formia, Alessandra; Tulliani, Jean-Marc; Palmero, Paola

2016-01-01

This paper assesses the feasibility of two industrial wastes, fly ash (FA) and rice husk ash (RHA), as raw materials for the production of geopolymeric pastes. Three typologies of samples were thus produced: (i) halloysite activated with potassium hydroxide and nanosilica, used as the reference sample (HL-S); (ii) halloysite activated with rice husk ash dissolved into KOH solution (HL-R); (iii) FA activated with the alkaline solution realized with the rice husk ash (FA-R). Dense and porous samples were produced and characterized in terms of mechanical properties and environmental impact. The flexural and compressive strength of HL-R reached about 9 and 43 MPa, respectively. On the contrary, the compressive strength of FA-R is significantly lower than the HL-R one, in spite of a comparable flexural strength being reached. However, when porous samples are concerned, FA-R shows comparable or even higher strength than HL-R. Thus, the current results show that RHA is a valuable alternative to silica nanopowder to prepare the activator solution, to be used either with calcined clay and fly ash feedstock materials. Finally, a preliminary evaluation of the global warming potential (GWP) was performed for the three investigated formulations. With the mix containing FA and RHA-based silica solution, a reduction of about 90% of GWP was achieved with respect to the values obtained for the reference formulation. PMID:28773587

Seasonal Variations in Ash Content of Some Michigan Forest Floor Fuels

Treesearch

Robert M. Loomis

1982-01-01

Samples from the forest floor litter layer were collected seasonally from under medium to fully stocked larger sapling to sawtimber stands in Lower Michigan to study seasonal ash content changes. The total ash and silica-free ash content of tree foliage in the upper part of the litter layer differed little from season to season. Differences in ash content due to...

PYFLOW_2.0: a computer program for calculating flow properties and impact parameters of past dilute pyroclastic density currents based on field data

NASA Astrophysics Data System (ADS)

Dioguardi, Fabio; Mele, Daniela

2018-03-01

This paper presents PYFLOW_2.0, a hazard tool for the calculation of the impact parameters of dilute pyroclastic density currents (DPDCs). DPDCs represent the dilute turbulent type of gravity flows that occur during explosive volcanic eruptions; their hazard is the result of their mobility and the capability to laterally impact buildings and infrastructures and to transport variable amounts of volcanic ash along the path. Starting from data coming from the analysis of deposits formed by DPDCs, PYFLOW_2.0 calculates the flow properties (e.g., velocity, bulk density, thickness) and impact parameters (dynamic pressure, deposition time) at the location of the sampled outcrop. Given the inherent uncertainties related to sampling, laboratory analyses, and modeling assumptions, the program provides ranges of variations and probability density functions of the impact parameters rather than single specific values; from these functions, the user can interrogate the program to obtain the value of the computed impact parameter at any specified exceedance probability. In this paper, the sedimentological models implemented in PYFLOW_2.0 are presented, program functionalities are briefly introduced, and two application examples are discussed so as to show the capabilities of the software in quantifying the impact of the analyzed DPDCs in terms of dynamic pressure, volcanic ash concentration, and residence time in the atmosphere. The software and user's manual are made available as a downloadable electronic supplement.

Progression of ash canopy thinning and dieback outward from the initial infestation of emerald ash borer (Coleoptera: Buprestidae) in southeastern Michigan.

PubMed

Smitley, David; Davis, Terrance; Rebek, Eric

2008-10-01

Our objective was to characterize the rate at which ash (Fraxinus spp.) trees decline in areas adjacent to the leading edge of visible ash canopy thinning due to emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae). Trees in southeastern Michigan were surveyed from 2003 to 2006 for canopy thinning and dieback by comparing survey trees with a set of 11 standard photographs. Freeways stemming from Detroit in all directions were used as survey transects. Between 750 and 1,100 trees were surveyed each year. A rapid method of sampling populations of emerald ash borer was developed by counting emerald ash borer emergence holes with binoculars and then felling trees to validate binocular counts. Approximately 25% of the trees surveyed for canopy thinning in 2005 and 2006 also were sampled for emerald ash borer emergence holes using binoculars. Regression analysis indicates that 41-53% of the variation in ash canopy thinning can be explained by the number of emerald ash borer emergence holes per tree. Emerald ash borer emergence holes were found at every site where ash canopy thinning averaged > 40%. In 2003, ash canopy thinning averaged 40% at a distance of 19.3 km from the epicenter of the emerald ash borer infestation in Canton. By 2006, the point at which ash trees averaged 40% canopy thinning had increased to a distance of 51.2 km away from Canton. Therefore, the point at which ash trees averaged 40% canopy thinning, a state of decline clearly visible to the average person, moved outward at a rate of 10.6 km/yr during this period.

Identification and characterization of individual airborne volcanic ash particles by Raman microspectroscopy.

PubMed

Ivleva, Natalia P; Huckele, Susanne; Weinzierl, Bernadett; Niessner, Reinhard; Haisch, Christoph; Baumann, Thomas

2013-11-01

We present for the first time the Raman microspectroscopic identification and characterization of individual airborne volcanic ash (VA) particles. The particles were collected in April/May 2010 during research aircraft flights, which were performed by Deutsches Zentrum für Luft- und Raumfahrt in the airspace near the Eyjafjallajökull volcano eruption and over Europe (between Iceland and Southern Germany). In addition, aerosol particles were sampled by an Electrical Low Pressure Impactor in Munich, Germany. As references for the Raman analysis, we used the spectra of VA collected at the ground near the place of eruption, of mineral basaltic rock, and of different minerals from a database. We found significant differences in the spectra of VA and other aerosol particles (e.g., soot, nitrates, sulfates, and clay minerals), which allowed us to identify VA among other atmospheric particulate matter. Furthermore, while the airborne VA shows a characteristic Raman pattern (with broad band from ca. 200 to ca. 700 cm(-1) typical for SiO₂ glasses and additional bands of ferric minerals), the differences between the spectra of aged and fresh particles were observed, suggesting differences in their chemical composition and/or structure. We also analyzed similarities between Eyjafjallajökull VA particles collected at different sampling sites and compared the particles with a large variety of glassy and crystalline minerals. This was done by applying cluster analysis, in order to get information on the composition and structure of volcanic ash.

Elemental analyses of pine bark and wood in an environmental study.

PubMed

Saarela, K-E; Harju, L; Rajander, J; Lill, J-O; Heselius, S-J; Lindroos, A; Mattsson, K

2005-05-01

Bark and wood samples were taken from the same individuals of Scots pine (Pinus sylvestris L.) from a polluted area close to a Cu-Ni smelter in Harjavalta and from some relatively unpolluted areas in western Finland. The samples were analysed by thick-target particle induced X-ray emission (PIXE) after preconcentration by dry ashing at 550 degrees C. The elemental contents of pine bark and wood were compared to study the impact of heavy metal pollution on pine trees. By comparison of the elemental contents in ashes of bark and wood, a normalisation was obtained. For the relatively clean areas, the ratios of the concentration in bark ash to the concentration in wood ash for different elements were close to 1. This means that the ashes of Scots Pine wood and bark have quite similar elemental composition. For the samples from the polluted area the mean concentration ratios for some heavy metals were elevated (13-28), reflecting the effect of direct atmospheric contamination. The metal contents in the ashes of pine bark and wood were also compared to recommendations for ashes to be recycled back to the forest environment. Bark from areas close to emission sources of heavy metal pollution should be considered with caution if aiming at recycling the ash. Burning of bark fuel of pine grown within 6 km of the Cu-Ni smelter is shown to generate ashes with high levels of Cu, Ni as well as Cd, As and Pb.

ASHE Reader on Organization and Governance in Higher Education. Third Edition. ASHE Reader Series.

ERIC Educational Resources Information Center

Peterson, Marvin W., Ed.

An anthology of supplementary text material on organization and governance in higher education is presented for use in graduate courses in the field of higher education administration. The chapters are divided into three sections: organization, governance, and responses to internal and external pressures. Chapter titles and personal/corporate…

Water Adsorption Isotherms on Fly Ash from Several Sources.

PubMed

Navea, Juan G; Richmond, Emily; Stortini, Talia; Greenspan, Jillian

2017-10-03

In this study, horizontal attenuated total reflection (HATR) Fourier-transform infrared (FT-IR) spectroscopy was combined with quartz crystal microbalance (QCM) gravimetry to investigate the adsorption isotherms of water on fly ash, a byproduct of coal combustion in power plants. Because of composition variability with the source region, water uptake was studied at room temperature as a function of relative humidity (RH) on fly ash from several regions: United States, India, The Netherlands, and Germany. The FT-IR spectra show water features growth as a function of RH, with water absorbing on the particle surface in both an ordered (ice-like) and a disordered (liquid-like) structure. The QCM data was modeled using the Brunauer, Emmett, and Teller (BET) adsorption isotherm model. The BET model was found to describe the data well over the entire range of RH, showing that water uptake on fly ash takes place mostly on the surface of the particle, even for poorly combusted samples. In addition, the source region and power-plant efficiency play important roles in the water uptake and ice nucleation (IN) ability of fly ash. The difference in the observed water uptake and IN behavior between the four samples and mullite (3Al 2 O 3 ·2SiO 2 ), the aluminosilicate main component of fly ash, is attributed to differences in composition and the density of OH binding sites on the surface of each sample. A discussion is presented on the RH required to reach monolayer coverage on each sample as well as a comparison between surface sites of fly ash samples and enthalpies of adsorption of water between the samples and mullite.

Morphology and petrography of volcanic ashes.

NASA Technical Reports Server (NTRS)

Heiken, G.

1972-01-01

Study of volcanic ash samples collected from a variety of recent eruptions using petrography, chemical analyses, and scanning electron microscopy to characterize each type and to relate ash morphology to magma composition and the type of eruption. The ashes are placed in the broad genetic categories of magmatic and phreatomagmatic. The morphology of ash particles from magmatic eruptions of high viscosity magma is governed primarily by vesicle density and shape. Ash particles from eruptions of low viscosity magmas are mostly droplets. The morphology of ash particles from phreatomagmatic eruptions is controlled by stresses within the chilled magma which result in fragmentation of the glass to form small blocky or pyramidal glass ash particles.

Thermo-mechanical properties and microfabric of fly ash-stabilized gold tailings.

PubMed

Lee, Joon Kyu; Shang, Julie Q; Jeong, Sangseom

2014-07-15

This paper studies the changes in thermal conductivity, temperature, and unconfined compressive strength of gold tailings and fly ash mixtures during the curing period of 5 days. The microfabric of the cured mixtures was investigated with mercury intrusion porosimetry (MIP). The mixture samples were prepared at their maximum dry unit weight and optimum moisture content. Effect of adding fly ash to gold tailings (i.e., 0, 20, and 40% of the dry weight of tailings) was examined, and a comparison was made on samples prepared at the same fly ash content by replacing gold tailings with humic acid (i.e., gold tailings and humic acid ratios of 100:0, 90:10, and 80:20 by weight) or by varying pore fluid chemistry (i.e., water and salt solutions of 1M NaCl and CaCl2). The results show that the initial thermal conductivity of the samples is sensitive to the mixture proportion and a declination in the thermal conductivity is observed due to hydration of fly ash and evaporation. Inclusion of fly ash and salts into gold tailings improves the unconfined compressive strength but the presence of humic acid in samples leads to the decrease of the strength. MIP results reveal the pore structure changes associated with the packing states of the samples that reflect the influential factors considered. Copyright © 2014 Elsevier B.V. All rights reserved.

Comparative study of the microstructural and magnetic properties of fly ashes obtained from different thermal power plants in West Bengal, India.

PubMed

Bhattacharjee, Ashis; Mandal, Haradhan; Roy, Madhusudan; Kusz, Joachim; Hofmeister, Wolfgang

2013-10-01

This paper deals with the physical nature of the fly ashes obtained from two thermal power plants, situated in West Bengal, India. The fly ash samples are characterized by using comprehensive techniques with an emphasis on their ultrafine nature. The particle sizes of the samples are estimated using scanning electron microcopy (SEM) and found to lie within 0.18-5.90 μm. For morphology and compositional analysis, we also use SEM coupled with energy dispersive X-ray spectrometry. From X-ray study of the fly ashes the nature of conglomeration is seen to be crystalline, and the major components are mullite (Al6Si2O13) and quartz (SiO2). The magnetic measurement of the fly ash samples was carried out by SQUID magnetometer. (57)Fe Mössbauer spectra are obtained using a conventional constant-acceleration spectrometer with a (57)Co/Rh Mössbauer source. The hyperfine parameters obtained, in general, support the findings as made from XRD analysis and provide a quantitative measure of different iron ions present in the samples. The paper presents experimental data on the physical aspects of the fly ash samples of the thermal power plants which comprise coarse, fine, and ultrafine magnetic particulate materials and attempts to provide an exhaustive analysis.

Characterization and environmental risk assessment of heavy metals found in fly ashes from waste filter bags obtained from a Chinese steel plant.

PubMed

Zhou, Yun; Ning, Xun-an; Liao, Xikai; Lin, Meiqing; Liu, Jingyong; Wang, Jianghui

2013-09-01

The environmental risk of exposure to six heavy metals (Cu, Pb, Zn, Cr, Ni, and Cd) found in fly ashes from waste filter bags obtained from a steel plant was estimated based on the mineralogical compositions, total concentrations and speciation of the metals in the fly ashes. The results indicated that the fly ashes mainly consisted of hematite, magnetite, cyanite, spinel, coesite and amorphous materials. The concentrations of Zn and Pb were much higher than that of other materials. After Zn and Pb, Ni was present in the highest concentration, followed by Cu, Cr and Cd. Each heavy metal was distributed differently in fly ashes. The levels of Zn, Cd and Pb in the active fraction were very high, and ranged from 64.83 to 81.96%, 34.48 to 82.4% and 6.92 to 79.65% respectively, while Cu, Cr and Ni were mainly present in the residual fraction. The risk assessment code (RAC) values of fly ashes showed that the Zn and Cd present in the H3 sample presented a very high risk, with RAC values greater than 50%. The Cu present in the H3 sample, Cd in the H2 sample and Zn in the H4 and H5 samples presented a high risk. The Pb present in the H2 sample, Cd in the H4 sample, Ni in the H1 and H5 samples, and Zn in the H1 sample presented a medium risk. A low risk was presented by the Cu present in the H1, H2, H4 and H5 samples, the Pb in the H1, H3 and H5 samples, the Cd in the H1 and H5 samples, and the Ni in the H2 sample. No risk was presented by Cr in any sample. Copyright © 2013 Elsevier Inc. All rights reserved.

Comparison of digestion methods for determination of trace and minor metals in plant samples.

PubMed

Lavilla, I; Filgueiras, A V; Bendicho, C

1999-12-01

In this paper, three dissolution methods using pressure digestion vessels (low-, medium-, and high-pressure vessels) for the determination of metals in plant samples are described. The Plackett-Burman saturated factorial design was used to identify the significant factors influencing wet ashing and to select optimized dissolution conditions. The three methods were statistically compared (on-way ANOVA) on the same sample; no significant differences were obtained. In all cases the relative standard deviation values were <3%. The digestion method based on the use of low-pressure vessels and a microwave oven was validated against CRM GBW07605 tea leaves. This method was applied to the determination of Cu, Zn, Mn, Fe, Mg, and Ca in 22 different medicinal, aromatic, and seasoning plants by flame-atomic absorption spectrometry. The concentration intervals of metal in the plants analyzed were the following: Cu, 4 (Allium sativum)-35 (Thea sinensis) microg g(-1); Zn, 7 (Piper nigrum)-90 (Betula alba) microg g(-1); Mn, 9 (Allium sativum)-939 (Caryophylus aromaticus) microg g(-1); Fe, 33 (Allium sativum)-2486 (Anethum graveolens) microg g(-1); Mg, 495 (Allium sativum)-7458 (Ocimum basilicum) microg g(-1); Ca, 386 (Allium sativum)-21500 (Ocimum basilicum) microg g(-1).

Mercury removal from coal combustion flue gas by modified fly ash.

PubMed

Xu, Wenqing; Wang, Hairui; Zhu, Tingyu; Kuang, Junyan; Jing, Pengfei

2013-02-01

Fly ash is a potential alternative to activated carbon for mercury adsorption. The effects of physicochemical properties on the mercury adsorption performance of three fly ash samples were investigated. X-ray fluorescence spectroscopy, X-ray photoelectron spectroscopy, and other methods were used to characterize the samples. Results indicate that mercury adsorption on fly ash is primarily physisorption and chemisorption. High specific surface areas and small pore diameters are beneficial to efficient mercury removal. Incompletely burned carbon is also an important factor for the improvement of mercury removal efficiency, in particular. The C-M bond, which is formed by the reaction of C and Ti, Si and other elements, may improve mercury oxidation. The samples modified with CuBr2, CuCl2 and FeCl3 showed excellent performance for Hg removal, because the chlorine in metal chlorides acts as an oxidant that promotes the conversion of elemental mercury (Hg0) into its oxidized form (Hg2+). Cu2+ and Fe3+ can also promote Hg0 oxidation as catalysts. HCl and O2 promote the adsorption of Hg by modified fly ash, whereas SO2 inhibits the Hg adsorption because of competitive adsorption for active sites. Fly ash samples modified with CuBr2, CuCl2 and FeCl3 are therefore promising materials for controlling mercury emissions.

Trace elements in coal ash

USGS Publications Warehouse

Deonarine, Amrika; Kolker, Allan; Doughten, Michael W.

2015-01-01

In this fact sheet, the form, distribution, and behavior of trace elements of environmental interest in samples of coal fly ash were investigated in response to concerns about element mobility in the event of an ash spill. The study includes laboratory-based leaching experiments to examine the behavior of trace elements, such as arsenic (As) and chromium (Cr), in response to key environmental factors including redox conditions (degree of oxygenation), which are known to vary with depth within coal ash impoundments and in natural ecosystems. The experiments show that As dissolves from samples of coal fly ash into simulated freshwater under both oxic (highly oxygenated) and anoxic (poorly oxygenated) conditions, whereas dissolved Cr concentrations are very redox dependent. This U.S. Geological Survey research helps define the distribution of elements such as As in coal ash and shows that element mobility can vary considerably under different conditions expected in the environment.

Microwave digestion for the quantification of inorganic elements in coal and coal ash using ICP-OES.

PubMed

Low, Fiona; Zhang, Lian

2012-11-15

In this paper, microwave digestion conditions have been optimised to achieve complete recoveries for the ash-forming inorganic elements in coal and coal combustion fly ash, during the analysis by inductively coupled plasma optical emission spectroscopy (ICP-OES). The elements analysed include six major (Al, Ca, Fe, K, Mg and Na) and twelve trace (As, Ba, Be, Co, Cr, Cu, Li, Mn, Ni, Pb, Sr and V). Seven reference samples have been tested, including two standard coal references, SRM1632c and SARM19, their corresponding high-temperature ashes (HTAs), and three coal fly ash references, SRM1633c, SRM2690 and BCR38. The recoveries of individual elements in these samples have been examined intensively, as a function of the amount of hydrofluoric acid (HF, 0-2.0 ml), microwave power (900 W vs. 1200 W) and sample mass (0.05 g vs. 0.1 g). As have been confirmed, the recoveries of these individual elements varied significantly with the microwave digestion condition, elemental type and sample property. For the coal references and their HTAs, the use of HF can be ruled out for most of the elements, except K associated with feldspar, Pb and V. In particular, the recovery of Pb in coal is highly sample-specific and thus unpredictable. The majority of elements in fly ash references require the use of 0.1-0.2 ml HF for a complete recovery. Al in fly ash is the only exceptional element which gave incomplete recoveries throughout, suggesting the use of a complementary technique for its quantification. As has proven to be the only element inconsequential of sample type and digestion conditions, achieving complete recoveries for all cases. On the power parameter, using a higher power such as 1200 W is critical, which has proved to be an ultimatum for the recovery of certain elements, especially in fly ash. Halving sample mass from 0.1 g to 0.05 g was also found to be insignificant. Copyright © 2012 Elsevier B.V. All rights reserved.

Development of Fly Ash-Based Sorbent to Capture CO2 from Flue Gas

NASA Astrophysics Data System (ADS)

Majchrzak-Kucęba, I.; Nowak, W.

In the present work the thermogravimetric characterization of the sorption of carbon dioxide on polymer-modifiedmesoporous materials (MCM-41) from fly ashes is described. In order to obtain MCM-41 materials from three different types fly ashes,(including CFB fly ash) hydrothermal processesusing the supernatantsof coal fly ashes and surfactantsas the structure-directing agents,have been carried out. The obtained mesoporous materials were subjected to polyethylenimine (PEI) modification by their impregnation to obtain samples with PEl contents of 30, 50 and 70%, respectively. CO2 sorption/desorption tests on loaded PEl samples were carried out in a flow of a mixture of gasses (CO2-1O%, O2-10%, N2-80%) at different temperatures: 25 and 75°C. The highest CO2 sorption value was obtained for the sample that contained the best-quality MCM-41 and was impregnatedwith PEI in the amount of 50%. This sample at a temperatureof 75°C can take CO2 in an amount equivalent to 111.7 mgCO2/g sample weight. Under the same conditions, but without PEI impregnation, this sample can take CO2 in an amount equivalent to 3.2 mgCO2/g sample weight, thus 35 times less. The research of CO2 adsorption on polymer-modified mesoporous materials from fly ashes carried out within this work has shown that these materials are characterized by high CO2 adsorption capacity under conditions typical of coal combustionboiler flue gas and have the chance of becoming an efficient adsorbent for application to post-combustion CO2 separation. For PEI impregnated samples, a different behaviour of adsorption/desorption profiles has also been observed (both sorption and desorptionprogressesvery rapidly).

Liquid chromatography/mass spectrometry for the detection of ash tree metabolites following Emerald Ash Borer infestation.

PubMed

Stock, Naomi L; Doran, Michael C; Bonners, Ron F; March, Raymond E

2018-03-15

The Emerald Ash Borer (EAB), Agrilus planipennis, an invasive insect detected in the USA and Canada in 2002, is a threat to ash trees with both ecological and economic implications. Early detection of EAB-infestation is difficult due to lack of visible signs and symptoms in the early stages of attack, but is essential to prevent ash mortality. An efficient and reliable tool for the early detection of EAB-infestation would be advantageous. A mass spectrometry based metabolomics approach, using liquid chromatography/mass spectrometry (LC/MS), has been used to investigate the leaf metabolites of both healthy and EAB-infested trees. Leaves from 40 healthy and 40 EAB-infested trees were extracted and analyzed using LC/MS. Resulting data were examined to differentiate between foliage from healthy and EAB-infested trees. Possible biomarkers of EAB attack have been detected. Twenty-one metabolites with increased average ion intensity in EAB-infested ash tree samples and nine metabolites with increased average ion intensity in healthy ash tree samples were identified. Results of this study indicate that metabolomic screening of leaf samples using LC/MS can be useful as a potential tool for the early detection of EAB-infestation. Copyright © 2018 John Wiley & Sons, Ltd.

Study on hot melt pressure sensitive coil material for removing surface nuclear pollution dust

NASA Astrophysics Data System (ADS)

Wang, Jing; Li, Jiao; Wang, Jianhui; Zheng, Li; Li, Jian; Lv, Linmei

2018-02-01

A new method for removing surface nuclear pollution by using hot melt pressure sensitive membrane was presented. The hot melt pressure sensitive membrane was designed and prepared by screening hot melt pressure sensitive adhesive and substrate. The simulated decontamination test of the hot melt pressure sensitive membrane was performed by using 100 mesh and 20 mesh standard sieve dust for simulation of nuclear explosion fall ash and radioactive contaminated particles, respectively. It was found that the single decontamination rate of simulated fall ash and contaminated particles were both above 80% under pressure conditions of 25kPa or more at 140°C. And the maximum single decontamination rate was 92.5%. The influence of heating temperature and pressure on the decontamination rate of the membrane was investigated at the same time. The results showed that higher heating temperature could increase the decontamination rate by increasing the viscosity of the adhesive. When the adhesive amount of the adhesive layer reached saturation, a higher pressure could increase the single decontamination rate also.

Grain-size analysis of volcanic ash for the rapid assessment of respiratory health hazard.

PubMed

Horwell, Claire J

2007-10-01

Volcanic ash has the potential to cause acute and chronic respiratory diseases if the particles are sufficiently fine to enter the respiratory system. Characterization of the grain-size distribution (GSD) of volcanic ash is, therefore, a critical first step in assessing its health hazard. Quantification of health-relevant size fractions is challenging without state-of-the-art technology, such as the laser diffractometer. Here, several methods for GSD characterization for health assessment are considered, the potential for low-cost measurements is investigated and the first database of health-pertinent GSD data is presented for a suite of ash samples from around the world. Methodologies for accurate measurement of the GSD of volcanic ash by laser diffraction are presented by experimental analysis of optimal refractive indices for different magmatic compositions. Techniques for representative sampling of small quantities of ash are also experimentally investigated. GSD results for health-pertinent fractions for a suite of 63 ash samples show that the fraction of respirable (<4 microm) material ranges from 0-17 vol%, with the variation reflecting factors such as the style of the eruption and the distance from the source. A strong correlation between the amount of <4 and <10 microm material is observed for all ash types. This relationship is stable at all distances from the volcano and with all eruption styles and can be applied to volcanic plume and ash fallout models. A weaker relationship between the <4 and <63 microm fractions provides a novel means of estimating the quantity of respirable material from data obtained by sieving.

Assessment of the potential respiratory hazard of volcanic ash from future Icelandic eruptions: A study of archived basaltic to rhyolitic ash samples

USGS Publications Warehouse

Damby, David; Horwell, Claire J.; Larsen, Gudrun; Thordarson, Thorvaldur; Tomatis, Maura; Fubini, Bice; Donaldson, Ken

2017-01-01

BackgroundThe eruptions of Eyjafjallajökull (2010) and Grímsvötn (2011), Iceland, triggered immediate, international consideration of the respiratory health hazard of inhaling volcanic ash, and prompted the need to estimate the potential hazard posed by future eruptions of Iceland’s volcanoes to Icelandic and Northern European populations. MethodsA physicochemical characterization and toxicological assessment was conducted on a suite of archived ash samples spanning the spectrum of past eruptions (basaltic to rhyolitic magmatic composition) of Icelandic volcanoes following a protocol specifically designed by the International Volcanic Health Hazard Network. ResultsIcelandic ash can be of a respirable size (up to 11.3 vol.% < 4 μm), but the samples did not display physicochemical characteristics of pathogenic particulate in terms of composition or morphology. Ash particles were generally angular, being composed of fragmented glass and crystals. Few fiber-like particles were observed, but those present comprised glass or sodium oxides, and are not related to pathogenic natural fibers, like asbestos or fibrous zeolites, thereby limiting concern of associated respiratory diseases. None of the samples contained cristobalite or tridymite, and only one sample contained quartz, minerals of interest due to the potential to cause silicosis. Sample surface areas are low, ranging from 0.4 to 1.6 m2 g−1, which aligns with analyses on ash from other eruptions worldwide. All samples generated a low level of hydroxyl radicals (HO•), a measure of surface reactivity, through the iron-catalyzed Fenton reaction compared to concurrently analyzed comparative samples. However, radical generation increased after ‘refreshing’ sample surfaces, indicating that newly erupted samples may display higher reactivity. A composition-dependent range of available surface iron was measured after a 7-day incubation, from 22.5 to 315.7 μmol m−2, with mafic samples releasing more iron than silicic samples. All samples were non-reactive in a test of red blood cell-membrane damage. ConclusionsThe primary particle-specific concern is the potential for future eruptions of Iceland’s volcanoes to generate fine, respirable material and, thus, to increase ambient PM concentrations. This particularly applies to highly explosive silicic eruptions, but can also hold true for explosive basaltic eruptions or discrete events associated with basaltic fissure eruptions.

Assessment of the potential respiratory hazard of volcanic ash from future Icelandic eruptions: a study of archived basaltic to rhyolitic ash samples.

PubMed

Damby, David E; Horwell, Claire J; Larsen, Gudrun; Thordarson, Thorvaldur; Tomatis, Maura; Fubini, Bice; Donaldson, Ken

2017-09-11

The eruptions of Eyjafjallajökull (2010) and Grímsvötn (2011), Iceland, triggered immediate, international consideration of the respiratory health hazard of inhaling volcanic ash, and prompted the need to estimate the potential hazard posed by future eruptions of Iceland's volcanoes to Icelandic and Northern European populations. A physicochemical characterization and toxicological assessment was conducted on a suite of archived ash samples spanning the spectrum of past eruptions (basaltic to rhyolitic magmatic composition) of Icelandic volcanoes following a protocol specifically designed by the International Volcanic Health Hazard Network. Icelandic ash can be of a respirable size (up to 11.3 vol.% < 4 μm), but the samples did not display physicochemical characteristics of pathogenic particulate in terms of composition or morphology. Ash particles were generally angular, being composed of fragmented glass and crystals. Few fiber-like particles were observed, but those present comprised glass or sodium oxides, and are not related to pathogenic natural fibers, like asbestos or fibrous zeolites, thereby limiting concern of associated respiratory diseases. None of the samples contained cristobalite or tridymite, and only one sample contained quartz, minerals of interest due to the potential to cause silicosis. Sample surface areas are low, ranging from 0.4 to 1.6 m 2  g -1 , which aligns with analyses on ash from other eruptions worldwide. All samples generated a low level of hydroxyl radicals (HO • ), a measure of surface reactivity, through the iron-catalyzed Fenton reaction compared to concurrently analyzed comparative samples. However, radical generation increased after 'refreshing' sample surfaces, indicating that newly erupted samples may display higher reactivity. A composition-dependent range of available surface iron was measured after a 7-day incubation, from 22.5 to 315.7 μmol m -2 , with mafic samples releasing more iron than silicic samples. All samples were non-reactive in a test of red blood cell-membrane damage. The primary particle-specific concern is the potential for future eruptions of Iceland's volcanoes to generate fine, respirable material and, thus, to increase ambient PM concentrations. This particularly applies to highly explosive silicic eruptions, but can also hold true for explosive basaltic eruptions or discrete events associated with basaltic fissure eruptions.

Leaching characteristics of solid wastes from thermal power plants of western Turkey and comparison of toxicity methodologies.

PubMed

Baba, Alper; Kaya, Abidin

2004-11-01

Use of lignite in power generation has led to increasing environmental problems associated not only with gaseous emissions, but also with the disposal of ash residues. In particular, use of low quality coals with high ash content results in huge quantities of both fly and bottom ashes to be disposed of. A main problem related to coal ash disposal is the heavy metal content of the residue. In this regard, experimental results of numerous studies indicate that toxic trace metals may leach when fly and bottom ashes are in contact with water. In this study, fly and bottom ash samples obtained from thermal power plants, namely Yenikoy, Kemerkoy and Yatagan, located at the southwestern coast of Turkey, were subjected to toxicity tests such as the extraction (EP) and toxicity characteristic leaching (TCLP) procedures of the US Environmental Protection Agency (USEPA) and the so-called 'Method A' extraction procedure of the American Society of Testing and Material (ASTM). The geochemical composition of ash samples showed variations depending on the coal burned in the plants. Furthermore, the EP, TCLP and ASTM toxicity tests showed variations such that the ash samples were classified as 'toxic waste' based on EP and TCLP results whereas they were classified as 'non-toxic' based on ASTM results, indicating test results are pH dependent. When the extraction results were compared with the chemical composition of water samples obtained in the vicinity of the thermal power plants, it was found that the results obtained using the ASTM procedure cannot be used to predict subsurface contamination whereas the EP and TCLP procedures can be used.

Development of the chemical and electrochemical coal cleaning process

NASA Astrophysics Data System (ADS)

Basilio, C. I.; Yoon, Roe-Hoan

The continuous testing of the Chemical and Electrochemical Coal Cleaning (CECC) was completed successfully using Middle Wyodak and Elkhorn No. 3 coal samples. The CECC unit was run under the optimum conditions established for these coal samples. For the Middle Wyodak coal, the ash content was reduced from 6.96 percent to as low 1.61 percent, corresponding to an ash rejection (by weight) of about 83 percent. The ash and sulfur contents of the Elkhorn No. 3 coal were reduced to as low as 1.8 percent and 0.9 percent. The average ash and sulfur rejections were calculated to be around 84 percent and 47 percent. The CECC continuous unit was used to treat -325 mesh Elkhorn No. 3 coal samples and gave ash and sulfur rejection values of as high as 77 percent and 66 percent. In these test, the clean -325 mesh coal particles were separated from the liberated mineral matter through microbubble column flotation, instead of wet-screening.

Ash Analysis

NASA Astrophysics Data System (ADS)

Marshall, Maurice R.

Ash refers to the inorganic residue remaining after either ignition or complete oxidation of organic matter in a foodstuff. A basic knowledge of the characteristics of various ashing procedures and types of equipment is essential to ensure reliable results. Two major types of ashing are used: dry ashing, primarily for proximate composition and for some types of specific mineral analyses; wet ashing (oxidation), as a preparation for the analysis of certain minerals. Microwave systems now are available for both dry and wet ashing, to speed the processes. Most dry samples (i.e., whole grain, cereals, dried vegetables) need no preparation, while fresh vegetables need to be dried prior to ashing. High-fat products such as meats may need to be dried and fat extracted before ashing. The ash content of foods can be expressed on either a wet weight (as is) or on a dry weight basis. For general and food-specific information on measuring ash content, see references (1-11).

Mineralogy of ash of some American coals: variations with temperature and source

USGS Publications Warehouse

Mitchell, R.S.; Gluskoter, H.J.

1976-01-01

Ten samples of mineral-matter residue were obtained by the radio-frequency low-temperature ashing of subbituminous and bituminous coals. The low-temperature ash samples were then heated progressively from 400 ??C to 1400 ??C at 100 ??C intervals. Mineral phases present at each temperature interval were determined by X-ray diffraction analyses. The minerals originally present in the coals (quartz, kaolinite, illite, pyrite, calcite, gypsum, dolomite, and sphalerite) were all altered to higher temperature phases. Several of these phases, including kaolinite, metakaolinite, mullite, anhydrite, and anorthite, were found only in limited temperature ranges. Therefore the temperature of formation of the ashes in which they occur may be determined. Mineralogical differences were observed between coal samples from the Rocky Mountain Province, the Illinois Basin, and the Appalachians; and as a result of these mineralogical differences, different high-temperature phases resulted as the samples were heated. However, regional generalizations cannot be made until a greater number of samples have been studied. ?? 1976.

Chemical and ecotoxicological characterization of ashes obtained from sewage sludge combustion in a fluidised-bed reactor.

PubMed

Lapa, N; Barbosa, R; Lopes, M H; Mendes, B; Abelha, P; Boavida, D; Gulyurtlu, I; Oliveira, J Santos

2007-08-17

In 1999, the DEECA/INETI and the UBiA/FCT/UNL started a researching project on the partition of heavy metals during the combustion of stabilised sewage sludge (Biogran), in a fluidised-bed reactor, and on the quality of the bottom ashes and fly ashes produced. This project was entitled Bimetal and was funded by the Portuguese Foundation for Science and Technology. In this paper only the results on the combustion of Biogran are reported. The combustion process was performed in two different trials, in which different amounts of sewage sludge and time of combustion were applied. Several ash samples were collected from the bed (bottom ashes) and from two cyclones (first cyclone and second cyclone ashes). Sewage sludge, bed material (sand) and ash samples were submitted to the leaching process defined in the European leaching standard EN 12457-2. The eluates were characterized for a set of inorganic chemical species. The ecotoxicological levels of the eluates were determined for two biological indicators (Vibrio fischeri and Daphnia magna). The results were compared with the limit values of the CEMWE French Regulation. The samples were also ranked according to an index based on the chemical characterization of the eluates. It was observed an increase of the concentration of metals along the combustion system. The ashes trapped in the second cyclone, for both combustion trials, showed the highest concentration of metals in the eluates. Chemically, the ashes of the second cyclone were the most different ones. In the ecotoxicological point of view, the ecotoxicity levels of the eluates of the ashes, for both combustion cycles, did not follow the same pattern as observed for the chemical characterization. The ashes of the first cyclone showed the highest ecotoxicity levels for V. fischeri and D. magna. This difference on chemical and ecotoxicological results proves the need for performing both chemical and ecotoxicological characterizations of the sub-products of such type of thermal processes.

Differences in gasification behaviors and related properties between entrained gasifier fly ash and coal char

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jing Gu; Shiyong Wu; Youqing Wu

2008-11-15

In the study, two fly ash samples from Texaco gasifiers were compared to coal char and the physical and chemical properties and reactivity of samples were investigated by scanning electron microscopy (SEM), SEM-energy-dispersive spectrometry (EDS), X-ray diffraction (XRD), N{sub 2} and CO{sub 2} adsorption method, and isothermal thermogravimetric analysis. The main results were obtained. The carbon content of gasified fly ashes exhibited 31-37%, which was less than the carbon content of 58-59% in the feed coal. The fly ashes exhibited higher Brunauer-Emmett-Teller (BET) surface area, richer meso- and micropores, more disordered carbon crystalline structure, and better CO{sub 2} gasification reactivitymore » than coal char. Ashes in fly ashes occurred to agglomerate into larger spherical grains, while those in coal char do not agglomerate. The minerals in fly ashes, especial alkali and alkaline-earth metals, had a catalytic effect on gasification reactivity of fly ash carbon. In the low-temperature range, the gasification process of fly ashes is mainly in chemical control, while in the high-temperature range, it is mainly in gas diffusion control, which was similar to coal char. In addition, the carbon in fly ashes was partially gasified and activated by water vapor and exhibited higher BET surface area and better gasification activity. Consequently, the fact that these carbons in fly ashes from entrained flow gasifiers are reclaimed and reused will be considered to be feasible. 15 refs., 7 figs., 5 tabs.« less

The mechanical and physical properties of concrete containing polystyrene beads as aggregate and palm oil fuel ash as cement replacement material

NASA Astrophysics Data System (ADS)

Adnan, Suraya Hani; Abadalla, Musab Alfatih Salim; Jamellodin, Zalipah

2017-10-01

One of the disadvantages of normal concrete is the high self-weight of the concrete. Density of the normal concrete is in the range of 2200 kg/m3 to 2600 kg/ m3. This heavy self-weight make it as an uneconomical structural material. Advantages of expended polystyrene beads in lightweight concrete is its low in density which can reduce the dead load (self-weight) Improper disposal of the large quantity of palm oil fuel ash which has been produced may contribute to environmental problem in future. In this study, an alternative of using palm oil fuel ash as a cement replacement material is to improve the properties of lightweight concrete. The tests conducted in this study were slump test, compression strength, splitting tensile and water absorption test. These samples were cured under water curing condition for 7, 28 and 56 days before testing. Eight types of mixtures were cast based on percentage (25%, 50%) of polystyrene beads replacement for control samples and (25%, 50%) of polystyrene beads by different ratio 10%, 15%, and 20% replacement of palm oil fuel ash, respectively. Samples with 25% polystyrene beads and 10% palm oil fuel ash obtained the highest compressive strength which is 16.8 MPa, and the splitting tensile strength is 1.57 MPa. The water absorption for samples 25%, 50% polystyrene and 20% palm oil fuel ash is 3.89% and 4.67%, respectively which is lower compared to control samples.

[Correlation of Persistent Free Radicals, PCDD/Fs and Metals in Waste Incineration Fly Ash].

PubMed

Wang, Tian-jiao; Chen, Tong; Zhan, Ming-xiu; Guo, Ying; Li, Xiao-dong

2016-03-15

Environmentally persistent free radicals (EPFRs) are relatively highly stable and found in the formation of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs). Recent studies have concentrated on model dioxin formation reactions and there are few studies on actual waste incineration fly ash. In order to study EPFRs and the correlation with dioxins and heavy metals in waste incineration fly ash, the spins of EPFRs, concentration of PCDD/Fs and metals in samples from 6 different waste incinerators were detected. The medical waste incineration fly ash from Tianjin, municipal solid waste incineration fly ash from Jiangxi Province, black carbon and slag from municipal solid waste incinerator in Lanxi, Zhejiang Province, all contained EPFRs. Above all the signal in Tianjin sample was the strongest. Hydroxyl radicals, carbon-center radicals and semiquinone radicals were detected. Compared with other samples, Jiangxi fly ash had the highest toxic equivalent quantity (TEQ) of dioxins, up to 7.229 4 ng · g⁻¹. However, the dioxin concentration in the Tianjin sample containing the strongest EPFR signals was only 0.092 8 ng · g⁻¹. There was perhaps little direct numeric link between EPFRs and PCDD/Fs. But the spins of EPFRs in samples presented an increasing trend as the metal contents increased, especially with Al, Fe, Zn. The signal strength of radicals was purposed to be related to the metal contents. The concentration of Zn (0.813 7% ) in the Tianjin sample was the highest and this sample contained much more spins of oxygen-center radicals. We could presume the metal Zn had a greater effect on the formation of EPFRs, and was easier to induce the formation of radicals with a longer half-life period.

Simultaneous Determination of 10 Ultratrace Elements in Infant Formula, Adult Nutritionals, and Milk Products by ICP/MS After Pressure Digestion: Single-Laboratory Validation.

PubMed

Dubascoux, Stephane; Nicolas, Marine; Rime, Celine Fragniere; Payot, Janique Richoz; Poitevin, Eric

2015-01-01

A single-laboratory validation (SLV) is presented for the simultaneous determination of 10 ultratrace elements (UTEs) including aluminum (Al), arsenic (As), cadmium (Cd), cobalt (Co), chromium (Cr), mercury (Hg), molybdenum (Mo), lead (Pb), selenium (Se), and tin (Sn) in infant formulas, adult nutritionals, and milk based products by inductively coupled plasma (ICP)/MS after acidic pressure digestion. This robust and routine multielemental method is based on several official methods with modifications of sample preparation using either microwave digestion or high pressure ashing and of analytical conditions using ICP/MS with collision cell technology. This SLV fulfills AOAC method performance criteria in terms of linearity, specificity, sensitivity, precision, and accuracy and fully answers most international regulation limits for trace contaminants and/or recommended nutrient levels established for 10 UTEs in targeted matrixes.

Evaluation of physical health effects due to volcanic hazards: crystalline silica in Mount St. Helens volcanic ash.

PubMed

Dollberg, D D; Bolyard, M L; Smith, D L

1986-03-01

This investigation has shown that crystalline silica has been identified as being present in the Mount St. Helens volcanic ash at levels of 3 to 7 per cent by weight. This identification has been established using X-ray powder diffraction, infrared spectrophotometry, visible spectrophotometry, electron microscopy, and Laser Raman spectrophotometry. Quantitative analysis by IR, XRD, and visible spectrophotometry requires a preliminary phosphoric acid digestion of the ash sample to remove the plagioclase silicate material which interferes with the determination by these methods. Electron microscopic analysis as well as Laser Raman spectrophotometric analysis of the untreated ash confirms the presence of silica and at levels found by the XRD and IR analysis of the treated samples. An interlaboratory study of volcanic ash samples by 15 laboratories confirms the presence and levels of crystalline silica. Although several problems with applying the digestion procedure were observed in this hastily organized supply, all laboratories employing the digestion procedure reported the presence of crystalline silica. These results unequivocally put to rest the question of the presence of silica in the volcanic ash from eruptions of Mount St. Helens in 1980.

Determination of the elastic modulus of fly ash-based stabilizer applied in the trackbed

NASA Astrophysics Data System (ADS)

Lojda, Vít; Lidmila, Martin; Pýcha, Marek

2017-09-01

This paper describes a unique application of a fly ash-based stabilizer in the trackbed of a railway main line. The key goals of the stabilizer application are to protect the subgrade against the ingress of rain water, to increase the frost resistance and to remediate the natural ground constituted of weathered rock. The stabilizer was designed as a mixture of fly ash, generated as a waste material from coal plants, gypsum, calcium oxide and water. The mixture recipe was developed in a laboratory over several years. In 2005, a trial section of a railway line with subgrade consisting of clay limestone (weathered marlite) was built in the municipality of Smiřice. Since then, periodical measurements including collection of samples for laboratory evaluation of the fly ash-based stabilizer have taken place. Over the time span of the measurements, changes in mineral composition and development of fly ash transforming structures leading to the formation of C-A-S-H gel were detected. This paper describes the experimental laboratory investigation of the influence of dynamic loading on the elastic modulus of fly ash stabilizer samples and the development of permanent deformation of the samples with increasing number of loading cycles.

The Effect of Volcanic Ash Composition on Ice Nucleation Affinity

NASA Astrophysics Data System (ADS)

Genareau, K. D.; Cloer, S.; Primm, K.; Woods, T.; Tolbert, M. A.

2017-12-01

Understanding the role that volcanic ash plays in ice nucleation is important for knowledge of lightning generation in both volcanic plumes and in clouds developing downwind from active volcanoes. Volcanic ash has long been suggested to influence heterogeneous ice nucleation following explosive eruptions, but determining precisely how composition and mineralogy affects ice nucleation affinity (INA) is poorly constrained. For the study presented here, volcanic ash samples with different compositions and mineral/glass contents were tested in both the deposition and immersion modes, following the methods presented in Schill et al. (2015). Bulk composition was determined with X-ray fluorescence (XRF), grain size distribution was determined with laser diffraction particle size analysis (LDPSA), and mineralogy was determined with X-ray diffraction (XRD) and scanning electron microscopy (SEM). Results of the deposition-mode experiments reveal that there is no relationship between ice saturation ratios (Sice) and either mineralogy or bulk ash composition, as all samples have similar Sice ratios. In the immersion-mode experiments, frozen fractions were determined from -20 °C to -50 °C using three different amounts of ash (0.5, 1.0, and 2.0 wt% of slurry). Results from the immersion freezing reveal that the rhyolitic samples (73 wt% SiO2) nucleate ice at higher temperatures compared to the basaltic samples (49 wt% SiO2). There is no observed correlation between frozen fractions and mineral content of ash samples, but the two most efficient ice nuclei are rhyolites that contain the greatest proportion of amorphous glass (> 90 %), and are enriched in K2O relative to transition metals (MnO and TiO2), the latter of which show a negative correlation with frozen fraction. Higher ash abundance in water droplets increases the frozen fraction at all temperatures, indicating that ash amount plays the biggest role in ice nucleation. If volcanic ash can reach sufficient abundance (≥ 2 wt%) in hydrometeors, and be compositionally enriched in K2O relative to MnO and TiO2, the nucleation of ice should efficiently occur. These chemical relationships are not only important for understanding ice nucleation in volcanic plumes, but also for constraining the effect of composition on the INA of other atmospheric aerosols.

Quality and generation rate of solid residues in the boiler of a waste-to-energy plant.

PubMed

Allegrini, E; Boldrin, A; Jansson, S; Lundtorp, K; Fruergaard Astrup, T

2014-04-15

The Danish waste management system relies significantly on waste-to-energy (WtE) plants. The ash produced at the energy recovery section (boiler ash) is classified as hazardous waste, and is commonly mixed with fly ash and air pollution control residues before disposal. In this study, a detailed characterization of boiler ash from a Danish grate-based mass burn type WtE was performed, to evaluate the potential for improving ash management. Samples were collected at 10 different points along the boiler's convective part, and analysed for grain size distribution, content of inorganic elements, polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD and PCDF), and leaching of metals. For all samples, PCDD and PCDF levels were below regulatory limits, while high pH values and leaching of e.g. Cl were critical. No significant differences were found between boiler ash from individual sections of the boiler, in terms of total content and leaching, indicating that separate management of individual ash fractions may not provide significant benefits. Copyright © 2014 Elsevier B.V. All rights reserved.

Immersion freezing induced by different kinds of coal fly ash: Comparing particle generation methods and measurement techniques

NASA Astrophysics Data System (ADS)

Grawe, Sarah; Augustin-Bauditz, Stefanie; Clemen, Hans-Christian; Eriksen-Hammer, Stine; Lubitz, Jasmin; Schneider, Johannes; Stratmann, Frank; Wex, Heike

2017-04-01

To date, a lot of effort has been put into the identification and characterization of atmospheric ice nucleating particles (INPs), which may influence both weather and climate. The majority of studies focuses on INPs from natural origin such as biological particles or mineral dust particles (Hoose and Möhler 2012, Murray et al. 2012). Combustion ashes, being possible sources of anthropogenic INPs, have rarely been investigated in the past. Ash particles may be emitted into the atmosphere either by the action of wind from ash deposits on the ground (bottom ash), or during the combustion process (fly ash). Two recent studies (Umo et al., 2015; Grawe et al., 2016) identified fly ash from coal combustion as the most efficient of the investigated samples (including also bottom ashes from wood and coal combustion). These results motivate the here presented study in which we investigated the immersion freezing behavior of four coal fly ash samples taken from the filters of different coal-fired power plants in Germany. A combination of two instruments was used to capture the temperature range from 0 °C to the homogeneous freezing limit at around -38 °C. Firstly, the new Leipzig Ice Nucleation Array (LINA) was used, where droplets from an ash-water suspension are pipetted onto a cooled plate. Secondly, we used the Leipzig Aerosol Cloud Interaction Simulator (LACIS; Hartmann et al., 2011), a laminar flow tube in which every droplet contains a single size-segregated ash particle. Here, it was possible to study the effect of different kinds of particle generation, i.e., atomization of an ash-water suspension, and aerosolization of dry ash material. The composition of the ash particles was investigated by means of single particle aerosol mass spectrometry and particles were sampled on filters for environmental scanning electron microscope analysis. Our measurements show that all four fly ash samples feature a similar immersion freezing behavior (ice fractions vary by a factor of 5 at most) when particles are generated via dry dispersion. Furthermore, we found that the ice nucleation ability of all samples is lowered significantly when changing from dry to wet particle generation. The aim of the study is to identify possible reasons for these observations. References: S. Grawe, S. Augustin-Bauditz, S. Hartmann, L. Hellner, J. B. C. Pettersson, A. Prager, F. Stratmann, and H. Wex, Atmos. Chem. Phys., 16, 13911-13928, 2016 S. Hartmann, D. Niedermeier, J. Voigtländer, T. Clauß, R. A. Shaw, H. Wex, A. Kiselev, and F. Stratmann, Atmos. Chem. Phys., 11, 1753-1767, 2011 C. Hoose and O. Möhler, Atmos. Chem. Phys., 12, 9817-9854, 2012 B. J. Murray, D. O'Sullivan, J. D. Atkinson, and M. E. Webb, Chem. Soc. Rev., 41, 6519-6554, 2012 N. S. Umo, B. J. Murray, M. T. Baeza-Romero, J. M. Jones, A. R. Lea-Langton, T. L. Malkin, D. O'Sullivan, L. Neve, J. M. C. Plane, and A. Williams, Atmos. Chem. Phys., 15, 5195-5210, 2015

Cytotoxicity and genotoxicity induced by coal and coal fly ash particles samples in V79 cells.

PubMed

León-Mejía, Grethel; Silva, Luis F O; Civeira, Matheus S; Oliveira, Marcos L S; Machado, Miriana; Villela, Izabel Vianna; Hartmann, Andreas; Premoli, Suziane; Corrêa, Dione Silva; Da Silva, Juliana; Henriques, João Antônio Pêgas

2016-12-01

Exposure to coal and coal ashes can cause harmful effects in in vitro and in vivo systems, mainly by the induction of oxidative damage. The aim of this work was to assess cytotoxic and genotoxic effects using the V79 cell line treated with coal and coal fly ash particles derived from a coal power plant located in Santa Catarina, Brazil. Two coal samples (COAL11 and COAL16) and two coal fly ash samples (CFA11 and CFA16) were included in this study. COAL16 was co-firing with a mixture of fuel oil and diesel oil. The comet assay data showed that exposure of V79 cells to coal and coal fly ash particles induced primary DNA lesions. Application of lesion-specific endonucleases (FPG and ENDO III) demonstrated increased DNA effects indicating the presence of high amounts of oxidative DNA lesions. The cytokinesis-block micronucleus cytome assay analysis showed that exposure of V79 cells to high concentrations of coal and coal fly ash particles induced cytotoxic effects (apoptosis and necrosis) and chromosomal instability (nucleoplasmic bridges, nuclear buds, and micronucleus (MN) formation). These results may be associated with compounds contained in the surface of the particles as hazardous elements, ultrafine/nanoparticles, and polycyclic aromatic hydrocarbons (PAHs) which were detected in the samples. Graphical abstract ᅟ.

ENVIRONMENTAL EVALUATION FOR UTILIZATION OF ASH IN SOIL STABILIZATION

DOE Office of Scientific and Technical Information (OSTI.GOV)

David J. Hassett; Loreal V. Heebink

2001-08-01

The Minnesota Pollution Control Agency (MPCA) approved the use of coal ash in soil stabilization, indicating that environmental data needed to be generated. The overall project goal is to evaluate the potential for release of constituents into the environment from ash used in soil stabilization projects. Supporting objectives are: (1) To ensure sample integrity through implementation of a sample collection, preservation, and storage protocol to avoid analyte concentration or loss. (2) To evaluate the potential of each component (ash, soil, water) of the stabilized soil to contribute to environmental release of analytes of interest. (3) To use laboratory leaching methodsmore » to evaluate the potential for release of constituents to the environment. (4) To facilitate collection of and to evaluate samples from a field runoff demonstration effort. The results of this study indicated limited mobility of the coal combustion fly ash constituents in laboratory tests and the field runoff samples. The results presented support previous work showing little to negligible impact on water quality. This and past work indicates that soil stabilization is an environmentally beneficial CCB utilization application as encouraged by the U.S. Environmental Protection Agency. This project addressed the regulatory-driven environmental aspect of fly ash use for soil stabilization, but the demonstrated engineering performance and economic advantages also indicate that the use of CCBs in soil stabilization can and should become an accepted engineering option.« less

Structure, properties, and surfactant adsorption behavior of fly ash carbon

NASA Astrophysics Data System (ADS)

Kulaots, Indrek

The objective of this research was to suggest methods by which certain problems associated with use of coal fly ash as a pozzolanic agent in concrete mixtures could be alleviated, guided by a better characterization of fly ash properties. A sample suite of eighty fly ashes was gathered from utilities across the world (mainly US-based) and included ashes from coals ranging in rank from bituminous to lignite. The widely used foam index test is used to characterize ashes with respect to their propensity to adsorb surfactants (called Air Entraining Admixtures or AEAs) used to impart freeze-thaw resistance to concrete. In ash-containing concrete mixtures, AEAs are adsorbed from the polar concrete-water solution onto non-polar unburned carbon surfaces in the ash. The AEA uptake by fly ashes only crudely correlates with the amount of carbon in the fly ash, because carbon surface area, accessibility and polarity all play a role in determining adsorption capacities. Fly ash carbon particle size distribution is also a key factor. Fine carbon particles in fly ash fractions of <106mum are responsible for about 90% of surfactant adsorption capacity. Surfactant adsorption on fly ash carbon is, in the foam index test, a dynamic process. The time of the test (typically <10 minutes) is not long enough to permit penetration of small porosity by the relatively large AEA molecules, and only the most readily available adsorption surface near the geometrical surface of the carbon particles is utilized. The nature of the foam index test was also examined, and it is recommended that a more standardized test procedure based upon pure reagents be adopted for examining the nature of fly ashes. Several possible reagents were identified. Room temperature fly ash ozonation is a powerful technique that allows increasing fly ash surface polarity in a relatively short time and thus is very effective for decreasing the AEA uptake capacity. Depending on the ozone input concentration, sample amount and contact time, surfactant uptake capacity decreases by a factor of two or more following reaction of only 0--1g O3/kg-ash, bringing many ashes into compliance with AEA uptake requirements.

Study on the Volatility of Cesium in Dry Ashing Pretreatment and Dissolution of Ash by Microwave Digestion System - 13331

DOE Office of Scientific and Technical Information (OSTI.GOV)

Choi, Kwang-Soon; Lee, Chang Heon; Ahn, Hong-Joo

2013-07-01

Based on the regulation of the activity concentration of Cs-137, Co-58, Co-60, Fe-55, Ni-59, Ni-63, Sr-90, Nb-94, and Tc-99, and the total alpha from the radioactive waste acceptance criteria, the measurement of the activity concentration of these nuclides in low and intermediate levels of radioactive waste such as in paper, cotton, vinyl and plastic samples was investigated. A dry ashing method was applied to obtain a concentration effect of the samples. Owing to the temperature dependence of the volatility for cesium, the temperature of 300 to 650 deg. C was examined. It was found that 450 deg. C is themore » optimum dry ashing temperature. After dry ashing, the produced ash was dissolved with HNO{sub 3}, HCl, and HF by a high-performance microwave digestion system. The ash sample, for the most part, was completely dissolved with 10 mL of HNO{sub 3}, 4 mL of HCl, and 0.25 mL of HF by a high-performance microwave digestion system using a nova high temperature rotor at 250 deg. C for 90 min until reaching 0.2 g. To confirm the reliability of cesium loss after the performance of the dry ashing procedure, a cesium standard solution for AAS and a Cs-137 standard solution for gamma spectrometry were added to a paper towel or a planchet of stainless steel, respectively. Cesium was measured by AAS, ICP-MS, and gamma spectrometry. The volatility of cesium did not occur until 450 deg. C ashing. (authors)« less

Mercury in coals and fly ashes from Republika and Bobov dol thermoelectric power plants

USGS Publications Warehouse

Kostova, I.; Vassileva, C.; Hower, J.; Mastalerz, Maria; Vassilev, S.; Nikolova, N.

2011-01-01

Feed coal and y ash samples were collected at Republika and Bobov Dol thermoelectric power plants (TPPs). The y ashes (FAs) were collected fromthree rows of the hot-side electrostatic precipitators (ESPs) array. Each sam- ple was wet-screened at 100, 200, 325 and 500 mesh. The coals and y ashes were characterized with regard to their petrological and chemical composition (including mercury content) and to their surface area properties. The calculated enrichment factor (EF) shows that the Hg concentrations in the bulk coal samples from Republika and Bobov Dol TPPs are 2.19 and 1.41, respectively. In some coal size fractions the EF can be up to 4 times higher than the Clarke value. The calculated EF for fly ashes shows that the Hg concentrations in the bulk samples studied are lower (between 0.03 and 0.32) than the Clarke value. The most enriched in Hg are the fly ashes from the 3rd ESP row of Republika TPP. The Hg distribution in bulk FAs taken from dierent rows of the electrostatic precipitators of both TPPs studied shows well established tendency of gradual increase in the Hg content from the 1st to the 2nd and 3rd ESP rows. The correlation between Hg content and surface area, mesopore and micropore volume of y ashes was also done in the present investigation.

The stability of clay using mount Sinabung ash with unconfined compression test (uct) value

NASA Astrophysics Data System (ADS)

Puji Hastuty, Ika; Roesyanto; Hutauruk, Ronny; Simanjuntak, Oberlyn

2018-03-01

The soil has a important role as a highway’s embankment material (sub grade). Soil conditions are very different in each location because the scientifically soil is a very complex and varied material and the located on the field is very loose or very soft, so it is not suitable for construction, then the soil should be stabilized. The additive material commonly used for soil stabilization includes cement, lime, fly ash, rice husk ash, and others. This experiment is using the addition of volcanic ash. The purpose of this study was to determine the Index Properties and Compressive Strength maximum value with Unconfined Compression Test due to the addition of volcanic ash as a stabilizing agent along with optimum levels of the addition. The result showed that the original soil sample has Water Content of 14.52%; the Specific Weight of 2.64%; Liquid limit of 48.64% and Plasticity Index of 29.82%. Then, the Compressive Strength value is 1.40 kg/cm2. According to USCS classification, the soil samples categorized as the (CL) type while based on AASHTO classification, the soil samples are including as the type of A-7-6. After the soil is stabilized with a variety of volcanic ash, can be concluded that the maximum value occurs at mixture variation of 11% Volcanic Ash with Unconfined Compressive Strength value of 2.32 kg/cm2.

DNA damage induced by coal dust, fly and bottom ash from coal combustion evaluated using the micronucleus test and comet assay in vitro.

PubMed

Matzenbacher, Cristina Araujo; Garcia, Ana Letícia Hilario; Dos Santos, Marcela Silva; Nicolau, Caroline Cardoso; Premoli, Suziane; Corrêa, Dione Silva; de Souza, Claudia Telles; Niekraszewicz, Liana; Dias, Johnny Ferraz; Delgado, Tânia Valéria; Kalkreuth, Wolfgang; Grivicich, Ivana; da Silva, Juliana

2017-02-15

Coal mining and combustion generating huge amounts of bottom and fly ash are major causes of environmental pollution and health hazards due to the release of polycyclic aromatic hydrocarbons (PAH) and heavy metals. The Candiota coalfield in Rio Grande do Sul, is one of the largest open-cast coal mines in Brazil. The aim of this study was to evaluate genotoxic and mutagenic effects of coal, bottom ash and fly ash samples from Candiota with the comet assay (alkaline and modified version) and micronucleus test using the lung fibroblast cell line (V79). Qualitative and quantitative analysis of PAH and inorganic elements was carried out by High Performance Liquid Chromatography (HPLC) and by Particle-Induced X-ray Emission (PIXE) techniques respectively. The samples demonstrated genotoxic and mutagenic effects. The comet assay modified using DNA-glicosilase formamidopirimidina (FPG) endonuclease showed damage related to oxidative stress mechanisms. The amount of PAHs was higher in fly ash followed by pulverized coal. The amount of inorganic elements was highest in fly ash, followed by bottom ash. It is concluded that the samples induce DNA damage by mechanisms that include oxidative stress, due to their complex composition, and that protective measures have to be taken regarding occupational and environmental hazards. Copyright © 2016 Elsevier B.V. All rights reserved.

Optimization of Pressurized Oxy-Combustion with Flameless Reactor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Malavasi, Massimo; Landegger, Gregory

2014-06-30

Pressurized OxyECombustion is one of the most promising technologies for utility-scale power generation plants. Benefits include the ability to burn low rank coal and capture CO 2. By increasing the flue gas pressure during this process, greater efficiencies are derived from increased quantity and quality of thermal energy recovery. UPA with modeling support from MIT and testing and data verification by Georgia Tech’s Research Center designed and built a 100 kW system capable of demonstrating pressurized oxyEcombustion using a flameless combustor. Wyoming PRB coal was run at 15 and 32 bar. Additional tests were not completed but sampled data demonstratedmore » the viability of the technology over a broader range of operating pressures, Modeling results illustrated a flat efficiency curve over 20 bar, with optimum efficiency achieved at 29 bar. This resulted in a 33% (HHV) efficiency, a 5 points increase in efficiency versus atmospheric oxy-combustion, and a competitive cost of electricity plus greater CO 2 avoidance costs then prior study’s presented. UPA’s operation of the bench-scale system provided evidence that key performance targets were achieved: flue gas sampled at the combustor outlet had non-detectable residual fly ashes, and low levels of SO3 and heavy-metal. These results correspond to prior pressurized oxy-combustion testing completed by IteaEEnel.« less

Influence of heating on the weight loss and mineral phase in MSWI ash: LOI of incineration ash

NASA Astrophysics Data System (ADS)

Yang, Shuo

2017-04-01

Loss on ignition (LOI) is a very common method for estimating the volatile species in solid sample. Normally, the measurement of LOI can be convenient and accurate, but for municipal solid waste incineration (MSWI) ash, the process may become intricate due to the complexity of the sample. In the incineration ash, there exist various phases, such as mineral, metal, organic and glass. The reaction and transformation of some materials during heating will influence the measurement. 5 incineration ash samples were selected and tested in this study. LOI content was basically measured at high (850°C) and relatively low (440°C) temperatures. The comparison between these two measurements showed a large difference. X-ray diffraction (XRD) and thermal analysis (TG-DTA) were carried out to investigate the mineral changes and weight losses with different ignition temperatures. The mineralogical analysis suggests that the decomposition of hydrate and carbonate phases cannot be neglected for LOI measurement of incineration. A long-time heating under relatively lower temperature (400∼450°C) compared with soil sample measurement (≥500°C) was recommended by this study.

Microwave plasma generation of arsine from hydrogen and solid arsenic

NASA Astrophysics Data System (ADS)

Omstead, Thomas R.; Annapragada, Ananth V.; Jensen, Klavs F.

1990-12-01

The generation of arsine from the reactions of hydrogen and elemental arsenic in a microwave plasma reactor is described. The arsenic is evaporated from a solid source upstream and carried into the microwave plasma region by a mixture of hydrogen and argon. Stable reaction products, arsine and diarsine are observed by molecular beam sampled mass spectroscopy along with partially hydrogenated species (e.g., AsH and AsH2). The effect of composition and flow rate of the argon/hydrogen carrier gas mixture on the amount of arsine generated is investigated. The arsine production reaches a maximum for an argon-to-hydrogen ratio of unity indicating that metastable argon species act as energy transfer intermediates in the overall reaction. The generation of arsine and diarsine from easily handled solid arsenic by this technique makes it attractive as a possible arsenic source for the growth of compound semiconductors by low-pressure metalorganic chemical vapor deposition.

Sample collection of ash and burned soils from the October 2007 southern California Wildfires

USGS Publications Warehouse

Hoefen, Todd M.; Kokaly, Raymond F.; Martin, Deborah A.; Rochester, Carlton J.; Plumlee, Geoffrey S.; Mendez, Greg; Reichard, Eric G.; Fisher, Robert N.

2009-01-01

Between November 2 through 9, 2007 scientists from the U.S. Geological Survey (USGS) collected samples of ash and burned soils from 28 sites in six areas burned as a result of the Southern California wildfires of October 2007, including the Harris, Witch, Santiago, Ammo, Canyon, and Grass Valley Fires. The primary goal of this sampling and analysis effort was to understand how differences in ash and burned soil composition relate to vegetation type, underlying bedrock geology, burn intensity, and residential versus wildland. Sampling sites were chosen with the input of local experts from the USGS Water Resources and Biological Resources Disciplines to help understand possible effects of the fires on water supplies, ecosystems, and endangered species. The sampling was also carried out in conjunction with detailed field analysis of the spectral reflectance characteristics of the ash, so that chemical and mineralogical characteristics of the field samples could be used to help interpret data collected as part of an airborne, hyperspectral remote-sensing survey of several of the burned areas in mid-late November, 2007.This report presents an overview of the field sampling methodologies used to collect the samples, includes representative photos of the sites sampled, and summarizes important characteristics of each of the collection sites. In this report we use the term “ash” to refer collectively to white mineral ash, which results from full combustion of vegetation and black charred organic matter from partial combustion of vegetation or other materials. These materials were found to be intermingled as a deposited residue on the soil surface following the Southern California fires of 2007.

Physical and chemical characterization of fly ashes from Swiss waste incineration plants and determination of the ash fraction in the nanometer range.

PubMed

Buha, Jelena; Mueller, Nicole; Nowack, Bernd; Ulrich, Andrea; Losert, Sabrina; Wang, Jing

2014-05-06

Waste incineration had been identified as an important source of ultrafine air pollutants resulting in elaborated treatment systems for exhaust air. Nowadays, these systems are able to remove almost all ultrafine particles. However, the fate of ultrafine particles caught in the filters has received little attention so far. Based on the use of engineered nano-objects (ENO) and their transfer into the waste stream, it can be expected that not only combustion generated nanoparticles are found in fly ashes but that many ENO finally end up in this matrix. A more detailed characterization of the nanoparticulate fraction of fly ashes is therefore needed. Physical and chemical characterizations were performed for fly ashes from five selected waste incineration plants (WIPs) with different input materials such as municipal waste, wood and sewage sludge. The intrinsic densities of the fly ashes were in the range of 2.7-3.2 g/cm(3). When the fly ash particle became airborne, the effective density depended on the particle size, increasing from 0.7-0.8 g/cm(3) for 100-150 nm to 2 g/cm(3) for 350-500 nm. The fly ash samples were fractionated at 2 μm, yielding fine fractions (<2 μm) and coarse fractions (>2 μm). The size distributions of the fine fractions in the airborne form were further characterized, which allowed calculation of the percentage of the fly ash particles below 100 nm. We found the highest mass-based percentage was about 0.07%; the number percentage in the fine fraction was in the range of 4.8% to 22%. Comparison with modeling results showed that ENO may constitute a considerable part of the fly ash particles below 100 nm. Chemical analyses showed that for the municipal waste samples Ca and Al were present in higher concentrations in the coarse fraction; for the mixed wood and sludge sample the P concentration was higher in the coarse fraction; for most other samples and elements they were enriched in the fine fraction. Electron microscopic images of fly ashes showed a wide range of particle sizes, from nanometer range to micrometer range. Many aggregated particles were observed, demonstrating that ENO, bulk-derived nano-objects and combustion-generated nano-objects can form aggregates in the incineration process.

Leachate Geochemical Results for Ash Samples from the June 2007 Angora Wildfire Near Lake Tahoe in Northern California

USGS Publications Warehouse

Hageman, Philip L.; Plumlee, Geoffrey S.; Martin, Deborah A.; Hoefen, Todd M.; Adams, Monique; Lamothe, Paul J.; Todorov, Todor I.; Anthony, Michael W.

2008-01-01

This report releases leachate geochemical data for ash samples produced by the Angora wildfire that burned from June 24 to July 2, 2007, near Lake Tahoe in northern California. The leaching studies are part of a larger interdisciplinary study whose goal is to identify geochemical characteristics and properties of the ash that may adversely affect human health, water quality, air quality, animal habitat, endangered species, debris flows, and flooding hazards. The leaching study helps characterize and understand the interactions that occur when the ash comes in contact with rain or snowmelt, and helps identify the constituents that may be mobilized as run-off from these materials. Similar leaching studies were conducted on ash and burned soils from the October 2007 southern California wildfires (Hageman and others, 2008; Plumlee and others, 2007).

Illinois basin coal fly ashes. 1. Chemical characterization and solubility

USGS Publications Warehouse

Roy, W.R.; Griffin, R.A.; Dickerson, D.R.; Schuller, R.M.; Martin, S.M.C.

1984-01-01

Twelve precipitator-collected fly ash samples (nine derived from high-sulfur Illinois Basin coals and three from Western U.S. coals) were found to contain a variety of paraffins, aryl esters, phenols, and polynuclear aromatic hydrocarbons including phenanthrene, pyrene, and chrysene but all at very low concentrations. Less than 1% of the organic carbon in the samples was extractable into benzene. Solubility studies with a short-term (24-h) extraction procedure and a long-term (20-week) procedure indicate that the inorganic chemical composition of some types of fly ash effluent is time dependent and may be most toxic to aquatic ecosystems when initially mixed with water and pumped to disposal ponds. Some acidic, high-Cd fly ashes would be classified as hazardous wastes if coal ash was included in this waste category by future RCRA revisions. ?? 1984 American Chemical Society.

Leaching kinetics of As, Mo, and Se from acidic coal fly ash samples

DOE Office of Scientific and Technical Information (OSTI.GOV)

Neupane, Ghanashyam; Donahoe, Rona J.; Bhattacharyya, Siddhartha

Annually, coal-fired electric power plants produce large volumes potentially hazardous coal combustion products (CCPs) including fly ash. Since majority of the coal fly ash and other CCPs deposited in dry land fills or wet lagoons, they pose risk of contamination to local environment and hydrogeology. In this study, we present results of leaching kinetics for As, Mo, and Se from three acidic fly ash samples. This study shows that the leachate concentrations of As, Mo, and Se increase over time. Three kinetics equations, pseudo-second order, Elovich, and power-function, are able to adequately describe the experimental leaching kinetics data. Experimental leachingmore » data and modeling results indicate that the rate limiting leaching of As, Mo, and Se is largely controlled by the dissolution of the fly ash particles. Furthermore, it is important to adopt effective containment/treatment schemes to avoid potential and persistent dispersion of trace elements from ash disposal facilities to surrounding environment for a long time.« less

Leaching kinetics of As, Mo, and Se from acidic coal fly ash samples

DOE PAGES

Neupane, Ghanashyam; Donahoe, Rona J.; Bhattacharyya, Siddhartha; ...

2017-07-03

Annually, coal-fired electric power plants produce large volumes potentially hazardous coal combustion products (CCPs) including fly ash. Since majority of the coal fly ash and other CCPs deposited in dry land fills or wet lagoons, they pose risk of contamination to local environment and hydrogeology. In this study, we present results of leaching kinetics for As, Mo, and Se from three acidic fly ash samples. This study shows that the leachate concentrations of As, Mo, and Se increase over time. Three kinetics equations, pseudo-second order, Elovich, and power-function, are able to adequately describe the experimental leaching kinetics data. Experimental leachingmore » data and modeling results indicate that the rate limiting leaching of As, Mo, and Se is largely controlled by the dissolution of the fly ash particles. Furthermore, it is important to adopt effective containment/treatment schemes to avoid potential and persistent dispersion of trace elements from ash disposal facilities to surrounding environment for a long time.« less

Ash leaf metabolomes reveal differences between trees tolerant and susceptible to ash dieback disease.

PubMed

Sambles, Christine M; Salmon, Deborah L; Florance, Hannah; Howard, Thomas P; Smirnoff, Nicholas; Nielsen, Lene R; McKinney, Lea V; Kjær, Erik D; Buggs, Richard J A; Studholme, David J; Grant, Murray

2017-12-19

European common ash, Fraxinus excelsior, is currently threatened by Ash dieback (ADB) caused by the fungus, Hymenoscyphus fraxineus. To detect and identify metabolites that may be products of pathways important in contributing to resistance against H. fraxineus, we performed untargeted metabolomic profiling on leaves from five high-susceptibility and five low-susceptibility F. excelsior individuals identified during Danish field trials. We describe in this study, two datasets. The first is untargeted LC-MS metabolomics raw data from ash leaves with high-susceptibility and low-susceptibility to ADB in positive and negative mode. These data allow the application of peak picking, alignment, gap-filling and retention-time correlation analyses to be performed in alternative ways. The second, a processed dataset containing abundances of aligned features across all samples enables further mining of the data. Here we illustrate the utility of this dataset which has previously been used to identify putative iridoid glycosides, well known anti-herbivory terpenoid derivatives, and show differential abundance in tolerant and susceptible ash samples.

Ash leaf metabolomes reveal differences between trees tolerant and susceptible to ash dieback disease

PubMed Central

Sambles, Christine M.; Salmon, Deborah L.; Florance, Hannah; Howard, Thomas P.; Smirnoff, Nicholas; Nielsen, Lene R.; McKinney, Lea V.; Kjær, Erik D.; Buggs, Richard J. A.; Studholme, David J.; Grant, Murray

2017-01-01

European common ash, Fraxinus excelsior, is currently threatened by Ash dieback (ADB) caused by the fungus, Hymenoscyphus fraxineus. To detect and identify metabolites that may be products of pathways important in contributing to resistance against H. fraxineus, we performed untargeted metabolomic profiling on leaves from five high-susceptibility and five low-susceptibility F. excelsior individuals identified during Danish field trials. We describe in this study, two datasets. The first is untargeted LC-MS metabolomics raw data from ash leaves with high-susceptibility and low-susceptibility to ADB in positive and negative mode. These data allow the application of peak picking, alignment, gap-filling and retention-time correlation analyses to be performed in alternative ways. The second, a processed dataset containing abundances of aligned features across all samples enables further mining of the data. Here we illustrate the utility of this dataset which has previously been used to identify putative iridoid glycosides, well known anti-herbivory terpenoid derivatives, and show differential abundance in tolerant and susceptible ash samples. PMID:29257137

Spreading dynamic of viscous volcanic ash in stimulated jet engine conditions

NASA Astrophysics Data System (ADS)

song, wenjia; Lavallée, Yan; Hess, Kai-Uwe; Kueppers, Ulrich; Cimarelli, Corrado

2016-04-01

The ingestion of volcanic ash is widely recognised as a potentially fatal hazard for aircraft operation. The volcanic ash deposition process in a jet turbine is potentially complex. Volcanic ash in the air stream enters the inner liners of the combustors and partially or completely melts under the flames up to 2000 °C, at which point part of the ash deposits in the combustor fuel nozzle. Molten volcanic particles within high energy airflow escape the combustor to enter the turbine and impact the stationary (e.g., inlet nozzle guide vanes) and rotating airfoils (e.g., first stage high-pressure turbine blades) at high speed (up to Mach 1.25) in different directions, with the result that ash may stick, flow and remain liquid or solidify. Thus, the wetting behaviour of molten volcanic ash particle is fundamental to investigate impingement phenomena of ash droplet on the surface of real jet engine operation. The topic of wetting has received tremendous interest from both fundamental and applied points of view. However, due to the interdisciplinary gap between jet engine engineering and geology science, explicit investigation of wetting behaviour of volcanic ash at high temperature is in its infancy. We have taken a big step towards meeting this challenge. Here, we experimentally and theoretically investigate the wetting behaviour of viscous volcanic ash over a wide temperature range from 1100 to 1550 °C using an improved sessile-drop method. The results of our experiment demonstrate that temperature and viscosity play a critical role in determining the wetting possibility and governing the spreading kinetics of volcanic ash at high temperatures. Our systemic analysis of spreading of molten volcanic ash systems allows us to report on the fundamental differences between the mechanisms controlling spreading of organic liquids at room temperature and molten volcanic ash droplets.

Bio fuel ash in a road construction: impact on soil solution chemistry.

PubMed

Thurdin, R T; van Hees, P A W; Bylund, D; Lundström, U S

2006-01-01

Limited natural resources and landfill space, as well as increasing amounts of ash produced from incineration of bio fuel and municipal solid waste, have created a demand for useful applications of ash, of which road construction is one application. Along national road 90, situated about 20 km west of Sollefteå in the middle of Sweden, an experiment road was constructed with a 40 cm bio fuel ash layer. The environmental impact of the ash layer was evaluated from soil solutions obtained by centrifugation of soil samples taken on four occasions during 2001-2003. Soil samples were taken in the ash layer, below the ash layer at two depths in the road and in the ditch. In the soil solutions, pH, conductivity, dissolved organic carbon (DOC) and the total concentration of cations (metals) and anions were determined. Two years after the application of the ash layers in the test road, the concentrations in the ash layer of K, SO4, Zn, and Hg had increased significantly while the concentration of Se, Mo and Cd had decreased significantly. Below the ash layer in the road an initial increase of pH was observed and the concentrations of K, SO4, Se, Mo and Cd increased significantly, while the concentrations of Cu and Hg decreased significantly in the road and also in the ditch. Cd was the element showing a potential risk of contamination of the groundwater. The concentrations of Ca in the ash layer indicated an ongoing hardening, which is important for the leaching rate and the strength of the road construction.

Can the collapse of a fly ash heap develop into an air-fluidized flow? - Reanalysis of the Jupille accident (1961)

NASA Astrophysics Data System (ADS)

Stilmant, Frédéric; Pirotton, Michel; Archambeau, Pierre; Erpicum, Sébastien; Dewals, Benjamin

2015-01-01

A fly ash heap collapse occurred in Jupille (Liege, Belgium) in 1961. The subsequent flow of fly ash reached a surprisingly long runout and had catastrophic consequences. Its unprecedented degree of fluidization attracted scientific attention. As drillings and direct observations revealed no water-saturated zone at the base of the deposits, scientists assumed an air-fluidization mechanism, which appeared consistent with the properties of the material. In this paper, the air-fluidization assumption is tested based on two-dimensional numerical simulations. The numerical model has been developed so as to focus on the most prominent processes governing the flow, with parameters constrained by their physical interpretation. Results are compared to accurate field observations and are presented for different stages in the model enhancement, so as to provide a base for a discussion of the relative influence of pore pressure dissipation and pore pressure generation. These results show that the apparently high diffusion coefficient that characterizes the dissipation of air pore pressures is in fact sufficiently low for an important degree of fluidization to be maintained during a flow of hundreds of meters.

Ecological risk assessment for residual coal fly ash at Watts Bar Reservoir, Tennessee: Limited alteration of riverine-reservoir benthic invertebrate community following dredging of ash-contaminated sediment.

PubMed

Buys, David J; Stojak, Amber R; Stiteler, William; Baker, Tyler F

2015-01-01

Benthic invertebrate communities were assessed after the December 2008 release of approximately 4.1 million m(3) coal fly ash from a disposal dredge cell at the Tennessee Valley Authority (TVA) Kingston Fossil Plant on Watts Bar Reservoir in Roane County, Tennessee, USA. Released ash filled the adjacent embayments and the main channel of the Emory River, migrating into reaches of the Emory, Clinch, and Tennessee Rivers. Dredging was completed in summer 2010, and the benthic community sampling was conducted in December 2010. This study is part of a series that supported an Ecological Risk Assessment for the Kingston site. Benthic invertebrate communities were sampled at transects spread across approximately 20 miles of river that includes both riverine and reservoirlike conditions. Community composition was assessed on a grab sample and transect basis across multiple cross-channel transects to gain an understanding of the response of the benthic community to a fly ash release of this magnitude. This assessment used invertebrate community metrics, similarity analysis, geospatial statistics, and correlations with sediment chemistry and habitat. The community composition was reflective of a reservoir system, with dominant taxa being insect larva, bivalves, and aquatic worms. Most community metric results were similar for ash-impacted areas and upstream reference areas. Variation in the benthic community was correlated more with habitat than with sediment chemistry or residual ash. Other studies have reported that a benthic community can take several years to a decade to recover from ash or ash-related constituents. Although released ash undoubtedly had some initial impacts on the benthic community in this study, the severity of these effects appears to be limited to the initial smothering of the organisms followed by a rapid response and the initial start of recovery postdredging. © 2014 SETAC.

Generation and distribution of PAHs in the process of medical waste incineration

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, Ying, E-mail: echochen327@163.com; National Center of Solid Waste Management, Ministry of Environmental Protection, Beijing 100029; Zhao, Rongzhi

Highlights: ► PAHs generation and distribution features of medical waste incineration are studied. ► More PAHs were found in fly ash than that in bottom ash. ► The highest proportion of PAHs consisted of the seven most carcinogenic ones. ► Increase of free oxygen molecule and burning temperature promote PAHs degradation. ► There is a moderate positive correlation between total PCDD/Fs and total PAHs. - Abstract: After the deadly earthquake on May 12, 2008 in Wenchuan county of China, several different incineration approaches were used for medical waste disposal. This paper investigates the generation properties of polycyclic aromatic hydrocarbons (PAHs)more » during the incineration. Samples were collected from the bottom ash in an open burning slash site, surface soil at the open burning site, bottom ash from a simple incinerator, bottom ash generated from the municipal solid waste (MSW) incinerator used for medical waste disposal, and bottom ash and fly ash from an incinerator exclusively used for medical waste. The species of PAHs were analyzed, and the toxicity equivalency quantities (TEQs) of samples calculated. Analysis results indicate that the content of total PAHs in fly ash was 1.8 × 10{sup 3} times higher than that in bottom ash, and that the strongly carcinogenic PAHs with four or more rings accumulated sensitively in fly ash. The test results of samples gathered from open burning site demonstrate that Acenaphthylene (ACY), Acenaphthene (ACE), Fluorene (FLU), Phenanthrene (PHE), Anthracene (ANT) and other PAHs were inclined to migrate into surrounding environment along air and surface watershed corridors, while 4- to 6-ring PAHs accumulated more likely in soil. Being consistent with other studies, it has also been confirmed that increases in both free oxygen molecules and combustion temperatures could promote the decomposition of polycyclic PAHs. In addition, without the influence of combustion conditions, there is a positive correlation between total PCDD/Fs and total PAHs, although no such relationship has been found for TEQ.« less

Effect of Trona on the leaching of trace elements from coal fly ash.

DOT National Transportation Integrated Search

2013-07-01

Fly ashes were sampled from the ESPs by on-site contractors during air emission control tests. The injection tests were short-term, : lasting approximately three hours per test condition. EPRI received three batches of samples since November 2011, re...

Alkaline modified oil shale fly ash: optimal synthesis conditions and preliminary tests on CO2 adsorption.

PubMed

Reinik, Janek; Heinmaa, Ivo; Kirso, Uuve; Kallaste, Toivo; Ritamäki, Johannes; Boström, Dan; Pongrácz, Eva; Huuhtanen, Mika; Larsson, William; Keiski, Riitta; Kordás, Krisztián; Mikkola, Jyri-Pekka

2011-11-30

Environmentally friendly product, calcium-silica-aluminum hydrate, was synthesized from oil shale fly ash, which is rendered so far partly as an industrial waste. Reaction conditions were: temperature 130 and 160°C, NaOH concentrations 1, 3, 5 and 8M and synthesis time 24h. Optimal conditions were found to be 5M at 130°C at given parameter range. Original and activated ash samples were characterized by XRD, XRF, SEM, EFTEM, (29)Si MAS-NMR, BET and TGA. Semi-quantitative XRD and MAS-NMR showed that mainly tobermorites and katoite are formed during alkaline hydrothermal treatment. Physical adsorption of CO(2) on the surface of the original and activated ash samples was measured with thermo-gravimetric analysis. TGA showed that the physical adsorption of CO(2) on the oil shale fly ash sample increases from 0.06 to 3-4 mass% after alkaline hydrothermal activation with NaOH. The activated product has a potential to be used in industrial processes for physical adsorption of CO(2) emissions. Copyright © 2011 Elsevier B.V. All rights reserved.

Effects of Machine Traffic on the Physical Properties of Ash-Cap Soils

Treesearch

Leonard R. Johnson; Debbie Page-Dumroese; Han-Sup Han

2007-01-01

With pressure and vibration on a soil, air spaces between soil particles can be reduced by displaced soil particles. Activity associated with heavy machine traffic increases the density of the soil and can also increase the resistance of the soil to penetration. This paper reviews research related to disturbance of forest soils with a primary focus on compaction in ash...

Lunar ash flow with heat transfer.

NASA Technical Reports Server (NTRS)

Pai, S. I.; Hsieh, T.; O'Keefe, J. A.

1972-01-01

The most important heat-transfer process in the ash flow under consideration is heat convection. Besides the four important nondimensional parameters of isothermal ash flow (Pai et al., 1972), we have three additional important nondimensional parameters: the ratio of the specific heat of the gas, the ratio of the specific heat of the solid particles to that of gas, and the Prandtl number. We reexamine the one dimensional steady ash flow discussed by Pai et al. (1972) by including the effects of heat transfer. Numerical results for the pressure, temperature, density of the gas, velocities of gas and solid particles, and volume fraction of solid particles as function of altitude for various values of the Jeffreys number, initial velocity ratio, and two different gas species (steam and hydrogen) are presented.

Catalog of Mount St. Helens 2004 - 2005 Tephra Samples with Major- and Trace-Element Geochemistry

USGS Publications Warehouse

Rowe, Michael C.; Thornber, Carl R.; Gooding, Daniel J.; Pallister, John S.

2008-01-01

This open-file report presents a catalog of information about 135 ash samples along with geochemical analyses of bulk ash, glass and individual mineral grains from tephra deposited as a result of volcanic activity at Mount St. Helens, Washington, from October 1, 2004 until August 15, 2005. This data, in conjunction with that in a companion report on 2004?2007 Mount St. Helens dome samples by Thornber and others (2008a) are presented in support of the contents of the U.S. Geological Survey Professional Paper 1750 (Sherrod and others, ed., 2008). Readers are referred to appropriate chapters in USGS Professional Paper 1750 for detailed narratives of eruptive activity during this time period and for interpretations of sample characteristics and geochemical data presented here. All ash samples reported herein are currently archived at the David A. Johnston Cascades Volcano Observatory in Vancouver, Washington. The Mount St. Helens 2004?2005 Tephra Sample Catalogue along with bulk, glass and mineral geochemistry are tabulated in 6 worksheets of the accompanying Microsoft Excel file, of2008-1131.xls. Samples in all tables are organized by collection date. Table 1 is a detailed catalog of sample information for tephra deposited downwind of Mount St. Helens between October 1, 2004 and August 18, 2005. Table 2 provides major- and trace-element analyses of 8 bulk tephra samples collected throughout that interval. Major-element compositions of 82 groundmass glass fragments, 420 feldspar grains, and 213 mafic (clinopyroxene, amphibole, hypersthene, and olivine) mineral grains from 12 ash samples collected between October 1, 2004 and March 8, 2005 are presented in tables 3 through 5. In addition, trace-element abundances of 198 feldspars from 11 ash samples (same samples as major-element analyses) are provided in table 6. Additional mineral and bulk ash analyses from 2004 and 2005 ash samples are published in chapters 30 (oxide thermometry; Pallister and others, 2008), 32 (amphibole major elements; Thornber and others, 2008b) and 37 (210Pb; 210Pb/226Pa; Reagan and others, 2008) of U.S. Geological Survey Professional Paper 1750 (Sherrod and others, 2008). A brief overview of sample collection methods is given below as an aid to deciphering the tephra sample catalog. This is followed by an explanation of the categories of sample information (column headers) in table 1. A summary of the analytical methods used to obtain the geochemical data in this report introduces the presentation of major- and trace-element geochemistry of Mount St. Helens 2004?2005 tephra samples in tables 2?6. Rhyolite glass standard analyses are reported (Appendix 1) to demonstrate the accuracy and precision of similar glass analyses presented herein.

Sulfur-bearing coatings on fly ash from a coal-fired power plant: Composition, origin, and influence on ash alteration

USGS Publications Warehouse

Fishman, N.S.; Rice, C.A.; Breit, G.N.; Johnson, R.D.

1999-01-01

Fly ash samples collected from two locations in the exhaust stream of a coal-fired power plant differ markedly with respect to the abundance of thin (???0.1 ??m) sulfur-rich surface coatings that are observable by scanning electron microscopy. The coatings, tentatively identified as an aluminum-potassium-sulfate phase, probably form upon reaction between condensed sulfuric acid aerosols and glass surfaces, and are preferentially concentrated on ash exposed to exhaust stream gases for longer. The coatings are highly soluble and if sufficiently abundant, can impart an acidic pH to solutions initially in contact with ash. These observations suggest that proposals for ash use and predictions of ash behavior during disposal should consider the transient, acid-generating potential of some ash fractions and the possible effects on initial ash leachability and alteration. ?? 1998 Elsevier Science Ltd.

In vitro effects of coal fly ashes: hydroxyl radical generation, iron release, and DNA damage and toxicity in rat lung epithelial cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

van Maanen, J.M.; Borm, P.J.; Knaapen, A

1999-12-15

The authors measured iron release, acellular generation of hydroxyl radicals, and oxidative DNA damage and cytotoxicity in rat lung epithelial (RLE) cells by different coal fly ashes (CFA) that contain both quartz and iron. Seven samples of CFA with different particle size and quartz content (up to 14.1%) were tested along with silica (alpha-quartz), ground coal, and coal mine dust (respirable) as positive control particles, and fine TiO{sub 2} (anatase) as a negative control. Five test samples were pulverized fuel ashes (PFA), two samples were coal gasification (SCG) ashes (quartz content {lt} 0.1%), and one sample was a ground coal.more » No marked differences between SCG and PFA fly ashes were observed, and toxicity did not correlate with physicochemical characteristics or effect parameters. Stable surface radicals were only detected in the reference particles silica and coal mine dust, but not in CFA. On the other hand, hydroxyl radical generation by all fly ashes was observed in the presence of hydrogen peroxide. Also a relationship between acellular hydroxyl radical generation and oxidative DNA damage in RLE cells by CFA was observed. The respirable ashes (MAT023, 38, and 41) showed an extensive level of hydroxyl radical generation in comparison to nonrespirable fly ashes and respirable references. This was related to the iron mobilization from these particles. Themechanisms by which CFA and the positive references (silica, coal mine dust) affect rat lung epithelial cells seem to be different, and the data suggest that quartz in CFA does not act the same as quartz in silica or coal mine dust. However, the results indicate an important role for size and iron release in generation and subsequent effects of reactive oxygen species caused by CFA.« less

Wear resistance of Polymethyl Methacrylate (PMMA) with the Addition of Bone Ash, Hydroxylapatite and Keratin

NASA Astrophysics Data System (ADS)

Emre, G.; Akkus, A.; Karamış, M. B.

2018-01-01

In this study mechanichal and tribological properties of keratin, bone ash and hydroxylapatite by adding to PMMA ( known as the main prosthesis material) were investigated. Hydroxylapatite, bone ash, and keratin materials were added as PMMA in to the content of PMMA, in the proportions of %1, %3 and %5, respectively. The resulting mixtures were put into the molds and solidified in order to obtain samples to be used in the wear experiments. Each experiment was conducted by preparing three experimental samples. The wear data were compared according to the average values of the experimental samples. In the wear test, the results were also evaluated according to the average values obtained from each group and the results of the control group. It was observed that, the wear resistance of the PMMA including 3%, 5% bone ash and PMMA including 5% keratin flour were higher than the values of the control group.

Binary effect of fly ash and palm oil fuel ash on heat of hydration aerated concrete.

PubMed

Mehmannavaz, Taha; Ismail, Mohammad; Radin Sumadi, Salihuddin; Rafique Bhutta, Muhammad Aamer; Samadi, Mostafa; Sajjadi, Seyed Mahdi

2014-01-01

The binary effect of pulverized fuel ash (PFA) and palm oil fuel ash (POFA) on heat of hydration of aerated concrete was studied. Three aerated concrete mixes were prepared, namely, concrete containing 100% ordinary Portland cement (control sample or Type I), binary concrete made from 50% POFA (Type II), and ternary concrete containing 30% POFA and 20% PFA (Type III). It is found that the temperature increases due to heat of hydration through all the concrete specimens especially in the control sample. However, the total temperature rises caused by the heat of hydration through both of the new binary and ternary concrete were significantly lower than the control sample. The obtained results reveal that the replacement of Portland cement with binary and ternary materials is beneficial, particularly for mass concrete where thermal cracking due to extreme heat rise is of great concern.

Binary Effect of Fly Ash and Palm Oil Fuel Ash on Heat of Hydration Aerated Concrete

PubMed Central

Mehmannavaz, Taha; Ismail, Mohammad; Radin Sumadi, Salihuddin; Rafique Bhutta, Muhammad Aamer; Samadi, Mostafa

2014-01-01

The binary effect of pulverized fuel ash (PFA) and palm oil fuel ash (POFA) on heat of hydration of aerated concrete was studied. Three aerated concrete mixes were prepared, namely, concrete containing 100% ordinary Portland cement (control sample or Type I), binary concrete made from 50% POFA (Type II), and ternary concrete containing 30% POFA and 20% PFA (Type III). It is found that the temperature increases due to heat of hydration through all the concrete specimens especially in the control sample. However, the total temperature rises caused by the heat of hydration through both of the new binary and ternary concrete were significantly lower than the control sample. The obtained results reveal that the replacement of Portland cement with binary and ternary materials is beneficial, particularly for mass concrete where thermal cracking due to extreme heat rise is of great concern. PMID:24696646

Fly Ash Porous Material using Geopolymerization Process for High Temperature Exposure

PubMed Central

Abdullah, Mohd Mustafa Al Bakri; Jamaludin, Liyana; Hussin, Kamarudin; Bnhussain, Mohamed; Ghazali, Che Mohd Ruzaidi; Ahmad, Mohd Izzat

2012-01-01

This paper presents the results of a study on the effect of temperature on geopolymers manufactured using pozzolanic materials (fly ash). In this paper, we report on our investigation of the performance of porous geopolymers made with fly ash after exposure to temperatures from 600 °C up to 1000 °C. The research methodology consisted of pozzolanic materials (fly ash) synthesized with a mixture of sodium hydroxide and sodium silicate solution as an alkaline activator. Foaming agent solution was added to geopolymer paste. The geopolymer paste samples were cured at 60 °C for one day and the geopolymers samples were sintered from 600 °C to 1000 °C to evaluate strength loss due to thermal damage. We also studied their phase formation and microstructure. The heated geopolymers samples were tested by compressive strength after three days. The results showed that the porous geopolymers exhibited strength increases after temperature exposure. PMID:22605984

Physical and Chemical Character of Fly Ash of Coal Fired Power Plant in Java

NASA Astrophysics Data System (ADS)

Triwulan; Priadana, K. A.; Ekaputri, J. J.; Bayuaji, R.

2017-11-01

Quality of fly ash is varying widely in the field, it depends on the combustion process and the quality of the basic ingredients, namely coal. It will affect the physical and mechanical properties of the concrete mixtures used. This study used 12 samples of fly ash. The physical and chemical properties and finesse modulus were analyzed. The fly ash was mixed with OPC (Ordinary Portland Cement) with the proportion of 20% fly ash and 80% OPC. The specimens were form with mortar dimension of 5cm x 5 cm. The test was affected by the correlation of fly ash fineness modulus to compressive strength, correlation density of fly ash to compressive strength, and correlation of carbon content to the compressive strength.

An atlas of volcanic ash

NASA Technical Reports Server (NTRS)

Heiken, G.

1974-01-01

Volcanic ash samples collected from a variety of recent eruptions were studied, using petrography, chemical analyses, and scanning electron microscopy to characterize each ash type and to relate ash morphology to magma composition and eruption type. The ashes are best placed into two broad genetic categories: magnetic and hydrovolcanic (phreatomagmatic). Ashes from magmatic eruptions are formed when expanding gases in the magma form a froth that loses its coherence as it approaches the ground surface. During hydrovolcanic eruptions, the magma is chilled on contact with ground or surface waters, resulting in violent steam eruptions. Within these two genetic categories, ashes from different magma types can be characterized. The pigeon hole classification used here is for convenience; there are eruptions which are driven by both phreatic and magmatic gases.

Heavy metals and PCDD/Fs in solid waste incinerator fly ash in Zhejiang province, China: chemical and bio-analytical characterization.

PubMed

Yao, Jun; Li, Wenbing; Xia, Fangfang; Zheng, Yuange; Fang, Chengran; Shen, Dongsheng

2012-06-01

Fly ash samples were taken from solid waste incinerators with different feeding waste, furnace type, and air pollution control device in six cities of Zhejiang province. The solid waste incinerators there constitute one fifth of incinerators in China. Heavy metals and polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) were analyzed in the fly ash. Moreover, the fly ash samples were extracted by toxicity characteristic leaching procedure (TCLP). The biotoxicity of the leachate was evaluated by Chlorella pyrenoidosa. High variation and contents were found for both the heavy metals and PCDD/Fs. The contents of Zn, Cu, As, Pb, Cd, Cr, Ni, and Hg in the fly ash samples varied from 300 to 32,100, 62.1-1175, 1.1-57, 61.6-620, 0.4-223, 16.6-4380, 1.2-94.7, and 0.03-1.4 μg g(-1) dw, respectively. The total contents of 17 PCDD/Fs varied from 0.1128 to 127.7939 μg g(-1) dw, and the 2,3,7,8-TeCDD toxic equivalents (TEQ) of PCDD/Fs ranged from 0.009 to 6.177 μg g(-1) dw. PCDF congeners were the main contributor to the TEQ. The leachate of the fly ash showed biotoxicity to C. pyrenoidosa. A significant correlation was found between the Cd and EC(50) values. Further research is required to investigate the environmental impact of the various pollutants in the fly ash.

Physicochemical and toxicological profiling of ash from the 2010 and 2011 eruptions of Eyjafjallajökull and Grímsvötn volcanoes, Iceland using a rapid respiratory hazard assessment protocol.

PubMed

Horwell, C J; Baxter, P J; Hillman, S E; Calkins, J A; Damby, D E; Delmelle, P; Donaldson, K; Dunster, C; Fubini, B; Kelly, F J; Le Blond, J S; Livi, K J T; Murphy, F; Nattrass, C; Sweeney, S; Tetley, T D; Thordarson, T; Tomatis, M

2013-11-01

The six week eruption of Eyjafjallajökull volcano in 2010 produced heavy ash fall in a sparsely populated area of southern and south eastern Iceland and disrupted European commercial flights for at least 6 days. We adopted a protocol for the rapid analysis of volcanic ash particles, for the purpose of informing respiratory health risk assessments. Ash collected from deposits underwent a multi-laboratory physicochemical and toxicological investigation of their mineralogical parameters associated with bio-reactivity, and selected in vitro toxicology assays related to pulmonary inflammatory responses. Ash from the eruption of Grímsvötn, Iceland, in 2011 was also studied. The results were benchmarked against ash from Soufrière Hills volcano, Montserrat, which has been extensively studied since the onset of eruptive activity in 1995. For Eyjafjallajökull, the grain size distributions were variable: 2-13 vol% of the bulk samples were <4 µm, with the most explosive phases of the eruption generating abundant respirable particulate matter. In contrast, the Grímsvötn ash was almost uniformly coarse (<3.5 vol%<4 µm material). Surface area ranged from 0.3 to 7.7 m2 g(-1) for Eyjafjallajökull but was very low for Grímsvötn (<0.6 m2 g(-1)). There were few fibre-like particles (which were unrelated to asbestos) and the crystalline silica content was negligible in both eruptions, whereas Soufrière Hills ash was cristobalite-rich with a known potential to cause silicosis. All samples displayed a low ability to deplete lung antioxidant defences, showed little haemolysis and low acute cytotoxicity in human alveolar type-1 like epithelial cells (TT1). However, cell-free tests showed substantial hydroxyl radical generation in the presence of hydrogen peroxide for Grímsvötn samples, as expected for basaltic, Fe-rich ash. Cellular mediators MCP-1, IL-6, and IL-8 showed chronic pro-inflammatory responses in Eyjafjallajökull, Grímsvötn and Soufrière Hills samples, despite substantial differences in the sample mineralogy and eruptive styles. The value of the pro-inflammatory profiles in differentiating the potential respiratory health hazard of volcanic ashes remains uncertain in a protocol designed to inform public health risk assessment, and further research on their role in volcanic crises is warranted. Copyright © 2013 The Authors. Published by Elsevier Inc. All rights reserved.

Study on cement mortar and concrete made with sewage sludge ash.

PubMed

Chang, F C; Lin, J D; Tsai, C C; Wang, K S

2010-01-01

This study investigated the feasibility of reusing wastewater sludge ash in construction materials to replace partial materials. Wastewater sludge sampled from thermal power plant was burned into sludge ash at 800°C in the laboratory. The sludge incineration ash has low heavy metal including Pb, Cd, Cr and Cu, so it belongs to general enterprise waste. The chemical composition of sludge incineration ash was summed up in SiO₂, CaO, Fe₂O₃ and MgO. Then the wastewater sludge ash is also found to be a porous material with irregular surface. When the sludge ash was used to replace mortar or concrete cement, its water-adsorption capability will result in the reduction of mortar workability and compressive strength. Cement is being substituted for sludge ash, and 10 percent of sludge ash is more appropriate. Sludge ash is reused to take the place of construction materials and satisfies the requests of standard specification except for higher water absorption.

Evaluation of Preduster in Cement Industry Based on Computational Fluid Dynamic

NASA Astrophysics Data System (ADS)

Septiani, E. L.; Widiyastuti, W.; Djafaar, A.; Ghozali, I.; Pribadi, H. M.

2017-10-01

Ash-laden hot air from clinker in cement industry is being used to reduce water contain in coal, however it may contain large amount of ash even though it was treated by a preduster. This study investigated preduster performance as a cyclone separator in the cement industry by Computational Fluid Dynamic method. In general, the best performance of cyclone is it have relatively high efficiency with the low pressure drop. The most accurate and simple turbulence model, Reynold Average Navier Stokes (RANS), standard k-ε, and combination with Lagrangian model as particles tracking model were used to solve the problem. The measurement in simulation result are flow pattern in the cyclone, pressure outlet and collection efficiency of preduster. The applied model well predicted by comparing with the most accurate empirical model and pressure outlet in experimental measurement.

The immersion freezing behavior of ash particles from wood and brown coal burning

NASA Astrophysics Data System (ADS)

Grawe, Sarah; Augustin-Bauditz, Stefanie; Hartmann, Susan; Hellner, Lisa; Pettersson, Jan B. C.; Prager, Andrea; Stratmann, Frank; Wex, Heike

2016-11-01

It is generally known that ash particles from coal combustion can trigger ice nucleation when they interact with water vapor and/or supercooled droplets. However, data on the ice nucleation of ash particles from different sources, including both anthropogenic and natural combustion processes, are still scarce. As fossil energy sources still fuel the largest proportion of electric power production worldwide, and biomass burning contributes significantly to the global aerosol loading, further data are needed to better assess the ice nucleating efficiency of ash particles. In the framework of this study, we found that ash particles from brown coal (i.e., lignite) burning are up to 2 orders of magnitude more ice active in the immersion mode below -32 °C than those from wood burning. Fly ash from a coal-fired power plant was shown to be the most efficient at nucleating ice. Furthermore, the influence of various particle generation methods on the freezing behavior was studied. For instance, particles were generated either by dispersion of dry sample material, or by atomization of ash-water suspensions, and then led into the Leipzig Aerosol Cloud Interaction Simulator (LACIS) where the immersion freezing behavior was examined. Whereas the immersion freezing behavior of ashes from wood burning was not affected by the particle generation method, it depended on the type of particle generation for ash from brown coal. It was also found that the common practice of treating prepared suspensions in an ultrasonic bath to avoid aggregation of particles led to an enhanced ice nucleation activity. The findings of this study suggest (a) that ash from brown coal burning may influence immersion freezing in clouds close to the source and (b) that the freezing behavior of ash particles may be altered by a change in sample preparation and/or particle generation.

Relating the physical properties of volcanic rocks to the characteristics of ash generated by experimental abrasion

NASA Astrophysics Data System (ADS)

Buckland, Hannah M.; Eychenne, Julia; Rust, Alison C.; Cashman, Katharine V.

2018-01-01

Interactions between clasts in pyroclastic density currents (PDCs) generate volcanic ash that can be dispersed to the atmosphere in co-PDC plumes, and due to its small size, is far-travelled. We designed a series of experiments to determine the effects of pyroclast vesicularity and crystal content on the efficiency and type of ash generated by abrasion. Two different pyroclastic materials were used: (1) basaltic-andesite pyroclasts from Fuego volcano (Guatemala) with 26-46% vesicularity and high groundmass crystallinity and (2) tephri-phonolite Avellino pumice (Vesuvius, Italy) with 55-75% vesicularity and low groundmass crystallinity. When milled, both clast types produced bimodal grain size distributions with fine ash modes between 4 and 5φ (32-63 μm). Although the vesicular Avellino pumice typically generated more ash than the denser Fuego pyroclasts, the ash-generating potential of a single pyroclast was independent of density, and instead governed by heterogeneous crystal and vesicle textures. One consequence of these heterogeneities was to cause the vesicular Avellino clasts to split in addition to abrading, which further enhanced abrasion efficiency. The matrix characteristics also affected ash shape and componentry, which will influence the elutriation and transport properties of ash in the atmosphere. The experimental abrasion successfully replicated some of the characteristics of natural co-PDC ash samples, as shown by similarities in the Adherence Factor, which measures the proportion of attached matrix on phenocrysts, of both the experimentally generated ash and natural co-PDC ash samples. Our results support previous studies, which have shown that abrasion is an effective mechanism for generating fine ash that is similar in size ( 5φ; 30 μm) to that found in co-PDC deposits. We further show that both the abundance and nature (shape, density, components, size distribution) of those ash particles are strongly controlled by the matrix properties of the abraded pyroclasts.

Magnetic susceptibility mapping of fly ash in soil samples near a coal-burning power plant in Pointe Coupee Parish, Louisiana.

NASA Astrophysics Data System (ADS)

Elhelou, O.; Richter, C.

2015-12-01

Atmospheric deposition of pollutants is a major health and environmental concern. In a 2010 study, the CATF attributed over 13,000 deaths each year to fly ash and other fine particles emitted by U.S. coal-burning power plants. The magnetic properties of fly ash allows for mapping an area suspect of PM pollution faster and more efficiently than by conducting chemical analysis as the former alternative. The objective of this study is to detect the presence of magnetic particles related to the migration of fly ash from a nearby coal power plant over parts of Pointe Coupee Parish, LA. This is based on the idea that the fly ash that is released into the atmosphere during the coal burning process contains heavy metals and magnetic particles in the form of ferrospheres, which can be used to trace back to the source. Maps of the top and sub soil were generated to differentiate the magnetic susceptibility values of the heavy metals potentially attributed to the migration and settling of fly ash onto the surface from any pre-existing or naturally occurring heavy metals in the sub soil. A 60 km2 area in Pointe Coupee Parish was investigated in approximately 0.5 km2 subsets. The area in Pointe Coupee Parish, LA was selected because land use is predominantly rural with the Big Cajun II power plant as the main contributor for air borne contaminants. Samples of fly ash obtained directly from the source below one of the power plant's precipitators were also analyzed to verify the field and laboratory analysis. Contour maps representing the spatial distribution of fly ash over Pointe Coupee, LA, along with histograms of magnetic susceptibility values, and chemical analysis all indicate a correlation between the proximity to the power plant and the predominant wind direction. Acquisition curves of the isothermal remnant magnetization demonstrate the presence of predominantly low coercivity minerals (magnetite) with a small amount of a high-coercivity phase. The microstructure of the magnetic fractions of the fly ash along with select top and sub soil samples were observed using a reflective light microscope for identifying and confirming the presence of ferrospheres associated with fly ash. Chemical analyses of select samples revealed their heavy metal composition and the correlation with their SIRM and low field mass susceptibility values.

Volcanic plume and bomb field masses from thermal infrared camera imagery

NASA Astrophysics Data System (ADS)

Harris, A. J. L.; Delle Donne, D.; Dehn, J.; Ripepe, M.; Worden, A. K.

2013-03-01

Masses erupted during normal explosions at Stromboli volcano (Italy) are notoriously difficult to measure. We present a method that uses thermal infrared video for cooling bomb fields to obtain the total power emitted by all hot particles emitted during an explosion. A given mass of magma (M) will emit a finite amount of thermal power, defined by M cp(Te-T0), cp and Te being magma specific heat capacity and temperature, and T0 being ambient temperature. We use this relation to convert the total power emitted by the bomb field to the mass required to generate that power. To do this we extract power flux curves for the field and integrate this through time to obtain total power (E). This is used to estimate mass (Q) in Q=E/cp(Te-T0). When applied to individual bombs we obtain masses of between 1 and 9 kg per bomb, or a volume of 970 and 6500 cm3. These volumes equate to spheres with diameters 12 and 27 cm. For the entire bomb field we obtain volumes of 7-28 m3. We calculate masses for 32 eruptions and obtain typical bomb masses of between 103 and 104 kg per eruption. In addition, we estimate that between 102 and 103 kg of gas and ash are emitted as part of a mixed plume of bombs, gas and ash. We identify two types of eruption on the basis of the erupted bomb masses and the ratio of the plume's gas-and-ash component to the bomb component. The first type is bomb-dominated, is characterized by bomb masses of 104 kg and has ash-gas/ bomb ratios of ˜0.02. The second type is ash-and-gas dominated, is characterized by erupted bomb masses of 103 kg and has ash-gas/bomb ratios of around one, and as high as two. There is no correlation between the quantity of bombs and quantity of gas-ash erupted. In addition, while source pressure for each explosion correlates with the quantity of gas and ash erupted, the mass of bombs emitted varies independently of pressure.

Ash content: its effect on combustion of corn plants

Treesearch

A. Broido; M. A. Nelson

1964-01-01

Two corn plant samples, one cut in the fall while green, the other after weathering over the winter, exhibited strikingly different combustion properties. The increased susceptibility to flaming combustion of the spring-harvested sample is attributable to its decreased ash content, and not directly to its moisture content.

Detoxification and generation of useful products from coal combustion wastes: Quarterly technical report, (October--December 1988)

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

1988-01-01

This quarter, samples of dry fly ash, wet bottom ash, and desulfurization gypsum slurry were provided from an Ohio Edison power plant. Chemical analysis mineralogical examination, and an anion analysis were performed on the samples. 2 figs., 1 tab. (CBS)

Enhancing the compressive strength of landfill soil using cement and bagasse ash

NASA Astrophysics Data System (ADS)

Azim, M. A. M.; Azhar, A. T. S.; Tarmizi, A. K. A.; Shahidan, S.; Nabila, A. T. A.

2017-11-01

The stabilisation of contaminated soil with cement and agricultural waste is a widely applied method which contributes to the sustainability of the environment. Soil may be stabilised to increase strength and durability or to prevent erosion and other geotechnical failure. This study was carried out to evaluate the compressive strength of ex-landfill soil when cement and bagasse ash (BA) are added to it. Different proportions of cement (5%, 10%, 15% and 20%) was added to sample weights without BA. On the other hand, the cement in a different batch of sample weights was replaced by 2.5%, 5%, 7.5% and 10% of BA. All samples were allowed to harden and were cured at room temperature for 7, 14 and 28 days respectively. The strength of the contaminated soil was assessed using an unconfined compressive strength test (UCS). The laboratory tests also included the index properties of soil, cement and bagasse ash in raw form. The results indicated that the samples with cement achieved the highest compressive strength measuring 4.39 MPa. However, this study revealed that the use of bagasse ash produced low quality products with a reduction in strength. For example, when 5% of cement was replaced with 5% ash, the compressive strength decreased by about 54% from 0.72 MPa to 0.33 MPa. Similarly, the compressive strength of each sample after a curing period of 28 days was higher compared to samples cured for 7 and 14 days respectively. This is proved that a longer curing period is needed to increase the compressive strength of the samples.

Reference data set of volcanic ash physicochemical and optical properties

NASA Astrophysics Data System (ADS)

Vogel, A.; Diplas, S.; Durant, A. J.; Azar, A. S.; Sunding, M. F.; Rose, W. I.; Sytchkova, A.; Bonadonna, C.; Krüger, K.; Stohl, A.

2017-09-01

Uncertainty in the physicochemical and optical properties of volcanic ash particles creates errors in the detection and modeling of volcanic ash clouds and in quantification of their potential impacts. In this study, we provide a data set that describes the physicochemical and optical properties of a representative selection of volcanic ash samples from nine different volcanic eruptions covering a wide range of silica contents (50-80 wt % SiO2). We measured and calculated parameters describing the physical (size distribution, complex shape, and dense-rock equivalent mass density), chemical (bulk and surface composition), and optical (complex refractive index from ultraviolet to near-infrared wavelengths) properties of the volcanic ash and classified the samples according to their SiO2 and total alkali contents into the common igneous rock types basalt to rhyolite. We found that the mass density ranges between ρ = 2.49 and 2.98 g/cm3 for rhyolitic to basaltic ash types and that the particle shape varies with changing particle size (d < 100 μm). The complex refractive indices in the wavelength range between λ = 300 nm and 1500 nm depend systematically on the composition of the samples. The real part values vary from n = 1.38 to 1.66 depending on ash type and wavelength and the imaginary part values from k = 0.00027 to 0.00268. We place our results into the context of existing data and thus provide a comprehensive data set that can be used for future and historic eruptions, when only basic information about the magma type producing the ash is known.

Effect of industrial and domestic ash from biomass combustion, and spent coffee grounds, on soil fertility and plant growth: experiments at field conditions.

PubMed

Ribeiro, João Peres; Vicente, Estela Domingos; Gomes, Ana Paula; Nunes, Maria Isabel; Alves, Célia; Tarelho, Luís A C

2017-06-01

An experimental study was conducted at field conditions in order to evaluate the effect of application of ash from biomass combustion on some soil fertility characteristics and plant growth. Application of 7.5 Mg ha -1 industrial fly ash (IA), domestic ash (DA), and a 50:50 mix of domestic ash (DA) and spent coffee grounds (SCG) was made in different soil parcels. Lolium perenne seeds were sown and the grown biomass was harvested and quantified after 60 days. Soil samples from each parcel were also collected after that period and characterized. Both soil and grown biomass samples were analyzed for Ca, Mg, Na, K, P, Fe, Mn, Zn, and Al contents. Soil pH was determined before and after amendment. All applications rose significantly soil pH. Domestic ash, whether combined with coffee grounds or not, proved to be efficient at supplying available macronutrients Ca, Mg, K, and P to the soil and also reducing availability of Al (more than industrial ash). However, it inhibited plant growth, even more when combined with spent coffee grounds. As regards to elemental abundance in plant tissue, both domestic ash treatments reduced Ca and enhanced Al contents, unlike industrial ash, which proved less harmful for the load applied in the soil. Hence, it was possible to conclude that application load should be a limiting factor for this management option for the studied materials.

Increased PCDD/F formation in the bottom ash from fires of CCA-treated wood.

PubMed

Tame, N W; Dlugogorski, B Z; Kennedy, E M

2003-03-01

Bottom ash that was the result of the combustion of chromated copper arsenate (CCA) treated wood under controlled fire conditions showed an increase of several orders of magnitude in the levels of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), compared to that of untreated timber. Wood that has been pressure treated with CCA contains copper (II), which is known to catalyse the so-called de novo formation of PCDD/Fs. Comparable levels of PCDD/Fs would be expected in residual ash from burning CCA-treated wood in backyard fires, stoves and wood heaters, as a consequence of similar combustion conditions.

Recovery of Precious and Base Metals from Waste Printed Circuit Boards Using a Sequential Leaching Procedure

NASA Astrophysics Data System (ADS)

Batnasan, Altansukh; Haga, Kazutoshi; Shibayama, Atsushi

2018-02-01

This paper considers the issue of recycling of waste printed circuit boards (WPCBs) containing precious and base metals in appreciable amounts. High-pressure oxidative leaching (HPOL) with dilute sulfuric acid resulted in removal of a significant amount of base metals from a WPCB ash sample obtained by incineration at 800°C. The parameters investigated in the precious metal leaching from WPCB residue after HPOL included the sulfuric acid concentration, thiourea concentration, oxidant concentration, leaching temperature, and leaching time. Recovery of gold, silver, and palladium of 100%, 81%, and 13% from the WPCB residue sample was achieved by thiourea leaching under optimized conditions. The results show that the efficiency of precious metal dissolution from the WPCB sample using thiourea solution depended strongly on the concentration of both thiourea and oxidant.

Recovery of Precious and Base Metals from Waste Printed Circuit Boards Using a Sequential Leaching Procedure

NASA Astrophysics Data System (ADS)

Batnasan, Altansukh; Haga, Kazutoshi; Shibayama, Atsushi

2017-12-01

This paper considers the issue of recycling of waste printed circuit boards (WPCBs) containing precious and base metals in appreciable amounts. High-pressure oxidative leaching (HPOL) with dilute sulfuric acid resulted in removal of a significant amount of base metals from a WPCB ash sample obtained by incineration at 800°C. The parameters investigated in the precious metal leaching from WPCB residue after HPOL included the sulfuric acid concentration, thiourea concentration, oxidant concentration, leaching temperature, and leaching time. Recovery of gold, silver, and palladium of 100%, 81%, and 13% from the WPCB residue sample was achieved by thiourea leaching under optimized conditions. The results show that the efficiency of precious metal dissolution from the WPCB sample using thiourea solution depended strongly on the concentration of both thiourea and oxidant.

Slags and ashes from municipal waste incineration in Poland - mineralogical and chemical composition

NASA Astrophysics Data System (ADS)

Kowalski, Piotr; Michalik, Marek

2013-04-01

In the next few years there will be a large change in the waste management system in Poland. Its primary aim will be reduction of the amount of landfilled waste by enhancing level of recycling, waste segregation, composting of biomass and incineration. The biggest investment during this transformation is construction of nine incinerators with assumed slags production around 200 thousand tons per year. Slag production is accompanied by fly ash generating. This ash can be a valuable raw material as fly ash from the power industry. Waste management system transformation will cause big increase in slag production in comparison to the present amount and will require taking necessary steps to ensure environmental safety. For this purpose, studies of slags and fly ashes in terms of environmental risk and potential impact on human health are significant. The object of the study are fly ashes and slags produced in the biggest municipal waste incineration power plant in Poland. Two series of samples obtained in municipal waste incineration process were studied in order to characterize mineralogical and chemical composition and to determine the concentrations of heavy metals and their possible negative environmental impact. Characteristics of these materials will be the basis for determining their value in application, for example in building industry. Mineralogical characteristic of slags was based on X-ray diffraction. Characteristic of structures and forms of occurrence of mineral phases was based on the optical microscopy and SEM imaging coupled with EDS analysis. Chemical analysis were performed using ICP-MS/ICP-AES methods. They allowed to follow variability between studied samples and gave basic information about metals. Metals in samples of slag and ashes are present as component of mineral phases and in the form of metallic inclusions in glass or minerals. Potentially hazardous concentrations for environment are observed for copper (330-4900ppm), zinc (1500-8100ppm) and lead (50-2400ppm). All samples are rich in amorphous phase. Municipal slags are rich in Si, Ca and Al, whereas Fe and Na are minor component. Fly ashes from incineration of waste are similar to Ca-type ashes from power industry. They are rich in Ca and Si and they contain minor amount of Al, K and Na. The main mineral components of municipal slags are quartz, gehlenite, calcite and lime. They are present in all samples. Smaller quantities of apatite, wollastonite, feldspar, anhydrite and magnetite were also detected. In addition to main components, two groups of associated minerals can be identified. The first group is represented by wollastonite and apatite, whereas in the second group magnetite and feldspar or anhydrite were detected. Moreover, if feldspar is present in the sample there is no anhydrite. Also the presence of magnetite is correlated with the absence of wollastonite and apatite. In all fly ash samples quartz, calcite, anhydrite, lime and halite or sylvite are present. Minor components are periclase, portlandite and syngenite, wollastonite and meionite. Here we can observe also some dependence. When halite and syngenite are present in sample there is no wollastonite and when gelenite is present, portlandite is absent.

Development of an automatic volcanic ash sampling apparatus for active volcanoes

NASA Astrophysics Data System (ADS)

Shimano, Taketo; Nishimura, Takeshi; Chiga, Nobuyuki; Shibasaki, Yoshinobu; Iguchi, Masato; Miki, Daisuke; Yokoo, Akihiko

2013-12-01

We develop an automatic system for the sampling of ash fall particles, to be used for continuous monitoring of magma ascent and eruptive dynamics at active volcanoes. The system consists of a sampling apparatus and cameras to monitor surface phenomena during eruptions. The Sampling Apparatus for Time Series Unmanned Monitoring of Ash (SATSUMA-I and SATSUMA-II) is less than 10 kg in weight and works automatically for more than a month with a 10-kg lead battery to obtain a total of 30 to 36 samples in one cycle of operation. The time range covered in one cycle varies from less than an hour to several months, depending on the aims of observation, allowing researchers to target minute-scale fluctuations in a single eruptive event, as well as daily to weekly trends in persistent volcanic activity. The latest version, SATSUMA-II, also enables control of sampling parameters remotely by e-mail commands. Durability of the apparatus is high: our prototypes worked for several months, in rainy and typhoon seasons, at windy and humid locations, and under strong sunlight. We have been successful in collecting ash samples emitted from Showa crater almost everyday for more than 4 years (2008-2012) at Sakurajima volcano in southwest Japan.

The Effect of Baggase Ash on Fly Ash-Based Geopolimer Binder

NASA Astrophysics Data System (ADS)

Bayuaji, R.; Darmawan, M. S.; Husin, N. A.; Banugraha, R.; Alfi, M.; Abdullah, M. M. A. B.

2018-06-01

Geopolymer concrete is an environmentally friendly concrete. However, the geopolymer binder has a problem with setting time; mainly the composition comprises high calcium fly ash. This study utilized bagasse ash to improve setting time on fly ash-based geopolymer binder. The characterization of bagasse ash was carried out by using chemical and phase analysis, while the morphology characterization was examined by scanning electron microscope (SEM). The setting time test and the compressive strength test used standard ASTM C 191-04 and ASTM C39 / C39M respectively. The compressive strength of the samples determined at 3, 28 and 56 days. The result compared the requirement of the standards.

Effects Of Crystallographic Properties On The Ice Nucleation Properties Of Volcanic Ash Particles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kulkarni, Gourihar R.; Nandasiri, Manjula I.; Zelenyuk, Alla

2015-04-28

Specific chemical and physical properties of volcanic ash particles that could affect their ability to induce ice formation are poorly understood. In this study, the ice nucleating properties of size-selected volcanic ash and mineral dust particles in relation to their surface chemistry and crystalline structure at temperatures ranging from –30 to –38 °C were investigated in deposition mode. Ice nucleation efficiency of dust particles was higher compared to ash particles at all temperature and relative humidity conditions. Particle characterization analysis shows that surface elemental composition of ash and dust particles was similar; however, the structural properties of ash samples weremore » different.« less

Rock magnetic finger-printing of soil from a coal-fired thermal power plant.

PubMed

Gune, Minal; Harshavardhana, B G; Balakrishna, K; Udayashankar, H N; Shankar, R; Manjunatha, B R

2016-05-01

We present seasonal rock magnetic data for 48 surficial soil samples collected seasonally around a coal-fired thermal power plant on the southwest coast of India to demonstrate how fly ash from the power plant is transported both spatially and seasonally. Sampling was carried out during pre-monsoon (March), early-monsoon (June), monsoon (September) and post-monsoon (December) seasons. Low- and high-frequency magnetic susceptibility (χlf and χhf), frequency-dependent magnetic susceptibility (χfd), χfd %, isothermal remanent magnetization (IRM), "hard" IRM (HIRM), saturation IRM (SIRM) and inter-parametric ratios were determined for the samples. Scanning electron microscopy (SEM) was used on limited number of samples. NOAA HYSPLIT MODEL backward trajectory analysis and principal component analysis were carried out on the data. Fly ash samples exhibit an average HIRM value (400.07 × 10(-5) Am(2) kg(-1)) that is comparable to that of soil samples. The pre- and post-monsoon samples show a consistent reduction in the concentration of magnetically "hard" minerals with increasing distance from the power plant. These data suggest that fly ash has indeed been transported from the power plant to the sampling locations. Hence, HIRM may perhaps be used as a proxy for tracking fly ash from coal-fired thermal power plants. Seasonal data show that the distribution of fly ash to the surrounding areas is minimum during monsoons. They also point to the dominance of SP magnetite in early-monsoon season, whereas magnetic depletion is documented in the monsoon season. This seasonal difference is attributable to both pedogenesis and anthropogenic activity i.e. operation of the thermal power plant.

A Modern Analog to the Depositional Age Problem: Zircon and Apatite Fission Track and U-Pb Age Distributions by LA-ICP-MS

NASA Astrophysics Data System (ADS)

Donelick, H. M.; Donelick, M. B.; Donelick, R. A.

2012-12-01

Sand from three river systems in North Idaho (Snake River near Lewiston, Clearwater River near Lewiston and the Salmon River near White Bird) and two regional ash fall events (Mt. Mazama and Mt. St. Helens) were collected for zircon U-Pb detrital age analysis. Up to 120 grains of zircon per sample were ablated using a Resonetics M-50 193 nm ArF Excimer laser ablation (LA) system and the Pb, Th, and U isotopic signals were quantified using an Agilent 7700x quadrupole inductively coupled plasma-mass spectrometer (ICP-MS). Isotopic signals for major, minor, and trace elements, including all REEs, were also monitored. The youngest zircon U-Pb ages from the river samples were approximately 44 Ma; Cenozoic Idaho Batholith and Precambrian Belt Supergroup ages were well represented. Significant common Pb contamination of the Clearwater River sample (e.g., placer native Cu was observed in the sample) precluded detailed analysis of the zircon U-Pb ages but no interpretable ages <44 Ma were observed. Interestingly, not one of the river samples yielded zircon U-Pb ages near 0 Ma, despite all three catchment areas having received significant ash from Mt. St. Helens in 1980, and Mount Mazama 7,700 years ago, and no doubt other events during the Quaternary. Work currently in progress seeks to address bias against near 0 Ma ages in the catchment areas due to: a) small, local ash fall grain sizes and b) overwhelming number of older grains relative to the ash fall grains. Data from Mt. St. Helens ash from several localities near the mountain (Toutle River and Maple Flats, WA) and several far from the mountain (Spokane, WA; Princeton, ID; Kalispell, MT) and Mt. Mazama ash fall deposits near Lewiston, ID and Spokane, WA will be presented to address these possibilities. Additionally, fission track and U-Pb ages from apatites collected from these river and ash fall samples will also be shown to help constrain the problem.

Aquatic ecotoxicity of ashes from Brazilian savanna wildfires.

PubMed

Brito, Darlan Q; Passos, Carlos José S; Muniz, Daphne H F; Oliveira-Filho, Eduardo C

2017-08-01

In a global scenario of climate change, several studies have predicted an increase in fires in different parts of the world. With the occurrence of rains following the fires in the Brazilian savanna (Cerrado biome), the compounds present in ashes may enter aquatic environments and cause adverse effects to these ecosystems. In this context, this study evaluated the potential toxicity of ashes from two areas of Cerrado and an area of pasture, through ecotoxicological bioassays and using three aquatic species from distinct trophic levels, which were exposed to different dilutions of ashes: the microcrustacean Ceriodaphnia dubia, the fish Danio rerio and the mollusc Biomphalaria glabrata. The ashes from the three sampled areas showed higher concentrations of some elements in relation to the soil samples (B, Ca, K, Mg, Mn, P, S, Si, Sr, Zn), but only a small quantity of these compounds was solubilised. Our data showed that all ash samples caused acute toxicity to C. dubia (48hs-LC 50  = 13.4 g L -1 ; 48hs-LC 50  = 6.33 g L -1 ; 48hs-LC 50  = 9.73 g L -1 respectively for transition area, pasture, typical cerrado areas), while in relation to D. rerio and B. glabrata, no acute toxicity was observed when they were exposed to ashes from native Cerrado vegetation and pasture areas. Ashes from a transition area showed toxicity for D. rerio (48hs-LC 50  = 25.0 g L -1 ); possibly, this was due to the combination of multiple preponderant inorganic elements of ashes with other organic compounds not analysed, such as polycyclic aromatic hydrocarbons (PAHs). In summary, these results suggest that wildfires may pose risks to zooplankton communities and emphasize the need for more studies to better understand the complexity of the ecological effects of fire on aquatic ecosystems.

Long-range volcanic ash transport and fallout during the 2008 eruption of Chaiten volcano, Chile

NASA Astrophysics Data System (ADS)

Durant, A. J.; Prata, A. J.; Villarosa, G.; Rose, W. I.; Delmelle, P.; Viramonte, J.

2012-04-01

The May 2008 eruption of Chaitén volcano, Chile, provided a rare opportunity to measure the long-range transport of volcanic emissions and characteristics of a widely-dispersed terrestrial ash deposit. Airborne ash mass, quantified using thermal infrared satellite remote sensing, ranged between 0.2-0.4 Tg during the period 3-7 May 2008. A high level of spatiotemporal correspondence was observed between cloud trajectories and changes in surface reflectivity, which was inferred to indicate ash deposition. The evolution of the deposit was mapped for the first time using satellite-based observations of surface reflectivity. The distal (>80 km) ash deposit was poorly sorted and fine grained, and mean particle size varied very little beyond a distance >300 km. There were 3 consistent particle size subpopulations in fallout at distances >300 km which suggests that aggregation influenced particle settling. Discrete temporal sampling and characterisation of fallout demonstrated contributions from specific eruptive phases. Some evidence for winnowing was identified through comparison of samples collected at the time of deposition to bulk samples collected months after deposition. X-Ray Photoelectron Spectroscopy (XPS) analyses revealed surface enrichments in Ca, Na and Fe and the presence of coatings of mixed Ca-, Na- and Fe-rich salts on ash particles prior to deposition. XPS analyses revealed strong surface Fe enrichments (in contrast to the results from bulk leachate analyses), which indicates that surface analysis techniques should be applied to investigate potential influences on ocean productivity in response to volcanic ash fallout over oceans. Low S:Cl ratios in leachates indicate that the eruption had a low S content, and high Cl:F ratios imply gas-ash interaction within a Cl-rich environment. We estimate that ash fallout had potential to scavenge ~42 % of total S released into the atmosphere prior to deposition.

Physical factors affecting the mutagenicity of fly ash from a coal-fired power plant.

PubMed

Fisher, G L; Chrisp, C E; Raabe, O G

1979-05-25

The two finest, most respirable coal fly ash fractions collected from the smokestack of a power plant were more mutagenic than two coarser fractions. Mutagenicity was evaluated in the histidine-requiring bacterial strains TA 1538, TA 98, and TA 100 of Salmonella typhimurium. Ash samples collected from the hoppers of an electrostatic precipitator in the plant were not mutagenic. The mutagens in coal fly ash were resistant to x-ray or ultraviolet irradiation, possibly as a result of stabilization by fly ash surfaces. All mutagenic activity is lost with heating to 350 degrees C.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Black, R.A.; Mack, R.N.

The 18 May 1980 ash fall from Mount St. Helens was experimentally reproduced in May 1982 by applying silt-sized ash to a stand of the Artemisia tridentata/Agropyron spicatum association in south-central Washington. Compared to the adjacent control site, ash caused an immediate increase in albedo from 13% to 28%, while other parameters of the energy budget were simultaneously lowered: net radiation by approx. = 20%, soil surface temperatures by as much as 10/sup 0/C, and soil heat flux by as much as 50%. The ash's mulching action initially increased water availability and delayed leaf abscission in Artemisia tridentata (Big sagebrush)more » by 2 wk in summer 1982. But after summer 1982 water availability declined, while water use increased, illustrating the diverse effects of the ash. Increased reflection from the ash-covered surface increased the radiation load on plant canopies. In turn, air temperature at 0.5 m increased, latent heat flux often doubled in summer, and xylem pressure potentials decreased. Available water at the -1 m soil depth eventually decreased as much as 40%. This decrease was the result of the increase in latent heat flux and the decline in infiltration through the stratified layer created by the ash cap. In addition to allowing assessment of the effects of the 18 May 1980 ash fall on arid steppe, application of ash provided an unexpected level of precision in detecting the often subtle effects that occur when some microenvironmental parameters change while the overall macroclimate remains the same.« less

Volcanic ash supports a diverse bacterial community in a marine mesocosm

USGS Publications Warehouse

Verena Witt,; Paul M Ayris,; Damby, David; Corrado Cimarelli,; Ulrich Kueppers,; Donald B Dingwell,; Gert Wörheide,

2017-01-01

Shallow-water coral reef ecosystems, particularly those already impaired by anthropogenic pressures, may be highly sensitive to disturbances from natural catastrophic events, such as volcanic eruptions. Explosive volcanic eruptions expel large quantities of silicate ash particles into the atmosphere, which can disperse across millions of square kilometres and deposit into coral reef ecosystems. Following heavy ash deposition, mass mortality of reef biota is expected, but little is known about the recovery of post-burial reef ecosystems. Reef regeneration depends partly upon the capacity of the ash deposit to be colonised by waterborne bacterial communities and may be influenced to an unknown extent by the physiochemical properties of the ash substrate itself. To determine the potential for volcanic ash to support pioneer bacterial colonisation, we exposed five well-characterised volcanic and coral reef substrates to a marine aquarium under low light conditions for 3 months: volcanic ash, synthetic volcanic glass, carbonate reef sand, calcite sand and quartz sand. Multivariate statistical analysis of Automated Ribosomal Intergenic Spacer Analysis (ARISA) fingerprinting data demonstrates clear segregation of volcanic substrates from the quartz and coral reef substrates over 3 months of bacterial colonisation. Overall bacterial diversity showed shared and substrate-specific bacterial communities; however, the volcanic ash substrate supported the most diverse bacterial community. These data suggest a significant influence of substrate properties (composition, granulometry and colour) on bacterial settlement. Our findings provide first insights into physicochemical controls on pioneer bacterial colonisation of volcanic ash and highlight the potential for volcanic ash deposits to support bacterial diversity in the aftermath of reef burial, on timescales that could permit cascading effects on larval settlement.

Particulate Hot Gas Stream Cleanup Technical Issues: Quarterly report, July 1-September 30, 1996

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pontius, D.H.

1996-12-09

This is the eighth in a series of quarterly reports describing the activities performed under Contract No. DE-AC21-94MC31160. Analyses of Hot Gas Stream Cleanup (HGCU) ashes and descriptions of filter performance address aspects of filter operation that are apparently linked to the characteristics of the collected ash or the performance of the ceramic barrier filter elements. Task 1 is designed to generate a data base of the key characteristics of ashes collected from operating advanced particle filters (APFS) and to relate these ash properties to the operation and performance of these filters. Task 2 concerns testing and failure analysis ofmore » ceramic filter elements. Under Task I during the past quarter, additional analyses were performed on ashes from the Ahlstrom 10 MWt Pressurized Fluidized Circulating Fluid Bed (PCFB) facility located at Karhula, Finland. Work continued on the HGCU data base being constructed in Microsoft Access. A variety of information has been entered into the data base, including numerical values, short or long text entries, and photographs. Detailed design of a bench top device for high temperature measurement of ash permeability has also begun. In addition to these activities, a paper was prepared and a poster was presented summarizing recent work performed under this contract at the 1996 DOE/METC Contractor`s Conference. A presentation was also given corresponding to the manuscript entitled Particle Characteristics and High-Temperature Filtration that was prepared for publication in the Proceedings of the Thirteenth Annual International Pittsburgh Coal Conference held this September in Pittsburgh, PA. Arrangements have been made to be present at the DOE/METC Modular Gas Cleanup Rig (MGCR) at the conclusion of the next run of the DOE/METC air blown Fluid Bed Gasifier (FBG). This visit will include on-site sampling to collect and characterize the filter cakes collected during FGB operation. Task 2 efforts during the past quarter focused on hoop tensile testing of Schumacher FT20 and Refractron 326 candle filter elements removed from the Karhula APF after 540 hours of service.« less

HIGH PRESSURE COAL COMBUSTION KINETICS PROJECT

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chris Guenther; Bill Rogers

2001-09-15

The HPCCK project was initiated with a kickoff meeting held on June 12, 2001 in Morgantown, WV, which was attended by all project participants. SRI's existing g-RCFR reactor was reconfigured to a SRT-RCFR geometry (Task 1.1). This new design is suitable for performing the NBFZ experiments of Task 1.2. It was decided that the SRT-RCFR apparatus could be modified and used for the HPBO experiments. The purchase, assembly, and testing of required instrumentation and hardware is nearly complete (Task 1.1 and 1.2). Initial samples of PBR coal have been shipped from FWC to SRI (Task 1.1). The ECT device formore » coal flow measurements used at FWC will not be used in the SRI apparatus and a screw type feeder has been suggested instead (Task 5.1). NEA has completed a upgrade of an existing Fluent simulator for SRI's RCFR to a version that is suitable for interpreting results from tests in the NBFZ configuration (Task 1.3) this upgrade includes finite-rate submodels for devolatilization, secondary volatiles pyrolysis, volatiles combustion, and char oxidation. Plans for an enhanced version of CBK have been discussed and development of this enhanced version has begun (Task 2.5). A developmental framework for implementing pressure and oxygen effects on ash formation in an ash formation model (Task 3.3) has begun.« less

Use of Brazilian sugarcane bagasse ash in concrete as sand replacement

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sales, Almir, E-mail: almir@ufscar.b; Lima, Sofia Araujo, E-mail: sofiaalima@yahoo.com.b

2010-06-15

Sugarcane today plays a major role in the worldwide economy, and Brazil is the leading producer of sugar and alcohol, which are important international commodities. The production process generates bagasse as a waste, which is used as fuel to stoke boilers that produce steam for electricity cogeneration. The final product of this burning is residual sugarcane bagasse ash (SBA), which is normally used as fertilizer in sugarcane plantations. Ash stands out among agroindustrial wastes because it results from energy generating processes. Many types of ash do not have hydraulic or pozzolanic reactivity, but can be used in civil construction asmore » inert materials. The present study used ash collected from four sugar mills in the region of Sao Carlos, SP, Brazil, which is one of the world's largest producers of sugarcane. The ash samples were subjected to chemical characterization, sieve analysis, determination of specific gravity, X-ray diffraction, scanning electron microscopy, and solubilization and leaching tests. Mortars and concretes with SBA as sand replacement were produced and tests were carried out: compressive strength, tensile strength and elastic modulus. The results indicated that the SBA samples presented physical properties similar to those of natural sand. Several heavy metals were found in the SBA samples, indicating the need to restrict its use as a fertilizer. The mortars produced with SBA in place of sand showed better mechanical results than the reference samples. SBA can be used as a partial substitute of sand in concretes made with cement slag-modified Portland cement.« less

[Near-infrared reflectance spectroscopy predicts protein, moisture and ash in beans].

PubMed

Gao, Huiyu; Wang, Guodong; Men, Jianhua; Wang, Zhu

2017-05-01

To explore the potential of near-infrared reflectance( NIR)spectroscopy to determine macronutrient contents in beans. NIR spectra and analytical measurements of protein, moisture and ash were collected from 70 kinds of beans. Reference methods were used to analyze all the ground beans samples. NIR spectra on intact and ground beans samples were registered. Partial least-squares( PLS)regression models were developed with principal components analysis( PCA) to assign 49 bean accessions to a calibration data set and 21 accessions to an external validation set. For intact beans, the relative predictive determinant( RPD) values for protein and ash( 3. 67 and 3. 97, respectively) were good for screening. RPD value for moisture was only 1. 39, which was not recommended. For ground beans, the RPD values for protein, moisture and ash( 6. 63, 5. 25 and 3. 57, respectively) were good enough for screening. The protein, moisture and ash levels for intact and ground beans were all significantly correlated( P < 0. 001) between the NIR and reference method and there was no statistically significant difference in the mean with these three traits. This research demonstrates that NIR is a promising technique for simultaneous sorting ofmultiple traits in beans with no or easy sample preparation.

Relationship between textural properties, fly ash carbons, and Hg capture in fly ashes derived from the combustion of anthracitic pulverized feed blends

DOE Office of Scientific and Technical Information (OSTI.GOV)

Isabel Surez-Ruiz; Jose B. Parra

2007-08-15

In this work, the textural properties of a series of whole anthracitic-derived fly ashes sampled in eight hoppers from the electrostatic precipitators and their sized fractions (from {gt}150 to {lt}25 {mu}m) are investigated. Data from N{sub 2} adsorption isotherms at 77 K, helium density, and mercury porosimetry have contributed to establish a relationship between the Brunauer-Emmett-Teller (BET) surface areas, VTOT, porosity, carbon content (the type of fly ash carbons), and Hg retention in these fly ashes. The unburned carbons in these ashes are macroporous materials, and they are different from the carbons in fly ashes from classes C and Fmore » (the latter derived from the combustion of bituminous coals) and show different textural properties. These ashes represent the end member of the fly ash classes C and F with respect to certain textural properties. Although the BET surface area and VTOT values for the studied samples are the lowest reported, they increase with the increase in carbon content, anisotropic carbon content, and particle size of the ashes. Thus, a positive relationship between all these parameters and Hg capture by the coarser ash fractions was found. The finest fraction of carbons ({lt}25 {mu}m) represented an exception. Although it makes a significant contribution to the total carbon of the whole fly ashes and shows relatively higher surface areas and VTOT values, its Hg concentration was found to be the lowest. This suggests that the type of unburned carbons in the finest fraction and/or other adsorption mechanisms may play a role in Hg concentration. Because the textural properties of anisotropic carbons depend on their subtype and on their origin, the need for its differentiation has been evidenced. 54 refs., 8 figs., 3 tabs.« less

Characterization of polymer decomposition products by laser desorption mass spectrometry

NASA Technical Reports Server (NTRS)

Pallix, Joan B.; Lincoln, Kenneth A.; Miglionico, Charles J.; Roybal, Robert E.; Stein, Charles; Shively, Jon H.

1993-01-01

Laser desorption mass spectrometry has been used to characterize the ash-like substances formed on the surfaces of polymer matrix composites (PMC's) during exposure on LDEF. In an effort to minimize fragmentation, material was removed from the sample surfaces by laser desorption and desorbed neutrals were ionized by electron impact. Ions were detected in a time-of-flight mass analyzer which allows the entire mass spectrum to be collected for each laser shot. The method is ideal for these studies because only a small amount of ash is available for analysis. Three sets of samples were studied including C/polysulfone, C/polyimide and C/phenolic. Each set contains leading and trailing edge LDEF samples and their respective controls. In each case, the mass spectrum of the ash shows a number of high mass peaks which can be assigned to fragments of the associated polymer. These high mass peaks are not observed in the spectra of the control samples. In general, the results indicate that the ash is formed from decomposition of the polymer matrix.

Physical and biological studies of coal and oil fly ash.

PubMed Central

Fisher, G L; McNeill, K L; Prentice, B A; McFarland, A R

1983-01-01

Studies were performed to compare the physical and chemical characteristics and the in vitro macrophage cytotoxicity of oil and coal fly ash. Sampling methodology was developed to collect size-fractionated particulate matter from the smokestack of either a coal-fired or an oil-fired power plant. Morphological studies demonstrated particle heterogeneity, although most coal fly ash particles appeared to be spherical. Oil fly ash contained two major morphologies; nonopaque amorphous particles and opaque amorphous particles. Elemental analysis indicates that the coal ash is predominantly composed of aluminosilicate particles, while the oil ash is predominantly inorganic sulfates and carbonaceous particles. In vitro macrophage assays demonstrate that the finest coal fly ash particles are the most cytotoxic; the cytotoxicity is significantly less than that of alpha-quartz, the positive control particle. In contrast, the oil fly ash particles are more cytotoxic than quartz. The cytotoxicity of oil fly ash is due to soluble components, possibly vanadium salts. Images FIGURE 2. A FIGURE 2. B FIGURE 2. C FIGURE 2. D PMID:6641653

Heavy Metal Contamination of Soils around a Hospital Waste Incinerator Bottom Ash Dumps Site

PubMed Central

Adama, M.; Esena, R.; Fosu-Mensah, B.; Yirenya-Tawiah, D.

2016-01-01

Waste incineration is the main waste management strategy used in treating hospital waste in many developing countries. However, the release of dioxins, POPs, and heavy metals in fly and bottom ash poses environmental and public health concerns. To determine heavy metal (Hg, Pb, Cd, Cr, and Ag) in levels in incinerator bottom ash and soils 100 m around the incinerator bottom ash dump site, ash samples and surrounding soil samples were collected at 20 m, 40 m, 60 m, 80 m, 100 m, and 1,200 m from incinerator. These were analyzed using the absorption spectrophotometer method. The geoaccumulation (I geo) and pollution load indices (PLI) were used to assess the level of heavy metal contamination of surrounding soils. The study revealed high concentrations in mg/kg for, Zn (16417.69), Pb (143.80), Cr (99.30), and Cd (7.54) in bottom ash and these were above allowable limits for disposal in landfill. The study also found soils within 60 m radius of the incinerator to be polluted with the metals. It is recommended that health care waste managers be educated on the implication of improper management of incinerator bottom ash and regulators monitor hospital waste incinerator sites. PMID:27034685

The chemical and oxidation characteristics of semi-dry flue gas desulfurization ash from a steel factory.

PubMed

Liu, Ren-ping; Guo, Bin; Ren, Ailing; Bian, Jing-feng

2010-10-01

Some samples of semi-dry flue gas desulfurization (FGD) ash were taken from sinter gas of a steel factory. Scanning electron microscope (SEM) and X-ray diffraction (XRD) analyses were employed to identify the samples in order to investigate their physical and chemical characteristics. The results show that semi-dry FGD ash from a steel factory is stable under atmospheric conditions. It has irregular shape, a smooth surface and loose construction. The size of FGD ash particles is around 0.5-25 µm, the average size is about 5 µm and the median diameter is 4.18 µm. Semi-dry FGD ash from a steel factory consists of CaSO₃, CaSO₄, CaCO₃, some amorphous vitreous material and unburned carbon. An experimental method was found to study the oxidation characteristics of ash. A prediction model of the oxidation efficiency was obtained based on response surface methodology. The results show that not only the temperature, but also gas:solid ratio, play an important role in influencing the oxidation efficiency. The interactions of the gas:solid ratio with temperature play an essential role. An improved response surface model was obtained which can be helpful to describe the degree of oxidation efficiency of semi-dry FGD ash.

[Determining acid phosphatase (AcP[E.C. 3.1.3.2.]) and adenosine triphosphatase (ATPase [E.C. 3.6.1.3.]) activity in the lungs of rats following a single administration of ashes from industrial high-heat facilities].

PubMed

Romanowska-Sarlej, J; Staszyc, J; Królikowska-Prasał, I; Jedrzejewska, E; Kifer, E; Matysiak, W

1988-01-01

There was examined pulmonary tissue of white rats, which had been administered intratrachealy a single dose of the respirable fraction of ashes sample from 6 different power stations elektrohasting plants and hasting plants in Poland (0.2 ml suspension; 50 mg of the examined sample in 0.6 cm3 of NaCl solution). 9 months after the application of the ashes, biopsies of the left lung were taken and there was determined the activity of acid phosphatase (AcP) and adenosinetriphosphatase (ATP-ase) histoenzymatically. There was found sensitivity of these hydrolases and changes of their activity connected with chemical composition of the examined ashes.

Environmental hazard of oil shale combustion fly ash.

PubMed

Blinova, Irina; Bityukova, Liidia; Kasemets, Kaja; Ivask, Angela; Käkinen, Aleksandr; Kurvet, Imbi; Bondarenko, Olesja; Kanarbik, Liina; Sihtmäe, Mariliis; Aruoja, Villem; Schvede, Hedi; Kahru, Anne

2012-08-30

The combined chemical and ecotoxicological characterization of oil shale combustion fly ash was performed. Ash was sampled from the most distant point of the ash-separation systems of the Balti and Eesti Thermal Power Plants in North-Eastern Estonia. The fly ash proved potentially hazardous for tested aquatic organisms and high alkalinity of the leachates (pH>10) is apparently the key factor determining its toxicity. The leachates were not genotoxic in the Ames assay. Also, the analysis showed that despite long-term intensive oil-shale combustion accompanied by considerable fly ash emissions has not led to significant soil contamination by hazardous trace elements in North-Eastern Estonia. Comparative study of the fly ash originating from the 'new' circulating fluidized bed (CFB) combustion technology and the 'old' pulverized-fired (PF) one showed that CFB fly ash was less toxic than PF fly ash. Thus, complete transfer to the 'new' technology will reduce (i) atmospheric emission of hazardous trace elements and (ii) fly ash toxicity to aquatic organisms as compared with the 'old' technology. Copyright © 2012 Elsevier B.V. All rights reserved.

Investigation of air-entraining admixture dosage in fly ash concrete

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ley, M.T.; Harris, N.J.; Folliard, K.J.

The amount of air-entraining admixture (AEA) needed to achieve a target air content in fresh concrete can vary significantly with differences in the fly ash used in the concrete. The work presented in this paper evaluates the ability to predict the AEA dosage on the basis of tests on the fly ash alone. All results were compared with the dosage of AEA required to produce an air content of 6% in fresh concrete. Fly ash was sampled from six separate sources. For four of these sources, samples were obtained both before and after the introduction of 'low-NOx burners'. Lack ofmore » definitive data about the coal itself or the specifics of the burning processes prevents the ability to draw specific conclusions about the impact of low-NOx burners on AEA demand. Nevertheless, the data suggest that modification of the burning process to meet environmental quality standards may affect the fly ash-AEA interaction.« less

Distribution of polycyclic aromatic hydrocarbons in lime spray dryer ash

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ping Sun; Panuwat Taerakul; Linda K. Weavers

Four lime spray dryer (LSD) ash samples were collected from a spreader stoker boiler and measured for their concentrations of 16 U.S. EPA specified polycyclic aromatic hydrocarbons (PAHs). Results showed that the total measured PAH concentration correlated with the organic carbon content of the LSD ash. Each LSD ash sample was then separated using a 140 mesh sieve into two fractions: a carbon-enriched fraction ({gt}140 mesh) and a lime-enriched fraction ({lt}140 mesh). Unburned carbon was further separated from the carbon-enriched fraction with a lithiumheteropolytungstate (LST) solution. PAH measurements on these different fractions showed that unburned carbon had the highest PAHmore » concentrations followed by the carbon-enriched fraction, indicating that PAHs were primarily associated with the carbonaceous material in LSD ash. However, detectable levels of PAHs were also found in the lime-enriched fraction, suggesting that the fine spray of slaked lime may sorb PAH compounds from the flue gas in the LSD process. 37 refs., 5 figs., 4 tabs.« less

Leaching for recovery of copper from municipal solid waste incineration fly ash: influence of ash properties and metal speciation.

PubMed

Lassesson, Henric; Fedje, Karin Karlfeldt; Steenari, Britt-Marie

2014-08-01

Recovery of metals occurring in significant amounts in municipal solid waste incineration fly ash, such as copper, could offer several advantages: a decreased amount of potentially mobile metal compounds going to landfill, saving of natural resources and a monetary value. A combination of leaching and solvent extraction may constitute a feasible recovery path for metals from municipal solid waste incineration fly ash. However, it has been shown that the initial dissolution and leaching is a limiting step in such a recovery process. The work described in this article was focused on elucidating physical and chemical differences between two ash samples with the aim of explaining the differences in copper release from these samples in two leaching methods. The results showed that the chemical speciation is an important factor affecting the release of copper. The occurrence of copper as phosphate or silicate will hinder leaching, while sulphate and chloride will facilitate leaching. © The Author(s) 2014.

Ash effects on the thermal conductivity of a mediterranean loam soil

NASA Astrophysics Data System (ADS)

Rubio, Carles; Pereira, Paulo; Ubeda, Xavier

2014-05-01

The purpose of this work is to explore the variability on the soil thermal conductivity for a burnt soil and assessing the effects of the ashes on the heat transfer when they were incorporated into the soil matrix. A set of 42 soil samples from the Montgrí massif experimental plot between surface and 5 cm depth was collected before and after the soil was burnt. A thermal characterization of the soil was carried out. For that a dry out curve was constructed, which presented the relationship between water content and thermal conductivity for both types of soil samples, burnt and non-burnt soil. The results shown changes in the heat pulse transfer, being more conductive the soil before to be burnt (0.378 W•m-1•C-1) than the soil after to be exposed to the fire (0.337 W•m-1•C-1). Indeed, on the whole of moisture scenarios the values of thermal conductivity decreased after soil was burnt. Another experimental concern was based on to observe the soil thermal behaviour when ash collected after fire was incorporated into the burnt soil matrix. In this case, soil thermal and soil hydrodynamic behaviour presented differences according to the type of ash. Soil mixed with fly ash showed higher thermal conductivity than soil mixed with bottom ash. To sum up; the soil thermal conductivity decreased when soil was burnt. On the other hand, soil thermal conductivity shown differences depending on the type of ash incorporated into the matrix. Fly ash transferred the heat pulse better than bottom ash.

Leaching behaviour of coal-ash: a case study.

PubMed

Hajarnavis, M R; Bhide, A D

2003-10-01

Leaching of trace elements from fly ash dumps to subsoil layer due to the rain water results in contamination of ground water. The ground water pollution due to fly ash deposition on land so occurring was assessed by simulating the disposal site conditions using two lysimeter with two different soils. Leachate was collected and analysed daily to help understand the phenomenon of leaching of fly-ash constituents in the environment. The trace metals and physico-chemical parameters of fly ash and soil used were measured before and after the experiment. Results of analysis of soil and fly ash samples were then compared with the results of lysimeter-I and lysimeter-II. The study reveals that metals respond differently at dumping site while reacting with soil and water.

Effect of chitosan coatings enriched with cinnamon oil on proximate composition of rainbow trout fillets

NASA Astrophysics Data System (ADS)

Yıldız, Pınar Oǧuzhan

2017-04-01

The effects of chitosan coating enriched with cinnamon oil on proximate composition of rainbow trout (Oncorhynchus mykiss) during storage at 4°C was investigated. The treatments included the following: C1 (control samples), C2 (chitosan coating) and C3 (chitosan + 1 % [v/w] cinnamon EO added). The control and the coated fish samples were analysed for chemical (moisture, protein, lipid and ash) composition. The mean of moisture, protein, lipid and ash in the control samples (C1) were 70.3%, 20.1%, 2.6% and 1.2%, in coated samples (C2) 69.70%, 24.21%, 2.4% and 2.2% and coated+cinnamon oil samples (C3) 69.70%, 25.05%, 2.5% and 2.2%, respectively. Moisture and lipid contents in control groups were higher than other groups, but protein and ash contents were lower. Significant increases (p<0.05) in protein content were observed between samples, which subsequently decreased the moisture content of these samples.

Unburnt carbon from coal fly ashes as a precursor of activated carbon for nitric oxide removal.

PubMed

Rubio, Begoña; Izquierdo, M Teresa; Mayoral, M Carmen; Bona, M Teresa; Andres, Jose M

2007-05-08

The aim of this work is to evaluate the characteristics of an activated carbon obtained from unburnt carbon in coal fly ashes to be used in the removal of NO. Carbon-rich fraction was obtained by mechanical sieving of fly ashes. The mineral matter was removed by conventional HCl and HF demineralization procedure. Activation was carried out with steam at 900 degrees C in order to develop porosity onto the sample. Characterization of samples was performed by several techniques with a main objective: to follow the mineral matter content, composition and distribution on the samples in order to better understand how to remove it from unburnt carbon in fly ashes. To study the use of this unburnt carbon as a precursor for the preparation of activated carbons for gas cleaning, the NO removal by ammonia using activated carbon as a catalyst at low temperature was performed. Results show a good performance of activated carbon in this reaction that is in relationship with BET surface area.

Characterization of black carbon and organic contaminants in wood ash from different feedstocks and types of furnaces

NASA Astrophysics Data System (ADS)

Merino, Agustin; Rey-Salgueiro, Ledicia; Omil, Beatriz; Martinez-Carballo, Elena; Simal-Gandara, Jesus

2015-04-01

Due to their important concentration of nutrient and charcoal, wood ash from biomass power plants (WA) can be used as a fertilizer and organic amendment in intensively managed soils. Unlike biochar produced in under anoxic conditions, the nature of the organic compounds present in wood ash has been scarcely studied. Due to the incomplete combustion, wood ash may contain a wide range of organic compounds, from charred to highly condensed refractory biomass, which determines the possibilities of WA as an organic amendment. In addition, the possible environmental risk of this practice must be assessed by determining the content of water-soluble and insoluble organic contaminants. due to the incomplete combustion of organic matter, organic pollutants, such as Polycyclic Aromatic Hydrocarbons (PAHs), can be formed and can remain in the combustion residue. Also, the four alkyl benzene volatile organic compounds (benzene, toluene, ethylbenzene, and the ortho, para, and meta xylenes) can be formed, depending on certain conditions during combustion. For this study 15 biomass power stations in Spain were selected. In all of them the feedstock is pine or eucalyptus branches and bark. Nine of them were bottom wood ash generated from wood fires furnaces, obtained from grate-fired or water-tube boilers. Whereas four of them were fly ash, obtained in cyclone separators. The samples were collected following a common procedure to ensure the representiveness of the sampling. Bottom ash samples were fraccionated in three fractions: < 2mm, 2-5 mm and > 5mm. Each fraction was characterized for organic matter and BTEX, styrene and total petroleum hydrocarbons Polycyclic Aromatic Hydrocarbons. For each analyzes, three replicates were analyzed per sample. Mixes wood ash shows higher amounts of charred material than fly ash. The 13 C CPMAS NMR, DSC/TG and FTIR analysis showed the loss of carbohydrates and aliphatic constituents and revealed the formation of aromatic compounds. The atomic H/C ratios, NMR spectra, DSC and FTIR confirmed the presence of condensed structures, specially in the coarse particles. However, the different wood ash showed an important range of properties revealing the presence from charred material to charcoal containing condensed structures (H/C ratios lower than 0.6; aromaticity higher than 80 % and T50-DSC higher than 500 °C). Typical organic pollutants including those water-soluble such as BTEX plus styrene, but also those water-insoluble such as polycyclic aromatic hydrocarbons (PAHs), together with aliphatic hydrocarbons, were examined in the ash. Their contents were related to degree of combustion of the biomass, determined through the content and composition of the organic matter in the wood ash. The sum of BTEX plus styrene varied from non-detected to 30 mg/kg, and the total amounts of PAHs (total PAHs) ranged between non-detected and 422 µg/kg, not exceeding the regulated limits. This research provides basic information for the evaluation of the environmental risk and potential uses of WW incinerator bottom ash The results demonstrate the important variability in the charred material properties of the different power plants and size-particles. The organic compounds contents are also variable, but in all cases were levels of pollutants in all the samples were below the limits for both soil and industrial use (Environmental Protection Agency in the European Union and the USA.

Theoretical Investigation of the Process of Steam-Oxygen Gasification of Coke-Ash Particles in a Fluidized Bed Under Pressure

NASA Astrophysics Data System (ADS)

Rokhman, B. B.

2015-03-01

The problem on the evolution of the state of an ensemble of reacting coke-ash particles in a fluidized-bed gas generator is considered. A kinetic equation for the distribution function of particles within small ranges of carbon concentration variation for the stages of surface and bulk reaction has been constructed and integrated. Boundary conditions ("matching" conditions) at the boundaries between these ranges are formulated. The influence of the granulometric composition of the starting coal, height, porosity, and of the bed temperature on the process of steam-oxygen gasification of coke-ash particles of individual sorts of fuel and of a binary coal mixture has been investigated.

Evaluation of techniques for sampling volatile arsenic on volcanoes

NASA Astrophysics Data System (ADS)

Arndt, Julia; Ilgen, Gunter; Planer-Friedrich, Britta

2017-02-01

Volatile arsenic (As) species, like arsine, mono-, di-, and trimethylarsine (AsH3, MeAsH2, Me2AsH, Me3As) are reported to be released from volcanoes but their determination is difficult because of low concentrations, low boiling points, and high reactivity, especially in the presence of volcanic gases like H2S and SO2. We tested needle trap devices (NTDs), cryotrapping, and Tedlar® bags for quantitative and species-preserving sampling. NTDs did not trap AsH3, MeAsH2, Me2AsH, did not release sorbed Me3As quantitatively, and lead to artifact formation of dimethylchloroarsine, which also questions the reliability of previous reports from solid phase micro extraction fibers using the same sorption materials. Cryotrapping in dry ice was insufficient to trap AsH3 and MeAsH2; Me2AsH and Me3As were only partially retained. Sampling in Tedlar® bags remained the best alternative. Stability of all four arsines was confirmed for dark storage at 5 °C for 19 days in a matrix of dry N2, 11 days in 20% O2, and 19 days in 3800 ppmv CO2 (> 80% recovery for all species), while in the presence of H2S, Me3As recovery was only 67% and in the presence of SO2, Me2AsH and Me3As recovery was 40 and 11%, respectively. Removing interfering reactive gases by a NaOH trap, we sampled natural volcanic emissions at fumaroles of Vulcano and Solfatara (Italy). Detected total arsine concentrations of 0.5-77 ng·m- 3 were 1-2 orders of magnitude higher than the calculated background. Inorganic arsine was the dominant species suggesting that secondary microbially catalyzed methylation is a process of minor importance in the fumarolic gases.

Influence of carbonation under oxy-fuel combustion flue gas on the leachability of heavy metals in MSWI fly ash.

PubMed

Ni, Peng; Xiong, Zhuo; Tian, Chong; Li, Hailong; Zhao, Yongchun; Zhang, Junying; Zheng, Chuguang

2017-09-01

Due to the high cost of pure CO 2 , carbonation of MSWI fly ash has not been fully developed. It is essential to select a kind of reaction gas with rich CO 2 instead of pure CO 2 . The CO 2 uptake and leaching toxicity of heavy metals in three typical types of municipal solid waste incinerator (MSWI) fly ash were investigated with simulated oxy-fuel combustion flue gas under different reaction temperatures, which was compared with both pure CO 2 and simulated air combustion flue gas. The CO 2 uptake under simulated oxy-fuel combustion flue gas were similar to that of pure CO 2 . The leaching concentration of heavy metals in all MSWI fly ash samples, especially in ash from Changzhou, China (CZ), decreased after carbonation. Specifically, the leached Pb concentration of the CZ MSWI fly ash decreased 92% under oxy-fuel combustion flue gas, 95% under pure CO 2 atmosphere and 84% under the air combustion flue gas. After carbonation, the leaching concentration of Pb was below the Chinese legal limit. The leaching concentration of Zn from CZ sample decreased 69% under oxy-fuel combustion flue gas, which of Cu, As, Cr and Hg decreased 25%, 33%, 11% and 21%, respectively. In the other two samples of Xuzhou, China (XZ) and Wuhan, China (WH), the leaching characteristics of heavy metals were similar to the CZ sample. The speciation of heavy metals was largely changed from the exchangeable to carbonated fraction because of the carbonation reaction under simulated oxy-fuel combustion flue gas. After carbonation reaction, most of heavy metals bound in carbonates became more stable and leached less. Therefore, oxy-fuel combustion flue gas could be a low-cost source for carbonation of MSWI fly ash. Copyright © 2017 Elsevier Ltd. All rights reserved.

Dispersal of emerald ash borer at outlier sites: three case studies

Treesearch

Deborah G. McCullough; Nathan W. Siegert; Therese M. Poland; David L. Cappaert; Ivich Fraser; David Williams

2005-01-01

We worked with cooperators from several state and federal agencies in 2003 and 2004 to assess dispersal of emerald ash borer (EAB), Agrilus planipennis Fairmaire, from known source points in three outlier sites. In February 2003, we felled and sampled more than 200 ash trees at an outlier site near Tipton, Michigan, where one generation of adult...

Determination of Total Solids and Ash in Algal Biomass: Laboratory Analytical Procedure (LAP)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Van Wychen, Stefanie; Laurens, Lieve M. L.

2016-01-13

This procedure describes the methods used to determine the amount of moisture or total solids present in a freeze-dried algal biomass sample, as well as the ash content. A traditional convection oven drying procedure is covered for total solids content, and a dry oxidation method at 575 deg. C is covered for ash content.

Stand Parameters of 11- to 15-Year Old Green Ash Plantings

Treesearch

Roger M. Krinard

1989-01-01

Three green ash (Fraxinus pennsylvanica Marsh.) plantings, ages 11, 13, and 15, and a 13-year-old pumpkin ash (F. profunda (Bush) Bush) planting were sampled to determine d.b.h. and height development and survival of free-to-grow trees. On medium-textured (Commerce) and clay-capped (Bowdre and Tunica) soils, the average d.b.h...

Immersion Freezing of Coal Combustion Ash Particles from the Texas Panhandle

NASA Astrophysics Data System (ADS)

Whiteside, C. L.; Tobo, Y.; Mulamba, O.; Brooks, S. D.; Mirrielees, J.; Hiranuma, N.

2017-12-01

Coal combustion aerosol particles contribute to the concentrations of ice-nucleating particles (INPs) in the atmosphere. Especially, immersion freezing can be considered as one of the most important mechanisms for INP formation in supercooled tropospheric clouds that exist at temperatures between 0°C and -38°C. The U.S. contains more than 550 operating coal-burning plants consuming 7.2 x 108 metric tons of coal (in 2016) to generate a total annual electricity of >2 billion MW-h, resulting in the emission of at least 4.9 x 105 metric tons of PM10 (particulate matter smaller than 10 µm in diameter). In Texas alone, 19 combustion plants generate 0.15 billion MW-h electricity and >2.4 x 104 metric tons of PM10. Here we present the immersion freezing behavior of combustion fly ash and bottom ash particles collected in the Texas Panhandle region. Two types of particulate samples, namely <45 µm sieved bottom ash (B_Ash_TX_PH) and <45 µm sieved fly ash (F_Ash_TX_PH), were prepared. Afterwards, their immersion freezing abilities were measured using the Cryogenic Refrigerator Applied to Freezing Test (CRAFT) system covering the heterogeneous freezing temperature down to -30 °C. The results were generated and are reported through two metrics, frozen fraction, ffrozen(T), and ice nucleation active site density per unit mass, nm(T) as a function of temperature. Our preliminary results show that an onset increase in ffrozen(T) for B_Ash_TX_PH (ffrozen) occurred as high as at -15°C, whereas the onset for F_Ash_TX_PH is at -18°C. Secondly, B_Ash_TX_PH exhibited a higher nm(-20 °C) of 105 g-1 than that of F_Ash_TX_PH ( 5 x 103 g-1). On the other hand, previous studies on different combustion ash samples have reported that the opposite trend (i.e., ice nucleation efficiency of fly ash is greater than that of bottom ash; Grawe et al., 2016, ACP; Umo et al., 2015, ACP). We will discuss possible reasons for the observed differences. In addition, the results of complementary physico-chemical analyses via X-ray diffraction technique, Raman microscopy and scanning electron microscopy on both ash types will also be presented to relate the crystallographic and chemical properties to their ice nucleation abilities.

Evaluation of gas-particle partition of dioxins in flue gas I: evaluation of gasification behavior of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans in fly ash by thermal treatment.

PubMed

Yokohama, Naoki; Otaka, Hiroaki; Minato, Ichiro; Nakata, Munetaka

2008-05-01

The gasification behavior of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) in fly ash by thermal treatment has been investigated to estimate gas-particle partition in flue gas. The results obtained in thermal experiments under various conditions showed that gasification of PCDD/Fs depends on air flow rate and treatment weight of fly ash as well as treatment temperature. On the other hand, the results obtained in the thermal experiments using dioxin-free fly ash revealed that during thermal treatment, the de novo synthesis, gasification, and decomposition of PCDFs proceeded at different rates. This difference in the reaction rates indicates that thermal treatment time is also a factor in determining the gas-particle partition of PCDD/Fs in fly ash. Therefore, reasonable thermal treatment conditions were established and applied to three ash samples. For all samples, PCDD/Fs started to gasify at 350 degrees C treatment, whereas 53-98% of PCDD/F homologs gasified at 400 degrees C treatment, implying that gaseous PCDD/Fs are dominant in flue gas at temperatures in the range 350-400 degrees C regardless of particle concentration.

The use of PFBC ashes to ameliorate acid conditions: An equilibrium and greenhouse study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brown, T.H.; Bland, A.E.

1999-07-01

Pilot-scale development at the Foster Wheeler Energia Oy 10 MW{sub th} circulating PFBC at Karhula, Finland, has demonstrated the advantages of pressurized fluidized bed combustion (PFBC) technology. Commercial scale deployment of the technology at the Lakeland Utilities MacIntosh Unit No. 4 has been proposed. Development of uses for the ashes from PFBC systems is being actively pursued as part of commercial demonstration of PFBC technologies. Western Research Institute (WRI), in conjunction with the US Department of Energy (DOE), Federal Energy Technology Center (FETC), Foster Wheeler Energy International, Inc., and the Electric Power Research Institute (EPRI), conducted a laboratory scale investigationmore » of the technical feasibility of PFBC ash as an amendment for acidic soils and spoils encountered in agricultural and reclamation applications. Ashes were collected from the Foster Wheeler Energia Oy pilot circulating PFBC tests in Karhula, Finland, operating on (1) low-sulfur subbituminous and (2) high-sulfur bituminous coals. The results of the technical feasibility testing indicated the following: (1) PFBC fly ash (Karhula-low S fly ash) and ag-lime (CaCO{sub 3}) were used as amendments attempting to ameliorate acid spoil conditions. These materials were found to be effective acid mine spoil amendments. (2) The greenhouse study demonstrated that PFBC ash and/or bed ash amended spoils resulted in similar seed germination numbers as compared to the ag-lime amended spoils. (3) The greenhouse study also demonstrated that PFBC fly ash and/or bed ash amended spoils resulted in comparable plant productivity to the ag-lime amended spoils. In fact, all amendments resulted in statistically the same levels of plant production for each plant species.« less

The Hazard of Volcanic Ash Ingestion

NASA Technical Reports Server (NTRS)

Lekki, John

2017-01-01

A research team of U.S. Government agencies and engine manufacturers conducted an experiment to test volcanic-ash ingestion by a NASA owned engine in the same family as the PW 2000 that was donated by the U.S. Air Force. The experiment, called Vehicle Integrated Propulsions Research (VIPR) test, was conducted under the auspices of NASAs Convergent Aeronautics Solutions (CAS) Program and took place in summer of 2015 at Edwards AFB in California as an on-ground, on-wing test. The primary objectives of the volcanic ash test were to determine the effect on the engine of several hours of exposure to low to moderate ash concentrations and to evaluate the capability of engine health management technologies for detecting these effects. The target concentrations of volcanic ash tested were at 1 and 10 mgm3. A natural volcanic ash was used that is representative of distal ash clouds many 100s to 1000 km from a volcanic source. The glassy ash particles were expected to soften and become less viscous when exposed to the high temperatures of the combustion chamber, then stick to the nozzle guide vanes of the high-pressure turbine and this was observed. Numerous observations and measurements of the engines performance and degradation were made during the course of the experiment, including borescope inspections after each test run. The engine has been disassembled so that detailed inspections of the engine effects have been made. A summary of the test methodology and execution will be made along with results from the test. While not intended to be sufficient for rigorous certification of engine performance when ash is ingested, the experiment should provide useful information to aircraft manufacturers, airline operators, and military and civil regulators in their efforts to evaluate the range of risks that ash hazards pose to aviation.

Volcanic ash supports a diverse bacterial community in a marine mesocosm.

PubMed

Witt, V; Ayris, P M; Damby, D E; Cimarelli, C; Kueppers, U; Dingwell, D B; Wörheide, G

2017-05-01

Shallow-water coral reef ecosystems, particularly those already impaired by anthropogenic pressures, may be highly sensitive to disturbances from natural catastrophic events, such as volcanic eruptions. Explosive volcanic eruptions expel large quantities of silicate ash particles into the atmosphere, which can disperse across millions of square kilometres and deposit into coral reef ecosystems. Following heavy ash deposition, mass mortality of reef biota is expected, but little is known about the recovery of post-burial reef ecosystems. Reef regeneration depends partly upon the capacity of the ash deposit to be colonised by waterborne bacterial communities and may be influenced to an unknown extent by the physiochemical properties of the ash substrate itself. To determine the potential for volcanic ash to support pioneer bacterial colonisation, we exposed five well-characterised volcanic and coral reef substrates to a marine aquarium under low light conditions for 3 months: volcanic ash, synthetic volcanic glass, carbonate reef sand, calcite sand and quartz sand. Multivariate statistical analysis of Automated Ribosomal Intergenic Spacer Analysis (ARISA) fingerprinting data demonstrates clear segregation of volcanic substrates from the quartz and coral reef substrates over 3 months of bacterial colonisation. Overall bacterial diversity showed shared and substrate-specific bacterial communities; however, the volcanic ash substrate supported the most diverse bacterial community. These data suggest a significant influence of substrate properties (composition, granulometry and colour) on bacterial settlement. Our findings provide first insights into physicochemical controls on pioneer bacterial colonisation of volcanic ash and highlight the potential for volcanic ash deposits to support bacterial diversity in the aftermath of reef burial, on timescales that could permit cascading effects on larval settlement. © 2017 The Authors. Geobiology Published by John Wiley & Sons Ltd.

Preparation of Cu and Fly Ash Composite by Powder Metallurgy Technique

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chew, P. Y.; Lim, P. S.; Ng, M. C.

2011-03-30

Cu and Fly Ash (FA) mixtures with different weight percentages were prepared. Pellets of the mixture powder were produced with the dimension of 17.7 mm in diameter and 10-15 mm in height. These different composites were compacted at a constant pressure of 280 MPa. One of the selected weight percentages was then compacted to form into pellet and sintered at different temperatures which were at 900, 950 and 1000 deg. C respectively for 2 hours. Density of green pellet was measured before sintered in furnace. After sintering, all the pellets with different temperatures were re-weighed and sintered density were calculated.more » The densification of the green and sintered pellets was required to be measured as one of the parameter in selection of the best material properties. Porosity of the pellet shall not be ignored in order to analyze the close-packed particles stacking in the pellet. SEM micrograph had been captured to observe the presence of pores and agglomeration of particles in the sample produced.« less

Multi-Partner Experiment to Test Volcanic-Ash Ingestion by a Jet Engine

NASA Technical Reports Server (NTRS)

Lekki, John; Lyall, Eric; Guffanti, Marianne; Fisher, John; Erlund, Beth; Clarkson, Rory; van de Wall, Allan

2013-01-01

A research team of U.S. Government agencies and engine manufacturers are designing an experiment to test volcanic-ash ingestion by a NASA owned F117 engine that was donated by the U.S. Air Force. The experiment is being conducted under the auspices of NASA s Vehicle Integrated Propulsion Research (VIPR) Program and will take place in early 2014 at Edwards AFB in California as an on-ground, on-wing test. The primary objectives are to determine the effect on the engine of several hours of exposure to low to moderate ash concentrations, currently proposed at 1 and 10 mg/m3 and to evaluate the capability of engine health management technologies for detecting these effects. A natural volcanic ash will be used that is representative of distal ash clouds many 100's to approximately 1000 km from a volcanic source i.e., the ash should be composed of fresh glassy particles a few tens of microns in size. The glassy ash particles are expected to soften and become less viscous when exposed to the high temperatures of the combustion chamber, then stick to the nozzle guide vanes of the high-pressure turbine. Numerous observations and measurements of the engine s performance and degradation will be made during the course of the experiment, including borescope and tear-down inspections. While not intended to be sufficient for rigorous certification of engine performance when ash is ingested, the experiment should provide useful information to aircraft manufacturers, airline operators, and military and civil regulators in their efforts to evaluate the range of risks that ash hazards pose to aviation.

Grain shape of basaltic ash populations: implications for fragmentation

NASA Astrophysics Data System (ADS)

Schmith, Johanne; Höskuldsson, Ármann; Holm, Paul Martin

2017-02-01

Here, we introduce a new quantitative method to produce grain shape data of bulk samples of volcanic ash, and we correlate the bulk average grain shape with magma fragmentation mechanisms. The method is based on automatic shape analysis of 2D projection ash grains in the size range 125-63 μm. Loose bulk samples from the deposits of six different basaltic eruptions were analyzed, and 20,000 shape measurements for each were obtained within 45 min using the Particle Insight™ dynamic shape analyzer (PIdsa). We used principal component analysis on a reference grain dataset to show that circularity, rectangularity, form factor, and elongation best discriminate between the grain shapes when combined. The grain population data show that the studied eruptive environments produce nearly the same range of grain shapes, although to different extents. Our new shape index (the regularity index (RI)) places an eruption on a spectrum between phreatomagmatic and dry magmatic fragmentation. Almost vesicle-free Surtseyan ash has an RI of 0.207 ± 0.002 (2σ), whereas vesiculated Hawaiian ash has an RI of 0.134 ± 0.001 (2σ). These two samples define the end-member RI, while two subglacial, one lacustrine, and another submarine ash sample show intermediate RIs of 0.168 ± 0.002 (2σ), 0.175 ± 0.002 (2σ), 0.187 ± 0.002 (2σ), and 0.191 ± 0.002 (2σ), respectively. The systematic change in RI between wet and dry eruptions suggests that the RI can be used to assess the relative roles of magmatic vs. phreatomagmatic fragmentation. We infer that both magmatic and phreatomagmatic fragmentation processes played a role in the subglacial eruptions.

Detectability of the emerald ash borer (Coleoptera: Buprestidae) in asymptomatic urban trees by using branch samples.

PubMed

Ryall, Krista L; Fidgen, Jeffrey G; Turgeon, Jean J

2011-06-01

The emerald ash borer, Agrilus planipennis Fairmaire, is an exotic invasive insect causing extensive mortality to ash trees, Fraxinus spp., in Canada and the United States. Detection of incipient populations of this pest is difficult because of its cryptic life stages and a multiyear time lag between initial attack and the appearance of signs or symptoms of infestation. We sampled branches from open-grown urban ash trees to develop a sample unit suitable for detecting low density A. planipennis infestation before any signs or symptoms are evident. The sample unit that maximized detection rates consisted of one 50-cm-long piece from the base of a branch ≥6 cm diameter in the midcrown. The optimal sample size was two such branches per tree. This sampling method detected ≈75% of asymptomatic trees known to be infested by using more intensive sampling and ≈3 times more trees than sampling one-fourth of the circumference of the trunk at breast height. The method is less conspicuous and esthetically damaging to a tree than the removal of bark from the main stem or the use of trap trees, and could be incorporated into routine sanitation or maintenance of city-owned trees to identify and delineate infested areas. This research indicates that branch sampling greatly reduces false negatives associated with visual surveys and window sampling at breast height. Detection of A. planipennis-infested asymptomatic trees through branch sampling in urban centers would provide landowners and urban foresters with more time to develop and implement management tactics.

Utilization of Yatagan Power Plant Fly Ash in Production of Building Bricks

NASA Astrophysics Data System (ADS)

Önel, Öznur; Tanriverdi, Mehmet; Cicek, Tayfun

2017-12-01

Fly ash is a by-product of coal combustion, which accumulates in large quantities near the coal-fired power plants as waste material. Fly ash causes serious operational and environmental problems. In this study, fly ash from Yatağgan thermal power plant was used to produce light-weight building bricks. The study aimed to reduce the problems related to fly ash by creating a new area for their use. The optimum process parameters were determined for the production of real size bricks to be used in construction industry. The commercial size bricks (200 × 200 × 90-110 mm) were manufactured using pilot size equipment. Mechanical properties, thermal conductivity coefficients, freezing and thawing strengths, water absorption rates, and unit volume weights of the bricks were determined. Etringite (Ca6Al2 (SO4)3 (OH)12 25(H2O)) and Calcium Silicate Hydrate (2CaO.SiO2.4H2O) were identified as the binding phases in the real size brick samples after 2 days of pre-curing and 28 days curing at 50° C and 95% relative moisture. The water absorption rate was found to be 27.7 % in terms of mass. The mechanical and bending strength of the brick samples with unit volume weight of 1.29 g.cm-3 were determined as 6.75 MPa and 1,56 MPa respectively. The thermal conductivity of the fly ash bricks was measured in average as 0,340 W m-1 K-1. The fly ash sample produced was subjected to toxic leaching tests (Toxic Property Leaching Procedure (EPA-TCLP 1311), Single-step BATCH Test and Method-A Disintegration Procedure (ASTM)). The results of these tests suggested that the materials could be classified as non-hazardous wastes / materials.

Potential use of fly ash to soil treatment in the Morava region

NASA Astrophysics Data System (ADS)

Bulíková, Lucia; Kresta, František; Rochovanský, Martin

2017-09-01

Soil treatment by binders is a standard technology and leads to optimal utilization of excavated soils in road constructions. Soil treatment is controlled in the Czech Republic by EN 14227-15 and Technical Requirement TP 94. Soil treatment using fly ash has not been performed in the Czech Republic, although there is a sufficient normative base. Fly ash produced by burning of hard coal in the Moravian region was tested as a potential binder. Fly ash samples were mixed with loess loams (CI). Tested siliceous fly ash of class F (ASTM C618) did not showed hydraulic properties but it showed positive effect on reducing maximum dry density of mixtures, increasing the IBI value (Immediate bearing index) and decreasing tendency to volume changes when the amount of fly ash was increased. The results of laboratory tests demonstrate the possibility of using fly ashes as a binder for soil treatment.

Evaluation of the mechanical properties of class-F fly ash.

PubMed

Kim, Bumjoo; Prezzi, Monica

2008-01-01

Coal-burning power plants in the United States (US) generate more than 70 million tons of fly ash as a by-product annually. Recycling large volumes of fly ash in geotechnical applications may offer an attractive alternative to the disposal problem as most of it is currently dumped in ponds or landfills. Class-F fly ash, resulting from burning of bituminous or anthracite coals, is the most common type of fly ash in the US. In the present study, the mechanical characteristics (compaction response, compressibility, and shear strength) of class-F fly ash were investigated by performing various laboratory tests (compaction test, one-dimensional compression test, direct shear test and consolidated-drained triaxial compression test) on fly ash samples collected from three power plants in the state of Indiana (US). Test results have shown that despite some morphological differences, class-F fly ash exhibits mechanical properties that are, in general, comparable to those observed in natural sandy soils.

Potential for thermochemical conversion of biomass residues from the integrated sugar-ethanol process - Fate of ash and ash-forming elements.

PubMed

Dirbeba, Meheretu Jaleta; Brink, Anders; DeMartini, Nikolai; Zevenhoven, Maria; Hupa, Mikko

2017-06-01

In this work, potential for thermochemical conversion of biomass residues from an integrated sugar-ethanol process and the fate of ash and ash-forming elements in the process are presented. Ash, ash-forming elements, and energy flows in the process were determined using mass balances and analyses of eight different biomass samples for ash contents, elemental compositions, and heating values. The results show that the ash content increases from the sugarcane to the final residue, vinasse. The cane straw, which is left in the field, contains one-third of the energy and 25% of the K and Cl while the vinasse contains 2% of the energy and 40% of the K and Cl in the cane. K and Cl in biomass fuels cause corrosion and fouling problems in boilers and gasifiers. Over 85% of these elements in the straw are water soluble indicating that water leaching would improve it for utilization in thermochemical conversion. Copyright © 2017 Elsevier Ltd. All rights reserved.

Thermal Stability of Volcanic Ash versus Turbine Ingestion Test Sands: an Experimental Investigation

NASA Astrophysics Data System (ADS)

Cimarelli, C.; Kueppers, U.; Hess, K.; Dingwell, D. B.; Rickerby, D. S.; Madden, P. C.

2010-12-01

Volcanic eruptions are an inevitable natural threat. The range of eruptive styles is large and short term fluctuations of explosivity or vent position pose a large risk not necessarily confined to the immediate vicinity of a volcano. Explosive eruptions rather may also affect aviation, infrastructure and climate, regionally as well as globally. The recent eruption of Eyjafjallajökull drastically brought into common awareness how volcanic activity can affect every day’s life and disrupt air traffic. The presence of solid particles in the air ingested in jet turbines may cause harm as it 1) may deposit on surfaces upon being heated up and 2) abrade upon impact. Particles suspended in the atmosphere may have different origins, including volcanic ash, aeolian sand, or incineration residues, each of them having different chemical and physical characteristics. To date, aircraft turbine operability has been investigated - amongst other tests - through the ingestion of sands whose grains have different mineralogical nature. Due to high cooling rates, volcanic ash is usually made up of glass, i.e. an amorphous phase lacking crystallographic order. Glass and crystal behave very differently to heating up. Glass will soften - and accordingly change shape or stick to surfaces - at temperatures as low as 700 °C, depending on the chemical composition. Crystals however need higher melting temperatures; quartz for example has a melting point at around 1700 °C. Accordingly, the effect of ash on the operational reliability of aircraft turbines may not be judged solely based on knowledge commonly derived from mineral sand ingestion testing. In order to investigate the behaviour upon heating, we performed a series of experiments at ten temperature steps between 700 and 1600 °C. We used three different samples: 1) Ash from the explosive phase of Eyjafjallajökull; 2) MIL E-5007C test sand (MTS), and 3) Arizona Test Dust (ATD). MTS and ATD are commonly used for aircraft turbine testing. Experiments have been performed on two different grain sizes, < 63 and 90

Evaluation of Pollutant Leaching Potential of Coal Ashes for Recycling

NASA Astrophysics Data System (ADS)

Park, D.; Woo, N. C.; Kim, H.; Yoon, H.; Chung, D.

2011-12-01

By 2009, coal ashes produced from coal-based power plants in Korea have been reused as cement supplement materials; however, the rest is mostly disposed in landfills inside the plant properties. Continuous production of coal ashes and limited landfill sites require more recycles of coal ashes as base materials, specifically in constructions of roads and of huge industrial complex. Previous researches showed that coal ashes could contain various metals such as arsenic(As), chromium(Cr), lead(Pb), nickel(Ni), selenium(Se), etc. In this study, we collected four types of bottom ashes and two of fly ashes from four coal-based power plants. These ash samples were tested with distilled water through the column leaching process in oxidized conditions. The column test results were compared with those of total digestion, sequential extraction processes and TCLP. Concentrations of metals in outflows from columns are generally greater in fly ashes than in bottom ashes, specifically for As, Se, B, Sr and SO4. Only one fly ash (J2-F) shows high concentrations of arsenic and selenium in leachate. Sequential extraction results indicate that these metals are in readily soluble forms, such as adsorbed, carbonated, and reducible forms. Results of TCLP analysis indicate no potential contaminants leached from the ashes. In conclusion, recycling of coal combustion ashes could be encouraged with proper tests such as sequential and leaching experiments.

Naturally occurring radioactive materials (NORMs) generated from lignite-fired power plants in Kosovo.

PubMed

Hasani, F; Shala, F; Xhixha, G; Xhixha, M K; Hodolli, G; Kadiri, S; Bylyku, E; Cfarku, F

2014-12-01

The energy production in Kosovo depends primarily on lignite-fired power plants. During coal combustion, huge amounts of fly ash and bottom ash are generated, which may result in enriched natural radionuclides; therefore, these radionuclides need to be investigated to identify the possible processes that may lead to the radiological exposure of workers and the local population. Lignite samples and NORMs of fly ash and bottom ash generated in lignite-fired power plants in Kosovo are analyzed using a gamma-ray spectrometry method for the activity concentration of natural radionuclides. The average activity concentrations of (40)K, (226)Ra and (232)Th in lignite are found to be 36 ± 8 Bq kg(-1), 9 ± 1 Bq kg(-1) and 9 ± 3 Bq kg(-1), respectively. Indications on the occurrence and geochemical behavior of uranium in the lignite matrix are suggested. The activity concentrations of natural radionuclides in fly ash and bottom ash samples are found to be concentrated from 3 to 5 times that of the feeding lignite. The external gamma-ray absorbed dose rate and the activity concentration index are calculated to assess the radiological hazard arising from ash disposal and recycling in the cement industry. Copyright © 2014 Elsevier Ltd. All rights reserved.

Investigation on Leaching Behaviour of Fly Ash and Bottom Ash Replacement in Self-Compacting Concrete

NASA Astrophysics Data System (ADS)

Kadir, Aeslina Abdul; Ikhmal Haqeem Hassan, Mohd; Bakri Abdullah, Mohd Mustafa Al

2016-06-01

Fly ash and bottom ash are some of the waste generated by coal-fired power plants, which contains large quantities of toxic and heavy metals. In recent years, many researchers have been interested in studying on the properties of self-compacting concrete incorporated with fly ash and bottom ash but there was very limited research from the combination of fly ash and bottom ash towards the environmental needs. Therefore, this research was focused on investigating the leachability of heavy metals of SCC incorporated with fly ash and bottom ash by using Toxicity Characteristic Leaching Procedure, Synthetic Precipitation Leaching Procedure and Static Leaching Test. The samples obtained from the coal-fired power plant located at Peninsula, Malaysia. In this study, the potential heavy metals leached out from SCC that is produced with fly ash as a replacement for Ordinary Portland Cement and bottom ash as a substitute for sand with the ratios from 10% to 30% respectively were designated and cast. There are eight heavy metals of concern such as As, Cr, Pb, Zn, Cu, Ni, Mn and Fe. The results indicated that most of the heavy metals leached below the permissible limits from the United States Environmental Protection Agency and World Health Organization limit for drinking water. As a conclusion, the minimum leaching of the heavy metals from the incorporation of fly ash and bottom ash in self-compacting concrete was found in 20% of fly ash and 20% of bottom ash replacement. The results also indicate that this incorporation could minimize the potential of environmental problems.

Assessment of soil contamination by (210)Po and (210)Pb around heavy oil and natural gas fired power plants.

PubMed

Al-Masri, M S; Haddad, Kh; Doubal, A W; Awad, I; Al-Khatib, Y

2014-06-01

Soil contamination by (210)Pb and (210)Po around heavy oil and natural gas power plants has been investigated; fly and bottom ash containing enhanced levels of (210)Pb and (210)Po were found to be the main source of surface soil contamination. The results showed that (210)Pb and (210)Po in fly-ash (economizer, superheater) is highly enriched with (210)Pb and (210)Po, while bottom-ash (boiler) is depleted. The highest (210)Pb and (210)Po activity concentrations were found to be in economizer ash, whereas the lowest activity concentration was in the recirculator ash. On the other hand, (210)Pb and (210)Po activity concentrations in soil samples were found to be higher inside the plant site area than those samples collected from surrounding areas. The highest levels were found in the vicinity of Mhardeh and Tishreen power plants; both plants are operated by heavy oil and natural fuels, while the lowest values were found to be in those samples collected from Nasrieh power plant, which is only operated by one type of fuel, viz. natural gas. In addition, the levels of surface soil contamination have decreased as the distance from the power plant site center increased. Copyright © 2014 Elsevier Ltd. All rights reserved.

Effect of combustion temperature on the emission of trace elements under O2/CO2 atmosphere during coal combustion

NASA Astrophysics Data System (ADS)

Qu, Chengrui; Zhang, Mo; Mann, Michael. D.

2018-03-01

The effect of combustion temperature on the emission of trace elementswas studied under O2/CO2 atmosphere during coal combustion in a laboratory scale fluidized bed combustor. The elemental composition of fine fly ash particles collected with a low pressure impactor(LPI)was quantified by X-Ray F1uorescence Spectrometer (XRF). The elemental composition of coal and bottom ash was quantified byinductively coupled plasma-atomic emission spectroscopy (ICP-AES). The results indicate that the contents of Mn, Zn, Cd and Cr in the fly ash increase with the rise of combustion temperature. It is found that the enrichment of Zn and Cd is greater in the submicrometer particles than the supermicrometer particles, but Mn and Cr do not enrich in the submicrometer particles. Mn, Zn, Cd and Cr display one peak around 0.1 μm. The relative enrichment factor (Rij) of four elements is in the order of Zn, Cd, Mn and Cr. Zn and Cd are mostly retained in fly ashwhileMn and Cr are retained in both the fly ash and bottom ash.

Environmentally critical elements in channel and cleaned samples of Illinois coals

USGS Publications Warehouse

Demir, I.; Ruch, R.R.; Damberger, H.H.; Harvey, R.D.; Steele, J.D.; Ho, K.K.

1998-01-01

Sixteen trace and minor elements that occur in coal are listed among 189 substances identified as 'hazardous air pollutants' (HAPs) in the US Clean Air Act Amendments of 1990. We investigated the occurrence and cleanability of the 16 HAPs in Illinois coals, as a contribution to the discussion about the potential effect of pending environmental regulations on the future use of these coals in power generation. The average ash content of the samples of conventionally cleaned as-shipped coals is about 20% lower than that of standard channel samples. Conventional cleaning reduces the average concentrations of As, Cd, Co, Hg, Mn, Ni, Pb, Sb and Th in the as-shipped coals by more than 20% relative to channel samples. Thus, basing assessments of health risks from emissions of HAPs during coal combustion on channel samples without appropriate adjustment would overestimate the risk. Additional cleaning by froth-flotation reduces the ash content of finely-ground as-shipped coals by as much as 76% at an 80% combustibles recovery. Although the average froth-flotation cleanability for the majority of HAPs is less than that for ash, the cleanabilities in some individual cases approaches, or even exceeds, the cleanability for ash, depending on the modes of occurrences of the elements. ?? 1997 Elsevier Science Ltd.

Size fractionation of waste-to-energy boiler ash enables separation of a coarse fraction with low dioxin concentrations.

PubMed

Weidemann, E; Allegrini, E; Fruergaard Astrup, T; Hulgaard, T; Riber, C; Jansson, S

2016-03-01

Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/F) formed in modern Waste-to-Energy plants are primarily found in the generated ashes and air pollution control residues, which are usually disposed of as hazardous waste. The objective of this study was to explore the occurrence of PCDD/F in different grain size fractions in the boiler ash, i.e. ash originating from the convection pass of the boiler. If a correlation between particle size and dioxin concentrations could be found, size fractionation of the ashes could reduce the total amount of hazardous waste. Boiler ash samples from ten sections of a boiler's convective part were collected over three sampling days, sieved into three different size fractions - <0.09 mm, 0.09-0.355 mm, and >0.355 mm - and analysed for PCDD/F. The coarse fraction (>0.355 mm) in the first sections of the horizontal convection pass appeared to be of low toxicity with respect to dioxin content. While the total mass of the coarse fraction in this boiler was relatively small, sieving could reduce the amount of ash containing toxic PCDD/F by around 0.5 kg per tonne input waste or around 15% of the collected boiler ash from the convection pass. The mid-size fraction in this study covered a wide size range (0.09-0.355 mm) and possibly a low toxicity fraction could be identified by splitting this fraction into more narrow size ranges. The ashes exhibited uniform PCDD/F homologue patterns which suggests a stable and continuous generation of PCDD/F. Copyright © 2016 Elsevier Ltd. All rights reserved.

Effects of trap type, placement and ash distribution on emerald ash borer captures in a low density site.

PubMed

McCullough, Deborah G; Siegert, Nathan W; Poland, Therese M; Pierce, Steven J; Ahn, Su Zie

2011-10-01

Effective methods for early detection of newly established, low density emerald ash borer (Agrilus planipennis Fairmaire) infestations are critically needed in North America. We assessed adult A. planipennis captures on four types of traps in a 16-ha site in central Michigan. The site was divided into 16 blocks, each comprised of four 50- by 50-m cells. Green ash trees (Fraxinus pennsylvanica Marshall) were inventoried by diameter class and ash phloem area was estimated for each cell. One trap type was randomly assigned to each cell in each block. Because initial sampling showed that A. planipennis density was extremely low, infested ash logs were introduced into the center of the site. In total, 87 beetles were captured during the summer. Purple double-decker traps baited with a blend of ash leaf volatiles, Manuka oil, and ethanol captured 65% of all A. planipennis beetles. Similarly baited, green double-decker traps captured 18% of the beetles, whereas sticky bands on girdled trees captured 11% of the beetles. Purple traps baited with Manuka oil and suspended in the canopies of live ash trees captured only 5% of the beetles. At least one beetle was captured on 81% of the purple double-decker traps, 56% of the green double-decker traps, 42% of sticky bands, and 25% of the canopy traps. Abundance of ash phloem near traps had no effect on captures and trap location and sun exposure had only weak effects on captures. Twelve girdled and 29 nongirdled trees were felled and sampled in winter. Current-year larvae were present in 100% of the girdled trees and 72% of the nongirdled trees, but larval density was five times higher on girdled than nongirdled trees.

Analyses of known and new types of polyhalogenated aromatic substances in oven ash from recycled aluminium production.

PubMed

Sinkkonen, Seija; Lahtiperä, Mirja; Vattulainen, Antero; Takhistov, Viatcheslav V; Viktorovskii, Igor V; Utsal, Viktor A; Paasivirta, Jaakko

2003-07-01

Persistent aromatic bromine, chlorine and mixed chlorine-bromine compounds were analysed from recycled aluminium smelter (ALS) ashes to explore the impact of brominated flame retardants (BFR) on their formation. Polybrominated diphenyl ethers (PBDE) were the most abundant original BFRs found. Induction furnace ash contained tetra- to octa-BDEs about 2000ng g(-1) in similar congener ratios as the original scrap, but contents of nona- and deca-BDEs were only 25 and 5ng g(-1) indicating their significant degradation in ALS process. In the most non-polar fraction, PCB levels and profiles were similar as earlier ALS ash samples in 1990s. The highest PCB level measured was that of deca-CB (450ng g(-1)) in the induction furnace ash. In this fraction, bromo compounds were non-detectable (<5ng g(-1)). Fraction of the most polar compounds (from reversed toluene elution of carbon column ("dioxin fraction") contained PCDDs, PCDFs and polychlorinated dibenzothiophenes (PCDTs) in similar amounts and congener profiles as earlier investigated ALS ash samples. Bromine-containing dioxin and furan congeners were not detected. From individual PCDDs and PCDFs, octaCDF was the most abundant (205ng g(-1)) in induction furnace ash. In this fraction, the original BFR, tetrabromo-bisphenol-A, was identified. Its level in the induction furnace ash was approximated to be 388ng g(-1). In addition, 12 novel brominated and chlorinated compounds were found as abundant (8-441ng g(-1) in the induction furnace ash) contaminants from the fraction. Four of them were bisphenol derivatives, five biphenylols, then octachlorofluorenone (OCFL) and octachlorobiphenylene (OCBP). Their structures or structure types were deduced from total low-resolution EI mass spectra by theoretical isotope cluster simulation (ICLU) and through known fragmentation rules.

Interspecific comparison of constitutive ash phloem phenolic chemistry reveals compounds unique to manchurian ash, a species resistant to emerald ash borer.

PubMed

Whitehill, Justin G A; Opiyo, Stephen O; Koch, Jennifer L; Herms, Daniel A; Cipollini, Donald F; Bonello, Pierluigi

2012-05-01

The emerald ash borer (Agrilus planipennis, EAB) is an invasive wood-borer indigenous to Asia and is responsible for widespread ash (Fraxinus spp.) mortality in the U.S. and Canada. Resistance and susceptibility to EAB varies among Fraxinus spp., which is a result of their co-evolutionary history with the pest. We characterized constitutive phenolic profiles and lignin levels in the phloem of green, white, black, blue, European, and Manchurian ash. Phloem was sampled twice during the growing season, coinciding with phenology of early and late instar EAB. We identified 66 metabolites that displayed a pattern of variation, which corresponded strongly with phylogeny. Previously identified lignans and lignan derivatives were confirmed to be unique to Manchurian ash, and may contribute to its high level of resistance to EAB. Other compounds that had been considered unique to Manchurian ash, including hydroxycoumarins and the phenylethanoids calceolarioside A and B, were detected in closely related, but susceptible species, and thus are unlikely to contribute to EAB resistance of Manchurian ash. The distinct phenolic profile of blue ash may contribute to its relatively high resistance to EAB.

The contribution of air-fluidization to the mobility of rapid flowslides involving fine particles

NASA Astrophysics Data System (ADS)

Stilmant, Frédéric; Dewals, Benjamin; Archambeau, Pierre; Erpicum, Sébastien; Pirotton, Michel

2016-04-01

Air-fluidization can be the origin of the long runout of gravitational flows involving fine particles such as ash. An excessive air pore pressure dramatically reduces the friction angle of the material as long as this pressure has not been dissipated, which occurs during the flow. This phenomenon can be modelled thanks to the 2D depth-averaged equations of mass and momentum conservation and an additional transport equation for basal pore pressure evolution (Iverson and Denlinger, 2001). In this contribution, we discuss the application of this model in relation to recent experimental results on air-fluidized flows by Roche et al. (2008) and Roche (2012). The experimental results were used to set a priori the value of the diffusion coefficient in the model, taking into account the difference of scale between the experiments and real-world applications. We also compare the model predictions against detailed observations of a well-documented historical event, the collapse of a fly-ash heap in Belgium (Stilmant et al., 2015). In particular, we analyse the influence of the different components of the model on the results (pore pressure dissipation vs. pore pressure generation). The diffusion coefficient which characterizes the dissipation of air pore pressure is found sufficiently low for maintaining a fluidized flow over hundreds of meters. The study concludes that an air-fluidization theory is consistent with the field observations. These findings are particularly interesting as they seem not in line with the mainstream acceptation in landslide modelling that air generally plays a secondary role (e.g., Legros, 2002). References Iverson, R.M., Denlinger, R.P., 2001. Flow of variably fluidized granular masses across three-dimensional terrain - 1. Coulomb mixture theory. J. Geophys. Res. 106, 537 552. Legros, F., 2002. The mobility of long-runout landslides. Eng. Geol. 63, 301-331. Roche, O., 2012. Depositional processes and gas pore pressure in pyroclastic flows: an experimental perspective. Bull. Volcanol. 74, 1807-1820. Roche, O., Montserrat, S., Niño, Y., Tamburrino, A., 2008. Experimental observations of water-like behavior of initially fluidized, dam break granular flows and their relevance for the propagation of ash-rich pyroclastic flows. J. Geophys. Res. 113, B12203. Stilmant, F., Pirotton, M., Archambeau, P., Erpicum, S., & Dewals, B. (2015). Can the collapse of a fly ash heap develop into an air-fluidized flow? - Reanalysis of the Jupille accident (1961). Geomorphology, 228, 746-755.

Leachability of uranium and other elements from freshly erupted volcanic ash

USGS Publications Warehouse

Smith, D.B.; Zielinski, R.A.; Rose, W.I.

1982-01-01

A study of leaching of freshly erupted basaltic and dacitic air-fall ash and bomb fragment samples, unaffected by rain, shows that glass dissolution is the dominant process by which uranium is initially mobilized from air-fall volcanic ash. Si, Li, and V are also preferentially mobilized by glass dissolution. Gaseous transfer followed by fixation of soluble uranium species on volcanic-ash particles is not an important process affecting uranium mobility. Gaseous transfer, however, may be important in forming water-soluble phases, adsorbed to ash surfaces, enriched in the economically and environmentally important elements Zn, Cu, Cd, Pb, B, F, and Ba. Quick removal of these adsorbed elements by the first exposure of freshly erupted ash to rain and surface water may pose short-term hazards to certain forms of aquatic and terrestrial life. Such rapid release of material may also represent the first step in transportation of economically important elements to environments favorable for precipitation into deposits of commercial interest. Ash samples collected from the active Guatemalan volcanoes Fuego and Pacaya (high-Al basalts) and Santiaguito (hornblende-hypersthene dacite); bomb fragments from Augustine volcano (andesite-dacite), Alaska, and Heimaey (basalt), Vestmann Islands, Iceland; and fragments of "rhyolitic" pumice from various historic eruptions were subjected to three successive leaches with a constant water-to-ash weight ratio of 4:1. The volcanic material was successively leached by: (1) distilled-deionized water (pH = 5.0-5.5) at room temperature for 24 h, which removes water-soluble gases and salts adsorbed on ash surfaces during eruption; (2) dilute HCl solution (pH = 3.5-4.0) at room temperature for 24 h, which continues the attack initiated by the water and also attacks acid-soluble sulfides and oxides; (3) a solution 0.05 M in both Na,CO, and NaHCO, (pH = 9.9) at 80°C for one week, which preferentially dissolves volcanic glass. The first two leaches mimic interaction of ash with rain produced in the vicinity of an active eruption. The third leach accelerates the effect of prolonged contact of volcanic ash with alkaline ground water present during ash diagenesis.

Chemistry, toxicology, and persistence of particulates during and after the 2016 Fort McMurray Wildfires in Alberta, Canada

NASA Astrophysics Data System (ADS)

Kohl, L.; Chan, A. W. H.; Cooke, C. A.; Hustins, S.; Jackson, B.; Wang, S.; Jing, X.; Meng, M.

2017-12-01

The Horse River Fire in May 2016 forced the evacuation of 88,000 Fort McMurray residents, and led to the destruction of over 2000 houses. After re-entry to homes, there is significant concern about exposures to residual fire-derived contaminants in residential houses. Wildfire research, however, provides little guidance on how long ashes and pollutants persist in household dust after major fires. The FACET project studies the chemistry and toxicology of samples of urban and forest ashes and airborne particles collected during the fire, as well as over 500 house dust samples collected in July 2017 (14 months after the fire). Here we present results on the chemical composition of the urban and forest ash samples collected during the fire along with initial results from house dust samples. Wildfire ashes contained elevated concentrations of polycyclic aromatic hydrocarbons (PAH), heavy metals, and dioxin like compounds (DLC). Relative to EPA reference doses, As and Sb constitute the greatest non-carcinogenic health hazard, whereas PAHs Benzo(a)pyrene and Indeno(1,2,3-cd)pyrene are the most relevant carcinogens. Ashes from urban locations contained higher concentrations of heavy metals and DLC than samples collected from forested areas outside of the City of Fort McMurray. Urban samples furthermore had a greater potential for generating oxidative stress than rural samples, as determined by dithiothreitol (DTT) consumption assays. The oxidative potential was positively correlated to Al, Cu, As, and V concentrations. Airborne particulate matter samples from the smoke plume contained consistent concentrations of levoglucosan (99 ± 5 mg g-1), along with other tracers for biomass burning (free lignin monomers, retene). Together these results will serve as proxies for understanding the contribution and the persistence of fire-derived pollutants in house dust in Fort McMurray homes.

Determination of ash in coals unusually high in calcite and pyrite

USGS Publications Warehouse

Rees, O.W.; Selvig, W.A.

1942-01-01

The preliminary hearth heating method (A and E) gave results within the A. S. T. M. tolerances for all duplicates obtained in the same laboratory. Checks between different laboratories within A. S. T. M. tolerances were obtained for coals containing up to about 3.6 per cent mineral carbon dioxide, but these ashes contained larger amounts of retained sulfur. The determination of ash by the cold furnace method (B and F) gave duplicate results within A. S. T. M. tolerances for all samples in the U. S. Bureau of Mines laboratory and for samples up to about 1.6 per cent mineral carbon dioxide content in the Illinois Geological Survey laboratory. Checks between average values from the two laboratories were within A. S. T. M. tolerances for all samples.

Bench-scale performance testing and economic analyses of electrostatic dry coal cleaning. Final report, October 1980-July 1983

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rich, S.R.

1987-02-01

The report gives results of preliminary performance evaluations and economic analyses of the Advanced Energy Dynamics (AED) electrostatic dry coal-cleaning process. Grab samples of coal-feed-product coals were obtained from 25 operating physical coal-cleaning (PCC) plants. These samples were analyzed for ash, sulfur, and energy content and splits of the original samples of feed run-of-mine coal were provided for bench-scale testing in an electrostatic separation apparatus. The process showed superior sulfur-removal performance at equivalent cost and energy-recovery levels. The ash-removal capability of the process was not evaluated completely: overall, ash-removal results indicated that the process did not perform as well asmore » the PCC plants.« less

Measuring the impact of biotic factors on populations of immature emerald ash borers (Coleoptera: Buprestidae).

PubMed

Duan, Jian J; Ulyshen, Michael D; Bauer, Leah S; Gould, Juli; Van Driesche, Roy

2010-10-01

Cohorts of emerald ash borer larvae, Agrilus planipennis Fairmaire, were experimentally established in July of 2008 on healthy green ash (Fraxinus pennsylvanica) trees in two wooded plots at each of three sites near Lansing, MI, by caging gravid emerald ash borer females or placing laboratory-reared eggs on trunks (0.5-2 m above the ground) of selected trees. One plot at each site was randomly chosen for release of two introduced larval parasitoids, Tetrastichus planipennisi Yang (Hymenoptera: Eulophidae) and Spathius agrili Yang (Hymenoptera: Braconidae), whereas the other served as the control. Stage-specific mortality factors and rates were measured for all experimentally established cohorts and for associated wild (i.e., naturally occurring) emerald ash borer immature stages via destructive sampling of 2.5 m (above the ground) trunk sections of cohort-bearing trees in the spring and fall of 2009. Host tree defense was the most important mortality factor, causing 32.0 to 41.1% mortality in the experimental cohorts and 17.5 to 21.5% in wild emerald ash borer stages by spring 2009, and 16.1 to 29% for the remaining experimental cohorts, and 9.9 to 11.8% for wild immature emerald ash borer stages by fall 2009. Woodpecker predation was the second most important factor, inflicting no mortality in the experimental cohorts but causing 5.0 to 5.6% mortality to associated wild emerald ash borer stages by spring 2009 and 9.2 to 12.8% and 3.2 to 17.7%, respectively, for experimental cohorts and wild emerald ash borer stages by fall 2009. Mortality from disease in both the experimental and wild cohorts was low (<3%) in both the spring and fall sample periods. In the fall 2009 samples, ≈ 1.5% of experimental cohorts and 0.8% of the wild emerald ash borer stages were parasitized by T. planipennisi. While there were no significant differences in mortality rates because of parasitism between parasitoid-release and control plots, T. planipennisi was detected in each of the three release sites by the end of the study but was not detected in the experimental cohorts or associated wild larvae in any of the three control plots.

Volcanic degassing and secondary hydration of volcanic ash and scoria: Implications for paleoaltimetry and paleoclimate studies

NASA Astrophysics Data System (ADS)

Seligman, A. N.; Bindeman, I. N.

2013-12-01

The use of δD of ash as a reliable recorder of δD (and δ18O) values of paleoprecipitation in paleoclimate and paleoaltimetry research still requires experimental verification and testing. It is currently assumed that ash is deposited with a water content of no significance, and that within a few thousand years it becomes sufficiently (up to 4 wt.% H2O) hydrated, although the rate of hydration and whether or not the initial isotopic signature is held, are not well understood. We report analyses of δD and H2O of distal ash from recent eruptions (1980 Mount St. Helens, 1992 Mt. Spurr, and 1974 Volcán de Fuego) that were collected syneruption, in addition to scoria ranging in age from ~50 to 7300 years old from Klyuchevskoy volcano (Kamchatka, Russia), using the TC/EA - MAT 253 continuous flow system. Natural variability of studied samples in wt.% H2O (δD in ‰), with errors represented as 1 s.d. for the average, for recent ash eruptions, range from 0.1 × 0.07 (-102 × 4.7) for Volcán de Fuego up to 0.7 × 0.10 (-104 × 3.5) for Mount St. Helens. Ash from the Mt. Spurr eruption averaged 0.4 × 0.04 (-109 × 4.0), and we plan to also analyze ash from Mt. Pinatubo. The δD values are consistent with a magmatic degassing trend, where the last remaining water is depleted in deuterium, suggesting ash may be deposited with up to 0.7 wt.% H2O as primary magmatic water. Klyuchevskoy scoria (basaltic andesite) shows a general trend of increasing wt.% H2O with increasing age: the youngest samples (<2.0 ka) have ~0.2 wt.% water (-99 to -109 ‰), which is likely primary magmatic, while the older samples (4.7-7.3 ka) generally have a higher water concentration (~0.3-0.5 wt.%); likely local meteoric water based on δD values that are lower than degassed magmatic δD values and higher water content. The samples between ~2.3 and 3.6 ka (0.1 to 0.4 wt.% water) have variable water concentrations due to variations in porosity and therefore surface area between the different scoria. We do not observe a trend between the SiO2 wt.% (51-56 wt.%) and the water content of the samples. The δD values (between -99 × 5.6 and -121 × 1.2 per mil are near equilibrium with local postglacial meteoric waters, when incorporating a -30‰ fractionation, and provide a trend between δD and wt.% H2O, where higher water concentrations are associated with lower δD values. We also report preliminary results of δ18O in extracted water, using experimentally hydrated dacite and rhyolite glass, and a large set of natural ash (ash described above and ash from the Lava Creek Tuff of Yellowstone). These results show water-glass fractionations between -11.5 and -12.7 for experimental glasses and -2.2 to -11.4 for natural ash. We are looking into using δ18Owater in glass as a more robust and retentive proxy of past environmental waters for paleoclimate and paleoaltimetry research.

Characterising boiler ash from a circulating fluidised bed municipal solid waste incinerator and distribution of PCDD/F and PCB.

PubMed

Zhang, Mengmei; Buekens, Alfons; Li, Xiaodong

2018-05-31

In this study, ash samples were collected from five locations situated in the boiler of a circulating fluidised bed municipal solid waste incinerator (high- and low-temperature superheater, evaporator tubes and upper and lower economiser). These samples represent a huge range of flue gas temperatures and were characterised for their particle size distribution, surface characteristics, elemental composition, chemical forms of carbon and chlorine and distribution of polychlorinated dibenzo-p-dioxins (PCDD), dibenzofurans (PCDF) and biphenyls (PCB). Enrichment of chlorine, one of the main elements of organochlorinated pollutants, and copper, zinc and lead, major catalytic metals for dioxin-like compounds, was observed in lower-temperature ash deposits. The speciation of carbon and chlorine on ash surfaces was established, showing a positive correlation between organic chlorine and oxygen-containing carbon functional groups. The load of PCDD/F and PCB (especially dioxin-like PCB) tends to rise rapidly with falling temperature of flue gas, reaching their highest value in economiser ashes. The formation of PCDD/F congeners through the chlorophenol precursor route apparently was enhanced downstream the boiler. Principal component analysis (PCA) was applied to study the links between the ash characteristics and distribution of chloro-aromatics. The primary purpose of this study is improving the understanding of any links between the characteristics of ash from waste heat systems and its potential to form PCDD/F and PCB. The question is raised whether further characterisation of fly ash may assist to establish a diagnosis of poor plant operation, inclusive the generation, destruction and eventual emission of persistent organic pollutants (POPs).

Evaluation of genotoxicity of coal fly ash in Allium cepa root cells by combining comet assay with the Allium test.

PubMed

Chakraborty, Rajarshi; Mukherjee, Ashit Kumar; Mukherjee, Anita

2009-06-01

Fly ash is a by-product of coal-fired electricity generation plants. Its utilization and disposal is of utmost importance. Using onion (Allium cepa) root tip system, the present study was carried out to evaluate the potential toxic and genotoxic effects of fly ash, collected from a thermal power plant in West Bengal, India. Prior to testing, the collected fly ash sample was mixed with sand in different proportions. Allium bulbs were allowed to germinate directly in fly ash and after five days the germinating roots were processed for the Allium test. Additionally, the Allium test was adapted for detecting DNA damage through comet assay. The results from the Allium test indicate that fly ash at 100% concentration inhibits root growth and mitotic indices; induces binucleated cells as a function of the proportion, but is not toxic at very low concentration. In the comet assay, a statistical increase for DNA strand breaks was found only at higher concentrations. The sample was analyzed by flame atomic absorption spectrometer for Zn, Pb, Cu, Ni, Cd and As, whose presence could partly be responsible for the toxicity of fly ash. The study concludes that the classical Allium test can give a more comprehensive data when done in combination with the comet assay, which is faster, simpler and independent of mitosis. Also when fly ash is used for other purposes in combination with soils, it should be judiciously used at very low concentrations in order to protect the ecosystem health from any potential adverse effects.

Recovery of Rare Earth Elements from Coal and Coal Byproducts via a Closed Loop Leaching Process: Final Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Peterson, Richard; Heinrichs, Michael; Argumedo, Darwin

Objectives: Through this grant, Battelle proposes to address Area of Interest (AOI) 1 to develop a bench-scale technology to economically separate, extract, and concentrate mixed REEs from coal ash. U.S. coal and coal byproducts provide the opportunity for a domestic source of REEs. The DOE’s National Energy Technology Laboratory (NETL) has characterized various coal and coal byproducts samples and has found varying concentrations of REE ranging up to 1,000 parts per million by weight. The primary project objective is to validate the economic viability of recovering REEs from the coal byproduct coal ash using Battelle’s patented closed-loop Acid Digestion Processmore » (ADP). This will be accomplished by selecting coal sources with the potential to provide REE concentrations above 300 parts per million by weight, collecting characterization data for coal ash samples generated via three different methods, and performing a Techno-Economic Analysis (TEA) for the proposed process. The regional availability of REE-laden coal ash, the regional market for rare earth concentrates, and the system capital and operating costs for rare earth recovery using the ADP technology will be accounted for in the TEA. Limited laboratory testing will be conducted to generate the parameters needed for the design of a bench scale system for REE recovery. The ultimate project outcome will be the design for an optimized, closed loop process to economically recovery REEs such that the process may be demonstrated at the bench scale in a Phase 2 project. Project Description: The project will encompass evaluation of the ADP technology for the economic recovery of REEs from coal and coal ash. The ADP was originally designed and demonstrated for the U.S. Army to facilitate demilitarization of cast-cured munitions via acid digestion in a closed-loop process. Proof of concept testing has been conducted on a sample of Ohio-based Middle Kittanning coal and has demonstrated the feasibility of recovering REEs using the ADP technology. In AOI 1, Ohio coal sources with the potential to provide a consistent source of rare earth element concentrations above 300 parts per million will be identified. Coal sample inventories from West Virginia and Pennsylvania will also be assessed for purposes of comparison. Three methods of preparing the coal ash will be evaluated for their potential to enhance the technical feasibility and economics of REE recovery. Three sources of coal ash are targeted for evaluation of the economics of REE recovery in this project: (1) coal ash from power generation stations, to include fly ash and/or bottom ash, (2) ash generated in a lower temperature ashing process, and (3) ash residual from Battelle’s coal liquefaction process. Making use of residual ash from coal liquefaction processes directly leverages work currently being conducted by Battelle for DOE NETL in response to DE-FOA-0000981 entitled “Greenhouse Gas Emissions Reductions Research and Development Leading to Cost-Competitive Coal-to-Liquids Based Jet Fuel Production.” Using the sample characterization results and regional information regarding REE concentration, availability and cost, a TEA will be developed. The previously generated laboratory testing results for leaching and REE recovery via the ADP will be used to perform the TEA, along with common engineering assumptions for scale up of equipment and labor costs. Finally, upon validation of the economic feasibility of the process by the TEA, limited laboratory testing will be performed to support the design of a bench scale system. In a future project phase, it is envisioned that the bench scale system will be constructed and operated to prove the process on a continuous basis.« less

Remobilisation of industrial lead depositions in ash during Australian wildfires.

PubMed

Wu, Liqin; Taylor, Mark Patrick; Handley, Heather K

2017-12-01

This study examined the recycling of lead (Pb) in ash from wildfires, its source and potential contribution to environmental contamination. Ash from wildfires was collected from four Australian sites following uncontrolled fires during 2012 to 2013 close to major urban populations in Sydney (New South Wales), Hobart (Tasmania) and Adelaide (South Australia). The samples were analysed for their total Pb concentration and Pb isotopic composition to determine the sources of Pb and the extent, if any, of industrial contamination and its recycling into the ecosystem. Median ash concentrations (23mg/kg) released from a wildfire close to Australia's largest city, Sydney, exceeded the median ash Pb concentrations from wildfires from the less populated locations of Hobart, Adelaide and NSW Central Coast. Lead isotopic compositions of Duffys Forest wildfire ash demonstrate that anthropogenic inputs from legacy leaded petrol depositions were the predominant source of contamination. Despite the cessation of leaded petrol use in Australia in 2002, historic petrol Pb deposits continue to be a substantial source of contamination in ash: petrol Pb contributed 35% of the Pb in the Woy Woy ash, 73% in Duffys Forest ash, 39% in Forcett ash and 5% in Cherryville ash. The remobilisation of legacy industrial Pb depositions by wildfires in ash results in it being a persistent and problematic contaminant in contemporary environmental systems because of its known toxicity. Copyright © 2017 Elsevier B.V. All rights reserved.

Atomic emission spectrometer/spectrograph for the determination of barium in microamounts of diatom ash

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bankston, D.C.; Fisher, N.S.

1977-06-01

The development and routine application of a method for the determination of trace levels of barium in microsamples (5-10 mg) of diatom ash is described Acid-dissolved lithium metaborate fusion melts of ash samples are analyzed using a spectrometer/spectrograph equipped with a dc argon plasma jet excitation source and an echelle diffraction grating. Sample, standard, and blank solutions are buffered by lithium contributed by the flux, to a degree sufficient to reduce matrix effects to acceptable levels. Previous barium determinations by other analytical techniques, on seven interlaboratory reference materials, have been used to establish the accuracy of our results. The averagemore » relative standard deviation for the instrumental analyses was 0.07. Using recommended instrument settings, moreover, the lowest concentration of barium visible in synthetic standard solutions lies just below 2 ..mu..g/L, which is equivalent to 2 ..mu..g/g in the ash.« less

Leachate Geochemical Results for Ash and Burned Soil Samples from the October 2007 Southern California Wildfires

USGS Publications Warehouse

Hageman, Philip L.; Plumlee, Geoffrey S.; Martin, Deborah A.; Hoefen, Todd M.; Meeker, Gregory P.; Adams, Monique; Lamothe, Paul J.; Anthony, Michael W.

2008-01-01

This report is the second release of leachate geochemical data included as part of a multidisciplinary study of ash and burned soil samples from the October 2007 wildfires in southern California. Geochemical data for the first set of samples were released in an Open-File Report (Plumlee and others, 2007). This study is a continuation of that work. The objectives of this leaching study are to aid in understanding the interactions of ash and burned soil with rainfall. For this study, 12 samples collected in early November 2007 were leached using the U.S. Geological Survey (USGS) Field Leach Test (FLT). Following leaching, sub-samples of the leachate were analyzed for pH and specific conductance. The leachate was then filtered, and aliquots were preserved for geochemical analysis. This report presents leachate geochemical data for pH, specific conductance, alkalinity, anions using ion chromatography (I.C.), cations using inductively coupled plasma?atomic mass spectrometry (ICP-MS), and mercury by continuous flow injection?cold vapor?atomic fluorescence (CVAFS).

Viscoelastic behavior of basaltic ash from Stromboli volcano inferred from intermittent compression experiments

NASA Astrophysics Data System (ADS)

Kurokawa, A. K.; Miwa, T.; Okumura, S.; Uesugi, K.

2017-12-01

After ash-dominated Strombolian eruption, considerable amount of ash falls back to the volcanic conduit forming a dense near-surface region compacted by weights of its own and other fallback clasts (Patrick et al., 2007). Gas accumulation below this dense cap causes a substantial increase in pressure within the conduit, causing the volcanic activity to shift to the preliminary stages of a forthcoming eruption (Del Bello et al., 2015). Under such conditions, rheology of the fallback ash plays an important role because it controls whether the fallback ash can be the cap. However, little attention has been given to the point. We examined the rheology of ash collected at Stromboli volcano via intermittent compression experiments changing temperature and compression time/rate. The ash deformed at a constant rate during compression process, and then it was compressed without any deformation during rest process. The compression and rest processes repeated during each experiment to see rheological variations with progression of compaction. Viscoelastic changes during the experiment were estimated by Maxwell model. The results show that both elasticity and viscosity increases with decreasing porosity. On the other hand, the elasticity shows strong rate-dependence in the both compression and rest processes while the viscosity dominantly depends on the temperature, although the compression rate also affects the viscosity in the case of the compression process. Thus, the ash behaves either elastically or viscously depending on experimental process, temperature, and compression rate/time. The viscoelastic characteristics can be explained by magnitude relationships between the characteristic relaxation times and times for compression and rest processes. This indicates that the balance of the time scales is key to determining the rheological characteristics and whether the ash behaves elastically or viscously may control cyclic Strombolian eruptions.

Temporal and spatial variations in fly ash quality

USGS Publications Warehouse

Hower, J.C.; Trimble, A.S.; Eble, C.F.

2001-01-01

Fly ash quality, both as the amount of petrographically distinguishable carbons and in chemistry, varies in both time and space. Temporal variations are a function of a number of variables. Variables can include variations in the coal blend organic petrography, mineralogy, and chemistry; variations in the pulverization of the coal, both as a function of the coal's Hardgrove grindability index and as a function of the maintenance and settings of the pulverizers; and variations in the operating conditions of the boiler, including changes in the pollution control system. Spatial variation, as an instantaneous measure of fly ash characteristics, should not involve changes in the first two sets of variables listed above. Spatial variations are a function of the gas flow within the boiler and ducts, certain flow conditions leading to a tendency for segregation of the less-dense carbons in one portion of the gas stream. Caution must be applied in sampling fly ash. Samples from a single bin, or series of bins, m ay not be representative of the whole fly ash, providing a biased view of the nature of the material. Further, it is generally not possible to be certain about variation until the analysis of the ash is complete. ?? 2001 Elsevier Science B.V. All rights reserved.

Category 5 Suppressive Shield (TDP)

DTIC Science & Technology

1975-10-01

side- on overpressure. 3.1.3 Quasi -static Pressure. Pressure levels as measured by the PCB101A02 trans- ducers were in general difficult to...apparent: (1) The observed quasi -static pressures PnM are in general somewhnl less than the OOOiipomMng calculated values based on closed-box...explained by off-center combustion of the illuminant mix and directional convection of the reaction pro- ducts. Posttest ash deposits on the floor

Study of morphology, chemical, and amino acid composition of red deer meat.

PubMed

Okuskhanova, Eleonora; Assenova, Bahytkul; Rebezov, Maksim; Amirkhanov, Kumarbek; Yessimbekov, Zhanibek; Smolnikova, Farida; Nurgazezova, Almagul; Nurymkhan, Gulnur; Stuart, Marilyne

2017-06-01

The aim of this study was to evaluate red deer (maral) meat quality based on chemical composition, pH, water-binding capacity (WBC), and amino acid content. Maral meat surface morphology measurements were obtained by scanning electron microscopy. Active acidity (pH) was determined by potentiometry. Samples were analyzed for WBC by exudation of moisture to a filter paper by the application of pressure. Chemical composition (moisture, protein, fat, and ash fractions) was obtained by drying at 150°C and by extraction, using ethylic ether, and ashing at 500-600°C. The amino acid composition was obtained by liquid chromatography. Maral meat, with a pH of 5.85 and an average moisture content of 76.82%, was found to be low in fat (2.26%). Its protein content was 18.71% while its ash content was 2.21%. The amino acid composition showed that lysine (9.85 g/100 g), threonine (5.38 g/100 g), and valine (5.84 g/100 g) predominated in maral meat, while phenylalanine (4.08 g/100 g), methionine (3.29 g/100 g), and tryptophan (0.94 g/100 g) were relatively low in maral meat compared to other meats. The average WBC was found to be 65.82% and WBC was found to inversely correlate with moisture content. Low-fat content, high mineral content, and balanced amino-acid composition qualify maral meat as a worthy dietary and functional food.

Study of morphology, chemical, and amino acid composition of red deer meat

PubMed Central

Okuskhanova, Eleonora; Assenova, Bahytkul; Rebezov, Maksim; Amirkhanov, Kumarbek; Yessimbekov, Zhanibek; Smolnikova, Farida; Nurgazezova, Almagul; Nurymkhan, Gulnur; Stuart, Marilyne

2017-01-01

Aim: The aim of this study was to evaluate red deer (maral) meat quality based on chemical composition, pH, water-binding capacity (WBC), and amino acid content. Materials and Methods: Maral meat surface morphology measurements were obtained by scanning electron microscopy. Active acidity (pH) was determined by potentiometry. Samples were analyzed for WBC by exudation of moisture to a filter paper by the application of pressure. Chemical composition (moisture, protein, fat, and ash fractions) was obtained by drying at 150°C and by extraction, using ethylic ether, and ashing at 500-600°C. The amino acid composition was obtained by liquid chromatography. Results: Maral meat, with a pH of 5.85 and an average moisture content of 76.82%, was found to be low in fat (2.26%). Its protein content was 18.71% while its ash content was 2.21%. The amino acid composition showed that lysine (9.85 g/100 g), threonine (5.38 g/100 g), and valine (5.84 g/100 g) predominated in maral meat, while phenylalanine (4.08 g/100 g), methionine (3.29 g/100 g), and tryptophan (0.94 g/100 g) were relatively low in maral meat compared to other meats. The average WBC was found to be 65.82% and WBC was found to inversely correlate with moisture content. Conclusion: Low-fat content, high mineral content, and balanced amino-acid composition qualify maral meat as a worthy dietary and functional food. PMID:28717313

Ash Features from Present-day Activity at Stromboli

NASA Astrophysics Data System (ADS)

Cannata, Chiara; Taddeucci, Jacopo; Lautze, Nicole; de Rosa, Rosanna; Donato, Paola; Scarlato, Piergiorgio

2010-05-01

The present-day explosive activity at Stromboli volcano (Aeolian Islands, Italy) is characterized by a relatively large variability of eruptive styles on a relatively small temporal and spatial scale. Despite volcanic ash is a common product of this explosive activity, few studies have been conducted so far on ash of Stromboli and in particular on the products of individual explosions. Here we focus on micro-scale textural observations of ash particles erupted from a number of different vents during three sampling campaigns. Component analysis under the binocular microscope reveal that ash from present-day activity at Stromboli is dominated by two main end-members of fragments with a wide variability of color and degree of surface alteration: blocky and dark, fragments (i.e. tachylite) and glassy, highly vesiculated and fluidal fragments (i.e. sideromelane). In addition, individual phenocrysts or composite fragments (crystals plus tachylite or sideromelane) and rare, highly altered accessory lithic fragments are also present. Thin section investigation show that tachylite has micro- to crypto-crystalline groundmass, while sideromelane is partially or totally glassy. Component and modal analyses reveal that, in the sampling period, sideromelane is the most abundant component only in one vent while the other vents erupted mainly tachylite-rich ash. The morphology, micro-textures and chemical composition of particles surface were also analyzed using a Field Emission SEM equipped with EDS. In general, particle morphology and surface chemistry poorly discriminates between the different samples, while tachylite particles show a higher compactness, lower elongation, and more extensive overgrowth of secondary phases (mainly gypsum, sulphate and halide salts) in respect with sideromelane ones.

Degradation of thermal barrier coatings on an Integrated Gasification Combined Cycle (IGCC) simulated film-cooled turbine vane pressure surface due to particulate fly ash deposition

NASA Astrophysics Data System (ADS)

Luo, Kevin

Coal synthesis gas (syngas) can introduce contaminants into the flow of an Integrated Gasification Combined Cycle (IGCC) industrial gas turbine which can form molten deposits onto components of the first stage of a turbine. Research is being conducted at West Virginia University (WVU) to study the effects of particulate deposition on thermal barrier coatings (TBC) employed on the airfoils of an IGCC turbine hot section. WVU had been working with U.S. Department of Energy, National Energy Technology Laboratory (NETL) to simulate deposition on the pressure side of an IGCC turbine first stage vane to study the effects on film cooling. To simulate the particulate deposition, TBC coated, angled film-cooled test articles were subjected to accelerated deposition injected into the flow of a combustor facility with a pressure of approximately 4 atm and a gas temperature of 1560 K. The particle characteristics between engine conditions and laboratory are matched using the Stokes number and particulate loading. To investigate the degradation on the TBC from the particulate deposition, non-destructive evaluations were performed using a load-based multiple-partial unloading micro-indentation technique and were followed by scanning electron microscopy (SEM) evaluation and energy dispersive X-ray spectroscopy (EDS) examinations. The micro-indentation technique used in the study was developed by Kang et al. and can quantitatively evaluate the mechanical properties of materials. The indentation results found that the Young's Modulus of the ceramic top coat is higher in areas with deposition formation due to the penetration of the fly ash. The increase in the modulus of elasticity has been shown to result in a reduction of strain tolerance of the 7% yttria-stabilized zirconia (7YSZ) TBC coatings. The increase in the Young's modulus of the ceramic top coat is due to the stiffening of the YSZ columnar microstructure from the cooled particulate fly ash. SEM evaluation was used to evaluate the microstructure of the layers within the TBC system, and the SEM micrographs showed that the TBC/fly ash deposition interaction zone made the YSZ coating more susceptible to delamination and promoted a dissolution-reprecipitation mechanism that changes the YSZ morphology and composition. EDS examination provided elemental maps which showed a shallow infiltration depth of the fly ash deposits and an elemental distribution spectrum analysis showed yttria migration from the YSZ top coating into the molten deposition. This preliminary work should lead to future studies in gas turbine material coating systems and their interaction with simulated fly ash and potentially CMAS or volcanic ash deposition.

Molecular recognition of emerald ash borer infestation using leaf spray mass spectrometry.

PubMed

Falcone, Caitlin E; Cooks, R Graham

2016-06-15

The introduction of the emerald ash borer (Agrilus planipennis) (EAB) from Asia to Michigan, USA, in the 1990s caused the widespread death of ash trees in two Canadian provinces and 24 US states. The three current methods for the detection of emerald ash borer infestation, visual surveys, tree girdling and artificial traps, can be unreliable, and there is clearly a need for a rapid, dependable technique for the detection of emerald ash borer infestation. Leaf spray, an ambient ionization method for mass spectrometry (MS), gives direct chemical information on a leaf sample by applying a high voltage to a naturally or artificially sharply pointed leaf piece causing ions to be generated directly from the leaf tip for MS analysis. Leaflets from 23 healthy and EAB-infested ash trees were analyzed by leaf spray mass spectrometry in an attempt to distinguish healthy and EAB-infested ash trees. In negative ion mode, healthy ash trees showed an increased abundance of ions m/z 455.5, 471.5 and 487.5, and ash trees infested with the EAB displayed an increased abundance of ions m/z 181 and 217. The identities of the chemical discriminators ursolic acid and oleanolic acid in healthy ash trees, and six-carbon sugar alcohols in infested ash trees, were determined by tandem mass spectrometry and confirmed with standards. This preliminary study suggests that leaf spray mass spectrometry of ash tree leaflets provides a potential tool for the early detection of ash tree infestation by the emerald ash borer. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Mass Spectrometric Determination of Uranium and Thorium in High Radiopurity Polymers Using Ultra Low Background Electroformed Copper Crucibles for Dry Ashing.

PubMed

Arnquist, Isaac J; Hoppe, Eric J; Bliss, Mary; Grate, Jay W

2017-03-07

A rapid new method for determining the U and Th mass concentrations in high radiopurity plastics is described, consisting of (1) dry ashing the plastic sample and tracers in low mass crucibles made of ultra low background electroformed copper (ULB EF-Cu) foil cut and folded into boats, (2) dissolving both the ash and the boat in acid, (3) performing a column separation to remove copper, and (4) determining the elements of interest by isotope dilution mass spectrometry. This method was demonstrated on both unfluorinated and fluorinated plastics, demonstrating high tracer recoveries and detection limits to pg/g (i.e., parts per trillion) levels or below, corresponding to μBq/kg of material. Samples of biomedical polyester (Max-Prene 955) and a fluoropolymer (polyvinylidene fluoride, PVDF) were analyzed in powder raw material forms as well as solids in the form of pellets or injection molded parts. The polyester powder contained 6 pg/g and 2 pg/g for 232 Th and 238 U, respectively. These levels correspond to 25 and 25 μBq/kg radioactivity, respectively. Determinations on samples of PVDF powder were typically below 1 pg/g for 232 Th and 2 pg/g for 238 U, corresponding to 4 and 25 μBq/kg radioactivity, respectively. The use of low mass ULB EF-Cu boats for dry ashing successfully overcame the problem of crucible-generated contaminants in the analysis; absolute detection limits, calculated as 3 × standard deviation of the process blanks, were typically 20-100 fg within a sample set. Complete dissolution of the ash and low mass boat provided high tracer recoveries and provides a convincing method to recover both the tracer and sample isotopes when full equilibration of tracer isotopes with sample isotopes is not possible prior to beginning chemical sample processing on solids.

Mass Spectrometric Determination of Uranium and Thorium in High Radiopurity Polymers Using Ultra Low Background Electroformed Copper Crucibles for Dry Ashing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Arnquist, Isaac J.; Hoppe, Eric J.; Bliss, Mary

A rapid new method for determining the U and Th mass concentrations in high radiopurity plastics is described, consisting of 1) dry ashing the plastic sample and tracers in low mass crucibles made of ultra low background electroformed copper (ULB EF-Cu) foil cut and folded into boats, 2) dissolving both the ash and the boat in acid, 3) performing a column separation to remove copper, and 4) determining the elements of interest by isotope dilution mass spectrometry. This method was demonstrated on both unfluorinated and fluorinated plastics, demonstrating high tracer recoveries and detection limits to pg/g (i.e., parts per trillion)more » levels or below, corresponding to μBq/kg of material. Samples of biomedical polyester (Max-Prene® 955) and a fluoropolymer (polyvinylidene fluoride, PVDF) were analyzed in powder raw material forms as well as solids in the form of pellets or injection molded parts. The polyester powder contained 6 pg/g and 2 pg/g for Th and U respectively. These levels correspond to 25 and 25 μBq/kg radioactivity, respectively. Determinations on samples of PVDF powder were typically below 1 pg/g for Th and 2 pg/g for U, corresponding to 4 and 25 μBq/kg radioactivity, respectively. The use of low mass ULB EF-Cu boats for dry ashing successfully overcame the problem of crucible-generated contaminants in the analysis; absolute detection limits, calculated as 3 × standard deviation of the process blanks, were typically 20-100 fg within a sample set. Complete dissolution of the ash and low mass boat provided high tracer recoveries, and provides a convincing method to recover both the tracer and sample isotopes when full equilibration of tracer isotopes with sample isotopes is not possible prior to beginning chemical sample processing on solids.« less

The influence of sugarcane bagasse ash as fly ash on cement quality

NASA Astrophysics Data System (ADS)

Rauf, N.; Damayanti, M. C.; Pratama, S. W. I.

2017-01-01

Fly ash often is used as the third material for cement. The fly ash from sugarcane bagasse is usually considered as industrial waste material that can be added to the base material of cement (clinker, trash, gypsum and lime stone) for economic and environment reason. The amount of fly ash usually up to 30 % of cement material, but in this research the percentage of sugarcane bagasse ash (SBA) is added to cement material is up to 15% total weight. Then the x-rays fluorescence (XRF) was used to determine its chemical composition of raw material and cement samples. The physical properties of cement such as fineness, setting time, expansion, and compressive strength were measured using Automatic Blaine, Vicat, Autoclave, respectively. The result show that the percentage of sugarcane bagasse ash influences the quality of cement and concrete, and this is confirmed with Indonesia National Standard (SNI). It is showed that the sugarcane bagasse ash could be use as material to improve the quality of cement and will solve the environment waste material

Resuspension of ash after the 2014 phreatic eruption at Ontake volcano, Japan

NASA Astrophysics Data System (ADS)

Miwa, Takahiro; Nagai, Masashi; Kawaguchi, Ryohei

2018-02-01

We determined the resuspension process of an ash deposit after the phreatic eruption of September 27th, 2014 at Ontake volcano, Japan, by analyzing the time series data of particle concentrations obtained using an optical particle counter and the characteristics of an ash sample. The time series of particle concentration was obtained by an optical particle counter installed 11 km from the volcano from September 21st to October 19th, 2014. The time series contains counts of dust particles (ash and soil), pollen, and water drops, and was corrected to calculate the concentration of dust particles based on a polarization factor reflecting the optical anisotropy of particles. The dust concentration was compared with the time series of wind velocity. The dust concentration was high and the correlation coefficient with wind velocity was positive from September 28th to October 2nd. Grain-size analysis of an ash sample confirmed that the ash deposit contains abundant very fine particles (< 30 μm). Simple theoretical calculations revealed that the daily peaks of the moderate wind (a few m/s at 10 m above the ground surface) were comparable with the threshold wind velocity for resuspension of an unconsolidated deposit with a wide range of particle densities. These results demonstrate that moderate wind drove the resuspension of an ash deposit containing abundant fine particles produced by the phreatic eruption. Histogram of polarization factors of each species experimentally obtained. The N is the number of analyzed particles.

Rapid releases of metal salts and nutrients following the deposition of volcanic ash into aqueous environments

NASA Astrophysics Data System (ADS)

Jones, Morgan T.; Gislason, Sigurður R.

2008-08-01

Deposition of volcanic ash into aqueous environments leads to dissolution of adsorbed metal salts and aerosols, increasing the bioavailability of key nutrients. Volcanogenic fertilization events could increase marine primary productivity, leading to a drawdown of atmospheric CO 2. Here we conduct flow-through experiments on unhydrated volcanic ash samples from a variety of locations and sources, measuring the concentrations and fluxes of elements into de-ionized water and two contrasting ocean surface waters. Comparisons of element fluxes show that dissolution of adsorbed surface salts and aerosols dominates over glass dissolution, even in sustained low pH conditions. These surface ash-leachates appear unstable, decaying in situ even if kept unhydrated. Volcanic ash from recent eruptions is shown to have a large fertilization potential in both fresh and saline water. Fluorine concentrations are integral to bulk dissolution rates and samples with high F concentrations display elevated fluxes of some nutrients, particularly Fe, Si, and P. Bio-limiting micronutrients are released in large quantities, suggesting that subsequent biological growth will be limited by macronutrient availability. Importantly, acidification of surface waters and high fluxes of toxic elements highlights the potential of volcanic ash-leachates to poison aqueous environments. In particular, large pH changes can cause undersaturation of CaCO 3 polymorphs, damaging populations of calcifying organisms. Deposition of volcanic ash can both fertilize and/or poison aqueous environments, causing significant changes to surface water chemistry and biogeochemical cycles.

The adsorption of HCl on volcanic ash

NASA Astrophysics Data System (ADS)

Gutiérrez, Xochilt; Schiavi, Federica; Keppler, Hans

2016-03-01

Understanding the interaction between volcanic gases and ash is important to derive gas compositions from ash leachates and to constrain the environmental impact of eruptions. Volcanic HCl could potentially damage the ozone layer, but it is unclear what fraction of HCl actually reaches the stratosphere. The adsorption of HCl on volcanic ash was therefore studied from -76 to +150 °C to simulate the behavior of HCl in the dilute parts of a volcanic plume. Finely ground synthetic glasses of andesitic, dacitic, and rhyolitic composition as well as a natural obsidian from Vulcano (Italy) served as proxies for fresh natural ash. HCl adsorption is an irreversible process and appears to increase with the total alkali content of the glass. Adsorption kinetics follow a first order law with rate constants of 2.13 ṡ10-6 s-1 to 1.80 ṡ10-4 s-1 in the temperature range investigated. For dacitic composition, the temperature and pressure dependence of adsorption can be described by the equation ln ⁡ c = 1.26 + 0.27 ln ⁡ p - 715.3 / T, where c is the surface concentration of adsorbed HCl in mg/m2, T is temperature in Kelvin, and p is the partial pressure of HCl in mbar. A comparison of this model with a large data set for the composition of volcanic ash suggests that adsorption of HCl from the gas phase at relatively low temperatures can quantitatively account for the majority of the observed Cl concentrations. The model implies that adsorption of HCl on ash increases with temperature, probably because of the increasing number of accessible adsorption sites. This temperature dependence is opposite to that observed for SO2, so that HCl and SO2 are fractionated by the adsorption process and the fractionation factor changes by four orders of magnitude over a temperature range of 250 K. The assumption of equal adsorption of different species is therefore not appropriate for deriving volcanic gas compositions from analyses of adsorbates on ash. However, with the experimental data provided here, the gas compositions in equilibrium with the ash surfaces can be calculated. In particular, for dacitic composition, the molar ratio of S/Cl adsorbed to the ash surface is related to the molar S/Cl ratio in the gas phase according to the equation ln ⁡(S / Cl) adsorbed = 2855T-1 + 0.28 ln ⁡(S / Cl) gas - 11.14. Our data also show that adsorption on ash will significantly reduce the fraction of HCl reaching the stratosphere, only if the initial HCl content in the volcanic gas is low (<1 mol%). For higher initial HCl concentrations, adsorption on ash has only a minor effect. While HCl scavenging by hydrometeors may remove a considerable fraction of HCl from the eruption column, recent models suggest that this process is much less efficient than previously thought. Our experimental data therefore support the idea that the HCl loading from major explosive eruptions may indeed cause severe depletions of stratospheric ozone.

Use of Incineration Solid Waste Bottom Ash as Cement Mixture in Cement Production

NASA Astrophysics Data System (ADS)

Jun, N. H.; Abdullah, M. M. A. B.; Jin, T. S.; Kadir, A. A.; Tugui, C. A.; Sandu, A. V.

2017-06-01

Incineration solid waste bottom ash was use to examine the suitability as a substitution in cement production. This study enveloped an innovative technology option for designing new equivalent cement that contains incineration solid waste bottom ash. The compressive strength of the samples was determined at 7, 14, 28 and 90 days. The result was compared to control cement with cement mixture containing incineration waste bottom ash where the result proved that bottom ash cement mixture able achieve its equivalent performance compared to control cement which meeting the requirement of the standards according to EN 196-1. The pozzolanic activity index of bottom ash cement mixture reached 0.92 at 28 days and 0.95 at 90 and this values can be concluded as a pozzolanic material with positive pozzolanic activity. Calcium hydroxide in Portland cement decreasing with the increasing replacement of bottom ash where the reaction occur between Ca(OH)2 and active SiO2.

Geotechnical properties of ash deposits near Hilo, Hawaii

USGS Publications Warehouse

Wieczorek, G.F.; Jibson, R.W.; Wilson, R.C.; Buchanan-Banks, J. M.

1982-01-01

Two holes were hand augered and sampled in ash deposits near Hilo, Hawaii. Color, water content and sensitivity of the ash were measured in the field. The ash alternated between reddish brown and dark reddish brown in color and had water contents as high as 392%. A downhole vane shear device measured sensitivities as high as 6.9. A series of laboratory tests including grain size distribution, Atterberg limits, X-ray diffraction analysis, total carbon determination, vane shear, direct shear and triaxial tests were performed to determine the composition and geotechnical properties of the ash. The ash is very fine grained, highly plastic and composed mostly of gibbsite and amorphous material presumably allophane. The ash has a high angle of internal friction ranging from 40-43? and is classified as medium to very sensitive. A series of different ash layers was distinguished on the basis of plasticity and other geotechnical properties. Sensitivity may be due to a metastable fabric, cementation, leaching, high organic content, and thixotropy. The sensitivity of the volcanic ash deposits near Hilo is consistent with documented slope instability during earthquakes in Hawaii. The high angles of internal friction and cementation permit very steep slopes under static conditions. However, because of high sensitivity of the ash, these slopes are particularly susceptible to seismically-induced landsliding.

Controls on the surface chemical reactivity of volcanic ash investigated with probe gases

NASA Astrophysics Data System (ADS)

Maters, Elena C.; Delmelle, Pierre; Rossi, Michel J.; Ayris, Paul M.; Bernard, Alain

2016-09-01

Increasing recognition that volcanic ash emissions can have significant impacts on the natural and human environment calls for a better understanding of ash chemical reactivity as mediated by its surface characteristics. However, previous studies of ash surface properties have relied on techniques that lack the sensitivity required to adequately investigate them. Here we characterise at the molecular monolayer scale the surfaces of ash erupted from Eyjafjallajökull, Tungurahua, Pinatubo and Chaitén volcanoes. Interrogation of the ash with four probe gases, trimethylamine (TMA; N(CH3)3), trifluoroacetic acid (TFA; CF3COOH), hydroxylamine (HA; NH2OH) and ozone (O3), reveals the abundances of acid-base and redox sites on ash surfaces. Measurements on aluminosilicate glass powders, as compositional proxies for the primary constituent of volcanic ash, are also conducted. We attribute the greater proportion of acidic and oxidised sites on ash relative to glass surfaces, evidenced by comparison of TMA/TFA and HA/O3 uptake ratios, in part to ash interaction with volcanic gases and condensates (e.g., H2O, SO2, H2SO4, HCl, HF) during the eruption. The strong influence of ash surface processing in the eruption plume and/or cloud is further supported by particular abundances of oxidised and reduced sites on the ash samples resulting from specific characteristics of their eruptions of origin. Intense interaction with water vapour may result in a higher fraction of oxidised sites on ash produced by phreatomagmatic than by magmatic activity. This study constitutes the first quantification of ash chemical properties at the molecular monolayer scale, and is an important step towards better understanding the factors that govern the role of ash as a chemical agent within atmospheric, terrestrial, aquatic or biotic systems.

Transpressional deformation style and AMS fabrics adjacent to the southernmost segment of the San Andreas fault, Durmid Hill, CA

NASA Astrophysics Data System (ADS)

French, M.; Wojtal, S. F.; Housen, B.

2006-12-01

In the Salton Trough, the trace of the San Andreas Fault (SAF) ends where it intersects the NNW-trending Brawley seismic zone at Durmid Hill (DH). The topographic relief of DH is a product of faulting and folding of Pleistocene Borrego Formation strata (Babcock, 1974). Burgmann's (1991) detailed mapping and analysis of the western part of DH showed that the folds and faults accommodate transpression. Key to Burgmann's work was the recognition that the ~2m thick Bishop Ash, a prominent marker horizon, has been elongated parallel to the hinges of folds and boudinaged. We are mapping in detail the eastern portion of DH, nearer to the trace of the SAF. Folds in the eastern part of DH are tighter and thrust faulting is more prominent, consistent with greater shortening magnitude oblique to the SAF. Boudinage of the ash layer again indicates elongation parallel to fold hinges and subparallel to the SAF. The Bishop Ash locally is <1m thick along fold limbs in eastern DH, suggesting that significant continuous deformation accompanied the development of map-scale features. We measured anisotropy of magnetic susceptibility (AMS) fabrics in the Bishop Ash in order to assess continuous deformation in the Ash at DH. Because the Bishop Ash at DH is altered, consisting mainly of silica glass and clay minerals, samples from DH have significantly lower magnetic susceptibilities than Bishop Ash samples from elsewhere in the Salton Trough. With such low susceptibilities, there is significant scatter in the orientation of magnetic foliation and lineation in our samples. Still, in some Bishop samples within 1 km of the SAF, magnetic foliation is consistent with fold-related flattening. Magnetic lineation in these samples is consistently sub-parallel to fold hinges, parallel to the elongation direction inferred from boudinage. Even close to the trace of the SAF, this correlation breaks down in map-scale zones where fold hinge lines change attitude, fold shapes change, and the distribution and orientations of fractures and veins changes. These zones of structural complication separate broader regions of more uniform deformation patterns. Together, the geometry of structures and AMS fabrics suggest that deformation in eastern DH occurs by the distortion and reorientation of more or less coherent blocks separated by narrow zones where structural elements change orientation.

Experimental Study on Semi-Dry Flue Gas Desulfurization Ash Used in Steel Slag Composite Material

NASA Astrophysics Data System (ADS)

Lu, Lijun; Fang, Honghui

This article carried out the experimental study on using desulfurization ash in steel slag composite material. This was done by investigating the desulfurization ash content in formula one and formula two samples on the influence of setting time and strength of mortar. Through this study the following conclusions were reached for formula one: (1) a setting time of more than 10 hours is required, (2) a dosage of desulfurization ash of 1 2% is optimal, where flexural strength is reduced by 10% 23% and compressive strength reduced by 5.7% 16.4%. The conclusions of formula two were: (1) when the dosage of desulfurization ash is within 5%, the setting time is within 10 hours; (2) when the dosage of desulfurization ash is 1 2%, the flexural strength is increased by 5 7% and the compressive strength is reduced by 1 2%. The results show that the formula two is better.

Wetting and Spreading of Molten Volcanic Ash in Jet Engines.

PubMed

Song, Wenjia; Lavallée, Yan; Wadsworth, Fabian B; Hess, Kai-Uwe; Dingwell, Donald B

2017-04-20

A major hazard to jet engines posed by volcanic ash is linked to the wetting and spreading of molten ash droplets on engine component surfaces. Here, using the sessile drop method, we study the evolution of the wettability and spreading of volcanic ash. We employ rapid temperature changes up to 1040-1450 °C, to replicate the heating conditions experienced by volcanic ash entering an operating jet engine. In this scenario, samples densify as particles coalesce under surface tension until they form a large system-sized droplet (containing remnant gas bubbles and crystals), which subsequently spreads on the surface. The data exhibit a transition from a heterogeneous to a homogeneous wetting regime above 1315 °C as crystals in the drops are dissolved in the melt. We infer that both viscosity and microstructural evolution are key controls on the attainment of equilibrium in the wetting of molten volcanic ash droplets.

pH-dependent leaching of dump coal ash - retrospective environmental analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Popovic, A.; Djordjevic, D.

2009-07-01

Trace and major elements in coal ash particles from dump of 'Nikola Tesla A' power plant in Obrenovac near Belgrade (Serbia) can cause pollution, due to leaching by atmospheric and surface waters. In order to assess this leaching potential, dump ash samples were subjected to extraction with solutions of decreasing pH values (8.50, 7.00, 5.50, and 4.00), imitating the reactions of the alkaline ash particles with the possible alkaline, neutral, and acidic (e.g., acid rain) waters. The most recently deposited ash represents the greatest environmental threat, while 'aged' ash, because of permanent leaching on the dump, was shown to havemore » already lost this pollution potential. On the basis of the determined leachability, it was possible to perform an estimation of the acidity of the regional rainfalls in the last decades.« less

Aerosols from the soufriere eruption plume of 17 april 1979.

PubMed

Sedlacek, W A; Heiken, G; Zoller, W H; Germani, M S

1982-06-04

Aerosol samples collected from the 17 April 1979 eruption plume of Soufriere, St. Vincent, at altitudes between 1.8 and 5.5 kilometers were physically and chemically very similar to the ash that fell on the island. Higher altitude samples (7.3 and 9.5 kilometers) had a much lower ash content but comparable concentrations of sulfate, which were above the background concentration found at these altitudes.

Aerosols from the Soufriere eruption plume of 17 April 1979

NASA Technical Reports Server (NTRS)

Sedlacek, W. A.; Heiken, G.; Zoller, W. H.; Germani, M. S.

1982-01-01

Aerosol samples collected from the April 17, 1979 eruption plume of Soufriere, St. Vincent, at altitudes between 1.8 and 5.5 kilometers were physically and chemically very similar to the ash that fell on the island. Higher altitude samples (7.3 and 9.5 kilometers) had a much lower ash content but comparable concentrations of sulfate, which were above the background concentration found at these altitudes.

Market assessment of PFBC ash use

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bland, A. E.; Brown, T. H., Western Research Institute

1998-01-01

Pressurized fluidized bed combustion (PFBC) of coal is undergoing demonstration in the United States, as well as throughout the world. American Electric Power`s (AEP`s) bubbling PFBC 70 MWe Tidd demonstration program in Ohio and pilot-scale development at Foster Wheeler Energia Oy 10 MWth circulating PFBC at Karhula, Finland, have demonstrated the advantages of PFBC technology. Further technology development in the US is planned with the deployment of the technology at the MacIntosh Clean Coal project in Lakeland, Florida. Development of uses for solid wastes from PFBC coal-fired power systems is being actively pursued as part of the demonstration of PFBCmore » technologies. Ashes collected from Foster Wheeler Energia Oy pilot circulating PFBC tests in Karhula, Finland, operating on (1) low sulfur subbituminous and (2) high sulfur bituminous coal; and ash from the AEP`s high-sulfur bituminous coal-fired bubbling PFBC in Brilliant, Ohio, were evaluated in laboratory and pilot-scale ash use testing at Western Research Institute (WRI).« less

Investigations of some building materials for γ-rays shielding effectiveness

NASA Astrophysics Data System (ADS)

Mann, Kulwinder Singh; Kaur, Baljit; Sidhu, Gurdeep Singh; Kumar, Ajay

2013-06-01

For construction of residential and non-residential buildings bricks are used as building blocks. Bricks are made from mixtures of sand, clay, cement, fly ash, gypsum, red mud and lime. Shielding effectiveness of five soil samples and two fly ash samples have been investigated using some energy absorption parameters (Mass attenuation coefficients, mass energy absorption coefficients, KERMA (kinetic energy released per unit mass), HVL, equivalent atomic number and electron densities) firstly at 14 different energies from 81-1332 keV then extended to wide energy range 0.015-15 MeV. The soil sample with maximum shielding effectiveness has been used for making eight fly ash bricks [(Lime)0.15 (Gypsum)0.05 (Fly Ash)x (Soil)0.8-x, where values of x are from 0.4-0.7]. High Purity Germanium (HPGe) detector has been used for gamma-ray spectroscopy. The elemental compositions of samples were analysed using an energy dispersive X-ray fluorescence (EDXRF) spectrometer. The agreements of theoretical and experimental values of mass attenuation coefficient have been found to be quite satisfactory. It has been verified that common brick possess the maximum shielding effectiveness for wide energy range 0.015-15 MeV. The results have been shown graphically with some useful conclusions for making radiation safe buildings.

Performance of fly ash based geopolymer incorporating palm kernel shell for lightweight concrete

NASA Astrophysics Data System (ADS)

Razak, Rafiza Abd; Abdullah, Mohd Mustafa Al Bakri; Yahya, Zarina; Jian, Ang Zhi; Nasri, Armia

2017-09-01

A concrete which cement is totally replaced by source material such as fly ash and activated by highly alkaline solutions is known as geopolymer concrete. Fly ash is the most common source material for geopolymer because it is a by-product material, so it can get easily from all around the world. An investigation has been carried out to select the most suitable ingredients of geopolymer concrete so that the geopolymer concrete can achieve the desire compressive strength. The samples were prepared to determine the suitable percentage of palm kernel shell used in geopolymer concrete and cured for 7 days in oven. After that, other samples were prepared by using the suitable percentage of palm kernel shell and cured for 3, 14, 21 and 28 days in oven. The control sample consisting of ordinary Portland cement and palm kernel shell and cured for 28 days were prepared too. The NaOH concentration of 12M, ratio Na2SiO3 to NaOH of 2.5, ratio fly ash to alkaline activator solution of 2.0 and ratio water to geopolymer of 0.35 were fixed throughout the research. The density obtained for the samples were 1.78 kg/m3, water absorption of 20.41% and the compressive strength of 14.20 MPa. The compressive strength of geopolymer concrete is still acceptable as lightweight concrete although the compressive strength is lower than OPC concrete. Therefore, the proposed method by using fly ash mixed with 10% of palm kernel shell can be used to design geopolymer concrete.

Biomass fly ash incorporation in cement based materials =

NASA Astrophysics Data System (ADS)

Rajamma, Rejini

In recent years, pressures on global environment and energy security have led to an increasing demand on renewable energy sources, and diversification of Europe's energy supply. Among these resources the biomass could exert an important role, since it is considered a renewable and CO2 neutral energy resource once the consumption rate is lower than the growth rate, and can potentially provide energy for heat, power and transports from the same installation. Currently, most of the biomass ash produced in industrial plants is either disposed of in landfill or recycled on agricultural fields or forest, and most times this goes on without any form of control. However, considering that the disposal cost of biomass ashes are raising, and that biomass ash volumes are increasing worldwide, a sustainable ash management has to be established. The main objective of the present study is the effect of biomass fly ashes in cement mortars and concretes in order to be used as a supplementary cementitious material. The wastes analyzed in the study were collected from the fluidized bed boilers and grate boilers available in the thermal power plants and paper pulp plants situated in Portugal. The physical as well as chemical characterisations of the biomass fly ashes were investigated. The cement was replaced by the biomass fly ashes in 10, 20 and 30% (weight %) in order to investigate the fresh properties as well as the hardened properties of biomass fly ash incorporated cement mortar and concrete formulations. Expansion reactions such as alkali silica reaction (ASR), sulphate attack (external and internal) were conducted in order to check the durability of the biomass fly ash incorporated cement mortars and concretes. Alternative applications such as incorporation in lime mortars and alkali activation of the biomass fly ashes were also attempted. The biomass fly ash particles were irregular in shape and fine in nature. The chemical characterization revealed that the biomass fly ashes were similar to a class C fly ash. The mortar results showed a good scope for biomass fly ashes as supplementary cementitious materials in lower dosages (<20%). The poor workability, concerns about the organic content, alkalis, chlorides and sulphates stand as the reasons for preventing the use of biomass fly ash in high content in the cement mortars. The results obtained from the durability tests have shown a clear reduction in expansion for the biomass fly ash mortars/concretes and the binder blend made with biomass fly ash (20%) and metakaolin (10%) inhibited the ASR reaction effectively. The biomass fly ash incorporation in lime mortars did not improve the mortar properties significantly though the carbonation was enhanced in the 15-20% incorporation. The biomass fly ash metakaolin blend worked well in the alkali activated complex binder application also. Portland cement free binders (with 30-40 MPa compressive strength) were obtained on the alkali activation of biomass fly ashes (60-80%) blended with metakaolin (20-40%).

Coal Fly Ash Ceramics: Preparation, Characterization, and Use in the Hydrolysis of Sucrose

PubMed Central

dos Santos, Ricardo Pires; Martins, Jorge; Gadelha, Carlos; Cavada, Benildo; Albertini, Alessandro Victor; Arruda, Francisco; Vasconcelos, Mayron; Teixeira, Edson; Alves, Francisca; Lima Filho, José; Freire, Valder

2014-01-01

Coal ash is a byproduct of mineral coal combustion in thermal power plants. This residue is responsible for many environmental problems because it pollutes soil, water, and air. Thus, it is important to find ways to reuse it. In this study, coal fly ash, obtained from the Presidente Médici Thermal Power Plant, was utilized in the preparation of ceramic supports for the immobilization of the enzyme invertase and subsequent hydrolysis of sucrose. Coal fly ash supports were prepared at several compaction pressures (63.66–318.30 MPa) and sintered at 1200°C for 4 h. Mineralogical composition (by X-ray diffraction) and surface area were studied. The ceramic prepared with 318.30 MPa presented the highest surface area (35 m2/g) and amount of immobilized enzyme per g of support (76.6 mg/g). In assays involving sucrose inversion, it showed a high degree of hydrolysis (around 81%) even after nine reuses and 30 days' storage. Therefore, coal fly ash ceramics were demonstrated to be a promising biotechnological alternative as an immobilization support for the hydrolysis of sucrose. PMID:25110726

The enrichment of natural radionuclides in oil shale-fired power plants in Estonia--the impact of new circulating fluidized bed technology.

PubMed

Vaasma, Taavi; Kiisk, Madis; Meriste, Tõnis; Tkaczyk, Alan Henry

2014-03-01

Burning oil shale to produce electricity has a dominant position in Estonia's energy sector. Around 90% of the overall electric energy production originates from the Narva Power Plants. The technology in use has been significantly renovated - two older types of pulverized fuel burning (PF) energy production units were replaced with new circulating fluidized bed (CFB) technology. Additional filter systems have been added to PF boilers to reduce emissions. Oil shale contains various amounts of natural radionuclides. These radionuclides concentrate and become enriched in different boiler ash fractions. More volatile isotopes will be partially emitted to the atmosphere via flue gases and fly ash. To our knowledge, there has been no previous study for CFB boiler systems on natural radionuclide enrichment and their atmospheric emissions. Ash samples were collected from Eesti Power Plant's CFB boiler. These samples were processed and analyzed with gamma spectrometry. Activity concentrations (Bq/kg) and enrichment factors were calculated for the (238)U ((238)U, (226)Ra, (210)Pb) and (232)Th ((232)Th, (228)Ra) family radionuclides and for (40)K in different CFB boiler ash fractions. Results from the CFB boiler ash sample analysis showed an increase in the activity concentrations and enrichment factors (up to 4.5) from the furnace toward the electrostatic precipitator block. The volatile radionuclide ((210)Pb and (40)K) activity concentrations in CFB boilers were evenly distributed in finer ash fractions. Activity balance calculations showed discrepancies between input (via oil shale) and output (via ash fractions) activities for some radionuclides ((238)U, (226)Ra, (210)Pb). This refers to a situation where the missing part of the activity (around 20% for these radionuclides) is emitted to the atmosphere. Also different behavior patterns were detected for the two Ra isotopes, (226)Ra and (228)Ra. A part of (226)Ra input activity, unlike (228)Ra, was undetectable in the solid ash fractions of the boiler. Most probably it is released to the surrounding environment. Copyright © 2014 Elsevier Ltd. All rights reserved.

Study of PCDD/Fs distribution in fly ash, ash deposits, and bottom ash from a medical waste incinerator in China.

PubMed

Du, Yingzhe; Jin, Yuqi; Lu, Shengyong; Peng, Zheng; Li, Xiaodong; Yan, Jianhua

2013-02-01

Over the past decades in China, the number of medical waste incinerators (MWIs) has been rising rapidly, causing emissions of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs). In this study, samples of fly ash, ash deposits, and bottom ash from typical MWIs were analyzed for PCDD/Fs and their distribution characteristics. Results showed international toxic equivalent (I-TEQ) values in the range of 6.9-67 ng I-TEQ/g in fly ash and ash deposits, whereas the concentration in bottom ash was extremely low (only 1.33 pg I-TEQ/g), yet the generation of PCDD/Fs was mostly de novo synthesis in fly ash and ash deposits according to the ratio of PCDFs to PCDDs; the major distribution differences of PCDD/Fs in fly ash was manifested by the content of toxic furan 2,3,7,8-TCDF but other toxic PCDD/Fs showed similar distribution. Other findings are that 2,3,4,7,8-PeCDF had the most contribution to TEQ concentration, and that the most abundant toxic furan congener is 1,2,3,4,6,7,8-HpCDF. Correlation analysis showed that there was no significant correlation between PCDD/Fs concentration and several other physical and chemical parameters. This paper is of interest because it presents the emission performances of PCDD/Fs in ash from medical waste incineration in China. PCDD/F contents in fly ash and ash deposits vary between 6.9 and 67.3 ng I-TEQ/g. However, the concentration in bottom ash was extremely low (only 1.33 x 10(-3) ng I-TEQ/g). The fingerprints of PCDD/Fs in fly ash are almost similar, except for 2,3,7,8-TCDF. There is no marked correlation between PCDD/Fs and other physicochemical properties.

Transcriptomic Signatures of Ash (Fraxinus spp.) Phloem

PubMed Central

Mamidala, Praveen; Bonello, Pierluigi; Herms, Daniel A.; Mittapalli, Omprakash

2011-01-01

Background Ash (Fraxinus spp.) is a dominant tree species throughout urban and forested landscapes of North America (NA). The rapid invasion of NA by emerald ash borer (Agrilus planipennis), a wood-boring beetle endemic to Eastern Asia, has resulted in the death of millions of ash trees and threatens billions more. Larvae feed primarily on phloem tissue, which girdles and kills the tree. While NA ash species including black (F. nigra), green (F. pennsylvannica) and white (F. americana) are highly susceptible, the Asian species Manchurian ash (F. mandshurica) is resistant to A. planipennis perhaps due to their co-evolutionary history. Little is known about the molecular genetics of ash. Hence, we undertook a functional genomics approach to identify the repertoire of genes expressed in ash phloem. Methodology and Principal Findings Using 454 pyrosequencing we obtained 58,673 high quality ash sequences from pooled phloem samples of green, white, black, blue and Manchurian ash. Intriguingly, 45% of the deduced proteins were not significantly similar to any sequences in the GenBank non-redundant database. KEGG analysis of the ash sequences revealed a high occurrence of defense related genes. Expression analysis of early regulators potentially involved in plant defense (i.e. transcription factors, calcium dependent protein kinases and a lipoxygenase 3) revealed higher mRNA levels in resistant ash compared to susceptible ash species. Lastly, we predicted a total of 1,272 single nucleotide polymorphisms and 980 microsatellite loci, among which seven microsatellite loci showed polymorphism between different ash species. Conclusions and Significance The current transcriptomic data provide an invaluable resource for understanding the genetic make-up of ash phloem, the target tissue of A. planipennis. These data along with future functional studies could lead to the identification/characterization of defense genes involved in resistance of ash to A. planipennis, and in future ash breeding programs for marker development. PMID:21283712

Lab-scale ash production by abrasion and collision experiments of porous volcanic samples

NASA Astrophysics Data System (ADS)

Mueller, S. B.; Lane, S. J.; Kueppers, U.

2015-09-01

In the course of explosive eruptions, magma is fragmented into smaller pieces by a plethora of processes before and during deposition. Volcanic ash, fragments smaller than 2 mm, has near-volcano effects (e.g. increasing mobility of PDCs, threat to human infrastructure) but may also cause various problems over long duration and/or far away from the source (human health and aviation matters). We quantify the efficiency of ash generation during experimental fracturing of pumiceous and scoriaceous samples subjected to shear and normal stress fields. Experiments were designed to produce ash by overcoming the yield strength of samples from Tenerife (Canary Islands, Spain), Sicily and Lipari Islands (Italy), with this study having particular interest in the < 355 μm fraction. Fracturing within volcanic conduits, plumes and pyroclastic density currents (PDCs) was simulated through a series of abrasion (shear) and collision (normal) experiments. An understanding of these processes is crucial as they are capable of producing very fine ash (< 10 μm). These particles can remain in the atmosphere for several days and may travel large distances ( 1000s of km). This poses a threat to the aviation industry and human health. From the experiments we establish that abrasion produced the finest-grained material and up to 50% of the generated ash was smaller than 10 μm. In comparison, the collision experiments that applied mainly normal stress fields produced coarser grain sizes. Results were compared to established grain size distributions for natural fall and PDC deposits and good correlation was found. Energies involved in collision and abrasion experiments were calculated and showed an exponential correlation with ash production rate. Projecting these experimental results into the volcanic environment, the greatest amounts of ash are produced in the most energetic and turbulent regions of volcanic flows, which are proximal to the vent. Finest grain sizes are produced in PDCs and can be observed as co-ignimbrite clouds above density currents. Finally, a significant dependency was found between material density and the mass of fines produced, also observable in the total particle size distribution: higher values of open porosity promote the generation of finer-grained particles and overall greater ratios of ash. While this paper draws on numerous previous studies of particle comminution processes, it is the first to analyze and compare results of several comminution experiments with each other in order to characterize these mechanisms.

The effects of fire temperatures on water soluble heavy metals.

NASA Astrophysics Data System (ADS)

Pereira, P.; Ubeda, X.; Martin, D. A.

2009-04-01

Fire ash are majority composed by base cations, however the mineralized organic matter, led also available to transport a higher quantity of heavy metals that potentially could increase a toxicity in soil and water resources. The amount availability of these elements depend on the environment were the fire took place, burning temperature and combusted tree specie. The soil and water contamination from fire ash has been neglected, because the majority of studies are focused on base cations dynamic. Our research, beside contemplate major elements, is focused in to study the behavior of heavy metals released from ash slurries created at several temperatures under laboratory environment, prescribed fires and wildland fires. The results presented in these communication are preliminary and study the presence of Aluminium (Al3+), Manganese (Mn2+), Iron (Fe2+) and Zinc (Zn2+) of ash slurries generated in laboratory environment at several temperatures (150°, 200°, 250°, 300°, 350°, 400°,450°, 500°, 550°C) from Quercus suber, Quercus robur, Pinus pinea and Pinus pinaster and from a low medium temperature prescribed fire in a forest dominated Quercus suber trees. We observed that ash produced at lower and medium temperatures (<300-400°C) released in water higher contents of Al3+ than unburned sample, especially in Quercus species and Mn2+ in Pinus ashes. Fe2+ and Zn2+ showed a reduced concentration in test solution in relation to unburned sample at all temperatures of exposition. In the results obtained from prescribed fire, we identify a higher release of Al3+ and a decrease of the remain elements. The solubilization of these elements are related with pH levels and ash calcite content, because their ability to capture ions in solution. Moreover, the amount and the type of ions released in relation to unburned sample vary in each specie. In this study Al3+ release is related with Quercus species and Mn2+ with Pinus species. Fire ashes can be an environmental problem, because at long term can increase soil acidity. After all base cations have being leached, pH values decrease, and the heavy metals remaining in the ash are easily transported with unknown impacts on soil and water resources. Research is needed in the study at long term of the effects of fire in metals accumulation in soil resources, and all these aspects will be discussed. Keywords: Fire ash, heavy metals, Quercus suber, Quercus robur, Pinus pinea, Pinus pinaster, prescribed fire, pH, Calcite

Tracing industrial heavy metal inputs to topsoils using using cadmium isotopes

NASA Astrophysics Data System (ADS)

Huang, Y.; Ma, L.; Ni, S.; Lu, H.; Liu, Z.; Zhang, C.; Guo, J.; Wang, N.

2015-12-01

Anthropogenic activities have dominated heavy metal (such as Cd, Pb, and Zn) cycling in many environments. The extent and fate of these metal depositions in topsoils, however, have not been adequately evaluated. Here, we utilize an innovative Cadmium (Cd) isotope tool to trace the sources of metal pollutants in topsoils collected from surrounding a Vanadium Titanium Magnetite smelting plant in Sichuan, China. Topsoil samples and possible pollution end-members such as fly ashes, bottom ashes, ore materials, and coal were also collected from the region surrounding the smelting plant and were analyzed for Cd isotope ratios (d114Cd relative to Cd NIST 3108). Large Cd isotope fractionation (up to 3 ‰) was observed in these industrial end-members: fly ashes possessed higher δ114Cd values ranging from +0.03 to +0.19‰; bottom fly ashes have lower δ114Cd values ranging from -0.35 to -2.46‰; and unprocessed ore and coal samples has δ114Cd value of -0.40‰. This fractionation can be attributed to the smelting processes during which bottom ashes acquired lighter Cd isotope signatures while fly ashes were mainly characterized by heavy isotope ratios, in comparison to the unprocessed ore and coal samples. Indeed, δ114Cd values of topsoils in the smelting area range from 0.29 to -0.56‰, and more than half of the soils analyzed have distinct δ114Cd values > 0‰. Cd isotopes and concentrations measured in topsoils suggested that processed materials (fly and bottom ashes from ore and coal actually used by the smelting plant) were the major source of Cd in soils. In a δ114Cd vs 1/Cd mixing diagram, the soils represent a mixture of three identified end members (fly ash, bottom ash and deep unaffected soil) with distinct Cd isotopic compositions and concentrations. Deep soils have the same δ114Cd values range as the unprocessed ore and coal, which indicated the Cd isotope fractionation did occur during evaporation and condensation processes inside the smelting plant. The signatures of fly ash end member might be even higher according to the δ114Cd increasing trend of topsoils with the increasing of Cd concentration of the topsoils. Our study suggested that δ114Cd values can be used to distinguish sources of anthropogenic Cd and to construct metal budgets in in this studying area.

Chemical conversion of sulphur dioxide on Eyjafjallajökull's volcanic ash from the 2010 eruption

NASA Astrophysics Data System (ADS)

Dupart, Yoan; Burel, Laurence; Delichere, Pierre; George, Christian; D'Anna, Barbara

2013-04-01

Volcanic eruptions induce important climatic and weather modifications. When volcanic ashes are emitted into the atmosphere they can travel for several weeks according to their size distribution and altitude of the emission. Eyjafjallajökull eruption, between April 14th and May 23th, is considered as a medium-size eruption. The upper level winds advected ashes over the UK and continental Europe. During volcanic eruptions high amounts of SO2 were injected into the atmosphere (from 50 to 200 ppbv)[1]. Previous works showed that SO2 could be convert into sulfate on mineral dust surfaces under dark conditions[2]. However, no conversion has been studied with real volcanic ashes and under day conditions (light exposure). For this study, real Eyjafjallajökull's ashes samples, collected on the 2010.04.18 at Seljavellir, were used. The ashes were deposited on a horizontal cylindrical coated-wall flow tube reactor surrounded by 5 fluorescent lamps (340-420 nm). The kinetic studies revealed that the presence of UV-A irradiation enhanced the conversion of SO2 on ashes samples. Moreover chemical analyses as XPS, Ion Chromatography and SEM were performed on volcanic ashes before and after exposition to SO2. XPS and ion chromatography analyzes showed that the presence of light increase the SO2 uptake on ashes surfaces and convert it into ions sulphate. Beside SEM analyses disclosed that the conversion takes place systematically on an iron oxide site . By combining kinetics and chemical analysis we are able to propose a new mechanism for the SO2 conversion on mineral surfaces under light conditions. 1. Self, S., et al., Volatile fluxes during flood basalt eruptions and potential effects on the global environment: A Deccan perspective. Earth and Planetary Science Letters, 2006. 248(1-2): p. 518-532. 2. Zhang et al., Heterogeneous Reactions of Sulfur Dioxide on Typical Mineral Particles, J. Phys. Chem. B, 2006

The 1815 Tambora ash fall: implications for transport and deposition of distal ash on land and in the deep sea

NASA Astrophysics Data System (ADS)

Kandlbauer, Jessica; Carey, Steven N.; Sparks, R. Stephen J.

2013-04-01

Tambora volcano lies on the Sanggar Peninsula of Sumbawa Island in the Indonesian archipelago. During the great 1815 explosive eruption, the majority of the erupted pyroclastic material was dispersed and subsequently deposited into the Indian Ocean and Java Sea. This study focuses on the grain size distribution of distal 1815 Tambora ash deposited in the deep sea compared to ash fallen on land. Grain size distribution is an important factor in assessing potential risks to aviation and human health, and provides additional information about the ash transport mechanisms within volcanic umbrella clouds. Grain size analysis was performed using high precision laser diffraction for a particle range of 0.2 μm-2 mm diameter. The results indicate that the deep-sea samples provide a smooth transition to the land samples in terms of grain size distributions despite the different depositional environments. Even the very fine ash fraction (<10 μm) is deposited in the deep sea, suggesting vertical density currents as a fast and effective means of transport to the seafloor. The measured grain size distribution is consistent with an improved atmospheric gravity current sedimentation model that takes into account the finite duration of an eruption. In this model, the eruption time and particle fall velocity are the critical parameters for assessing the ash component depositing while the cloud advances versus the ash component depositing once the eruption terminates. With the historical data on eruption duration (maximum 24 h) and volumetric flow rate of the umbrella cloud (˜1.5-2.5 × 1011 m3/s) as input to the improved model, and assuming a combination of 3 h Plinian phase and 21 h co-ignimbrite phase, it reduces the mean deviation of the predicted versus observed grain size distribution by more than half (˜9.4 % to ˜3.7 %) if both ash components are considered.

Amelioration of soil PAH and heavy metals by combined application of fly ash and biochar

NASA Astrophysics Data System (ADS)

Masto, Reginald; George, Joshy; Ansari, Md; Ram, Lal

2016-04-01

Generation of electricity through coal combustion produces huge quantities of fly ash. Sustainable disposal and utilization of these fly ash is a major challenge. Fly ash along with other amendments like biochar could be used for amelioration of soil. In this study, fly ash and biochar were used together for amelioration of polycyclic aromatic hydrocarbon (PAH) contaminated soil. Field experiment was conducted to investigate the effects of fly ash and biochar on the amelioration of soil PAH, and the yield of Zea mays. The treatments were control, biochar (4 t/ha), fly ash (4 t/ha), ash + biochar ( 2 + 2 t/ha). Soil samples were collected after the harvest of maize crop and analysed for chemical and biological parameters. Thirteen PAHs were analysed in the postharvest soil samples. Soil PAHs were extracted in a microwave oven at 120 °C using hexane : acetone (1:1) mixture. The extracted solutions were concentrated, cleaned and the 13 PAHs [Acenaphthene (Ace), fluorene (Flr), phenanthrene (Phn), anthracene(Ant), pyrene(Pyr), benz(a)anthracene (BaA), chrysene (Chy), benzo(b)fluoranthene (BbF), benzo(k)fluoranthene (BkF), benzo(a)pyrene, benzo(g,h,i)perylene (BghiP), dibenzo(a,h)anthracene, and indeno(1,2,3-cd)pyrene)(Inp)] were analysed using GC-MS. The mean pH increased from 6.09 in control to 6.64 and 6.58 at biochar and fly ash treated soils, respectively. N content was not affected, whereas addition of biochar alone and in combination with fly ash, has significantly increased the soil organic carbon content. P content was almost double in combined (9.06 mg/kg) treatment as compared to control (4.32 mg/kg). The increase in K due to biochar was 118%, whereas char + ash increased soil K by 64%. Soil heavy metals were decreased: Zn (-48.4%), Ni (-41.4%), Co (-36.9%), Cu (-35.7%), Mn (-34.3%), Cd (-33.2%), and Pb (-30.4%). Soil dehydrogenase activity was significantly increased by ash and biochar treatments and the maximum activity was observed for the combined treatment. Peroxidase, phenol oxidase, and catalase activities were not affected by these treatments. Acid phosphatase activity decreased, whereas alkaline phosphatase activity increased due to biochar and fly ash treatment. Microbial biomass carbon increased significantly (P < 0.05) with biochar (+27.9%), fly ash (19.8%), and char + ash (+27.9%) applications. Maize grain yield was increased by biochar (+11.4%) and char + ash (+28.1%) treatments. The total PAH concentration decreased from 4191 μg/kg in control to 1930 μg/kg in fly ash; 1509 μg/kg in biochar and 1011 μg/kg in ash + char treatments. Among the different PAHs the concentration was higher for BkF, which decreased from 713 μg/kg in control to 139 - 315 μg/kg under different treatments. Overall, combined application of fly ash and biochar was found to be effective in amelioration of soil quality parameters and improving crop yield.

Chemical composition and some trace element contents in coals and coal ash from Tamnava-Zapadno Polje Coal Field, Serbia

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vukasinovic-Pesic, V.; Rajakovic, L.J.

2009-07-01

The chemical compositions and trace element contents (Zn, Cu, Co, Cr, Ni, Pb, Cd, As, B, Hg, Sr, Se, Be, Ba, Mn, Th, V, U) in coal and coal ash samples from Tamnava-Zapadno Polje coal field in Serbia were studied. The coal from this field belongs to lignite. This high volatility coal has high moisture and low S contents, moderate ash yield, and high calorific value. The coal ash is abundant in alumosilicates. Many trace elements such as Ni > Cd > Cr > B > As > Cu > Co > Pb > V > Zn > Mn inmore » the coal and Ni > Cr > As > B > Cu > Co = Pb > V > Zn > Mn in the coal ash are enriched in comparison with Clarke concentrations.« less

Synthesis of geopolymer composites from a mixture of ferronickel slag and fly ash

NASA Astrophysics Data System (ADS)

Liu, Yun; Zhang, Kang; Feng, Enjuan; Zhao, Hongyi; Liu, Futian

2017-03-01

The synthesis of geopolymers using ferronickel slag and fly ash under alkaline activation was studied. In order to study the effects of different fly ash content on the mechanical properties of the geopolymers produced, the compressive strength of samples was tested at 3, 7, 28 days. The results showed that when the fly ash content was 40%, the compressive strength reached the highest (110.32MPa) at 28 days. XRD analysis showed that the ferronickel slag geopolymers had amorphous aluminosilicate phase formation, indicating that the hydration reaction occurred. FTIR analysis showed the reaction of the geopolymers generated at Si-O-T (Si, Al) and Al-O-Si three-dimensional network. In SEM images, the structure of the geopolymers with 40% fly ash was more compact and cohesive.

Naturally Occurring Radionuclides of Ash Produced by Coal Combustion. The Case of the Kardia Mine in Northern Greece

NASA Astrophysics Data System (ADS)

Fotakis, M.; Tsikritzis, L.; Tzimkas, N.; Kolovos, N.; Tsikritzi, R.

2008-08-01

West Macedonia Lignite Center (WMLC), located in Northwest Greece, releases into the atmosphere about 21,400 tons/year of fly ash through the stacks of four coal fired plants. The lignite ash contains naturally occurring radionuclides, which are deposited on the WMLC basin. This work investigates the natural radioactivity of twenty six ash samples, laboratory produced from combustion of lignite, which was sampled perpendicularly to the benches of the Kardia mine. The concentrations of radionuclides 40K, 235U, 238U, 226Ra, 228Ra and 232Th, were measured spectroscopically and found round one order of magnitude as high as those of lignite. Subsequently the Radionuclide Partitioning Coefficients of radionuclides were calculated and it was found that they are higher for 232Th, 228Ra and 40K, because the latter have closer affinity with the inorganic matrix of lignite. During combustion up to one third of the naturally occurring radioisotopes escape from the solid phase into the flue gases. With comparison to relative global data, the investigated ash has been found to have relatively high radioactivity, but the emissions of the WMLC radionuclides contribute only 0.03% to the mean annual absorbed dose.

Get immersed and black in fire ash world. Field Wildgeographers experience.

NASA Astrophysics Data System (ADS)

Pereira, Paulo; Cerdà, Artemi; Misiune, Ieva; Jordan, Antonio

2015-04-01

Ash is the footprint left by the fire. This residue is very important to landscape recover and is an important source of soil protection after the fire. Get immersed in fire ash world is the same thing of get dirty and do not be recognizable in a fire affected area. To measure ash in the field we have to be careful where to step, how to do the experimental design, collect samples and find with accuracy the places measured before. A good methodology is needed in design field experiments, collect ash samples and monitoring ash evolution (Cerdà and Doerr, 2008; Bodi et al., 2014; Pereira and Ubeda, 2010; Pereira et al. 2011; 2012, 2013, 2014, 2015). The objective of this work is to share with the Avatar world the methodologies used when wildgeographers get immersed in fire ash world, including: 1) Identify the best study area 2) Experimental design 3) Sample collection 4) Get dirty and have fun in the field 5) Laboratory, Statistical and spatial analysis Acknoledgements The author are thankful for the support of the projects POSTFIRE (Soil quality, erosion control and plant cover recovery under different post-fire management scenarios, CGL2013-47862-C2-1-R) funded by the Spanish Ministry of Economy and Competitiveness; GL2008-02879/BTE, LEDDRA 243857, RECARE (Preventing and Remediating Degradation of Soils in Europe Through Land Care, FP7-ENV-2013-TWO STAGE), funded by the European Commission; and for the COST action ES1306 (Connecteur: Connecting European Connectivity Research), FUEGORED (Spanish Network of Forest Fire Effects on Soils, http://grupo.us.es/fuegored/) and to Comissionat per a Universitats i Recerca del DIUE de la Generalitat de Catalunya. References Bodi, M., Martin, D.A., Santin, C., Balfour, V., Doerr, S.H., Pereira, P., Cerda, A., Mataix-Solera, J. (2014) Wildland fire ash: production, composition and eco-hydro-geomorphic effects. Earth-Science Reviews, 130, 103-127. Cerdà, A. y Doerr, S.H. 2008. The effect of ash and needle cover on surface runoff and erosion in the immediate post-fire period. Catena, 74 , 256- 263. doi:10.1016/S0341-8162(02)00027-9 Pereira, P., Cerdà, A., Úbeda, X., Mataix-Solera, J. Arcenegui, V., Zavala, L. 2015. Modelling the impacts of wildfire on ash thickness in a short-term period, Land Degradation and Development, (In Press), DOI: 10.1002/ldr.2195 Pereira, P., Cerdà, A., Úbeda, X., Mataix-Solera, J., Jordan, A. Burguet, M. (2013) Spatial models for monitoring the spatio-temporal evolution of ashes after fire - a case study of a burnt grassland in Lithuania, Solid Earth, 4, 153-165. Pereira, P., Úbeda, X. (2010) Spatial variation of heavy metals released from ashes after a wildfire, Journal of Environmental Engineering and Landscape Management, 18(1), 13-22. Pereira, P., Ubeda, X., Martin, D. (2012) Fire severity effects on ash chemical composition and water-extractable elements, Geoderma, 191, 105-114. Pereira, P., Úbeda, X., Martin, D., Mataix-Solera, J., Guerrero, C. (2011) Effects of a low prescribed fire in ash water soluble elements in a Cork Oak (Quercus suber) forest located in Northeast of Iberian Peninsula, Environmental Research, 111(2), 237-247. Pereira, P., Úbeda, X., Martin, D., Mataix-Solera, J., Cerdà, A., Burguet, M. (2014) Wildfire effects on extractable elements in ash from a Pinus pinaster forest in Portugal, Hydrological Processes, 28, 3681-3690

A comparison of landfill leachates based on waste composition.

PubMed

Moody, Chris M; Townsend, Timothy G

2017-05-01

Samples of leachate were collected from fourteen landfills in the state of Florida, United States that contained primarily putrescible waste (municipal solid waste, MSW, and yard waste), MSW incinerator (MSWI) ash, or a combination of both. Assessment of leachates included trace metals, anions, and nutrients in order to create a mass balance of total dissolved solids (TDS). As expected from previously literature, MSW leached a complex matrix of contaminants while MSWI ash leachate TDS was more than 98% metallic salts. The pH of the MSWI ash leachate samples was slightly acidic or neutral in character, which is contradictory to the results commonly reported in the literature. The cause of this is hypothesized to be a short-circuiting of rainfall in the landfill due to low hydraulic conductivities reported in ash landfills. The difference in pH likely contributed to the findings with respect to MSWI ash-characteristic trace metals in leachates such as aluminum. The authors have concluded that the research findings in this study are an indication of the differences between laboratory leachate quality studies and the conditions encountered in the field. In addition, a characterization of organic matter using qualitative and quantitative analyses determined that COD is not an accurate indicator of organic matter in leachates from landfills with a significant fraction of MSWI ash. Copyright © 2016 Elsevier Ltd. All rights reserved.

Oxidation characteristics of gasoline direct-injection (GDI) engine soot: Catalytic effects of ash and modified kinetic correlation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Choi, Seungmok; Seong, Heeje

In this paper, experimental analyses are conducted into the GDI soot oxidation characteristics as dependent on engine operating conditions. Soot is sampled at various engine operating conditions of a commercial 2.4 L GDI engine with a naturally aspirated, homogeneous, and stoichiometric operation strategy. The oxidation reactivity, ash composition, and carbon nanostructure of the GDI soot samples are analyzed using thermogravimetric analysis (TGA), scanning electron microscope–energy-dispersive spectroscopy (SEM-EDS), high-resolution transmission electron microscopy (HR-TEM), and Raman spectroscopy. Based on the analyses, a global GDI soot oxidation mechanism is proposed which includes the effects of soluble organic fractions (SOF)/weakly bonded carbon (WBC), andmore » three types of ash on GDI soot oxidation. The results show that GDI soot contains an order of magnitude higher ash fraction than does conventional diesel soot, and oxidation reactivity is significantly enhanced by the catalytic effects of ash, as a function of ash content in soot. A modified empirical kinetic correlation for GDI soot oxidation is suggested on the basis of the results, and the modified kinetic correlation predicts the GDI soot oxidation rate accurately for various engine operation points at wide ranges of soot conversion and temperature without modifying kinetic parameters. The kinetic parameters are determined from isothermal and non-isothermal thremogravimetric analysis (TGA) soot oxidation tests; the methods are elucidated in detail.« less

Oxidation characteristics of gasoline direct-injection (GDI) engine soot: Catalytic effects of ash and modified kinetic correlation

DOE PAGES

Choi, Seungmok; Seong, Heeje

2015-03-02

In this paper, experimental analyses are conducted into the GDI soot oxidation characteristics as dependent on engine operating conditions. Soot is sampled at various engine operating conditions of a commercial 2.4 L GDI engine with a naturally aspirated, homogeneous, and stoichiometric operation strategy. The oxidation reactivity, ash composition, and carbon nanostructure of the GDI soot samples are analyzed using thermogravimetric analysis (TGA), scanning electron microscope–energy-dispersive spectroscopy (SEM-EDS), high-resolution transmission electron microscopy (HR-TEM), and Raman spectroscopy. Based on the analyses, a global GDI soot oxidation mechanism is proposed which includes the effects of soluble organic fractions (SOF)/weakly bonded carbon (WBC), andmore » three types of ash on GDI soot oxidation. The results show that GDI soot contains an order of magnitude higher ash fraction than does conventional diesel soot, and oxidation reactivity is significantly enhanced by the catalytic effects of ash, as a function of ash content in soot. A modified empirical kinetic correlation for GDI soot oxidation is suggested on the basis of the results, and the modified kinetic correlation predicts the GDI soot oxidation rate accurately for various engine operation points at wide ranges of soot conversion and temperature without modifying kinetic parameters. The kinetic parameters are determined from isothermal and non-isothermal thremogravimetric analysis (TGA) soot oxidation tests; the methods are elucidated in detail.« less

Occurrence, profiles, and toxic equivalents of chlorinated and brominated polycyclic aromatic hydrocarbons in E-waste open burning soils.

PubMed

Nishimura, Chiya; Horii, Yuichi; Tanaka, Shuhei; Asante, Kwadwo Ansong; Ballesteros, Florencio; Viet, Pham Hung; Itai, Takaaki; Takigami, Hidetaka; Tanabe, Shinsuke; Fujimori, Takashi

2017-06-01

We conducted this study to assess the occurrence, profiles, and toxicity of chlorinated polycyclic aromatic hydrocarbons (Cl-PAHs) and brominated polycyclic aromatic hydrocarbons (Br-PAHs) in e-waste open burning soils (EOBS). In this study, concentrations of 15 PAHs, 26 Cl-PAHs and 14 Br-PAHs were analyzed in EOBS samples. We found that e-waste open burning is an important emission source of Cl-PAHs and Br-PAHs as well as PAHs. Concentrations of total Cl-PAHs and Br-PAHs in e-waste open burning soil samples ranged from 21 to 2800 ng/g and from 5.8 to 520 ng/g, respectively. Compared with previous studies, the mean of total Cl-PAH concentrations of the EOBS samples in this study was higher than that of electronic shredder waste, that of bottom ash, and comparable to fly ash from waste incinerators in Korea and Japan. The mean of total Br-PAH concentrations of the EOBS samples was generally three to four orders of magnitude higher than those in incinerator bottom ash and comparable to incinerator fly ash, although the number of Br-PAH congeners measured differed among studies. We also found that the Cl-PAH and Br-PAH profiles were similar among all e-waste open burning soil samples but differed from those in waste incinerator fly ash. The profiles and principal component analysis results suggested a unique mechanism of Cl-PAH and Br-PAH formation in EOBS. In addition, the Cl-PAHs and Br-PAHs showed high toxicities equivalent to PCDD/Fs measured in same EOBS samples when calculated based on their relative potencies to benzo[a]pyrene. Along with chlorinated and brominated dioxins and PAHs, Cl-PAHs and Br-PAHs are important environmental pollutants to investigate in EOBS. Copyright © 2016 Elsevier Ltd. All rights reserved.

Impact assessment of fly ash on ground water quality: An experimental study using batch leaching tests.

PubMed

Dandautiya, Rahul; Singh, Ajit Pratap; Kundu, Sanghamitra

2018-05-01

The fly ash, generated at the coal-based thermal power plant, is always a cause of concern to environmentalists owing to its adverse impact on air, water and land. There exists a high environmental risk when it is disposed to the environment. Thus, two different type of fly ash samples (FA-1 and FA-2) have been considered in this study to examine the leaching potential of the elements magnesium, aluminium, silicon, calcium, titanium, vanadium, chromium, manganese, iron, nickel, cobalt, copper, zinc, arsenic, selenium, strontium, cadmium, barium and lead for different types of leachant. Toxicity characteristics leaching procedure and ASTM tests have been performed in the laboratory to simulate different natural leaching scenarios. Characterisation of samples have been done through X-ray diffraction and field emission gun scanning electron microscope. The effect of different liquid to solid ratios (i.e. 5, 10, 20 and 50) on the mobilisation of elements has been analysed. The results indicated that the maximum leaching of all elements occurred at a liquid to solid ratio of 5 except for arsenic, barium and silicon. The groundwater analysis has also been done to understand the actual effects of leachate. The elements presenting the highest leachability in the two fly ash samples under all tested conditions were magnesium, aluminium, silicon and calcium. It has been observed that calcium exhibits greater leaching effects than all other constituents. The study presented here has been found very useful for assessing contamination levels in groundwater owing to leaching effects of fly ash under different scenarios, which can be helpful to prevent spreading of the contaminants by efficient management of fly ash.

Carbon-enriched coal fly ash as a precursor of activated carbons for SO2 removal.

PubMed

Izquierdo, M T; Rubio, B

2008-06-30

Carbon-enriched coal fly ash was evaluated in this work as a low-cost adsorbent for SO2 removal from stack gases. The unburned carbon in coal fly ash was concentrated by mechanical sieving and vegetal oil agglomeration. The carbon concentrates were activated with steam at 900 degrees C in order to develop porosity onto the samples. The performance of these samples in the SO2 abatement was tested in the following conditions: 100 degrees C, 1000 ppmv SO2, 5% O2, 6% water vapor. A good SO2 removal capacity was shown by some of the studied samples that can be related to their textural properties. Cycles of SO2 adsorption/regeneration were carried out in order to evaluate the possibility of thermal regeneration and re-use of these carbons. Regeneration of the exhausted carbons was carried out at 400 degrees C of temperature and a flow of 25 ml/min of Ar. After each cycle, the SO2 removal capacity of the sample decreases.

Trace elements by instrumental neutron activation analysis for pollution monitoring

NASA Technical Reports Server (NTRS)

Sheibley, D. W.

1975-01-01

Methods and technology were developed to analyze 1000 samples/yr of coal and other pollution-related samples. The complete trace element analysis of 20-24 samples/wk averaged 3-3.5 man-hours/sample. The computerized data reduction scheme could identify and report data on as many as 56 elements. In addition to coal, samples of fly ash, bottom ash, crude oil, fuel oil, residual oil, gasoline, jet fuel, kerosene, filtered air particulates, ore, stack scrubber water, clam tissue, crab shells, river sediment and water, and corn were analyzed. Precision of the method was plus or minus 25% based on all elements reported in coal and other sample matrices. Overall accuracy was estimated at 50%.

Environmental Benefit Assessment for the Carbonation Process of Petroleum Coke Fly Ash in a Rotating Packed Bed.

PubMed

Pei, Si-Lu; Pan, Shu-Yuan; Li, Ye-Mei; Chiang, Pen-Chi

2017-09-19

A high-gravity carbonation process was deployed at a petrochemical plant using petroleum coke fly ash and blowdown wastewater to simultaneously mineralized CO 2 and remove nitrogen oxides and particulate matters from the flue gas. With a high-gravity carbonation process, the CO 2 removal efficiency was found to be 95.6%, corresponding to a capture capacity of 600 kg CO 2 per day, at a gas flow rate of 1.47 m 3 /min under ambient temperature and pressure. Moreover, the removal efficiency of nitrogen oxides and particulate matters was 99.1% and 83.2%, respectively. After carbonation, the reacted fly ash was further utilized as supplementary cementitious materials in the blended cement mortar. The results indicated that cement with carbonated fly ash exhibited superior compressive strength (38.1 ± 2.5 MPa at 28 days in 5% substitution ratio) compared to the cement with fresh fly ash. Furthermore, the environmental benefits for the high-gravity carbonation process using fly ash were critically assessed. The energy consumption of the entire high-gravity carbonation ranged from 80 to 169 kWh/t-CO 2 (0.29-0.61 GJ/t-CO 2 ). Compared with the scenarios of business-as-usual and conventional carbon capture and storage plant, the economic benefit from the high-gravity carbonation process was approximately 90 and 74 USD per ton of CO 2 fixation, respectively.

Investigation on electrical surface modification of waste to energy ash for possible use as an electrode material in microbial fuel cells.

PubMed

Webster, Megan; Lee, Hae Yang; Pepa, Kristi; Winkler, Nathan; Kretzschmar, Ilona; Castaldi, Marco J

2018-03-01

With the world population expected to reach 8.5 billion by 2030, demand for access to electricity and clean water will grow at unprecedented rates. Municipal solid waste combusted at waste to energy (WtE) facilities decreases waste volume and recovers energy, but yields ash as a byproduct, the beneficial uses of which are actively being investigated. Ash is intrinsically hydrophobic, highly oxidized, and exhibits high melting points and low conductivities. The research presented here explores the potential of ash to be used as an electrode material for a microbial fuel cell (MFC). This application requires increased conductivity and hydrophilicity, and a lowered melting point. Three ash samples were investigated. By applying an electric potential in the range 50-125 V across the ash in the presence of water, several key property changes were observed: lower melting point, a color change within the ash, evidence of changes in surface morphologies of ash particles, and completely wetting water-ash contact angles. We analyzed this system using a variety of analytical techniques including sector field inductively coupled plasma mass spectrometry, scanning electron microscopy, X-ray diffraction, differential scanning calorimetry, and tensiometry. Ability to make such surface modifications and significant property changes could allow ash to become useful in an application such as an electrode material for a MFC.

Relation between leaching characteristics of heavy metals and physical properties of fly ashes from typical municipal solid waste incinerators.

PubMed

Ni, Peng; Li, Hailong; Zhao, Yongchun; Zhang, Junying; Zheng, Chuguang

2017-09-01

Due to the alkalinity and high concentration of potentially hazardous heavy metals, fly ash from a municipal solid waste (MSW) incinerator is classified as hazardous waste, which should be of particular concern. Physical and chemical characterizations of the contrasted fly ashes were investigated to explore the relation between leaching characteristics of heavy metals and physical properties of fly ashes. The results showed that CaClOH, NaCl, Ca(OH) 2 , KCl and SiO 2 were primary mineral compositions in the MSWI fly ashes, and the particle size distribution of fly ash ranged between 10 μm and 300 μm. The smaller the particle size distribution of fly ash, the larger the BET-specific surface area, which was beneficial to the leaching of heavy metals. As a result of various pores, it easily accumulated heavy metals as well. The leaching tests exhibited a high leachability of heavy metals and the leaching concentration of Pb in almost all of the fly ash samples went far beyond the Standard for Pollution Control on the Landfill Site of Municipal Solid Waste. Thereupon, it is necessary to establish proper disposal systems and management strategies for environmental protection based on the characteristics of MSW incineration (MSWI) fly ash in China.

Discussion on 'characteristics of fly ashes from full-scale coal-fired power plants and their relationship to mercury adsorption' by Lu et al.

DOE Office of Scientific and Technical Information (OSTI.GOV)

James C. Hower; Bruno Valentim; Irena J. Kostova

2008-03-15

Mercury capture by coal-combustion fly ash is a function of the amount of Hg in the feed coal, the amount of carbon in the fly ash, the type of carbon in the fly ash (including variables introduced by the rank of the feed coal), and the flue gas temperature at the point of ash collection. In their discussion of fly ash and Hg adsorption, Lu et al. (Energy Fuels 2007, 21, 2112-2120) had some fundamental flaws in their techniques, which, in turn, impact the validity of analyzed parameters. First, they used mechanical sieving to segregate fly ash size fractions. Mechanicalmore » sieving does not produce representative size fractions, particularly for the finest sizes. If the study samples were not obtained correctly, the subsequent analyses of fly ash carbon and Hg cannot accurately represent the size fractions. In the analysis of carbon forms, it is not possible to accurately determine the forms with scanning electron microscopy. The complexity of the whole particles is overlooked when just examining the outer particle surface. Examination of elements such as Hg, present in very trace quantities in most fly ashes, requires careful attention to the analytical techniques. 36 refs., 3 figs., 1 tab.« less

Bubbles and Dust: Dissolution Rates of Unhydrated Volcanic Ash as a Function of Morphology, Composition, and Particle Size

NASA Astrophysics Data System (ADS)

Wygel, C. M.; Sahagian, D. L.

2017-12-01

Volcanic eruptions are natural hazards due to their explosive nature and widespread transportation and deposition of ash particles. After deposition and subsequent leaching in soils or water bodies, ash deposition positively (nutrients) and negatively (contaminants) impacts the health of flora and fauna, including humans. The effects of ash leachates have been difficult to replicate in field and laboratory studies due to the many complexities and differences between ash particles. Ash morphology is characteristic for each eruption, dependent upon eruption energy, and should play a critical role in determining leaching rates. Morphology reflects overall particle surface area, which is strongly influenced by the presence of surface dust. In addition, ash composition, which in part controls morphology and particle size, may also affect leaching rates. This study determines the extent to which ash morphology, surface area, composition, and particle size control ash dissolution rates. Further, it is necessary to determine whether compound vesicular ash particles permit water into their interior structures to understand if both the internal and external surface areas are available for leaching. To address this, six fresh, unhydrated ash samples from diverse volcanic environments and a large range in morphology, from Pele's spheres to vesicular compound ash, are tested in the laboratory. Ash morphology was characterized on the Scanning Electron Microscope (SEM) before and after leaching and surface area was quantified by Brunauer Emmett Teller (BET) analysis and with geometric calculations. Column Leachate Tests (CLT) were conducted to compare leaching rates over a range of basaltic to silicic ashes as a function of time and surface area, to recreate the effects of ash deposition in diverse volcanic environments. After the CLT, post-leaching water analyses were conducted by Ion Coupled Plasma-Mass Spectrometry (ICP-MS) and Ion Chromatography (IC). We find that leaching rates are correlated to characteristic surface area of ash particles.

Effects of combined lime and fly ash stabilization on the elastic moduli of montmorillonitic soils : final report.

DOT National Transportation Integrated Search

1988-04-01

A laboratory study using bentonite to simulate the montmorillonite component of soils common to Louisiana was undertaken to evaluate the effects of combined lime and fly ash additions on stabilization reactions. Samples containing bentonite (75 weigh...

Composition, diagenetic transformation and alkalinity potential of oil shale ash sediments.

PubMed

Mõtlep, Riho; Sild, Terje; Puura, Erik; Kirsimäe, Kalle

2010-12-15

Oil shale is a primary fuel in the Estonian energy sector. After combustion 45-48% of the oil shale is left over as ash, producing about 5-7 Mt of ash, which is deposited on ash plateaus annually almost without any reuse. This study focuses on oil shale ash plateau sediment mineralogy, its hydration and diagenetic transformations, a study that has not been addressed. Oil shale ash wastes are considered as the biggest pollution sources in Estonia and thus determining the composition and properties of oil shale ash sediment are important to assess its environmental implications and also its possible reusability. A study of fresh ash and drillcore samples from ash plateau sediment was conducted by X-ray diffractometry and scanning electron microscopy. The oil shale is highly calcareous, and the ash that remains after combustion is derived from the decomposition of carbonate minerals. It is rich in lime and anhydrite that are unstable phases under hydrous conditions. These processes and the diagenetic alteration of other phases determine the composition of the plateau sediment. Dominant phases in the ash are hydration and associated transformation products: calcite, ettringite, portlandite and hydrocalumite. The prevailing mineral phases (portlandite, ettringite) cause highly alkaline leachates, pH 12-13. Neutralization of these leachates under natural conditions, by rainwater leaching/neutralization and slow transformation (e.g. carbonation) of the aforementioned unstable phases into more stable forms, takes, at best, hundreds or even hundreds of thousands of years. Copyright © 2010 Elsevier B.V. All rights reserved.

Topological and thermal properties of polypropylene composites based on oil palm biomass

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bhat, A. H., E-mail: aamir.bhat@petronas.com.my, E-mail: anie-yal88@yahoo.com; Dasan, Y. K., E-mail: aamir.bhat@petronas.com.my, E-mail: anie-yal88@yahoo.com

Roughness on pristine and polymer composite surfaces is of enormous practical importance for polymer applications. This study deals with the use of varying quantity of oil palm ash as a nanofiller in a polypropylene based matrix. The oil palm ash sample was preprocessed to break the particles into small diameter by using ultra sonication before using microfluidizer for further deduction in size and homogenization. The oil palm ash was made to undergo many passes through the microfluidizer for fine distribution of particles. Polypropylene based composites containing different loading percentage oil palm ash was granulated by twin screw extruder and thenmore » injection molded. The surface morphology of the OPA passed through microfluidizer was analyzed by Tapping Mode - Atomic Force Microscopy (TMAFM). Thermal analysis results showed an increase in the activation energy values. The thermal stability of the composite samples showed improvement as compared to the virgin polymer as corroborated by the on-set degradation temperatures and the temperatures at which 50% degradation occurred.« less

Mineralogical, Microstructural and Thermal Characterization of Coal Fly Ash Produced from Kazakhstani Power Plants

NASA Astrophysics Data System (ADS)

Tauanov, Z.; Abylgazina, L.; Spitas, C.; Itskos, G.; Inglezakis, V.

2017-09-01

Coal fly ash (CFA) is a waste by-product of coal combustion. Kazakhstan has vast coal deposits and is major consumer of coal and hence produces huge amounts of CFA annually. The government aims to recycle and effectively utilize this waste by-product. Thus, a detailed study of the physical and chemical properties of material is required as the data available in literature is either outdated or not applicable for recently produced CFA samples. The full mineralogical, microstructural and thermal characterization of three types of coal fly ash (CFA) produced in two large Kazakhstani power plants is reported in this work. The properties of CFAs were compared between samples as well as with published values.

Size distribution of rare earth elements in coal ash

USGS Publications Warehouse

Scott, Clinton T.; Deonarine, Amrika; Kolker, Allan; Adams, Monique; Holland, James F.

2015-01-01

Rare earth elements (REEs) are utilized in various applications that are vital to the automotive, petrochemical, medical, and information technology industries. As world demand for REEs increases, critical shortages are expected. Due to the retention of REEs during coal combustion, coal fly ash is increasingly considered a potential resource. Previous studies have demonstrated that coal fly ash is variably enriched in REEs relative to feed coal (e.g, Seredin and Dai, 2012) and that enrichment increases with decreasing size fractions (Blissett et al., 2014). In order to further explore the REE resource potential of coal ash, and determine the partitioning behavior of REE as a function of grain size, we studied whole coal and fly ash size-fractions collected from three U.S commercial-scale coal-fired generating stations burning Appalachian or Powder River Basin coal. Whole fly ash was separated into , 5 um, to 5 to 10 um and 10 to 100 um particle size fractions by mechanical shaking using trace-metal clean procedures. In these samples REE enrichments in whole fly ash ranges 5.6 to 18.5 times that of feedcoals. Partitioning results for size separates relative to whole coal and whole fly ash will also be reported. 

Nanoparticles of volcanic ash as a carrier for toxic elements on the global scale.

PubMed

Ermolin, Mikhail S; Fedotov, Petr S; Malik, Natalia A; Karandashev, Vasily K

2018-06-01

At present, there is concern about engineered nanoparticles in the environment, whereas natural nanoparticles (NPs) and their impact are often neglected. In our paper, we demonstrate the important role of nanoparticles of volcanic ash in transport of toxic elements on a global scale. A single volcanic eruption can eject millions of tons of ash. NPs of volcanic ash reach the upper troposphere and the stratosphere and may "travel" around the world for years affecting human health, environment, and even climate. So far, there is a gap in exposure assessment of volcanic ash NPs since their chemical composition remains largely unknown. Here we show for the first time that volcanic ash NPs can serve as an important carrier for potentially toxic elements. The concentrations of Ni, Zn, Cd, Ag, Sn, Se, Te, Hg, Tl, Pb, Bi in volcanic ash NPs (<100 nm) were found to be 10-500 times higher than total contents of these elements in bulk samples. This is valid for volcanoes from different regions of the world (Kamchatka, Far East of Russia and Andes, Chile). The work opens a new door into studies on biogeochemical impact of volcanic ash. Copyright © 2018 Elsevier Ltd. All rights reserved.

Volcanic Ashes Intercalated with Cultural Vestiges at Archaeological Sites from the Piedmont to the Amazon, Ecuador

NASA Astrophysics Data System (ADS)

Valverde, Viviana; Mothes, Patricia; Andrade, Daniel

2014-05-01

A mineralogical analysis was done on 70 volcanic ashes; 9 corresponding to proximal samples of seven volcanoes: Cotopaxi (4500 yBP), Guagua Pichincha (3300 yBP, 1000 yBP and 1660 yAD), Cuicocha (3100 yBP), Pululahua (2400 yBP), Ninahuilca (2350 yBP and 4600 yBP) and 61 to distal ashes collected at eight archaeological sites in the Coastal, Sierra and Amazon regions of Ecuador. Cultural vestiges are from Pre-ceramic, Formative, Regional Development and Integration periods, with the exception of a site denominated Hacienda Malqui, which also has Inca vestiges. The sampling process was done in collaboration with various archaeologists in 2011-2013. The volcanic ashes were washed, dried and divided in order to obtain a representative fraction and their later analysis with binocular microscope. The microscope analysis allowed determination of the characteristics of each component of volcanic ash. These main elements are: pumice fragments, minerals, volcanic glass, lithics and exogenous material (non volcanic). The petrographic analysis of distal volcanic ash layers at each archaeological site was correlated by their components and characteristics with proximal volcanic ashes of source volcanoes. Some correlations permitted obtaining a relative age for the layers of distal volcanic ash in the archaeological sites. The petrographic analysis showed a correlation between the archaeological sites of Las Mercedes - Los Naranjos, Rumipamba and El Condado (located west of Quito) with the eruptive activity of Guagua Pichincha volcano (3300 yBP, 1000 yBP and 1660 yAD) and Pululahua volcano (2400 yBP). Also, a correlation with eruptive activity of Ninahuilca (2350 yBP), Cotopaxi (4500 yBP) and Quilotoa (800 yBP) volcanoes at Hda. Malqui (60 km west of Latacunga) was provided by mineralogy of the respective ashes expulsed by these volcanoes. The ash layers at Cuyuja (50 km east of Quito) are mostly superficial; they are associated with Quilotoa's 800 yBP plinian. Finally at the Huapula and Pablo VI sites (in the western Amazon region of Ecuador), the reworked ashes are predominantly of Sangay volcano (in permanent eruptive activity since 1628). Finally, the work shared between archaeologists and volcanologists allowed us to discover more deposits of volcanic ashes at archaeological sites. These layers sometimes have more than 30 cm thickness in distal regions, such as the thick ash layer left by Pululahua's 2400 yBP eruption, a fact which helps us to comprehend the impact of volcanoes on past cultures.

Chemical and radiological characterization of fly and bottom ash landfill of the former sulfate pulp factory Plaški and its surroundings.

PubMed

Oreščanin, Višnja; Kollar, Robert; Buben, Kresimir; Mikelic, Ivanka Lovrencic; Kollar, Karlo; Kollar, Melkior; Medunic, Gordana

2012-01-01

The subject of this study was chemical and radiological characterization of the fly and bottom ash, by-product of the combustion of coal used as an energy source in the former sulfate pulp factory in Plaški. The research involves determination of the concentration of macro, micro and trace elements and activities of the radionuclides in: (i) ash from different positions of the landfill; (ii) soil samples in the zone of the influence of the landfill; (iii) control soil samples and (iv) sediment sample from the river Dretulja. Besides, in situ measurement of an effective dose rate above ash/soil was also determined. In relation with the control soil the average increase of the concentrations of the elements Ca, Cd, Hg, Ni, Se, Sr, Th and U in the samples taken from the fly and bottom ash landfill as well as soil samples within the radius of 300 m from the landfill was 38.3, 6.7, 9.9, 8.5, 9.4, 7.2, 3.6 and 5.7 times, respectively. In these samples, the concentrations of the above mentioned elements were in the following ranges: calcium from 7.94 to 19.7 %; cadmium from 0.33 to 1.66 mg/kg; mercury from 0.18 to 0.49 mg/kg; nickel from 260 to 1500 mg/kg; selenium from 2.7 to 21 mg/kg; strontium from 176 to 542 mg/kg; thorium from 8 to 55 mg/kg and uranium from 5.6 to 19.7 mg/kg. Compared to the world's average soil concentration, uranium and thorium values increased 3.7 and 1.7 times, respectively. The mean value of the total effective dose rate measured in the air at the height of 1 m for all samples of ash and soil under the influence of the landfill was 1.60 mSv/yr. Compared to the Croatian average (0.7015 mSv/yr), the determined mean value for the Plaški landfill is two times higher. However, compared to the local background (0.14 mSv/yr), the mean value of the total effective dose rate measured above the Plaški landfill is 11.4 times higher. In the samples of ash and contaminated soil regardless of the sampling location the activity concentrations of the radionuclides in Bq/kg vary in the following ranges: (226)Ra from 82.10 to 314.90 (mean value 145.99), (232)Th from 32.50 to 223.60 (mean value 76.76) and (238)U from 69.10 to 243.20 (mean value 134.38). Compared to the mean values found in the background soil (226)Ra and (238)U mean activity concentrations increased from 1.6 to 6.4 times and (232)Th from 1.4 to 4.3 times. In order to reduce total effective dose rate to the local "background" values and to prevent redistribution of the radionuclides and heavy metals from the deposited material into the environment fly and bottom ash landfill must be sealed with 10 cm thick layer of the material with low permeability.

Method for Hot Real-Time Sampling of Gasification Products

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pomeroy, Marc D

The Thermochemical Process Development Unit (TCPDU) at the National Renewable Energy Laboratory (NREL) is a highly instrumented half-ton/day pilot scale plant capable of demonstrating industrially relevant thermochemical technologies from lignocellulosic biomass conversion, including gasification. Gasification creates primarily Syngas (a mixture of Hydrogen and Carbon Monoxide) that can be utilized with synthesis catalysts to form transportation fuels and other valuable chemicals. Biomass derived gasification products are a very complex mixture of chemical components that typically contain Sulfur and Nitrogen species that can act as catalysis poisons for tar reforming and synthesis catalysts. Real-time hot online sampling techniques, such as Molecular Beammore » Mass Spectrometry (MBMS), and Gas Chromatographs with Sulfur and Nitrogen specific detectors can provide real-time analysis providing operational indicators for performance. Sampling typically requires coated sampling lines to minimize trace sulfur interactions with steel surfaces. Other materials used inline have also shown conversion of sulfur species into new components and must be minimized. Sample line Residence time within the sampling lines must also be kept to a minimum to reduce further reaction chemistries. Solids from ash and char contribute to plugging and must be filtered at temperature. Experience at NREL has shown several key factors to consider when designing and installing an analytical sampling system for biomass gasification products. They include minimizing sampling distance, effective filtering as close to source as possible, proper line sizing, proper line materials or coatings, even heating of all components, minimizing pressure drops, and additional filtering or traps after pressure drops.« less

Characterization of Residential Scale Biofuel Boilers and Fuels

NASA Astrophysics Data System (ADS)

Chandrasekaran, Sriraam R.

The objectives of this study were to: 1) characterize commercially available wood pellets and wood chips for basic properties such as calorific, ash, moisture contents; 2) analyze elements and ions and other possible contamination during the pellet manufacturing processes; 3) characterize the chemical and thermo-chemical property of grass pellets for their combustion potential; 4) characterize the emissions from 6 different residential scale boiler/furnace appliances burning grass and wood pellets; 5) characterize the emitted particulate matter for toxic and marker species with respect to combustion appliance and combustion conditions; and 6) determine the effects of the biomass fuel properties of 5 different grass pellets on particulate and gaseous emissions from a single type of boiler. The results from characterization of wood pellets and chips indicated that the wood pellet samples generally meet the quality standards. However, there are some samples that would fail the ash content requirements. Only the German standards have extensive trace element limits. Most of the samples would meet these standards, but some samples failed to meet these standards based on their lead, arsenic, cadmium, and copper concentrations. It is likely that inclusion of extraneous materials such as painted or pressure treated lumber led to the observed high concentrations. Given increasing use of pellets and chips as a renewable fuel, standards for the elemental composition of commercial wood pellets and chips are needed in United States to avoid the inclusion of extraneous materials. Such standards would reduce the environmental impact of toxic species that would be released when the wood is burned. Grass pellets were characterized for chemical and thermochemical properties. Switch grass pellets were studied for it thermal degradation process under inert and oxidizing atmosphere using TGA. The thermal degradation of grass pellet measured the activation energy and pre-exponential factors for switch grass decomposition. Two major losses occurred due to volatilization of cellulose, hemicelluloses, and lignin and burning or slow oxidation of residual char. The parameters were high for oxidative environment indicating high temperature sensitivity of the charcoal formation reaction. There was a substantial effect of heating rate on the mass loss and mass loss rate. The TG curve shifted to higher temperature ranges on increasing the heating rate. In both pyrolyzing and oxidizing conditions, average combustion and devolatlization rates increased. Emissions measurements and efficiency estimation were conducted on six commercially available residential scale appliances that utilize different technologies including direct combustion, gasification, lambda control, or fixed air flow rates that were designed to burn low ash wood (less than 1%). The grass has high ash and chlorine content producing more PM and chlorinated hydrocarbons including dioxins and furans. The results also indicated that the air supply and geometry of the furnace, and the type of furnace are also major influencing factors that affect the pollutant formation. To determine the effect of fuel properties on emissions formation, gaseous and particulate characterization was conducted of six fuels that include five different grass pellets types with ash content ranging from 3% to 13% and a premium wood pellet with ash content 0.6% on a boiler. Emissions from grass pellets were found to be higher than wood pellets and the PM; SO2 and NOx emissions were strongly related to the fuel properties such as ash content, sulfur and nitrogen content, respectively. CO emissions that indicate the completeness of reactions were higher for grass pellets and were strongly correlated to PAHs emissions. The PCDD/F emission was clearly a function of chlorine content of the fuel. A strong correlation existed between levoglucosan and PM2.5 concentrations indicated that levoglucosan is also a molecular marker for grass pellet combustion. All of the emissions were found to be higher for grass pellets when compared to the wood pellets and are higher at high loads than at low loads. These results show that the grass pellets cannot be used as a fuel in current generation wood pellet systems. It will be necessary to design systems that effectively deal with the higher ash and chlorine content if grass pellets are to be a significant fuel for home heating. (Abstract shortened by UMI.)

Sustainable asphalt pavement: Application of slaughterhouse waste oil and fly ash in asphalt binder

NASA Astrophysics Data System (ADS)

Sanchez Ramos, Jorge Luis

Increasing energy costs, lack of sufficient natural resources and the overwhelming demand for petroleum has stimulated the development of alternative binders to modify or replace petroleum-based asphalt binders. In the United States, the petroleum-based asphalt binder is mainly used to produce the Hot Mix Asphalt (HMA). There are approximately 4000 asphalt plants that make 500 million tons of asphalt binder valued at roughly 3 billion/year. The instability of the world's oil market has pushed oil prices to more than 80 per barrel in 2012, which increased the cost of asphalt binder up to $570 per ton. Therefore, there is a timely need to find alternative sustainable resources to the asphalt binder. This paper investigates the possibility of the partial replacement of the asphalt binder with slaughterhouse waste and/or fly ash. In order to achieve this objective, the asphalt binder is mixed with different percentages of waste oil and/or fly ash. In order to investigate the effect of these additives to the performance of the asphalt binder, a complete performance grade test performed on multiple samples. The results of the performance grade tests are compared with a control sample to observe how the addition of the waste oil and/or fly ash affects the sample. Considering the increasing cost and demand of asphalt, the use of slaughterhouse waste oil and/or fly ash as a partial replacement may result in environmental and monetary improvements in the transportation sector.

In vitro toxicology of respirable Montserrat volcanic ash

PubMed Central

Wilson, M.; Stone, V.; Cullen, R.; Searl, A.; Maynard, R.; Donaldson, K.

2000-01-01

OBJECTIVES—In July 1995 the Soufriere Hills volcano on the island of Montserrat began to erupt. Preliminary reports showed that the ash contained a substantial respirable component and a large percentage of the toxic silica polymorph, cristobalite. In this study the cytotoxicity of three respirable Montserrat volcanic ash (MVA) samples was investigated: M1 from a single explosive event, M2 accumulated ash predominantly derived from pyroclastic flows, and M3 from a single pyroclastic flow. These were compared with the relatively inert dust TiO2 and the known toxic quartz dust, DQ12.
METHODS—Surface area of the particles was measured with the Brunauer, Emmet, and Teller (BET) adsorption method and cristobalite content of MVA was determined by x ray diffraction (XRD). After exposure to particles, the metabolic competence of the epithelial cell line A549 was assessed to determine cytotoxic effects. The ability of the particles to induce sheep blood erythrocyte haemolysis was used to assess surface reactivity.
RESULTS—Treatment with either MVA, quartz, or titanium dioxide decreased A549 epithelial cell metabolic competence as measured by ability to reduce 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT). On addition of mannitol, the cytotoxic effect was significantly less with M1, quartz, and TiO2. All MVA samples induced a dose dependent increase in haemolysis, which, although less than the haemolysis induced by quartz, was significantly greater than that induced by TiO2. Addition of mannitol and superoxide dismutase (SOD) significantly reduced the haemolytic activity only of M1, but not M2 or M3, the samples derived from predominantly pyroclastic flow events.
CONCLUSIONS—Neither the cristobalite content nor the surface area of the MVA samples correlated with observed in vitro reactivity. A role for reactive oxygen species could only be shown in the cytotoxicity of M1, which was the only sample derived from a purely explosive event. These results suggest that in general the bioreactivity of MVA samples in vitro is low compared with pure quartz, but that the bioreactivity and mechanisms of biological interaction may vary according to the ash source.


Keywords: volcanic ash; cristobalite; surface reactivity PMID:11024195

Investigation of polycyclic aromatic hydrocarbon content in fly ash and bottom ash of biomass incineration plants in relation to the operating temperature and unburned carbon content.

PubMed

Košnář, Zdeněk; Mercl, Filip; Perná, Ivana; Tlustoš, Pavel

2016-09-01

The use of biomass fuels in incineration power plants is increasing worldwide. The produced ashes may pose a serious threat to the environment due to the presence of polycyclic aromatic hydrocarbons (PAHs), because some PAHs are potent carcinogens, mutagens and teratogens. The objective of this study was to investigate the content of total and individual PAHs in fly and bottom ash derived from incineration of phytomass and dendromass, because the data on PAH content in biomass ashes is limited. Various operating temperatures of incineration were examined and the relationship between total PAH content and unburned carbon in ashes was also considered. The analysis of PAHs was carried out in fly and bottom ash samples collected from various biomass incineration plants. PAH determination was performed using gas chromatography coupled with mass spectrometry. The correlations between the low, medium and high molecular weight PAHs and each other in ashes were conducted. The relationship between PAH content and unburned carbon, determined as a loss on ignition (L.O.I.) in biomass ashes, was performed using regression analysis. The PAH content in biomass ashes varied from 41.1±1.8 to 53,800.9±13,818.4ng/g dw. This variation may be explained by the differences in boiler operating conditions and biomass fuel composition. The correlation coefficients for PAHs in ash ranged from 0.8025 to 0.9790. The regression models were designed and the coefficients of determination varied from 0.908 to 0.980. The PAH content in ash varied widely with fuel type and the effect of operating temperature on PAH content in ash was evident. Fly ashes contained higher amounts of PAHs than bottom ashes. The low molecular weight PAHs prevailed in tested ashes. The exponential relationship between the PAH content and L.O.I. for fly ashes and the linear for bottom ashes was observed. Copyright © 2016 Elsevier B.V. All rights reserved.

Causes of Variability in the Effects of Vegetative Ash on Post-Fire Runoff and Erosion

NASA Astrophysics Data System (ADS)

Balfour, V.; Woods, S.

2008-12-01

Vegetative ash formed during forest wildfires has varying effects on post-fire runoff and erosion. In some cases the ash layer reduces runoff and erosion by storing rainfall and by protecting the soil surface from surface sealing and rainsplash detachment. In other cases, the ash layer increases runoff and erosion by forming a surface crust, clogging soil pores, and providing a ready source of highly erodible fine material. Since only a handful of studies have measured the hydrogeomorphic effect of ash, it is unclear whether the observed variability in its effect reflects initial spatial variability in the ash properties due to factors such as fuel type and fire severity, or differences that develop over time due to compaction and erosion or exposure of the ash to rainfall and air. The goal of our research was to determine if the observed differences in the effect of ash on runoff and erosion are due to: 1) variability in initial ash hydrologic properties due to differences in combustion temperature and fuel type, or 2) variability in ash hydrologic properties caused by mineralogical phase changes that develop after the ash is exposed to water. We created ash in the laboratory using wood and needles of Lodgepole pine (Pinus contorta), Ponderosa pine (Pinus Ponderosa) and Douglas fir (Pseudotsuga menziesii) and at 100° C temperature increments from 300 to 900° C. A subsample of ash from each fuel type / temperature combination was saturated, left undisturbed for 24 hours and then oven dried at 104° C. Dry and wetted ash samples were characterized in terms of: structure (using a scanning electron microscope), carbon content, mineralogy (using X-ray diffraction), porosity, water retention properties and hydraulic conductivity. Ash produced at the higher combustion temperatures from all three fuel types contained lime (CaO), which on wetting was transformed to portlandite (Ca(OH)2) and calcite (CaCO3). This mineralogical transformation resulted in irreversible hardening and crusting of the ash, and hardened ash had a significantly lower hydraulic conductivity than unhardened ash. Ash produced by high severity fires may undergo this same hardening and crusting process after it is wetted by rainfall whereas ash produced by lower severity fires will not, and this may explain in part the contrasting hydrogeomorphic effects of ash that have been reported in the literature.

Boron detection from blood samples by ICP-AES and ICP-MS during boron neutron capture therapy.

PubMed

Linko, S; Revitzer, H; Zilliacus, R; Kortesniemi, M; Kouri, M; Savolainen, S

2008-01-01

The concept of boron neutron capture therapy (BNCT) involves infusion of a (10)B containing tracer into the patient's bloodstream followed by local neutron irradiation(s). Accurate estimation of the blood boron level for the treatment field before irradiation is required. Boron concentration can be quantified by inductively coupled plasma atomic emission spectrometry (ICP-AES), mass spectrometry (ICP-MS), spectrofluorometric and direct current atomic emission spectrometry (DCP-AES) or by prompt gamma photon detection methods. The blood boron concentrations were analysed and compared using ICP-AES and ICP-MS to ensure congruency of the results if the analysis had to be changed during the treatment, e.g. for technical reasons. The effect of wet-ashing on the results was studied in addition. The mean of all samples analysed with ICP-MS was 5.8 % lower than with ICP-AES coupled to wet-ashing (R (2) = 0.88). Without wet-ashing, the mean of all samples analysed with ICP-MS was 9.1 % higher than with ICP-AES (R (2) = 0.99). Boron concentration analysed from whole blood samples with ICP-AES correlated well with the values of ICP-MS with wet-ashing of the sample matrix, which is generally considered the reference method. When using these methods in parallel at certain intervals during the treatments, reliability of the blood boron concentration values remains satisfactory, taking into account the required accuracy of dose determination in the irradiation of cancer patients.

ASSESSING SPECIATION AND RELEASE OF HEAVY METALS FROM COAL COMBUSTION PRODUCTS

EPA Science Inventory

In this study, the speciation of heavy metals such as arsenic, selenium, lead, zinc and mercury in coal combustion products (CCPs) was evaluated using sequential extraction procedures. Coal fly ash, bottom ash and flue gas desulphurization (FGD) sludge samples were used in the ex...

The effect of water binder ratio and fly ash on the properties of foamed concrete

NASA Astrophysics Data System (ADS)

Saloma, Hanafiah, Urmila, Dea

2017-11-01

Foamed concrete is a lightweight concrete composed by cement, water, fine aggregate and evenly distributed foam. Foamed concrete is produced by adding foam to the mixture. The function of foam is to create air voids in the mixture, so the weight of the concrete becomes lighter. The foaming agent is diluted in water then given air pressure by foam generator to produce foam. This research utilizes coal combustion, which is fly ash as cementitious material with a percentage of 0%, 10%, 15%, and 20%. The purpose of the research is to examine the effect of water binder ratio 0.425, 0.450, 0.475, and 0.500 using fly ash on the properties of foamed concrete. Fresh concrete tests include slump flow and setting time test while hardened concrete tests include density and compressive strength. The maximum value of slump flow test result is 59.50 cm on FC-20-0.500 mixture with w/b = 0.500 and 20% of fly ash percentage. The results of the setting time tests indicate the fastest initial and final time are 335 and 720 minutes, respectively on FC-0-0.425 mixture with w/b = 0.425 without fly ash. The lowest density is 978.344 kg/m3 on FC-20-0.500 mixture with w/b = 0.500 and 20% of fly ash percentage. The maximum compressive strength value is 4.510 MPa at 28 days on FC-10-0.450 mixture with w/b = 0.450 and 10% of fly ash percentage.

Effects of a layer of vegetative ash layer on wettable and water repellent soil hydrology

NASA Astrophysics Data System (ADS)

Bodí, Merche B.; Doerr, Stefan H.; Cerdà, Artemi; Mataix-Solera, Jorge

2010-05-01

Following a wildfire, a layer of vegetative ash often covers the ground until it is dissolved or redistributed by wind and water erosion. Much of the existing literature suggests that the ash layer temporally reduces infiltration by clogging soil pores or by forming a surface crust (Mallik et al., 1984; Onda et al., 2008). However, an increasing number of field-based studies have found that, at least in the short term, ash increases infiltration by storing rainfall and protecting the underlying soil from sealing (Cerdà and Doerr, 2008; Woods and Balfour, 2008). On the other hand, after a fire the soil may have produced, enhanced or reduced its water repellency (Doerr et al., 2000). Very few studies have been taken into account the interaction of the ash and the repellent soil. The layer of ash may have similar role as a litter layer in delaying runoff and reducing erosion by storing water. In order to examine this interaction, it was been made a series of experiments using a laboratory rainfall simulation. It has been assessed the effects of an ash layer i) on a wettable and water repellent soil (WDPT > 7200s), ii) with different ash thicknesses (bare soil and 5 mm, 15 mm and 30 mm of ash), iii) preceding and following the first rain after a fire when the ground is still wetted and after being partially dried. Three replicates were done, being a total of 40 simulations. The ash used was collected from a Wildfire in Teruel (Spain) during summer of 2009. The simulations were conducted in metal boxes of 30x30 cm and filled with 3 cm of soil. The slope of the box was set at 10° (17%) and the intensity applied was 78-84 mm h-1during 40 minutes. The splash detachment was determined also using four splash cups. Overland flow and subsurface drainage was collected at 1-minute intervals and the former stored every 5 min to allow determination of sediment concentrations, yield and erosion rates. Each sample was examined at the end in terms of water repellency, infiltration pattern and ash incorporation into the soil. The results show that when ash covers the wettable soil, runoff occur for a short period of time in the middle of the event. It occurred latter on time but larger in quantity as the ash thickness increases (from 0% to 2% of runoff coefficient) and at the same time drainage is reduced (from 57 to 24%). This suggests that the ash layer became saturated and produce runoff until the water is able to drain into the soil. Oppositely, in water repellent soil as ash thickness increases both runoff is reduced (from 78% to 26%) and drainage is increased (from 0 to 16%). That fact indicates a modification in the hydraulic conductivity of the repellent soil due to the pressure of the ash layer. Splash and erosion rates are bigger in water repellent soils yet erosion rates never exceed 2.5 g m-2 h-1. The fact of wetting increases the runoff and drainage rates in wettable but reduce them in the water repellent soil. An irregular infiltration pattern is observed afterwards. After drying the soil, the increase in runoff indicates a crust formation. Moreover, in water repellent soils part of the repellency is reestablished. These findings demonstrate that the interaction of the soil-ash layer should be considered and better studied in the immediate hydrological response after wildfire due to its particular behavior. References Cerdà, A. and Doerr, S.H., 2008. The effect of ash and needle cover on surface runoff and erosion in the immediate post-fire period. Catena, 74: 256-263. Doerr, S.H., Shakesby, R.A. and Walsh, R.P.D., 2000. Soil Water repellency: Its causes, characteristics and hydro-geomorphological significance. Earth Science Reviews, 51: 33-65. Mallik, A.U., Gimingham, C.H. and Rahman, A.A., 1984. Ecological effects of heater burning. I. Water infiltration, moisture retention and porosity of surface soil. Journal of Ecology, 72: 767-776. Onda, Y., Dietrich, W.E. and Booker, F., 2008. Evolution of overland flow after a severe forest fire, Point Reyes, California. Catena, 72: 13-20. Woods, S.W. and Balfour, V., 2008. The effect of ash on runoff and erosion after a forest wildfire, Montana, U.S.A. International Journal of Wildland Fire, 17(5): 535-548.

Re-cycling of sugar-ash: a raw feed material for rotary kilns.

PubMed

Kantiranis, Nikolaos

2004-01-01

Large amounts of sugar-ash, a material rich in calcium carbonate, are produced as a by-product in the Greek Sugar Industry. This work explores the possibility of re-cycling sugar-ash for use in the lime industry. A representative sample of sugar-ash from the Plati Imathias sugar plant was studied by PXRD, TG/DTG, calcination experiments at temperatures between 650 and 1150 degrees C and experiments to determine the quality of the quicklime produced at temperatures between 850 and 1150 degrees C following methods described in ASTM C110 standard. The sugar-ash was found to consist of 90 wt% calcium rich minerals (calcite and monohydrocalcite) and 10 wt% amorphous material. Traces of quartz were also detected. The quicklime of highest quality was produced at 950 degrees C. It is concluded that this "useless" material (sugar-ash) can be re-cycled for use in rotary kilns in the lime industry at calcination temperatures up to 950-1000 degrees C.

Combustion characteristics and retention-emission of selenium during co-firing of torrefied biomass and its blends with high ash coal.

PubMed

Ullah, Habib; Liu, Guijian; Yousaf, Balal; Ali, Muhammad Ubaid; Abbas, Qumber; Zhou, Chuncai

2017-12-01

The combustion characteristics, kinetic analysis and selenium retention-emission behavior during co-combustion of high ash coal (HAC) with pine wood (PW) biomass and torrefied pine wood (TPW) were investigated through a combination of thermogravimetric analysis (TGA) and laboratory-based circulating fluidized bed combustion experiment. Improved ignition behavior and thermal reactivity of HAC were observed through the addition of a suitable proportion of biomass and torrefied. During combustion of blends, higher values of relative enrichment factors in fly ash revealed the maximum content of condensing volatile selenium on fly ash particles, and depleted level in bottom ash. Selenium emission in blends decreased by the increasing ratio of both PW and TPW. Higher reductions in the total Se volatilization were found for HAC/TPW than individual HAC sample, recommending that TPW have the best potential of selenium retention. The interaction amongst selenium and fly ash particles may cause the retention of selenium. Copyright © 2017 Elsevier Ltd. All rights reserved.

The Elusive Evidence of Volcanic Lightning.

PubMed

Genareau, K; Gharghabi, P; Gafford, J; Mazzola, M

2017-11-14

Lightning strikes are known to morphologically alter and chemically reduce geologic formations and deposits, forming fulgurites. A similar process occurs as the result of volcanic lightning discharge, when airborne volcanic ash is transformed into lightning-induced volcanic spherules (LIVS). Here, we adapt the calculations used in previous studies of lightning-induced damage to infrastructure materials to determine the effects on pseudo-ash samples of simplified composition. Using laboratory high-current impulse experiments, this research shows that within the lightning discharge channel there is an ideal melting zone that represents roughly 10% or less of the total channel radius at which temperatures are sufficient to melt the ash, regardless of peak current. The melted ash is simultaneously expelled from the channel by the heated, expanding air, permitting particles to cool during atmospheric transport before coming to rest in ash fall deposits. The limited size of this ideal melting zone explains the low number of LIVS typically observed in volcanic ash despite the frequent occurrence of lightning during explosive eruptions.

Mechanism of sand slide - cold lahar induced by extreme rainfall

NASA Astrophysics Data System (ADS)

Fukuoka, Hiroshi; Yamada, Masumi; Dok, Atitkagna

2014-05-01

Along with the increasing frequencies of extreme rainfall events in almost every where on the earth, shallow slide - debris flow, i.e. cold lahars running long distance often occurs and claims downslope residents lives. In the midnight of 15 October 2013, Typhoon Wilpha attacked the Izu-Oshima, a active volcanic Island and the extreme rainfall of more than 800 mm / 24 hours was recorded. This downpour of more than 80 mm/hr lasted 4 hours at its peak and caused a number of cold lahars. The initial stage of those lahars was shallow slides of surface black volcanic ash deposits, containing mostly fine sands. The thickness was only 50 cm - 1 m. In the reconnaissance investigation, author found that the sliding surface was the boundary of two separate volcanic ash layers between the black and yellow colored and apparently showing contrast of permeability and hardness. Permeability contrast may have contributed to generation of excess pore pressure on the border and trigger the slide. Then, the unconsolidated, unpacked mass was easily fluidized and transformed into mud flows, that which volcanologists call cold lahars. Seismometers installed for monitoring the active volcano's activities, succeeded to detect many tremors events. Many are spikes but 5 larger and longer events were extracted. They lasted 2 -3 minutes and if we assume that this tremors reflects the runout movement, then we can calculate the mean velocity of the lahars. Estimated velocity was 45 - 60 km/h, which is much higher than the average speed 30 - 40 km/h of debris flows observed in Japan. Flume tests of volcanic ash flows by the Forestry and Forest Products Research Institute showed the wet volcanic ash can run at higher speed than other materials. The two tremor records were compare d with the local residents witnessed and confirmed by newspaper reported that the reach of the lahar was observed at the exact time when tremor ends. We took the black volcanic ash and conducted ring shear tests to reveal the mechanism of rapid motion. In the undrained or partially drained tests under pore water pressure test, monotonic loading of shear stress, and constant shear speed conditions, we found that immediately after failure takes place, a big excess pore pressure was generated and accelerating motions had stated in all cases. The reduced shear resistance thereafter was maintained because of the lasting high pore pressure. Even in the partially-drained test, we found once the pore pressure reached almost same with the normal stress and then gradually decreased due to dissipation. Those tests apparently shows that the high mobility and high acceleration of the motion are expected and this could be the key mechanism of the fluidization of initial shallow slides into sand flows, i.e., cold lahars. In the past ring shear test series on volcanic materials from fluidized landslides at El Picaccho of El Salvador, Mt Aso of Kumamto Prefecture, and Nagari Tandikat near Padang, Indonesia, show very similar trends. In all those cases, we expected serious grain crushing during shear, contributed to the generation of excess pore pressure, because those material are deposited recently (in geological time) and suffered no big overburden pressure which means no consolidation and no serious grain crushing ever before. So those volcanic materials are generally susceptible to crushing and expect high mobility when slides are initiated under fully saturated condition.

Attrition-enhanced sulfur capture by limestone particles in fluidized beds

DOE Office of Scientific and Technical Information (OSTI.GOV)

Saastamoinen, J.J.; Shimizu, T.

2007-02-14

Sulfur capture by limestone particles in fluidized beds is a well-established technology. The underlying chemical and physical phenomena of the process have been extensively studied and modeled. However, most of the studies have been focused on the relatively brief initial stage of the process, which extends from a few minutes to hours, yet the residence time of the particles in the boiler is much longer. Following the initial stage, a dense product layer will be formed on the particle surface, which decreases the rate of sulfur capture and the degree of utilization of the sorbent. Attrition can enhance sulfur capturemore » by removing this layer. A particle model for sulfur capture has been incorporated with an attrition model. After the initial stage, the rate of sulfur capture stabilizes, so that attrition removes the surface at the same rate as diffusion and chemical reaction produces new product in a thin surface layer of a particle. An analytical solution for the conversion of particles for this regime is presented. The solution includes the effects of the attrition rate, diffusion, chemical kinetics, pressure, and SO{sub 2} concentration, relative to conversion-dependent diffusivity and the rate of chemical reaction. The particle model results in models that describe the conversion of limestone in both fly ash and bottom ash. These are incorporated with the residence time (or reactor) models to calculate the average conversion of the limestone in fly ash and bottom ash, as well as the efficiency of sulfur capture. Data from a large-scale pressurized fluidized bed are compared with the model results.« less

Reaction mechanisms in the organometallic vapor phase epitaxial growth of GaAs

NASA Technical Reports Server (NTRS)

Larsen, C. A.; Buchan, N. I.; Stringfellow, G. B.

1988-01-01

The decomposition mechanisms of AsH3, trimethylgallium (TMGa), and mixtures of the two have been studied in an atmospheric-pressure flow system with the use of D2 to label the reaction products which are analyzed in a time-of-flight mass spectrometer. AsH3 decomposes entirely heterogeneously to give H2. TMGa decomposes by a series of gas-phase steps, involving methyl radicals and D atoms to produce CH3D, CH4, C2H6, and HD. TMGa decomposition is accelerated by the presence of AsH3. When the two are mixed, as in the organometallic vapor phase epitaxial growth of GaAs, both compounds decompose in concert to produce only CH4. A likely model is that of a Lewis acid-base adduct that forms and subsequently eliminates CH4.

Reaction mechanisms in the organometallic vapor phase epitaxial growth of GaAs

NASA Astrophysics Data System (ADS)

Larsen, C. A.; Buchan, N. I.; Stringfellow, G. B.

1988-02-01

The decomposition mechanisms of AsH3, trimethylgallium (TMGa), and mixtures of the two have been studied in an atmospheric-pressure flow system with the use of D2 to label the reaction products which are analyzed in a time-of-flight mass spectrometer. AsH3 decomposes entirely heterogeneously to give H2. TMGa decomposes by a series of gas-phase steps, involving methyl radicals and D atoms to produce CH3D, CH4, C2H6, and HD. TMGa decomposition is accelerated by the presence of AsH3. When the two are mixed, as in the organometallic vapor phase epitaxial growth of GaAs, both compounds decompose in concert to produce only CH4. A likely model is that of a Lewis acid-base adduct that forms and subsequently eliminates CH4.

An evaluation of benthic macroinvertebrate biomass methodology : Part 1. Laboratory analytical methods.

PubMed

Mason, W T; Lewis, P A; Weber, C I

1983-03-01

Evaluation of analytical methods employed for wet weight (live or preserved samples) of benthic macroinvertebrates reveals that centrifugation at 140 x gravity for one minute yields constant biomass estimates. Less relative centrifugal force increases chance of incomplete removal of body moisture and results in weighing error, while greater force may rupture fragile macroinvertebrates, such as mayflies. Duration of specimen exposure in ethanol, formalin, and formol (formaling-ethanol combinations) causes significant body weight loss with within 48 hr formalin and formol cause less body weight loss than ethanol. However, as all preservatives tested cause body weight loss, preservation time of samples collected for comparative purposes should be treated uniformly. Dry weight estimates of macroinvertebrates are not significantly affected by kind of preservative or duration of exposure. Constant dry weights are attained by oven drying at 103 °C at a minimum of four hours or vacuum oven drying (15 inches of mercury pressure) at 103 °C for a minimum of one hour. Although requiring more time in preparation than oven drying and inalterably changing specimen body shape, freeze drying (10 microns pressure, -55 °C, 24 hr) provides constant dry weights and is advantageous for long term sample storage by minimizing curatorial attention. Constant ash-free dry weights of macroinvertebrate samples are attained by igniting samples at 500-550 °C for a minimum of one hour with slow cooling to room temperature in desiccators before weighing.

Emerald ash borer genetics: an update

Treesearch

Alicia M. Bray; Leah S. Bauer; Robert A. Haack; Therese Poland; James J. Smith

2008-01-01

Emerald ash borer (EAB), Agrilus planipennis Fairmaire, samples were collected from introduced sites in Michigan, Ohio, Indiana, Pennsylvania, Illinois, and Ontario, Canada, as well as native sites in China, Japan, and South Korea with the help of a network of collaborators. The beetles were analyzed using DNA sequences from mitochondrial cytochrome...

Investigation of occupational radiation exposures to NORM at an Irish peat-fired power station and potential use of peat fly ash by the construction industry.

PubMed

Organo, C; Lee, E M; Menezes, G; Finch, E C

2005-12-01

Annually, approximately 15% of Ireland's electricity requirement is provided through the combustion of 3 x 10(6) tonnes of peat. While the literature on coal-fired power generation is quite abundant, studies on the peat-fired power generation industry from a radiological point of view are scarce. A study of the largest Irish peat-fired power plant was initiated to review the potential occupational radiation exposures arising from the occurrence of naturally occurring radioactive material (NORM) at different stages of the industrial process and to investigate any radiological health consequences that may arise should peat fly ash be used as a component of building materials. Ambient gamma dose rate measurements, radon measurements, quantification of the occupational exposure from inhalation of airborne particles (personal air sampling) and gamma spectrometry analysis of peat, peat ash and effluent samples from the ash ponds were undertaken. The results indicate that the radiation dose received by any worker involved in the processing of the peat and the handling of the ash resulting from peat combustion does not exceed 150 microSv per annum. Regulatory control of the peat-fired power generation is therefore unnecessary according to the Irish legislation with regards to NORM. The potential use of peat fly ash as a by-product in the building industry was also found to have a negligible radiological impact for construction workers and for members of the public.

Dual polarisation C-band weather radar imagery of the 6 August 2012 Te Maari Eruption, Mount Tongariro, New Zealand

NASA Astrophysics Data System (ADS)

Crouch, John F.; Pardo, Natalia; Miller, Craig A.

2014-10-01

The 6 August 2012 eruption of Mt. Tongariro from Upper Te Maari Crater in the central North Island of New Zealand was the first volcanic eruption observed by an operational weather radar in New Zealand, and is believed to be one of only a small number of eruptions observed by a dual-polarisation radar worldwide. The eruption was also observed by a GeoNet webcam, and detailed ash deposit studies have permitted analysis of the plume characteristics. A combination of radar and webcam imagery show 5 pulses within the first 13 min of the eruption, and also the subsequent ash transport downwind. Comparison with ash samples show the radar was likely detecting ash particles down to about 0.5 mm diameter. The maximum plume height estimated by the radar is 7.8 ± 1.0 km above mean sea level (amsl), although it is possible this may be a slight under estimation if very small ash particles not detected by the radar rose higher and comprised the very top of the plume. The correlation coefficient and differential reflectivity fields that are additionally measured by the dual polarisation radar provide extra information about the structure and composition of the eruption column and ash cloud. The correlation coefficient easily discriminates between the eruption column and the ash plume, and provides some information about the diversity of ash particle size within both the ash plume and the subsequent detached ash cloud drifting downwind. The differential reflectivity shows that the larger ash particles are falling with a horizontal orientation, and indicates that ice nucleation and aggregation of fine ash particles was probably occurring at high altitudes within 20-25 min of the eruption.

Geohydrologic data from test hole USW UZ-7, Yucca Mountain area, Nye County, Nevada

USGS Publications Warehouse

Kume, Jack; Hammermeister, D.P.

1990-01-01

This report contains a description of the methods used in drilling and coring of the test-hole USW UZ-7, a description of the methods used in collecting, handling, and testing of test-hole samples; Lithologic information from the test hole; and water-content, water-potential, bulk-density, grain-density, porosity, and tritium data for the test hole. Test-hole USW UZ-7 was drilled and cored to a total depth of 62.94 m. The drilling was done using air as a drilling fluid to minimize disturbance to the water content of cores, drill-bit cuttings, and borehole wall-rock. Beginning at the land surface, the unsaturated-zone rock that was penetrated consisted of alluvium; welded and partially to nonwelded ash-flow tuff; bedded and reworked ash-fall tuff; nonwelded ash-flow tuff; and welded ash-flow tuff. Values of gravimetric water content and water potential of alluvium were intermediate between the extreme values in welded and nonwelded units of tuff. Gravimetric water content was largest in bedded and nonwelded ash-fall tuffs and was smallest in welded ash-flow tuff. Values of water potential were more negative in densely welded ash-flow tuffs and were less negative in bedded and nonwelded ash-fall tuffs. Bulk density was largest in densely welded ash-flow tuffs and smallest in nonwelded and bedded ash-fall tuffs. Grain density was uniform but was slightly larger in nonwelded and bedded ash-fall tuffs than in welded ash-flow tuffs. Porosity trends were opposite to bulk-density trends. Tritium content in alluvium was smallest near the alluvium-bedrock contact, markedly increased in the middle of the deposit, and decreased in the near-surface zone of the deposit. (Author 's abstract)

Effects of burn temperature on ash nutrient forms and availability from cattail (Typha domingensis) and sawgrass (Cladium jamaicense) in the Florida Everglades.

PubMed

Qian, Y; Miao, S L; Gu, B; Li, Y C

2009-01-01

Plant ash derived from fire plays an important role in nutrient balance and cycling in ecosystems. Factors that determine the composition and availability of ash nutrients include fire intensity (burn temperature and duration), plant species, habitat nutrient enrichment, and leaf type (live or dead leaf). We used laboratory simulation methods to evaluate temperature effects on nutrient composition and metals in the residual ash of sawgrass (Cladium jamaicense) and cattail (Typha domingensis), particularly on post-fire phosphorus (P) availability in plant ash. Live and dead leaf samples were collected from Water Conservation Area 2A in the northern Everglades along a soil P gradient, where prescribed fire may be used to accelerate recovery of this unique ecosystem. Significant decreases in total carbon and total nitrogen were detected with increasing fire temperature. Organic matter combustion was nearly complete at temperatures > or = 450 degrees C. HCl-extractable P (average, 50% of total P in the ash) and NH(4)Cl-extractable P (average, 33% of total P in the ash) were the predominant P fractions for laboratory-burned ash. Although a low-intensity fire could induce an elevation of P availability, an intense fire generally resulted in decreased water-soluble P. Significant differences in nutrient compositions were observed between species, habitat nutrient status, and leaf types. More labile inorganic P remained in sawgrass ash than in cattail ash; hence, sawgrass ash has a greater potential to release available P than cattail. Fire intensity affected plant ash nutrient composition, particularly P availability, and the effects varied with plant species and leaf type. Therefore, it is important to consider fire intensity and vegetation community when using a prescribed fire for ecosystem management.

Artificial cloud test confirms volcanic ash detection using infrared spectral imaging

PubMed Central

Prata, A. J.; Dezitter, F.; Davies, I.; Weber, K.; Birnfeld, M.; Moriano, D.; Bernardo, C.; Vogel, A.; Prata, G. S.; Mather, T. A.; Thomas, H. E.; Cammas, J.; Weber, M.

2016-01-01

Airborne volcanic ash particles are a known hazard to aviation. Currently, there are no means available to detect ash in flight as the particles are too fine (radii < 30 μm) for on-board radar detection and, even in good visibility, ash clouds are difficult or impossible to detect by eye. The economic cost and societal impact of the April/May 2010 Icelandic eruption of Eyjafjallajökull generated renewed interest in finding ways to identify airborne volcanic ash in order to keep airspace open and avoid aircraft groundings. We have designed and built a bi-spectral, fast-sampling, uncooled infrared camera device (AVOID) to examine its ability to detect volcanic ash from commercial jet aircraft at distances of more than 50 km ahead. Here we report results of an experiment conducted over the Atlantic Ocean, off the coast of France, confirming the ability of the device to detect and quantify volcanic ash in an artificial ash cloud created by dispersal of volcanic ash from a second aircraft. A third aircraft was used to measure the ash in situ using optical particle counters. The cloud was composed of very fine ash (mean radii ~10 μm) collected from Iceland immediately after the Eyjafjallajökull eruption and had a vertical thickness of ~200 m, a width of ~2 km and length of between 2 and 12 km. Concentrations of ~200 μg m−3 were identified by AVOID at distances from ~20 km to ~70 km. For the first time, airborne remote detection of volcanic ash has been successfully demonstrated from a long-range flight test aircraft. PMID:27156701

Artificial cloud test confirms volcanic ash detection using infrared spectral imaging.

PubMed

Prata, A J; Dezitter, F; Davies, I; Weber, K; Birnfeld, M; Moriano, D; Bernardo, C; Vogel, A; Prata, G S; Mather, T A; Thomas, H E; Cammas, J; Weber, M

2016-05-09

Airborne volcanic ash particles are a known hazard to aviation. Currently, there are no means available to detect ash in flight as the particles are too fine (radii < 30 μm) for on-board radar detection and, even in good visibility, ash clouds are difficult or impossible to detect by eye. The economic cost and societal impact of the April/May 2010 Icelandic eruption of Eyjafjallajökull generated renewed interest in finding ways to identify airborne volcanic ash in order to keep airspace open and avoid aircraft groundings. We have designed and built a bi-spectral, fast-sampling, uncooled infrared camera device (AVOID) to examine its ability to detect volcanic ash from commercial jet aircraft at distances of more than 50 km ahead. Here we report results of an experiment conducted over the Atlantic Ocean, off the coast of France, confirming the ability of the device to detect and quantify volcanic ash in an artificial ash cloud created by dispersal of volcanic ash from a second aircraft. A third aircraft was used to measure the ash in situ using optical particle counters. The cloud was composed of very fine ash (mean radii ~10 μm) collected from Iceland immediately after the Eyjafjallajökull eruption and had a vertical thickness of ~200 m, a width of ~2 km and length of between 2 and 12 km. Concentrations of ~200 μg m(-3) were identified by AVOID at distances from ~20 km to ~70 km. For the first time, airborne remote detection of volcanic ash has been successfully demonstrated from a long-range flight test aircraft.

Effects of a low severity prescribed fire on water-soluble elements in ash from a cork oak (Quercus suber) forest located in the northeast of the Iberian Peninsula

USGS Publications Warehouse

Pereira, P.; beda, X.; Martin, D.; Mataix-Solera, J.; Guerrero, C.

2011-01-01

Wildfire is the major disturbance in Mediterranean forests. Prescribed fire can be an alternative to reduce the amount of fuel and hence decrease the wildfire risk. However the effects of prescribed fire must be studied, especially on ash properties, because ash is an important nutrient source for ecosystem recovery. The aim of this study is to determine the effects of a low severity prescribed fire on water-soluble elements in ash including pH, electrical conductivity (EC), calcium (Ca), magnesium (Mg), sodium (Na), potassium (K), aluminum (Al), manganese (Mn), iron (Fe), zinc (Zn), silica (SiO2) and total sulphur (TS). A prescribed fire was conducted in a cork oak (Quercus suber) (Q.S) forest located in the northeast part of the Iberian Peninsula. Samples were collected from a flat plot of 40??70m mainly composed of Q.S and Quercus robur (Q.R) trees. In order to understand the effects of the prescribed fire on the soluble elements in ash, we conducted our data analysis on three data groups: all samples, only Q.S samples and only Q.R samples. All three sample groups exhibited a significant increase in pH, EC (p<0.001), water-soluble Ca, Mg, Na, SiO2 and TS and a decrease in water-soluble Mn, Fe and Zn. Differences were identified between oak species for water-soluble K, Al and Fe. In Q.S samples we registered a significant increase in the first two elements p<0.001 and p<0.01, respectively, and a non-significant impact in the third, at p<0.05. In Q.R data we identified a non-significant impact on water-soluble K and Al and a significant decrease in water-soluble Fe (p<0.05). These differences are probably due to vegetation characteristics and burn severity. The fire induced a higher variability in the ash soluble elements, especially in Q.S samples, that at some points burned with higher severity. The increase of pH, EC, Ca, Mg, Na and K will improve soil fertility, mainly in the study area where soils are acidic. The application of this low severity prescribed fire will improve soil nutrient status without causing soil degradation and thus is considered to be a good management strategy. ?? 2010 Elsevier Inc.

Effects of a low severity prescribed fire on water-soluble elements in ash from a cork oak (Quercus suber) forest located in the northeast of the Iberian Peninsula.

PubMed

Pereira, Paulo; Ubeda, Xavier; Martin, Deborah; Mataix-Solera, Jorge; Guerrero, César

2011-02-01

Wildfire is the major disturbance in Mediterranean forests. Prescribed fire can be an alternative to reduce the amount of fuel and hence decrease the wildfire risk. However the effects of prescribed fire must be studied, especially on ash properties, because ash is an important nutrient source for ecosystem recovery. The aim of this study is to determine the effects of a low severity prescribed fire on water-soluble elements in ash including pH, electrical conductivity (EC), calcium (Ca), magnesium (Mg), sodium (Na), potassium (K), aluminum (Al), manganese (Mn), iron (Fe), zinc (Zn), silica (SiO(2)) and total sulphur (TS). A prescribed fire was conducted in a cork oak (Quercus suber) (Q.S) forest located in the northeast part of the Iberian Peninsula. Samples were collected from a flat plot of 40×70m mainly composed of Q.S and Quercus robur (Q.R) trees. In order to understand the effects of the prescribed fire on the soluble elements in ash, we conducted our data analysis on three data groups: all samples, only Q.S samples and only Q.R samples. All three sample groups exhibited a significant increase in pH, EC (p<0.001), water-soluble Ca, Mg, Na, SiO(2) and TS and a decrease in water-soluble Mn, Fe and Zn. Differences were identified between oak species for water-soluble K, Al and Fe. In Q.S samples we registered a significant increase in the first two elements p<0.001 and p<0.01, respectively, and a non-significant impact in the third, at p<0.05. In Q.R data we identified a non-significant impact on water-soluble K and Al and a significant decrease in water-soluble Fe (p<0.05). These differences are probably due to vegetation characteristics and burn severity. The fire induced a higher variability in the ash soluble elements, especially in Q.S samples, that at some points burned with higher severity. The increase of pH, EC, Ca, Mg, Na and K will improve soil fertility, mainly in the study area where soils are acidic. The application of this low severity prescribed fire will improve soil nutrient status without causing soil degradation and thus is considered to be a good management strategy. Copyright © 2010 Elsevier Inc. All rights reserved.

Spatial and temporal trends in contaminant concentrations in Hexagenia nymphs following a coal ash spill at the Tennessee Valley Authority's Kingston Fossil Plant

DOE PAGES

Baker, Tyler F; Jett, Robert Trent; Smith, John G.; ...

2016-02-25

A dike failure at the Tennessee Valley Authority Kingston Fossil Plant in East Tennessee, United States, in December 2008, released approximately 4.1 million m3 of coal ash into the Emory River. From 2009 through 2012, samples of mayfly nymphs ( Hexagenia bilineata) were collected each spring from sites in the Emory, Clinch, and Tennessee Rivers upstream and downstream of the spill. Samples were analyzed for 17 metals. Concentrations of metals were generally highest the first 2 miles downstream of the spill, and then decreased with increasing distance from the spill. Arsenic, B, Ba, Be, Mo, Sb, Se, Sr, and Vmore » appeared to have strong ash signatures, whereas Co, Cr, Cu, Ni, and Pb appeared to be associated with ash and other sources. Furthermore, the concentrations for most of these contaminants were modest and are unlikely to cause widespread negative ecological effects. Trends in Hg, Cd, and Zn suggested little (Hg) or no (Cd, Zn) association with ash. Temporal trends suggested that concentrations of ash-related contaminants began to subside after 2010, but because of the limited time period of that analysis (4 yr), further monitoring is needed to verify this trend. The present study provides important information on the magnitude of contaminant exposure to aquatic receptors from a major coal ash spill, as well as spatial and temporal trends for transport of the associated contaminants in a large open watershed. Environ Toxicol Chem 2016;35:1159 1171. Published 2015 Wiley Periodicals Inc. on behalf of SETAC. This article is a US government work and, as such, is in the public domain in the United States of America.« less

Critical Elements in Fly Ash from the Combustion of Bituminous Coal in Major Polish Power Plants

NASA Astrophysics Data System (ADS)

Bielowicz, Barbara; Botor, Dariusz; Misiak, Jacek; Wagner, Marian

2018-03-01

The concentration of critical elements, including such REE as Fe, Co, W, Zn, Cr, Ni, V, Mn, Ti, Ag, Ga, Ta, Sr, Li, and Cu, in the so-called fly ash obtained from the 9 Polish power plants and 1 thermal power station has been determined. The obtained values, compared with the global average concentration in bituminous coal ash and sedimentary rocks (Clarke values), have shown that the enrichment of fly ash in the specified elements takes place in only a few bituminous coal processing sites in Poland. The enrichment factor (EF) is only slightly higher (the same order of magnitude) than the Clarke values. The enrichment factor in relation to the Clarke value in the Earth's crust reached values above 10 in all of the examined ashes for the following elements: Cr, Ni, V, W, and, in some ash samples, also Cu and Zn. The obtained values are low, only slightly higher than the global average concentrations in sedimentary rocks and bituminous coal ashes. The ferromagnetic grains (microspheres) found in bituminous coal fly ashes seem to be the most economically prospective in recovery of selected critical elements. The microanalysis has shown that iron cenospheres and plerospheres in fly ash contain, in addition to enamel and iron oxides (magnetite and hematite), iron spinels enriched in Co, Cr, Cu, Mn, Ni, W, and Zn.

Evaluation of physicochemical properties of radioactive cesium in municipal solid waste incineration fly ash by particle size classification and leaching tests.

PubMed

Fujii, Kengo; Ochi, Kotaro; Ohbuchi, Atsushi; Koike, Yuya

2018-07-01

After the Fukushima Daiichi-Nuclear Power Plant accident, environmental recovery was a major issue because a considerable amount of municipal solid waste incineration (MSWI) fly ash was highly contaminated with radioactive cesium. To the best of our knowledge, only a few studies have evaluated the detailed physicochemical properties of radioactive cesium in MSWI fly ash to propose an effective method for the solidification and reuse of MSWI fly ash. In this study, MSWI fly ash was sampled in Fukushima Prefecture. The physicochemical properties of radioactive cesium in MSWI fly ash were evaluated by particle size classification (less than 25, 25-45, 45-100, 100-300, 300-500, and greater than 500 μm) and the Japanese leaching test No. 13 called "JLT-13". These results obtained from the classification of fly ash indicated that the activity concentration of radioactive cesium and the content of the coexisting matter (i.e., chloride and potassium) temporarily change in response to the particle size of fly ash. X-ray diffraction results indicated that water-soluble radioactive cesium exists as CsCl because of the cooling process and that insoluble cesium is bound to the inner sphere of amorphous matter. These results indicated that the distribution of radioactive cesium depends on the characteristics of MSWI fly ash. Copyright © 2018 Elsevier Ltd. All rights reserved.

The Early Detection of the Emerald Ash Borer (eab) Using Multi-Source Remotely Sensed Data

NASA Astrophysics Data System (ADS)

Hu, B.; Naveed, F.; Tasneem, F.; Xing, C.

2018-04-01

The objectives of this study were to exploit the synergy of hyperspectral imagery, Light Detection And Ranging (LiDAR) and high spatial resolution data and their synergy in the early detection of the EAB (Emerald Ash Borer) presence in trees within urban areas and to develop a framework to combine information extracted from multiple data sources. To achieve these, an object-oriented framework was developed to combine information derived from available data sets to characterize ash trees. Within this framework, an advanced individual tree delineation method was developed to delineate individual trees using the combined high-spatial resolution worldview-3 imagery was used together with LiDAR data. Individual trees were then classified to ash and non-ash trees using spectral and spatial information. In order to characterize the health state of individual ash trees, leaves from ash trees with various health states were sampled and measured using a field spectrometer. Based on the field measurements, the best indices that sensitive to leaf chlorophyll content were selected. The developed framework and methods were tested using worldview-3, airborne LiDAR data over the Keele campus of York University Toronto Canada. Satisfactory results in terms of individual tree crown delineation, ash tree identification and characterization of the health state of individual ash trees. Quantitative evaluations is being carried out.

Determination of Lead in Blood by Atomic Absorption Spectrophotometry1

PubMed Central

Selander, Stig; Cramér, Kim

1968-01-01

Lead in blood was determined by atomic absorption spectrophotometry, using a wet ashing procedure and a procedure in which the proteins were precipitated with trichloroacetic acid. In both methods the lead was extracted into isobutylmethylketone before measurement, using ammonium pyrrolidine dithiocarbamate as chelator. The simpler precipitation procedure was shown to give results identical with those obtained with the ashing technique. In addition, blood specimens were examined by the precipitation method and by spectral analysis, which method includes wet ashing of the samples, with good agreement. All analyses were done on blood samples from `normal' persons or from lead-exposed workers, and no additions of inorganic lead were made. The relatively simple protein precipitation technique gave accurate results and is suitable for the large-scale control of lead-exposed workers. PMID:5663425

Rare earth elements in fly ashes created during the coal burning process in certain coal-fired power plants operating in Poland - Upper Silesian Industrial Region.

PubMed

Smolka-Danielowska, Danuta

2010-11-01

The subject of the study covered volatile ashes created during hard coal burning process in ash furnaces, in power plants operating in the Upper Silesian Industrial Region, Southern Poland. Coal-fired power plants are furnished with dust extracting devices, electro precipitators, with 99-99.6% combustion gas extracting efficiency. Activity concentrations ofTh-232, Ra-226, K-40, Ac-228, U-235 and U-238 were measured with gamma-ray spectrometer. Concentrations of selected rare soil elements (La, Ce, Nd, Sm, Y, Gd, Th, U) were analysed by means of instrumental neutron activation analysis (INAA). Mineral phases of individual ash particles were identified with the use of scanning electron microscope equipped with EDS attachment. Laser granulometric analyses were executed with the use of Analyssette analyser. The activity of the investigated fly-ash samples is several times higher than that of the bituminous coal samples; in the coal, the activities are: 226Ra - 85.4 Bq kg(-1), 40 K-689 Bq kg(-1), 232Th - 100.8 Bq kg(-1), 235U-13.5 Bq kg(-1), 238U-50 Bq kg(-1) and 228Ac - 82.4 Bq kg(-1).

Leachability of Heavy Metals from Lightweight Aggregates Made with Sewage Sludge and Municipal Solid Waste Incineration Fly Ash

PubMed Central

Wei, Na

2015-01-01

Lightweight aggregate (LWA) production with sewage sludge and municipal solid waste incineration (MSWI) fly ash is an effective approach for waste disposal. This study investigated the stability of heavy metals in LWA made from sewage sludge and MSWI fly ash. Leaching tests were conducted to find out the effects of MSWI fly ash/sewage sludge (MSWI FA/SS) ratio, sintering temperature and sintering time. It was found that with the increase of MSWI FA/SS ratio, leaching rates of all heavy metals firstly decreased and then increased, indicating the optimal ratio of MSWI fly ash/sewage sludge was 2:8. With the increase of sintering temperature and sintering time, the heavy metal solidifying efficiencies were strongly enhanced by crystallization and chemical incorporations within the aluminosilicate or silicate frameworks during the sintering process. However, taking cost-savings and lower energy consumption into account, 1100 °C and 8 min were selected as the optimal parameters for LWA sample- containing sludge production. Furthermore, heavy metal leaching concentrations under these optimal LWA production parameters were found to be in the range of China’s regulatory requirements. It is concluded that heavy metals can be properly stabilized in LWA samples containing sludge and cannot be easily released into the environment again to cause secondary pollution. PMID:25961800

Leachability of heavy metals from lightweight aggregates made with sewage sludge and municipal solid waste incineration fly ash.

PubMed

Wei, Na

2015-05-07

Lightweight aggregate (LWA) production with sewage sludge and municipal solid waste incineration (MSWI) fly ash is an effective approach for waste disposal. This study investigated the stability of heavy metals in LWA made from sewage sludge and MSWI fly ash. Leaching tests were conducted to find out the effects of MSWI fly ash/sewage sludge (MSWI FA/SS) ratio, sintering temperature and sintering time. It was found that with the increase of MSWI FA/SS ratio, leaching rates of all heavy metals firstly decreased and then increased, indicating the optimal ratio of MSWI fly ash/sewage sludge was 2:8. With the increase of sintering temperature and sintering time, the heavy metal solidifying efficiencies were strongly enhanced by crystallization and chemical incorporations within the aluminosilicate or silicate frameworks during the sintering process. However, taking cost-savings and lower energy consumption into account, 1100 °C and 8 min were selected as the optimal parameters for LWA sample- containing sludge production. Furthermore, heavy metal leaching concentrations under these optimal LWA production parameters were found to be in the range of China's regulatory requirements. It is concluded that heavy metals can be properly stabilized in LWA samples containing sludge and cannot be easily released into the environment again to cause secondary pollution.

The chemical composition of tertiary Indian coal ash and its combustion behaviour - a statistical approach: Part 2

NASA Astrophysics Data System (ADS)

Sharma, Arpita; Saikia, Ananya; Khare, Puja; Dutta, D. K.; Baruah, B. P.

2014-08-01

In Part 1 of the present investigation, 37 representative Eocene coal samples of Meghalaya, India were analyzed and their physico-chemical characteristics and the major oxides and minerals present in ash samples were studied for assessing the genesis of these coals. Various statistical tools were also applied to study their genesis. The datasets from Part 1 used in this investigation (Part 2) show the contribution of major oxides towards ash fusion temperatures (AFTs). The regression analysis of high temperature ash (HTA) composition and initial deformation temperature (IDT) show a definite increasing or decreasing trend, which has been used to determine the predictive indices for slagging, fouling, and abrasion propensities during combustion practices. The increase or decrease of IDT is influenced by the increase of Fe2O3, Al2O3, SiO2, and CaO, respectively. Detrital-authigenic index (DAI) calculated from the ash composition and its relation with AFT indicates Sialoferric nature of these coals. The correlation analysis, Principal Component Analysis (PCA), and Hierarchical Cluster Analysis (HCA) were used to study the possible fouling, slagging, and abrasion potentials in boilers during the coal combustion processes. A positive relationship between slagging and heating values of the coal has been found in this study.

Trends in the Rare Earth Element Content of U.S.-Based Coal Combustion Fly Ashes.

PubMed

Taggart, Ross K; Hower, James C; Dwyer, Gary S; Hsu-Kim, Heileen

2016-06-07

Rare earth elements (REEs) are critical and strategic materials in the defense, energy, electronics, and automotive industries. The reclamation of REEs from coal combustion fly ash has been proposed as a way to supplement REE mining. However, the typical REE contents in coal fly ash, particularly in the United States, have not been comprehensively documented or compared among the major types of coal feedstocks that determine fly ash composition. The objective of this study was to characterize a broad selection of U.S. fly ashes of varied geological origin in order to rank their potential for REE recovery. The total and nitric acid-extractable REE content for more than 100 ash samples were correlated with characteristics such as the major element content and coal basin to elucidate trends in REE enrichment. Average total REE content (defined as the sum of the lanthanides, yttrium, and scandium) for ashes derived from Appalachian sources was 591 mg kg(-1) and significantly greater than in ashes from Illinois and Powder River basin coals (403 and 337 mg kg(-1), respectively). The fraction of critical REEs (Nd, Eu, Tb, Dy, Y, and Er) in the fly ashes was 34-38% of the total and considerably higher than in conventional ores (typically less than 15%). Powder River Basin ashes had the highest extractable REE content, with 70% of the total REE recovered by heated nitric acid digestion. This is likely due to the higher calcium content of Powder River Basin ashes, which enhances their solubility in nitric acid. Sc, Nd, and Dy were the major contributors to the total REE value in fly ash, based on their contents and recent market prices. Overall, this study shows that coal fly ash production could provide a substantial domestic supply of REEs, but the feasibility of recovery depends on the development of extraction technologies that could be tailored to the major mineral content and origins of the feed coal for the ash.

Mobility and toxicity of heavy metal(loid)s arising from contaminated wood ash application to a pasture grassland soil.

PubMed

Mollon, L C; Norton, G J; Trakal, L; Moreno-Jimenez, E; Elouali, F Z; Hough, R L; Beesley, L

2016-11-01

Heavy metal(loid) rich ash (≤10,000 mg kg -1 total As, Cr, Cu and Zn) originating from the combustion of contaminated wood was subjected to several experimental procedures involving its incorporation into an upland pasture soil. Ash was added to soil that had been prior amended with local cattle manure, replicating practices employed at the farm scale. Metal(loid) concentrations were measured in soil pore water and ryegrass grown on soil/manure plus ash mixtures (0.1-3.0% vol. ash) in a pot experiment; toxicity evaluation was performed on the same pore water samples by means of a bacterial luminescence biosensor assay. Thereafter a sequential extraction procedure was carried out on selected soil, manure and ash mixtures to elucidate the geochemical association of ash derived metal(loid)s with soil constituents. Predictive modelling was applied to selected data from the pot experiment to determine the risk of transfer of As to meat and milk products in cattle grazing pasture amended with ash. The inclusion of manure to soils receiving ash reduced phyto-toxicity and increased ryegrass biomass yields, compared to soil with ash, but without manure. Elevated As and Cu concentrations in pore water and ryegrass tissue resulting from ash additions were reduced furthest by the inclusion of manure due to an increase in their geochemical association with organic matter. Zinc was the only measured metal(loid) to remain uniformly soluble and bioavailable regardless of the addition of ash and manure. Risk modelling on pot experimental data highlighted that an ash addition of >1% (vol.) to this pasture soil could result in As concentrations in milk and meat products exceeding acceptable limits. The results of this study therefore suggest that even singular low doses of ash applied to soil increase the risk of leaching of metal(loid)s and intensify the risk of As transfer in the food chain. Copyright © 2016 Elsevier Ltd. All rights reserved.

Modeling Volcanic Eruption Parameters by Near-Source Internal Gravity Waves.

PubMed

Ripepe, M; Barfucci, G; De Angelis, S; Delle Donne, D; Lacanna, G; Marchetti, E

2016-11-10

Volcanic explosions release large amounts of hot gas and ash into the atmosphere to form plumes rising several kilometers above eruptive vents, which can pose serious risk on human health and aviation also at several thousands of kilometers from the volcanic source. However the most sophisticate atmospheric models and eruptive plume dynamics require input parameters such as duration of the ejection phase and total mass erupted to constrain the quantity of ash dispersed in the atmosphere and to efficiently evaluate the related hazard. The sudden ejection of this large quantity of ash can perturb the equilibrium of the whole atmosphere triggering oscillations well below the frequencies of acoustic waves, down to much longer periods typical of gravity waves. We show that atmospheric gravity oscillations induced by volcanic eruptions and recorded by pressure sensors can be modeled as a compact source representing the rate of erupted volcanic mass. We demonstrate the feasibility of using gravity waves to derive eruption source parameters such as duration of the injection and total erupted mass with direct application in constraining plume and ash dispersal models.

Modeling Volcanic Eruption Parameters by Near-Source Internal Gravity Waves

PubMed Central

Ripepe, M.; Barfucci, G.; De Angelis, S.; Delle Donne, D.; Lacanna, G.; Marchetti, E.

2016-01-01

Volcanic explosions release large amounts of hot gas and ash into the atmosphere to form plumes rising several kilometers above eruptive vents, which can pose serious risk on human health and aviation also at several thousands of kilometers from the volcanic source. However the most sophisticate atmospheric models and eruptive plume dynamics require input parameters such as duration of the ejection phase and total mass erupted to constrain the quantity of ash dispersed in the atmosphere and to efficiently evaluate the related hazard. The sudden ejection of this large quantity of ash can perturb the equilibrium of the whole atmosphere triggering oscillations well below the frequencies of acoustic waves, down to much longer periods typical of gravity waves. We show that atmospheric gravity oscillations induced by volcanic eruptions and recorded by pressure sensors can be modeled as a compact source representing the rate of erupted volcanic mass. We demonstrate the feasibility of using gravity waves to derive eruption source parameters such as duration of the injection and total erupted mass with direct application in constraining plume and ash dispersal models. PMID:27830768

Alternative group V precursors for CVD applications

NASA Astrophysics Data System (ADS)

Lum, R. M.; Klingert, J. K.

1991-01-01

The chemical vapor deposition (CVD) techniques used to grow III/V semiconductors films, such as metalorganic vapor phase epitaxy (MOVPE), hydride VPE, chemical beam epitaxy (CBE) and gas source molecular beam epitaxy (GS-MBE), all use hydrides (AsH 3 and PH 3) as the Group V source. However, the hydrides are extremely toxic gases which are stored under high pressure (200-2000 psi). To reduce the safety hazards associated with these gases, alternative Group V precursors have been investigated. Organoarsenic and phosphorous compounds have received the most attention as replacements for AsH 3 and PH 3 because they are typically low vapor pressure liquids, and thus present significantly lower exposure risks than the hydrides. For AsH 3 these have included the methyl, ethyl and butyl-based derivatives RnAsH 3- n, with varying degrees ( n = 1-3) of hydrogen atom substitution. In this paper the growth properties, thermochemistry and toxicity of the various alkylarsine precursors are compared with arsine. Data are presented on the impact of the thermochemistry of these compounds on film electrical properties, and on the effects of precursor composition and purity on overall film quality. The suitability of alternative As-precursors for device applications is demonstrated, and selection criteria are presented for the most effective alkylarsine compound for a particular CVD growth process.

Enrichment of naturally occurring radionuclides and trace elements in Yatagan and Yenikoy coal-fired thermal power plants, Turkey.

PubMed

Ozden, Banu; Guler, Erkan; Vaasma, Taavi; Horvath, Maria; Kiisk, Madis; Kovacs, Tibor

2018-08-01

Coal, residues and waste produced by the combustion of the coal contain naturally occurring radionuclides such as 238 U, 226 Ra, 210 Pb, 232 Th and 40 K and trace elements such as Cd, Cr, Pb, Ni and Zn. In this work, coal and its combustion residues collected from Yatagan and Yenikoy coal fired thermal power plants (CPPs) in Turkey were studied to determine the concentrations of natural radionuclides and trace elements, and their enrichments factors to better understand the radionuclide concentration processes within the combustion system. In addition, the utilization of coal fly ash as a secondary raw material in building industry was also studied in terms of radiological aspects. Fly ash samples were taken at different stages along the emission control system of the thermal power plants. Activity concentrations of naturally occurring radionuclides were determined with Canberra Broad Energy Germanium (BEGe) detector BE3830-P and ORTEC Soloist PIPS type semiconductor detector. The particle size distribution and trace elements contents were determined in various ash fractions by the laser scattering particle size distribution analyzer and inductively coupled plasma (ICP-OES). From the obtained data, natural radionuclides tend to condense on fly ash with and the activity concentrations increase as the temperature drop in CPPs. Measured 210 Pb and 210 Po concentration varied between 186 ± 20-1153 ± 44 Bq kg -1 , and 56 ± 5-1174 ± 45 Bq kg -1 , respectively. The highest 210 Pb and 210 Po activity concentrations were determined in fly ash taken from the temporary storage point as 1153 ± 44 Bq kg -1 and 1174 ± 45 Bq kg -1 , respectively. There were significant differences in the activity concentrations of some natural radionuclide and trace elements (Pb and Zn) contents in ash fractions among the sampling point inside both of the plants (ANOVA, p < 0.001). Coal and ash sample analysis showed an increase activity concentration and enrichment factors towards the electrostatic precipitators for both of the power plants. The enrichment factors for Zn follow a similar trend as Pb, increasing in value towards the end of the emission control system. The calculated activity indexes were above 1.0 value for both of the power plants, assuming the utilization of fly ash at 100%. It can be concluded that the reuse of fly ash as a secondary raw material may not be hazardous depending on the percentage of utilization of ash. Copyright © 2017 Elsevier Ltd. All rights reserved.

Geotechnical characterization of a Municipal Solid Waste Incineration Ash from a Michigan monofill.

PubMed

Zekkos, Dimitrios; Kabalan, Mohammad; Syal, Sita Marie; Hambright, Matt; Sahadewa, Andhika

2013-06-01

A field and laboratory geotechnical characterization study of a Municipal Solid Waste Incineration Ash disposed of at the Carleton Farms monofill in Michigan was performed. Field characterization consisted of field observations, collection of four bulk samples and performance of shear wave velocity measurements at two locations. Laboratory characterization consisted of basic geotechnical characterization, i.e., grain size distribution, Atterberg limits, specific gravity tests, compaction tests as well as moisture and organic content assessment followed by direct shear and triaxial shear testing. The test results of this investigation are compared to results in the literature. The grain size distribution of the samples was found to be very similar and consistent with the grain size distribution data available in the literature, but the compaction characteristics were found to vary significantly. Specific gravities were also lower than specific gravities of silicic soils. Shear strengths were higher than typically reported for sandy soils, even for MSWI ash specimens at a loose state. Strain rate was not found to impact the shear resistance. Significant differences in triaxial shear were observed between a dry and a saturated specimen not only in terms of peak shear resistance, but also in terms of stress-strain response. In situ shear wave velocities ranged from 500 to 800 m/s at a depth of about 8m, to 1100-1200 m/s at a depth of 50 m. These high shear wave velocities are consistent with field observations indicating the formation of cemented blocks of ash with time, but this "ageing" process in MSWI ash is still not well understood and additional research is needed. An improved understanding of the long-term behavior of MSWI ash, including the effects of moisture and ash chemical composition on the ageing process, as well as the leaching characteristics of the material, may promote unbound utilization of the ash in civil infrastructure. Copyright © 2013 Elsevier Ltd. All rights reserved.

Effects of fire temperature on the physical and chemical characteristics of the ash from two plots of Cork oak (Quercus Suber)

USGS Publications Warehouse

Ubeda, X.; Pereira, P.; Outeiro, L.; Martin, D.A.

2009-01-01

Cork oak, (Quercus suber) is widely distributed in the Mediterranean region, an area subject to frequent fires. The ash produced by burning can have impacts on the soil status and water resources that can differ according to the temperature reached during fire and the characteristics of the litter, defined as the dead organic matter accumulated on the soil surface prior to the fire. The aim of this work is to determine the physical and chemical characteristics of ash produced in laboratory experiments to approximate conditions typical of fires in this region. The litter of Quercus suber collected from two different plots on the Iberian Peninsula, Mas Bassets (Catalonia) and Albufeira (Portugal), was combusted at different temperatures for 2h. We measured Mass Loss (ML per cent), ash colour and CaCO3 content, pH, Electrical Conductivity (EC) and the major cations (Ca2+, Mg2+, K+ and Na+) released from ash slurries created by mixing ash with deionized water. The results showed that ML per cent is higher at all temperatures in Albufeira samples compared to Mas Bassets samples, except at 550??C, and the rate of loss increases faster with temperature than the Mas Bassets samples. At 150??C the ash colour is yellowish, becoming reddish at 200- 250??C and black at 300??C. Above 400??C the ash is grey/white. This thermal degradation is mostly observed in Albufeira litter. The formation of CaCO3 was identified at a lower temperature in Albufeira litter. At temperatures <300??C, pH and EC values are lower, rising at higher temperatures, especially in Albufeira slurries. The concentration of cations at lower temperatures does not differ substantially from the unburned sample except for Mg2+. The cation concentration increases at medium temperatures and decrease at higher temperatures, especially the concentration of divalent cations. The monovalent cations showed a larger concentration at moderate temperatures, mainly in Albufeira ash slurries. The analysis of the Ca:Mg ratio also showed that for the same temperature, a higher severity results for Albufeira litter. Potential negative effects on soil properties are observed at medium and higher temperatures. These negative effects include a higher percentage of mass loss, meaning more soil may be exposed to erosion, higher pH values and greater cation release from ash, especially monovalalent cations (K+,Na+) in higher proportions than the divalent ions (Ca2+, Mg2+), that can lead to impacts on soil physical properties like aggregate stability. Furthermore, the ions in ash may alter soil chemistry which may be detrimental to some plants thus altering the recovery of these ecosystems after fire. Low intensity prescribed fire can be a useful tool to land management in these sites, due to the reduced effects of fire temperatures on the physical and chemical properties of surface litter, and can reduce the risk of high temperature wildland fires by reducing fuel loadings. From the perspective of water resources, lower fire temperatures produce fewer impacts on the chemistry of overland flow and there is less probability that the soil surface will be eroded. Copyright ?? 2009 John Wiley & Sons, Ltd.

Clay Improvement with Burned Olive Waste Ash

PubMed Central

Mutman, Utkan

2013-01-01

Olive oil is concentrated in the Mediterranean basin countries. Since the olive oil industries are incriminated for a high quantity of pollution, it has become imperative to solve this problem by developing optimized systems for the treatment of olive oil wastes. This study proposes a solution to the problem. Burned olive waste ash is evaluated for using it as clay stabilizer. In a laboratory, bentonite clay is used to improve olive waste ash. Before the laboratory, the olive waste is burned at 550°C in the high temperature oven. The burned olive waste ash was added to bentonite clay with increasing 1% by weight from 1% to 10%. The study consisted of the following tests on samples treated with burned olive waste ash: Atterberg Limits, Standard Proctor Density, and Unconfined Compressive Strength Tests. The test results show promise for this material to be used as stabilizer and to solve many of the problems associated with its accumulation. PMID:23766671

From in-situ coal to fly ash: A study of coal mines and power plants from Indiana

USGS Publications Warehouse

Mastalerz, Maria; Hower, J.C.; Drobniak, A.; Mardon, S.M.; Lis, G.

2004-01-01

This paper presents data on the properties of coal and fly ash from two coal mines and two power plants that burn single-source coal from two mines in Indiana. One mine is in the low-sulfur (5%) Springfield Coal Member of the Petersburg Formation (Pennsylvanian). Both seams have comparable ash contents (???11%). Coals sampled at the mines (both raw and washed fractions) were analyzed for proximate/ultimate/sulfur forms/heating value, major oxides, trace elements and petrographic composition. The properties of fly ash from these coals reflect the properties of the feed coal, as well as local combustion and post-combustion conditions. Sulfur and spinel content, and As, Pb and Zn concentrations of the fly ash are the parameters that most closely reflect the properties of the source coal. ?? 2004 Elsevier B.V. All rights reserved.

Removal of polychlorinated naphthalenes by desulfurization and emissions of polychlorinated naphthalenes from sintering plant

PubMed Central

Wang, Mengjing; Liu, Wenbin; Hou, Meifang; Li, Qianqian; Han, Ying; Liu, Guorui; Li, Haifeng; Liao, Xiao; Chen, Xuebin; Zheng, Minghui

2016-01-01

The sintering flue gas samples were collected at the inlets and outlets of the desulfurization systems to evaluate the influence of the systems on PCNs emission concentrations, profiles, and emission factors. The PCNs concentrations at the inlets and outlets were 27888–153672 pg m−3 and 11988–42245 pg m−3,respectively. Desulfurization systems showed excellent removal for PCNs, and the removal efficiencies of PCNs increase with increasing chlorination level. Lower chlorinated homologs are more sensitive to the desulfurization process than higher ones. High levels of PCNs were also detected in the gypsum (11600–29720 pg g−1) and fly ash samples (4946–64172 pg g−1). The annual total emissions of PCNs released to flue gas and gypsum from the sintering plants were about 394 kg, 48.5% of which was in gypsum. The surface area of the fly ash samples increased significantly from the first to the fourth stage of the series-connected electrostatic precipitator, accompanying obvious rising of concentration of PCNs in the fly ash samples. PMID:27197591

The 15 September 1991 pyroclastic flows at Unzen Volcano (Japan): a flow model for associated ash-cloud surges

NASA Astrophysics Data System (ADS)

Fujii, Toshitsugu; Nakada, Setsuya

1999-04-01

Large-scale collapse of a dacite dome in the late afternoon of 15 September 1991 generated a series of pyroclastic-flow events at Unzen Volcano. Pyroclastic flows with a volume of 1×10 6 m 3 (as DRE) descended the northeastern slope of the volcano, changing their courses to the southeast due to topographic control. After they exited a narrow gorge, an ash-cloud surge rushed straight ahead, detaching the main body of the flow that turned and followed the topographic lows to the east. The surge swept the Kita-Kamikoba area, which had been devastated by the previous pyroclastic-flow events, and transported a car as far as 120 m. Following detachment, the surge lost its force after it moved several hundred meters, but maintained a high temperature. The deposits consist of a bottom layer of better-sorted ash (unit 1), a thick layer of block and ash (unit 2), and a thin top layer of fall-out ash (unit 3). Unit 2 overlies unit 1 with an erosional contact. The upper part of unit 2 grades into better-sorted ash. At distal block-and-ash flow deposits, the bottom part of unit 2 also consists of better-sorted ash, and the contact with the unit 1 deposits becomes ambiguous. Video footage of cascading pyroclastic flows during the 1991-1995 eruption, traveling over surfaces without any topographic barriers, revealed that lobes of ash cloud protruded intermittently from the moving head and sides, and that these lobes surged ahead on the ground surface. This fact, together with the inspection by helicopter shortly after the events, suggests that the protruded lobes consisted of better-sorted ash, and resulted in the deposits of unit 1. The highest ash-cloud plume at the Oshigadani valley exit, and the thickest deposition of fall-out ash over Kita-Kamikoba and Ohnokoba, indicate that abundant ash was also produced when the flow passed through a narrow gorge. In the model presented here, the ash clouds from the pyroclastic flows were composed of a basal turbulent current of high concentration (main body), an overriding and intermediate fluidization zone, and an overlying dilute cloud. Release of pressurized gas in lava block pores, due to collisions among blocks and the resulting upward current, caused a zone of fluidization just above the main body. The mixture of gas and ash sorted in the fluidization zone moved ahead and to the side of the main body as a gravitational current, where the ash was deposited as surge deposits. The main body, which had high internal friction and shear near its base, then overran the surge deposits, partially eroding them. When the upward current of gas (fluidization) waned, better-sorted ash suspended in the fluidization zone was deposited on block-and-ash deposits. In the distal places of block-and-ash deposits, unit 2 probably was deposited in non-turbulent fashion without any erosion of the underlying layer (unit 1).

Microphysical Properties of Alaskan Volcanic Ash

NASA Astrophysics Data System (ADS)

Puthukkudy, A.; Espinosa, R.; Rocha Lima, A.; Remer, L.; Colarco, P. R.; Whelley, P.; Krotkov, N. A.; Young, K.; Dubovik, O.; Wallace, K.; Martins, J. V.

2017-12-01

Volcanic ash has the potential to cause a variety of severe problems for human health and the environment. Therefore, effective monitoring of the dispersion and fallout from volcanic ash clouds and characterization of the aerosol particle properties are essential. One way to acquire information from volcanic clouds is through satellite remote sensing: such images have greater coverage than ground-based observations and can present a "big picture" perspective. A challenge of remote sensing is that assumptions of certain properties of the target are often a pre-requisite for making accurate and quantitative retrievals. For example, detailed information about size distribution, sphericity, and optical properties of the constituent matter is needed or must be assumed. The same kind of information is also needed for atmospheric transport models to properly simulate the dispersion and fallout of volcanic ash. Presented here is a laboratory method to determine the microphysical and optical properties of volcanic ash samples collected from two Alaskan volcanoes with markedly different compositions. Our method uses a Polarized Imaging Nephelometer (PI-Neph) and a system that re-suspends the particles in an air flow. The PI-Neph measures angular light scattering and polarization of the re-suspended particles from 3o to 175o in scattering angle, with an angular resolution of 1o . Primary measurements include phase function and polarized phase function at three wavelengths (445nm, 532nm, and 661nm). Size distribution, sphericity, and complex refractive index are retrieved indirectly from the PI-Neph measurements using the GRASP (Generalized Retrieval of Aerosol and Surface Properties) inversion algorithm. We report the results of this method applied to samples from the Mt. Okmok (2008) and Mt. Katmai (1912) volcanic eruptions. To our knowledge, this is the first time direct measurements of phase matrix elements of ash from Mt. Okmok and Mt. Katmai have been reported. Retrieved microphysical properties show that Mt. Katmai ash is less absorbing than the Mt. Okmok ash in visible wavelengths. Phase function of these Alaskan volcanic ashes is smooth curve without any significant features. Phase function and polarized phase function measured do not exhibit strong spectral dependence in visible wavelengths.

Concentration of heavy metals in ash produced from Lithuanian forests

NASA Astrophysics Data System (ADS)

Baltrenaite, Edita; Pereira, Paulo; Butkus, Donatas; Úbeda, Xavier

2010-05-01

Wood ash contains important amounts of heavy metals. This quantity depends on burned specie, temperature of exposition and heat duration time. Due the high mineralization imposed by the temperatures, ash is used as lime product in agriculture and forests. Also, after a forest fire large quantities of ash are produced and distributed in soil surface. This mineralized organic matter can induce important environmental problems, including soil toxicity provoked by heavy metals leachates from ash. There is an extensive literature about heavy metals contents on ash in different species. However, it recently highlighted that the same species placed in different environments can respond diversely to same temperatures. This question is of major importance because temperature effects on severity can be a function of the plant communities instead of specie characteristics. These findings add a higher degree of complexity in the understanding of temperature effects on ash composition and consequent availability of heavy metals. The aim of this study is to compare the ash chemical heavy metal composition, Cobalt (Co), Chromium (Cr), Cooper (Cu), Silver (Ag), Lead (Pb), Nickel (Ni), Manganese (Mn) and Zinc (Zn), from Pinus sylvestris and Betula pendula, collected in key and representative areas of Lithuanian forests, located in southern, coastal and central part. Samples were collected from alive trees, taken to laboratory and air dried. Subsequently were crushed and submitted to muffle furnace at temperature of 550°C during two hours. The ash samples were digested and in a HNO3-HCl solution and then analysed with AAS. Comparisons between species and sites were performed with a Non-parametric one-way ANOVA‘s on rank transformed data followed by Tukey‘s HSD, significant at a p<0.05. Results showed significant difference between Co and Ag concentrations between Pinus sylvestris and Betula pendula. Also, significantly different concentrations of Pb, Cu, Ni and Mn were determined among investigated sites. No significant difference was found for Zn and Cr among investigated sites. Variation of metals between sites and stands can be explained by their age, flammability difference between plant communities and anthropogenic heavy metal load. These and other aspects will be discussed with more detail in the communication.

Thermal Barrier Coatings Chemically and Mechanically Resistant to High Temperature Attack by Molten Ashes

NASA Astrophysics Data System (ADS)

Gledhill, Andrew

Thermal barrier coatings (TBCs) are ceramic coatings used on component in the hottest sections of gas turbine engines, used for power generation and aviation. These coatings insulate the underlying metal components and allow for much higher engine operating temperatures, improving the engine efficiency. These increase temperatures engender a new set of materials problems for TBCs. Operating temperatures in engines are now high enough for silicate impurities, either present in the fuel or ingested into the engines, to melt and adhere to the surface of the TBCs. The effects of four such impurities, two coal fly ashes, a petroleum coke-fly ash blend, and volcanic ash from the Eyjafjallajokull volcano were tested with conventional yttria-stabilized zirconia (YSZ) coatings, and found to penetrate through the entire thickness of the coating. This penetration reduces the strain tolerance of the coatings, and can result in premature failure. Testing on a newly built thermal gradient burner rig with simultaneous injection of ash impurities has shown a reduction of life up to 99.6% in these coatings when ash is present. Coatings of an alternative ceramic, gadolinium zirconate (Gd2Zr 2O7), were found to form a dense reaction layer with each of these impurities, preventing further penetration of the molten ash. This dense layer also reduces the strain tolerance, but these coatings were found to have a significantly higher life than the YSZ coatings. Testing with a small amount of ash baked onto the samples showed thirteen times the life of YSZ coatings. When the ash is continuously sprayed onto the hot sample, the life of the Gd2Zr2O7 coatings was nearly twice that of the YSZ. Finally, a delamination model was employed to explain the degradation of both types of coatings. This elastic model that takes into account the degree of penetration, differential cooling in thermal gradient testing, and thermal expansion mismatch with the underlying substrate, predicted the failure of YSZ coatings with the observed degree of penetration. The model shows that deposition optimization can be employed to further enhance the life of Gd 2Zr2O7coatings.

Characterization of boron tolerant bacteria isolated from a fly ash dumping site for bacterial boron remediation.

PubMed

Edward Raja, Chellaiah; Omine, Kiyoshi

2013-08-01

Boron is an essential micronutrient for plants, but can above certain concentrations be toxic to living organisms. A major environmental concern is the removal of boron from contaminated water and fly ash. For this purpose, the samples were collected from a fly ash dumping site, Nagasaki prefecture, Japan. The chemical characteristics and heavy metal concentration of the samples were performed by X-ray fluorescent analysis and leaching test. For bacterial analysis, samples were collected in sterile plastic sheets and isolation was carried out by serial dilution method. The boron tolerant isolates that showed values of maximum inhibitory concentration toward boron ranging from 100 to 260 mM level were screened. Based on 16S rRNA sequencing and phylogenetic analysis, the isolates were most closely related to the genera Bacillus, Lysinibacillus, Microbacterium and Ralstonia. The boron tolerance of these strains was also associated with resistant to several heavy metals, such as As (III), Cr (VI), Cd, Cu, Pb, Ni, Se (III) and Zn. Indeed, these strains were arsenic oxidizing bacteria confirmed by silver nitrate test. These strains exhibited their salt resistances ranging from 4 to 15 % were determined in Trypticase soy agar medium. The boron tolerant strains were capable of removing 0.1-2.0 and 2.7-3.7 mg l(-1) boron from the medium and fly ash at 168 h. Thus, we have successfully identified the boron tolerant and removal bacteria from a fly ash dumping site for boron remediation.

Low-temperature thermal decomposition of dioxin-like compounds in fly ash: combination of chemical analysis with in vitro bioassays (EROD and DR-CALUX).

PubMed

Behnisch, Peter A; Hosoe, Kazunori; Shiozaki, Ken; Ozaki, Hironori; Nakamura, Kazuo; Sakai, Shin-Ichi

2002-12-01

To investigate the dechlorination of fly ash during low-temperature treatment under oxygen-deficient conditions (thermocatalyic treatment or Hagenmaier process), six fly ash samples from six different incineration plants were treated in a laboratory experiment or in the actual plant, either under ideal (400 degrees C, 120 min) or intermediate (300 degrees C, 30 min) conditions. The aim of the present study was to confirm the decrease in the I-TEQ (international toxicity equivalency) of polychlorinated dibenzo-p-dioxins/-furans (PCDD/Fs) and coplanar polychlorinated biphenyls (co-PXBs) and, also for the first time, the decrease in the sum of dioxin-like toxicity (bioassay- or bio-TEQ) of all kinds of other dioxin-like Ah receptor agonists (such as PXDD/Fs, PXBs, PXN, X = Br, F) measured by two state-of-the-art cell-based Ah receptor-dependent bioassays: H4IIE-Ethoxy-Resorufin-o-Deethylase (EROD) and H4IIE-luc/DR-Chemical Activated Luciferase expression (DR-CALUX). The treatment efficiency was calculated on the basis of the reduction in the I-TEQ and bio-TED values. For these fly ash samples, the treatment efficiency, as measured by chemical analysis, was higher than 99%, and 85%-99%, in the case of the bio-TED values, indicating that these Ah receptor binding toxic compounds were sufficiently decomposed. Bio-TEQ values for untreated fly ash samples (n = 6) were on average 1.2 times (range 0.7-1.9), for the H4IIE-EROD assay, and 2.8 times (1.1-4.9), for the DR-CALUX assay, higher than I-TEQ values measured by chemical analyses (sum of PCDD/Fs and co-PCBs). In the case of these fly ash samples treated under ideal conditions and therefore low in contaminants, the bio-TEQ values were on average 1.4 times (range 0.9-1.8), for the H4IIE-EROD assay, and 5.1 times (range 1.2-12), for the DR-CALUX assay, higher than the I-TEQ values.

Magmatic and fragmentation controls on volcanic ash surface chemistry

NASA Astrophysics Data System (ADS)

Ayris, Paul M.; Diplas, Spyros; Damby, David E.; Hornby, Adrian J.; Cimarelli, Corrado; Delmelle, Pierre; Scheu, Bettina; Dingwell, Donald B.

2016-04-01

The chemical effects of silicate ash ejected by explosive volcanic eruptions on environmental systems are fundamentally mediated by ash particle surfaces. Ash surfaces are a composite product of magmatic properties and fragmentation mechanisms, as well as in-plume and atmospheric alteration processes acting upon those surfaces during and after the eruption. Recent attention has focused on the capacity of alteration processes to shape ash surfaces; most notably, several studies have utilised X-ray photoelectron spectroscopy (XPS), a technique probing the elemental composition and coordination state of atoms within the top 10 nm of ash surfaces, to identify patterns of elemental depletions and enrichments relative to bulk ash chemical composition. Under the presumption of surface and bulk equivalence, any disparities have been previously attributed to surface alteration processes, but the ubiquity of some depletions (e.g., Ca, Fe) across multiple ash studies, irrespective of eruptive origin, could suggest these to be features of the surface produced at the instant of magma fragmentation. To investigate this possibility further, we conducted rapid decompression experiments at different pressure conditions and at ambient and magmatic temperature on porous andesitic rocks. These experiments produced fragmented ash material untouched by secondary alteration, which were compared to particles produced by crushing of large clasts from the same experiments. We investigated a restricted size fraction (63-90 μm) from both fragmented and crushed materials, determining bulk chemistry and mineralogy via XRF, SEM-BSE and EPMA, and investigated the chemical composition of the ash surface by XPS. Analyses suggest that fragmentation under experimental conditions partitioned a greater fraction of plagioclase-rich particles into the selected size fraction, relative to particles produced by crushing. Trends in surface chemical composition in fragmented and crushed particles mirror that partitioning effect, but crucially, disparities between surface and bulk chemistry remain evident. Simple glass-plagioclase mixing calculations suggest that this feature may indicate differences in bulk and surface mineral distributions; future QEMSCAN analysis will investigate this possibility further. Additionally, surface iron enrichments observed in our high temperature experiments suggest that hot oxidation effects can have a near-instantaneous, measurable effect on ash surface chemistry at the nanometre scale. Our preliminary results suggest that the chemical and mineral properties of the source magma, coupled with high temperature fragmentation processes, may have a significant influence on ash surface chemistry and mineralogy, and subsequently, on the post-eruptive alteration of ash particles and their reactivity within biotic and abiotic systems.

Correlation of quantitative computed tomographic subchondral bone density and ash density in horses.

PubMed

Drum, M G; Les, C M; Park, R D; Norrdin, R W; McIlwraith, C W; Kawcak, C E

2009-02-01

The purpose of this study was to compare subchondral bone density obtained using quantitative computed tomography with ash density values from intact equine joints, and to determine if there are measurable anatomic variations in mean subchondral bone density. Five adult equine metacarpophalangeal joints were scanned with computed tomography (CT), disarticulated, and four 1-cm(3) regions of interest (ROI) cut from the distal third metacarpal bone. Bone cubes were ashed, and percent mineralization and ash density were recorded. Three-dimensional models were created of the distal third metacarpal bone from CT images. Four ROIs were measured on the distal aspect of the third metacarpal bone at axial and abaxial sites of the medial and lateral condyles for correlation with ash samples. Overall correlations of mean quantitative CT (QCT) density with ash density (r=0.82) and percent mineralization (r=0.93) were strong. There were significant differences between abaxial and axial ROIs for mean QCT density, percent bone mineralization and ash density (p<0.05). QCT appears to be a good measure of bone density in equine subchondral bone. Additionally, differences existed between axial and abaxial subchondral bone density in the equine distal third metacarpal bone.

Development of a host-based semiochemical lure for trapping emerald ash borer (Agrilus planipennis (Coleoptera: Buprestidae)

Treesearch

Damon J. Crook; Ashot Khrimian; Joseph A. Francese; Ivich Fraser; Therese M. Poland; Alan J. Sawyer; Victor C. Mastro

2008-01-01

Bark volatiles from green ash Fraxinus pennsylvanica were tested for electrophysiological activity by Agrilus planipennis using gas chromatographic-electroantennographic detection (GC-EAD) and for behavioral activity using baited purple traps in Michigan. GC-EAD analysis of the headspace volatiles of bark tissue samples from 0...

EFFECT OF CONVENTIONAL AND ADVANCED COAL CONVERSION BY-PRODUCTS ON THE PULMONARY SYSTEM

EPA Science Inventory

To evaluate the environmental impact of different energy technologies, fly ash samples collected from a coal-fired and from an oil-fired electric power plant were used in aerosol inhalation exposures of mice. The effects of multiple 3-h exposures to the fly ash particles at 2 and...

Coal fly ash based carbons for SO2 removal from flue gases.

PubMed

Rubio, B; Izquierdo, M T

2010-07-01

Two different coal fly ashes coming from the burning of two coals of different rank have been used as a precursor for the preparation of steam activated carbons. The performance of these activated carbons in the SO(2) removal was evaluated at flue gas conditions (100 degrees C, 1000 ppmv SO(2), 5% O(2), 6% H(2)O). Different techniques were used to determine the physical and chemical characteristics of the samples in order to explain the differences found in their behaviour. A superior SO(2) removal capacity was shown by the activated carbon obtained using the fly ash coming from a sub-bituminous-lignite blend. Experimental results indicated that the presence of higher amount of certain metallic oxides (Ca, Fe) in the carbon-rich fraction of this fly ash probably has promoted a deeper gasification in the activation with steam. A more suitable surface chemistry and textural properties have been obtained in this case which explains the higher efficiency shown by this sample in the SO(2) removal. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

National Coal Quality Inventory (NACQI)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Robert Finkelman

2005-09-30

The U.S. Geological Survey (USGS) conducted the National Coal Quality Inventory (NaCQI) between 1999 and 2005 to address a need for quality information on coals that will be mined during the next 20-30 years. Collaboration between the USGS, State geological surveys, universities, coal burning utilities, and the coal mining industry plus funding support from the Electric Power Research Institute (EPRI) and the U.S. Department of Energy (DOE) permitted collection and submittal of coal samples for analysis. The chemical data (proximate and ultimate analyses; major, minor and trace element concentrations) for 729 samples of raw or prepared coal, coal associated shale,more » and coal combustion products (fly ash, hopper ash, bottom ash and gypsum) from nine coal producing States are included. In addition, the project identified a new coal reference analytical standard, to be designated CWE-1 (West Elk Mine, Gunnison County, Colorado) that is a high-volatile-B or high-volatile-A bituminous coal with low contents of ash yield and sulfur, and very low, but detectable contents of chlorine, mercury and other trace elements.« less

Determination of coal ash content by the combined x-ray fluorescence and scattering spectrum

NASA Astrophysics Data System (ADS)

Mikhailov, I. F.; Baturin, A. A.; Mikhailov, A. I.; Borisova, S. S.; Fomina, L. P.

2018-02-01

An alternative method is proposed for the determination of the inorganic constituent mass fraction (ash) in solid fuel by the ratio of Compton and Rayleigh X-ray scattering peaks IC/IR subject to the iron fluorescence intensity. An original X-ray optical scheme with a Ti/Mo (or Sc/Cu) double-layer secondary radiator allows registration of the combined fluorescence-and-scattering spectrum at the specified scattering angle. An algorithm for linear calibration of the Compton-to-Rayleigh IC/IR ratio is proposed which uses standard samples with two certified characteristics: mass fractions of ash (Ad) and iron oxide (WFe2O3). Ash mass fractions have been determined for coals of different deposits in the wide range of Ad from 9.4% to 52.7% mass and WFe2O3 from 0.3% to 4.95% mass. Due to the high penetrability of the probing radiation with energy E > 17 keV, the sample preparation procedure is rather simplified in comparison with the traditional method of Ad determination by the sum of fluorescence intensities of all constituent elements.

NDA issues with RFETS vitrified waste forms

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hurd, J.; Veazey, G.

1998-12-31

A study was conducted at Los Alamos National Laboratory (LANL) for the purpose of determining the feasibility of using a segmented gamma scanner (SGS) to accurately perform non-destructive analysis (NDA) on certain Rocky Flats Environmental Technology Site (RFETS) vitrified waste samples. This study was performed on a full-scale vitrified ash sample prepared at LANL according to a procedure similar to that anticipated to be used at RFETS. This sample was composed of a borosilicate-based glass frit, blended with ash to produce a Pu content of {approximately}1 wt %. The glass frit was taken to a degree of melting necessary tomore » achieve a full encapsulation of the ash material. The NDA study performed on this sample showed that SGSs with either {1/2}- or 2-inch collimation can achieve an accuracy better than 6 % relative to calorimetry and {gamma}-ray isotopics. This accuracy is achievable, after application of appropriate bias corrections, for transmissions of about {1/2} % through the waste form and counting times of less than 30 minutes. These results are valid for ash material and graphite fines with the same degree of plutonium particle size, homogeneity, sample density, and sample geometry as the waste form used to obtain the results in this study. A drum-sized thermal neutron counter (TNC) was also included in the study to provide an alternative in the event the SGS failed to meet the required level of accuracy. The preliminary indications are that this method will also achieve the required accuracy with counting times of {approximately}30 minutes and appropriate application of bias corrections. The bias corrections can be avoided in all cases if the instruments are calibrated on standards matching the items.« less

Relative abundance and distribution of fishes and crayfish at Ash Meadows National Wildlife Refuge, Nye County, Nevada, 2007-08

USGS Publications Warehouse

Scoppettone, G. Gary; Rissler, Peter; Johnson, Danielle; Hereford, Mark

2011-01-01

This study provides baseline data of native and non-native fish populations in Ash Meadows National Wildlife Refuge (NWR), Nye County, Nevada, that can serve as a gauge in native fish enhancement efforts. In support of Carson Slough restoration, comprehensive surveys of Ash Meadows NWR fishes were conducted seasonally from fall 2007 through summer 2008. A total of 853 sampling stations were created using Geographic Information Systems and National Agricultural Imagery Program. In four seasons of sampling, Amargosa pupfish (genus Cyprinodon) was captured at 388 of 659 stations. The number of captured Amargosa pupfish ranged from 5,815 (winter 2008) to 8,346 (summer 2008). The greatest success in capturing Amargosa pupfish was in warm water spring-pools with temperature greater than 25 degrees C, headwaters of warm water spring systems, and shallow (depths less than 10 centimeters) grassy marshes. In four seasons of sampling, Ash Meadows speckled dace (Rhinichthys osculus nevadesis) was captured at 96 of 659 stations. The number of captured Ash Meadows speckled dace ranged from 1,009 (summer 2008) to 1,552 (winter 2008). The greatest success in capturing Ash Meadows speckled dace was in cool water spring-pools with temperature less than 20 degrees C and in the high flowing water outflows. Among 659 sampling stations within the range of Amargosa pupfish, red swamp crayfish (Procambarus clarkii) was collected at 458 stations, western mosquitofish (Gambusia affinis) at 374 stations, and sailfin molly (Poecilia latipinna) at 128 stations. School Springs was restored during the course of this study. Prior to restoration of School Springs, maximum Warm Springs Amargosa pupfish (Cyprinodon nevadensis pectoralis) captured from the six springs of the Warm Springs Complex was 765 (fall 2007). In four seasons of sampling, Warm Springs Amargosa pupfish were captured at 85 of 177 stations. The greatest success in capturing Warm Springs Amargosa pupfish when co-occurring with red swamp crayfish and western mosquitofish was in water with temperature greater than 26 degrees C near the springhead, and in shallow (depths less than 10 centimeters) grassy marshes. Among 177 sampling stations within the range of Warm Springs Amargosa pupfish, red swamp crayfish were collected at 96 stations and western mosquitofish were collected at 49 stations. Removal of convict cichlid (Amatitlania nigrofasciata) from Fairbanks Spring was followed by a substantial increase in Ash Meadows Amargosa pupfish (Cyprinodon nevadensis mionectes) captures from 910 pre-removal to 3,056 post-removal. Red swamp crayfish was continually removed from Bradford 1 Spring, which seemed to cause an increase in the speckled dace population. Restoration of Kings Pool and Jackrabbit Springs promoted the success of native fishes with the greatest densities in restored reaches. Ongoing restoration of Carson Slough and its tributaries, as well as control and elimination of invasive species, is expected to increase abundance and distribution of Ash Meadows' native fish populations. Further analysis of data from this study will help determine the habitat characteristic(s) that promote native species and curtail non-native species.

In vitro toxicology of respirable Montserrat volcanic ash.

PubMed

Wilson, M R; Stone, V; Cullen, R T; Searl, A; Maynard, R L; Donaldson, K

2000-11-01

In July 1995 the Soufriere Hills volcano on the island of Montserrat began to erupt. Preliminary reports showed that the ash contained a substantial respirable component and a large percentage of the toxic silica polymorph, cristobalite. In this study the cytotoxicity of three respirable Montserrat volcanic ash (MVA) samples was investigated: M1 from a single explosive event, M2 accumulated ash predominantly derived from pyroclastic flows, and M3 from a single pyroclastic flow. These were compared with the relatively inert dust TiO(2) and the known toxic quartz dust, DQ12. Surface area of the particles was measured with the Brunauer, Emmet, and Teller (BET) adsorption method and cristobalite content of MVA was determined by x ray diffraction (XRD). After exposure to particles, the metabolic competence of the epithelial cell line A549 was assessed to determine cytotoxic effects. The ability of the particles to induce sheep blood erythrocyte haemolysis was used to assess surface reactivity. Treatment with either MVA, quartz, or titanium dioxide decreased A549 epithelial cell metabolic competence as measured by ability to reduce 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT). On addition of mannitol, the cytotoxic effect was significantly less with M1, quartz, and TiO(2). All MVA samples induced a dose dependent increase in haemolysis, which, although less than the haemolysis induced by quartz, was significantly greater than that induced by TiO(2). Addition of mannitol and superoxide dismutase (SOD) significantly reduced the haemolytic activity only of M1, but not M2 or M3, the samples derived from predominantly pyroclastic flow events. Neither the cristobalite content nor the surface area of the MVA samples correlated with observed in vitro reactivity. A role for reactive oxygen species could only be shown in the cytotoxicity of M1, which was the only sample derived from a purely explosive event. These results suggest that in general the bioreactivity of MVA samples in vitro is low compared with pure quartz, but that the bioreactivity and mechanisms of biological interaction may vary according to the ash source.

Glass import and production in Hispania during the early medieval period: The glass from Ciudad de Vascos (Toledo)

PubMed Central

2017-01-01

One hundred and forty-one glass fragments from medieval Ciudad de Vascos (Toledo, Spain) were analysed by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). The glasses fall into three types according to the fluxing agents used: mineral natron, soda-rich plant ash, and a combination of soda ash and lead. The natron glasses can be assigned to various established primary production groups of eastern Mediterranean provenance. Different types of plant ash glasses indicate differences in the silica source as well as the plant ash component, reflecting changing supply mechanisms. While the earlier plant ash groups can be related to Islamic glasses from the Near East, both in terms of typology and composition, the chemical signature of the later samples appear to be specific to glass from the Iberian Peninsula. This has important implications for our understanding of the emerging glass industry in Spain and the distribution patterns of glass groups and raw materials. The plant ash that was used for the Vascos glasses is rich in soda with low levels of potash, similar to ash produced in the eastern Mediterranean. It could therefore be possible that Levantine plant ash was imported and used in Islamic period glass workshops in Spain. Unlike central and northern Europe where an independent glass industry based on potassium-rich wood ash developed during the Carolingian period, the prevalence of soda ash and soda ash lead glass on the Iberian Peninsula indicates its commercial and technological interconnection with the Islamic east. Our study thus traces several stages leading to the development of a specifically Spanish primary glassmaking industry. PMID:28746419

Indirect effects of emerald ash borer-induced ash mortality and canopy gap formation on epigaeic beetles.

PubMed

Gandhi, Kamal J K; Smith, Annemarie; Hartzler, Diane M; Herms, Daniel A

2014-06-01

Exotic herbivorous insects have drastically and irreversibly altered forest structure and composition of North American forests. For example, emerald ash borer (Agrilus planipennis Fairmaire) from Asia has caused wide-scale mortality of ash trees (Fraxinus spp.) in eastern United States and Canada. We studied the effects of forest changes resulting from emerald ash borer invasion on epigaeic or ground beetles (Coleoptera: Carabidae) along a gradient of ash dieback and gap sizes in southeastern Michigan. Ground beetles were sampled in hydric, mesic, and xeric habitats in which black (Fraxinus nigra Marshall), green (Fraxinus pennsylvanica Marshall), and white (Fraxinus americana L.) ash were the most common species, respectively. During 2006-2007, we trapped 2,545 adult ground beetles comprising 52 species. There was a negative correlation between percent ash tree mortality in 2006 and catches of all beetles. Catches of Agonum melanarium Dejean (in 2006) and Pterostichus mutus (Say) (in 2006-2007) were negatively correlated with tree mortality and gap size, respectively. However, catches of Pterostichus corvinus Dejean were positively correlated with gap size in 2006. As ash mortality and average gap size increased from 2006 to 2007, catches of all beetles as well as P. mutus and Pterostichus stygicus (Say) increased (1.3-3.9 times), while species diversity decreased, especially in mesic and xeric stands. Cluster analysis revealed that beetle assemblages in hydric and mesic stand diverged (25 and 40%, respectively) in their composition from 2006 to 2007, and that hydric stands had the most unique beetle assemblages. Overall, epigaeic beetle assemblages were altered in ash stands impacted by emerald ash borer; however, these impacts may dissipate as canopy gaps close.

Environmental impact assessment of wood ash utilization in forest road construction and maintenance--A field study.

PubMed

Oburger, Eva; Jäger, Anna; Pasch, Alexander; Dellantonio, Alex; Stampfer, Karl; Wenzel, Walter W

2016-02-15

The ever increasing use of wood material as fuel for green energy production requires innovative, environmentally safe strategies for recycling of the remaining wood ash. Utilizing wood ash in forest road construction and maintenance to improve mechanical stability has been suggested as a feasible recycling option. To investigate the environmental impact of wood ash application in forest road maintenance, a two-year field experiment was conducted at two Austrian forest sites (Kobernausserwald (KO) (soil pH 5.5) and Weyregg (WE) (pH 7.7)) differing in their soil chemical properties. Two different ashes, one produced by grate incineration (GA) and the other by fluidized bed incineration in a mixture with 15 vol% burnt lime (FBA), were incorporated in repeated road sections at a 15:85% (V/V) ash-to-soil rate. Leaching waters from the road body were collected and analyzed for 32 environmentally relevant parameters over two years. Upon termination of the experiment, sub-road soil samples were collected and analyzed for ash-related changes in soil chemistry. Even though a larger number of parameters was affected by the ash application at the alkaline site (WE), we observed the most pronounced initial increases of pH as well as Al, As, Fe, Mn, Ni, Co, Cu, Mo, and NO2(−) concentrations in leachates beneath GA-treated road bodies at Kobernausserwald due to the lower soil buffer capacity at this site. Despite the observed effects our results indicate that, when specific requirements are met (i.e. appropriate ash quality, sufficient soil buffer capacity below the road body, and single time-point ash incorporation within several decades), wood ash application in forest road construction is generally environmentally acceptable.

[Proximate analysis of straw by near infrared spectroscopy (NIRS)].

PubMed

Huang, Cai-jin; Han, Lu-jia; Liu, Xian; Yang, Zeng-ling

2009-04-01

Proximate analysis is one of the routine analysis procedures in utilization of straw for biomass energy use. The present paper studied the applicability of rapid proximate analysis of straw by near infrared spectroscopy (NIRS) technology, in which the authors constructed the first NIRS models to predict volatile matter and fixed carbon contents of straw. NIRS models were developed using Foss 6500 spectrometer with spectra in the range of 1,108-2,492 nm to predict the contents of moisture, ash, volatile matter and fixed carbon in the directly cut straw samples; to predict ash, volatile matter and fixed carbon in the dried milled straw samples. For the models based on directly cut straw samples, the determination coefficient of independent validation (R2v) and standard error of prediction (SEP) were 0.92% and 0.76% for moisture, 0.94% and 0.84% for ash, 0.88% and 0.82% for volatile matter, and 0.75% and 0.65% for fixed carbon, respectively. For the models based on dried milled straw samples, the determination coefficient of independent validation (R2v) and standard error of prediction (SEP) were 0.98% and 0.54% for ash, 0.95% and 0.57% for volatile matter, and 0.78% and 0.61% for fixed carbon, respectively. It was concluded that NIRS models can predict accurately as an alternative analysis method, therefore rapid and simultaneous analysis of multicomponents can be achieved by NIRS technology, decreasing the cost of proximate analysis for straw.

Determination of iodine in bread and fish using the iodide ion-selective electrode

DOE Office of Scientific and Technical Information (OSTI.GOV)

Steiner, J.B.

The purpose of this study was to assess the potential for use of the ion-selective electrode (ISE) as a method for measuring the iodine content in bread and fish. Ashing methods, sample preparation and electrode responses were evaluated. The iodine values obtained using the iodide electrode were compared to iodine values obtained by the arsenic-cerium method (As-Ce). Ashing methods were used in preparing bread and haddock for iodine analysis by the ISE. The values were compared to unashed samples measured by the ISE. Electrode response to iodide was examined by varying the sample pH, measuring electrode equilibrium times, and comparingmore » direct measurement in ppm to iodide values obtained by the method of known addition. Oyster reference tissue with a known iodine concentration was used to determine rates of recovery. For the As-Ce procedure, an alkaline dry ash for two hour followed by colorimetric analysis at 320 nm was recommended. The study showed that the pre-treatment of bread and fish was necessary for ISE measurement. The iodine values obtained by the ISE in the analysis of oyster reference tissue, haddock and bread were not in agreement with their corresponding As-Ce values. Further work needs to be done to determine an ashing procedure that has minimal iodide loss an/or develop sample treatments that will improve the reliability and precision of iodine values obtained using the ion-selective electrode.« less

Impact of Collection Equipment on Ash Variability of Baled Corn Stover Biomass for Bioenergy

DOE Office of Scientific and Technical Information (OSTI.GOV)

William Smith; Jeffery Einerson; Kevin Kenney

2014-09-01

Cost-effective conversion of agricultural residues for renewable energy hinges not only on the material’s quality but also the biorefinery’s ability to reliably measure quality specifications. The ash content of biomass is one such specification, influencing pretreatment and disposal costs for the conversion facility and the overall value of a delivered lot of biomass. The biomass harvest process represents a primary pathway for accumulation of soil-derived ash within baled material. In this work, the influence of five collection techniques on the total ash content and variability of ash content within baled corn stover in southwest Kansas is discussed. The equipment testedmore » included a mower for cutting the corn stover stubble, a basket rake, wheel rake, or shred flail to gather the stover, and a mixed or uniform in-feed baler for final collection. The results showed mean ash content to range from 11.5 to 28.2 % depending on operational choice. Resulting impacts on feedstock costs for a biochemical conversion process range from $5.38 to $22.30 Mg-1 based on the loss of convertible dry matter and ash disposal costs. Collection techniques that minimized soil contact (shred flail or nonmowed stubble) were shown to prevent excessive ash contamination, whereas more aggressive techniques (mowing and use of a wheel rake) caused greater soil disturbance and entrainment within the final baled material. Material sampling and testing were shown to become more difficult as within-bale ash variability increased, creating uncertainty around feedstock quality and the associated costs of ash mitigation.« less

Occurrence and severity of foliar ozone symptoms on sensitive hardwood species in Shenandoah National Park, VA

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hildebrand, E.; Skelly, J.M.

1993-02-01

To assess the extent of foliar symptoms due to ozone on sensitive hardwoods in the Shenandoah National Park in Virginia, three species were sampled and evaluated at sites of differing elevations adjacent to 3 ozone monitors in 1991 and 1992: black cherry, yellow poplar, and white ash. All foliar samples were evaluated to precent of symptomatic leaves on each branch and average precent leaf area affected. The Horsfall-Barratt rating scale was used to estimate the precent leaf area symptomatic. Ozone symptoms were manifested as stipple on the adazial leaf surface. In the preliminary 1991 sampling, 40, 87, and 7% ofmore » black cherry trees sampled were found to be symptomatic at the 3 sites; 63 and 67% of yellow poplar trees sampled were found to be symptomatic at sites 1 and 3, as were 43 and 63% of the white ash at sites 1 and 2 (3 complete sets were not found in 1991). In 1992, the sampling and rating of injury were repeated. Symptoms of ozone injury appeared on 23, 88, and 10% of black cherry, on 17, 7, and 80% of yellow poplar, and 27, 40, and 40% of white ash. Elevation and ozone exposure will be discussed.« less

Evaluation of interactions between soil and coal fly ash leachates using column percolation tests.

PubMed

Tsiridis, V; Petala, M; Samaras, P; Sakellaropoulos, G P

2015-09-01

The aim of this work was the assessment of the environmental impact of different origin fly ashes with regard to their final disposal. The experimental procedure included the performance of single column tests and column tests of fly ash and soil in series. The appraisal of the potential environmental hazards was implemented using physicochemical analyses and bioassays. Two different fly ash samples were examined, one fly ash produced from the combustion of sub-bituminous coal (CFA) and one fly ash produced from the combustion of lignite (LFA). Single column percolation tests were performed according to NEN 7343 protocol, while fly ash/soil experiments were conducted incorporating slight modifications to this protocol. The study focused on the release of metals Ba, Cr, Cu, Mo, Se and Zn and the ecotoxic behavior of leachates on crustacean Daphnia magna and bacteria Vibrio fischeri. The infiltration of the leachates of both fly ashes through soil affected considerably their leaching profile. The transport of Cu and Zn was facilitated by the dynamic leaching conditions and influenced by the pH of the leachates. Moreover, the release and bioavailability of Cr, Cu and Zn was probably altered during the infiltration experiments and organisms' response was not always correlated with the concentration of metals. Nevertheless, the results are signalling that possible manipulations and final disposal of fly ash should be considered when environmental threats are investigated. Copyright © 2015 Elsevier Ltd. All rights reserved.

Retrieval of volcanic ash height from satellite-based infrared measurements

NASA Astrophysics Data System (ADS)

Zhu, Lin; Li, Jun; Zhao, Yingying; Gong, He; Li, Wenjie

2017-05-01

A new algorithm for retrieving volcanic ash cloud height from satellite-based measurements is presented. This algorithm, which was developed in preparation for China's next-generation meteorological satellite (FY-4), is based on volcanic ash microphysical property simulation and statistical optimal estimation theory. The MSG satellite's main payload, a 12-channel Spinning Enhanced Visible and Infrared Imager, was used as proxy data to test this new algorithm. A series of eruptions of Iceland's Eyjafjallajökull volcano during April to May 2010 and the Puyehue-Cordón Caulle volcanic complex eruption in the Chilean Andes on 16 June 2011 were selected as two typical cases for evaluating the algorithm under various meteorological backgrounds. Independent volcanic ash simulation training samples and satellite-based Cloud-Aerosol Lidar with Orthogonal Polarization data were used as validation data. It is demonstrated that the statistically based volcanic ash height algorithm is able to rapidly retrieve volcanic ash heights, globally. The retrieved ash heights show comparable accuracy with both independent training data and the lidar measurements, which is consistent with previous studies. However, under complicated background, with multilayers in vertical scale, underlying stratus clouds tend to have detrimental effects on the final retrieval accuracy. This is an unresolved problem, like many other previously published methods using passive satellite sensors. Compared with previous studies, the FY-4 ash height algorithm is independent of simultaneous atmospheric profiles, providing a flexible way to estimate volcanic ash height using passive satellite infrared measurements.

Combining sieving and washing, a way to treat MSWI boiler fly ash.

PubMed

De Boom, Aurore; Degrez, Marc

2015-05-01

Municipal Solid Waste Incineration (MSWI) fly ashes contain some compounds that could be extracted and valorised. A process based on wet sieving and washing steps has been developed aiming to reach this objective. Such unique combination in MSWI fly ash treatment led to a non-hazardous fraction from incineration fly ashes. More specifically, MSWI Boiler Fly Ash (BFA) was separately sampled and treated. The BFA finer particles (13wt%) were found to be more contaminated in Pb and Zn than the coarser fractions. After three washing steps, the coarser fractions presented leaching concentrations acceptable to landfill for non-hazardous materials so that an eventual subsequent valorisation may be foreseen. At the contrary, too much Pb leached from the finest particles and this fraction should be further treated. Wet sieving and washing permit thus to reduce the leachability of MSWI BFA and to concentrate the Pb and Zn contamination in a small (in particle size and volume) fraction. Such combination would therefore constitute a straightforward and efficient basis to valorise coarse particles from MSWI fly ashes. Copyright © 2015 Elsevier Ltd. All rights reserved.

Arsenic and selenium capture by fly ashes at low temperature

DOE Office of Scientific and Technical Information (OSTI.GOV)

M. Antonia Lopez-Anton; Mercedes Diaz-Somoano; D. Alan Spears

2006-06-15

Arsenic and selenium compounds may be emitted to the environment during coal conversion processes, although some compounds are retained in the fly ashes, in different proportions depending on the characteristics of the ashes and process conditions. The possibility of optimizing the conditions to achieve better trace element retention appears to be an attractive, economical option for reducing toxic emissions. This approach requires a good knowledge of fly ash characteristics and a thorough understanding of the capture mechanism involved in the retention. In this work the ability of two fly ashes, one produced in pulverized coal combustion and the other inmore » fluidized bed combustion, to retain arsenic and selenium compounds from the gas phase in coal combustion and coal gasification atmospheres was investigated. To explore the possible simultaneous retention of mercury, the influence of the unburned coal particle content was also evaluated. Retention capacities between 2 and 22 mg g{sup -1} were obtained under different conditions. The unburned coal particle content in the fly ash samples does not significantly modify retention capacities. 21 refs., 6 figs., 5 tabs.« less

Concordant 241Pu-241Am Dating of Environmental Samples: Results from Forest Fire Ash

NASA Astrophysics Data System (ADS)

Goldstein, S. J.; Oldham, W. J.; Murrell, M. T.; Katzman, D.

2010-12-01

We have measured the Pu, 237Np, 241Am, and 151Sm isotopic systematics for a set of forest fire ash samples from various locations in the western U.S. including Montana, Wyoming, Idaho, and New Mexico. The goal of this study is to develop a concordant 241Pu (t1/2 = 14.4 y)-241Am dating method for environmental collections. Environmental samples often contain mixtures of components including global fallout. There are a number of approaches for subtracting the global fallout component for such samples. One approach is to use 242Pu/239Pu as a normalizing isotope ratio in a three-isotope plot, where this ratio for the non-global fallout component can be estimated or assumed to be small. This study investigates a new, complementary method of normalization using the long-lived fission product, 151Sm (t1/2 = 90 y). We find that forest fire ash concentrates actinides and fission products with ~1E10 atoms 239Pu/g and ~1E8 atoms 151Sm/g, allowing us to measure these nuclides by mass spectrometric (MIC-TIMS) and radiometric (liquid scintillation counting) methods. The forest fire ash samples are characterized by a western U.S. regional isotopic signature representing varying mixtures of global fallout with a local component from atmospheric testing of nuclear weapons at the Nevada Test Site (NTS). Our results also show that 151Sm is well correlated with the Pu nuclides in the forest fire ash, suggesting that these nuclides have similar geochemical behavior in the environment. Results of this correlation indicate that the 151Sm/239Pu atom ratio for global fallout is ~0.164, in agreement with an independent estimate of 0.165 based on 137Cs fission yields for atmospheric weapons tests at the NTS. 241Pu-241Am dating of the non-global fallout component in the forest fire ash samples yield ages in the late 1950’s-early 1960’s, consistent with a peak in NTS weapons testing at that time. The age results for this component are in agreement using both 242Pu and 151Sm normalizations, although the errors for the 151Sm correction are currently larger due to the greater uncertainty of their measurements. Additional efforts to develop a concordant 241Pu-241Am dating method for environmental collections are underway with emphasis on soil cores.

Concordant plutonium-241-americium-241 dating of environmental samples: results from forest fire ash

DOE Office of Scientific and Technical Information (OSTI.GOV)

Goldstein, Steven J; Oldham, Warren J; Murrell, Michael T

2010-12-07

We have measured the Pu, {sup 237}Np, {sup 241}Am, and {sup 151}Sm isotopic systematics for a set of forest fire ash samples from various locations in the western U.S. including Montana, Wyoming, Idaho, and New Mexico. The goal of this study is to develop a concordant {sup 241}Pu (t{sub 1/2} = 14.4 y)-{sup 241}Am dating method for environmental collections. Environmental samples often contain mixtures of components including global fallout. There are a number of approaches for subtracting the global fallout component for such samples. One approach is to use {sup 242}/{sup 239}Pu as a normalizing isotope ratio in a three-isotopemore » plot, where this ratio for the nonglobal fallout component can be estimated or assumed to be small. This study investigates a new, complementary method of normalization using the long-lived fission product, {sup 151}Sm (t{sub 1/2} = 90 y). We find that forest fire ash concentrates actinides and fission products with {approx}1E10 atoms {sup 239}Pu/g and {approx}1E8 atoms {sup 151}Sm/g, allowing us to measure these nuclides by mass spectrometric (MIC-TIMS) and radiometric (liquid scintillation counting) methods. The forest fire ash samples are characterized by a western U.S. regional isotopic signature representing varying mixtures of global fallout with a local component from atmospheric testing of nuclear weapons at the Nevada Test Site (NTS). Our results also show that {sup 151}Sm is well correlated with the Pu nuclides in the forest fire ash, suggesting that these nuclides have similar geochemical behavior in the environment. Results of this correlation indicate that the {sup 151}Sm/{sup 239}Pu atom ratio for global fallout is {approx}0.164, in agreement with an independent estimate of 0.165 based on {sup 137}Cs fission yields for atmospheric weapons tests at the NTS. {sup 241}Pu-{sup 241}Am dating of the non-global fallout component in the forest fire ash samples yield ages in the late 1950's-early 1960's, consistent with a peak in NTS weapons testing at that time. The age results for this component are in agreement using both {sup 242}Pu and {sup 151}Sm normalizations, although the errors for the {sup 151}Sm correction are currently larger due to the greater uncertainty of their measurements. Additional efforts to develop a concordant {sup 241}Pu-{sup 241}Am dating method for environmental collections are underway with emphasis on soil cores.« less

Deposition or not? The fate of volcanic ash after aggregation processes

NASA Astrophysics Data System (ADS)

Mueller, Sebastian B.; Kueppers, Ulrich; Wadsworth, Fabian B.; Ayris, Paul M.; Casas, Ana S.; Cimarelli, Corrado; Ametsbichler, Jonathan; Delmelle, Pierre; Taddeucci, Jacopo; Jacob, Michael; Dingwell, Donald B.

2017-04-01

In the course of explosive volcanic eruptions, large amounts of ash are released into the atmosphere and may subsequently pose a threat to infrastructure, such as aviation industry. Ash plume forecasting is therefore a crucial tool for volcanic hazard mitigation but may be significantly affected by aggregation, altering the aerodynamic properties of particles. Models struggle with the implementation of aggregation since external conditions promoting aggregation have not been completely understood; in a previous study we have shown the rapid generation of ash aggregates through liquid bonding via the use of fluidization bed technology and further defined humidity and temperature ranges necessary to trigger aggregation. Salt (NaCl) was required for the recovery of stable aggregates, acting as a cementation agent and granting aggregate cohesion. A numerical model was used to explain the physics behind particle aggregation mechanisms and further predicted a dependency of aggregation efficiency on liquid binder viscosity. In this study we proof the effect of viscosity on particle aggregation. HCl and H2SO4 solutions were diluted to various concentrations resulting in viscosities between 1 and 2 mPas. Phonolitic and rhyolitic ash samples as well as soda-lime glass beads (serving as analogue material) were fluidized in the ProCell Lab® of Glatt Ingenieurtechnik GmbH and treated with the acids via a bottom-spray technique. Chemically driven interaction between acid liquids and surfaces of the three used materials led to crystal precipitation. Salt crystals (e.g. NaCl) have been confirmed through scanning electron microscopy (SEM) and leachate analysis. Both volcanic ash samples as well as the glass beads showed a clear dependency of aggregation efficiency on viscosity of the sprayed HCl solution. Spraying H2SO4 provoked a collapse of the fluidized bed and no aggregation has been observed. This is accounted by the high hygroscopicity of H2SO4. Dissolving CaCl2 (known to be a highly hygroscopic salt) in de-ionized water yielded comparable results without observable aggregation. In case of successful aggregation, concentration of salts has been found to be in the range of published values. We conclude that non-hygroscopic salt crystal precipitation from an aqueous liquid interacting with the glass phase in volcanic ash is a very efficient way to produce cohesive ash aggregates that can survive external forces acting during transport and sedimentation. Our parameterization of ash aggregation processes shall now be implemented in ash plume dispersal modelling for improved and more accurate ash distribution forecasting in the event of explosive volcanic eruptions.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baker, Tyler F; Jett, Robert Trent; Smith, John G.

A dike failure at the Tennessee Valley Authority Kingston Fossil Plant in East Tennessee, United States, in December 2008, released approximately 4.1 million m3 of coal ash into the Emory River. From 2009 through 2012, samples of mayfly nymphs ( Hexagenia bilineata) were collected each spring from sites in the Emory, Clinch, and Tennessee Rivers upstream and downstream of the spill. Samples were analyzed for 17 metals. Concentrations of metals were generally highest the first 2 miles downstream of the spill, and then decreased with increasing distance from the spill. Arsenic, B, Ba, Be, Mo, Sb, Se, Sr, and Vmore » appeared to have strong ash signatures, whereas Co, Cr, Cu, Ni, and Pb appeared to be associated with ash and other sources. Furthermore, the concentrations for most of these contaminants were modest and are unlikely to cause widespread negative ecological effects. Trends in Hg, Cd, and Zn suggested little (Hg) or no (Cd, Zn) association with ash. Temporal trends suggested that concentrations of ash-related contaminants began to subside after 2010, but because of the limited time period of that analysis (4 yr), further monitoring is needed to verify this trend. The present study provides important information on the magnitude of contaminant exposure to aquatic receptors from a major coal ash spill, as well as spatial and temporal trends for transport of the associated contaminants in a large open watershed. Environ Toxicol Chem 2016;35:1159 1171. Published 2015 Wiley Periodicals Inc. on behalf of SETAC. This article is a US government work and, as such, is in the public domain in the United States of America.« less

Characterization of coal fly ash components by laser-induced breakdown spectroscopy

NASA Astrophysics Data System (ADS)

Ctvrtnickova, Tereza; Mateo, Mari-Paz; Yañez, Armando; Nicolas, Gines

2009-10-01

The high sensitivity of laser-induced breakdown spectroscopy (LIBS) for the detection of most of the fly ash components enables the analysis of these residues produced during the combustion of coal. Fly ash consists of oxides (SiO 2, Al 2O 3, Fe 2O 3, CaO…) and unburnt carbon which is the major determinant of combustion efficiency in coal fired boilers. For example, an excessive amount of residual carbon dispersed in the fly ash means a significant loss of energy (Styszko et al., 2004 [1]). Standard methods employed for the analysis of fly ash make not possible a control of boiler in real time. LIBS technique can significantly reduce the time of analysis, in some cases even an online detection can be performed. For this reason, some studies have been addressed in order to demonstrate the capability of the laser-induced breakdown spectroscopy technique for the detection of carbon content in high pressure conditions typical of thermal power plants (Noda et al., 2002 [2]) and for the monitoring of unburnt carbon for the boiler control in real time (Kurihara et al., 2003 [3]). In particular, the content of unburnt carbon is a valuable indicator for the control of fly ash quality and for the boiler combustion. Depending on this unburnt carbon content, fly ash can be disposed as an industrial waste or as a raw material for the production of concrete in the construction sector. In this study, analyses were performed on specimens of various forms of preparation. Pressed pellets were prepared with two different binders. Presented results concern the nature and amount of the binder used to pelletize the powder, and the laser-induced breakdown spectroscopy parameters and procedure required to draw calibration curves of elements from the fly ash. Analysis "on tape" was performed in order to establish the experimental conditions for the future "online analysis".

Radionuclide concentration variations in the fuel and residues of oil shale-fired power plants: Estimations of the radiological characteristics over a 2-year period.

PubMed

Vaasma, Taavi; Loosaar, Jüri; Kiisk, Madis; Tkaczyk, Alan Henry

2017-07-01

Several multi-day samplings were conducted over a 2-year period from an oil shale-fired power plant operating with pulverized fuel type of boilers that were equipped with either novel integrated desulphurization system and bag filters or with electrostatic precipitators. Oil shale, bottom ash and fly ash samples were collected and radionuclides from the 238 U and 232 Th series as well as 40 K were determined. The work aimed at determining possible variations in the concentrations of naturally occurring radionuclides within the collected samples and detect the sources of these fluctuations. During the continuous multi-day samplings, various boiler parameters were recorded as well. With couple of exceptions, no statistically significant differences were detected (significance level 0.05) between the measured radionuclide mean values in various ash samples within the same sampling. When comparing the results between multiple years and samplings, no statistically significant variations were observed between 238 U and 226 Ra values. However, there were significant differences between the values in the fly ashes when comparing 210 Pb, 40 K, 228 Ra and 232 Th values between the various samplings. In all cases the radionuclide activity concentrations in the specific fly ash remained under 100 Bq kg -1 , posing no radiological concerns when using this material as an additive in construction or building materials. Correlation analysis between the registered boiler parameters and measured radionuclide activity concentrations showed weak or no correlation. The obtained results suggest that the main sources of variations are due to the characteristics of the used fuel. The changes in the radionuclide activity concentrations between multiple years were in general rather modest. The radionuclide activity concentrations varied dominantly between 4% and 15% from the measured mean within the same sampling. The relative standard deviation was however within the same range as the relative measurement uncertainty, suggesting that the main component of fluctuations is derived from the measurement method and approach. The obtained results indicate that representativeness of the data over a longer time period is valid only when a fuel with a similar composition is used and when the combustion boilers operate with a uniform setup (same boiler type and purification system). The results and the accompanying statistical analysis clearly demonstrated that in order to obtain data with higher reliability, a repeated multi-day sampling should be organized and combined with the registered boiler technical and operational parameters. Copyright © 2016 Elsevier Ltd. All rights reserved.

Experiment Investigation of the Influencing Factors on Bed Agglomeration During Fluidized-Bed Gasification of Biomass Fuels

NASA Astrophysics Data System (ADS)

Chen, Y. Q.; Chen, H. P.; Yang, H. P.; Wang, X. H.; Zhang, S. H.

With the depleting of fossil fuel and environmental polluting increasing, the utilization of biomass resources caught increasing concern. Biomass gasification in fluidized bed, as one promising technology, developed quickly. However, serious agglomeration was displayed as biomass ash reacted with bed material (silica sand) at higher temperature. It hindered the wide utilization of CFB gasifier. The objective ofthis work is to investigate the agglomeration behavior between biomass ash and silica sand, and catch the inherent mechanism. Firstly, the influence of ash compounds on the agglomeration behavior was analyzed with biomass ash and synthesis ash compounds addition in fixed bed as ash sample mixed with bed material evenly before every trial. The reaction temperature was set 850°C that is the operated temperature for many fluidized bed gasificated biomass fuels. Then the influence of reaction time was analyzed. The characteristics of the agglomerated silica sand particles were analyzed by the XRD. Finally, it was simulated with HSC computer mode based on thermodynamic equilibrium. It was observed that when the ratio of the biomass ash to the silica sand was above 0.2, the agglomeration was observed. With the increase of the reaction time, more silica sand particles agglomerated with the biomass ash. There are two kinds of silicate eutecticum investigated by the XRD. It is of great significance for the running ofCFB biomass gasifier and the development ofbiomass utilization technology.

Potentially harmful elements released by volcanic ashes: Examples from the Mediterranean area

NASA Astrophysics Data System (ADS)

Cangemi, Marianna; Speziale, Sergio; Madonia, Paolo; D'Alessandro, Walter; Andronico, Daniele; Bellomo, Sergio; Brusca, Lorenzo; Kyriakopoulos, Konstantinos

2017-05-01

We have performed leaching experiments on the fine (< 2 mm) particulate sampled in seven active and quiescent volcanic systems in the Mediterranean area. We reacted the particulate both in pure water and in a synthetic gastric solution. The amount of As, Mn, Pb, Ba, U and Ni leached by pure water exceeded the MAC limits for drinking water in all the materials under investigation. We defined a tolerable ash intake index (TAI) to evaluate the impact of ash ingestion, and we find that 0.2 g and 12 g of ingested fine ash from Vesuvius and Vulcano are enough to exceed the safety limits for Pb and As. Six grams of fine ashes from Stromboli are sufficient to overstep the safety limits for As. Based on our mineralogical characterisation of the particulate, we expect that the submillimetric ash fraction, with a higher surface/volume ratio, releases a greater relative amount of trace metals, which are concentrated in the thin surface layer produced by the reaction of the pristine volcanic particles with coexisting volcanic gases. This means that our measurements represent lower bounds to the actual amount of metal released in aqueous solutions by the volcanic ashes from the locations under investigation. Our results place the first constraints on the mobilisation of toxic elements from volcanic ash, which are necessary to assess the associated potential health risk of volcanic areas.

Metal roof corrosion related to volcanic ash deposition

NASA Astrophysics Data System (ADS)

Oze, C.; Cole, J. W.; Scott, A.; Wilson, T.; Wilson, G.; Gaw, S.; Hampton, S.; Doyle, C.; Li, Z.

2013-12-01

Volcanoes produce a wide range of hazards capable of leading to increased rates of corrosion to the built environment. Specifically, widely distributed volcanic ash derived from explosive volcanic eruptions creates both short- and long-term hazards to infrastructure including increased corrosion to exposed building materials such as metal roofing. Corrosion has been attributed to volcanic ash in several studies, but these studies are observational and are beset by limitations such as not accounting for pre-existing corrosion damage and/or other factors that may have also directly contributed to corrosion. Here, we evaluate the corrosive effects of volcanic ash, specifically focusing on the role of ash leachates, on a variety of metal roofing materials via weathering chamber experiments. Weathering chamber tests were carried out for up to 30 days using a synthetic ash dosed with an acidic solution to produce a leachate comparable to a real volcanic ash. Visual, chemical and surface analyses did not definitively identify significant corrosion in any of the test roofing metal samples. These experiments attempted to provide quantitative information with regards to the rates of corrosion of different types of metal roof materials. However, they demonstrate that no significant corrosion was macroscopically or microscopically present on any of the roofing surfaces despite the presence of corrosive salts after a duration of thirty days. These results suggest ash leachate-related corrosion is not a major or immediate concern in the short-term (< 1 month).

Oxidation resistance of biochars as a function of feedstock and pyrolysis condition

USDA-ARS?s Scientific Manuscript database

This study investigated the chemical stability of a wide range of biochar samples (pyrochars from ash-poor (pine wood) and ash-rich feedstocks (rice straw, swine solids and poultry litter) at 250, 450 and 600 Celsius, and 250 °C hydrochars from swine solids and poultry litter) to short- and long-ter...

Design and Evaluation of a Chamber Capable of Containing the Detonation Effects of 40 Pounds of TNT

DTIC Science & Technology

1975-11-01

Boiler and Pressure Vessel Code , 197A. For the girth welds, short lengths of 26-in.-dia. pipe were tacked to the vessel around the...and tensile tests meet the requirements of Section IX, ASHE Boiler and Pressure Vessel Code , 1974. Weld made by W. H. Stefanov ■.^^ w-^iiMaLwärt...Macro Results Kos, No Remarl.s The results of the bond and it^nsile tests met the requirements of Section IX, ASME Boiler and Pressure

Proximate Composition Analysis.

PubMed

2016-01-01

The proximate composition of foods includes moisture, ash, lipid, protein and carbohydrate contents. These food components may be of interest in the food industry for product development, quality control (QC) or regulatory purposes. Analyses used may be rapid methods for QC or more accurate but time-consuming official methods. Sample collection and preparation must be considered carefully to ensure analysis of a homogeneous and representative sample, and to obtain accurate results. Estimation methods of moisture content, ash value, crude lipid, total carbohydrates, starch, total free amino acids and total proteins are put together in a lucid manner.

Reference dataset of volcanic ash physicochemical and optical properties for atmospheric measurement retrievals and transport modelling

NASA Astrophysics Data System (ADS)

Vogel, Andreas; Durant, Adam; Sytchkova, Anna; Diplas, Spyros; Bonadonna, Costanza; Scarnato, Barbara; Krüger, Kirstin; Kylling, Arve; Kristiansen, Nina; Stohl, Andreas

2016-04-01

Explosive volcanic eruptions emit up to 50 wt.% (total erupted mass) of fine ash particles (<63 microns), which individually can have theoretical atmospheric lifetimes that span hours to days. Depending on the injection height, fine ash may be subsequently transported and dispersed by the atmosphere over 100s - 1000s km and can pose a major threat for aviation operations. Recent volcanic eruptions, such as the 2010 Icelandic Eyjafjallajökull event, illustrated how volcanic ash can severely impact commercial air traffic. In order to manage the threat, it is important to have accurate forecast information on the spatial extent and absolute quantity of airborne volcanic ash. Such forecasts are constrained by empirically-derived estimates of the volcanic source term and the nature of the constituent volcanic ash properties. Consequently, it is important to include a quantitative assessment of measurement uncertainties of ash properties to provide realistic ash forecast uncertainty. Currently, information on volcanic ash physicochemical and optical properties is derived from a small number of somewhat dated publications. In this study, we provide a reference dataset for physical (size distribution and shape), chemical (bulk vs. surface chemistry) and optical properties (complex refractive index in the UV-vis-NIR range) of a representative selection of volcanic ash samples from 10 different volcanic eruptions covering the full variability in silica content (40-75 wt.% SiO2). Through the combination of empirical analytical methods (e.g., image analysis, Energy Dispersive Spectroscopy, X-ray Photoelectron Spectroscopy, Transmission Electron Microscopy and UV/Vis/NIR/FTIR Spectroscopy) and theoretical models (e.g., Bruggeman effective medium approach), it was possible to fully capture the natural variability of ash physicochemical and optical characteristics. The dataset will be applied in atmospheric measurement retrievals and atmospheric transport modelling to determine the sensitivity to uncertainty in ash particle characteristics.

A robust method to forecast volcanic ash clouds

USGS Publications Warehouse

Denlinger, Roger P.; Pavolonis, Mike; Sieglaff, Justin

2012-01-01

Ash clouds emanating from volcanic eruption columns often form trails of ash extending thousands of kilometers through the Earth's atmosphere, disrupting air traffic and posing a significant hazard to air travel. To mitigate such hazards, the community charged with reducing flight risk must accurately assess risk of ash ingestion for any flight path and provide robust forecasts of volcanic ash dispersal. In response to this need, a number of different transport models have been developed for this purpose and applied to recent eruptions, providing a means to assess uncertainty in forecasts. Here we provide a framework for optimal forecasts and their uncertainties given any model and any observational data. This involves random sampling of the probability distributions of input (source) parameters to a transport model and iteratively running the model with different inputs, each time assessing the predictions that the model makes about ash dispersal by direct comparison with satellite data. The results of these comparisons are embodied in a likelihood function whose maximum corresponds to the minimum misfit between model output and observations. Bayes theorem is then used to determine a normalized posterior probability distribution and from that a forecast of future uncertainty in ash dispersal. The nature of ash clouds in heterogeneous wind fields creates a strong maximum likelihood estimate in which most of the probability is localized to narrow ranges of model source parameters. This property is used here to accelerate probability assessment, producing a method to rapidly generate a prediction of future ash concentrations and their distribution based upon assimilation of satellite data as well as model and data uncertainties. Applying this method to the recent eruption of Eyjafjallajökull in Iceland, we show that the 3 and 6 h forecasts of ash cloud location probability encompassed the location of observed satellite-determined ash cloud loads, providing an efficient means to assess all of the hazards associated with these ash clouds.

One-Pot Synthesis of GeAs Ultrafine Particles from Coal Fly Ash by Vacuum Dynamic Flash Reduction and Inert Gas Condensation.

PubMed

Zhang, Lingen; Xu, Zhenming

2017-06-16

Ge-monopnictides (GeAs) plays critical role in high-tech industry, especially in the field of advanced optical devices and infrared. As a secondary material, coal fly ash could be further recycled to retrieve germanium and prepare GeAs material with high added values. Hence, the aim of this paper is to propose a one-pot synthesis that uses vacuum flash reduction and inert-gas consolidation method to prepare GeAs ultrafine particles. Germanium in coal fly ash can be successfully recycled; simultaneously, GeAs ultrafine particles were prepared. Separation principle and feasibility of this process was discussed. Temperature, carrier gas flow rate and system pressure were the major factors on formation, morphology and distribution of particle size of GeAs ultrafine particles. A three steps synthetic mechanism was clarified, namely, thermal rupture of coal fly ash and release of GeO 2 and As 2 O 3 , the gas-solid phase reaction of GeO 2 , As 2 O 3 and coke to generate metallic Ge and As in vacuum flash reduction. Meantime, GeAs were produced in the gas phase reaction. Finally, GeAs ultrafine particles were obtained by carrier gas condensation. In short, this research developed a practical and environment-friendly one-pot synthesis to recycle germanium in coal fly ash and prepare GeAs ultrafine particles with high added values.

Waste oil shale ash as a novel source of calcium for precipitated calcium carbonate: carbonation mechanism, modeling, and product characterization.

PubMed

Velts, O; Uibu, M; Kallas, J; Kuusik, R

2011-11-15

In this paper, a method for converting lime-containing oil shale waste ash into precipitated calcium carbonate (PCC), a valuable commodity is elucidated. The mechanism of ash leachates carbonation was experimentally investigated in a stirred semi-batch barboter-type reactor by varying the CO(2) partial pressure, gas flow rate, and agitation intensity. A consistent set of model equations and physical-chemical parameters is proposed to describe the CaCO(3) precipitation process from oil shale ash leachates of complex composition. The model enables the simulation of reactive species (Ca(2+), CaCO(3), SO(4)(2-), CaSO(4), OH(-), CO(2), HCO(3)(-), H(+), CO(3)(2-)) concentration profiles in the liquid, gas, and solid phases as well as prediction of the PCC formation rate. The presence of CaSO(4) in the product may also be evaluated and used to assess the purity of the PCC product. A detailed characterization of the PCC precipitates crystallized from oil shale ash leachates is also provided. High brightness PCC (containing up to ∼ 96% CaCO(3)) with mean particle sizes ranging from 4 to 10 μm and controllable morphology (such as rhombohedral calcite or coexisting calcite and spherical vaterite phases) was obtained under the conditions studied. Copyright © 2011 Elsevier B.V. All rights reserved.

Study on emission of hazardous trace elements in a 350 MW coal-fired power plant. Part 2. arsenic, chromium, barium, manganese, lead.

PubMed

Zhao, Shilin; Duan, Yufeng; Chen, Lei; Li, Yaning; Yao, Ting; Liu, Shuai; Liu, Meng; Lu, Jianhong

2017-07-01

Hazardous Trace elements (HTEs) emitted from coal combustion has raised widespread concern. Studies on the emission characteristics of five HTEs, namely arsenic (As), chromium (Cr), barium (Ba), manganese (Mn), lead (Pb) at three different loads (100%, 83%, 71% output) and different coal types were performed on a 350 MW coal-fired power plant equipped with SCR, ESP + FF, and WFGD. HTEs in the flue gas at the inlet/outlet of each air pollution control device (APCD) were sampled simultaneously based on US EPA Method 29. During flue gas HTEs sampling, coal, bottom ash, fly ash captured by ESP + FF, fresh desulfurization slurry, desulfurization wastewater were also collected. Results show that mass balance rate for the system and each APCD is in an acceptable range. The five studied HTEs mainly distribute in bottom and ESP + FF ash. ESP + FF have high removal efficiency of 99.75-99.95%. WFGD can remove part of HTEs further. Total removal rate across the APCDs ranges from 99.84 to 99.99%. Concentration of HTEs emitted to atmosphere is within the extremely low scope of 0.11-4.93 μg/m 3 . Emission factor of the five studied HTEs is 0.04-1.54 g/10 12 J. Content of As, Pb, Ba, Cr in solid samples follows the order of ESP + FF ash > bottom ash > gypsum. More focus should be placed on Mn in desulfuration wastewater, content of which is more than the standard value. This work is meaningful for the prediction and removal of HTEs emitted from coal-fired power plants. Copyright © 2017 Elsevier Ltd. All rights reserved.

Radiological and material characterization of high volume fly ash concrete.

PubMed

Ignjatović, I; Sas, Z; Dragaš, J; Somlai, J; Kovács, T

2017-03-01

The main goal of research presented in this paper was the material and radiological characterization of high volume fly ash concrete (HVFAC) in terms of determination of natural radionuclide content and radon emanation and exhalation coefficients. All concrete samples were made with a fly ash content between 50% and 70% of the total amount of cementitious materials from one coal burning power plant in Serbia. Physical (fresh and hardened concrete density) and mechanical properties (compressive strength, splitting tensile strength and modulus of elasticity) of concrete were tested. The radionuclide content ( 226 Ra, 232 Th and 40 K) and radon massic exhalation of HVFAC samples were determined using gamma spectrometry. Determination of massic exhalation rates of HVFAC and its components using radon accumulation chamber techniques combined with a radon monitor was performed. The results show a beneficial effect of pozzolanic activity since the increase in fly ash content resulted in an increase in compressive strength of HVFAC by approximately 20% for the same mass of cement used in the mixtures. On the basis of the obtained radionuclide content of concrete components the I -indices of different HVFAC samples were calculated and compared with measured values (0.27-0.32), which were significantly below the recommended 1.0 index value. The prediction was relatively close to the measured values as the ratio between the calculated and measured I-index ranged between 0.89 and 1.14. Collected results of mechanical and radiological properties and performed calculations clearly prove that all 10 designed concretes with a certain type of fly ash are suitable for structural and non-structural applications both from a material and radiological point of view. Copyright © 2016 Elsevier Ltd. All rights reserved.

Study of the SRF-derived ashes melting behavior and the effects generated by the optimization of their composition on the furnaces energy efficiency in the incineration plants.

PubMed

Mercurio, Vittorio; Venturelli, Chiara; Paganelli, Daniele

2014-12-01

As regards the incineration process of the urban solid waste, the composition correct management allows not only the valorization of precise civil and industrial groups of waste as alternative fuels but also a considerable increase of the furnace work temperature leading to a remarkable improvement of the related energy efficiency. In this sense, the study of the melting behavior of ashes deriving from several kinds of fuels that have to be processed to heat treatment is really important. This approach, indeed, ensures to know in depth the features defining the melting behavior of these analyzed samples, and as a consequence, gives us the necessary data in order to identify the best mixture of components to be incinerated as a function of the specific working temperatures of the power plant. Firstly, this study aims to find a way to establish the softening and melting temperatures of the ashes because they are those parameters that strongly influence the use of fuels. For this reason, in this work, the fusibility of waste-derived ashes with different composition has been investigated by means of the heating microscope. This instrument is fundamental to prove the strict dependence of the ashes fusion temperature on the heating rate that the samples experienced during the thermal cycle. In addition, in this work, another technological feature of the instrument has been used allowing to set an instantaneous heating directly on the sample in order to accurately reproduce the industrial conditions which characterize the incineration plants. The comparison between the final results shows that, in effect, the achievement of the best performances of the furnace is due to the a priori study of the melting behavior of the single available components.

Remediation of AMD using industrial waste adsorbents

NASA Astrophysics Data System (ADS)

Mohammed, Nuur Hani Bte; Yaacob, Wan Zuhairi Wan

2016-11-01

The study investigates the characteristic of industrial waste as adsorbents and its potential as heavy metals absorbents in AMD samples. The AMD sample was collected from active mine pond and the pH was measured in situ. The metal contents were analyzed by ICP-MS. The AMD water was very acidic (pH< 3.5), and the average heavy metals content in AMD were high especially in Fe (822.029 mg/l). Fly ash was found to be the most effective absorbent material containing high percentage of CaO (57.24%) and SiO2 (13.88%), followed by ladle furnace slag containing of high amount of CaO (51.52%) and Al2O3 (21.23%), while biomass ash consists of SiO2 (43.07%) and CaO (12.97%). Tank analysis display a huge changes due to pH value change from acidity to nearly neutral phases. After 50 days, fly ash remediation successfully increase the AMD pH values from pH 2.57-7.09, while slag change from acidity to nearly alkaline phase from pH 2.60-7.3 and biomass has change to pH 2.54-6.8. Fly ash has successfully remove Fe, Mn, Cu, and Ni. Meanwhile, slag sample displays as an effective adsorbent to adsorb more Pb and Cd in acid mine drainage.

Progression in sulfur isotopic compositions from coal to fly ash: Examples from single-source combustion in Indiana

USGS Publications Warehouse

Yaofa, Jiang; Elswick, E.R.; Mastalerz, Maria

2008-01-01

Sulfur occurs in multiple mineral forms in coals, and its fate in coal combustion is still not well understood. The sulfur isotopic composition of coal from two coal mines in Indiana and fly ash from two power plants that use these coals were studied using geological and geochemical methods. The two coal beds are Middle Pennsylvanian in age; one seam is the low-sulfur ( 5%) Springfield Coal Member of the Petersburg Formation. Both seams have ash contents of approximately 11%. Fly-ash samples were collected at various points in the ash-collection system in the two plants. The results show notable difference in ??34S for sulfur species within and between the low-sulfur and high-sulfur coal. The ??34S values for all sulfur species are exclusively positive in the low-sulfur Danville coal, whereas the ??34S values for sulfate, pyritic, and organic sulfur are both positive and negative in the high-sulfur Springfield coal. Each coal exhibits a distinct pattern of stratigraphic variation in sulfur isotopic composition. Overall, the ??34S for sulfur species values increase up the section in the low-sulfur Danville coal, whereas they show a decrease up the vertical section in the high-sulfur Springfield coal. Based on the evolution of ??34S for sulfur species, it is suggested that there was influence of seawater on peat swamp, with two marine incursions occurring during peat accumulation of the high-sulfur Springfield coal. Therefore, bacterial sulfate reduction played a key role in converting sulfate into hydrogen sulfide, sulfide minerals, and elemental sulfur. The differences in ??34S between sulfate sulfur and pyritic sulfur is very small between individual benches of both coals, implying that some oxidation occurred during deposition or postdeposition. The ??34S values for fly ash from the high-sulfur Springfield coal (averaging 9.7???) are greatly enriched in 34S relative to those in the parent coal (averaging 2.2???). This indicates a fractionation of sulfur isotopes during high-sulfur coal combustion. By contrast, the ??34S values for fly-ash samples from the low-sulfur Danville coal average 10.2???, only slightly enriched in 34S relative to those from the parent coal (average 7.5???). The ??34S values for bulk S determined directly from the fly-ash samples show close correspondence with the ??34S values for SO4- 2 leached from the fly ash in the low-sulfur coal, suggesting that the transition from pyrite to sulfate occurred via high-temperature oxidation during coal combustion. ?? 2007 Elsevier B.V. All rights reserved.

What makes hydromagmatic eruptions violent? Some insights from the Keanakāko'i Ash, Kı̄lauea Volcano, Hawai'i

USGS Publications Warehouse

Mastin, Larry G.; Christiansen, Robert L.; Thornber, Carl R.; Lowenstern, Jacob B.; Beeson, Melvin H.

2004-01-01

Volcanic eruptions at the summit of Ki??ilauea volcano, Hawai'i, are of two dramatically contrasting types: (1) benign lava flows and lava fountains; and (2) violent, mostly prehistoric eruptions that dispersed tephra over hundreds of square kilometers. The violence of the latter eruptions has been attributed to mixing of water and magma within a wet summit caldera; however, magma injection into water at other volcanoes does not consistently produce widespread tephras. To identify other factors that may have contributed to the violence of these eruptions, we sampled tephra from the Keanaka??ko'i Ash, the most recent large hydromagmatic deposit, and measured vesicularity, bubble-number density and dissolved volatile content of juvenile matrix glass to constrain magma ascent rate and degree of degassing at the time of quenching. Bubble-number densities (9 ?? 104- 1 ?? 107 cm-3) of tephra fragments exceed those of most historically erupted Ki??lauean tephras (3 ?? 103-1.8 ?? 105 cm-3), and suggest exceptionally high magma effusion rates. Dissolved sulfur (average = 330 ppm) and water (0.15-0.45 wt.%) concentrations exceed equilibrium-saturation values at 1 atm pressure (100-150 ppm and ???0.09%, respectively), suggesting that clasts quenched before equilibrating to atmospheric pressure. We interpret these results to suggest rapid magma injection into a wet crater, perhaps similar to continuous-uprush jets at Surtsey. Estimates of Reynolds number suggest that the erupting magma was turbulent and would have mixed with surrounding water in vortices ranging downward in size to centimeters. Such fine-scale mixing would have ensured rapid heat exchange and extensive magma fragmentation, maximizing the violence of these eruptions.

Particle size distribution of fly ash from co-incineration of bituminous coal with municipal solid waste

NASA Astrophysics Data System (ADS)

Cieślik, Ewelina; Konieczny, Tomasz; Bobik, Bartłomiej

2018-01-01

One of the source of air pollutants is emission from local coal-fired boiler-houses and domestic heating boilers. The consequence of incineration of municipal waste is the introduction of additional pollutants into the atmosphere, including fly ash. The aim of this work was to evaluate the particle size distribution of fly ash emitted by coal combustion and co-incineration of coal with municipal waste in a domestic 18 kW central heating boiler equipped with an automatic fuel feeder. Mixtures of bituminous coal with different types of solid waste (5, 10 and 15% of mass fraction) were used. Solid waste types consisted of: printed, colored PE caps, fragmented cable trunking, fragmented car gaskets and shredded tires from trucks. During the incineration of a given mixture of municipal waste with bituminous coal, the velocity of exhaust gas was specified, the concentration and mass flow of fly ash were determined together with the physico-chemical parameters of the exhaust gas, the samples of emitted fly ash were taken as the test material. Particle size analysis of fly ash was performed using laser particle sizer Fritch Analysette 22. The PM10 share from all fly ashes from incineration of mixtures was about 100%. Differences were noted between PM2.5 and PM1.

First experimental observations on melting and chemical modification of volcanic ash during lightning interaction.

PubMed

Mueller, S P; Helo, C; Keller, F; Taddeucci, J; Castro, J M

2018-01-23

Electrification in volcanic ash plumes often leads to syn-eruptive lightning discharges. High temperatures in and around lightning plasma channels have the potential to chemically alter, re-melt, and possibly volatilize ash fragments in the eruption cloud. In this study, we experimentally simulate temperature conditions of volcanic lightning in the laboratory, and systematically investigate the effects of rapid melting on the morphology and chemical composition of ash. Samples of different size and composition are ejected towards an artificially generated electrical arc. Post-experiment ash morphologies include fully melted spheres, partially melted particles, agglomerates, and vesiculated particles. High-speed imaging reveals various processes occurring during the short lightning-ash interactions, such as particle melting and rounding, foaming, and explosive particle fragmentation. Chemical analyses of the flash-melted particles reveal considerable bulk loss of Cl, S, P and Na through thermal vaporization. Element distribution patterns suggest convection as a key process of element transport from the interior of the melt droplet to rim where volatiles are lost. Modeling the degree of sodium loss delivers maximum melt temperatures between 3290 and 3490 K. Our results imply that natural lighting strikes may be an important agent of syn-eruptive morphological and chemical processing of volcanic ash.

Effects of digestion, chemical separation, and deposition on Po-210 quantitative analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Seiner, Brienne N.; Morley, Shannon M.; Beacham, Tere A.

Polonium-210 is a radioactive isotope often used to study sedimentation processes, food chains, aerosol behavior, and atmospheric circulations related to environmental sciences. Materials for the analysis of Po-210 range from tobacco leaves or cotton fibers, to soils and sediments. The purpose of this work was to determine polonium losses from a variety of sample types (soil, cotton fiber, and air filter) due to digestion technique, chemical separation, and deposition method for alpha energy analysis. Results demonstrated that yields from a perchloric acid wet-ash were similar to that from a microwave digestion. Both were greater than the dry-ash procedure. The poloniummore » yield from the perchloric acid wet ash was 87 ± 5%, the microwave digestion had a yield of 100 ± 7%, and the dry ash had a yield of 38 ± 5%. The chemical separation of polonium by an anion exchange resin was used only on the soil samples due to the complex nature of this sample. The yield of Po-209 tracer after chemical separation and deposition for alpha analysis was 83 ± 7% for the soil samples. Spontaneous deposition yields for the cotton and air filters were 87 ± 4% and 92 ± 6%, respectively. Based on the overall process yields for each sample type the amount of Po-210 was quantified using alpha energy analysis. The soil contained 0.18 ± 0.08 Bq/g, the cotton swipe contained 0.7 mBq/g, and the air filter contained 0.04 ± 0.02 mBq/g. High and robust yields of polonium are possible using a suitable digestion, separation, and deposition method.« less

Atmospheric pressure solid analysis probe coupled to quadrupole-time of flight mass spectrometry as a tool for screening and semi-quantitative approach of polycyclic aromatic hydrocarbons, nitro-polycyclic aromatic hydrocarbons and oxo-polycyclic aromatic hydrocarbons in complex matrices.

PubMed

Carrizo, Daniel; Domeño, Celia; Nerín, Isabel; Alfaro, Pilar; Nerín, Cristina

2015-01-01

A new screening and semi-quantitative approach has been developed for direct analysis of polycyclic aromatic hydrocarbons (PAHs) and their nitro and oxo derivatives in environmental and biological matrices using atmospheric pressure solid analysis probe (ASAP) quadrupole-time of flight mass spectrometry (Q-TOF-MS). The instrumental parameters were optimized for the analysis of all these compounds, without previous sample treatment, in soil, motor oil, atmospheric particles (ashes) and biological samples such as urine and saliva of smokers and non-smokers. Ion source parameters in the MS were found to be the key parameters, with little variation within PAHs families. The optimized corona current was 4 µA, sample cone voltage 80 V for PAHs, nitro-PAHs and oxo-PAHs, while the desolvation temperatures varied from 300°C to 500°C. The analytical method performance was checked using a certified reference material. Two deuterated compounds were used as internal standards for semi-quantitative purposes together with the pure individual standard for each compound and the corresponding calibration plot. The compounds nitro PAH 9-nitroanthracene and oxo-PAH 1,4-naphthalenedione, were found in saliva and urine in a range below 1 µg/g while the range of PAHs in these samples was below 2 µg/g. Environmental samples provided higher concentration of all pollutants than urine and saliva. Copyright © 2014 Elsevier B.V. All rights reserved.

Compressional and shear wave velocities in granular materials to 2.5 kilobars

NASA Technical Reports Server (NTRS)

Talwani, P.; Nur, A.; Kovach, R. L.

1973-01-01

The velocities of seismic compressional waves and, for the first time, shear wave velocities in silica sand, volcanic ash, and basalt powder were determined under hydrostatic confining pressures to 2.5 kb. Simultaneously, the porosity of these materials was obtained as a function of confining pressure. The presented results have important implications for the self-compaction hypothesis that has been postulated to explain the lunar near-surface seismic velocity variation.

Trace element partitioning in ashes from boilers firing pure wood or mixtures of solid waste with respect to fuel composition, chlorine content and temperature.

PubMed

Saqib, Naeem; Bäckström, Mattias

2014-12-01

Trace element partitioning in solid waste (household waste, industrial waste, waste wood chips and waste mixtures) incineration residues was investigated. Samples of fly ash and bottom ash were collected from six incineration facilities across Sweden including two grate fired and four fluidized bed incinerators, to have a variation in the input fuel composition (from pure biofuel to mixture of waste) and different temperature boiler conditions. As trace element concentrations in the input waste at the same facilities have already been analyzed, the present study focuses on the concentration of trace elements in the waste fuel, their distribution in the incineration residues with respect to chlorine content of waste and combustion temperature. Results indicate that Zn, Cu and Pb are dominating trace elements in the waste fuel. Highly volatile elements mercury and cadmium are mainly found in fly ash in all cases; 2/3 of lead also end up in fly ash while Zn, As and Sb show a large variation in distribution with most of them residing in the fly ash. Lithophilic elements such as copper and chromium are mainly found in bottom ash from grate fired facilities while partition mostly into fly ash from fluidized bed incinerators, especially for plants fuelled by waste wood or ordinary wood chips. There is no specific correlation between input concentration of an element in the waste fuel and fraction partitioned to fly ash. Temperature and chlorine content have significant effects on partitioning characteristics by increasing the formation and vaporization of highly volatile metal chlorides. Zinc and cadmium concentrations in fly ash increase with the incineration temperature. Copyright © 2014 Elsevier Ltd. All rights reserved.

Sakurajima volcano: a physico-chemical study of the health consequences of long-term exposure to volcanic ash

NASA Astrophysics Data System (ADS)

Hillman, S. E.; Horwell, C. J.; Densmore, A. L.; Damby, D. E.; Fubini, B.; Ishimine, Y.; Tomatis, M.

2012-05-01

Regular eruptions from Sakurajima volcano, Japan, repeatedly cover local urban areas with volcanic ash. The frequency of exposure of local populations to the ash led to substantial concerns about possible respiratory health hazards, resulting in many epidemiological and toxicological studies being carried out in the 1980s. However, very few mineralogical data were available for determination of whether the ash was sufficiently fine to present a respiratory hazard. In this study, we review the existing studies and carry out mineralogical, geochemical and toxicological analyses to address whether the ash from Sakurajima has the potential to cause respiratory health problems. The results show that the amount of respirable (<4 μm) material produced by the volcano is highly variable in different eruptions (1.1-18.8 vol.%). The finest samples derive from historical, plinian eruptions but considerable amounts of respirable material were also produced from the most recent vulcanian eruptive phase (since 1955). The amount of cristobalite, a crystalline silica polymorph which has the potential to cause chronic respiratory diseases, is ~3-5 wt.% in the bulk ash. Scanning electron microscope and transmission electron microscope imaging showed no fibrous particles similar to asbestos particles. Surface reactivity tests showed that the ash did not produce significant amounts of highly reactive hydroxyl radicals (0.09-1.35 μmol m-2 at 30 min.) in comparison to other volcanic ash types. A basic toxicology assay to assess the ability of ash to rupture the membrane of red blood cells showed low propensity for haemolysis. The findings suggest that the potential health hazard of the ash is low, but exposure and respiratory conditions should still be monitored given the high frequency and durations of exposure.

Biomimetic thermal barrier coating in jet engine to resist volcanic ash deposition

NASA Astrophysics Data System (ADS)

Song, Wenjia; Major, Zsuzsanna; Schulz, Uwe; Muth, Tobias; Lavallée, Yan; Hess, Kai-Uwe; Dingwell, Donald B.

2017-04-01

The threat of volcanic ash to aviation safety is attracting extensive attention when several commercial jet aircraft were damaged after flying through volcanic ash clouds from the May 1980 eruptions of Mount St. Helen in Washington, U.S. and especially after the air traffic disruption in 2010 Eyjafjallajökull eruption. A major hazard presented by volcanic ash to aircraft is linked to the wetting and spreading of molten ash droplets on engine component surfaces. Due to the fact ash has a lower melting point, around 1100 °C, than the gas temperature in the hot section (between 1400 to 2000 °C), this cause the ash to melt and potentially stick to the internal components (e.g., combustor and turbine blades), this cause the ash to melt and potentially stick to the internal components of the engine creating, substantial damage or even engine failure after ingestion. Here, inspiring form the natural surface of lotus leaf (exhibiting extreme water repellency, known as 'lotus effect'), we firstly create the multifunctional surface thermal barrier coatings (TBCs) by producing a hierarchical structure with femtosecond laser pulses. In detail, we investigate the effect of one of primary femtosecond laser irradiation process parameter (scanning speed) on the hydrophobicity of water droplets onto the two kinds of TBCs fabricated by electron-beam physical vapor deposition (EB-PVD) and air plasma spray (APS), respectively as well as their corresponding to morphology. It is found that, comparison with the original surface (without femtosecond laser ablation), all of the irradiated samples demonstrate more significant hydrophobic properties due to nanostructuring. On the basis of these preliminary room-temperature results, the wettability of volcanic ash droplets will be analysed at the high temperature to constrain the potential impact of volcanic ash on the jet engines.

Wet-dry cycles effect on ash water repellency. A laboratory experiment.

NASA Astrophysics Data System (ADS)

Pereira, Paulo; Cerdà, Artemi; Oliva, Marc; Mataix, Jorge; Jordán, Antonio

2014-05-01

In the immediate period after the fire, the ash layer has a strong influence on soil hydrological processes, as runoff, infiltration and erosion. Ash is very dynamic in the space and time. Until the first rainfall periods, ash is (re)distributed by the wind. After it can cover the soil surface, infiltrate or transported to other areas by water transport (Pereira et al., 2013a, b). This will have strong implications on nutrient redistribution and vegetation recovery. Ash layer may affect soil water repellency in different ways, depending on fire severity, soil properties and vegetation. Ash produced at low temperatures after low-severity burning is usually hydrophobic (Bodi et al., 2011, 2012). Wet-dry cycles have implications on ash physical and chemical properties, changing their effects in space and time. The aim of this study is to analyse the effects of fire temperature and severity on ash water repellency. Pinus sylvestris needles were collected in a Lithuania forest in Dzukija National Park (53º 54' N and 24º 22' E), transported to laboratory and washed with deionized water to remove soil particles and other residues. Needle samples were dried during 24 hours and exposed to different temperatures: 200, 300, 400 and 500 ºC, during 2 hours. Ash colour was analysed according to the Munsell Soil Color charts. Ash was black (10 YR 2/1) at 200 ºC, very dark grey (10YR 3/1) at 300 ºC, gray (10YR 5/1) at 400 ºC and light gray (10YR 7/1) at 500 ºC. Ten samples of ash released after each treatment were placed in plastic dishes (50 mm in diameter) in an amount enough to form a 5 mm thick layer, and ash water repellency was measured according to the Water Drop Penetration Test. Later, ash was carefully wetted with 15 ml of deionized water and placed in an oven during 4 days (96 hours), as in Bodí et al. (2012). This procedure was repeated 5 times in order to observe the effects of wet-dry cycles in ash water repellency. The results showed significant differences among wet-dry cycles (Chi Sqr = 184.13 p <0.001) and among temperatures, immediately after treatments (Kruskal-Wallis test: H = 13.64, p<0.01) and after first wet-dry cycle (Kruskal-Wallis test: H =13.85 p<0.01). In the second (Kruskal-Wallis test: =5.80, p >0.05), third (Kruskal-Wallis test: H =3.07, p>0.05), fourth (Kruskal-Wallis test: H=0.75, p>0.05) and fifth (Kruskal-Wallis test: H =0.199, p<0.05) wet-dry cycles, ash water repellency did not show significant differences. After wetting, ash water repellency decreased substantially in the first cycle. These results suggest that wet-dry cycles have important impacts in the reduction of ash water repellency. Nevertheless, this reduction at least in the first cycle is different according to the temperature/severity. Black ash (200 ºC) water repellency was significantly higher than the other temperatures/severities. Further research will be carried out using burned soils and different species. References Bodi, M.B., Doerr, S., Cerda, A., Mataix-Solera, J. (2012) Hydrological effects of a layer of vegetation ash on underlying wettable and water repellent soil. Geoderma, 161, 14-23, 2011. DOI: 10.1016/j.geoderma.2012.01.006. Bodí, M.B., Mataix-Solera, J., Doerr, S.H., Cerdà, A. (2011). The wettability of ash from burned vegetation and its relationship to Mediterranean plant species type, burn severity and total organic carbon content. Geoderma 160, 599-607. DOI:10.1016/j.geoderma.2010.11.009. Pereira, P., Cerdà, A., Úbeda, X., Mataix-Solera, J. Arcenegui, V., Zavala, L. (2013a) Modelling the impacts of wildfire on ash thickness in a short-term period, Land Degradation and Development. DOI: 10.1002/ldr.2195. Pereira, P., Cerdà, A., Úbeda, X., Mataix-Solera, J., Jordan, A. Burguet, M. (2013b) Spatial models for monitoring the spatio-temporal evolution of ashes after fire - a case study of a burnt grassland in Lithuania, Solid Earth, 4, 153-165. DOI: 10.5194/se-4-153-2013.

Uranium mobility during interaction of rhyolitic glass with alkaline solutions: dissolution of glass

USGS Publications Warehouse

Zielinski, Robert A.

1977-01-01

This report concerns investigations designed to identify the important physical and chemical parameters influencing the rate of release of uranium from glass shards of rhyolitic air-fall ash. Oxidizing, silica undersaturated, alkaline solutions are eluted through a column of rhyolitic glass shards at a carefully controlled temperature, pressure, and flow rate. The solutions are monitored for the concentration of uranium and selected additional elements (Si, K, Li, F), and the glass is recovered and examined for physical and/or chemical evidence of attack. The flushing mode is designed to mimic leaching of glass shards by intermittent, near-surface waters with which the glass is not in equilibrium. Reported rates are applicable only to the experimental conditions (120?C, 7,000 psi), but it is assumed that the reaction mechanisms and the relative importance of rate-influencing parameters remain unchanged, at reduced temperature and pressure. Results of the above experiment indicate that silica and uranium are released from glass shards at comparable rates, while lithium and potassium are released faster and fluorine slower than either Si or U. Rates of release of silica and uranium correlate positively with the surface area of the shards. Rhyolitic shards release uranium at faster rates than rhyodacitic shards of comparable surface area. Changes in the shards resulting from experimental treatment and observed in the original glass separates from an Oligocene ash (compared to a Pleistocene ash) include; surface pitting, increased surface area, devitrification rinds (<1l micron wide) and reduced lithium contents. Future investigations will study the effect of temperature, pressure, solution composition, and flow rate on the relative mobility of U, Si, Li, F, and K.

Proximate composition of CELSS crops grown in NASA's Biomass Production Chamber.

PubMed

Wheeler, R M; Mackowiak, C L; Sager, J C; Knott, W M; Berry, W L

1996-01-01

Edible biomass from four crops of wheat (Triticum aestivum L.), four crops of lettuce (Lactuca sativa L.), four crops of potato (Solanum tuberosum L.), and three crops of soybean (Glycine max (L.) Merr.) grown in NASA's CELSS Biomass Production Chamber were analyzed for proximate composition. All plants were grown using recirculating nutrient (hydroponic) film culture with pH and electrical conductivity automatically controlled. Temperature and humidity were controlled to near optimal levels for each species and atmospheric carbon dioxide partial pressures were maintained near 100 Pa during the light cycles. Soybean seed contained the highest percentage of protein and fat, potato tubers and wheat seed contained the highest levels of carbohydrate, and lettuce leaves contained the highest level of ash. Analyses showed values close to data published for field-grown plants with several exceptions: In comparison with field-grown plants, wheat seed had higher protein levels; soybean seed had higher ash and crude fiber levels; and potato tubers and lettuce leaves had higher protein and ash levels. The higher ash and protein levels may have been a result of the continuous supply of nutrients (e.g., potassium and nitrogen) to the plants by the recirculating hydroponic culture.

Proximate composition of CELSS crops grown in NASA's Biomass Production Chamber

NASA Technical Reports Server (NTRS)

Wheeler, R. M.; Mackowiak, C. L.; Sager, J. C.; Knott, W. M.; Berry, W. L.

1996-01-01

Edible biomass from four crops of wheat (Triticum aestivum L.), four crops of lettuce (Lactuca sativa L.), four crops of potato (Solanum tuberosum L.), and three crops of soybean (Glycine max (L.) Merr.) grown in NASA's CELSS Biomass Production Chamber were analyzed for proximate composition. All plants were grown using recirculating nutrient (hydroponic) film culture with pH and electrical conductivity automatically controlled. Temperature and humidity were controlled to near optimal levels for each species and atmospheric carbon dioxide partial pressures were maintained near 100 Pa during the light cycles. Soybean seed contained the highest percentage of protein and fat, potato tubers and wheat seed contained the highest levels of carbohydrate, and lettuce leaves contained the highest level of ash. Analyses showed values close to data published for field-grown plants with several exceptions: In comparison with field-grown plants, wheat seed had higher protein levels; soybean seed had higher ash and crude fiber levels; and potato tubers and lettuce leaves had higher protein and ash levels. The higher ash and protein levels may have been a result of the continuous supply of nutrients (e.g., potassium and nitrogen) to the plants by the recirculating hydroponic culture.

Proximate composition of CELSS crops grown in NASA's Biomass Production Chamber

NASA Astrophysics Data System (ADS)

Wheeler, R. M.; Mackowiak, C. L.; Sager, J. C.; Knott, W. M.; Berry, W. L.

Edible biomass from four crops of wheat (Triticum aestivum L.), four crops of lettuce (Lactuca sativa L.), four crops of potato (Solanum tuberosum L.), and three crops of soybean (Glycine max (L.) Merr.) grown in NASA's CELSS Biomass Production Chamber were analyzed for proximate composition. All plants were grown using recirculating nutrient (hydroponic) film culture with pH and electrical conductivity automatically controlled. Temperature and humidity were controlled to near optimal levels for each species and atmospheric carbon dioxide partial pressures were maintained near 100 Pa during the light cycles. Soybean seed contained the highest percentage of protein and fat, potato tubers and wheat seed contained the highest levels of carbohydrate, and lettuce leaves contained the highest level of ash. Analyses showed values close to data published for field-grown plants with several exceptions: In comparison with field-grown plants, wheat seed had higher protein levels; soybean seed had higher ash and crude fiber levels; and potato tubers and lettuce leaves had higher protein and ash levels. The higher ash and protein levels may have been a result of the continuous supply of nutrients (e.g., potassium and nitrogen) to the plants by the recirculating hydroponic culture.

Vanadium Recovery from Oil Fly Ash by Carbon Removal and Roast-Leach Process

NASA Astrophysics Data System (ADS)

Jung, Myungwon; Mishra, Brajendra

2018-02-01

This research mainly focuses on the recovery of vanadium from oil fly ash by carbon removal and the roast-leach process. The oil fly ash contained about 85% unburned carbon and 2.2% vanadium by weight. A vanadium-enriched product was obtained after carbon removal, and the vanadium content of this product was 19% by weight. Next, the vanadium-enriched product was roasted with sodium carbonate to convert vanadium oxides to water-soluble sodium metavanadate. The roasted sample was leached with water at 60°C, and the extraction percentage of vanadium was about 92% by weight. Several analytical techniques, such as inductively coupled plasma atomic emission spectroscopy (ICP-AES), x-ray fluorescence (XRF), and thermogravimetric and differential thermal analysis (TG-DTA), were utilized for sample analyses. Thermodynamic modeling was also conducted with HSC chemistry software to explain the experimental results.

Durability and Strength of Sustainable Self-Consolidating Concrete Containing Fly Ash

NASA Astrophysics Data System (ADS)

Mohamed, O.; Hawat, W. Al

2018-03-01

In this paper, the durability and strength of self-consolidating concrete (SCC) is assessed through development and testing of six binary mixes at fixed water-to-binder (w/b) ratio of 0.36. In each of the six SCC mixes, a different percentage of cement is replaced with fly ash. The development of compressive strength for each of the mixes is assessed by testing samples after 3, 7, and 28 days of curing. Durability of each of the six SCC mixes is assessed by measuring the charge passed in Rapid Chloride Permeability (RCP) test. Charge passed was measured in samples cured for 1, 3, 7, 14, 28, and 40 days of curing. All mixes out-performed the control mix in terms of resistance to chloride penetration. Binary mix in which 20% of cement is replaced with fly ash exhibited 28-day strength slightly surpassing the control mix.

Aluminium alloys in municipal solid waste incineration bottom ash.

PubMed

Hu, Yanjun; Rem, Peter

2009-05-01

With the increasing growth of incineration of household waste, more and more aluminium is retained in municipal solid waste incinerator bottom ash. Therefore recycling of aluminium from bottom ash becomes increasingly important. Previous research suggests that aluminium from different sources is found in different size fractions resulting in different recycling rates. The purpose of this study was to develop analytical and sampling techniques to measure the particle size distribution of individual alloys in bottom ash. In particular, cast aluminium alloys were investigated. Based on the particle size distribution it was computed how well these alloys were recovered in a typical state-of-the-art treatment plant. Assessment of the cast alloy distribution was carried out by wet physical separation processes, as well as chemical methods, X-ray fluorescence analysis and electron microprobe analysis. The results from laboratory analyses showed that cast alloys tend to concentrate in the coarser fractions and therefore are better recovered in bottom ash treatment plants.

Leaching behaviour of municipal solid waste incineration bottom ash: From granular material to monolithic concrete.

PubMed

Sorlini, Sabrina; Collivignarelli, Maria Cristina; Abbà, Alessandro

2017-09-01

The aim of this work was to assess the leaching behaviour of the bottom ash derived from municipal solid waste incineration (MSWI) used in concrete production. In particular, the release of pollutants was evaluated by the application of different leaching tests, both on granular materials and monolithic samples (concrete mixtures cast with bottom ash). The results confirmed that, according to Italian regulations, unwashed bottom ashes present critical issues for the use as alternative aggregates in the construction sector due to the excessive release of pollutants; instead, the leachate from washed bottom ashes was similar to natural aggregates. The concentration of pollutants in the leachate from concrete mixtures was lower than regulation limits for reuse. The crushing process significantly influenced the release of pollutants: this behaviour was due both to the increase in surface area and the release of contaminants from cement. Moreover, the increase in contact time (up to 64 days) involved more heavy metals to be released.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jan D. Miller; Terrence Chatwin; Jan Hupka

The two-year Department of Energy (DOE) project ''Treatment of Cyanide Solutions and Slurries Using Air-Sparged Hydrocyclone (ASH) Technology'' (ASH/CN) has been completed. This project was also sponsored by industrial partners, ZPM Inc., Elbow Creek Engineering, Solvay Minerals, EIMCO-Baker Process, Newmont Mining Corporation, Cherokee Chemical Co., Placer Dome Inc., Earthworks Technology, Dawson Laboratories and Kennecott Minerals. Development of a new technology using the air-sparged hydrocyclone (ASH) as a reactor for either cyanide recovery or destruction was the research objective. It was expected that the ASH could potentially replace the conventional stripping tower presently used for HCN stripping and absorption with reducedmore » power costs. The project was carried out in two phases. The first phase included calculation of basic processing parameters for ASH technology, development of the flowsheet, and design/adaptation of the ASH mobile system for hydrogen cyanide (HCN) recovery from cyanide solutions. This was necessary because the ASH was previously used for volatile organics removal from contaminated water. The design and modification of the ASH were performed with the help from ZPM Inc. personnel. Among the modifications, the system was adapted for operation under negative pressure to assure safe operating conditions. The research staff was trained in the safe use of cyanide and in hazardous material regulations. Cyanide chemistry was reviewed resulting in identification of proper chemical dosages for cyanide destruction, after completion of each pilot plant run. The second phase of the research consisted of three field tests that were performed at the Newmont Mining Corporation gold cyanidation plant near Midas, Nevada. The first field test was run between July 26 and August 2, 2002, and the objective was to demonstrate continuous operation of the modified ASH mobile system. ASH units were applied for both stripping and absorption, to recover cyanide, using the acidification-volatilization-reabsorption chemistry. Plant barren cyanide solution was used during the field tests. The original ASH system used for the field tests had been designed and fabricated by ZPM Inc. to remove volatile organic compounds from ground water. The system, even with a number of modifications, could not operate at optimum conditions for cyanide recovery. Reactors and pumps installed in the mobile system only allowed for the treatment of clear solutions, not slurries. Also the original mobile system was limited with respect to Q, the relative air flow rate, and the extent of recovery in a single stage. Due to the lack of automatic controls, the system required constant supervision of the University of Utah (U/U) team. In spite of these difficulties, application of the ASH mobile system was particularly attractive due to compactness of the apparatus and less than 1 second residence time of the aqueous phase in the cyclones. The performance of the ASH system was evaluated by comparison with theoretical predictions.« less

Quantification of main and trace metal components in the fly ash of waste-to-energy plants located in Germany and Switzerland: An overview and comparison of concentration fluctuations within and between several plants with particular focus on valuable metals.

PubMed

Haberl, Jasmin; Koralewska, Ralf; Schlumberger, Stefan; Schuster, Michael

2018-05-01

The elemental composition of fly ash from six waste-to-energy (WTE) plants in Germany and two WTE plants in Switzerland were analyzed. Samples were taken daily over a period of one month and mixed to a composite sample for each German plant. From two Swiss plants, two and three of these composite samples, respectively, were collected for different months in order to assess temporal differences between these months. In total, 61 elements, including rare earth elements, were analyzed using ICP-OES and ICP-MS. The analysis method was validated for 44 elements either by reference materials (BCR 176R and NIST 1633c) or analysis with both methods. Good recoveries, mostly ±10%, and high agreements between both methods were achieved. As long as no additives from flue gas cleaning were mixed with the fly ash, quite similar element contents were observed between all of the different incinerators. For most elements, the variations between the different months within the two Swiss plants were lower than differences between various plants. Especially main components show low variations between different months. To get a more detailed insight into temporal fluctuations within the mentioned Swiss plants, the concentrations of Zn, Pb, Cu, Cd, Sb, and Sn are presented over a period of three years (Jan. 2015 - Oct. 2017). The concentration profiles are based on weekly composite samples (consisting of daily taken samples) analyzed by the routine control of these plants using ED-XRF. The standard deviations of the average concentrations were around 20% over the three years for the regarded elements. The fluctuations were comparable at both plants. Due to the relatively low temporal concentration fluctuations observed within the plants, fly ash would be a continuous and constant source of secondary raw materials. Beside Zn, Pb, Cu, and Cd, which were already recovered on an industrial scale, Sb, Sn, and Bi also show a high potential as secondary raw material due to the high concentration of these elements in fly ash. Copyright © 2018 Elsevier Ltd. All rights reserved.

Effects of detrital influx in the Pennsylvanian Upper Freeport peat swamp

USGS Publications Warehouse

Ruppert, L.F.; Stanton, R.W.; Blaine, Cecil C.; Eble, C.F.; Dulong, F.T.

1991-01-01

Quartz cathodoluminescence properties and mineralogy of three sets of samples and vegetal and/ or miospore data from two sets of samples from the Upper Freeport coal bed, west-central Pennsylvania, show that detrital influence from a penecontemporaneous channel is limited to an area less than three km from the channel. The sets of samples examined include localities of the coal bed where (1) the coal is thin, split by partings, and near a penecontemporaneous fluvial channel, (2) the coal is relatively thick and located approximately three km from the channel, and (3) the coal is thick and located approximately 12 km from the channel. Samples from locality 1 (nearest the channel) have relatively high-ash yields (low-temperature ash average = 27.3% on a pyrite- and calcite-free basis) and high proportions of quartz and clay minerals. The quartz is primarily detrital, as determined by cathodoluminescent properties, and the ratio of kaolinite to illite is low. In addition, most of the plant remains and miospores indicate peat-forming plants that required low nutrient levels for growth. In contrast, samples from localities 2 and 3, from the more interior parts of the bed, contained predominantly authigenic quartz grains nd yielded low-temperature ash values of less than 14% on a pyrite- and calcite-free basis. The low-temperature ash contains low concentrations of quartz and clay minerals and the ratio of kaolinite to illite is relatively high. Although intact core was not available for paleobotanical analyses, another core collected within 1 km from locality 3 contained plant types interpreted to have required high nutrient levels for growth. These data indicate that mineral formation is dominated by authigenic processes in interior parts of the coal body. Some of the authigenic quartz may have been derived from herbaceous ferns as indicated by patterns in the palynological and paleobotanical data. In contrast, detrital processes appeared to be limited to in areas directly adjacent to the penecontemporaneous channel where the coal bed is high in ash, split by mineral-rich partings, and of little or no economic value. ?? 1991.

Characterization of fly ash, slag and glass hull for the obtaining of vitreous materials

NASA Astrophysics Data System (ADS)

Ayala Valderrama, D. M.; Gómez Cuaspud, J. A.

2017-12-01

This article presents the structural and thermal characterization of fly ash, the waste from blast furnace slag and the glass hull, generated as common residues in industry, which cannot be recycled easily or destroyed in a simple and fast way. In the particular case of fly ash, at present are being used as a lightweight aggregate in the production of cement, concrete and additive in the production of glass and glass ceramics. As far as the slag and hull, are being used as additives for the asphalt and concretes, however its use still is restricted, reason why its use in alternative ways are necessary. Initially the chemical composition of residues was established, determining that the fly ashes contains SiO2, Al2O3 and Fe2O3 oxides; 90% of the total composition, was confirmed by X-ray diffraction analysis. As minor constituents, small percentages of Mg, P, S, K, Na and Ti were found. For the slag case, the phases of Fe3O4, Ca3Mg (SiO2)4 and Ca(MgAl)(Si,Al)2O6 were identified, observing the presence of amorphous phase higher than 94% of the total phase of the system. Meanwhile, the glass hull sample showed a higher percentage of 95% amorphicity, mainly identifying a weak signal associated with silicon oxide SiO2. The thermal analyses of the samples, exhibit a decrease in mass for samples between 25-1000°C was observed, which can be attributed to different physical-chemical events that occur in the materials. The heat flow for each sample is related with the removal of the water retained by the physisorption processes around 92-110°C in all cases. With this previous characterization of the precursors, a sample was composed using 70% fly ash, 10% slag and 20% of glass hull was composed and treated at 1200°C/1.5 hours, obtaining a dense black glassy material for potential applications in field of the glass ceramics.

Characterization of Eyjafjallajokull volcanic ash particles and a protocol for rapid risk assessment.

PubMed

Gislason, S R; Hassenkam, T; Nedel, S; Bovet, N; Eiriksdottir, E S; Alfredsson, H A; Hem, C P; Balogh, Z I; Dideriksen, K; Oskarsson, N; Sigfusson, B; Larsen, G; Stipp, S L S

2011-05-03

On April 14, 2010, when meltwaters from the Eyjafjallajökull glacier mixed with hot magma, an explosive eruption sent unusually fine-grained ash into the jet stream. It quickly dispersed over Europe. Previous airplane encounters with ash resulted in sandblasted windows and particles melted inside jet engines, causing them to fail. Therefore, air traffic was grounded for several days. Concerns also arose about health risks from fallout, because ash can transport acids as well as toxic compounds, such as fluoride, aluminum, and arsenic. Studies on ash are usually made on material collected far from the source, where it could have mixed with other atmospheric particles, or after exposure to water as rain or fog, which would alter surface composition. For this study, a unique set of dry ash samples was collected immediately after the explosive event and compared with fresh ash from a later, more typical eruption. Using nanotechniques, custom-designed for studying natural materials, we explored the physical and chemical nature of the ash to determine if fears about health and safety were justified and we developed a protocol that will serve for assessing risks during a future event. On single particles, we identified the composition of nanometer scale salt coatings and measured the mass of adsorbed salts with picogram resolution. The particles of explosive ash that reached Europe in the jet stream were especially sharp and abrasive over their entire size range, from submillimeter to tens of nanometers. Edges remained sharp even after a couple of weeks of abrasion in stirred water suspensions.

Characterization of Eyjafjallajökull volcanic ash particles and a protocol for rapid risk assessment

PubMed Central

Gislason, S. R.; Hassenkam, T.; Nedel, S.; Bovet, N.; Eiriksdottir, E. S.; Alfredsson, H. A.; Hem, C. P.; Balogh, Z. I.; Dideriksen, K.; Oskarsson, N.; Sigfusson, B.; Larsen, G.; Stipp, S. L. S.

2011-01-01

On April 14, 2010, when meltwaters from the Eyjafjallajökull glacier mixed with hot magma, an explosive eruption sent unusually fine-grained ash into the jet stream. It quickly dispersed over Europe. Previous airplane encounters with ash resulted in sandblasted windows and particles melted inside jet engines, causing them to fail. Therefore, air traffic was grounded for several days. Concerns also arose about health risks from fallout, because ash can transport acids as well as toxic compounds, such as fluoride, aluminum, and arsenic. Studies on ash are usually made on material collected far from the source, where it could have mixed with other atmospheric particles, or after exposure to water as rain or fog, which would alter surface composition. For this study, a unique set of dry ash samples was collected immediately after the explosive event and compared with fresh ash from a later, more typical eruption. Using nanotechniques, custom-designed for studying natural materials, we explored the physical and chemical nature of the ash to determine if fears about health and safety were justified and we developed a protocol that will serve for assessing risks during a future event. On single particles, we identified the composition of nanometer scale salt coatings and measured the mass of adsorbed salts with picogram resolution. The particles of explosive ash that reached Europe in the jet stream were especially sharp and abrasive over their entire size range, from submillimeter to tens of nanometers. Edges remained sharp even after a couple of weeks of abrasion in stirred water suspensions. PMID:21518890

Plutonium and uranium in human bones from areas surrounding the Semipalatinsk nuclear test site.

PubMed

Yamamoto, Masayoshi; Hoshi, Masaharu; Sakaguchi, Aya; Shinohara, Kunihiko; Kurihara, Osamu; Apsalikov, Kazbek N; Gusev, Boris I

2006-02-01

To evaluate the present levels of 239,240Pu and U in residents living near the Semipalatinsk nuclear test site, more than 70 bone samples were obtained at autopsy. The subjects ranged in age from 30 to 86 years (mean 59.3+/-12.9). Most of the samples consisted of victims who died of various diseases. Plutonium and U were radiochemically separated and determined by alpha-ray spectrometry. The mean concentrations of 239,240Pu and 238U observed were 0.050+/-0.041 mBq/g-ash (vertebrae 71, long-bones 18) and 0.28+/-0.13 mBq/g-ash (22.8+/-10.6 microg U/kg-ash) (vertebrae 58, long bones 16), respectively. The present 239,240Pu levels were within the range found for human bone samples from other countries due solely to global fallout in the early 1980s. The average U concentration was close to the estimate (mean 22.5 microg U/kg-ash) for the UK, and about 10 times higher than those estimated for residents in New York City and Japan. By assuming that the average concentration of 239,240Pu in bone samples is the value at 45 years after instantaneous inhalation in 1955, the initial total intake and the effective dose for 45 years were estimated as 10 Bq and 0.2 mSv, respectively. The annual intake of total U (234,235,238U) and its effective dose for 60 years were estimated as 30 Bq for adult and 0.1 mSv, respectively, for chronic ingestion.

Biogeochemical sampling in the Mahd Adh Dhahab District, Kingdom of Saudi Arabia

USGS Publications Warehouse

Ebens, Richard J.; Shacklette, Hansford T.; Worl, Ronald G.

1983-01-01

A biogeochemical reconnaissance of the Mahd adh Dhahab district, Kingdom of Saudi Arabia, confirms the ability of deep-rooted Acacia trees to reflect bedrock concentrations of some trace elements. The analytical values for lead, zinc, selenium, and cadmium in ash of tree branches are significantly higher in samples from areas of known mineralization (13 sites) than in samples from areas of no known mineralization (12 sites). Geometric mean concentrations of these elements in the two areas (mineralized; nonmineralized), quoted as parts per million in ash, are lead (122; 28), zinc (713; 443), selenium (1.2; 0.6), and cadmium (1.4; 0.5). The range of molybdenum values in ash from the two areas is similar, but a cluster of four sites in an area classified as nonmineralized corresponds to an area where the U.S. Geological Survey reported anomalous molybdenum values in rock in 1965. Results for other elements were either equivocal (mercury, tellurium, silver) or showed no correspondence to the two areas. Mean values for barium, manganese, potassium, and sodium are significantly higher in areas of no known mineralization, but we conclude that this reflects a difference in country rock major-element chemistry rather than the effect of ore-forming processes. The pattern of trace-metal values in Acacia ash is present whether the sampled tree grows on bedrock, on talus, or on residual or modern alluvium. This fact suggests that the trace-element chemistry of the trees reflects bedrock geochemistry and implies that Acacia biogeochemistry could be applied as a prospecting tool in areas where bedrock is not well exposed.

Character, mass, distribution, and origin of tephra-fall deposits from the 2009 eruption of Redoubt Volcano, Alaska: highlighting the significance of particle aggregation

USGS Publications Warehouse

Wallace, Kristi; Coombs, Michelle L; Schaefer, Janet R.

2013-01-01

Particle size data showing a preponderance of fine ash, even in the most proximal locations, along with the abundance of aggregate lapilli documented in most samples, confirms that particle aggregation played a significant role in the 2009 eruption and induced premature fallout of fine ash.

Effect of water washing on the thermal behavior of rice straw.

PubMed

Said, N; Bishara, T; García-Maraver, A; Zamorano, M

2013-11-01

Rice straw can be used as a renewable fuel for heat and power generation. It is a viable mean of replacing fossil fuels and preventing pollution caused by open burning, especially in the areas where this residual biomass is generated. Nevertheless, the thermal conversion of rice straw can cause some operating problems such as slag formation, which negatively affects thermal conversion systems. So, the main objective of this research is studying the combustion behavior of rice straw samples collected from various regions by applying thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). In addition, the thermal behavior of ashes from rice straw was also analyzed in order to detect their melting points, and ash sintering was detected at different temperatures within the range between 550 and 1000°C. Since washing rice straw with water could reduce the content of undesirable inorganic compounds related to the ash fusibility, samples of washed rice straw were analyzed under combustion conditions to investigate its differences regarding the thermal behavior of rice straw. The results showed that rice straw washing led to a significant improvement in its thermal behavior, since it reduced the ash contents and sintering formation. Copyright © 2013 Elsevier Ltd. All rights reserved.

Assessment of tolerant sunfish populations (Lepomis sp.) inhabiting selenium-laden coal ash effluents. 3. Serum chemistry and fish health indicators.

PubMed

Lohner, T W; Reash, R J; Willet, V E; Fletcher, J

2001-11-01

Sunfish were collected from fly ash discharge-receiving streams to assess the possible effects of exposure to elevated selenium. Concentrations of selenium, copper, and arsenic were statistically higher in fish tissue (liver) samples from effluent-exposed fish than in reference fish. Several biomarkers were indicative of metal exposure and effect. Plasma protein levels and cholesterol levels were significantly lower in exposed fish, indicating nutritional stress. Ion levels (i.e., K) increased with exposure to ash pond metals, indicating possible gill damage. Fish from the receiving streams also had increased serum glucose and osmolality indicating possible acute stress due to sampling. Fish health assessments revealed a lower incidence of fin erosion, kidney discoloration, urolithiasis or nephrocalcinosis, liver discoloration, and parasites in exposed fish and a higher incidence of skin, eye, and gill aberrations. Condition factors of exposed fish were correlated with biomarker response and were the same as or lower than those of reference fish, but not related to selenium levels. Although several serum biochemical indicators differed between the ash pond-receiving stream and reference sites, pollutant exposure was apparently not sufficient to cause functional damage to critical organ systems.

Fire severity effects on ash extractable Total Phosphorous

NASA Astrophysics Data System (ADS)

Pereira, Paulo; Úbeda, Xavier; Martin, Deborah

2010-05-01

Phosphorous (P) is a crucial element to plant nutrition and limits vegetal production. The amounts of P in soil are lower and great part of this nutrient is absorbed or precipitated. It is well known that fire has important implications on P cycle, that can be lost throughout volatilization, evacuated with the smoke, but also more available to transport after organic matter mineralization imposed by the fire. The release of P depends on ash pH and their chemical and physical characteristics. Fire temperatures impose different severities, according to the specie affected and contact time. Fire severity is often evaluated by ash colour and this is a low-cost and excellent methodology to assess the fire effects on ecosystems. The aim of this work is study the ash properties physical and chemical properties on ash extractable Total Phosphorous (TP), collected in three wildfires, occured in Portugal, (named, (1) Quinta do Conde, (2) Quinta da Areia and (3) Casal do Sapo) composed mainly by Quercus suber and Pinus pinaster trees. The ash colour was assessed using the Munsell color chart. From all three plots we analyzed a total of 102 ash samples and we identified 5 different ash colours, ordered in an increasing order of severity, Very Dark Brown, Black, Dark Grey, Very Dark Grey and Light Grey. In order to observe significant differences between extractable TP and ash colours, we applied an ANOVA One Way test, and considered the differences significant at a p<0.05. The results showed that significant differences in the extractable TP among the different ash colours. Hence, to identify specific differences between each ash colour, we applied a post-hoc Fisher LSD test, significant at a p<0.05. The results obtained showed significant differences between the extractable TP from Very dark Brown and Black ash, produced at lower severities, in relation to Dark Grey, Very Dark Grey and Light Grey ash, generated at higher severities. The means of the first group were higher than the observed in the second one. This indicates that ash produced lower temperatures release in solution higher amounts of TP. These divergences occur due temperature of combustion, affected specie, ash pH values and CaCO3 content, which affects the quantity of this element in solution. Discussions about these effects will be accurate in the communication.

Validation of a continuous flow method for the determination of soluble iron in atmospheric dust and volcanic ash.

PubMed

Simonella, Lucio E; Gaiero, Diego M; Palomeque, Miriam E

2014-10-01

Iron is an essential micronutrient for phytoplankton growth and is supplied to the remote areas of the ocean mainly through atmospheric dust/ash. The amount of soluble Fe in dust/ash is a major source of uncertainty in modeling-Fe dissolution and deposition to the surface ocean. Currently in the literature, there exist almost as many different methods to estimate fractional solubility as researchers in the field, making it difficult to compare results between research groups. Also, an important constraint to evaluate Fe solubility in atmospheric dust is the limited mass of sample which is usually only available in micrograms to milligrams amounts. A continuous flow (CF) method that can be run with low mass of sediments (<10mg) was tested against a standard method which require about 1g of sediments (BCR of the European Union). For validation of the CF experiment, we run both methods using South American surface sediment and deposited volcanic ash. Both materials tested are easy eroded by wind and are representative of atmospheric dust/ash exported from this region. The uncertainty of the CF method was obtained from seven replicates of one surface sediment sample, and shows very good reproducibility. The replication was conducted on different days in a span of two years and ranged between 8 and 22% (i.e., the uncertainty for the standard method was 6-19%). Compared to other standardized methods, the CF method allows studies of dissolution kinetic of metals and consumes less reagents and time (<3h). The method validated here is suggested to be used as a standardized method for Fe solubility studies on dust/ash. Copyright © 2014 Elsevier B.V. All rights reserved.

Thermodynamic analysis of vapor-phase epitaxial growth of GaAsN on Ge

NASA Astrophysics Data System (ADS)

Kawano, Jun; Kangawa, Yoshihiro; Ito, Tomonori; Kakimoto, Koichi; Koukitu, Akinori

2012-03-01

In this paper, we use thermodynamic analysis to determine how the nitrogen (N) ratio in the source gases affects the solid composition of coherently grown GaAs1-xNx(x˜0.03). The source gases for Ga, As, and N are trimethylgallium ((CH3)3Ga), arsine (AsH3), and ammonia (NH3), respectively. The growth occurs on a Ge substrate, and the analysis includes the stress from the substrate-crystal lattice mismatch. Calculation results indicate that to have just a few percent N incorporation into the grown solid, the V/III ratio in the source gases should be several thousands and the input-gas partial-pressure ratio NH3/(NH3+AsH3) should exceed 0.99. We also find that the lattice mismatch stress from the Ge substrate increases the V/III source-gas ratio required for stable growth, whereas an increase in input Ga partial pressure ratio has the opposite effect.

Leaching characteristics of selected South African fly ashes: Effect of pH on the release of major and trace species

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gitari, W.M.; Fatoba, O.O.; Petrik, L.F.

2009-07-01

Fly ash samples from two South African coal-fired power stations were subjected to different leaching tests under alkaline and acidic conditions in an attempt to assess the effect of pH on the leachability of species from the fly ashes and also assess the potential impact of the fly ashes disposal on groundwater and the receiving environment. To achieve this, German Standard leaching (DIN-S4) and Acid Neutralization Capacity (ANC) tests were employed. Ca, Mg, Na, K and SO{sub 4} were significantly leached into solution under the two leaching conditions with the total amounts in ANC leachates higher than that of DIN-S4.more » This indicates that a large fraction of the soluble salts in unweathered fly ash are easily leached. These species represents the fraction that can be flushed off initially from the surface of ash particles on contacting the ash with water. The amounts of toxic trace elements such as As, Se, Cd, Cr and Pb leached out of the fly ashes when in contact with de-mineralized water (DIN-S4 test) were low and below the Target Water Quality Range (TWQR) of South Africa. This is explained by their low concentrations in the fly ashes and their solubility dependence on the pH of the leaching solution. However the amounts of some minor elements such as B, Mn, Fe, As and Se leached out at lower pH ranging between 10 to 4 (ANC test) were slightly higher than the TWQR, an indication that the pH of the leaching solution plays a significant role on the leaching of species in fly ash. The high concentrations of the toxic elements released from the fly ashes at lower pH gives an indication that the disposal of the fly ash could have adverse effects on the receiving environment if the pH of the solution contacting the ashes is not properly monitored.« less

Quantity, composition and water contamination potential of ash produced under different wildfire severities.

PubMed

Santín, Cristina; Doerr, Stefan H; Otero, Xosé L; Chafer, Chris J

2015-10-01

Wildfires frequently threaten water quality through the transfer of eroded ash and soil into rivers and reservoirs. The ability to anticipate risks for water resources from wildfires is fundamental for implementing effective fire preparedness plans and post-fire mitigation measures. Here we present a new approach that allows quantifying the amount and characteristics of ash generated under different wildfire severities and its respective water contamination potential. This approach is applied to a wildfire in an Australian dry sclerophyll eucalypt forest, but can be adapted for use in other environments. The Balmoral fire of October 2013 affected 12,694 ha of Sydney's forested water supply catchment. It produced substantial ash loads that increased with fire severity, with 6, 16 and 34 Mg ha(-1) found in areas affected by low, high and extreme fire severity, respectively. Ash bulk density was also positively related to fire severity. The increase with fire severity in the total load and bulk density of the ash generated is mainly attributed to a combination of associated increases in (i) total amount of fuel affected by fire and (ii) contribution of charred mineral soil to the ash layer. Total concentrations of pollutants and nutrients in ash were mostly unrelated to fire severity and relatively low compared to values reported for wildfire ash in other environments (e.g. 4.0-7.3mg As kg(-1); 2.3-4.1 B mg kg(-1); 136-154 P mg kg(-1)). Solubility of the elements analysed was also low, less than 10% of the total concentration for all elements except for B (6-14%) and Na (30-50%). This could be related to a partial loss of soluble components by leaching and/or wind erosion before the ash sampling (10 weeks after the fire and before major ash mobilisation by water erosion). Even with their relatively low concentrations of potential pollutants, the substantial total ash loads found here represent a water contamination risk if transported into the hydrological network during severe erosion events. For example, up to 4 Mg of ash-derived P could be delivered into a single water supply reservoir. Copyright © 2015 Elsevier Inc. All rights reserved.

Effects of wildfires on ash Carbon, Nitrogen and C/N ratio in Mediterranean forests

NASA Astrophysics Data System (ADS)

Pereira, P.; Ubeda, X.; Martin, D. A.

2009-04-01

Carbon (C) and Nitrogen(N) are key nutrients in ecosystems health and the more affected by fire temperatures, because of their low temperatures of volatilization. After a wildfire, due higher temperatures reached, a great amount of C and N can be evacuated from the ecosystems and the percentage of C and N not vaporized is concentrated in ashes. Hence, the study of ash C and N is of major importance because will be linked with the capacity of ecosystem recuperation. The aim of this work is study the C, and C/N of three wildfires occurred in Mediterranean forests dominated by Quercus suber and Pinus pinea in Portugal. In the first wildfire, named "Quinta do Conde", we collected 30 samples, in the second, "Quinta da Areia", 32 samples and the third, "Casal do Sapo" 40 samples To estimate the consequences of wildfires in the parameters in study, we collected several samples of unburned litter near burned areas, composed by the same vegetation. The results showed that wildfires induced in % of Total Carbon (%TC) ashes content a non significantly reduction in Quinta do Conde plot (at a p<0,05) and significantly in Quinta da Areia plot (p<0.001) and Casal do Sapo plot (p<0.001). In % of Total Nitrogen (%TN) ashes content we observed in Quinta do Conde plot a significant increase (p<0.001), a non significant decrease in Quinta da Areia plot (at a p<0,05) and a significant reduce in Casal do Sapo plot (p<0.01). The The C/N ratio suffer a significant (p<0.001) reduction in Quinta do Conde and Quinta da Areia plots and at a p<0.01 in Casal do Sapo plot. In all parameters in study, wilfires induced a greater spatial variability, by the analysis of the Coefficient of Variation. Our tests effectuated in laboratory with samples collected near wildfires occurrence and exposed to the temperature gradient (150°, 200°, 250°, 300°, 350°, 400°, 450°, 500°, 550°C) fit with the results obtained. With temperature gradient, we identified a decrease of %TC ash content of Quercus suber samples and a rise until the 300°C in Pinus pinaster samples decreasing thereafter especially after the 400°C. In %TN we identified a rise in both species reducing abruptly at 450°C. C/N ratio decrease importantly after the 150°C. Theses results showed us that wildfires can have different effects C and N litter resources, depending on the severity and temperature reached. Crossing the results obtained in laboratory simulations with the samples collected in wildfires we will have an idea about the severity and temperature occurred in each wildfire. Overall, the lower severity were observed in Quinta do Conde plot and the higher in Casal do Sapo plot, being Quinta da Areia in a middle position. The C and N levels after a wildfire will determine the capacity of landscape recuperation and according the data obtained this will be higher in Quinta do Conde plot and lesser in Casal do Sapo plot. These hypothesis will be confirmed by field observation. Keywords: Carbon, Nitrogen, C/N ratio, wildfires, ashes, Quinta do Conde, Quinta da Areia, Casal do Sapo, Quercus suber, Pinus pinaster, Laboratory simulations, Severity, Landscape recuperation.

A study of surfactant interaction in cement-based systems and the role of the surfactant in frost protection

NASA Astrophysics Data System (ADS)

Tunstall, Lori Elizabeth

Air voids are deliberately introduced into concrete to provide resistance against frost damage. However, our ability to control air distribution in both traditional and nontraditional concrete is hindered by the limited amount of research available on air-entraining agent (AEA) interaction with both the solid and solution components of these systems. This thesis seeks to contribute to the information gap in several ways. Using tensiometry, we are able to quantify the adsorption capacity of cement, fly ash, and fly ash carbon for four commercial AEAs. These results indicate that fly ash interference with air entrainment is due to adsorption onto the glassy particles tucked inside carbon, rather than adsorption onto the carbon itself. Again using tensiometry, we show that two of the AEA show a stronger tendency to micellize and to interact with calcium ions than the others, which seems to be linked to the freezing behavior in mortars, since mortars made with these AEA require smaller dosages to achieve similar levels of protection. We evaluate the frost resistance of cement and cement/fly ash mortars by measuring the strain in the body as it is cooled and reheated. All of the mortars show some expansion at temperatures ≥ -42 °C. Many of the cement mortars are able to maintain net compression during this expansion, but none of the fly ash mortars maintain net compression once expansion begins. Frost resistance improves with an increase in AEA dosage, but no correlation is seen between frost resistance and the air void system. Thus, another factor must contribute to frost resistance, which we propose is the microstructure of the shell around the air void. The strain behavior is attributed to ice growth surrounding the void, which can plug the pores in the shell and reduce or eliminate the negative pore pressure induced by the ice inside the air void; the expansion would then result from the unopposed crystallization pressure, but this must be verified by future work. If the shell has numerous, tiny pores it is more difficult to eliminate suction, since more ice is needed to plug all the pores.

Synthesis and characterization of grinding aid fly ash blended mortar effect on bond strength of masonry prisms

NASA Astrophysics Data System (ADS)

Krishnaraj, L.; Ravichandran, P. T.; Sagadevan, Suresh

2018-04-01

The aim of the present work is to study the effect of particle size reduction by applying top-down nanotechnology such as ball mill grinding process with the addition of amine-based grinding aids. The particle size reduction in synthesis process and its characterization were investigated for fly ash particles. The Rosin-Rammler-Bennet (RRB) distribution model using mathematical formulations were studied for fly ash ground particles. The hardened properties of grinding aid fly ash composite mortar were studied using compressive strength test. The optimum grinding time was 120 min identified through the particle size distribution analysis. The mean particle size decreased from 92.09 μm to 10.5 μm in which there is 89% reduction in particle size due to the grinding of fly ash particle with grinding aids. The compressive strength results show that substitutions of Ordinary Portland Cement (OPC) mortar by Amine-based Grinding aid Fly Ash (AGFA) 15% gives 12, 23% and at 30% gives 6, 8% of higher strength compare to the substitutions of raw fly ash. The addition of grinding aids in grinding process gives more advantages to reduce the particle size without changing chemical composition. The AGFA sample shows better performance in compressive strength and bond strength behavior of masonry prism. It may suggest that amine based grinding aids play a vital role and feasible to use in fly ash grinding process.

Characterization of morphology and hydration products of high-volume fly ash paste by monochromatic scanning x-ray micro-diffraction (μ-SXRD)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bae, Sungchul; Meral, Cagla; Department of Civil Engineering, Middle East Technical University, 06800 Ankara

2014-05-01

The present study focuses on identification and micro-structural characterization of the hydration products formed in high-volume fly ash (HVFA)/portland cement (PC) systems using monochromatic scanning x-ray micro-diffraction (μ-SXRD) and SEM-EDS. Pastes with up to 80% fly ash replacement were studied. Phase maps for HVFA samples using μ-SXRD patterns prove that μ-SXRD is an effective method to identify and visualize the distribution of phases in the matrix. μ-SXRD and SEM-EDS analysis shows that the C-S-H formed in HVFA system containing 50% or more of fly ash has a similar structure as C-S-H(I) with comparatively lower Ca/Si ratio than the one producedmore » in PC system. Moreover, coexistence of C-S-H(I) and strätlingite is observed in the system containing 80% of fly ash, confirming that the amount of alumina and silicate phases provided by the fly ash is a major factor for the formation of C-S-H(I) and strätlingite in HVFA system. - Highlights: • High-volume fly ash (HVFA) paste was studied by scanning x-ray micro-diffraction. • Coexistence of C-S-H(I) and strätlingite in the HVFA system is clearly shown. • The distribution of minor phases in the HVFA system is shown. • Differences between inner and outer products of fly ash are observed by SEM-EDS.« less

Mutagenicity and genotoxicity of coal fly ash water leachate

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chakraborty, R.; Mukherjee, A.

2009-03-15

Fly ash is a by-product of coal-fired electricity generation plants. The prevalent practice of disposal is as slurry of ash and water to storage or ash ponds located near power stations. This has lain to waste thousands of hectares of land all over the world. Since leaching is often the cause of off-site contamination and pathway of introduction into the human environment, a study on the genotoxic effects of fly ash leachate is essential. Leachate prepared from the fly ash sample was analyzed for metal content, and tested for mutagenicity and genotoxicity. Analyses of metals show predominance of the metalsmore » - sodium, silicon, potassium, calcium, magnesium, iron, manganese, zinc, and sulphate. The Ames Salmonella mutagenicity assay, a short-term bacterial reverse mutation assay, was conducted on two-tester strains of Salmonella typhimurium strains TA97a and TA102. For genotoxicity, the alkaline version of comet assay on fly ash leachate was carried in vitro on human blood cells and in vivo on Nicotiana plants. The leachate was directly mutagenic and induced significantconcentration-dependent increases in DNA damage in whole blood cells, lymphocytes, and in Nicotiana plants. The comet parameters show increases in tail DNA percentage (%), tail length (mu m), and olive tail moment (arbitrary units). Our results indicate that leachate from fly ash dumpsites has the genotoxic potential and may lead to adverse effects on vegetation and on the health of exposed human populations.« less

Dealing with the aftermath of Fukushima Daiichi nuclear accident: decontamination of radioactive cesium enriched ash.

PubMed

Parajuli, Durga; Tanaka, Hisashi; Hakuta, Yukiya; Minami, Kimitaka; Fukuda, Shigeharu; Umeoka, Kuniyoshi; Kamimura, Ryuichi; Hayashi, Yukie; Ouchi, Masatoshi; Kawamoto, Tohru

2013-04-16

Environmental radioactivity, mainly in the Tohoku and Kanto areas, due to the long living radioisotopes of cesium is an obstacle to speedy recovery from the impacts of the Fukushima Daiichi Nuclear Power Plant accident. Although incineration of the contaminated wastes is encouraged, safe disposal of the Cs enriched ash is the big challenge. To address this issue, safe incineration of contaminated wastes while restricting the release of volatile Cs to the atmosphere was studied. Detailed study on effective removal of Cs from ash samples generated from wood bark, household garbage, and municipal sewage sludge was performed. For wood ash and garbage ash, washing only with water at ambient conditions removed radioactivity due to (134)Cs and (137)Cs, retaining most of the components other than the alkali metals with the residue. However, removing Cs from sludge ash needed acid treatment at high temperature. This difference in Cs solubility is due to the presence of soil particle originated clay minerals in the sludge ash. Because only removing the contaminated vegetation is found to sharply decrease the environmental radioactivity, volume reduction of contaminated biomass by incineration makes great sense. In addition, need for a long-term leachate monitoring system in the landfill can be avoided by washing the ash with water. Once the Cs in solids is extracted to the solution, it can be loaded to Cs selective adsorbents such as Prussian blue and safely stored in a small volume.

Hydromagmatic and peperitic interactions: A new experimental approach.

NASA Astrophysics Data System (ADS)

Downey, W. S.; Spieler, O.; Kunzmann, T.; Mastin, L.; Dingwell, D. B.; Shaw, C. J.

2007-12-01

Hydromagmatic interactions in general and the formation of peperites in particular, are poorly understood. We have designed and tested a new series of experiments to analyze the formation of fine hydromagmatic basaltic ash, and the processes occurring during magma/wet-sediment interaction. This study evaluates the mechanism of "turbulent shedding", (Mastin, 2007) where fine hydromagmatic ash is produced by the removal of quenched glassy rinds on clast surfaces that are rapidly deforming within turbulent transport. During magma/wet-sediment interactions the rapid heat transfer rate can lead to oscillations in the vapor film, and its possible collapse to generate a vapor explosion, between the two media producing either fluidal or brecciated textures of the silicate. In these experiment 0.5 kg of basaltic melt is generated in an internally heated autoclave at temperatures of up to 1300 (º)C and ejected via gas pressure into a low pressure tank. The autoclave can be pressurized to 50 MPa and is designed to eject the melt directly into water, wet sediments or water spray. The later technique is commonly used by powder metallurgists to produce micron-sized fragments of metallic glass, and is the desired technique to aid in the production of fine-ash via "turbulent shedding". Two molybdenum wound furnaces are used to produce the melt while a third Kanthal-wound furnace is used to control the temperature at the ejection orifice. Six thermocouples are used to control the furnaces and to record the thermal gradient throughout the setup. Pressure transducers in the high and low pressure section record the expansion volume due thermal interaction. The autoclave is separated from the low pressure tank with a diaphragm to prevent water from entering the high temperature zone. The goal of these experiments is to give insight into the role of hydrodynamic process during magma/water interaction and in the generation of peperites. The first experiments have resulted in the formation of Pelee's hairs and tears reflecting the high strain rates accompanying melt ejection. Post-experiment, grain size and surface area analysis of the hydromagmatic clasts is in progress to quantify the thermal interaction area, the influence of the turbulence and the heat transfer rate on magma-water mixing. The sediments will be impregnated with epoxy to yield textural insights for comparison with field descriptions of peperites.

Procedural uncertainties of Proctor compaction tests applied on MSWI bottom ash.

PubMed

Izquierdo, Maria; Querol, Xavier; Vazquez, Enric

2011-02-28

MSWI bottom ash is a well-graded highly compactable material that can be used as a road material in unbound pavements. Achieving the compactness assumed in the design of the pavement is of primary concern to ensure long term structural stability. Regulations on road construction in a number of EU countries rely on standard tests originally developed for natural aggregates, which may not be appropriate to accurately assess MSWI bottom ash. This study is intended to assist in consistently assessing MSWI bottom ash compaction by means of the Proctor method. This test is routinely applied to address unbound road materials and suggests two methods. Compaction parameters show a marked procedural dependency due to the particle morphology and weak particle strength of ash. Re-compacting a single batch sample to determine Proctor curves is a common practise that turns out to overvalue optimum moisture contents and maximum dry densities. This could result in wet-side compactions not meeting stiffness requirements. Inaccurate moisture content measurements during testing may also induce erroneous determinations of compaction parameters. The role of a number of physical properties of MSWI bottom ash in compaction is also investigated. Copyright © 2011 Elsevier B.V. All rights reserved.

Preparation of poly-o-phenylenediamine/TiO 2/fly-ash cenospheres and its photo-degradation property on antibiotics

NASA Astrophysics Data System (ADS)

Huo, Pengwei; Yan, Yongsheng; Li, Songtian; Li, Huaming; Huang, Weihong

2010-03-01

A series of poly-o-phenylenediamine/TiO 2/fly-ash cenospheres(POPD/TiO 2/fly-ash cenospheres) composites have been prepared from o-phenylenediamine and TiO 2/fly-ash cenospheres under various polymerization conditions. The properties of the samples were characterized by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), specific surface area (BET), X-ray diffraction (XRD), Fourier transform infrared (FT-IR) and UV-vis diffuse reflectance spectrum (UV-vis DRS). Photocatalytic activity was studied by degradation of antibiotics waste water under visible light. The results indicate that the photo-induced method is viable for preparing modified photocatalysts, and the modified photocatalysts have good absorption in visible light range. The photocatalysts of POPD/TiO 2/fly-ash cenospheres which have good performance are prepared at pH 3 and 4, and the polymerized time around 40 min. When the photocatalysts are prepared under the conditions of pH 3 and polymerized time 40 min, the degradation rate of roxithromycin waste water could reach near 60%, and it indicates that the way of POPD modified TiO 2/fly-ash cenospheres to degrade the antibiotics waste water is viable.

Petrography and geochemistry of the San Miguel lignite, Jackson Group (Eocene), south Texas

USGS Publications Warehouse

Warwick, Peter D.; Crowley, Sharon S.; Ruppert, Leslie F.; Pontolillo, James

1996-01-01

The San Miguel lignite deposit (late Eocene, lower Jackson Group) of south Texas consists of four or more thin (generally < 1 m thick) lignite benches that are separated by claystone and mudstone partings. The partings are composed of altered volcanic air-fall ash that has been reworked by tidal or channel processes associated with a back-barrier depositional environment. The purpose of this study is to examine the relationship between the ash yield and the petrographic and geochemical characteristics of the San Miguel lignite as mined. Particular attention is given to 12 of the environmentally sensitive trace elements (As, Be, Cd, Cr, Co, Hg, Mn, Ni, Pb, Sb, Se, and U) that have been identified as possible hazardous air pollutants (HAPs) by the United States Clean Air Act Amendments of 1990. A total of 29 rock and lignite samples were collected and characterized by geochemical and petrographic methods. The major conclusions of the study are as follows: (1) The distribution of Mn is inversely related to the ash yield of the lignite samples. This indicates an organic affinity, or an association with finely disseminated minerals in the lignite that contain this element. (2) On a whole-coal basis, the concentration of the HAPs' element Pb is positively related to ash yield in lignite samples. This indicates an inorganic affinity for Pb. (3) Average whole-coal concentrations of As, Be, Sb, and U in the San Miguel samples are greater than published averages for these elements in other U.S. lignites. (4) The upper and lower lignite benches of the San Miguel deposit are both ash- and algal-rich, indicating that these intervals were probably deposited in wetter conditions than those in which the middle intervals formed. (5) The dominance of the eugelinite maceral subgroup over the huminite subgroup indicates that the San Miguel lignites were subjected to peat-forming conditions (either biogenic or chemical) that enabled degradation of wood cellular material into matrix gels, or that the plants that formed these lignite benches were less woody and more prone to formation of matrix gels. (6) An inertinite-rich layer (top of the B bed) might have formed from widespread oxidation of the San Miguel peat as a result of a volcanic ash fall which was subsequently reworked.

Factors affecting the geochemistry of a thick, subbituminous coal bed in the Powder River Basin: volcanic, detrital, and peat-forming processes

USGS Publications Warehouse

Crowley, S.S.; Ruppert, L.F.; Belkin, H.E.; Stanton, R.W.; Moore, T.A.

1993-01-01

The inorganic geochemistry and mineralogy of three cores from the Anderson-Dietz 1 coal bed, a 15.2-m-thick subbituminous coal bed in the Tongue River Member (Paleocene) of the Fort Union Formation, were examined (1) to determine if the cores could be correlated by geochemical composition alone over a total distance of 2 km and (2) to identify the major factors that influenced the geochemistry of the coal bed. Chemical data (46 elements on a coal-ash basis) for 81 coal samples and 4 carbonaceous rock samples, with most samples representing a 0.6-m-thick (2-ft) interval of core, were grouped into compositional clusters by means of cluster analysis. Seven major clusters were produced; two of these clusters can be used to correlate the coal bed throughout the study area. Data from scanning electron and optical microscope analyses indicate that several factors influenced the geochemistry of the Anderson-Dietz 1 coal bed. The majority of mineral grains in the coal bed are interpreted to be detrital (water borne); evidence includes the presence of rounded to subrounded quartz grains having two-phase, aqueous fluid inclusions characteristic of hydrothermal or low-to-moderate grade metamorphic quartz. These quartz grains are found throughout the coal bed but are most abundant in samples from the midpart of the bed, which was influenced by detrital input associated with the deposition of the clastic rocks that form the split between the Anderson and Dietz 1 coal beds 900 m to the east of the study area. In addition to the detrital minerals mentioned above, volcanic ash that was fluvially transported to the sites of peat deposition or possibly deposited as air-fall volcanic ash also affected the geochemistry of the coal bed. For example, crandallite(?), a mineral reported to form as an alteration product of volcanic ash, is found in seven samples from the coal bed. The presence of quartz grains containing silicate-melt inclusions in eight samples from the coal bed.provides further support for a volcanic ash component. Other factors that probably affected the geochemistry of the coal bed include (1) detrital input associated with the deposition of the roof rocks of the coal bed, (2) peat-forming processes and plant material, and (3) epigenetic ground-water flow. ?? 1993.

MX Siting Investigation. Geotechnical Evaluation. Verification Study - Pahroc Valley, Nevada. Volume I. Synthesis.

DTIC Science & Technology

1981-06-30

Range both consist of Paleozoic limestone and dolomite overlain by Tertiary ash-flow tuffs and undiffer- entiated volcanic rocks. The central portion...andesite, detrital material, volcanic tuff, pumice). FAULT - A plane or zone of fracture along which there has been * I displacement. FAULT BLOCK...D2850-70). To conduct the test, a cylindrical specimen of soil is surrounded by a fluid in a pressure chamber and subjected to an isotropic pressure . An

Effects of sodium hydroxide (NaOH) solution concentration on fly ash-based lightweight geopolymer

NASA Astrophysics Data System (ADS)

Ibrahim, W. M. W.; Hussin, K.; Abdullah, M. M. A.; Kadir, A. A.; Deraman, L. M.

2017-09-01

In this study, the effects of NaOH concentration on properties of fly ash-based lightweight geopolymer were investigated. Lightweight geopolymer was produced using fly ash as source materials and synthetic foaming agents as air entraining agent. The alkaline solutions used in this study are combination of sodium hydroxide (NaOH) and sodium silicate (Na2SiO3) solution. Different molarities of NaOH solution (6M, 8M, 10M, 12M, and 14M) are taken for preparation of 50 x 50 x 50 mm cubes of lightweight geopolymer. The ratio of fly ash/alkaline solution, Na2SiO3/NaOH solution, foaming agent/water and foam/geopolymer paste were kept constant at 2.0, 2.5, 1:10 and 1:1 respectively. The samples were cured at 80°C for 24 hours and left at room temperature for tested at 7 days of ageing. Physical and mechanical properties such as density, water absorption, compressive strength and microstructure property were determined from the cube dried samples. The results show that the NaOH molarity had effects on the properties of lightweight geopolymer with the optimum NaOH molarity found is 12M due to the high strength of 15.6 MPa, lower water absorption (7.3%) and low density (1440 kg/m3). Microstructure analysis shows that the lightweight geopolymer contain some porous structure and unreacted fly ash particles remains.

²²⁶Ra, ²³²Th and ⁴⁰K radionuclides enhancement rate and dose assessment for residues of lignite-fired thermal power plants in Turkey.

PubMed

Parmaksiz, A; Arikan, P; Vural, M; Yeltepe, E; Tükenmez, I

2011-11-01

A total of 77 coal, slag and fly ash samples collected from six thermal power plants were measured by gamma-ray spectrometry. The average (226)Ra activity concentrations in coal, slag and fly ash were measured as 199.8±16.7, 380.3±21.8 and 431.5±29.0 Bq kg(-1), respectively. The average (232)Th activity concentrations in coal, slag and fly ash were measured as 32.0±2.4, 74.0±9.0 and 87.3±9.8 Bq kg(-1), respectively. The average (40)K activity concentrations in coal, slag and fly ash were found to be 152.8±12.1, 401.3±25.0 and 439.0±30.2 Bq kg(-1), respectively. The radium equivalent activities of samples varied from 147.6±8.5 to 1077.4±53.3 Bq kg(-1). The gamma and alpha index of one thermal power plant's fly ash were calculated to be 3.5 and 5 times higher than that of the reference values. The gamma absorbed dose rates were found to be higher than that of the average Earth's crust. The annual effective dose of residues measured in four thermal power plants were calculated higher than that of the permitted dose rate for public, i.e. 1 mSv y(-1).

Melting Behavior of Volcanic Ash relevant to Aviation Ash Hazard

NASA Astrophysics Data System (ADS)

Song, W.; Hess, K.; Lavallee, Y.; Cimarelli, C.; Dingwell, D. B.

2013-12-01

Volcanic ash is one of the major hazards caused by volcanic eruptions. In particular, the threat to aviation from airborne volcanic ash has been widely recognized and documented. In the past 12 years, more than 60 modern jet airplanes, mostly jumbo jets, have been damaged by drifting clouds of volcanic ash that have contaminated air routes and airport facilities. Seven of these encounters are known to have caused in-flight loss of engine power to jumbo jets carrying a total of more than 2000 passengers. The primary cause of engine thrust loss is that the glass in volcanic ash particles is generated at temperatures far lower than the temperatures in the combustion chamber of a jet engine ( i.e. > 1600 oC) and when the molten volcanic ash particles leave this hottest section of the engine, the resolidified molten volcanic ash particles will be accumulated on the turbine nozzle guide vanes, which reduced the effective flow of air through the engine ultimately causing failure. Thus, it is essential to investigate the melting process and subsequent deposition behavior of volcanic ash under gas turbine conditions. Although few research studies that investigated the deposition behavior of volcanic ash at the high temperature are to be found in public domain, to the best our knowledge, no work addresses the formation of molten volcanic ash. In this work, volcanic ash produced by Santiaguito volcano in Guatemala in November 8, 2012 was selected for study because of their recent activity and potential hazard to aircraft safety. We used the method of accessing the behavior of deposit-forming impurities in high temperature boiler plants on the basis of observations of the change in shape and size of a cylindrical coal ash to study the sintering and fusion phenomena as well as determine the volcanic ash melting behavior by using characteristic temperatures by means of hot stage microscope (HSM), different thermal analysis (DTA) and Thermal Gravimetric Analysis (TGA) to investigate the sintering process of volcanic ash. In order to analyze the mineral transformation and microstructure evolution, the qualitative as well as quantitative crystalline phase analysis of volcanic ash samples directly taken from furnace by per 100 oC in the range of between 100 and 1400 oC as well as evaluation of microstructure of volcanic ash taken from from furnace by per 20 oC in the range of between 1000 and 1300 oC has been made by X-ray diffraction (XRD) and observed by scanning electron microscopy (SEM). Finally, we obtain the viscosity temperature curve for volcanic ash during melting process on the basis of the characteristic temperature obtained by HSM.

A Study on Factors Affecting Strength of Solidified Peat through XRD and FESEM Analysis

NASA Astrophysics Data System (ADS)

Rahman, J. A.; Napia, A. M. A.; Nazri, M. A. A.; Mohamed, R. M. S. R.; Al-Geethi, A. S.

2018-04-01

Peat is soft soil that often causes multiple problems to construction. Peat has low shear strength and high deformation characteristics. Thus, peat soil needs to be stabilized or treated. Study on peat stabilization has been conducted for decades with various admixtures and mixing formulations. This project intends to provide an overview of the solidification of peat soil and the factors that affecting the strength of solidified peat soil. Three types of peats which are fabric, hemic and sapric were used in this study to understand the differences on the effect. The understanding of the factors affecting strength of solidified peat in this study is limited to XRD and FESEM analysis only. Peat samples were collected at Pontian, Johor and Parit Raja, Johor. Peat soil was solidified using fly ash, bottom ash and Portland cement with two mixing formulation following literature review. The solidified peat were cured for 7 days, 14 days, 28 days and 56 days. All samples were tested using Unconfined Compressive Strength Test (UCS), X-ray diffraction (XRD) and Field Emission Scanning Electron Microscope (FESEM). The compressive strength test of solidified peat had shown consistently increase of sheer strength, qu for Mixing 1 while decrease of its compressive strength value for Mixing 2. All samples were tested and compared for each curing days. Through XRD, it is found that all solidified peat are dominated with pargasite and richterite. The highest qu is Fabric Mixing 1(FM1) with the value of 105.94 kPa. This sample were proven contain pargasite. Samples with high qu were observed to be having fly ash and bottom ash bound together with the help of pargasite. Sample with decreasing strength showed less amount of pargasite in it. In can be concluded that XRD and FESEM findings are in line with UCS values.

The Ash that Closed Europe's Airspace in 2010

NASA Astrophysics Data System (ADS)

Gislason, S. R.; Alfredsson, H.; Olsson, J.; Eiriksdottir, E.; Oskarsson, N.; Hassenkam, T.; Nedel, S.; Bovet, N.; Hem, C.; Balogh, Z.; Dideriksen, K.; Stipp, S. L.

2011-12-01

On 14 April 2010, when meltwater from the Eyjafjallajökull glacier mixed with hot magma, an explosive phreato-magmatic eruption sent unusually fine-grained ash into the jet stream. It quickly dispersed over Europe. Previous airplane encounters with ash had caused sand blasted windows and particles melted inside jet engines, causing them to fail. Therefore, air traffic was grounded for several days. Concerns also arose about health risks from fallout, because ash can transport acids as well as toxic compounds. Studies on ash are usually made on material collected far from the source, where it could have mixed with other atmospheric particles, or after exposure to water as rain or fog, which would alter surface composition. In this study, a unique set of dry ash samples was collected during the explosive eruption and compared with fresh ash with the same bulk composition from a later more typical magmatic event, when meltwater did not have access to the magma.[1] Up to 70 mass % of the phreato-magmatic ash particles, collected 60 km from the source, was <60 μm in diameter, 22% was <10 μm and 11% was ≤ 4.4 μm. The finest grain size was found in the centre of the "collapsed" plume. The magmatic ash was coarser and its surface area was an order of magnitude smaller than for the explosive ash. The relative concentration of surface salts down to 10 nm depth was significantly lower on the explosive ash than the magmatic ash, because less volatile compounds were available to condense on the surfaces when water and steam were present. Instead, they dissolved in the meltwater and were transported as solutes in the ensuing floodwaters. The surface salts dissolved rapidly when exposed to experimental and natural waters, releasing pollutants and nutrients. Some of the salts further enhanced bulk dissolution of the ash. The particles of phreato-magmatic ash that reached Europe in the jet stream were especially sharp and hard, therefore abrasive, over their entire size range, from submillimeter to tens of nanometers. Edges remained sharp, even after 2 weeks of abrasion in stirred water suspensions. From the composition of the particles, we could predict that they would soften and melt at the temperatures typical of a jet engine (1500 to 2000 °C). [1] Gislason S.R. et al. (2011), PNAS, 108, 7307-7312

[Volatile ashes and their biological effect. 2. Fibrogenic effect of volatile ashes].

PubMed

Woźniak, H; Wiecek, E; Lao, I; Wojtczak, J

1989-01-01

In experiments on white Wistar rats fibrogenic effects of 6 samples of fly-ashes collected from electric precipitators in power engineering plants have been evaluated. The coal came from different national deposits. All the ashes have been found to contain: quartz and mullite, 3 ashes contained additionally orthoclase, whereas 1, apart from quartz and mullite, contained kaolinite; naturally radioactive elements (Ra226, K40, Th228) and trace elements (As, Ba, Be, Cd, Ce, Cu, Fe, Pa, Mo, Ni, Pb, Se, U Zu). Experimental pneumoconiosis was induced through intratracheal administration of single doses of 50 mg of dust; the experiment was carried out at 3 time intervals of 3, 6 and 9 months. The fibrogenic activity was evaluated both qualitatively (histopathological methods) and quantitatively (lung weight, hydroxyproline content in lungs, dust elimination from lungs); control groups consisted of animals which obtained NaCl solution and quartz sands. Fly-ashes were found to exhibit different fibrogenic effects, yet, their fibrogenic activity was weaker, compared to quartz sands. No clear correlation was found between fibrogenic effects of ashes and test physico-chemical properties, such as the content of SiO2, trace elements or naturally radioactive elements. Analysis of occupational diseases (for the period section): (1979-1983) demonstrated occupational diseases of dust-related aetiology among power engineering workers, pneumoconioses, constituting 7.8% of 127 cases of occupational diseases.

Passive treatment of acid mine drainage using coal combustion by-products and spent mushroom substrate: Results of column study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Crisp, T.E.; Nairn, R.W.; Strevett, K.A.

1998-12-31

A column study was conducted to evaluate the feasibility of using of coal combustion by-products (CCB) as alkaline materials in a field scale downflow constructed wetlands for acid mine drainage treatment. Five columns (15.24 cm in diameter and 91.44 cm high) were constructed and filled with a combination of spent mushroom substrate (SMS) and one of three alkaline materials (limestone, hydrated fly ash, or fluidized bed ash). The five mixtures utilized were 10% fluidized bed ash/40% limestone (FBA/LS), 10% fluidized bed ash (FBA), 50% limestone (LS), 50% hydrated fly ash (HFA),m and 50% sieved (>1.5 cm) hydrated fly ash (S.more » HFA) with the remainder as SMS on a w/w basis. Column received synthetic acid mine drainage containing: 400 mg/L iron, 59 mg/L aluminum, 11 mg/L manganese, 50% mg/L magnesium, 40 mg/L calcium, and 1200 mg/L sulfate for 5 months. Anoxic conditions in the influent reservoirs were maintained by a positive nitrogen pressure head. Flow rates of 2.0 mL/minute to each column were maintained by a multichannel peristaltic pump. For all columns, effluent acidity concentrations were less than influent acidity concentration (877{sup {minus}}30, n = 75f). Mean effluent acidity concentrations were 241 mg/L (FBA/LS), 186 mg/L (FBA), 419 mg/L (LS), {minus}28.5 mg/L (HFA), and 351 mg/L (S. HFA), respectively. While all column produced measurable alkalinity, only the HFA column produced a net alkaline discharge. The results of these column studies are applicable to the design and sizing of innovative field scale systems using alkaline-rich CCB`s.« less

Cooling, degassing and compaction of rhyolitic ash flow tuffs: a computational model

USGS Publications Warehouse

Riehle, J.R.; Miller, T.F.; Bailey, R.A.

1995-01-01

Previous models of degassing, cooling and compaction of rhyolitic ash flow deposits are combined in a single computational model that runs on a personal computer. The model applies to a broader range of initial and boundary conditions than Riehle's earlier model, which did not integrate heat and mass flux with compaction and which for compound units was limited to two deposits. Model temperatures and gas pressures compare well with simple measured examples. The results indicate that degassing of volatiles present at deposition occurs within days to a few weeks. Compaction occurs for weeks to two to three years unless halted by devitrification; near-emplacement temperatures can persist for tens of years in the interiors of thick deposits. Even modest rainfall significantly chills the upper parts of ash deposits, but compaction in simple cooling units ends before chilling by rainwater influences cooling of the interior of the sheet. Rainfall does, however, affect compaction at the boundaries of deposits in compound cooling units, because the influx of heat from the overlying unit is inadequate to overcome heat previously lost to vaporization of water. Three density profiles from the Matahina Ignimbrite, a compound cooling unit, are fairly well reproduced by the model despite complexities arising from numerous cooling breaks. Uncertainties in attempts to correlate in detail among the profiles may be the result of the non-uniform distribution of individual deposits. Regardless, it is inferred that model compaction is approximately valid. Thus the model should be of use in reconstructing the emplacement history of compound ash deposits, for inferring the depositional environments of ancient deposits and for assessing how long deposits of modern ash flows are capable of generating phreatic eruptions or secondary ash flows. ?? 1995 Springer-Verlag.

Leaching of mixtures of biochar and fly ash

DOE Office of Scientific and Technical Information (OSTI.GOV)

Palumbo, Anthony V.; Porat, Iris; Phillips, Jana R.

2009-06-22

Increasing atmospheric levels of greenhouse gases, especially CO2, and their effects on global temperature have led to interest in the possibility of carbon storage in terrestrial environments. Both the residual char from biomass pyrolysis (biochar) and fly ash from coal combustion have the potential to significantly expand terrestrial sequestration options. Both biochar and fly ash also have potentially beneficial effects on soil properties. Fly ash has been shown to increase porosity, water-holding capacity, pH, conductivity, and dissolved SO42-, CO32-, Cl- and basic cations. Adding biochar to soil generally raises pH, increases total nitrogen and total phosphorous, encourages greater root development,more » improves cation exchange capacity and decreases available aluminum. A combination of these benefits likely is responsible for observed increases in yields for crops such as corn and sugarcane. In addition, it has been found that soils with added biochar emit lower amounts of other greenhouse gases (methane and nitrous oxide) than do unamended soils. Biochar and fly ash amendments may be useful in promoting terrestrial carbon sequestration on currently underutilized and degraded lands. For example, about 1% of the US surface lands consist of previously mined lands or highway rights-of-way. Poorly managed lands could count for another 15% of US area. Biochar and fly ash amendments could increase productivity of these lands and increase carbon storage in the soil. Previous results showed minimal leaching of organic carbon and metals from a variety of fly ashes. In the present study, we examined the properties of mixtures of biochar, fly ash, and soil and evaluated the leaching of organic carbon and metals from these mixtures. The carbon sorption experiments showed release of carbon from biochar, rather than sorption, except at the highest concentrations in the Biochar HW sample. Similar results were obtained by others for oxidative leaching of bituminous coal, in which more C was released as dissolved C than was oxidized to CO2 by the oxygen in water. We confirmed that both fly ash and two types of biochar (oak char [OKEB], and hardwood [HW] char) exhibited minimal leaching of heavy metals including Cr, Ni, Zn, Ga, and Ag, and no detectable leaching of Pb or Cd (data not shown) under the conditions tested. The Biochar HW had a slightly higher C/N ratio (334) and pH (7.7) than did the Biochar OKEB (284 and 6.5). There was no toxicity exhibited by the fly ash (not shown) or biochar leachates as measured by the Microtox© assay under the conditions tested. In previous results no toxicity was reported in testing the fly ash samples except for one high-pH sample. The most notable leachate component from both types of biochar, but not the fly ash, was organic carbon with the HW biochar leaching less organic carbon than the OKEB biochar (5.71 ppm vs. 59.3 ppm). Alone (in batch sorption experiments), or in mixtures of 90% soil and 10% biochar (column studies), we noted significant loss of carbon from the biochar into soluble components. However, when we added fly ash to the column experiments (80% soil, 10% fly ash, and 10% biochar) we observed significant decreases in the amounts of C leached (20% for HW, and 47% for OKEB). The results indicate that applying a combination of fly ash and biochar may result in maximizing the amount of carbon sequestration in soil while also increasing beneficial soil properties and fertility. The lower amount of carbon leached from the HW biochar compared to the OKEB biochar is likely due to the more recalcitrant form of the carbon in the HW char, due to its preparation at a higher temperature (600 ºC) than the OKEB biochar (450 ºC). High heat treatment temperatures during biochar preparation increase both the total carbon content of the biochar and the proportion of the carbon that is present in fused aromatic rings resistant to chemical and physical degradation.« less

Implications of elastic wave velocities for Apollo 17 rock powders

NASA Technical Reports Server (NTRS)

Talwani, P.; Nur, A.; Kovach, R. L.

1974-01-01

Ultrasonic P- and S-wave velocities of lunar rock powders 172701, 172161, 170051, and 175081 were measured at room temperature and to 2.5 kb confining pressure. The results compare well with those of terrestrial volcanic ash and powdered basalt. P-wave velocity values up to pressures corresponding to a lunar depth of 1.4 km preclude cold compaction alone as an explanation for the observed seismic velocity structure at the Apollo 17 site. Application of small amounts of heat with simultaneous application of pressure causes rock powders to achieve equivalence of seismic velocities for competent rocks.

Distribution and mass of tephra-fall deposits from volcanic eruptions of Sakurajima Volcano based on posteruption surveys

NASA Astrophysics Data System (ADS)

Oishi, Masayuki; Nishiki, Kuniaki; Geshi, Nobuo; Furukawa, Ryuta; Ishizuka, Yoshihiro; Oikawa, Teruki; Yamamoto, Takahiro; Nanayama, Futoshi; Tanaka, Akiko; Hirota, Akinari; Miwa, Takahiro; Miyabuchi, Yasuo

2018-04-01

We estimate the total mass of ash fall deposits for individual eruptions of Sakurajima Volcano, southwest Japan based on distribution maps of the tephra fallout. Five ash-sampling campaigns were performed between 2011 and 2015, during which time Sakurajima continued to emit ash from frequent Vulcanian explosions. During each survey, between 29 and 53 ash samplers were installed in a zone 2.2-43 km downwind of the source crater. Total masses of erupted tephra were estimated using several empirical methods based on the relationship between the area surrounded by a given isopleth and the thickness of ash fall within each isopleth. We obtained 70-40,520 t (4.7 × 10-8-2.7 × 10-5-km3 DRE) as the minimum estimated mass of erupted materials for each eruption period. The minimum erupted mass of tephra produced during the recorded events was calculated as being 890-5140 t (5.9 × 10-7-3.6 × 10-6-km3 DRE). This calculation was based on the total mass of tephra collected during any one eruptive period and the number of eruptions during that period. These values may thus also include the contribution of continuous weak ash emissions before and after prominent eruptions. We analyzed the meteorological effects on ash fall distribution patterns and concluded that the width of distribution area of an ash fall is strongly controlled by the near-ground wind speed. The direction of the isopleth axis for larger masses is affected by the local wind direction at ground level. Furthermore, the wind direction influences the direction of the isopleth axes more at higher altitude. While a second maximum of ash fall can appear, the influence of rain might only affect the finer particles in distal areas.

Phenolic acids as bioindicators of fly ash deposit revegetation.

PubMed

Djurdjević, L; Mitrović, M; Pavlović, P; Gajić, G; Kostić, O

2006-05-01

The floristic composition, the abundance, and the cover of pioneer plant species of spontaneously formed plant communities and the content of total phenolics and phenolic acids, as humus constituents, of an ash deposit after 7 years of recultivation were studied. The restoration of both the soil and the vegetation on the ash deposits of the "Nikola Tesla-A" thermoelectric power plant in Obrenovac (Serbia) is an extremely slow process. Unfavorable physical and chemical characteristics, the toxicity of fly ash, and extreme microclimatic conditions prevented the development of compact plant cover. The abundance and cover of plants increased from the central part of the deposit towards its edges (ranging from 1-80%). Festuca rubra L., Crepis setosa Hall., Erigeron canadensis L., Cirsium arvense (L.) Scop., Calamagrostis epigeios (L.) Roth., and Tamarix gallica L. were the most abundant species, thus giving the highest cover. Humus generated during the decomposition process of plant remains represents a completely new product absent in the ash as the starting material. The amount of total phenolics and phenolic acids (38.07-185.16 microg/g of total phenolics and 4.12-27.28 microg/g of phenolic acids) in fly ash increased from the center of the deposit towards its edges in correlation with the increase in plant abundance and cover. Ash samples contained high amounts of ferulic, vanillic, and p-coumaric acid, while the content of both p-hydroxybenzoic and syringic acid was relatively low. The presence of phenolic acids indicates the ongoing process of humus formation in the ash, in which the most abundant pioneer plants of spontaneously formed plant communities play the main role. Phenolic compounds can serve as reliable bioindicators in an assessment of the success of the recultivation process of thermoelectric power plants' ash deposits.

Environmental scanning electron microscope imaging examples related to particle analysis.

PubMed

Wight, S A; Zeissler, C J

1993-08-01

This work provides examples of some of the imaging capabilities of environmental scanning electron microscopy applied to easily charged samples relevant to particle analysis. Environmental SEM (also referred to as high pressure or low vacuum SEM) can address uncoated samples that are known to be difficult to image. Most of these specimens are difficult to image by conventional SEM even when coated with a conductive layer. Another area where environmental SEM is particularly applicable is for specimens not compatible with high vacuum, such as volatile specimens. Samples from which images were obtained that otherwise may not have been possible by conventional methods included fly ash particles on an oiled plastic membrane impactor substrate, a one micrometer diameter fiber mounted on the end of a wire, uranium oxide particles embedded in oil-bearing cellulose nitrate, teflon and polycarbonate filter materials with collected air particulate matter, polystyrene latex spheres on cellulosic filter paper, polystyrene latex spheres "loosely" sitting on a glass slide, and subsurface tracks in an etched nuclear track-etch detector. Surface charging problems experienced in high vacuum SEMs are virtually eliminated in the low vacuum SEM, extending imaging capabilities to samples previously difficult to use or incompatible with conventional methods.

Anomalously high porosity in subduction inputs to the Nankai Trough (SW Japan) potentially caused by volcanic ash and pumice

NASA Astrophysics Data System (ADS)

Huepers, A.; Ikari, M.; Underwood, M.; Kopf, A.

2013-12-01

At convergent margins, the sedimentary section seaward of the trench on the subducting oceanic lithosphere provides the source material for accretionary prisms and eventually becomes the host rock of the plate boundary megathrust. The mechanical properties of the sediments seaward of the subduction zone have therefore a first order control on subduction zone forearc mechanics and hydrogeology. At the Nankai Trough (SW Japan) the majority of sediment approaching the subduction zone is clay-rich. Scientific drilling expeditions in the framework of the Ocean Drilling Program (ODP) and the Integrated Ocean Drilling Program (IODP) have revealed an anomalous zone of high porosity in a major lithologic unit known as the Upper Shikoku Basin facies (USB), which is associated with elevated volcanic ash content and high amounts of silica in the interstitial water. The existence of the high porosity zone has previously been associated with advanced silica cementation, driven by the dual diagenetic transition of opal-A to opal-CT, and opal-CT to quartz. However, temperature estimates from recent drilling expeditions offshore the Kii peninsula reveal different in situ temperatures at the proposed diagenetic boundary in the Shikoku Basin. Furthermore, laboratory measurements using core samples from the USB show that cohesive strength is not elevated in the high porosity zone, suggesting that a process other than cementation may be responsible. The USB sediment is characterized by abundant volcanic ash and pumice, therefore the high porosity zone in the USB may be closely linked to the mechanical behavior of this phase. We conducted consolidation tests in the range 0.1 to 8 MPa effective vertical stress on artificial ash-smectite and pumice-smectite mixtures, as well as intact and remolded natural samples from the IODP Sites C0011 and C0012 to investigate the role of the volcanic constituent on porosity loss with progressive burial. Our results show that both remolded and intact natural samples have high porosities of up to ~71 to 75% at a vertical effective stress of 0.1 MPa, which decreases to 39 to 49% at 8 MPa vertical effective stress. The behavior of the remolded samples is in good accordance with compiled in-situ porosity vs. depth profiles from the high porosity zone. This suggests that cementation is not the cause for the anomalously high porosity. The consolidation tests on the artificial samples document that pure ash and pumice samples are highly resistant to consolidation. Between 0.1 to 8 MPa vertical effective stress, the porosity decreases from 51 to 47% for the ash sample and 60% to 46% for the pumice sample. The higher initial porosity in the pumice may be explained by a porous internal grain structure that allows storage of additional water. Mixtures with smectite are characterized by higher compressibility and higher porosity. For a mixture of 80% smectite and 20% pumice the porosity decreases from 65% to 39%, similar to that of the natural samples. Our results suggest that the high porosity zone is caused by the bulk mechanical behavior of pumice in the USB.

Human and Environmental Dangers Posed by Ongoing Global Tropospheric Aerosolized Particulates for Weather Modification.

PubMed

Herndon, J Marvin

2016-01-01

U.S. military perception of nuclear warfare led to countless unethical nuclear experiments performed on unsuspecting individuals without their informed consent. As evidenced here, subsequent perception of weather warfare has led to exposing millions of unsuspecting individuals to toxic coal fly ash with no public disclosure, no informed consent, and no health warnings. Three methods were used: (1) comparison of eight elements analyzed in rainwater samples, thought to have leached from aerosolized coal fly ash, with corresponding coal fly ash laboratory leachate; (2) comparison of 14 elements analyzed in air filter dust with corresponding elements in coal fly ash; and (3) comparison of 23 elements analyzed in fibrous mesh found after snow melted with corresponding elements in coal fly ash. The rainwater element ratios show that the aerial particulate matter has essentially the same water-leach characteristics as coal fly ash. The air filter dust element ratios occur in the same range of compositions as coal fly ash, as do element ratios in fibrous mesh found on grass after snow melted. The fibrous mesh provides an inferred direct connection with the aerosolizing jet aircraft via coal fly ash association with the jet combustion environment. Strong evidence for the correctness of the hypothesis: coal fly ash is likely the aerosolized particulate emplaced in the troposphere for geoengineering, weather modification, and/or climate alteration purposes. The documented public health associations for ≤2.5 μm particulate pollution are also applicable to aerosolized coal fly ash. The ability of coal fly ash to release aluminum in a chemically mobile form upon exposure to water or body moisture has potentially grave human and environmental consequences over a broad spectrum, including implications for neurological diseases and biota debilitation. The ability of coal fly ash to release heavy metals and radioactive elements upon exposure to body moisture has potentially grave human health implications including cancer, cardiovascular disease, diabetes, respiratory diseases, reduced male fertility, and stroke. The fibrous mesh data admit the possibility of environmentally disastrous formation of methylmercury and ozone-depleting chlorinated-fluorinated hydrocarbons in jet exhaust. Geophysical implications include atmospheric warming and rainfall retardation.

Carbon dioxide and methane sorption in high volatile bituminous coals from Indiana, USA

USGS Publications Warehouse

Mastalerz, Maria; Gluskoter, Harold J.; Rupp, J.

2004-01-01

Samples of coals from several coalbeds in Indiana were analyzed for CO2 and CH4 sorption capacity using a high-pressure adsorption isotherm technique. Coal quality and petrographic composition of the coals were determined to study their relationships to the volume of CO2 and CH4 that could be sorbed into the coal. At the temperature of 17 ??C and 400 psi (??? 2.8 MPa), the coals can sorb (on dry ash-free basis) from 4 to 6.3 m3/ton (128-202 scf/ton) of CH4 and 19.5-24.6 m3/ton4 (624 to 788 scf/ton) of CO2. The ratio of CO2/CH4 at these conditions ranges from 3.5 to 5.3 and decreases with an increasing pressure for all coals. The coals studied are of a very similar coal rank (Ro from 0.48 to 0.62%) but of varying petrographic composition, and CO2 sorption volumes appear to be positively correlated to the content of maceral telocollinite. ?? 2004 Elsevier B.V. All rights reserved.

Large-magnitude Middle Ordovician volcanic ash falls in North America and Europe: Dimensions, emplacement and post-emplacement characteristics

USGS Publications Warehouse

Huff, W.D.; Kolata, Dennis R.; Bergstrom, Stig M.; Zhang, Y.-S.

1996-01-01

Middle Ordovician K-bentonites represent some of the largest known fallout ash deposits in the Phanerozoic Era. They cover minimally 2.2 ?? 106 km2 in eastern North America and 6.9 ?? 105 km2 in northwestern Europe, and represents the coeval accumulation of plinian and co-ignimbrite ash on both Laurentia and Baltica during the closure of the Iapetus Ocean. The three most widespread beds are the Deicke and Millbrig K-bentonites in North America and the Kinnekulle K-bentonite in northwestern Europe. The vents were located near the Laurentian margin of Iapetus on an arc or microplate undergoing collision with Laurentia. The volume of ash preserved in the stratigraphic record converted to dense rock equivalent (DRE) of silicic magma is minimally estimated to be 943 km3 for the Deicke, 1509 km3 for the Millbrig and 972 km3 for the Kinnekulle. The Millbrig and Kinnekulle beds are coeval and possibly equivalent, yielding a combined DRE volume of nearly 2500 km3. Some unknown but probably large amount of additional ash fell into oceanic regions of the Iapetus, but these areas became subducted and the ash is not preserved in the geologic record. The symmetry of the thickness contours is suggestive that one or more ash clouds interacting with equatorial stratospheric and tropospheric wind patterns dispersed pyroclastic material to both the northwest and southeast in terms of Ordovician paleogeography. Based on grain size measurements and thickness/area1/2 plots we conclude the three beds were each formed from co-ignimbrite or possibly phreatoplinian eruption columns. Analyses of melt inclusions in primary quartz crystals indicate the parental magma contained approximately 4% dissolved water at the time of the eruption. This water provided the explosive energy during the initial gas thrust phase. The implied fragmentation pressure on the magma would have reduced much of the ejecta to small particles, forming a deposit composed largely of single crystals and glassy dust. Conversion of the ash to K-bentonite resulted in a mass loss of approximately 35%, mostly in the form of Si with lesser amounts of Na and K.

Radiological impact of airborne effluents of coal and nuclear plants.

PubMed

McBride, J P; Moore, R E; Witherspoon, J P; Blanco, R E

1978-12-08

Radiation doses from airborne effluents of model coal-fired and nuclear power plants (1000 megawatts electric) are compared. Assuming a 1 percent ash release to the atmosphere (Environmental Protection Agency regulation) and 1 part per million of uranium and 2 parts per million of thorium in the coal (approximately the U.S. average), population doses from the coal plant are typically higher than those from pressurized-water or boiling-water reactors that meet government regulations. Higher radionuclide contents and ash releases are common and would result in increased doses from the coal plant. The study does not assess the impact of non-radiological pollutants or the total radiological impacts of a coal versus a nuclear economy.

Faculty of Color and Role Performance. ASHE Annual Meeting Paper.

ERIC Educational Resources Information Center

Alexander-Snow, Mia; Johnson, Barbara J.

This study examined the issues and pressures that new and junior faculty of color experienced at predominantly white colleges and universities, and includes recommendations for administrators, graduate students, majority faculty, and faculty of color. Twelve African American and 19 Latino first-, second-, and third-year tenure-track faculty…

The Study of Money: Science, Technology or Philosophy? ASHE Annual Meeting Paper.

ERIC Educational Resources Information Center

DeBard, Robert

With the current pressures for increased accountability and improved productivity, financial management in the study of higher education has become increasingly important. This study examined whether the "how" or the "why" of management were more important to prospective budget administrators. The study hypothesized that an…

Composition and trace element content of coal in Taiwan

USGS Publications Warehouse

Tsai, L.-Y.; Chen, C.-F.; Finkelman, R.B.

2005-01-01

To investigate the trace element contents of local coal, four coal samples were collected from operating mines in NW Taiwan. Detailed petrographic and chemical characterization analyses were then conducted. Analytical results indicate that (1) the samples were high volatile bituminous coal in rank with ash content ranging from 4.2 to 14.4% and with moisture content ranging from 2.7 to 4.6%; (2) the macerals were mostly composed of vitrinite with vitrinite reflectance less than 0.8%; (3) the sample of Wukeng mine has the highest Fe2O3 (29.5%), TI (54.8 ppm), Zn (140 ppm), and As (697 ppm) contents in ash and Hg (2.3 ppm) in the coal. If used properly, these coals should not present health hazards.

Ternary blends containing demercurated lighting phosphor and MSWI fly ash as high-performance binders for stabilizing and recycling electroplating sludge.

PubMed

Huang, Wu-Jang; Wu, Chia-Teng; Wu, Chang-En; Hsieh, Lin-Huey; Li, Chang-Chien; Lain, Chi-Yuan; Chu, Wei

2008-08-15

This paper describes the solidification and stabilization of electroplating sludge treated with a high-performance binder made from portland type-I cement, municipal solid waste incineration fly ash, and lighting phosphor powder (called as cement-fly ash-phosphor binder, CFP). The highest 28-day unconfined compressive strength of the CFP-treated paste was 816 kg/cm(2) at a ratio of cement to fly ash to lighting phosphor powder of 90:5:5; the strength of this composition also fulfilled the requirement of a high-strength concrete (>460 kg/cm(2) at 28 days). The CFP-stabilized sludge paste samples passed the Taiwanese EPA toxicity characteristic leaching procedure test and, therefore, could be used either as a building material or as a controlled low-strength material, depending on the sludge-to-CFP binder ratio.

Chemical characterization of biomass fuel particulate deposits and ashes in households of Mt. Everest region (NEPAL).

PubMed

Ielpo, Pierina; Fermo, Paola; Comite, Valeria; Mastroianni, Domenico; Viviano, Gaetano; Salerno, Franco; Tartari, Gianni

2016-12-15

During a sampling campaign, carried out during June 2012, inside some traditional households located in four villages (Phakding, Namche, Pangboche and Tukla) of Mt. Everest region in southern part of the central Himalaya (Nepal), particulate matter (PM) depositions and ashes have been collected. Moreover, outdoor PM depositions have also been analyzed. Chemical characterization of PM depositions and ashes for major ions, organic carbon, elemental carbon (EC), metal content and PAHs (Polycyclic Aromatic Hydrocarbons) allowed identifying, as major contributes to indoor PM, the following sources: biomass burning, cooking and chimney ashes. These sources significantly affect outdoor PM depositions: in-house biomass burning is the major source for outdoor EC and K + as well as biomass burning and cooking activities are the major sources for Polycyclic Aromatic Hydrocarbons. Copyright © 2016 Elsevier B.V. All rights reserved.

'Is Ash Falling?', an online ashfall reporting tool in support of improved ashfall warnings and investigations of ashfall processes

USGS Publications Warehouse

Wallace, Kristi; Snedigar, Seth; Cameron, Cheryl

2015-01-01

The primary volcano hazard in Alaska is airborne ash, which endangers aircraft flying the busy North Pacific air routes and consequently affects global commerce. Downwind ashfall is also a significant threat to commerce, transportation and day-to-day activities in nearby Alaska communities. A web-enabled database, "Is Ash Falling?" has been developed to collect ashfall observations and encourage sample collections from the public during eruptions, enabling volcano observatory staff to concentrate on eruption response. Knowing the locations of filed ashfall reports improves public ashfall warnings and forecasts by providing on-the-ground checks for ash dispersion and fallout computer models and satellite imagery interpretation. Reports of ashfall are shared with emergency management agencies and the wider public. These reports also give scientists a more complete record of the amount, duration and other conditions of ashfall.

Fractionation and Mobility of Thallium in Volcanic Ashes after Eruption of Eyjafjallajökull (2010) in Iceland.

PubMed

Karbowska, Bozena; Zembrzuski, Wlodzimierz

2016-07-01

Volcanic ash contains thallium (Tl), which is highly toxic to the biosphere. The aim of this study was to determine the Tl concentration in fractions of volcanic ash samples originating from the Eyjafjallajökull volcano. A sequential extraction scheme allowed for a study of element migration in the environment. Differential pulse anodic stripping voltammetry using a flow measuring system was selected as the analytical method to determine Tl content. The highest average content of Tl in volcanic ash was determined in the fraction entrapped in the aluminosilicate matrix (0.329 µg g(-1)), followed by the oxidizable fraction (0.173 µg g(-1)). The lowest content of Tl was found in the water soluble fraction (0.001 µg g(-1)); however, this fraction is important due to the fact that Tl redistribution among all the fractions occurs through the aqueous phase.

Recycling of Pre-Washed Municipal Solid Waste Incinerator Fly Ash in the Manufacturing of Low Temperature Setting Geopolymer Materials

PubMed Central

Ferone, Claudio; Colangelo, Francesco; Messina, Francesco; Santoro, Luciano; Cioffi, Raffaele

2013-01-01

In this work, three samples of municipal solid waste incinerators fly ash (MSWI-FA) have been stabilized in systems containing coal fly ash to create geopolymers through a polycondensation reaction. Monolithic products have been obtained with both MSWI fly ash as received and after the partial removal of chloride and sulfate by water washing. The polycondensation products have been characterized qualitatively by means of Fourier transform infrared spectroscopy, X-ray diffraction and scanning electron microscopy and quantitatively, through the determination of the volume of reacted water and silicate. Furthermore, the heavy metals and chloride releases together with the physico-mechanical properties have been evaluated on the hardened products. In conclusion, considering the technological and environmental performances of the obtained geopolymers, they could be suitable for many non-structural applications, such as backfilling of abandoned quarries, decorative materials or brick fireplaces, hearths, patios, etc. PMID:28811443

Microwave-assisted digestion using nitric acid for heavy metals and sulfated ash testing in active pharmaceutical ingredients.

PubMed

Pluhácek, T; Hanzal, J; Hendrych, J; Milde, D

2016-04-01

The monitoring of inorganic impurities in active pharmaceutical ingredients plays a crucial role in the quality control of the pharmaceutical production. The heavy metals and residue on ignition/sulfated ash methods employing microwave-assisted digestion with concentrated nitric acid have been demonstrated as alternatives to inappropriate compendial methods recommended in United States Pharmacopoeia (USP) and European Pharmacopoeia (Ph. Eur.). The recoveries using the heavy metals method ranged between 89% and 122% for nearly all USP and Ph. Eur. restricted elements as well as the recoveries of sodium sulfate spikes were around 100% in all tested matrices. The proposed microwave-assisted digestion method allowed simultaneous decomposition of 15 different active pharmaceutical ingredients with sample weigh up to 1 g. The heavy metals and sulfated ash procedures were successfully applied to the determination of heavy metals and residue on ignition/sulfated ash content in mycophenolate mofetil, nicergoline and silymarin.

Fragmentation efficiency of explosive volcanic eruptions: A study of experimentally generated pyroclasts

NASA Astrophysics Data System (ADS)

Kueppers, Ulrich; Scheu, Bettina; Spieler, Oliver; Dingwell, Donald B.

2006-05-01

Products of magma fragmentation can pose a severe threat to health, infrastructure, environment, and aviation. Systematic evaluation of the mechanisms and the consequences of volcanic fragmentation is very difficult as the adjacent processes cannot be observed directly and their deposits undergo transport-related sorting. However, enhanced knowledge is required for hazard assessment and risk mitigation. Laboratory experiments on natural samples allow the precise characterization of the generated pyroclasts and open the possibility for substantial advances in the quantification of fragmentation processes. They hold the promise of precise characterization and quantification of fragmentation efficiency and its dependence on changing material properties and the physical conditions at fragmentation. We performed a series of rapid decompression experiments on three sets of natural samples from Unzen volcano, Japan. The analysis comprised grain-size analysis and surface area measurements. The grain-size analysis is performed by dry sieving for particles larger than 250 μm and wet laser refraction for smaller particles. For all three sets of samples, the grain-size of the most abundant fraction decreases and the weight fraction of newly generated ash particles (up to 40 wt.%) increases with experimental pressure/potential energy for fragmentation. This energy can be estimated from the volume of the gas fraction and the applied pressure. The surface area was determined through Argon adsorption. The fragmentation efficiency is described by the degree of fine-particle generation. Results show that the fragmentation efficiency and the generated surface correlate positively with the applied energy.

Mode of occurrence of arsenic in feed coal and its derivative fly ash, Black Warrior Basin, Alabama

USGS Publications Warehouse

Zielinski, R.A.; Foster, A.L.; Meeker, G.P.; Brownfield, I.K.

2007-01-01

An arsenic-rich (As = 55 ppm) bituminous feed coal from the Black Warrior Basin, Alabama and its derivative fly ash (As = 230 ppm) were selected for detailed investigation of arsenic residence and chemical forms. Analytical techniques included microbeam analysis, selective extraction, and As K-edge X-ray absorption fine-structure (XAFS) spectroscopy. Most As in the coal is contained in a generation of As-bearing pyrite (FeS2) that formed in response to epigenetic introduction of hydrothermal fluids. XAFS results indicate that approximately 50% of the As in the coal sample occurs as the oxidized As(V) species, possibly the result of incipient oxidation of coal and pyrite prior to our analysis. Combustion of pyrite and host coal produced fly ash in which 95% of As is present as As(V). Selective extraction of the fly ash with a carbonate buffer solution (pH = 10) removed 49% of the As. A different extraction with an HCl-NH2OH mixture, which targets amorphous and poorly crystalline iron oxides, dissolved 79% of the As. XAFS spectroscopy of this highly acidic (pH = 3.0) fly ash indicated that As is associated with some combination of iron oxide, oxyhydroxide, or sulfate. In contrast, a highly alkaline (pH = 12.7) fly ash from Turkey shows most As associated with a phase similar to calcium orthoarsenate (Ca3(AsO4)2). The combined XAFS results indicate that fly ash acidity, which is determined by coal composition and combustion conditions, may serve to predict arsenic speciation in fly ash.

Laser fluorometric analysis of plants for uranium exploration

USGS Publications Warehouse

Harms, T.F.; Ward, F.N.; Erdman, J.A.

1981-01-01

A preliminary test of biogeochemical exploration for locating uranium occurrences in the Marfa Basin, Texas, was conducted in 1978. Only 6 of 74 plant samples (mostly catclaw mimosa, Mimosa biuncifera) contained uranium in amounts above the detection limit (0.4 ppm in the ash) of the conventional fluorometric method. The samples were then analyzed using a Scintrex UA-3 uranium analyzer* * Use of trade names in this paper is for descriptive purposes only and does not constitute endorsement by the U.S. Geological Survey. - an instrument designed for direct analysis of uranium in water, and which can be conveniently used in a mobile field laboratory. The detection limit for uranium in plant ash (0.05 ppm) by this method is almost an order of magnitude lower than with the fluorometric conventional method. Only 1 of the 74 samples contained uranium below the detection limit of the new method. Accuracy and precision were determined to be satisfactory. Samples of plants growing on mineralized soils and nonmineralized soils show a 15-fold difference in uranium content; whereas the soils themselves (analyzed by delayed neutron activation analysis) show only a 4-fold difference. The method involves acid digestion of ashed tissue, extraction of uranium into ethyl acetate, destruction of the ethyl acetate, dissolution of the residue in 0.005% nitric acid, and measurement. ?? 1981.

Fly-ash geo-polymer foamed concrete

NASA Astrophysics Data System (ADS)

Kargin, Aleksey; Baev, Vladimir; Mashkin, Nikolay

2017-01-01

In recent years, the interest of researchrs in using fly-ash as a raw material for the geo-polymer synthesis is increasing. Kuzbass region (in Russia) has a large amount of ash wastes generated, which defined the relevace of the study performed in this paper. Results of investigating load-bearing capacity of structural insulating material produced by geo-polymerization of fly-ash of Kemerovo hydro-electric power plant with the addition of complex activator are described in the paper. Hydrogen peroxide solution was used as the foaming agent. The activation time, the temperature of isothermal holding and hardening in normal conditions for all samples were constant. The compressive strength and the mean density of geo-polymer foamed concrete were determined. The influence of the material composition on its properties was revealed. It is found that of the geo-polymer foamed concrete with the optimum composition has hardness of 1,1-3,5 MPa at the density of 400 to 900 kg/m3. Thus, the production of the fly-ash geo-polymer concretes and mortars is feasible, justified and promising.

Observations on Cretaceous abyssal hills in the northeast Pacific

USGS Publications Warehouse

Eittreim, S.L.; Piper, D.Z.; Chezar, H.; Jones, D.R.; Kaneps, A.

1984-01-01

An abyssal hills area of 50 ?? 60 km in the northeast Pacific was studied using bottom transponder navigation, closely spaced survey lines, and long-traverse oblique photography. The block-faulted north-south hills are bounded by scarps, commonly with 40?? slopes. On these steep scarps sedimentation is inhibited and pillow basalts often crop out. An ash layer of high acoustic reflectivity at about 7 m subbottom depth blankets the area. This ash occurs in multiple beds altered to phillipsite and is highly consolidated. A 24 m.y. age for the ash is based on ichthyolith dates from samples in the overlying sediments. Acoustically transparent Neogene sediments above the ash are thickest in trough bottoms and are absent or thin on steep slopes. These Neogene sediments are composed of pale-brown pelagic clays of illite, quartz, smectite, chlorite and kaolinite. Dark-brown pelagic clays, rich in smectite and amorphous iron oxides, underlie the Neogene surficial sediments. Manganese nodules cover the bottom in varying percentages. The nodules are most abundant near basement outcrops and where the subbottom ash layer is absent. ?? 1984.

Designing of Multiphase Fly Ash/MWCNT/PU Composite Sheet Against Electromagnetic Environmental Pollution

NASA Astrophysics Data System (ADS)

Gujral, Parth; Varshney, Swati; Dhawan, S. K.

2016-06-01

Fly ash and multiwalled carbon nanotubes (MWCNT) reinforced multiphase polyurethane (PU) composite sheets have been fabricated by using a solution casting technique. Utilization of fly ash was the prime objective in order to reduce environmental pollution and to enhance the shielding properties of PU polymer. Our study proves that fly ash particles with MWCNTs in a PU matrix leads to novel hybrid high performance electromagnetic shielding interference material. Scanning electron microscopy confirms the existence of fly ash particles along with MWCNTs in a PU matrix. This multiphase composite shows total shielding effectiveness of 35.8 dB (>99.99% attenuation) in the Ku-band (12.4-18 GHz) frequency range. This is attributed to high dielectric losses of reinforcement present in the polymers matrix. The Nicolson-Ross-Weir algorithm has been applied to calculate the electromagnetic attributes and dielectric parameters of the PU samples by using scattering parameters ( S 11, S 22, S 12, S 21). The synthesized multiphase composites were further characterized by using x-ray diffraction, Fourier transform infrared spectroscopy, and thermo gravimetric analysis.

The role of sample preparation in interpretation of trace element concentration variability in moss bioindication studies

USGS Publications Warehouse

Migaszewski, Z.M.; Lamothe, P.J.; Crock, J.G.; Galuszka, A.; Dolegowska, S.

2011-01-01

Trace element concentrations in plant bioindicators are often determined to assess the quality of the environment. Instrumental methods used for trace element determination require digestion of samples. There are different methods of sample preparation for trace element analysis, and the selection of the best method should be fitted for the purpose of a study. Our hypothesis is that the method of sample preparation is important for interpretation of the results. Here we compare the results of 36 element determinations performed by ICP-MS on ashed and on acid-digested (HNO3, H2O2) samples of two moss species (Hylocomium splendens and Pleurozium schreberi) collected in Alaska and in south-central Poland. We found that dry ashing of the moss samples prior to analysis resulted in considerably lower detection limits of all the elements examined. We also show that this sample preparation technique facilitated the determination of interregional and interspecies differences in the chemistry of trace elements. Compared to the Polish mosses, the Alaskan mosses displayed more positive correlations of the major rock-forming elements with ash content, reflecting those elements' geogenic origin. Of the two moss species, P. schreberi from both Alaska and Poland was also highlighted by a larger number of positive element pair correlations. The cluster analysis suggests that the more uniform element distribution pattern of the Polish mosses primarily reflects regional air pollution sources. Our study has shown that the method of sample preparation is an important factor in statistical interpretation of the results of trace element determinations. ?? 2010 Springer-Verlag.

Process for fixed bed coal gasification

DOEpatents

Sadowski, Richard S.

1992-01-01

The combustion of gas produced from the combination of coal pyrolysis and gasification involves combining a combustible gas coal and an oxidant in a pyrolysis chamber and heating the components to a temperature of at least 1600.degree. F. The products of coal pyrolysis are dispersed from the pyrolyzer directly into the high temperature gasification region of a pressure vessel. Steam and air needed for gasification are introduced in the pressure vessel and the materials exiting the pyrolyzer flow down through the pressure vessel by gravity with sufficient residence time to allow any carbon to form carbon monoxide. Gas produced from these reactions are then released from the pressure vessel and ash is disposed of.

Continuous Removal of Coal-Gasification Residue

NASA Technical Reports Server (NTRS)

Collins, Earl R., Jr.; Suitor, J.; Dubis, D.

1986-01-01

Continuous-flow hopper processes solid residue from coal gasification, converting it from ashes, cinders, and clinkers to particles size of sand granules. Unit does not require repeated depressurization of lockhopper to admit and release materials. Therefore consumes less energy. Because unit has no airlock valves opened and closed repeatedly on hot, abrasive particles, subjected to lesser wear. Coal-gasification residue flows slowly through pressure-letdown device. Material enters and leaves continuously. Cleanout door on each pressure-letdown chamber allows access for maintenance and emergencies.

New 40Ar/39Ar age of the Bishop Tuff from multiple sites and sediment rate calibration for the Matuyama-Brunhes boundary

USGS Publications Warehouse

Sarna-Wojcicki, A. M.; Pringle, M.S.; Wijbrans, J.

2000-01-01

Precise dating of sanidine from proximal ash flow Bishop Tuff and air fall Bishop pumice and ash, California, can be used to derive an absolute age of the Matuyama Reversed-Brunhes Normal (M-B) paleomagnetic transition, identified stratigraphically close beneath the Bishop Tuff and ash at many sites in the western United States. An average age of 758.9 ?? 1.8 ka, standard error of the mean (SEM), was obtained for individual sanidine crystals or groups of several crystals, determined from ???70 individual analyses of sanidine separates from 11 sample groups obtained at five localities. The basal air fall pumice (757.7 ?? 1.8 ka) and overlying ash flow tuff (762.2 ?? 4.7 ka) from near the source yield essentially the same dates within errors of analysis, suggesting that the two units were emplaced close in time. A date on distal Bishop air fall ash bed at Friant, California, ???100 km to the west of the source area, is younger, 750.1 ?? 4.3 ka, but not significantly different within analytical error (??1 standard deviation). Previous dates of the Bishop Tuff, obtained by others using conventional K-Ar and the fission track method on zircons, ranged from ???650 ka to ???1.0 Ma. The most recent, generally accepted date by the K-Ar method on sanidine was 738 ?? 3 ka. We infer, as others before, that many K-Ar dates on sanidine feldspar are too young owing to incomplete degassing of radiogenic Ar during fusion in the K-Ar technique and that many older K-Ar dates are too old owing to detrital or xenocrystic contamination in the larger samples that are necessary for the technique. The new dates are similar to recent 40Ar/39Ar ages of the Bishop Tuff determined on individual samples by others but are derived from a larger proximal sample population and from multiple analysis of each sample. The results provide a definitive and precise age calibration of this widespread chronostratigraphic marker in the western United States and northeastern Pacific Ocean. We calculated the age of the M-B transition at five sites, assuming constant sedimentation rates, the age of the Bishop ash bed and one or more well-dated chronostratigraphic horizons above and below the Bishop Tuff ash bed and M-B transition, and stratigraphic separations between these datum levels. The age of the M-B transition is 774.2 ?? 2.8 ka, based on the average of eight such calculations, close to other recent determinations, and similar to that determined from the astronomically tuned polarity timescale. Our approach provides an alternative and surprisingly precise method for determining the age of the M-B and other chronostratigraphic levels. The above dates, calculated using U.S. Geological Survey values of 27.92 Ma for the Taylor Creek (TC) sanidine can be recalculated to other widely used values for these monitors. For example, using recently published values of 28.34 Ma (TC) and 523.1 Ma (McLure Mountain hornblende, MMhb-1), the resulting ages are ???774 ka for the Bishop Tuff and ash bed and ???789 ka for the M-B transition. Copyright 2000 by the American Geophysical Union.

RARE EARTH ELEMENTS IN FLY ASHES AS POTENTIAL INDICATORS OF ANTHROPOGENIC SOIL CONTAMINATION

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mattigod, Shas V.

2003-08-01

Studies of rare earth element (REE) content of disposed fly ashes and their potential mobility were neglected for decades because these elements were believed to be environmentally benign. A number of recent studies have now shown that REE may pose a long-term risk to the biosphere. Therefore, there is a critical need to study the REE concentrations in fly ash and their potential mobilization and dispersal upon disposal in the environment. We analyzed the REE content of bulk, size fractionated, and density separated fractions of three fly ash samples derived from combustion of sub bituminous coals from the western Unitedmore » States and found that the concentrations of these elements in bulk ashes were within the range typical of fly ashes derived from coals from the North American continent. The concentrations of light rare earth elements (LREE) such as La, Ce, and Nd, however, tended towards the higher end of the concentration range whereas, the concentrations of middle rare earth elements (MREE) (Sm and Eu) and heavy rare earth elements (HREE) (Lu) were closer to the lower end of the observed range for North American fly ashes. The concentrations of REE did not show any significant enrichment with decreasing particle size, this is typical of nonvolatile lithophilic element behavior during the combustion process. The lithophilic nature of REE was also confirmed by their concentrations in heavy density fractions of these fly ashes being on average about two times more enriched than the concentrations in the light density fractions. Shale normalized average of REE concentrations of fly ashes and coals revealed significant positive anomalies for Eu and Dy. Because of these distinctive positive anomalies of Eu and Dy, we believe that fly ash contamination of soils can be fingerprinted and distinguished from other sources of anthropogenic REE inputs in to the environment.« less

Estimating rates of decompression from textures of erupted ash particles produced by 1999-2006 eruptions of Tungurahua volcano, Ecuador

USGS Publications Warehouse

Wright, Heather M.N.; Cashman, Katharine V.; Mothes, Patricia A.; Hall, Minard L.; Ruiz, Andrés Gorki; Le Pennec, Jean-Luc

2012-01-01

Persistent low- to moderate-level eruptive activity of andesitic volcanoes is difficult to monitor because small changes in magma supply rates may cause abrupt transitions in eruptive style. As direct measurement of magma supply is not possible, robust techniques for indirect measurements must be developed. Here we demonstrate that crystal textures of ash particles from 1999 to 2006 Vulcanian and Strombolian eruptions of Tungurahua volcano, Ecuador, provide quantitative information about the dynamics of magma ascent and eruption that is difficult to obtain from other monitoring approaches. We show that the crystallinity of erupted ash particles is controlled by the magma supply rate (MSR); ash erupted during periods of high magma supply is substantially less crystalline than during periods of low magma supply. This correlation is most easily explained by efficient degassing at very low pressures (<<50 MPa) and degassing-driven crystallization controlled by the time available prior to eruption. Our data also suggest that the observed transition from intermittent Vulcanian explosions at low MSR to more continuous periods of Strombolian eruptions and lava fountains at high MSR can be explained by the rise of bubbles through (Strombolian) or trapping of bubbles beneath (Vulcanian) vent-capping, variably viscous (and crystalline) magma.

Trace metal inventories and lead isotopic composition chronicle a forest fire's remobilization of industrial contaminants deposited in the angeles national forest.

PubMed

Odigie, Kingsley O; Flegal, A Russell

2014-01-01

The amounts of labile trace metals: [Co] (3 to 11 µg g-1), [Cu] (15 to 69 µg g-1), [Ni] (6 to 15 µg g-1), [Pb] (7 to 42 µg g-1), and [Zn] (65 to 500 µg g-1) in ash collected from the 2012 Williams Fire in Los Angeles, California attest to the role of fires in remobilizing industrial metals deposited in forests. These remobilized trace metals may be dispersed by winds, increasing human exposures, and they may be deposited in water bodies, increasing exposures in aquatic ecosystems. Correlations between the concentrations of these trace metals, normalized to Fe, in ash from the fire suggest that Co, Cu, and Ni in most of those samples were predominantly from natural sources, whereas Pb and Zn were enriched in some ash samples. The predominantly anthropogenic source of excess Pb in the ash was further demonstrated by its isotopic ratios (208Pb/207Pb: 206Pb/207Pb) that fell between those of natural Pb and leaded gasoline sold in California during the previous century. These analyses substantiate current human and environmental health concerns with the pyrogenic remobilization of toxic metals, which are compounded by projections of increases in the intensity and frequency of wildfires associated with climate change.

Alkali-activated concrete with Serbian fly ash and its radiological impact.

PubMed

Nuccetelli, Cristina; Trevisi, Rosabianca; Ignjatović, Ivan; Dragaš, Jelena

2017-03-01

The present paper reports the results of a study on different types of fly ash from Serbian coal burning power plants and their potential use as a binder in alkali-activated concrete (AAC) depending on their radiological and mechanical properties. Five AAC mixtures with different types of coal burning fly ash and one type of blast furnace slag were designed. Measurements of the activity concentrations of 40 K, 226 Ra and 232 Th were done both on concrete constituents (fly ash, blast furnace slag and aggregate) and on the five solid AAC samples. Experimental results were compared by using the activity concentration assessment tool for building materials - the activity concentration index I, as introduced by the EU Basic Safety Standards (CE, 2014). All five designed alkali-activated concretes comply with EU BSS screening requirements for indoor building materials. Finally, index I values were compared with the results of the application of a more accurate index - I(ρd), which accounts for thickness and density of building materials (Nuccetelli et al., 2015a). Considering the actual density and thickness of each concrete sample index - I(ρd) values are lower than index I values. As an appendix, a synthesis of main results concerning mechanical and chemical properties is provided. Copyright © 2016 Elsevier Ltd. All rights reserved.

[Determination of trivalent chromium and hexavalent chromium in dried edible fungi by microwave ashing-liquid chromatography with inductively coupled plasma mass spectrometry].

PubMed

Ni, Zhanglin; Tang, Fubin; Qu, Minghua; Mo, Runhong

2014-02-01

An analytical method using liquid chromatography with inductively coupled plasma mass spectrometry (LC-ICP-MS) for the determination of trivalent chromium (Cr(III)) and hexavalent chromium (Cr(VI)) in dried edible fungi was established. Edible fungi sample was ashed by a microwave ashing system and Na2 EDTA was added to the ashing sample to stabilize the Cr(III). An anion exchange column (250 mm x 4.6 mm, 10 microm) with a 60 mmol/L nitric acid (pH 9.3) solution as mobile phase was used for the separation and using ICP-MS as a detector for the determination of trivalent chromium and hexavalent chromium. The calibration curves were linear in the range of 0.5-50 microg/L and the correlation coefficients were 0. 999 9 for Cr(III) and Cr(VI). The average recoveries of Cr(III) and Cr(VI) ranged from 78.0% to 90.7% with the relative standard deviations (RSDs, n = 6) less than 4%. The limits of quantification (LOQ) of Cr(III) and Cr(VI) were 0.5 microg/L. The method is efficient, reliable and sensitive, and can meet the requirement for the determination of Cr(III) and Cr(VI) in dried edible fungi.

Treatability of stabilize landfill leachate by using pressmud ash as an adsorbent

NASA Astrophysics Data System (ADS)

Azme, N. N. Mohd; Murshed, M. F.

2018-04-01

Leachate is a liquid produced from the landfill that contains high concentration of heavy metals, chemicals and nutrient loading. The treatability of these contaminants are complicated since the current treatment technology are costly and site specific. Therefore, this study was conducted to evaluate the treatability of stabilized landfill leachate by using waste (pressmud ash) as an absorbent. Pressmud ash was prepared by burning at different temperature from 100 to 700 degree Celsius and test at 24 hours shaking time, pH 8, and 4000 rpm. Leachate samples were collected from municipal solid waste (MSW) Pulau Burung Sanitary Landfill (PBSL) and were analyzed for heavy metal, COD, ammonia and colour. This study was performed in two phases i) leachate characteristic, ii) treatability assessment by using pressmud ash. Pressmud was sampled from the sugar mill, Malaysian Sugar Manufacturing (MSM) Sdn Bhd, Seberang Perai, Pulau Pinang. The pressmud with 400°C are highly potential material with a low cost which can be a good adsorbent was capable reducing efficiencies of COD (60.76%), ammonia (64.37%) and colour (35.78%) from real wastewater leachate. Pressmud showed good sorption capability. Surface modification with burning greatly enhanced the reducing efficiency of sugar waste based adsorbent with adsorption efficiency.

Effects of fasting and refeeding on body composition of captive gray wolves (Canis lupus)

USGS Publications Warehouse

Kreeger, T.J.; DelGiudice, G.D.; Mech, L.D.

1997-01-01

We examined the effects of fasting and refeeding on body composition in 9 captive adult gray wolves, Canis lupus (6 males, 3 females), during May-June 1995. Body composition was estimated by the technique of tritiated water dilution. Wolves were immobilized and weighed, baseline blood samples were taken, tritiated water was injected, and additional blood samples were taken before fasting, after 10 d of fasting, and again after 2 d of refeeding. Male wolves lost 8% (P = 0.0001) and females lost 7% body mass (P = 0.01) during the 10 d. Males lost 54% of this mass in water, 28% in fat, and 18% in protein/ash; females lost 58% in water, 20% in fat, and 22% in protein/ash. Upon refeeding, male wolves consumed an average of 6.8 kg (15.3% body mass) of deer meat per day and females consumed 6.4 kg (18.7% body mass). All wolves regained their initial mass. Males regained 24% of this mass in water, 70% in fat, and 6% in protein/ash; females regained 35% in water, 51% in fat, and 14% in protein/ash. This study provided evidence that after prolonged fasting, captive wolves could quickly and efficiently regain lost body mass after refeeding.

Comparative leaching of six toxic metals from raw and chemically stabilized MSWI fly ash using citric acid.

PubMed

Wang, Huawei; Fan, Xinxiu; Wang, Ya-Nan; Li, Weihua; Sun, Yingjie; Zhan, Meili; Wu, Guizhi

2018-02-15

The leaching behavior of six typical toxic metals (Pb, Zn, Cr, Cd, Cu and Ni) from raw and chemically stabilized (phosphate and chelating agent) municipal solid waste incineration (MSWI) fly ash were investigated using citric acid. Leaching tests indicated that phosphate stabilization can effectively decrease the leaching of Zn, Cd and Cr; whereas chelating agent stabilization shows a strong ability to lower the release of Pb, Cd and Cu, but instead increases the solubility of Zn and Cr at low pH conditions. Sequential extraction results suggested that the leaching of Pb, Zn and Cd in both the stabilized MSWI fly ash samples led to the decrease in Fe/Mn oxide fraction and the increase in exchangeable and carbonate fractions. The leaching of Cr was due to the decrease in exchangeable, carbonate and Fe/Mn oxide fractions in phosphate-stabilized and chelating agent-stabilized MSWI fly ash. The leaching of Cu in both stabilized MSWI fly ash was greatly ascribed to the decrease in Fe/Mn oxide and oxidisable fractions. Moreover, predicted curves by geochemical model indicated that both stabilized MSWI fly ash have the risk of releasing toxic metals under strong acid environment. Copyright © 2017 Elsevier Ltd. All rights reserved.

Pulmonary epithelial response in the rat lung to instilled Montserrat respirable dusts and their major mineral components.

PubMed

Housley, D G; Bérubé, K A; Jones, T P; Anderson, S; Pooley, F D; Richards, R J

2002-07-01

The Soufriere Hills, a stratovolcano on Montserrat, started erupting in July 1995, producing volcanic ash, both from dome collapse pyroclastic flows and phreatic explosions. The eruptions/ash resuspension result in high concentrations of suspended particulate matter in the atmosphere, which includes cristobalite, a mineral implicated in respiratory disorders. To conduct toxicological studies on characterised samples of ash, together with major components of the dust mixture (anorthite, cristobalite), and a bioreactive mineral control (DQ12 quartz). Rats were challenged with a single mass (1 mg) dose of particles via intratracheal instillation and groups sacrificed at one, three, and nine weeks. Acute bioreactivity of the particles was assessed by increases in lung permeability and inflammation, changes in epithelial cell markers, and increase in the size of bronchothoracic lymph nodes. Data indicated that respirable ash derived from pyroclastic flows (20.1% cristobalite) or phreatic explosion (8.6% cristobalite) had minimal bioreactivity in the lung. Anorthite showed low bioreactivity, in contrast to pure cristobalite, which showed progressive increases in lung damage. Results suggests that either the percentage mass of cristobalite particles present in Montserrat ash was not sufficient as a catalyst in the lung environment, or its surface reactivity was masked by the non-reactive volcanic glass components during the process of ash formation.

Sorption of cadmium and lead by clays from municipal incinerator ash- water suspensions

USGS Publications Warehouse

Roy, W.R.; Krapac, I.G.; Steele, J.D.

1993-01-01

The effect of Cl complexation in extracts of a flue gas-scrubber incinerator fly ash sample on the sorption of Cd and Pb by kaolinite and illite was investigated using batch-sorption methods. In the pH range of 5 to 9, Cl complexation may reduce sorption and thus increase the mobility of these metals. When an ash-water suspension was acidified to pH 6.85, the dissolution of Cl and Ca essentially eliminated Cd sorption because of complexation and cationic competition. Cadmium would be considered as either mobile or very mobile under these conditions. Lead was not soluble in the pH- 6.85 suspension. At pH 12, the approximate pH of water in contact with flue gas-scrubber fly ash, Cd was essentially insoluble and Pb occurred as anionic Pb hydroxide. Anionic Pb was sorbed by the two clays, and the extent of sorption was not influenced by Cl or carbonate complexation. Sorption constants, derived from isotherms, suggested that Pb would be relatively immobile in saturated soil-water systems. The recent concern that highly alkaline, flue gas-scrubber fly ash may release environmentally significant concentrations of mobile Pb when placed in an ash-disposal site with a soil liner should be reevaluated in light of this study.