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)

Ash production by attrition in volcanic conduits and plumes.

PubMed

Jones, T J; Russell, J K

2017-07-17

Tephra deposits result from explosive volcanic eruption and serve as indirect probes into fragmentation processes operating in subsurface volcanic conduits. Primary magmatic fragmentation creates a population of pyroclasts through volatile-driven decompression during conduit ascent. In this study, we explore the role that secondary fragmentation, specifically attrition, has in transforming primary pyroclasts upon transport in volcanic conduits and plumes. We utilize total grain size distributions from a suite of natural and experimentally produced tephra to show that attrition is likely to occur in all explosive volcanic eruptions. Our experimental results indicate that fine ash production and surface area generation is fast (<15 min) thereby rapidly raising the fractal dimension of tephra deposits. Furthermore, a new metric, the Entropy of Information, is introduced to quantify the degree of attrition (secondary fragmentation) from grain size data. Attrition elevates fine ash production which, in turn, has consequences for eruption column stability, tephra dispersal, aggregation, volcanic lightening generation, and has concomitant effects on aviation safety and Earth's climate.

Coal ash by-product reutilization

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

Muncy, J.; Miller, B.

1997-09-01

Potomac Electric Power Company (PEPCO) has as part of its vision and value statement that, ``We are responsible stewards of environmental and corporate resources.`` With this moral imperative in mind, a project team was charged with initiating the Coal Pile Liner Project--installing a membrane liner under the existing coal storage pile at the Morgantown Generating Station. The existing coal yard facilities were constructed prior to the current environmental regulations, and it became necessary to upgrade the storage facilities to be environmentally friendly. The project team had two objectives in this project: (1) prevent coal pile leachate from entering the groundwatermore » system; (2) test the viability of using coal ash by-products as an aggregate substitute for concrete applications. Both objectives were met, and two additional benefits were achieved as well: (1) the use of coal ash by-products as a coal liner produced significant cost savings to the project directly; (2) the use of coal ash by-products reduced plant operation and maintenance expenses.« less

Effect of unground oil palm ash as mixing ingredient towards properties of concrete

NASA Astrophysics Data System (ADS)

Sulaiman, M. A.; Muthusamy, K.; Mat Aris, S.; Rasid, M. H. Mohd; Paramasivam, R.; Othman, R.

2018-04-01

Malaysia being one of the world largest palm oil producers generates palm oil fuel ash (POFA), a by-product in increasing quantity. This material which usually disposed as solid waste causes pollution to the environment. Success in converting this waste material into benefitting product would reduce amount of waste disposed and contributes towards cleaner environment. This research explores the potential of unground oil palm ash being used as partial sand replacement in normal concrete production. Experimental work has been conducted to determine the workability, compressive strength and flexural strength of concrete when unground oil palm ash is added as partial sand replacement. A total of five mixes containing various percentage of oil palm ash, which are 0%, 5%, 10%, 15% and 20% have been prepared. All specimens were water cured until the testing date. The slump test, compressive strength test and flexural strength test was conducted. The findings show that mix produced using 10% of palm oil fuel ash exhibit higher compressive strength and flexural strength as compared to control specimen. Utilization of unground oil palm ash as partial sand replacement would be able to reduce dependency of construction industry on natural sand supply and also as one of the solution to reuse palm oil industry waste.

APhoRISM FP7 project: the Multi-platform volcanic Ash Cloud Estimation (MACE) infrastructure

NASA Astrophysics Data System (ADS)

Merucci, Luca; Corradini, Stefano; Bignami, Christian; Stramondo, Salvatore

2014-05-01

APHORISM is an FP7 project that aims to develop innovative products to support the management and mitigation of the volcanic and the seismic crisis. Satellite and ground measurements will be managed in a novel manner to provide new and improved products in terms of accuracy and quality of information. The Multi-platform volcanic Ash Cloud Estimation (MACE) infrastructure will exploit the complementarity between geostationary, and polar satellite sensors and ground measurements to improve the ash detection and retrieval and to fully characterize the volcanic ash clouds from source to the atmosphere. The basic idea behind the proposed method consists to manage in a novel manner, the volcanic ash retrievals at the space-time scale of typical geostationary observations using both the polar satellite estimations and in-situ measurements. The typical ash thermal infrared (TIR) retrieval will be integrated by using a wider spectral range from visible (VIS) to microwave (MW) and the ash detection will be extended also in case of cloudy atmosphere or steam plumes. All the MACE ash products will be tested on three recent eruptions representative of different eruption styles in different clear or cloudy atmospheric conditions: Eyjafjallajokull (Iceland) 2010, Grimsvotn (Iceland) 2011 and Etna (Italy) 2011-2012. The MACE infrastructure will be suitable to be implemented in the next generation of ESA Sentinels satellite missions.

Imidacloprid concentration effects on adult emerald ash borer: a greenhouse study

Treesearch

David Cappaert; Deborah G. McCullough; Therese M. Poland; Phil Lewis; John Molongoski

2008-01-01

Imidacloprid is the active ingredient of many widely used products applied to control the emerald ash borer (EAB), Agrilus planipennis Fairmaire, in valuable urban trees. Systemic treatment with imidacloprid is typically made in the spring to reduce the number of larvae that would otherwise be generated by oviposition during the summer. Substantial...

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.

Correlation between the critical viscosity and ash fusion temperatures of coal gasifier ashes

DOE PAGES

Hsieh, Peter Y.; Kwong, Kyei-Sing; Bennett, James

2015-09-27

Coal gasification yields synthesis gas, an important intermediate in chemical manufacturing. It is also vital to the production of liquid fuels through the Fischer-Tropsch process and electricity in Integrated Gasification Combined Cycle power generation. Minerals naturally present in coal become molten in entrained-flow slagging gasifiers. Molten coal ash slag penetrates and dissolves refractory bricks, leading to costly plant shutdowns. The extent of coal ash slag penetration and refractory brick dissolution depends on the slag viscosity, the gasification temperature, and the composition of slag and bricks. We measured the viscosity of several synthetic coal ash slags with a high-temperature rotary viscometermore » and their ash fusion temperatures through optical image analysis. All measurements were made in a carbon monoxide-carbon dioxide reducing atmosphere that approximates coal gasification conditions. Empirical correlation models based on ash fusion temperatures were used to calculate critical viscosity temperatures based on the coal ash compositions. These values were then compared with those obtained from thermodynamic phase-transition models. An understanding of slag viscosity as a function of ash composition is important to reducing refractory wear in slagging coal gasifiers, which would help to reduce the cost and environmental impact of coal for chemical and electricity production.« less

Correlation between the critical viscosity and ash fusion temperatures of coal gasifier ashes

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

Hsieh, Peter Y.; Kwong, Kyei-Sing; Bennett, James

Coal gasification yields synthesis gas, an important intermediate in chemical manufacturing. It is also vital to the production of liquid fuels through the Fischer-Tropsch process and electricity in Integrated Gasification Combined Cycle power generation. Minerals naturally present in coal become molten in entrained-flow slagging gasifiers. Molten coal ash slag penetrates and dissolves refractory bricks, leading to costly plant shutdowns. The extent of coal ash slag penetration and refractory brick dissolution depends on the slag viscosity, the gasification temperature, and the composition of slag and bricks. We measured the viscosity of several synthetic coal ash slags with a high-temperature rotary viscometermore » and their ash fusion temperatures through optical image analysis. All measurements were made in a carbon monoxide-carbon dioxide reducing atmosphere that approximates coal gasification conditions. Empirical correlation models based on ash fusion temperatures were used to calculate critical viscosity temperatures based on the coal ash compositions. These values were then compared with those obtained from thermodynamic phase-transition models. An understanding of slag viscosity as a function of ash composition is important to reducing refractory wear in slagging coal gasifiers, which would help to reduce the cost and environmental impact of coal for chemical and electricity production.« less

Solid Catalyst Nanoparticles derived from Oil-Palm Empty Fruit Bunches (OP-EFB) as a Renewable Catalyst for Biodiesel Production

NASA Astrophysics Data System (ADS)

Husin, H.; Asnawi, T. M.; Firdaus, A.; Husaini, H.; Ibrahim, I.; Hasfita, F.

2018-05-01

Solid nanocatalyst derived from oil-palm empty fruit bunches (OP-EFB) fiber was successfully synthesized and its application for biodiesel production was investigated. The OPEFB was treated by burning, milling and heating methods to generate ashes in a nanoparticle size. The nanoparticle palm-bunch ash was characterized by scanning electron microscopy (SEM) and x-ray diffraction (XRD). The effects of the calcination temperature and catalyst amounts for transesterification reactions were investigated. XRD analysis of palm bunch ash exhibited that the highest composition of peaks characteristic were potassium oxide (K2O). SEM analysis showed that the nano palm bunch ash have a particle size ranging of 150-400 nm. The highest conversion of palm-oil to biodiesel reach to 97.90% was observed by using of palm bunch ash nanocatalyst which heated at 600°C, 3 h reaction time and 1% catalyst amount. Reusability of palm bunch ash catalysts was also examined. It was found that of its high active sites, reusable solid catalyst was obtained by just heating of palm bunch ash. It has a capability to reduce not only the amount of catalyst consumption but also reduce the reaction time of transesterification process.

Biodegradability and methane production from secondary paper and pulp sludge: effect of fly ash and modeling.

PubMed

Huiliñir, César; Montalvo, Silvio; Guerrero, Lorna

2015-01-01

The effect of fly ash on biodegradability and methane production from secondary paper and pulp sludge, including its modeling, was evaluated. Three tests with fly ash concentrations of 0, 10 and 20 mg/L were evaluated at 32 °C. Methane production was modeled using the modified Gompertz equation. The results show that the doses used produce a statistically significant increase of accumulated methane, giving values greater than 225 mL of CH4 per gram of volatile solids (VS) added, and 135% greater than that obtained in the control assay. Biodegradability of VS increased 143% with respect to the control assays, giving values around 43%. The modified Gompertz model can describe well methane generation from residual sludge of the paper industry water treatment, with parameter values between those reported in the literature. Thus, the addition of fly ash to the process causes a significant increase of accumulated methane and VS removal, improving the biodegradability of paper and pulp sludge.

Volcanic ash as a driver of enhanced organic carbon burial in the Cretaceous.

PubMed

Lee, Cin-Ty A; Jiang, Hehe; Ronay, Elli; Minisini, Daniel; Stiles, Jackson; Neal, Matthew

2018-03-08

On greater than million year timescales, carbon in the ocean-atmosphere-biosphere system is controlled by geologic inputs of CO 2 through volcanic and metamorphic degassing. High atmospheric CO 2 and warm climates in the Cretaceous have been attributed to enhanced volcanic emissions of CO 2 through more rapid spreading at mid-ocean ridges and, in particular, to a global flare-up in continental arc volcanism. Here, we show that global flare-ups in continental arc magmatism also enhance the global flux of nutrients into the ocean through production of windblown ash. We show that up to 75% of Si, Fe and P is leached from windblown ash during and shortly after deposition, with soluble Si, Fe and P inputs from ash alone in the Cretaceous being higher than the combined input of dust and rivers today. Ash-derived nutrient inputs may have increased the efficiency of biological productivity and organic carbon preservation in the Cretaceous, possibly explaining why the carbon isotopic signature of Cretaceous seawater was high. Variations in volcanic activity, particularly continental arcs, have the potential of profoundly altering carbon cycling at the Earth's surface by increasing inputs of CO 2 and ash-borne nutrients, which together enhance biological productivity and burial of organic carbon, generating an abundance of hydrocarbon source rocks.

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.

Hydration of Hybrid Alkaline Cement Containing a Very Large Proportion of Fly Ash: A Descriptive Model

PubMed Central

Garcia-Lodeiro, Inés; Donatello, Shane; Fernández-Jiménez, Ana; Palomo, Ángel

2016-01-01

In hybrid alkaline fly ash cements, a new generation of binders, hydration, is characterized by features found in both ordinary portland cement (OPC) hydration and the alkali activation of fly ash (AAFA). Hybrid alkaline fly ash cements typically have a high fly ash (70 wt % to 80 wt %) and low clinker (20 wt % to 30 wt %) content. The clinker component favors curing at ambient temperature. A hydration mechanism is proposed based on the authors’ research on these hybrid binders over the last five years. The mechanisms for OPC hydration and FA alkaline activation are summarized by way of reference. In hybrid systems, fly ash activity is visible at very early ages, when two types of gel are formed: C–S–H from the OPC and N–A–S–H from the fly ash. In their mutual presence, these gels tend to evolve, respectively, into C–A–S–H and (N,C)–A–S–H. The use of activators with different degrees of alkalinity has a direct impact on reaction kinetics but does not modify the main final products, a mixture of C–A–S–H and (N,C)–A–S–H gels. The proportion of each gel in the mix does, however, depend on the alkalinity generated in the medium. PMID:28773728

A Relocatable Environmental Prediction System for Volcanic Ash Forecasts

NASA Astrophysics Data System (ADS)

Cook, J.; Geiszler, D.

2009-12-01

Timeliness is an essential component for any system generating volcanic ash forecasts for aviation. Timeliness implies that the steps required for estimating the concentration of volcanic ash in the atmosphere are streamlined into a process that can accurately identify the volcano’s source function, utilize atmospheric conditions to predict the movement of the volcanic ash plume, and ultimately produce a volcanic ash forecast product in a useable format for aviation interests. During the past decade, the Naval Research Laboratory (NRL) has developed a suite of software integrated with the Coupled Ocean/Atmosphere Mesoscale Prediction System (COAMPS®) that is designed with a similar automated purpose in support of the Navy’s operational (24/7) schedule and diverse mission requirements worldwide. The COAMPS-OS® (On-demand System) provides web-based interfaces to COAMPS that allows Navy users to rapidly (in a few minutes) set up and start a new forecast in response to short-fused requests. A unique capability in COAMPS unlike many regional numerical weather prediction models is the option to initialize a volcanic ash plume and use the model’s full three-dimensional atmospheric grid (e.g. winds and precipitation) to predict the movement and concentration of the plume. This paper will describe the efforts to automate volcanic ash forecasts using COAMPS-OS including the specification of the source function, initialization and configuration of COAMPS, and generation of output products for aviation. This research is in response to requirements and funding by the Federal Aviation Administration (FAA). The views expressed are those of the authors and do not necessarily represent the official policy or position of the FAA. COAMPS® and COAMPS-OS® are registered trademarks of the Naval Research Laboratory.

Fly ashes from coal and petroleum coke combustion: current and innovative potential applications.

PubMed

González, Aixa; Navia, Rodrigo; Moreno, Natalia

2009-12-01

Coal fly ashes (CFA) are generated in large amounts worldwide. Current combustion technologies allow the burning of fuels with high sulfur content such as petroleum coke, generating non-CFA, such as petroleum coke fly ash (PCFA), mainly from fluidized bed combustion processes. The disposal of CFA and PCFA fly ashes can have severe impacts in the environment such as a potential groundwater contamination by the leaching of heavy metals and/or particulate matter emissions; making it necessary to treat or reuse them. At present CFA are utilized in several applications fields such as cement and concrete production, agriculture and soil stabilization. However, their reuse is restricted by the quality parameters of the end-product or requirements defined by the production process. Therefore, secondary material markets can use a limited amount of CFA, which implies the necessity of new markets for the unused CFA. Some potential future utilization options reviewed herein are zeolite synthesis and valuable metals extraction. In comparison to CFA, PCFA are characterized by a high Ca content, suggesting a possible use as neutralizers of acid wastewaters from mining operations, opening a new potential application area for PCFA that could solve contamination problems in emergent and mining countries such as Chile. However, this potential application may be limited by PCFA heavy metals leaching, mainly V and Ni, which are present in PCFA in high concentrations.

Influence of Kaolin in Fly Ash Based Geopolymer Concrete: Destructive and Non-Destructive Testing

NASA Astrophysics Data System (ADS)

Yahya, Z.; Abdullah, M. M. A. B.; Ramli, N. Mohd; Burduhos-Nergis, D. D.; Razak, R. Abd

2018-06-01

Development of geopolymer concrete is mainly to reduce the production of ordinary Portland cement (OPC) that adverse the natural effect. Fly ash is a by-product collected from electrical generating power plant which resulted from burning pulverized coal. Since fly ash is waste materials, it can be recycled for future advantages particularly as pozzolanic materials in construction industry. This study focused on the feasibility of fly ash based geopolymer concrete to which kaolin has been added. The main constituents of geopolymer production for this study were class F fly ash, sodium silicate and sodium hydroxide (NaOH) solution. The concentration of NaOH solution was fixed at 12 Molar, ratio of fly ash/alkaline activator and sodium silicate/NaOH fixed at 1.5 and 2.5, respectively. Kaolin was added in range 5% to 15% from the mass of fly ash and all the samples were cured at room temperature. Destructive and non-destructive test were performed on geopolymer concrete to evaluate the best mix proportions that yield the highest strength as well as the quality of the concrete. Compressive strength, flexural strength, rebound hammer and ultrasonic pulse velocity (UPV) result have been obtained. It shown that 5% replacement of kaolin contributed to maximum compressive strength and flexural strength of 40.4 MPa and 12.35 MPa at 28 days. These result was supported by non-destructive test for the same mix proportion.

Utilization of fly ash as partial sand replacement in oil palm shell lightweight aggregate concrete

NASA Astrophysics Data System (ADS)

Nazrin Akmal, A. Z. Muhammad; Muthusamy, K.; Mat Yahaya, F.; Hanafi, H. Mohd; Nur Azzimah, Z.

2017-11-01

Realization on the increasing demand for river sand supply in construction sector has inspired the current research to find alternative material to reduce the use of natural sand in oil palm shell lightweight aggregate concrete (OPS LWAC) production. The existence of fly ash, a by-product generated from coal power plant, which pose negative impact to the environment when it is disposed as waste, were used in this research. The effect of fly ash content as partial sand replacement towards workability and compressive strength of OPS lightweight aggregate concrete were investigated. Four concrete mixes containing various percentage of fly ash that are 0%, 10%, 20% and 30% by weight of sand were used in the experimental work. All mixes were cast in form of cubes before subjected to water curing until the testing age. Compressive strength test were conducted at 1, 3, 7 and 28 days. The finding shows that the workability of the OPS LWAC decreases when more fly ash are used as sand replacement. It was found that adding of 10% fly ash as sand replacement content resulted in better compressive strength of OPS LWAC, which is higher than the control mix.

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.

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

Conversion of Army Heating Plants to Coal: Three Case Studies

DTIC Science & Technology

1982-03-01

compared to the 50% wet sludge flue gas desulfurized product. All fly ash produced is collected without further processing. The product can be used to...Existing Turbine Generators 26 11 Picatinny Arsenal -- Summary of Capital Costs for Stoker Boilers, Flue Gas Desulfurization . New Turbine Generators...27 12 Picatinny Arsenal -- Summary of Operating Costs for Stoker Boilers, Flue Gas Desulfurization . New Turbine Generators 28 13 Picatinny Arsenal

Production of a bioflocculant from Pseudomonas veronii L918 using the hydrolyzate of peanut hull and its application in the treatment of ash-flushing wastewater generated from coal fired power plant.

PubMed

Liu, Weijie; Hao, Yan; Jiang, Jihong; Zhu, Aihua; Zhu, Jingrong; Dong, Zhen

2016-10-01

In this study, bioflocculant produced by Pseudomonas veronii L918 was applied to treat ash-flushing wastewater. The strain L918 could convert the hydrolyzate of peanut hull into bioflocculant, which can effectively reduce the production cost of bioflocculant. The yield of 3.39g/L bioflocculant MBF-L918 was achieved when 300mL/L peanut hull hydrolyzate was used as carbon source. The bioflocculant MBF-L918 contains 77.14% polysaccharides and 4.84% proteins, and the molecular weight (MW) of MBF-L918 is 24.77kDa. Furthermore, MBF-L918 showed good flocculating efficiency of 92.51% to ash-flushing wastewater when 2.83mg/L MBF-L918 was added, and thus achieved the recycling of ash-flushing wastewater. This study reported for the first time that the bioflocculant was produced using peanut hull hydrolyzate and effectively applied in the treatment of coal ash-flushing wastewater. Copyright © 2016 Elsevier Ltd. All rights reserved.

Effect of fly ash content towards Sulphate resistance of oil palm shell lightweight aggregate concrete

NASA Astrophysics Data System (ADS)

Muthusamy, K.; Fadzil, M. Y.; Nazrin Akmal, A. Z. Muhammad; Ahmad, S. Wan; Nur Azzimah, Z.; Hanafi, H. Mohd; Mohamad Hafizuddin, R.

2018-04-01

Both oil palm shell (OPS) and fly ash are by-product generated from the industries. Disposal of these by-product as wastes cause negative impact to the environment. The use of both oil palm shell and fly ash in concrete is seen as an economical solution for making green and denser concrete. The primary aim of this research is to determine the effects of FA utilization as sand replacement in oil palm shell lightweight aggregate concrete (OPS LWAC) towards sulphate resistance. Five concrete mixes containing fly ash as sand replacement namely 0%, 10%, 20%, 30% and 40% were prepared in these experimental work. All mixes were cast in form of cubes before subjected to sulphate solution for the period of 5 months. It was found that addition of 10% fly ash as sand replacement content resulted in better sulphate resistance of OPS LWAC. The occurrence of pozzolanic reaction due to the presence of FA in concrete has consumed the vulnerable Calcium hydroxide to be secondary C-S-H gel making the concrete denser and more durable.

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.

Fly ash carbon burn-out at TVA`s Colbert and Shawnee Stations: Site specific application study. Final report

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

Cochran, J.W.; Kirkconnell, S.F.

1996-04-01

Many power plants, particularly after conversion to low-NOx burners, produce fly ash that is too high in carbon content to be successfully marketed as a concrete admixture. Fly ash beneficiation using Carbon Burn-Out (CBO) technology offers the opportunity to market fly ash that was previously landfilled. This site application study of beneficiating pulverized coal boiler fly ash at Tennessee Valley Authority`s Colbert and Shawnee Stations indicates this process is a cost effective solution for decreasing solid waste disposal, increasing landfill life, improving boiler heat rate, and generating a positive revenue stream. Results indicate that the Colbert Station has the flymore » ash market, site integration potential, and positive economics to support construction and operation of a CBO plant with an annual production rate of approximately 150,000 tons. As the market for fly ash increases, this capacity may be expanded to handle the majority of fly ash generated at Colbert. Results of the Shawnee Station analysis indicate that site integration constraints combined with the lack of near term local area fly ash market growth do not support construction and operation of a CBO plant. CBO commercial process design work in developing a generic commercial design resulted in a major improvement to the heat recovery portion of the process. This development resulted in the elimination of five major equipment items, with a corresponding reduction in plant complexity and costs. The design change is now considered part of the commercial offering.« less

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.

Residues from the thermal conversion of waste from the meat industry as a source of valuable macro- and micronutrients.

PubMed

Staroń, Paweł; Kowalski, Zygmunt; Staroń, Anita; Seidlerová, Jana; Banach, Marcin

2016-03-01

The increased consumption of meat (including poultry) observed over the last decade has led to the intensification of its production. With the production increase, the amount of generated waste also increases. Appropriate disposal of waste from the meat industry will significantly reduce the amount of such waste and its negative impact on the environment. The paper presents a method for the thermal neutralisation of feathers, poultry litter and meat and bone meal (MBM). Waste incineration was carried out in a stationary electric furnace, at a temperature varying in the range of 600-900°C. The resulting ashes were characterised by a high percentage of phosphorus (30-170 g/kg ash), calcium (20-360 g/kg ash) and other valuable macro- and micronutrients like copper, iron, manganese and zinc. The ashes produced during the thermal treatment are safe in terms of sanitary and can be used as additives enriching the fertilisers and soil improvers. Copyright © 2016 Elsevier Ltd. All rights reserved.

A pilot study of mercury liberation and capture from coal-fired power plant fly ash.

PubMed

Li, Jin; Gao, Xiaobing; Goeckner, Bryna; Kollakowsky, Dave; Ramme, Bruce

2005-03-01

The coal-fired electric utility generation industry has been identified as the largest anthropogenic source of mercury (Hg) emissions in the United States. One of the promising techniques for Hg removal from flue gas is activated carbon injection (ACI). The aim of this project was to liberate Hg bound to fly ash and activated carbon after ACI and provide high-quality coal combustion products for use in construction materials. Both bench- and pilot-scale tests were conducted to liberate Hg using a thermal desorption process. The results indicated that up to 90% of the Hg could be liberated from the fly ash or fly-ash-and-activated-carbon mixture using a pilot-scale apparatus (air slide) at 538 degrees C with a very short retention time (less than 1 min). Scanning electron microscope (SEM) evaluation indicated no significant change in fly ash carbon particle morphology following the thermal treatment. Fly ash particles collected in the baghouse of the pilot-scale apparatus were smaller in size than those collected at the exit of the air slide. A similar trend was observed in carbon particles separated from the fly ash using froth flotation. The results of this study suggest a means for power plants to reduce the level of Hg in coal-combustion products and potentially recycle activated carbon while maintaining the resale value of fly ash. This technology is in the process of being patented.

Cesium distribution and phases in proxy experiments on the incineration of radioactively contaminated waste from the Fukushima area.

PubMed

Saffarzadeh, Amirhomayoun; Shimaoka, Takayuki; Kakuta, Yoshitada; Kawano, Takashi

2014-10-01

After the March 11, 2011 Tohoku earthquake and Fukushima I Nuclear Power Plant accident, incineration was initially adopted as an effective technique for the treatment of post-disaster wastes. Accordingly, considerable amounts of radioactively contaminated residues were immediately generated through incineration. The level of radioactivity associated with radiocesium in the incineration ash residues (bottom ash and fly ash) became significantly high (several thousand to 100,000 Bq/kg) as a result of this treatment. In order to understand the modes of occurrence of radiocesium, bottom ash products were synthesized through combusting of refuse-derived fuel (RDF) with stable Cs salts in a pilot incinerator. Microscopic and microanalytical (SEM-EDX) techniques were applied and the following Cs categories were identified: low and high concentrations in the matrix glass, low-level partitioning into some newly-formed silicate minerals, partitioning into metal-sulfide compounds, and occurring in newly-formed Cs-rich minerals. These categories that are essentially silicate-bound are the most dominant forms in large and medium size bottom ash particles. It is expected that these achievements provide solutions to the immobilization of radiocesium in the incineration ash products contaminated by Fukushima nuclear accident. Copyright © 2014 Elsevier Ltd. All rights reserved.

Valorization of lignite combustion residues and ferroalumina in the production of aggregates.

PubMed

Anagnostopoulos, I M; Stivanakis, V E; Angelopoulos, G N; Papamantellos, D C

2010-02-15

The present research study investigates the synergy of industrial solid by-products from lignite combustion (fly ash and bottom ash) and aluminum production (ferroalumina) in the production of lightweight aggregates (LWA). The process consists of two stages, pelletization and sintering. Bottom ash (BA) is used as the principal raw material in mixtures while ferroalumina (FAL) is added in lower percentages (5-30 wt%). BA carbon content is used as the fuel of sintering process in high temperatures, around 1250 degrees C, and gas generation is responsible for porous structure formation. Physical properties such as porosity, water absorption and bulk density, of sintering products are measured. Increase of FAL percentage in sintering mixtures results in decrease of porosity from 61% to 35% and of water absorption from 61% to 21% and in increase of bulk density from 1.02 g/cm(3) to 1.80 g/cm(3) of the produced aggregates. Aggregates produced by FAL addition up to 20 wt% are characterized as LWA. Aggregates formed are used in the production of concrete specimens. Compressive strength of concrete increases by increasing FAL addition in aggregates from 5 wt% to 15 wt% (highest strength value), while decrease by increasing FAL addition from 20 wt% to 30 wt%. FAL addition in lignite ashes sintering mixtures (up to 15 wt%) is considered as an important parameter for enhancing aggregates strength.

Coal combustion products

USGS Publications Warehouse

Kalyoncu, R.S.; Olson, D.W.

2001-01-01

Coal-burning powerplants, which supply more than half of U.S. electricity, also generate coal combustion products, which can be both a resource and a disposal problem. The U.S. Geological Survey collaborates with the American Coal Ash Association in preparing its annual report on coal combustion products. This Fact Sheet answers questions about present and potential uses of coal combustion products.

Volcanic ash aggregation in the lab - can we mimic natural processes?

NASA Astrophysics Data System (ADS)

Mueller, Sebastian B.; Kueppers, Ulrich; Jacob, Michael; Ayris, Paul; Cimarelli, Corrado; Dingwell, Donald B.; Guttzeit, Melanie; Hess, Kai-Uwe; Walter, Ulrich

2015-04-01

Explosive volcanic eruptions release large amounts of particles into the atmosphere. Volcanic ash, by definition pyroclasts smaller than 2 mm, can be distributed around the globe by prevailing winds. Ash poses hazards to aviation industry by melting in jet turbines, to human health by entering respiration systems and to society by damaging infrastructure. Under certain circumstances, ash particles can cluster together and build ash aggregates. Aggregates range in size from few mm to few cm and may exhibit complex internal stratigraphy. During growth, weight, density and aerodynamic properties change, leading to a significantly different settling behavior compared to individual ash particles. Although ash aggregation has been frequently observed in the geologic record, the physical and chemical mechanisms generating the aggregates remain poorly understood. During several field campaigns, we collected numerous ash aggregates and analyzed their textural, chemical and mechanical properties. Based on this knowledge, we have designed experiments using the ProCell Lab System® of Glatt Ingenieurtechnik GmbH, Germany. In this device, a continuous fluidized bed can be applied on solid particles and simulate gas-particle flow conditions as they would be expected in volcanic plumes or pyroclastic density currents. The geological record and direct observations have shown that both processes are capable of producing ash aggregates. As starting material we used Na-glass beads as an analogue and volcanic ash from Laacher See Volcano, Eifel Volcanic Field, Germany. We define parameters such as grainsize, specific surface area and concentration of the starting material, degree of turbulence, temperature and moisture in the process chamber and the composition of the liquid phase to influence form, size, stability and production rate of aggregates. We were able to experimentally produce round, unstructured ash pellets up to 5mm in diameter. A detailed textural description highlights the strongly different properties of single ash grains and ash aggregates. These experiments aim at experimentally constraining the boundary conditions required for the generation of strong ash aggregates. A better mechanistic understanding will serve for more adequate ash mass distribution modeling.

Exploration of using stripped ammonia and ash from poultry litter for the cultivation of the cyanobacterium Arthrospira platensis and the green microalga Chlorella vulgaris.

PubMed

Markou, Giorgos; Iconomou, Dimitris; Sotiroudis, Theodore; Israilides, Cleanthes; Muylaert, Koenraad

2015-11-01

Herein a new approach of exploiting poultry litter (PL) is demonstrated. The suggested method includes drying of PL with simultaneously striping and recovery of ammonia, followed by the direct combustion of dried PL. The generated ash after the combustion, and the striped ammonia consequently, could be used as nutrient source for the cultivation of microalgae or cyanobacteria to produce feed additives. The present study explored the application of PL ash and recovered ammonia for the cultivation of Arthrospira platensis and Chlorella vulgaris. For a simultaneously 90% dissolution of ash potassium and phosphorus, a ratio of acid to ash of 0.02mol-H(+)/g was required. The optimum mass of ash required was 0.07-0.08g/g dry biomass, while the addition of ammoniac nitrogen of 8-9mgN per g of dry biomass per day was adequate for a satisfactory production of A. platensis and C. vulgaris. Copyright © 2015 Elsevier Ltd. All rights reserved.

Fundamental study of ash formation and deposition: Effect of reducing stoichiometry. Final report, April 1, 1993--June 30, 1995

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

Bool, L.E. III; Helble, J.J.; Shah, N.

1995-09-01

The technical objectives of this project are: (1) To identify the partitioning of inorganic coal constituents among vapor, submicron fume, and fly ash products generated during the combustion of pulverized coal under a variety of combustion conditions. Fuel lean and fuel rich combustion conditions are considered. (2) To identify and quantify the fundamental processes by which the transformations of minerals and organically-associated inorganic species occur. Emphasis is placed on identifying any changes that occur as a result of combustion under sub-stoichiometric combustion conditions. (3) To incorporate the effects of combustion stoichiometry into an Engineering Model for Ash Formation.

Potassic zeolites from Brazilian coal ash for use as a fertilizer in agriculture.

PubMed

Flores, Camila Gomes; Schneider, Helena; Marcilio, Nilson Romeu; Ferret, Lizete; Oliveira, João Carlos Pinto

2017-12-01

Brazilian coal has an ash content ranging from 30 to 50% by weight. Consequently, its use in coal-fired thermoelectric for power production generates a lot of waste. The construction sector is the largest consumer of coal ash, but it cannot absorb the entire amount generated. Thus, other applications for coal ash should be studied in aim to optimize the use of this industrial waste. This research had as focus to synthesize potassic zeolite from of the coal ash into on potassium fertilizer for the grown wheat plant. In this work, it was used a subbituminous coal from Mina do Leão (RS, Brazil) presenting 48.7% ash content on a dry basis. Concerning the synthesis of potassic zeolite, it was adopted the conventional method of hydrothermal treatment with potassium hydroxide. A schedule of experiments was conducted in order to define the optimum condition of zeolite synthesis that was then used an alkaline solution of 5M KOH with a reaction time of 24h at 150°C. According to this procedure, it was obtained a zeolite with a single crystalline phase, identified through X-ray diffraction as Merlinoite. Subsequently, it was performed a set of tests using potassic zeolite asa fertilizer for plants in a greenhouse. The synthesized potassic zeolite showed a good potential for its use as fertilizer in agriculture. Copyright © 2017 Elsevier Ltd. All rights reserved.

Biomass ashes from pyrolytic wood liquefaction as novel soil amendments

NASA Astrophysics Data System (ADS)

Fernández-Delgado Juárez, Marina; Gómez Brandón, María; Mazzier, Thomas; Schönegger, Deborah; Hermanns, Roy; Leijenhorst, Evert; Insam, Heribert

2017-04-01

What happens when an old soil amendment is in fact a new one? Traditionally, ashes from biomass combustion were considered as a valuable resource, and widely used as an agricultural soil amendment. However, in recent decades we have been reluctant to apply them to soils, despite the increase in the production of combustion ashes resulting from the development of new fuels derived from biomass residues. The production of Fast Pyrolysis Bio Oil (FPBO) out of various lignocellulosic biomass streams is one of the newest technologies for gaining a liquid biofuel that can be seen as a future substitute for mineral oils. During the pyrolysis process, the by-products (charcoal and low calorific gases) are combusted to generate energy, resulting in the production of ashes that contain the majority of the minerals and salts originally present in the feedstock. The main objective of the present work is to investigate if the recovered ashes from the pyrolysis process can be used as a soil amendment. A greenhouse trial was set up in order to evaluate the impact of the ashes on an acid grassland soil (eutric Cambisol) from the region of Tyrol (Austria). A two-level experimental design (ash treatment, and plant effect) was set up. The ashes were mixed with the soil columns at a ratio of 1% (w:w, fresh weight). A control treatment that consisted of soil without the addition of ashes was also included. Moreover, to understand the effect that the ashes would have on crop growth, ten seeds of a traditional wheat variety (Tiroler Früher Dinkel; Triticum aestivum subsp. spelta), were placed in half of the columns with and without ashes, so as to determine the seed germination index and plant growth. Moreover, specific microbial groups related to N cycle were quantified by real-time PCR. A total of 24 experimental units (2 ash treatments x 2 incubation times x 2 plant levels x 3 replicates) were analysed. After an equilibration period of 24 h at 4 °C (referred as time zero), the columns were arranged in a completely randomized design and destructively sampled after 60 and 100 days. The amendment with ashes induced a soil pH increase of almost 2 units over time and independent of the crop presence. Moreover, ash addition did also increase soil plant available P and dissolved organic carbon content; however, it also increased nitrogen loss to the soil eluates compared to the control. On the other hand, the presence of ashes enhanced both plant growth and grain yield after 60 and 100 days. Similar effects have been observed when "traditional" biomass ashes have been applied to agricultural soils, leading us to conclude that ashes derived from FPBO process might be used for agricultural purposes. The Residue2Heat project has received funding from the European Union's Horizon 2020 Research and Innovation programme under Grant Agreement No. 654650.

Sustainability Impact Assessment of two forest-based bioenergy production systems related to mitigation and adaption to Climate Change

NASA Astrophysics Data System (ADS)

Gartzia-Bengoetxea, Nahia; Arias-González, Ander; Tuomasjukka, Diana

2016-04-01

New forest management strategies are necessary to resist and adapt to Climate Change (CC) and to maintain ecosystem functions such as forest productivity, water storage and biomass production. The increased use of forest-based biomass for energy generation as well as the application of combustion or pyrolysis co-products such as ash or biochar back into forest soils is being suggested as a CC mitigation and adaptation strategy while trying to fulfil the targets of both: (i) Europe 2020 growth strategy in relation to CC and energy sustainability and (ii) EU Action Plan for the Circular Economy. The energy stored in harvested biomass can be released through combustion and used for energy generation to enable national energy security (reduced oil dependence) and the substitution of fossil fuel by renewable biomass can decrease the emission of greenhouse gases.In the end, the wood-ash produced in the process can return to the forest soil to replace the nutrients exported by harvesting. Another way to use biomass in this green circular framework is to pyrolyse it. Pyrolysis of the biomass produce a carbon-rich product (biochar) that can increase carbon sequestration in the soils and liquid and gas co-products of biomass pyrolysis can be used for energy generation or other fuel use thereby offsetting fossil fuel consumption and so avoiding greenhouse gas emissions. Both biomass based energy systems differ in the amount of energy produced, in the co-product (biochar or wood ash) returned to the field, and in societal impacts they have. The Tool for Sustainability Impact Assessment (ToSIA) was used for modelling both energy production systems. ToSIA integrates several different methods, and allows a quantification and objective comparison of economic, environmental and social impacts in a sustainability impact assessment for different decision alternatives/scenarios. We will interpret the results in order to support the bioenergy planning in temperate forests under the light of its implications for different policy aims and concerns.

Issuance of Volcanic Ash Advisories: Washington VAAC Perspective

NASA Astrophysics Data System (ADS)

Salemi, A.; Ruminski, M. G.

2011-12-01

In the event of a volcanic eruption, one of the nine Volcanic Ash Advisory Centers (VAAC) across the globe is responsible for issuing a Volcanic Ash Advisory (VAA). The VAA contains information about which volcano is erupting, the volcanoes location, as well as the time and duration of the eruption. If ash is observed in satellite imagery, a 6, 12 and 18 hour forecast are provided to specify the possible location of ash. The goal of the VAA is to help airlines create accurate flight guidance for their aircraft. The priority of each VAAC is to prevent aircraft from flying through ash with a secondary priority of minimizing unnecessary diversions. Remote sensing platforms provide a unique perspective for volcanic ash detection especially in the cases of remote and unmonitored volcanoes. This includes monitoring of multispectral satellite imagery (Visible, Infrared) from both geostationary and polar orbiting platforms as well as derived products such as SO2, Volcanic Ash Masks/Loading and LIDAR data. To generate the VAA, satellite analysts use the satellite imagery in combination with observations from local Meteorological Watch Offices (MWO), Volcano Observatories, Pilot Reports (PIREP), seismic stations, web cameras and meteorological forecast grids. Challenges arise in regard to availability of data for each individual volcano, reliability of model wind fields over data sparse regions, as well as timeliness and availability of satellite imagery and products. These challenges become further exacerbated when volcanic ash crosses VAAC and MWO boundaries and interagency communication becomes essential. While working through multi-lingual communications and operational variation (e.g. data availability, standard operation procedures), VAACs face the challenge of maintaining coordination and avoiding the pitfalls of break downs in communication and guidance confusion. This talk will discuss these issues and pose potential communication and coordination efforts from the Washington VAAC perspective.

Studies of corona and back discharges in carbon dioxide

NASA Astrophysics Data System (ADS)

Czech, Tadeusz; Sobczyk, Arkadiusz Tomasz; Jaworek, Anatol; Krupa, Andrzej; Rajch, Eryk

2013-01-01

Results of spectroscopic investigations and current-voltage characteristics of corona and back discharges generated in point-plane electrode geometry in CO2 at atmospheric pressure for positive and negative polarity of the discharge electrode are presented in the paper. Three forms of back discharge, for both polarities, were investigated: glow, streamer and low-current back-arc. To generate the back-discharges for the conditions similar to electrostatic precipitator, the plate electrode was covered with fly ash layer. In order to characterize back discharge processes, the emission spectra were measured and compared with those obtained for normal discharge, generated in the same electrode configuration but without the fly ash layer on the plate electrode. The measurements have shown that optical emission spectral lines of atoms and molecules, excited or ionised in back discharge, depend on the forms of the discharge, the discharge current, and are different in the zones close to needle electrode and fly ash layer. From the comparison of spectral lines of back and normal discharges, an effect of fly ash layer on discharge characteristics and morphology has been determined. In normal corona, the emission spectra are mainly predetermined by the working gas components, but in the case of back discharge, the atomic and molecular lines, resulting from chemical composition of fly ash, are also identified. Differences in the spectra of back discharge for positive and negative polarities of the needle electrode have been explained by considering the kind of ions generated in the crater in fly ash layer. For back arc, the emission of spectral lines of atoms and molecules from fly ash layer can be recorded in the crater zone, but in the needle zone, only the emission lines of CO2 and its decomposition products (CO and C2) can be noticed. The studies of back discharge in CO2, as one of the main components of flue gases, were undertaken because this type of discharge, after unwanted inception, decreases the energy and collection efficiencies of electrostatic precipitator. The second reason behind these studies is that CO2 is the main component of flue gas leaving oxyfuel boiler that re-circulates in the combustion-precipitation cycle. It was shown that discharges in CO2 lead to contamination of discharge electrode with carbonaceous products that can cause severe maintenance problems of electrostatic precipitator. The recognition of the characteristics of electrostatic precipitator operating in the oxyfuel system is, therefore, of crucial importance for exhaust gas cleaning in modern combustion systems.

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.

Alkaline bioleaching of municipal solid waste incineration fly ash by autochthonous extremophiles.

PubMed

Ramanathan, Thulasya; Ting, Yen-Peng

2016-10-01

The increasing demand for energy and the generation of solid waste have caused an alarming rise in fly ash production globally. Since heavy metals continue to be in demand for the production of materials, resource recovery from the recycling of these wastes has the potential to delay the depletion of natural ores. The use of microorganisms for the leaching of metals, in a process called bioleaching, is an eco-friendly and economical way to treat the metal-laden wastes. Bioleaching of fly ash is challenging due largely to the alkaline nature and toxic levels of heavy metals which are detrimental to microbial growth and bioleaching activity. The present work reports the isolation of indigenous bacteria from a local landfill site and their bioleaching performance [corrected]. 38 autochthonous strains of bacteria were isolated from eight samples collected and plated on five different media. 18 of the isolates showed bioleaching potential, with significant alkaline pH or fly ash tolerance. Genetic characterization of the strains revealed a dominance of Firmicutes, with Alkalibacterium sp. TRTYP6 showing highest fly ash tolerance of up to 20% w/v fly ash, and growth over a pH range 8-12.5. The organism selectively recovered about 52% Cu from the waste. To the best of our knowledge, this is the first time a study on bioleaching with extreme alkaliphiles is reported. Copyright © 2016 Elsevier Ltd. All rights reserved.

Production of MHD fluid

DOEpatents

Lacey, James J.; Kurtzrock, Roy C.; Bienstock, Daniel

1976-08-24

A hot gaseous fluid of low ash content, suitable for use in open-cycle MHD (magnetohydrodynamic) power generation, is produced by means of a three-stage process comprising (1) partial combustion of a fossil fuel to produce a hot gaseous product comprising CO.sub.2 CO, and H.sub.2 O, (2) reformation of the gaseous product from stage (1) by means of a fluidized char bed, whereby CO.sub.2 and H.sub.2 O are converted to CO and H.sub.2, and (3) combustion of CO and H.sub.2 from stage (2) to produce a low ash-content fluid (flue gas) comprising CO.sub.2 and H.sub.2 O and having a temperature of about 4000.degree. to 5000.degree.F.

Ash cap influences on site productivity and fertilizer response in forests of the Inland Northwest

Treesearch

Mariann T. Garrison-Johnston; Peter G. Mika; Dan L. Miller; Phil Cannon; Leonard R. Johnson

2007-01-01

Data from 139 research sites throughout the Inland Northwest were analyzed for effects of ash cap on site productivity, nutrient availability and fertilization response. Stand productivity and nitrogen (N) fertilizer response were greater on sites with ash cap than on sites without. Where ash was present, depth of ash had no effect on site productivity or N fertilizer...

Uptake of ¹³⁷Cs by berries, mushrooms and needles of Scots pine in peatland forests after wood ash application.

PubMed

Vetikko, Virve; Rantavaara, Aino; Moilanen, Mikko

2010-12-01

Increasing use of wood fuels for energy production in Finland since the 1990s implies that large quantities of the generated ashes will be available for forest fertilization. The aim of this study was to analyse the effect of wood ash application on ¹³⁷Cs activity concentrations in Scots pine (Pinus sylvestris L.) needles and certain berries and mushrooms on drained peatlands. The study was based on field experiments carried out on two mires in Finland in 1997-1998. Two different types of wood ash were applied at dosages of 3500, 3700, 10 500 and 11 100 kg ha⁻¹. Wood ash did not increase ¹³⁷Cs activity concentration in plants in the second growing season following application. On the contrary, a decrease in ¹³⁷Cs activity concentration was seen in the plants of the ecosystem on drained peatlands. This result is of importance, for instance, when recycling of ash is being planned. Copyright © 2010 Elsevier Ltd. All rights reserved.

Nanominerals and nanoparticles in feed coal and bottom ash: implications for human health effects.

PubMed

Silva, Luis F O; da Boit, Kátia M

2011-03-01

Environmental and human health risk assessments of nanoparticle effects from coal and bottom ash require thorough characterisation of nanoparticles and their aggregates. In this manuscript, we expand the study of human exposure to nanosized particles from coal combustion sources (typically <100 nm in size), characterising the complex micromineralogy of these airborne combustion-derived nanomaterials. Our study focuses on bottom ash generated in the Santa Catarina power station (Brazil) which uses coal enriched in ashes, many potential elements (e.g. Cr and Ni) and pyrite. Transmission electron microscope data reveal nanoscale C deposits juxtaposed with and overgrown by slightly larger aluminosilicate (Al-Si) glassy spheres, oxides, silicates, carbonated, phosphates and sulphates. Iron oxides (mainly hematite and magnetite) are the main bottom ash products of the oxidation of pyrite, sometimes via intermediate pyrrhotite formation. The presence of iron oxide nanocrystals mixed with silicate glass particles emphasises the complexity of coal and bottom ash micromineralogy. Given the potentially bioreactive nature of such transition metal-bearing materials, there is likely to be an increased health risk associated with their inhalation.

Chemical composition of biomass generated in the guava tree pruning

PubMed Central

Camarena-Tello, Julio César; Rocha-Guzmán, Nuria Elizabeth; Gallegos-Infante, José Alberto; González-Laredo, Rubén Francisco; Pedraza-Bucio, Fabiola Eugenia; López-Albarrán, Pablo; Herrera-Bucio, Rafael; Rutiaga-Quiñones, José Guadalupe

2015-01-01

Psidium guajava L. (Myrtaceae) is a native plant of Central America and is now widely cultivated in many tropical regions of the world for the fruit production. In Mexico, in the guava orchards common practices to control fruit production are: water stress, defoliation and pruning. In this study, we report the chemical composition of the biomass (branches and leaves) generated in the pruning practices. The results ranged as follows: pH (4.98-5.88), soda solubility (39.01-70.49 %), ash (1.87-8.20 %); potassium and calcium were the major inorganic elements in ash. No heavy metals were detected in the studied samples; total solubility (15.21-46.60 %), Runkel lignin (17.77-35.26 %), holocellulose (26.56 -69.49 %), α-cellulose (15.53-35.36 %), hemicelluloses (11.02-34.12 %), tannins in aqueous extracts (3.81-9.06 %), and tannins in ethanolic extracts (3.42-15.24 %). PMID:26417359

Chemical composition of biomass generated in the guava tree pruning.

PubMed

Camarena-Tello, Julio César; Rocha-Guzmán, Nuria Elizabeth; Gallegos-Infante, José Alberto; González-Laredo, Rubén Francisco; Pedraza-Bucio, Fabiola Eugenia; López-Albarrán, Pablo; Herrera-Bucio, Rafael; Rutiaga-Quiñones, José Guadalupe

2015-01-01

Psidium guajava L. (Myrtaceae) is a native plant of Central America and is now widely cultivated in many tropical regions of the world for the fruit production. In Mexico, in the guava orchards common practices to control fruit production are: water stress, defoliation and pruning. In this study, we report the chemical composition of the biomass (branches and leaves) generated in the pruning practices. The results ranged as follows: pH (4.98-5.88), soda solubility (39.01-70.49 %), ash (1.87-8.20 %); potassium and calcium were the major inorganic elements in ash. No heavy metals were detected in the studied samples; total solubility (15.21-46.60 %), Runkel lignin (17.77-35.26 %), holocellulose (26.56 -69.49 %), α-cellulose (15.53-35.36 %), hemicelluloses (11.02-34.12 %), tannins in aqueous extracts (3.81-9.06 %), and tannins in ethanolic extracts (3.42-15.24 %).

The Effect of an Ultrasound Radiation on the Synthesis of 4A Zeolite from Fly Ash

NASA Astrophysics Data System (ADS)

Susanto, H.; Imani, N. A. C.; Aslamiyah, N. R.; Istirokhatun, T.; Robbani, M. H.

2018-05-01

The use of coal as a fuel source generates a lot of solid waste fly ash. Thus, efforts to reduce or utilize the amount of fly ash are urgently needed. This paper presents zeolite synthesis from fly ash. The fly ash was activated by using NaOH solution prior to fusing process with a weight ratio of 1:2 and mixing with distilled water at a weight ratio of 1:5. Thereafter, the addition of alumina with a concentration of 0.71 %, 1.42 %, 2.12 %, and 2.8 % w/v was performed. The effects of heating and ultrasound radiation on the characteristic of zeolite products were investigated. The results showed that the addition of alumina 2.8 % w/v resulted in the Si/Al ratio of zeolite 4A is ∼1. SEM images demonstrated that the presence of ultrasound wave resulted in crystals structure morphology as also supported by XRD characterization. The average crystal size for the ultrasonic treatment was 42.46 nm.

Properties of ceramics prepared using dry discharged waste to energy bottom ash dust.

PubMed

Bourtsalas, Athanasios; Vandeperre, Luc; Grimes, Sue; Themelis, Nicolas; Koralewska, Ralf; Cheeseman, Chris

2015-09-01

The fine dust of incinerator bottom ash generated from dry discharge systems can be transformed into an inert material suitable for the production of hard, dense ceramics. Processing involves the addition of glass, ball milling and calcining to remove volatile components from the incinerator bottom ash. This transforms the major crystalline phases present in fine incinerator bottom ash dust from quartz (SiO(2)), calcite (CaCO(3)), gehlenite (Ca(2)Al(2)SiO(7)) and hematite (Fe(2)O(3)), to the pyroxene group minerals diopside (CaMgSi(2)O(6)), clinoenstatite (MgSi(2)O(6)), wollastonite (CaSiO(3)) together with some albite (NaAlSi(3)O(8)) and andradite (Ca(3)Fe(2)Si(3)O(12)). Processed powders show minimal leaching and can be pressed and sintered to form dense (>2.5 g cm(-3)), hard ceramics that exhibit low firing shrinkage (<7%) and zero water absorption. The research demonstrates the potential to beneficially up-cycle the fine incinerator bottom ash dust from dry discharge technology into a raw material suitable for the production of ceramic tiles that have potential for use in a range of industrial applications. © The Author(s) 2015.

Wood ash amendment to biogas reactors as an alternative to landfilling? A preliminary study on changes in process chemistry and biology.

PubMed

Podmirseg, Sabine M; Seewald, Martin S A; Knapp, Brigitte A; Bouzid, Ourdia; Biderre-Petit, Corinne; Peyret, Pierre; Insam, Heribert

2013-08-01

Wood ash addition to biogas plants represents an alternative to commonly used landfilling by improving the reactor performance, raising the pH and alleviating potential limits of trace elements. This study is the first on the effects of wood ash on reactor conditions and microbial communities in cattle slurry-based biogas reactors. General process parameters [temperature, pH, electrical conductivity, ammonia, volatile fatty acids, carbon/nitrogen (C/N), total solids (TS), volatile solids, and gas quantity and quality] were monitored along with molecular analyses of methanogens by polymerase chain reaction- denaturing gradient gel electrophoresis and modern microarrays (archaea and bacteria). A prompt pH rise was observed, as was an increase in C/N ratio and volatile fatty acids. Biogas production was inhibited, but recovered to even higher production rates and methane concentration after single amendment. High sulphur levels in the wood ash generated hydrogen sulphide and potentially hampered methanogenesis. Methanosarcina was the most dominant methanogen in all reactors; however, diversity was higher in ash-amended reactors. Bacterial groups like Firmicutes, Proteobacteria and Acidobacteria were favoured, which could improve the hydrolytic efficiency of the reactors. We recommend constant monitoring of the chemical composition of the used wood ash and suggest that ash amendment is adequate if added to the substrate at a rate low enough to allow adaptation of the microbiota (e.g. 0.25 g g(-1) TS). It could further help to enrich digestate with important nutrients, for example phosphorus, calcium and magnesium, but further experiments are required for the evaluation of wood ash concentrations that are tolerable for anaerobic digestion.

Design and evaluation of high-volume fly ash (HVFA) concrete mixes.

DOT National Transportation Integrated Search

2012-10-01

Concrete is the worlds most consumed man-made material. Unfortunately, the production of portland cement, the active ingredient in concrete, generates a significant amount of carbon dioxide. For each pound of cement produced, approximately one pou...

Design and evaluation of high-volume fly ash (HVFA) concrete mixes.

DOT National Transportation Integrated Search

2012-10-01

Concrete is the worlds most consumed man-made material. Unfortunately, the production of portland cement, the active : ingredient in concrete, generates a significant amount of carbon dioxide. For each pound of cement produced, approximately one :...

The Next Generation of leaching Tests

EPA Science Inventory

Coal ash and other industrial by-products are used in building, construction, engineering and even agricultural applications. Changes in multi-pollutant control technology at coal-fired power plants and other combustion sources are shifting mercury (Hg) and other constituents of...

Extending the usage of high volume fly ash in concrete.

DOT National Transportation Integrated Search

2014-07-01

Concrete is the worlds most consumed man-made material. Unfortunately, the production of Portland cement, the active ingredient in : concrete, generates a significant amount of carbon dioxide. For each pound of cement produced, approximately one p...

Deportment and management of metals produced during combustion of CCA-treated timbers.

PubMed

Rogers, Joseph M; Stewart, Mary; Petrie, James G; Haynes, Brian S

2007-01-31

Experiments were conducted to study CCA-treated wood combustion over a range of temperature and oxygen concentrations with a view to understanding the factors affecting energy and metals recovery from waste treated timber. CCA-treated wood was burned in a furnace at temperatures from 400 to 940 degrees C and oxygen concentrations between 5 and 21%. The ash and condensed volatiles were digested for total concentrations of metals and subjected to leaching tests to determine the stabilized concentrations of metals. Arsenic volatilisation increased with increasing furnace temperature whereas the copper and chromium reported mainly to the ash product. The effect of oxygen concentration was weak although it appeared that more arsenic volatilises at higher oxygen concentrations. However, a larger proportion of the arsenic in the ash generated at lower oxygen concentrations is solubilised during leaching tests, with the result that the concentration of stabilized arsenic in the ash is relatively unaffected by oxygen concentration.

Perspective usage estimation of Volga region combustible shale as a power generating fuel alternative

NASA Astrophysics Data System (ADS)

Korolev, E.; Barieva, E.; Eskin, A.

2018-05-01

A comprehensive study of combustible shale, common within Tatarstan and Ulyanovsk region, is carried out. The rocks physicochemical parameters are found to meet the power generating fuels requirements. The predictive estimate of ash products properties of combustible shale burning is held. Minding furnace process technology it is necessary to know mineral and organic components behavior when combustible shale is burnt. Since the first will determine slagging properties of energy raw materials, the second – its calorific value. In consideration of this the main research methods were X-ray, thermal and X-ray fluorescence analyses. Summing up the obtained results, we can draw to the following conclusions: 1. The combustible shale in Tatarstan and the Ulyanovsk region has predominantly low calorific value (Qb d = 5-9 MJ/kg). In order to enhance its efficiency and to reduce cost it is possible to conduct rocks burning together with some other organic or organic mineral power generating fuels. 2. High ash content (Ad = 60-80%) that causes a high external ballast content in shale implies the appropriateness of using this fuel resource next to its exploitation site. The acceptable distance to a consumer will reduce unproductive transportation charges for large ash and moisture masses. 3. The performed fuel ash components characteristics, as well as the yield and volatiles composition allow us to specify the basic parameters for boiler units, designed for the Volga combustible shale burning. 4. The noncombustible residual components composition shows that shale ash can be used in manufacture of materials of construction.

Characterization of Fly and Bottom Ashes Mixtures Treated using Sodium Lauryl Sulphate and Polyvinyl Alcohol

NASA Astrophysics Data System (ADS)

Robert, C. G.; Ayob, A.; Zaki, M. F. Muhammad; Razali, M. E.; Lew, E. V.; Hong, P. Y.

2018-03-01

Malaysia promotes coal as an option for solid fuel in electric power generation. Demanding of electricity needs, therefore, has led to increase the coal consumption and thus producing more coal waste products. The disposal of coal waste ashes has been a main concern to power generation station due to the need of disposal sites and operational costs. This study investigates the composition of fly ash (FA) and bottom ash (BA) mixtures with difference component percentage treated with sodium lauryl sulphate (SLS) and polyvinyl alcohol (PVA) at 1.5 and 2.5 wt% solutions and examined in terms of specific gravity, pH, maximum dry density properties, and its surface morphology. Although the chemical composition of the SLS and PVA treated fly and bottom ashes studied in this current work is not altered extensively, significant changes could be observed in its physicochemical properties. Chemically treated fly and bottom ashes mixtures with SLS and PVA at 1.5 wt% solution exhibited specific gravity of 1.97 to 2.92 and high pH values within range of 9.28 to 10.52. The mixture of BA:FA=0:1 ratio depicting high maximum dry density of 1.35 to 1.56 g/cm3 in both SLS and PVA solutions at 1.5 and 2.5 wt%. Scanning electron microscopy image shows distinct surface morphologies of SLS-treated fly and bottom ashes mixture that the particles are packed closely, strongly bonded similar to popcorn shape due to the effect of active silanol groups acted on coal ashes surface with the presence of Al-O/Si-O/other oxides. These findings suggest that higher level of chemical interaction between the fly and bottom ashes particles, significantly enhances pozzolanic reactions such as shear strength, plasticity, cementing properties, and thus other engineering properties.

Advancing the Renewable Industry in Minnesota

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

Sparby, Michael; Doering, Alan; Timmerman, Denny

This report deals with seven topics: 1. "Utilizing Ash Wastes as a Nutrient Source for Corn": As forms of gasification and combustion grow in the area of renewable energy in Minnesota the question arises regarding the utilization/application of the ash co product produced from these processes. Currently there are four facilities in Minnesota producing an ash co product (three ethanol facilities and one combusting biomass to produce energy). These ash wastes are generated from using ethanol by-products as a fuel or heating source for fermentation. Other ash wastes from agricultural sources include turkey litter ash. When applied to agricultural fields,more » ash wastes can be a source of nutrients for agricultural crops. Chemical analyses of ash wastes vary, but 200 to 300 lb of P 2O 5 and K 2O per ton of ash is typical. The value of ash wastes as a fertilizer has increased because commercial fertilizer prices have increased significantly over the last few years. Specifically: Compaction/Agglomeration research- Research included development of an appropriate product for use in current delivery systems by densifying the ash into the form of pellets or briquettes which may reduce fertilizer input cost to farmers. The initiative addresses the use of phosphorus and potassium from co-firing or gasification processes as a fertilizer source. 2. "Use of Glycerol as a Corn Replacement in Calf Starter Diets": Glycerol is a sugar alcohol by-product of bio-diesel production. About 1 gallon of glycerin is produced for every 10 gallons of bio-diesel of which the glycerol content may vary between 63 and almost 100%. There is some uncertainty of the exact energy value of glycerol as an ingredient for animal feed but it has been successfully used as a replacement for corn up to 10% of the diet dry matter for lactating dairy cows. There is a lack of information on incorporating glycerol into diets for pre- and post weaned dairy heifer calves which has the potential to expand the market for this by product. Preliminary work at SROC indicates that there are no palatability problems using glycerol up to 6% of the mix in post weaning pellets for group fed dairy heifers. 3. "Intervention Strategies for Reduction of Food-borne Pathogens in Cattle Fed Ethanol Byproducts": Ethanol plants and cattle producers create a symbiotic relationship: The use of wet and dry distiller’s grains in beef cattle rations provides significant improvement in overall feedlot performance for many producers in Minnesota and the Upper Midwest. Distiller’s grain is the coproduct that remains following the distillation of ethanol. It may be dehydrated to produce dried distiller’s grain (DDG) which is then commonly used as livestock feed. The use of distiller’s grains in livestock rations has been the subject of numerous research projects over the past ten years. Recently published research data conducted at Kansas State University (K-State) has created controversy over the feeding of distiller’s grains in beef cattle rations. The research indicates that cattle fed distiller’s grain may have an increased probability of Escherichia coli O157 in their hindgut. Specifically: This research assessment was a two part project consisting of feeding trials conducted at the University of Minnesota and an intervention study conducted at Kansas State University. This report is the Kansas State University portion. This report is a task-level final technical report. 4. "Impact of Distillers' Grains and Glycerin on Cattle Fecal Shedding of Escherichia coli O157:H7" 5. "Study Assessing the Opportunities and Potential of Soybean Based Products and Technologies": Based on demand/market potential, economic feasibility, stage of development and strength of institutional support, Informa Economics, Inc. ("Informa") narrowed down a list of more than 100 emerging soybean products and to 8 of the most promising for soybean, considered to have the greatest potential to add significant value to Minnesota's soybean commodity production. However, as with the potential of any biobased product or technology, the development of these emerging soybean products and technologies will be heavily reliant on future market price environments (especially for petroleum) and government policies. This report identifies what the contractor believes are the top 8 products and technologies for soybeans at the time of publishing. 6. "Study Assessing the Opportunities and Potential of Corn-Based Products and Technologies": Based on demand/market potential, economic feasibility, stage of development and strength of institutional support, Informa Economics, Inc. ("Informa") narrowed down a list of more than 100 emerging corn products and technologies to 8 of the most promising for corn, considered to have the greatest potential to add significant value to Minnesota's corn commodity production. However, as with the potential of any biobased product or technology, the development of these emerging corn products and technologies will be heavily reliant on future market price environments (especially for petroleum) and government policies. This report identifies what the contractor believes are the top 8 products and technologies for corn at the time of publishing. 7. "Distributed Power Generation Technology (Roseau Gasification)."« less

Economical and Environmentally Benign Extraction of Rare Earth Elements (REES) from Coal & Coal Byproducts

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

Carlson, Gary

This final report provides a complete summary of the activities, results, analytical discussion, and overall evaluation of the project titled “Economical and Environmentally Benign Extraction of Rare Earth Elements (REES) from Coal & Coal Byproducts” under DOE Award Number DE-FE-0027155 that started in March 2016 and ended December 2017. Fly ash was selected as the coal-byproduct source material due to fact that it is readily available with no need for extensive methods to obtain the material, it is produced in large quantities (>50 million tons per year) and had REE concentrations similar to other coal-byproducts. The selected fly ash usedmore » throughout this project was from the Mill Creek power generating facility operated by Louisville Gas and Electric located in Louisville, KY and was subjected to a variety of physical and chemical characterization tests. Results from fusion extractions showed that the selected fly-ash had a TREE+Y concentration of 480 ppm with critical REEs concentration of 200 ppm. The fly ash had an outlook ratio of 1.25 and an estimated value of $16-$18 worth of salable REEs per 1-tonne of fly ash. Additional characterizations by optical evaluation, QEMSCAN, XRD, size fractionation, and SEM analysis showed the fly ash consisted of small glassy spherules with a size range between 1 to 110 µm (ave. diam. of 13 um), was heterogeneous in chemical composition (main crystalline phases: aluminum oxides and iron oxides) and was primarily an amorphous material (75 to 80%). A simple stepped approach was completed to estimate the total REE resource quantity. The approach included REE characterization of the representative samples, evaluation of fly-ash availability, and final determination estimated resource availability with regards to REE grade on a regional and national scale. This data represents the best available information and is based upon the assumptions that the power generating facility where the fly-ash was obtained will use the same coal sources (actual mines were identified), the coal materials will have relatively consistent REE concentrations, and the REE extraction process developed during this project can achieve 42% REE recovery (validated and confirmed). Calculations indicated that the estimated REE resource is approximately 175,000 tonnes with a current estimated value of $3,330MM. The proposed REE extraction and production process developed during this project used four fundamental steps; 1) fly-ash pretreatment to enhance REE extraction, 2) REE extraction by acid digestion, 3) REE separation/concentration by carbon adsorption and column chromatography, and 4) REE oxide production. Secondary processing steps to manage process residuals and additional processing techniques to produce value-added products were incorporated into the process during the project. These secondary steps were not only necessary to manage residuals, but also provided additional revenue streams that offset operational and capital expenditures. The process produces one value product stream (production of zeolite Na-P1), a solids waste stream, and one liquid stream that met RCRA discharge requirements. Based upon final design criteria and operational parameters, the proposed system could produce approximately 200 grams of REOs from 1-tonne of fly-ash, thereby representing a TREE+Y recovery of 42% (project target of > 25%). A detailed economic model was developed to evaluate both CAPEX and OPEX estimates for systems with varying capacities between 100 kg to 200 tonnes of fly ash processed per day. Using a standard system capacity of 10 tonne/day system, capital costs were estimated at $88/kg fly ash while operating costs were estimated at approximately $450/kg fly ash. This operating cost estimate includes a revenue of $495/tonne of fly ash processed from the value-added product produced from the system (zeolite Na-P1). Although operating cost savings due to zeolite production were significant, the capital + operating cost for a 10 tonne system was more expensive than the total dollar value of REEs present in the fly ash material. Specifically, the estimated cost per 1-tonne of fly ash treated is approximately $540 while the estimated value of REEs in the fly ash is $18-$20/tonne. This is an excessive difference showing that the proposed process is not economically feasible strictly on the basis of REE revenue compared to extraction costs. Although the current proposed system does not produce sufficient quantities of REEs or additional revenue sources to offset operational and capital costs, supplementary factors including US strategic concerns, commercial demands, and defense department requirements must be factored. At this time, the process developed during this project provides foundational information for future development of simple processes that require low capital investment and one that will extract a valuable quality and quantity of REE oxides from industrial waste.« less

Publication sites productive uses of combustion ash

Science.gov Websites

Publication Sites Productive Uses of Combustion Ash For more information contact: e:mail: Public waste combustion ash in landfills. The new technology brief describes recent studies where ash was used

Soil quality in a cropland soil treated with wood ash containing charcoal

NASA Astrophysics Data System (ADS)

Omil, Beatriz; Balboa, Miguel A.; Fonturbel, M. Teresa; Gartzia-Bengoetxea, Nahia; Arias-González, Ander; Vega, Jose A.; Merino, Agustin

2014-05-01

The strategy of the European Union "Europe 2020" states that by 2020, 20% of final energy consumption must come from renewables. In this scenario, there is an increasing use of biomass utilization for energy production. Indeed, it is expected that the production of wood-ash will increase in coming years. Wood ash, a mixture of ash and charcoal, generated as a by-product of biomass combustion in power plants, can be applied to soil to improve the soil quality and crop production. Since the residue contains significant content of charcoal, the application of mixed wood ash may also improve the SOM content and soil quality in the long term, in soils degraded as a consequence of intensive management. The objective of this study was asses the changes in SOM quality and soil properties in a degraded soils treated with wood ash containing charcoal. The study was carried out in a field devoted to cereal crops during the last decades. The soil was acidic (pH 4.5) with a low SOC content (3 %) and fine texture. The experiment was based on a randomised block design with four replicates. Each block included the following four treatments: Control, 16 Mg fly wood ash ha-1, 16 Mg mixed wood ash ha-1 (16 Mg) and 32 Mg mixed wood ash ha-1 (32 Mg). The application was carried out once. The ash used in the study was obtained from a thermal power plant and was mainly derived from the combustion of Pinus radiata bark and branches. The wood ash is highly alkaline (pH= 10), contains 10 % of highly condensed black carbon (atomic H/C ratio < 0.5 and T50 en DSC= 500 ºC). The evolution of SOM properties were monitored over three years by solid state 13C CPMAS NMR and Differential Scanning Calorimetry (DSC). These techniques were applied in bulk samples and aggregates of different sizes. The changes in microbial activity were studied by analysis of microbial biomass C and basal respiration. The soil bacterial community was studied by the Biolog method. Several physical properties, such soil aggregate distribution, hydraulic conductivity and available water contente were also determined. Three years after applications the SOM content increased lightly in the treatment receiving more than 16 Mg ha-1 of wood ash. SOM in the treated soils displayed a higher degree of aromaticity than in the untreated soils, indicating a gain in more stable SOM compounds probably as a consequence of the charcoal application. However, both methods also revealed increases in labile C compounds, probably due to the carbohydrates added through root system. Microbial biomass-C and soil respiration increased significantly. The treatments also led to increases in the functional diversity indices. The amended soils showed greater utilization of substrates and the ability of soil bacteria to utilize different C resources was also greatly altered. The application of mixed wood ash did not lead to any difference in MWD, which was around 6 mm in all cases. The application of 16 Mg fly wood ash ha-1 increased significantly the hydraulic conductivity (4.07 cmh-1) when compared with in control plots (1.3 cmh-1) and mixed ash plots (1.52 and 2.45 cmh-1, 16 Mg and 32 Mg respectively). However, air-filled porosity was not higher in 16 Mg fly ash plots. AWC was not improved by wood ash application.

Elemental analyses of chars isolated from a biomass gasifier fly ash

Treesearch

Thomas L. Eberhardt; Hui Pan

2012-01-01

Processing of pine wood chips in a pilot-scale downdraft gasifier generated a carbon-rich fly ash as a byproduct. Studies on biomass-derived fly ashes have generally focused on their direct characterisation, as generated, to develop options for utilisation or disposal. Analogous to studies on coal-derived fly ashes, strategies were applied here to assess the...

Production of thermal insulation blocks from bottom ash of fluidized bed combustion system.

PubMed

Mandal, A K; Sinha, O P

2017-08-01

The issues of disposal and environmental problems are increased by the generation of bottom ash from the thermal power plants day by day; hence, its recycling is required. The present study aimed to make thermal insulation blocks using as raw material bottom ash and iron ore slime as a binder and to characterize their engineering properties. Two different fineness values of bottom ash were considered with varying amounts of iron ore slime (0-10%) to make the blocks. Blocks were dried followed by firing at 1000, 1100 and 1200°C, respectively. Cold crushing strength, density and thermal conductivity of these fired blocks showed increasing behaviour with firing temperature, fineness of bottom ash and iron ore slime content. In contrast, a reverse trend was observed in the case of porosity. With increasing firing temperature, the formation of lower melting phases like iron silicate followed by iron aluminium silicate was observed, which imparts the strength inside the blocks. The coarser particles of bottom ash increase the interparticle spaces, which enhances the apparent porosity, resulting in higher thermal insulation property in the blocks. Blocks having better thermal insulation property could be possible to make effectively from coarse bottom ash by adding iron ore slime as a binder.

Leachability of heavy metals in geopolymer-based materials synthesized from red mud and rice husk ash

NASA Astrophysics Data System (ADS)

Nguyen, Hoc Thang; Pham, Vo Thi Ha Quyen; Dang, Thanh Phong; Dao, Thanh Khe

2018-04-01

Red mud is an industrial waste generated during aluminum production from bauxite whereas rice husk ash is an agricultural waste from burning of rice husk that could cause negative impact on the environment if not properly managed. This study demonstrates the utilization of red mud in combination with rice husk ash to form a geopolymer-based material which can be used as bricks or replacement for traditional cement materials. The focus of this study is on the leachability of heavy metals in the raw materials and the geopolymer as this would be significant in assessing the environmental impact of the product. Leachability of metals such as Cu, Zn, Cd, Pb, Fe, and Cr was evaluated based on European (EN 124572-2 EU CEN TC292/ CEN TC 308) standard with pH value 7. Results indicate that the leachability of these metals in the geopolymer matrix is lower than that of the raw materials.

Monitoring Volcanic Ash with MSG Seviri Image and RGB Application

NASA Astrophysics Data System (ADS)

Erturk, Aydin Gurol; Kerkman, Jochen

2011-01-01

The eruption from the Eyjafjallajökull Volcano, Iceland recently became a high importance for the Meteorological Institutes, Aviation, Satellite Centers and other related institutions. Urgent forecasts were requested by the air control centers, aviation industry and even the passengers who stuck at the airports. It was announced that thousands of flights are canceled; hundreds of thousands of passengers affected and the airlines lost around 1.7 billion dollars in April-May 2010. This is the worst aviation crises. MSG (METEOSAT Second Generation) SEVIRI (Spinning Enhanced Visible and Infrared Imagery) with its 11 narrow and 1 broad band channels have been providing a worth of data sources for nowcasting and very short forecasting. SEVIRI images and RGB applications have been acted an important role to monitor Volcanic Ash during above aviation crises. SEVIRI has an infrared channel (centered @8.7 micron) which is sensitive sand, dust and ash in the atmosphere. In this study we present Ash RGB applications derived from SEVIRI data to monitor and track Ash clouds over Europe. Two main eruptions during 14-20 April and 7-17 May 2010 will be demonstrated. In addition to this, we will propose an Ash product algorithm and discuss its weakness and strength.

Gasification of high ash, high ash fusion temperature bituminous coals

DOEpatents

Liu, Guohai; Vimalchand, Pannalal; Peng, WanWang

2015-11-13

This invention relates to gasification of high ash bituminous coals that have high ash fusion temperatures. The ash content can be in 15 to 45 weight percent range and ash fusion temperatures can be in 1150.degree. C. to 1500.degree. C. range as well as in excess of 1500.degree. C. In a preferred embodiment, such coals are dealt with a two stage gasification process--a relatively low temperature primary gasification step in a circulating fluidized bed transport gasifier followed by a high temperature partial oxidation step of residual char carbon and small quantities of tar. The system to process such coals further includes an internally circulating fluidized bed to effectively cool the high temperature syngas with the aid of an inert media and without the syngas contacting the heat transfer surfaces. A cyclone downstream of the syngas cooler, operating at relatively low temperatures, effectively reduces loading to a dust filtration unit. Nearly dust- and tar-free syngas for chemicals production or power generation and with over 90%, and preferably over about 98%, overall carbon conversion can be achieved with the preferred process, apparatus and methods outlined in this invention.

16 CFR 1305.4 - Artificial fireplace ash and embers as banned hazardous products.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 16 Commercial Practices 2 2011-01-01 2011-01-01 false Artificial fireplace ash and embers as... CONSUMER PRODUCT SAFETY ACT REGULATIONS BAN OF ARTIFICIAL EMBERIZING MATERIALS (ASH AND EMBERS) CONTAINING RESPIRABLE FREE-FORM ASBESTOS § 1305.4 Artificial fireplace ash and embers as banned hazardous products. On...

16 CFR 1305.4 - Artificial fireplace ash and embers as banned hazardous products.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Artificial fireplace ash and embers as... CONSUMER PRODUCT SAFETY ACT REGULATIONS BAN OF ARTIFICIAL EMBERIZING MATERIALS (ASH AND EMBERS) CONTAINING RESPIRABLE FREE-FORM ASBESTOS § 1305.4 Artificial fireplace ash and embers as banned hazardous products. On...

Experimental aggregation of volcanic ash: the role of liquid bonding

NASA Astrophysics Data System (ADS)

Mueller, S.; Kueppers, U.; Jacob, M.; Ayris, P. M.; Dingwell, D. B.

2015-12-01

Explosive volcanic eruptions may release vast quantities of ash. Because of its size, it has the greatest dispersal potential and can be distributed globally. Ash may pose severe risks for 1) air traffic, 2) human and animal health, 3) agriculture and 4) infrastructure. Such ash particles can however cluster and form ash aggregates that range in size from millimeters to centimeters. During their growth, weight and aerodynamic properties change. This leads to significantly changed transport and settling behavior. The physico-chemical processes involved in aggregation are quantitatively poorly constrained. We have performed laboratory ash aggregation experiments using the ProCell Lab System® of Glatt Ingenieurtechnik GmbH. Solid particles are set into motion in a fluidized bed over a range of well-controlled boundary conditions (e.g., air flow rate, gas temperature, humidity, liquid composition). In this manner we simulate the variable gas-particle flow conditions expected in eruption plumes and pyroclastic density currents. We have used 1) soda-lime glass beads as an analogue material and 2) natural volcanic ash from Laacher See Volcano (Germany). In order to influence form, size, stability and the production rate of aggregates, a range of experimental conditions (e.g., particle concentration, degree of turbulence, temperature and moisture in the process chamber and the composition of the liquid phase) have been employed. We have successfully reproduced several features of natural ash aggregates, including round, internally structured ash pellets up to 3 mm in diameter. These experimental results help to constrain the boundary conditions required for the generation of spherical, internally-structured ash aggregates that survive deposition and are preserved in the volcanological record. These results should also serve as input parameters for models of ash transport and ash mass distribution.

Environmental and economic life cycle assessment for sewage sludge treatment processes in Japan.

PubMed

Hong, Jinglan; Hong, Jingmin; Otaki, Masahiro; Jolliet, Olivier

2009-02-01

Life cycle assessment for sewage sludge treatment was carried out by estimating the environmental and economic impacts of the six alternative scenarios most often used in Japan: dewatering, composting, drying, incineration, incinerated ash melting and dewatered sludge melting, each with or without digestion. Three end-of-life treatments were also studied: landfilling, agricultural application and building material application. The results demonstrate that sewage sludge digestion can reduce the environmental load and cost through reduced dry matter volume. The global warming potential (GWP) generated from incineration and melting processes can be significantly reduced through the reuse of waste heat for electricity and/or heat generation. Equipment production in scenarios except dewatering has an important effect on GWP, whereas the contribution of construction is negligible. In addition, the results show that the dewatering scenario has the highest impact on land use and cost, the drying scenario has the highest impact on GWP and acidification, and the incinerated ash melting scenario has the highest impact on human toxicity due to re-emissions of heavy metals from incinerated ash in the melting unit process. On the contrary, the dewatering, composting and incineration scenarios generate the lowest impact on human toxicity, land use and acidification, respectively, and the incinerated ash melting scenario has the lowest impact on GWP and cost. Heavy metals released from atmospheric effluents generated the highest human toxicity impact, with the effect of dioxin emissions being significantly lower. This study proved that the dewatered sludge melting scenario is an environmentally optimal and economically affordable method.

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.

Modeling the formation of the quench product in municipal solid waste incineration (MSWI) bottom ash.

PubMed

Inkaew, Kanawut; Saffarzadeh, Amirhomayoun; Shimaoka, Takayuki

2016-06-01

This study investigated changes in bottom ash morphology and mineralogy under lab-scale quenching conditions. The main purpose was to clarify the mechanisms behind the formation of the quench product/layer around bottom ash particles. In the experiments, the unquenched bottom ashes were heated to 300°C for 1h, and were quenched by warm water (65°C) with different simulated conditions. After having filtered and dried, the ashes were analyzed by a combination of methodologies namely, particle size distribution analysis, intact particle and thin-section observation, X-ray diffractometry, and scanning electron microscope with energy dispersive X-ray spectroscopy. The results indicated that after quenching, the morphology and mineralogy of the bottom ash changed significantly. The freshly quenched bottom ash was dominated by a quench product that was characterized by amorphous and microcrystalline calcium-silicate-hydrate (CSH) phases. This product also enclosed tiny minerals, glasses, ceramics, metals, and organic materials. The dominant mineral phases produced by quenching process and detected by XRD were calcite, Friedel's salt, hydrocalumite and portlandite. The formation of quench product was controlled by the fine fraction of the bottom ash (particle size <0.425mm). From the observations, a conceptual model of the ash-water reactions and formation of the quench product in the bottom ash was proposed. Copyright © 2016 Elsevier Ltd. All rights reserved.

Breckinridge Project, initial effort

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

None

1982-01-01

The project cogeneration plant supplies electric power, process steam and treated boiler feedwater for use by the project plants. The plant consists of multiple turbine generators and steam generators connected to a common main steam header. The major plant systems which are required to produce steam, electrical power and treated feedwater are discussed individually. The systems are: steam, steam generator, steam generator fuel, condensate and feedwater deaeration, condensate and blowdown collection, cooling water, boiler feedwater treatment, coal handling, ash handling (fly ash and bottom ash), electrical, and control system. The plant description is based on the Phase Zero design basismore » established for Plant 31 in July of 1980 and the steam/condensate balance as presented on Drawing 31-E-B-1. Updating of steam requirements as more refined process information becomes available has generated some changes in the steam balance. Boiler operation with these updated requirements is reflected on Drawing 31-D-B-1A. The major impact of updating has been that less 600 psig steam generated within the process units requires more extraction steam from the turbine generators to close the 600 psig steam balance. Since the 900 psig steam generation from the boilers was fixed at 1,200,000 lb/hr, the additional extraction steam required to close the 600 psig steam balance decreased the quantity of electrical power available from the turbine generators. In the next phase of engineering work, the production of 600 psig steam will be augmented by increasing convection bank steam generation in the Plant 3 fired heaters by 140,000 to 150,000 lb/hr. This modification will allow full rated power generation from the turbine generators.« less

Potential of phosphorus recovery from sewage sludge and manure ash by thermochemical treatment.

PubMed

Havukainen, Jouni; Nguyen, Mai Thanh; Hermann, Ludwig; Horttanainen, Mika; Mikkilä, Mirja; Deviatkin, Ivan; Linnanen, Lassi

2016-03-01

All life forms require phosphorus (P), which has no substitute in food production. The risk of phosphorus loss from soil and limited P rock reserves has led to the development of recycling P from industrial residues. This study investigates the potential of phosphorus recovery from sewage sludge and manure ash by thermochemical treatment (ASH DEC) in Finland. An ASH DEC plant could receive 46-76 kt/a of sewage sludge ash to produce 51-85 kt/a of a P-rich product with a P2O5 content of 13-18%, while 320-750 kt/a of manure ash could be supplied to produce 350-830 kt/a of a P-rich product with a P content of 4-5%. The P2O5 potential in the total P-rich product from the ASH DEC process using sewage sludge and manure ash is estimated to be 25-47 kt/a, which is significantly more than the P fertilizer demand in Finland's agricultural industries. The energy efficiency of integrated incineration and the ASH DEC process is more dependent on the total solid content and the subsequent need for mechanical dewatering and thermal drying than on the energy required by the ASH DEC process. According to the results of this study, the treated sewage sludge and manure ash using the ASH DEC process represent significant potential phosphorus sources for P fertilizer production. Copyright © 2016 Elsevier Ltd. All rights reserved.

Recycling of inorganic nutrients for hydroponic crop production following incineration of inedible biomass.

PubMed

Bubenheim, D L; Wignarajah, K

1997-01-01

The goal of resource recovery in a regenerative life support system is maintenance of product quality to sure support of reliable and predictable levels of life support function performance by the crop plant component. Further, these systems must be maintained over extended periods of time, requiring maintenance of nutrient solutions to avoid toxicity and deficiencies. The focus of this study was to determine the suitability of the ash product following incineration of inedible biomass as a source of inorganic nutrients for hydroponic crop production. Inedible wheat biomass was incinerated and ash quality characterized. The incinerator ash was dissolved in adequate nitric acid to establish a consistent nitrogen concentration is all nutrient solution treatments. Four experimental nutrient treatments were included: control, ash only, ash supplemented to match the control treatment, and ash only quality formulated with reagent grade chemicals. When nutrient solutions were formulated using only ash following incineration of inedible biomass, a balance in solution is established representing elemental retention following incineration and nutrient proportions present in the original biomass. The resulting solution is not identical to the control. This imbalance resulted in a suppression of crop growth. When the ash is supplemented with reagent grade chemicals to establish the same balance as in the control--growth is identical to the control. The ash appears to carry no phytotoxic materials. Growth in solution formulated with reagent grade chemicals but matching the quality of the ash only treatment resulted in similar growth to that of the ash only treatment. The ash product resulting from incineration of inedible biomass appears to be a suitable form for recycle of inorganic nutrients to crop production.

Tracing remobilization of nutrients and toxic elements after application of rice straw or derived ash / biochar in paddy soils

NASA Astrophysics Data System (ADS)

Schaller, Jörg; Wang, Jiajia; Planer-Friedrich, Britta

2017-04-01

More than 600 million tons of rice straw are produced each year as byproduct of rice grain production. As an increasing application, besides e.g. composting or fodder for animals, the straw remains on the field for decomposition and nutrient supply. A central concern during rice cultivation is accumulation of arsenic, but it is currently unclear how the application of rice straw or derived ash or biochar to paddy soils will influence arsenic uptake by the next generation of rice plants. Consequently, we assessed the element mobilization via soil microcosm incubations with straw or derived ash or biochar or without those amendments under flooding (40 days) and subsequent drainage (14 days). We focused on elements potentially influencing the uptake of arsenic by the next generation of rice plants (e.g. silicon, phosphorus, iron), or which are nutrients but toxic themselves at higher levels (sulfur, sulfide, iron, iron(II), manganese, copper, and zinc). We found significant differences in the release of arsenic, iron(II), sulfide, total sulfur, DOC, manganese, copper, and zinc . For example highest pore water Mn and As concentrations were found for soil amended with straw, whereas the straw amendment reduced S mobilization, possibly due to sulfate reduction by straw decomposing microbes. For P, we found highest pore water concentrations for straw, followed by biochar, ash and control. In summary, application of rice straw or derived ash or biochar strongly affect the element availability in paddy soil.

Effect of Bauxite addition on Adhesion Strength and Surface Roughness of Fly ash based Plasma Sprayed Coatings

NASA Astrophysics Data System (ADS)

Bhuyan, S. K.; Samal, S.; Pattnaik, D.; Sahu, A.; Swain, B.; Thiyagarajan, T. K.; Mishra, S. C.

2018-03-01

The environment is being contaminated with advancement of new technology, day by day. One of the primary sources for this contamination is the industrial waste. Industrialization is the prime reason behind the prosperity of any country to meet the materialistic demand. To run the industries, a huge amount of (electric) power is needed and hence need for thermal power plants to serve the purpose. In present scenario, coal fired thermal power plants are set up which generates a huge quantity of Fly ash. Consumption of industrial waste (Fly ash), continually a major concern for human race. In recent years, fly ash is being utilized for various purposes i.e. making bricks, mine reclamation, production of cements etc. The presence of Silica and Alumina in fly ash makes it useful for thermal barrier applications also. The plasma spray technology has the advantage of being able to process any types of metal/ceramic mineral, low-grade-ore minerals etc. to make value-added products and also to deposit ceramics, metals and a combination of these to deposit composite coatings with desired microstructure and required properties on a range of substrate materials. The present work focuses on utilization of fly ash mixing with bauxite (ore mineral) for a high valued application. Fly ash with 10 and 20% bauxite addition is used to deposit plasma spray overlay coatings at different power levels (10-20kW) on aluminum and mild steel substrates. Adhesion strength and surface roughness of the coatings are evaluated. Phase composition analysis of the coatings were done using X-ray diffraction analysis. Surface morphology of the coatings was studied using a scanning electron microscope (SEM). Maximum adhesion strength of 4.924 MPa is obtained for the composition fly ash and bauxite (10%), coated on mild steel at 16kW torch power level. The surface roughness (Ra) of the coatings is found to vary between 10.0102 to 17.2341 micron.

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.

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

Persistent free radicals, heavy metals and PAHs generated in particulate soot emissions and residue ash from controlled combustion of common types of plastic.

PubMed

Valavanidis, Athanasios; Iliopoulos, Nikiforos; Gotsis, George; Fiotakis, Konstantinos

2008-08-15

The production and use of polymeric materials worldwide has reached levels of 150 million tonnes per year, and the majority of plastic materials are discarded in waste landfills where are burned generating toxic emissions. In the present study we conducted laboratory experiments for batch combustion/burning of commercial polymeric materials, simulating conditions of open fire combustion, with the purpose to analyze their emissions for chemical characteristics of toxicological importance. We used common types of plastic materials: poly(vinyl chloride) (PVC), low and high density poly(ethylene) (LDPE, HDPE), poly(styrene) (PS), poly(propylene) (PP) and poly(ethylene terephthalate) (PET). Samples of particulate smoke (soot) collected on filters and residue solid ash produced by controlled burning conditions at 600-750 degrees C are used for analysis. Emissions of particulate matter, persistent free radicals embedded in the carbonaceous polymeric matrix, heavy metals, other elements and PAHs were determined in both types of samples. Results showed that all plastics burned easily generating charred residue solid ash and black airborne particulate smoke. Persistent carbon- and oxygen-centered radicals, known for their toxic effects in inhalable airborne particles, were detected in both particulate smoke emissions and residue solid ash. Concentrations of heavy metals and other elements (determined by Inductively Coupled Plasma Emission Spectrometry, ICP, method) were measured in the airborne soot and residue ash. Toxic heavy metals, such as Pb, Zn, Cr, Ni, and Cd were relatively at were found at low concentrations. High concentrations were found for some lithophilic elements, such as Na, Ca, Mg, Si and Al in particulate soot and residue solid ash. Measurements of PAHs showed that low molecular weight PAHs were at higher concentrations in the airborne particulate soot than in the residue solid ash for all types of plastic. Higher-ringed PAHs were detected at higher concentrations in the residue solid ash of PVC as compared to those from the other types of plastic. The open-air burning of plastic material and their toxic emissions is of growing concern in areas of municipal solid waste where open-fires occur intentionally or accidentally. Another problem is building fires in which victims may suffer severe smoke inhalation from burning plastic materials in homes and in working places.

Hydrologic conditions controlling runoff generation immediately after wildfire

USGS Publications Warehouse

Ebel, Brian A.; Moody, John A.; Martin, Deborah A.

2012-01-01

We investigated the control of postwildfire runoff by physical and hydraulic properties of soil, hydrologic states, and an ash layer immediately following wildfire. The field site is within the area burned by the 2010 Fourmile Canyon Fire in Colorado, USA. Physical and hydraulic property characterization included ash thickness, particle size distribution, hydraulic conductivity, and soil water retention curves. Soil water content and matric potential were measured indirectly at several depths below the soil surface to document hydrologic states underneath the ash layer in the unsaturated zone, whereas precipitation and surface runoff were measured directly. Measurements of soil water content showed that almost no water infiltrated below the ash layer into the near-surface soil in the burned site at the storm time scale (i.e., minutes to hours). Runoff generation processes were controlled by and highly sensitive to ash thickness and ash hydraulic properties. The ash layer stored from 97% to 99% of rainfall, which was critical for reducing runoff amounts. The hydrologic response to two rain storms with different rainfall amounts, rainfall intensity, and durations, only ten days apart, indicated that runoff generation was predominantly by the saturation-excess mechanism perched at the ash-soil interface during the first storm and predominantly by the infiltration-excess mechanism at the ash surface during the second storm. Contributing area was not static for the two storms and was 4% (saturation excess) to 68% (infiltration excess) of the catchment area. Our results showed the importance of including hydrologic conditions and hydraulic properties of the ash layer in postwildfire runoff generation models.

Properties of Fly Ash Blocks Made from Adobe Mould

NASA Astrophysics Data System (ADS)

Chokhani, Alankrit; Divakar, B. S.; Jawalgi, Archana S.; Renukadevi, M. V.; Jagadish, K. S.

2018-02-01

Fly ash being one of the industrial waste products poses a serious disposal problem. This paper presents an experimental study of utilization of fly ash to produce blocks with varying proportions and mix combinations. Composition of fly ash blocks mainly consist of fly ash and sand, with cementitious product as either cement, lime or both, such as fly ash-sand-cement, fly ash-sand-lime and fly ash-sand-cement-lime are used. Four different proportions for each of the mix combinations are experimented. Compressive strength, water absorption, Initial rate of absorption, and dry density of fly ash blocks are studied. The influence of partial and complete replacement of cement by lime is examined.

Properties of Fly Ash Blocks Made from Adobe Mould

NASA Astrophysics Data System (ADS)

Chokhani, Alankrit; Divakar, B. S.; Jawalgi, Archana S.; Renukadevi, M. V.; Jagadish, K. S.

2018-06-01

Fly ash being one of the industrial waste products poses a serious disposal problem. This paper presents an experimental study of utilization of fly ash to produce blocks with varying proportions and mix combinations. Composition of fly ash blocks mainly consist of fly ash and sand, with cementitious product as either cement, lime or both, such as fly ash-sand-cement, fly ash-sand-lime and fly ash-sand-cement-lime are used. Four different proportions for each of the mix combinations are experimented. Compressive strength, water absorption, Initial rate of absorption, and dry density of fly ash blocks are studied. The influence of partial and complete replacement of cement by lime is examined.

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

Phenolic acids as bioindicators of fly ash deposit revegetation

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

L. Djurdjevic; M. Mitrovic; P. Pavlovic

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 partmore » of the deposit towards its edges. 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 in fly ash increased from the center of the deposit towards its edges in correlation with the increase in plant abundance and cover. 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.« less

Behavior of TiO₂ nanoparticles during incineration of solid paint waste: a lab-scale test.

PubMed

Massari, Andrea; Beggio, Marta; Hreglich, Sandro; Marin, Riccardo; Zuin, Stefano

2014-10-01

In order to assess the potential impacts posed by products containing engineered nanoparticles, it is essential to generate more data about the release of these particles from products' life cycle. Although first studies were performed to investigate the release of nanoparticles from use phase, very few data are available on the potential release from recycling or disposal of nano-enhanced products. In this work, we investigated the behavior of TiO2 nanoparticles from incineration of solid paint waste containing these particles. Solid paint debris with and without TiO2 nanoparticles were treated in a lab scale incineration plant at 950°C (combustion temperature) and in oxidizing atmosphere. The obtained ashes were also vitrified with additives and the release of Ti was finally evaluated by leaching test. From our incineration lab-scale experiment, we did not observe a release of TiO2 nanoparticles into the atmosphere, and Ti was attached to the surface of obtained solid residues (i.e. ashes). The characterization of ashes showed that TiO2 nanoparticles reacted during the incineration to give calcium titanate. Finally, a very low release of Ti was measured, less 1 mg/kg, during the leaching test of ashes vitrified with glass cullet and feldspathic inert. Our work suggests that TiO2 nanoparticles added in paints may undergo to physicochemical transformation during the incineration, and that Ti found in ashes may be strongly immobilized in glass matrix. Since this conclusion is based on lab-scale experiment, further research is required to identify which nanoparticles will be emitted to the environment from a real-word-incineration system of household hazardous waste. Copyright © 2014 Elsevier Ltd. All rights reserved.

High-volume use of self-cementing spray dry absorber material for structural applications

NASA Astrophysics Data System (ADS)

Riley, Charles E.

Spray dry absorber (SDA) material, or spray dryer ash, is a byproduct of energy generation by coal combustion and sulfur emissions controls. Like any resource, it ought to be used to its fullest potential offsetting as many of the negative environmental impacts of coal combustion as possible throughout its lifecycle. Its cementitious and pozzolanic properties suggest it be used to augment or replace another energy and emissions intensive product: Portland cement. There is excellent potential for spray dryer ash to be used beneficially in structural applications, which will offset CO2 emissions due to Portland cement production, divert landfill waste by further utilizing a plentiful coal combustion by-product, and create more durable and sustainable structures. The research into beneficial use applications for SDA material is relatively undeveloped and the material is highly underutilized. This dissertation explored a specific self-cementing spray dryer ash for use as a binder in structural materials. Strength and stiffness properties of hydrated spray dryer ash mortars were improved by chemical activation with Portland cement and reinforcement with polymer fibers from automobile tire recycling. Portland cement at additions of five percent of the cementitious material was found to function effectively as an activating agent for spray dryer ash and had a significant impact on the hardened properties. The recycled polymer fibers improved the ductility and toughness of the material in all cases and increased the compressive strength of weak matrix materials like the pure hydrated ash. The resulting hardened materials exhibited useful properties that were sufficient to suggest that they be used in structural applications such as concrete, masonry block, or as a hydraulic cement binder. While the long-term performance characteristics remain to be investigated, from an embodied-energy and carbon emissions standpoint the material investigated here is far superior to Portland cement.

Aviation Applications for Satellite-Based Observations of Cloud Properties, Convection Initiation, In-flight Icing, Turbulence and Volcanic Ash

NASA Technical Reports Server (NTRS)

Mecikalski, John R.; Feltz, Wayne F.; Murray, John J.; Johnson, David B.; Bedka, Kristopher M.; Bedka, Sarah M.; Wimmers, Anthony J.; Pavolonis, Michael; Berendes, Todd A.; Haggerty, Julie;

Self-degradable Slag/Class F Fly Ash-Blend Cements

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

Sugama, T.; Warren, J.; Butcher, T.

2011-03-01

Self-degradable slag/Class F fly ash blend pozzolana cements were formulated, assuming that they might serve well as alternative temporary fracture sealers in Enhanced Geothermal System (EGS) wells operating at temperatures of {ge} 200 C. Two candidate formulas were screened based upon material criteria including an initial setting time {ge} 60 min at 85 C, compressive strength {ge} 2000 psi for a 200 C autoclaved specimen, and the extent of self-degradation of cement heated at {ge} 200 C for it was contacted with water. The first screened dry mix formula consisted of 76.5 wt% slag-19.0 wt% Class F fly ash-3.8 wt%more » sodium silicate as alkali activator, and 0.7 wt% carboxymethyl cellulose (CMC) as the self-degradation promoting additive, and second formula comprised of 57.3 wt% slag, 38.2 wt% Class F fly ash, 3.8 wt% sodium silicate, and 0.7 wt% CMC. After mixing with water and autoclaving it at 200 C, the aluminum-substituted 1.1 nm tobermorite crystal phase was identified as hydrothermal reaction product responsible for the development of a compressive strength of 5983 psi. The 200 C-autoclaved cement made with the latter formula had the combined phases of tobermorite as its major reaction product and amorphous geopolymer as its minor one providing a compressive strength of 5271 psi. Sodium hydroxide derived from the hydrolysis of sodium silicate activator not only initiated the pozzolanic reaction of slag and fly ash, but also played an important role in generating in-situ exothermic heat that significantly contributed to promoting self-degradation of cementitious sealers. The source of this exothermic heat was the interactions between sodium hydroxide, and gaseous CO{sub 2} and CH{sub 3}COOH by-products generated from thermal decomposition of CMC at {ge} 200 C in an aqueous medium. Thus, the magnitude of this self-degradation depended on the exothermic temperature evolved in the sealer; a higher temperature led to a sever disintegration of sealer. The exothermic temperature was controlled by the extent of thermal decomposition of CMC, demonstrating that CMC decomposed at higher temperature emitted more gaseous reactants. Hence, such large emission enhanced the evolution of in-situ exothermic heat. In contrast, the excessive formation of geopolymer phase due to more incorporation of Class F fly ash into this cementitious system affected its ability to self-degrade, reflecting that there was no self-degradation. The geopolymer was formed by hydrothermal reactions between sodium hydroxide from sodium silicate and mullite in Class F fly ash. Thus, the major reason why geopolymer-based cementitiuos sealers did not degrade after heated sealers came in contact with water was their lack of free sodium hydroxide.« less

Characterization the potential of biochar from cow and pig manure for geoecology application

NASA Astrophysics Data System (ADS)

Gunamantha, I. M.; Widana, G. A. B.

2018-03-01

Biochar is a solid product generated from the carbonization of biomass with various potential benefits. The utilisation of biochar should be adapted to its characteristic which is mainly influenced by its feedstock. In this study, cow and pig manure biochar generated by a conventional process, were characterized by its physical and chemical analysis and its potential to be used as soil amendment. For this purpose, several main parameters were analyzed: organic carbon, Nutrient (total-N, available P and K) status, Cation Exchange Capacity (CEC), proximate data analysis (moisture content, ash, volatile matter and fixed carbon) and its ash composition. The comparison between biochar and feedstock will be based on these parameters. The results of this study show that the organic carbon, available P, ash, and fixed carbon content of pig-manure biochar is higher than cow manure-derived biochar; while total-N, available K, CEC and volatile matter is lower. On its ash composition, the pig manure-derived biochar is dominated by SiO2, Al2O3, Fe2O3, P2O5, and CaO while the cow manure-derived biochar is dominated by SiO2, CaO, Al2O3, K2O, and P2O5. However, both biochar show potential for improving soil quality and reducing carbon emission from animal manure.

Optimising Ambient Setting Bayer Derived Fly Ash Geopolymers

PubMed Central

Jamieson, Evan; Kealley, Catherine S.; van Riessen, Arie; Hart, Robert D.

2016-01-01

The Bayer process utilises high concentrations of caustic and elevated temperature to liberate alumina from bauxite, for the production of aluminium and other chemicals. Within Australia, this process results in 40 million tonnes of mineral residues (Red mud) each year. Over the same period, the energy production sector will produce 14 million tonnes of coal combustion products (Fly ash). Both industrial residues require impoundment storage, yet combining some of these components can produce geopolymers, an alternative to cement. Geopolymers derived from Bayer liquor and fly ash have been made successfully with a compressive strength in excess of 40 MPa after oven curing. However, any product from these industries would require large volume applications with robust operational conditions to maximise utilisation. To facilitate potential unconfined large-scale production, Bayer derived fly ash geopolymers have been optimised to achieve ambient curing. Fly ash from two different power stations have been successfully trialled showing the versatility of the Bayer liquor-ash combination for making geopolymers. PMID:28773513

Optimising Ambient Setting Bayer Derived Fly Ash Geopolymers.

PubMed

Jamieson, Evan; Kealley, Catherine S; van Riessen, Arie; Hart, Robert D

2016-05-19

The Bayer process utilises high concentrations of caustic and elevated temperature to liberate alumina from bauxite, for the production of aluminium and other chemicals. Within Australia, this process results in 40 million tonnes of mineral residues (Red mud) each year. Over the same period, the energy production sector will produce 14 million tonnes of coal combustion products (Fly ash). Both industrial residues require impoundment storage, yet combining some of these components can produce geopolymers, an alternative to cement. Geopolymers derived from Bayer liquor and fly ash have been made successfully with a compressive strength in excess of 40 MPa after oven curing. However, any product from these industries would require large volume applications with robust operational conditions to maximise utilisation. To facilitate potential unconfined large-scale production, Bayer derived fly ash geopolymers have been optimised to achieve ambient curing. Fly ash from two different power stations have been successfully trialled showing the versatility of the Bayer liquor-ash combination for making geopolymers.

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.

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.

An appraisal of the potential use of fly ash for reclaiming coal mine spoil.

PubMed

Ram, Lal C; Masto, Reginald E

2010-01-01

Growing dependence on coal-fired power plants for electrical generation in many countries presents ongoing environmental challenges. Burning pulverized coal in thermal power plants (TPPs) generates large amounts of fly ash (FA) that must be disposed of or otherwise handled, in an environmentally-sound manner. A possible option for dealing with fly ash is to use it as an amendment for mine spoil or other damaged soil. It has been demonstrated through studies in India and other countries that FA alone or in combination with organic or inorganic materials can be used in a productive manner for reclamation of mine spoil. The characteristics of FA, including silt-sized particles, lighter materials with low bulk density (BD), higher water holding capacity, favorable pH and significant concentrations of many essential plant nutrients, make it a potentially favorable amendment for mine spoil reclamation. Studies have indicated that the application of FA has improved the physical, chemical and biological qualities of soil to which it is applied. The release of trace metals and soluble salts from FA could be a major limitation to its application. This is particularly true of fresh, un-weathered FA or acidic FA, although perhaps not a concern for weathered/pond ash or alkaline FA. Some potential contaminants, especially metals and other salt ions, could be immobilized and rendered biologically inert by the addition of certain inorganic and organic amendments. However, in view of the variability in the characteristics of FAs that are associated with location, feed coal, combustion conditions and other factors, the suitability of a particular FA for a specific soil/mine spoil needs to be critically evaluated before it is applied in order to maximize favorable results and eliminate unexpected consequences. FA generated in India tends to be mostly alkaline, with lower levels of trace elements than are often found in FAs from other countries. The concentrations of potential chemical stressors, predominantly metals, in Indian FAs are often less than established or proposed permissible limits and are thus better suited for soil application. A major logistic limitation to the use of FA could be the cost involved in transport of ash from production to utilization sites. 2009 Elsevier Ltd. All rights reserved.

Effects of hot-water extraction on the thermochemical conversion of shrub willow via fast pyrolysis

USDA-ARS?s Scientific Manuscript database

Hot-water extraction (TM) (HWE) is a pretreatment technology designed to facilitate the subsequent hydrolysis of cellulose by removing the majority of the hemicellulose and ash content from the solid biomass. The HWE process generates salable sugars and other products as part of the process. The bio...

Lauryl Amine as heavy metal collector of boiler ash from pulp and paper mill waste

NASA Astrophysics Data System (ADS)

Sembiring, M. P.; Kaban, J.; Bangun, N.; Saputra, E.

2018-04-01

Theincreasing of demand of pulp and paper products, will following with the growing the pulp and paper industryand generate significant mill waste. The total waste reached 1/3 of the amount raw materials used and ash boiler is the waste with the largest percentage of 52%. For that it takes effort to manage the existing waste. The boiler ash contained the chemical elements, it can be utilized such as fertilizer, because it also contains transition metals in form of heavy metal such as Cadmium (Cd), Cobalt (Co), Chrome (Cr), Cupprum (Cu), Ferrum (Fe), Nickel (Ni), and Zinc (Zn), the use of boiler ash must follow the threshold specified by the Government. Several studies have been undertaken to reduce and extract heavy metals from ash and sand of the boiler by using carbon dioxide as its ligand. Eelectrochemical method was used to remove and recovery of heavy metals from the incenerator. This study focused on removal of heavy metals using Lauryl Amine as collector and three solvents namely Dichloromethane, Ethanol and n-Hexane. The treatmentswas able to extract the heavy metal and generally reduce the heavy metal content of ash boiler pulp and paper mill waste. The combination treatment used toreduce the heavy metal content of 5 gram Lauryl Amine collector in Dichloromethane solvent for 4 hours process time.

Preparation and characterization of a hybrid alkaline binder based on a fly ash with no commercial value

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

Mejia, Johanna M.; Rodriguez, Erich; Mejia de Gutierrez, Ruby

2015-05-18

Alkali-activated Portland fly ash cement (FA/OPC) and alkali activated blast furnace slag-fly ash cement (FA/GBFS) were prepared using 70% of a low quality fly ash (FA). The low quality is associated with a high content of unburned material (loss of ignition of 14.6%). The hybrid cements were activated by the alkaline solution in order to obtain an overall SiO 2/Al 2O 3 molar ratio of 5.0 and 6.0 and unique overall Na 2O/SiO 2 molar ratio of 0.21. The microstructural characterization of the blended pastes generated in the systems showed the coexistence of amorphous gels C-A-S-H and N-A-S-H gels inmore » the hybrid systems. The addition of OPC or GBFS increases the compressive strength (at 28 days of curing) up to 127% compared with the geopolymer systems based only on FA used in this study. The content of silicates soluble also plays an important role in the reaction products and higher SiO 2/Al 2O 3 lead to obtain higher mechanical performance and denser structure. The results obtained show that these hybrid cements are an effective way for valorization the waste used in this study for the production of high strength and low-carbon footprint cement-type material.« less

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

Cristobalite in volcanic ash of the soufriere hills volcano, montserrat, british west indies

PubMed

Baxter; Bonadonna; Dupree; Hards; Kohn; Murphy; Nichols; Nicholson; Norton; Searl; Sparks; Vickers

1999-02-19

Crystalline silica (mostly cristobalite) was produced by vapor-phase crystallization and devitrification in the andesite lava dome of the Soufriere Hills volcano, Montserrat. The sub-10-micrometer fraction of ash generated by pyroclastic flows formed by lava dome collapse contains 10 to 24 weight percent crystalline silica, an enrichment of 2 to 5 relative to the magma caused by selective crushing of the groundmass. The sub-10-micrometer fraction of ash generated by explosive eruptions has much lower contents (3 to 6 percent) of crystalline silica. High levels of cristobalite in respirable ash raise concerns about adverse health effects of long-term human exposure to ash from lava dome eruptions.

Recycle of Inorganic Nutrients for Hydroponic Crop Production Following Incineration of Inedible Biomass

NASA Technical Reports Server (NTRS)

Bubenheim, David L.; Wignarajah, Kanapathipillai; Kliss, Mark H. (Technical Monitor)

1996-01-01

Recovery of resources from waste streams is essential for future implementation and reliance on a regenerative life support system. The major waste streams of concern are from human activities and plant wastes. Carbon, water and inorganics are the primary desired raw materials of interest. The goal of resource recovery is maintenance of product quality to insure support of reliable and predictable levels of life support function performance by the crop plant component. Further, these systems must be maintained over extended periods of time, requiring maintenance of nutrient solutions to avoid toxicity and deficiencies. Today, reagent grade nutrients are used to make nutrient solutions for hydroponic culture and these solutions are frequently changed during the life cycle or sometimes managed for only one crop life cycle. The focus of this study was to determine the suitability of the ash product following incineration of inedible biomass as a source of inorganic nutrients for hydroponic crop production. Inedible wheat biomass was incinerated and ash quality characterized. The incinerator ash was dissolved in adequate nitric acid to establish a consistent nitrogen concentration in all nutrient solution treatments. Four experimental nutrient treatments were included: control, ash only, ash supplemented to match control, and ash only quality formulated with reagent grade chemicals. When nutrient solutions are formulated using only ash following-incineration of inedible biomass, a balance in solution is established representing elemental retention following incineration and nutrient proportions present in the original biomass. The resulting solution is not identical to the control. This imbalance resulted in suppression of crop growth. When the ash is supplemented with nutrients to establish the same balance as in the control, growth is identical to the control. The ash appears to carry no phytotoxic materials. Growth in solution formulated with reagent grade chemicals but matching the quality of the ash only treatment resulted in growth similar to that of the ash only treatment. The ash product resulting from incineration of inedible biomass appears to be a suitable form for recycle of inorganic nutrients to crop production.

Highlights of worldwide production and utilization of coal ash -- A survey for the period 1959--1989

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

Manz, O.E.; Stewart, B.R.

1997-09-01

In 1960, the Coal Committee for the United Nations Economic Committee for Europe requested a group of rapporteurs to undertaken work on the utilization of ash from coal fueling thermal power stations. This later became the Group of Experts on the Utilization of Ash. In 1959, out of a world production of 100 million tons of ash, only 2% was put to use, whereas in 1969, about 15% of a production of 200 million tons was used. In 1989, 562 million tons were produced, and 90.5 million tons were used. The main uses of coal ash have been in cementmore » and concrete manufacture; in road construction and as filler on construction sites; in cellular concrete; and in lightweight aggregate and brick. Worldwide, in 1989, 27.7 million tons were used in cement and concrete manufacture, 23.6 million tons in road construction and as filler on construction sites, 2.8 million tons in cellular concrete, and 6.8 million tons in lightweight aggregate and bricks. This paper presents a worldwide survey of the production and utilization of coal ash from 1959 to 1989. The data were collected from various working papers of the US Group of Experts on the utilization of Ash and from two papers by O.E. Manz on the worldwide production and utilization of coal ash.« less

New-Generation Sealing Slurries For Borehole Injection Purposes

NASA Astrophysics Data System (ADS)

Stryczek, Stanisław; Gonet, Andrzej; Wiśniowski, Rafał; Złotkowski, Albert

2015-12-01

The development of techniques and technologies thanks to which parameters of the ground medium can be modified makes specialists look for new recipes of geopolymers - binders for the reinforcing and sealing of unstable and permeable grounds. The sealing slurries are expected to meet a number of strict requirements, therefore it is important to find new admixtures and additives which could modify the fresh and hardened slurry. Special attention has been recently paid to the fluid ash - a by-product of the combustion of hard coals. However, the use of this additive is associated with the application of appropriate superplastifier. Laboratory analyses of rheological parameters of fresh sealing slurries and the ways of improving their liquidity by a properly selected third-generation superplastifier are presented in the paper. The slurries were based on Portland cement CEM I, milled granulated large-furnace slag and fly ash from fluidized-bed combustion of hard coal.

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

Bottom ash test section evaluation Erwinville, LA.

DOT National Transportation Integrated Search

2009-02-01

Bottom ash is a by-product of the energy industry and the residual of burning coal in a kiln : firing process. Bottom ash is black and the consistency of coarse sand with gravel clinker : traces. The product is used in other states as embankment mate...

Environmentally friendly use of non-coal ashes in Sweden.

PubMed

Ribbing, C

2007-01-01

The Swedish Thermal Engineering Research Institute (Värmeforsk) initiated an applied research program "Environmentally friendly use of non-coal ashes", in 2002. The program aims at increasing knowledge on the by-products of energy production and their application. The goal of formulating technical and environmental guidelines and assessments is a major point of the program, which is supported by about forty authorities and private organisations. The programme has been divided into four areas: recycling of ashes to forests, geotechnical applications, use in landfilling, and environmental aspects and chemistry. Among all results obtained, the following progress is shown: *Evidence for the positive effects of spreading ashes on forest growth. *A proposal for environmental guidelines on the utilisation of ashes in construction. *A handbook for using non-coal fly ashes in unpaved roads. *Technical and environmental assessments of MSWI bottom ashes in road construction. *Development of the use of ashes with municipal wastewater sludge as a cover for landfills and mine tailings. *Use of ashes from bio-fuels in concrete and replacement of cement in stoop mining. *A method to classify those by-products from combustion that have mirror entries in the EWC as a hazardous or non-hazardous compound. The Ash Programme has also made it possible to increase knowledge on ashes as valuable materials, on quality assurance and on markets for recovered materials.

Metal Recovery from Industrial Solid Waste — Contribution to Resource Sustainability

NASA Astrophysics Data System (ADS)

Yang, Yongxiang

Increased demand of metals has driven the accelerated mining and metallurgical production in recent years, causing fast depletion of primary metals resources. On the contrary, the mining and metallurgical industry generates large amount of solid residues and waste such as tailings, slags, flue dust and leach residues, with relative low valuable metal contents. On the other hand, end-of-life (EoL) consumer products form another significant resources. The current technology and processes for primary metals production are not readily applicable for direct metals extraction from these waste materials, and special adaptation and tailor-made processes are required. In the present paper, various solid waste resources are reviewed, and current technologies and R&D trends are discussed. The recent research at author's group is illustrated for providing potential solutions to future resource problems, including metal recovery from MSW incinerator bottom ashes, zinc recovery from industrial ashes and residues, and rare earth metals recovery from EoL permanent magnets.

Wastes and by-products - alternatives for agricultural use

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

Boles, J.L.; Craft, D.J.; Parker, B.R.

1994-10-01

Top address a growing national problem with generation of wastes and by-products, TVA has been involved for several years with developing and commercializing environmentally responsible practices for eliminating, minimizing, or utilizing various wastes/by-products. In many cases, reducing waste generation is impractical, but the wastes/by-products can be converted into other environmentally sound products. In some instances, conversion of safe, value-added agricultural products in the best or only practical alternative. TVA is currently involved with a diversity of projects converting wastes/by-products into safe, economical, and agriculturally beneficial products. Environmental improvement projects have involved poultry litter, cellulosic wastes, used battery acid, ammonium sulfatemore » fines, lead smelting effluents, deep-welled sulfuric acid/ammonium bisulfate solutions, wood ash, waste magnesium ammonium sulfate slurry from recording tape production, and ammunition plant waste sodium nitrate/ammonium nitrate streams.« less

Prediction of the Chloride Resistance of Concrete Modified with High Calcium Fly Ash Using Machine Learning

PubMed Central

Marks, Michał; Glinicki, Michał A.; Gibas, Karolina

2015-01-01

The aim of the study was to generate rules for the prediction of the chloride resistance of concrete modified with high calcium fly ash using machine learning methods. The rapid chloride permeability test, according to the Nordtest Method Build 492, was used for determining the chloride ions’ penetration in concrete containing high calcium fly ash (HCFA) for partial replacement of Portland cement. The results of the performed tests were used as the training set to generate rules describing the relation between material composition and the chloride resistance. Multiple methods for rule generation were applied and compared. The rules generated by algorithm J48 from the Weka workbench provided the means for adequate classification of plain concretes and concretes modified with high calcium fly ash as materials of good, acceptable or unacceptable resistance to chloride penetration. PMID:28793740

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.

Artificial lightweight aggregates as utilization for future ashes - A case study.

PubMed

Sarabèr, Angelo; Overhof, Robert; Green, Terry; Pels, Jan

2012-01-01

In the future, more electricity in the Netherlands will be produced using coal with co-combustion. Due to this, the generated annual ash volume will increase and the chemical composition will be influenced. One of the options for utilization if present markets are saturated and for use of fly ashes with different compositions, is as raw material for lightweight aggregates. This was selected as one of the best utilizations options regarding potential ash volume to be applied, environmental aspects and status of technology. Because of this, a study has been performed to assess the potential utilization of fly ash for the production of lightweight aggregate. Lightweight aggregate has been produced in a laboratory scale rotary kiln. The raw material consisted of class F fly ash with high free lime content. An addition of 8% clay was necessary to get green pellets with sufficient green strength. The basic properties of the produced lightweight aggregate and its behaviour in concrete have been investigated. The concrete has a good compressive strength and its leaching behaviour meets the most stringent requirements of Dutch environmental regulations. The carbon foot print of concrete will be negatively influenced if only the concrete itself is taken into account, but the reduction of the volume weight has advantages regarding design, transport emissions and isolation properties which may counteract this. In the Dutch situation the operational costs are higher than expected potential selling price for the LWA, which implies that the gate fee for the fly ash is negative. Copyright © 2011 Elsevier Ltd. All rights reserved.

Exposure-Reducing Behaviors Among Residents Living Near a Coal Ash Storage Site.

PubMed

Zierold, Kristina M; Sears, Clara G; Brock, Guy N

2016-10-01

Coal ash, a waste product generated from burning coal for energy, is composed of highly respirable particles containing heavy metals, radioactive elements, and polycylic aromatic hydrocarbons. Coal ash is stored in landfills and surface impoundments frequently located near neighborhoods. Fugitive dust from the storage sites exposes neighborhoods, affecting the health and welfare of residents. The research questions of interest were (1) are community members concerned about coal ash exposure from the storage site; (2) what, if any, behaviors do community members engage in to reduce exposure; and (3) do exposure reducing behaviors differ by level of concern about coal ash. A community-based mixed-methods approach was used. Focus groups (n = 26) were conducted in 2012, and a cross-sectional survey was administered in 2013 (n = 231). The majority of survey respondents (62%) worried "a lot" about being exposed to coal ash; however, most did not engage in exposure-reducing behaviors, such as wearing protective equipment when doing chores. Compared with respondents who worry "some, very little, or none," or responded "I don't know," respondents who worried "a lot" about being exposed to coal ash did more exposure-reducing behaviors outdoors (p < .001) and indoors (p = .01). For people living near environmental hazards, reducing exposure is a priority. Although challenging because of the chronic nature of exposure, some behaviors can be useful in reducing exposure, such as wearing a particle-specific respirator when mowing the lawn. Communities at risk for chronic exposure to environmental toxins could benefit from education about exposure-reducing behaviors. © 2015 Society for Public Health Education.

Thermal treatment of stabilized air pollution control residues in a waste incinerator pilot plant. Part 2: Leaching characteristics of bottom ashes.

PubMed

Baun, Dorthe L; Christensen, Thomas H; Bergfeldt, Brita; Vehlow, Jürgen; Mogensen, Erhardt P B

2004-02-01

With the perspective of generating only one solid residue from waste incineration, co-feeding of municipal solid waste and air pollution control residues stabilized by the Ferrox process was investigated in the TAMARA pilot plant incinerator as described in Bergfeldt et al. (Waste Management Research, 22, 49-57, 2004). This paper reports on leaching from the combined bottom ashes. Batch leaching test, pH-static leaching tests, availability tests and column leaching tests were used to characterize the leaching properties. The leaching properties are key information in the context of reuse in construction or in landfilling of the combined residue. In general, the combined bottom ashes had leaching characteristics similar to the reference bottom ash, which contained no APC residue. However, As and Pb showed slightly elevated leaching from the combined bottom ashes, while Cr showed less leaching. The investigated combined bottom ashes had contents of metals comparable to what is expected at steady state after continuous co-feeding of APC residues. Only Cd and Pb were partly volatilized (30-40%) during the incineration process and thus the combined bottom ashes had lower contents of Cd and Pb than expected at steady state. Furthermore, a major loss of Hg was, not surprisingly, seen and co-feeding of Ferrox-products together with municipal solid waste will require dedicated removal of Hg in the flue gas to prevent a build up of Hg in the system. In spite of this, a combined single solid residue from waste incineration seems to be a significant environmental improvement to current technology.

Volcanic ash impacts on critical infrastructure

NASA Astrophysics Data System (ADS)

Wilson, Thomas M.; Stewart, Carol; Sword-Daniels, Victoria; Leonard, Graham S.; Johnston, David M.; Cole, Jim W.; Wardman, Johnny; Wilson, Grant; Barnard, Scott T.

2012-01-01

Volcanic eruptions can produce a wide range of hazards. Although phenomena such as pyroclastic flows and surges, sector collapses, lahars and ballistic blocks are the most destructive and dangerous, volcanic ash is by far the most widely distributed eruption product. Although ash falls rarely endanger human life directly, threats to public health and disruption to critical infrastructure services, aviation and primary production can lead to significant societal impacts. Even relatively small eruptions can cause widespread disruption, damage and economic loss. Volcanic eruptions are, in general, infrequent and somewhat exotic occurrences, and consequently in many parts of the world, the management of critical infrastructure during volcanic crises can be improved with greater knowledge of the likely impacts. This article presents an overview of volcanic ash impacts on critical infrastructure, other than aviation and fuel supply, illustrated by findings from impact assessment reconnaissance trips carried out to a wide range of locations worldwide by our international research group and local collaborators. ‘Critical infrastructure’ includes those assets, frequently taken for granted, which are essential for the functioning of a society and economy. Electricity networks are very vulnerable to disruption from volcanic ash falls. This is particularly the case when fine ash is erupted because it has a greater tendency to adhere to line and substation insulators, where it can cause flashover (unintended electrical discharge) which can in turn cause widespread and disruptive outages. Weather conditions are a major determinant of flashover risk. Dry ash is not conductive, and heavy rain will wash ash from insulators, but light rain/mist will mobilise readily-soluble salts on the surface of the ash grains and lower the ash layer’s resistivity. Wet ash is also heavier than dry ash, increasing the risk of line breakage or tower/pole collapse. Particular issues for water supply managers include: monitoring turbidity levels in raw water intakes, and if necessary increasing chlorination to compensate for higher turbidity; managing water demand; and communicating monitoring results with the public to allay fears of contamination. Ash can cause major damage to wastewater disposal systems. Ash deposited onto impervious surfaces such as roads and car parks is very easily washed into storm drains, where it can form intractable masses and lead to long-term flooding problems. It can also enter wastewater treatment plants (WWTPs), both through sewer lines and by direct fallout. Damage to modern WWTPs can run into millions of dollars. Ash falls reduce visibility creating hazards for ground transportation. Dry ash is also readily remobilised by vehicle traffic and wind, and dry and wet ash deposits will reduce traction on paved surfaces, including airport runways. Ash cleanup from road and airports is commonly necessary, but the large volumes make it logistically challenging. Vehicles are vulnerable to ash; it will clog filters and brake systems and abrade moving parts within engines. Lastly, modern telecommunications networks appear to be relatively resilient to volcanic ash fall. Signal attenuation and interference during ash falls has not been reported in eruptions over the past 20 years, with the exception of interference from ash plume-generated lightning. However, some telecommunications equipment is vulnerable to airborne ash, in particular heating, ventilation and air-conditioning (HVAC) systems which may become blocked from ash ingestion leading to overheating. This summary of volcanic ash impacts on critical infrastructure provides insight into the relative vulnerability of infrastructure under a range of different ashfall scenarios. Identifying and quantifying these impacts is an essential step in building resilience within these critical systems. We have attempted to consider interdependencies between sectors in a holistic way using systems thinking. As modern society becomes increasingly complex and interdependent this approach is likely to become increasingly necessary.

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.

COAL-FIRED POWER PLANT ASH UTILIZATION IN THE TVA REGION

EPA Science Inventory

The report gives results of a study: (1) to summarize (a) production of coal ash nationally and by TVA's 12 major ash-producing steam/electric power plants, and (b) the physical/chemical characteristics of coal ash that affect ash disposal and/or use; (2) to review reported metho...

Thermal treatment and vitrification of boiler ash from a municipal solid waste incinerator.

PubMed

Yang, Y; Xiao, Y; Voncken, J H L; Wilson, N

2008-06-15

Boiler ash generated from municipal solid waste (MSW) incinerators is usually classified as hazardous materials and requires special disposal. In the present study, the boiler ash was characterized for the chemical compositions, morphology and microstructure. The thermal chemical behavior during ash heating was investigated with thermal balance. Vitrification of the ash was conducted at a temperature of 1400 degrees C in order to generate a stable silicate slag, and the formed slag was examined with chemical and mineralogical analyses. The effect of vitrification on the leaching characteristics of various elements in the ash was evaluated with acid leaching. The study shows that the boiler ash as a heterogeneous fine powder contains mainly silicate, carbonate, sulfates, chlorides, and residues of organic materials and heavy metal compounds. At elevated temperatures, the boiler ash goes through the initial moisture removal, volatilization, decomposition, sintering, melting, and slag formation. At 1400 degrees C a thin layer of salt melt and a homogeneous glassy slag was formed. The experimental results indicate that leaching values of the vitrified slag are significantly reduced compared to the original boiler ash, and the vitrification could be an interesting alternative for a safer disposal of the boiler ash. Ash compacting, e.g., pelletizing can reduce volatilization and weight loss by about 50%, and would be a good option for the feed preparation before vitrification.

Impact of volcanic eruptions on the marine carbon cycle

NASA Astrophysics Data System (ADS)

Segschneider, Joachim; Ulrike, Niemeier; Martin, Wiesner; Claudia, Timmreck

2010-05-01

The impact of volcanic eruptions on the marine carbon cycle is investigated for the example of the Pinatubo eruption with model simulations of the distribution of the ash cloud and deposition on the ocean surface and the impact of the nutrient addition from ash leachates on the oceanic biological production and hence biological carbon pump. Natural variations of aerosols, especially due to large-magnitude volcanic eruptions, are recognized as a significant climate forcing, altering the Earth's radiation balance and thus tending to cause global temperature changes. While the impact of such events on climate and the terrestrial biosphere is relatively well documented, scientific knowledge of their effects on marine ecosystems and consequent feedbacks to the atmosphere is still very limited. In the deep sea, subaerial eruptive events of global significance are commonly recorded as widespread ash layers, which were often found to be associated with increased abundances of planktic organisms. This has led to the hypothesis that the influx of volcanic ash may provide an external nutrient source for primary production (in particular through iron fertilization) in ocean surface waters. Recent laboratory experiments have demonstrated that pristine volcanic ash indeed releases significant amounts of macronutrients and bioactive trace metals (including phosphate, iron and silica) adsorbed to the surface of the ash particles. The release of these components most likely has its largest impact in ocean regions where their availability is crucial for the growth of oceanic biomass, which are the high-nutrient but low-productivity (low-iron) areas in the Pacific and the Southern Ocean. These in turn are neighbored by most of those subaerially active volcanoes that are capable of ejecting huge amounts of aerosols into the high-velocity stratospheric wind fields. The dispersal and fallout of ash thus has a high potential to induce globally significant, transient net CO2 removal from the upper ocean and hence the atmosphere. Large-magnitude eruptions such as of Mount Pinatubo in 1991 were in fact followed by a slowing-down in the increase of atmospheric CO2 for several years, entailing a weakening of the global warming trend. For Mount Pinatubo it has been argued that the estimated CO2 uptake (1.6 x 1015 g C) could have been caused by rapid iron fertilization of the Southern Ocean with about 6.3 x 1015 g of ash. However, this would approximate the overall amount of the ash generated by the eruption, of which about 80% fell out over the South China Sea (~4.9 x 1015 g). This suggests additional avenues for the removal of CO2, among which the 1991 explosive eruption of Cerro Hudson could have played an important role as more than 2 km3 of the aerosols released by the volcano fell out directly over the Southern Ocean.

Ocean iron-fertilisation by volcanic ash

NASA Astrophysics Data System (ADS)

Langmann, B.; Zaksek, K.; Hort, M. K.; Duggen, S.

2009-12-01

Marine primary productivity (MPP) can be limited by the availability of macro-nutrients like nitrate and phosphate. In so-called ‘High-Nutrient-Low-Chlorophyll’ (HNLC) areas, macro-nutrient concentrations are high, but iron is the key biologically limiting micro-nutrient for primary production. Three major sources for iron supply into the ocean have been considered so far: upwelling of deep ocean water, advection from the continental margins and atmospheric deposition with aeolian dust deposition commonly assumed to dominate external iron supply to the open ocean. Iron supply to HNLC regions can affect climate relevant ocean-atmosphere exchanges of chemical trace species, e.g. organic carbon aerosols, DMS and CO2. Marine aerosols can act as efficient cloud condensation nuclei and significantly influence cloud properties and thus the Earth’s radiative budget via the indirect aerosol effects whereas a drawdown of atmospheric CO2 due to ocean fertilisation can have important implications for the global CO2 budget. Recent laboratory experiments suggest that material from volcanic eruptions such as ash may also affect the MPP through rapid iron-release on contact with seawater. Direct evidence, however, that volcanic activity can cause natural iron-fertilisation and MPP increase has been lacking so far. Here first evidence for a large-scale phytoplankton bloom in the NE Pacific resulting from volcanic ash fall after the eruption of Kasatochi volcano in August 2008 is presented. Atmospheric and oceanic conditions were favourable to generate this phytoplankton bloom. We present satellite observations to show the connection between volcanic ash fall and oceanic MPP. In addition, three-dimensional atmosphere/chemistry-aerosol model results are presented showing the atmospheric distribution of volcanic ash and its fall-out after the eruption of Kasatochi volcano. The amount of ash and that of iron attached to it is sufficient to explain measured seawater CO2 decrease at the ocean station Papa in August 2008 as well as the phytoplankton bloom in the Gulf of Alaska.

The current state of the science related to the re-release of mercury from coal combustion products

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

Debra F. Pflughoeft-Hassett; David J. Hassett; Loreal V. Heebink

2006-07-01

The stability of mercury associated with CCPs is an issue that has only recently been under investigation but has become a prominent question as the industry strives to determine if current management options for CCPs will need to be modified. Mercury and other air toxic elements can be present in fly ash, FGD material and bottom ash and boiler slag. Mercury concentrations ranging from {lt} 0.01 to 2.41 ppm in fly ash and from 0.001 to 0.342 ppm in bottom ash have been reported. Stability of mercury must be evaluated by tests that include 1) direct leachability; 2) vapor-phase releasemore » at ambient and elevated temperatures; and 3) microbiologically induced leachability and vapor-phase release. The amount of mercury leached from currently produced CCPs is extremely low and does not appear to represent an environmental or re-release hazard. Concentrations of mercury in leachates from fly ashes and FGD material using either the toxicity characteristic leaching procedure (TCLP) or the synthetic groundwater leaching procedure (SGLP) are generally below detection limits. The release of mercury vapor from CCPs resulting from the use of mercury control technologies has been evaluated on a limited basis. Research indicates that mercury bound to the ash or activated carbon is fairly stable. The EERC found that organomercury species were detected at very low levels both in the vapor and leachate generated from the microbiologically mediated release experiments. The current state of the science indicates that mercury associated with CCPs is stable and highly unlikely to be released under most management conditions, including utilisation and disposal. The exception to this is exposure to high temperatures such as those that may be achieved in cement and wallboard production. Therefore, existing CCPs management options are expected to be environmentally sound options for CCPs from systems with mercury control technologies installed. 2 refs., 2 photos.« less

Optimization of hydrogen and syngas production from PKS gasification by using coal bottom ash.

PubMed

Shahbaz, Muhammad; Yusup, Suzana; Inayat, Abrar; Patrick, David Onoja; Pratama, Angga; Ammar, Muhamamd

2017-10-01

Catalytic steam gasification of palm kernel shell is investigated to optimize operating parameters for hydrogen and syngas production using TGA-MS setup. RSM is used for experimental design and evaluating the effect of temperature, particle size, CaO/biomass ratio, and coal bottom ash wt% on hydrogen and syngas. Hydrogen production appears highly sensitive to all factors, especially temperature and coal bottom ash wt%. In case of syngas, the order of parametric influence is: CaO/biomass>coal bottom ash wt%>temperature>particle size. The significant catalytic effect of coal bottom ash is due to the presence of Fe 2 O 3 , MgO, Al 2 O 3 , and CaO. A temperature of 692°C, coal bottom ash wt% of 0.07, CaO/biomass of 1.42, and particle size of 0.75mm are the optimum conditions for augmented yield of hydrogen and syngas. The production of hydrogen and syngas is 1.5% higher in the pilot scale gasifier as compared to TGA-MS setup. Copyright © 2017 Elsevier Ltd. All rights reserved.

Investigation on by-products of bioenergy systems (anaerobic digestion and gasification) as potential crop nutrient using FTIR, XRD, SEM analysis and phyto-toxicity test.

PubMed

Kataki, Sampriti; Hazarika, Samarendra; Baruah, D C

2017-07-01

Success and acceptability of the bio energy conversion technology to a large extent depend upon management of the inevitable by-products generated during the conversion process. By-products can be considered favourable as organic fertilizer as they retain nutrients with varying composition depending upon input biomass. However, characteristics of these heterogeneous resources with respect to feedstock and processing conditions have to be assessed to state on their agricultural and environmental benefits. Therefore, 3 types of anaerobic digestion by-products (digestate) from surplus biomass viz. cow dung, Ipomoea carnea:cow dung (60:40 dry weight basis) and rice straw:green gram stover:cow dung (30:30:40 dry weight basis) and one gasification by-product (biochar) from rice husk are considered to understand the fertilizer prospects. Considering 3 potential application options, digestate from each feedstock option was further processed as separated solid, separated liquid and ash from solid digestates. Thus, a total of 10 by-products were investigated for understanding their prospects as fertilizer using Fourier Transform Infrared Spectroscopy (FTIR), X-ray diffraction (XRD), Scanning Electron Microscopy (SEM) and Energy Dispersive X ray Spectroscopy (EDX) and phyto-toxicity test to have a broad insight in terms of their organic, mineral, elemental composition, morphological feature and potential phyto-toxicity. In general, irrespective of origin of feedstock, solid digestate, ash digestate and char showed similarity in terms of composition of functional groups with some degree of variation in relative content as reflected by FTIR analysis. Dominance of organic functional groups in separated solid digestates compared to liquid fraction indicated the former as favourable organic amendments. Quartz was the prevalent mineral phase in all separated solid, ash digestate and rice husk char. Digestates in ash phase represent more concentrated plant nutrient source with higher content of K, Ca, P, Na and Mg than their respective solid phase. Application of ash digestates and char is likely to improve adsorptive capacity of soil for water and nutrient due to presence of relatively uniformly distributed porous particles. Liquid fraction of Ipomoea digestates exhibited inhibitory effect on seed germination of greengram (Vigna radiate) with significant reduction of germination index. Inhibitory effects of by-products were found to correlate negatively with their electrical conductivity and ammonia-nitrogen content. Understanding on spectroscopic, morphological and phytotoxic properties of different application options of bioenergy by-products would be useful for assessment of their appropriate use in agriculture. Copyright © 2017 Elsevier Ltd. All rights reserved.

Evaluation of various agro-wastes for traditional black soap production.

PubMed

Taiwo, O E; Osinowo, F A

2001-08-01

The agricultural wastes, cocoa-pod husks, palm-bunch waste, sorghum chaff and groundnut shells, which are normally thrown away have been used in the production of black soap. Unlike other soaps which are made from oils and chemicals, black soap is made from oils and agro-wastes ashes. Chemical analysis indicated that the liquid extract from the ashes of the different agro-wastes used contained various amounts of potassium and sodium compounds. The most common ingredient in the agro-wastes was potassium carbonate. The amount of potassium carbonate was 56.73 +/- 0.16% in cocoa-pod ash, 43.15 +/- 0.13% in palm-bunch ash, 16.65 +/- 0.05% in groundnut shell ash and 12.40 +/- 0.08% in sorghum chaff ash. Soaps made from the agro-wastes ashes had excellent solubility, consistency, cleansing and lathering abilities.

Biotic and abiotic factors affect green ash volatile production and emerald ash borer adult feeding preference.

PubMed

Chen, Yigen; Poland, Therese M

2009-12-01

The emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), is an exotic woodborer first detected in 2002 in Michigan and Ontario and is threatening the ash resource in North America. We examined the effects of light exposure and girdling on green ash (Fraxinus pennsylvanica Marsh) volatile production, and effects of light exposure, girdling, and leaf age on emerald ash borer adult feeding preferences and phototaxis. Green ash seedlings grown under higher light exposure had lower amounts of three individual volatile compounds, (Z)-3-hexenol, (E)-beta-ocimene, and (Z,E)-alpha-farnesene, as well as the total amount of six detected volatile compounds. Girdling did not affect the levels of these volatiles. Emerald ash borer females preferred mature leaves, leaves from girdled trees, and leaves grown in the sun over young leaves, leaves from nongirdled trees, and leaves grown in the shade, respectively. These emerald ash borer preferences were most likely because of physical, nutritional, or biochemical changes in leaves in response to the different treatments. Emerald ash borer females and males showed positive phototaxis in laboratory arenas, a response consistent with emerald ash borer preference for host trees growing in sunlight.

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.

Classification and categorization of treatment methods for ash generated by municipal solid waste incineration: a case for the 2 greater metropolitan regions of Greece.

PubMed

Karagiannidis, A; Kontogianni, St; Logothetis, D

2013-02-01

The primary goal of managing MSW incineration residues is to avoid any impact on human health or the environment. Incineration residues consist of bottom ash, which is generally considered as rather harmless and fly ash which usually contains compounds which are potentially harmful for public health. Small quantities of ash (both bottom and fly) are produced currently in Greece, mainly from the healthcare waste incineration facility in Attica region. Once incineration plants for MSW (currently under planning) are constructed in Greece, the produced ash quantities will increase highly. Thus, it is necessary to organize, already at this stage, a roadmap towards disposal/recovery methods of these ash quantities expected. Certain methods, related to the treatment of the future generated ash which are more appropriate to be implemented in Greece are highlighted in the present paper. The performed analysis offers a waste management approach, having 2016 as a reference year for two different incineration rates; 30% and 100% of the remaining MSW after recycling process. The results focus on the two greater regions of Greece: Attica and Central Macedonia. The quantity of potential future ash generation ranges from 137 to 459 kt for Attica region and from 62 to 207 kt for central Macedonia region depending on the incineration rate applied. Three alternative scenarios for the treatment of each kind of ash are compiled and analysed. Metal recovery and reuse as an aggregate in concrete construction proved to be the most advantageous -in terms of economy-bottom ash management scenario. Concerning management of the fly ash, chemical treatment with phosphoric solution addition results to be the lowest total treatment cost and is considered as the most profitable solution. The proposed methodology constitutes a safe calculation model for operators of MSW incineration plants regardless of the region or country they are located in. Crown Copyright © 2012. Published by Elsevier Ltd. All rights reserved.

A life history study of the ash seed weevils, Thysanocnemis bischoffi Blatchley and T. Helvola leconte (Coleoptera: curculionidae)

Treesearch

Jack H. Barger; Ralph H. Davidson

1967-01-01

A life history study was made of the ash seed weevils, Thysanocnemis bischoffi Blatchley and T. helvola LeConte. Over-wintering occurs as larvae in ash seeds or in soil, with adults appearing in July and August. Adults soon deposit eggs within ash seeds, where larval development occurs. Only one generation...

Natural enemies implicated in the regulation of an invasive pest: a life table analysis of the population dynamics of the emerald ash Borer

USDA-ARS?s Scientific Manuscript database

The emerald ash borer (EAB), Agrilus planipennis Fairmaire, is a serious invasive forest pest that has killed tens of millions of ash (Fraxinus) trees in the United States and Canada. By caging EAB adults on trunks of healthy ash trees, we established three generations of experimental cohorts from ...

Chemical and engineering properties of fired bricks containing 50 weight percent of class F fly ash

USGS Publications Warehouse

Chou, I.-Ming; Patel, V.; Laird, C.J.; Ho, K.K.

2001-01-01

The generation of fly ash during coal combustion represents a considerable solid waste disposal problem in the state of Illinois and nationwide. In fact, the majority of the three million tons of fly ash produced from burning Illinois bituminous coals is disposed of in landfills. The purpose of this study was to obtain a preliminary assessment of the technical feasibility of mitigating this solid waste problem by making fired bricks with the large volume of fly ash generated from burning Illinois coals. Test bricks were produced by the extrusion method with increasing amounts (20-50% by weight) of fly ash as a replacement for conventional raw materials. The chemical characteristics and engineering properties of the test bricks produced with and without 50 wt% of fly ash substitutions were analyzed and compared. The properties of the test bricks containing fly ash were at least comparable to, if not better than, those of standard test bricks made without fly ash and met the commercial specifications for fired bricks. The positive results of this study suggest that further study on test bricks with fly ash substitutions of greater than 50wt% is warranted. Successful results could have an important impact in reducing the waste disposal problem related to class F fly ash while providing the brick industry with a new low cost raw material. Copyright ?? 2001 Taylor & Francis.

Long-term strength properties of HVFA concretes

NASA Astrophysics Data System (ADS)

Špak, M.; Bašková, R.

2015-01-01

Fly ash from coal burning is used as active addition for concrete in Middle-Europe region for several decades. The intensity of its utilization increases still. In the role of supplementary cement addition it serves as binder, whereby it helps to reduce final price of concrete as well as improves both the rheological properties of fresh concrete and several characteristics of hardened concrete. Fly ash presents the co-product of energetic industry. Its production increases together with growth of energy consumption. These factors bring the opportunity and requirement of production of concretes with high volume of fly ash based addition. Thus, significant economic, environmental, technological and technical benefits can be achieved by using of high amount of fly ash for concrete production.

Eyjafjallajökull2010 - The activity of the eruption plume during the first 2 weeks

NASA Astrophysics Data System (ADS)

Sigurősson, Árni; Pálmason, Bolli; Hlíőar Jensen, Esther; Petersen, Gudrun Nina; Björnsson, Halldór; Şorsteinsson, Hróbjartur; Arason, Şórőur

2010-05-01

On 14 April 2010 an eruption started in Eyjafjallajökull, in southern Iceland. This was an explosive eruption in the caldera, beneath the glacier. During the first two weeks the eruption went through two phases, an explosive phase with much tephra and ash production and a calmer phase with less productivity and some lava production. During the explosive phase 14-17 April, the plume altititude was about 5-7 km but occasionally increased up to 8 km height, there was lightning activity in the plume and the material produced was mainly ash and tephra. It is estimated that the production was peaked at about 750 tons/s. The local ash fall on 17 April was the worst by far for the local community to the south of the volcano as about a 1 km thick ash cloud flowed almost continuously from the volcano and over the region. During this phase the upper level winds over Iceland were strong, northwesterly 40-50 m/s, and the emitted ash was advected southeastward toward northwestern Europe. This caused major disruption in air traffic. During the second phase 18-29 April there was a reduced net output form the volcano, lava production was estimated as 10-30 tons/s and tephra and ash production of less than 10 tons/s. The height of the plume was estimated as 3-5 km. Local ash fall predictions were made for the areas within a 500 km radius from the eruption site and prediction maps published on the website of the Icelandic Met Office. Information on local ash fall were collected from synoptic weather stations but also from the general public and the media. An internet web registration form was made public and advertised. In 6 days 95 reports of ash fall were made. This information together with other ground observations and remote sense observations are important for validations of ash fall prediction, near field and far field, as well as ensuring that the impact of the volcanic eruption is well understood, in a geological, geophysical and biological sense but also the societal impact on the communities affected.

Alkali content of fly ash : measuring and testing strategies for compliance.

DOT National Transportation Integrated Search

2015-04-01

Sodium and potassium are the common alkalis present in fly ash. Excessive amounts of fly ash alkalis can cause efflorescence : problems in concrete products and raise concern about the effectiveness of the fly ash to mitigate alkali-silica reaction (...

Self-cementitious properties of fly ashes from CFBC boilers co-firing coal and high-sulphur petroleum coke

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

Sheng Guanghong; Li Qin; Zhai Jianping

2007-06-15

Self-cementitious properties of fly ash from circulating fluidized bed combustion boiler co-firing coal and high-sulphur petroleum coke (CPFA) were investigated. CPFA was self-cementitious which was affected by its fineness and chemical compositions, especially the contents of SO{sub 3} and free lime (f-CaO). Higher contents of SO{sub 3} and f-CaO were beneficial to self-cementitious strength; the self-cementitious strength increases with a decrease of its 45 {mu}m sieve residue. The expansive ratio of CPFA hardened paste was high because of generation of ettringite (AFt), which was influenced by its water to binder ratio (W/A), curing style and grinding of the ash. Themore » paste cured in water had the highest expansive ratio, and grinding of CPFA was beneficial to its volume stability. The hydration products of CPFA detected by X-ray diffraction (XRD) and scanning electron microscopy (SEM) were portlandite, gypsum, AFt and hydrated calcium silicate (C-S-H)« less

Control of emerald ash borer adults and larvae with insecticides

Treesearch

Deborah G. McCullough; David Cappaert; Therese Poland; David R. Smitley

2003-01-01

Virtually no information is available from Asia regarding the ability of insecticide products and application methods to protect ash trees from emerald ash borer. Many landscapers in the Core infestation in southeastern Michigan have promoted various treatments to their customers, but there has been no objective evaluation of these products. Insecticides may also be...

Development of a sintering process for recycling oil shale fly ash and municipal solid waste incineration bottom ash into glass ceramic composite

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

Zhang, Zhikun; Zhang, Lei; Li, Aimin, E-mail: leeam@dlut.edu.cn

Highlights: • Glass ceramic composite is prepared from oil shale fly ash and MSWI bottom ash. • A novel method for the production of glass ceramic composite is presented. • It provides simple route and lower energy consumption in terms of recycling waste. • The vitrified slag can promote the sintering densification process of glass ceramic. • The performances of products decrease with the increase of oil shale fly ash content. - Abstract: Oil shale fly ash and municipal solid waste incineration bottom ash are industrial and municipal by-products that require further treatment before disposal to avoid polluting the environment.more » In the study, they were mixed and vitrified into the slag by the melt-quench process. The obtained vitrified slag was then mixed with various percentages of oil shale fly ash and converted into glass ceramic composites by the subsequent sintering process. Differential thermal analysis was used to study the thermal characteristics and determine the sintering temperatures. X-ray diffraction analysis was used to analyze the crystalline phase compositions. Sintering shrinkage, weight loss on ignition, density and compressive strength were tested to determine the optimum preparation condition and study the co-sintering mechanism of vitrified amorphous slag and oil shale fly ash. The results showed the product performances increased with the increase of sintering temperatures and the proportion of vitrified slag to oil shale fly ash. Glass ceramic composite (vitrified slag content of 80%, oil shale fly ash content of 20%, sintering temperature of 1000 °C and sintering time of 2 h) showed the properties of density of 1.92 ± 0.05 g/cm{sup 3}, weight loss on ignition of 6.14 ± 0.18%, sintering shrinkage of 22.06 ± 0.6% and compressive strength of 67 ± 14 MPa. The results indicated that it was a comparable waste-based material compared to previous researches. In particular, the energy consumption in the production process was reduced compared to conventional vitrification and sintering method. Chemical resistance and heavy metals leaching results of glass ceramic composites further confirmed the possibility of its engineering applications.« less

Rare and Rare-Earth Metals in Coal Processing Waste

NASA Astrophysics Data System (ADS)

Cherkasova, Tatiana; Cherkasova, Elizaveta; Tikhomirova, Anastasia; Bobrovni-kova, Alyona; Goryunova, Irina

2017-11-01

An urgent issue for power plants operating on solid fuels (coal) is the issue of utilization or use of accumulated production waste - ash and slag materials - in the related production. Ash-slag materials are classified as "waste", usually grade 5; tens of millions of tons of them being pro-duced annually in the Kemerovo region, which threatens the ecology of the region. At the same time, ash and slag is a very promising raw material. The use of this material as a base for the final product allows us to signifi-cantly expand the possibilities of using coal. The most widespread is the system of ash and slag involving in construction or as a replacement for sand in road construction, or as an additive to building mixtures. However, there are both industrially valuable and environmentally dangerous ele-ments in ash-slag materials. Ash-slag materials can be considered as inde-pendent ore deposits located on the surface and requiring the costs of their extraction.

Activation of fly ash

DOEpatents

Corbin, David R.; Velenyi, Louis J.; Pepera, Marc A.; Dolhyj, Serge R.

1986-01-01

Fly ash is activated by heating a screened magnetic fraction of the ash in a steam atmosphere and then reducing, oxidizing and again reducing the hydrothermally treated fraction. The activated fly ash can be used as a carbon monoxide disproportionating catalyst useful in the production of hydrogen and methane.

Activation of fly ash

DOEpatents

Corbin, D.R.; Velenyi, L.J.; Pepera, M.A.; Dolhyj, S.R.

1986-08-19

Fly ash is activated by heating a screened magnetic fraction of the ash in a steam atmosphere and then reducing, oxidizing and again reducing the hydrothermally treated fraction. The activated fly ash can be used as a carbon monoxide disproportionating catalyst useful in the production of hydrogen and methane.

Mercury and trace element distribution in density separates of a South African Highveld (#4) coal: Implications for mercury reduction and preparation of export coal

USGS Publications Warehouse

Kolker, Allan; Senior, Connie L.; van Alphen, Chris; Koenig, Alan E.; Geboy, Nicholas J.

2017-01-01

Eight density separates of Permian Highveld (#4) coal were investigated for partitioning of Hg and trace elements. The separates include float fractions obtained in heavy media having densities of 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, and 2.0 g/cm3, and the sink fraction for 2.0 g/cm3. Bulk analysis of the separates shows strong (R2 ≥ 0.80) positive correlations between pyritic sulfur and mercury, and between ash yield and both pyritic sulfur and mercury. Laser ablation (LA) ICP-MS analysis of individual pyrite grains in the separates confirms association of Hg and As with pyrite as indicated by bulk analysis. Other elements detected in pyrite by LA-ICP-MS include Mn, Co, Ni, Tl, and Pb. Results for the separates allow prediction of Hg, trace elements, and ash yields expected in specific South African coal products. These range from 0.06 ppm Hg and an ash yield of 11.5% ash for the export fraction to 0.47 ppm Hg and an ash yield of 60.9% for the discard (stone) fraction (dry basis). Results show pronounced differences expected between coal used for domestic power generation and coal which is exported.

Higher Activities of Defense-Associated Enzymes may Contribute to Greater Resistance of Manchurian Ash to Emerald Ash Borer Than A closely Related and Susceptible Congener.

PubMed

Rigsby, Chad M; Herms, Daniel A; Bonello, Pierluigi; Cipollini, Don

2016-08-01

Emerald ash borer (EAB) is an invasive beetle native to Asia that infests and kills ash (Fraxinus spp.) in North America. Previous experiments indicated that larvae feeding on co-evolved, resistant Manchurian ash (F. mandshurica) have increased antioxidant and quinone-protective enzyme activities compared to larvae feeding on susceptible North American species. Here, we examined mechanisms of host-generated oxidative and quinone-based stress and other putative defenses in Manchurian ash and the closely related and chemically similar, but susceptible, black ash (F. nigra), with and without exogenous application of methyl jasmonate (MeJA) to induce resistance mechanisms. Peroxidase activities were 4.6-13.3 times higher in Manchurian than black ash, although both species appeared to express the same three peroxidase isozymes. Additionally, peroxidase-mediated protein cross-linking activity was stronger in Manchurian ash. Polyphenol oxidase, β-glucosidase, chitinase, and lipoxygenase activities also were greater in Manchurian ash, but only lipoxygenase activity increased with MeJA application. Phloem H 2 O 2 levels were similar and were increased by MeJA application in both species. Lastly, trypsin inhibitor activity was detected in methanol and water extracts that were not allowed to oxidize, indicating the presence of phenolic-based trypsin inhibitors. However, no proteinaceous trypsin inhibitor activity was detected in either species. In response to MeJA application, Manchurian ash had higher trypsin inhibitor activity than black ash using the unoxidized water extracts, but no treatment effects were detected using methanol extracts. Based on these results we hypothesize that peroxidases, lignin polymerization, and quinone generation contribute to the greater resistance to EAB displayed by Manchurian ash.

Impact of secondary generated minerals on toxic element immobilization for air pollution control fly ash of a municipal solid waste incinerator.

PubMed

Kitamura, Hiroki; Dahlan, Astryd Viandila; Tian, Yu; Shimaoka, Takayuki; Yamamoto, Takashi; Takahashi, Fumitake

2018-05-12

Impacts of secondary generated minerals on mineralogical and physical immobilization of toxic elements were investigated for chelate-treated air pollution control (APC) fly ash of a municipal solid waste incinerator. Scanning electron microscope (SEM) observation showed that ettringite was generated after the moistening treatment with/without chelate. Although ettringite can incorporate toxic elements into its structure, elemental analysis by energy dispersive X-ray could not find concentrated points of toxic elements in ettringite structure. This implies that mineralogical immobilization of toxic element by the encapsulation to ettringite structure seems to be limited. Physical immobilization was also investigated by SEM observation of the same APC fly ash particles before and after the moistening treatment. The transfer of soluble elements was inhibited only when insoluble minerals such as gypsum were generated and covered the surface of fly ash particles. Neoformed insoluble minerals prevented soluble elements from leaching and transfer. However, such physical immobilization seems to be limited because insoluble mineral formation with surface coverage was monitored only one time of more than 20 observations. Although uncertainty owing to limited samples with limited observations should be considered, this study concludes that mineralogical and physical immobilization of toxic elements by secondary minerals is limited although secondary minerals are always generated on the surface of APC fly ash particles during chelate treatment.

Geoenvironmental impacts of using high carbon fly ash in structural fill applications : [research summary].

DOT National Transportation Integrated Search

2013-03-01

Coal power plants generate approximately 50% of the electricity in the : United States. As a result, large amounts of coal combustion byproducts, : especially fly ash, are produced annually. Only 40% of the fly ash : (mainly C and F-type classificati...

Biomass ash reutilisation as an additive in the composting process of organic fraction of municipal solid waste.

PubMed

Asquer, Carla; Cappai, Giovanna; De Gioannis, Giorgia; Muntoni, Aldo; Piredda, Martina; Spiga, Daniela

2017-11-01

In this work the effects of selected types of biomass ash on the composting process and final product quality were studied by conducting a 96-day long experiment where the source separated organic fraction of municipal waste, mixed with wood prunings that served as bulking agent, was added with 0%, 2%, 4% and 8% wt/wt of biomass ash. The evolution over time of the main process parameters was observed, and the final composts were characterised. On the basis of the results, both the composting process and the quality of the final product were improved by ash addition. Enhanced volatile solids reduction and biological stability (up to 32% and 52%, respectively, as compared to the unamended product) were attained when ash was added, since ash favored the aerobic degradation by acting asa physical conditioner. In the final products, higher humification of organic matter (expressed in terms of the humification index, that was 2.25 times higher in the most-enriched compost than in the unamended one) and total Ca, K, Mg and P content were observed when ash was used. The latter aspect may influence the composts marketability positively, particularly with regards to potassium and phosphorus. The heavy metals content, that is regarded as the main environmental disadvantage when using ash asa composting additive, did not negatively affect the final composts quality. However, some other controversial effects of ash, related to the moisture and temperature values attained during the process, pH (8.8-9.2 as compared to 8.2 of the unamended compost) and electrical conductivity levels (up to 53% higher as compared to the unamended compost) in the final composts, were also observed. Copyright © 2017 Elsevier Ltd. All rights reserved.

Estimating potential emerald ash borer (Coleoptera: Buprestidae) populations using ash inventory data.

PubMed

McCullough, Deborah G; Siegert, Nathan W

2007-10-01

Emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), a phloem-feeding pest native to Asia, was identified in June 2002 as the cause of widespread ash (Fraxinus spp.), mortality in southeastern Michigan and Windsor, Ontario, Canada. Localized populations of A. planipennis have since been found across lower Michigan and in areas of Ohio, Indiana, Illinois, Maryland, and Ontario. Officials working to contain A. planipennis and managers of forestlands near A. planipennis infestations must be able to compare alternative strategies to allocate limited funds efficiently and effectively. Empirical data from a total of 148 green ash, Fraxinus pennsylvanica Marsh., and white ash, Fraxinus americana L., trees were used to develop models to estimate surface area of the trunk and branches by using tree diameter at breast height (dbh). Data collected from 71 additional F. pennsylvanica and F. americana trees killed by A. planipennis showed that on average, 88.9 +/- 4.6 beetles developed and emerged per m2 of surface area. Models were applied to ash inventory data collected at two outlier sites to estimate potential production of A. planipennis beetles at each site. Large trees of merchantable size (dbh > or = 26 cm) accounted for roughly 6% of all ash trees at the two sites, but they could have contributed 55-65% of the total A. planipennis production at both sites. In contrast, 75- 80% of the ash trees at the outlier sites were < or =13 cm dbh, but these small trees could have contributed only < or =12% of the potential A. planipennis production at both sites. Our results, in combination with inventory data, can be used by regulatory officials and resource managers to estimate potential A. planipennis production and to compare options for reducing A. planipennis density and slowing the rate of spread for any area of interest.

The impact of changes in the rheological parameters of fine-grained hydromixtures on the efficiency of a selected industrial gravitational hydraulic transport system

NASA Astrophysics Data System (ADS)

Popczyk, Marcin

2017-11-01

Polish hard coal mines commonly use hydromixtures in their fire prevention practices. The mixtures are usually prepared based on mass-produced power production wastes, namely the ashes resulting from power production [1]. Such hydromixtures are introduced to the caving area which is formed due to the advancement of a longwall. The first part of the article presents theoretical fundamentals of determining the parameters of gravitational hydraulic transport of water and ash hydromixtures used in the mining pipeline systems. Each hydromixture produced based on fine-grained wastes is characterized by specified rheological parameters that have a direct impact on the future flow parameters of a given pipeline system. Additionally, the gravitational character of the hydraulic transport generates certain limitations concerning the so-called correct hydraulic profile of the system in relation to the applied hydromixture characterized by required rheological parameters that should ensure safe flow at a correct efficiency [2]. The paper includes an example of a gravitational hydraulic transport system and an assessment of the correctness of its hydraulic profile as well as the assessment of the impact of rheological parameters of fine-grained hydromixtures (water and ash) produced based on laboratory tests, depending on the specified flow parameters (efficiency) of the hydromixture in the analyzed system.

A new process for nickel ammonium disulfate production from ash of the hyperaccumulating plant Alyssum murale.

PubMed

Barbaroux, R; Plasari, E; Mercier, G; Simonnot, M O; Morel, J L; Blais, J F

2012-04-15

The extraction of nickel (Ni) from ultramafic soils by phytomining can be achieved using Alyssum murale cultures. This study presents a new process for the valorization of Ni accumulated by this plant through the production of a Ni ammonium disulfate salt (Ni(NH(4))(2)(SO(4))(2).6H(2)O). The process comprises an initial leaching of the ashes of A. murale with a sulphuric acid solution (1.9 M H(2)SO(4), T=95 °C, t=240 min, TS=150 g ash L(-1)), producing a leachate rich in Ni (10.2 g Ni L(-1); 96% Ni solubilisation), Mg, P, K, Fe, Ca and Al. The pH of the acid leachate is increased to 5.0 with NaOH (5M), followed by an evaporation step which produced a purified solution rich in Ni (21.3 g NiL(-1)) and an iron hydroxide precipitate. The cold crystallization (T=2 °C, t=6h) of this solution by the stoichiometric addition (× 1.2) of ammonium sulfate generates a Ni ammonium disulfate salt, containing 13.2% Ni, that is potentially valuable to industry. Copyright © 2012 Elsevier B.V. All rights reserved.

Effect of palm oil fuel ash on compressive strength of palm oil boiler stone lightweight aggregate concrete

NASA Astrophysics Data System (ADS)

Muthusamy, K.; Zamri, N. A.; Kusbiantoro, A.; Lim, N. H. A. S.; Ariffin, M. A. Mohd

2018-04-01

Both palm oil fuel ash (POFA) and palm oil boiler stone (POBS) are by-products which has been continuously generated by local palm oil mill in large amount. Both by products is usually disposed as profitless waste and considered as nuisance to environment. The present research investigates the workability and compressive strength performance of lightweight aggregate concrete (LWAC) made of palm oil boiler stone (POBS) known as palm oil boiler stone lightweight aggregate concrete (POBS LWAC) containing various content of palm oil fuel ash. The control specimen that is POBS LWAC of grade 60 were produced using 100% OPC. Then, another 4 mixes were prepared by varying the POFA percentage from 10%, 20%, 30% and 40% by weight of cement. Fresh mixes were subjected to slump test to determine its workability before casted in form of cubes. Then, all specimens were subjected to water curing up to 28 days and then tested for its compressive strength. It was found out that utilizing of optimum amount of POFA in POBS LWAC would improve the workability and compressive strength of the concrete. However, inclusion of POFA more than optimum amount is not recommended as it will increase the water demand leading to lower workability and strength reduction.

The Use of OMPS Near Real Time Products in Volcanic Cloud Risk Mitigation and Smoke/Dust Air Quality Assessments

NASA Astrophysics Data System (ADS)

Seftor, C. J.; Krotkov, N. A.; McPeters, R. D.; Li, J. Y.; Durbin, P. B.

2015-12-01

Near real time (NRT) SO2 and aerosol index (AI) imagery from Aura's Ozone Monitoring Instrument (OMI) has proven invaluable in mitigating the risk posed to air traffic by SO2 and ash clouds from volcanic eruptions. The OMI products, generated as part of NASA's Land, Atmosphere Near real-time Capability for EOS (LANCE) NRT system and available through LANCE and both NOAA's NESDIS and ESA's Support to Aviation Control Service (SACS) portals, are used to monitor the current location of volcanic clouds and to provide input into Volcanic Ash (VA) advisory forecasts. NRT products have recently been developed using data from the Ozone Mapping and Profiler Suite onboard the Suomi NPP platform; they are currently being made available through the SACS portal and will shortly be incorporated into the LANCE NRT system. We will show examples of the use of OMPS NRT SO2 and AI imagery to monitor recent volcanic eruption events. We will also demonstrate the usefulness of OMPS AI imagery to detect and track dust storms and smoke from fires, and how this information can be used to forecast their impact on air quality in areas far removed from their source. Finally, we will show SO2 and AI imagery generated from our OMPS Direct Broadcast data to highlight the capability of our real time system.

Sewage sludge conditioning with the application of ash from biomass-fired power plant

NASA Astrophysics Data System (ADS)

Wójcik, Marta; Stachowicz, Feliks; Masłoń, Adam

2018-02-01

During biomass combustion, there are formed combustion products. Available data indicates that only 29.1 % of biomass ashes were recycled in Poland in 2013. Chemical composition and sorptive properties of ashes enable their application in the sewage sludge treatment. This paper analyses the impact of ashes from biomass-combustion power plant on sewage sludge dewatering and higienisation. The results obtained in laboratory tests proved the possitive impact of biomass ashes on sewage sludge hydration reduction after dewatering and the increase of filtrate volume. After sludge conditioning with the use of biomass combustion by-products, the final moisture content decreased by approximatelly 10÷25 % in comparison with raw sewage sludge depending on the method of dewatering. The application of biomass combustion products in sewage sludge management could provide an alternative method of their utilization according to law and environmental requirements.

The geochemistry and bioreactivity of fly-ash from coal-burning power stations.

PubMed

Jones, Timothy; Wlodarczyk, Anna; Koshy, Lata; Brown, Patrick; Shao, Longyi; BéruBé, Kelly

2009-07-01

Fly-ash is a byproduct of the combustion of coal in power stations for the generation of electricity. The fly-ash forms from the melting of incombustible minerals found naturally in the coal. The very high coal combustion temperatures result in the formation of microscopic glass particles from which minerals such as quartz, haematite and mullite can later recrystallize. In addition to these minerals, the glassy fly-ash contains a number of leachable metals. Mullite is a well-known material in the ceramics industry and a known respiratory hazard. Macroscopically mullite can be found in a large range of morphologies; however microscopic crystals appear to favour a fibrous habit. Fly-ash is a recognized bioreactive material in rat lung, generating hydroxyl radicals, releasing iron, and causing DNA damage. However, the mechanisms of the bioreactivity are still unclear and the relative contributions of the minerals and leachable metals to that toxicity are not well known.

Development of a standard operating procedure for analysis of ammonia concentrations in coal fly ash : [summary].

DOT National Transportation Integrated Search

2015-04-01

Fly ash produced when pulverized coal is burned in electrical generators can be used as a : concrete additive with many benefits. However, fly ash can have a high ammonia content, : which is released when used in concrete, potentially exposing worker...

Use of solid residue from thermal power plant (fly ash) for enhancing sewage sludge anaerobic digestion: Influence of fly ash particle size.

PubMed

Montalvo, S; Cahn, I; Borja, R; Huiliñir, C; Guerrero, L

2017-11-01

The influence of fly ash particle size on methane production and anaerobic biodegradability was evaluated. Assays with different fly ash particle sizes (0.8-2.36mm) at a concentration of 50mg/L were ran under mesophilic conditions. In anaerobic processes operating with fly ash, greater removal of both volatile total and suspended solids, chemical oxygen demand (total and soluble) was achieved, with an increase of methane production between 28% and 96% compared to the control reactors. The highest increase occurred at ash particles sizes of 1.0-1.4mm. The metal concentrations in the digestates obtained after anaerobic digestion of sewage sludge are far below those considered as limiting for the use of sludge in soils. Copyright © 2017 Elsevier Ltd. All rights reserved.

Spatial distribution of volcanic ash deposits of 2011 Puyehue-Cordón Caulle eruption in Patagonia as measured by a perturbation in NDVI temporal dynamics

NASA Astrophysics Data System (ADS)

Easdale, M. H.; Bruzzone, O.

2018-03-01

Volcanic ash fallout is a recurrent environmental disturbance in forests, arid and semi-arid rangelands of Patagonia, South America. The ash deposits over large areas are responsible for several impacts on ecological processes, agricultural production and health of local communities. Public policy decision making needs monitoring information of the affected areas by ash fallout, in order to better orient social, economic and productive aids. The aim of this study was to analyze the spatial distribution of volcanic ash deposits from the eruption of Puyehue-Cordón Caulle in 2011, by identifying a sudden change in the Normalized Difference Vegetation Index (NDVI) temporal dynamics, defined as a perturbation located in the time series. We applied a sparse-wavelet transform using the Basis Pursuit algorithm to NDVI time series obtained from the Moderate Resolution Image Spectroradiometer (MODIS) sensor, to identify perturbations at a pixel level. The spatial distribution of the perturbation promoted by ash deposits in Patagonia was successfully identified and characterized by means of a perturbation in NDVI temporal dynamics. Results are encouraging for the future development of a new platform, in combination with data from forecasting models and tracking of ash cloud trajectories and dispersion, to inform stakeholders to mitigate impact of volcanic ash on agricultural production and to orient public intervention strategies after a volcanic eruption followed by ash fallout over a wide region.

Real Time Volcanic Cloud Products and Predictions for Aviation Alerts

NASA Technical Reports Server (NTRS)

Krotkov, Nickolay A.; Habib, Shahid; da Silva, Arlindo; Hughes, Eric; Yang, Kai; Brentzel, Kelvin; Seftor, Colin; Li, Jason Y.; Schneider, David; Guffanti, Marianne;

Fly ash zeolite catalyst support for Fischer-Tropsch synthesis

NASA Astrophysics Data System (ADS)

Campen, Adam

This dissertation research aimed at evaluating a fly ash zeolite (FAZ) catalyst support for use in heterogeneous catalytic processes. Gas phase Fischer-Tropsch Synthesis (FTS) over a fixed-bed of the prepared catalyst/FAZ support was identified as an appropriate process for evaluation, by comparison with commercial catalyst supports (silica, alumina, and 13X). Fly ash, obtained from the Wabash River Generating Station, was first characterized using XRD, SEM/EDS, particle size, and nitrogen sorption techniques. Then, a parametric study of a two-step alkali fusion/hydrothermal treatment process for converting fly ash to zeolite frameworks was performed by varying the alkali fusion agent, agent:flyash ratio, fusion temperature, fused ash/water solution, aging time, and crystallization time. The optimal conditions for each were determined to be NaOH, 1.4 g NaOH: 1 g fly ash, 550 °C, 200 g/L, 12 hours, and 48 hours. This robust process was applied to the fly ash to obtain a faujasitic zeolite structure with increased crystallinity (40 %) and surface area (434 m2/g). Following the modification of fly ash to FAZ, ion exchange of H+ for Na+ and cobalt incipient wetness impregnation were used to prepare a FTS catalyst. FTS was performed on the catalysts at 250--300 °C, 300 psi, and with a syngas ratio H2:CO = 2. The HFAZ catalyst support loaded with 11 wt% cobalt resulted in a 75 % carbon selectivity for C5 -- C18 hydrocarbons, while methane and carbon dioxide were limited to 13 and 1 %, respectively. Catalyst characterization was performed by XRD, N2 sorption, TPR, and oxygen pulse titration to provide insight to the behavior of each catalyst. Overall, the HFAZ compared well with silica and 13X supports, and far exceeded the performance of the alumina support under the tested conditions. The successful completion of this research could add value to an underutilized waste product of coal combustion, in the form of catalyst supports in heterogeneous catalytic processes.

Co-gasification of municipal solid waste and material recovery in a large-scale gasification and melting system.

PubMed

Tanigaki, Nobuhiro; Manako, Kazutaka; Osada, Morihiro

2012-04-01

This study evaluates the effects of co-gasification of municipal solid waste with and without the municipal solid waste bottom ash using two large-scale commercial operation plants. From the viewpoint of operation data, there is no significant difference between municipal solid waste treatment with and without the bottom ash. The carbon conversion ratios are as high as 91.7% and 95.3%, respectively and this leads to significantly low PCDD/DFs yields via complete syngas combustion. The gross power generation efficiencies are 18.9% with the bottom ash and 23.0% without municipal solid waste bottom ash, respectively. The effects of the equivalence ratio are also evaluated. With the equivalence ratio increasing, carbon monoxide concentration is decreased, and carbon dioxide and the syngas temperature (top gas temperature) are increased. The carbon conversion ratio is also increased. These tendencies are seen in both modes. Co-gasification using the gasification and melting system (Direct Melting System) has a possibility to recover materials effectively. More than 90% of chlorine is distributed in fly ash. Low-boiling-point heavy metals, such as lead and zinc, are distributed in fly ash at rates of 95.2% and 92.0%, respectively. Most of high-boiling-point heavy metals, such as iron and copper, are distributed in metal. It is also clarified that slag is stable and contains few harmful heavy metals such as lead. Compared with the conventional waste management framework, 85% of the final landfill amount reduction is achieved by co-gasification of municipal solid waste with bottom ash and incombustible residues. These results indicate that the combined production of slag with co-gasification of municipal solid waste with the bottom ash constitutes an ideal approach to environmental conservation and resource recycling. Copyright © 2011 Elsevier Ltd. All rights reserved.

Predicting the ability to produce emerald ash borer: a comparison of riparian and upland ash forests in southern lower Michigan

Treesearch

Susan J. Crocker; Deborah G. McCullough; Nathan W. Siegert

2009-01-01

Concern for the future of ash trees in the United States has risen since the 2002 discovery of emerald ash borer (EAB) (Agrilus planipennis Fairmaire) in southeastern Michigan. The ability of ash forests in the Southern Lower Peninsula of Michigan to produce EAB was compared by physiographic class and stand size. Results showed that EAB production...

Evaluation of concrete incorporating bottom ash as a natural aggregates replacement.

PubMed

Andrade, L B; Rocha, J C; Cheriaf, M

2007-01-01

A study on the incorporation of coal bottom ash from thermoelectric power stations as a substitute material for natural sand in the production of concrete is here presented. The normally coarse, fused, glassy texture of bottom ash makes it an ideal substitute for natural aggregates. The use of bottom ash in concrete presents several technical challenges: the physical and mineralogical characteristics of the bottom ash; the effect on water demand and the participation on cements hydratation. In the production of the concrete, substitutions in volume were used. Two different ways to employ bottom ash were used to make up the mix proportions: one considering the natural humidity present in the porous particles and the other not considering it, seeking to maintain the same strength. These considerations are fundamental given that the process of bottom ash extraction is carried out through moisture. Mechanical tests by compressive strength were performed and the elastic modulus was determined. An analysis of the influence of bottom ash in the formation of pores was carried out through tests for the water loss by air drying and water uptake by capillary absorption. The results show that the higher the bottom ash contents in the concrete, the worse the performance regarding moisture transport. However, for one bottom ash concrete type, the mechanical properties were maintained.

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.

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.

The environmental status of coal ash produced in Israel

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

Metzger, L.A.

1996-12-31

From the 6.1 million tons of coal ash produced by Israeli power stations during the 1982--95 period, 65% were utilized for cement production, 18% served to construct embankments around the Hadera coastal power station, and the remaining 17% were disposed to the sea, according to permits issued by the governmental authorities. The coal imported to Israel is typically low-sulfur, beneficiated bituminous coal, and ash produced from it is alkaline and characterized by low concentrations of trace elements. According to the results of leaching tests, the potential release of trace elements from the ash is low, thus there is only amore » minor risk of contaminating groundwater under disposal or utilization sites. However, while the annual ash production increases and is planned to reach one million tons in the year 2000, the promotion of ash employment for new applications, for example as a road base material or for shore extension projects, is still prevented by the absence of regulations fixing the environmental status of coal ash.« less

Evaluation of resource recovery from waste incineration residues--the case of zinc.

PubMed

Fellner, J; Lederer, J; Purgar, A; Winterstetter, A; Rechberger, H; Winter, F; Laner, D

2015-03-01

Solid residues generated at European Waste to Energy plants contain altogether about 69,000 t/a of Zn, of which more than 50% accumulates in air pollution control residues, mainly boiler and filter ashes. Intensive research activities aiming at Zn recovery from such residues recently resulted in a technical scale Zn recovery plant at a Swiss waste incinerator. By acidic leaching and subsequent electrolysis this technology (FLUREC) allows generating metallic Zn of purity>99.9%. In the present paper the economic viability of the FLUREC technology with respect to Zn recovery from different solid residues of waste incineration has been investigated and subsequently been categorised according to the mineral resource classification scheme of McKelvey. The results of the analysis demonstrate that recovery costs for Zn are highly dependent on the costs for current fly ash disposal (e.g. cost for subsurface landfilling). Assuming current disposal practice costs of 220€/ton fly ash, resulting recovery costs for Zn are generally higher than its current market price of 1.6€/kg Zn. With respect to the resource classification this outcome indicates that none of the identified Zn resources present in incineration residues can be economically extracted and thus cannot be classified as a reserve. Only for about 4800 t/a of Zn an extraction would be marginally economic, meaning that recovery costs are only slightly (less than 20%) higher than the current market price for Zn. For the remaining Zn resources production costs are between 1.5 and 4 times (7900 t/a Zn) and 10-80 times (55,300 t/a Zn) higher than the current market value. The economic potential for Zn recovery from waste incineration residues is highest for filter ashes generated at grate incinerators equipped with wet air pollution control. Copyright © 2014 Elsevier Ltd. All rights reserved.

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.

Synthesis of geopolymer from biomass-coal ash blends

NASA Astrophysics Data System (ADS)

Samadhi, Tjokorde Walmiki; Wulandari, Winny; Prasetyo, Muhammad Iqbal; Fernando, Muhammad Rizki; Purbasari, Aprilina

2017-09-01

Geopolymer is an environmentally attractive Portland cement substitute, owing to its lower carbon footprint and its ability to consume various aluminosilicate waste materials as its precursors. This work describes the development of geopolymer formulation based on biomass-coal ash blends, which is predicted to be the prevalent type of waste when biomass-based thermal energy production becomes mainstream in Indonesia. The ash blends contain an ASTM Class F coal fly ash (FA), rice husk ash (RHA), and coconut shell ash (CSA). A mixture of Na2SiO3 and concentrated KOH is used as the activator solution. A preliminary experiment identified the appropriate activator/ash mass ratio to be 2.0, while the activator Na2SiO3/KOH ratio varies from 0.8 to 2.0 with increasing ash blend Si/Al ratio. Both non-blended FA and CSA are able to produce geopolymer mortars with 7-day compressive strength exceeding the Indonesian national SNI 15-2049-2004 standard minimum value of 2.0 MPa stipulated for Portland cement mortars. Ash blends have to be formulated with a maximum RHA content of approximately 50 %-mass to yield satisfactory 7-day strength. No optimum ash blend composition is identified within the simplex ternary ash blend compositional region. The strength decreases with Si/Al ratio of the ash blends due to increasing amount of unreacted silicate raw materials at the end of the geopolymer hardening period. Overall, it is confirmed that CSA and blended RHA are feasible raw materials for geopolymer production..

Respiratory Health Effects of Volcanic Ash - a new Approach

NASA Astrophysics Data System (ADS)

Horwell, C. J.; Fenoglio, I.; Sparks, R. J.; Ragnarsdottir, K. V.; Fubini, B.

2003-12-01

Attempts to characterise the toxicity of volcanic ash have focused on the presence of the crystalline silica polymorph cristobalite, which is known to cause silicosis and lung cancer in industrial settings. Within the lung, it is the surface of the particles which will react with endogenous molecules. Free radicals, produced on particle surfaces, can react with DNA and other cellular components, instigating a chain of toxic events. For the first time, the ability of volcanic ash to form free radicals has been assessed using Electron Paramagnetic Resonance techniques specific to the hydroxyl radical. Respirable (< 4 microns) crystalline silica, separated from volcanic ash from the Soufriere Hills volcano, Montserrat, West Indies, did not produce hydroxyl free radicals or surface radicals. However, the ash, itself, generated up to 3 times more hydroxyl radicals than a quartz of known toxicity. The cause of the reactivity is reduced iron on the surface of iron-rich minerals such as amphiboles and pyroxenes. Fresh volcanic ash generates more free radicals than weathered volcanic ash which will have oxidised (and leached away) surface iron. These results have implications for volcanic health hazard research as it was previously assumed that volcanoes which did not produce respirable crystalline silica presented a lesser respiratory health hazard. The International Volcanic Health Hazard Network (IVHHN) promotes research into the health effects of volcanic emissions. Under the auspices of IVHHN, volcanic ash samples from volcanoes world-wide are being analysed for surface reactivity, grain-size distribution and composition to form a comprehensive database for use by volcano observatories, emergency managers, medical practitioners and researchers. The results will highlight volcanoes which have the potential to cause a respiratory health hazard through generation of iron-catalysed free radicals, as well as more conventional markers such as concentration of respirable particles. At the onset of new eruptions, the database will be used to aid the rapid assessment of health hazard from volcanic ash.

Greatly increased use of fly ash in hydraulic cement concrete (HCC) for pavement layers and transportation structures - volume I.

DOT National Transportation Integrated Search

2012-03-01

The purpose of this phase is to evaluate the past, current and future trends of use of fly ash in concrete and restrictions to its use. The American Coal Ash Association (ACAA) conducts an annual survey of fly ash production and use. Typically on an ...

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

Effect of lime addition during sewage sludge treatment on characteristics of resulting SSA when it is used in cementitious materials.

PubMed

Vouk, D; Nakic, D; Štirmer, N; Baricevic, A

2017-02-01

Final disposal of sewage sludge is important not only in terms of satisfying the regulations, but the aspect of choosing the optimal wastewater treatment technology, including the sludge treatment. In most EU countries, significant amounts of stabilized and dewatered sludge are incinerated, and sewage sludge ash (SSA) is generated as a by product. At the same time, lime is one of the commonly used additives in the sewage sludge treatment primarily to stabilize the sludge. In doing so, the question arose how desirable is such addition of lime if the sludge is subsequently incinerated, and the generated ash is further used in the production of cementitious materials. A series of mortars were prepared where 10-20% of the cement fraction was replaced by SSA. Since all three types of analyzed SSA (without lime, with lime added during sludge stabilization and with extra lime added during sludge incineration) yielded nearly same results, it can be concluded that if sludge incineration is accepted solution, lime addition during sludge treatment is unnecessary even from the standpoint of preserving the pozzolanic properties of the resulting SSA. Results of the research carried out on cement mortars point to the great possibilities of using SSA in concrete industry.

Ash from thermal power plants as secondary raw material.

PubMed

Cudić, Vladica; Kisić, Dragica; Stojiljković, Dragoslava; Jovović, Aleksandar

2007-06-01

The basic characteristic of thermal power plants in the Republic of Serbia is that they use low-grade brown coal (lignite) as a fuel. Depending on the location of coal mines, lignite may have different properties such as heating value, moisture, and mineral content, resulting in different residue upon combustion. Because of several million tonnes of ash and slag generated every year, their granularmetric particle size distribution, and transport and disposal methods, these plants have a negative impact on the environment. According to the waste classification system in the Republic of Serbia, ash and slag from thermal power plants are classified as hazardous waste, but with an option of usability. The proposed revision of waste legislation in Serbia brings a number of simple and modern solutions. A procedure is introduced which allows for end-of-waste criteria to be set, clarifying the point where waste ceases to be waste, and thereby introducing regulatory relief for recycled products or materials that represent low risk for the environment. The new proposal refocuses waste legislation on the environmental impacts of the generation and management of waste, taking into account the life cycle of resources, and develops new waste prevention programmes. Stakeholders, as well as the general public, should have the opportunity to participate in the drawing up of the programmes, and should have access to them.

The 2013 eruption of Pavlof Volcano, Alaska: a spatter eruption at an ice- and snow-clad volcano

USGS Publications Warehouse

Waythomas, Christopher F.; Haney, Matthew M.; Fee, David; Schneider, David J.; Wech, Aaron G.

2014-01-01

The 2013 eruption of Pavlof Volcano, Alaska began on 13 May and ended 49 days later on 1 July. The eruption was characterized by persistent lava fountaining from a vent just north of the summit, intermittent strombolian explosions, and ash, gas, and aerosol plumes that reached as high as 8 km above sea level and on several occasions extended as much as 500 km downwind of the volcano. During the first several days of the eruption, accumulations of spatter near the vent periodically collapsed to form small pyroclastic avalanches that eroded and melted snow and ice to form lahars on the lower north flank of the volcano. Continued lava fountaining led to the production of agglutinate lava flows that extended to the base of the volcano, about 3–4 km beyond the vent. The generation of fountain-fed lava flows was a dominant process during the 2013 eruption; however, episodic collapse of spatter accumulations and formation of hot spatter-rich granular avalanches was a more efficient process for melting snow and ice and initiating lahars. The lahars and ash plumes generated during the eruption did not pose any serious hazards for the area. However, numerous local airline flights were cancelled or rerouted, and trace amounts of ash fall occurred at all of the local communities surrounding the volcano, including Cold Bay, Nelson Lagoon, Sand Point, and King Cove.

An FP7 "Space" project: Aphorism "Advanced PRocedures for volcanic and Seismic Monitoring"

NASA Astrophysics Data System (ADS)

Di Iorio, A., Sr.; Stramondo, S.; Bignami, C.; Corradini, S.; Merucci, L.

2014-12-01

APHORISM project proposes the development and testing of two new methods to combine Earth Observation satellite data from different sensors, and ground data. The aim is to demonstrate that this two types of data, appropriately managed and integrated, can provide new improved GMES products useful for seismic and volcanic crisis management. The first method, APE - A Priori information for Earthquake damage mapping, concerns the generation of maps to address the detection and estimate of damage caused by a seism. The use of satellite data to investigate earthquake damages is not an innovative issue. We can find a wide literature and projects concerning such issue, but usually the approach is only based on change detection techniques and classifications algorithms. The novelty of APE relies on the exploitation of a priori information derived by InSAR time series to measure surface movements, shake maps obtained from seismological data, and vulnerability information. This a priori information is then integrated with change detection map to improve accuracy and to limit false alarms. The second method deals with volcanic crisis management. The method, MACE - Multi-platform volcanic Ash Cloud Estimation, concerns the exploitation of GEO (Geosynchronous Earth Orbit) sensor platform, LEO (Low Earth Orbit) satellite sensors and ground measures to improve the ash detection and retrieval and to characterize the volcanic ash clouds. The basic idea of MACE consists of an improvement of volcanic ash retrievals at the space-time scale by using both the LEO and GEO estimations and in-situ data. Indeed the standard ash thermal infrared retrieval is integrated with data coming from a wider spectral range from visible to microwave. The ash detection is also extended in case of cloudy atmosphere or steam plumes. APE and MACE methods have been defined in order to provide products oriented toward the next ESA Sentinels satellite missions.The project is funded under the European Union FP7 program and the Kick-Off meeting has been held at INGV premises in Rome on 18th December 2013.

Combustion of horse manure for heat production.

PubMed

Lundgren, J; Pettersson, E

2009-06-01

The main objectives of this paper have been to evaluate the use of horse manure and wood-shavings as a fuel for heat production and to provide sets of data on the chemical composition, ash characteristics and ash forming elements of the fuel. Another objective has been to investigate the possibility to use the ash as fertiliser by analysing the heavy metal and nutrient contents. The results showed that the fuel is well suited for combustion for heat production causing low emissions of products of incomplete combustion. The emissions of NO(x) were however high due to the high content of fuel bound nitrogen. Emissions of CO and NO(x) were typically in the range of 30-150 mg/Nm(3) and 280-350 mg/Nm(3) at 10 vol% O(2), respectively. The analysis of the ash showed on sufficiently low concentration of heavy metals to allow recycling.

Properties of fresh and hardened sustainable concrete due to the use of palm oil fuel ash as cement replacement

NASA Astrophysics Data System (ADS)

Hamada, Hussein M.; Jokhio, Gul Ahmed; Mat Yahaya, Fadzil; Humada, Ali M.

2018-04-01

Palm oil fuel ash (POFA) is a by-product resulting from the combustion of palm oil waste such as palm oil shell and empty fruit bunches to generate electricity in the palm oil mills. Considerable quantities of POFA thus generated, accumulate in the open fields and landfills, which causes atmospheric pollution in the form of generating toxic gases. Firstly, to protect the environment; and secondly, having excellent properties for this purpose; POFA can be and has been used as partial cement replacement in concrete preparation. Therefore, this paper compiles the results obtained from previous studies that address the properties of concrete containing POFA as cement replacement in fresh and hardened states. The results indicate that there is a great potential to using POFA as cement replacement because of its ability to improve compressive strength, reduce hydration heat of cement mortar and positively affect other fresh and hardened concrete properties. The paper recommends that conducting further studies to exploit high volume of POFA along with other additives as cement replacement while maintaining high quality of concrete can help minimize CO2 emissions due to concrete.

Wood Ash Induced pH Changes Strongly Affect Soil Bacterial Numbers and Community Composition

PubMed Central

Bang-Andreasen, Toke; Nielsen, Jeppe T.; Voriskova, Jana; Heise, Janine; Rønn, Regin; Kjøller, Rasmus; Hansen, Hans C. B.; Jacobsen, Carsten S.

2017-01-01

Recirculation of wood ash from energy production to forest soil improves the sustainability of this energy production form as recycled wood ash contains nutrients that otherwise would be lost at harvest. In addition, wood-ash is beneficial to many soils due to its inherent acid-neutralizing capabilities. However, wood ash has several ecosystem-perturbing effects like increased soil pH and pore water electrical conductivity both known to strongly impact soil bacterial numbers and community composition. Studies investigating soil bacterial community responses to wood ash application remain sparse and the available results are ambiguous and remain at a general taxonomic level. Here we investigate the response of bacterial communities in a spruce forest soil to wood ash addition corresponding to 0, 5, 22, and 167 t wood ash ha-1. We used culture-based enumerations of general bacteria, Pseudomonas and sporeforming bacteria combined with 16S rRNA gene amplicon sequencing to valuate soil bacterial responses to wood ash application. Results showed that wood ash addition strongly increased soil pH and electrical conductivity. Soil pH increased from acidic through neutral at 22 t ha-1 to alkaline at 167 t ha-1. Bacterial numbers significantly increased up to a wood ash dose of 22 t ha-1 followed by significant decrease at 167 t ha-1 wood ash. The soil bacterial community composition changed after wood ash application with copiotrophic bacteria responding positively up to a wood ash dose of 22 t ha-1 while the adverse effect was seen for oligotrophic bacteria. Marked changes in bacterial community composition occurred at a wood ash dose of 167 t ha-1 with a single alkaliphilic genus dominating. Additionally, spore-formers became abundant at an ash dose of 167 t ha-1 whereas this was not the case at lower ash doses. Lastly, bacterial richness and diversity strongly decreased with increasing amount of wood ash applied. All of the observed bacterial responses can be directly explained by the wood ash induced changes in pH, electrical conductivity and the addition of wood ash inherent nutrients. PMID:28804476

Wood Ash Induced pH Changes Strongly Affect Soil Bacterial Numbers and Community Composition.

PubMed

Bang-Andreasen, Toke; Nielsen, Jeppe T; Voriskova, Jana; Heise, Janine; Rønn, Regin; Kjøller, Rasmus; Hansen, Hans C B; Jacobsen, Carsten S

2017-01-01

Recirculation of wood ash from energy production to forest soil improves the sustainability of this energy production form as recycled wood ash contains nutrients that otherwise would be lost at harvest. In addition, wood-ash is beneficial to many soils due to its inherent acid-neutralizing capabilities. However, wood ash has several ecosystem-perturbing effects like increased soil pH and pore water electrical conductivity both known to strongly impact soil bacterial numbers and community composition. Studies investigating soil bacterial community responses to wood ash application remain sparse and the available results are ambiguous and remain at a general taxonomic level. Here we investigate the response of bacterial communities in a spruce forest soil to wood ash addition corresponding to 0, 5, 22, and 167 t wood ash ha -1 . We used culture-based enumerations of general bacteria, Pseudomonas and sporeforming bacteria combined with 16S rRNA gene amplicon sequencing to valuate soil bacterial responses to wood ash application. Results showed that wood ash addition strongly increased soil pH and electrical conductivity. Soil pH increased from acidic through neutral at 22 t ha -1 to alkaline at 167 t ha -1 . Bacterial numbers significantly increased up to a wood ash dose of 22 t ha -1 followed by significant decrease at 167 t ha -1 wood ash. The soil bacterial community composition changed after wood ash application with copiotrophic bacteria responding positively up to a wood ash dose of 22 t ha -1 while the adverse effect was seen for oligotrophic bacteria. Marked changes in bacterial community composition occurred at a wood ash dose of 167 t ha -1 with a single alkaliphilic genus dominating. Additionally, spore-formers became abundant at an ash dose of 167 t ha -1 whereas this was not the case at lower ash doses. Lastly, bacterial richness and diversity strongly decreased with increasing amount of wood ash applied. All of the observed bacterial responses can be directly explained by the wood ash induced changes in pH, electrical conductivity and the addition of wood ash inherent nutrients.

Waste heat generation: A comprehensive review.

PubMed

Yeşiller, Nazli; Hanson, James L; Yee, Emma H

2015-08-01

A comprehensive review of heat generation in various types of wastes and of the thermal regime of waste containment facilities is provided in this paper. Municipal solid waste (MSW), MSW incineration ash, and mining wastes were included in the analysis. Spatial and temporal variations of waste temperatures, thermal gradients, thermal properties of wastes, average temperature differentials, and heat generation values are provided. Heat generation was influenced by climatic conditions, mean annual earth temperatures, waste temperatures at the time of placement, cover conditions, and inherent heat generation potential of the specific wastes. Time to onset of heat generation varied between months and years, whereas timelines for overall duration of heat generation varied between years and decades. For MSW, measured waste temperatures were as high as 60-90°C and as low as -6°C. MSW incinerator ash temperatures varied between 5 and 87°C. Mining waste temperatures were in the range of -25 to 65°C. In the wastes analyzed, upward heat flow toward the surface was more prominent than downward heat flow toward the subsurface. Thermal gradients generally were higher for MSW and incinerator ash and lower for mining waste. Based on thermal properties, MSW had insulative qualities (low thermal conductivity), while mining wastes typically were relatively conductive (high thermal conductivity) with ash having intermediate qualities. Heat generation values ranged from -8.6 to 83.1MJ/m(3) and from 0.6 to 72.6MJ/m(3) for MSW and mining waste, respectively and was 72.6MJ/m(3) for ash waste. Conductive thermal losses were determined to range from 13 to 1111MJ/m(3)yr. The data and analysis provided in this review paper can be used in the investigation of heat generation and thermal regime of a wide range of wastes and waste containment facilities located in different climatic regions. Copyright © 2015 Elsevier Ltd. All rights reserved.

Prospects for the development of coal-steam plants in Russia

NASA Astrophysics Data System (ADS)

Tumanovskii, A. G.

2017-06-01

Evaluation of the technical state of the modern coal-fired power plants and quality of coal consumed by Russian thermal power plants (TPP) is provided. Measures aimed at improving the economic and environmental performance of operating 150-800 MW coal power units are considered. Ways of efficient use of technical methods of NO x control and electrostatic precipitators' upgrade for improving the efficiency of ash trapping are summarized. Examples of turbine and boiler equipment efficiency upgrading through its deep modernization are presented. The necessity of the development and introduction of new technologies in the coal-fired power industry is shown. Basic technical requirements for a 660-800 MW power unit with the steam conditions of 28 MPa, 600/600°C are listed. Design solutions taking into account features of Russian coal combustion are considered. A field of application of circulating fluidized bed (CFB) boilers and their effectiveness are indicated. The results of development of a new generation coal-fired TPP, including a steam turbine with an increased efficiency of the compartments and disengaging clutch, an elevated steam conditions boiler, and a highly efficient NO x /SO2 and ash particles emission control system are provided. In this case, the resulting ash and slag are not to be sent to the ash dumps and are to be used to a maximum advantage. Technical solutions to improve the efficiency of coal gasification combined cycle plants (CCP) are considered. A trial plant based on a 16 MW gas turbine plant (GTP) and an air-blown gasifier is designed as a prototype of a high-power CCP. The necessity of a state-supported technical reequipment and development program of operating coal-fired power units, as well as putting into production of new generation coal-fired power plants, is noted.

Heavy metal leaching from coal fly ash amended container substrates during Syngonium production

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

Li, Q.S.; Chen, J.J.; Li, Y.C.

2008-02-15

Coal fly ash has been proposed to be an alternative to lime amendment and a nutrient source of container substrates for ornamental plant production. A great concern over this proposed beneficial use, however, is the potential contamination of surface and ground water by heavy metals. In this study, three fly ashes collected from Florida, Michigan, and North Carolina and a commercial dolomite were amended in a basal substrate. The formulated substrates were used to produce Syngonium podophyllum Schott 'Berry Allusion' in 15-cm diameter containers in a shaded greenhouse. Leachates from the containers were collected during the entire six months ofmore » plant production and analyzed for heavy metal concentrations. There were no detectable As, Cr, Hg, Pb, and Se in the leachates; Cd and Mo were only detected in few leachate samples. The metals constantly detected were Cu, Mn, Ni, and Zn. The total amounts of Cu, Mn, Ni, and Zn leached during the six-month production period were 95, 210, 44, and 337 {mu} g per container, indicating that such amounts in leachates may contribute little to contamination of surface and ground water. In addition, plant growth indices and fresh and dry weights of S. podophyllum 'Berry Allusion' produced from fly ash and dolomite-amended substrates were comparable except for the plants produced from the substrate amended with fly ash collected from Michigan which had reduced growth indices and fresh and dry weights. Thus, selected fly ashes can be alternatives to commercial dolomites as amendments to container substrates for ornamental plant production. The use of fly ashes as container substrate amendments should represent a new market for the beneficial use of this coal combustion byproduct.« less

Kinetics of fly ash beneficiation by carbon burnout: Quarterly report, October 1-December 31, 1997

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

NONE

To investigate the kinetics of beneficiation of fly ash by carbon burnout The project is a joint venture between Delmarva Power, a power generating company on the eastern shore of Maryland, and the University of Maryland Eastern Shore. The studies have focused on the beneficiation of fly ash by carbon burnout.

Effects of broiler litter ash, layer manure ash and calcium phosphate on corn, wheat and soybean growth, phosphorus and arsenic uptake

USDA-ARS?s Scientific Manuscript database

Poultry litter is being incinerated in order to reduce excess litter and to increase the percentage of renewable fuel used to generate electricity. Ash from incinerated litter has been effective in increasing crop growth. However, there is no current literature comparing phosphorus availability fr...

Bottom ash boosts poor soil

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

Stanley, D.

1993-04-01

This article describes agricultural uses of fluidized bed bottom ash residue from burning limestone and coal in electric power generating plants: as a limestone substitute, to increase calcium levels in both soil and plants, and as a gypsom-containing soil amendment. Apples and tomatoes are the crops used. The industrial perspective and other uses of bottom ash are also briefly described.

Influence of pH, curing time and environmental stress on the immobilization of hazardous waste using activated fly ash.

PubMed

Srivastava, Shefali; Chaudhary, Rubina; Khale, Divya

2008-05-30

The current work is related to inorganic species in sludge generated from Common Effluent Treatment Plant contaminated with hazardous wastes at relatively high concentration. The environmental sensitive metals studied in the sludge are Pb, Fe, Ni, Zn and Mn. The solidification/stabilization (S/S) of heavy metals within fly ash-cement-based matrix was conducted for low cost treatment and reuse of sludge. The study examines the strength of the S/S product by predicting the effect of supplementary cementing material from efficiency factor (k) at 60 degrees C curing temperature. The leaching test was performed at two different pH 7 and 4 to determine the efficiency of heavy metal immobilization. It was observed that replacing 76% OPC by 56% fly ash and 20% sludge for 28 days curing period shows increase in strength as well as rate of stabilization for zinc, iron and manganese at pH 7, lead and nickel were stabilized by 79 and 82%, respectively. Environmental stress test was performed to evaluate the tolerance of extreme adverse environmental condition.

Integrated coal cleaning, liquefaction, and gasification process

DOEpatents

Chervenak, Michael C.

1980-01-01

Coal is finely ground and cleaned so as to preferentially remove denser ash-containing particles along with some coal. The resulting cleaned coal portion having reduced ash content is then fed to a coal hydrogenation system for the production of desirable hydrocarbon gases and liquid products. The remaining ash-enriched coal portion is gasified to produce a synthesis gas, the ash is removed from the gasifier usually as slag, and the synthesis gas is shift converted with steam and purified to produce the high purity hydrogen needed in the coal hydrogenation system. This overall process increases the utilization of as-mined coal, reduces the problems associated with ash in the liquefaction-hydrogenation system, and permits a desirable simplification of a liquids-solids separation step otherwise required in the coal hydrogenation system.

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

Effect of dilution and ash supplement on the bio-methane potential of palm oil mill effluent (POME)

NASA Astrophysics Data System (ADS)

Jijai, Sunwanee; Muleng, Saina; Siripatana, Chairat

2017-08-01

This study aimed to evaluate the bio-methane potential of POME at different dilutions (100, 80, 60, 40, and 20 percent of initial POME) and different pH dues to different levels of ash supplement. Five different amounts of ash were added to digesters (0, 2, 4, 6, and 8 grams of ash were added to 170 ml of POME respectively). The digesters were operated in batch anaerobic digestion systems at room temperature (28-30 °C) and the experiments were performed in duplicate manner. The results showed that POME without dilution gave highest cumulative biogas (950 ml). However, 80% dilution from original POME gave the highest methane yield (45.83 mL CH4/ gCODadded or 103.13 mL CH4/ gCODremoved). Finally, the results of experiment 2, this adding ash into POME increased pH as well as enhanced the biogas production. It was found that adding ash at the ash:POME ratio of 2 g: 170 ml gave the highest both the cumulative biogas and methane yield (1,520 mL and 218.79 mL CH4/ gCODremoved respectively). The addition of ash in the raw waste of POME gave the pH in the range of criteria and highest bio-methane potential. The modified Gompertz equation, Schnute as well as Monod kinetic models were used to compare the data from the experiments. It was found that the factors that affected included, the bio-methane production and the kinetic parameters (the maximum specific methane production rates (Rm ml/day) and the methane production potential (P, mL)), initial COD, nutrients, levels of dilution, and initial pH (by adding different level of ash). However, λ (lag phase period) was not affected by initial COD and other factors. While Monod kinetics provides valuable insight in explaining what could happen behind the systematic trends.

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).

Study on the valorization routes of ashes from thermoelectric power plants working under mono-and co-combustion regimes

NASA Astrophysics Data System (ADS)

Barbosa, Rui Pedro Fernandes

The main objective of this thesis was to study new valorization routes of ashes produced in combustion and co-combustion processes. Three main valorization pathways were analyzed: (i)production of cement mortars, (ii) production of concretes, and (iii) use as chemical agents to remove contaminants from wastewaters. Firstly, the ashes produced during the mono-combustion of coal, co-combustion of coal and meat and bone meal (MBM), and mono-combustion of MBM were characterized. The aim of this study was to understand the ashes properties in extreme levels of substitution of coal by a residue with a high contamination of specific metals. The substitution of coal by MBM produced ashes with higher content of heavy metals. Secondly, the ashes coming from an industrial power plant working under mono-combustion(coal) and co-combustion conditions (coal+sewage sludge+MBM) were studied. The use of cofuels did not promote significant changes in the chemical and ecotoxicological properties of ashes. Fly ashes were successfully stabilized/solidified in cement mortar, and bottom and circulating ashes were successfully used as raw materials in concrete. The third step involved the characterization and valorization of biomass ashes resulting from the combustion of forestry residues. The highest concentrations of metals/metalloids were found in the lowest particle size fractions of ashes. Biomass ashes successfully substituted cement and natural aggregates in concretes, without compromising their mechanical, chemical, and ecotoxicological properties. Finally, the biomass ashes were tested as chemical agents to remove contaminants from wastewaters. The removal of P, mainly phosphates, and Pb from wastewaters was assayed. Biomass ashes presented a high capacity to remove phosphates. As fly ashes were more efficient in removing phosphates, they were further used to remove Pb from wastewaters. Again, they presented a high efficiency in Pb removal. New potential valorization routes for these ashes are now opened, contributing to improve their valorization rates.

Use of co-combustion bottom ash to design an acoustic absorbing material for highway noise barriers

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

Arenas, Celia; Leiva, Carlos; Vilches, Luis F.

2013-11-15

Highlights: • The particle size of bottom ash influenced the acoustic behavior of the barrier. • The best sound absorption coefficients were measured for larger particle sizes. • The maximum noise absorption is displaced to lower frequencies for higher thickness. • A noise barrier was designed with better properties than commercial products. • Recycling products from bottom ash no present leaching and radioactivity problems. - Abstract: The present study aims to determine and evaluate the applicability of a new product consisting of coal bottom ash mixed with Portland cement in the application of highway noise barriers. In order to effectivelymore » recycle the bottom ash, the influence of the grain particle size of bottom ash, the thickness of the panel and the combination of different layers with various particle sizes have been studied, as well as some environmental properties including leachability (EN-12457-4, NEN-7345) and radioactivity tests. Based on the obtained results, the acoustic properties of the final composite material were similar or even better than those found in porous concrete used for the same application. According to this study, the material produced presented no environmental risk.« less

Chemical analysis and biorefinery of red algae Kappaphycus alvarezii for efficient production of glucose from residue of carrageenan extraction process.

PubMed

Masarin, Fernando; Cedeno, Fernando Roberto Paz; Chavez, Eddyn Gabriel Solorzano; de Oliveira, Levi Ezequiel; Gelli, Valéria Cress; Monti, Rubens

2016-01-01

Biorefineries serve to efficiently utilize biomass and their by-products. Algal biorefineries are designed to generate bioproducts for commercial use. Due to the high carbohydrate content of algal biomass, biorefinery to generate biofuels, such as bioethanol, is of great interest. Carrageenan is a predominant polysaccharide hydrocolloid found in red macroalgae and is widely used in food, cosmetics, and pharmaceuticals. In this study, we report the biorefinery of carrageenan derived from processing of experimental strains of the red macroalgae Kappaphycus alvarezii. Specifically, the chemical composition and enzymatic hydrolysis of the residue produced from carrageenan extraction were evaluated to determine the conditions for efficient generation of carbohydrate bioproducts. The productivity and growth rates of K. alvarezii strains were assessed along with the chemical composition (total carbohydrates, ash, sulfate groups, proteins, insoluble aromatics, galacturonic acid, and lipids) of each strain. Two strains, brown and red, were selected based on their high growth rates and productivity and were treated with 6 % KOH for extraction of carrageenan. The yields of biomass from treatment with 6 % KOH solution of the brown and red strains were 89.3 and 89.5 %, respectively. The yields of carrageenan and its residue were 63.5 and 23 %, respectively, for the brown strain and 60 and 27.8 %, respectively, for the red strain. The residues from the brown and red strains were assessed to detect any potential bioproducts. The galactan, ash, protein, insoluble aromatics, and sulfate groups of the residue were reduced to comparable extents for the two strains. However, KOH treatment did not reduce the content of glucan in the residue from either strain. Glucose was produced by enzymatic hydrolysis for 72 h using both strains. The glucan conversion was 100 % for both strains, and the concentrations of glucose from the brown and red strains were 13.7 and 11.5 g L(-1), respectively. The present results highlight the efficiency of generating a key bioproduct from carrageenan residue. This study demonstrates the potential for glucose production using carrageenan residue. Thus, the biorefinery of K. alvarezii can be exploited not only to produce carrageenan, but also to generate glucose for future use in biofuel production.

Wide-scale utilization of MSWI fly ashes in cement production and its impact on average heavy metal contents in cements: The case of Austria.

PubMed

Lederer, Jakob; Trinkel, Verena; Fellner, Johann

2017-02-01

A number of studies present the utilization of fly ashes from municipal solid waste incineration (MSWI) in cement production as a recycling alternative to landfilling. While there is a lot of research on the impact of MSWI fly ashes utilization in cement production on the quality of concrete or the leaching of heavy metals, only a few studies have determined the resulting heavy metal content in cements caused by this MSWI fly ashes utilization. Making use of the case of Austria, this study (1) determines the total content of selected heavy metals in cements currently produced in the country, (2) designs a scenario and calculates the resulting heavy metal contents in cements assuming that all MSWI fly ashes from Austrian grate incinerators were used as secondary raw materials for Portland cement clinker production and (3) evaluates the legal recyclability of demolished concretes produced from MSWI fly ash amended cements based on their total heavy metal contents. To do so, data from literature and statistics are combined in a material flow analysis model to calculate the average total contents of heavy metals in cements and in the resulting concretes according to the above scenario. The resulting heavy metal contents are then compared (i) to their respective limit values for cements as defined in a new technical guideline in Austria (BMLFUW, 2016), and (ii) to their respective limit values for recycling materials from demolished concrete. Results show that MSWI fly ashes utilization increases the raw material input in cement production by only +0.9%, but the total contents of Cd by +310%, and Hg, Pb, and Zn by +70% to +170%. However these and other heavy metal contents are still below their respective limit values for Austrian cements. The same legal conformity counts for recycling material derived from concretes produced from the MSWI fly ash cements. However, if the MSWI fly ash ratio in all raw materials used for cement production were increased from 0.9% to 22%, which is suggested by some studies, the limit values for cements as defined by the BMLFUW (2016) will be exceeded. Furthermore, the concrete produced from this cement will not be recyclable anymore due to its high total heavy metal contents. This and the comparatively high contribution of MSWI fly ashes to total heavy metal contents in cements indicate their relatively low resource potential if compared to other secondary raw materials in the cement industry. Copyright © 2016 Elsevier Ltd. All rights reserved.

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.

The study of the burning possibilities of solid combustibles in the determined conditions for complete usage of caloric [energy] and ashes resulted

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

Voina, N.I.; Barca, F.; Mogos, D.

1995-12-31

In modern combustors, 95--98% of the organic mass of a solid combustible is converted into caloric energy; 2--4% remain in the fly ash captured in electrofilters and hydraulically removed in most cases. The 2--4% unburned materials in fly ash, together with the water from being hydraulically transported, make it difficult for the use of the fly ash for metal extraction or as a binder in the materials industry. This work presents the research results of a study in which the burning process was modified to result in fly ash without carbon content and fly ash removal by dry capture. Laboratorymore » fluidized-bed combustion of lignite with and without addition of limestone for sulfur capture was used to generate ashes for further study. The ashes were studied for their use as binders and as a cement substitute.« less

Kinetics of fly ash beneficiation by carbon burnout. [Quarterly report], October 1, 1995--January 30, 1996

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

Dodoo, J.N.; Okoh, J.M.; Yilmaz, E.

The objective is to investigate the kinetics of beneficiation of fly ash by carbon burnout. The three year project that was proposed is a joint venture between Delmarva Power, a power generating company on the eastern shore of Maryland, and the University of Maryland Eastern Shore. The studies have focused on the beneficiation of fly ash by carbon burnout. The increasing use of coal fly ash as pozzolanic material in Portland cement concrete means that there is the highest economic potential in marketability of large volumes of fly ash. For the concrete industry to consider large scale use the flymore » ash must be of the highest quality. This means that the residual carbon content of the fly ash must have an acceptable loss on ignition (LOI) value, usually between 7--2% residual carbon. The economic gains to be had from low-carbon ash is a fact that is generally accepted by the electricity generating companies. However, since the cost of producing low-carbon in large quantities, based on present technology, far outweighs any financial gains, no electrical power company using coal as its fuel at present considers the effort worthwhile. The concrete industry would use fly ash in cement concrete mix if it can be assured of its LOI value. At present no utility company would give such assurance. Hence with several million tons of fly ash produced by a single power plant per year all that can be done is to dump the fly ash in landfills. The kinetics of fly ash beneficiation have been investigated in the zone II kinetic regime, using a Cahn TG 121 microbalance in the temperature 550--750{degrees}C. The P{sub 02} and total surface area dependence of the reaction kinetics were determined using a vacuum accessory attached to the microbalance and a surface area analyzer (ASAP 2010), respectively.« less

Steam gasification of a thermally pretreated high lignin corn stover simultaneous saccharification and fermentation digester residue

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

Howe, Daniel T.; Taasevigen, Danny; Garcia-Perez, Manuel

Efficient conversion of all components in lignocellulosic biomass is essential to realizing economic feasibility of biorefineries. However, when utilizing biochemical pathways, lignin cannot be fermented. Furthermore, the high lignin and high ash residue resulting from simultaneous saccharification and fermentation (SSF) reactors is difficult to thermochemically process due to feed line plugging and bed agglomeration. In this study a corn stover SSF digester residue was thermally pretreated at 300°C for 22.5 minutes (min) and then gasified in a bubbling fluidized bed gasifier to study the effect of thermal pretreatment on its processing behavior. Untreated, pelletized SSF residue was gasified at themore » same conditions to establish the baseline processing behavior. Results indicate that the thermal pretreatment process removes a substantial portion of the polar and non-polar extractives, with a resultant increase in the concentration of lignin, cellulose, and ash. Feed line plugging was not observed, although bed agglomeration was occurring at similar rates for both feedstocks, suggesting that overall ash content is the most important factor affecting bed agglomeration. Benzene, phenol, and polyaromatic hydrocarbons in the tar were present at higher concentrations in the treated material, with higher tar loading in the product gas. Total product gas generation is lower for the treated material, although the overall gas composition does not change.« less

Correlating the electrification of volcanic plumes with ashfall textures at Sakurajima Volcano, Japan

NASA Astrophysics Data System (ADS)

Smith, Cassandra M.; Van Eaton, Alexa R.; Charbonnier, Sylvain; McNutt, Stephen R.; Behnke, Sonja A.; Thomas, Ronald J.; Edens, Harald E.; Thompson, Glenn

2018-06-01

Volcanic lightning detection has become a useful resource for monitoring remote, under-instrumented volcanoes. Previous studies have shown that the behavior of volcanic plume electrification responds to changes in the eruptive processes and products. However, there has not yet been a study to quantify the links between ash textures and plume electrification during an actively monitored eruption. In this study, we examine a sequence of vulcanian eruptions from Sakurajima Volcano in Japan to compare ash textural properties (grain size, shape, componentry, and groundmass crystallinity) to plume electrification using a lightning mapping array and other monitoring data. We show that the presence of the continual radio frequency (CRF) signal is more likely to occur during eruptions that produce large seismic amplitudes (>7 μm) and glass-rich volcanic ash with more equant particle shapes. We show that CRF is generated during energetic, impulsive eruptions, where charge buildup is enhanced by secondary fragmentation (milling) as particles travel out of the conduit and into the gas-thrust region of the plume. We show that the CRF signal is influenced by a different electrification process than later volcanic lightning. By using volcanic CRF and lightning to better understand the eruptive event and its products these key observations will help the monitoring community better utilize volcanic electrification as a method for monitoring and understanding ongoing explosive eruptions.

Utilization of SRS pond ash in controlled low strength material. Technical report

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

Langton, C.A.; Rajendran, N.

1995-12-01

Design mixes for Controlled Low Strength Material (CLSM) were developed which incorporate pond ashes (fly ashes) from the A-Area Ash Pile, the old F-Area Ash Basin and the D-Area Ash Basin. CLSM is a pumpable, flowable, excavatable backfill used in a variety of construction applications at SRS. Results indicate that CLSM which meets all of the SRS design specifications for backfill, can be made with the A-, D-, and F-Area pond ashes. Formulations for the design mixes are provided in this report. Use of the pond ashes may result in a cost savings for CLSM used at SRS and willmore » utilize a by-product waste material, thereby decreasing the amount of material requiring disposal.« less

Evaluation of Vitrification Processing Step for Rocky Flats Incinerator Ash

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

Wigent, W.L.; Luey, J.K.; Scheele, R.D.

In 1997, Pacific Northwest National Laboratory (PNNL) staff developed a processing option for incinerator ash at the Rocky Flats Environmental Technology Sites (RFETS). This work was performed with support from Los Alamos National Laboratory (LANL) and Safe Sites of Colorado (SSOC). A description of the remediation needs for the RFETS incinerator ash is provided in a report summarizing the recommended processing option for treatment of the ash (Lucy et al. 1998). The recommended process flowsheet involves a calcination pretreatment step to remove carbonaceous material followed by a vitrification processing step for a mixture of glass tit and calcined incinerator ash.more » Using the calcination pretreatment step to remove carbonaceous material reduced process upsets for the vitrification step, allowed for increased waste loading in the final product, and improved the quality of the final product. Figure 1.1 illustrates the flow sheet for the recommended processing option for treatment of RFETS incinerator ash. In 1998, work at PNNL further developed the recommended flow sheet through a series of studies to better define the vitrification operating parameters and to address secondary processing issues (such as characterizing the offgas species from the calcination process). Because a prototypical rotary calciner was not available for use, studies to evaluate the offgas from the calcination process were performed using a benchtop rotary calciner and laboratory-scale equipment (Lucy et al. 1998). This report focuses on the vitrification process step after ash has been calcined. Testing with full-scale containers was performed using ash surrogates and a muffle furnace similar to that planned for use at RFETS. Small-scale testing was performed using plutonium-bearing incinerator ash to verify performance of the waste form. Ash was not obtained from RFETS because of transportation requirements to calcine the incinerator ash prior to shipment of the material. Because part of PNNL's work was to characterize the ash prior to calcination and to investigate the effect of calcination on product quality, representative material was obtained from LANL. Ash obtained from LANL was selected based on its similarity to that currently stored at RFETS. The plutonium-bearing ashes obtained from LANL are likely from a RFETS incinerator, but the exact origin was not identified.« less

Fluidized bed combustion bottom ash: A better and alternative geo-material resource for construction.

PubMed

Mandal, A K; Paramkusam, Bala Ramudu; Sinha, O P

2018-04-01

Though the majority of research on fly ash has proved its worth as a construction material, the utility of bottom ash is yet questionable due to its generation during the pulverized combustion process. The bottom ash produced during the fluidized bed combustion (FBC) process is attracting more attention due to the novelty of coal combustion technology. But, to establish its suitability as construction material, it is necessary to characterize it thoroughly with respect to the geotechnical as well as mineralogical points of view. For fulfilling these objectives, the present study mainly aims at characterizing the FBC bottom ash and its comparison with pulverized coal combustion (PCC) bottom ash, collected from the same origin of coal. Suitability of FBC bottom ash as a dike filter material in contrast to PCC bottom ash in replacing traditional filter material such as sand was also studied. The suitability criteria for utilization of both bottom ash and river sand as filter material on pond ash as a base material were evaluated, and both river sand and FBC bottom ash were found to be satisfactory. The study shows that FBC bottom ash is a better geo-material than PCC bottom ash, and it could be highly recommended as an alternative suitable filter material for constructing ash dikes in place of conventional sand.

Stabilization of cesium in alkali-activated municipal solid waste incineration fly ash and a pyrophyllite-based system.

PubMed

Shiota, Kenji; Nakamura, Takafumi; Takaoka, Masaki; Aminuddin, Siti Fatimah; Oshita, Kazuyuki; Fujimori, Takashi

2017-11-01

Environmentally sound treatments are required to dispose of municipal solid waste incineration fly ash (MSWIFA) contaminated with radioactive cesium (Cs) from the Fukushima Daiichi nuclear power plant accident in Japan. This study focuses on the stabilization of Cs using an alkali-activated MSWIFA and pyophyllite-based system. Three composite solid products were synthesized after mixtures of raw materials (dehydrated pyrophyllite, MSWIFA, 14 mol/L aqueous sodium hydroxide, and sodium silicate solution) were cured at 105 °C for 24 h. Three types of MSWIFAs were prepared as raw fly ash, raw fly ash with 0.1% CsCl, and raw fly ash with 40% CsCl to understand the stabilization mechanism of Cs. Cs stabilization in two solid products was successful, with less than 6.9% leaching observed from two types tests, and was partly successful for the solid product with the highest concentration of Cs. X-ray diffraction showed that all of the solid products produced several crystalline phases, and that pollucite was formed in the highest Cs concentration product. The X-ray absorption fine structure and scanning electron microscopy with X-ray analysis suggested that most Cs species formed pollucite in the two solid products from MSWIFA with added CsCl. This system provides a technique for the direct stabilization of Cs in MSWIFA. Copyright © 2017 Elsevier Ltd. All rights reserved.

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

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...

Dispersal of emerald ash borer: a case study at Tipton, Michigan

Treesearch

Deborah G. McCullough; Therese Poland; David Cappaert

2003-01-01

We had a unique opportunity to assess the dispersal of one generation of emerald ash borer adults for spread pattern in a rural area near Tipton, Lenawee County, Michigan. A Michigan Department of Agriculture inspector discovered adult beetles ovipositing on small ash trees in 2002 in this area, well beyond the core infestation area. Discussions with the property owner...

Removal of ash, sulfur, and trace elements of environmental concern from eight selected Illinois coals

USGS Publications Warehouse

Demir, I.

1998-01-01

Release analysis (RA) and float-sink (F-S) data were generated to assess the beneficiation potential of washed coals from selected Illinois coal preparation plants through the use of advanced physical cleaning at -60 mesh size. Generally, the F-S process removed greater amounts of ash, sulfur, and trace elements of environmental concern from the coals than the RA process, indicating that the cleanability of Illinois coals by advanced methods can be estimated best by F-S testing. At an 80%-combustibles recovery, the ash yield in the clean F-S products decreased by 47-75%, relative to the parent coals. Average decreases for the elements As(67%), Cd(78%), Hg(73%), Mn(71%), and P(66%) exceeded the average decrease for ash yield (55%). Average decreases for other elements were: Co(31%), Cr(27%), F(39%), Ni(25%), Pb(50%), S(28%), Sb(20%), Se(39), Th(32%), and U(8%). Only Be was enriched (up to 120%) in the clean products relative to the parent coals. These results suggested that the concentration of elements with relatively high atmospheric mobilities (As, Cd, F, Hg, Pb, and Se) during coal combustion can be reduced substantially in Illinois coals through the use of advanced physical cleaning. Advanced physical cleaning can be effective also for the removal of inorganic S. Environmental risks from the emission of other elements with enrichment or relatively low cleanabilities could be small because these elements generally have very low concentrations in Illinois coals or are largely retained in solid residues during coal combustion. ?? 1998 OPA (Overseas Publishers Association) N.V. Published by license under the Gordon and Breach Science Publishers imprint.

Interspecific Proteomic Comparisons Reveal Ash Phloem Genes Potentially Involved in Constitutive Resistance to the Emerald Ash Borer

PubMed Central

Whitehill, Justin G. A.; Popova-Butler, Alexandra; Green-Church, Kari B.; Koch, Jennifer L.; Herms, Daniel A.; Bonello, Pierluigi

2011-01-01

The emerald ash borer (Agrilus planipennis) is an invasive wood-boring beetle that has killed millions of ash trees since its accidental introduction to North America. All North American ash species (Fraxinus spp.) that emerald ash borer has encountered so far are susceptible, while an Asian species, Manchurian ash (F. mandshurica), which shares an evolutionary history with emerald ash borer, is resistant. Phylogenetic evidence places North American black ash (F. nigra) and Manchurian ash in the same clade and section, yet black ash is highly susceptible to the emerald ash borer. This contrast provides an opportunity to compare the genetic traits of the two species and identify those with a potential role in defense/resistance. We used Difference Gel Electrophoresis (DIGE) to compare the phloem proteomes of resistant Manchurian to susceptible black, green, and white ash. Differentially expressed proteins associated with the resistant Manchurian ash when compared to the susceptible ash species were identified using nano-LC-MS/MS and putative identities assigned. Proteomic differences were strongly associated with the phylogenetic relationships among the four species. Proteins identified in Manchurian ash potentially associated with its resistance to emerald ash borer include a PR-10 protein, an aspartic protease, a phenylcoumaran benzylic ether reductase (PCBER), and a thylakoid-bound ascorbate peroxidase. Discovery of resistance-related proteins in Asian species will inform approaches in which resistance genes can be introgressed into North American ash species. The generation of resistant North American ash genotypes can be used in forest ecosystem restoration and urban plantings following the wake of the emerald ash borer invasion. PMID:21949771

Interspecific proteomic comparisons reveal ash phloem genes potentially involved in constitutive resistance to the emerald ash borer.

PubMed

Whitehill, Justin G A; Popova-Butler, Alexandra; Green-Church, Kari B; Koch, Jennifer L; Herms, Daniel A; Bonello, Pierluigi

2011-01-01

The emerald ash borer (Agrilus planipennis) is an invasive wood-boring beetle that has killed millions of ash trees since its accidental introduction to North America. All North American ash species (Fraxinus spp.) that emerald ash borer has encountered so far are susceptible, while an Asian species, Manchurian ash (F. mandshurica), which shares an evolutionary history with emerald ash borer, is resistant. Phylogenetic evidence places North American black ash (F. nigra) and Manchurian ash in the same clade and section, yet black ash is highly susceptible to the emerald ash borer. This contrast provides an opportunity to compare the genetic traits of the two species and identify those with a potential role in defense/resistance. We used Difference Gel Electrophoresis (DIGE) to compare the phloem proteomes of resistant Manchurian to susceptible black, green, and white ash. Differentially expressed proteins associated with the resistant Manchurian ash when compared to the susceptible ash species were identified using nano-LC-MS/MS and putative identities assigned. Proteomic differences were strongly associated with the phylogenetic relationships among the four species. Proteins identified in Manchurian ash potentially associated with its resistance to emerald ash borer include a PR-10 protein, an aspartic protease, a phenylcoumaran benzylic ether reductase (PCBER), and a thylakoid-bound ascorbate peroxidase. Discovery of resistance-related proteins in Asian species will inform approaches in which resistance genes can be introgressed into North American ash species. The generation of resistant North American ash genotypes can be used in forest ecosystem restoration and urban plantings following the wake of the emerald ash borer invasion.

Heavy metal content in ash of energy crops growing in sewage-contaminated natural wetlands: potential applications in agriculture and forestry?

PubMed

Bonanno, Giuseppe; Cirelli, Giuseppe Luigi; Toscano, Attilio; Lo Giudice, Rosa; Pavone, Pietro

2013-05-01

One of the greatest current challenges is to find cost-effective and eco-friendly solutions to the ever increasing needs of modern society. Some plant species are suitable for a multitude of biotechnological applications such as bioenergy production and phytoremediation. A sustainable practice is to use energy crops to clean up polluted lands or to treat wastewater in constructed wetlands without claiming further arable land for biofuel production. However, the disposal of combustion by-products may add significant costs to the whole process, especially when it deals with toxic waste. This study aimed to investigate the possibility of recycling ash from energy biomass as a fertilizer for agriculture and forestry. In particular, the concentrations of Cd, Cr, Cu, Mn, Pb and Zn were analyzed in the plant tissues and corresponding ash of the grasses Phragmites australis and Arundo donax, collected in an urban stream affected by domestic sewage. Results showed that the metal concentration in ash is 1.5-3 times as high as the values in plant tissues. However, metal enriched ash showed much lower element concentrations than the legal limits for ash reutilization in agriculture and forestry. This study found that biomass ash from constructed wetlands may be considered as a potential fertilizer rather than hazardous waste. Energy from biomass can be a really sustainable and clean option not only through the reduction of greenhouse gas emissions, but also through ash recycling for beneficial purposes, thus minimizing the negative impacts of disposal. Copyright © 2013 Elsevier B.V. All rights reserved.

Real-Time Estimation of Volcanic ASH/SO2 Cloud Height from Combined Uv/ir Satellite Observations and Numerical Modeling

NASA Astrophysics Data System (ADS)

Vicente, Gilberto A.

An efficient iterative method has been developed to estimate the vertical profile of SO2 and ash clouds from volcanic eruptions by comparing near real-time satellite observations with numerical modeling outputs. The approach uses UV based SO2 concentration and IR based ash cloud images, the volcanic ash transport model PUFF and wind speed, height and directional information to find the best match between the simulated and the observed displays. The method is computationally fast and is being implemented for operational use at the NOAA Volcanic Ash Advisory Centers (VAACs) in Washington, DC, USA, to support the Federal Aviation Administration (FAA) effort to detect, track and measure volcanic ash cloud heights for air traffic safety and management. The presentation will show the methodology, results, statistical analysis and SO2 and Aerosol Index input products derived from the Ozone Monitoring Instrument (OMI) onboard the NASA EOS/Aura research satellite and from the Global Ozone Monitoring Experiment-2 (GOME-2) instrument in the MetOp-A. The volcanic ash products are derived from AVHRR instruments in the NOAA POES-16, 17, 18, 19 as well as MetOp-A. The presentation will also show how a VAAC volcanic ash analyst interacts with the system providing initial condition inputs such as location and time of the volcanic eruption, followed by the automatic real-time tracking of all the satellite data available, subsequent activation of the iterative approach and the data/product delivery process in numerical and graphical format for operational applications.

Merging two waste streams, wood ash and biowaste, results in improved composting process and end products.

PubMed

Fernández-Delgado Juárez, M; Gómez-Brandón, M; Insam, H

2015-04-01

A trial was carried out to evaluate the influence of wood ash admixture on biowaste composting. The aim was to find the optimal dosage of ash addition to enhance the composting process without endangering the final compost characteristics and use. Six treatments including an unamended control (K0) and composts with additions of 3% (K3), 6% (K6), 9% (K9), 12% (K12) and 15% (K15) of wood ash (w/w) were studied. The composting process was monitored in situ for 49days, by measuring temperature, CO2, O2, and CH4 in the piles and pH, electric conductivity (EC), and inorganic N in the laboratory. At the end of the process, the products were tested for Reifegrad (maturity), toxicity and quality. The addition of up to 15% of wood ash to biowaste did not negatively affect the composting process, and the initial differences found between both the low and high ash-treated composts were attenuated with the ongoing process development. Nevertheless, and mainly due to Cd level, composts with higher ash amendment did not comply with the highest quality standards established by the Austrian Compost Ordinance. The failure of obtaining class A+ quality after ash amendment emphasizes the need for a rigid quality selection of (bottom) ashes and thus reducing environmental risks related to high pollutant loads originating from the ashes. Copyright © 2014 Elsevier B.V. All rights reserved.

Satellite Derived Volcanic Ash Product Inter-Comparison in Support to SCOPE-Nowcasting

NASA Astrophysics Data System (ADS)

Siddans, Richard; Thomas, Gareth; Pavolonis, Mike; Bojinski, Stephan

2016-04-01

In support of aeronautical meteorological services, WMO organized a satellite-based volcanic ash retrieval algorithm inter-comparison activity, to improve the consistency of quantitative volcanic ash products from satellites, under the Sustained, Coordinated Processing of Environmental Satellite Data for Nowcasting (SCOPEe Nowcasting) initiative (http:/ jwww.wmo.int/pagesjprogjsatjscopee nowcasting_en.php). The aims of the intercomparison were as follows: 1. Select cases (Sarychev Peak 2009, Eyjafyallajökull 2010, Grimsvötn 2011, Puyehue-Cordón Caulle 2011, Kirishimayama 2011, Kelut 2014), and quantify the differences between satellite-derived volcanic ash cloud properties derived from different techniques and sensors; 2. Establish a basic validation protocol for satellite-derived volcanic ash cloud properties; 3. Document the strengths and weaknesses of different remote sensing approaches as a function of satellite sensor; 4. Standardize the units and quality flags associated with volcanic cloud geophysical parameters; 5. Provide recommendations to Volcanic Ash Advisory Centers (VAACs) and other users on how to best to utilize quantitative satellite products in operations; 6. Create a "road map" for future volcanic ash related scientific developments and inter-comparison/validation activities that can also be applied to SO2 clouds and emergent volcanic clouds. Volcanic ash satellite remote sensing experts from operational and research organizations were encouraged to participate in the inter-comparison activity, to establish the plans for the inter-comparison and to submit data sets. RAL was contracted by EUMETSAT to perform a systematic inter-comparison of all submitted datasets and results were reported at the WMO International Volcanic Ash Inter-comparison Meeting to held on 29 June - 2 July 2015 in Madison, WI, USA (http:/ /cimss.ssec.wisc.edujmeetings/vol_ash14). 26 different data sets were submitted, from a range of passive imagers and spectrometers and these were inter-compared against each other and against validation data such as CALIPSO lidar, ground-based lidar and aircraft observations. Results of the comparison exercise will be presented together with the conclusions and recommendations arising from the activity.

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.

Development and testing of synthetic riprap constructed from coal combustion products (CCPs).

DOT National Transportation Integrated Search

2014-07-01

Even with an increase in the amount of coal combustion products (CCPs) used in concrete con-struction, soil stabilization, and other : applications, the coal power industry must dispose of a sig-nificant amount of fly ash and bottom ash. One potentia...

ELECTROSTATIC ENHANCEMENT OF FABRIC FILTRATION OF FLY ASH AND SPRAY DRYER BY-PRODUCT

EPA Science Inventory

The paper describes small pilot-scale experiments, showing that the pressure drop increase during the fabric filtration of redispersed spray dryer by-product (chiefly calcium salts and fly ash) is significantly reduced by electrostatic enhancement of the filtration. The pressure ...

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.

Process for the production of fuel gas from coal

DOEpatents

Patel, Jitendra G.; Sandstrom, William A.; Tarman, Paul B.

1982-01-01

An improved apparatus and process for the conversion of hydrocarbonaceous materials, such as coal, to more valuable gaseous products in a fluidized bed gasification reaction and efficient withdrawal of agglomerated ash from the fluidized bed is disclosed. The improvements are obtained by introducing an oxygen containing gas into the bottom of the fluidized bed through a separate conduit positioned within the center of a nozzle adapted to agglomerate and withdraw the ash from the bottom of the fluidized bed. The conduit extends above the constricted center portion of the nozzle and preferably terminates within and does not extend from the nozzle. In addition to improving ash agglomeration and withdrawal, the present invention prevents sintering and clinkering of the ash in the fluidized bed and permits the efficient recycle of fine material recovered from the product gases by contacting the fines in the fluidized bed with the oxygen as it emanates from the conduit positioned within the withdrawal nozzle. Finally, the present method of oxygen introduction permits the efficient recycle of a portion of the product gases to the reaction zone to increase the reducing properties of the hot product gas.

Optimizing and Characterizing Geopolymers from Ternary Blend of Philippine Coal Fly Ash, Coal Bottom Ash and Rice Hull Ash.

PubMed

Kalaw, Martin Ernesto; Culaba, Alvin; Hinode, Hirofumi; Kurniawan, Winarto; Gallardo, Susan; Promentilla, Michael Angelo

2016-07-15

Geopolymers are inorganic polymers formed from the alkaline activation of amorphous alumino-silicate materials resulting in a three-dimensional polymeric network. As a class of materials, it is seen to have the potential of replacing ordinary Portland cement (OPC), which for more than a hundred years has been the binder of choice for structural and building applications. Geopolymers have emerged as a sustainable option vis-à-vis OPC for three reasons: (1) their technical properties are comparable if not better; (2) they can be produced from industrial wastes; and (3) within reasonable constraints, their production requires less energy and emits significantly less CO₂. In the Philippines, the use of coal ash, as the alumina- and silica- rich geopolymer precursor, is being considered as one of the options for sustainable management of coal ash generation from coal-fired power plants. However, most geopolymer mixes (and the prevalent blended OPC) use only coal fly ash. The coal bottom ash, having very few applications, remains relegated to dumpsites. Rice hull ash, from biomass-fired plants, is another silica-rich geopolymer precursor material from another significantly produced waste in the country with only minimal utilization. In this study, geopolymer samples were formed from the mixture of coal ash, using both coal fly ash (CFA) and coal bottom ash (CBA), and rice hull ash (RHA). The raw materials used for the geopolymerization process were characterized using X-ray fluorescence spectroscopy (XRF) for elemental and X-ray diffraction (XRD) for mineralogical composition. The raw materials' thermal stability and loss on ignition (LOI) were determined using thermogravimetric analysis (TGA) and reactivity via dissolution tests and inductively-coupled plasma mass spectrometry (ICP) analysis. The mechanical, thermal and microstructural properties of the geopolymers formed were analyzed using compression tests, Fourier transform infra-red spectroscopy (FTIR), scanning electron microscopy (SEM) and thermogravimetric analysis (TGA). Using a Scheffé-based mixture design, targeting applications with low thermal conductivity, light weight and moderate strength and allowing for a maximum of five percent by mass of rice hull ash in consideration of the waste utilization of all three components, it has been determined that an 85-10-5 by weight ratio of CFA-CBA-RHA activated with 80-20 by mass ratio of 12 M NaOH and sodium silicate (55% H₂O, modulus = 3) produced geopolymers with a compressive strength of 18.5 MPa, a volumetric weight of 1660 kg/m³ and a thermal conductivity of 0.457 W/m-°C at 28-day curing when pre-cured at 80 °C for 24 h. For this study, the estimates of embodied energy and CO₂ were all below 1.7 MJ/kg and 0.12 kg CO₂/kg, respectively.

Alkali-Activated Geopolymers: A Literature Review

DTIC Science & Technology

2010-07-01

Typical Fly Ash Composition (%) [32] .................................................................................... 15 3. Typical Geopolymer ... geopolymer matrix. Fly ash composition is generally measured and evaluated by the percentage of existing elements present in the by-product...pozzolan bear great significance to the strength potential of a given geopolymer specimen. Table 2. Typical Fly Ash Composition (%) [32

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

40 CFR 98.296 - Data reporting requirements.

Code of Federal Regulations, 2012 CFR

2012-07-01

... of trona or liquid alkaline feedstock for each manufacturing line (tons). (2) Annual production of... trona or liquid alkaline feedstock for each manufacturing line (tons). (6) Monthly production of soda... manufacturing lines located used to produce soda ash. (10) If you produce soda ash using the liquid alkaline...

40 CFR 98.296 - Data reporting requirements.

Code of Federal Regulations, 2011 CFR

2011-07-01

... of trona or liquid alkaline feedstock for each manufacturing line (tons). (2) Annual production of... trona or liquid alkaline feedstock for each manufacturing line (tons). (6) Monthly production of soda... manufacturing lines located used to produce soda ash. (10) If you produce soda ash using the liquid alkaline...

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...

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.

Enhanced Ethanol Production from De-Ashed Paper Sludge by Simultaneous Saccharification and Fermentation and Simultaneous Saccharification and Co-Fermentation

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

Kang, L.; Wang, W.; Pallapolu, V. R.

2011-11-01

A previous study demonstrated that paper sludges with high ash contents can be converted to ethanol by simultaneous saccharification and fermentation (SSF) or simultaneous saccharification and co-fermentation (SSCF). High ash content in the sludge, however, limited solid loading in the bioreactor, causing low product concentration. To overcome this problem, sludges were de-ashed before SSF and SSCF. Low ash content in sludges also increased the ethanol yield to the extent that the enzyme dosage required to achieve 70% yield in the fermentation process was reduced by 30%. High solid loading in SSF and SSCF decreased the ethanol yield. High agitation andmore » de-ashing of the sludges were able to restore the part of the yield loss caused by high solid loading. Substitution of the laboratory fermentation medium (peptone and yeast extract) with corn steep liquor did not bring about any adverse effects in the fermentation. Fed-batch operation of the SSCF and SSF using low-ash content sludges was effective in raising the ethanol concentration, achieving 47.8 g/L and 60.0 g/L, respectively.« less

Recovery of soluble chloride salts from the wastewater generated during the washing process of municipal solid wastes incineration fly ash.

PubMed

Tang, Hailong; Erzat, Aris; Liu, Yangsheng

2014-01-01

Water washing is widely used as the pretreatment method to treat municipal solid waste incineration fly ash, which facilitates the further solidification/stabilization treatment or resource recovery of the fly ash. The wastewater generated during the washing process is a kind of hydrosaline solution, usually containing high concentrations of alkali chlorides and sulphates, which cause serious pollution to environment. However, these salts can be recycled as resources instead of discharge. This paper explored an effective and practical recovery method to separate sodium chloride, potassium chloride, and calcium chloride salts individually from the hydrosaline water. In laboratory experiments, a simulating hydrosaline solution was prepared according to composition of the waste washing water. First, in the three-step evaporation-crystallization process, pure sodium chloride and solid mixture of sodium and potassium chlorides were obtained separately, and the remaining solution contained potassium and calcium chlorides (solution A). And then, the solid mixture was fully dissolved into water (solution B obtained). Finally, ethanol was added into solutions A and B to change the solubility of sodium, potassium, and calcium chlorides within the mixed solvent of water and ethanol. During the ethanol-adding precipitation process, each salt was separated individually, and the purity of the raw production in laboratory experiments reached about 90%. The ethanol can be recycled by distillation and reused as the solvent. Therefore, this technology may bring both environmental and economic benefits.

Rice Husk Ash-Derived Silica Nanofluids: Synthesis and Stability Study

NASA Astrophysics Data System (ADS)

Zhang, Zhiliang; He, Wenxiu; Zheng, Jianzhong; Wang, Guangquan; Ji, Jianbing

2016-11-01

Nanofluids, colloidal suspensions consisting of base fluids and nanoparticles, are a new generation of engineering working fluids. Nanofluids have shown great potential in heat/mass transfer applications. However, their practical applications are limited by the high production cost and low stability. In this study, a low-cost agricultural waste, rice husk ash (RHA), was used as a silicon source to the synthesis of silica nanofluids. First, silica nanoparticles with an average size of 47 nm were synthesized. Next, by dispersing the silica nanoparticles in water with ultrasonic vibration, silica nanofluids were formed. The results indicated that the dispersibility and stability of nanofluids were highly dependent on sonication time and power, dispersant types and concentrations, as well as pH; an optimal experiment condition could result in the highest stability of silica nanofluid. After 7 days storage, the nanofluid showed no sedimentation, unchanged particle size, and zeta potential. The results of this study demonstrated that there is a great potential for the use of RHA as a low-cost renewable resource for the production of stable silica nanofluids.

[Statistical analysis of body and lung mass of animals subjected to a single experimental insufflation of soil dust and electro-energetic ashes].

PubMed

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

1989-01-01

The studies were performed on 44 white female Wistar rats which were intratracheally administered the suspension of the soil dust and the electro-energetic ashes. The electro-energetic ashes were collected from 6 different local heat and power generating plants while the soil dust from several random places of our country. The statistical analysis of the body and the lung mass of the animals subjected to the single dust and ash insufflation was performed. The applied variants proved the statistically significant differences between the body and the lung mass. The observed differences are connected with the kinds of dust and ash used in the experiment.

Iron Determination in Meat Using Ferrozine Assay

NASA Astrophysics Data System (ADS)

Carpenter, Charles; Ward, Robert

Chromogens are chemicals that react with compounds of interest and form colored products that can be quantified using spectroscopy. Several chromogens that selectively react with minerals are available. In this lab, ferrozine is used to measure ferrous iron in an ashed food sample. The relationship between the absorbance of the chromogen-mineral complex is described by Beer's Law; in this procedure, a standard curve is generated with a stock iron solution to quantify the mineral in beef samples.

Deployment Area Selection and Land Withdrawal/Acquisition. M-X/MPS (M-X/Multiple Protective Shelter) Environmental Technical Report. Power and Energy.

DTIC Science & Technology

1981-10-02

acceptable levels under the worst case condition of coal firing. The flue gas desulfurization system would be designed to reduce the sulfer dioxide content...approaches taken. There exists federal statutory authority to implement gas rationing under certain conditions. Thus, federal controls on oil production...such as air quality deterioration, water consumption, P wastewater generation, disposal of flue gas scrubbing sludge, and ash. Another alternative is

White Fringetree as a Novel Larval Host for Emerald Ash Borer.

PubMed

Cipollini, Don

2015-02-01

Emerald ash borer is an invasive Asian pest of ash species in North America. All North American species of ash tested so far are susceptible to it, but there are no published reports of this insect developing fully in non-ash hosts in the field in North America. I report here evidence that emerald ash borer can attack and complete development in white fringetree, Chionanthus virginicus L., a species native to the southeastern United States that is also planted ornamentally. Four of 20 mature ornamental white fringetrees examined in the Dayton, Ohio area showed external symptoms of emerald ash borer attack, including the presence of adult exit holes, canopy dieback, and bark splitting and other deformities. Removal of bark from one of these trees yielded evidence of at least three generations of usage by emerald ash borer larvae, several actively feeding live larvae, and a dead adult confirmed as emerald ash borer. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Effect of lime and wood ash on the nixtamalization of maize and tortilla chemical and nutritional characteristics.

PubMed

Pappa, María Renée; de Palomo, Patricia Palacios; Bressani, Ricardo

2010-06-01

The objective of the study was to obtain information on the chemical composition, functional properties, sensory quality and protein value of tortillas made from the nixtamalization of maize using either lime or wood ashes. The Ca, K, Mg, Fe, and Zn content of lime and wood ashes showed lime to be high in Ca content while wood ash contained more K and about 71% of the Ca content of lime. Both contained relatively high levels of Mg, Fe and Zn, but more so in the wood ashes. The level of reagent for nixtamalization was set at 0.8% of the maize weight. All other processing conditions were kept constant. The pH of the cooking solution was 12.0 for lime and 10.9 for wood ash. The moisture content of maize at 60 min of cooking was 45.8% for both treatments, however after 12 h of soaking, moisture level was 51.0% for the lime treatment and only 46.8% for the ash treatment. Solids (2.4%) in the lime cooking liquor were higher than in the wood ash liquor (1.0%). Chemical composition changes were similar between treatments in masa and tortilla; however, both masa and tortillas absorbed relatively high levels of all minerals including Fe and Zn from the wood ash treatment. The different treatment influenced functional properties particularly hardness and color. Tortilla characteristics were also similar. Protein quality of both alkali cooked products was lower than that of raw corn, more so the product from the wood ash treatment. Although some differences were observed in the sensory studies, human subjects did not dislike the wood ash made tortillas.

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

Post-processing, energy production use of sugarcane bagasse ash

USDA-ARS?s Scientific Manuscript database

Sugarcane bagasse ash (SBA) is a multi-process by-product produced from the milling of sugarcane. Bagasse is the fibrous material remaining after removing the sugar, water, and other impurities from the sugarcane delivered to the mill. Louisiana produces an estimated 2.7 mt of bagasse each year. In ...

Post-processing, energy production use of sugarcane bagasse ash

USDA-ARS?s Scientific Manuscript database

Sugarcane bagasse ash (SBA) is a multi-processed by-product produced from the milling of sugarcane. Bagasse is the fibrous material remaining after removing the sugar, water, and other impurities from the sugarcane delivered to the mill. Louisiana produces an estimated 3 million tons of bagasse each...

Ash production and dispersal from sustained low-intensity Mono-Inyo eruptions

NASA Astrophysics Data System (ADS)

Black, Benjamin A.; Manga, Michael; Andrews, Benjamin

2016-08-01

Recent rhyolitic volcanism has demonstrated that prolonged low-intensity ash venting may accompany effusive dome formation. We examine the possibility and some consequences of episodes of extended, weak ash venting at the rhyolitic Mono-Inyo chain in Eastern California. We describe ash-filled cracks within one of the youngest domes, Panum Crater, which provide a textural record of ash venting during dome effusion. We use synchrotron-based X-ray computed tomography to characterize the particles in these tuffisites. Particle sizes in well-sorted tuffisite layers agree well with grain size distributions observed during weak ash venting at Soufrière Hills Volcano, Montserrat, and yield approximate upper and lower bounds on gas velocity and mass flux during the formation of those layers. We simulate ash dispersal with Ash3d to assess the consequences of long-lived Mono-Inyo ash venting for ash deposition and the accompanying volcanic hazards. Our results highlight the sensitivity of large-scale outcomes of volcanic eruptions to small-scale processes.

Development of a sintering process for recycling oil shale fly ash and municipal solid waste incineration bottom ash into glass ceramic composite.

PubMed

Zhang, Zhikun; Zhang, Lei; Li, Aimin

2015-04-01

Oil shale fly ash and municipal solid waste incineration bottom ash are industrial and municipal by-products that require further treatment before disposal to avoid polluting the environment. In the study, they were mixed and vitrified into the slag by the melt-quench process. The obtained vitrified slag was then mixed with various percentages of oil shale fly ash and converted into glass ceramic composites by the subsequent sintering process. Differential thermal analysis was used to study the thermal characteristics and determine the sintering temperatures. X-ray diffraction analysis was used to analyze the crystalline phase compositions. Sintering shrinkage, weight loss on ignition, density and compressive strength were tested to determine the optimum preparation condition and study the co-sintering mechanism of vitrified amorphous slag and oil shale fly ash. The results showed the product performances increased with the increase of sintering temperatures and the proportion of vitrified slag to oil shale fly ash. Glass ceramic composite (vitrified slag content of 80%, oil shale fly ash content of 20%, sintering temperature of 1000 °C and sintering time of 2h) showed the properties of density of 1.92 ± 0.05 g/cm(3), weight loss on ignition of 6.14 ± 0.18%, sintering shrinkage of 22.06 ± 0.6% and compressive strength of 67 ± 14 MPa. The results indicated that it was a comparable waste-based material compared to previous researches. In particular, the energy consumption in the production process was reduced compared to conventional vitrification and sintering method. Chemical resistance and heavy metals leaching results of glass ceramic composites further confirmed the possibility of its engineering applications. Copyright © 2015 Elsevier Ltd. All rights reserved.

Production of coloured glass-ceramics from incinerator ash using thermal plasma technology.

PubMed

Cheng, T W; Huang, M Z; Tzeng, C C; Cheng, K B; Ueng, T H

2007-08-01

Incineration is a major treatment process for municipal solid waste in Taiwan. It is estimated that over 1.5 Mt of incinerator ash are produced annually. This study proposes using thermal plasma technology to treat incinerator ash. Sintered glass-ceramics were produced using quenched vitrified slag with colouring agents added. The experimental results showed that the major crystalline phases developed in the sintered glass-ceramics were gehlenite and wollastonite, but many other secondary phases also appeared depending on the colouring agents added. The physical/mechanical properties, chemical resistance and toxicity characteristic leaching procedure of the coloured glass-ceramics were satisfactory. The glass-ceramic products obtained from incinerator ash treated with thermal plasma technology have great potential for building applications.

"MERAPIDATA": New Petrologic and Geochemical Database of the Merapi Volcano, Central Java, Indonesia

NASA Astrophysics Data System (ADS)

Borisova, A. Y.; Martel, C.; Pratomo, I.; Toutain, J.; Sumarti, S.; Surono, S.

2011-12-01

Petrologic and geochemical databases of erupted products are critical for monitoring and predicting the evolution of active volcanoes. To monitor the activity of one of the most dangerous volcanoes in the world, Merapi Volcano in Indonesia, in the framework of the new instrumental site VELI (Volcans Explosifs - Laboratoires Indonésiens labelled by INSU in 2009 in France), we generated "MERAPIDATA", a complete database of available petrologic and geochemical data published in the literature on pyroclastic flows, tephra, lavas and xenoliths coupled with the exact ages of historical flows [1] or estimated ages based on 14C geochronology [2]. "MERAPIDATA" permits to access complete petrologic, geochemical, and geochronological information (e.g., major, trace element and Sr-Nd-Pb-O isotopic composition of the bulk volcanic rocks, xenoliths, minerals and glasses; textural information; type of eruption; classification) of a given volcanic product or series. In addition to ~300 published volcanic products, new data on 2 pyroclastic flows, 1 tephra and 4 ash samples collected on northern and western slopes of the volcano in October and November 2010 during subplinian type eruption have been added to "MERAPIDATA". The 2010 ash sample chemistry allows classifying them as high-K basaltic andesite. The ash samples demonstrate major and trace element compositions typical for the high-K series. For the first time, we obtained complete data on the Merapi ash samples which characterized by low L.O.I. ≤ 0.58 wt%, CO2total ≤ 0.05 wt%, H2Ototal = 0.3 - 0.5 wt%, Stotal ≤ 0.13 wt% and moderate Cl (550 - 1120 ppm) contents. The ash-leachates produced by leaching experiments demonstrate constant F/Cl ratios (0.05 ± 0.01) and Ca-Na-K enrichment (Ca/Na= 3 - 7, Na/K = 1 - 5). Sr-Nd-Pb-O isotopic analyses on the 2010 Merapi products are in progress. New petrologic (e.g., melt and fluid inclusion data, T - P - fO2 - aH2O - aCO2) and geochemical (e.g., volatile, major, trace element and isotopic composition of the bulk volcanic rocks and glassy matrix) data will permit to explain unexpected subplinian type of the 2010 eruption. The complete "MERAPIDATA" programmed with MS Access 2007 will be available in English version for open access at the website of the Observatory of Midi-Pyrénées (Toulouse, France): "http://www.get.obs-mip.fr/index.php/Annuaire/Borisova-Anastassia/MERAPIDATA". [1] Camus et al., (2000). JVGR 100, 139-163. [2] Gertisser & Keller (2003). JVGR 123, 1-23.

Using fly ash to mitigate explosions

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

Taulbee, D.

2008-07-01

In 2005 the University of Kentucky's Center for Applied Energy Research was given funding to evaluate the use of coal combustion by-products (CCBs) to reduce the explosive potential of ammonium nitrate (AN) fertilizers. Fly ash C (FAC), fly ash F (FAF) and flue gas desulfurization by-product (FGD) were evaluated. It was found that applying a CCB coating to the AN particles at concentrations of 5 wt% or greater prevented the AN explosion from propagating. The article reports on results so far and outlines further work to be done. 6 figs.

Respiratory hazard assessment of combined exposure to complete gasoline exhaust and respirable volcanic ash in a multicellular human lung model at the air-liquid interface

USGS Publications Warehouse

Tomasek, Ines; Horwell, Claire J.; Bisig, Christoph; Damby, David; Comte, Pierre; Czerwinski, Jan; Petri-Fink, Alke; Clift, Martin J D; Drasler, Barbara; Rothen-Rutishauer, Barbara

2018-01-01

Communities resident in urban areas located near active volcanoes can experience volcanic ash exposures during, and following, an eruption, in addition to sustained exposures to high concentrations of anthropogenic air pollutants (e.g., vehicle exhaust emissions). Inhalation of anthropogenic pollution is known to cause the onset of, or exacerbate, respiratory and cardiovascular diseases. It is further postulated similar exposure to volcanic ash can also affect such disease states. Understanding of the impact of combined exposure of volcanic ash and anthropogenic pollution to human health, however, remains limited.The aim of this study was to assess the biological impact of combined exposure to respirable volcanic ash (from Soufrière Hills volcano (SHV), Montserrat and Chaitén volcano (ChV), Chile; representing different magmatic compositions and eruption styles) and freshly-generated complete exhaust from a gasoline vehicle. A multicellular human lung model (an epithelial cell-layer composed of A549 alveolar type II-like cells complemented with human blood monocyte-derived macrophages and dendritic cells cultured at the air-liquid interface) was exposed to diluted exhaust (1:10) continuously for 6 h, followed by immediate exposure to the ash as a dry powder (0.54 ± 0.19 μg/cm2 and 0.39 ± 0.09 μg/cm2 for SHV and ChV ash, respectively). After an 18 h incubation, cells were exposed again for 6 h to diluted exhaust, and a final 18 h incubation (at 37 °C and 5% CO2). Cell cultures were then assessed for cytotoxic, oxidative stress and (pro-)inflammatory responses.Results indicate that, at all tested (sub-lethal) concentrations, co-exposures with both ash samples induced no significant expression of genes associated with oxidative stress (HMOX1, NQO1) or production of (pro-)inflammatory markers (IL-1β, IL-8, TNF-α) at the gene and protein levels. In summary, considering the employed experimental conditions, combined exposure of volcanic ash and gasoline vehicle exhaust has a limited short-term biological impact to an advanced lung cell in vitro model.

Respiratory hazard assessment of combined exposure to complete gasoline exhaust and respirable volcanic ash in a multicellular human lung model at the air-liquid interface.

PubMed

Tomašek, Ines; Horwell, Claire J; Bisig, Christoph; Damby, David E; Comte, Pierre; Czerwinski, Jan; Petri-Fink, Alke; Clift, Martin J D; Drasler, Barbara; Rothen-Rutishauser, Barbara

2018-07-01

Communities resident in urban areas located near active volcanoes can experience volcanic ash exposures during, and following, an eruption, in addition to sustained exposures to high concentrations of anthropogenic air pollutants (e.g., vehicle exhaust emissions). Inhalation of anthropogenic pollution is known to cause the onset of, or exacerbate, respiratory and cardiovascular diseases. It is further postulated similar exposure to volcanic ash can also affect such disease states. Understanding of the impact of combined exposure of volcanic ash and anthropogenic pollution to human health, however, remains limited. The aim of this study was to assess the biological impact of combined exposure to respirable volcanic ash (from Soufrière Hills volcano (SHV), Montserrat and Chaitén volcano (ChV), Chile; representing different magmatic compositions and eruption styles) and freshly-generated complete exhaust from a gasoline vehicle. A multicellular human lung model (an epithelial cell-layer composed of A549 alveolar type II-like cells complemented with human blood monocyte-derived macrophages and dendritic cells cultured at the air-liquid interface) was exposed to diluted exhaust (1:10) continuously for 6 h, followed by immediate exposure to the ash as a dry powder (0.54 ± 0.19 μg/cm 2 and 0.39 ± 0.09 μg/cm 2 for SHV and ChV ash, respectively). After an 18 h incubation, cells were exposed again for 6 h to diluted exhaust, and a final 18 h incubation (at 37 °C and 5% CO 2 ). Cell cultures were then assessed for cytotoxic, oxidative stress and (pro-)inflammatory responses. Results indicate that, at all tested (sub-lethal) concentrations, co-exposures with both ash samples induced no significant expression of genes associated with oxidative stress (HMOX1, NQO1) or production of (pro-)inflammatory markers (IL-1β, IL-8, TNF-α) at the gene and protein levels. In summary, considering the employed experimental conditions, combined exposure of volcanic ash and gasoline vehicle exhaust has a limited short-term biological impact to an advanced lung cell in vitro model. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

Potential production of emerald ash borer adults: tree, site and landscape-level applications

Treesearch

Nathan W. Siegert; Deborah G. McCullough

2007-01-01

Emerald ash borer (Agrilus planipennis Fairmaire; Coleoptera: Buprestidae), a phloem-feeding beetle native to Asia, was identified in June 2002 as the cause of widespread ash (Fraxinus spp.) mortality in forest and urban settings in southeastern lower Michigan and Windsor, Ontario. To date, 21 Michigan counties have been...

Design and evaluation of high-volume fly ash (HVFA) concrete mixes, report E : hardened mechanical properties and durability performance of HVFA concrete.

DOT National Transportation Integrated Search

2012-10-01

A rising concern in todays construction industry is environmental responsibility. : The addition of fly ash is a leading innovation in sustainable design of concrete. Fly ash, : a waste by-product of coal burning power plants, can be used to repla...

Review of palm oil fuel ash and ceramic waste in the production of concrete

NASA Astrophysics Data System (ADS)

Natasya Mazenan, Puteri; Sheikh Khalid, Faisal; Shahidan, Shahiron; Shamsuddin, Shamrul-mar

2017-11-01

High demand for cement in the concrete production has been increased which become the problems in the industry. Thus, this problem will increase the production cost of construction material and the demand for affordable houses. Moreover, the production of Portland cement leads to the release of a significant amount of CO2 and other gases leading to the effect on global warming. The need for a sustainable and green construction building material is required in the construction industry. Hence, this paper presents utilization of palm oil fuel ash and ceramic waste as partial cement replacement in the production of concrete. Using both of this waste in the concrete production would benefit in many ways. It is able to save cost and energy other than protecting the environment. In short, 20% usage of palm oil fuel ash and 30% replacement of ceramic waste as cement replacement show the acceptable and satisfactory strength of concrete.

Leaching of major and trace elements from paper-plastic gasification chars: an experimental and modelling study.

PubMed

Fuente-Cuesta, A; Lopez-Anton, M A; Diaz-Somoano, M; Zomeren, A van; Cieplik, M; Martínez-Tarazona, M R

2013-01-15

The control of soluble metal species in the sub-product leachate generated in electricity production processes is of great concern from an environmental and health point of view. Unlike fly ash, the leaching behaviour of char materials has received little attention. Yet, these solids are captured together with fly ashes in the particle control devices of power plants and are emitted in the same way as by-products. The present study was carried out using two char samples: (i) a raw char and (ii) the same type of char employed in a previous study so that it could serve as a sorbent for mercury species in gas phase. The char samples were by-products (residues) that had been generated during the gasification of plastic and paper waste. The leachates were analyzed for the following elements: Al, Ca, Si, Mg, Ba, Cu, Ni, Pb, Zn, Mo and Hg. In addition, geochemical modelling of the leaching test results was employed to identify the underlying chemical processes that led to the release of toxic elements. The results showed that at alkaline pH values, sorption on the solid surfaces of the char was negligible due to the inorganic complexation of cations in the solution. When the char was used as mercury sorbent slight changes occurred on the reactive surface resulting in the modification of the binding of some elements. As the pH increased, complexation with dissolved organic matter played a more important role in the case of some elements such as Cu because of the greater concentration of dissolved organic matter in solution. Copyright © 2012 Elsevier B.V. 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.

Drivers for innovation in waste-to-energy technology.

PubMed

Gohlke, Oliver; Martin, Johannes

2007-06-01

This paper summarizes developments made in the field of waste-to-energy technology between the 1980s and the present. In the USA, many waste-to-energy systems were developed in the 1980s and early 1990s. These plants generated power relatively efficiently (typically 23%) in 60 bar/ 443 degrees C boilers. Unfortunately, the development came to a stop when the US Supreme Court rejected the practice of waste flow control in 1994. Consequently, waste was directed to mega-landfills, associated with very negative environmental impacts. However, given landfill taxes and increased fuel prices, new waste-to-energy projects have recently been developed. Attractive premiums for renewable power production from municipal waste have been introduced in several European countries. This triggered important innovations in the field of improved energy recovery. Examples of modern waste-to-energy plants are Brescia and Amsterdam with net efficiencies of 24 and 30%, respectively. Incineration is traditionally preferred in Japan due to space constraints. New legislation promoted ash melting or gasification to obtain improved ash quality. However, these processes reduce the efficiency in terms of energy, cost and availability. A new oxygen-enriched waste-to-energy system is under development in order to better achieve the required inert ash quality.

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.

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.

STUDY OF RADON, THORON EXHALATION AND NATURAL RADIOACTIVITY IN COAL AND FLY ASH SAMPLES OF KOTA SUPER THERMAL POWER PLANT, RAJASTHAN, INDIA.

PubMed

Singh, Lalit Mohan; Kumar, Mukesh; Sahoo, B K; Sapra, B K; Kumar, Rajesh

2016-10-01

Electricity generation in India is largely dependent on coal-based thermal power plants, and increasing demand of energy raised the coal consumption in the power plants. In recent years, study of natural radioactivity content and radon/thoron exhalation from combustion of coal and its by-products has given considerable attention as they have been recognised as one of the important technically enhanced naturally occurring radioactive materials. In the present study, radon, thoron exhalation rate and the radioactivity concentration of radionuclides in coal and fly ash samples collected from Kota Super Thermal Power Plant, Rajasthan, India have been measured and compared with data of natural soil samples. The results have been analysed and discussed. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Iron fertilisation of the ocean through major volcanic eruptions. A case study of the Kasatochi eruption 2008

NASA Astrophysics Data System (ADS)

Lindenthal, A.; Langmann, B.; Hort, M.; Hoshyaripour, G.; Paetsch, J.; Lorkowski, I.

2012-04-01

Until recently it was more or less common sense that once volcanic ash enters the ocean it simply deposits into the sediments without any further impact on ocean biochemistry. This view has been notably revised after the eruption of Kasatochi volcano in 2008. During the eruption significant amounts of ash were deposited into oceanic NE Pacific. The NE Pacific is known as a high-nutrient-low-chlorophyll (HNLC) region where algae growth is limited by the bio-available, i.e. soluble iron. These bio-available iron salts residing on the volcanic ash are most likely formed by gas-ash/aerosol interactions inside the volcanic plume. The physico-chemical mechanisms behind the processes contributing to bio-available iron production in volcanic plumes, however, are still poorly constrained. As the eruption occurred in early August, the atmospheric and oceanic conditions were favourable to generate a massive phytoplankton bloom as was observed by satellite instruments and in-situ measurements. Here we investigate this event with the marine biogeochemical model ECOHAM, which is a regional scale three-dimensional ocean biogeochemistry model, coupled to the hydrodynamic model HAMSON. It has been successfully applied mainly over the NW European continental shelf area where iron limitation does not play a role. For applications of this model to the eruption of Kasatochi volcano, an iron cycle model has been implemented, which considers the influence of iron addition to the euphotic zone on diatoms, flagellates, and carbon dioxide concentrations. This model-approach assumes that all dissolved iron in the first meters of seawater is bio-available for phytoplankton uptake. It describes the limitation of phytoplankton growth rates by iron in addition to the limitation by the macro-nutrients nitrogen, phosphate and silicate as well as by light. The surface ocean iron input associated with the eruption of Kasatochi volcano has been determined by an atmospheric-aerosol model to be on the order of 4.5-6x1011kg (ash volume of 0.23-0.3km3). This amount of volcanic ash is consistent with estimates from 1D eruption column models. ECOHAM model results show that volcanic ash can stimulate algae blooms in surface ocean waters in HNLC regions like the NE Pacific. Soluble iron released from volcanic ash acts as a key micro nutrient for phytoplankton growth, especially for diatoms. Model results have been verified with measurements of station Papa (50°N, 145°W). Here a deposition of bio-available iron of 968 micromol Fe/m2 into the surface ocean between Aug. 8-11 lead to an increase in the primary production of chlorophyll in the upper 10m of the ocean of 3.7mg Chl/m3. Following the ash deposition the CO2 partial pressure at station Papa dropped by about 40microatm, which compares well with the 50microatm drop observed in our model calculations.

Regeneratively cooled coal combustor/gasifier with integral dry ash removal

DOEpatents

Beaufrere, A.H.

1982-04-30

A coal combustor/gasifier is disclosed which produces a low or medium combustion gas fired furnances or boilers. Two concentric shells define a combustion air flows to provide regenerative cooling of the inner shell for dry ash operation. A fuel flow and a combustion air flow having opposed swirls are mixed and burned in a mixing-combustion portion of the combustion volume and the ash laden combustion products flow with a residual swirl into an ash separation region. The ash is cooled below the fusion temperature and is moved to the wall by centrifugal force where it is entrained in the cool wall boundary layer. The boundary layer is stabilized against ash re-entrainment as it is moved to an ash removal annulus by a flow of air from the plenum through slots in the inner shell, and by suction on an ash removal skimmer slot.

The Wireless Sensor Network (WSN) Based Coal Ash Impoundments Safety Monitoring System

NASA Astrophysics Data System (ADS)

Sun, E. J.; Nieto, A.; Zhang, X. K.

2017-01-01

Coal ash impoundments are inevitable production of the coal-fired power plants. All coal ash impoundments in North Carolina USA that tested for groundwater contamination are leaking toxic heavy metals and other pollutants. Coal ash impoundments are toxic sources of dangerous pollutants that pose a danger to human and environmental health if the toxins spread to adjacent surface waters and drinking water wells. Coal ash impoundments failures accidents resulted in serious water contamination along with toxic heavy metals. To improve the design and stability of coal ash impoundments, the Development of a Coal Ash Impoundment Safety Monitoring System (CAISM) was proposed based on the implementation of a wireless sensor network (WSN) with the ability to monitor the stability of coal ash impoundments, water level, and saturation levels on-demand and remotely. The monitoring system based on a robust Ad-hoc network could be adapted to different safety conditions.

Construction of a Dry Ash Dam with Soilbags and Slope Stability Analysis

NASA Astrophysics Data System (ADS)

Li, Hui; Song, Yingjun; Gao, Jiaorong; Li, Longhua; Zhou, Yuqi; Qi, Hui

2017-12-01

In thermal power plants, it is necessary to build ash dams to store fly ash, which is the by-product after the combustion of coals. To solve the problem of lacking rockfill materials in Africa, A new technology of constructing ash dams using solibags filled with local sands is proposed and the method of analyzing its slope stability is suggested. The design of the ash dam using soilbags in Lamb Thermal Power Plant of Kenya is introduced in detail. The slope stability of the soilbags-constructed ash dam was analyzed by adopting the suggested method. The results show that the soilbags filled with ash or sands have high compressive strength, and the primary dam constructed with soilbags can effectively retain the backfill ash and the stacking dam reinforced with soilbags can stand stable even with the slope of 1:1.5.

Process for producing low-sulfur boiler fuel by hydrotreatment of solvent deashed SRC

DOEpatents

Roberts, George W.; Tao, John C.

1985-01-01

In this invention, a process is disclosed characterized by heating a slurry of coal in the presence of a process-derived recycle solvent and passing same to a dissolver zone, separating the resultant gases and liquid/solid products therefrom, vacuum distilling the liquid/solids products, separating the portions of the liquid/solids vacuum distillation effluent into a solid ash, unconverted coal particles and SRC material having a boiling point above 850.degree. F. and subjecting same to a critical solvent deashing step to provide an ash-free SRC product. The lighter liquid products from the vacuum distillation possess a boiling point below 850.degree. F. and are passed through a distillation tower, from which recycled solvent is recovered in addition to light distillate boiling below 400.degree. F. (overhead). The ash-free SRC product in accompanyment with at least a portion of the process derived solvent is passed in combination to a hydrotreating zone containing a hydrogenation catalyst and in the presence of hydrogen is hydroprocessed to produce a desulfurized and denitrogenized low-sulfur, low-ash boiler fuel and a process derived recycle solvent which is recycled to slurry the coal in the beginning of the process before heating.

Potential production of emerald ash borer adults: tree, site and landscape-level applications

Treesearch

Deborah G. McCullough; Nathan W. Siegert

2007-01-01

Emerald ash borer (Agrilus planipennis Fairmaire), an Asian phloem-feeding pest discovered in 2002, is established across southeast Michigan and parts of southern Ontario. More than 35 outlier populations have been identified in other areas of Michigan, Ohio and Indiana. An estimated 12 to 15 million ash (Fraxinus sp.) trees in...

Susceptibility of volcanic ash-influenced soil in northern Idaho to mechanical compaction

Treesearch

Deborah S. Page-Dumroese

1993-01-01

Timber harvesting and mechanical site preparation can reduce site productivity if they excessively disturb or compact the soil. Volcanic ash-influenced soils with low undisturbed bulk densities and rock content are particularly susceptible. This study evaluates the effects of harvesting and site preparation on changes in the bulk density of ash-influenced forest soils...

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.

In-situ study of beneficial utilization of coal fly ash in reactive mine tailings.

PubMed

Lee, Joon Kyu; Shang, Julie Q; Wang, Hongliu; Zhao, Cheng

2014-03-15

Oxidation of reactive mine tailings and subsequent generation of acid mine drainage (AMD) have been long recognized as the largest environmental concern for the mining industry. Laboratory studies on utilization of coal fly ash in management of reactive mine tailings have shown reducing water and oxygen infiltration into tailings matrix, thus preventing oxidation of sulphide minerals and acid generation. However, few data from field studies to evaluate the performance of co-placement of mine tailings and fly ash (CMF hereafter) are reported in the open literature. This paper documents the construction and instrumentation of three CMF systems on the Musselwhite mine located in Ontario, Canada and presents results of 3-year real time monitoring. The field data indicates that the CMFs reduced the ingress of water due to cementation generated by hydration of fly ash. It was also found that the electrical conductivity of leachate from CMFs decreased in the early stage of co-placement, compared to the control. With further study, the principle and approach demonstrated in this paper can be adopted as a sustainable technology in the mine tailings management. Copyright © 2014 Elsevier Ltd. All rights reserved.

Effect of granulated wood ash fertilization on N2O emissions in boreal peat forests

NASA Astrophysics Data System (ADS)

Liimatainen, Maarit; Martikainen, Pertti J.; Hytönen, Jyrki; Maljanen, Marja

2016-04-01

Peatlands cover one third of the land surface area in Finland and over half of that are drained for forestry. Natural peatlands are either small sources of nitrous oxide (N2O) or they can also act as a sinks of N2O. When peatlands are drained, oxygen concentration in the peat increases, organic matter decomposition accelerates and N2O emissions may increase significantly, especially in nutrient rich peat soils. Hence drainage and land-use changes can have a big impact on N2O fluxes in peatlands. The annual consumption of wood chips is to be increased to 13.5 M m3 from the present 8.7 M m3 in Finland. This will also increase the amount of wood ash in the power plants. Wood ash contains considerable amounts of mineral nutrients but lacks nitrogen. Therefore, it has been used as a fertilizer in nitrogen rich peatland forests lacking other nutrients. Recycling of ash would also return the nutrients lost during biomass harvesting back to the forests. We studied the effects of granulated wood ash as a fertilizer in peat soils drained for forestry. Ash is nowadays granulated mainly to facilitate its handling and spreading. Granulation also stabilizes the ash decreasing the solubility of most of the nutrients and minimizing harmful effects of ash spread over the vegetation. Granulated wood ash increases soil pH less than loose ash. Drainage of peatland forests increases microbial activity in the soil which is furthermore intensified with the addition of ash promoting organic matter decomposition and possibly affecting N2O emissions. We studied the effect of granulated wood ash on N2O fluxes in three different peat forests in Finland in both field and laboratory experiments. In the field, N2O emissions were not affected by granulated wood ash fertilization but the soil respiration rate increased. However, in the laboratory studies we observed a clear decrease in N2O production due to wood ash addition, although changes in pH values were only minor. We studied what could explain this decrease in N2O production. Despite of the granulation process some nutrients (e.g. K, Na, B, S) still leach quickly from the ash in form of ions, which was observed as an increased electrical conductivity. Granulated ash contains a high concentration of sulfates and we created in the laboratory experiments with the addition of K2SO4 or (NH4)2SO4 similar decrease in N2O production as observed with the addition of granulated wood ash. Our results indicate that quickly leaching ions inhibit nitrification in peat. In the field experiments the same phenomena was not observed, probably due to leaching of the nutrients (ions) deeper into the soil and due to the competition of vegetation which outcompetes microbes for available nutrients. In conclusion, the use of granulated wood ash does not increase N2O emissions in boreal peat forests.

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

Eco-friendly porous concrete using bottom ash aggregate for marine ranch application.

PubMed

Lee, Byung Jae; Prabhu, G Ganesh; Lee, Bong Chun; Kim, Yun Yong

2016-03-01

This article presents the test results of an investigation carried out on the reuse of coal bottom ash aggregate as a substitute material for coarse aggregate in porous concrete production for marine ranch applications. The experimental parameters were the rate of bottom ash aggregate substitution (30%, 50% and 100%) and the target void ratio (15%, 20% and 25%). The cement-coated granular fertiliser was substituted into a bottom ash aggregate concrete mixture to improve marine ranch applications. The results of leaching tests revealed that the bottom ash aggregate has only a negligible amount of the ten deleterious substances specified in the Ministry of Environment - Enforcement Regulation of the Waste Management Act of Republic Korea. The large amount of bubbles/air gaps in the bottom ash aggregate increased the voids of the concrete mixtures in all target void ratios, and decreased the compressive strength of the porous concrete mixture; however, the mixture substituted with 30% and 10% of bottom ash aggregate and granular fertiliser, respectively, showed an equal strength to the control mixture. The sea water resistibility of the bottom ash aggregate substituted mixture was relatively equal to that of the control mixture, and also showed a great deal of improvement in the degree of marine organism adhesion compared with the control mixture. No fatality of fish was observed in the fish toxicity test, which suggested that bottom ash aggregate was a harmless material and that the combination of bottom ash aggregate and granular fertiliser with substitution rates of 30% and 10%, respectively, can be effectively used in porous concrete production for marine ranch application. © The Author(s) 2015.

SHS synthesis of Si-SiC composite powders using Mg and reactants from industrial waste

NASA Astrophysics Data System (ADS)

Chanadee, Tawat

2017-11-01

Si-SiC composite powders were synthesized by self-propagating high-temperature synthesis (SHS) using reactants of fly ash-based silica, sawdust-based activated carbon, and magnesium. Fly ash-based silica and sawdust-based activated carbon were prepared from coal mining fly ash and Para rubber-wood sawdust, respectively. The work investigated the effects of the synthesis atmosphere (air and Ar) on the phase and morphology of the SHS products. The SHS product was leached by a two-step acid leaching processes, to obtain the Si-SiC composite powder. The SHS product and SHS product after leaching were characterized by X-ray diffractometry, scanning electron microscopy and energy dispersive X-ray spectrometry. The results indicated that the SHS product synthesized in air consisted of Si, SiC, MgO, and intermediate phases (SiO2, Mg, Mg2SiO4, Mg2Si), whereas the SHS product synthesized in Ar consisted of Si, SiC, MgO and a little Mg2SiO4. The SiC content in the leached-SHS product was higher when Ar was used as the synthesis atmosphere. As well as affecting the purity, the synthesis atmospheres also affected the average crystalline sizes of the products. The crystalline size of the product synthesized in Ar was smaller than that of the product synthesized in air. All of the results showed that fly ash and sawdust could be effective waste-material reactants for the synthesis of Si-SiC composite powders.

Thermal Shock-resistant Cement

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

Sugama T.; Pyatina, T.; Gill, S.

2012-02-01

We studied the effectiveness of sodium silicate-activated Class F fly ash in improving the thermal shock resistance and in extending the onset of hydration of Secar #80 refractory cement. When the dry mix cement, consisting of Secar #80, Class F fly ash, and sodium silicate, came in contact with water, NaOH derived from the dissolution of sodium silicate preferentially reacted with Class F fly ash, rather than the #80, to dissociate silicate anions from Class F fly ash. Then, these dissociated silicate ions delayed significantly the hydration of #80 possessing a rapid setting behavior. We undertook a multiple heating -watermore » cooling quenching-cycle test to evaluate the cement’s resistance to thermal shock. In one cycle, we heated the 200 and #61616;C-autoclaved cement at 500 and #61616;C for 24 hours, and then the heated cement was rapidly immersed in water at 25 and #61616;C. This cycle was repeated five times. The phase composition of the autoclaved #80/Class F fly ash blend cements comprised four crystalline hydration products, boehmite, katoite, hydrogrossular, and hydroxysodalite, responsible for strengthening cement. After a test of 5-cycle heat-water quenching, we observed three crystalline phase-transformations in this autoclaved cement: boehmite and #61614; and #61543;-Al2O3, katoite and #61614; calcite, and hydroxysodalite and #61614; carbonated sodalite. Among those, the hydroxysodalite and #61614; carbonated sodalite transformation not only played a pivotal role in densifying the cementitious structure and in sustaining the original compressive strength developed after autoclaving, but also offered an improved resistance of the #80 cement to thermal shock. In contrast, autoclaved Class G well cement with and without Class F fly ash and quartz flour failed this cycle test, generating multiple cracks in the cement. The major reason for such impairment was the hydration of lime derived from the dehydroxylation of portlandite formed in the autoclaved cement, causing its volume to expand.« less

Recycling of municipal solid waste incinerator fly ash by using hydrocyclone separation.

PubMed

Ko, Ming-Sheng; Chen, Ying-Liang; Wei, Pei-Shou

2013-03-01

The municipal solid waste incinerators (MSWIs) in Taiwan generate about 300,000 tons of fly ash annually, which is mainly composed of calcium and silicon compounds, and has the potential for recycling. However, some heavy metals are present in the MSWI fly ash, and before recycling, they need to be removed or reduced to make the fly ash non-hazardous. Accordingly, the purpose of this study was to use a hydrocyclone for the separation of the components of the MSWI fly ash in order to obtain the recyclable portion. The results show that chloride salts can be removed from the fly ash during the hydrocyclone separation process. The presence of a dense medium (quartz sand in this study) is not only helpful for the removal of the salts, but also for the separation of the fly ash particles. After the dense-medium hydrocyclone separation process, heavy metals including Pb and Zn were concentrated in the fine particles so that the rest of the fly ash contained less heavy metal and became both non-hazardous and recyclable. Copyright © 2012 Elsevier Ltd. All rights reserved.

Case study of fly ash brick manufacturing units at Kota in Rajasthan

NASA Astrophysics Data System (ADS)

Sharma, Y.; Saxena, B. K.; Rao, K. V. S.

2018-03-01

Kota Super Thermal Power Station of 1240 MW is located at Kota in Rajasthan, India. The quantity of fly ash generated by it is about 1.64 to 2.03 million tonnes per year. This fly ash is being utilized for making bricks, tiles, portland pozzolana cement, construction of highways, and other purposes. 1.79 million tonnes of fly ash was utilized for different applications in one year duration from April 01st, 2015 to March 31st, 2016. Out of this total utilization, 0.6439 million tonnes (36.06 %) of fly ash was used for making bricks, blocks, and tiles. In this paper, a case study of two fly ash brick manufacturing units using fly ash produced from Kota Super Thermal Power Station is described. These units produce about 15,000 and 20,000 bricks respectively by employing 10 and 16 workers each and are making a profit of about Rs. 6,000 and Rs. 8,000 per day in one shift.

The influence of α-Al2O3 addition on microstructure, mechanical and formaldehyde adsorption properties of fly ash-based geopolymer products.

PubMed

Huang, Yi; Han, Minfang

2011-10-15

Fly ash-based geopolymer with α-Al(2)O(3) addition were synthesized and used to remove formaldehyde from indoor air. The microstructure, mechanical and formaldehyde adsorption properties of the geopolymer products obtained were investigated. The results showed that α-Al(2)O(3) addition with appropriate amount (such as 5 wt%) increased the geopolymerization extent, resulting in the increase of surface area and compressive strength. In addition, the improvement of structural ordering level for geopolymer sample with 5 wt% α-Al(2)O(3) addition was found through FTIR analysis. By contrast, excessive addition (such as 10 wt%) had the opposite effect. The test of formaldehyde adsorption capacity confirmed that fly ash-based geopolymer product exhibited much better property of adsorbing indoor formaldehyde physically and chemically than fly ash itself. The surface area was an important but not unique factor influencing the adsorption capacity of geopolymers. Copyright © 2011 Elsevier B.V. All rights reserved.

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.

Optimizing and Characterizing Geopolymers from Ternary Blend of Philippine Coal Fly Ash, Coal Bottom Ash and Rice Hull Ash

PubMed Central

Kalaw, Martin Ernesto; Culaba, Alvin; Hinode, Hirofumi; Kurniawan, Winarto; Gallardo, Susan; Promentilla, Michael Angelo

2016-01-01

Geopolymers are inorganic polymers formed from the alkaline activation of amorphous alumino-silicate materials resulting in a three-dimensional polymeric network. As a class of materials, it is seen to have the potential of replacing ordinary Portland cement (OPC), which for more than a hundred years has been the binder of choice for structural and building applications. Geopolymers have emerged as a sustainable option vis-à-vis OPC for three reasons: (1) their technical properties are comparable if not better; (2) they can be produced from industrial wastes; and (3) within reasonable constraints, their production requires less energy and emits significantly less CO2. In the Philippines, the use of coal ash, as the alumina- and silica- rich geopolymer precursor, is being considered as one of the options for sustainable management of coal ash generation from coal-fired power plants. However, most geopolymer mixes (and the prevalent blended OPC) use only coal fly ash. The coal bottom ash, having very few applications, remains relegated to dumpsites. Rice hull ash, from biomass-fired plants, is another silica-rich geopolymer precursor material from another significantly produced waste in the country with only minimal utilization. In this study, geopolymer samples were formed from the mixture of coal ash, using both coal fly ash (CFA) and coal bottom ash (CBA), and rice hull ash (RHA). The raw materials used for the geopolymerization process were characterized using X-ray fluorescence spectroscopy (XRF) for elemental and X-ray diffraction (XRD) for mineralogical composition. The raw materials’ thermal stability and loss on ignition (LOI) were determined using thermogravimetric analysis (TGA) and reactivity via dissolution tests and inductively-coupled plasma mass spectrometry (ICP) analysis. The mechanical, thermal and microstructural properties of the geopolymers formed were analyzed using compression tests, Fourier transform infra-red spectroscopy (FTIR), scanning electron microscopy (SEM) and thermogravimetric analysis (TGA). Using a Scheffé-based mixture design, targeting applications with low thermal conductivity, light weight and moderate strength and allowing for a maximum of five percent by mass of rice hull ash in consideration of the waste utilization of all three components, it has been determined that an 85-10-5 by weight ratio of CFA-CBA-RHA activated with 80-20 by mass ratio of 12 M NaOH and sodium silicate (55% H2O, modulus = 3) produced geopolymers with a compressive strength of 18.5 MPa, a volumetric weight of 1660 kg/m3 and a thermal conductivity of 0.457 W/m-°C at 28-day curing when pre-cured at 80 °C for 24 h. For this study, the estimates of embodied energy and CO2 were all below 1.7 MJ/kg and 0.12 kg CO2/kg, respectively. PMID:28773702

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.

Thermal co-treatment of combustible hazardous waste and waste incineration fly ash in a rotary kiln.

PubMed

Huber, Florian; Blasenbauer, Dominik; Mallow, Ole; Lederer, Jakob; Winter, Franz; Fellner, Johann

2016-12-01

As current disposal practices for municipal solid waste incineration (MSWI) fly ash are either associated with significant costs or negative environmental impacts, an alternative treatment was investigated in a field scale experiment. Thereto, two rotary kilns were fed with hazardous waste, and moistened MSWI fly ash (water content of 23%) was added to the fuel of one kiln with a ratio of 169kg/Mg hazardous waste for 54h and 300kg/Mg hazardous waste for 48h while the other kiln was used as a reference. It was shown that the vast majority (>90%) of the inserted MSWI fly ash was transferred to the bottom ash of the rotary kiln. This bottom ash complied with the legal limits for non-hazardous waste landfills, thereby demonstrating the potential of the investigated method to transfer hazardous waste (MSWI fly ash) into non-hazardous waste (bottom ash). The results of a simple mixing test (MSWI fly ash and rotary kiln bottom ash have been mixed accordingly without thermal treatment) revealed that the observed transformation of hazardous MSWI fly ash into non-hazardous bottom ash during thermal co-treatment cannot be referred to dilution, as the mixture did not comply with legal limits for non-hazardous waste landfills. For the newly generated fly ash of the kiln, an increase in the concentration of Cd, K and Pb by 54%, 57% and 22%, respectively, was observed. In general, the operation of the rotary kiln was not impaired by the MSWI fly ash addition. Copyright © 2016 Elsevier Ltd. All rights reserved.

Comparative in vitro culture of white and green ash from seed to plantlet production

Treesearch

J. W. Van Sambeek; John E. Preece; Nadia E. Navarrete-Tindall

2002-01-01

In vitro procedures have already been reported for white ash (Fraxinus americana L.) to establish cut dormant seeds, force axillary shoot proliferation, and induce rapid rooting to produce clonal plantlets (Preece et al., 1987, Navarrete et al., 1989, Preece et al., 1989, Preece et al., 1995). Hypothetically, a production cycle from seed to...

Treatment of fly ash from power plants using thermal plasma.

PubMed

Al-Mayman, Sulaiman; AlShunaifi, Ibrahim; Albeladi, Abdullah; Ghiloufi, Imed; Binjuwair, Saud

2017-01-01

Fly ash from power plants is very toxic because it contains heavy metals. In this study fly ash was treated with a thermal plasma. Before their treatment, the fly ash was analyzed by many technics such as X-ray fluorescence, CHN elemental analysis, inductively coupled plasma atomic emission spectroscopy and scanning electron microscopy. With these technics, the composition, the chemical and physical proprieties of fly ash are determined. The results obtained by these analysis show that fly ash is mainly composed of carbon, and it contains also sulfur and metals such as V, Ca, Mg, Na, Fe, Ni, and Rh. The scanning electron microscopy analysis shows that fly ash particles are porous and have very irregular shapes with particle sizes of 20-50 μm. The treatment of fly ash was carried out in a plasma reactor and in two steps. In the first step, fly ash was treated in a pyrolysis/combustion plasma system to reduce the fraction of carbon. In the second step, the product obtained by the combustion of fly ash was vitrified in a plasma furnace. The leaching results show that the fly ash was detoxified by plasma vitrification and the produced slag is amorphous and glassy.

Treatment of fly ash from power plants using thermal plasma

PubMed Central

Al-Mayman, Sulaiman; AlShunaifi, Ibrahim; Albeladi, Abdullah; Binjuwair, Saud

2017-01-01

Fly ash from power plants is very toxic because it contains heavy metals. In this study fly ash was treated with a thermal plasma. Before their treatment, the fly ash was analyzed by many technics such as X-ray fluorescence, CHN elemental analysis, inductively coupled plasma atomic emission spectroscopy and scanning electron microscopy. With these technics, the composition, the chemical and physical proprieties of fly ash are determined. The results obtained by these analysis show that fly ash is mainly composed of carbon, and it contains also sulfur and metals such as V, Ca, Mg, Na, Fe, Ni, and Rh. The scanning electron microscopy analysis shows that fly ash particles are porous and have very irregular shapes with particle sizes of 20–50 μm. The treatment of fly ash was carried out in a plasma reactor and in two steps. In the first step, fly ash was treated in a pyrolysis/combustion plasma system to reduce the fraction of carbon. In the second step, the product obtained by the combustion of fly ash was vitrified in a plasma furnace. The leaching results show that the fly ash was detoxified by plasma vitrification and the produced slag is amorphous and glassy. PMID:28546898

Fluidized bed combustion of pelletized biomass and waste-derived fuels

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

Chirone, R.; Scala, F.; Solimene, R.

2008-10-15

The fluidized bed combustion of three pelletized biogenic fuels (sewage sludge, wood, and straw) has been investigated with a combination of experimental techniques. The fuels have been characterized from the standpoints of patterns and rates of fuel devolatilization and char burnout, extent of attrition and fragmentation, and their relevance to the fuel particle size distribution and the amount and size distribution of primary ash particles. Results highlight differences and similarities among the three fuels tested. The fuels were all characterized by limited primary fragmentation and relatively long devolatilization times, as compared with the time scale of particle dispersion away frommore » the fuel feeding ports in practical FBC. Both features are favorable to effective lateral distribution of volatile matter across the combustor cross section. The three fuels exhibited distinctively different char conversion patterns. The high-ash pelletized sludge burned according to the shrinking core conversion pattern with negligible occurrence of secondary fragmentation. The low-ash pelletized wood burned according to the shrinking particle conversion pattern with extensive occurrence of secondary fragmentation. The medium-ash pelletized straw yielded char particles with a hollow structure, resembling big cenospheres, characterized by a coherent inorganic outer layer strong enough to prevent particle fragmentation. Inert bed particles were permanently attached to the hollow pellets as they were incorporated into ash melts. Carbon elutriation rates were very small for all the fuels tested. For pelletized sludge and straw, this was mostly due to the shielding effect of the coherent ash skeleton. For the wood pellet, carbon attrition was extensive, but was largely counterbalanced by effective afterburning due to the large intrinsic reactivity of attrited char fines. The impact of carbon attrition on combustion efficiency was negligible for all the fuels tested. The size distribution of primary ash particles liberated upon complete carbon burnoff largely reflected the combustion pattern of each fuel. Primary ash particles of size nearly equal to that of the parent fuel were generated upon complete burnoff of the pelletized sludge. Nonetheless, secondary attrition of primary ash from pelletized sludge is large, to the point where generation of fine ash would be extensive over the typical residence time of bed ash in fluidized bed combustors. Very few and relatively fine primary ash particles were released after complete burnoff of wood pellets. Primary ash particles remaining after complete burnoff of pelletized straw had sizes and shapes that were largely controlled by the occurrence of ash agglomeration phenomena. (author)« less

Adsorption of Cu2+ to biomass ash and its modified product.

PubMed

Xu, Lei; Cui, Hongbiao; Zheng, Xuebo; Liang, Jiani; Xing, Xiangyu; Yao, Lunguang; Chen, Zhaojin; Zhou, Jing

2017-04-01

Ash produced by biomass power plants has great potential for the removal of heavy metal ions from aqueous solution. The pollution of toxic heavy metals to water is a worldwide environmental problem. Discharges containing copper, in particular, are strictly controlled because the excessive copper can cause serious harm to the environment and human health. This work aims to investigate the adsorption characteristics of copper ions in aqueous solution by biomass ash and the modified products, and to evaluate their potential application in water pollution control. The biomass ash was modified with a mesoporous siliceous material and functionalized with 3-aminopropyltriethoxysilane. The surface properties of the biomass ash and the new matrix were studied to evaluate their adsorption property for Cu 2+ ions at different pHs, initial metal concentrations and the thermodynamic and kinetic were studied. The chemical and morphological properties of this modified material are analyzed; the specific surface area of the modified biomass ash was nine times that of the initial ash. Both of the two materials showed a strong affinity for Cu 2+ , and the Langmuir model could best represent the adsorption characteristics of Cu 2+ on the two kinds of materials. The adsorption capacity of copper on the material increased with the increase of pH and pH 6 was the optimum pH. Thermodynamic analysis results showed that the adsorption of Cu 2+ was spontaneous and endothermic in nature. The adsorptions of Cu 2+ onto the modified biomass ash followed pseudo-second-order kinetics.

The Impact of Coal Combustion Fly Ash Used as a Supplemental Cementitious Material on the Leaching of Constituents from Cements and Concretes

EPA Science Inventory

The objective of this report is to compare the leaching of portland cement-based materials that have been prepared with and without coal combustion fly ash to illustrate whether there is evidence that the use of fly ash in cement and concrete products may result in increased leac...

Throwing down the Gauntlet: Ten Ways to Ensure That Higher Education Research Continues to Matter

ERIC Educational Resources Information Center

Perna, Laura W.

2016-01-01

As members of ASHE, we have an obligation to ensure that ASHE is an association that both promotes career development of members and advances the production and dissemination of high-quality research-based knowledge on current and emerging issues in higher education. In this presidential address, I look to the future of ASHE, offering questions…

Planning for and implementing an emerald ash borer-induced forest restoration program in municipal woodlands in Oakville, Ontario

Treesearch

Peter A. Williams; Candace. Karandiuk

2017-01-01

Oakville is an urban municipality with 846 ha of woodland. Management priorities are to maintain forest health, environmental health, and safety; wood production is a minor objective. The town developed a comprehensive strategy to plan for emerald ash borer (EAB; Agrilus planipennis) induced ash mortality and forest restoration. Oakville has begun...

Accelerating Planted Green Ash Establishment on an Abandoned Soybean Field

Treesearch

John W. Groninger; Didier A. Babassana

2002-01-01

Planted green ash seedlings exhibit high survival rates on most bottomland sites that have recently come out of row crop production, making this species a popular choice for afforestation. Sub-optimal growth of planted hardwood tree species, including green ash, often delays the realization of many of the economic and environmental benefits that are used to justify the...

National volcanic ash operations plan for aviation

USGS Publications Warehouse

,; ,

2007-01-01

The National Aviation Weather Program Strategic Plan (1997) and the National Aviation Weather Initiatives (1999) both identified volcanic ash as a high-priority informational need to aviation services. The risk to aviation from airborne volcanic ash is known and includes degraded engine performance (including flameout), loss of visibility, failure of critical navigational and operational instruments, and, in the worse case, loss of life. The immediate costs for aircraft encountering a dense plume are potentially major—damages up to $80 million have occurred to a single aircraft. Aircraft encountering less dense volcanic ash clouds can incur longer-term costs due to increased maintenance of engines and external surfaces. The overall goal, as stated in the Initiatives, is to eliminate encounters with ash that could degrade the in-flight safety of aircrews and passengers and cause damage to the aircraft. This goal can be accomplished by improving the ability to detect, track, and forecast hazardous ash clouds and to provide adequate warnings to the aviation community on the present and future location of the cloud. To reach this goal, the National Aviation Weather Program established three objectives: (1) prevention of accidental encounters with hazardous clouds; (2) reduction of air traffic delays, diversions, or evasive actions when hazardous clouds are present; and (3) the development of a single, worldwide standard for exchange of information on airborne hazardous materials. To that end, over the last several years, based on numerous documents (including an OFCMsponsored comprehensive study on aviation training and an update of Aviation Weather Programs/Projects), user forums, and two International Conferences on Volcanic Ash and Aviation Safety (1992 and 2004), the Working Group for Volcanic Ash (WG/VA), under the OFCM-sponsored Committee for Aviation Services and Research, developed the National Volcanic Ash Operations Plan for Aviation and Support of the International Civil Aviation Organization’s (ICAO) International Airways Volcano Watch. This plan defines agency responsibilities, provides a comprehensive description of an interagency standard for volcanic ash products and their formats, describes the agency backup procedures for operational products, and outlines the actions to be taken by each agency following an occurrence of a volcanic eruption that subsequently affects and impacts aviation services. Since our most recent International Conference on Volcanic Ash and Aviation Safety, volcanic ash-related product and service activities have grown considerably along with partnerships and alliances throughout the aviation community. In January 2005, the National Oceanic and Atmospheric Administration’s National Centers for Environment Prediction began running the Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model in place of the Volcanic Ash Forecast Transport and Dispersion (VAFTAD) model, upgrading support to the volcanic ash advisory community. Today, improvements to the HYSPLIT model are ongoing based on recommendations by the OFCM-sponsored Joint Action Group for the Selection and Evaluation of Atmospheric Transport and Diffusion Models and the Joint Action Group for Atmospheric Transport and Diffusion Modeling (Research and Development Plan). Two international workshops on volcanic ash have already taken place, noticeable improvements and innovations in education, training, and outreach have been made, and federal and public education and training programs on volcanic ash-related products, services, and procedures iv continue to evolve. For example, in partnership with Embry-Riddle Aeronautical University and other academic institutions, volcanic ash hazard and mitigation training has been incorporated into aviation meteorology courses. As an essential next step, our volcanic ash-related efforts in the near term will be centered on the development of an interagency implementation plan to document and address the most critical needs of the volcanic ash advisory community. This interagency plan, developed as the result of the cooperative efforts of six federal agencies, follows the guidelines in support of the ICAO International Airways Volcano Watch. The signatories on the next page are committed to volcanic ash operations for aviation and will work toward full implementation through agency programs, initiatives, and procedures. I extend my sincere thanks to all members of the WG/VA, subject-matter experts, and to my staff for their collaborative and cooperative efforts in developing this first-ever national volcanic ash operations plan.

Spin injection and detection via the anomalous spin Hall effect of a ferromagnetic metal

NASA Astrophysics Data System (ADS)

Das, K. S.; Schoemaker, W. Y.; van Wees, B. J.; Vera-Marun, I. J.

2017-12-01

We report a spin injection and detection mechanism via the anomalous Hall effect in a ferromagnetic metal. The anomalous spin Hall effect (ASHE) refers to the transverse spin current generated within the ferromagnet. We utilize the ASHE and its reciprocal effect to electrically inject and detect magnons in a magnetic insulator (yttrium iron garnet) in a nonlocal geometry. Our experiments reveal that permalloy has a comparable spin injection and detection efficiency to that of platinum, owing to the ASHE. We also demonstrate the tunability of the ASHE via the orientation of the permalloy magnetization, thus creating possibilities for spintronic applications.

Volatile arsenic species released from Escherichia coli expressing the AsIII S-adenosylmethionine methyltransferase gene.

PubMed

Yuan, Chungang; Lu, Xiufen; Qin, Jie; Rosen, Barry P; Le, X Chris

2008-05-01

Biological systems, ranging from bacteria and fungi to humans, can methylate arsenic. Recent studies have suggested that the AsIII S-adenosylmethionine methyltransferase (arsM) gene in bacteria was responsible for the removal of arsenic as the volatile arsines from the bacteria. However, there has been no direct measure of the arsines released from bacteria cultures. We describe here an integrated system incorporating the bacterial incubation and volatile arsenic species analysis, and we demonstrate its application to the identification of the volatile arsines produced in bacterial cultures. The headspace of the bacterial cultures was purged with helium, and the volatile arsenic species were trapped in a chromatographic column immersed in liquid nitrogen. The cryogenically trapped arsines [AsH3, (CH3)AsH2, (CH3)2AsH, and (CH3)3As] were separated by gas chromatography and were detected by inductively coupled plasma mass spectrometry. A hydride generation system was coupled to the bacterial culture system, allowing for spiking standards and for generating calibration arsines necessary for quantitative analysis. Both bacteria containing the arsM gene or its variant arsMC2 gene were able to produce 400-500 ng of trimethylarsine. No trimethylarsine was detectable in bacteria lacking the arsM gene (containing the vector plasmid as negative control). These results confirm that arsM is responsible for releasing arsenic as volatile species from the arsenic-resistant bacteria. Our results also show traces of AsH3, CH3AsH2, and (CH3)2AsH in cultures of bacteria expressing arsM. The method detection limits for AsH3, CH3AsH2, (CH3)2AsH, and (CH3)3As were 0.5, 0.5, 0.7, and 0.6 pg, respectively. The ability to quantify trace levels of these volatile arsenic species makes it possible to study the biotransformation and biochemical roles of the evolution of these volatile arsenic species by biological systems.

Wildland fire ash: future research directions

NASA Astrophysics Data System (ADS)

Bodí, Merche B.; Martins, Deborah A.; Cerdà, Artemi; Balfour, Victoria N.; Santin, Cristina; Doerr, Stefan H.; Pereira, Paulo; Mataix-Solera, Jorge

2014-05-01

Ash is a key component of the forest fires affected land (Cerdà, 1998; Bodí et al., 2011; Pereira et al., 2013a). Ash controls the hydrological processes and determines the water repellency (Dlapa et al., 2012) and the infiltration rates (Cerdà and Doerr, 2008;). Moreover, ash is the key factor on runoff initiation and then on the soil erosion. Little is known about the impact of ash in different ecosystems, but during the last decade a substantial increase in the papers that show the role of ash in the Earth and Soil System were published (Bodí et al., 2012; Pereira et al., 2013b).. Ash is being found as the key component of the post-fire pedological, geomorphological and hydrological response after forest fires (Fernández et al., 2012; Martín et al., 2012; Bodí et al., 2013; Guénon et al., 2013; Pereira et al., 2013c). A recent State-of-the-Art review about wildland fire ash (Bodí et al., 2014) compiles the knowledge regarding the production, composition and eco-hydro-geomorphic effects of wildland fire ash. In the present paper we indicate the knowledge gaps detected and suggest topics that need more research effort concerning: i) data collection and analysis techniques: a) To develop standardized sampling techniques that allow cross comparison among sites and avoid inclusion of the underlying soil unless the burned surface soil forms part of the ash layer, b) To develop standardized methods to define and characterize ash, including its color, physical properties such as particle size distribution or density, proportion of pyrogenic C, chemical and biological reactivity and persistence in the environment, c) To validate, calibrate and test measurements collected through remote sensing with on-the-ground measurements. ii) ash production, deposition redistribution and fate: d) To untangle the significance of the effects of maximum temperature reached during combustion versus the duration of heating, e) To understand the production of ash by measuring its depth, density, and size fraction distribution compared to that of the underlying soil, f) To measure the spatial variability of ash at the plot or hillslope scale, g) To address issues of how much ash stays on site after fire, especially how much is incorporated into underlying soil layers, compared to how much is eroded by wind and water and becomes incorporated into depositional environments located away from the site. iii) ash effects h) To study the connectivity of patches of ash to make progress in understanding the role of ash in infiltration, the generation of runoff and erosion, i) To take into account the role of ash in the fate of the ecosystem immediately after the fire, as well as the combination of ash and other cover, such as the needles, in the post-fire period, j) To study the amount and forms of C in ash, including studies characterizing its chemical and biological reactivity and degradability in soil and sedimentary environments, k) To understanding the legacy of atmospherically-deposited elements (e.g. P, Si, Mn) and dust to fully understand the complex chemistry of ash, and at the same time assess its effects on human health. iii) enhance collaboration across the globe on the multidisciplinary topic of ash research since research in large areas of the world that burn (e.g., Africa and Russia) is underrepresented. We are sure that several activities, such as land and water supply management, risk reduction, and planning for societal and ecosystem resilience in the face of a changing climate, will benefit from the insights gained from the ash research community. Acknowledgements The research projects GL2008-02879/BTE, LEDDRA 243857 and RECARE FP7 project 603498 supported this research. References: Bodí, M. B., Mataix-Solera, J., Doerr, S. H., Cerdà, A. 2011.The wettability of ash from burned vegetation and its relatioship to Mediterranean plant species type, burn. Geoderma 160: 599-607. Bodí, M.B. Doerr, S.H., Cerdà, A. and Mataix-Solera, J. 2012. Hydrological effects of a layer of vegetation ash on underlying wettable and water repellent soils. Geoderma, 191, 14-23. http://dx.doi.org/10.1016/j.geoderma.2012.01.006 Bodí, M.B., Muñoz-Santa, I., Armero, C., Doerr, S.H., Mataix-Solera, J., Cerdà, A. 2013. Spatial and temporal variations of water repellency and probability of its occurrence in calcareous Mediterranean rangeland soils affected by fires. Catena, 108, 14-24. http://dx.doi.org/10.1016/j.catena.2012.04.002 Bodí, Merche B., Martin, Deborah A., Balfour, Victoria N., Santín, Cristina, Doerr, Stefan H., Pereira, Paulo, Cerdà, Artemi, Mataix-Solera, Jorge, Wildland fire ash: Production, composition and eco-hydro-geomorphic effects, Earth Science Reviews (2014), doi: 10.1016/j.earscirev.2013.12.007 Cerdà, A. 1998. Changes in overland flow and infiltration after a rangeland fire in a Mediterranean scrubland. Hydrological Processes, 12, 1031-1042. 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 Dlapa, P., Bodí, M.B., Mataix-Solera, J., Cerdà, A., &, Doerr, S.H. 2013. FT-IR spectroscopy reveals that ash water repellency is highly dependent on ash chemical composition. Catena, 108, 35-43. Doi:10.1016/j.catena.2012.02.011 Fernández, C., Vega, J. A., Jiménez, E., Vieira, D. C. S., Merino, A., Ferreiro, A., Fonturbel, T. 2012. Seeding and mulching + seeding effects on post-fire runoff, soil erosion and species diversity in Galicia (NW Spain). Land Degradation & Development, 23: 150- 156. DOI 10.1002/ldr.1064 Guénon, R., Vennetier, M., Dupuy, N., Roussos, S., Pailler, A., Gros, R. 2013. Trends in recovery of Mediterranean soil chemical properties and microbial activities after infrequent and frequent wildfires. Land Degradation & Development, 24: 115- 128. DOI 10.1002/ldr.1109 Martín, A., Díaz-Raviña, M., Carballas, T. 2012. Short- and medium-term evolution of soil properties in Atlantic forest ecosystems affected by wildfires. Land Degradation & Development, 23: 427- 439. DOI 10.1002/ldr.1078 Pereira, P., Úbeda, X., Martin, D., Mataix-Solera, J., Cerdà, A., Burguet, M. 2013a. Wildfire effects on extractable elements in ash from a Pinus pinaster forest in Portugal, Hydrological Processes, DOI: 10.1002/hyp.9907 Pereira, P., Cerda, A., Jordan, A., Bolutiene, V., Pranskevicius, M., Ubeda, X., Mataix-Solera, J. 2013b. Spatio-temporal vegetation recuperation after a grassland fire in Lithuania, Procedia Environmental Sciences, 19, 856-864. DOI:10.1016/j.proenv.2013.06.095. Pereira, P., Cerdà, A., Úbeda, X., Mataix-Solera, J. Martin, D., Jordan, A. and Burguet, M. 2013c. 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. www.solid-earth.net/4/153/2013/ doi:10.5194/se-4-153-2013

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.

Chemical composition and properties of ashes from combustion plants using Miscanthus as fuel.

PubMed

Lanzerstorfer, Christof

2017-04-01

Miscanthus giganteus is one of the energy crops considered to show potential for a substantial contribution to sustainable energy production. In the literature there is little data available about the chemical composition of ashes from the combustion of Miscanthus and practically no data about their physical properties. However, for handling, treatment and utilization of the ashes this information is important. In this study ashes from two biomass combustion plants using Miscanthus as fuel were investigated. The density of the ashes was 2230±35kg/m 3 , which was similar to the density of ashes from straw combustion. Also the bulk densities were close to those reported for straw ashes. The flowability of the ashes was a little worse than the flowability of ashes from wood combustion. The measured heavy metal concentrations were below the usual limits for utilization of the ashes as soil conditioner. The concentrations in the bottom ash were similar to those reported for ash from forest residue combustion plants. In comparison with cyclone fly ashes from forest residue combustion the measured heavy metal concentrations in the cyclone fly ash were considerably lower. Cl - , S and Zn were enriched in the cyclone fly ash which is also known for ashes from wood combustion. In comparison with literature data obtained from Miscanthus plant material the concentrations of K, Cl - and S were lower. This can be attributed to the fact that the finest fly ash is not collected by the cyclone de-dusting system of the Miscanthus combustion plants. Copyright © 2016. Published by Elsevier B.V.

To fractionate municipal solid waste incineration bottom ash: Key for utilisation?

PubMed

Sormunen, Laura Annika; Rantsi, Riina

2015-11-01

For the past decade, the Finnish waste sector has increasingly moved from the landfilling of municipal solid waste towards waste incineration. New challenges are faced with the growing amounts of municipal solid waste incineration bottom ash, which are mainly landfilled at the moment. Since this is not a sustainable or a profitable solution, finding different utilisation applications for the municipal solid waste incineration bottom ash is crucial. This study reports a comprehensive analysis of bottom ash properties from one waste incineration plant in Finland, which was first treated with a Dutch bottom ash recovery technique called advanced dry recovery. This novel process separates non-ferrous and ferrous metals from bottom ash, generating mineral fractions of different grain sizes (0-2 mm, 2-5 mm, 5-12 mm and 12-50 mm). The main aim of the study was to assess, whether the advanced bottom ash treatment technique, producing mineral fractions of different grain sizes and therefore properties, facilitates the utilisation of municipal solid waste incineration bottom ash in Finland. The results were encouraging; the bottom ash mineral fractions have favourable behaviour against the frost action, which is especially useful in the Finnish conditions. In addition, the leaching of most hazardous substances did not restrict the utilisation of bottom ash, especially for the larger fractions (>5 mm). Overall, this study has shown that the advanced bottom ash recovering technique can be one solution to increase the utilisation of bottom ash and furthermore decrease its landfilling in Finland. © The Author(s) 2015.

Esterification free fatty acid in sludge palm oil using ZrO2/SO42- - rice husk ash catalyst

NASA Astrophysics Data System (ADS)

Hidayat, Arif; Sutrisno, Bachrun

2017-05-01

Indonesia, as one of the biggest palm oil producers and exporters in the world, is producing large amounts of low-grade oil such as sludge palm oil (SPO) from palm oil industries. The use of SPO can lower the cost of biodiesel production significantly, which makes SPO a highly potential alternative feedstock for biodiesel production. In this paper, the esterification of free fatty acid on sludge palm oil was studied using rice husk ash as heterogeneous solid catalysts. Heterogeneous solid catalysts offer significant advantages of eliminating separation, corrosion, toxicity and environmental problems. In this paper the esterification of SPO, a by-product from palm oil industry, in the presence of modified rice husk ash catalysts was studied. The rice husk ash catalysts were synthesized by impregnating of Zirconia (Zr) on rice husk ash followed by sulfonation. The rice husk ash catalysts were characterized by using different techniques, such as FT-IR, XRD, and porous analysis. The effects of the mass ratio of catalyst to oil (1 - 10%), the molar ratio of methanol to oil (4:1 - 10:1), and the reaction temperature (40 - 60°C) were studied for the conversion of free fatty acids (FFAs) to optimize the reaction conditions. The results showed that the optimal conditions were an methanol to oil molar ratio of 10:1, the amount of catalyst of 10%w, and reaction temperature of 60°C.

Wood ash residue causes a mixture of growth promotion and toxicity in Lemna minor.

PubMed

Jagodzinski, Lucas S; O'Donoghue, Marian T; Heffernan, Liam B; van Pelt, Frank N A M; O'Halloran, John; Jansen, Marcel A K

2018-06-01

The use of wood as a sustainable biofuel results in the generation of residual wood ash. The ash contains high amounts of plant macronutrients such as phosphorus, potassium, calcium as well as several micronutrients. To explore the potential use of wood ash as a fertiliser, the growth enhancing properties of Sitka spruce (Picea sitchensis Bong.) wood ash were contrasted with the potential toxic action, using common duckweed (Lemna minor L.) as a model test species. The growth of L. minor exposed to wood bottom and fly ash solids and corresponding leachates was assessed in ultra-oligotrophic and eutrophic media. Ash solids and leachates were also tested as neutralized preparations. Suspended ash solids promoted L. minor growth up to concentrations of 2.5-5g/L. Leachates promoted growth up to 10g ash equivalents per litre, but for bottom ash only. Beneficial effects of wood ash were most pronounced on ultra-oligotrophic medium. However, on such nutrient-deficient medium severe inhibition of L. minor biomass and frond growth was observed at relatively low concentrations of fly ash (EC 50 =14g/L). On standard, eutrophic medium, higher concentrations of fly ash (EC 50 =21g/L), or neutralized fly ash (EC 50 =37g/L) were required to impede growth. Bottom ash, or neutralized bottom ash retarded growth at concentrations of 51g/L and 74g/L (EC 50 ), respectively, in eutrophic medium. It appears that phytotoxicity is due to the elemental composition of the ash, its alkaline character, and possible interactions between these two properties. Growth promotion was due to the substantial content of plant nutrients. This study underlines the importance of the receiving environment (nutrient status and pH) in determining the balance between toxicity and growth promotion, and shows that the margin between growth promoting and toxicity inducing concentrations can be enlarged through ash neutralization. Copyright © 2017 Elsevier B.V. All rights reserved.

The effect of nano-silica fertilizer concentration and rice hull ash doses on soybean (Glycine max (L.) Merrill) growth and yield

NASA Astrophysics Data System (ADS)

Suciaty, T.; Purnomo, D.; Sakya, A. T.; Supriyadi

2018-03-01

Agriculture is facing a number of challenges included limited water supply, low nutrient use efficiency, etc affected by climate change. Nano-silica is a product of nanotechnology, the frontier technologies to enhance crop productivity under climate change threats. The purpose of the research was to investigate the effects of nano silica concentration and rice hull ash on growth and yield of soybean. The experiment was conducted at Gagasari village, Cirebon, West Java from March until June 2017. The treatments were arranged by using factorial completely randomized block design with two factors. The first factor was a concentration of nano silica fertilizer consisted of four levels i.e., 0, 1.75, 2.5, and 3.75 ml.l‑1. The second factor was doses of rice hull ash consisted of four levels i.e., 0, 1, 2, and 3 ton.ha‑1. Each treatment combinations was repeated three times. The result showed that concentration of nano silica individually affected the number of leaves and number of branches, NAR and RGR, productive branches at 21, 30-45, and 35 daps, respectively. It also affected the seed dry weight plant‑1 and plot‑1. Meanwhile, doses of rice hull ash affected LAI, NAR, and RGR, 15-30, and 30-45 dap, respectively. Dry seed weight plot‑1 was also affected by doses of rice hull ash. There was an interaction effect between nano-silica concentration and doses of rice hull ash on number pods.plant‑1. Combinations of 2.5 ml.l‑1 nano-silica and 3 ton.ha‑1 of rice hull ash gave the highest number pods.plant‑1.

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.

Review: Application of coal bottom ash as aggregate replacement in highway embankment, acoustic absorbing wall and asphalt mixtures

NASA Astrophysics Data System (ADS)

Afiza Mohammed, Syakirah; Rehan Karim, Mohamed

2017-06-01

Worldwide annual production of coal bottom ash waste was increased in the last decade and is being dumped on landfill over the years. Its improper disposal has become an environmental concern and resulted in a waste of recoverable resources. There is a pressing and on-going need to develop new recycling methods for coal bottom ash. The utilization of coal bottom ash in highway engineering is one of the options to reduce the environmental problems related to the disposal of bottom ash. The present review describe the physical and chemical properties of coal bottom ash waste and its current application as highway embankment material, as acoustic absorbing material and as aggregate replacement in asphalt mixtures. The purpose of this review is to stimulate and promote the effective recycling of coal bottom ash in highway engineering industry.

A comparative study on different burning method of sewage sludge ash in mortar brick with eggshell powder as additive

NASA Astrophysics Data System (ADS)

Ing, Doh Shu; Azed, Muhammad Aizat; Chin, Siew Choo

2017-11-01

Population growth that increase every year has led to the increasing amount of waste generated annually. The content of heavy metal Cadmium (Cd), Lead (Pb) and Zinc (Zn) represent the biggest concentrations of heavy metals in sewage sludge waste which can be the source of pollution. Furthermore, the excessive disposal of eggshells waste to landfills may attract rats and worms due to the organic protein matrix that may pose health problem to the public. In the last decade, the demand on cement mortar brick has increased has resulted in higher cement production. However, cement plant is one of the major contributors of carbon dioxide emission. Hence, this research focuses on the production of environmental friendly cement with sewage sludge since there is occurrence of pozolonic material in Sewage Sludge Ash (SSA). From the initial finding, the major components of SSA are Silicon Dioxide (SiO2), Calcium oxide (CaO), Aluminium Oxide (Al2O3), Iron (III) Oxide (Fe2O3), Sodium Oxide (Na2O), Potassium oxide (K2O), Magnesium Oxide (MgO) and Iron (II) Oxide (FeO). Sewage sludge needed to be incinerated to remove the heavy metal before it can be used as cement replacement in mortar brick production. The sewage sludge were treated using two methods namely incineration and microwave. Both types of sewage sludge were then added with eggshell powder as additive. Eggshell powder act as additive in this research due to its high content of calcium carbonate and has nearly same composition of limestone used in the production of cement. Different percentages of Eggshell Powder (ESP) (0%, 5%, 10%, 15%) and 10% fixed of Microwaved Sewage Sludge Ash (MSSA) and Incinerated Sewage Sludge Ash (ISSA) as optimum dosage partially replacing the cement used to test the brick mortar properties in term of compressive strength, flexural strength and also water absorption. Result showed that ISSA with 5% of ESP is the most optimum brick with highest compressive strength and flexural strength compared to MSSA brick. While, MSSA brick with 10% of ESP shown the best result in water absorption. But, the water absorption rate for 10% ESP in ISSA is still within acceptable range.

Regeneratively cooled coal combustor/gasifier with integral dry ash removal

DOEpatents

Beaufrere, Albert H.

1983-10-04

A coal combustor/gasifier is disclosed which produces a low or medium combustion gas for further combustion in modified oil or gas fired furnaces or boilers. Two concentric shells define a combustion volume within the inner shell and a plenum between them through which combustion air flows to provide regenerative cooling of the inner shell for dry ash operation. A fuel flow and a combustion air flow having opposed swirls are mixed and burned in a mixing-combustion portion of the combustion volume and the ash laden combustion products flow with a residual swirl into an ash separation region. The ash is cooled below the fusion temperature and is moved to the wall by centrifugal force where it is entrained in the cool wall boundary layer. The boundary layer is stabilized against ash re-entrainment as it is moved to an ash removal annulus by a flow of air from the plenum through slots in the inner shell, and by suction on an ash removal skimmer slot.

Equilibrium, Kinetic, and Thermodynamic Studies on the Adsorption of Cadmium from Aqueous Solution by Modified Biomass Ash

PubMed Central

Zheng, Xuebo; Cui, Hongbiao; Zhu, Zhenqiu; Liang, Jiani

2017-01-01

Natural biomass ash of agricultural residuals was collected from a power plant and modified with hexagonal mesoporous silica and functionalized with 3-aminopropyltriethoxysilane. The physicochemical and morphological properties of the biomass ash were analyzed by ICP-OES, SEM, TEM-EDS, FTIR, and BET analysis. The adsorption behavior of the modified product for Cd2+ in aqueous solution was studied as a function of pH, initial metal concentration, equilibrium time, and temperature. Results showed that the specific surface area of the modified product was 9 times that of the natural biomass ash. The modified biomass ash exhibited high affinity for Cd2+ and its adsorption capacity increased sharply with increasing pH from 4.0 to 6.0. The maximum adsorption capacity was 23.95 mg/g in a pH 5 solution with an initial metal concentration of 50 mg/L and a contact time of 90 min. The adsorption of Cd2+ onto the modified biomass ash was well fitted to the Langmuir model and it followed pseudo-second-order kinetics. Thermodynamic analysis results showed that the adsorption of Cd2+ was spontaneous and endothermic in nature. The results suggest that the modified biomass ash is promising for use as an inexpensive and effective adsorbent for Cd2+ removal from aqueous solution. PMID:28348509

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

Effect of bacterial inoculants on phytomining of metals from waste incineration bottom ash.

PubMed

Rosenkranz, Theresa; Kidd, Petra; Puschenreiter, Markus

2018-03-01

Waste incineration bottom ash is considered a secondary resource for valuable trace elements (TE), which is currently neglected in most European countries. Phytomining could potentially recover valuable TE from such waste materials but is still at an exploratory stage with many challenges. The use of bioaugmentation to improve plant growth and TE accumulation of metal-tolerant high biomass plants growing on waste incineration bottom ash was evaluated. Bacterial strains that were previously isolated from rhizosphere, roots and contaminated soil were selected according to their plant growth promoting characteristics and tolerance to the bottom ash substrate. Those selected bacterial strains were tested for their beneficial effects on Nicotiana tabacum and Salix smithiana with regards to phytomining. The rhizobacterial strain Rhodococcus erythropolis P30 enhanced the shoot dry weight of N. tabacum by on average 57% compared to the control plants. Several bacterial inoculants enhanced biomass production and the nutritional status of S. smithiana. Moreover, those bacterial strains previously described to enhance biomass production of N. tabacum and members of the Salicaceae on TE-contaminated soils, also enhanced biomass production of these species on bottom ash. However, bacterial inoculants could not enhance trace element accumulation in plants. Copyright © 2017 Elsevier Ltd. All rights reserved.

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.

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.

Comparing Two Independent Satellite-Based Algorithms for Detecting and Tracking Ash Clouds by Using SEVIRI Sensor.

PubMed

Falconieri, Alfredo; Cooke, Michael C; Filizzola, Carolina; Marchese, Francesco; Pergola, Nicola; Tramutoli, Valerio

2018-01-27

The Eyjafjallajökull (Iceland) volcanic eruption of April-May 2010 caused unprecedented air-traffic disruption in Northern Europe, revealing some important weaknesses of current operational ash-monitoring and forecasting systems and encouraging the improvement of methods and procedures for supporting the activities of Volcanic Ash Advisory Centers (VAACs) better. In this work, we compare two established satellite-based algorithms for ash detection, namely RST ASH and the operational London VAAC method, both exploiting sensor data of the spinning enhanced visible and infrared imager (SEVIRI). We analyze similarities and differences in the identification of ash clouds during the different phases of the Eyjafjallajökull eruption. The work reveals, in some cases, a certain complementary behavior of the two techniques, whose combination might improve the identification of ash-affected areas in specific conditions. This is indicated by the quantitative comparison of the merged SEVIRI ash product, achieved integrating outputs of the RST ASH and London VAAC methods, with independent atmospheric infrared sounder (AIRS) DDA (dust-detection algorithm) observations.

Multi-scale analytical investigation of fly ash in concrete

NASA Astrophysics Data System (ADS)

Aboustait, Mohammed B.

Much research has been conducted to find an acceptable concrete ingredient that would act as cement replacement. One promising material is fly ash. Fly ash is a by-product from coal-fired power plants. Throughout this document work on the characterization of fly ash structure and composition will be explored. This effort was conducted through a mixture of cutting edge multi-scale analytical X-ray based techniques that use both bulk experimentation and nano/micro analytical techniques. Furtherly, this examination was coupled by performing Physical/Mechanical ASTM based testing on fly ash-enrolled-concrete to examine the effects of fly ash introduction. The most exotic of the cutting edge characterization techniques endorsed in this work uses the Nano-Computed Tomography and the Nano X-ray Fluorescence at Argonne National Laboratory to investigate single fly ash particles. Additional Work on individual fly ash particles was completed by laboratory-based Micro-Computed Tomography and Scanning Electron Microscopy. By combining the results of individual particles and bulk property tests, a compiled perspective is introduced, and accessed to try and make new insights into the reactivity of fly ash within concrete.

Combined disc pelletisation and thermal treatment of MSWI fly ash.

PubMed

Huber, Florian; Herzel, Hannes; Adam, Christian; Mallow, Ole; Blasenbauer, Dominik; Fellner, Johann

2018-03-01

An environmentally friendly and cost efficient way for the management of municipal solid waste incineration (MSWI) fly ash represents its thermal co-treatment together with combustible waste. However, the safe introduction and storage of MSWI fly ash in the waste bunker is challenging and associated with severe problems (e.g. dust emissions, generation of undefined lumps and heat in case of moistened MSWI fly ash). Therefore, the aim of this study is to investigate the suitability of pelletisation as a pretreatment of MSWI fly ash. In particular, MSWI fly ash was characterised after sampling, pelletisation and thermal treatment and the transfer of constituents to secondary fly ash and flue gas was investigated. For this purpose, MSWI fly ash pellets with a water content of about 0.15 kg/kg and a diameter of about 8 mm have been produced by disc pelletiser and treated in an electrically heated pilot-scale rotary kiln at different temperatures, ranging from 450 °C to 1050 °C. The total contents of selected elements in the MSWI fly ash before and after thermal treatment and in the generated secondary fly ash have been analysed in order to understand the fate of each element. Furthermore, leachable contents of selected elements and total content of persistent organic pollutants of the thermally treated MSWI fly ash were determined. Due to the low total content of Hg (0.7 mg/kg) and the low leachate content of Pb (<0.36 mg/kg), even at the lowest treatment temperature of 450 °C, thermally treated MSWI fly ash pellets can be classified as non-hazardous waste. However, temperatures of at least 650 °C are necessary to decrease the toxic equivalency of PCDD/F and DL-PCB. The removal of toxic heavy metals like Cd and Pb is significantly improved at temperatures of 850 °C, 950 °C or even 1050 °C. The observed metal removal led to relatively high contents of e.g. Cu (up to 11,000 mg/kg), Pb (up to 91,000 mg/kg) and Zn (up to 21,000 mg/kg) in the secondary fly ash. This metal enriched secondary fly ash might represent a potential raw material for metal recovery (e.g. via acidic leaching). Due to the high content of total dissolved solids observed in the leachate of thermally treated MSWI fly ash pellets, a wet extraction procedure is suggested to enable its safe disposal at non-hazardous waste landfills. Copyright © 2017 Elsevier Ltd. All rights reserved.

75 FR 55552 - Polyvinyl Alcohol From Taiwan: Preliminary Determination of Sales at Less Than Fair Value and...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-09-13

...-grade low-ash PVA are not included in the scope of this investigation. PVB-grade low-ash PVA is defined... amended the scope of the petition and the definition of the domestic like product to exclude ``PVB-grade... that fall within or that are functionally equivalent to and commercially competitive with products that...

Semiconductivity in Organoarsenic Materials.

DTIC Science & Technology

1977-12-01

element halide with ferrocene in an organic solvent; the structure of one of the products, [Fe(95-C5H5)21 8iC14, determined by X-ray crystallography...homoatomic catenates from primary alkyl phosphines , arsines and stibines . From CH3PH2, CH3AsH2 and C2H5AsH2, the products are Hg 0 and the

The effect of organic wheat flour by-products on sourdough performances assessed by a multi-criteria approach.

PubMed

Clément, Héliciane; Prost, Carole; Chiron, Hubert; Ducasse, Maren Bonnand; Della Valle, Guy; Courcoux, Philippe; Onno, Bernard

2018-04-01

In this study, we determined the effect of organic (i) flour ash content (1%-1.4%) and (ii) flour by-product addition (bran, shorts and germ) on sourdough performances. After five consecutive back-sloppings, sourdough was used for bread-making and its bread-related properties were assessed. No effect of flour composition factors (i & ii) on sourdough lactic acid bacteria and yeasts were highlighted. Nonetheless, they greatly altered lactic acid and acetic acid sourdough contents from 6.9 to 17.4 g/kg and from 0.9 to 2.2 g/kg, respectively. The flour ash content (i) had a significant and positive effect on sourdough acidity and CO 2 production. Bread made with sourdough with a high ash content had a significantly higher acidity and specific volume. These physicochemical differences between breads were perceived by sensory evaluation in a significant way. Sourdough supplemented (ii) with germ had higher lactic acid and carbon dioxide contents than sourdough supplemented with bran and shorts. Hence, flour composition, combining ash content and flour by-products, appears to be an effective factor to obtain a better control of sourdough performances. Copyright © 2018 Elsevier Ltd. All rights reserved.

Physical and Chemical Characteristics of Ash-influenced Soils of Inland Northwest Forests

Treesearch

P. A. McDaniel; M. A. Wilson

2007-01-01

Holocene ash from the cataclysmic eruption of Mount Mazama (now Crater Lake) in southeastern Oregon is a major component of many forest soils that lie to the east of Cascade Mountains in the Pacific Northwest region. The relatively high productivity of the region’s ecosystems is closely linked to this volcanic ash component. This paper reports on the ecologically...

Design and evaluation of high-volume fly ash (HVFA) concrete mixes, report C : shear behavior of HVFA reinforced concrete.

DOT National Transportation Integrated Search

2012-10-01

Concrete is the most widely used man-made material on the planet. Unfortunately, producing Portland cement generates carbon dioxide (a greenhouse gas) at roughly a pound for pound ratio. High-volume fly ash (HVFA) concrete concrete with at least ...

DESIGN AND CHARACTERIZATION OF AN ULTRAFINE COAL ASH AEROSOL GENERATOR FOR DIRECT ANIMAL EXPOSURE STUDIES

EPA Science Inventory

Primary ultrafine particulate matter (PM) is produced during pulverized coal combustion by the nucleation and heterogeneous condensation of vapor-phase species. This differs from the mechanisms that control the formation of the supermicron fly ash that is heavily influenced by t...

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.

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.

Geotechnical applications of CCPs in Wisconsin

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

Edil, T.C.; Benson, C.H.

2006-07-01

The article reports research case histories on applications of coal combustion products (CCPs) in Wisconsin developed by the University of Wisconsin Consortium for Fly Ash Use in Geotechnical Applications (FAUGA). Fly ash was used to stabilize poor soils during construction of Wisconsin State Highway (STH) 60, and bottom ash was used as a granular working platform. Long term performance is proving good. Nearly all Class C fly ash in Wisconsin is now used in construction. Leaching characteristics of pavements incorporating fly ash are being monitored by pan lysimeters underneath. A computer model, WiscLEACH has been developed to predict the maximummore » concentration of chemicals in ground water adjacent to roadways using CCPs. 1 photo.« less

Selenium in pollen gathered by bees foraging on fly ash-grown plants

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

De Jong, D.; Morse, R.A.; Gutenmann, W.H.

1977-10-01

Fly ash is the material collected in the stacks of coal burning electric power-generating plants by electrostatic precipitators. About 26 million metric tons of fly ash was estimated to have been produced in 1975 (BRACKETT, 1970). Aside from a small percentage of the material which is used as a base material for roads and in concrete, the bulk of it is deposited in landfills. It was first reported by Gutenmann et al. (1976) that sweet clover, found voluntarily growing on a fly ash landfill site, contained up to 200 ppM of selenium. Fly ashes from 21 states were found tomore » contain the element. Cabbage grown on each of these fly ashes added (7 percent w/w) to soil was shown to absorb selenium in proportion to its concentration in the particular ash (GUTENMANN et al., 1976). The percentage of fly ash in soil was also shown to dictate the extent of selenium absorption by a variety of plants (FURR et al., 1976). In the work reported, pollen collected by honey bees foraging on plants growing on a fly ash landfill was analyzed for selenium and compared with that collected by bees from the same plants growing on soil.« less

Effect of Sodium Carboxymethyl Celluloses on Water-catalyzed Self-degradation of 200-degree C-heated Alkali-Activated Cement

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

Sugama T.; Pyatina, T.

2012-05-01

We investigated the usefulness of sodium carboxymethyl celluloses (CMC) in promoting self-degradation of 200°C-heated sodium silicate-activated slag/Class C fly ash cementitious material after contact with water. CMC emitted two major volatile compounds, CO2 and acetic acid, creating a porous structure in cement. CMC also reacted with NaOH from sodium silicate to form three water-insensitive solid reaction products, disodium glycolate salt, sodium glucosidic salt, and sodium bicarbonate. Other water-sensitive solid reaction products, such as sodium polysilicate and sodium carbonate, were derived from hydrolysates of sodium silicate. Dissolution of these products upon contact with water generated heat that promoted cement’s self-degradation. Thus,more » CMC of high molecular weight rendered two important features to the water-catalyzed self-degradation of heated cement: One was the high heat energy generated in exothermic reactions in cement; the other was the introduction of extensive porosity into cement.« less

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. 

Fate and aqueous transport of mercury in light of the Clean Air Mercury Rule for coal-fired electric power plants

NASA Astrophysics Data System (ADS)

Arzuman, Anry

Mercury is a hazardous air pollutant emitted to the atmosphere in large amounts. Mercury emissions from electric power generation sources were estimated to be 48 metric tons/year, constituting the single largest anthropogenic source of mercury in the U.S. Settled mercury species are highly toxic contaminants of the environment. The newly issued Federal Clean Air Mercury Rule requires that the electric power plants firing coal meet the new Maximum Achievable Mercury Control Technology limit by 2018. This signifies that all of the air-phase mercury will be concentrated in solid phase which, based on the current state of the Air Pollution Control Technology, will be fly ash. Fly ash is utilized by different industries including construction industry in concrete, its products, road bases, structural fills, monifills, for solidification, stabilization, etc. Since the increase in coal combustion in the U.S. (1.6 percent/year) is much higher than the fly ash demand, large amounts of fly ash containing mercury and other trace elements are expected to accumulate in the next decades. The amount of mercury transferred from one phase to another is not a linear function of coal combustion or ash production, depends on the future states of technology, and is unknown. The amount of aqueous mercury as a function of the future removal, mercury speciation, and coal and aquifer characteristics is also unknown. This paper makes a first attempt to relate mercury concentrations in coal, flue gas, fly ash, and fly ash leachate using a single algorithm. Mercury concentrations in all phases were examined and phase transformation algorithms were derived in a form suitable for probabilistic analyses. Such important parameters used in the transformation algorithms as Soil Cation Exchange Capacity for mercury, soil mercury selectivity sequence, mercury activity coefficient, mercury retardation factor, mercury species soil adsorption ratio, and mercury Freundlich soil adsorption isotherm coefficients were derived. Mercury air-phase removal efficiency was studied as a function of dominant mercury species vapor pressures, the amount of chlorine, sorbent injection rate and adsorption capacities, and process temperature and modifications. A mercury air phase removal algorithm was derived which defines the future removal efficiencies as a function of activated carbon injection rate. Mercury adsorption on soil was studied as a function of Mercury Mass Law incorporating the dominant aquatic mercury species, pH, chlorine and sulfur concentrations, and the amount of complexed hydroxyl groups. Aquatic mercury longitudinal plume delineation was studied using the Domenico and Robbins function. A Monte Carlo simulation was performed using random number series (5000) for all of the variables in the Domenico and Robbins and mercury retardation functions. The probability that the Maximum Contaminant Level for mercury will be exceeded was found to be equal approximately 1 percent of all soil-related fly ash applications.

Reuse of Coconut Shell, Rice Husk, and Coal Ash Blends in Geopolymer Synthesis

NASA Astrophysics Data System (ADS)

Walmiki Samadhi, Tjokorde; Wulandari, Winny; Prasetyo, Muhammad Iqbal; Rizki Fernando, Muhammad

2017-10-01

Mixtures of biomass and coal ashes are likely to be produced in increasing volume as biomass-based energy production is gaining importance in Indonesia. This work highlights the reuse of coconut shell ash (CSA), rice husk ash (RHA), and coal fly ash (FA) for geopolymer synthesis by an activator solution containing concentrated KOH and Na2SiO3. Ash blend compositions are varied according to a simplex-centroid mixture experimental design. Activator to ash mass ratios are varied from 0.8 to 2.0, the higher value being applied for ash compositions with higher Si/Al ratio. The impact of ash blend composition on early strength is adequately modeled by an incomplete quadratic mixture model. Overall, the ashes can produce geopolymer mortars with an early strength exceeding the Indonesian SNI 15-2049-2004 standard minimum value of 2.0 MPa. Good workability of the geopolymer is indicated by their initial setting times which are longer than the minimum value of 45 mins. Geopolymers composed predominantly of RHA composition exhibit poor strength and excessive setting time. FTIR spectroscopy confirms the geopolymerization of the ashes by the shift of the Si-O-Si/Al asymmetric stretching vibrational mode. Overall, these results point to the feasibility of geopolymerization as a reuse pathway for biomass combustion waste.

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.

Integrated Waste Treatment Unit (IWTU) Input Coal Analyses and Off-Gass Filter (OGF) Content Analyses

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

Jantzen, Carol M.; Missimer, David M.; Guenther, Chris P.

A full engineering scale Fluidized Bed Steam Reformer (FBSR) system is being used at the Idaho Nuclear Technology and Engineering Center (INTEC) to stabilize acidic Low Activity Waste (LAW) known as Sodium Bearing Waste (SBW). The INTEC facility, known as the Integrated Waste Treatment Unit (IWTU), underwent an Operational Readiness Review (ORR) and a Technology Readiness Assessment (TRA) in March 2014. The IWTU began non-radioactive simulant processing in late 2014 and by January, 2015 ; the IWTU had processed 62,000 gallons of simulant. The facility is currently in a planned outage for inspection of the equipment and will resume processingmore » simulated waste feed before commencing to process 900,000 gallons of radioactive SBW. The SBW acidic waste will be made into a granular FBSR product (carbonate based) for disposal in the Waste Isolation Pilot Plant (WIPP). In the FBSR process calcined coal is used to create a CO2 fugacity to force the waste species to convert to carbonate species. The quality of the coal, which is a feed input, is important because the reactivity, moisture, and volatiles (C,H,N,O, and S) in the coal impact the reactions and control of the mineralizing process in the primary steam reforming vessel, the Denitration and Mineralizing Reformer (DMR). Too much moisture in the coal can require that additional coal be used. However since moisture in the coal is only a small fraction of the moisture from the fluidizing steam this can be self-correcting. If the coal reactivity or heating value is too low then the coal feedrate needs to be adjusted to achieve the desired heat generation. Too little coal and autothermal heat generation in the DMR cannot be sustained and/or the carbon dioxide fugacity will be too low to create the desired carbonate mineral species. Too much coal and excess S and hydroxide species can form. Excess sulfur from coal that (1) is too rich in sulfur or (2) from overfeeding coal can promote wall scale and contribute to corrosion in process piping and materials, in excessive off-gas absorbent loading, and in undesired process emissions. The ash content of the coal is important as the ash adds to the DMR and other vessel products which affect the final waste product mass and composition. The amount and composition of the ash also affects the reaction kinetics. Thus ash content and composition contributes to the mass balance. In addition, sodium, potassium, calcium, sulfur, and maybe silica and alumina in the ash may contribute to wall-scale formation. Sodium, potassium, and alumina in the ash will be overwhelmed by the sodium, potassium, and alumina from the feed but the impact from the other ash components needs to be quantified. A maximum coal particle size is specified so the feed system does not plug and a minimum particle size is specified to prevent excess elutriation from the DMR to the Process Gas Filter (PGF). A vendor specification was used to procure the calcined coal for IWTU processing. While the vendor supplied a composite analysis for the 22 tons of coal (Appendix A), this study compares independent analyses of the coal performed at the Savannah River National Laboratory (SRNL) and at the National Energy Technology Laboratory (NETL). Three supersacks a were sampled at three different heights within the sack in order to determine within bag variability and between bag variability of the coal. These analyses were also compared to the vendor’s composite analyses and to the coal specification. These analyses were also compared to historic data on Bestac coal analyses that had been performed at Hazen Research Inc. (HRI) between 2004-2011.« less

An LCA model for waste incineration enhanced with new technologies for metal recovery and application to the case of Switzerland.

PubMed

Boesch, Michael E; Vadenbo, Carl; Saner, Dominik; Huter, Christoph; Hellweg, Stefanie

2014-02-01

A process model of municipal solid waste incinerators (MSWIs) and new technologies for metal recovery from combustion residues was developed. The environmental impact is modeled as a function of waste composition as well as waste treatment and material recovery technologies. The model includes combustion with a grate incinerator, several flue gas treatment technologies, electricity and steam production from waste heat recovery, metal recovery from slag and fly ash, and landfilling of residues and can be tailored to specific plants and sites (software tools can be downloaded free of charge). Application of the model to Switzerland shows that the treatment of one tonne of municipal solid waste results on average in 425 kg CO2-eq. generated in the incineration process, and 54 kg CO2-eq. accrue in upstream processes such as waste transport and the production of operating materials. Downstream processes, i.e. residue disposal, generates 5 kg CO2-eq. Savings from energy recovery are in the range of 67 to 752 kg CO2-eq. depending on the assumptions regarding the substituted energy production, while the recovery of metals from slag and fly ash currently results in a net saving of approximately 35 kg CO2-eq. A similar impact pattern is observed when assessing the MSWI model for aggregated environmental impacts (ReCiPe) and for non-renewable resource consumption (cumulative exergy demand), except that direct emissions have less and no relevance, respectively, on the total score. The study illustrates that MSWI plants can be an important element of industrial ecology as they provide waste disposal services and can help to close material and energetic cycles. Copyright © 2013 Elsevier Ltd. All rights reserved.

The impacts of biomass properties on pyrolysis yields, economic and environmental performance of the pyrolysis-bioenergy-biochar platform to carbon negative energy.

PubMed

Li, Wenqin; Dang, Qi; Brown, Robert C; Laird, David; Wright, Mark M

2017-10-01

This study evaluated the impact of biomass properties on the pyrolysis product yields, economic and environmental performance for the pyrolysis-biochar-bioenergy platform. We developed and applied a fast pyrolysis, feedstock-sensitive, regression-based chemical process model to 346 different feedstocks, which were grouped into five types: woody, stalk/cob/ear, grass/plant, organic residue/product and husk/shell/pit. The results show that biomass ash content of 0.3-7.7wt% increases biochar yield from 0.13 to 0.16kg/kg of biomass, and decreases biofuel yields from 87.3 to 40.7 gallons per tonne. Higher O/C ratio (0.88-1.12) in biomass decreases biochar yield and increases biofuel yields within the same ash content level. Higher ash content of biomass increases minimum fuel selling price (MFSP), while higher O/C ratio of biomass decreases MFSP within the same ash content level. The impact of ash and O/C ratio of biomass on GHG emissions are not consistent for all feedstocks. Copyright © 2017 Elsevier Ltd. All rights reserved.

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.

Properties of concrete modified with waste Low Density Polyethylene and saw dust ash

NASA Astrophysics Data System (ADS)

Srimanikandan, P.; Sreenath, S.

2017-07-01

The increase in industrialization creates need for disposal of large quantity of by-products. To overcome the difficulty of disposal, these by-products can be used as a replacement for raw material. In this concern, non-conventional industrial wastes such as plastic bags, PET bottles, pulverized waste Low Density Polyethylene (LDPE) and biological waste such as saw-dust ash, coconut coir were used as a replacement in concrete. In this project, saw-dust ash and pulverized waste LDPE were introduced as the partial replacement for cement and fine aggregates respectively. 0%, 5%, 10%, 15% and 20% of sand by volume was replaced with LDPE and 0%, 1%, 3%, 5% and 10% of cement by volume was replaced with saw dust ash. Standard cube, cylinder and prism specimens were cast to assess the compressive strength, split tensile strength and flexural strength of modified concrete after 28 days of curing. Optimum percentage of replacement was found by comparing the test results. The mix with 5% of LDPE and 3% of saw dust ash showed a better result among the other mixes.

Calcium phosphate stabilization of fly ash with chloride extraction.

PubMed

Nzihou, Ange; Sharrock, Patrick

2002-01-01

Municipal solid waste incinerator by products include fly ash and air pollution control residues. In order to transform these incinerator wastes into reusable mineral species, soluble alkali chlorides must be separated and toxic trace elements must be stabilized in insoluble form. We show that alkali chlorides can be extracted efficiently in an aqueous extraction step combining a calcium phosphate gel precipitation. In such a process, sodium and potassium chlorides are obtained free from calcium salts, and the trace metal ions are immobilized in the calcium phosphate matrix. Moderate calcination of the chemically treated fly ash leads to the formation of cristalline hydroxylapatite. Fly ash spiked with copper ions and treated by this process shows improved stability of metal ions. Leaching tests with water or EDTA reveal a significant drop in metal ion dissolution. Hydroxylapatite may trap toxic metals and also prevent their evaporation during thermal treatments. Incinerator fly ash together with air pollution control residues, treated by the combined chloride extraction and hydroxylapatite formation process may be considered safe to use as a mineral filler in value added products such as road base or cement blocks.

Effect of lightweight aggregates prepared from fly ash on lightweight concrete performances

NASA Astrophysics Data System (ADS)

Punlert, S.; Laoratanakul, P.; Kongdee, R.; Suntako, R.

2017-09-01

Lightweight aggregates were prepared from fly ash of by-products from the paper industry. The influence of the ratio of clay to fly ash and processing conditions on lightweight aggregates properties were investigated. It was found that the amount of fly ash directly affected to porosity of lightweight aggregates. Lightweight aggregates with the ratio of clay to fly ash at 80:20 wt% using the sintering temperature at 1210°C exhibits bulk density of 1.66 g cm-3, compressive strength of 25 MPa and water absorption of 0.55%. The replacement of coarse aggregates with lightweight aggregates at 100 wt% for concrete production showed the ultimate properties of concrete with density of 1780 g cm-3, water absorption of 3.55%, compressive strength of 40.94 MPa and thermal conductivity of 0.77 W m-1K-1. The concrete had more than 25% weight reduction while keeping a similar compressive strength to an ordinary concrete. This is revealed that lightweight aggregates could be applied into structural concrete because it was able to reduce work load and increase safety factor of construction.

Hexavalent chromium bioreduction and chemical precipitation of sulphate as a treatment of site-specific fly ash leachates.

PubMed

Cason, Errol D; Williams, Peter J; Ojo, Elizabeth; Castillo, Julio; DeFlaun, Mary F; van Heerden, Esta

2017-05-01

Most of the power generation globally is by coal-fired power plants resulting in large stockpiles of fly ash. The trace elements associated with the ash particles are subjected to the leaching effects of precipitation which may lead to the subsequent contamination of surface and groundwater systems. In this study, we successfully demonstrate an efficient and sustainable dual treatment remediation strategy for the removal of high levels of Cr 6+ and SO 4 2- introduced by fly ash leachate generated by a power station situation in Mpumalanga, South Africa. The treatment consisted of a primary fixed-bed bioreactor kept at a reduction potential for Cr 6+ reduction. Metagenome sequencing clearly indicated a diverse bacterial community containing various bacteria, predominantly of the phylum Proteobacteria which includes numerous species known for their ability to detoxify metals such as Cr 6+ . This was followed by a secondary BaCO 3 /dispersed alkaline substrate column for SO 4 2- removal. The combination of these two systems resulted in the removal of 99% Cr 6+ and 90% SO 4 2- . This is the first effective demonstration of an integrated system combining a biological and chemical strategy for the remediation of multi-contaminants present in fly ash leachate in South Africa.

40 CFR 98.297 - Records that must be retained.

Code of Federal Regulations, 2011 CFR

2011-07-01

... production of soda ash (tons) (2) Monthly consumption of trona or liquid alkaline feedstock (tons) (3) Annual... technical basis for these estimates must be provided. (5) If you produce soda ash using the liquid alkaline...

40 CFR 98.297 - Records that must be retained.

Code of Federal Regulations, 2012 CFR

2012-07-01

... production of soda ash (tons) (2) Monthly consumption of trona or liquid alkaline feedstock (tons) (3) Annual... technical basis for these estimates must be provided. (5) If you produce soda ash using the liquid alkaline...

40 CFR 98.297 - Records that must be retained.

Code of Federal Regulations, 2014 CFR

2014-07-01

... production of soda ash (tons) (2) Monthly consumption of trona or liquid alkaline feedstock (tons) (3) Annual... technical basis for these estimates must be provided. (5) If you produce soda ash using the liquid alkaline...

40 CFR 98.297 - Records that must be retained.

Code of Federal Regulations, 2010 CFR

2010-07-01

... production of soda ash (tons) (2) Monthly consumption of trona or liquid alkaline feedstock (tons) (3) Annual... technical basis for these estimates must be provided. (5) If you produce soda ash using the liquid alkaline...

40 CFR 98.297 - Records that must be retained.

Code of Federal Regulations, 2013 CFR

2013-07-01

... production of soda ash (tons) (2) Monthly consumption of trona or liquid alkaline feedstock (tons) (3) Annual... technical basis for these estimates must be provided. (5) If you produce soda ash using the liquid alkaline...

Effect of the addition of by-product ash of date palms on the mechanical characteristics of gypsum-calcareous materials used in road construction

NASA Astrophysics Data System (ADS)

Khellou, A.; Kriker, A.; Hafssi, A.; Belbarka, K.; Baali, K.

2016-07-01

The gypsum-calcareous materials, also known as the crusting tuff, are used in the pavement layers of low -traffic road and considered as the materials of first choice in the Saharan region of Algeria. The objective of this paper is to study the mechanical characteristics of tuff of Ouargla town that is situated in the Southeast of Algeria, by adding different percentage of ash resulted from the combustion of by-products of date palms, such as 4%, 8% and l2%, to the tuff. The results obtained have shown a remarkable improvement both in compressive strength at different ages and in the bearing index in the two cases immediate and after immersion in water. These characteristics of the mixture (tuff+ash) reach their maximum values at the 8% of ash addition.

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

Sustainability, Eco-Point and Engineering Performance of Different Workability OPC Fly-Ash Mortar Mixes.

PubMed

Razi, Putri Zulaiha; Abdul Razak, Hashim; Khalid, Nur Hafizah A

2016-05-06

This study investigates the engineering performance and CO₂ footprint of mortar mixers by replacing Portland cement with 10%, 20%, 40% and 60% fly ash, a common industrial waste material. Samples of self-compacting mortar (SCM) were prepared with four different water/binder ratios and varying dosages of superplasticizer to give three ranges of workability, i.e. , normal, high and self-compacting mortar mix. The engineering performance was assessed in term of compressive strength after designated curing periods for all mixes. CO₂ footprint was the environmental impact indicator of each production stage. The optimum mix obtained was at 10% replacement rate for all mixes. Total production emission reduced by 56% when the fly ash replacement rate increased from 0% to 60% (maximum). This is translated to a reduction of 80% in eco-points (assuming that the energy consumption rate of production with 0% fly ash is at 100%). Such re-utilization is encouraged since it is able to reduce possible soil toxicity due to sulfur leaching by 5% to 27% and landfill area by 15% to 91% on average.

Compressive strength and interfacial transition zone of sugar cane bagasse ash concrete: A comparison to the established pozzolans

NASA Astrophysics Data System (ADS)

Hussein, Asma Abd Elhameed; Shafiq, Nasir; Nuruddin, Muhd Fadhil

2015-05-01

Agricultural and industrial by-products are commonly used in concrete production as cement replacement materials (CRMs) or as admixtures to enhance both fresh and hardened properties of concrete as well as to save the environment from the negative effects caused by their disposal. Sugar Cane Bagasse Ash (SCBA) is one of the promising CRMs, it is used as a partial replacement of cement for producing concrete; properties of such concrete depend on the chemical composition, fineness, and burning temperature of SCBA. Approximately 1500 Million tons of sugarcane are annually produced over all the world which leave about 40-45% bagasse after juice crushing for sugar industry giving an average annual production of about 600 Million tons of bagasse as a waste material. This paper presents some findings on the effect of SCBA on workability, compressive strength and microstructure of interfacial zone of concrete and its performance is compared to some of the established CRMs namely Densified Silica Fume, Fly Ash and Microwave Incinerated Rice Husk Ash.

Direct synthesis of carbon nanofibers from South African coal fly ash

NASA Astrophysics Data System (ADS)

Hintsho, Nomso; Shaikjee, Ahmed; Masenda, Hilary; Naidoo, Deena; Billing, Dave; Franklyn, Paul; Durbach, Shane

2014-08-01

Carbon nanofibers (CNFs), cylindrical nanostructures containing graphene, were synthesized directly from South African fly ash (a waste product formed during the combustion of coal). The CNFs (as well as other carbonaceous materials like carbon nanotubes (CNTs)) were produced by the catalytic chemical vapour deposition method (CCVD) in the presence of acetylene gas at temperatures ranging from 400°C to 700°C. The fly ash and its carbonaceous products were characterized by transmission electron microscopy (TEM), thermogravimetric analysis (TGA), laser Raman spectroscopy and Brunauer-Emmett-Teller (BET) surface area measurements. It was observed that as-received fly ash was capable of producing CNFs in high yield by CCVD, starting at a relatively low temperature of 400°C. Laser Raman spectra and TGA thermograms showed that the carbonaceous products which formed were mostly disordered. Small bundles of CNTs and CNFs observed by TEM and energy-dispersive spectroscopy (EDS) showed that the catalyst most likely responsible for CNF formation was iron in the form of cementite; X-ray diffraction (XRD) and Mössbauer spectroscopy confirmed these findings.

Sustainability, Eco-Point and Engineering Performance of Different Workability OPC Fly-Ash Mortar Mixes

PubMed Central

Razi, Putri Zulaiha; Abdul Razak, Hashim; Khalid, Nur Hafizah A.

2016-01-01

This study investigates the engineering performance and CO2 footprint of mortar mixers by replacing Portland cement with 10%, 20%, 40% and 60% fly ash, a common industrial waste material. Samples of self-compacting mortar (SCM) were prepared with four different water/binder ratios and varying dosages of superplasticizer to give three ranges of workability, i.e., normal, high and self-compacting mortar mix. The engineering performance was assessed in term of compressive strength after designated curing periods for all mixes. CO2 footprint was the environmental impact indicator of each production stage. The optimum mix obtained was at 10% replacement rate for all mixes. Total production emission reduced by 56% when the fly ash replacement rate increased from 0% to 60% (maximum). This is translated to a reduction of 80% in eco-points (assuming that the energy consumption rate of production with 0% fly ash is at 100%). Such re-utilization is encouraged since it is able to reduce possible soil toxicity due to sulfur leaching by 5% to 27% and landfill area by 15% to 91% on average. PMID:28773465

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.

Utilization of lignite power generation residues for the production of lightweight aggregates.

PubMed

Anagnostopoulos, Iason M; Stivanakis, Victor E

2009-04-15

A novel process is proposed for the utilization of lignite combustion solid residues in the production of inflammable lightweight aggregates (LWA). The process consists of two stages, pelletization and sintering, and carbon contained in BA was used as the process fuel. The main residues bottom ash (BA) and fly ash (FA) from Megalopolis power plant were characterized, mixed in different proportions and treated through pelletization and sintering process. Sintering benefits from combustion of BA carbon content and the product is a hardened porous cake. The energy required for achievement of high temperatures, in the range of 1250 degrees C, was offered by carbon combustion and CO(2) evolution is responsible for porous structure formation. Selected physical properties of sintered material relevant to use as lightweight aggregates were determined, including bulk density, porosity and water absorption. Bulk density varies from 0.83 to 0.91 g/cm(3), porosity varies from 60% to 64% and water absorption varies from 66% to 80%. LWA formed is used for the production of lightweight aggregate concrete (LWAC). Thermal conductivity coefficient varies from 0.25 to 0.37 W/mK (lower than maximum limit 0.43 W/mK) and compressive strength varies from 19 to 23 MPa (higher than minimum limit 17 MPa). The results indicate that sintering of lignite combustion residues is an efficient method of utilization of carbon containing BA and production of LWA for structural and insulating purposes. Carbon content of BA is a key factor in LWA production. Finally, this research work comprises the first proposed application for utilization of BA in Greece.

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.

Ultraviolet Satellite Measurements of Volcanic Ash. Chapter 12

NASA Technical Reports Server (NTRS)

Carn, S. A.; Krotkov, N. A.

2016-01-01

Ultraviolet (UV) remote sensing of volcanic ash and other absorbing aerosols from space began with the launch of the first Total Ozone Mapping Spectrometer (TOMS) instrument in 1978. Subsequent UV satellite missions (TOMS, GOME, SCIAMACHY, OMI, GOME-2, OMPS) have extended UV ash measurements to the present, generating a unique multidecadal record. A UV Aerosol Index (UVAI) based on two near-UV wavelengths, equally applicable to multispectral (TOMS, DSCOVR) or hyperspectral (GOME, SCIAMACHY, OMI, GOME-2, OMPS) instruments, has been used to derive a unique absorbing aerosol climatology across multiple UV satellite missions. Advantages of UV ash measurements relative to infrared (IR) techniques include the ability to detect ash at any altitude (assuming no clouds), above clouds, and over bright surfaces, where visible and IR techniques may fail. Disadvantages include the daytime-only restriction and nonspecificity to silicate ash, since UV measurements are sensitive to any UV-absorbing aerosol, including smoke, desert dust, and pollution. However, simultaneous retrieval of sulfur dioxide (SO2) abundance and UVAI provides robust discrimination of volcanic clouds. Although the UVAI is only semiquantitative, it has proved successful at detecting and tracking volcanic ash clouds from many volcanic eruptions since 1978. NASA A-Train measurements since 2006 (eg, CALIOP) have provided much improved constraints on volcanic ash altitude, and also permit identification of aerosol type through sensor synergy. Quantitative UV retrievals of ash optical depth, effective particle size, and ash column mass are possible and require assumptions of ash refractive index, particle size distribution, and ash layer altitude. The lack of extensive ash refractive index data in the UV-visible and the effects of ash particle shape on retrievals introduce significant uncertainty in the retrieved parameters, although limited validation against IR ash retrievals has been successful. In this contribution, we review UV ash detection and retrieval techniques and provide examples of volcanic eruptions detected in the approx. 37 year data record.

Unsaturated flow processes in structurally-variable pathways in wildfire-affected soils and ash

NASA Astrophysics Data System (ADS)

Ebel, B. A.

2016-12-01

Prediction of flash flood and debris flow generation in wildfire-affected soils and ash hinges on understanding unsaturated flow processes. Water resources issues, such as groundwater recharge, also rely on our ability to quantify subsurface flow. Soil-hydraulic property data provide insight into unsaturated flow processes and timescales. A literature review and synthesis of existing data from the literature for wildfire-affected soils, including ash and unburned soils, facilitated calculating metrics and timescales of hydrologic response related to infiltration and surface runoff generation. Sorptivity (S) and the Green-Ampt wetting front parameter (Ψf) were significantly lower in burned soils compared to unburned soils, while field-saturated hydraulic conductivity (Kfs) was not significantly different. The magnitude and duration of the influence of capillarity was substantially reduced in burned soils, leading to faster ponding times in response to rainfall. Ash had large values of S and Kfs compared to unburned and burned soils but intermediate values of Ψf, suggesting that ash has long ponding times in response to rainfall. The ratio of S2/Kfs was nearly constant ( 100 mm) for unburned soils, but was more variable in burned soils. Post-wildfire changes in this ratio suggested that unburned soils had a balance between gravity and capillarity contributions to infiltration, which may depend on soil organic matter, while burning shifted infiltration more towards gravity contributions by reducing S. Taken together, the changes in post-wildfire soil-hydraulic properties increased the propensity for surface runoff generation and may have enhanced subsurface preferential flow through pathways altered by wildfire.

Coexistence of Cu, Fe, Pb, and Zn oxides and chlorides as a determinant of chlorinated aromatics generation in municipal solid waste incinerator fly ash.

PubMed

Fujimori, Takashi; Tanino, Yuta; Takaoka, Masaki

2014-01-01

We investigated chemical determinants of the generation of chlorinated aromatic compounds (aromatic-Cls), such as polychlorinated biphenyls (PCBs) and chlorobenzenes (CBzs), in fly ash from municipal solid waste incineration. The influences of the following on aromatic-Cls formation in model fly ash (MFA) were systematically examined quantitatively and statistically: (i) inorganic chlorides (KCl, NaCl, CaCl2), (ii) base materials (SiO2, Al2O3, CaCO3), (iii) metal oxides (CuO, Fe2O3, PbO, ZnO), (iv) metal chlorides (CuCl2, FeCl3, PbCl2, ZnCl2), and (v) "coexisting multi-models." On the basis of aromatic-Cls concentrations, the ∑CBzs/∑PCBs ratio, and the similarity between distribution patterns, MFAs were categorized into six groups. The results and analysis indicated that the formation of aromatic-Cls depended strongly on the "coexistence condition", namely multimodels composed of not only metal chlorides, but also of metal oxides. The precise replication of metal chloride to oxide ratios, such as the precise ratios of Cu-, Fe-, Pb-, and Zn-chlorides and oxides, may be an essential factor in changing the thermochemical formation patterns of aromatic-Cls. Although CuCl2 acted as a promoter of aromatic-Cls generation, statistical analyses implied that FeCl3 also largely influenced the generation of aromatic-Cls under mixture conditions. Various additional components of fly ash were also comprehensively analyzed.

Wildfire ash: its production and hydro-eco-geomorphic effects in forested landscapes

NASA Astrophysics Data System (ADS)

Doerr, S. H.; Bodi, M.; Santin, C.; Balfour, V.; Woods, S.; Mataix-Solera, J.; Cerda, A.; Shakesby, R.

2012-12-01

Fire, whether ignited naturally or by humans, is one of the most important disturbance agents in many of the world's forested ecosystems. Amongst its direct consequences is the deposition of a range of solid and largely powdery residues on the ground consisting of charred organic material including charcoal and residual mineral material. This fragile 'ash' layer can be removed in large quantities from hillslopes within days by wind or water erosion, with the latter facilitating its transfer to the hydrological system. Probably as a result of its ephemeral nature and not being soil, vegetation or litter, ash has seen limited attention in studies on hydrological impacts of wildfire. Those few studies available show that ash can substantially affect the hydrological system. When present on hillslopes as a water-absorbent layer, it can reduce surface runoff, protect soil against rainsplash erosion, and its leachates can reportedly reduce soil erodibility by promoting flocculation of dispersed clays. In contrast, however, ash can also increase surface runoff by blocking soil pores or by forming a crust. Furthermore, ash is thought capable of promoting debris flows. Its net effect probably depends on the nature of the ash and soil including their respective water repellency levels, the pore size distribution of the soil, and general terrain and rainfall characteristics. Being very mobile, ash can be the source of substantial organic and inorganic sediment inputs, and of solute influxes into the fluvial system. These can affect water quality sometimes with detrimental effects on aquatic organisms and domestic water supply. This presentation aims to provide an overview of the current knowledge base regarding the production and potential effects of wildfire ash on the hydrological system in and beyond forested landscapes..The late Scott Woods examining a thick ash layer following a severe fire in a conifer forest. Montana, USA.

Mount St. Helens ash and mud: Chemical properties and effects on germination and establishment of trees and browse plants.

Treesearch

M.A. Radwan; Dan L. Campbell

1981-01-01

Chemical properties of ash and mud from the 1980 volcanic eruption of Mount St. Helens and their effect on germination and seedling production of selected plants were studied. The volcanic materials were low in some important nutrients and cation exchange capacity, and they adversely affected seedling production. Catsear, a preferred wildlife browse, and lodgepole pine...

Volcanic-ash-derived forest soils of the inland Northwest: Properties and implications for management and restoration

Treesearch

Deborah Page-Dumroese; Richard Miller; Jim Mital; Paul McDaniel; Dan Miller

2007-01-01

Volcanic ash from the eruption of Mt. Mazama ~7,700 years ago has a strong influence on many forested landscapes of the Pacific Northwest and Intermountain regions of the USA and Canada. Because of the unique biological, physical and chemical properties of the ash, it is closely tied to plant communities and forest productivity, and should therefore be considered as a...

Characterization and modes of occurrence of elements in feed coal and fly ash; an integrated approach

USGS Publications Warehouse

Brownfield, M.E.

2002-01-01

Despite certain environmental concerns, coal is likely to remain an important component of the United States energy supply, partly because it is the most abundant domestically available fossil fuel. One of the concerns about coal combustion for electricity production is the potential release of elements from coal and coal combustion products (CCPs) - fly ash - to the environment. This concern prompted the need for accurate, reliable, and comprehensive information on the contents and modes of occurrence of selected elements in power-plant feed coal and fly ash. The U.S. Geological Survey (USGS) is collaborating with several electric utilities to determine the chemical and mineralogical properties of feed coal and fly ash. Our first study analyzed coal and fly ash from a Kentucky power plant, which uses many different bituminous coals from the Appalachian and Illinois Basins. Sulfur content of these feed coals rangedfrom 2.5 to 3.5 percent. The second study analyzed coal and fly ash from an Indiana power plant, which uses subbituminous coal from the Powder River Basin (fig. 1). Sulfur content of this feed coal ranged from 0.23 to 0.47 percent. A summary of important aspects of our approach and results are presented in this report. 

Impact of socioeconomic status on municipal solid waste generation rate.

PubMed

Khan, D; Kumar, A; Samadder, S R

2016-03-01

The solid waste generation rate was expected to vary in different socioeconomic groups due to many environmental and social factors. This paper reports the assessment of solid waste generation based on different socioeconomic parameters like education, occupation, income of the family, number of family members etc. A questionnaire survey was conducted in the study area to identify the different socioeconomic groups that may affect the solid waste generation rate and composition. The average waste generated in the municipality is 0.41 kg/capita/day in which the maximum waste was found to be generated by lower middle socioeconomic group (LMSEG) with average waste generation of 0.46 kg/capita/day. Waste characterization indicated that there was no much difference in the composition of wastes among different socioeconomic groups except ash residue and plastic. Ash residue is found to increase as we move lower down the socioeconomic groups with maximum (31%) in lower socioeconomic group (LSEG). The study area is a coal based city hence application of coal and wood as fuel for cooking in the lower socioeconomic group is the reason for high amount of ash content. Plastic waste is maximum (15%) in higher socioeconomic group (HSEG) and minimum (1%) in LSEG. Food waste is a major component of generated waste in almost every socioeconomic group with maximum (38%) in case of HSEG and minimum (28%) in LSEG. This study provides new insights on the role of various socioeconomic parameters on generation of household wastes. Copyright © 2016 Elsevier Ltd. All rights reserved.

The enormous Chillos Valley Lahar: An ash-flow-generated debris flow from Cotopaxi Volcano, Ecuador

USGS Publications Warehouse

Mothes, P.A.; Hall, M.L.; Janda, R.J.

1998-01-01

The Chillos Valley Lahar (CVL), the largest Holocene debris flow in area and volume as yet recognized in the northern Andes, formed on Cotopaxi volcano's north and northeast slopes and descended river systems that took it 326 km north-northwest to the Pacific Ocean and 130+ km east into the Amazon basin. In the Chillos Valley, 40 km downstream from the volcano, depths of 80-160 m and valley cross sections up to 337000m2 are observed, implying peak flow discharges of 2.6-6.0 million m3/s. The overall volume of the CVL is estimated to be ???3.8 km3. The CVL was generated approximately 4500 years BP by a rhyolitic ash flow that followed a small sector collapse on the north and northeast sides of Cotopaxi, which melted part of the volcano's icecap and transformed rapidly into the debris flow. The ash flow and resulting CVL have identical components, except for foreign fragments picked up along the flow path. Juvenile materials, including vitric ash, crystals, and pumice, comprise 80-90% of the lahar's deposit, whereas rhyolitic, dacitic, and andesitic lithics make up the remainder. The sand-size fraction and the 2- to 10-mm fraction together dominate the deposit, constituting ???63 and ???15 wt.% of the matrix, respectively, whereas the silt-size fraction averages less than ???10 wt.% and the clay-size fraction less than 0.5 wt.%. Along the 326-km runout, these particle-size fractions vary little, as does the sorting coefficient (average = 2.6). There is no tendency toward grading or improved sorting. Limited bulking is recognized. The CVL was an enormous non-cohesive debris flow, notable for its ash-flow origin and immense volume and peak discharge which gave it characteristics and a behavior akin to large cohesive mudflows. Significantly, then, ash-flow-generated debris flows can also achieve large volumes and cover great areas; thus, they can conceivably affect large populated regions far from their source. Especially dangerous, therefore, are snowclad volcanoes with recent silicic ash-flow histories such as those found in the Andes and Alaska.

Thermal treatment of toxic metals of industrial hazardous wastes with fly ash and clay.

PubMed

Singh, I B; Chaturvedi, K; Morchhale, R K; Yegneswaran, A H

2007-03-06

Waste generated from galvanizing and metal finishing processes is considered to be a hazardous due to the presence of toxic metals like Pb, Cu, Cr, Zn, etc. Thermal treatment of such types of wastes in the presence of clay and fly ash can immobilizes their toxic metals to a maximum level. After treatment solidified mass can be utilized in construction or disposed off through land fillings without susceptibility of re-mobilization of toxic metals. In the present investigation locally available clay and fly ash of particular thermal power plant were used as additives for thermal treatment of both of the wastes in their different proportions at 850, 900 and 950 degrees C. Observed results indicated that heating temperature to be a key factor in the immobilization of toxic metals of the waste. It was noticed that the leachability of metals of the waste reduces to a negligible level after heating at 950 degrees C. Thermally treated solidified specimen of 10% waste and remaining clay have shown comparatively a higher compressive strength than clay fired bricks used in building construction. Though, thermally heated specimens made of galvanizing waste have shown much better strength than specimen made of metal finishing waste. The lechability of toxic metals like Cr, Cu, Pb and Zn became far below from their regulatory threshold after heating at 950 degrees C. Addition of fly ash did not show any improvement either in engineering property or in leachability of metals from the solidified mass. X-ray diffraction (XRD) analysis of the solidified product confirmed the presence of mixed phases of oxides of metals.

Relative abundance and distribution of fishes and crayfish at Ash Meadows National Wildlife Refuge, Nye County, Nevada, 2010-11

USGS Publications Warehouse

Scoppettone, G.G.; Johnson, D.M.; Hereford, M.E.; Rissler, Peter; Fabes, Mark; Salgado, Antonio; Shea, Sean

2012-01-01

Habitat restoration that favors native species can help control non-native species (McShane and others, 2004; Scoppettone and others, 2005; Kennedy and others, 2006). Restoration of Carson Slough and its tributaries present an opportunity to promote habitat types that favor native species over non-natives. Historically, the majority of Ash Meadows spring systems were tributaries to Carson Slough. In 2007 and 2008, a survey of Ash Meadows spring systems was conducted to generate baseline information on the distribution of fishes throughout AMNWR (Scoppettone and others, 2011b). In this study, we conducted a follow-up survey with emphasis on upper Carson Slough. This permitted us to gauge the early effects of spring system restoration on fish populations and to generate further baseline data relevant to future restoration efforts. 

Volcanic and atmospheric controls on ash iron solubility: A review

NASA Astrophysics Data System (ADS)

Ayris, Paul; Delmelle, Pierre

2012-01-01

The ash material produced by volcanic eruptions carries important information about the underground magma eruptive conditions and subsequent modifications in the volcanic plume and during atmospheric transport. Volcanic ash is also studied because of its impacts on the environment and human health. In particular, there is a growing interest from a multidisciplinary scientific community to understand the role that ash deposition over open ocean regions may play as a source of bioavailable Fe for phytoplankton production. Similar to aeolian mineral dust, the processes that affect the mineralogy and speciation of Fe in ash may promote solubilisation of Fe in ash, and thus may increase the amount of volcanic Fe supplied to ocean surface waters. Our knowledge of these controls is still very limited, a situation which has hindered quantitative interpretation of experimental Fe release measurements. In this review, we identify the key volcanic and atmospheric controls that are likely to modulate ash Fe solubility. We also briefly discuss existing data on Fe release from ash and make some recommendations for future studies in this area.

Glass-ceramic from mixtures of bottom ash and fly ash.

PubMed

Vu, Dinh Hieu; Wang, Kuen-Sheng; Chen, Jung-Hsing; Nam, Bui Xuan; Bac, Bui Hoang

2012-12-01

Along with the gradually increasing yield of the residues, appropriate management and treatment of the residues have become an urgent environmental protection problem. This work investigated the preparation of a glass-ceramic from a mixture of bottom ash and fly ash by petrurgic method. The nucleation and crystallization kinetics of the new glass-ceramic can be obtained by melting the mixture of 80% bottom ash and 20% fly ash at 950 °C, which was then cooled in the furnace for 1h. Major minerals forming in the glass-ceramics mainly are gehlenite (Ca(2)Al(2)SiO(7)) & akermanite (Ca(2)MgSiO(7)) and wollastonite (CaSiO(3)). In addition, regarding chemical/mechanical properties, the chemical resistance showing durability, and the leaching concentration of heavy metals confirmed the possibility of engineering and construction applications of the most superior glass-ceramic product. Finally, petrurgic method of a mixture of bottom ash and fly ash at 950 °C represents a simple, inexpensive, and energy saving method compared with the conventional heat treatment. Copyright © 2012 Elsevier Ltd. All rights reserved.

Mercury release from fly ashes and hydrated fly ash cement pastes

NASA Astrophysics Data System (ADS)

Du, Wen; Zhang, Chao-yang; Kong, Xiang-ming; Zhuo, Yu-qun; Zhu, Zhen-wu

2018-04-01

The large-scale usage of fly ash in cement and concrete introduces mercury (Hg) into concrete structures and a risk of secondary emission of Hg from the structures during long-term service was evaluated. Three fly ashes were collected from coal-fired power plants and three blend cements were prepared by mixing Ordinary Portland cement (OPC) with the same amount of fly ash. The releasing behaviors of Hg0 from the fly ash and the powdered hydrated cement pastes (HCP) were measured by a self-developed Hg measurement system, where an air-blowing part and Hg collection part were involved. The Hg release of fly ashes at room temperature varied from 25.84 to 39.69 ng/g fly ash during 90-days period of air-blowing experiment. In contrast, the Hg release of the HCPs were in a range of 8.51-18.48 ng/g HCP. It is found that the Hg release ratios of HCPs were almost the same as those of the pure fly ashes, suggesting that the hydration products of the HCP have little immobilization effect on Hg0. Increasing temperature and moisture content markedly promote the Hg release.

[Skin diseases and sensitization to metals in construction workers engaged in the production of pre-cast cellular concrete slabs].

PubMed

Kieć-Swierczyńska, M; Woźniak, H; Wojtczak, J

1989-01-01

The study involved 461 building workers exposed to ashes, cement and ash-cement mixtures in direct production and at auxiliary posts (fitters, welders, mechanics, electricians etc.). In addition, all those workers were exposed to lubricants ans machine oils, as well as anti-adhesive oils used to lubricate moulds. All the subjects underwent patch tests. Dermatitis was found in 18.9%, whereas oil acne in 7.4% of subjects, 23.0% exhibited chromium allergy, 15.2% - cobalt allergy and 5.0% - nickel allergy. Two workers were ++hypersensitive to zinc. No differences were found in the rates of dermatitis, oil acne and metal allergy between production workers and auxiliary ones. Airborne dust concentrations at those workplaces were similar. Cement and ashes contained compounds of chromium, cobalt and nickel.

Review of coal bottom ash and coconut shell in the production of concrete

NASA Astrophysics Data System (ADS)

Faisal, S. K.; Mazenan, P. N.; Shahidan, S.; Irwan, J. M.

2018-04-01

Concrete is the main construction material in the worldwide construction industry. High demand of sand in the concrete production have been increased which become the problems in industry. Natural sand is the most common material used in the construction industry as natural fine aggregate and it caused the availability of good quality of natural sand keep decreasing. The need for a sustainable and green construction building material is required in the construction industry. Hence, this paper presents utilization of coal bottom ash and coconut shell as partial sand replacement in production of concrete. It is able to save cost and energy other than protecting the environment. In summary, 30% usage of coal bottom ash and 25% replacement of coconut shell as aggregate replacement show the acceptable and satisfactory strength of concrete.

Volcanic ash as an oceanic iron source and sink

NASA Astrophysics Data System (ADS)

Rogan, Nicholas; Achterberg, Eric P.; Le Moigne, Frédéric A. C.; Marsay, Chris M.; Tagliabue, Alessandro; Williams, Richard G.

2016-03-01

Volcanic ash deposition to the ocean forms a natural source of iron (Fe) to surface water microbial communities. Inputs of lithogenic material may also facilitate Fe removal through scavenging. Combining dissolved Fe (dFe) and thorium-234 observations alongside modeling, we investigate scavenging of Fe in the North Atlantic following the Eyjafjallajökull volcanic eruption. Under typical conditions biogenic particles dominate scavenging, whereas ash particles dominate during the eruption. The size of particles is important as smaller scavenging particles can become saturated with surface-associated ions. Model simulations indicate that ash deposition associated with Eyjafjallajökull likely led to net Fe removal. Our model suggests a threefold greater stimulation of biological activity if ash deposition had occurred later in the growing season when the region was Fe limited. The implications of ash particle scavenging, eruption timing, and particle saturation need to be considered when assessing the impact of ash deposition on the ocean Fe cycle and productivity.

Volcanic ash in the water column: Physiological impact on the suspension-feeding bivalve Mytilus chilensis.

PubMed

Salas-Yanquin, L P; Navarro, J M; Pechenik, J A; Montory, J A; Chaparro, O R

2018-02-01

Ashes settling into the sea from volcanic explosions expose suspension-feeding species to reduced seston quality. Adults and juveniles of the mussel Mytilus chilensis were exposed for 15days to the phytoplankton Isochrysis galbana together with various concentrations of ashes. We then quantified impact on survival and physiology. Although no individuals died during the experiment, by the end of the study clearance rates and oxygen consumption rates had decreased substantially, and tissue weight of mussels exposed to the highest ash concentrations declined substantially. Gills showed no physical damage, but did show abundant mucus secretion in response to ash particles. Moreover, as the relative proportions of microalgae to ash in the diet decreased, individuals showed increasing preferential ingestion of microalgal particles. Increased ash content in the diet altered physiological rates and activated distinct particle selection with a high production of pseudofeces and high energy costs, with potential long-term consequences. Copyright © 2017 Elsevier Ltd. All rights reserved.

Optical emission spectroscopy of point-plane corona and back-corona discharges in air

NASA Astrophysics Data System (ADS)

Czech, T.; Sobczyk, A. T.; Jaworek, A.

2011-12-01

Results of spectroscopic investigations and current-voltage characteristics of corona discharge and back discharge on fly-ash layer, generated in point-plane electrode geometry in air at atmospheric pressure are presented in the paper. The characteristics of both discharges are similar but differ in the current and voltage ranges of all the discharge forms distinguished during the experiments. Three forms of back discharge, for positive and negative polarity, were investigated: glow, streamer and low-current back-arc. In order to characterize ionisation and excitation processes in back discharge, the emission spectra were measured and compared with those obtained for normal corona discharge generated in the same electrode configuration but with fly ash layer removed. The emission spectra were measured in two discharge zones: near the tip of needle electrode and near the plate. Visual forms of the discharge were recorded with digital camera and referred to current-voltage characteristics and emission spectra. The measurements have shown that spectral lines emitted by back discharge depend on the form of discharge and the discharge current. From the comparison of the spectral lines of back and normal discharges an effect of fly ash layer on the discharge morphology can be determined. The recorded emission spectra formed by ionised gas and plasma near the needle electrode and fly ash layer are different. It should be noted that in back arc emission, spectral lines of fly ash layer components can be distinguished. On the other hand, in needle zone, the emission of high intensity N2 second positive system and NO γ lines can be noticed. Regardless of these gaseous lines, also atomic lines of dust layer were present in the spectrum. The differences in spectra of back discharge for positive and negative polarities of the needle electrode have been explained by considering the kind of ions generated in the crater in fly ash layer. The aim of these studies is to better understand the discharge processes encountered in electrostatic precipitators.

Continuous air agglomeration method for high carbon fly ash beneficiation

DOEpatents

Gray, McMahon L.; Champagne, Kenneth J.; Finseth, Dennis H.

2000-01-01

The carbon and mineral components of fly ash are effectively separated by a continuous air agglomeration method, resulting in a substantially carboree mineral stream and a highly concentrated carbon product. The method involves mixing the fly ash comprised of carbon and inorganic mineral matter with a liquid hydrocarbon to form a slurry, contacting the slurry with an aqueous solution, dispersing the hydrocarbon slurry into small droplets within the aqueous solution by mechanical mixing and/or aeration, concentrating the inorganic mineral matter in the aqueous solution, agglomerating the carbon and hydrocarbon in the form of droplets, collecting the droplets, separating the hydrocarbon from the concentrated carbon product, and recycling the hydrocarbon.

Mechanical Properties and Microstructure of Class C Fly Ash-Based Geopolymer Paste and Mortar.

PubMed

Li, Xueying; Ma, Xinwei; Zhang, Shoujie; Zheng, Enzu

2013-04-09

This paper presents workability, compressive strength and microstructure for geopolymer pastes and mortars made of class C fly ash at mass ratios of water-to-fly ash from 0.30 to 0.35. Fluidity was in the range of 145-173 mm for pastes and 131-136 mm for mortars. The highest strengths of paste and mortar were 58 MPa and 85 MPa when they were cured at 70 °C for 24 h. In XRD patterns, unreacted quartz and some reacted product were observed. SEM examination indicated that reacted product has formed and covered the unreacted particles in the paste and mortar that were consistent with their high strength.

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.

Experimental studies on effect of cow dung ash (pozzolanic binder) and coconut fiber on strengthproperties of concrete

NASA Astrophysics Data System (ADS)

Venkatasubramanian, C.; Muthu, D.; Aswini, G.; Nandhini, G.; Muhilini, K.

2017-07-01

The studies on durability of concrete have attracted attention in the recent years and its long term strength depends on quality of ingredients used in production of concrete. Now a days, the availability of ingredients is limited and in order to overcome this problem, research studies focuses on some alternate materials in the concrete production process. Also, Incorporation of waste materials consumes less energy leading to reduction of emission of green house gases. The application of fly ash and cow dung ash as a pozzolanic binder instead of cement and coir fibers finds extensive application in the manufacturing process of building materials. In this project an attempt has been made to utilize cow dung ash and coconut fiber as a replacement material of cement in the production of concrete. The cement is partially replaced with cow dung ash by about 2.5, 3 & 3.5 % by weight and with 1% of coconut fiber. The Compressive and Tensile strengths of concrete were found at different curing periods (7,14 & 28 days). From this study, it is inferred that these replacements will have a reasonable improvement in the strength properties of concrete by about 55-70%. The substitution of CDA, CF is economical in terms of cost and this usage eliminates the problem of landfills, reducing the environmental risk, maintaining the ecological balance, which is very much required for our nation.

Properties of palm oil fuel ash cement sand brick containing pulverized cockle shell as partial sand replacement

NASA Astrophysics Data System (ADS)

Mat Aris, S.; Muthusamy, K.; Uzer, A.; Ahmad, S. Wan

2018-04-01

Environmental pollution caused by the disposal of solid wastes generated from both palm oil industry and cockle shell trade has motivated researches to explore the potential of these wastes. Integrating these wastes in production of construction material is one of the ways to reduce amount of waste thrown at dumping area. Thus, the present investigation investigates the performance of palm oil fuel ash (POFA) cement sand brick containing pulverized cockle shell as partial fine aggregate replacement. All mixes used contain 20% of POFA as partial cement replacement. Total of six mixes were prepared by adding a range of pulverized cockle shell that is 0%, 10%, 20%, 30%, 40% and 50% as partial sand replacement. The mixes were prepared in form of brick. All the water cured samples were tested for compressive strength and flexural strength until 28 days. Findings show that brick produced using 20% pulverized cockle shell exhibit the highest compressive strength and flexural strength also the lowest water absorption value.

Life cycle assessment of sewage sludge co-incineration in a coal-based power station.

PubMed

Hong, Jingmin; Xu, Changqing; Hong, Jinglan; Tan, Xianfeng; Chen, Wei

2013-09-01

A life cycle assessment was conducted to evaluate the environmental and economic effects of sewage sludge co-incineration in a coal-fired power plant. The general approach employed by a coal-fired power plant was also assessed as control. Sewage sludge co-incineration technology causes greater environmental burden than does coal-based energy production technology because of the additional electricity consumption and wastewater treatment required for the pretreatment of sewage sludge, direct emissions from sludge incineration, and incinerated ash disposal processes. However, sewage sludge co-incineration presents higher economic benefits because of electricity subsidies and the income generating potential of sludge. Environmental assessment results indicate that sewage sludge co-incineration is unsuitable for mitigating the increasing pressure brought on by sewage sludge pollution. Reducing the overall environmental effect of sludge co-incineration power stations necessitates increasing net coal consumption efficiency, incinerated ash reuse rate, dedust system efficiency, and sludge water content rate. Copyright © 2013 Elsevier Ltd. All rights reserved.

A commitment to coal

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

Shea, Q.

2006-07-15

Quin Shea explores the need for power generated with coal and the advanced technologies that will generate that power more efficiently and cleanly in the future. The article considers the air and waste challenges of using coal, including progress toward reducing emissions of SO{sub 2}, NOx, and mercury; efforts to address CO{sub 2}, including voluntary programs like the Climate Challenge, Power Partners, and the Asia-Pacific Partnership on Clean Development and Climate; and the regulation and beneficial use of coal-combustion byproducts (e.g., fly ash, bottom ash, flue gas desulfurization materials, boiler slag). 17 refs.

The relation between pre-eruptive bubble size distribution, ash particle morphology, and their internal density: Implications to volcanic ash transport and dispersion models

NASA Astrophysics Data System (ADS)

Proussevitch, Alexander

2014-05-01

Parameterization of volcanic ash transport and dispersion (VATD) models strongly depends on particle morphology and their internal properties. Shape of ash particles affects terminal fall velocities (TFV) and, mostly, dispersion. Internal density combined with particle size has a very strong impact on TFV and ultimately on the rate of ash cloud thinning and particle sedimentation on the ground. Unlike other parameters, internal particle density cannot be measured directly because of the micron scale sizes of fine ash particles, but we demonstrate that it varies greatly depending on the particle size. Small simple type ash particles (fragments of bubble walls, 5-20 micron size) do not contain whole large magmatic bubbles inside and their internal density is almost the same as that of volcanic glass matrix. On the other side, the larger compound type ash particles (>40 microns for silicic fine ashes) always contain some bubbles or the whole spectra of bubble size distribution (BSD), i.e. bubbles of all sizes, bringing their internal density down as compared to simple ash. So, density of the larger ash particles is a function of the void fraction inside them (magmatic bubbles) which, in turn, is controlled by BSD. Volcanic ash is a product of the fragmentation of magmatic foam formed by pre-eruptive bubble population and characterized by BSD. The latter can now be measured from bubble imprints on ash particle surfaces using stereo-scanning electron microscopy (SSEM) and BubbleMaker software developed at UNH, or using traditional high-resolution X-Ray tomography. In this work we present the mathematical and statistical formulation for this problem connecting internal ash density with particle size and BSD, and demonstrate how the TFV of the ash population is affected by variation of particle density.

The leaching characteristics of selenium from coal fly ashes

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

Wang, T.; Wang, J.; Burken, J.G.

2007-11-15

The leaching characteristics of selenium from several bituminous and subbituminous coal fly ashes under different pH conditions were investigated using batch methods. Results indicated that pH had a significant effect on selenium leaching from bituminous coal ash. The minimum selenium leaching occurred in the pH range between 3 and 4, while the maximum selenium leaching occurred at pH 12. The release of selenium from subbituminous coal ashes was very low for the entire experimental pH range, possibly due to the high content of calcium which can form hydration or precipitation products as a sink for selenium. The adsorption results formore » different selenium species indicated that Se(VI) was hardly adsorbable on either bituminous coal ashes or subbitumminous coal ashes at any pH. However, Se(I) was highly adsorbed by bituminous coal ashes under acidic pH conditions and was mostly removed by subbitumminous coal ashes across the entire pH range. This result suggests that the majority of selenium released from the tested fly ashes was Se(IV). A speciation-based model was developed to simulate the adsorption of Se(IV) on bituminous coal fly ash, and the pH-independent adsorption constants of HSeO{sup 3-} and SeO{sub 3}{sup 2-} were determined. The modeling approach is useful for understanding and predicting the release process of selenium from fly ash.« less

Seed production and advance regeneration in Allegheny hardwood forests

Treesearch

John C. Bjorkbom

1979-01-01

The production of flowers and seeds of black cherry, red maple, sugar maple, and white ash and their relation to advance regeneration were observed from 1971 through 1976 on the Allegheny Plateau of northwestern Pennsylvania. There were good seed crops 1 year out of 2 for black cherry, 1 year out of 3 for red maple, and 1 year out of 6 for sugar maple. No white ash...

DSCOVR_EPIC_L2_SO2_01

Atmospheric Science Data Center

2018-06-18

... UV and infrared sensors, offering ample opportunities for data intercomparisons and for demonstrating advanced retrievals of volcanic ash ... developed for TOMS and OMI to enable SO2 and Ash Index (AI) products from EPIC UV observations to demonstrate improved estimates of ...

Geochemically structural characteristics of municipal solid waste incineration fly ash particles and mineralogical surface conversions by chelate treatment.

PubMed

Kitamura, Hiroki; Sawada, Takaya; Shimaoka, Takayuki; Takahashi, Fumitake

2016-01-01

Leaching behaviors of heavy metals contained in municipal solid waste incineration (MSWI) fly ash have been studied well. However, micro-characteristics of MSWI fly ash particles are still uncertain and might be non-negligible to describe their leaching behaviors. Therefore, this study investigated micro-characteristics of MSWI fly ash particles, especially their structural properties and impacts of chelate treatment on surface characteristics. According to SEM observations, raw fly ash particles could be categorized into four types based on their shapes. Because chelate treatment changed the surface of fly ash particles dramatically owing to secondary mineral formations like ettringite, two more types could be categorized for chelate-treated fly ash particles. Acid extraction experiments suggest that fly ash particles, tested in this study, consist of Si-base insoluble core structure, Al/Ca/Si-base semi-soluble matrices inside the body, and KCl/NaCl-base soluble aggregates on the surface. Scanning electron microscope (SEM) observations of the same fly ash particles during twice moistening treatments showed that KCl/NaCl moved under wet condition and concentrated at different places on the particle surface. However, element mobility depended on secondary mineral formations. When insoluble mineral like gypsum was generated and covered the particle surface, it inhibited element transfer under wet condition. Surface characteristics including secondary mineral formation of MSWI fly ash particles are likely non-negligible to describe trace element leaching behaviors.

Volatile Arsenic Species Released from Escherichia coli Expressing the AsIII S-adenosylmethionine Methyltransferase Gene

PubMed Central

YUAN, CHUNGANG; LU, XIUFEN; QIN, JIE; ROSEN, BARRY P.; LE, X. CHRIS

2015-01-01

Biological systems, ranging from bacteria and fungi to humans, can methylate arsenic. Recent studies have suggested that the AsIII S-adenosylmethionine methyltransferase (arsM) gene in bacteria was responsible for the removal of arsenic as the volatile arsines from the bacteria. However, there has been no direct measure of the arsines released from bacteria cultures. We describe here an integrated system incorporating the bacterial incubation and volatile arsenic species analysis, and we demonstrate its application to the identification of the volatile arsines produced in bacterial cultures. The headspace of the bacterial cultures was purged with helium, and the volatile arsenic species were trapped in a chromatographic column immersed in liquid nitrogen. The cryogenically trapped arsines [AsH3, (CH3)AsH2, (CH3)2AsH, and (CH3)3As] were separated by gas chromatography and were detected by inductively coupled plasma mass spectrometry. A hydride generation system was coupled to the bacterial culture system, allowing for spiking standards and for generating calibration arsines necessary for quantitative analysis. Both bacteria containing the arsM gene or its variant arsMC2 gene were able to produce 400–500 ng of trimethylarsine. No trimethylarsine was detectable in bacteria lacking the arsM gene (containing the vector plasmid as negative control). These results confirm that arsM is responsible for releasing arsenic as volatile species from the arsenic-resistant bacteria. Our results also show traces of AsH3, CH3AsH2, and (CH3)2AsH in cultures of bacteria expressing arsM. The method detection limits for AsH3, CH3AsH2, (CH3)2AsH, and (CH3)3As were 0.5, 0.5, 0.7, and 0.6 pg, respectively. The ability to quantify trace levels of these volatile arsenic species makes it possible to study the biotransformation and biochemical roles of the evolution of these volatile arsenic species by biological systems. PMID:18522094

The measurement of unburned carbon in fly ash using infrared photoacoustics

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

Waller, D.J.; Brown, R.C.

1995-12-31

Unburned carbon in fly ash yields valuable information on coal combustion efficiency in coal-fired boilers. The carbon content of fly ash is also an important parameters in the sale of fly ash for Portland cement. Unfortunately, a reliable and inexpensive instrument for measuring unburned carbon is not commercially available. The authors have developed an off-line instrument that detects carbon in fly ash via the photoacoustic effect. In this process, amplitude-modulated radiation is absorbed by a bulk sample of fly ash. The wavelength of the radiation is chosen such that mineral compounds and moisture in the fly ash are transparent tomore » the radiation but carbon is strongly absorbing. The modulated absorption generates a periodic pressure wave at the surface of the sample which propagates through the surrounding air as an acoustic wave. This wave is detected by a sensitive microphone, and is dependent on the carbon content of the sample. The resulting instrument has been used to measure fly ash carbon concentrations from less than 0.1% to nearly 7% by mass. The precision of these measurements is nominally within 4%, which is equivalent to the precision of the chemical analysis used to develop the calibration standards. The applicability of a theoretical model to the empirical results is discussed with respect to fly ash sample preparation.« less

Theoretical analysis of tsunami generation by pyroclastic flows

USGS Publications Warehouse

Watts, P.; Waythomas, C.F.

2003-01-01

Pyroclastic flows are a common product of explosive volcanism and have the potential to initiate tsunamis whenever thick, dense flows encounter bodies of water. We evaluate the process of tsunami generation by pyroclastic flow by decomposing the pyroclastic flow into two components, the dense underflow portion, which we term the pyroclastic debris flow, and the plume, which includes the surge and coignimbrite ash cloud parts of the flow. We consider five possible wave generation mechanisms. These mechanisms consist of steam explosion, pyroclastic debris flow, plume pressure, plume shear, and pressure impulse wave generation. Our theoretical analysis of tsunami generation by these mechanisms provides an estimate of tsunami features such as a characteristic wave amplitude and wavelength. We find that in most situations, tsunami generation is dominated by the pyroclastic debris flow component of a pyroclastic flow. This work presents information sufficient to construct tsunami sources for an arbitrary pyroclastic flow interacting with most bodies of water. Copyright 2003 by the American Geophysical Union.

Today's challange in MSW incineration

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

Vaux, W.G.

A decade ago, incinerator ash was of little concern. There wasn't much of it, and it was treated like soil of fill and therefore disposed of without much concern. Today, however, the situation is far different. Waste-to-energy plants reduce the amount of trash they process by 90%, but they require environmentally sound landfills to dispose of residue. This paper examines the management of incinerator ash. At its best, incinerator ash is well burned out; at worst, it is more pyrolized and contains unburned carbon. This latter case is likely following receipt of rain-saturated waste at the incinerator. Ash contains aboutmore » 15 to 20 weight of unburnables; for example metal cans, ceramics, other metals and so on. According to the author, recent work on presence of combustion products in the ash does not show appreciable levels of dioxins leaching form ash.« less

Deashing macroalgae biomass by pulsed electric field treatment.

PubMed

Robin, Arthur; Sack, Martin; Israel, Alvaro; Frey, Wolfgang; Müller, Georg; Golberg, Alexander

2018-05-01

Among all biomass constituents, the ashes are major hurdles for biomass processing. Ashes currently have low market value and can make a non-negligible fraction of the biomass dry weight significantly impacting its further processing by degrading equipment, lowering process yield, inhibiting reactions and decreasing products qualities. However, most of the current treatments for deashing biomass are of poor efficiency or industrial relevance. This work is the first report on the use of Pulsed Electric Field (PEF) to enhance deashing of biomass from a high ash content green marine macroalga, Ulva sp., using hydraulic pressing. By inducing cell permeabilization of the fresh biomass, PEF was able to enhance the ash extraction from 18.4% (non-treated control) to 37.4% of the total ash content in average, significantly enhancing the extraction of five of the major ash elements (K, Mg, Na, P and S) compared to pressing alone. Copyright © 2018 Elsevier Ltd. All rights reserved.

Prevention of trace and major element leaching from coal combustion products by hydrothermally-treated coal ash

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

Adnadjevic, B.; Popovic, A.; Mikasinovic, B.

2009-07-01

The most important structural components of coal ash obtained by coal combustion in 'Nikola Tesla A' power plant located near Belgrade (Serbia) are amorphous alumosilicate, alpha-quartz, and mullite. The phase composition of coal ash can be altered to obtain zeolite type NaA that crystallizes in a narrow crystallization field (SiO{sub 2}/Al{sub 2}O{sub 3}; Na{sub 2}O/SiO{sub 2}; H{sub 2}O/Na{sub 2}O ratios). Basic properties (crystallization degree, chemical composition, the energy of activation) of obtained zeolites were established. Coal ash extracts treated with obtained ion-exchange material showed that zeolites obtained from coal ash were able to reduce the amounts of iron, chromium, nickel,more » zinc, copper, lead, and manganese in ash extracts, thus proving its potential in preventing pollution from dump effluent waters.« less

Characterization, partitioning, and potential ecological risk quantification of trace elements in coal fly ash.

PubMed

Usmani, Zeba; Kumar, Vipin

2017-06-01

Coal-based thermal power plants are the major source of power generation in India. Combustion of coal gives rise to by-products such as fly ash (FA) in huge quantities. The current study focuses on physico-chemical and mineralogical characterization and risk evaluation of FA, generated from five thermal power plants (TPPs) of India. The coal, and corresponding FA and bottom ash (BA) were further analyzed for trace elements in order to observe the enrichment and partitioning behavior of elements. The environmental risk assessment of trace elements in FA was performed in accordance with geoaccumulation index (I geo ) and potential ecological risk index (PERI). The results demonstrated that FA was enriched predominantly in SiO 2 , Al 2 O 3 , and Fe 2 O 3 along with small concentrations of CaO and MgO. The mineral phases identified in FA were quartz, mullite, hematite, and magnetite. Elemental characterization indicated that the metals were more enriched in FA as compared to coal and BA. The concentrations of trace elements, Cr, Pb, Hg, and As in FA (TPPs), varied from 12.59-24.28, 22.68-43.19, <0.0001-2.29, and 0.08-3.39 mg/kg, respectively. Maximum enrichment ratio (ER) was observed for Pb (5.21) in TPP3 FA. Hg in TPP1 showed the highest partition ratio (PR) value. I geo values for metals were mostly below zero. The PERI values indicated moderate risk from TPP4 FA and low risk from TPP1, TPP2, TPP3, and TPP5 FA to the environment, according to the threshold values provided.

Co-composting of biowaste and wood ash, influence on a microbially driven-process.

PubMed

Fernández-Delgado Juárez, Marina; Prähauser, Barbara; Walter, Andreas; Insam, Heribert; Franke-Whittle, Ingrid H

2015-12-01

A trial at semi-industrial scale was conducted to evaluate the effect of wood ash amendment on communal biowaste in a composting process and on the final composts produced. For this purpose, three treatments including an unamended control (C0) and composts with additions of 6% (C6), and 12% (C12) of wood ash (w/w) were studied, and physico-chemical parameters as well as microbial activity and community composition were investigated. At the end of the process, composts were tested for toxicity and quality, and microbial physiological activity. The influence of ash addition on compost temperature, pH, microbial activity and composition was stronger during the early composting stages and diminished with time, whereby composts became more similar. Using the COMPOCHIP microarray, a reduction in the pathogenic genera Listeria and Clostridium was observed, which together with the temperature increases of the composting process helped in the hygienisation of composts. Lactobacillus species were also affected, such that reduced hybridisation signals were observed with increased ash addition, due to the increased pH values in amended composts. Organic matter mineralisation was also increased through ash addition, and no negative effects on the composting process were observed. The nutrient content of the final products was increased through the addition of ash, and no toxic effects were observed. Nonetheless, greater concentrations of heavy metals were found in composts amended with more ash, which resulted in a downgrading of the compost quality according to the Austrian Compost Ordinance. Thus, regulation of both input materials and end-product quality is essential in optimising composting processes. Copyright © 2015 Elsevier Ltd. All rights reserved.

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.

Search for possible relationship between volcanic ash particles and thunderstorm lightning activity

NASA Astrophysics Data System (ADS)

Várai, A.; Vincze, M.; Lichtenberger, J.; Jánosi, I. M.

2011-12-01

Explosive volcanic eruptions that eject columns of ash from the crater often generate lightning discharges strong enough to be remotely located by very low frequency radio waves. A fraction of volcanic ash particles can stay and disperse long enough to have an effect on weather phenomena days later such as thunderstorms and lightnings. In this work we report on lightning activity analysis over Europe following two recent series of volcanic eruptions in order to identify possible correlations between ash release and subsequent thunderstorm flash frequency. Our attempts gave negative results which can be related to the fact that we have limited information on local atmospheric variables of high enough resolution, however lightning frequency is apparently determined by very local circumstances.

Study of the activity of the local adding [ash from palm plantation wastes

NASA Astrophysics Data System (ADS)

Rezig, D.; Bentabba, M. T.

2018-05-01

The objectify of this work is to study the activity of the ash by substitution of 25℅ cement of mineral powder ash from palm plantation wastes, and its influences mechanical performances on mortar. Such as the resistance of the compression, the traction, and durability by reducing calcium hydroxide content Ca[OH]2 generated by chemical reaction of cement, which has a harmful effect in durability. The activity of this waste was evaluated in the utilized of mechanic attempts resistance of the compression and flexion in 28 day] was also studied, the obtained results shows the best result of the index of ash activity is i=0,69 was obtained in mixing cement with CRS.

A model for tropical-extratropical transport of volcanic ash in the lower stratosphere

NASA Technical Reports Server (NTRS)

Rietmeijer, Frans J. M.

1993-01-01

Large nonspherical volcanic ash particles up to 30 micrometer in size were collected between 17-19 km altitude over the Northern Hemisphere at high latitudes between October 1988 and April 1990. These particles may be derived from minor Plinian eruptions in the tropics rather than from localized volcanic activity close to the collection region. Ash particles were injected into the lower equatorial stratosphere where they entered a regime of efficient transport just above the tropopause from the tropical region towards the northern extratropical region. Transport is enhanced by stable autorotation that generates a sufficient lift force to loft nonspherical ash with a rough surface during transport, and by the gradually decreasing altitude of the tropopause from the tropics to the polar regions.

An LCA model for waste incineration enhanced with new technologies for metal recovery and application to the case of Switzerland

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

Boesch, Michael E.; Vadenbo, Carl, E-mail: vadenbo@ifu.baug.ethz.ch; Saner, Dominik

2014-02-15

Highlights: • An enhanced process-based LCA model for MSWI is featured and applied in case study. • LCA modeling of recent technological developments for metal recovery from fly ash. • Net release from Swiss MSWI 133 kg CO{sub 2}-eq/tonne waste from attributional LCA perspective. • Net savings from a consequential LCA perspective reach up to 303 kg CO{sub 2}-eq/tonne waste. • Impacts according to ReCiPe and CExD show similar pattern to climate change. - Abstract: A process model of municipal solid waste incinerators (MSWIs) and new technologies for metal recovery from combustion residues was developed. The environmental impact is modeledmore » as a function of waste composition as well as waste treatment and material recovery technologies. The model includes combustion with a grate incinerator, several flue gas treatment technologies, electricity and steam production from waste heat recovery, metal recovery from slag and fly ash, and landfilling of residues and can be tailored to specific plants and sites (software tools can be downloaded free of charge). Application of the model to Switzerland shows that the treatment of one tonne of municipal solid waste results on average in 425 kg CO{sub 2}-eq. generated in the incineration process, and 54 kg CO{sub 2}-eq. accrue in upstream processes such as waste transport and the production of operating materials. Downstream processes, i.e. residue disposal, generates 5 kg CO{sub 2}-eq. Savings from energy recovery are in the range of 67 to 752 kg CO{sub 2}-eq. depending on the assumptions regarding the substituted energy production, while the recovery of metals from slag and fly ash currently results in a net saving of approximately 35 kg CO{sub 2}-eq. A similar impact pattern is observed when assessing the MSWI model for aggregated environmental impacts (ReCiPe) and for non-renewable resource consumption (cumulative exergy demand), except that direct emissions have less and no relevance, respectively, on the total score. The study illustrates that MSWI plants can be an important element of industrial ecology as they provide waste disposal services and can help to close material and energetic cycles.« less

EVALUATION OF TOXICITY BY OIL FLY-ASHES IN RAT ALVEOLAR EPITHELIAL CELLS: ROLE OF FENTON DRIVEN OH-RADICAL GENERATION AND PARATICLE FRACTION

EPA Science Inventory

Leachable transition metals are considered to be important mediators in the biological effects of ambient particulate matter (PM) and model particles such as oil-fly ashes (OFA). We determined metal driven Fenton activity in 10 OFA in the presence of hydrogen peroxide using elect...

The energy-water quality nexus: insights from the 2008 coal ash spill in Tennessee

NASA Astrophysics Data System (ADS)

Vengosh, A.; Ruhl, L.; Dwyer, G. S.; Hsu-Kim, H.; Deonarine, A.

2010-12-01

Energy production consumes a large volume of water. The USGS estimated that about 52 percent of the total USA fresh surface-water withdrawal in 2000 was for thermoelectric consumption (fresh water use ~188 for thermoelectric out of 563 billion cubic meters a year total water withdrawal in the USA). While water availability and possible changes induced from climate change and increasing demands for other sectors are important limiting factors, this presentation highlights the critical long-term impact on water quality. The Clean Smokestacks Act was enacted to reduce emissions from coal-fired power plants through installation of scrubbers and selective catalytic reduction, aiming to cut emissions of sulfur dioxide, nitrogen oxides and mercury. In addition to the capture of these air pollutants, volatile elements are attached to the residual coal combustion products (CCPs). Consequently, toxic metals concentrations in CCPs are extremely high and become mobile upon interaction of CCPs with aquatic solutions. In particular, several studies have demonstrated the high mobilization of boron, arsenic, selenium, barium and other toxic oxi-anions and metals from CCPs. The 2008 coal ash spill in Kingston, Tennessee, where approximately 4.1 million cubic meters of coal ash was spilled onto the surrounding land surface and into the adjacent Emory and Clinch Rivers, has demonstrated the possible impact of CCPs on the environment. An eighteen-month survey has revealed elevated levels of contaminants in surface water with restricted water exchange and in pore water extracted from the bottom sediments, downstream from the spill. Our research has shown that arsenic concentration in the pore water reached to 2,000 ppb due to the reducing conditions and the high mobility of the non-charged arsenic species. Generation of CCPs however is not restricted to a single accidental release, as over five hundred power plants nationwide generate approximately 130 million tons of CCPs each year, in which more than half is stored in 194 landfills and 161 holding ponds. In each of these sites effluents that are generated from leaching of CCPs could contain high levels of contaminants that could pose severe ecological hazards to the local aquatic systems. Preliminary results from Hyco Lake in North Carolina have demonstrated high levels of toxic metals in effluents that are generated from adjacent coal-fired plant combined with high boron concentrations (1000 ppb) in the fresh lake water. The notion that CCPs generates a direct threat to the aquatic systems through holding ponds, landfills, or even “beneficial use” in sites where CCPs could be exposed and interact with the ambient environment should become an additional factor in evaluating the cost of “cheap coal” and its impact on the environment.

Use of Biomass Ash as a stabilization agent for expansive marly soils (SE Spain)

NASA Astrophysics Data System (ADS)

Ureña, C.; Azañón, J. M.; Caro, J. M.; Irigaray, C.; Corpas, F.; Ramirez, A.; Rivas, F.; Salazar, L. M.; Mochón, I.

2012-04-01

In recent years, several biomass power plants have been installed in Southeastern Spain to reuse olive oil industry residues. This energy production tries to reduce the high costs associated with fossil fuels, but without entering into direct competition to traditional food crops. The waste management in these biomass energy plants is still an issue since there are non-flammable materials which remains after incineration in the form of ashes. In Southeastern Spain there is also a great amount of clayey and marly soils whose volume is very sensitive to changes in climate conditions, making them unsuitable for civil engineering. We propose the use of biomass ash (both fly ash and bottom ash) as a stabilization agent for expansive soils in order to improve the efficiency of construction processes by using locally available materials. In this work biomass ashes from a biomass power plant in Southeastern Spain have been used to stabilize 6 samples of local marly soil. Those 6 samples of expansive soil were mixed with different dosages of biomass ash (2%, 4% and 7%) to create 18 specimens of treated soil, which were submitted to Proctor, Atterberg Limits, pH and Free Swell Index tests, following Spanish Standards UNE by AENOR. X-Ray Diffraction (XRD) tests by powder method were also carried out, using a diffractometer Philips X'Pert-MPD. The results obtained for the original untreated marly soil were: PI = 34.6; Free Swell = 12.5; pH = 8. By adding biomass ash the value of the plasticity index (PI) became slightly lower although it was not low enough as to obtain a non-plastic soil (PI under 25). However, there were dramatical decreases of free swell index (FSI) after the stabilization treatment: FSI < 8.18 (2% biomass); FSI < 6.15 (4% biomass); FSI < 4.18 (7% biomass); These results suggest that treated soil is quite less susceptible than the original soil to moisture changes. The pH of the mixes after adding biomass ash rose from 8 to 11±1 leading to an alkaline environment which, as reviewed literature points out, helps to the development of pozzolanic reactions and stabilization process. Finally, XRD tests indicated a sharp decrease in the intensity of reflection of the Smectite peak, suggesting a reduction in the amount of this expansive mineral in treated soils. This positive and durable effect may be related to cation exchange from Na+ to smaller cations or even the formation of mixed-layered clay minerals. A further research must be conducted to determine the pozzolanic properties of biomass ash (i.e., its suitability for concrete composites), the optimum dosages, etc. The further research is also necessary to better understand the mineralogy changes occurred within the crystalline structure. Nevertheless, these first results let us infer that biomass ash from power plants has a high capacity to enhance mechanical properties of expansive soils. Given the widespread use of biomass in industry today, the secondary use of biomass ash might improve the sustainability and efficiency of the biomass generation, incineration and waste management process.

Leaching behavior of coal combustion products and the environmental implication in road construction.

DOT National Transportation Integrated Search

2011-10-01

This project assessed the physical and chemical characteristics of fly ashes produced from trona injection plants (used for SO2 : emission control), and investigated the leaching of a group of concerned inorganic contaminants from these fly ashes. A ...

DIOXIN AND FURAN FORMATION ON FLY ASH FROM A MIXTURE OF CHLOROPHENOLS

EPA Science Inventory

To establish the relationship between specific chlorophenol (CP) congener distributions and polychlorinated dibenzo-p-dioxin and dibenzofuran (PCDD/F) products this work investigated the formation of PCDDs/Fs from different CP mixtures passed over fly ash under selected reaction ...

Sustainable sources of biomass for bioremediation of heavy metals in waste water derived from coal-fired power generation.

PubMed

Saunders, Richard J; Paul, Nicholas A; Hu, Yi; de Nys, Rocky

2012-01-01

Biosorption of heavy metals using dried algal biomass has been extensively described but rarely implemented. We contend this is because available algal biomass is a valuable product with a ready market. Therefore, we considered an alternative and practical approach to algal bioremediation in which algae were cultured directly in the waste water stream. We cultured three species of algae with and without nutrient addition in water that was contaminated with heavy metals from an Ash Dam associated with coal-fired power generation and tested metal uptake and bioremediation potential. All species achieved high concentrations of heavy metals (to 8% dry mass). Two key elements, V and As, reached concentrations in the biomass of 1543 mg.kg(-1) DW and 137 mg.kg(-1) DW. Growth rates were reduced by more than half in neat Ash Dam water than when nutrients were supplied in excess. Growth rate and bioconcentration were positively correlated for most elements, but some elements (e.g. Cd, Zn) were concentrated more when growth rates were lower, indicating the potential to tailor bioremediation depending on the pollutant. The cosmopolitan nature of the macroalgae studied, and their ability to grow and concentrate a suite of heavy metals from industrial wastes, highlights a clear benefit in the practical application of waste water bioremediation.

Use of bottom ash from olive pomace combustion in the production of eco-friendly fired clay bricks.

PubMed

Eliche-Quesada, D; Leite-Costa, J

2016-02-01

Olive pomace bottom ash was used to replace different amounts (10-50wt%) of clay in brick manufacturing. The aim of this study is both studying bricks properties and showing a new way of olive pomace bottom ash recycling. Properties of waste bricks were compared to conventional products following standard procedures in order to determine the maximum waste percentage. The amount of olive pomace bottom ash is limited to 20wt%, obtaining bricks with superior engineering properties when 10wt% of waste is added. Adding higher amount of waste (30-50wt%) resulted in bricks with water absorption and compressive strength values on the edge of meeting those established by standards. Therefore, the addition of 10 and 20wt% of olive pomace bottom ash produced bricks with a bulk density of 1635 and 1527kg/m(3) and a compressive strength of 33.9MPa and 14.2MPa, respectively. Fired bricks fulfil standards requirements for clay masonry units, offering, at the same time, better thermal insulation of buildings due to a reduction in thermal conductivity of 14.4% and 16.8% respectively, compared to control bricks (only clay). Copyright © 2015 Elsevier Ltd. All rights reserved.

Engineering properties of cement mortar with pond ash in South Korea as construction materials: from waste to concrete

NASA Astrophysics Data System (ADS)

Jung, Sang Hwa; Kwon, Seung-Jun

2013-09-01

Among the wastes from coal combustion product, only fly ash is widely used for mineral mixture in concrete for its various advantages. However the other wastes including bottom ash, so called PA (pond ash) are limitedly reused for reclamation. In this paper, the engineering properties of domestic pond ash which has been used for reclamation are experimentally studied. For this, two reclamation sites (DH and TA) in South Korea are selected, and two domestic PAs are obtained. Cement mortar with two different w/c (water to cement) ratios and 3 different replacement ratios (0%, 30%, and 60%) of sand are prepared for the tests. For workability and physical properties of PA cement mortar, several tests like flow, setting time, and compressive strength are evaluated. Several durability tests including porosity measuring, freezing and thawing, chloride migration, and accelerated carbonation are also performed. Through the tests, PA (especially from DH area) in surface saturated condition is evaluated to have internal curing action which leads to reasonable strength development and durability performances. The results show a potential applicability of PA to concrete aggregate, which can reduce consuming natural resources and lead to active reutilization of coal product waste.

The design of control system of livestock feeding processing

NASA Astrophysics Data System (ADS)

Sihombing, Juna; Napitupulu, Humala L.; Hidayati, Juliza

2018-03-01

PT. XYZ is a company that produces animal feed. One type of animal feed produced is 105 ISA P. In carrying out its production process, PT. XYZ faces the problem of rejected feed amounts during 2014 to June 2015 due to the amount of animal feed that exceeds the standard feed quality of 13% of moisture content and 3% for ash content. Therefore, the researchers analyzed the relationship between factors affecting the quality and extent of damage by using regression and correlation and determine the optimum value of each processing process. Analysis results found that variables affecting product quality are mixing time, steam conditioning temperature and cooling time. The most dominant variable affecting the product moisture content is mixing time with the correlation coefficient of (0.7959) and the most dominant variable affecting the ash content of the product during the processing is mixing time with the correlation coefficient of (0.8541). The design of the proposed product processing control is to run the product processing process with mixing time 235 seconds, steam conditioning temperature 87 0C and cooling time 192 seconds. Product quality 105 ISA P obtained by using this design is with 12.16% moisture content and ash content of 2.59%.

Laboratory Evaluation of the Toxicity of Systemic Insecticides to Emerald Ash Borer Larvae.

PubMed

Poland, Therese M; Ciaramitaro, Tina M; McCullough, Deborah G

2016-04-01

Emerald ash borer (Agrilus planipennis Fairmaire) (Coleoptera: Buprestidae), an invasive phloem-feeding insect native to Asia, threatens at least 16 North American ash (Fraxinus) species and has killed hundreds of millions of ash trees in landscapes and forests. We conducted laboratory bioassays to assess the relative efficacy of systemic insecticides to control emerald ash borer larvae in winter 2009 and 2010. Second- and third-instar larvae were reared on artificial diet treated with varying doses of emamectin benzoate (TREE-äge, Arborjet, Inc., Woburn, MA), imidacloprid (Imicide, J. J Mauget Co., Arcadia, CA), dinotefuran (Safari, Valent Professional Products, Walnut Creek, CA), and azadirachtin (TreeAzin, BioForest Technologies, Inc., Sault Ste. Marie, Ontario, and Azasol, Arborjet, Inc., Woburn, MA). All of the insecticides were toxic to emerald ash borer larvae, but lethal concentrations needed to kill 50% of the larvae (LC50), standardized by larval weight, varied with insecticide and time. On the earliest date with a significant fit of the probit model, LC50 values were 0.024 ppm/g at day 29 for TREE-äge, 0.015 ppm/g at day 63 for Imicide, 0.030 ppm/g at day 46 for Safari, 0.025 ppm/g at day 24 for TreeAzin, and 0.027 ppm/g at day 27 for Azasol. The median lethal time to kill 50% (LT50) of the tested larvae also varied with insecticide product and dose, and was longer for Imicide and Safari than for TREE-äge or the azadirachtin products. Insecticide efficacy in the field will depend on adult and larval mortality as well as leaf and phloem insecticide residues.

Geotechnical approaches to coal ash content control in mining of complex structure deposits

NASA Astrophysics Data System (ADS)

Batugin, SA; Gavrilov, VL; Khoyutanov, EA

2017-02-01

Coal deposits having complex structure and nonuniform quality coal reserves require improved processes of production quality control. The paper proposes a method to present coal ash content as components of natural and technological dilution. It is chosen to carry out studies on the western site of Elginsk coal deposit, composed of four coal beds of complex structure. The reported estimates of coal ash content in the beds with respect to five components point at the need to account for such data in confirmation exploration, mine planning and actual mining. Basic means of analysis and control of overall ash content and its components are discussed.

Quantification of geopolymers production by chemical methods- A short review

NASA Astrophysics Data System (ADS)

Siyal, Ahmer Ali; Azizli, Khairun Azizi; Ismail, Lukman; Man, Zakaria; Khan, Muhammad Irfan

2015-07-01

Inorganic polymers are the aluminosilicate materials possessing properties superior than ordinary Portland cement. In this review paper the chemical techniques used for determining degree of reaction of fly ash or the quantity of geopolymer material produced have been discussed. These methods determine the amount of product formed in percentages. The methods include HCl method, salicylic acid method, and picric acid method. These methods are not only used for fly ash but they are being used for determining the degree of reactions of metakaolin and other pozzolanic materials. The picric acid is an explosive material and its transportation in high concentration is dangerous. During its use in laboratory there is also the risk of fire associated with it. According to the microscopic analysis results the picric acid attack dissolves small amount of fine unreacted fly ash particles also. The salicylic acid is easily available but the residue from its treatment contains unreacted fly ash particles, hydration phases, and certain parts of unreacted OPC. The residue from HCl and salicylic acid attack contains MgO particles which is the part of the hydration product. The HCl method is mostly used due to simple process and lower standard deviation.

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.

Enviromental impact of a hospital waste incineration plant in Krakow (Poland).

PubMed

Gielar, Agnieszka; Helios-Rybicka, Edeltrauda

2013-07-01

The environmental impact of a hospital waste incineration plant in Krakow was investigated. The objective of this study was to assess the degree of environmental effect of the secondary solid waste generated during the incineration process of medical waste. The analysis of pollution of the air emissions and leaching test of ashes and slag were carried out. The obtained results allowed us to conclude that (i) the hospital waste incineration plant significantly solves the problems of medical waste treatment in Krakow; (ii) the detected contaminant concentrations were generally lower than the permissible values; (iii) the generated ashes and slag contained considerable concentrations of heavy metals, mainly zinc, and chloride and sulfate anions. Ashes and slag constituted 10-15% of the mass of incinerated wastes; they are more harmful for the environment when compared with untreated waste, and after solidification they can be deposited in the hazardous waste disposal.

Development and testing of synthetic RIPRAP constructed from coal combustion products.

DOT National Transportation Integrated Search

2013-11-01

Even with an increase in the amount of CCPs used in concrete construction, soil stabilization, and other applications, the coal power : industry must dispose of a significant amount of fly ash and bottom ash. One potential avenue for the material is ...

Leaching behavior of coal combustion products and the environmental implication in road construction.

DOT National Transportation Integrated Search

2011-04-01

Leaching of trace elements may raise environmental concerns when using coal fly ash in road construction. US EPA is in the process : of creating the first national rule on coal ash management, including beneficial use. Meanwhile, driven by the tighte...

FLY ASH RECYCLE IN DRY SCRUBBING

EPA Science Inventory

The paper describes the effects of fly ash recycle in dry scrubbing. (Previous workers have shown that the recycle of product solids improves the utilization of slaked lime--Ca(OH)2--for sulfur dioxide (SO2) removal by spray dryers with bag filters.) In laboratory-scale experimen...

Natural Environmental Hazards Reflected in High-Altitude Patagonian Lake Sediments (lake Caviahue, Argentina)

NASA Astrophysics Data System (ADS)

Müller, Anne; Scharf, Burkhard; von Tümpling, Wolf; Pirrung, Michael

2009-03-01

Two 6-m long sediment cores drilled in the two basins of Lake Caviahue give new evidence of the impact of natural hazards such as ash fallouts linked to nearby volcanic eruptions in the ecologically sensitive environment of the high-altitude region of the Argentinan Patagonian Andes. The two cores show distinct signals of changes in autochthonous productivity and terrigenous input into the lake from ash fallout as well as from river load and shore erosion. Multiproxy records of the sediments indicate whether these changes can be related to volcanic activity. High values of magnetic susceptibility in the cores reflect periods of basaltic ash fallouts during eruptions of the nearby Copahue Volcano. The southern basin is located in the prevalent direction of ash fallouts and has been affected by these volcanic inputs more intensely than the northern basin of the lake. In contrast, sedimentation and authochthonous productivity in the northern basin are strongly affected by fluvial inputs such as suspended river load and acidic stream waters.

Natural Environmental Hazards Reflected in High-Altitude Patagonian Lake Sediments (Lake Caviahue, Argentina)

NASA Astrophysics Data System (ADS)

Mueller, A.; Pirrung, M.; Scharf, B.; von Tuempling, W.

2007-05-01

Two 6-m long sediment cores drilled in the two basins of Lake Caviahue give new evidence of the impact of natural hazards such as ash fallouts linked to nearby volcanic eruptions in the ecologically sensitive environment of the high-altitude region of the Argentinan Patagonian Andes. The two cores show distinct signals of changes in autochthonous productivity and terrigenous input into the lake from ash fallout, river load and shore erosion. Multiproxy records of the sediments indicate whether these changes can be related to volcanic activity. High values of magnetic susceptibility in the cores reflect periods of basaltic ash fallouts during eruptions of the nearby Copahue volcano. The southern basin is located in the prevalent direction of ash fallouts and has been affected by these volcanic inputs more intensely than the northern basin of the lake. In contrast, sedimentation and authochthonous productivity in the northern basin are strongly affected by fluvial inputs such as suspended river load and acidic stream waters.

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.

Mechanical Properties and Microstructure of Class C Fly Ash-Based Geopolymer Paste and Mortar

PubMed Central

Li, Xueying; Ma, Xinwei; Zhang, Shoujie; Zheng, Enzu

2013-01-01

This paper presents workability, compressive strength and microstructure for geopolymer pastes and mortars made of class C fly ash at mass ratios of water-to-fly ash from 0.30 to 0.35. Fluidity was in the range of 145–173 mm for pastes and 131–136 mm for mortars. The highest strengths of paste and mortar were 58 MPa and 85 MPa when they were cured at 70 °C for 24 h. In XRD patterns, unreacted quartz and some reacted product were observed. SEM examination indicated that reacted product has formed and covered the unreacted particles in the paste and mortar that were consistent with their high strength. PMID:28809222

Energy efficient continuous flow ash lockhopper

NASA Technical Reports Server (NTRS)

Collins, Earl R., Jr. (Inventor); Suitor, Jerry W. (Inventor); Dubis, David (Inventor)

1989-01-01

The invention relates to an energy efficient continuous flow ash lockhopper, or other lockhopper for reactor product or byproduct. The invention includes an ash hopper at the outlet of a high temperature, high pressure reactor vessel containing heated high pressure gas, a fluidics control chamber having an input port connected to the ash hopper's output port and an output port connected to the input port of a pressure letdown means, and a control fluid supply for regulating the pressure in the control chamber to be equal to or greater than the internal gas pressure of the reactor vessel, whereby the reactor gas is contained while ash is permitted to continuously flow from the ash hopper's output port, impelled by gravity. The main novelty resides in the use of a control chamber to so control pressure under the lockhopper that gases will not exit from the reactor vessel, and to also regulate the ash flow rate. There is also novelty in the design of the ash lockhopper shown in two figures. The novelty there is the use of annular passages of progressively greater diameter, and rotating the center parts on a shaft, with the center part of each slightly offset from adjacent ones to better assure ash flow through the opening.

Improvements of nano-SiO2 on sludge/fly ash mortar.

PubMed

Lin, D F; Lin, K L; Chang, W C; Luo, H L; Cai, M Q

2008-01-01

Sewage sludge ash has been widely applied to cementitious materials. In this study, in order to determine effects of nano-SiO(2) additives on properties of sludge/fly ash mortar, different amounts of nano-SiO(2) were added to sludge/fly ash mortar specimens to investigate their physical properties and micro-structures. A water-binding ratio of 0.7 was assigned to the mix. Substitution amounts of 0%, 10%, 20%, and 30% of sludge/fly ash (1:1 ratio) were proposed. Moreover, 0%, 1%, 2%, and 3% of nano-SiO(2) was added to the mix. Tests, including SEM and compressive strength, were carried out on mortar specimens cured at 3, 7, and 28 days. Results showed that sludge/fly ash can make the crystals of cement hydration product finer. Moreover, crystals increased after nano-SiO(2) was added. Hence, nano-SiO(2) can improve the effects of sludge/fly ash on the hydration of mortar. Further, due to the low pozzolanic reaction active index of sludge ash, early compressive strengths of sludge/fly ash mortar were decreased. Yet, nano-SiO(2) could help produce hydration crystals, which implies that the addition of nano-SiO(2) to mortar can improve the influence of sludge/fly ash on the development of the early strength of the mortar.

Physiological responses of emerald ash borer larvae to feeding on different ash species reveal putative resistance mechanisms and insect counter-adaptations.

PubMed

Rigsby, C M; Showalter, D N; Herms, D A; Koch, J L; Bonello, P; Cipollini, D

2015-07-01

Emerald ash borer, Agrilus planipennis Fairmaire, an Asian wood-boring beetle, has devastated ash (Fraxinus spp.) trees in North American forests and landscapes since its discovery there in 2002. In this study, we collected living larvae from EAB-resistant Manchurian ash (Fraxinus mandschurica), and susceptible white (Fraxinus americana) and green (Fraxinus pennsylvanica) ash hosts, and quantified the activity and production of selected detoxification, digestive, and antioxidant enzymes. We hypothesized that differences in larval physiology could be used to infer resistance mechanisms of ash. We found no differences in cytochrome P450, glutathione-S-transferase, carboxylesterase, sulfotransferase, and tryptic BApNAase activities between larvae feeding on different hosts. Despite this, Manchurian ash-fed larvae produced a single isozyme of low electrophoretic mobility that was not produced in white or green ash-fed larvae. Additionally, larvae feeding on white and green ash produced two serine protease isozymes of high electrophoretic mobility that were not observed in Manchurian ash-fed larvae. We also found lower activity of β-glucosidase and higher activities of monoamine oxidase, ortho-quinone reductase, catalase, superoxide dismutase, and glutathione reductase in Manchurian ash-fed larvae compared to larvae that had fed on susceptible ash. A single isozyme was detected for both catalase and superoxide dismutase in all larval groups. The activities of the quinone-protective and antioxidant enzymes are consistent with the resistance phenotype of the host species, with the highest activities measured in larvae feeding on resistant Manchurian ash. We conclude that larvae feeding on Manchurian ash could be under quinone and oxidative stress, suggesting these may be potential mechanisms of resistance of Manchurian ash to EAB larvae, and that quinone-protective and antioxidant enzymes are important counter-adaptations of larvae for dealing with these resistance mechanisms. Copyright © 2015 Elsevier Ltd. All rights reserved.

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.

A brief review on fly ash and its use in surface engineering

NASA Astrophysics Data System (ADS)

Bhajantri, Vishwanath; Krishna, Prasad; Jambagi, Sudhakar

2018-04-01

Fly ash is a by-product obtained from coal power plants. Over the past two decades, handling this industrial waste has been a great challenge for many developing countries. However, this menace can be used in many industrial applications viz., civil, automobile and aerospace applications. In civil industry, the fly ash has been used in concreate to enhance the porosity that increases the curing time of the concrete. The fly ash has been gaining importance these days as a feedstock material for many thermal spray processes. In automobile sector, the fly ash has been used as a thermal barrier coating in IC engines, whereas in aerospace industry, which demands lighter and stronger materials, the fly ash has been used as a reinforcement material. Hence, so far, fly ash has been used as an either single or a composite feed stock material in thermal spray processes. The fly ash with other materials like alumina, titania and red mud have been deposited using thermal spray processes. These coatings have exhibited higher wear, corrosion and erosion resistance as compared to the uncoated specimens. In this paper, a brief review on fly ash and its use, especially its use as a feed stock in thermal spray coating, is presented. Therefore, the use of fly ash has opened a new frontier of research in thermal spray coating area where economically viable coatings can be produced using industrial waste like fly ash.

Hydration kinetics and morphology of cement pastes with pozzolanic volcanic ash studied via synchrotron-based techniques

DOE PAGES

Kupwade-Patil, Kunal; Chin, Stephanie; Ilavsky, Jan; ...

2017-10-13

Here, this study investigates the early ages of hydration behavior when basaltic volcanic ash was used as a partial substitute to ordinary Portland cement using ultra-small-angle X-ray scattering and wide-angle X-ray scattering (WAXS). The mix design consisted of 10, 30 and 50% substitution of Portland cement with two different-sized volcanic ashes. The data showed that substitution of volcanic ash above 30% results in excess unreacted volcanic ash, rather than additional pozzolanic reactions along longer length scales. WAXS studies revealed that addition of finely ground volcanic ash facilitated calcium-silicate-hydrate related phases, whereas inclusion of coarser volcanic ash caused domination by calcium-aluminum-silicate-hydratemore » and unreacted MgO phases, suggesting some volcanic ash remained unreacted throughout the hydration process. Addition of more than 30% volcanic ash leads to coarser morphology along with decreased surface area and higher intensity of scattering at early-age hydration. This suggests an abrupt dissolution indicated by changes in surface area due to the retarding gel formation that can have implication on early-age setting influencing the mechanical properties of the resulting cementitious matrix. The findings from this work show that the concentration of volcanic ash influences the specific surface area and morphology of hydration products during the early age of hydration. Therefore, natural pozzolanic volcanic ashes can be a viable substitute to Portland cement by providing environmental benefits in terms of lower-carbon footprint along with long-term durability.« less

Hydration kinetics and morphology of cement pastes with pozzolanic volcanic ash studied via synchrotron-based techniques

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

Kupwade-Patil, Kunal; Chin, Stephanie; Ilavsky, Jan

Here, this study investigates the early ages of hydration behavior when basaltic volcanic ash was used as a partial substitute to ordinary Portland cement using ultra-small-angle X-ray scattering and wide-angle X-ray scattering (WAXS). The mix design consisted of 10, 30 and 50% substitution of Portland cement with two different-sized volcanic ashes. The data showed that substitution of volcanic ash above 30% results in excess unreacted volcanic ash, rather than additional pozzolanic reactions along longer length scales. WAXS studies revealed that addition of finely ground volcanic ash facilitated calcium-silicate-hydrate related phases, whereas inclusion of coarser volcanic ash caused domination by calcium-aluminum-silicate-hydratemore » and unreacted MgO phases, suggesting some volcanic ash remained unreacted throughout the hydration process. Addition of more than 30% volcanic ash leads to coarser morphology along with decreased surface area and higher intensity of scattering at early-age hydration. This suggests an abrupt dissolution indicated by changes in surface area due to the retarding gel formation that can have implication on early-age setting influencing the mechanical properties of the resulting cementitious matrix. The findings from this work show that the concentration of volcanic ash influences the specific surface area and morphology of hydration products during the early age of hydration. Therefore, natural pozzolanic volcanic ashes can be a viable substitute to Portland cement by providing environmental benefits in terms of lower-carbon footprint along with long-term durability.« less

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.

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.

Direct coal liquefaction process

DOEpatents

Rindt, John R.; Hetland, Melanie D.

1993-01-01

An improved multistep liquefaction process for organic carbonaceous mater which produces a virtually completely solvent-soluble carbonaceous liquid product. The solubilized product may be more amenable to further processing than liquid products produced by current methods. In the initial processing step, the finely divided organic carbonaceous material is treated with a hydrocarbonaceous pasting solvent containing from 10% and 100% by weight process-derived phenolic species at a temperature within the range of 300.degree. C. to 400.degree. C. for typically from 2 minutes to 120 minutes in the presence of a carbon monoxide reductant and an optional hydrogen sulfide reaction promoter in an amount ranging from 0 to 10% by weight of the moisture- and ash-free organic carbonaceous material fed to the system. As a result, hydrogen is generated via the water/gas shift reaction at a rate necessary to prevent condensation reactions. In a second step, the reaction product of the first step is hydrogenated.

Direct coal liquefaction process

DOEpatents

Rindt, J.R.; Hetland, M.D.

1993-10-26

An improved multistep liquefaction process for organic carbonaceous mater which produces a virtually completely solvent-soluble carbonaceous liquid product. The solubilized product may be more amenable to further processing than liquid products produced by current methods. In the initial processing step, the finely divided organic carbonaceous material is treated with a hydrocarbonaceous pasting solvent containing from 10% and 100% by weight process-derived phenolic species at a temperature within the range of 300 C to 400 C for typically from 2 minutes to 120 minutes in the presence of a carbon monoxide reductant and an optional hydrogen sulfide reaction promoter in an amount ranging from 0 to 10% by weight of the moisture- and ash-free organic carbonaceous material fed to the system. As a result, hydrogen is generated via the water/gas shift reaction at a rate necessary to prevent condensation reactions. In a second step, the reaction product of the first step is hydrogenated.

Comparison of phosphorus recovery from incineration and gasification sewage sludge ash.

PubMed

Parés Viader, Raimon; Jensen, Pernille Erland; Ottosen, Lisbeth M; Thomsen, Tobias P; Ahrenfeldt, Jesper; Hauggaard-Nielsen, Henrik

2017-03-01

Incineration of sewage sludge is a common practice in many western countries. Gasification is an attractive option because of its high energy efficiency and flexibility in the usage of the produced gas. However, they both unavoidably produce sewage sludge ashes, a material that is rich in phosphorus, but which is commonly landfilled or used in construction materials. With current uncertainty in phosphate rock supply, phosphorus recovery from sewage sludge ashes has become interesting. In the present work, ashes from incineration and gasification of the same sewage sludge were compared in terms of phosphorus extractability using electrodialytic (ED) methods. The results show that comparable recovery rates of phosphorus were achieved with a single ED step for incineration ashes and a sequential combination of two ED steps for gasification ashes, which was due to a higher influence of iron and/or aluminium in phosphorus solubility for the latter. A product with lower level of metallic impurities and comparable to wet process phosphoric acid was eventually obtained from gasification ashes. Thus, gasification becomes an interesting alternative to incineration also in terms of phosphorus separation.

Recyclability of Concrete Pavement Incorporating High Volume of Fly Ash.

PubMed

Yoshitake, Isamu; Ishida, Takeo; Fukumoto, Sunao

2015-08-21

Recyclable concrete pavement was made from fly ash and crushed limestone sand and gravel as aggregates so that the concrete pavement could be recycled to raw materials for cement production. With the aim to use as much fly ash as possible for the sustainable development of society, while achieving adequate strength development, pavement concrete having a cement-replacement ratio of 40% by mass was experimentally investigated, focusing on the strength development at an early age. Limestone powder was added to improve the early strength; flexural strength at two days reached 3.5 MPa, the minimum strength for traffic service in Japan. The matured fly ash concrete made with a cement content of 200 kg/m3 achieved a flexural strength almost equal to that of the control concrete without fly ash. Additionally, Portland cement made from the tested fly ash concrete was tested to confirm recyclability, with the cement quality meeting the Japanese classification of ordinary Portland cement. Limestone-based recyclable fly ash concrete pavement is, thus, a preferred material in terms of sustainability.

Recyclability of Concrete Pavement Incorporating High Volume of Fly Ash

PubMed Central

Yoshitake, Isamu; Ishida, Takeo; Fukumoto, Sunao

2015-01-01

Recyclable concrete pavement was made from fly ash and crushed limestone sand and gravel as aggregates so that the concrete pavement could be recycled to raw materials for cement production. With the aim to use as much fly ash as possible for the sustainable development of society, while achieving adequate strength development, pavement concrete having a cement-replacement ratio of 40% by mass was experimentally investigated, focusing on the strength development at an early age. Limestone powder was added to improve the early strength; flexural strength at two days reached 3.5 MPa, the minimum strength for traffic service in Japan. The matured fly ash concrete made with a cement content of 200 kg/m3 achieved a flexural strength almost equal to that of the control concrete without fly ash. Additionally, Portland cement made from the tested fly ash concrete was tested to confirm recyclability, with the cement quality meeting the Japanese classification of ordinary Portland cement. Limestone-based recyclable fly ash concrete pavement is, thus, a preferred material in terms of sustainability. PMID:28793518

Comparing Two Independent Satellite-Based Algorithms for Detecting and Tracking Ash Clouds by Using SEVIRI Sensor

PubMed Central

Cooke, Michael C.; Filizzola, Carolina

2018-01-01

The Eyjafjallajökull (Iceland) volcanic eruption of April–May 2010 caused unprecedented air-traffic disruption in Northern Europe, revealing some important weaknesses of current operational ash-monitoring and forecasting systems and encouraging the improvement of methods and procedures for supporting the activities of Volcanic Ash Advisory Centers (VAACs) better. In this work, we compare two established satellite-based algorithms for ash detection, namely RSTASH and the operational London VAAC method, both exploiting sensor data of the spinning enhanced visible and infrared imager (SEVIRI). We analyze similarities and differences in the identification of ash clouds during the different phases of the Eyjafjallajökull eruption. The work reveals, in some cases, a certain complementary behavior of the two techniques, whose combination might improve the identification of ash-affected areas in specific conditions. This is indicated by the quantitative comparison of the merged SEVIRI ash product, achieved integrating outputs of the RSTASH and London VAAC methods, with independent atmospheric infrared sounder (AIRS) DDA (dust-detection algorithm) observations. PMID:29382058

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.

On-line determination of the ash content in coal using industrial, natural gamma-ray equipment

NASA Astrophysics Data System (ADS)

Alvarez, M. C.; Dopico, M. T.

1995-12-01

This work presents phases of an investigation carried out in Spain to develop industrial natural-γ equipment to determine the ash content in coals. Initially the programme was on a laboratory scale and later tests were performed in a coal washing plant on a mixture of washed products. The results obtained are very satisfactory since the equipment permits the ash content to be determined with a mean error of 1.3% and a SD of 1.

Suitability of aquatic biomass from Lake Toba (North Sumatra, Indonesia) for energy generation by combustion process

NASA Astrophysics Data System (ADS)

Brunerová, A.; Roubík, H.; Herák, D.

2017-09-01

Several aquatic plant species were identified as aquatic pollution of Lake Toba, North Sumatra (Indonesia); specifically, water hyacinth Eichhornia crassipes and aquatic weeds Hydrilla verticillata and Myriophyllum spicatum due to their high biomass yield which causes impenetrable mats at the bottom and surface of the lake. That complicates other vegetation growth and utilization of water areas for fishing or recreation. In attempt to clean the lake and prevent plants expansion, great amount of plants populations are removed from water but subsequent efficient utilization of such aquatic biomass is not ensured. Present research investigated energy potential of aquatic biomass originated from mentioned aquatic plants from Lake Toba and its possible utilization for energy production by direct combustion. Performed chemical analysis contained from determination of moisture, ash and volatile matter contents and calorific values. Evaluation of results proved highest suitability and energy potential of Eichhornia crassipes with gross calorific value (GCV) 16.31 MJ·kg-1, followed by Hydrilla verticillata with GCV 15.24 MJ·kg-1. Samples of Myriophyllum spicatum exhibited unsatisfactory results due to its low GCV (11.27 MJ·kg-1) in combination with high ash content (36.99%) which indicates complications during combustion, thus, low energy production efficiency and overall unsuitability for combustion purposes.

Utilization of construction and agricultural waste in Malaysia for development of Green Concrete: A Review

NASA Astrophysics Data System (ADS)

Tambichik, M. A.; Mohamad, N.; Samad, A. A. A.; Bosro, M. Z. M.; Iman, M. A.

2018-04-01

Green Concrete (GC) is defined as a concrete that utilize a waste material for at least one of its component. The production of GC has been increasing due to the drawback of conventional concrete that create many environmental problems. In Malaysia, the amount of waste generates from agricultural and construction industries were increasing every year. Hence, one of the solutions to reduce the impact of conventional concrete and limited landfill spaces due to excessive waste is by utilizing it in concrete. This paper reviews the possible use of construction waste (Recycle Concrete Aggregate) and agricultural waste (Palm Oil Fuel Ash, Rice Husk Ash and Palm Oil Fibre) as partial replacement for the basic material in a concrete to produce an innovative Green Concrete. The optimum replacement level for each type of waste was also been review. Green Concrete also has the potential to reduce environmental pollution and solve the depletion of natural sources. The result from this review shows that the addition of agricultural waste or construction waste in concrete indicate positive and satisfactory strength when compared to normal concrete. Finally, a mass production of Green Concrete can fulfil the Construction Industry Transformation Plan (CITP) 2016-2020 made by CIDB that emphasizes on a construction system which is environmentally sustainable.

Preparation of clinker from paper pulp industry wastes.

PubMed

Buruberri, Leire H; Seabra, M P; Labrincha, J A

2015-04-09

The production of paper pulp by the Kraft method generates considerable amounts of wastes. Namely, lime mud generated in the recovery circuit of chemical reagents, biological sludge from the wastewater treatment of wood digestion process and fly ash collected in the fluidized bed combustor used to generate electricity from biomass burning. The final destination of such wastes is an important concern, since environmental regulations are becoming stricter regarding their landfill. Driven by this fact, industries are looking for more sustainable solutions, such as the recycling in distinct products. This work tested these wastes as secondary raw materials to produce clinker/cement that was then experienced in mortar formulations. The first step involved the residues detailed characterization and a generated amounts survey. Then, specific but simple steps were suggested, aiming to facilitate transport and manipulation. Distinct blends were prepared and fired in order to get belitic and Portland clinkers. The Portland clinkers were processed at lower temperatures than the normally used in the industry due to the presence of mineralizing impurities in some wastes. Belite-based cements were used to produce mortars that developed satisfactory mechanical strength and did not reveal signs of deterioration or durability weaknesses. Copyright © 2014 Elsevier B.V. All rights reserved.

Utilization of fly ash and ultrafine GGBS for higher strength foam concrete

NASA Astrophysics Data System (ADS)

Gowri, R.; Anand, K. B.

2018-02-01

Foam concrete is a widely accepted construction material, which is popular for diverse construction applications such as, thermal insulation in buildings, lightweight concrete blocks, ground stabilization, void filling etc. Currently, foam concrete is being used for structural applications with a density above 1800kg/m3. This study focuses on evolving mix proportions for foam concrete with a material density in the range of 1200 kg/m3 to 1600 kg/m3, so as to obtain strength ranges that will be sufficient to adopt it as a structural material. Foam concrete is made lighter by adding pre-formed foam of a particular density to the mortar mix. The foaming agent used in this study is Sodium Lauryl Sulphate and in order to densify the foam generated, Sodium hydroxide solution at a normality of one is also added. In this study efforts are made to make it a sustainable construction material by incorporating industrial waste products such as ultrafine GGBS as partial replacement of cement and fly ash for replacement of fine aggregate. The fresh state and hardened state properties of foam concrete at varying proportions of cement, sand, water and additives are evaluated. The proportion of ultrafine GGBS and fly ash in the foam concrete mix are varied aiming at higher compressive strength. Studies on air void-strength relationship of foam concrete are also included in this paper.

Coal combustion products: trash or treasure?

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

Hansen, T.

2006-07-15

Coal combustion by-products can be a valuable resource to various industries. The American Coal Ash Association (ACAA) collects data on production and uses of coal combustion products (CCPs). 122.5 million tons of CCPs were produced in 2004. The article discusses the results of the ACCA's 2004 survey. Fly ash is predominantly used as a substitute for Portland cement; bottom ash for structural fill, embankments and paved road cases. Synthetic gypsum from the FGD process is commonly used in wallboard. Plant owners are only likely to have a buyer for a portion of their CCPs. Although sale of hot water (frommore » Antelope Valley Station) from condensers for use in a fish farm to raise tilapia proved unviable, the Great Plains Synfuels Plant which manufactures natural gas from lignite produces a wide range of products including anhydrous ammonia, phenol, krypton, carbon dioxide (for enhanced oil recovery), tar oils and liquid nitrogen. ACCA's goal is to educate people about CCPs and how to make them into useful products, and market them, in order to reduce waste disposal and enhance revenue. The article lists members of the ACCA. 2 photos., 1 tab.« less

Study of Polyolefines Waste Thermo-Destruction in Large Laboratory and in Industrial Installations

DTIC Science & Technology

2014-12-15

coke ”–waste after thermo-destruction carried out on the module No 2 showed an content to 46.1% of ash [20]. This ash content indicates a very large... coke (post-production waste) from the wastes thermo-destruction on 2 modules of vertical modular installation for thermo-destruction of used polymer...of receivedwaste water, the quantity of received coke , the quantity of gaseous product in periods of carrying out installation work before (first

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.

Peak exposures to main components of ash and gaseous diesel exhausts in closed and open ash loading stations at biomass-fuelled power plants.

PubMed

Laitinen, Juha; Koponen, Hanna; Sippula, Olli; Korpijärvi, Kirsi; Jumpponen, Mika; Laitinen, Sirpa; Aatamila, Marjaleena; Tissari, Jarkko; Karhunen, Tommi; Ojanen, Kari; Jokiniemi, Jorma; Korpinen, Leena

2017-10-01

Fly and bottom ashes are collected at power plants to reduce the environmental effects of energy production. However, handling the ashes causes health problems for operators, maintenance workers and truck drivers at the power plants. Hence, we evaluated ash loaders' peak inhalation exposures to the chemical components of ash and diesel exhausts in open and closed ash loading stations at biomass-fuelled combined heat and power plants. We also carried out chemical and morphological analyses of the ashes to evaluate their health hazard potential in order to find practical technical measures to reduce workers' exposure. On the basis of X-ray diffraction analyses, the main respirable crystalline ash compounds were SiO 2 , CaSO 4 , CaO, Ca 2 Al 2 SiO 7 , NaCl and Ca 3 Al 2 O 6 in the fly ashes and SiO 2 , KAlSi 3 O 8 , NaAlSi 3 O 8 and Ca 2 Al 2 SiO 7 in the bottom ashes. The short-term exposure levels of respirable crystalline silica, inhalable inorganic dust, Cr, Mn, Ni and nitric oxide exceeded their Finnish eight hours occupational exposure limit values in the closed ash loading station. According to our observations, more attention should be paid to the ash-moistening process, the use of tank trucks instead of open cassette flatbed trucks, and the sealing of the loading line from the silo to the truck which would prevent spreading the ash into the air. The idling time of diesel trucks should also be limited, and ash loading stations should be equipped with exhaust gas ventilators. If working conditions make it impossible to keep to the OEL values, workers must use respirators and protect their eyes and skin. Copyright © 2017 Elsevier Ltd. All rights reserved.

Heterogeneous photochemistry of oxalic acid on Mauritanian sand and Icelandic volcanic ash.

PubMed

Styler, Sarah A; Donaldson, D J

2012-08-21

Teragram quantities of crustal and volcanic aerosol are released into the atmosphere on an annual basis. Although these substrates contain photoactive metal oxides, little is known about the role that they may play in catalyzing the heterogeneous phototransformation of semivolatile organic species. In the present study, we have investigated oxalic acid photochemistry at the surface of Fe(2)O(3), TiO(2), Mauritanian sand, and Icelandic volcanic ash in the presence and absence of oxygen using a photochemical Knudsen cell reactor. Illumination of all sample types resulted in the production of gas-phase CO(2). In the case of Mauritanian sand, the production of gas-phase CO(2) scaled with the loss of surface oxalic acid. In the absence of oxygen, the production of CO(2) by the sand and ash films scaled with the absorption spectrum of iron oxalate, which suggests that the reaction is at least in part iron-mediated. The presence of oxygen suppressed CO(2) production at the Fe(2)O(3) surface, enhanced CO(2) production at the Mauritanian sand surface, and did not have a net effect upon CO(2) production at the Icelandic ash surface. These different oxygen dependencies imply that oxalic acid photochemistry at the authentic surfaces under study was not solely iron-mediated. Experiments at the TiO(2) surface, which showed enhanced CO(2) production from oxalic acid in the presence of oxygen, suggest that Ti-mediated photochemistry played an important role. In summary, these results provide evidence that solid-phase aerosol photochemistry may influence the atmospheric lifetime of oxalic acid in arid regions, where its removal via wet deposition is insignificant.

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.

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.

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

Utilization of coal fly ash as a slow-release granular medium for soil improvement.

PubMed

Yoo, Jeong Gun; Jo, Young Min

2003-01-01

This work proposes a new potential application of waste coal fly ash as a K fertilizer support. Fly ash was reacted with KOH to facilitate the impregnation of K as well as to enhance the bonding force. In particular, the applied process resulted in a significant slow-releasing characteristic of fertilizer elements. To examine the effect of K impregnation, a few detailed leaching tests were carried out in terms of process variables such as reaction time and temperature, sintering time and temperature, and KOH concentration. The current experiment presented an optimum preparation condition that is competitive with conventional commercial fertilizers. The manufactured ash fertilizers inhibited release of the K elements. It was also found through the continuous leaching test with pure water that the ash fertilizer had excellent moisture absorbability. However, the effects of some trace elements in fly ash on soil health and crop productivity as well as environmental considerations need to be established with long-term studies.

SEVIRI 4D-var assimilation analysing the April 2010 Eyjafjallajökull ash dispersion

NASA Astrophysics Data System (ADS)

Lange, Anne Caroline; Elbern, Hendrik

2016-04-01

We present first results of four dimensional variational (4D-var) data assimilation analysis applying SEVIRI observations to the Eulerian regional chemistry and aerosol transport model EURAD-IM (European Air Pollution Dispersion - Inverse Model). Optimising atmospheric dispersion models in terms of volcanic ash transport predictions by observations is especially essential for the aviation industry and associated interests. Remote sensing satellite observations are instrumental for ash detection and monitoring. We choose volcanic ash column retrievals of the Spinning Enhanced Visible and Infrared Imager (SEVIRI) because as infrared instrument on the geostationary satellite Meteosat Second Generation it delivers measurements with high temporal resolution during day and night. The retrieval method relies on the reverse absorption effect. In the framework of the national initiative ESKP (Earth System Knowledge Platform) and the European ACTRIS-2 (Aerosol, Clouds, and Trace gases Research InfraStructure) project, we developed new modules (forward and adjoint) within the EURAD-IM, which are able to process SEVIRI ash column data as observational input to the 4D-var system. The focus of the 4D-var analysis is on initial value optimisation of the volcanic ash clouds that were emitted during the explosive Eyjafjallajökull eruption in April 2010. This eruption caused high public interest because of air traffic closures and it was particularly well observed from many different observation systems all over Europe. Considering multiple observation periods simultaneously in one assimilation window generates a continuous trajectory in the phase space and ensures that past observations are considered within their uncertainties. Results are validated mainly by lidar (LIght Detection And Ranging) observations, both ground and satellite based.

Life cycle based risk assessment of recycled materials in roadway construction.

PubMed

Carpenter, A C; Gardner, K H; Fopiano, J; Benson, C H; Edil, T B

2007-01-01

This paper uses a life-cycle assessment (LCA) framework to characterize comparative environmental impacts from the use of virgin aggregate and recycled materials in roadway construction. To evaluate site-specific human toxicity potential (HTP) in a more robust manner, metals release data from a demonstration site were combined with an unsaturated contaminant transport model to predict long-term impacts to groundwater. The LCA determined that there were reduced energy and water consumption, air emissions, Pb, Hg and hazardous waste generation and non-cancer HTP when bottom ash was used in lieu of virgin crushed rock. Conversely, using bottom ash instead of virgin crushed rock increased the cancer HTP risk due to potential leachate generation by the bottom ash. At this scale of analysis, the trade-offs are clearly between the cancer HTP (higher for bottom ash) and all of the other impacts listed above (lower for bottom ash). The site-specific analysis predicted that the contaminants (Cd, Cr, Se and Ag for this study) transported from the bottom ash to the groundwater resulted in very low unsaturated zone contaminant concentrations over a 200 year period due to retardation in the vadose zone. The level of contaminants predicted to reach the groundwater after 200 years was significantly less than groundwater maximum contaminant levels (MCL) set by the US Environmental Protection Agency for drinking water. Results of the site-specific contaminant release estimates vary depending on numerous site and material specific factors. However, the combination of the LCA and the site specific analysis can provide an appropriate context for decision making. Trade-offs are inherent in making decisions about recycled versus virgin material use, and regulatory frameworks should recognize and explicitly acknowledge these trade-offs in decision processes.

Sugarcane boiler ash as an amendment for soilless growing media

USDA-ARS?s Scientific Manuscript database

In 2016, research was conducted to investigate the use of sugarcane bagasse ash (SBA) as an amendment to soilless planting media for the production of vegetable seedlings. Typically, the eleven Louisiana sugarcane mills use a portion of the sugarcane bagasse for fuel, producing over 60,000 tons of S...

Use of coal fly ash and other waste products in soil stabilization and road construction including non-destructive testing of roadways.

DOT National Transportation Integrated Search

2012-06-01

An extensive laboratory testing program was performed on subgrade soils stabilized using fly ash and : lime kiln dust. The laboratory program included measurements of: compaction curves, small strain elastic moduli, : resilient modulus (Mr), Briaud C...

Use of coal fly ash and other waste products in soil stabilization and road construction-including non-destructive testing of roadways.

DOT National Transportation Integrated Search

2012-02-01

An extensive laboratory testing program was performed on subgrade soils stabilized using fly ash and lime kiln dust. The laboratory : program included measurements of: compaction curves, small strain elastic moduli, resilient modulus (Mr), Briaud Com...

Aversive Behavior in the Nematode C. elegans Is Modulated by cGMP and a Neuronal Gap Junction Network

PubMed Central

Krzyzanowski, Michelle C.; Wood, Jordan F.; Brueggemann, Chantal; Bowitch, Alexander; Bethke, Mary; L’Etoile, Noelle D.; Ferkey, Denise M.

2016-01-01

All animals rely on their ability to sense and respond to their environment to survive. However, the suitability of a behavioral response is context-dependent, and must reflect both an animal’s life history and its present internal state. Based on the integration of these variables, an animal’s needs can be prioritized to optimize survival strategies. Nociceptive sensory systems detect harmful stimuli and allow for the initiation of protective behavioral responses. The polymodal ASH sensory neurons are the primary nociceptors in C. elegans. We show here that the guanylyl cyclase ODR-1 functions non-cell-autonomously to downregulate ASH-mediated aversive behaviors and that ectopic cGMP generation in ASH is sufficient to dampen ASH sensitivity. We define a gap junction neural network that regulates nociception and propose that decentralized regulation of ASH signaling can allow for rapid correlation between an animal’s internal state and its behavioral output, lending modulatory flexibility to this hard-wired nociceptive neural circuit. PMID:27459302

Aversive Behavior in the Nematode C. elegans Is Modulated by cGMP and a Neuronal Gap Junction Network.

PubMed

Krzyzanowski, Michelle C; Woldemariam, Sarah; Wood, Jordan F; Chaubey, Aditi H; Brueggemann, Chantal; Bowitch, Alexander; Bethke, Mary; L'Etoile, Noelle D; Ferkey, Denise M

2016-07-01

All animals rely on their ability to sense and respond to their environment to survive. However, the suitability of a behavioral response is context-dependent, and must reflect both an animal's life history and its present internal state. Based on the integration of these variables, an animal's needs can be prioritized to optimize survival strategies. Nociceptive sensory systems detect harmful stimuli and allow for the initiation of protective behavioral responses. The polymodal ASH sensory neurons are the primary nociceptors in C. elegans. We show here that the guanylyl cyclase ODR-1 functions non-cell-autonomously to downregulate ASH-mediated aversive behaviors and that ectopic cGMP generation in ASH is sufficient to dampen ASH sensitivity. We define a gap junction neural network that regulates nociception and propose that decentralized regulation of ASH signaling can allow for rapid correlation between an animal's internal state and its behavioral output, lending modulatory flexibility to this hard-wired nociceptive neural circuit.

Characteristics of wood ash and influence on soil properties and nutrient uptake: an overview.

PubMed

Demeyer, A; Voundi Nkana, J C; Verloo, M G

2001-05-01

Wood industries and power plants generate enormous quantities of wood ash. Disposal in landfills has been for long a common method for removal. New regulations for conserving the environment have raised the costs of landfill disposal and added to the difficulties for acquiring new sites for disposal. Over a few decades a number of studies have been carried out on the utilization of wood ashes in agriculture and forestry as an alternative method for disposal. Because of their properties and their influence on soil chemistry the utilization of wood ashes is particularly suited for the fertility management of tropical acid soils and forest soils. This review principally focuses on ash from the wood industry and power plants and considers its physical, chemical and mineralogical characteristics, its effect on soil properties, on the availability of nutrient elements and on the growth and chemical composition of crops and trees, as well as its impact on the environment.

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.

Recovery of phosphorus compounds from thermally-processed wastes

NASA Astrophysics Data System (ADS)

Czechowska-Kosacka, A.; Pawłowski, L.; Niedbala, G.; Cel, W.

2018-05-01

Depletion of phosphorus deposits is one of the most serious global problems, which may soon lead to a crisis in food production. It is estimated that if the current living standard is maintained, the available reserves will be depleted in 130 years. Considering the principle of sustainable development, searching for alternative phosphorus sources is extremely important. The work presented the results of the research on the possibility of utilizing wastes as a source of phosphorus. The studies were conducted on poultry manure. The physicochemical properties of phosporus-rich wastes were determined as well. The fertilizing properties of ashes from poultry manure combustion – obtained from different systems, i.e. caged and barn production. The assimilability of phosphorus from the obtained ashes was determined. Potential applications of phosphorus-rich ashes were proposed as well.

Use of municipal solid waste incineration bottom ashes in alkali-activated materials, ceramics and granular applications: A review.

PubMed

Silva, R V; de Brito, J; Lynn, C J; Dhir, R K

2017-10-01

This paper presents a literature review on the incorporation of municipal solid waste incinerated bottom ash as raw material in several markets, other than those where it is conventionally used, such as geotechnical applications and road pavement construction. The main findings of an ample selection of experimental investigations on the use of the bottom ash as precursor of alkali-activated materials, as an adsorbent material for the removal of hazardous elements from wastewater and landfill gases, as soil replacement in agricultural activities, as partial or complete substitute of raw materials for the manufacture of ceramic-based products, as landfill cover and as biogas production enhancer, were gathered, collated and analysed. Copyright © 2017 Elsevier Ltd. All rights reserved.

The normalised wildfire ash index (NWAI): a remote sensing approach for quantifying post-wildfire ash loads

NASA Astrophysics Data System (ADS)

Chris, Chafer; Doerr, Stefan; Santin, Cristina

2017-04-01

The impacts of wildfire ash, the powdery residue from fuel burning, on post-fire ecosystems are many and diverse. Ash is a source of nutrients and can help the recovery of vegetation. It can also contain substantial amounts of recalcitrant carbon and thus contribute to long-term carbon storage. In its initial state, the ash layer on the ground can protect the bare soil, mitigating post-fire water erosion by runoff. However, when the adsorbent capability of this layer is exceeded, ash can be transported into the hydrological network and be a major contributor to water contamination. Ash can also contribute to post-fire mass movements such as debris flows. The eco-hydro-geomorphic impacts of ash on post-fire ecosystems are therefore important, but remain poorly quantified. A fundamental step in that direction is the understanding of ash production and distribution at the landscape scale, which would allow incorporating ash as a key parameter into post-fire risk models. We have developed a new spectral index (NWAI) using Landsat imagery to model the spatial distribution of ash loads in the post-fire landscape. It was developed based on a severe wildfire that burnt 13,000 ha of dry eucalyptus forest near Sydney and has also been tested for a forested area burnt by the catastrophic 2009 Black Saturday fires near Melbourne. Although ecosystem and fire characteristics differed substantially between the Sydney and Melbourne fires, our NWAI index performs well. In this contribution we will discuss the (i) the principles of the NWAI and (ii) its potential for pollution risk forecasting.

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.

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.

The Role of Authigenic Volcanic Ash in Marine Sediment

NASA Astrophysics Data System (ADS)

Scudder, R.; McKinley, C. C.; Thomas, D. J.; Murray, R. W.

2016-12-01

Marine sediments are a fundamental archive of the history of weathering and erosion, biological productivity, volcanic activity, patterns of deep-water formation and circulation, and a multitude of other earth, ocean, and atmosphere processes. In particular, the record and consequences of volcanic eruptions have long fascinated humanity. Volcanic ash layers are often visually stunning, and can have thicknesses of 10s of cm or more. While the ash layer records are of great importance by themselves, we are missing a key piece of information-that of the very fined grained size fractions. Dispersed ash is the very fine grained-component that has either been mixed into the bulk sediment by bioturbation, or is deposited from subaqueous eruptions, erosion of terrestrial deposits, general input during time periods of elevated global volcanism, or other mechanisms, plays an important role in the marine sediment. The presence of dispersed ash in the marine record has previously been relatively over-looked as it is difficult to identify petrographically due to its commonly extremely fine grain size and/or alteration to authigenic clay. The dispersed ash, either altered or unaltered, is extremely difficult to differentiate from detrital/terrigenous/authigenic clay, as they are all "aluminosilicates". Here we apply a combined geochemical, isotopic, and statistical technique that enables us to resolve volcanic from detrital terrigenous inputs at DSDP/ODP/IODP sites from both the Brazil Margin and the Northwest Pacific Oceans. Incorporating the combined geochemical/statistical techniques with radiogenic isotope records allows us to address paleoceanographic questions in addition to studies of the effect of sediment fluxes on carbon cycling, the relationship between volcanic ash and biological productivity of the open ocean and nutrient availability for subseafloor microbial life.

Leaching characteristics of toxic constituents from coal fly ash mixed soils under the influence of pH.

PubMed

Komonweeraket, Kanokwan; Cetin, Bora; Benson, Craig H; Aydilek, Ahmet H; Edil, Tuncer B

2015-04-01

Leaching behaviors of Arsenic (As), Barium (Ba), Calcium (Ca), Cadmium (Cd), Magnesium (Mg), Selenium (Se), and Strontium (Sr) from soil alone, coal fly ash alone, and soil-coal fly ash mixtures, were studied at a pH range of 2-14 via pH-dependent leaching tests. Seven different types of soils and coal fly ashes were tested. Results of this study indicated that Ca, Cd, Mg, and Sr showed cationic leaching pattern while As and Se generally follows an oxyanionic leaching pattern. On the other hand, leaching of Ba presented amphoteric-like leaching pattern but less pH-dependent. In spite of different types and composition of soil and coal fly ash investigated, the study reveals the similarity in leaching behavior as a function of pH for a given element from soil, coal fly ash, and soil-coal fly ash mixtures. The similarity is most likely due to similar controlling mechanisms (e.g., solubility, sorption, and solid-solution formation) and similar controlling factors (e.g., leachate pH and redox conditions). This offers the opportunity to transfer knowledge of coal fly ash that has been extensively characterized and studied to soil stabilized with coal fly ash. It is speculated that unburned carbon in off-specification coal fly ashes may provide sorption sites for Cd resulting in a reduction in concentration of these elements in leachate from soil-coal fly ash mixture. Class C fly ash provides sufficient CaO to initiate the pozzolanic reaction yielding hydrated cement products that oxyanions, including As and Se, can be incorporated into. Copyright © 2014 Elsevier Ltd. All rights reserved.

Improving volcanic ash predictions with the HYSPLIT dispersion model by assimilating MODIS satellite retrievals

NASA Astrophysics Data System (ADS)

Chai, Tianfeng; Crawford, Alice; Stunder, Barbara; Pavolonis, Michael J.; Draxler, Roland; Stein, Ariel

2017-02-01

Currently, the National Oceanic and Atmospheric Administration (NOAA) National Weather Service (NWS) runs the HYSPLIT dispersion model with a unit mass release rate to predict the transport and dispersion of volcanic ash. The model predictions provide information for the Volcanic Ash Advisory Centers (VAAC) to issue advisories to meteorological watch offices, area control centers, flight information centers, and others. This research aims to provide quantitative forecasts of ash distributions generated by objectively and optimally estimating the volcanic ash source strengths, vertical distribution, and temporal variations using an observation-modeling inversion technique. In this top-down approach, a cost functional is defined to quantify the differences between the model predictions and the satellite measurements of column-integrated ash concentrations weighted by the model and observation uncertainties. Minimizing this cost functional by adjusting the sources provides the volcanic ash emission estimates. As an example, MODIS (Moderate Resolution Imaging Spectroradiometer) satellite retrievals of the 2008 Kasatochi volcanic ash clouds are used to test the HYSPLIT volcanic ash inverse system. Because the satellite retrievals include the ash cloud top height but not the bottom height, there are different model diagnostic choices for comparing the model results with the observed mass loadings. Three options are presented and tested. Although the emission estimates vary significantly with different options, the subsequent model predictions with the different release estimates all show decent skill when evaluated against the unassimilated satellite observations at later times. Among the three options, integrating over three model layers yields slightly better results than integrating from the surface up to the observed volcanic ash cloud top or using a single model layer. Inverse tests also show that including the ash-free region to constrain the model is not beneficial for the current case. In addition, extra constraints on the source terms can be given by explicitly enforcing no-ash for the atmosphere columns above or below the observed ash cloud top height. However, in this case such extra constraints are not helpful for the inverse modeling. It is also found that simultaneously assimilating observations at different times produces better hindcasts than only assimilating the most recent observations.

Exploring the reaction channels between arsine and the hydroxyl radical

NASA Astrophysics Data System (ADS)

Viana, Rommel B.

2017-10-01

The aim of this study was to present the reaction mechanism channels between arsine (AsH3) and hydroxyl (OH) which was evaluated at CCSD(T)/CBS//CCSD/cc-pVTZ level. One potential channel is the hydrogen abstraction pathway (R1), leading to AsH2 and H2O products, which occurs due to the formation of an entrance complex (AsH3OH) followed by a 1,2-hydrogen shift pathway (involving the proton transfer from the arsine group to hydroxyls, with one leading to the products). Additional channels are accessed via H-elimination pathways of the entrance complexes, forming arsinous acid (AsH2OH; R2) and arsine oxide (AsH3O; R3). In this respect, R2 is the only exoergic route of the three exit channels, representing the major branching ratio at 200-1000 K and, after 2000 K, R1 increases gradually becoming the major route of this reaction. In contrast, even at 4000 K, R3 is a highly unfeasible pathway. Therefore, the information predicted here provides new insights into the neutral-neutral chemical reaction dynamics regarding the Group V hydrides. On the other side, the R2 pathway may have some potential to solve the arsine oxidation puzzle as a possible primary pathway to the arsenic-oxygen species formation.

The effects of different types of nano-silicon dioxide additives on the properties of sludge ash mortar.

PubMed

Luo, Huan-Lin; Chang, Wei-Che; Lin, Deng-Fong

2009-04-01

To improve the drawbacks caused by the sludge ash replacement in mortar, the previous studies have shown that the early strength and durability of sludge ash/cement mortar are improved by adding nano-silicon dioxide (nano-SiO2) to mortar. In this article, three types of nano-SiO2--SS, HS, and SP (manufacturer code names)--were applied to sludge ash/cement mixture to make paste or mortar specimens. The object is to further extend the recycle of the sludge ash by determining the better type of nano-SiO2 additive to improve properties of sludge ash/ cement paste or mortar. The cement was replaced by 0, 10, 20, and 30% of sludge ash, and 0 and 2% of nano-SiO2 additives were added to the sludge ash paste or mortar specimens. Tests such as setting time, compressive strength, scanning electron microscopy, X-ray diffraction, nuclear magnetic resonance, and thermogravimetric analysis/differential thermal analysis were performed in this study. Test results show that nano-SiO2 additives can not only effectively increase the hydration product (calcium silicate hydrate [C-S-H] gel), but also make the crystal structure denser. Among the three types of nano-SiO2 additive, the SS type can best improve the properties of sludge ash/cement paste or mortar, followed by the SP and HS types.

Constraining the Energetics of Explosive Lava-Water Interactions

NASA Astrophysics Data System (ADS)

Fitch, E. P.; Fagents, S. A.

2017-12-01

During volcanic eruptions, water, such as groundwater or melted ice or snow, may interact with magma within the conduit during eruption, generating explosions when the heat of the magma causes the water to rapidly turn to steam and expand, resulting in what we call a "phreatomagmatic" eruption. In 2010, the eruption of Eyjafjallajökull volcano in Iceland produced a plume of fine ash, through the interaction between magma and glacial melt water, which resulted in the closure of substantial airspace, ultimately costing a total of almost 5 billion dollars. Although an important area of study, it is difficult to quantify the effect of eternal water on eruption intensity when the gas inside of magma is also expanding and fragmenting the magma. In an attempt to understand the energetics of magma-water interactions, small-scale laboratory experiments have been performed. Explosion energy is found to depend mostly on kinetic energy, which is proportional to dispersal distance, and fragmentation energy, which is proportional to the mean grain size of the ejecta, and the mass percent of ash-sized grains. It is thought that in order to generate heat transfer rates sufficiently rapid to cause explosive detonation, the source melt must be finely fragmented, producing ash-sized grains. Those grains undergo brittle fragmentation due to rapid cooling and weak shock waves generated by the vaporization of superheated water. We take the novel approach of studying explosive interactions between lava and water to obtain additional explosion energy constraints. We identified and analyzed numerous beds of lava-water explosion ejecta of varying explosion energy, and we analyzed the ash-sized grains of these beds in detail. We verified that the mass of ash-sized grains increases with increasing explosion energy, and can form at the interface between lava and water. We found that brittle fragmentation occurs to a greater degree as grain size decreases and that the ash of highly-energetic explosions undergoes the most brittle fragmentation. Therefore, our next steps will be to use these results to constrain the fragmentation and kinetic energy, in order to calculate the total energy and heat-transfer rate of lava-water explosions as important analogs for phreatomagmatic eruptions.

Wood ash to treat sewage sludge for agricultural use

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

White, R.K.

About 90% of the three million tons of wood ash generated in the United States from wood burning facilities is being landfilled. Many landfills are initiated tipping fees and/or restrictions on the disposal of special wastes such as ash. The purpose of this work was to evaluate (1) the feasibility of using wood ash to stabilize sewage sludge and (2) the fertilizer and liming value of the sludge/ash mixture on plant response and soil pH. Research showed that wood ash, when mixed with sludge, will produce a pH above 12.0, which meets US EPA criteria for pathogen reduction for landmore » application on non-direct food chain crops. Different ratios of wood ash to sludge mixtures were tested and the 1:1 ratio (by weight) was found to be optimal. Five replications of wood ash from four sources were tested for moisture content, pH and fertilizer nutrients. The pH of the ash/sludge mixture (1:1) on day one ranged from 12.4 to 13.2. In most cases the pH remained the same over a 21 day test or only dropped 0.1 to 0.3 units. Analyses of the mixtures showed that heavy metal concentrations (As, B, Cd, Co, Cr, Cu, Mn, Mo, Ni, Pb, S, Se, Zn) were low. The 1:1 ash/sludge mixture had a calcium carbonate equivalency of 17%. Green house pot studies using tall fescue grass were loadings of 300 to 750 pounds per acre of TKN-N than for 500 lb/acre of 10-10-10 commercial fertilizer. Plant tissue analysis showed N, P, K, Ca, and Mg levels to be within the sufficiency range for tall fescue.« less

Heating Plant Options Economic Analysis System (HPECON): User’s Manual and Technical Reference

DTIC Science & Technology

1991-03-01

Bulb Temperature: The temperature of dry air. Dry Scrubber: A flue gas desulfurization system in which sulfur dioxide is collected by a solid medium...method of solution of a problem. Flue Gas : The gaseous products of combustion. Fly Ash: The fine particles of ash which are carried by the products...AFM 88-29 (U.S. Air Force, July 1978); TM 5-785 (U.S. Army, July 1978); NAVFAC P-89 (Naval Facilities Engineering Command, July 1978). " Flue Gas

Environmentally-mediated ash aggregate formation: example from Tungurahua volcano, Ecuador

NASA Astrophysics Data System (ADS)

Kueppers, Ulrich; Ayris, Paul M.; Bernard, Benjamin; Delmelle, Pierre; Douillet, Guilhem A.; Lavallée, Yan; Mueller, Sebastian B.; Dingwell, Donald B.; Dobson, Kate J.

2016-04-01

Volcanic ash is generated during explosive eruptions through an array of different processes; it can be produced in large quantities and can, in some circumstances, have the potential for far-reaching impacts beyond the flanks of the volcano. Aggregation of ash particles can significantly impact the dispersal within the atmosphere, and its subsequent deposition into terrestrial or aquatic environments. However, our understanding of the complex interplay of the boundary conditions which permit aggregation to occur remain incomplete. Tungurahua volcano, Ecuador, has been intermittently active since 1999. In August 2006, a series of pyroclastic density currents (PDC) were generated during a series of dry, Vulcanian explosions and travelled down the western and northern flanks of the volcano. In some locations, the related PDC deposits temporarily dammed the Chambo river, and the residual heat within those deposits produced vigorous steam plumes. During several field campaigns (2009-2015), we mapped, sampled, and analysed the related deposits. At the base of the Rea ravine, a large delta fan of PDC deposits had dammed the river over a length of several hundred metres. In several outcrops adjacent to the river and in small erosional gullies we found a peculiar stratigraphic layer (up to ten centimetres thick) at the top of the PDC deposits. As this layer is capped by a thin fall unit of coarse ash that we also find elsewhere at the top of the August 2006 deposits, the primary nature is without doubt. In this unit, we observed abundant ash aggregates up to eight millimetres in diameter within a poorly sorted, ash-depleted lapilli tuff, primarily comprised of rounded pumiceous and scoriaceous clasts of similar size. Leaching experiments have shown that these aggregates contain several hundred ppm of soluble sulphate and chloride salts. Recent laboratory experiments (Mueller et al. 2015) have suggested that in order for accretionary lapilli to be preserved within ash deposits likely requires a combination of sufficient humidity and a pre-existing soluble salt load on aggregating ash particles. We suggest that steam pluming from the dammed Chambo river, coupled with soluble salts emplaced by gas-ash interactions between ejection and deposition, provided a unique opportunity for the formation of accretionary lapilli with sufficient mechanical strength to survive deposition, accounting for their presence in a deposit otherwise absent of such aggregates. This possibility provides an important reminder of the role played by external environmental triggers in shaping the properties volcanic ash deposits.

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.

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.

Volcanic Ash on Slopes of Karymsky

NASA Technical Reports Server (NTRS)

2007-01-01

A volcanic eruption can produce gases, lava, bombs of rock, volcanic ash, or any combination of these elements. Of the volcanic products that linger on the land, most of us think of hardened lava flows, but volcanic ash can also persist on the landscape. One example of that persistence appeared on Siberia's Kamchatka Peninsula in spring 2007. On March 25, 2007, the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA's Terra satellite captured this image of the area around the Karymsky Volcano. In this image, volcanic ash from earlier eruptions has settled onto the snowy landscape, leaving dark gray swaths. The ash stains are confined to the south of the volcano's summit, one large stain fanning out toward the southwest, and another toward the east. At first glance, the ash stain toward the east appears to form a semicircle north of the volcano and sweep back east. Only part of this dark shape, however, is actually volcanic ash. Near the coast, the darker color may result from thicker vegetation. Similar darker coloring appears to the south. Volcanic ash is not really ash at all, but tiny, jagged bits of rock and glass. These jagged particles pose serious health risks to humans and animals who might inhale them. Likewise, the ash poses hazards to animals eating plants that have been coated with ash. Because wind can carry volcanic ash thousands of kilometers, it poses a more far-reaching hazard than other volcanic ejecta. Substantial amounts of ash can even affect climate by blocking sunlight. Karymsky is a stratovolcano composed of alternating layers of solidified ash, hardened lava, and volcanic rocks. It is one of many active volcanoes on Russia's Kamchatka Peninsula, which is part of the 'Ring of Fire' around the Pacific Rim. NASA image created by Jesse Allen, using data provided courtesy of the NASA/GSFC/MITI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team.

Assessment of mobility and bioavailability of contaminants in MSW incineration ash with aquatic and terrestrial bioassays.

PubMed

Ribé, V; Nehrenheim, E; Odlare, M

2014-10-01

Incineration of municipal solid waste (MSW) is a waste treatment method which can be sustainable in terms of waste volume reduction as well as a source of renewable energy. In the process fly and bottom ash is generated as a waste material. The ash residue may vary greatly in composition depending on the type of waste incinerated and it can contain elevated levels of harmful contaminants such as heavy metals. In this study, the ecotoxicity of a weathered, untreated incineration bottom ash was characterized as defined by the H14 criterion of the EU Waste Framework Directive by means of an elemental analysis, leaching tests followed by a chemical analysis and a combination of aquatic and solid-phase bioassays. The experiments were conducted to assess the mobility and bioavailability of ash contaminants. A combination of aquatic and terrestrial bioassays was used to determine potentially adverse acute effects of exposure to the solid ash and aqueous ash leachates. The results from the study showed that the bottom ash from a municipal waste incineration plant in mid-Sweden contained levels of metals such as Cu, Pb and Zn, which exceeded the Swedish EPA limit values for inert wastes. The chemical analysis of the ash leachates showed high concentrations of particularly Cr. The leachate concentration of Cr exceeded the limit value for L/S 10 leaching for inert wastes. Filtration of leachates prior to analysis may have underestimated the leachability of complex-forming metals such as Cu and Pb. The germination test of solid ash and ash leachates using T. repens showed a higher inhibition of seedling emergence of seeds exposed to the solid ash than the seeds exposed to ash leachates. This indicated a relatively low mobility of toxicants from the solid ash into the leachates, although some metals exceeded the L/S 10 leaching limit values for inert wastes. The Microtox® toxicity test showed only a very low toxic response to the ash leachate exposure, while the D. magna immobility test showed a moderately high toxic effect of the ash leachates. Overall, the results from this study showed an ecotoxic effect of the solid MSW bottom ash and the corresponding ash leachates. The material may therefore pose an environmental risk if used in construction applications. However, as the testing of the solid ash was rather limited and the ash leachate showed an unusually high leaching of Cr, further assessments are required in order to conclusively characterize the bottom ash studied herein as hazardous according to the H14 criterion. Copyright © 2014 Elsevier Ltd. All rights reserved.

The enrichment behavior of natural radionuclides in pulverized oil shale-fired power plants.

PubMed

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

2014-12-01

The oil shale industry is the largest producer of NORM (Naturally Occurring Radioactive Material) waste in Estonia. Approximately 11-12 million tons of oil shale containing various amounts of natural radionuclides is burned annually in the Narva oil shale-fired power plants, which accounts for approximately 90% of Estonian electricity production. The radionuclide behavior characteristics change during the fuel combustion process, which redistributes the radionuclides between different ash fractions. Out of 24 operational boilers in the power plants, four use circulating fluidized bed (CFB) technology and twenty use pulverized fuel (PF) technology. Over the past decade, the PF boilers have been renovated, with the main objective to increase the efficiency of the filter systems. Between 2009 and 2012, electrostatic precipitators (ESP) in four PF energy blocks were replaced with novel integrated desulphurization technology (NID) for the efficient removal of fly ash and SO2 from flue gases. Using gamma spectrometry, activity concentrations and enrichment factors for the (238)U ((238)U, (226)Ra, (210)Pb) and (232)Th ((232)Th, (228)Ra) family radionuclides as well as (40)K were measured and analyzed in different PF boiler ash fractions. The radionuclide activity concentrations in the ash samples increased from the furnace toward the back end of the flue gas duct. The highest values in different PF boiler ash fractions were in the last field of the ESP and in the NID ash, where radionuclide enrichment factors were up to 4.2 and 3.3, respectively. The acquired and analyzed data on radionuclide activity concentrations in different PF boiler ashes (operating with an ESP and a NID system) compared to CFB boiler ashes provides an indication that changes in the fuel (oil shale) composition and boiler working parameters, as well as technological enhancements in Estonian oil shale fired power plants, have had a combined effect on the distribution patterns of natural radionuclides in the oil shale combustion products. Copyright © 2014 Elsevier Ltd. All rights reserved.

Stochastic Modelling of the Hydraulic Anisotropy of Ash Impoundment Sediment

NASA Astrophysics Data System (ADS)

Slávik, Ivan

2017-12-01

In the case reported here the impoundments of a 400 MW coal heated power plant with an annual production of about 1.5 million tons of fuel ash are of the cross-valley type, operated by the simple and cheap „upstream method”. The aim of the research was to determine overall and local values of the permeability in horizontal as well as in vertical direction and the anisotropy of the thin-layered sedimented ash. The coal ashes are hydraulically transported through pipelines in form of a slurry and periodically floated on the beach of the impoundment. The ashes are deposited in the form of a thin-layered sediment, with random alternation of layers with a coarser or finer granularity. The ash impoundment sediment is anthropogenic sediment with horizontally laminated texture. Therefore, the sediment is anisotropic from the viewpoint of water seepage. The knowledge of the permeability and the seepage anisotropy of the sediment is a basic requirement for the design of an appropriate dewatering system. The seepage anisotropy of the ash sediment has been checked by means of stochastic modelling, based on the correlation between the effective grain diameter and the coefficient of permeability of the ash: the effective grain diameter and the thickness of individual layers have been proposed to be random events.

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

Lindberg, Daniel, E-mail: daniel.lindberg@abo.fi; Molin, Camilla, E-mail: camilla.molin@abo.fi; Hupa, Mikko, E-mail: mikko.hupa@abo.fi

Highlights: • We review the thermal treatment methods for ashes and residues from WtE plants. • We review the results from extensive laboratory work on vitrification, melting and vaporization of ash. • We analyze the results from the extensive patent literature on thermal treatment. • We review industrial concepts for thermal treatment of ash. - Abstract: Thermal treatment methods of bottom ash, fly ash and various types of APC (air pollution control) residues from waste-to-energy plants can be used to obtain environmentally stable material. The thermal treatment processes are meant to reduce the leachability of harmful residue constituents, destroy toxicmore » organic compounds, reduce residue volume, and produce material suitable for utilization. Fly ash and APC residues often have high levels of soluble salts, particularly chlorides, metals such as cadmium, lead, copper and zinc, and trace levels of organic pollutants such as dioxins and furans. Different thermal treatment methods can be used to either decompose or stabilize harmful elements and compounds in the ash, or separate them from the ash to get a material that can be safely stored or used as products or raw materials. In the present paper, thermal treatment methods, such as sintering, vitrification, and melting have been reviewed. In addition to a review of the scientific literature, a survey has been made of the extensive patent literature in the field.« less

Hydrothermal liquefaction of harvested high-ash low-lipid algal biomass from Dianchi Lake: effects of operational parameters and relations of products.

PubMed

Tian, Chunyan; Liu, Zhidan; Zhang, Yuanhui; Li, Baoming; Cao, Wei; Lu, Haifeng; Duan, Na; Zhang, Li; Zhang, Tingting

2015-05-01

Hydrothermal liquefaction (HTL) allows a direct conversion of algal biomass into biocrude oil, not only solving the environmental issues caused by the over-growing algae but also producing renewable energy. This study reports HTL of algae after separation from eutrophicated Dianchi Lake in China. Conversion efficiency was studied under different operational conditions via an orthogonal design, including holding temperature (HT) (260-340 °C), retention time (RT) (30-90 min) and total solid (TS) (10-20%). A highest biocrude oil yield (18.4%, dry ash-free basis, daf) was achieved at 300 °C, 60 min, and 20% (TS), due to the low contents of lipids (1.9%, daf) and proteins (24.8%, daf), and high contents of ash (41.6%, dry basis) and carbohydrates (71.8%, daf). Operational parameters significantly affected the biocrude yields, and chemical distribution of HTL products. The biocrude production also related to other HTL products, and involved chemical reactions, such as deoxygenation and/or denitrogenation. Copyright © 2014 Elsevier Ltd. All rights reserved.

Preliminary study on removing Cs⁺/Sr²⁺ by activated porous calcium silicate-A by-product from high-alumina fly ash recycling industry.

PubMed

Chu, Yingying; Wang, Rong; Chen, Mengjun

2015-01-01

¹³⁷Cs⁺/⁹⁰Sr²⁺-containing radioactive wastewater is one of the most important problems that the world has been facing with. A by-product, activated porous calcium silicate, is generated at high levels by the pre-desiliconizing and soda-lime-sintering processes for producing Al₂O₃from high-alumina fly ash. In order to examine if this by-product could be used as an absorbent for removal of ¹³⁷Cs⁺/⁹⁰Sr²⁺ from radioactive wastewater, various parameters, such as pH, adsorbent dose, contact time, and initial concentration, were discussed. Results indicated that the equilibrium reached in about 2 hr. Activated porous calcium silicate was highly pH sensitive and able to remove Cs(+)/Sr²⁺ in a near-neutral environment. The adsorption equilibrium was best described by Freundlich isotherm equations, and the adsorption of Cs⁺/Sr²⁺ was a physical process. The adsorption kinetic data could be better fitted by the pseudo-second-order model, and the adsorption was controlled by multidiffusion. Current study showed that activated porous calcium silicate has a good adsorption of Cs⁺/Sr²⁺ for their removal. However, other characteristics, such as selectivity because of coexisting cations, elution and regeneration, thermal stability, and acid resistance, should be discussed carefully before using it in an actual field.

Modified fly ash from municipal solid waste incineration as catalyst support for Mn-Ce composite oxides

NASA Astrophysics Data System (ADS)

Chen, Xiongbo; Liu, Ying; Yang, Ying; Ren, Tingyan; Pan, Lang; Fang, Ping; Chen, Dingsheng; Cen, Chaoping

2017-08-01

Fly ash from municipal solid waste incineration was modified by hydrothermal treatment and used as catalyst support for Mn-Ce composite oxides. The prepared catalyst showed good activity for the selective catalytic reduction (SCR) of NO by NH3. A NO conversion of 93% could be achieved at 300 °C under a GHSV of 32857 h-1. With the help of characterizations including XRD, BET, SEM, TEM, XPS and TPR, it was found that hydrothermal treatment brought a large surface area and abundant mesoporous to the modified fly ash, and Mn-Ce composite oxides were highly dispersed on the surface of the support. These physical and chemical properties were the intrinsic reasons for the good SCR activity. This work transformed fly ash into high value-added products, providing a new approach to the resource utilization and pollution control of fly ash.

Synthesis, crystal growth, optical, thermal, and mechanical properties of a nonlinear optical single crystal: ammonium sulfate hydrogen sulphamate (ASHS)

NASA Astrophysics Data System (ADS)

Sudhakar, K.; Nandhini, S.; Muniyappan, S.; Arumanayagam, T.; Vivek, P.; Murugakoothan, P.

2018-04-01

Ammonium sulfate hydrogen sulphamate (ASHS), an inorganic nonlinear optical crystal, was grown from the aqueous solution by slow evaporation solution growth technique. The single-crystal XRD confirms that the grown single crystal belongs to the orthorhombic system with the space group of Pna21. Powder XRD confirms the crystalline nature and the diffraction planes were indexed. Crystalline perfection of grown crystal was analysed by high-resolution X-ray diffraction rocking curve technique. UV-Vis-NIR studies revealed that ASHS crystal has optical transparency 65% and lower cut-off wavelength at 218 nm. The violet light emission of the crystal was identified by photoluminescence studies. The particle size-dependent second-harmonic generation efficiency for ASHS crystal was evaluated by Kurtz-Perry powder technique using Nd:YAG laser which established the existence of phase matching. Surface laser damage threshold value was evaluated using Nd:YAG laser. Optical homogeneity of the crystal was evaluated using modified channel spectrum method through birefringence study. Thermal analysis reveals that ASHS crystal is stable up to 213 °C. The mechanical behaviour of the ASHS crystal was analysed using Vickers microhardness study.

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.

Heavy metals in MSW incineration fly ashes

NASA Astrophysics Data System (ADS)

Ferreira, C.; Ribeiro, A.; Ottosen, L.

2003-05-01

Incineration is a common solution for dealing with the increasing amount of municipal solid waste (MSW). During the process, the heavy metals initially present in the waste go through several transformations, ending up in combustion products, such as fly ash. This article deals with some issues related to the combustion of MSW and the formation of fly ash, especially in what concerns heavy metals. Treatment of the flue gas in air pollution control equipment plays an important role and the basic processes to accomplish this are explained. Fly ash from a semi-dry flue gas treatment system is characterized regarding its physical-chemical properties: pH, solubility, chemical composition, and leaching, amongst others. Results indicate a high alkalinity and the presence of large amounts of calcium, chlorides, sulfates, carbonates, sodium and potassium. Metal concentrations in fly ash are: 6,2g/kg for zinc, 2,4g/kg for lead, 1,7g/kg for iron, and 7,9g/kg for magnesium. Copper, manganese, chromium and cadmium are also present with 546, 338, 104 and 91mg/kg of fly ash, respectively. These results are extremely important in subsequent studies on the treatment of fly ash.

Risk assessment of heavy metals from combustion of pelletized municipal sewage sludge.

PubMed

Xiao, Zhihua; Yuan, Xingzhong; Leng, Lijian; Jiang, Longbo; Chen, Xiaohong; Zhibin, Wu; Xin, Peng; Jiachao, Zhang; Zeng, Guangming

2016-02-01

Fly ash and slag are important by-products obtained from combustion of municipal sewage sludge (MSS) after pelletization. The quantitative environmental impact assessment of heavy metals in fly ash and slag, compared to MSS, were performed in accordance with bioavailability and eco-toxicity, geo-accumulation index (GAI), risk assessment code (RAC), and potential ecological risk index (PERI). The results demonstrated that not only direct but also long-term bioavailability and eco-toxicity of heavy metals in fly ash and slag decreased except direct bioavailability and eco-toxicity of Pb in fly ash. The GAI demonstrated that combustion significantly weakened (P < 0.05) the pollution levels of heavy metals. PERI indicated that all risks attributed to heavy metals were significantly lowered (P < 0.05) from 777.07 (very high risk) in MSS to 288.72 (moderate risk) and 64.55 (low risk) in fly ash and slag, respectively. In terms of the RAC, seven heavy metals had low even no risk to the environments after combustion besides As in slag. The environmental risk of heavy metals in fly ash and slag was decreased compared with MSS. However, the results of PERI showed that fly ash had a moderate risk.

Assessing quality in volcanic ash soils

Treesearch

Terry L. Craigg; Steven W. Howes

2007-01-01

Forest managers must understand how changes in soil quality resulting from project implementation affect long-term productivity and watershed health. Volcanic ash soils have unique properties that affect their quality and function; and which may warrant soil quality standards and assessment techniques that are different from other soils. We discuss the concept of soil...

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...

Evaluation of non-invasive trunk sprays and trunk-injected emamectic benzoate

Treesearch

Deborah G. McCullough; D.L. Cappaert; T.M. Poland; A.C. Anulewicz; P. Lewis; J. Molongoski

2008-01-01

In 2007, we continued to evaluate two neo-nicotinoid insecticides, imidacloprid and dinotefuron, applied as non-invasive trunk sprays to control emerald ash borer (EAB), Agrilus planipennis Fairmaire. Neo-nicotinoid products are widely used to protect landscape ash trees because they are relatively safe for humans and non-target species. These...

Petrographic, mineralogical, and chemical characterization of certain Alaskan coals and washability products. Final report, July 11, 1978-October 11, 1980

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

Rao, P.D.; Wolff, E.N.

1981-05-01

Petrological, mineralogical and chemical characterization provides basic information needed for proper utilization of coals. Since many of these coals are likely to be beneficiated to reduce ash, the influence of coal washing on the characteristics of the washed product is important. Twenty samples of Alaskan coal seams were used for this study. The coals studied ranged in rank from lignite to high volatile A bituminous with vitrinite/ulminite reflectance ranging from 0.25 to 1.04. Fifteen raw coals were characterized for proximate and ultimate analysis reflectance rank, petrology, composition of mineral matter, major oxides and trace elements in coal ash. Washability productsmore » of three coals from Nenana, Beluga and Matanuska coal fields were used for characterization of petrology, mineral matter and ash composition. Petrological analysis of raw coals and float-sink products showed that humodetrinite was highest in top seam in a stratigraphic sequence« less

Applications of Nano palm oil fuel ash and Nano fly ash in concrete

NASA Astrophysics Data System (ADS)

Hamada, Hussein M.; Jokhio, Gul Ahmed; Mat Yahaya, Fadzil; Humada, Ali M.

2018-04-01

This paper discusses the applications of Nano waste materials including palm oil fuel ash and fly ash in the concrete production. The implementation of nanotechnology has been instrumental in the development of significant interest among the stakeholders to improve the mechanical and chemical properties of materials involved in the production of concrete. Although many researchers have shown the potential of nanomaterials to increase strength and durability of concrete and improve its physical and chemical properties, there is still a knowledge gap regarding the preparation of Nano waste materials from agricultural waste to use as cement replacement instead of non-renewable materials. Therefore, it should be focused on to study Nano- waste materials to benefit from these characteristics during preparation of concrete mixtures. Therefore, this paper highlights the potential of waste materials in the Nano size to partially replace cement in concrete and achieve the same or better result than the traditional concrete. This paper recommends to conduct further experimental works to improve the concrete material properties by investigating the properties of waste materials in Nano size.

New spectrophotometric and radiochemical assays for acetyl-CoA: arylamine N-acetyltransferase applicable to a variety of arylamines

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

Andres, H.H.; Klem, A.J.; Szabo, S.M.

1985-03-01

Simple and sensitive spectrophotometric and radiochemical procedures are described for the assay of acetyl-CoA:arylamine N-acetyltransferase (NAT), which catalyzes the reaction acetyl-CoA + arylamine----N-acetylated arylamine + CoASH. The methods are applicable to crude tissue homogenates and blood lysates. The spectrophotometric assay is characterized by two features: (i) NAT activity is measured by quantifying the disappearance of the arylamine substrate as reflected by decreasing Schiff's base formation with dimethylaminobenzaldehyde. (ii) During the enzymatic reaction, the inhibitory product CoASH is recycled by the system acetyl phosphate/phosphotransacetylase to the substrate acetyl-CoA. The radiochemical procedure depends on enzymatic synthesis of (/sup 3/H)acetyl-CoA in the assaymore » using (/sup 3/H)acetate, ATP, CoASH, and acetyl-CoA synthetase. NAT activity is measured by quantifying N-(/sup 3/H)acetylarylamine after separation from (/sup 3/H)acetate by extraction. Product inhibition by CoASH is prevented in this system by the use of acetyl-CoA synthetase.« less