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Sample records for cement treated soils

  1. Physical and geotechnical properties of cement-treated clayey soil using silica nanoparticles: An experimental study

    NASA Astrophysics Data System (ADS)

    Ghasabkolaei, N.; Janalizadeh, A.; Jahanshahi, M.; Roshan, N.; Ghasemi, Seiyed E.

    2016-05-01

    This study investigates the use of nanosilica to improve geotechnical characteristics of cement-treated clayey soil from the coastal area of the eastern Caspian Sea in the Golestan province, Iran. Atterberg limits, unconfined compressive strength, and California bearing ratio (CBR) tests were performed to investigate the soil plastic and strength parameters. The specimens were prepared by mixing soil with 9% cement and various contents of nanosilica. An ultrasonic bath device was used to disperse nanosilica in water. The addition of nanosilica enhanced the strength parameters of the clayey soil. Moreover, a nanosilica percentage of 1.5% by weight of cement improved the compressive strength of the cement-treated clay up to 38%, at age of 28 days. A scanning electron microscope (SEM) and an atomic force microscope (AFM) were used to evaluate specimen morphology. SEM and AFM results confirm the experimental ones. Therefore, nanosilica can be employed for soil improvement in geotechnical engineering.

  2. pH-dependent leaching behaviour and other performance properties of cement-treated mixed contaminated soil.

    PubMed

    Kogbara, Reginald B; Al-Tabbaa, Abir; Yi, Yaolin; Stegemann, Julia A

    2012-01-01

    Portland cement has been widely used for stabilisation/solidification (S/S) treatment of contaminated soils. However, there is a dearth of literature on pH-dependent leaching of contaminants from cement-treated soils. This study investigates the leachability of Cu, Pb, Ni, Zn and total petroleum hydrocarbons (TPH) from a mixed contaminated soil. A sandy soil was spiked with 3000 mg/kg each of Cd, Cu, Pb, Ni and Zn, and 10,000 mg/kg of diesel, and treated with ordinary Portland cement (CEM I). Four different binder dosages, 5%, 10%, 15% and 20% (m/m) and different water contents ranging from 13%-19% dry weight were used in order to find a safe operating envelope for the treatment process. The pH-dependent leaching behaviour of the treated soil was monitored over an 84-day period using a 3-point acid neutralisation capacity (ANC) test. The monolithic leaching test was also conducted. Geotechnical properties such as unconfined compressive strength (UCS), hydraulic conductivity and porosity were assessed over time. The treated soils recorded lower leachate concentrations of Ni and Zn compared to the untreated soil at the same pH depending on binder dosage. The binder had problems with Pb stabilisation and TPH leachability was independent of pH and binder dosage. The hydraulic conductivity of the mixes was generally of the order, 10(-8) m/sec, while the porosity ranged from 26%-44%. The results of selected performance properties are compared with regulatory limits and the range of operating variables that lead to acceptable performance described. PMID:23520871

  3. Apparatus for treating cement kiln dust

    SciTech Connect

    Galli, R.

    1986-04-22

    An apparatus is described for treating cement kiln dust comprising an elongate reaction chamber, kiln dust entry means in the reaction chamber, atomized-spray nozzles in the reaction chamber for introducing atomized spray to kiln dust, separate conduits for liquid and gas separately connected to the atomized-spray nozzles for atomizing liquid by gas to form a fog of the liquid in an atmosphere of the gas, mixing means in the reaction chamber for mixing the kiln dust in contact with the fog and gaseous atmosphere of the reaction chamber, discharge means at one end of the reaction chamber for discharging the mixed and contacted kiln dust product from the reaction chamber. The kiln dust entry means are located in an upper region of the reaction chamber for depositing kiln dust gravitationally to a lower region of the reaction chamber. The atomized-spray nozzles are located in the upper region of the reaction chamber for depositing fog on kiln dust during mixing thereof, gas entry means on the reaction chamber for delivering gas to the reaction chamber for reaction with kiln dust and fog, gas exit means on the reaction chamber for discharging gas products from the reaction chamber. The gas entry and exit means are at opposite ends of the reaction chamber, and pre-entry liquid atomizing spray means in the gas entry means for treating gas by atomized liquid spray to effectively saturate the gas before delivery to the reaction chamber.

  4. Experimental study on the electrical resistivity of soil cement admixtures

    NASA Astrophysics Data System (ADS)

    Liu, Song Yu; Du, Yan Jun; Han, L. H.; Gu, M. F.

    2008-05-01

    Recently in China, soil cement is widely used to improve the soft ground in the highway construction engineering. Literature studies are mainly investigating the mechanical properties of the soil cement, while its properties of the electrical resistivity are not well addressed. In this paper, the properties of the electrical resistivity of the reconstituted soil-cement and the in situ soil cement columns are investigated. The test results show that the electrical resistivity of the soil cement increases with the increase in the cement-mixing ratio and curing time, whereas it decreases with the increase in the water content, degree of saturation and water cement ratio. A simple equation is proposed to predict the electrical resistivity of soil cement under the condition of the specified curing time and water cement ratio. It is found that the electrical resistivity has a good relationship with the unconfined compression strength and blow count of SPT. It is expected that the electrical resistivity method can be widely used for checking/controlling the quality of soil cement in practice.

  5. Process for treating contaminated soil

    SciTech Connect

    Lebowitz, H.E.; Kulik, C.J.

    1995-10-24

    A process is provided for treating soil contaminated with oils, tars and light hydrocarbons. A slurry is formed with coal, water and the contaminated soil and agitated at elevated temperature, resulting in the transfer of the oil from the soil to the coal. The coal and soil mixture is then dewatered for disposal by burning or burial in a landfill. 2 figs.

  6. Hydraulic Conductivity of Residual Soil-Cement Mix

    NASA Astrophysics Data System (ADS)

    Govindasamy, P.; Taha, M. R.

    2016-07-01

    In Malaysia, although there are several researches on engineering properties of residual soils, however study on the hydraulic conductivity properties of metasedimentary residual soils is still lacking. Construction of containment walls like slurry wall techniques can be achieved with hydraulic conductivity of approximately 5 x 10-7cm/sec. The objectives of the study were to determine the physical properties of metasedimentary residual soils and to determine the influence of 1%, 3%, 5% and 10% of cement on hydraulic conductivity parameters. The coefficient of hydraulic conductivity of the soil naturally and soil-cement mixtures were determined by using the falling head test. According to the test, the hydraulic conductivity of the original soil was 4.16 x 10-8 m/s. The value decreases to 3.89 x 10-8 m/s, 2.78 x 10-8 m/s then 6.83 x 10-9 m/s with the addition of 1%, 3% and 5% of cement additives, respectively. During the hydration process, cement hydrates is formed followed by the increase in pH value and Ca(OH)2 which will alter the modification of pores size and distribution. When the quantity of cement increases, the pores size decrease. But, the addition of 10% cement gives an increased hydraulic conductivity value to 2.78 x 10-8 m/s. With 10%, the pore size increase might due to flocculation and agglomeration reaction. The generated hydraulic conductivity values will indirectly become a guide in the preliminary soil cement stabilization to modify the properties of the soil to become more like the properties of a soft rock.1. Introduction

  7. Criteria for Remote Sensing Detection of Sulfate Cemented Soils on Mars

    NASA Technical Reports Server (NTRS)

    Cooper, Christopher D.; Mustard, John F.

    2000-01-01

    Spectral measurements of loose and cemented mixtures of palagonitic soil and sulfates were made to determine whether cemented soils could be identified on Mars. Cemented MgSO4 mixtures exhibit an enhanced 9 micron sulfate fundamental compared to gypsum mixtures due to more diffuse and pervasive cementing.

  8. Stabilization/solidification of selenium-impacted soils using Portland cement and cement kiln dust.

    PubMed

    Moon, Deok Hyun; Grubb, Dennis G; Reilly, Trevor L

    2009-09-15

    Stabilization/solidification (S/S) processes were utilized to immobilize selenium (Se) as selenite (SeO(3)(2-)) and selenate (SeO(4)(2-)). Artificially contaminated soils were prepared by individually spiking kaolinite, montmorillonite and dredged material (DM; an organic silt) with 1000 mg/kg of each selenium compound. After mellowing for 7 days, the Se-impacted soils were each stabilized with 5, 10 and 15% Type I/II Portland cement (P) and cement kiln dust (C) and then were cured for 7 and 28 days. The toxicity characteristic leaching procedure (TCLP) was used to evaluate the effectiveness of the S/S treatments. At 28 days curing, P doses of 10 and 15% produced five out of six TCLP-Se(IV) concentrations below 10mg/L, whereas only the 15% C in DM had a TCLP-Se(IV) concentration <10mg/L. Several treatments satisfied the USEPA TCLP best demonstrated available technology (BDAT) limits (5.7 mg/L) for selenium at pozzolan doses up to 10 times less than the treatments that established the BDAT. Neither pozzolan was capable of reducing the TCLP-Se(VI) concentrations below 25mg/L. Se-soil-cement slurries aged for 30 days enabled the identification of Se precipitates by X-ray powder diffraction (XRD) and scanning electron microscopy (SEM)-energy dispersive X-ray spectroscopy (EDX). XRD and SEM-EDX analyses of the Se(IV)- and Se(VI)-soil-cement slurries revealed that the key selenium bearing phases for all three soil-cement slurries were calcium selenite hydrate (CaSeO(3).H(2)O) and selenate substituted ettringite (Ca(6)Al(2)(SeO(4))(3)(OH)(12).26H(2)O), respectively.

  9. Compressive strength of cement stabilized fly ash-soil mixtures

    SciTech Connect

    Kaniraj, S.R.; Havanagi, V.G.

    1999-05-01

    Rajghat fly ash from Delhi, India, and Baumineral fly ash near Bochum, Germany, were mixed with the locally available soils -- silt and Yamuna sand with Rajghat fly ash and Rhine sand with Baumineral fly ash -- in different proportions. Cement, varying from 3--9%, was added to stabilize the fly ash-soil mixtures. Cylindrical samples were prepared at optimum moisture content and maximum dry density and were cured for different duration. Unconfined compression tests were conducted on these samples. Correlations for unconfined compressive strength and secant modulus as functions of curing time, fly ash content, and cement content have been established. The data were analyzed with other correlations recommended in literature and comparisons between the correlations have been made. Correlations for water content as functions of curing time and cement content have also been established.

  10. Peach leaf responses to soil and cement dust pollution.

    PubMed

    Maletsika, Persefoni A; Nanos, George D; Stavroulakis, George G

    2015-10-01

    Dust pollution can negatively affect plant productivity in hot, dry and with high irradiance areas during summer. Soil or cement dust were applied on peach trees growing in a Mediterranean area with the above climatic characteristics. Soil and cement dust accumulation onto the leaves decreased the photosynthetically active radiation (PAR) available to the leaves without causing any shade effect. Soil and mainly cement dust deposition onto the leaves decreased stomatal conductance, photosynthetic and transpiration rates, and water use efficiency due possibly to stomatal blockage and other leaf cellular effects. In early autumn, rain events removed soil dust and leaf functions partly recovered, while cement dust created a crust partially remaining onto the leaves and causing more permanent stress. Leaf characteristics were differentially affected by the two dusts studied due to their different hydraulic properties. Leaf total chlorophyll decreased and total phenol content increased with dust accumulation late in the summer compared to control leaves due to intense oxidative stress. The two dusts did not cause serious metal imbalances to the leaves, except of lower leaf K content.

  11. Cemented Volcanic Soils, Martian Spectra and Implications for the Martian Climate

    NASA Technical Reports Server (NTRS)

    Bishop, J. L.; Schiffman, P.; Drief, A.; Southard, R. J.

    2004-01-01

    Cemented soils formed via reactions with salts are studied here and provide information about the climate when they formed. Spectroscopic and microprobe studies have been performed on cemented volcanic crusts in order to learn about the composition of these materials, how they formed, and what they can tell us about climatic interactions with surface material on Mars to form cemented soils. These crusts include carbonate, sulfate and opaline components that may all be present in cemented soil units on Mars.

  12. A Model of Thermal Conductivity for Planetary Soils. 2; Theory for Cemented Soils

    NASA Technical Reports Server (NTRS)

    Piqueux, S.; Christensen, P. R.

    2009-01-01

    A numerical model of heat conduction through particulate media made of spherical grains cemented by various bonding agents is presented. The pore-filling gas conductivity, volume fraction, and thermal conductivity of the cementing phase are tunable parameters. Cement fractions <0.001-0.01% in volume have small effects on the soil bulk thermal conductivity. A significant conductivity increase (factor 3-8) is observed for bond fractions of 0.01 to 1% in volume. In the 1 to 15% bond fraction domain, the conductivity increases continuously but less intensely (25-100% conductivity increase compared to a 1% bond system). Beyond 15% of cements, the conductivity increases vigorously and the bulk conductivity rapidly approaches that of bedrock. The composition of the cements (i.e. conductivity) has little influence on the bulk thermal inertia of the soil, especially if the volume of bond <10%. These results indicate that temperature measurements are sufficient to detect cemented soils and quantify the amount of cementing phase, but the mineralogical nature of the bonds and the typical grain size are unlikely to be determined from orbit. On Mars, a widespread surface unit characterized by a medium albedo (0.19-0.26) and medium/high thermal inertia (200-600 J s(0.5)/sq m/K) has long been hypothesized to be associated with a duricrust. The fraction of cement required to fit the thermal data is less than approx.1-5% by volume. This small amount of material is consistent with orbital observations, confirming that soil cementation is an important factor controlling the thermal inertia of the Martian surface

  13. Mechanism for the stabilization/solidification of arsenic-contaminated soils with Portland cement and cement kiln dust.

    PubMed

    Yoon, In-Ho; Moon, Deok Hyun; Kim, Kyoung-Woong; Lee, Keun-Young; Lee, Ji-Hoon; Kim, Min Gyu

    2010-11-01

    In this study, the mechanism for the stabilization/solidification (S/S) of arsenic (As)-contaminated soils with Portland cement (PC), and cement kiln dust (CKD) using 1 N HCl extraction fluid, X-ray powder diffraction (XRPD), X-ray absorption near edge structure (XANES) and Extended X-ray absorption fine structure (EXAFS) spectroscopy was investigated. The degree of As immobilization after stabilization was assessed using a 1 N HCl extraction on the basis of the Korean Standard Test (KST). After 1 day of curing with 30 wt% PC and 7 days of curing with 50 wt% CKD, the concentration of As leached from the amended soils was less than the Korean countermeasure standard (3 mg L(-1)). The As concentrations in the leachate treated with PC and CKD were significantly decreased at pH > 3, indicating that pH had a prevailing influence on As mobility. XRPD results indicated that calcium arsenite (Ca-As-O) and sodium calcium arsenate hydrate (NaCaAsO(4).7.5H(2)O) were present in the PC- and CKD-treated slurries as the key phases responsible for As(III) and As(V) immobilization, respectively. The XANES spectroscopy confirmed that the As(III) and As(V) oxidation states of the PC and CKD slurry samples were consistent with the speciated forms in the crystals identified by XRPD. EXAFS spectroscopy showed As-Ca bonding in the As(III)-PC and As(III)-CKD slurries. The main mechanism for the immobilization of As-contaminated soils with PC and CKD was strongly associated with the bonding between As(III) or As(V) and Ca.

  14. Iron filings cement engineered soil mix

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bioretention cells are used in urban stormwater management to reduce storm surge and nutrient loss. The cells are filled with mixtures of soil, sand, compost, and other materials, and are underlain by a drain. The purpose of this study was to determine if iron filings would be a suitable filter for ...

  15. A mild alkali treated jute fibre controlling the hydration behaviour of greener cement paste.

    PubMed

    Jo, Byung-Wan; Chakraborty, Sumit

    2015-01-16

    To reduce the antagonistic effect of jute fibre on the setting and hydration of jute reinforced cement, modified jute fibre reinforcement would be a unique approach. The present investigation deals with the effectiveness of mild alkali treated (0.5%) jute fibre on the setting and hydration behaviour of cement. Setting time measurement, hydration test and analytical characterizations of the hardened samples (viz., FTIR, XRD, DSC, TGA, and free lime estimation) were used to evaluate the effect of alkali treated jute fibre. From the hydration test, the time (t) required to reach maximum temperature for the hydration of control cement sample is estimated to be 860 min, whilst the time (t) is measured to be 1040 min for the hydration of a raw jute reinforced cement sample. However, the time (t) is estimated to be 1020 min for the hydration of an alkali treated jute reinforced cement sample. Additionally, from the analytical characterizations, it is determined that fibre-cement compatibility is increased and hydration delaying effect is minimized by using alkali treated jute fibre as fibre reinforcement. Based on the analyses, a model has been proposed to explain the setting and hydration behaviour of alkali treated jute fibre reinforced cement composite.

  16. A mild alkali treated jute fibre controlling the hydration behaviour of greener cement paste

    NASA Astrophysics Data System (ADS)

    Jo, Byung-Wan; Chakraborty, Sumit

    2015-01-01

    To reduce the antagonistic effect of jute fibre on the setting and hydration of jute reinforced cement, modified jute fibre reinforcement would be a unique approach. The present investigation deals with the effectiveness of mild alkali treated (0.5%) jute fibre on the setting and hydration behaviour of cement. Setting time measurement, hydration test and analytical characterizations of the hardened samples (viz., FTIR, XRD, DSC, TGA, and free lime estimation) were used to evaluate the effect of alkali treated jute fibre. From the hydration test, the time (t) required to reach maximum temperature for the hydration of control cement sample is estimated to be 860 min, whilst the time (t) is measured to be 1040 min for the hydration of a raw jute reinforced cement sample. However, the time (t) is estimated to be 1020 min for the hydration of an alkali treated jute reinforced cement sample. Additionally, from the analytical characterizations, it is determined that fibre-cement compatibility is increased and hydration delaying effect is minimized by using alkali treated jute fibre as fibre reinforcement. Based on the analyses, a model has been proposed to explain the setting and hydration behaviour of alkali treated jute fibre reinforced cement composite.

  17. A mild alkali treated jute fibre controlling the hydration behaviour of greener cement paste.

    PubMed

    Jo, Byung-Wan; Chakraborty, Sumit

    2015-01-01

    To reduce the antagonistic effect of jute fibre on the setting and hydration of jute reinforced cement, modified jute fibre reinforcement would be a unique approach. The present investigation deals with the effectiveness of mild alkali treated (0.5%) jute fibre on the setting and hydration behaviour of cement. Setting time measurement, hydration test and analytical characterizations of the hardened samples (viz., FTIR, XRD, DSC, TGA, and free lime estimation) were used to evaluate the effect of alkali treated jute fibre. From the hydration test, the time (t) required to reach maximum temperature for the hydration of control cement sample is estimated to be 860 min, whilst the time (t) is measured to be 1040 min for the hydration of a raw jute reinforced cement sample. However, the time (t) is estimated to be 1020 min for the hydration of an alkali treated jute reinforced cement sample. Additionally, from the analytical characterizations, it is determined that fibre-cement compatibility is increased and hydration delaying effect is minimized by using alkali treated jute fibre as fibre reinforcement. Based on the analyses, a model has been proposed to explain the setting and hydration behaviour of alkali treated jute fibre reinforced cement composite. PMID:25592665

  18. A mild alkali treated jute fibre controlling the hydration behaviour of greener cement paste

    PubMed Central

    Jo, Byung-Wan; Chakraborty, Sumit

    2015-01-01

    To reduce the antagonistic effect of jute fibre on the setting and hydration of jute reinforced cement, modified jute fibre reinforcement would be a unique approach. The present investigation deals with the effectiveness of mild alkali treated (0.5%) jute fibre on the setting and hydration behaviour of cement. Setting time measurement, hydration test and analytical characterizations of the hardened samples (viz., FTIR, XRD, DSC, TGA, and free lime estimation) were used to evaluate the effect of alkali treated jute fibre. From the hydration test, the time (t) required to reach maximum temperature for the hydration of control cement sample is estimated to be 860 min, whilst the time (t) is measured to be 1040 min for the hydration of a raw jute reinforced cement sample. However, the time (t) is estimated to be 1020 min for the hydration of an alkali treated jute reinforced cement sample. Additionally, from the analytical characterizations, it is determined that fibre-cement compatibility is increased and hydration delaying effect is minimized by using alkali treated jute fibre as fibre reinforcement. Based on the analyses, a model has been proposed to explain the setting and hydration behaviour of alkali treated jute fibre reinforced cement composite. PMID:25592665

  19. Reduction of soil pollution by usingwaste of the limestone in the cement industry

    NASA Astrophysics Data System (ADS)

    Muñoz, M. Cecilia Soto; Robles Castillo, Marcelo; Blanco Fernandez, David; Diaz Gonzalez, Marcos; Naranjo Lamilla, Pedro; Moore Undurraga, Fernando; Pardo Fabregat, Francisco; Vidal, Manuel Miguel Jordan; Bech, Jaume; Roca, Nuria

    2016-04-01

    In the cement manufacturing process (wet) a residue is generated in the flotation process. This builds up causing contamination of soil, groundwater and agricultural land unusable type. In this study to reduce soil and water pollution 10% of the dose of cement was replaced by waste of origin limestone. Concretes were produced with 3 doses of cement and mechanical strengths of each type of concrete to 7, 28 and 90 days were determined. the results indicate that the characteristics of calcareous residue can replace up to 10% of the dose of cement without significant decreases in strength occurs. It is noted that use of the residue reduces the initial resistance, so that the dose of cement should not be less than 200 kg of cement per m3. The results allow recommends the use of limestone waste since it has been observed decrease in soil and water contamination without prejudice construction material Keywords: Soil contamination; Limestone residue; Adding concrete

  20. Stabilization/solidification of lead-contaminated soil using cement and rice husk ash.

    PubMed

    Yin, Chun-Yang; Mahmud, Hilmi Bin; Shaaban, Md Ghazaly

    2006-10-11

    This paper presents the findings of a study on solidification/stabilization (S/S) of lead-contaminated soil using ordinary Portland cement (OPC) and rice husk ash (RHA). The effects of varying lead concentrations (in the form of nitrates) in soil samples on the physical properties of their stabilized forms, namely unconfined compressive strength (UCS), setting times of early mixtures and changes in crystalline phases as well as chemical properties such as leachability of lead, pH and alkalinity of leachates are studied. Results have indicated that usage of OPC with RHA as an overall binder system for S/S of lead-contaminated soils is more favorable in reducing the leachability of lead from the treated samples than a binder system with standalone OPC. On the other hand, partial replacement of OPC with RHA in the binder system has reduced the UCS of solidified samples. PMID:16784809

  1. Soil Remediation of an Arsenic-Contaminated Site With Ferrous Sulfate and Type V Portland Cement

    NASA Astrophysics Data System (ADS)

    Illera, V.; O'Day, P. A.; Rivera, N.; Root, R.; Rafferty, M. T.; Vlassopoulos, D.

    2005-12-01

    High levels of arsenic are present in a site adjacent to San Francisco Bay (in East Palo Alto, CA) as a consequence of the activity of a former pesticide manufacturing plant. Most of the readily accessible arsenic at the site has been removed by remedial excavation and surface capping. In-situ fixation of residual arsenic was performed close to the source about 10 years ago where arsenic values in capped soils ranged from 500 to 5000 mg kg-1. The fixation method consisted of the addition of ferrous sulfate (3% w/w), type V Portland cement (10% w/w) and water. Both products were mixed with the contaminated soil to a treatment depth between 1.5 and 9 meters. The treated soil was then capped to prevent weathering. This long-term amended soil offers an opportunity to compare the processes that prevent microbial arsenic reduction and control the immobilization of arsenic in the treated soils versus natural soils, and to study the aging effects of arsenic sorption. Solid phase characterization of soil samples from both the field and controlled laboratory experiments were carried out to study the speciation and bioavailability of arsenic and to ascertain the mechanisms of the arsenic immobilization in the treated soil. These methods included physical description by field observations, X-ray diffraction (XRD), scanning electron microscopy with energy dispersive spectroscopy, total elemental concentrations, and solid phase fractionation by sequential extraction. Both synchrotron X-ray absorption spectroscopy (XAS) and XRD measurements were used to determine oxidation state of arsenic and iron and host phases present in the soil. The remedial treatment was successful in immobilizing the arsenic in the contaminated soil, and decreasing its leachability. Measurements taken at short aging times (during the first month) showed that the treatment was effective in reducing leachable arsenic as evidenced by the TCLP wet test (< 5 mg l-1 leached). The field amendment influenced

  2. Mechanical and leaching behaviour of slag-cement and lime-activated slag stabilised/solidified contaminated soil.

    PubMed

    Kogbara, Reginald B; Al-Tabbaa, Abir

    2011-05-01

    Stabilisation/solidification (S/S) is an effective technique for reducing the leachability of contaminants in soils. Very few studies have investigated the use of ground granulated blast furnace slag (GGBS) for S/S treatment of contaminated soils, although it has been shown to be effective in ground improvement. This study sought to investigate the potential of GGBS activated by cement and lime for S/S treatment of a mixed contaminated soil. A sandy soil spiked with 3000mg/kg each of a cocktail of heavy metals (Cd, Ni, Zn, Cu and Pb) and 10,000mg/kg of diesel was treated with binder blends of one part hydrated lime to four parts GGBS (lime-slag), and one part cement to nine parts GGBS (slag-cement). Three binder dosages, 5, 10 and 20% (m/m) were used and contaminated soil-cement samples were compacted to their optimum water contents. The effectiveness of the treatment was assessed using unconfined compressive strength (UCS), permeability and acid neutralisation capacity (ANC) tests with determination of contaminant leachability at the different acid additions. UCS values of up to 800kPa were recorded at 28days. The lowest coefficient of permeability recorded was 5×10(-9)m/s. With up to 20% binder dosage, the leachability of the contaminants was reduced to meet relevant environmental quality standards and landfill waste acceptance criteria. The pH-dependent leachability of the metals decreased over time. The results show that GGBS activated by cement and lime would be effective in reducing the leachability of contaminants in contaminated soils. PMID:21420148

  3. Mechanical and leaching behaviour of slag-cement and lime-activated slag stabilised/solidified contaminated soil.

    PubMed

    Kogbara, Reginald B; Al-Tabbaa, Abir

    2011-05-01

    Stabilisation/solidification (S/S) is an effective technique for reducing the leachability of contaminants in soils. Very few studies have investigated the use of ground granulated blast furnace slag (GGBS) for S/S treatment of contaminated soils, although it has been shown to be effective in ground improvement. This study sought to investigate the potential of GGBS activated by cement and lime for S/S treatment of a mixed contaminated soil. A sandy soil spiked with 3000mg/kg each of a cocktail of heavy metals (Cd, Ni, Zn, Cu and Pb) and 10,000mg/kg of diesel was treated with binder blends of one part hydrated lime to four parts GGBS (lime-slag), and one part cement to nine parts GGBS (slag-cement). Three binder dosages, 5, 10 and 20% (m/m) were used and contaminated soil-cement samples were compacted to their optimum water contents. The effectiveness of the treatment was assessed using unconfined compressive strength (UCS), permeability and acid neutralisation capacity (ANC) tests with determination of contaminant leachability at the different acid additions. UCS values of up to 800kPa were recorded at 28days. The lowest coefficient of permeability recorded was 5×10(-9)m/s. With up to 20% binder dosage, the leachability of the contaminants was reduced to meet relevant environmental quality standards and landfill waste acceptance criteria. The pH-dependent leachability of the metals decreased over time. The results show that GGBS activated by cement and lime would be effective in reducing the leachability of contaminants in contaminated soils.

  4. Reuse of grits waste for the production of soil--cement bricks.

    PubMed

    Siqueira, F B; Holanda, J N F

    2013-12-15

    This investigation focuses on the reuse of grits waste as a raw material for replacing Portland cement by up to 30 wt.% in soil-cement bricks. The grits waste was obtained from a cellulose factory located in south-eastern Brazil. We initially characterized the waste sample with respect to its chemical composition, X-ray diffraction, fineness index, morphology, pozzolanic activity, and pollution potential. Soil-cement bricks were then prepared using the waste material and were tested to determine their technological properties (e.g., water absorption, apparent density, volumetric shrinkage, and compressive strength). Microstructural evolution was accompanied by confocal microscopy. It was found that the grits waste is mainly composed of calcite (CaCO3) particles. Our results indicate that grits waste can be used economically, safely, and sustainably at weight percentages of up to 20% to partially replace Portland cement in soil-cement bricks. PMID:24140481

  5. Reuse of grits waste for the production of soil--cement bricks.

    PubMed

    Siqueira, F B; Holanda, J N F

    2013-12-15

    This investigation focuses on the reuse of grits waste as a raw material for replacing Portland cement by up to 30 wt.% in soil-cement bricks. The grits waste was obtained from a cellulose factory located in south-eastern Brazil. We initially characterized the waste sample with respect to its chemical composition, X-ray diffraction, fineness index, morphology, pozzolanic activity, and pollution potential. Soil-cement bricks were then prepared using the waste material and were tested to determine their technological properties (e.g., water absorption, apparent density, volumetric shrinkage, and compressive strength). Microstructural evolution was accompanied by confocal microscopy. It was found that the grits waste is mainly composed of calcite (CaCO3) particles. Our results indicate that grits waste can be used economically, safely, and sustainably at weight percentages of up to 20% to partially replace Portland cement in soil-cement bricks.

  6. Effect of drying-wetting cycles on leaching behavior of cement solidified lead-contaminated soil.

    PubMed

    Li, Jiang-Shan; Xue, Qiang; Wang, Ping; Li, Zhen-Ze; Liu, Lei

    2014-12-01

    Lead contaminated soil was treated by different concentration of ordinary Portland cement (OPC). Solidified cylindrical samples were dried at 40°C in oven for 48 h subsequent to 24h of immersing in different solution for one drying-wetting. 10 cycles were conducted on specimens. The changes in mass loss of specimens, as well as leaching concentration and pH of filtered leachates were studied after each cycle. Results indicated that drying-wetting cycles could accelerate the leaching and deterioration of solidified specimens. The cumulative leached lead with acetic acid (pH=2.88) in this study was 109, 83 and 71 mg respectively for solidified specimens of cement-to-dry soil (C/Sd) ratios 0.2, 0.3 and 0.4, compared to 37, 30, and 25mg for a semi-dynamic leaching test. With the increase of cycle times, the cumulative mass loss of specimens increased linearly, but pH of filtered leachates decreased. The leachability and deterioration of solidified specimens increased with acidity of solution. Increases of C/Sd clearly reduced the leachability and deterioration behavior.

  7. [Peculiarities of structure-function organization of microbial groups of soil contaminated by cement dust].

    PubMed

    Stefurak, V P

    2001-01-01

    Long-term contamination of the forest soil by the cement dust leads to disturbances of stability of natural microbial groups, changes their quantitative and qualitative composition, results in substitution of some microbial associations by other ones. The intensive contamination of the soil by the effluents of cement integrated works, inhibits the intensity of nitrogen fixation processes and decay of the forest litter, development of micromycetes, results in the decrease of the length of mycelium and its biomass. PMID:11692672

  8. May bone cement be used to treat benign aggressive bone tumors of the feet with confidence?

    PubMed

    Özer, Devrim; Er, Turgay; Aycan, Osman Emre; Öke, Ramadan; Coşkun, Mehmet; Kabukçuoğlu, Yavuz Selim

    2014-03-01

    Using bone cement for the reconstruction of defects created after curettage of benign aggressive bone tumors is among acceptable methods. The study aimed to assess the effect of bone cement used in aggressive bone tumors in the feet on the function of the feet. Five patients were reviewed. They were treated between 2004 and 2010. Three cases were female and two male. Their age ranged from 16 to 55 with an average of 34.8. Follow up period ranged from 14 to 86 months with an average of 34. Two cases were giant cell tumor of bone located in calcaneus and 3 were solid variant aneurysmal bone cyst located in talus, navicular and first proximal phalanx. None had any previous treatment. A biopsy was done in all cases. Treatment was curettage, high speed burring (except phalanx case), and filling the cavity with bone cement. The case located in talus recurred and re-operated 1 year later doing the same procedure. Final evaluation included physical examination, X-ray and Maryland Foot Score. No recurrence was present in the final evaluation. No problems were detected related to bone cement. Maryland Foot Scores ranged 84-100, average of 94. Cement integrity was not disturbed. The procedure is found not to effect foot functions adversely.

  9. Stabilization treatment of soft subgrade soil by sewage sludge ash and cement.

    PubMed

    Chen, Li; Lin, Deng-Fong

    2009-02-15

    In this study, incinerated sewage sludge ash (ISSA) is mixed with cement in a fixed ratio of 4:1 for use as a stabilizer to improve the strength of soft, cohesive, subgrade soil. Five different ratios (in wt%: 0%, 2%, 4%, 8%, and 16%) of ISSA/cement admixture are mixed with cohesive soil to make soil samples. In order to understand the influences of admixtures on the soil properties, tests of the pH value, Atterberg limits, compaction, California bearing ratio (CBR), unconfined compressive strength, and triaxial compression were performed on those samples. The study shows that the unconfined compressive strength of specimens with the ISSA/cement addition was improved to approximately 3-7 times better than that of the untreated soil; furthermore, the swelling behavior was also effectively reduced as much as 10-60% for those samples. In some samples, the ISSA/cement additive improved the CBR values by up to 30 times that of untreated soil. This suggests that ISSA/cement has many potential applications in the field of geotechnical engineering. PMID:18579294

  10. Characteristics and mechanical properties of acrylolpamidronate-treated strontium containing bioactive bone cement.

    PubMed

    Li, Z Y; Yang, C; Lu, W W; Xu, B; Lam, W M; Ni, G X; Abbah, S A; Yang, F; Cheung, K M C; Luk, K D K

    2007-11-01

    The aim of the present study was to determine the influence of surface treatment on the mechanical properties of strontium-containing hydroxyapatite (Sr-HA) bioactive bone cement. Previously we developed an injectable bioactive cement (SrHAC) system composed of Sr-HA powders and bisphenol A diglycidylether dimethacrylate (Bis-GMA). In this study, the Sr-HA powder was subjected to surface treatment using acrylolpamidronate, a bisphosphonate derivative, which has a polymerizable group, to improve the interface between inorganic filler and organic matrix by binding Sr-HA and copolymerizing into the matrix. After surface treatment, the compression strength, bending strength, and stiffness of the resulting composites were defined by using a material testing machine (MTS) according to ISO 5833. The fracture surface of the bone cement specimen was observed with a scanning electron microscope. Invitro cytotoxicity of surface-treated SrHAC was also studied using a tetrazolium-based cell viability assay (MTS/pms) on human osteoblast-like cells, the SaOS-2 cell line. Cells were seeded at a density of 10(4)/mL and allowed to grow in an incubator for 48 h at 37 degrees C. Results indicated that after surface treatment, the compression strength and stiffness significantly improved by 22.68 and 14.51%, respectively. The bending strength and stiffness of the bioactive bone cement also showed 19.06 and 8.91% improvements via three-point bending test. The fracture surface micromorphology after compression and bending revealed that the bonding between the resin to surface-treated filler considerably improved. The cell viability indicated that the treated particles were nontoxic and did not inhibit cell growth. This study demonstrated a new surface chemistry route to enhance the covalent bonds between inorganic fillers and polymer matrix for improving the mechanical properties of bone cement. This method not only improves the overall mechanical performance but also increases

  11. Effects of direct land application of calcitic lime and lime- and cement kiln dust-sanitized biosolids on the chemical and spectroscopic characteristics of soil lipids

    SciTech Connect

    Dinel, H.; Schnitzer, M.; Pare, T.; Topp, E. ); Lemee, L.; Ambles, A. . Lab. de Chimie); Pelzer, N. )

    1999-05-01

    To determine the extent to which applications of calcitic lime and sanitized biosolids affect the quality of soil organic matter (SOM), lipids extracted from an unamended soil (CON) and from soils amended with calcitic lime (CAL), and lime (LSB)- and cement kiln dust (CDB)-sanitized biosolids were characterized by chemical analysis and Pyrolysis-Gas chromatography (Py-GC). From diethyl ether (DEE) and CHCl[sub 3] soluble lipids, and from weight ratios of the extracts, the organic matter in the soil amended with CDB-treated biosolids seemed to be more biodegraded and biochemically inert than the organic matter in soils that received LSB-treated biosolids and calcitic lime and that in the control soil.

  12. Metals distribution in soils around the cement factory in southern Jordan.

    PubMed

    Al-Khashman, Omar A; Shawabkeh, Reyad A

    2006-04-01

    Thirty one soil samples were collected from south Jordan around the cement factory in Qadissiya area. The samples were obtained at two depths, 0-10 cm and 10-20 cm and were analyzed by atomic absorption spectrophotometery for Pb, Zn, Cd, Fe, Cu and Cr. Physicochemical factors believed to affect their mobility of metals in soil of the study area were examined such as; pH, TOM, CaCO3, CEC and conductivity. The relatively high concentrations of lead, zinc and cadmium in the soil samples of the investigated area were related to anthropogenic sources such as cement industry, agriculture activities and traffic emissions. It was found that the lead, zinc and cadmium have the highest level in area close to the cement factory, while the concentration of chromium was low. This study indicate that all of the metals are concentrated on the surface soil, and decreased in the lower part of the soil, this due to reflects their mobility and physical properties of soil and its alkaline pH values. The use of factor analysis showed that anthropogenic activities seem to be the responsible source of pollution for metals in urban soils. PMID:16361028

  13. Metals distribution in soils around the cement factory in southern Jordan.

    PubMed

    Al-Khashman, Omar A; Shawabkeh, Reyad A

    2006-04-01

    Thirty one soil samples were collected from south Jordan around the cement factory in Qadissiya area. The samples were obtained at two depths, 0-10 cm and 10-20 cm and were analyzed by atomic absorption spectrophotometery for Pb, Zn, Cd, Fe, Cu and Cr. Physicochemical factors believed to affect their mobility of metals in soil of the study area were examined such as; pH, TOM, CaCO3, CEC and conductivity. The relatively high concentrations of lead, zinc and cadmium in the soil samples of the investigated area were related to anthropogenic sources such as cement industry, agriculture activities and traffic emissions. It was found that the lead, zinc and cadmium have the highest level in area close to the cement factory, while the concentration of chromium was low. This study indicate that all of the metals are concentrated on the surface soil, and decreased in the lower part of the soil, this due to reflects their mobility and physical properties of soil and its alkaline pH values. The use of factor analysis showed that anthropogenic activities seem to be the responsible source of pollution for metals in urban soils.

  14. Treating giant cell tumours with curettage, electrocautery, burring, phenol irrigation, and cementation.

    PubMed

    Moon, Myung-Sang; Kim, Sung-SooS S; Moon, Jeong-Lim; Kim, Sung-Sim; Moon, Hanlim

    2013-08-01

    PURPOSE. To report on 23 patients with giant cell tumour (GCT) of the femur or tibia treated with curettage, electrocautery, burring, phenol irrigation, and cementation. METHODS. Records of these 14 men and 9 women aged 22 to 38 (mean, 31) years were reviewed. The most common site involved was the distal femur (n=13), followed by proximal tibia (n=8), proximal femur (n=1), and distal tibia (n=1). The lesions were classified as grade I (n=3), grade II (n=18), and grade III (n=2). Based on histology, the tumour stage was classified as grade I (n=5) and grade II (n=18). Two of these patients had recurrences, which were initially treated with simple curettage and bone grafting of the distal femur and distal tibia. RESULTS. The mean follow-up period was 5.7 (range, 2.5-10.1) years. 14 of the 23 patients were followed up for over 10 years. No patient developed any local recurrence, remote metastasis, or complication related to surgery or adjuvant therapy. CONCLUSION. Combined treatment entailing curettage, electrocautery, burring, phenol irrigation, and cementation was effective in treating GCT of bone.

  15. ALTERNATIVE FIELD METHODS TO TREAT MERCURY IN SOIL

    SciTech Connect

    Ernest F. Stine Jr; Steven T. Downey

    2002-08-14

    contamination and to increase the TCLP mercury values. IT/NFS investigated ambient temperature amalgamation/stabilization/fixation of mercury-contaminated soils to meet these objectives. Treatment ranged in size from a few ounces to 10 pounds. The treatability study philosophy was to develop working envelops of formulations where reasonable minimum and maximum amounts of each reagent that would successfully treat the contaminated soil were determined. The dosages investigated were based on ratios of stoichiometric reactions and applications of standard sets of formulations. The approach purposely identified formulations that failed short or longer cure-time performance criteria to define the limits of the envelope. Reagent envelops successfully met the project requirements one day after treatment and after greater than 30-day cures. The use of multiple levels of spikes allowed the establishment of reagent dosages that were successful across a broad range of mercury values, e.g., 50 to 6000 mg/kg mercury. The treatment products were damp to slightly wet material. Enough drying reagent, e.g., Portland cement or lime by-product, were added to some formulations to control the leachability of uranium and other hazardous metals and to ensure the product passed the paint filter test. Cost analyzes and conceptual designs for four alternatives for full-scale treatments were prepared. The alternatives included two in-situ treatments and two ex-situ treatments. The cost estimates were based on the results from the bench-scale study. All four alternatives treatment costs were well below the baseline costs.

  16. Soil stabilization and pavement recycling with self-cementing coal fly ash

    SciTech Connect

    2008-01-15

    This manual provides design information for self-cementing coal fly ash as the sole stabilizing agent for a wide range of engineering applications. As in any process, the application of sound engineering practices, appropriate testing, and evaluation of fly ash quality and characteristics will lend themselves to successful projects using the guidelines in this manual. Topics discussed include: self-cementing coal fly ash characteristics; laboratory mix design; stabilization of clay soils; stabilisation of granular materials; construction considerations; high sulfate ash; environmental considerations for fly ash stabilization; design considerations; state specification/guidelines/standards; and a sample of a typical stabilization specification.

  17. Hybrid life cycle assessment comparison of colloidal silica and cement grouted soil barrier remediation technologies.

    PubMed

    Gallagher, Patricia M; Spatari, Sabrina; Cucura, Jeffrey

    2013-04-15

    Site remediation involves balancing numerous costs and benefits but often neglects the environmental impacts over the entire project life cycle. Life cycle assessment (LCA) offers a framework for inclusion of global environmental "systems-level" decision metrics in combination with technological and cost analysis. We compare colloidal silica (CS) and cement grouted soil barrier remediation technologies for soils affected by low level radionuclides at a U.S. Superfund site using hybrid LCA methods. CS is a new, high performance grouting material installed using permeation grouting techniques. Cement, a more traditional grouting material, is typically installed using jet grouting techniques. Life cycle impacts were evaluated using the US EPA TRACI 2 model. Results show the highest life cycle environmental impacts for the CS barrier occur during materials production and transportation to the site. In general, the life cycle impacts for the cement barrier were dominated by materials production; however, in the extreme scenario the life cycle impacts were dominated by truck transportation of spoils to a distant, off-site radioactive waste facility. It is only in the extreme scenario tested in which soils are transported by truck (Option 2) that spoils waste transport dominates LCIA results. Life cycle environmental impacts for both grout barriers were most sensitive to resource input requirements for manufacturing volumes and transportation. Uncertainty associated with the efficacy of new technology such as CS over its required design life indicates that barrier replacement could increase its life cycle environmental impact above that of the cement barrier.

  18. Lithological and land-use based assessment of heavy metal pollution in soils surrounding a cement plant in SW Europe.

    PubMed

    Cutillas-Barreiro, Laura; Pérez-Rodríguez, Paula; Gómez-Armesto, Antía; Fernández-Sanjurjo, María José; Álvarez-Rodríguez, Esperanza; Núñez-Delgado, Avelino; Arias-Estévez, Manuel; Nóvoa-Muñoz, Juan Carlos

    2016-08-15

    We study the influence of phasing out a cement plant on the heavy metal (Hg, Pb and Cr) content in the surrounding soils, taking into account factors often neglected, such as contributions due to local lithology or land use. The range of total Hg was 10-144µg kg(-1), reaching up to 41 and 145mgkg(-1) for total contents of Pb and Cr, respectively. Forest soils showed higher concentration of Hg than prairie soils, indicating the importance of land use on the accumulation of volatile heavy metals in soils. In forest soils, total Hg showed a trend to decrease with soil depth, whereas in prairie soils the vertical pattern of heavy metal concentrations was quite homogeneous. In most cases, the distance to the cement plant was not a factor of influence in the soils content of the analyzed heavy metals. Total Pb and Cr contents in soils nearby the cement plant were quite similar to those found in the local lithology, resulting in enrichment factor values (EF's) below 2. This suggests that soil parent material is the main source of these heavy metals in the studied soils, while the contribution of the cement plant to Pb and Cr soil pollution was almost negligible. On the contrary, the soils surrounding the cement plant accumulate a significant amount of Hg, compared to the underlying lithology. This was especially noticeable in forest soils, where Hg EF achieved values up to 36. These results are of relevance, bearing in mind that Hg accumulation in soils may be an issue of environmental concern, particularly in prairie soils, where temporal flooding can favor Hg transformation to highly toxic methyl-Hg. In addition, the concurrence of acid soils and total-Cr concentrations in the range of those considered phytotoxic should be also stressed.

  19. An assessment of post-remediation changes in sediment chemistry partitioning in an S/S treated soil.

    NASA Astrophysics Data System (ADS)

    Cutter, S.; MacLeod, C. L.; Canning, K.; Carey, P. J.; Hills, C. D.

    2003-04-01

    The Astra Pyrotechnics plant located in the Dartford Marshes, Kent, UK was the site of a field trial utilizing cement stabilization/solidification (S/S) in September 2000. A hotspot containing 35% copper and several thousand part per million lead and zinc was treated in order to trial an new form of cement stabilization (accelerated carbonation technology or ACT) developed by the Centre for Contaminated Land Remediation. A 10 by 20 meter plot was divided into 4 cells into which untreated, OPC (ordinary Portland cement) treated, Envirocem (a Lafarge special cement) treated and ACT treated soil was placed. Each cell has a leachate collection system and the leachate is monitored monthly. In August 2003, 24 cm cores were collected from each cell. These cores were analysed to determine changes in sediment chemistry and metal partitioning characteristics. Sediment chemistry was determined using an aqua regia digestion followed by ICP OES analysis. The CISMED extraction procedure was used to examine partitioning changes. The contaminant concentrations in the leachates remain below UK drinking water standards. However, seasonal cyclicity is observed with an increase of metals in the leachates during winter months. The sediment cores were analysed for Ca, Cr, Cu, Fe, K, Mn, Mg, Na, Ni, Pb and Zn. Only the untreated cell showed any discernable changes in metal concentration with depth. The S/S treated cells show no trends although differences in partitioning between the cells is observed.

  20. A Novel Injectable Borate Bioactive Glass Cement as an Antibiotic Delivery Vehicle for Treating Osteomyelitis

    PubMed Central

    Cui, Xu; Gu, Yi-Fei; Jia, Wei-Tao; Rahaman, Mohamed N.; Wang, Yang; Huang, Wen-Hai; Zhang, Chang-Qing

    2014-01-01

    Background A novel injectable cement composed of chitosan-bonded borate bioactive glass (BG) particles was evaluated as a carrier for local delivery of vancomycin in the treatment of osteomyelitis in a rabbit tibial model. Materials and Methods The setting time, injectability, and compressive strength of the borate BG cement, and the release profile of vancomycin from the cement were measured in vitro. The capacity of the vancomycin-loaded BG cement to eradicate methicillin-resistant Staphylococcus aureus (MRSA)-induced osteomyelitis in rabbit tibiae in vivo was evaluated and compared with that for a vancomycin-loaded calcium sulfate (CS) cement and for intravenous injection of vancomycin. Results The BG cement had an injectability of >90% during the first 3 minutes after mixing, hardened within 30 minutes and, after hardening, had a compressive strength of 18±2 MPa. Vancomycin was released from the BG cement into phosphate-buffered saline for up to 36 days, and the cumulative amount of vancomycin released was 86% of the amount initially loaded into the cement. In comparison, vancomycin was released from the CS cement for up 28 days and the cumulative amount released was 89%. Two months post-surgery, radiography and microbiological tests showed that the BG and CS cements had a better ability to eradicate osteomyelitis when compared to intravenous injection of vancomycin, but there was no significant difference between the BG and CS cements in eradicating the infection. Histological examination showed that the BG cement was biocompatible and had a good capacity for regenerating bone in the tibial defects. Conclusions These results indicate that borate BG cement is a promising material both as an injectable carrier for vancomycin in the eradication of osteomyelitis and as an osteoconductive matrix to regenerate bone after the infection is cured. PMID:24427311

  1. Effect of acid rain pH on leaching behavior of cement stabilized lead-contaminated soil.

    PubMed

    Du, Yan-Jun; Wei, Ming-Li; Reddy, Krishna R; Liu, Zhao-Peng; Jin, Fei

    2014-04-30

    Cement stabilization is a practical approach to remediate soils contaminated with high levels of lead. However, the potential for leaching of lead out of these stabilized soils under variable acid rain pH conditions is a major environmental concern. This study investigates the effects of acid rain on the leaching characteristics of cement stabilized lead contaminated soil under different pH conditions. Clean kaolin clay and the same soil spiked with 2% lead contamination are stabilized with cement contents of 12 and 18% and then cured for 28 days. The soil samples are then subjected to a series of accelerated leaching tests (or semi-dynamic leaching tests) using a simulated acid rain leachant prepared at pH 2.0, 4.0 or 7.0. The results show that the strongly acidic leachant (pH ∼2.0) significantly altered the leaching behavior of lead as well as calcium present in the soil. However, the differences in the leaching behavior of the soil when the leachant was mildly acidic (pH ∼4.0) and neutral (pH ∼7.0) prove to be minor. In addition, it is observed that the lead contamination and cement content levels can have a considerable impact on the leaching behavior of the soils. Overall, the leachability of lead and calcium is attributed to the stability of the hydration products and their consequent influence on the soil buffering capacity and structure.

  2. Effect of acid rain pH on leaching behavior of cement stabilized lead-contaminated soil.

    PubMed

    Du, Yan-Jun; Wei, Ming-Li; Reddy, Krishna R; Liu, Zhao-Peng; Jin, Fei

    2014-04-30

    Cement stabilization is a practical approach to remediate soils contaminated with high levels of lead. However, the potential for leaching of lead out of these stabilized soils under variable acid rain pH conditions is a major environmental concern. This study investigates the effects of acid rain on the leaching characteristics of cement stabilized lead contaminated soil under different pH conditions. Clean kaolin clay and the same soil spiked with 2% lead contamination are stabilized with cement contents of 12 and 18% and then cured for 28 days. The soil samples are then subjected to a series of accelerated leaching tests (or semi-dynamic leaching tests) using a simulated acid rain leachant prepared at pH 2.0, 4.0 or 7.0. The results show that the strongly acidic leachant (pH ∼2.0) significantly altered the leaching behavior of lead as well as calcium present in the soil. However, the differences in the leaching behavior of the soil when the leachant was mildly acidic (pH ∼4.0) and neutral (pH ∼7.0) prove to be minor. In addition, it is observed that the lead contamination and cement content levels can have a considerable impact on the leaching behavior of the soils. Overall, the leachability of lead and calcium is attributed to the stability of the hydration products and their consequent influence on the soil buffering capacity and structure. PMID:24637445

  3. Assessment of cement kiln dust (CKD) for stabilization/solidification (S/S) of arsenic contaminated soils.

    PubMed

    Moon, Deok Hyun; Wazne, Mahmoud; Yoon, In-Ho; Grubb, Dennis G

    2008-11-30

    A stabilization/solidification (S/S) process for arsenic (As) contaminated soils was evaluated using cement kiln dust (CKD). Laboratory-prepared slurries, made of either kaolinite or montmorillonite, and field soils spiked with either As(3+) or As(5+) were prepared and treated with CKD ranging from 10 to 25 wt%. Sodium arsenite and sodium arsenate at 0.1 wt% were used to simulate arsenite (As(3+)) and arsenate (As(5+)) source contamination in soils, respectively. The effectiveness of treatment was evaluated at curing periods of 1- and 7-days based on the toxicity characteristic leaching procedure (TCLP). As-CKD and As-clay-CKD slurries were also spiked at 10 wt% to evaluate As immobilization mechanism using X-ray powder diffraction (XRPD) analyses. Overall, the TCLP results showed that only the As(5+) concentrations in kaolinite amended with 25 wt% CKD after 1 day of curing were less than the TCLP regulatory limit of 5mg/L. Moreover, at 7 days of curing, all As(3+) and As(5+) concentrations obtained from kaolinite soils were less than the TCLP criteria. However, none of the CKD-amended montmorillonite samples satisfied the TCLP-As criteria at 7 days. Only field soil samples amended with 20 wt% CKD complied with the TCLP criteria within 1 day of curing, where the source contamination was As(5+). XRPD and scanning electron microscopy (SEM)-energy dispersive X-ray spectroscopy (EDX) results showed that Ca-As-O and NaCaAsO(4).7.5H(2)O were the primary phases responsible for As(3+) and As(5+) immobilization in the soils, respectively.

  4. Thermal-treated soil for mercury removal: Soil and phytotoxicity tests

    SciTech Connect

    Roh, Y.; Edwards, N.T.; Lee, S.Y.; Stiles, C.A.; Armes, S.; Foss, J.E.

    2000-04-01

    Mercury (Hg) contamination of soils and sediments is one of many environmental problems at the Oak Ridge Reservation, Oak Ridge, TN. Mercury-contaminated soil from the Lower East Fork Poplar Creek (LEFPC) at the Oak Ridge Reservation was treated thermally to reduce Hg concentration to a below target level (20 mg kg{sup {minus}1}) as a pilot scale thermal treatment demonstration. As a part of performance evaluation, the soil characteristics and plant growth response of the untreated and treated soil were examined. The soil treated at 350 C retained most of its original soil properties, but the soil treated at 600 C exhibited considerable changes in mineralogical composition and physicochemical characteristics. Growth and physiological response of the three plant species radish (Raphanus sativus L.), fescue (Festuca arundinacea Schreb.), and oat (Avena sativa L.) indicated adverse effects of the thermal treatment. The addition of N fertilizer had beneficial effects in the 350 C treated soil, but had little beneficial effect in the 600 C treated soil. Some changes of soil characteristics induced by thermal treatment cannot be avoided. Soil characteristics and phytotoxicity test results strongly suggest that changes occurring following the 350 C treatment do not limit the use of the treated soil to refill the excavated site for full-scale remediation. The only problem with the 350 C treatment is that small amounts of Hg compounds (<15 mg kg{sup {minus}1}) remain in the soil and a processing cost of $45/Mg.

  5. Resistance to bond degradation between dual-cure resin cements and pre-treated sintered CAD-CAM dental ceramics

    PubMed Central

    Osorio, Raquel; Monticelli, Francesca; Osorio, Estrella; Toledano, Manuel

    2012-01-01

    Objective: To evaluate the bond stability of resin cements when luted to glass-reinforced alumina and zirconia CAD/CAM dental ceramics. Study design: Eighteen glass-infiltrated alumina and eighteen densely sintered zirconia blocks were randomly conditioned as follows: Group 1: No treatment; Group 2: Sandblasting (125 µm Al2O3-particles); and Group 3: Silica-coating (50 µm silica-modified Al2O3-particles). Composite samples were randomly bonded to the pre-treated ceramic surfaces using different resin cements: Subgroup 1: Clearfil Esthetic Cement (CEC); Subgroup 2: RelyX Unicem (RXU); and Subgroup 3: Calibra (CAL). After 24 h, bonded specimens were cut into 1 ± 0.1 mm2 sticks. One-half of the beams were tested for microtensile bond strength (MTBS). The remaining one-half was immersed in 10 % NaOCl aqueous solution (NaOClaq) for 5 h before testing. The fracture pattern and morphology of the debonded surfaces were assessed with a field emission gun scanning electron microscope (FEG-SEM). A multiple ANOVA was conducted to analyze the contributions of ceramic composition, surface treatment, resin cement type, and chemical challenging to MTBS. The Tukey test was run for multiple comparisons (p < 0.05). Results: After 24 h, CEC luted to pre-treated zirconia achieved the highest MTBS. Using RXU, alumina and zirconia registered comparable MTBS. CAL failed prematurely, except when luted to sandblasted zirconia. After NaOClaq storage, CEC significantly lowered MTBS when luted to zirconia or alumina. RXU decreased MTBS only when bonded to silica-coated alumina. CAL recorded 100 % of pre-testing failures. Micromorphological alterations were evident after NaOClaq immersion. Conclusions: Resin-ceramic interfacial longevity depended on cement selection rather than on surface pre-treatments. The MDP-containing and the self-adhesive resin cements were both suitable for luting CAD/CAM ceramics. Despite both cements being prone to degradation, RXU luted to zirconia or untreated or

  6. Geochemical analysis of leachates from cement/low-level radioactive waste/soil systems

    SciTech Connect

    Criscenti, L.J.; Serne, R.J.

    1988-09-01

    Laboratory experiments were conducted as part of the Special Waste Form Lysimeters/endash/Arid Program. These experiments were conducted to investigate the performance of solidified low-level nuclear waste in a typical arid, near-surface disposal site, and to evaluate the ability of laboratory tests to predict leaching in actual field conditions. Batch leaching, soil adsorption column, and soil/waste form column experiments were conducted using Portland III cement waste forms containing boiling-water reactor evaporator concentrate and ion-exchange resin waste. In order to understand the reaction chemistry of the cement waste form/soil/ground-water system, the compositions of the leachates from the laboratory experiments were studied with the aid of the MINTEQ ion speciation/solubility and mass transfer computer code. The purpose of this report is to describe the changes in leachate composition that occur during the course of the experiments, to discuss the geochemical modeling results, and to explore the factors controlling the major element chemistry of these leachates. 18 refs., 84 figs., 14 tabs.

  7. Bond strength of resin cement to CO2 and Er:YAG laser-treated zirconia ceramic

    PubMed Central

    Kasraei, Shahin; Heidari, Bijan; Vafaee, Fariborz

    2014-01-01

    Objectives It is difficult to achieve adhesion between resin cement and zirconia ceramics using routine surface preparation methods. The aim of this study was to evaluate the effects of CO2 and Er:YAG laser treatment on the bond strength of resin cement to zirconia ceramics. Materials and Methods In this in-vitro study 45 zirconia disks (6 mm in diameter and 2 mm in thickness) were assigned to 3 groups (n = 15). In control group (CNT) no laser treatment was used. In groups COL and EYL, CO2 and Er:YAG lasers were used for pretreatment of zirconia surface, respectively. Composite resin disks were cemented on zirconia disk using dual-curing resin cement. Shear bond strength tests were performed at a crosshead speed of 0.5 mm/min after 24 hr distilled water storage. Data were analyzed by one-way ANOVA and post hoc Tukey's HSD tests. Results The means and standard deviations of shear bond strength values in the EYL, COL and CNT groups were 8.65 ± 1.75, 12.12 ± 3.02, and 5.97 ± 1.14 MPa, respectively. Data showed that application of CO2 and Er:YAG lasers resulted in a significant higher shear bond strength of resin cement to zirconia ceramics (p < 0.0001). The highest bond strength was recorded in the COL group (p < 0.0001). In the CNT group all the failures were adhesive. However, in the laser groups, 80% of the failures were of the adhesive type. Conclusions Pretreatment of zirconia ceramic via CO2 and Er:YAG laser improves the bond strength of resin cement to zirconia ceramic, with higher bond strength values in the CO2 laser treated samples. PMID:25383349

  8. Leaching from solid waste incineration ashes used in cement-treated base layers for pavements.

    PubMed

    Cai, Z; Bager, Dirch H; Christensen, T H

    2004-01-01

    Waste incineration bottom ash and treated flue gas cleaning products mixed with 2.5% of cement (50 kg/m3) were tested in the laboratory in terms of compressive strength and tank leaching tests over a 64-day period. Although the material displayed lower mechanical strength than a reference concrete, the strength still was sufficient for use as a base layer for roads. The metal content in the incineration-residue-based specimens was up to 100 times higher than in the reference concrete, suggesting that the mixed waste incineration residue should be used only for dedicated purposes. The leaching of Cl and Na was increased by a factor of 20-100 from the incineration-residue-based specimens as compared to the reference, while the leaching of K, Ca and SO4 was increased by a factor of 2-10. The leaching of heavy metals was also higher from the incineration-residue-based specimens than from the reference with respect to Cu (50 times), Cd, Pb and Zn (5 times), but not with respect to Cr and Ni. The leaching curves did only allow for a closer evaluation of the leaching process in a few cases. The physical retention of the constituents seemed to be the same in the reference as in the incineration-residue-based specimens. Heavy metal leaching was limited by enhanced chemical retention in the incineration-residue-specimens as compared to the reference. Since no quality criteria in terms of leaching from a monolithic material are currently available, the leaching issue must be evaluated case by case.

  9. Clastogenicity of landfarming soil treated with sugar cane vinasse.

    PubMed

    da Silva Souza, Tatiana; Hencklein, Fabiana Aparecida; de Franceschi de Angelis, Dejanira; Fontanetti, Carmem Silvia

    2013-02-01

    The addition of nutrients and/or soil bulking agents is used in bioremediation to increase microbial activity in contaminated soils. For this purpose, some studies have assessed the effectiveness of vinasse in the bioremediation of soils contaminated with petroleum waste. The present study was aimed at investigating the clastogenic/aneugenic potential of landfarming soil from a petroleum refinery before and after addition of sugar cane vinasse using the Allium cepa bioassay. Our results show that the addition of sugar cane vinasse to landfarming soil potentiates the clastogenic effects of the latter probably due the release of metals that were previously adsorbed into the organic matter. These metals may have interacted synergistically with petroleum hydrocarbons present in the landfarming soil treated with sugar cane vinasse. We recommend further tests to monitor the effects of sugar cane vinasse on soils contaminated with organic wastes. PMID:22580848

  10. Earthworm (Eisenia andrei) Avoidance of Soils Treated with Cypermethrin

    PubMed Central

    de Sousa, Ana Paula A.; de Andréa, Mara M.

    2011-01-01

    The pyrethroid insecticide cypermethrin is used for agricultural and public health campaigns. Its residues may contaminate soils and the beneficial soil organisms, like the earthworms, that may ingest the contaminated soil particles. Due to its ecological relevance, earthworms Eisenia andrei/fetida have been used in different ecotoxicological tests. The avoidance of soils treated with cypermethrin by compost worms Eisenia andrei was studied here as a bioindicator of the influence of treatment dosage and the pesticide formulation in three different agricultural soils indicated by the Brazilian environmental authorities for ecotoxicological tests. This earthworms’ behavior was studied here as a first attempt to propose the test for regulation purposes. The two-compartment test systems, where the earthworms were placed for a two-day exposure period, contained samples of untreated soil alone or together with soil treated with technical grade or wettable powder formulation of cypermethrin. After 48 h, there was no mortality, but the avoidance was clear because all earthworms were found in the untreated section of each type of soil (p < 0.05). No differences were found by the Fisher’s exact test (p ≤ 1.000) for each soil and treatment, demonstrating that the different soil characteristics, the cypermethrin concentrations and formulation, as well as the smaller amounts of soil and earthworms did not influence the avoidance behavior of the earthworms to cypermethrin. The number and range of treatments used in this study do not allow a detailed recommendation of the conditions applied here, but to the best of our knowledge, this is the first reported attempt to identify the avoidance of pesticide treated tropical soils by earthworms. PMID:22247652

  11. Soil-based treatment of partially treated liquid swine manure.

    PubMed

    Yang, H; Xiao, J; El-Din, M Gamal; Buchanan, I D; Bromley, D; Ikehata, K

    2007-01-01

    A soil-column system was tested for the removal of soluble organics and nutrients from partially treated liquid swine manure. The liquid manure was applied to the 900 mm deep (300 mm of local topsoil and 600 mm of local subsoil) soil columns continuously for an eight-week period, and leachate as well as soil samples were analysed. An effective liquid manure application rate of 17 mm d(-1) was determined based on a preliminary liquid manure soil-based treatment experiment. It was found that more than 90% of five-day biochemical oxygen demand, chemical oxygen demand, total Kjeldahl and ammonia nitrogen, and total phosphorus could be effectively removed from the liquid manure by the soil system. Nitrogen contents accumulated in the soil matrix mostly within the 0 to 300 mm depth, while no significant increase was observed in sub soils. Soil analyses indicated the occurrence of nitrification and denitrification in the soil columns. Nitrogen balance showed that about 42% of the applied nitrogen was lost from the system during the liquid manure soil-based treatment experiment, suggesting the emission of ammonia and other gaseous nitrogen generated through nitrification and denitrification. The leachate of the soil treatment system was used to irrigate Bermuda grass. No negative effect of leachate was observed on the plant growth.

  12. An evaluation of the inflammatory response of lipopolysaccharide-treated primary dental pulp cells with regard to calcium silicate-based cements.

    PubMed

    Lai, Wei-Yun; Kao, Chia-Tze; Hung, Chi-Jr; Huang, Tsui-Hsien; Shie, Ming-You

    2014-06-01

    This study compared the biological changes of lipopolysaccharide (LPS)-treated dental pulp (DP) cells directly cultured on mineral trioxide aggregate (MTA) and calcium silicate (CS) cements. DP cells were treated with LPS for 24 h. Then, the LPS-treated DP cells were cultured on MTA or CS cements. Cell viability, cell death mechanism and interleukin (IL)-1β expressions were analysed. A one-way analysis of variance was used to evaluate the significance of the differences between the means. A significantly higher IL-1β expression (2.9-fold) was found for LPS-treated cells (P<0.05) compared with DP cells without LPS treatment at 24 h. Absorbance values of LPS-treated cells cultured on CS cement were higher than a tissue culture plate. A significant difference (P<0.05) in cell viability was observed between cells on CS and MTA cements 24 h after seeding. At 48 h, a high concentration of Si (5 mM) was released from MTA, which induced LPS-treated DP cell apoptosis. The present study demonstrates that CS cement is biocompatible with cultured LPS-treated DP cells. MTA stimulates inflammation in LPS-treated DP cells, which leads to greater IL-1β expression and apoptosis.

  13. Sulfur cement production using by products of the perchloroethylene coal cleaning process and the FC4-1 cleaned soil

    SciTech Connect

    Bassam Masri, K.L.; Fullerton, S.L.

    1995-12-31

    An introductory set of experiments to show the feasibility of making sulfur cement were carried out at the University of Akron according to Parrett and Currett`s patent which requires the use of sulfur, a filler, a plasticizer, and a vulcanization accelerator. Small blocks of cement were made using byproducts of the perchloroethylene coal cleaning process. Extracted elemental and organic sulfur, ash and mineral matters from the float sink portion of the PCE process, and FC4-1 cleaned soil were used as substitutes for sulfur and filler needed for the production of sulfur cement. Leaching tests in different solutions and under different conditions were conducted on the sulfur blocks. Other tests such as strength, durability, resistance to high or low temperatures will be conducted in the future. Sulfur cement can be used as a sealing agent at a joint, roofing purposes, forming ornamental figures, and coating of exposed surfaces of iron or steel. When mixed with an aggregate, sulfur concrete is formed. This concrete can be used for structural members, curbings, guthers, slabs, and can be precast or cast at the job site. An advantage of sulfur cement over Portland cement is that it reaches its design strength in two to three hours after processing and it can be remelted and recast.

  14. Treating Soil Solution Samplers To Prevent Microbial Removal of Analytes

    PubMed Central

    Lewis, David L.; Simons, Alex P.; Moore, W. Bruce; Gattie, David K.

    1992-01-01

    Soil microorganisms colonizing soil water sampling devices (lysimeters) reduced concentrations of biodegradable organic chemicals, including 2,4-dichlorophenoxyacetic acid methyl ester, alachlor, methyl m-chlorobenzoate, and metolachlor as water entered through porous ceramic cups. In some cases, losses exceeded 99%. Additions of either a biocide (sodium hypochlorite) or a bacteriostat (copper salt) prevented microbial activity so that concentrations of test chemicals inside lysimeters equaled those outside. Field studies further indicated that treating lysimeters with a copper salt effectively prevented microbial activity. Thus, chemically treating soil water samplers could improve the accuracy of soil water data for a wide variety of analytes, including environmentally important organics, such as pesticides and industrial wastes, and inorganics, such as ammonia and nitrate. Images PMID:16348616

  15. Soil microorganisms in cotton fields sequentially treated with insecticides.

    PubMed

    Vig, K; Singh, D K; Agarwal, H C; Dhawan, A K; Dureja, P

    2008-02-01

    A crop protection system consisting of sequential treatments by six insecticides--dimethoate, monocrotophos, deltamethrin, endosulfan, cypermethrin, and triazophos--at recommended dosages in cotton fields in Punjab, India was investigated for its effects on nontarget soil microorganisms and their activities. Successive applications of the insecticides caused only short-lived adverse effects on the soil microorganisms. None of the insecticides used had any adverse effects on soil fungi as reflected by their total numbers. Significant change in Azotobacter numbers were observed after dimethoate, triazophos, and endosulfan treatment in 1998 soil. An increase of up to 71% in actinomycetes numbers was observed after deltamethrin treatment in the treated fields in 1995. Few short-term changes in iron-reduction capacity were observed after endosulfan and cypermethrin treatments. No adverse effect was observed on the soil respiration during all the experimental periods. The amount of residues detected in soil ranged from 8.5 to 42.0 ng g(-1)dry wt. soil for organophosphorus insecticides and from nondetectable to 5.55 ng g (-1)dry wt. soil for synthetic pyrethroids. It ranged between 7.3 and 35.6 ng g(-1)dry wt. soil for endosulfan. On many occasions two or three insecticide residues were detected together; therefore, the effect observed on soil microorganisms and their activities was a multiresidue effect. In 1998, crop soil amounts of insecticide residues were generally more than those in 1995 and 1996. Persistence and dissipation patterns in soils with a history of exposure to the insecticides compared to the non-history soils were similar.

  16. Application of soil quality indices to assess the status of agricultural soils irrigated with treated wastewaters

    NASA Astrophysics Data System (ADS)

    Morugán-Coronado, A.; Arcenegui, V.; García-Orenes, F.; Mataix-Solera, J.; Mataix-Beneyto, J.

    2013-03-01

    The supply of water is limited in some parts of the Mediterranean region, such as southeastern Spain. The use of treated wastewater for the irrigation of agricultural soils is an alternative to using better-quality water, especially in semi-arid regions. On the other hand, this practice can modify some soil properties, change their relationships and influence soil quality. In this work two soil quality indices were used to evaluate the effects of irrigation with treated wastewater in soils. The indices were developed studying different soil properties in undisturbed soils in SE Spain, and the relationships between soil parameters were established using multiple linear regressions. These indices represent the balance reached among properties in "steady state" soils. This study was carried out in four study sites from SE Spain irrigated with wastewater, including four study sites. The results showed slight changes in some soil properties as a consequence of irrigation with wastewater, the obtained levels not being dangerous for agricultural soils, and in some cases they could be considered as positive from an agronomical point of view. In one of the study sites, and as a consequence of the low quality wastewater used, a relevant increase in soil organic matter content was observed, as well as modifications in most of the soil properties. The application of soil quality indices indicated that all the soils of study sites are in a state of disequilibrium regarding the relationships between properties independent of the type of water used. However, there were no relevant differences in the soil quality indices between soils irrigated with wastewater with respect to their control sites for all except one of the sites, which corresponds to the site where low quality wastewater was used.

  17. Greater Trochanter Reconstruction in Unstabl Intertrochanteric Fractures Treated With Cemented Bipolar Hemiarthroplasty: A Technical Note.

    PubMed

    Subramanian, G V; Guravareddy, A V; Reddy, Anil Kumar K R; Chiranjeevi, T

    2012-01-01

    Cemented Bipolar arthroplasty is an established method for treatment of comminuted Intertrochanteric fractures. Reconstruction of greater trochanter is an essential technical step to avoid complications like abductor lurch gait. We here describe a technique of reconstruction and fixation of greater trochanter using cancellous screws with wide washers made of reconstruction plate and tension band wiring. This gives a stable fixation of greater trochanter and avoids cut out, slippage of implants. PMID:27298870

  18. Evaluation of solidification/stabilization for treating explosives contaminated soils

    SciTech Connect

    Cullinane, M.J. Jr.; Channell, M.

    1996-12-31

    The success of solidification/stabilization (S/S) for treating explosives contaminated soils was evaluated using a variety of physical, chemical, and contaminant release testing methods. The analytes of concern included explosives and their degradation products (TNT, RDX, HMX, 2, 4-Dinitrotoluene, 2,6-dinitrotoluene, 2,4,6-Trinitrotoluene, 2-Amino-4,6-Dinitrotoluene, 4-Amino-2,6-Dinitrobenzene, 2,4-Dinitrotoluene) and PAH`s (Benzo(a)anthracene, Benzo(b)fluoranthene, Benzo(k)fluoranthene, Benzo(a)pyrene, Chrysene, Dibenz(a,h) anthracene, and Ideno (1,2,3-cd)pyrene). All Toxicity Characteristic Leaching Procedure (TCLP) leachate analytes, except 2-Am-4,6-TNT was reduced approximately 97%. The release of 2,4-DNT was also significantly reduced. The results of the Sequential Batch Leach Test (SBLT) were mixed. The PAH compounds were not identified above detectable limits in the leachates from either the untreated soil or the treated soils. Release of 2,4,6-TNT was reduced to undetectable. However, other explosives related compounds (2-Am-4, 6-DNT) were identified in the leachates from the treated soils that were not identified in the untreated soil. Organic transformations in the highly alkaline environment associated with S/S or sample heterogeneity are suspected to cause this phenomena.

  19. Modeling Water Infiltration in Soil Irrigated with Treated Wastewater

    NASA Astrophysics Data System (ADS)

    Gharaibeh, Mamoun; Albalasmeh, Ammar; Alghzawi, Ma'in

    2015-04-01

    Infiltration of soils irrigated with treated wastewater (TWW) was modeled using Philip, Horton, Kostiakov, and modified Kostiakov. Treatments were: soil irrigated with TWW for 5 years, 2 years, and a control site. Cumulative (Ft), rate of infiltration (ft), and hydraulic conductivity (HC) were measured in the field and aggregate stability (AS) in the lab. Both HC and ft were decreased with and AS was increased with TWW use and period of application. The Root Mean Squared Error (RMSE) and correlation coefficient (R2) were used to measure the goodness of fit and linearity of the relationship between models and measured data. Philip model was best to fit infiltration compared to other models. High AS values in treated areas compared to control area indicated that infiltration was more affected by pore clogging than soil dispersion and swelling,

  20. Effect of antioxidants on push-out bond strength of hydrogen peroxide treated glass fiber posts bonded with two types of resin cement

    PubMed Central

    Khoroushi, Maryam; Mazaheri, Hamid; Tarighi, Pardis; Samimi, Pouran

    2014-01-01

    Objectives Hydrogen peroxide (H2O2) surface treatment of fiber posts has been reported to increase bond strength of fiber posts to resin cements. However, residual oxygen radicals might jeopardize the bonding procedure. This study examined the effect of three antioxidant agents on the bond strength of fiber posts to conventional and self-adhesive resin cements. Materials and Methods Post spaces were prepared in forty human maxillary second premolars. Posts were divided into five groups of 8 each: G1 (control), no pre-treatment; G2, 10% H2O2 pre-treatment; G3, G4 and G5. After H2O2 application, Hesperidin (HES), Sodium Ascorbate (SA) or Rosmarinic acid (RA) was applied on each group respectively. In each group four posts were cemented with Duo-Link conventional resin cement and the others with self-adhesive BisCem cement. Push-out test was performed and data were analyzed using 2-way ANOVA and tukey's post-hoc test (α = 0.05). Results There was a statistically significant interaction between the cement type and post surface treatment on push-out bond strength of fiber posts (p < 0.001, F = 16). Also it was shown that different posts' surface treatments significantly affect the push-out bond strength of fiber posts (p = 0.001). H2O2 treated posts (G2) and control posts (G1) cemented with Duo-link showed the highest (15.96 ± 5.07MPa) and lowest bond strengths (6.79 ± 3.94) respectively. Conclusions It was concluded that H2O2 surface treatment might enhance the bond strength of fiber posts cemented with conventional resin cements. The effect of antioxidants as post's surface treatment agents depends on the characteristics of resin cements used for bonding procedure. PMID:25383350

  1. Application of soil quality indices to assess the status of agricultural soils irrigated with treated wastewaters

    NASA Astrophysics Data System (ADS)

    Morugán-Coronado, A.; Arcenegui, V.; García-Orenes, F.; Mataix-Solera, J.; Mataix-Beneyto, J.

    2012-12-01

    The supply of water is limited in some parts of the Mediterranean region, such as southeastern Spain. The use of treated wastewater for the irrigation of agricultural soils is an alternative to using better-quality water, especially in semi-arid regions. On the other hand, this practice can modify some soil properties, change their relationships, the equilibrium reached and influence soil quality. In this work two soil quality indices were used to evaluate the effects of irrigation with treated wastewater in soils. The indices were developed studying different soil properties in undisturbed soils in SE Spain, and the relationships between soil parameters were established using multiple linear regressions. This study was carried out in three areas of Alicante Province (SE Spain) irrigated with wastewater, including four study sites. The results showed slight changes in some soil properties as a consequence of irrigation with wastewater, the obtained levels not being dangerous for agricultural soils, and in some cases they could be considered as positive from an agronomical point of view. In one of the study sites, and as a consequence of the low quality wastewater used, a relevant increase in soil organic matter content was observed, as well as modifications in most of the soil properties. The application of soil quality indices indicated that all the soils of study sites are in a state of disequilibrium regarding the relationships between properties independent of the type of water used. However, there were no relevant differences in the soil quality indices between soils irrigated with wastewater with respect to their control sites for all except one of the sites, which corresponds to the site where low quality wastewater was used.

  2. Disposal of historically contaminated soil in the cement industry and the evaluation of environmental performance.

    PubMed

    Li, Yeqing; Zhang, Jiang; Miao, Wenjuan; Wang, Huanzhong; Wei, Mao

    2015-09-01

    Approximately 400000t of DDTs/HCHs-contaminated soil (CS) needed to be co-processed in a cement kiln with a time limitation of 2y. A new pre-processing facility with a "drying, grinding and DDTs/HCHs vaporizing" ability was equipped to meet the technical requirements for processing cement raw meal and the environmental standards for stack emissions. And the bottom of the precalciner with high temperatures >1000°C was chosen as the CS feeding point for co-processing, which has rarely been reported. To assess the environmental performance of CS pre- and co-processing technologies, according to the local regulation, a test burn was performed by independent and accredited institutes systematically for determination of the clinker quality, kiln stack gas emissions and destruction efficiency of the pollutant. The results demonstrated that the clinker was of high quality and not adversely affected by CS co-processing. Stack emissions were all below the limits set by Chinese standards. Particularly, PCDD/PCDF emissions ranged from 0.0023 to 0.0085ngI-TEQNm(-3). The less toxic OCDD was the peak congener for CS co-processing procedure, while the most toxic congeners (i.e. 2,3,7,8-TeCDD, 1,2,3,7,8-PeCDD and 2,3,4,7,8-PeCDD) remained in a minor proportion. Destruction and removal efficiency (DRE) and destruction efficiency (DE) of the kiln system were better than 99.9999% and 99.99%, respectively, at the highest CS feeding rate during normal production. To guarantee the environmental performance of the system the quarterly stack gas emission was also monitored during the whole period. And all of the results can meet the national standards requirements.

  3. Disposal of historically contaminated soil in the cement industry and the evaluation of environmental performance.

    PubMed

    Li, Yeqing; Zhang, Jiang; Miao, Wenjuan; Wang, Huanzhong; Wei, Mao

    2015-09-01

    Approximately 400000t of DDTs/HCHs-contaminated soil (CS) needed to be co-processed in a cement kiln with a time limitation of 2y. A new pre-processing facility with a "drying, grinding and DDTs/HCHs vaporizing" ability was equipped to meet the technical requirements for processing cement raw meal and the environmental standards for stack emissions. And the bottom of the precalciner with high temperatures >1000°C was chosen as the CS feeding point for co-processing, which has rarely been reported. To assess the environmental performance of CS pre- and co-processing technologies, according to the local regulation, a test burn was performed by independent and accredited institutes systematically for determination of the clinker quality, kiln stack gas emissions and destruction efficiency of the pollutant. The results demonstrated that the clinker was of high quality and not adversely affected by CS co-processing. Stack emissions were all below the limits set by Chinese standards. Particularly, PCDD/PCDF emissions ranged from 0.0023 to 0.0085ngI-TEQNm(-3). The less toxic OCDD was the peak congener for CS co-processing procedure, while the most toxic congeners (i.e. 2,3,7,8-TeCDD, 1,2,3,7,8-PeCDD and 2,3,4,7,8-PeCDD) remained in a minor proportion. Destruction and removal efficiency (DRE) and destruction efficiency (DE) of the kiln system were better than 99.9999% and 99.99%, respectively, at the highest CS feeding rate during normal production. To guarantee the environmental performance of the system the quarterly stack gas emission was also monitored during the whole period. And all of the results can meet the national standards requirements. PMID:25966458

  4. Healing of root perforations treated with Mineral Trioxide Aggregate (MTA) and Portland cement.

    PubMed

    Juárez Broon, Norberto; Bramante, Clovis Monteiro; de Assis, Gerson Francisco; Bortoluzzi, Eduardo Antunes; Bernardineli, Norberti; de Moraes, Ivaldo Gomes; Garcia, Roberto Brandão

    2006-10-01

    Fourteen root perforations were performed for microscopic evaluation of the repair of interradicular tissue in dogs' teeth. These perforations were accomplished at low-speed with a STP 58 bur at the cervical third of the mesial root toward the furcation under irrigation with saline solution, followed by immediate sealing with ProRoot MTA, MTA-Angelus and white Portland cement. The dogs were killed after 90 days, revealing good results. The Kruskal-Wallis test did not demonstrate any statistically significant difference. It was concluded that the three materials showed good sealing in mineralized tissue, with complete closure, and they were free of inflammation in most teeth.

  5. HEALING OF ROOT PERFORATIONS TREATED WITH MINERAL TRIOXIDE AGGREGATE (MTA) AND PORTLAND CEMENT

    PubMed Central

    Broon, Norberto Juárez; Bramante, Clovis Monteiro; de Assis, Gerson Francisco; Bortoluzzi, Eduardo Antunes; Bernardineli, Norberti; de Moraes, Ivaldo Gomes; Garcia, Roberto Brandão

    2006-01-01

    Fourteen root perforations were performed for microscopic evaluation of the repair of interradicular tissue in dogs' teeth. These perforations were accomplished at low-speed with a STP 58 bur at the cervical third of the mesial root toward the furcation under irrigation with saline solution, followed by immediate sealing with ProRoot MTA, MTA-Angelus and white Portland cement. The dogs were killed after 90 days, revealing good results. The Kruskal-Wallis test did not demonstrate any statistically significant difference. It was concluded that the three materials showed good sealing in mineralized tissue, with complete closure, and they were free of inflammation in most teeth. PMID:19089049

  6. Use of treated wastewater in agriculture: effects on soil environment

    NASA Astrophysics Data System (ADS)

    Levy, Guy J.; Lado, Marcos

    2014-05-01

    Disposal of treated sewage, both from industrial and domestic origin (herein referred to as treated wastewater [TWW]), is often considered as an environmental hazard. However, in areas afflicted by water scarcity, especially in semi-arid and arid regions, where the future of irrigated agriculture (which produces approximately one third of crop yield and half the return from global crop production) is threatened by existing or expected shortage of fresh water, the use of TWW offers a highly effective and sustainable strategy to exploit a water resource. However, application of TWW to the soil is not free of risks both to organisms (e.g., crops, microbiota) and to the soil. Potential risks may include reduction in biological activity (including crop yield) due to elevated salinity and specific ion toxicity, migration of pollutants towards surface- and ground-water, and deterioration of soil structure. In recent years, new evidence about the possible negative impact of long-term irrigation with TWW on soil structure and physical and chemo-physical properties has emerged, thus putting the sustainability of irrigation with TWW in question. In this presentation, some aspects of the effects of long-term irrigation with TWW on soil properties are shown.

  7. Refracture of osteoporotic vertebral body concurrent with cement fragmentation at the previously treated vertebral level after balloon kyphoplasty: a case report.

    PubMed

    Li, Xigong; Lou, Xianfeng; Lin, Xiangjin; Du, Junhua

    2014-05-01

    Kyphoplasty has been shown to provide symptomatic relief of vertebral compression fractures refractory to medical therapy. However, few reports have focused on refracture of cemented vertebrae after kyphoplasty. The presence of cemented vertebrae refracture concurrent with cement fragmentation is an extremely rare condition. We reported an 86-year-old man with a T12 osteoporotic compression fracture undergoing the kyphoplasty treatment. The patient postoperatively continued to have back pain at the same level. The solid lumped polymethylmethacrylate (PMMA) mass and inadequate use and insufficient filling of PMMA cement were observed in postoperative radiographs and magnetic resonance image (MRI) examination. He refused to receive the surgical intervention, but had not strict compliance with oral anti-osteoporotic medications. Ten months postoperatively, refracture of osteoporotic vertebral body concurrent with cement fragmentation occurred at the previously kyphoplasty-treated vertebral level. Bone mineral analysis showed severe osteoporosis with a T-score of -4.0. The patient finally obtained therapeutic benefit of pain relief and bony union of T12 vertebral body by consistently adhering to anti-osteoporotic medication treatment. This case illustrated that patients who underwent kyphoplasty to treat osteoporotic vertebral compression fractures with intravertebral fracture should be strictly followed up and supervised in their anti-osteoporotic medication treatment. The interdigitation injection pattern of PMMA and sufficient PMMA filling with trabeculae in the kyphoplasty procedure also might prevent refracture of the cemented vertebrae concurrent with PMMA fragmentation.

  8. Raw and thermally treated cement asbestos exerts different cytotoxicity effects on A549 cells in vitro.

    PubMed

    Pugnaloni, Armanda; Lucarini, Guendalina; Rubini, Corrado; Smorlesi, Arianna; Tomasetti, Marco; Strafella, Elisabetta; Armeni, Tatiana; Gualtieri, Alessandro F

    2015-01-01

    Raw cement asbestos (RCA) undergoes a complete solid state transformation when heated at high temperatures. The secondary raw material produced, high temperatures-cement asbestos (HT-CA) is composed of newly-formed crystals in place of the asbestos fibers present in RCA. Our previous study showed that HT-CA exerts lower cytotoxic cell damage compared to RCA. Nevertheless further investigations are needed to deepen our understanding of pathogenic pathways involving oxidative and nitrative damage. Our aim is to deepen the understanding of the biological effects on A549 cells of these materials regarding DNA damage related proteins (p53, its isoform p73 and TRAIL) and nitric oxide (NO) production during inducible nitric oxide synthase (iNOS)-mediated inflammation. Increments of p53/p73 expression, iNOS positive cells and NO concentrations were found with RCA, compared to HT-CA and controls mainly at 48 h. Interestingly, ferrous iron causing reactive oxygen species (ROS)-mediated DNA damage was found in RCA as a contaminant. HT-CA thermal treatment induces a global recrystallization with iron in a crystal form poorly released in media. HT-CA slightly interferes with genome expression and exerts lower inflammatory potential compared to RCA on biological systems. It could represent a safe approach for storing or recycling asbestos and an environmentally friendly alternative to asbestos waste.

  9. Cement Calcaneoplasty: An Innovative Method for Treating Nonunion in Calcaneal Insufficiency Fracture.

    PubMed

    Godavitarne, Charles; Fawzy, Ernest; Giancola, Giorgio; Louette, Luc

    2016-01-01

    Insufficiency type stress fractures are common in older patients with osteoporosis. Persistent pain after nonunion of these fractures can be disabling, with the management options often limited. We aimed to assess the suitability of fluoroscopic-guided injection of bone cement into a persistently symptomatic nonuniting calcaneal insufficiency fracture. To the best of our knowledge, this technique has not previously been described in the published data. After local subcutaneous anesthesia, the midpoint of the fracture site was accessed by trocar insertion under radiographic guidance, and bone cement was injected directly into the site. A preprocedure visual analog scale pain score of 90 of 100 was recorded. This had improved to 0 of 100 at the 12-month follow-up point after the procedure. The aim of the present case report was to raise awareness of percutaneous calcaneoplasty, which we believe to be a safe and well-tolerated technique for the management of osteoporotic insufficiency fracture of the calcaneus. We propose that this technique be considered when conservative methods aimed at promoting fracture healing have failed. PMID:26875768

  10. ALTERNATIVE FIELD METHODS TO TREAT MERCURY IN SOIL

    SciTech Connect

    Ernie F. Stine

    2002-08-14

    The Department of Energy (DOE) currently has mercury (Hg) contaminated materials and soils at the various sites. Figure 1-1 (from http://www.ct.ornl.gov/stcg.hg/) shows the estimated distribution of mercury contaminated waste at the various DOE sites. Oak Ridge and Idaho sites have the largest deposits of contaminated materials. The majorities of these contaminated materials are soils, sludges, debris, and waste waters. This project concerns treatment of mercury contaminated soils. The technology is applicable to many DOE sites, in-particular, the Y-12 National Security Complex in Oak Ridge Tennessee and Idaho National Engineering and Environmental Laboratory (INEEL). These sites have the majority of the soils and sediments contaminated with mercury. The soils may also be contaminated with other hazardous metals and radionuclides. At the Y12 plant, the baseline treatment method for mercury contaminated soil is low temperature thermal desorption (LTTD), followed by on-site landfill disposal. LTTD is relatively expensive (estimated cost of treatment which exclude disposal cost for the collect mercury is greater than $740/per cubic yard [cy] at Y-12), does not treat any of the metal or radionuclides. DOE is seeking a less costly alternative to the baseline technology. As described in the solicitation (DE-RA-01NT41030), this project initially focused on evaluating cost-effective in-situ alternatives to stabilize or remove the mercury (Hg) contamination from high-clay content soil. It was believed that ex-situ treatment of soil contaminated with significant quantities of free-liquid mercury might pose challenges during excavation and handling. Such challenges may include controlling potential mercury vapors and containing liquid mercury beads. As described below, the focus of this project was expanded to include consideration of ex-situ treatment after award of the contract to International Technology Corporation (IT). After award of the contract, IT became part of Shaw

  11. Proximal Tibia Chondroblastoma Treated With Curettage and Bone Graft and Cement Use.

    PubMed

    Cho, Hwan Seong; Park, Yeong Kyoon; Oh, Joo Han; Lee, Jung Hyun; Han, Ilkyu; Kim, Han-Soo

    2016-01-01

    Chondroblastoma has a predilection for the epiphyses or apophyses of long tubular bones. Management of lesions in the proximal tibia is challenging because it is difficult to gain access to intraepiphyseal lesions for completion of curettage. From October 2007 to December 2011, 9 patients with de novo chondroblastoma of the proximal tibia underwent surgery at the authors' institution. All patients initially presented with pain, and 5 patients had limitation of range of motion of the ipsilateral knee. Four lesions abutted the tibial attachment sites of the cruciate ligaments. Surgical procedures included intralesional tumor curettage, additional burring, and packing of the defect with bone graft and/or bone cement. The extra-articular approach was used according to tumor location. The medial or lateral parapatellar approach was used when the tumor was located in the anterior two-thirds of the horizontal plane. When a lesion was located in the posterior third, the posteromedial or posterolateral approach was used as the lesion was cornered. Mean duration of follow-up was 47.2 months (range, 27-80 months). No local recurrence or pulmonary metastasis was noted at latest follow-up. Mean functional score was 29.3 points (range, 28-30 points). All patients fully recovered range of motion in the affected knee. No avulsion fracture or anteroposterior instability of the knee joint was detected. Results of the current study suggest that intralesion curettage followed by additional burring with an extra-articular approach is a successful treatment option for chondroblastoma of the proximal tibia.

  12. Proximal Tibia Chondroblastoma Treated With Curettage and Bone Graft and Cement Use.

    PubMed

    Cho, Hwan Seong; Park, Yeong Kyoon; Oh, Joo Han; Lee, Jung Hyun; Han, Ilkyu; Kim, Han-Soo

    2016-01-01

    Chondroblastoma has a predilection for the epiphyses or apophyses of long tubular bones. Management of lesions in the proximal tibia is challenging because it is difficult to gain access to intraepiphyseal lesions for completion of curettage. From October 2007 to December 2011, 9 patients with de novo chondroblastoma of the proximal tibia underwent surgery at the authors' institution. All patients initially presented with pain, and 5 patients had limitation of range of motion of the ipsilateral knee. Four lesions abutted the tibial attachment sites of the cruciate ligaments. Surgical procedures included intralesional tumor curettage, additional burring, and packing of the defect with bone graft and/or bone cement. The extra-articular approach was used according to tumor location. The medial or lateral parapatellar approach was used when the tumor was located in the anterior two-thirds of the horizontal plane. When a lesion was located in the posterior third, the posteromedial or posterolateral approach was used as the lesion was cornered. Mean duration of follow-up was 47.2 months (range, 27-80 months). No local recurrence or pulmonary metastasis was noted at latest follow-up. Mean functional score was 29.3 points (range, 28-30 points). All patients fully recovered range of motion in the affected knee. No avulsion fracture or anteroposterior instability of the knee joint was detected. Results of the current study suggest that intralesion curettage followed by additional burring with an extra-articular approach is a successful treatment option for chondroblastoma of the proximal tibia. PMID:26726978

  13. Solidification/stabilisation of metals contaminated industrial soil from former Zn smelter in Celje, Slovenia, using cement as a hydraulic binder.

    PubMed

    Voglar, Grega E; Lestan, Domen

    2010-06-15

    In a laboratory study, Portland cement (15%, w/w) was used for solidification/stabilisation (S/S) of Cd, Pb, Zn, Cu, Ni and As contaminated soils from the former industrial site. Soils formed solid monoliths with cement. S/S effectiveness was assessed by measuring the mechanical strength of the monoliths, concentrations of metals in deionised water and TCLP (toxicity characteristic leaching procedure) soil extracts, and mass transfer of metals. Concentrations of Cd, Pb, Zn and Ni in water extracts from S/S soils generally decreased, concentrations of As remained unchanged, while concentrations of Cu increased. Concentrations of Cd, Pb, Zn and Ni in the TCLP extracts from S/S soils were lower than from original soils. Cu extractability was lower in most soil samples, while the extractability of As from S/S soils increased. Overall, the concentration of metals in deionised water and TCLP solution, obtained after extraction of the S/S soils, was below the regulatory limits. S/S greatly reduced the mass transfer of Cd (up to 83-times), Pb (up to 13.7-times) and Zn (up to 294-times). Mass transfer of Ni and As was generally also reduced, while that of Cu increased in some S/S soils. Based on the findings of mass-transfer mechanism analysis the predominant mechanism of release was surface wash-off of metals otherwise physically encapsulated within the cementous soil matrix. PMID:20207479

  14. Fate of Soil Organic Carbon and Polycyclic Aromatic Hydrocarbons in a Vineyard Soil Treated with Biochar.

    PubMed

    Rombolà, Alessandro G; Meredith, Will; Snape, Colin E; Baronti, Silvia; Genesio, Lorenzo; Vaccari, Francesco Primo; Miglietta, Franco; Fabbri, Daniele

    2015-09-15

    The effect of biochar addition on the levels of black carbon (BC) and polcyclic aromatic hydrocarbons (PAHs) in a vineyard soil in central Italy was investigated within a two year period. Hydropyrolysis (HyPy) was used to determine the contents of BC (BCHyPy) in the amended and control soils, while the hydrocarbon composition of the semi-labile (non-BCHyPy) fraction released by HyPy was determined by gas chromatography-mass spectrometry, together with the solvent-extractable PAHs. The concentrations of these three polycyclic aromatic carbon reservoirs changed and impacted differently the soil organic carbon over the period of the trial. The addition of biochar (33 ton dry biochar ha(-1)) gave rise to a sharp increase in soil organic carbon, which could be accounted for by an increase in BCHyPy. Over time, the concentration of BCHyPy decreased significantly from 36 to 23 mg g(-1) and as a carbon percentage from 79% to 61%. No clear time trends were observed for the non-BCHyPy PAHs varying from 39 to 34 μg g(-1) in treated soils, not significantly different from control soils. However, the concentrations of extractable PAHs increased markedly in the amended soils and decreased with time from 153 to 78 ng g(-1) remaining always higher than those in untreated soil. The extent of the BCHyPy loss was more compatible with physical rather than chemical processes.

  15. Just a drop of cement: a case of cervical spine bone aneurysmal cyst successfully treated by percutaneous injection of a small amount of polymethyl-methacrylate cement.

    PubMed

    Fahed, Robert; Clarençon, Frédéric; Riouallon, Guillaume; Cormier, Evelyne; Bonaccorsi, Raphael; Pascal-Mousselard, Hugues; Chiras, Jacques

    2016-01-01

    Aneurysmal bone cyst (ABC) is a benign hemorrhagic tumor, commonly revealed by local pain. The best treatment for this lesion is still controversial. We report the case of a patient with chronic neck pain revealing an ABC of the third cervical vertebra. After percutaneous injection of a small amount of polymethyl-methacrylate bone cement, the patient experienced significant clinical and radiological improvement.

  16. PCDD/F and metal concentrations in soil and herbage samples collected in the vicinity of a cement plant.

    PubMed

    Schuhmacher, M; Bocio, A; Agramunt, M C; Domingo, J L; de Kok, H A M

    2002-07-01

    In May 2000, the levels of a number of metals (As, Cd, Pb, Hg, Zn, Co, Cu, Mn, Sn, Tl, Cr, Ni and V) were determined in 16 soil and herbage samples collected in the vicinity of a cement plant from Sta. Margarida i els Monjos (Catalonia, Spain). Metal concentrations were also analyzed in air filters from three sampling stations placed nearthe facility. For most metals, concentrations were similar or even lower than previously reported values for other areas from Catalonia. On the other hand, the levels of polychlorinated dibenzo-p-dioxins (PCDD) and dibenzofurans (PCDF) were also determined in four soil and 16 herbage samples. Mean values were 0.37 and 0.16 ng I-TEQ/kg for soils and herbage, respectively, values which in comparison with data from other surveys are rather low. No significant differences between metal and PCDD/F concentrations in samples collected at distances lower or greater than 3.5 km of the facility were noted. The current results show that the cement plant has a low impact on the metal and PCDD/F levels in the environment under direct influence of the facility. These results should be of interest to assess future temporal variations in the levels of metals and PCDD/Fs in this area.

  17. Leaching of estrogenic hormones from manure-treated structured soils.

    PubMed

    Kjaer, Jeanne; Olsen, Preben; Bach, Kamilla; Barlebo, Heidi C; Ingerslev, Flemming; Hansen, Martin; Sørensen, Bent Halling

    2007-06-01

    The threat to the aquatic environment posed by root zone leaching of estrogens from manure-treated fields has hitherto been overlooked. The steroid hormones 17beta-estradiol (E2) and its degradation product estrone (E1) are of particular environmental concern as both are abundant in slurryfrom pregnant and cycling pigs and both are potential endocrine disruptors (lowest observable effect level (LOEL) 14 and 3.3 ng/L, respectively). The present one-year study examines the transport of E1 and E2 from manure to tile drainage systems at two field sites on structured, loamy soil. The estrogens leached from the root zone to tile drainage water in concentrations exceeding the LOEL for as long as 3 months after application, with the maximum recorded concentration of E1 and E2 being 68.1 and 2.5 ng/ L, respectively. Transport of estrogens from the soil to the aquatic environment was governed by pronounced macropore flow and consequent rapid movement of the estrogens to the tile drains. These findings suggest that the application of manure to structured soils poses a potential contamination risk to the aquatic environment with estrogen, particularly when manure is applied to areas where the majority of streamwater derives from drainage water.

  18. Re-use of stabilised flue gas ashes from solid waste incineration in cement-treated base layers for pavements.

    PubMed

    Cai, Zuansi; Jensen, Dorthe L; Christensen, Thomas H; Bager, Dirch H

    2003-02-01

    Fly ash from coal-burning power plants has been used extensively as a pozzolan and fine filler in concrete for many years. Laboratory experiments were performed investigating the effect of substituting the coal-based fly ash with chemically stabilised flue gas ashes (FGA) from waste incineration. Two types of FGA were treated by the Ferrox-process, which removes the majority of the easily soluble salts in the FGA and provides binding sites for heavy metals in terms of ferrihydrite. Cubes of cement treated base layer materials containing 5% stabilised FGA were cast, sealed and cured for two weeks. Cylinders (diameter 100 mm, length 150 mm) were drilled from these cubes for tank leaching experiments. Duplicate specimens were subject to compression strength testing and to tank leaching experiments. The compressive strength of the CTB fulfilled the Danish requirements for CTB, i.e. strength more than 5 MPa after 7 days. The tank leaching tests revealed that leaching of heavy metals was not significantly affected by the use of chemically stabilised flue gas ashes from waste incineration. Assuming that diffusion controls the leaching process it was calculated that less than 1% of the metals would leach during a 100-year period from a 0.5 m thick concrete slab exposed to water on one side. Leaching of the common ions Ca, Cl, Na and SO4 was increased 3-20 times from the specimens with chemically stabilised flue gas ashes from waste incineration. However, the quantities leached were still modest. These experiments suggest that FGA from waste incineration after Ferrox-treatment could be re-used in CTB without compromising the strength and leaching from the base layer.

  19. The Adsorption and Desorption of Pb(2+) and Cd(2+) in Freeze-Thaw Treated Soils.

    PubMed

    Li, Linhui; Ma, Jincai; Xu, Meng; Li, Xu; Tao, Jiahui; Wang, Guanzhu; Yu, Jitong; Guo, Ping

    2016-01-01

    Adsorption and desorption are important processes that influence the potential toxicity and bioavailability of heavy metals in soils. However, information regarding adsorption and desorption behavior of heavy metals in soils subjected to freeze-thaw cycles is poorly understood. In the current study, the effect of freeze-thaw cycles with different freezing temperature (-15, -25, -35°C) on soil properties was investigated. Then the adsorption and desorption behavior of Pb(2+) and Cd(2+) in freeze-thaw treated soils was studied. The adsorption amounts of Pb(2+) and Cd(2+) in freeze-thaw treated soils were smaller than those in unfrozen soils (p < 0.05), due to the fact that pH, cation exchange capacity, organic matter content, free iron oxide content, and CaCO3 content in freeze-thaw treated soils were smaller than those in unfrozen soils. The adsorption amounts of Pb(2+) and Cd(2+) in soils treated with lower freezing temperatures were higher than those in soils treated with higher freezing temperatures. Desorption percentages of Pb(2+) and Cd(2+) in unfrozen soils were smaller than those in freeze-thaw treated soils (p < 0.05). The desorption percentages of Pb(2+) and Cd(2+) were smaller in soils treated with lower freezing temperatures than those in soils treated with higher freezing temperatures. The results obtained highlight the change of the adsorption and desorption behavior of typical heavy metals in freeze-thaw treated soils located in seasonal frozen soils zone in northeast China.

  20. The partitioning behavior of trace element and its distribution in the surrounding soil of a cement plant integrated utilization of hazardous wastes.

    PubMed

    Yang, Zhenzhou; Chen, Yan; Sun, Yongqi; Liu, Lili; Zhang, Zuotai; Ge, Xinlei

    2016-07-01

    In the present study, the trace elements partitioning behavior during cement manufacture process were systemically investigated as well as their distribution behaviors in the soil surrounding a cement plant using hazardous waste as raw materials. In addition to the experimental analysis, the thermodynamic equilibrium calculations were simultaneously conducted. The results demonstrate that in the industrial-scale cement manufacture process, the trace elements can be classified into three groups according to their releasing behaviors. Hg is recognized as a highly volatile element, which almost totally partitions into the vapor phase. Co, Cu, Mn, V, and Cr are considered to be non-volatile elements, which are largely incorporated into the clinker. Meanwhile, Cd, Ba, As, Ni, Pb, and Zn can be classified into semi-volatile elements, as they are trapped into clinker to various degrees. Furthermore, the trace elements emitted into the flue gas can be adsorbed onto the fine particles, transport and deposit in the soil, and it is clarified here that the soil around the cement plant is moderately polluted by Cd, slightly polluted by As, Cr, Ba, Zn, yet rarely influenced by Co, Mn, Ni, Cu, Hg, and V elements. It was also estimated that the addition of wastes can efficiently reduce the consumption of raw materials and energy. The deciphered results can thus provide important insights for estimating the environmental impacts of the cement plant on its surroundings by utilizing wastes as raw materials. PMID:27040541

  1. 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

  2. Evaluation of fracture resistance of endodontically treated maxillary premolars, restored with ceromer or heat-pressed ceramic inlays and fixed with dual-resin cements.

    PubMed

    Ortega, V L; Pegoraro, L F; Conti, P C R; do Valle, A L; Bonfante, G

    2004-04-01

    The aim of this study was to evaluate the fracture resistance of endodontically maxillary premolars restored with mesio-occlusal-distal (MOD) inlays made with ceramic (IPS-Empress 2) and ceromer (Targis) and luted with three different dual-cured resin cements (Enforce, Variolink II, Panavia F). Sixty maxillary premolars were randomly distributed into six groups, according to their mesio-distal and facio-lingual dimensions. The teeth were endodontically treated and MOD cavities prepared. After the restorations were cemented, the samples were thermocycled and submitted to an axial compressive load by the action of a rounded end steel cylinder contacting the incline planes of occlusal surfaces of the teeth. The mode of fracture was analysed with a microscope. The best results were found with the combinations (cement/restorative material) Enforce/Targis (107.57 kgf) and Enforce/Empress (90.21 kgf) followed by Variolink II/Targis (86.44 kgf)-Variolink II/Empress (84.07 kgf) and Panavia F/Targis (82.43 kgf)-Panavia F/Empress (76.73 kgf). Analysis of variance (P < 0.05) showed a significant difference between Enforce and Panavia cements regardless of the restorative material. Considering the same luting agent there was no statistically significant difference between the restorative materials. Fracture of lingual cusps occurred in 55 of the 60 teeth and most of them were of the cohesive type.

  3. Soil pollution under the effect of treated municipal wastewater.

    PubMed

    Kalavrouziotis, Ioannis K; Koukoulakis, Prodromos H

    2012-10-01

    Soil heavy metal pollution due to wastewater reuse was assessed by means of the concentration factor (CF) and/or pollution load index (PLI).In this respect, a greenhouse pot experiment was conducted, using a completely randomized block design, including five treatments of treated municipal wastewater (0%, 25%, 50%, 75%, and 100%), in four replications. Brassica oleracea var. Capitata was used as a test crop. The optimum CFs were expressed as a function of maximum dry matter of cabbage plant parts yield, and the values obtained per plant part were as follows: stems-Zn-CF 2.96, Co-CF 0.85, Ni-CF 0.92; whole plant-Cu-CF 3.90, Ni-CF 0.87, and Pb-CF 11.52; and leaves-Pb-CF 11.78. The PLI was calculated as the geometric mean of the CF of each metal, and was related to the maximum dry mater yield of cabbage stems and heads. The optimum values found were: stems PLI 1.99-2.55 and heads 2.25.

  4. Chemical properties and biological activity in soils of Mallorca following twenty years of treated wastewater irrigation.

    PubMed

    Adrover, Maria; Farrús, Edelweïss; Moyà, Gabriel; Vadell, Jaume

    2012-03-01

    On the Mediterranean island of Mallorca, the use of secondary-treated municipal wastewater in irrigation was introduced with the construction of the first wastewater treatment plants in the 1970s. In this study, the chemical properties and biological activity of 21 arable soils, irrigated for more than 20 years with secondary-treated wastewater, were tested in order to assess their quality. Soil quality was evaluated by measuring cation exchange capacity, pH, calcium carbonate equivalent, soil organic matter, total nitrogen, available phosphorus, water-soluble organic carbon, soil microbial biomass, soil basal respiration, and the activities of the enzymes dehydrogenase, β-glucosidase and alkaline phosphatase. No negative effects of the irrigation treatment were observed on the measured soil parameters. Indeed, soil water-soluble organic carbon, soil microbial biomass and β-glucosidase and alkaline phosphatase activities increased under treated wastewater irrigation. Biological activity of soils irrigated with treated wastewater was affected mainly by soil organic matter content. Although the typical crop management of alfalfa, and other forage crops associated with treated wastewater irrigation, may have contributed to the increase of these parameters, the results suggest that irrigation with treated wastewater is a strategy with many benefits to agricultural land management.

  5. Germination of Blue Wildrye in Biochar Treated Mining Impacted Soils

    EPA Science Inventory

    Stabilization of mine sites with vegetation is an important management strategy to reduce metal movement off-site. Plant growth, however, is often hampered by poor soil conditions. Biochar is a novel soil amendment that may improve soil health conditions and improve plant growt...

  6. Cement Mason's Curriculum. Instructional Units.

    ERIC Educational Resources Information Center

    Hendirx, Laborn J.; Patton, Bob

    To assist cement mason instructors in providing comprehensive instruction to their students, this curriculum guide treats both the skills and information necessary for cement masons in commercial and industrial construction. Ten sections are included, as follow: related information, covering orientation, safety, the history of cement, and applying…

  7. Impact of cement dust pollution on Cedrela fissilis Vell. (Meliaceae): A potential bioindicator species.

    PubMed

    Siqueira-Silva, Advanio Inácio; Pereira, Eduardo Gusmão; Modolo, Luzia Valentina; Lemos-Filho, José Pires; Paiva, Elder Antonio Sousa

    2016-09-01

    Considering the impacts caused to vegetation in the vicinity of cement factories, the aim of this study was to evaluate the impacts of cement dust on the structural organization and physiological/biochemical traits of Cedrela fissilis leaflets, a woody species native to tropical America. Plants were exposed to 2.5 or 5 mg cm-2 cement dust applied to the leaf surface, to the soil or simultaneously to the leaf surface and the soil.. Leaves of shoot-treated plants exhibited chlorosis, marginal and inter veins necrosis, diminished thickness, epidermal cells less turgid, cellular collapse, obstructed stomata, senescence, rolling and some abscission. In few cases, individual death was recorded. Cement dust-treated plants also presented decreased amount of photosynthetic pigments and iron (Fe) and increase in calcium (Ca) levels. The cement crust formed in leaves surface blocked from 30 to 50% of the incoming light and reduced the stomatal conductance and the potential quantum yield of photosystem II. Control or soil-treated plants did not exhibit morphophysiological changes throughout the experiment. The activity of superoxide dismutase, catalase and ascorbate peroxidase increased in leaves of plants upon treatment with 2.5 mg cm(-2) cement dust, independent of the site application. Overall, these results indicate that C. fissilis is highly sensitive to cement dust at the initial stage of development.

  8. Impact of cement dust pollution on Cedrela fissilis Vell. (Meliaceae): A potential bioindicator species.

    PubMed

    Siqueira-Silva, Advanio Inácio; Pereira, Eduardo Gusmão; Modolo, Luzia Valentina; Lemos-Filho, José Pires; Paiva, Elder Antonio Sousa

    2016-09-01

    Considering the impacts caused to vegetation in the vicinity of cement factories, the aim of this study was to evaluate the impacts of cement dust on the structural organization and physiological/biochemical traits of Cedrela fissilis leaflets, a woody species native to tropical America. Plants were exposed to 2.5 or 5 mg cm-2 cement dust applied to the leaf surface, to the soil or simultaneously to the leaf surface and the soil.. Leaves of shoot-treated plants exhibited chlorosis, marginal and inter veins necrosis, diminished thickness, epidermal cells less turgid, cellular collapse, obstructed stomata, senescence, rolling and some abscission. In few cases, individual death was recorded. Cement dust-treated plants also presented decreased amount of photosynthetic pigments and iron (Fe) and increase in calcium (Ca) levels. The cement crust formed in leaves surface blocked from 30 to 50% of the incoming light and reduced the stomatal conductance and the potential quantum yield of photosystem II. Control or soil-treated plants did not exhibit morphophysiological changes throughout the experiment. The activity of superoxide dismutase, catalase and ascorbate peroxidase increased in leaves of plants upon treatment with 2.5 mg cm(-2) cement dust, independent of the site application. Overall, these results indicate that C. fissilis is highly sensitive to cement dust at the initial stage of development. PMID:27243585

  9. Soil recycling paves the way for treating brownfields

    SciTech Connect

    Gladdys, R.

    1996-02-01

    A soil recycling and stabilization process allows once-contaminated soil to be incorporated into paving materials. Contaminated soils is more widespread than often realized, with one of the more common sources being petroleum products such as fuel oil and gasoline. Until recently, the conventional solution was to have the material excavated, separated from remining soil and trucked to a hazardous waste landfill. This article describes an alternative approach under the following topics: move the solution, not the problem; on site recycling; heavy metals stabilization; economics.

  10. Effect of treated domestic wastewater on soil physicochemical and microbiological properties.

    PubMed

    Sklarz, Menachem Y; Zhou, Meiyang; Ferrando Chavez, Diana L; Yakirevich, Alexander; Gillor, Osnat; Gross, Amit; Soares, M Ines M

    2013-07-01

    A main concern with reuse of treated domestic wastewater (DWW) in irrigation is its possible effect on the soil. Few studies have focused on DWW treated in on-site settings, which generally use low-tech systems that can be constructed and serviced locally. One such system is the recirculating vertical flow constructed wetland (RVFCW). The aim of this study was to assess short- to midterm effects of irrigation with DWW treated in the RVFCW. Four groups of plastic barrels, filled with a sandy loam soil, were irrigated for 36 mo with fresh water (FW), FW with added fertilizer, raw DWW, or DWW treated in the RVFCW followed by ultraviolet disinfection. Principal component analysis revealed that the soil irrigated with treated DWW had physicochemical properties similar to those irrigated with FW amended with fertilizer. Levels of surfactants in soil irrigated with treated DWW were identical to those expected from standard irrigation practices, abating concerns for possible changes in soil hydraulic properties. was not detected in the soil irrigated with treated DWW, demonstrating the importance of disinfection of treated effluents before reuse in irrigation. Furthermore, irrigation with treated DWW did not alter the bacterial community structure according to terminal restriction fragment analysis. This 3-yr study suggests that the practice of irrigation with RVFCW effluents is safe. Continuation of the experiment is required to determine whether longer-term irrigation might show a different pattern.

  11. Pull-out bond strength of a self-adhesive resin cement to NaOCl-treated root dentin: effect of antioxidizing agents

    PubMed Central

    Kachuei, Marzieh

    2014-01-01

    Objectives This study evaluated the effect of three antioxidizing agents on pull-out bond strengths of dentin treated with sodium hypochlorite. Materials and Methods Root canals of 75 single-rooted human teeth were prepared. Fifteen teeth were irrigated with normal saline for a negative control group, and the remaining 60 teeth (groups 2 - 5) with 2.5% NaOCl. The teeth in group 2 served as a positive control. Prior to post cementation, the root canals in groups 3 - 5 were irrigated with three antioxidizing agents including 10% rosmarinic acid (RA, Baridge essence), 10% hesperidin (HPN, Sigma), and 10% sodium ascorbate hydrogel (SA, AppliChem). Seventy-five spreaders (#55, taper .02, Produits Dentaires S.A) were coated with silica and silanized with the Rocatec system and ceramic bond. All the prepared spreaders were cemented with a self-adhesive resin cement (Bifix SE, Voco Gmbh) in the prepared canals. After storage in distilled water (24 h/37℃), the spreaders were pulled out in a universal testing machine at a crosshead speed of 1.0 mm/min. Pull-out strength values were analyzed by one-way ANOVA and Tukey's HSD test (α = 0.05). Results There were significant differences between study groups (p = 0.016). The highest pull-out strength was related to the SA group. The lowest strength was obtained in the positive control group. Conclusions Irrigation with NaOCl during canal preparation decreased bond strength of resin cement to root dentin. Amongst the antioxidants tested, SA had superior results in reversing the diminishing effect of NaOCl irrigation on the bond strength to root dentin. PMID:24790921

  12. Chesterton soil concretions: ilmenite and not iron-manganese cementing matrix.

    PubMed

    White, K L

    1979-06-01

    Dark reddish-brown spherules are common in soils of the Chesterton soil series of a high marine terrace in southern California. The spherules are concretionary in structure and are bound by ilmenite rather than by an iron-manganese complex. The spherules have been mislabeled both with respect to structure and mineralogy.

  13. Strength Development of Lime Treated Artificial Organic Soil

    NASA Astrophysics Data System (ADS)

    Yeo, S. W.; Ling, F. N. L.; Sulaeman, A.; Low, V. S.; Toh, K. L.

    2016-07-01

    In over many years, considerable research has been carried out on organic soils which consists of various components of organic matter but the effect of particular organic matter is less reported. Thus, some of contributing factors for each organic matter are not fully understood yet. Hence, the aim of this study is to determine the effect of organic acid concentration on the strength of artificial organic soil. There are four types of artificial organic soil created by mixing kaolin (inorganic matter) and organic acid (a kind of humified organic matter) in different concentrations. Unconfined Compressive Strength test (UCT) was carried out for all soil samples after being cured for 7 and 28 days under room temperature and 50°C. Soil samples shows highest strength when cured for 28 days under 50°C compared to those cured under room temperature. However, when the organic acid concentration decrease, the strength increased for soil 2 after 7 and 28 days cured under room temperature and 50°C. Apart from this, soil 3 and soil 4 that were cured under room temperature shows decrease in strength when the organic acid concentration decreasing but different result shown for both samples when cured under 50°C.

  14. The enhanced biodegradation of fenamiphos in soils from previously treated sites and the effect of soil fumigants.

    PubMed

    Karpouzas, Dimitrios Georgios; Hatziapostolou, Polydoros; Papadopoulou-Mourkidou, Euphemia; Giannakou, Ioannis O; Georgiadou, Athena

    2004-09-01

    The application of fenamiphos either alone or in combination with soil fumigants is a common practice in greenhouses and potato-cultivation areas in Greece. However, repeated applications of fenamiphos in the same field for a number of years can lead to the development of enhanced biodegradation of the nematicide. Studies in previously treated greenhouse sites and potato field sites in Greece were employed in order to investigate the development of enhanced biodegradation of fenamiphos and the respective effect of soil fumigants on the development of the phenomenon. Enhanced biodegradation of fenamiphos in a soil from a previously treated greenhouse site from the area of Aggelohori in Northern Greece was observed using both incubation and bioassay studies with nematodes. Fumigation of the enhanced soil with methyl bromide (MeBr) only temporarily inhibited degradation of fenamiphos unlike metham sodium (MS) whose application significantly reduced microbial degradation of fenamiphos. Similarly, enhanced biodegradation of fenamiphos was evident in soil from potato fields that had a history of previous exposure to fenamiphos. The slow rates of fenamiphos degradation observed in soils from the previously treated sites after sterilization with broad-spectrum antibiotics and also in soils from previously untreated sites suggested that soil microorganisms were responsible for its rapid degradation. The inhibition of enhanced biodegradation of fenamiphos in soil from the previously treated greenhouse site caused by the antibiotic penicillin probably indicates that Gram+ or other bacteria sensitive to penicillin are responsible for the rapid degradation of fenamiphos in this soil. No cross-adaptation was observed between fenamiphos and other nematicides registered in Greece for the control of root-knot and potato cyst nematodes, including cadusafos, ethoprophos, and oxamyl. According to our results, applications of MS followed by fenamiphos or in rotation with other

  15. The enhanced biodegradation of fenamiphos in soils from previously treated sites and the effect of soil fumigants.

    PubMed

    Karpouzas, Dimitrios Georgios; Hatziapostolou, Polydoros; Papadopoulou-Mourkidou, Euphemia; Giannakou, Ioannis O; Georgiadou, Athena

    2004-09-01

    The application of fenamiphos either alone or in combination with soil fumigants is a common practice in greenhouses and potato-cultivation areas in Greece. However, repeated applications of fenamiphos in the same field for a number of years can lead to the development of enhanced biodegradation of the nematicide. Studies in previously treated greenhouse sites and potato field sites in Greece were employed in order to investigate the development of enhanced biodegradation of fenamiphos and the respective effect of soil fumigants on the development of the phenomenon. Enhanced biodegradation of fenamiphos in a soil from a previously treated greenhouse site from the area of Aggelohori in Northern Greece was observed using both incubation and bioassay studies with nematodes. Fumigation of the enhanced soil with methyl bromide (MeBr) only temporarily inhibited degradation of fenamiphos unlike metham sodium (MS) whose application significantly reduced microbial degradation of fenamiphos. Similarly, enhanced biodegradation of fenamiphos was evident in soil from potato fields that had a history of previous exposure to fenamiphos. The slow rates of fenamiphos degradation observed in soils from the previously treated sites after sterilization with broad-spectrum antibiotics and also in soils from previously untreated sites suggested that soil microorganisms were responsible for its rapid degradation. The inhibition of enhanced biodegradation of fenamiphos in soil from the previously treated greenhouse site caused by the antibiotic penicillin probably indicates that Gram+ or other bacteria sensitive to penicillin are responsible for the rapid degradation of fenamiphos in this soil. No cross-adaptation was observed between fenamiphos and other nematicides registered in Greece for the control of root-knot and potato cyst nematodes, including cadusafos, ethoprophos, and oxamyl. According to our results, applications of MS followed by fenamiphos or in rotation with other

  16. REVIEW OF SEPARATION TECHNOLOGIES FOR TREATING PESTICIDE-CONTAMINATED SOIL

    EPA Science Inventory

    Pesticide contamination results from manufacturing, improper storage, handling, or disposal of pesticides, and from agricultural processes. Since most pesticides are mixtures of different compounds, selecting a remedy for pesticide-contaminated soils can be a complicated process....

  17. Sensitivity of ice-cemented Antarctic soils to greenhouse-induced thawing: Are terrestrial archives at risk?

    NASA Astrophysics Data System (ADS)

    Swanger, Kate M.; Marchant, David R.

    2007-07-01

    We modeled the sensitivity of six ice-cemented slope deposits from the western McMurdo Dry Valleys, Antarctica to failure by shallow, thaw-induced planar sliding. The deposits examined have purportedly remained physically stable, without morphologic evidence for downslope movement, for millions of years. Could they fail in the near future from greenhouse-induced warming? To address this question, we first prescribed various increases in mean summertime soil surface temperature (MSSST) and modeled numerically the resultant changes in soil thaw depths using a one-dimensional heat diffusion equation (including the effects of latent heat of fusion). Second, we calculated the minimum thaw depths required to facilitate failure by shallow planar sliding for each deposit; for all numerical simulations, we maintained present soil-moisture conditions and used a Mohr-Coulomb-based equation of safety factor. Third, we calculated the rate of subsurface meltwater flow assuming Darcy's Law. Our results show that although most deposits contain sufficient subsurface ice to induce sliding upon thawing, lateral rates of water flow of as much as ˜ 40 m/day for some colluvial deposits prohibit the build-up of requisite pore pressures for failure. On the other hand, silty deposits, that contain gravimetric water ≥ 15%, occur on slopes > 20°, and possess low hydraulic conductivities (˜ 30-60 cm/day), common in the Dry Valleys region, could fail if MSSST, and by inference mean summertime atmospheric temperatures, increase by 4 to 9 °C. This temperature increase is similar to that predicted to occur from greenhouse-induced warming in Antarctica over the next century.

  18. Cement and concrete

    NASA Technical Reports Server (NTRS)

    Corley, Gene; Haskin, Larry A.

    1992-01-01

    To produce lunar cement, high-temperature processing will be required. It may be possible to make calcium-rich silicate and aluminate for cement by solar heating of lunar pyroxene and feldspar, or chemical treatment may be required to enrich the calcium and aluminum in lunar soil. The effects of magnesium and ferrous iron present in the starting materials and products would need to be evaluated. So would the problems of grinding to produce cement, mixing, forming in vacuo and low gravity, and minimizing water loss.

  19. Bioavailability of heavy metals in strongly acidic soils treated with exceptional quality biosolids

    SciTech Connect

    Basta, N.T.; Sloan, J.J.

    1999-03-01

    New federal regulations may increase application of exceptional quality (EQ) biosolids to acidic soils, and information on the effect of this practice on bioavailability of heavy metal is limited. The objective of this study was to compare bioavailability of heavy metal in soil treated with nonalkaline or alkaline EQ biosolids with limestone-treated soils. Three acidic soils (pH 3.7--4.3) were treated with three amounts of lime-stabilized biosolids (LS), anaerobic-digested biosolids (AN), or agricultural limestone (L), and incubated at 25 C. Soil solution Cd, Zn, and other chemical constituents were measured at 1, 30, 90, and 180 d incubation. Soil solution Cd and Zn were AN > LS {ge} L, C. Soil solution Cd and Zn increased with AN applied but decreased wit h LS applied. The high application of LS had soil solution Zn dramatically decreased at soil pH > 5.5 and >5.1, respectively. Soil solution Cd and Zn increases were AN > LS with incubation time. Biosolids treatments increased heavy metal in Ca(NO{sub 3}){sub 2} and NaOAc fractions. Except for Cd, most metal from biosolids were in EDTA and HNO{sub 3} fractions. Heavy metal bioavailability, measured using lettuce (Latuca sativa L.), was AN > LS {ge} L, C. Although state regulations prohibiting application of nonalkaline EQ biosolids to acidic soil is a prudent practice, application of EQ alkaline biosolids that achieves soil pH > 5 minimizes risk from soil solution Cd and Zn and plant uptake of heavy metal.

  20. Formation and preliminary in vitro evaluation of a zinc polycarboxylate cement reinforced with neat and acid-treated wollastonite fibers.

    PubMed

    Greish, Yaser E; Hamdan, Najwa M; El Maghraby, Hesham F

    2012-05-01

    Zinc polycarboxylate dental cement is known to form both molecular and mechanical bonds with native tooth materials. However, its relatively weak mechanical properties limit its applications. Wollastonite fibers, with different aspect ratios, were blended with ZnO, prior to its mixing with polyacrylic acid, at weight percentages up to 25%. Setting time, density, compressive strength, and Young's modulus of the formed composites were determined. Composition and morphology of the composites were determined by XRD, IR, and SEM before and after treatment in simulated body fluids. A slight delay in the setting time of the composites was observed. An overall improvement in the compressive strength and modulus of these composites was observed up to 5 wt % of wollastonites, followed by a decrease with increasing the proportion of wollastonite in the composites. Immersion of these composites in SBF solutions resulted in the formation of apatite deposits on the surfaces of the reinforcing fibers.

  1. Using Iron to Treat Chlorohydrocarbon-Contaminated Soil

    NASA Technical Reports Server (NTRS)

    Hitchens, G. Duncan; Hodko, Dalibor; Kim, Heekyung; Rogers, Tom; Singh, Waheguru Pal; Giletto, Anthony; Cisar, Alan

    2004-01-01

    A method of in situ remediation of soil contaminated with chlorinated hydrocarbon solvents involves injection of nanometer-size iron particles. The present method exploits a combination of prompt chemical remediation followed by longer-term enhanced bioremediation and, optionally, is practiced in conjunction with the method of bioremediation described earlier. Newly injected iron particles chemically reduce chlorinated hydrocarbons upon contact. Thereafter, in the presence of groundwater, the particles slowly corrode via chemical reactions that effect sustained release of dissolved hydrogen. The hydrogen serves as an electron donor, increasing the metabolic activity of the anaerobic bacteria and thereby sustaining bioremediation at a rate higher than the natural rate.

  2. Effects of incorporating differently-treated rice straw on phytoavailability of methylmercury in soil.

    PubMed

    Shu, Rui; Dang, Fei; Zhong, Huan

    2016-02-01

    Differently-treated crops straw is being widely used to fertilize soil, while the potential impacts of straw amendment on the biogeochemistry and phytoavailability of mercury in contaminated soils are largely unknown. In the present study, differently-treated rice straw (dry straw, composted straw, straw biochar, and straw ash) was incorporated into mercury-contaminated soil at an environment relevant level (1/100, w/w), and mercury speciation, methylmercury (MeHg) phytoavailability (using ammonium thiosulfate extraction method, validated elsewhere) and bioaccumulation (in Indian mustard Brassica junceas) were quantified. Our results indicated that incorporating straw biochar or composted straw into soil would decrease phytoavailable MeHg levels, possibly due to the strong binding of MeHg with particulate organic matter in amended straw ('MeHg immobilization effect'). Consequently, MeHg accumulation in aboveground tissue of Indian mustard harvested from straw biochar-amended soil decreased by 20% compared to the control. Differently, incorporation of dry straw resulted in elevated MeHg levels in soil ('Mercury methylation effect'). Decomposition of amended dry straw in soil would evidently increase DOC levels (averagely 40%-195% higher than the control), which may subsequently mobilize MeHg in the soil ('MeHg mobilization effect'). Accordingly, incorporation of dry straw led to increased phytoavailable MeHg levels in the soil and doubled MeHg accumulation in Indian mustard. Our results provided the first evidence that incorporating differently-treated rice straw into soil could have diverse effects on mercury biogeochemistry and phytoavailability, which should be taken into account in risk assessment or soil remediation. PMID:26694796

  3. Annual variation in the levels of metals and PCDD/PCDFs in soil and herbage samples collected near a cement plant.

    PubMed

    Schuhmacher, M; Agramunt, M C; Bocio, A; Domingo, J L; de Kok, H A M

    2003-07-01

    In May 2000, the levels of a number of metals (As, Cd, Co, Cr, Cu, Hg, Mn, Ni, Pb, Sn, Tl, V and Zn) and polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) were determined in soil and herbage samples collected near a cement plant from Sta. Margarida i els Monjos (Catalonia, Spain). To determine the temporal variation in the concentrations of metals and PCDD/PCDFs, in May 2001 soil and herbage samples were again collected at the same sampling points and analyzed for the levels of metals and PCDD/PCDFs. In general terms, metal concentrations in soils did not change between May 2000 and May 2001, while significant decreases in the levels of Cr, Ni and V were found in herbage. On the other hand, no significant differences in the mean I-TEQ values of PCDD/PCDFs were found in soil and herbage samples. The results of this survey show that according to the annual variation in the levels of metals and PCDD/PCDFs the environmental impact of the cement plant on the area under its direct influence is not relevant.

  4. The calcination process in a system for washing, calcinating, and converting treated municipal solid waste incinerator fly ash into raw material for the cement industry.

    PubMed

    Zhu, Fenfen; Takaoka, Masaki; Oshita, Kazuyuki; Morisawa, Shinsuke

    2011-07-01

    Calcination is the second step in a washing-calcination-conversion system in which treated municipal solid waste incinerator fly ash and bottom ash can be reused as raw material in the cement industry and can decompose or stabilize hazardous compounds, reduce residue amounts, and alter residue characteristics. In this research, only fly ash is discussed. Chloride reduction is important if treated fly ash is to be reused in cement; however, the relationship between washed fly ash properties and chloride reduction by calcination is not well understood. This study used washed residues of three types of fly ash-raw fly ash (RFA) from the boiler or economizer of an incineration system, fly ash collected in a bag filter injected with calcium hydroxide (Ca(OH)2) for acid removal (CaFA), and fly ash collected in a bag filter injected with sodium bicarbonate (NaHCO3) for acid removal (NaFA)-in calcination experiments with varying temperature (400-1100 degrees C) and atmosphere (100% nitrogen [N2] at 25 mL/min or 10% oxygen [O2] [90% N2] at fluxes of 25, 50, and 75 mL/min). From the perspective of chloride reduction, heating to 1000 degrees C with 1-hr heating time, 1-hr holding time, and an atmosphere of 10% O2/90% N2 was most suitable for calcination. Under these conditions, chloride levels were reduced by 91, 52, and 96% in washed residues of RFA, CaFA, and NaFA, respectively. Among the washed residues, the weight of the washed residue of NaFA decreased the most. PMID:21850828

  5. Long term irrigation with treated wastewater and soil structure stability - the Israeli experience

    NASA Astrophysics Data System (ADS)

    Levy, G. J.

    2009-04-01

    With the increased necessity to use treated waste water (TWW) for irrigation, especially in arid and semi-arid regions, farmers are faced with unique and unfamiliar problems among which is the possible degradation in soil structure and stability. Probable risks for adverse changes in the structural stability of soils and its hydraulic properties, following irrigation with TWW, may stem from the higher levels of organic matter, suspended solids, sodium adsorption ratio (SAR) and salinity in the TWW compared with its fresh water of origin. Laboratory studies with specimen clays have indicated that irrigation with TWW can lead to conditions in the soil that enhance clay swelling and dispersion. These phenomena can, in turn, initiate and/or increase clay depletion from the upper soil layer, deterioration in aggregate stability, a decrease in soil hydraulic conductivity and an increase in soil susceptibility to seal formation and soil erosion. These possible scenarios are expected to take place mostly during winter when the soil is exposed to rain water (i.e., water without electrolytes), which thus increase the sensitivity of the soil clays to swelling and dispersion. The current presentation has limited itself to Israeli studies from the past ten years because in studies prior to that period most of the TWW used for irrigation were of extremely poor quality. The impact of irrigation with TWW on clay movement and illuviation at deeper soil layers, aggregate stability, saturated hydraulic conductivity, and runoff and soil loss production, is presented. Results from the examined studies suggested that the effects of irrigation with TWW were inconsistent and complex. The results seemed to depend, beyond variation in the quality of the TWW, on soil properties (e.g., texture, lime content) and conditions prevailing in the field (e.g., type of tillage, rate of wetting, etc). It is therefore recommended that caution is exercised when TWW is used for irrigation and that

  6. Testing CO2 Sequestration in an Alkaline Soil Treated with Flue Gas Desulfurization Gypsum (FGDG)

    NASA Astrophysics Data System (ADS)

    Han, Y.; Tokunaga, T. K.

    2012-12-01

    Identifying effective and economical methods for increasing carbon storage in soils is of interest for reducing soil CO2 fluxes to the atmosphere in order to partially offset anthropogenic CO2 contributions to climate change This study investigates an alternative strategy for increasing carbon retention in soils by accelerating calcite (CaCO3) precipitation and promoting soil organic carbon (SOC) complexation on mineral surfaces. The addition of calcium ion to soils with pH > 8, often found in arid and semi-arid regions, may accelerate the slow process of calcite precipitation. Increased ionic strength from addition of a soluble Ca source also suppresses microbial activity which oxidizes SOC to gaseous CO2. Through obtaining C mass balances in soil profiles, this study is quantifying the efficiency of gypsum amendments for mitigating C losses to the atmosphere. The objective of this study is to identify conditions in which inorganic and organic C sequestration is practical in semi-arid and arid soils by gypsum treatment. As an inexpensive calcium source, we proposed to use flue gas desulfurization gypsum (FGDG), a byproduct of fossil fuel burning electric power plants. To test the hypothesis, laboratory column experiments have been conducted in calcite-buffered soil with addition of gypsum and FGDG. The results of several months of column monitoring are demonstrating that gypsum-treated soil have lowered amounts of soil organic carbon loss and increased inorganic carbon (calcite) production. The excess generation of FGDG relative to industrial and agricultural needs, FGDG, is currently regarded as waste. Thus application of FGDG application in some soils may be an effective and economical means for fixing CO2 in soil organic and inorganic carbon forms.Soil carbon cycle, with proposed increased C retention by calcite precipitation and by SOC binding onto soil mineral surfaces, with both processes driven by calcium released from gypsum dissolution.

  7. Assessing the use of treated waste water for irrigation agricultural lands by using soil quality indices

    NASA Astrophysics Data System (ADS)

    Arcenegui, V.; Morugán, A.; García-Orenes, F.; Zornoza, R.; Mataix-Solera, J.; Navarro, M. A.; Guerrero, C.; Mataix-Beneyto, J.

    2009-04-01

    The use of treated wastewater for the irrigation of agricultural soils is an alternative to utilizing better-quality water, especially in semiarid regions where water shortage is a very serious problem. However, this practise can modify the soil equilibrium and affect its quality. In this work two soil quality indices (models) are used to evaluate the effects of long-term irrigation with treated wastewater in soil. The models were developed studying different soil properties in undisturbed forest soils in SE Spain, and the relationships between soil parameters were established using multiple linear regressions. Model 1, that explained 92% of the variance in soil organic carbon (SOC) showed that the SOC can be calculated by the linear combination of 6 physical, chemical and biochemical properties (acid phosphatase, water holding capacity (WHC), electrical conductivity (EC), available phosphorus (P), cation exchange capacity (CEC) and aggregate stability (AS)). Model 2 explains 89% of the SOC variance, which can be calculated by means of 7 chemical and biochemical properties (urease, phosphatase, and

  8. Risk assessment applications for determining cleanup limits for uranium in treated and untreated soils

    SciTech Connect

    Armstrong, A.Q.; Layton, D.W.; Rutz, E.E.

    1994-06-01

    Uranium-contaminated soils are present at various locations across the US where uranium was processed for nuclear fuels or atomic weapons. Important issues relative to such contamination include the assessment of potential health risks associated with human exposures to the residual uranium and the determination of safe levels of uranium in soils that have been treated by a given technology. This paper discusses various risk assessment considerations that must be dealt with when developing cleanup limits for uranium in treated and untreated soils. Key issues addressed include alternative land use scenarios, potential exposure pathways, characterization of the bioavailability of uranium compounds in food and water, a brief overview of health risks associated with uranium and its daughter products as well as a summary of considerations for development of risk-based cleanup limits for uranium in soils.

  9. A feasibility study to use coal tar contaminated soil in asphalt cement mixture production

    SciTech Connect

    Dulam, C.S.; Hoag, G.E.; Dahmani, A.; Nadim, F.

    1996-11-01

    Coal tars are the residues produced during the gasification of coal. Traditionally, coal tars were buried onsite at the power plants or left as residuals in the bottom of gas holders. Currently, there are more than 1,500 such historic sites which will undergo site assessment in the near future. The use of coal tar residuals in asphalt-based products could result in greatly reduced disposal costs, in comparison to current methods of disposal. Present disposal practice of coal tar contaminated residuals includes disposal in hazardous waste landfills or incineration. Treatment and disposal costs are reported to be as much as $1,000/ton for current coal tar contaminated residuals disposal options. This feasibility study was performed to determine the use of coal tar contaminated soil (CTCS) in bituminous materials to produce hot asphalt mix. Mixtures of varying composition of CTCS and bituminous material were produced to perform TCLP. The air emissions during the mixing process were captured and analyzed. In this study, a bench scale investigation was performed to identify and quantify the emissions from heating the CTCS at the mixer temperature. The pilot scale investigations were performed by replacing reclaimable asphalt pavement (RAP) with CTCS during the hot asphalt mix production. The investigations were performed on two types of mixtures; using CTCS as the direct additive in the first type, and using SS-1 (slow setting asphalt emulsion) stabilized CTCS as an additive in the second type.

  10. Investigation into the artificial ageing effects on the microstructure of an industrial solid waste treated with cement.

    PubMed

    Choura, M; Keskes, M; Tayibi, H; Rouis, J

    2011-04-01

    Metal hydroxide sludges are classified as hazardous wastes in the European Hazardous Waste Catalogue (EHWC) because of their high heavy metal contents (Zn, Cr, Fe, Cu, etc.) and the release of these pollutants to the environment. Thereby, the disposal of this waste without any treatment is a substantial environmental problem. Stabilization/solidification technologies are widely used for the treatment of wastes and residues in order to obtain inert materials. This work aims to assess the effectiveness of the chemical fixation and solidification of a metal hydroxide sludge generated by the electrotyping surface treatment industry, using Portland Artificial Cement. In order to predict the medium- and long-term behaviour of the solidified waste, an artificial ageing by means of thermal shocks and humidity variation cycles was applied. Scanning Electron Microscopy (SEM) and X-ray Diffraction studies revealed a considerable increase in calcite within the solid matrix after the artificial ageing, which can be attributed to the phenomenon of carbonation. It was also found that the mechanical properties of the solidified material, after ageing, were improved by up to 30%. PMID:21877543

  11. Arsenic mobilization by citrate and malate from a red mud-treated contaminated soil.

    PubMed

    Castaldi, Paola; Silvetti, Margherita; Mele, Elena; Garau, Giovanni; Deiana, Salvatore

    2013-01-01

    The mobility and bioavailability of As in the soil-plant system can be affected by a number of organic acids that originate from the activity of plants and microorganisms. In this study we evaluated the ability of citrate and malate anions to mobilize As in a polluted subacidic soil (UP soil) treated with red mud (RM soil). Both anions promoted the mobilization of As from UP and RM soils, with citrate being more effective than malate. The RM treatment induced a greater mobility of As. The amounts of As released in RM and UP soils treated with 3.0 mmol L citric acid solution were 2.78 and 1.83 μmol g respectively, whereas an amount equal to 1.73 and 1.06 μmol g was found after the treatment with a 3.0 mmol L malic acid solution. The release of As in both soils increased with increasing concentration of organic acids, and the co-release of Al and Fe in solution also increased. The sequential extraction showed that Fe/Al (oxi)hydroxides in RM were the main phases involved in As binding in RM soil. Two possible mechanisms could be responsible for As solubilization: (i) competition of the organic anions for As adsorption sites and (ii) partial dissolution of the adsorbents (e.g., dissolution of iron and aluminum oxi-hydroxides) induced by citrate or malate and formation of complexes between dissolved Fe and Al and organic anions. This is the first report on the effect of malate and citrate on the As mobility in a polluted soil treated with RM.

  12. Evaluation of a soil slurry reactor system for treating soil contaminated with munitions compounds

    SciTech Connect

    Boopathy, R.; Manning, J.; Montemagno, C.; Kulpa, C.F.

    1994-05-01

    Two 0.5-L semicontinuous soil slurry reactors were operated for seven months to evaluate the performance of the slurry reactor system in bioremediating soil contaminated with munitions compounds. Nitrogen and carbon were supplemented. The soil slurry was mixed continuously and aerated 10 min/day. Ten percent of the contaminated soil was replaced every week. The 2,4,6-trinitrotoluene (TNT) concentration in soil began to drop after 15 days of treatment, falling to less than 0.5 mg/kg from 7800 mg/kg. Total plate counts in both reactors indicated that the bacterial population was maintained, with an average plate count of about 10{sup 8} CFU/mL. The soil slurry was slightly acidic. In addition to TNT, the slurry reactor also removed the other munitions compounds trinitrobenzene (TNB), 2,4-dinitrotoluene (2,4-DNT), RDX, and HMX. Radiolabeling studies on the reactor biomass showed that 23% of [{sup C}14]TNT was mineralized, while 27% was used as biomass and 8% was adsorbed on to the soil. The rest of the [{sup 14}C]TNT was accounted for as TNT metabolites. Increasing the frequency of soil replacement from once to two or three times weekly did not affect the TNT removal rates. However, the slurry system showed signs of stress, with highly acidic conditions and low oxygen uptake rates.

  13. Deca-brominated diphenyl ether destruction and PBDD/F and PCDD/F emissions from coprocessing deca-BDE mixture-contaminated soils in cement kilns.

    PubMed

    Yang, Yufei; Huang, Qifei; Tang, Zhenwu; Wang, Qi; Zhu, Xiaohua; Liu, Wenbin

    2012-12-18

    The disposal of soil contaminated with polybrominated diphenyl ether (PBDE) was studied using an industrial coprocessing cement kiln. Two tests, Test 1 and Test 2, studied the destruction, removal, and emissions of PBDE in soils with PBDE concentrations of 4160 and 25,000 mg/kg, respectively. Emissions of polybrominated dibenzo-p-dioxins and dibenzofurans (PBDD/Fs) and polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) were also quantified. The PBDE destruction and removal efficiencies for Tests 1 and 2 were 99.9997% and 99.9998%, respectively. PBDE stack gas concentrations were 39.1 and 85.9 ng/Nm³ for Tests 1 and 2, respectively. The mean PBDD/F TEQ stack gas concentrations related to Tests 1 and 2 were 11.0 and 11.4 pg/Nm³, and PBDFs contributed 60.0-64.2% of the total PBDD/F concentrations. 2,3,7,8-TeBDD made the greatest contribution to the total PBDD/Fs, 40%, of all the homologues. The mean PCDD/F TEQ stack gas concentrations in Tests 1 and 2 were 0.74 and 0.65 pg/Nm³. The total PBDE, PBDD/F, and PCDD/F TEQ at the kiln outlet was 0.006% and 0.001% of the feed material TEQ. Therefore, coprocessing heavily PBDE-contaminated soils in a cement kiln is a highly efficient and environmentally sound treatment technology.

  14. Evaluation of the use of solar irradiation for the decontamination of soils containing wood treating wastes

    SciTech Connect

    Dupont, R.R.; McLean, J.E.; Hoff, R.H.; Moore, W.M. )

    1990-08-01

    Laboratory evaluation of the efficacy of soil phase photodegradation of recalcitrant hazardous organic components of wood treating wastes is described. The photodecomposition of anthracene, biphenyl, 9H-carbazole, m-cresol, dibenzofuran, fluorene, pentachlorophenol, phenanthrene, pyrene and quinoline under UV and visible light was monitored over a 50-day reaction period in three test soils. Methylene blue, riboflavin, hydrogen peroxide, peat moss and diethylamine soil amendments were evaluated as to their effect on the enhancement of compound photoreaction rates in the test soil systems. Dark control samples monitored over the entire study period were utilized to quantify non-photo mediated reaction losses. Compounds losses in both the dark control and irradiated samples were found to follow first order kinetics, allowing the calculation of first order photodegradation reaction rate constants for each test soil/compound combination. Degradation due to photochemical activity was observed for all test compounds, with compound photolytic half-lives ranging from 7 to approximately 180 days. None of the soil amendments were found to improve soil phase photodegradation, although photosensitization by anthracene was shown to significantly enhance the rate of photodegradation of the other test compounds. Soil type, and its characteristic of internal reflectance, proved to be the most significant factor affecting compound degradation rates suggesting the necessity for site specific assessments of soil phase photodegradation potential.

  15. Immune response of earthworms (Lumbricus terrestris, Eisenia andrei and Aporrectodea tuberculata) following in situ soil exposure to atmospheric deposition from a cement factory.

    PubMed

    Massicotte, Richard; Robidoux, Pierre Yves; Sauvé, Sébastien; Flipo, Denis; Fournier, Michel; Trottier, Bertin

    2003-10-01

    In order to reduce their energy costs, many cement plants use fuel product substitutes (old tyres and used oil). The combustion of these products generates a metal increase (e.g. Cu, Cd, Pb and Zn) in the atmospheric emissions. After their release, these elements are deposited into the environment and could eventually accumulate up to concentrations of concern. At the Saint-Laurent cement factory (Joliette, QC, Canada), maximum deposition of these elements occurs in the direction of prevailing winds (North-East). We evaluated the potential impact of these depositions upon the immune system of three earthworm species (Lumbricus terrestris, Eisenia andrei and Aporrectodea tuberculata) exposed in a natural environment. The exposure sites were 0.5, 1.0, and 2.0 km downwind from the cement factory, along with an upwind reference site. The immune parameters studied were the cell viability and phagocytic potential of the immune cells (coelomocytes). For both L. terrestris and E. andrei, after 7 d exposure, none of the measured parameters showed significant differences among the sites. On the other hand, for the indigenous worm A. tuberculata, in the most exposed zone (at 0.5 km), we observed an increase in cell viability and phagocytic potential. This increase could possibly be attributed to physicochemical effects such as the alkaline pH of the soil, or alternatively, it could result from beneficial effects induced by an increased calcium supply.

  16. Effect of dissolved organic matter from treated effluents on sorption of atrazine and prometryn by soils

    SciTech Connect

    Seol, Y.; Lee, L.S.

    2000-01-02

    The apparent enhanced transport of soil-applied atrazine following irrigation of treated effluents has been hypothesized to be from complexation of atrazine with effluent-borne dissolved organic matter (DOM). Under long-term effluent irrigation, even small DOM-induced decreases in pesticide sorption can result in significant enhanced pesticide movement due to cumulative effects. The effect of atrazine and prometryn association with DOM extracted from municipal wastewater (MW), swine-derived lagoon wastewater (SW), and dissolved Aldrich humic acid (HA) on sorption by two soils was measured in batch equilibration studies. Individual association of pesticides to DOM, sorption of DOM to soil, and pesticide sorption by soil were also quantified. Pesticide association to DOM normalized to organic carbon (OC) ranged from 30 to 1000 L/kg OC. DOM sorption by soil ranged from 1.5 to 10 L/kg with a silt loam having a higher affinity for the DOM than the sandy loam. DOM up to 150 mg OC/L did not significantly suppress sorption by soils of either atrazine or prometryne in agreement with predictions using the independently measured binary distribution coefficients in a model that assumed linear equilibrium behavior among pesticide, soil, and DOM. A sensitivity analysis was performed using the same model to identify what combination of soil, pesticide, and DOC variables may suppress sorption, resulting in facilitated transport. Results from the sensitivity analysis are presented and the potential for effluent properties other than DOM to facilitate pesticide transport is discussed.

  17. Concentrations and allelopathic effects of benzoxazinoid compounds in soil treated with rye (Secale cereale) cover crop.

    PubMed

    Rice, Clifford P; Cai, Guimei; Teasdale, John R

    2012-05-01

    The concentration of benzoxazinoids (BX) was measured in field soils at selected intervals after rye residue was either incorporated or left on the soil surface. The spectrum of compounds arising in the soil persisted approximately two weeks and was dominated by methoxy containing BX compounds, which were only minor components of the rye foliage. Growth assays with lettuce and smooth pigweed species showed inhibition when treated soils were tested during the first two weeks after rye applications; however, there were no sufficient concentrations of any one BX compound in the soil to explain these affects. Solution applications of two pure BX compounds, benzoxazolin-2(3H)-one (BOA) and 6-methoxy-benzoxazolin-2(3H)-one (MBOA), to the surface of soils revealed that movement into the soil column was minimal (greater than 70% BOA and 97% MBOA remained in the top 1-cm of soil profiles) and that the time course for their complete dissipation was less than 24 h.

  18. E. coli transport in soil columns: implications for reuse of treated wastewater in irrigation.

    PubMed

    Smith, E; Hegazy, S

    2006-01-01

    Reuse of treated wastewater in irrigation is gaining recognition as a vital element in the water resources management plan of developing countries, especially those situated in arid and semi-arid regions. An understanding of the transport of residual pollutants from treated wastewater, such as bacteria, in soil as a result of irrigation is critical to assessing health risks and the possible contamination of limited groundwater resources. In this work, retention of E. coli is evaluated for a soil that is irrigated by treated wastewater for growth of non-food crops near Egypt's Red Sea coast. In particular, the effects of soil organic fraction (SOF) and hydraulic loading rate (HLR) were investigated in laboratory soil columns. The matrix of experiments included three HLRs and three SOFs. The retention of bacteria by adsorption was observed at HLRs of 5 and 13 cm/h, with the magnitude of the adsorption increasing proportionally to the SOF. The impact of SOF was greater for the lower HLR. At the lowest HLR investigated (5 cm/h), filtration was also observed for the two higher SOFs (0.674 and 2.04 per cent). At a high HLR (66 cm/h) simulating flood irrigation, retention of bacteria was minimal regardless of the SOF. Since the bacterial solution is applied to a dry soil column to simulate field conditions, E. coli breakthrough after two pore volumes of throughput (vs. one) provided a meaningful comparison of bacterial retention as a function of HLR and SOF.

  19. Calculating carbon mass balance from unsaturated soil columns treated with CaSO₄₋minerals: test of soil carbon sequestration.

    PubMed

    Han, Young-Soo; Tokunaga, Tetsu K

    2014-12-01

    Renewed interest in managing C balance in soils is motivated by increasing atmospheric concentrations of CO2 and consequent climate change. Here, experiments were conducted in soil columns to determine C mass balances with and without addition of CaSO4-minerals (anhydrite and gypsum), which were hypothesized to promote soil organic carbon (SOC) retention and soil inorganic carbon (SIC) precipitation as calcite under slightly alkaline conditions. Changes in C contents in three phases (gas, liquid and solid) were measured in unsaturated soil columns tested for one year and comprehensive C mass balances were determined. The tested soil columns had no C inputs, and only C utilization by microbial activity and C transformations were assumed in the C chemistry. The measurements showed that changes in C inventories occurred through two processes, SOC loss and SIC gain. However, the measured SOC losses in the treated columns were lower than their corresponding control columns, indicating that the amendments promoted SOC retention. The SOC losses resulted mostly from microbial respiration and loss of CO2 to the atmosphere rather than from chemical leaching. Microbial oxidation of SOC appears to have been suppressed by increased Ca(2+) and SO4(2)(-) from dissolution of CaSO4 minerals. For the conditions tested, SIC accumulation per m(2) soil area under CaSO4-treatment ranged from 130 to 260 g C m(-1) infiltrated water (20-120 g C m(-1) infiltrated water as net C benefit). These results demonstrate the potential for increasing C sequestration in slightly alkaline soils via CaSO4-treatment.

  20. Controllability of runoff and soil loss from small plots treated by vinasse-produced biochar.

    PubMed

    Sadeghi, Seyed Hamidreza; Hazbavi, Zeinab; Harchegani, Mahboobeh Kiani

    2016-01-15

    Many different amendments, stabilizers, and conditioners are usually applied for soil and water conservation. Biochar is a carbon-enriched substance produced by thermal decomposition of organic material in the absence of oxygen with the goal to be used as a soil amendment. Biochar can be produced from a wide range of biomass sources including straw, wood, manure, and other organic wastes. Biochar has been demonstrated to restore soil fertility and crop production under many conditions, but less is known about the effects of its application on soil erosion and runoff control. Therefore, a rainfall simulation study, as a pioneer research, was conducted to evaluate the performance of the application of vinasse-produced biochar on the soil erosion control of a sandy clay loam soil packed in small-sized runoff 0.25-m(2) plots with 3 replicates. The treatments were (i) no biochar (control), (ii) biochar (8 tha(-1)) application at 24h before the rainfall simulation and (iii) biochar (8 tha(-1)) application at 48 h before the rainfall simulation. Rainfall was applied at 50 mm h(-1) for 15 min. The mean change of effectiveness in time to runoff could be found in biochar application at 24 and 48 h before simulation treatment with rate of +55.10% and +71.73%, respectively. In addition, the mean runoff volume 24 and 48 h before simulation treatments decreased by 98.46% and 46.39%, respectively. The least soil loss (1.12 ± 0.57 g) and sediment concentration (1.44 ± 0.48 gl(-1)) occurred in the biochar-amended soil treated 48 h before the rainfall simulation. In conclusion, the application of vinasse-produced biochar could effectively control runoff and soil loss. This study provided a new insight into the effects of biochar on runoff, soil loss, and sediment control due to water erosion in sandy clay loam soils. PMID:26410722

  1. Controllability of runoff and soil loss from small plots treated by vinasse-produced biochar.

    PubMed

    Sadeghi, Seyed Hamidreza; Hazbavi, Zeinab; Harchegani, Mahboobeh Kiani

    2016-01-15

    Many different amendments, stabilizers, and conditioners are usually applied for soil and water conservation. Biochar is a carbon-enriched substance produced by thermal decomposition of organic material in the absence of oxygen with the goal to be used as a soil amendment. Biochar can be produced from a wide range of biomass sources including straw, wood, manure, and other organic wastes. Biochar has been demonstrated to restore soil fertility and crop production under many conditions, but less is known about the effects of its application on soil erosion and runoff control. Therefore, a rainfall simulation study, as a pioneer research, was conducted to evaluate the performance of the application of vinasse-produced biochar on the soil erosion control of a sandy clay loam soil packed in small-sized runoff 0.25-m(2) plots with 3 replicates. The treatments were (i) no biochar (control), (ii) biochar (8 tha(-1)) application at 24h before the rainfall simulation and (iii) biochar (8 tha(-1)) application at 48 h before the rainfall simulation. Rainfall was applied at 50 mm h(-1) for 15 min. The mean change of effectiveness in time to runoff could be found in biochar application at 24 and 48 h before simulation treatment with rate of +55.10% and +71.73%, respectively. In addition, the mean runoff volume 24 and 48 h before simulation treatments decreased by 98.46% and 46.39%, respectively. The least soil loss (1.12 ± 0.57 g) and sediment concentration (1.44 ± 0.48 gl(-1)) occurred in the biochar-amended soil treated 48 h before the rainfall simulation. In conclusion, the application of vinasse-produced biochar could effectively control runoff and soil loss. This study provided a new insight into the effects of biochar on runoff, soil loss, and sediment control due to water erosion in sandy clay loam soils.

  2. FIELD EVALUATION OF THE LIGNIN-DEGRADING FUNGUS PHANEROCHAETE SORDIDA TO TREAT CREOSOTE-CONTAMINATED SOIL

    EPA Science Inventory

    A field study to determine the ability of selected lignin-degrading fungi to remediate soil contaminated with creosote was performed at a wood-treating facility in south central Mississippi in the autumn of 1991. The effects of solid-phase bioremediation with Phanerochaete sordid...

  3. Strategies for Treating and Dewatering Contaminated Soils and Sediments Simultaneously - 13389

    SciTech Connect

    Bickford, Jody; Foote, Martin

    2013-07-01

    MSE Technology Applications, Inc. (MSE) was asked to perform a series of treatability studies by Global Technologies, Inc. (Global) and M{sup 2} Polymer Technologies, Inc. (M{sup 2} Polymer) using Global's metal treatment agent, Molecular Bonding System (MBS) and M{sup 2} Polymer's super-absorbent polymer, Waste Lock 770 (WL-770). The primary objective of the study was to determine if the two products could be used as a one-step treatment process to reduce the leachability of metals and de-water soils and/or sediments simultaneously. Three phases of work were performed during the treatability study. The first phase consisted of generating four bench-scale samples: two treated using only MBS and two treated using only WL- 770, each at variable concentrations. The second phase consisted of generating nine bench-scale samples that were treated using MBS and WL-770 in combination with three different addition techniques. The third phase consisted of generating four intermediate-scale samples that were treated using MBS and WL-770 simultaneously. The soils used in the treatability study were collected at the Mike Mansfield Advanced Technology Center in Butte, Montana. The collected soils were screened at 4 mesh (4.75 millimeters (mm)) to remove the coarse fraction of the soil and spiked with metallic contaminants of lead, cadmium, nickel, mercury, uranium, chromium, and zinc. (authors)

  4. Dechlorinating chloroacetanilide herbicides by dithionite-treated aquifer sediment and surface soil.

    PubMed

    Boparai, Hardiljeet K; Shea, Patrick J; Comfort, Steve D; Snow, Daniel D

    2006-05-01

    The prevalent use of chloroacetanilide herbicides has resulted in nonpoint contamination of some groundwater and surface water. We determined the efficacy of dithionite-treated sediment and soils to transform chloroacetanilides. When used alone, dithionite rapidly dechlorinates chloroacetanilides in water, with the following order of reactivity: propachlor > alachlor > acetochlor > metolachlor. Stoichiometric release of chloride occurs during reaction with dithionite, and thiosulfate herbicide derivatives are produced. Treating aquifer sediment with dithionite reduces native Fe(lII), creating a redox barrier of Fe(ll)-bearing minerals and surface-bound Fe(ll). Washing the reduced sediment (buffered with citrate-bicarbonate) with oxygen-free water removed Fe(ll) and excess dithionite and no alachlor transformation was observed. In contrast, a dithionite-treated surface soil, rich in clay and iron, effectively dechlorinated alachlor after washing. Exposing alachlor to aquifer sediment treated with dithionite in potassium carbonate buffer (pH 8.5-9.0) produced dechlorinated alachlor as the major degradation product. Our results provide proof-of-concept that dechlorination of chloroacetanilide herbicides by dithionite and dithionite-treated aquifer sediment and soil is a remediation option in natural environments where iron-bearing minerals are abundant.

  5. Seasonal changes in salinity and sodicity of soils irrigated with treated domestic wastewater

    NASA Astrophysics Data System (ADS)

    Lado, Marcos; Ben-Hur, Meni

    2014-05-01

    Semiarid and arid zones are characterized by short wet winters and long dry summers, when most of crop production relies on irrigation. In these areas, treated wastewater (TWW) is a valuable water resource whose use is rapidly expanding. However, the composition of TWW differs from that of freshwater, mainly due to higher salt, sodium and organic matter concentrations. Therefore, its continuous application to the soil could have an impact on soil properties, particularly soil salinity and sodicity. However, these changes could be reverted during the following rainy season, if the amount of rain infiltrating through the soil is enough to leach salts down the profile. In the present study, we analyzed the effects of long-term irrigation with secondary TWW on salinity and sodicity of two contrasting soils under semiarid Mediterranean conditions. Experiments were conducted in two grapefruit orchards, one with a non-calcareous sandy soil (Typic Haploxeralf) and the other with a calcareous clayey soil (Chromic Haploxerert). Two treatments were tested (>7 years): (i) irrigation with freshwater and (ii) irrigation with domestic, secondary TTW. During the duration of the experiment, soil profiles were sampled at regular intervals to a depth of 1.2 m two times each year: i) in spring, before the irrigation season started, and ii) in fall, after irrigation ended and before the rainy season. The results show that, in general, irrigation with TWW increased soil salinity compared with freshwater in the upper 30 cm of the soil profiles. However, leaching by rainwater resulted in similar salinity values in both treatments after the rainy season. Soil sodicity increased with the irrigation with TWW to a depth 1.2 m in the sandy soil and 0.6 m in the clay soil, but in general, these changes did not disappear during the rainy season. It can be concluded that in semiarid regions with >500 mm annual rainfall, the precipitation can be sufficient to prevent long-term salt accumulation in

  6. Calcium carbonate precipitation by strain Bacillus licheniformis AK01, newly isolated from loamy soil: a promising alternative for sealing cement-based materials.

    PubMed

    Vahabi, Ali; Ramezanianpour, Ali Akbar; Sharafi, Hakimeh; Zahiri, Hossein Shahbani; Vali, Hojatollah; Noghabi, Kambiz Akbari

    2015-01-01

    The relevant experiments were designed to determine the ability of indigenous bacterial strains isolated from limestone caves, mineral springs, and loamy soils to induce calcium carbonate precipitation. Among all isolates examined in this study, an efficient carbonate-precipitating soil bacterium was selected from among the isolates and identified by 16S rRNA gene sequences as Bacillus licheniformis AK01. The ureolytic isolate was able to grow well on alkaline carbonate-precipitation medium and precipitate calcium carbonate more than 1 g L(-1). Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) analyses, and scanning electron microscopy (SEM)/energy-dispersive X-ray spectroscopy (EDX) examinations were performed in order to confirm the presence of calcium carbonate in the precipitate and to determine which polymorphs were present. The selected isolate was determined to be an appropriate candidate for application in a surface treatment of cement-based material to improve the properties of the mortar. Biodeposition of a layer of calcite on the surface of cement specimens resulted in filling in pore spaces. This could be an alternative method to improve the durability of the mortar. The kind of bacterial culture and medium composition had a profound impact on the resultant CaCO(3) crystal morphology.

  7. Calcium carbonate precipitation by strain Bacillus licheniformis AK01, newly isolated from loamy soil: a promising alternative for sealing cement-based materials.

    PubMed

    Vahabi, Ali; Ramezanianpour, Ali Akbar; Sharafi, Hakimeh; Zahiri, Hossein Shahbani; Vali, Hojatollah; Noghabi, Kambiz Akbari

    2015-01-01

    The relevant experiments were designed to determine the ability of indigenous bacterial strains isolated from limestone caves, mineral springs, and loamy soils to induce calcium carbonate precipitation. Among all isolates examined in this study, an efficient carbonate-precipitating soil bacterium was selected from among the isolates and identified by 16S rRNA gene sequences as Bacillus licheniformis AK01. The ureolytic isolate was able to grow well on alkaline carbonate-precipitation medium and precipitate calcium carbonate more than 1 g L(-1). Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) analyses, and scanning electron microscopy (SEM)/energy-dispersive X-ray spectroscopy (EDX) examinations were performed in order to confirm the presence of calcium carbonate in the precipitate and to determine which polymorphs were present. The selected isolate was determined to be an appropriate candidate for application in a surface treatment of cement-based material to improve the properties of the mortar. Biodeposition of a layer of calcite on the surface of cement specimens resulted in filling in pore spaces. This could be an alternative method to improve the durability of the mortar. The kind of bacterial culture and medium composition had a profound impact on the resultant CaCO(3) crystal morphology. PMID:25590872

  8. Zinc movement in sewage-sludge-treated soils as influenced by soil properties, irrigation water quality, and soil moisture level

    USGS Publications Warehouse

    Welch, J.E.; Lund, L.J.

    1989-01-01

    A soil column study was conducted to assess the movement of Zn in sewage-sludge-amended soils. Varables investigated were soil properties, irrigation water quality, and soil moisture level. Bulk samples of the surface layer of six soil series were packed into columns, 10.2 cm in diameter and 110 cm in length. An anaerobically digested municipal sewage sludge was incorporated into the top 20 cm of each column at a rate of 300 mg ha-1. The columns were maintained at moisture levels of saturation and unsaturation and were leached with two waters of different quality. At the termination of leaching, the columns were cut open and the soil was sectioned and analyzed. Zinc movement was evaluated by mass balance accounting and correlation and regression analysis. Zinc movement in the unsaturated columns ranged from 3 to 30 cm, with a mean of 10 cm. The difference in irrigation water quality did not have an effect on Zn movement. Most of the Zn applied to the unsaturated columns remained in the sludge-amended soil layer (96.1 to 99.6%, with a mean of 98.1%). The major portion of Zn leached from the sludge-amended soil layer accumulated in the 0- to 3-cm depth (35.7 to 100%, with a mean of 73.6%). The mean final soil pH values decreased in the order: saturated columns = sludge-amended soil layer > untreated soils > unsaturated columns. Total Zn leached from the sludge-amended soil layer was correlated negatively at P = 0.001 with final pH (r = -0.85). Depth of Zn movement was correlated negatively at P = 0.001 with final pH (r = -0.91). Multiple linear regression analysis showed that the final pH accounted for 72% of the variation in the total amounts of Zn leached from the sludge-amended soil layer of the unsaturated columns and accounted for 82% of the variation in the depth of Zn movement among the unsaturated columns. A significant correlation was not found between Zn and organic carbon in soil solutions, but a negative correlation significant at P = 0.001 was found

  9. Responses of amphibian populations to water and soil factors in experimentally-treated aquatic macrocosms

    USGS Publications Warehouse

    Sparling, D.W.; Lowe, T.P.; Day, D.; Dolan, K.

    1995-01-01

    Survival of anuran embryos and tadpoles is reduced in acidic (pH < 5.0) waters under laboratory conditions. However, field data on the presence-absence of amphibian species and acidity are equivocal. This study attempts to reconcile some of this discrepancy by using macrocosms to examine the interaction of soil type and water acidification on free-ranging tadpole populations. Tadpoles were caught with activity traps in 24 aquatic macrocosms experimentally treated with H2SO4 and Al2(SO4)3 and lined with either comparatively high metal, Iow organic matter clay soils or lower metal, higher organic matter loams. Northern cricket frog (Acris crepitans) tadpole abundance was less in acidified macrocosms than in circumneutral ones (p < 0.05) and less in those with loam soils than in macrocosms with clay soils (p < 0.04). Gray treefrog (Hyla versicolor) abundance was affected by an interaction between soil and acidification (p < 0.07) in that treatment effects were only observed in macrocosms with clay soils (p < 0.01). No differences were observed among treatments for green frog (Rana clamitans) or southern leopard frog (R. utricularia) tadpoles. The study shows that soil type may interact with water conditions to affect amphibian populations in acidified waters

  10. Mobility and fractionation of arsenic, chromium and copper in thermally treated soil.

    PubMed

    Nordmark, Désirée; Kumpiene, Jurate; Andreas, Lale; Lagerkvist, Anders

    2011-01-01

    Thermal treatment is used to remediate soil co-contaminated with organic and inorganic contaminants. It destroys organic contaminants, but the remaining inorganic contaminants require further treatment. In this study the effects of thermal treatment on the mobility, speciation and chemical fractionation of As, Cr and Cu in a CCA-polluted soil were evaluated by leaching tests, As speciation assays and a sequential extraction procedure. The soil was sieved into four size fractions (<0.125, 0.125-0.250, 0.250-0.500 and 0.500-1.0 mm), each of which was treated at 800°C and analysed in comparison with the untreated soil. The leaching of As and Cr increased by factors of 18-40 and 2-23, respectively, while the mobility of Cu decreased 12-14-fold after treatment. The concentration of As(V) in pore water of the finest soil fraction increased 19-fold, whereas that of As(III) remained constant. The treatment reduced As, Cr and Cu associated with the reducible soil fraction. In addition, it increased the proportions of As and Cr (slightly) associated with the exchangeable and acid-soluble soil fractions, and the proportions of Cu and Cr (substantially) associated with the residual fraction.

  11. Effect of liming on sulfate transformation and sulfur gas emissions in degraded vegetable soil treated by reductive soil disinfestation.

    PubMed

    Meng, Tianzhu; Zhu, Tongbin; Zhang, Jinbo; Cai, Zucong

    2015-10-01

    Reductive soil disinfestation (RSD), namely amending organic materials and mulching or flooding to create strong reductive status, has been widely applied to improve degraded soils. However, there is little information available about sulfate (SO4(2-)) transformation and sulfur (S) gas emissions during RSD treatment to degraded vegetable soils, in which S is generally accumulated. To investigate the effects of liming on SO4(2-) transformation and S gas emissions, two SO4(2-)-accumulated vegetable soils (denoted as S1 and S2) were treated by RSD, and RSD plus lime, denoted as RSD0 and RSD1, respectively. The results showed that RSD0 treatment reduced soil SO4(2-) by 51% and 61% in S1 and S2, respectively. The disappeared SO4(2-) was mainly transformed into the undissolved form. During RSD treatment, hydrogen sulfide (H2S), carbonyl sulfide (COS), and dimethyl sulfide (DMS) were detected, but the total S gas emission accounted for <0.006% of total S in both soils. Compared to RSD0, lime addition stimulated the conversion of SO4(2-) into undissolved form, reduced soil SO4(2-) by 81% in S1 and 84% in S2 and reduced total S gas emissions by 32% in S1 and 57% in S2, respectively. In addition to H2S, COS and DMS, the emissions of carbon disulfide, methyl mercaptan, and dimethyl disulfide were also detected in RSD1 treatment. The results indicated that RSD was an effective method to remove SO4(2-), liming stimulates the conversion of dissolved SO4(2-) into undissolved form, probably due to the precipitation with calcium.

  12. Effect of irrigation with treated wastewater on soil chemical properties and infiltration rate.

    PubMed

    Bedbabis, Saida; Ben Rouina, Béchir; Boukhris, Makki; Ferrara, Giuseppe

    2014-01-15

    In Tunisia, water scarcity is one of the major constraints for agricultural activities. The reuse of treated wastewater (TWW) in agriculture can be a sustainable solution to face water scarcity. The research was conducted for a period of four years in an olive orchard planted on a sandy soil and subjected to irrigation treatments: a) rain-fed conditions (RF), as control b) well water (WW) and c) treated wastewater (TWW). In WW and TWW treatments, an annual amount of 5000 m(3) ha(-1) of water was supplied to the orchard. Soil samples were collected at the beginning of the study and after four years for each treatment. The main soil properties such as electrical conductivity (EC), pH, soluble cations, chloride (Cl(-)), sodium adsorption ratio (SAR), organic matter (OM) as well as the infiltration rate were investigated. After four years, either a significant decrease of pH and infiltration rate or a significant increase of OM, SAR and EC were observed in the soil subjected to treated wastewater treatment. PMID:24361727

  13. Potential nitrification in alum-treated soil slurries amended with poultry manure.

    PubMed

    Gandhapudi, S K; Coyne, M S; D'Angelo, E M; Matocha, C

    2006-03-01

    Alum is used to reduce environmental pollutants in poultry production. Alum decreases NH3 volatilization and increases total N and NH4+-N compared to untreated poultry manure. Nitrification in poultry wastes could therefore be stimulated due to higher NH4+ concentrations or could be inhibited because the soil environment is acidified. A 10-day laboratory study was conducted to study potential nitrification rates in soil slurries (20 g soil in 150 ml water) amended with 2.0 g alum-treated poultry manure. Fecal bacteria, NH4+, NO2-, NO3-, orthophosphate, pH, and NH3 were measured at 2-day intervals. Alum significantly reduced fecal bacteria concentrations through day 6. Water-soluble P was reduced 82% by day 10. Alum-treated manure had significantly increased NH4+ concentrations by day 8 and 10, and significantly decreased NO2- and NO3- concentrations by days 6-10. Alum's effect on potential nitrification was inhibitory in the soil environment. Slurries with alum-treated poultry manure had reduced nitrification rates, fecal bacteria, and soluble P. Therefore, in addition to reducing P loss, alum could temporarily reduce the risk for environmental pollution from land-applied manures in terms of both NO3- and fecal bacteria loss.

  14. Priming effects and enzymatic activity in Israeli soils under treated wastewater and freshwater irrigation

    NASA Astrophysics Data System (ADS)

    Anissimova, Marina; Heinze, Stefanie; Chen, Yona; Tarchitzky, Jorge; Marschner, Bernd

    2014-05-01

    Irrigation of soils with treated wastewater (TWW) directly influences microbial processes of soil. TWW contains easily decomposable organic material, which can stimulate the activity of soil microorganisms and, as a result, lead to the excessive consumption of soil organic carbon pool. We investigated the effects of irrigation with TWW relative to those of irrigation with freshwater (FW) on the microbial parameters in soils with low (7%) and medium (13%) clay content in a lysimeter experiment. The objectives of our study were to (i) determine the impact of water quality on soil respiration and enzymatic activity influenced by clay content and depth, and (ii) work out the changes in the turnover of soil organic matter (PE, priming effects). Samples were taken from three soil depths (0-10, 10-20, and 40-60 cm). Soil respiration and PE were determined in a 21-days incubation experiment after addition of uniformly 14C-labeled fructose. Activity of 10 extracellular enzymes (EEA, from C-, N-, P-, and S-cycle), phenol oxidase and peroxidase activity (PO+PE), and dehydrogenase activity (DHA) were assayed. Microbial Community-Level Physiological Profiles (CLPP) using four substrates, and microbial biomass were determined. The results showed that the clay content acted as the main determinative factor. In the soil with low clay content the water quality had a greater impact: the highest PE (56%) was observed in the upper layer (0-10cm) under FW irrigation; EEA of C-, P-, and S-cycles was significantly higher in the upper soil layer under TWW irrigation. Microbial biomass was higher in the soil under TWW irrigation and decreased with increasing of depth (50 μg/g soil in the upper layer, 15 μg/g soil in the lowest layer). This tendency was also observed for DHA. Contrary to the low clay content, in the soil with medium clay content both irrigation types caused the highest PE in the lowest layer (65% under FW irrigation, 48% under TWW irrigation); the higher substrate

  15. Leaching from CCA-Treated Wood into Soils: Preliminary PIXE Studies

    NASA Astrophysics Data System (ADS)

    Kelly, R. F.; Kravchenko, I. I.; Kuharik, J. C.; Van Rinsvelt, H. A.; Dunnam, F. E.; Huffman, J.

    2003-08-01

    Widespread use of chromated copper arsenate (CCA) as a wood preservative has led to increasing public concern regarding possible toxic contamination of areas surrounding CCA-treated structures, e.g., decks, playground equipment, etc. Appreciable leaching of arsenic, chromium, and copper into soils adjacent to such structures has been demonstrated via standard techniques of analytical chemistry. The advantages of PIXE [rapid analysis, quick sample turnover, possible lower cost] suggest its application to this area of interest. PIXE studies in our laboratory of CCA-contaminated soil samples show good agreement with previous analyses of As, Cu, Cr, and other heavy-elemental content, with some variability in diffusion rates.

  16. Effect of temperature and water on gaseous emissions from soils treated with animal slurry

    SciTech Connect

    Maag, M.; Vinther, F.P.

    1999-08-01

    Microbial respiration and denitrification are greatly affected by abiotic factors, but they are difficult to assess in natural environments. Under controlled conditions the interactions between temperature and soil water content on microbial respiration, N{sub 2}O production, and denitrification in soil amended with animal slurries were studied. The effects of the abiotic factors on the biological processes were monitored for 8 wk in repacked soil cores amended with pig or cattle slurry. The soil cores were incubated at 43, 57, and 72% water-filled pore space (WFPS) and at 10, 15, and 20 C with or without addition of 10% acetylene. The amount of N{sub 2}O lost at 72% WFPS corresponded to 8 to 22% of the slurry's NH{sub 4}{sup +} content, but for only 0.01 to 1.2% at 43 to 57% WFPS. The amount of available C accounted for by denitrification was 8 to 16% of total respiration at 72% WFPS, but only 0.03 to 0.4% at 43 to 57% WFPS. Both N{sub 2}O production and denitrification peaked earlier in the cattle-slurry treated soil than in the pig-slurry treated soil, whereas the total N loss was greatest from the latter. Neither amendments nor soil water contents seemed to affect the Q{sub 10}-values for the CO{sub 2} production, resulting in values between 1.6 and 2.6. At 72% WFPS, N{sub 2}O production and denitrification had Q{sub 10}-values ranging between 3.3 and 5.4. High temperatures enhanced both aerobic respiration and denitrification, and aerobic respiration further enhanced denitrification by consuming oxygen, resulting in strong sensitivity of denitrification to temperature.

  17. Salinity effect of irrigation with treated wastewater in basal soil respiration in SE of Spain

    NASA Astrophysics Data System (ADS)

    Morugan, A.; Garcia-Orenes, F.; Mataix-Solera, J.

    2012-04-01

    The use of treated wastewater for the irrigation of agricultural soils is an alternative to utilizing better-quality water, especially in semiarid regions where water shortage is a very serious problem. Wastewater use in agriculture is not a new practice, all over the world this reuse has been common practice for a long time, but the concept is of greater importance currently because of the global water crisis. Replacement of freshwater by treated wastewater is seen as an important conservation strategy contributing to agricultural production, substantial benefits can derive from using this nutrient-rich waste water but there can also be a negative impact. For this reason it is necessary to know precisely the composition of water before applying it to the soil in order to guarantee minimal impact in terms of contamination and salinization. In this work we have been studying, for more than three years, different parameters in calcareous soils irrigated with treated wastewater in an agricultural Mediterranean area located at Biar (Alicante, SE Spain), with a crop of grape (Vitis labrusca). Three types of waters were used for the irrigation of the soil: fresh water (control) (TC), and treated wastewater from secondary (T2) and tertiary treatment (T3). Three different doses of irrigation have been applied to fit the efficiency of the irrigation to the crop and soil type during the study period. A soil sampling was carried out every four months. We show the results of the evolution of basal soil respiration (BSR), and its relationship with other parameters. We observed a similar pattern of behavior for BSR between treatments, a decrease at the first eighteen months of irrigation and an increase at the end of study. In our study case, the variations of BSR obtained for all the treatments seem to be closely related to the dose and frequency of irrigation and the related soil wetting and drying cycles. However, the results showed a negative correlation between BSR and

  18. Thermal analysis of soil treated with biochars from different raw materials

    NASA Astrophysics Data System (ADS)

    Ana, Méndez; Paola, Cely; Gabriel, Gascó

    2014-05-01

    Thermal analysis (DTA, DSC, TG and dTG) has been used for decades to characterize carbonaceous materials used as fuels (oil, coal). In the last years, these techniques has been used with soils in order to assess proportions of labile and recalcitrant organic matter and to study the evolution of organic matter in amended soils during laboratory incubations. Indeed, thermogravimetric behaviour of soils can be quantified as the weight loss of samples attributed to different temperature ranges: WL1 from 25 to 150ºC; WL2 from 200 to 350ºC and WL3 from 375 to 600ºC . WL2 and WL3 correspond to weight loss associated to organic matter combustion (Worg=WL2+WL3). It is established that first peak was associated with combustion of less humified organic matter, while the second one was related to the more humified. Also, the WL3/WL2 ratio, named thermostability index, was previously identified as a reliable parameter for evaluating the level of stability of organic matter in composts and other organic wastes that indicated the relative amount of the thermally more stable fraction of organic matter with respect to less stable one. These stability can be related with the soil CO2 emmisions after biochar application. The objective of this presentation is to show the application of thermal analysis to study the stability of soil organic matter in soils treated with different biochars.

  19. Comparison of DNA extraction protocols for microbial communities from soil treated with biochar

    PubMed Central

    Leite, D.C.A.; Balieiro, F.C.; Pires, C.A.; Madari, B.E.; Rosado, A.S.; Coutinho, H.L.C.; Peixoto, R.S.

    2014-01-01

    Many studies have evaluated the effects of biochar application on soil structure and plant growth. However, there are very few studies describing the effect of biochar on native soil microbial communities. Microbial analysis of environmental samples requires accurate and reproducible methods for the extraction of DNA from samples. Because of the variety among microbial species and the strong adsorption of the phosphate backbone of the DNA molecule to biochar, extracting and purifying high quality microbial DNA from biochar-amended soil is not a trivial process and can be considerably more difficult than the extraction of DNA from other environmental samples. The aim of this study was to compare the relative efficacies of three commercial DNA extraction kits, the FastDNA® SPIN Kit for Soil (FD kit), the PowerSoil® DNA Isolation Kit (PS kit) and the ZR Soil Microbe DNA Kit Miniprep™ (ZR kit), for extracting microbial genomic DNA from sand treated with different types of biochar. The methods were evaluated by comparing the DNA yields and purity and by analysing the bacterial and fungal community profiles generated by PCR-DGGE. Our results showed that the PCR-DGGE profiles for bacterial and fungal communities were highly affected by the purity and yield of the different DNA extracts. Among the tested kits, the PS kit was the most efficient with respect to the amount and purity of recovered DNA and considering the complexity of the generated DGGE microbial fingerprint from the sand-biochar samples. PMID:24948928

  20. Dynamic changes in hydraulic properties of soils irrigated with treated wastewater

    NASA Astrophysics Data System (ADS)

    Assouline, Shmuel

    2014-05-01

    With increasing water scarcity, treated wastewater (TW) appears as an attractive alternative source of water for irrigation, especially in arid and semi-arid regions where freshwater is naturally scarce. However, it seems that long-term use of TW for irrigation cause to soil degradation and crop yield reduction. This study aims to describe and quantify the dynamic changes in the soil hydraulic properties resulting from the use of TW for irrigation. Combining between analysis of data from a set of complementary laboratory experiments involving infiltration, evaporation, swelling and saturated hydraulic conductivity measurements, and numerical simulations provide quantitative estimates of the negative impact of TW for irrigation on the soil properties. It appears that the soil degradation is a dynamic process that depends on the duration of the exposure to the low-quality irrigation water. The intensity of the changes distributes with depth and results from the irrigation management applied and the efficiency of the leaching process induced by rainfall. The negative impact is the result between increase of soil sodicity and changes in soil wettability. Such negative impact may affect the hydrological balance components at the field and at the regional scale.

  1. Comparison of DNA extraction protocols for microbial communities from soil treated with biochar.

    PubMed

    Leite, D C A; Balieiro, F C; Pires, C A; Madari, B E; Rosado, A S; Coutinho, H L C; Peixoto, R S

    2014-01-01

    Many studies have evaluated the effects of biochar application on soil structure and plant growth. However, there are very few studies describing the effect of biochar on native soil microbial communities. Microbial analysis of environmental samples requires accurate and reproducible methods for the extraction of DNA from samples. Because of the variety among microbial species and the strong adsorption of the phosphate backbone of the DNA molecule to biochar, extracting and purifying high quality microbial DNA from biochar-amended soil is not a trivial process and can be considerably more difficult than the extraction of DNA from other environmental samples. The aim of this study was to compare the relative efficacies of three commercial DNA extraction kits, the FastDNA® SPIN Kit for Soil (FD kit), the PowerSoil® DNA Isolation Kit (PS kit) and the ZR Soil Microbe DNA Kit Miniprep™ (ZR kit), for extracting microbial genomic DNA from sand treated with different types of biochar. The methods were evaluated by comparing the DNA yields and purity and by analysing the bacterial and fungal community profiles generated by PCR-DGGE. Our results showed that the PCR-DGGE profiles for bacterial and fungal communities were highly affected by the purity and yield of the different DNA extracts. Among the tested kits, the PS kit was the most efficient with respect to the amount and purity of recovered DNA and considering the complexity of the generated DGGE microbial fingerprint from the sand-biochar samples.

  2. Measurement of DDT fluxes from a historically treated agricultural soil in Canada.

    PubMed

    Kurt-Karakus, Perihan Binnur; Bidleman, Terry F; Staebler, Ralf M; Jones, Kevin C

    2006-08-01

    Organocohlorine pesticide (OCP) residues in agricultural soils are of concern due to the uptake of these compounds by crops, accumulation in the foodchain, and reemission from soils to the atmosphere. Although it has been about three decades since DDT was banned for agricultural uses in Canada, residues persist in soils of some agricultural areas. Emission of DDT compounds to the atmosphere from a historically treated field in southern Ontario was determined in fall 2004 and spring 2005. The sigmaDDTs concentration in the high organic matter (71%) soil was 19 +/- 4 microg g(-1) dry weight. Concentration gradients in the air were measured at 5, 20, 72, and 200 cm above soil using glass fiber filter-polyurethane foam cartridges. Air concentrations of sigmaDDTs averaged 5.7 +/- 5.1 ng m(-3) at 5 cm and decreased to 1.3 +/- 0.8 ng m(-3) at 200 cm and were 60-300 times higher than levels measured at a background site 30 km away. Soil-air fugacity fractions, fs/(fs + fa), of p,p'-DDE, p,p'-DDD, and p,p'-DDT ranged from 0.42 to 0.91 using air concentrations measured above the soil and > or = 0.99 using background air concentrations, indicating that the soil was a net source to the background air. Fractionation of DDT compounds during volatilization was predicted using either liquid-phase vapor pressures (PL) or octanol-air partition coefficients (KOA). Relative emissions of p,p'-DDE and p,p'-DDT were better described by PL than KOA, whereas either PL or KOA successfully accounted for the fractionation of p,p'-DDT and o,p'-DDT. Soil-to-air fluxes were calculated from air concentration gradients and turbulent exchange coefficients determined from micrometeorological measurements. Average fluxes of sigmaDDTs were 90 +/- 24 ng m(-2) h(-1) in fall and 660 +/- 370 ng m(-2) h(-1) in spring. Higher soil temperatures in spring accounted for the higher fluxes. A volatilization half-life of approximately 200 y was estimated for sigmaDDT in the upper 5 cm of the soil column, assuming

  3. Carbon dynamics in an almond orchard soil amended with raw and treated pig slurry

    NASA Astrophysics Data System (ADS)

    Domínguez, Sara G.; Zornoza, Raúl; Faz, Ángel

    2010-05-01

    In SE Spain, intensive farming is very common which supposes the generation of great amounts of pig slurries. These residues cause many storage problems due to their pollution capacity. A good management of them is necessary to avoid damages to the environment. The use of this effluent as fertilizer is a usual practice that in the correct dose is a good amend and important for sustainable development, but in excess can be a risk of polluting and damaging soil, water and crop conditions. Pig slurry is a source of many nutrients and specially rich in organic matter. The main objective of this study is to determine changes in soil organic carbon dynamics resulting from raw and treated slurry amendments applied in different doses. The experimental area is an almond orchard located in Cartagena (SE Spain). The climate of the area is semiarid Mediterranean with mean annual temperature of 18°C and mean annual rainfall of 275 mm. A total of 10 plots (12 m x 30 m) were designed, one of them being the control without fertilizer. Surface soil samples (0-25 cm) were collected in September 2009. Three different treatments were applied, raw slurry, the effluent obtained after solid-liquid separation and solid manure, all of them in three doses being the first one of 170 kg N/ha, (maximum permitted in nitrates directive 91/676/CEE), and the others two and three times the first one. Soil biochemical parameters are rapid indicators of changes in soil quality. According to this, total organic carbon, soil microbial biomass carbon, soluble carbon, and β-glucosidase, β-galactosidase and arylesterase activities were measured in order to assess some soil biochemical conditions and carbon dynamics in terms of the different treatments. As we expected, the use of these organic fertilizers rich in organic matter, had an effect on soil carbon and soil microbial activity resulting in an increase in most of the parameters; total organic carbon and β-galactosidase activity showed the

  4. Field evaluation of the lignin-degrading fungus 'phanerochaete sordida' to treat creosote-contaminated soil

    SciTech Connect

    Davis, M.W.; Glaser, J.A.; Evans, J.W.; Lamar, R.T.

    1993-01-01

    A field study to determine the ability of selected lignin-degrading fungi to remediate soil contaminated with pentachlorophenol and creosote was performed at a wood treating facility in south central Mississippi in the Autumn of 1991. The study was designed to evaluate 7 fungal treatments and appropriate control treatments. Soil concentrations of 14 priority pollutant polycyclic aromatic hydrocarbon (PAH) components of creosote were measured over time to determine treatment efficacies. Fungal treatments involved mixing fungal inocula and aspen chips into the contaminated soil and maintaining moisture by irrigation and aeration by tillage. PAHs of more than 4 rings persisted at their original concentrations during the 8 wk course of the study for all treatments and controls.

  5. Soil organic matter dynamics and microbial activity in a cropland and soil treated with wood ash containing charcoal

    NASA Astrophysics Data System (ADS)

    Omil, B.; Fonturbel, M. T.; Vega, J. A.; Balboa, M. A.; Merino, A.

    2012-04-01

    Wood ash is generated as a by-product of biomass combustion in power plants, and can be applied to soil to improve nutritional status and crop production. The application of mixed wood ash, a mixture of ash and charcoal, may also improve the SOM content and quality. The charcoal contained in mixed wood ash is a pyrogenic organic material, a heterogeneous mixture of thermally altered polymers with aromatic domains. This structure may favour oxidation, facilitating further microbial attack and generation of new SOM compounds. In addition, accelerated C mineralization of this material may also be due to the priming effect of the rhizosphere, which may even enhance the decomposition of more recalcitrant SOM. The study was carried out in a field devoted to cereal crops during the last few decades. The soil was acidic (pH 4.5) with a low SOC content (3 %). 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, 16 Mg mixed wood ash and 32 Mg mixed wood ash ha-1. The ash used in the study was obtained from a thermal power plant and was mainly derived from the combustion of Pinus radiata bark. The changes in SOM were monitored over two years by solid state 13C CPMAS NMR and Differential Scanning Calorimetry (DSC). 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. Both 13 C-CPMAS NMR spectra and DSC curves revealed that the SOM in the treated soils displayed a higher degree of aromaticity than in the untreated soils, indicating a gain in more stable SOM compounds. However, both methods also revealed increases in other labile C compounds. Microbial biomass and soil respiration increased significantly as a result of these effects and possibly also due to a priming effect. The treatments also led to increases in the functional diversity indices. The amended soils

  6. Shock-treated Lunar Soil Simulant: Preliminary Assessment as a Construction Material

    NASA Technical Reports Server (NTRS)

    Boslough, Mark B.; Bernold, Leonhard E.; Horie, Yasuyuki

    1992-01-01

    In an effort to examine the feasibility of applying dynamic compaction techniques to fabricate construction materials from lunar regolith, preliminary explosive shock-loading experiments on lunar soil simulants were carried out. Analysis of our shock-treated samples suggests that binding additives, such as metallic aluminum powder, may provide the necessary characteristics to fabricate a strong and durable building material (lunar adobe) that takes advantage of a cheap base material available in abundance: lunar regolith.

  7. Study of Mn Phytoavailability in Soil Treated with Biosolids Using NAA

    NASA Astrophysics Data System (ADS)

    de Fátima Mateus, Natalina; Filho, Tufic Madi

    2011-08-01

    This work evaluated the behavior of Mn absorption by Eucalyptus grandis that was cultivated in soil treated with biosolid. Neutron activation analysis (NAA) followed by gamma ray spectrometry was the analytical method used to determine the Mn content. Manganese is an important micronutrient because it is an activator of enzymes, controller of oxyreduction reactions, essential to the photosynthesis and synthesis of chlorophyll and protein. The results showed that the phytoavailability of Mn was reduced increasing the doses of biosolid applied.

  8. The impact of CCA-treated posts in vineyards on soil and ground water.

    PubMed

    Greven, M; Green, S; Robinson, B; Clothier, B; Vogeler, I; Agnew, R; Neal, S; Sivakumaran, S

    2007-01-01

    Grapes in Marlborough are typically grown on a vertical shoot positioned trellis system (VSP). For this purpose Pinus radiata posts are treated with CCA, a mixture of copper (Cu), chromium (Cr) and arsenic (As), giving a wood concentration of 1,730, 3,020 and 2,410 mg/kg, respectively on a dry matter basis. The CCA levels around the posts in different soils were investigated and assessed for the potential leaching of CCA into ground water. An initial survey showed leaching of all three heavy metals from the treated posts into the soil surrounding the posts (0.2% of the total vineyard area) compared with the control, depending on vineyard age and soil type. The rate of movement out of the posts was calculated from posts placed in lysimeters. HortResearch's Soil Plant Atmosphere Model (SPASMO) was used to predict the leaching rate of CCA. For As, leaching was found to be 5 mg/post/month, with the Cr rate being about twice that. Further modelling revealed a steady plume of As moving downwards after about 200-300 years. However, long-term hydrogeological modelling showed that sufficient aquifer water flow prevented the accumulation of CCA in the ground water. The modelling approaches are discussed.

  9. Chemical Speciation and Bioaccessibility of Arsenic and Chromiumin Chromated Copper Arsenate-Treated Wood and Soils

    SciTech Connect

    Nico, Peter S.; Ruby, Michael V.; Lowney, Yvette W.; Holm,Stewart E.

    2005-10-12

    This research compares the As and Cr chemistry ofdislodgeable residues from Chromated Copper Arsenate (CCA)-treated woodcollected by two different techniques (directly from the board surfaceeither by rubbing with a soft bristle brush or from human hands aftercontact with CCA-treated wood), and demonstrates that these materials areequivalent in terms of the chemical form and bonding of As and Cr and interms of the As leaching behavior. This finding links the extensivechemical characterization and bioavailability testing that has been donepreviously on the brush-removed residue to a material that is derivedfrom human skin contact with CCA-treated wood. Additionally, thisresearch characterizes the arsenic present in biological fluids (sweatand simulated gastric fluid) following contact with these residues. Thedata demonstrate that in biological fluids, the arsenic is presentprimarily as free arsenate ions.Arsenic-containing soils were alsoextracted into human sweat to evaluate the potential for arsenicdissolution from soils at the skin surface. For soils from field sites,only a small fraction of the total arsenic is soluble in sweat. Based oncomparisons to reference materials that have been used in in vivo dermalabsorption studies, these findings suggest that the actual relativebioavailability via dermal absorption of As from CCA-residues and soilmay be well below the current default value of 3 percent used by U.S.EPA.

  10. Soil temperatures and stability of ice-cemented ground in the McMurdo Dry Valleys, Antarctica

    NASA Technical Reports Server (NTRS)

    McKay, C.; Mellon, M. T.; Friedmann, E. I.

    1998-01-01

    Year-round temperature measurements at 1600 m elevation during 1994 in the Asgard Range Antarctica, indicate that the mean annual frost point of the ice-cemented ground, 25 cm below the surface, is -21.7 +/- 0.2 degrees C and the mean annual frost point of the atmosphere is -27.5 +/- 1.0 degrees C. The corresponding mean annual temperatures are -24.9 degrees C and -23.3 degrees C. These results imply that there is a net flux of water vapour from the ice to the atmosphere resulting in a recession of the ice-cemented ground by about 0.4-0.6 mm yr-1. The level of the ice-cemented permafrost is about 12 cm below the level of dry permafrost. The summer air temperatures would have to increase about 7 degrees C for thawing temperatures to just reach the top of the subsurface ice. Either subsurface ice at this location is evaporating over time or there are sporadic processes that recharge the ice and maintain equilibrium over long timescales.

  11. Soil-food chain-pesticide wildlife relationships in aldrin-treated fields

    USGS Publications Warehouse

    Korschgen, L.J.

    1970-01-01

    Soil-food-chain-pesticide wildlife relationships were investigated to learn the concentration of pesticide residues present in soils, macro-invertebrates, vertebrates, and seeds as a result of annual applications of aldrin at recommended rates for pest control. Two central Missouri cornfields treated witb aldrin at 1 lb/acre, for 16 and 15 of the past 17 years, were selected for study during 1965-67. Primary samples collected for residue analyses included soils, earthworms (Lumbricidae), crickets (GryIlidae), and two kinds of ground beetles (Carabidae) obtained during early April, June, August, and October. Vertebrates and plant seeds collected during 1967 included white-footed mice (Peromyscus maniculatus), toads (Bufo americanus), snakes (Thamnophis sirtalis and Pituophis sayi), corn (Zea Mays), foxtail (Setaria Faberii), and annual sunflower (Helianthus annuus). Pesticide residues consisted primarily of dieldrin, the degradation product of aldrin. Combined aldrin and dieldrin residues, as two field all-season averages, wet weight basis, were: soils, 0.31 ppm; earthworms, 1.49 ppm; crickets, 0.23 ppm; Harpalus ground beetles, 1.10 ppm; Poecilus ground beetles, 9.67 ppm; white-footed mice, 0.98 ppm; toads, 3.53 ppm; garter snakes, 12.35 ppm; and corn, foxtail, and sunflower seeds less than 0.02 ppm each. Unusually high average residues (37.48 ppm) in Poecilus beetles during June, 1967, were attributed to abnormally high soil moisture and predacious feeding habits of these insects.

  12. Exploring bacterial community structure and function associated with atrazine biodegradation in repeatedly treated soils.

    PubMed

    Fang, Hua; Lian, Jianjun; Wang, Huifang; Cai, Lin; Yu, Yunlong

    2015-04-01

    Substantial application of the herbicide atrazine in agriculture leads to persistent contamination, which may damage the succeeding crops and pose potential threats to soil ecology and environmental health. Here, the degradation characteristics of atrazine and dynamic change of soil bacterial community structure and function as well as their relations were studied during three repeated treatments at the recommended, double, and five-fold doses. The results showed that the degradation half-life of atrazine obviously decreased with increased treatment frequency. Soil microbial functional diversity displayed a variation trend of suppression-recovery-stimulation, which was associated with increased degradation rate of atrazine. 16S amplicon sequencing was conducted to explore bacterial community structure and correlate the genus to potential atrazine degradation. A total of seven potentially atrazine-degrading bacterial genera were found including Nocardioides, Arthrobacter, Bradyrhizobium, Burkholderia, Methylobacterium, Mycobacterium, and Clostridium. These bacterial genera showed almost complete atrazine degradation pathways including dechlorination, dealkylation, hydroxylation, and ring cleavage. Furthermore, the relative abundance of four of them (i.e., Nocardioides, Arthrobacter, Methylobacterium, and Bradyrhizobium) increased with treatment frequency and atrazine concentration, suggesting that they may participate in atrazine degradation during repeated treatments. Our findings reveal the potential relationship between atrazine degradation and soil bacterial community structure in repeatedly treated soils.

  13. Characterizing potential water quality impacts from soils treated with dust suppressants.

    PubMed

    Beighley, R Edward; He, Yiping; Valdes, Julio R

    2009-01-01

    Two separate laboratory experiment series, surface runoff and steady-state seepage, were performed to determine if dust suppressant products can be applied to soils with an expected minimal to no negative impact on water quality. The experiments were designed to mimic arid field conditions and used two soils (clayey and sandy) and six different dust suppressants. The two experiments consisted of: (i) simulated rainfall (intensities of 18, 33, or 61 mm h(-1)) and associated runoff from soil trays at a surface slope of 33%; and (ii) steady-state, constant head seepage through soil columns. Both experiment series involved two product application scenarios and three application ages (i.e., to account for degradation effects) for a total of 126 surface runoff and 80 column experiments. One composite effluent sample was collected from each experiment and analyzed for pH, electrical conductivity, total suspended solids (TSS), total dissolved solids, dissolved oxygen, total organic carbon, nitrate, nitrite, and phosphate. Paired t tests at 1 and 5% levels of significance and project specific data quality objectives are used to compare water quality parameters from treated and untreated soils. Overall, the results from this laboratory scale study suggest that the studied dust suppressants have minimal potential for adverse impacts to selected water quality parameters. The primary impacts were increased TSS for two synthetic products from the surface runoff experiments on both soils. The increase in TSS was not expected based on previous studies and may be attributed to this study's focus on simulating real-world soil agitation/movement at an active construction site subjected to rough grading.

  14. Persistence and fate of anthracene and benzo(a)pyrene in municipal sludge treated soil

    SciTech Connect

    Goodin, J.D.; Webber, M.D.

    1995-03-01

    Greenhouse studies using pots and microcosms were conducted to investigate the persistence and fate of nonlabeled and {sup 14}C-labeled anthracene (ANT) and benzo(a)Pyrene (B(a)P) in sludge treated soil. Results indicated that ANT degraded rapidly (t{sub {1/2}} {approx} 3 wk) from the experimental systems, but that B(a)P was persistent. Cropping did not affect the persistence of either compound. On completion of the experiments {le} 10% of the ANT added to soil was recovered intact, whereas 78% of the B(a)P added to soil was recovered intact. Most ({ge}85%) of the {sup 14}C added to soil as labeled ANT and B(a)P was accounted for. Recoveries of {sup 14}CO{sub 2} indicated significant mineralization of ANT, but not of B(a)P. Trivial amounts ({le}0.2%) of {sup 14}C were recovered as volatile organics and in plant materials, but large amounts were recovered from soil. A considerable proportion of the ANT derived {sup 14}C in soil was not extracted with acetone/hexane, which indicated that it had been converted to bound residue. a much smaller proportion of B(a)P than of ANT derived {sup 14}C in soil was converted to bound residue. No evidence was obtained for uptake of intact ANT or B(a)P by ryegrass (lolium multiflorum Lam.), soybean [Glycinemax (L.) Merr.], and cabbage (Brassica oleracea var. capitata L.). 25 refs., 3 figs., 6 tabs.

  15. Effects of Irrigating with Treated Oil and Gas Product Water on Crop Biomass and Soil Permeability

    SciTech Connect

    Terry Brown; Jeffrey Morris; Patrick Richards; Joel Mason

    2010-09-30

    Demonstrating effective treatment technologies and beneficial uses for oil and gas produced water is essential for producers who must meet environmental standards and deal with high costs associated with produced water management. Proven, effective produced-water treatment technologies coupled with comprehensive data regarding blending ratios for productive long-term irrigation will improve the state-of-knowledge surrounding produced-water management. Effective produced-water management scenarios such as cost-effective treatment and irrigation will discourage discharge practices that result in legal battles between stakeholder entities. The goal of this work is to determine the optimal blending ratio required for irrigating crops with CBNG and conventional oil and gas produced water treated by ion exchange (IX), reverse osmosis (RO), or electro-dialysis reversal (EDR) in order to maintain the long term physical integrity of soils and to achieve normal crop production. The soils treated with CBNG produced water were characterized with significantly lower SAR values compared to those impacted with conventional oil and gas produced water. The CBNG produced water treated with RO at the 100% treatment level was significantly different from the untreated produced water, while the 25%, 50% and 75% water treatment levels were not significantly different from the untreated water. Conventional oil and gas produced water treated with EDR and RO showed comparable SAR results for the water treatment technologies. There was no significant difference between the 100% treated produced water and the control (river water). The EDR water treatment resulted with differences at each level of treatment, which were similar to RO treated conventional oil and gas water. The 100% treated water had SAR values significantly lower than the 75% and 50% treatments, which were similar (not significantly different). The results of the greenhouse irrigation study found the differences in biomass

  16. Absorption of current use pesticides by snapping turtle (Chelydra serpentina) eggs in treated soil.

    PubMed

    Solla, Shane Raymond de; Martin, Pamela Anne

    2011-10-01

    Reptiles often breed within agricultural and urban environments that receive frequent pesticide use. Consequently, their eggs and thus developing embryos may be exposed to pesticides. Our objectives were to determine (i) if turtle eggs are capable of absorbing pesticides from treated soil, and (ii) if pesticide absorption rates can be predicted by their chemical and physical properties. Snapping turtle (Chelydra serpentina) eggs were incubated in soil that was treated with 10 pesticides (atrazine, simazine, metolachlor, azinphos-methyl, dimethoate, chlorpyrifos, carbaryl, endosulfan (I and II), captan, and chlorothalonil). There were two treatments, consisting of pesticides applied at application rate equivalents of 1.92 or 19.2 kg a.i/ha. Eggs were removed after one and eight days of exposure and analyzed for pesticides using gas chromatography coupled with a mass selective detector (GC-MSD) or high performance liquid chromatography (HPLC). Absorption of pesticides in eggs from soil increased with both magnitude and duration of exposure. Of the 10 pesticides, atrazine and metolachlor generally had the greatest absorption, while azinphos-methyl had the lowest. Chlorothalonil was below detection limits at both exposure rates. Our preliminary model suggests that pesticides having the highest absorption into eggs tended to have both low sorption to organic carbon or lipids, and high water solubility. For pesticides with high water solubility, high vapor pressure may also increase absorption. As our model is preliminary, confirmatory studies are needed to elucidate pesticide absorption in turtle eggs and the potential risk they may pose to embryonic development. PMID:21862099

  17. Effect of strength enhancement of soil treated with environment-friendly calcium carbonate powder.

    PubMed

    Park, Kyungho; Jun, Sangju; Kim, Daehyeon

    2014-01-01

    This study aims to investigate the effects of the strength improvement of soft ground (sand) by producing calcium carbonate powder through microbial reactions. To analyze the cementation effect of calcium carbonate produced through microbial reaction for different weight ratios, four different types of specimens (untreated, calcium carbonate, cement, and calcium carbonate + cement) with different weight ratios (2%, 4%, 6%, and 8%) were produced and cured for a period of 3 days, 7 days, 14 days, 21 days, and 28 days to test them. The uniaxial compression strength of specimens was measured, and the components in the specimen depending on the curing period were analyzed by means of XRD analysis. The result revealed that higher weight ratios and longer curing period contributed to increased strength of calcium carbonate, cement, and calcium carbonate + cement specimens. The calcium carbonate and the calcium carbonate + cement specimens in the same condition showed the tendency of decreased strength approximately 3 times and two times in comparison with the 8% cement specimens cured for 28 days, but the tendency of increased strength was approximately 4 times and 6 times in comparison with the untreated specimen.

  18. Effect of strength enhancement of soil treated with environment-friendly calcium carbonate powder.

    PubMed

    Park, Kyungho; Jun, Sangju; Kim, Daehyeon

    2014-01-01

    This study aims to investigate the effects of the strength improvement of soft ground (sand) by producing calcium carbonate powder through microbial reactions. To analyze the cementation effect of calcium carbonate produced through microbial reaction for different weight ratios, four different types of specimens (untreated, calcium carbonate, cement, and calcium carbonate + cement) with different weight ratios (2%, 4%, 6%, and 8%) were produced and cured for a period of 3 days, 7 days, 14 days, 21 days, and 28 days to test them. The uniaxial compression strength of specimens was measured, and the components in the specimen depending on the curing period were analyzed by means of XRD analysis. The result revealed that higher weight ratios and longer curing period contributed to increased strength of calcium carbonate, cement, and calcium carbonate + cement specimens. The calcium carbonate and the calcium carbonate + cement specimens in the same condition showed the tendency of decreased strength approximately 3 times and two times in comparison with the 8% cement specimens cured for 28 days, but the tendency of increased strength was approximately 4 times and 6 times in comparison with the untreated specimen. PMID:24688401

  19. Enhanced infiltration regime for treated-wastewater purification in soil aquifer treatment (SAT)

    NASA Astrophysics Data System (ADS)

    Nadav, Itamar; Arye, Gilboa; Tarchitzky, Jorge; Chen, Yona

    2012-02-01

    SummaryUtilization of treated wastewater (TWW) for agriculture is a widely accepted practice in regions suffering from freshwater (FW) shortages. Soil aquifer treatment is often employed for wastewater purification in regions with sandy soil. Infiltration rates of water through the soil can decrease as a result organic matter (OM) accumulation and the consequential water repellency. We examined several infiltration regimes with the aim of achieving lower levels of OM accumulation, reduced water repellency and increased infiltration rate in the topsoil layer of the infiltration basin. OM accumulation in the topsoil layer was found to be the main factor adversely affecting soil permeability. In measurements performed in the infiltration basins of the Tel Aviv wastewater-purification facility over a 1-year period, infiltration rates were found to differ with season, being low in the winter and high in the summer. Similar observations were made on small model infiltration ponds established to simulate the large basins. Several water-application regimes were tested for enhancement of the infiltration rates. Rapid application of TWW was the most efficient method in terms of reducing OM accumulation and water repellency in the topsoil layer. Low-rate, and spraying of TWW over the soil using sprinklers produced the highest OM accumulation and consequently, higher water repellency. Low-rate, single outlet application—the conventional infiltration method employed in the commercial infiltration basins—exhibited moderate OM accumulation and water repellency. Neither water repellency nor OM accumulation were observed in the FW-application regime. Accumulation of OM originating from the percolating TWW, at the topsoil layer was identified as dominating infiltration rate at the infiltration basins. Reduction of OM content by the means proposed and evaluated in this experiment can drastically increase infiltration rates.

  20. Impact of Long-Term Irrigation with Treated Sewage on Soil Magnetic Susceptibility and Organic Matter Content in North China.

    PubMed

    Yang, P G; Yang, M; Mao, R Z; Byrne, J M

    2015-07-01

    This study assessed the effect on magnetic susceptibility and organic matter content of arable soil by irrigation with either treated sewage or groundwater. Results indicated that organic matter and magnetic susceptibility values in the soil irrigated with sewage were increased by 7.1 % and 13.5 %, respectively, compared to agricultural soil that irrigated with groundwater. Both the sewage and groundwater irrigated soils contained a significant fraction of ultrafine superpara magnetic grains, as indicated by high frequency dependent susceptibility (χfd > 6 %). The enhancement of soil magnetic properties was determined to be caused by anthropogenic sewage irrigation and agrochemical use by investigation of vertical soil profiles. Magnetic susceptibility parameters were shown to be significantly correlated with organic matter content (y = 0.0057x + 1.3439, R(2) = 0.09, p < 0.05). This work indicates that measurements of magnetic susceptibility may offer a rapid first step for identifying the potential pollution in arable soils. PMID:25985871

  1. Biological functioning of PAH-polluted and thermal desorption-treated soils assessed by fauna and microbial bioindicators.

    PubMed

    Cébron, Aurélie; Cortet, Jérôme; Criquet, Stéven; Biaz, Asmaa; Calvert, Virgile; Caupert, Cécile; Pernin, Céline; Leyval, Corinne

    2011-11-01

    A large number of soil bioindicators were used to assess biological diversity and activity in soil polluted with polycyclic aromatic hydrocarbons (PAHs) and the same soil after thermal desorption (TD) treatment. Abundance and biodiversity of bacteria, fungi, protozoa, nematodes and microarthropods, as well as functional parameters such as enzymatic activities and soil respiration, were assessed during a two year period of in situ monitoring. We investigated the influence of vegetation (spontaneous vegetation and Medicago sativa) and TD treatment on biological functioning. Multivariate analysis was performed to analyze the whole data set. A principal response curve (PRC) technique was used to evaluate the different treatments (various vegetation and contaminated vs. TD soil) contrasted with control (bare) soil over time. Our results indicated the value of using a number of complementary bioindicators, describing both diversity and functions, to assess the influence of vegetation on soil and discriminate polluted from thermal desorption (TD)-treated soil. Plants had an influence on the abundance and activity of all organisms examined in our study, favoring the whole trophic chain development. However, although TD-treated soil had a high abundance and diversity of microorganisms and fauna, enzymatic activities were weak because of the strong physical and chemical modifications of this soil.

  2. Short-term effects of treated waste water irrigation on soil. Two years of a study monitoring a Mediterranean calcareous soil

    NASA Astrophysics Data System (ADS)

    Morugán, A.; García-Orenes, F.; Mataix-Solera, J.; Gómez, I.; Arcenegui, V.; Navarro, M. A.; Mataix-Beneyto, J.

    2009-04-01

    Shortage of water and soil degradation are the most important environmental problems in the Mediterranean areas due, in many cases, to inadequate agricultural management of irrigation to which organic matter is not correctly added, and the use of low quality waters for irrigation. For this reason strategies for saving water and for the restoration of the mean properties of soil are necessary. The use of treated waste water for the irrigation of agricultural land is a good solution to these problems, because it reduces the utilization of fresh water and potentially could improve key soil parameters, thus influencing crop production in a positive way by increasing soil nutrients and organic matter content. In this work we are studying the short-term effects of irrigation with waste waters on several soil properties related to fertility, in an agricultural area located at Biar (Alicante, SE of Spain), with a crop of grape (Vitis labrusca). Three treatments are being used in the irrigation of the soil: fresh water (control), and treated waste waters from secondary and tertiary treatment. A soil sampling was carried out every four months. We show here the results after two years of irrigation treatments. Results confirm a slight decrease of organic carbon and nitrogen contents in plots irrigated with water from secondary treatment, in these plots an increase of the electrical conductivity (EC) has also been observed. Laboratory analyses also show an increase in P available, pH and Na on plots with waste water application. At the moment, the changes found between treatments do not imply quantitatively great changes in soil properties and negative impacts into the soil with the exception of EC, which must be monitored to control their values. Although we show here partial results of a long-term experiment, the conclusion is positive since treated waste waters are not producing notable changes on soil parameters in comparison with plots treated with fresh water.

  3. Impact of treated urban wastewater for reuse in agriculture on crop response and soil ecotoxicity.

    PubMed

    Belhaj, Dalel; Jerbi, Bouthaina; Medhioub, Mounir; Zhou, John; Kallel, Monem; Ayadi, Habib

    2016-08-01

    The scarcity of freshwater resources is a serious problem in arid regions, such as Tunisia, and marginal quality water is gradually being used in agriculture. This study aims to study the impact of treated urban wastewater for reuse in agriculture on the health of soil and food crops. The key findings are that the effluents of Sfax wastewater treatment plant (WWTP) did not meet the relevant guidelines, therefore emitting a range of organic (e.g., up to 90 mg L(-1) COD and 30 mg L(-1) BOD5) and inorganic pollutants (e.g., up to 0.5 mg L(-1) Cu and 0.1 mg L(-1) Cd) in the receiving aquatic environments. Greenhouse experiments examining the effects of wastewater reuse on food plants such as tomato, lettuce, and radish showed that the treated effluent adversely affected plant growth, photosynthesis, and antioxidant enzyme contents. However, the pollution burden and biological effects on plants were substantially reduced by using a 50 % dilution of treated sewage effluent, suggesting the potential of reusing treated effluent in agriculture so long as appropriate monitoring and control is in place.

  4. Impact of treated urban wastewater for reuse in agriculture on crop response and soil ecotoxicity.

    PubMed

    Belhaj, Dalel; Jerbi, Bouthaina; Medhioub, Mounir; Zhou, John; Kallel, Monem; Ayadi, Habib

    2016-08-01

    The scarcity of freshwater resources is a serious problem in arid regions, such as Tunisia, and marginal quality water is gradually being used in agriculture. This study aims to study the impact of treated urban wastewater for reuse in agriculture on the health of soil and food crops. The key findings are that the effluents of Sfax wastewater treatment plant (WWTP) did not meet the relevant guidelines, therefore emitting a range of organic (e.g., up to 90 mg L(-1) COD and 30 mg L(-1) BOD5) and inorganic pollutants (e.g., up to 0.5 mg L(-1) Cu and 0.1 mg L(-1) Cd) in the receiving aquatic environments. Greenhouse experiments examining the effects of wastewater reuse on food plants such as tomato, lettuce, and radish showed that the treated effluent adversely affected plant growth, photosynthesis, and antioxidant enzyme contents. However, the pollution burden and biological effects on plants were substantially reduced by using a 50 % dilution of treated sewage effluent, suggesting the potential of reusing treated effluent in agriculture so long as appropriate monitoring and control is in place. PMID:26520100

  5. Candidal arthritis in revision knee arthroplasty successfully treated with sequential parenteral-oral fluconazole and amphotericin B-loaded cement spacer.

    PubMed

    Wu, Meng-Huang; Hsu, Kuo-Yao

    2011-02-01

    We present a case of a patient with preoperative cutaneous candidiasis, who developed candidal infection during stage revision knee arthroplasty. The patient received intravenous fluconazole for 6 weeks and resection arthroplasty with an amphotericin B-loaded cement spacer and continuous oral fluconazole therapy for 9 weeks. Revision surgery was successful.

  6. Fracture behavior of cemented sand

    NASA Astrophysics Data System (ADS)

    Alqasabi, Ahmad Othman

    While fracture mechanics for cementitious materials and composites in the past three decades have developed mainly in concrete applications, it has not yet gained its rightful place in the geotechnical field. There are many examples in the geotechnical literature, especially those related to brittle and stiff soils, where traditional approaches of analysis have proven to be inadequate. While geotechnical problems are inherently complex in nature, using the finite element method (FEM) with fracture mechanics (FM) have been shown to provide powerful analytical tool that could be used to investigate and solve many problems in geomechanics and geotechnical engineering. This thesis addresses the application of FM concepts and theories in analysis of cemented soils. In addition to theoretical aspects, experiments were conducted to evaluate the application of FM to cemented soils. Three point bending beam tests with crack mouth opening displacements (CMOD) conducted on cemented sand samples showed that fracture parameters, such as CMOD, indeed could play an important role in investigation of such soils. Using this unambiguous material parameter, field engineers might have a reliable measure that could prove to be useful in stability assessment of earth structures and soil structure system. By studying size effect on cemented sand, strong relationship was established between critical CMOD and failure, which might be a very useful index and analysis tool in geotechnical engineering practice.

  7. The assessment of treated wastewater quality and the effects of mid-term irrigation on soil physical and chemical properties (case study: Bandargaz-treated wastewater)

    NASA Astrophysics Data System (ADS)

    Kaboosi, Kami

    2016-05-01

    This study was conducted to investigate the characteristics of inflow and outflow wastewater of the Bandargaz wastewater treatment plant on the basis of the data collection of operation period and the samples taken during the study. Also the effects of mid-term use of the wastewater for irrigation (from 2005 to 2013) on soil physical and chemical characteristics were studied. For this purpose, 4 samples were taken from the inflow and outflow wastewater and 25 quality parameters were measured. Also, the four soil samples from a depth of 0-30 cm of two rice field irrigated with wastewater in the beginning and middle of the planting season and two samples from one adjacent rice field irrigated with fresh water were collected and their chemical and physical characteristics were determined. Average of electrical conductivity, total dissolved solids, sodium adsorption ratio, chemical oxygen demand and 5 days biochemical oxygen demand in treated wastewater were 1.35 dS/m, 707 ppm, 0.93, 80 ppm and 40 ppm, respectively. Results showed that although some restrictions exist about chlorine and bicarbonate, the treated wastewater is suitable for irrigation based on national and international standards and criteria. In comparison with fresh water, the mid-term use of wastewater caused a little increase of soil salinity. However, it did not lead to increase of soil salinity beyond rice salinity threshold. Also, there were no restrictions on soil in the aspect of salinity and sodium hazard on the basis of many irrigated soil classifications. In comparison with fresh water, the mid-term use of wastewater caused the increase of total N, absorbable P and absorbable K in soil due to high concentration of those elements in treated wastewater.

  8. Copper stabilization by zeolite synthesis in polluted soils treated with coal fly ash

    SciTech Connect

    Roberto Terzano; Matteo Spagnuolo; Luca Medici; Bart Vekemans; Laszlo Vincze; Koen Janssens; Pacifico Ruggiero

    2005-08-15

    This paper reports on the process of zeolite formation in an agricultural soil artificially polluted by high amounts of Cu (15 mg of Cu/g of soil dry weight) and treated with fused coal fly ash at 30 and 60 C and how this process affects the mobility and availability of the metal. As a consequence of the treatment, the amount of dissolved Cu, and thus its mobility, was strongly reduced, and the percentage of the metal stabilized in the solid phase increased over time, reaching values of 30% at 30{sup o}C and 40% at 60{sup o}C. The physicochemical phenomena responsible for Cu stabilization in the solid phase have been evaluated by EDTA sequential extractions and synchrotron radiation based X-ray microanalytical techniques. These techniques were used for the visualization of the spatial distribution and the speciation of Cu in and/or on the neo-formed zeolite particles. In particular, micro XRF (X-ray fluorescence) tomography showed direct evidence that Cu can be entrapped as clusters inside the porous zeolitic structures while -{mu}XANES (X-ray absorption near edge structure) spectroscopy determinations revealed Cu to be present mainly as Cu(II) hydroxide and Cu(II) oxide. The reported results could be useful as a basic knowledge for planning new technologies for the on-site physicochemical stabilization of heavy metals in heavily polluted soils. 32 refs., 5 figs.

  9. An example of treated waste water use for soil irrigation in the SAFIR project.

    NASA Astrophysics Data System (ADS)

    Cary, L.; Jovanovic, Z.; Stikic, R.; Blagojevic, S.; Kloppmann, W.

    2009-04-01

    The safe use of treated domestic wastewater for irrigation needs to address the risks for humans (workers, exposed via contact with irrigation water, soil, crops and food, consumers, exposed via ingestion of fresh and processed food), for animals (via ingestion of crops on soil), for the crops and agricultural productivity (via salinity and trace element uptake), for soil (via accumulation or release of pollutants) as well as for surface, groundwaters and the associated ecosystems (via runoff and infiltration, Kass et al., 2005, Bouwer, 2000). In this context, the European FP6 SAFIR project (Safe and High Quality Food Production using Low Quality Waters and Improved Irrigation Systems and Management) investigates the geochemical quality of the root zone soil, knowing it is the main transit and storage compartment for pollutants. The type of reaction (sorption, co-precipitation…) and the reactive mineral phases also determine the availability of trace elements for the plant and determine the passage towards crops and products. Reactions of the infiltrating water with the soil solid phase are important for the solute cycling, temporary fixation and remobilisation of trace pollutants. Therefore the soil water quality was directly or indirectly assessed. Direct measurements of soil water were made through porous cups. The experiments were carried out during the growing season of 2006, 2007 and 2008 in a vegetable commercial farm, located at 10 km north of Belgrade. The soil is silty clayey, and developed on alluvial deposits. It was classified as humogley according to USDA Soil Classification. The climate of the field side is a continental type with hot and dry summers and cold and rainy winters. As in the rest of Serbia, farm suffers from water deficits during the main growing season. The initial soil quality was assessed through a sampling campaign before the onset of first year irrigation; the soil quality was then monitored throughout three years. Soil sampling

  10. Impact of treated wastewater on growth, respiration and hydraulic conductivity of citrus root systems in light and heavy soils.

    PubMed

    Paudel, Indira; Cohen, Shabtai; Shaviv, Avi; Bar-Tal, Asher; Bernstein, Nirit; Heuer, Bruria; Ephrath, Jhonathan

    2016-06-01

    Roots interact with soil properties and irrigation water quality leading to changes in root growth, structure and function. We studied these interactions in an orchard and in lysimeters with clay and sandy loam soils. Minirhizotron imaging and manual sampling showed that root growth was three times lower in the clay relative to sandy loam soil. Treated wastewater (TWW) led to a large reduction in root growth with clay (45-55%) but not with sandy loam soil (<20%). Treated wastewater increased salt uptake, membrane leakage and proline content, and decreased root viability, carbohydrate content and osmotic potentials in the fine roots, especially in clay. These results provide evidence that TWW challenges and damages the root system. The phenology and physiology of root orders were studied in lysimeters. Soil type influenced diameter, specific root area, tissue density and cortex area similarly in all root orders, while TWW influenced these only in clay soil. Respiration rates were similar in both soils, and root hydraulic conductivity was severely reduced in clay soil. Treated wastewater increased respiration rate and reduced hydraulic conductivity of all root orders in clay but only of the lower root orders in sandy loam soil. Loss of hydraulic conductivity increased with root order in clay and clay irrigated with TWW. Respiration and hydraulic properties of all root orders were significantly affected by sodium-amended TWW in sandy loam soil. These changes in root order morphology, anatomy, physiology and hydraulic properties indicate rapid and major modifications of root systems in response to differences in soil type and water quality.

  11. Impact of treated wastewater on growth, respiration and hydraulic conductivity of citrus root systems in light and heavy soils.

    PubMed

    Paudel, Indira; Cohen, Shabtai; Shaviv, Avi; Bar-Tal, Asher; Bernstein, Nirit; Heuer, Bruria; Ephrath, Jhonathan

    2016-06-01

    Roots interact with soil properties and irrigation water quality leading to changes in root growth, structure and function. We studied these interactions in an orchard and in lysimeters with clay and sandy loam soils. Minirhizotron imaging and manual sampling showed that root growth was three times lower in the clay relative to sandy loam soil. Treated wastewater (TWW) led to a large reduction in root growth with clay (45-55%) but not with sandy loam soil (<20%). Treated wastewater increased salt uptake, membrane leakage and proline content, and decreased root viability, carbohydrate content and osmotic potentials in the fine roots, especially in clay. These results provide evidence that TWW challenges and damages the root system. The phenology and physiology of root orders were studied in lysimeters. Soil type influenced diameter, specific root area, tissue density and cortex area similarly in all root orders, while TWW influenced these only in clay soil. Respiration rates were similar in both soils, and root hydraulic conductivity was severely reduced in clay soil. Treated wastewater increased respiration rate and reduced hydraulic conductivity of all root orders in clay but only of the lower root orders in sandy loam soil. Loss of hydraulic conductivity increased with root order in clay and clay irrigated with TWW. Respiration and hydraulic properties of all root orders were significantly affected by sodium-amended TWW in sandy loam soil. These changes in root order morphology, anatomy, physiology and hydraulic properties indicate rapid and major modifications of root systems in response to differences in soil type and water quality. PMID:27022106

  12. Preliminary Systems Design Study assessment report. [Evaluation of using specific technologies, system concepts for treating the buried waste and the surrounding contaminated soil

    SciTech Connect

    Mayberry, J.L.; Feizollahi, F.; Del Signore, J.C.

    1992-01-01

    The System Design Study (SDS), part of the Waste Technology Development Department at the Idaho National Engineering Laboratory (INEL), examined techniques available for the remediation of hazardous and transuranic waste stored at the Radioactive Waste Management Complex's Subsurface Disposal Area at the INEL. Using specific technologies, system concepts for treating the buried waste and the surrounding contaminated soil were evaluated. Evaluation included implementability, effectiveness, and cost. The SDS resulted in the development of technology requirements including demonstration, testing, and evaluation activities needed for implementing each concept. This volume of the Systems Design Study contain four Appendixes that were part of the study. Appendix A is an EG G Idaho, Inc., report that represents a review and compilation of previous reports describing the wastes and quantities disposed in the Subsurface Disposal Area of the Idaho National Engineering Laboratory. Appendix B contains the process flowsheets considered in this study, but not selected for detailed analysis. Appendix C is a historical tabulation of radioactive waste incinerators. Appendix D lists Department of Energy facilities where cementation stabilization systems have been used.

  13. Distribution and mobility of chromium, copper, and arsenic in soils collected near CCA-treated wood structures in Korea.

    PubMed

    Kim, Hekap; Kim, Dong-Jin; Koo, Jin-Hoi; Park, Jeong-Gue; Jang, Yong-Chul

    2007-03-15

    Chromated copper arsenate (CCA) is currently the most commonly used wood preservative in Korea. Questions, however, have been raised regarding the potential environmental impacts of metal leaching from CCA-treated wood to soil. Although a number of researchers from other countries have reported that chromium, copper, and arsenic do leach from CCA-treated wood over time, to date few field studies have been performed on those metals in soils adjacent to CCA-treated wood structures in Korea. The present study was conducted to determine the lateral and vertical distributions and accumulation of chromium, copper, and arsenic in soils collected from CCA-treated wood structures. A total of fifty-five composite soil samples were collected from four CCA-treated wood structures of approximately one year in age. The samples were analyzed for physicochemical properties as well as for the total chromium, copper, and arsenic concentrations. The chromium, copper, and arsenic concentrations in soil samples adjacent to the structures were as high as 79.0, 98.9, and 128 mg/kg, respectively, compared to background soil samples (48.2, 26.9, and 6.27 mg/kg, respectively). Arsenic was more mobile in soil than chromium and copper. The concentration gradient of arsenic in soil was observed only to the depth of approximately 5 cm in one year of outdoor exposure, whereas chromium and copper apparently remained near the surface (approximately less than 1 cm) after their release. Future efforts should be made to observe seasonal impacts on the release of metals and incorporate metal speciation into determining more detailed mobility and distribution.

  14. Efficiency of Micro-fine Cement Grouting in Liquefiable Sand

    SciTech Connect

    Mirjalili, Mojtaba; Mirdamadi, Alireza; Ahmadi, Alireza

    2008-07-08

    In the presence of strong ground motion, liquefaction hazards are likely to occur in saturated cohesion-less soils. The risk of liquefaction and subsequent deformation can be reduced by various ground improvement methods including the cement grouting technique. The grouting method was proposed for non-disruptive mitigation of liquefaction risk at developed sites susceptible to liquefaction. In this research, a large-scale experiment was developed for assessment of micro-fine cement grouting effect on strength behavior and liquefaction potential of loose sand. Loose sand samples treated with micro-fine grout in multidirectional experimental model, were tested under cyclic and monotonic triaxial loading to investigate the influence of micro-fine grout on the deformation properties and pore pressure response. The behavior of pure sand was compared with the behavior of sand grouted with a micro-fine cement grout. The test results were shown that cement grouting with low concentrations significantly decreased the liquefaction potential of loose sand and related ground deformation.

  15. Extracellular peroxidase production by Coprinus species from urea-treated soil.

    PubMed

    Ikehata, Keisuke; Buchanan, Ian D; Smith, Daniel W

    2004-01-01

    Thirteen strains of inky-cap mushroom Coprinus species were evaluated for the production of extracellular peroxidase. The liquid fermentation was carried out in shake flasks containing 1% glucose, 0.5% peptone, 0.3% yeast extract, and 0.3% malt extract broth at 25 degrees C. Peroxidase activity was detected in the liquid culture of several Coprinus species, including C. echinosporus NBRC 30630; C. macrocephalus NBRC 30117; Coprinus spp. UAMH 10065, UAMH 10066, UAMH 10067, and 074, after 10 days of growth. Peroxidase production by Coprinus sp. UAMH 10067, a Coprinus species isolated from urea-treated soil, was comparable to that of C. cinereus and reached 15 U.mL(-1) after 10 days. In addition, the peroxidase from Coprinus sp. UAMH 10067 was apparently more thermally stable than the enzyme produced by C. cinereus.

  16. Impact of use of treated wastewater for irrigation on soil and quinoa crop in South of Morocco

    NASA Astrophysics Data System (ADS)

    El Youssfi, Lahcen; Choukr-Allah, Redouane; Zaafrani, Mina; Hirich, Aziz; Fahmi, Hasna; Abdelatif, Rami; Laajaj, Khadija; El Omari, Halima

    2015-04-01

    This work was conducted at the experimental station of the IAV Hassan II-CHA-Agadir in southwest Morocco between 2010 and 2012. It aimed the assessment of the effects of use of treated wastewater on soil properties and agronomic parameters by adopting crop rotation introducing quinoa (Chenopodium quinoa Willd.) as a new crop under semi-arid climate. Biomass production, yield, nutrient accumulation in leaves and the level of electrical conductivity and soil nitrate are the evaluated parameters during three growing seasons. Results show that quinoa has a performing behavior when it is preceded by fabae bean in term of water use efficiency; in addition, the recorded level of salt accumulation in the soil was the lowest in comparison with that of the combinations bean>quinoa and fallow>quinoa. Concerning growth and yield, it was found that growing quinoa after chickpea was more beneficial in terms of biomass productivity and yield. Keywords: Quinoa, soil, treated wastewater semi-arid

  17. Occurrence and distribution of PAHs, PCBs, and chlorinated pesticides in Tunisian soil irrigated with treated wastewater.

    PubMed

    Haddaoui, Imen; Mahjoub, Olfa; Mahjoub, Borhane; Boujelben, Abdelhamid; Di Bella, Giuseppa

    2016-03-01

    Treated wastewater (TWW) is a well recognized source of organic pollutants (OPs) that may accumulate during irrigation. For the first time, data on the occurrence of polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyles (PCBs) and organochlorinated pesticides (OCPs) in wastewater irrigated soil in Nabeul (Tunisia) are reported. 13 PAHs, 18 PCBs and 16 OCPs were analyzed in soil samples collected at 0-10 and 10-20 cm depth before each and every irrigation and after the irrigation period expanding from June to October. Soil was extracted with an accelerated solvent extractor and analyzed by a tandem gas chromatograph in selected reaction monitoring mode (GC/MS/MS/SRM). OPs residues were detected before irrigation and accumulated at the end of the season for some of them. The total concentration of PAHs varied between 120.01 and 365.18 μg kg(-1) dry weight (dw) at 0-10 cm depth before and at the end of irrigation, respectively. The total concentration of PCBs varied between 11.26 and 21.89 μg kg(-1) dw at 0-10 cm, being higher than those reported for 10-20 cm. The six indicator PCB congeners (28, 52, 101, 138, 153, 180) were predominant. OCPs concentrations ranged between 12.49 and 21.81 μg kg(-1) at 0-10 cm and between 74.03 and 310.54 μg kg(-1) at 10-20 cm depth. DDT was predominant accounting for more than 94% of the total OCPs. In view of the present results, OPs are relevant to the agricultural environment, calling for more research on their persistence and potential transfer to plants and/or groundwater while taking into account farmers' practices.

  18. Occurrence and distribution of PAHs, PCBs, and chlorinated pesticides in Tunisian soil irrigated with treated wastewater.

    PubMed

    Haddaoui, Imen; Mahjoub, Olfa; Mahjoub, Borhane; Boujelben, Abdelhamid; Di Bella, Giuseppa

    2016-03-01

    Treated wastewater (TWW) is a well recognized source of organic pollutants (OPs) that may accumulate during irrigation. For the first time, data on the occurrence of polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyles (PCBs) and organochlorinated pesticides (OCPs) in wastewater irrigated soil in Nabeul (Tunisia) are reported. 13 PAHs, 18 PCBs and 16 OCPs were analyzed in soil samples collected at 0-10 and 10-20 cm depth before each and every irrigation and after the irrigation period expanding from June to October. Soil was extracted with an accelerated solvent extractor and analyzed by a tandem gas chromatograph in selected reaction monitoring mode (GC/MS/MS/SRM). OPs residues were detected before irrigation and accumulated at the end of the season for some of them. The total concentration of PAHs varied between 120.01 and 365.18 μg kg(-1) dry weight (dw) at 0-10 cm depth before and at the end of irrigation, respectively. The total concentration of PCBs varied between 11.26 and 21.89 μg kg(-1) dw at 0-10 cm, being higher than those reported for 10-20 cm. The six indicator PCB congeners (28, 52, 101, 138, 153, 180) were predominant. OCPs concentrations ranged between 12.49 and 21.81 μg kg(-1) at 0-10 cm and between 74.03 and 310.54 μg kg(-1) at 10-20 cm depth. DDT was predominant accounting for more than 94% of the total OCPs. In view of the present results, OPs are relevant to the agricultural environment, calling for more research on their persistence and potential transfer to plants and/or groundwater while taking into account farmers' practices. PMID:26716883

  19. Inorganic arsenic speciation in soil and groundwater near in-service chromated copper arsenate-treated wood poles.

    PubMed

    Zagury, Gérald J; Dobran, Simona; Estrela, Sandra; Deschênes, Louise

    2008-04-01

    The environmental impact of chromated copper arsenate (CCA)-treated utility poles is linked to the possible soil and groundwater contamination with arsenic. The objective of the present study was to determine the arsenic speciation in soil and groundwater near in-service CCA-treated poles. Arsenite (As[III]) and arsenate (As[V]) concentrations were determined in 29 surface and subsurface soil samples collected near eight CCA-treated wood poles. Temporal variability of total arsenic concentrations and inorganic arsenic speciation was also assessed in groundwater at two sites through four sampling events over a 19-month period. Arsenic speciation was carried out by a solvent extraction method using ammonium pyrrolidine dithiocarbamate-methyl isobutyl ketone, and total arsenic was quantified by inductively coupled plasma/atomic emission spectrometry/hydride generation. Average arsenic concentrations in surface soils immediately adjacent to utility poles ranged from 153+/-49 to 410+/-150 mg/kg but approached background levels (below 5 mg/kg) within 0.50 m from the poles. A positive correlation was found between surface soil As concentration and total Fe content. In subsurface samples (0.50 m), arsenic levels were generally high in sandy soils (up to 223+/-32 mg/kg), moderate in clayey soils (up to 126+/-26 mg/kg), and relatively lower in organic soils (up to 56+/-24 mg/ kg). Arsenic(V) was the predominant arsenic species in surface (>78%) and subsurface soils (>66%). Total arsenic concentrations in groundwater below the clayey site were high and varied widely over time (79-390 microg/L), with 30 to 68% as As(III). Below the utility pole located on the organic site with a high Fe content, lower total arsenic levels (12-33 microg/L) were found, with As(III) ranging from 0 to 100%.

  20. Heavy metal input to agricultural soils from irrigation with treated wastewater: Insight from Pb isotopes

    NASA Astrophysics Data System (ADS)

    Kloppmann, Wolfram; Cary, Lise; Psarras, Georgios; Surdyk, Nicolas; Chartzoulakis, Kostas; Pettenati, Marie; Maton, Laure

    2010-05-01

    A major objective of the EU FP6 project SAFIR was to overcome certain drawbacks of wastewater reuse through the development of a new irrigation technology combining small-scale modular water treatment plants on farm level and improved irrigation hardware, in the aim to lower the risks related to low quality water and to increase water use efficiency. This innovative technology was tested in several hydro-climatic contexts (Crete, Italy, Serbia, China) on experimental irrigated tomato and potato fields. Here we present the heavy metal variations in soil after medium-term (3 irrigation seasons from 2006-2008) use of treated municipal wastewater with a special focus on lead and lead isotope signatures. The experimental site is located in Chania, Crete. A matrix of plots were irrigated, combining different water qualities (secondary, primary treated wastewater, tap water, partially spiked with heavy metals, going through newly developed tertiary treatment systems) with different irrigation strategies (surface and subsurface drip irrigation combined with full irrigation and partial root drying). In order to assess small scale heavy metal distribution around a drip emitter, Pb isotope tracing was used, combined with selective extraction. The sampling for Pb isotope fingerprinting was performed after the 3rd season of ww-irrigation on a lateral profile from a drip irrigator (half distance between drip lines, i.e. 50cm) and three depth intervals (0-10, 10-20, 20-40 cm). These samples were lixiviated through a 3 step selective extraction procedure giving rise to the bio-accessible, mobile and residual fraction: CaCl2/NaNO3 (bio-accessible fraction), DPTA (mobile fraction), total acid attack (residual fraction). Those samples were analysed for trace elements (including heavy metals) and major inorganic compounds by ICP-MS. The extracted fractions were then analysed by Thermal Ionisation Mass Spectrometry (TIMS) for their lead isotope fingerprints (204Pb, 206Pb, 207Pb, 208Pb

  1. Lunar cement

    NASA Technical Reports Server (NTRS)

    Agosto, William N.

    1992-01-01

    With the exception of water, the major oxide constituents of terrestrial cements are present at all nine lunar sites from which samples have been returned. However, with the exception of relatively rare cristobalite, the lunar oxides are not present as individual phases but are combined in silicates and in mixed oxides. Lime (CaO) is most abundant on the Moon in the plagioclase (CaAl2Si2O8) of highland anorthosites. It may be possible to enrich the lime content of anorthite to levels like those of Portland cement by pyrolyzing it with lunar-derived phosphate. The phosphate consumed in such a reaction can be regenerated by reacting the phosphorus product with lunar augite pyroxenes at elevated temperatures. Other possible sources of lunar phosphate and other oxides are discussed.

  2. Leaf structural traits of tropical woody species resistant to cement dust.

    PubMed

    Siqueira-Silva, Advanio Inácio; Pereira, Eduardo Gusmão; Modolo, Luzia Valentina; Paiva, Elder Antonio Sousa

    2016-08-01

    Cement industries located nearby limestone outcrops in Brazil have contributed to the coating of cement dust over native plant species. However, little is known about the extent of the response of tropical woody plants to such environmental pollutant particularly during the first stages of plant development and establishment. This work focused on the investigation of possible alterations in leaf structural and ultrastructural traits of 5-month-old Guazuma ulmifolia Lam. (Malvaceae), 6-month-old Myracrodruon urundeuva Allemão (Anacardiaceae), and 9-month-old Trichilia hirta L. (Meliaceae) challenged superficially with cement dust during new leaf development. Leaf surface of plants, the soil or both (leaf plus soil), were treated (or not) for 60 days, under controlled conditions, with cement dust at 2.5 or 5.0 mg cm(-2). After exposure, no significant structural changes were observed in plant leaves. Also, no plant death was recorded by the end of the experiment. There was also some evidence of localized leaf necrosis in G. ulmifolia and T. hirta, leaf curling in M. urundeuva and T. hirta, and bulges formation on epidermal surface of T. hirta, after cement dust contact with plant shoots. All species studied exhibited stomata obliteration while T. hirta, in particular, presented early leaf abscission, changes in cellular relief, and organization and content of midrib cells. No significant ultrastructural alterations were detected under the experimental conditions studied. Indeed, mesophyll cells presented plastids with intact membrane systems. The high plant survival rates, together with mild morphoanatomic traits alterations in leaves, indicate that G. ulmifolia is more resistant to cement dust pollutant, followed by M. urundeuva and T. hirta. Thus, the three plant species are promising for being used to revegetate areas impacted by cement industries activities. PMID:27146683

  3. Sculpting with Cement.

    ERIC Educational Resources Information Center

    Olson, Lynn

    1983-01-01

    Cement offers many creative possibilities for school art programs. Instructions are given for sculpting with fiber-cement and sand-cement, as well as for finishing processes and the addition of color. Safety is stressed. (IS)

  4. Influence of chemical and physical characteristics of cement kiln dusts (CKDs) on their hydration behavior and potential suitability for soil stabilization

    SciTech Connect

    Peethamparan, Sulapha Olek, Jan Lovell, Janet

    2008-06-15

    The interaction of CKDs with a given soil depends on the chemical and physical characteristics of the CKDs. Hence, the characterization of CKDs and their hydration products may lead to better understanding of their suitability as soil stabilizers. In the present article, four different CKD powders are characterized and their hydration products are evaluated. A detailed chemical (X-ray diffraction), thermogravimetric and morphological (scanning electron microscope) analyses of both the CKD powders and the hydrated CKD pastes are presented. In general, high free-lime content ({approx} 14-29%) CKDs, when reacted with water produced significant amounts of calcium hydroxide, ettringite and syngenite. These CKDs also developed higher unconfined compressive strength and higher temperature of hydration compared to CKDs with lower amounts of free-lime. An attempt was made to qualitatively correlate the performance of CKD pastes with the chemical and physical characteristics of the original CKD powders and to determine their potential suitability as soil stabilizers. To that effect a limited unconfined compressive strength testing of CKD-treated kaolinite clays was performed. The results of this study suggest that both the compressive strength and the temperature of hydration of the CKD paste can give early indications of the suitability of particular CKD for soil stabilization.

  5. Degradation of vanillin in soil-clay mixtures treated with simulated acid rain

    SciTech Connect

    Bewley, R.J.F.; Stotzky, G.

    1984-06-01

    Significant vanillin degradation occurred only in soil amended with 9% montmorillonite and not in soil amended with 9% kaolinite or in soil without addition of clay minerals. Progressively decreasing amounts of vanillin were mineralized in the montmorillonite-amended soil with increasing acidification with H/sub 2/SO/sub 4/, and complete inhibition of mineralization occurred at a soil pH of 1.6. 16 references, 1 table.

  6. [Cd uptake in rice cultivars and Cd fractions in soil treated with organic acids and EDTA].

    PubMed

    Zhang, Hai-Bo; Li, Yang-Rui; Xu, Wei-Hong; Chen, Gui-Qing; Wang, Hui-Xian; Han, Gui-Qi; Zhang, Xiao-Jing; Xiong, Zhi-Ting; Zhang, Jin-Zhong; Xie, De-Ti

    2011-09-01

    A pot experiment was conducted to examine the yield, quality and cadmium (Cd) uptake in different rice cultivars, and Cd speciation in soil after exposing to Cd (0, 1 and 5 mg x kg(-1)) in the presence of organic acids and ethylenediamine tetraacetic acid (EDTA). The results showed that general increase in the yield for cultivars Xiushui63 and II you527 was observed. Yield of two rice cultivars were in order of organic acids treatment or organic acids + 1/2EDTA treatment > EDTA treatment. The exchangeable, carbonate related and ferric-manganese oxidation related Cd increased; while organic complexation Cd and residules decreased in the presence of organic acids and EDTA. Cadmium concentrations in grain, straw and roots of both cultivars markedly reduced in the presence of organic acids and EDTA. Grain Cd concentration was the lowest for plants treated with EDTA, followed by organic acids + 1/2EDTA, and the highest Cd concentration in grain was found in the treatment with organic acids. Grain Cd concentration decreased by 9.0% to 49.3% and 16.5% to 30.6% at 1 mg x kg(-1) Cd in the presence of organic acids and EDTA, and by 12.7% to 28.5% and 4.3% to 19.1% at 5 mg x kg(-1) Cd. Cadmium concentration and accumulation in plants and total Cd content in soil were higher in Xiushui63 than in that in II you527. Grain Cd concentration decreased, and yield and quality of two rice cultivars increased at the same time in the presence of organic acids + 1/2EDTA.

  7. Tympanoplasty with ionomeric cement.

    PubMed

    Kjeldsen, A D; Grøntved, A M

    2000-01-01

    Patients with isolated erosion of the long incus process suffer from severe hearing loss caused by lack of continuity of the ossicular chain. This study is a retrospective evaluation of the hearing results using two different surgical procedures. Since January 1993, 12 consecutive patients with isolated erosion of the long incus process have been treated with a new surgical technique in which the ossicular chain was rebuilt with ionomeric cement. The results in hearing performance (mean pure-tone average (PTA) 0.5, 1 and 2 kHz) were evaluated pre- and post-surgery, and compared to those in a group of 20 historical controls who underwent surgery in 1991 and 1992 using incus autograft interposition. Among the 12 index patients, 7 (58%) achieved improvement in PTA of > 10 dB, in 3 there was no difference and in 2 a slight decline. Among the 20 controls, 14 (70%) achieved improvement in PTA of > 10 dB, in 4 there was a slight improvement and in 2 a decline. The difference was not statistically significant. Hearing improvement using ionomeric cement in type II tympanoplasty was satisfactory. Reconstruction of the ossicular chain with ionomeric cement is recommended, as the procedure is easy to perform, presents less risk of damage to the stapes and cochlea, requires less extensive surgery and does not exclude other surgical methods in cases of reoperation. PMID:10909000

  8. Water Consumption, Soil Temperature and Soil Respiration in Model Ecosystems of Young Oak Stands Treated by Air-warming and Drought

    NASA Astrophysics Data System (ADS)

    Kuster, Thomas; Arend, Matthias; Günthardt-Goerg, Madeleine S.; Schulin, Rainer

    2010-05-01

    IPCC scenarios predict a global mean annual temperature increase during the 21st century of 2 - 6 °C, as well as changes in precipitation patterns. The multidisciplinary project "Querco" addresses the question how increased air temperature and extended drought periods will influence stands of young oaks. For this purpose, mixed stands of young Q. robur, Q. pubescens and Q. petrea (4-year-old trees from seeds of four different provenances each) were composed in the WSL open-top model-ecosystem chambers on either acid or calcareous forest soils and grown under four different climate treatments (control, air-warming, drought, air-warming & drought) from 2007 to 2009. Drought treated chambers only received about one third of water during the growing seasons from May to October as compared to the control. Further, we established longer drought periods without any irrigation. The air-warming treatment was established by keeping the side walls of the open-top chambers more closed than in the controls. Unsurprisingly, evapotranspiration from dry soils was much lower than from irrigated soils. There was significantly more evapotranspiration from the acidic than from the calcareous soil. These findings are in line with increased leaf transpiration rates and a tendency towards higher leaf biomass in oaks growing on acid as compared to calcareous soil. The higher evapotranspiration from acid soils also was in line with the fact that soil water potentials decreased more in acidic than in calcareous soils, an effect that became particularly significant during periods of high consumptive water demand by the trees. While soil water potentials were strongly decreased by the drought treatments down to 1 m depth, the air-warming treatment had almost no effect on soil water potential. Treatments, air-warming and drought, significantly increased soil temperature. In drought treated soils, this effect was related to the lower water content as compared to the control soils. As intended

  9. Nitrous Oxide Fluxes, Soil Oxygen, and Dentrification Potential from Urine and Non-urine Treated Soil Under Different Irrigation Frequencies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Despite increased use of irrigation to improve forage quality and quantity for grazing cattle (Bos taurus), few studies have assessed how irrigation practices influence nitrous oxide (N2O) emissions from urine-impacted soils. In particular, irrigation effects on soil oxygen (O2) availability, one of...

  10. Temporal changes of antibiotic-resistance genes and bacterial communities in two contrasting soils treated with cattle manure.

    PubMed

    Hu, Hang-Wei; Han, Xue-Mei; Shi, Xiu-Zhen; Wang, Jun-Tao; Han, Li-Li; Chen, Deli; He, Ji-Zheng

    2016-02-01

    The emerging environmental spread of antibiotic-resistance genes (ARGs) and their subsequent acquisition by clinically relevant microorganisms is a major threat to public health. Animal manure has been recognized as an important reservoir of ARGs; however, the dissemination of manure-derived ARGs and the impacts of manure application on the soil resistome remain obscure. Here, we conducted a microcosm study to assess the temporal succession of total bacteria and a broad spectrum of ARGs in two contrasting soils following manure application from cattle that had not been treated with antibiotics. High-capacity quantitative PCR detected 52 unique ARGs across all the samples, with β-lactamase as the most dominant ARG type. Several genes of soil indigenous bacteria conferring resistance to β-lactam, which could not be detected in manure, were found to be highly enriched in manure-treated soils, and the level of enrichment was maintained over the entire course of 140 days. The enriched β-lactam resistance genes had significantly positive relationships with the relative abundance of the integrase intI1 gene, suggesting an increasing mobility potential in manure-treated soils. The changes in ARG patterns were accompanied by a significant effect of cattle manure on the total bacterial community compositions. Our study indicates that even in the absence of selective pressure imposed by agricultural use of antibiotics, manure application could still strongly impact the abundance, diversity and mobility potential of a broad spectrum of soil ARGs. Our findings are important for reliable prediction of ARG behaviors in soil environment and development of appropriate strategies to minimize their dissemination.

  11. Changes in metal speciation and pH in olive processing waste and sulphur-treated contaminated soil.

    PubMed

    de la Fuente, C; Clemente, R; Bernal, M P

    2008-06-01

    Degradation of organic matter from olive mill waste and changes in the heavy metal fractionation of a metal-contaminated calcareous soil were studied in a laboratory experiment, in which the olive mill waste was mixed with the soil and then incubated under aerobic conditions. The soil was calcareous (15% CaCO(3)) with high Zn and Pb concentrations (2058 and 2947 mg kg(-1), respectively). The organic amendment was applied at a rate equivalent to 20 g kg(-1) soil, and unamended soil was run as a control. To discern if changes in metal solubility were due to the acidic character of the waste, elemental sulphur was applied to soil as a non-organic acidifying material. The S(0) rates used were 3.14, 4.71 and 6.28 g kg(-1). The mineralisation of total organic-C (TOC) from the waste reached 14.8% of the original TOC concentration after 56 days of incubation. The CO(2)-C produced from S(0)-treated soils showed the carbonate destruction by the H(2)SO(4) formed through S(0) oxidation. The organic waste increased EDTA-extractable Zn and Pb concentrations and CaCl(2)-extractable Mn levels in soil after two days of incubation. The changes in metal availability with time indicated that the oxidation of phenols from the waste reduced Mn (IV) oxides, releasing Zn and Pb associated with this mineral phase. Organic waste addition did not decrease soil pH; the acidifying effect of S(0) did not change metal fractionation in the soil. PMID:17659778

  12. Efficiency of non-ionic surfactants - EDTA for treating TPH and heavy metals from contaminated soil

    PubMed Central

    2013-01-01

    Introduction of fuel hydrocarbons and inorganic compounds (heavy metals) into the soil, resulting in a change of the soil quality, which is likely to affect use of the soil or endangering public health and ground water. This study aimed to determine a series of parameters to remediation of TPH and heavy metals contaminated soil by non-ionic surfactants- chelating agents washing process. In this experimental study, the effects of soil washing time, agitation speed, concentration of surfactant, chelating agent and pH on the removal efficiency were studied. The results showed that TPH removal by nonionic surfactants (Tween 80, Brij 35) in optimal condition were 70–80% and 60–65%, respectively. Addition of chelating agent (EDTA) significantly increases Cd and Pb removal. The washing of soil by non- ionic surfactants and EDTA was effective in remediation of TPH and heavy metals from contaminated soil, thus it can be recommended for remediation of contaminated soil. PMID:24359927

  13. Nitrous Oxide Fluxes, Soil Oxygen, and Denitrification Potential of Urine- and Non-Urine-Treated Soil under Different Irrigation Frequencies.

    PubMed

    Owens, Jen; Clough, Tim J; Laubach, Johannes; Hunt, John E; Venterea, Rodney T; Phillips, Rebecca L

    2016-07-01

    Despite increased use of irrigation to improve forage quality and quantity for grazing cattle ( Linnaeus), there is a lack of data that assess how irrigation practices influence nitrous oxide (NO) emissions from urine-affected soils. Irrigation effects on soil oxygen (O) availability, a primary controller of NO fluxes, is poorly understood. It was hypothesized that increased irrigation frequency would result in lower NO emissions by increasing soil moisture and decreasing soil O concentrations. This would favor more NO reduction to dinitrogen (N). We examined effects of high (3-d) versus low (6-d) irrigation frequency with and without bovine urine addition to pasture. Nitrous oxide fluxes were measured daily for 35 d. Soil O, temperature, and water content were continuously measured at multiple depths. Inorganic nitrogen, organic carbon, and soil pH were measured at 6-d intervals. Measurements of denitrification enzyme activity with and without acetylene inhibition were used to infer the NO/(NO + N) ratio. The NO/(NO + N) ratio was lower under high- compared with low-frequency irrigation, suggesting greater potential for NO reduction to N with more frequent irrigation. Although NO fluxes were increased by urine addition, they were not affected by irrigation frequency. Soil O decreased temporarily after urine deposition, but O dynamics did not explain NO dynamics. Relative soil gas diffusivity (/) was a better predictor of NO fluxes than O concentration. On a free-draining soil, increasing irrigation frequency while providing the same total water volume did not enhance NO emissions under ruminant urine patches in a grazed pasture. PMID:27380064

  14. Long-term effects of poultry litter, alum-treated litter, and ammonium nitrate on aluminum availability in soils.

    PubMed

    Moore, P A; Edwards, D R

    2005-01-01

    Research has shown that alum [Al(2)(SO(4))(3).14H(2)O] applications to poultry litter can greatly reduce phosphorus (P) runoff, as well as decrease ammonia (NH(3)) volatilization. However, the long-term effects of fertilizing with alum-treated litter are unknown. The objectives of this study were to evaluate the long-term effects of normal poultry litter, alum-treated litter, and ammonium nitrate (NH(4)NO(3)) on aluminum (Al) availability in soils, Al uptake by tall fescue (Festuca arundinacea Schreb.), and tall fescue yields. A long-term study was initiated in April of 1995. There were 13 treatments (unfertilized control, four rates of normal litter, four rates of alum-treated litter, and four rates of NH(4)NO(3)) in a randomized block design. All fertilizers were broadcast applied to 52 small plots (3.05 x 1.52 m) cropped to tall fescue annually in the spring. Litter application rates were 2.24, 4.49, 6.73, and 8.98 Mg ha(-1) (1, 2, 3, and 4 tons acre(-1)); NH(4)NO(3) rates were 65, 130, 195, and 260 kg N ha(-1) and were based on the amount of N applied with alum-treated litter. Soil pH, exchangeable Al (extracted with potassium chloride), Al uptake by fescue, and fescue yields were monitored periodically over time. Ammonium nitrate applications resulted in reductions in soil pH beginning in Year 3, causing exchangeable Al values to increase from less than 1 mg Al kg(-1) soil in Year 2 to over 100 mg Al kg(-1) soil in Year 7 for many of the NH(4)NO(3) plots. In contrast, normal and alum-treated litter resulted in an increase in soil pH, which decreased exchangeable Al when compared to unfertilized controls. Severe yield reductions were observed with NH(4)NO(3) beginning in Year 6, which were due to high levels of acidity and exchangeable Al. Aluminum uptake by forage and Al runoff from the plots were not affected by treatment. Fescue yields were highest with alum-treated litter (annual average = 7.36 Mg ha(-1)), followed by normal litter (6.93 Mg ha(-1)), NH(4)NO

  15. Quartz cement in sandstones: a review

    NASA Astrophysics Data System (ADS)

    McBride, Earle F.

    the depositional basin, including possibly deeply buried rocks undergoing low-grade metamorphism, but the relative importance of potential sources remains controversial and likely differs for different formations. The most likely important silica sources within unmetamorphosed shales include clay transformation (chiefly illitization of smectite), dissolution/pressure solution of detrital grains, and dissolution of opal skeletal grains; the most likely important sources of silica within unmetamorphosed sandstones include pressure solution of detrital quartz grains at grain contacts and at stylolites, feldspar alteration/dissolution, and perhaps carbonate replacement of silicate minerals and the margins of some quartz grains. Silica released by pressure solution in many sandstones post-dates the episode of cementation by quartz; thus, this silica must migrate and cement shallower sandstones in the basin or escape altogether. Some quartz-cemented sandstones are separated vertically from potential silica source beds by a kilometer or more, requiring silica transport over long distances. The similarity of diagenetic sequences in sandstones of different composition and ages apparently is the result of the normal temperature and time-dependent maturation of sediments, organic matter and pore fluids during burial in sedimentary basins. Silica that forms overgrowths is released by one or more diagenetic processes that apparently are controlled by temperature and time. Most cementation by quartz takes place when sandstone beds were in the silica mobility window specific to a particular sedimentary basin. Important secondary controls are introduced by compartmentalized domains produced by faults (e.g., North Sea) or overpressure boundaries (e.g., Gulf Coast Tertiary). Shallow meteoric water precipitates only small amounts of silica cement (generally less than 5% in most fluvial and colian sandstones), except in certain soils and at water tables in high-flux sand aquifers. Soil

  16. Injection biomechanics of bone cements used in vertebroplasty.

    PubMed

    Baroud, G; Bohner, M; Heini, P; Steffen, T

    2004-01-01

    The incidence of osteoporotic bone fractures is growing exponentially as the western population ages and as life expectancy increases. Vertebroplasty, where acrylic or calcium phosphate cement is injected into the weakened vertebrae to augment them, is an emerging procedure for treating spinal fragility fractures. However, cement injection is currently limited because there are no clear standards for a safe, reproducible and predictable procedure. The purpose of this paper is to examine the role that bone cements play in the underlying bio-mechanisms that affect the outcomes of cement injection. Our most important finding after combining clinical, laboratory and theoretical research is that the process of cement injection poses conflicting demands on bone cements. The cements are required to be more viscous and less viscous at the same time. The challenge therefore is to develop biomaterials, techniques and/or devices that can overcome or manage the conflicting demands on cement viscosity.

  17. Effect of land application of manure from enrofloxacin-treated chickens on ciprofloxacin resistance of Enterobacteriaceae in soil.

    PubMed

    Pourcher, A-M; Jadas-Hécart, A; Cotinet, P; Dabert, P; Ziebal, C; Le Roux, S; Moraru, R; Heddadj, D; Kempf, I

    2014-06-01

    A field plot experiment was carried out to evaluate the impact of spreading chicken manure containing enrofloxacin (ENR) and its metabolite ciprofloxacin (CIP), on the levels of CIP-resistant Enterobacteriaceae in soil. The manures from chickens treated with ENR and from untreated control chickens were applied on six plots. Total and CIP-resistant Enterobacteriaceae were counted on Violet Red Bile Glucose medium containing 0 to 16mg L(-1) of CIP. A total of 145 isolates were genotyped by enterobacterial repetitive intergenic consensus-polymerase chain reaction (ERIC-PCR). The minimum inhibitory concentration (MIC) of CIP for the isolates of each ERIC-PCR profile was determined. The most frequently isolated Enterobacteriaceae included Escherichia coli, and to a lesser extent, Enterobacter and 5 other genera from environmental origin. The composition of the E. coli community differed between manure and manured soil suggesting that the E. coli genotypes determined by ERIC-PCR varied significantly in their ability to survive in soil. One of these genotypes, including both susceptible and resistant isolates, was detected up to 89 days after the manure was applied. Most of the E. coli isolated in soil amended with manure from treated chickens was resistant to CIP (with a MIC ranging between 2 and 32mg L(-1)). In contrast, despite the presence of ENR in soil at concentrations ranging from 13-518μg kg(-1), the environmental Enterobacteriaceae isolates had a CIP MIC≤0.064mg L(-1), except one isolate which had a MIC of 0.25mg L(-1), These results showed that spreading manure from ENR-treated chickens enabled CIP-resistant E. coli to persist for at least three months in the soil. However, neither the presence of fluoroquinolones, nor the persistence of CIP-resistant E. coli, increased the CIP-susceptibility of environmental Enterobacteriaceae.

  18. ULTRA-LIGHTWEIGHT CEMENT

    SciTech Connect

    Fred Sabins

    2002-07-30

    The objective of this project is to develop an improved ultra-lightweight cement using ultra-lightweight hollow glass spheres (ULHS). This report includes results from laboratory testing of ULHS systems along with other lightweight cement systems, including foamed and sodium silicate slurries. During this project quarter, a comparison study of the three cement systems examined the effect that cement drillout has on the three cement systems. Testing to determine the effect of pressure cycling on the shear bond properties of the cement systems was also conducted. This report discusses testing that was performed to analyze the alkali-silica reactivity of ULHS in cement slurries.

  19. Chemical speciation and bioavailability of cadmium in the temperate and semiarid soils treated with wheat residue.

    PubMed

    Safari Sinegani, Ali Akbar; Jafari Monsef, Milad

    2016-05-01

    Heavy metal bioavailability depends on metal fractions in soil. The impacts of mild wheat residue (<2 mm) and incubation time on fractions of Cd were studied in two different spiked soils sampled from Hamadan and Lahijan, Iran with semiarid and temperate climates, respectively. Two factorial experiments were done in two soils polluted with 10 μg Cd g(-1) soil separately. Organic matter (0 and 5 % wheat straw) and soil incubation time (24 and 3600 h) were factors examined in three replicates. The transformation of Cd from KNO3 extractable form to less available fractions was higher in semiarid soils with lower clay and OM contents and higher pH and carbonate contents compared to temperate soils. In polluted semiarid soils after 24 h incubation, greater content of Cd was observed in residual (HNO3 extractable) (45 %), carbonates associated (EDTA extractable) (34 %), organic matter associated (NaOH extractable) (11 %), and KNO3 extractable (10 %) fractions, but in temperate soils, greater content of Cd was observed in KNO3 extractable (61 %), HNO3 extractable (14 %), EDTA extractable (13 %), and NaOH extractable (12 %) fractions. KNO3 extractable form of Cd was decreased, and NaOH extractable and HNO3 extractable forms of Cd were increased by addition of wheat residue to both soils. The initial decrease of added Cd from KNO3 extractable form to less mobile fractions in Hamadan soil was very interesting. But this change was not observed in Lahijan soil. Since contamination factor was significantly high in temperate soils compared to semiarid soils in all treatments, the risk of Cd environmental pollution in temperate region is considerably high.

  20. Effects of long-term irrigation with treated wastewater on soil quality, soil-borne pathogens, and living organisms: case study of the vicinity of El Hajeb (Tunisia).

    PubMed

    Hentati, Olfa; Chaker, Sana; Wali, Ahmed; Ayoub, Tarek; Ksibi, Mohamed

    2014-05-01

    Medium (i.e. 15 years) and long-term (i.e. 20 years) impact of irrigation using secondary-treated municipal wastewater (TWW) was assessed on two agricultural soil samples, denoted by E and G, respectively, in the vicinity of El Hajeb region (Southern Tunisia). Soil pH, electrical conductivity particle size grading, potential risk of salinity, water holding capacity and chemical composition, as well as organic matter content, pathogenic microorganisms and heavy metal concentrations in the TWW-irrigated (E and G) and rainwater-irrigated (T) soils at various depths, were monitored and compared during a 5-year experiment. Our study showed that bacterial abundance is higher in sandy-clayey soil, which has an enhanced ability to retain moisture and nutrients. The high level of bacterial flora in TWW-irrigated soils was significantly (p < 0.05) correlated (r = ~0.5) with the high level of OM. Avoidance assays have been used to assess toxic effects generated by hazards in soils. The earthworms gradually avoided the soils from the surface (20 cm) to the depth (60 cm) of the G transect and then the E transect, preferring the T transect. The same behaviour was observed for springtails, but they seem to be less sensitive to the living conditions in transects G and E than the earthworms. The avoidance response test of Eisenia andrei was statistically correlated with soil layers at the sampling sites. However, the avoidance response test of Folsomia candida was positively correlated with silt-clay content (+0.744*) and was negatively correlated with sand content (-0.744*). PMID:24362513

  1. Investigation of 4-year-old stabilised/solidified and accelerated carbonated contaminated soil.

    PubMed

    Antemir, A; Hills, C D; Carey, P J; Magnié, M-C; Polettini, A

    2010-09-15

    The investigation of the pilot-scale application of two different stabilisation/solidification (S/S) techniques was carried out at a former fireworks and low explosives manufacturing site in SE England. Cores and granular samples were recovered from uncovered accelerated carbonated (ACT) and cement-treated soils (S/S) after 4 years to evaluate field-performance with time. Samples were prepared for microstructural examination and leaching testing. The results indicated that the cement-treated soil was progressively carbonated over time, whereas the mineralogy of the carbonated soil remained essentially unchanged. Distinct microstructures were developed in the two soils. Although Pb, Zn and Cu leached less from the carbonated soil, these metals were adequately immobilised by both treatments. Geochemical modeling of pH-dependent leaching data suggested that the retention of trace metals resulted from different immobilisation mechanisms operating in the two soils examined. PMID:20579807

  2. Investigation of 4-year-old stabilised/solidified and accelerated carbonated contaminated soil.

    PubMed

    Antemir, A; Hills, C D; Carey, P J; Magnié, M-C; Polettini, A

    2010-09-15

    The investigation of the pilot-scale application of two different stabilisation/solidification (S/S) techniques was carried out at a former fireworks and low explosives manufacturing site in SE England. Cores and granular samples were recovered from uncovered accelerated carbonated (ACT) and cement-treated soils (S/S) after 4 years to evaluate field-performance with time. Samples were prepared for microstructural examination and leaching testing. The results indicated that the cement-treated soil was progressively carbonated over time, whereas the mineralogy of the carbonated soil remained essentially unchanged. Distinct microstructures were developed in the two soils. Although Pb, Zn and Cu leached less from the carbonated soil, these metals were adequately immobilised by both treatments. Geochemical modeling of pH-dependent leaching data suggested that the retention of trace metals resulted from different immobilisation mechanisms operating in the two soils examined.

  3. Environmental applications of XANES: Speciation of {Tc} in cement after chemical treatment and Se after bacterial uptake

    SciTech Connect

    Shuh, D.K.; Kaltsoyannis, N.; Bucher, J.J.

    1994-03-01

    XANES (X-ray Absorption Near Edge Spectroscopy) has been employed to evaluate the efficacy of a process designed to encapsulate and reduce {Tc}O{sub 4}{sup {minus}} in cement matrices, thereby immobilizing {Tc}. The oxidation state of Se following.bioremediation of Se by bacteria has also been determined by XANES. The XANES measurements were performed at the Stanford Synchrotron Radiation Laboratory (SSRL) and the National Synchrotron Light Source (NSLS) at the respective K edges of {Tc} (21.0 keV) and Se (12.7 keV). Comparison of the XANES spectra of Tc in untreated cement to Tc in slag treated cement and to the chemical shifts of reference materials, shows that the oxidation state of {Tc} is the same in both cements. Thus, the addition of a reducing agent to the cement formulation does not significantly reduce the {Tc}O{sub 4} The common soil bacterium, Bacillus subtilis, is known to incorporate Se on or within the cell wall when exposed to a SE(IV) solution. The Se XANES spectra of B. subtilis, as well as bacillus isolated from selenium rich soil, show that the organisms reduce selenite to the red allotrope of elemental Se.

  4. A finite element model for simulating runoff and soil erosion from mechanically treated agricultural lands: 2. Field validation and applications

    NASA Astrophysics Data System (ADS)

    Sharda, V. N.; Singh, Sita Ram; Sastry, G.; Dhruvanarayana, V. V.

    1994-07-01

    The finite element model for simulation of runoff and soil erosion as developed by Sharda and Singh (this issue) is evaluated using data collected from agricultural land treated with major mechanical soil and water conservation measures, namely, contour bunding, graded bunding, bench terracing, and conservation bench terracing. The simulated and experimentally realized hydrographs and soil loss values are in reasonably good agreement for various measures. Probable reasons for discrepancies between the predicted and observed values are discussed. The model has the potential of being used on a single storm or a continuous basis provided the soil, crop, and climatic parameters are precisely known or estimated for a given location and for the period under consideration. The model logically simulates the effects of flow, topographic, soil, and crop parameters such as antecedent moisture level, roughness coefficient, saturated hydraulic conductivity, slope, depth of impoundment, size of outlet, longitudinal slope of the channel, vertical interval, and cropping management factor. The model is found to be quite sensitive to changes in roughness coefficient, rainfall excess rate, and cover management factor, and hence these parameters need to be assessed carefully in the field. The general applicability of the model as a planning tool for soil conservation measures and the scope for future development are also discussed.

  5. Community Structure of Ammonia-Oxidizing Archaea and Ammonia-Oxidizing Bacteria in Soil Treated with the Insecticide Imidacloprid

    PubMed Central

    Cycoń, Mariusz; Piotrowska-Seget, Zofia

    2015-01-01

    The purpose of this experiment was to assess the effect of imidacloprid on the community structure of ammonia-oxidizing archaea (AOA) and ammonia-oxidizing bacteria (AOB) in soil using the denaturing gradient gel electrophoresis (DGGE) approach. Analysis showed that AOA and AOB community members were affected by the insecticide treatment. However, the calculation of the richness (S) and the Shannon-Wiener index (H) values for soil treated with the field rate (FR) dosage of imidacloprid (1 mg/kg soil) showed no changes in measured indices for the AOA and AOB community members. In turn, the 10∗FR dosage of insecticide (10 mg/kg soil) negatively affected the AOA community, which was confirmed by the decrease of the S and H values in comparison with the values obtained for the control soil. In the case of AOB community, an initial decline followed by the increase of the S and H values was obtained. Imidacloprid decreased the nitrification rate while the ammonification process was stimulated by the addition of imidacloprid. Changes in the community structure of AOA and AOB could be due to an increase in the concentration of N-NH4+, known as the most important factor which determines the contribution of these microorganisms to soil nitrification. PMID:25705674

  6. Survival and nodulating ability of indigenous and inoculated Rhizobium leguminosarum biovar trifolii in sterilized and unsterilized soil treated with sewage sludge.

    PubMed

    Purchase, D; Miles, R J

    2001-01-01

    Rhizobium leguminosarum biovar trifolii was detected in soil from 41 of 47 plots, within nine sewage sludge-treated sites with different soil characteristics and heavy metal contents. However, although population size varied widely, there was no consistent correlation with soil heavy metal concentration. Indigenous populations in 20 plots within four selected sites retained their ability to induce effective nodule formation after incubation of soil in the dark for 165 days. In sterilized (gamma-irradiated) soil, Rhizobium survival varied from 0.01% to 95% depending on the soil sample and strain used. Metal-resistant strains with non-mucoid colonies survived less well than mucoid metal-sensitive strains.

  7. ZVI-CLAY SOIL MIXING TREATS DNAPL SOURCE AREA AT 35-FOOT DEPTH

    EPA Science Inventory

    The DuPont Company and Colorado State University (CSU) are collaborating in development and refinement of a technology that involves in-situ admixing of contaminated soil, granular zero valent iron (ZVI), and clay using conventional soil mixing equipment. A full-scale application...

  8. Sulfate attack on cement-stabilized sand

    SciTech Connect

    Rollings, R.S.; Burkes, J.P.; Rollings, M.P.

    1999-05-01

    A 3.5-km (2.2 mi) section of a road in Georgia developed unexpected transverse bumps within 6 months after construction. The source of the bumps appeared to be expansion within the cement-stabilized base course. Laboratory examination of samples from areas showing distress revealed the presence of ettringite, a calcium sulfoaluminate the formation of which can be accompanied by severe expansion. This expansive materials was the probable cause of the volume changes causing the transverse bumps. The calcium and alumina needed to form ettringite ware available from the portland cement and the stabilized soil`s clay minerals. The source of the sulfur was identified as the well water that was mixed with the cement-stabilized base. Sulfate attack of cement-stabilized soils is a relatively infrequent problem, but it is highly destructive when it occurs. Currently, there are no firm criteria for identifying when sulfate attack of a cement-stabilized soil is a potential problem nor are there established methods of preventing the attack.

  9. Field measurement and model prediction of infiltration in treated wastewater irrigated clayey soil

    NASA Astrophysics Data System (ADS)

    Albalasmeh, Ammar; Gharaibeh, Mamoun; Ghezzehei, Teamrat

    2016-04-01

    Soil water infiltration is a critical process in designing irrigation systems, especially if traded wastewater (TWW) is being used. In this study, the ability of seven different infiltration models (Kostiakov, Modified Kostiakov, Philip, Horton, Holaton, SCS (US-Soil Conservation Service) and Huggins and Monke) were compared to estimate and assess those models' parameters, and to evaluate their prediction ability for TWW irrigated soils. The field measurements were conducted in TWW irrigated soils using a hood infiltrometer. Six comparison criteria including Mean error, Geometric mean error, Root mean square error, Coefficient of determination, F-Statistic and Akaike information criterion were used to determine the best performing model with the least number of fitting parameters. The research indicated that three-parameter models had the best description of the relationship between cumulative infiltration and time in the researched TWW irrigated soils.

  10. Changes of lead speciation and microbial toxicity in soil treated with repeated Pb exposure in the presence of BDE209.

    PubMed

    Zhang, Rong; Zhang, Wei; Liu, Gao; Lin, Kuangfei; Fu, Rongbing

    2016-03-01

    Lead (Pb) and decabromodiphenyl ether (BDE209) are main pollutants at electric waste (e-waste) recycling sites (EWRSs), and their joint toxicological effects have received extensive attention. Frequently, soil pollution at EWRSs usually results from the occurrence of repeated single or multiple pollution events, with continuous impacts on soil microorganisms. Therefore, a laboratory incubation study was conducted to determine Pb bioavailability and microbial toxicity in repeated Pb-polluted soil in the presence of BDE209 for the first time. We evaluated the impacts of repetitive exposure trials on chemical fractions of Pb, and the results showed that repeated single Pb pollution event resulted in an increase of carbonates fraction of Pb, which was different from one-off single Pb exposure. Moreover, one-off Pb-treated groups exhibited higher I R (reduced partition index) values on day 30 and all treatments remained the same I R level at the end of incubation period. The parameters of microbial toxicity were well reflected by soil enzymes. During the entire incubation, the dehydrogenase and urease activities were significantly inhibited by Pb (P < 0.01), and BDE209 supply could weaken the adverse influence. Additionally, significant correlations between available or metastable Pb and the two soil enzymes were clearly observed (P < 0.05 or 0.01). Such observations would provide useful information for ecological effects of Pb and BDE209 at EWRSs.

  11. Phosphate-bonded calcium aluminate cements

    DOEpatents

    Sugama, Toshifumi

    1993-01-01

    A method is described for making a rapid-setting phosphate-bonded cementitious material. A powdered aluminous cement is mixed with an aqueous solution of ammonium phosphate. The mixture is allowed to set to form an amorphous cementitious material which also may be hydrothermally treated at a temperature of from about 120.degree. C. to about 300.degree. C. to form a crystal-containing phosphate-bonded material. Also described are the cementitious products of this method and the cement composition which includes aluminous cement and ammonium polyphosphate.

  12. Phosphate-bonded calcium aluminate cements

    DOEpatents

    Sugama, T.

    1993-09-21

    A method is described for making a rapid-setting phosphate-bonded cementitious material. A powdered aluminous cement is mixed with an aqueous solution of ammonium phosphate. The mixture is allowed to set to form an amorphous cementitious material which also may be hydrothermally treated at a temperature of from about 120 C to about 300 C to form a crystal-containing phosphate-bonded material. Also described are the cementitious products of this method and the cement composition which includes aluminous cement and ammonium polyphosphate. 10 figures.

  13. Heavy metal mobility in runoff water and absorption by eggplant fruits from sludge treated soil.

    PubMed

    Antonious, George F; Turley, Eric T; Sikora, Frank; Snyder, John C

    2008-08-01

    Sewage sludge addition to agricultural lands requires judicious management to avoid environmental risks arising from heavy metal and nitrate contamination of surface water and accumulation in edible plants. A field study was conducted on a silty-loam soil of 10% slope at Kentucky State University Research Farm. Eighteen plots of 22 x 3.7 m each were separated using metal borders and the soil in six plots was mixed with sewage sludge and yard waste compost mix (SS-YW) at 15 t acre(-1), six plots were mixed with sewage sludge (SS) at 15 t acre(-1), and six unamended plots that never received sludge were used for comparison purposes. Plots were planted with eggplant, Solanum melongena L. as the test plant. The objectives of this investigation were to: 1) assess the effect of soil amendments on the transport of NO3, NH4, and heavy metals (Cd, Cr, Ni, Pb, Zn, Cu, and Mo) into surface water; 2) investigate the effect of soil amendments on heavy metal bioavailability in eggplant fruits at harvest; and 3) assess chemical and physical properties of soil following addition of soil amendments and their impact on the yield and quality of eggplant fruit. SS-YW treatments reduced runoff water by 63% while plots incorporated with sewage sludge alone reduced runoff water by 37% compared to control treatment. The SS-YW treatments transported more mineral nitrogen (NO3-N and NH4-N) in runoff water than SS treatments. Total marketable yield (lbs acre(-1)) and number of eggplant fruits were greatest in SS-YW treatments. This response may be due to improved soil porosity, water, and nutrient retention of the soil amended with SS-YW mixture. Concentrations of heavy metals in soil amended with sludge were below the U.S. Environmental Protection Agency (USEPA) limits. Chromium, Ni, Zn, and Cu were taken up by eggplant fruits but their concentrations were below the Codex Commission allowable levels.

  14. Effect of interactions on the nutrient status of a tropical soil treated with green manures and inorganic phosphate fertilizers.

    PubMed

    Bah, Abdul R; Rahman, Zaharah A; Hussin, Aminuddin

    2004-06-01

    Integrated nutrient management systems using plant residues and inorganic P fertilizers have high potential for increasing crop production and ensuring sustainability in the tropics, but their adoption requires in-depth understanding of nutrient dynamics in such systems. This was examined in a highly weathered tropical soil treated with green manures (GMs) and P fertilizers in two experiments conducted in the laboratory and glasshouse. The treatments were factorial combinations of the GMs (Calopogonium caeruleum, Gliricidia sepium, and Imperata cylindrica) and P fertilizers (phosphate rocks [PRs] from North Carolina, China, and Algeria, and triple superphosphate) replicated thrice. Olsen P, mineral N, pH, and exchangeable K, Ca, and Mg were monitored in a laboratory incubation study for 16 months. The change in soil P fractions and available P was also determined at the end of the study. Phosphorus available from the amendments was quantified at monthly intervals for 5 months by 33P-32P double isotopic labeling in the glasshouse using Setaria sphacelata as test crop. The GMs were labeled with 33P to determine their contribution to P taken up by Setaria, while that from the P fertilizers was indirectly measured by labeling the soil with 32P. The P fertilizers hardly changed Olsen P and exchangeable cations during 16 months of incubation. The legume GMs and legume GM+P did not change Olsen P, lowered exchangeable Ca, and increased exchangeable K about threefold (4.5 cmol[+]kg(-1) soil) in the first 4 months, even as large amounts of NH4-N accumulated (approximately 1000 mg kg soil(-1)) and soil pH increased to more than 6.5. Afterwards, Olsen P and exchangeable Ca and Mg increased (threefold) as NH4+-N and soil pH declined. The legume GMs also augmented reversibly sorbed P in Al-P and Fe-P fractions resulting in high residual effect in the soil, while fertilizer-P was irreversibly retained. The GMs increased PR-P utilization by 40 to over 80%, mobilized soil P, and

  15. CCA transport in soil from treated-timber posts: pattern dynamics from the local to regional scale

    NASA Astrophysics Data System (ADS)

    Clothier, B. E.; Green, S. R.; Vogeler, I.; Greven, M. M.; Agnew, R.; van den Dijssel, C. W.; Neal, S.; Robinson, B. H.; Davidson, P.

    2006-08-01

    Winegrape growing in many parts of the world, including Marlborough, New Zealand, uses treated-timber posts to act as supports for the grapevine's canopy. At a density of 580 posts per hectare, the H4-process treated supports result in an areal loading of CCA of: Copper (12 kg-Cu ha-1), Chromium (21 kg-Cr ha-1) and Arsenic (17 kg-As ha-1). Arsenic is the most mobile and toxic of the CCA-treatment cocktail. We describe experiments which indicate that about 4-6 mg-As month-1 post-1 is released from the subterranean part of the post. We have used SPASMO (Soil Plant Atmosphere System Model) to predict post-to-soil leakage, as well as the pattern dynamics of leaching and exchange around the post. Locally the pattern dynamics of transport and fate are controlled by the soil's chemical characteristics and the prevailing weather. Over its 20-year lifetime, the concentration of arsenic, both that adsorbed on the soil and in the soil solution, exceeds guideline values for soils (100 mg-As kg-1) and drinking water (10 μg-As L-1). Under a regime of 5% annual replacement of posts, the spatially averaged concentration of arsenic leaching through the soil is predicted to rise to 1.25 to 1.7 times the drinking water standard, depending only slightly on the soil type. The steady value is primarily controlled by the arsenic-release rate from the post. These steady values were used in a simple hydrogeological model of the major Marlborough aquifer systems to determine whether the subterranean flow of water could dilute the descending plumes of arsenic coming from above. Except for the sluggish aquifers of the southern valleys in Marlborough, most of the aquifer systems seem capable of diluting the leachate to between one tenth and one twentieth of the drinking water standard. The upscaling of our modelling of the local pattern dynamics spanned six orders of spatial magnitude, and four orders of time dimension.

  16. TRACE ELEMENT CHEMISTRY IN RESIDUAL-TREATED SOIL: KEY CONCEPTS AND METAL BIOAVAILABILITY

    EPA Science Inventory

    Trace element solubility and availability in land-applied residuals is governed by fundamental chemical reactions between metal constituents, soil, and residual components. Iron, aluminum, and manganese oxides; organic matter; and phosphates, carbonates, and sulfides are importan...

  17. An assessment of fracture resistance of three composite resin core build-up materials on three prefabricated non-metallic posts, cemented in endodontically treated teeth: an in vitro study

    PubMed Central

    Pal, Bhupinder; Pujari, Prashant

    2015-01-01

    Endodontically treated teeth with excessive loss of tooth structure would require to be restored with post and core to enhance the strength and durability of the tooth and to achieve retention for the restoration. The non-metallic posts have a superior aesthetic quality. Various core build-up materials can be used to build-up cores on the posts placed in endodontically treated teeth. These materials would show variation in their bonding with the non-metallic posts thus affecting the strength and resistance to fracture of the remaining tooth structure. Aims. The aim of the study was to assess the fracture resistance of three composite resin core build-up materials on three prefabricated non-metallic posts, cemented in extracted endodontically treated teeth. Material and Methods. Forty-five freshly extracted maxillary central incisors of approximately of the same size and shape were selected for the study. They were divided randomly into 3 groups of 15 each, depending on the types of non-metallic posts used. Each group was further divided into 3 groups (A, B and C) of 5 samples each depending on three core build-up material used. Student’s unpaired ‘t’ test was also used to analyse and compare each group with the other groups individually, and decide whether their comparisons were statistically significant. Results. Luxacore showed the highest fracture resistance among the three core build-up materials with all the three posts systems. Ti-core had intermediate values of fracture resistance and Lumiglass had the least values of fracture resistance. PMID:25755926

  18. ULTRA-LIGHTWEIGHT CEMENT

    SciTech Connect

    Fred Sabins

    2003-10-31

    The objective of this project is to develop an improved ultra- lightweight cement using ultra-lightweight hollow glass spheres (ULHS). This report discusses testing that was performed for analyzing the alkali-silica reactivity of ULHS in cement slurries.

  19. The survival of Escherichia coli, faecal coliforms and enterobacteriaceae in general in soil treated with sludge from wastewater treatment plants.

    PubMed

    Estrada, I B; Aller, A; Aller, F; Gómez, X; Morán, A

    2004-06-01

    We monitored the effect of the application of treated sludge on the behaviour of enterobacteriaceae (mainly faecal coliforms and especially Escherichia coli) in the soil, and studied their evolution over time after application. Three different sludges were used: two from a municipal sewage plant, one of them had been subjected to anaerobic digestion and heat drying, and the other to anaerobic digestion and mechanical dehydration, and one from a dairy waste treatment to aerobic digestion and gravity thickening. Two types of tests were carried out: type O, in the open air, with no possibility of controlling humidity or temperature; and type L, under laboratory conditions, with controlled temperature and humidity. Sludge tests were also run on unscreened soil previously treated with chemical fertilizer. After 80 days of experimentation the populations of faecal coliforms and E. coli had decreased considerably or were undetectable in assays carried out on the soil/sludge mixtures, under both open-air and laboratory conditions, but that, over the same period, in the mixtures containing chemical fertilizer (calcium ammonium nitrate) there had been a considerable increase in the micro-organism populations studied. PMID:15051081

  20. Changes in the chemical composition of an acidic soil treated with marble quarry and marble cutting wastes.

    PubMed

    Tozsin, Gulsen; Oztas, Taskin; Arol, Ali Ihsan; Kalkan, Ekrem

    2015-11-01

    Soil acidity greatly affects the availability of plant nutrients. The level of soil acidity can be adjusted by treating the soil with certain additives. The objective of this study was to determine the effect of marble quarry waste (MQW) and marble cutting waste (MCW) on the chemical composition and the acidity of a soil. Marble wastes at different rates were applied to an acid soil. Their effectiveness in neutralizing the soil pH was compared with that of agricultural lime. The changes in the chemical composition of the soil were also evaluated with column test at the end of a 75-day incubation period. The results indicated that the MQW and MCW applications significantly increased the soil pH (from 4.71 up to 6.54), the CaCO3 content (from 0.33% up to 0.75%), and the exchangeable Ca (from 14.79 cmol kg(-1) up to 21.18 cmol kg(-1)) and Na (from 0.57 cmol kg(-1) up to 1.07 cmol kg(-1)) contents, but decreased the exchangeable K (from 0.46 cmol kg(-1) down to 0.28 cmol kg(-1)), the plant-available P (from 25.56 mg L(-1) down to 16.62 mg L(-1)), and the extractable Fe (from 259.43 mg L(-1) down to 55.4 mg L(-1)), Cu (from 1.97 mg L(-1) down to 1.42 mg L(-1)), Mn (from 17.89 mg L(-1) down to 4.61 mg L(-1)) and Zn (from 7.88 mg L(-1) down to 1.56 mg L(-1)) contents. In addition, the Cd (from 0.060 mg L(-1) down to 0.046 mg L(-1)), Ni (from 0.337 mg L(-1) down to 0.092 mg L(-1)) and Pb (from 28.00 mg L(-1) down to 20.08 mg L(-1)) concentrations decreased upon the treatment of the soil with marble wastes.

  1. Changes in the chemical composition of an acidic soil treated with marble quarry and marble cutting wastes.

    PubMed

    Tozsin, Gulsen; Oztas, Taskin; Arol, Ali Ihsan; Kalkan, Ekrem

    2015-11-01

    Soil acidity greatly affects the availability of plant nutrients. The level of soil acidity can be adjusted by treating the soil with certain additives. The objective of this study was to determine the effect of marble quarry waste (MQW) and marble cutting waste (MCW) on the chemical composition and the acidity of a soil. Marble wastes at different rates were applied to an acid soil. Their effectiveness in neutralizing the soil pH was compared with that of agricultural lime. The changes in the chemical composition of the soil were also evaluated with column test at the end of a 75-day incubation period. The results indicated that the MQW and MCW applications significantly increased the soil pH (from 4.71 up to 6.54), the CaCO3 content (from 0.33% up to 0.75%), and the exchangeable Ca (from 14.79 cmol kg(-1) up to 21.18 cmol kg(-1)) and Na (from 0.57 cmol kg(-1) up to 1.07 cmol kg(-1)) contents, but decreased the exchangeable K (from 0.46 cmol kg(-1) down to 0.28 cmol kg(-1)), the plant-available P (from 25.56 mg L(-1) down to 16.62 mg L(-1)), and the extractable Fe (from 259.43 mg L(-1) down to 55.4 mg L(-1)), Cu (from 1.97 mg L(-1) down to 1.42 mg L(-1)), Mn (from 17.89 mg L(-1) down to 4.61 mg L(-1)) and Zn (from 7.88 mg L(-1) down to 1.56 mg L(-1)) contents. In addition, the Cd (from 0.060 mg L(-1) down to 0.046 mg L(-1)), Ni (from 0.337 mg L(-1) down to 0.092 mg L(-1)) and Pb (from 28.00 mg L(-1) down to 20.08 mg L(-1)) concentrations decreased upon the treatment of the soil with marble wastes. PMID:26246275

  2. Speciation and phytoavailability of cadmium in soil treated with cadmium-contaminated rice straw.

    PubMed

    Wang, Shuai; Huang, Dao-You; Zhu, Qi-Hong; Zhu, Han-Hua; Liu, Shou-Long; Luo, Zun-Chang; Cao, Xiao-Ling; Wang, Ji-Yu; Rao, Zhong-Xiu; Shen, Xin

    2015-02-01

    When grown on Cd-contaminated soil, rice typically accumulates considerable Cd in straw, and which may return to the soil after harvest. This work was undertaken to assess the pollution risk of Cd associated to the Cd-contaminated rice straw after incorporating into an uncontaminated soil. With the Cd-contaminated rice straw added at 0, 1, 2, 3, 4 and 5 % (w/w), an incubation experiment (28 days) with non-planting and a followed pot experiment sequent with two planting (rice and Chinese cabbage, transplanted after 28-day incubation) were carried out to investigate the changes of soil Cd speciation and phytoavailability. The results indicated that the Cd-contaminated rice straw addition significantly increased soil pH and dissolved organic carbon during the 28-day incubation. For the high availability of Cd in contaminated rice straw, diethylenetriaminepentaacetic acid (DTPA) extractable Cd significantly increased, and the percentages of acetic acid extractable and reducible Cd in soil significantly enhanced after the addition of Cd-contaminated rice straw. However, the Cd-contaminated rice straw addition inhibited the rice growth and induced the decrease of Cd in rice grain and straw by 12.8 to 70.2 % and 39.3 to 57.3 %, respectively, whereas the Cd contents increased by 13.9 to 84.1 % in Chinese cabbage that planted after rice harvest. In conclusion, Cd associated with Cd-contaminated rice straw was highly available after incorporating into the soil, and thus the Cd pollution risk via the Cd-contaminated rice straw incorporation should be evaluated in the Cd-contaminated paddy region.

  3. Pyrosequence analysis of bacterial communities in aerobic bioreactors treating polycyclic aromatic hydrocarbon-contaminated soil

    PubMed Central

    Richardson, Stephen D.; Aitken, Michael D.

    2011-01-01

    Two aerobic, lab-scale, slurry-phase bioreactors were used to examine the biodegradation of polycyclic aromatic hydrocarbons (PAHs) in contaminated soil and the associated bacterial communities. The two bioreactors were operated under semi-continuous (draw-and-fill) conditions at a residence time of 35 days, but one was fed weekly and the other monthly. Most of the quantified PAHs, including high-molecular-weight compounds, were removed to a greater extent in the weekly-fed bioreactor, which achieved total PAH removal of 76%. Molecular analyses, including pyrosequencing of 16S rRNA genes, revealed significant shifts in the soil bacterial communities after introduction to the bioreactors and differences in the abundance and types of bacteria in each of the bioreactors. The weekly-fed bioreactor displayed a more stable bacterial community with gradual changes over time, whereas the monthly-fed bioreactor community was less consistent and may have been more strongly influenced by the influx of untreated soil during feeding. Phylogenetic groups containing known PAH-degrading bacteria previously identified through stable-isotope probing of the untreated soil were differentially affected by bioreactor conditions. Sequences from members of the Acidovorax and Sphingomonas genera, as well as the uncultivated ‘‘Pyrene Group 2’’ were abundant in the bioreactors. However, the relative abundances of sequences from the Pseudomonas, Sphingobium, and Pseudoxanthomonas genera, as well as from a group of unclassified anthracene degraders, were much lower in the bioreactors compared to the untreated soil. PMID:21369833

  4. Behavioral Effects and Tunneling Responses of Eastern Subterranean Termites (Isoptera: Rhinotermitidae) Exposed to Chlorantraniliprole-Treated Soils.

    PubMed

    Saran, Raj K; Ziegler, Melissa; Kudlie, Sara; Harrison, Danielle; Leva, David M; Scherer, Clay; Coffelt, Mark A

    2014-10-01

    Intrinsic toxicities of chlorantraniliprole, fipronil, and imidacloprid were evaluated with topical applications on worker termites. Worker termites were exposed to substrates treated with formulated chlorantraniliprole to study contact toxicity, tunneling, and postexposure behaviors. The intrinsic toxicities (LD50, ng/termite) of chlorantraniliprole (1.25, 0.96, and 0.44) and fipronil (0.12, 0.11, and 0.13) at 11 d were similar for workers from three termite colonies. Imidacloprid toxicity (LD50) values were highly variable among the workers from three different colonies, values at 11 d ranging from 0.7 to 75 ng/termite. Termite workers exposed to sand and soils treated with chlorantraniliprole at 50 ppm exhibited delayed mortality and, for most of the exposure times, it took >5 d to observe 90-100% mortality in termite workers. Exposure to chlorantraniliprole-treated sand (50 ppm) for as little as 1 min stopped feeding and killed 90-100% of the workers. Tunneling (≈ 2 h) in different soil types treated with chlorantraniliprole at 50 ppm, even those with high organic matter (6.3%) and clay content (30%), caused immediate feeding cessation in worker termites and mortality in the next 7-14 d. Worker termites exposed for 1 and 60 min to sand treated with chlorantraniliprole (50 ppm) were able to walk normally for 4 h after exposure in most cases. Delayed toxicity, increased aggregation, and grooming were observed in exposed termites and discussed in the context of horizontal transfer effects within termite colonies.

  5. DRIFT and HR MAS NMR characterization of humic substances from a soil treated with different organic and mineral fertilizers

    NASA Astrophysics Data System (ADS)

    Ferrari, Erika; Francioso, Ornella; Nardi, Serenella; Saladini, Monica; Ferro, Nicola Dal; Morari, Francesco

    2011-07-01

    In this study, using DRIFT and HR MAS NMR, we analyzed the humic substances isolated from a soil treated, over 40 years, with different organic, mineral and organic plus mineral treatments and cultivated with maize as the main crop. As expected, the structure of humic substances was very complex but by combining both techniques (DRIFT and HR MAS NMR) additional information was obtained on aromatic and aliphatic components, the most recalcitrant parts of these macromolecules. In so doing we wanted to investigate the relationship between HS structure and long-term management practices. An elevated content of lignin, aminoacids, peptides and proteins was observed mainly for farmyard manure treatments with respect to mineral or liquid manure amendments; this supports how the different management practices have greatly influenced the humification process of cultivated soils.

  6. Experimental evaluation of four infiltration models for calcareous soil irrigated with treated untreated grey water and fresh water

    NASA Astrophysics Data System (ADS)

    Gharaibeh, M. A.; Eltaif, N. I.; Alrababah, M. A.; Alhamad, M. N.

    2009-04-01

    Infiltration is vital for both irrigated and rainfed agriculture. The knowledge of infiltration characteristics of a soil is the basic information required for designing an efficient irrigation system. The objective of the present study was to model soil infiltration using four models: Green and Ampt, Horton, Kostaikov and modified Kostiakov. Infiltration tests were conducted on field plot irrigated with treated, untreated greywater and fresh water. The field water infiltration data used in these models were based on double ring infiltrometer tests conducted for 4 h. The algebraic parameters of the infiltration models and nonlinear least squares regression were fitted using measured infiltration time [I (t)] data. Among process-based infiltration models, the Horton model performed best and matched the measured I (t) data with lower sum of squares (SS).

  7. Lunar cement and lunar concrete

    NASA Technical Reports Server (NTRS)

    Lin, T. D.

    1991-01-01

    Results of a study to investigate methods of producing cements from lunar materials are presented. A chemical process and a differential volatilization process to enrich lime content in selected lunar materials were identified. One new cement made from lime and anorthite developed compressive strengths of 39 Mpa (5500 psi) for 1 inch paste cubes. The second, a hypothetical composition based on differential volatilization of basalt, formed a mineral glass which was activated with an alkaline additive. The 1 inch paste cubes, cured at 100C and 100 percent humidity, developed compressive strengths in excess of 49 Mpa (7100 psi). Also discussed are tests made with Apollo 16 lunar soil and an ongoing investigation of a proposed dry mix/steam injection procedure for casting concrete on the Moon.

  8. Composition of a Spanish sewage sludge and effects on treated soil and olive trees.

    PubMed

    Gascó, G; Lobo, M C

    2007-01-01

    The effects of sewage sludge (SL) application on the soil and olive trees (Olea europaea L., cultivar: cornicabra) were studied. The plants were grown in 8.5L pots and subjected to the following treatments: 0, 3.66, 7.32, 14.65, 29.3, 58.6, and 117.2 g SL kg(-1) soil that corresponded, respectively, to 0, 4, 8, 16, 32, 64 and 128 M g ha(-1) dry weight of sewage sludge. The application of SL at the rates 64 and 128 M g ha(-1) produced leaf tip burning and leaf drop after 120 days, although cumulative metal pollutant loading rates was below USEPA and European regulations. This toxicity symptom could be caused by the high sodium levels in the leaves (over 0.19%), which can damage olive tree development. The Na contents of leaves were well correlated with soil Na content (r2: 0.91). In general, SL rates significantly increased the level of Cr, Ni, Cu, Zn, Cd and Pb in soil and plants, but these concentrations were in the normal ranges, except for the Zn concentration, which was over the critical soil content for the rates of 32, 64, 128 Mg ha(-1) but not in the leaves. Results suggested that regulations about the utilization of sewage sludge on agricultural land should consider the limit values for salt, and not only metals, that may be added to soil, in order to minimize the risk of negative effects to plant health. PMID:17049835

  9. Water Repellency Effects on Water Retention in Heat Pre-treated Volcanic Ash Soil

    NASA Astrophysics Data System (ADS)

    Chhoden, T.; Karunarathna, A.; Kawamoto, K.; Komatsu, T.; Moldrup, P.

    2009-12-01

    Water repellency (WR) in soil is a common phenomenon after forest fires all over the world. It can induce hydrological problems such as preferential flow in soils and reduced water infiltration rate which in turn can lead to surface runoff and erosion. In this study, we examined the hydrophobicity for pre-heated volcanic ash soil samples with different temperatures between 60 and 200oC and non pre-heated samples (20oC) from a single surface soil profile down to 25 cm depth. Moreover, the pre-heated samples were used to investigate the effects of pre-heat treatment and hydrophobic severity on soil-water retention properties. We first assessed the degree of water repellency for pre-heated samples by the Water Droplet Penetration Time test and Molarity of Ethanol Droplet test and categorized the water repellency into four different classes (extremely, severely, strongly and non-WR) as proposed by Bisdom et al. (1993). The depth profiles of soil organic carbon (SOC) content for the pre-heated samples were also measured. Results showed the categorized WR classes changed depending on pre-heated temperatures and residual SOC contents. For top surface soil with 0-5cm depth, pre-heated samples at 105, 125, 150 and 175oC exhibited extremely WR, pre-heated samples at 60oC exhibited severely WR, non pre-heated samples (20oC) exhibited strongly WR, and pre-heated samples at 200oC exhibited non-WR. Moreover, the threshold value of SOC above which WR occurs was found to be around 7.4% based on the measured WR classes and SOC profiles. The water supply/drainage controlled hanging column setup equipped with a newly-developed mini tensiometer-TDR coil probe (5 cm in length and 0.5 cm in diameter) was used to measure wetting and drying processes of the soil-water retention curves (SWRCs) for the pre-heated samples. Results showed that the SWRCs on the wetting process were highly affected by the degree of water repellency. Clear water-entry pressures (hwe) were observed in the SWRCs

  10. Increased bioavailability of metals in two contrasting agricultural soils treated with waste wood-derived biochar and ash.

    PubMed

    Lucchini, P; Quilliam, R S; Deluca, T H; Vamerali, T; Jones, D L

    2014-03-01

    Recycled waste wood is being increasingly used for energy production; however, organic and metal contaminants in by-products produced from the combustion/pyrolysis residue may pose a significant environmental risk if they are disposed of to land. Here we conducted a study to evaluate if highly polluted biochar (from pyrolysis) and ash (from incineration) derived from Cu-based preservative-treated wood led to different metal (e.g., Cu, As, Ni, Cd, Pb, and Zn) bioavailability and accumulation in sunflower (Helianthus annuus L.). In a pot experiment, biochar at a common rate of 2 % w/w, corresponding to ∼50 t ha(-1), and an equivalent pre-combustion dose of wood ash (0.2 % w/w) were added to a Eutric Cambisol (pH 6.02) and a Haplic Podzol (pH 4.95), respectively. Both amendments initially raised soil pH, although this effect was relatively short-term, with pH returning close to the unamended control within about 7 weeks. The addition of both amendments resulted in an exceedance of soil Cu statutory limit, together with a significant increase of Cu and plant nutrient (e.g., K) bioavailability. The metal-sorbing capacity of the biochar, and the temporary increase in soil pH caused by adding the ash and biochar were insufficient to offset the amount of free metal released into solution. Sunflower plants were negatively affected by the addition of metal-treated wood-derived biochar and led to elevated concentration of metals in plant tissue, and reduced above- and below-ground biomass, while sunflower did not grow at all in the Haplic Podzol. Biochar and ash derived from wood treated with Cu-based preservatives can lead to extremely high Cu concentrations in soil and negatively affect plant growth. Identifying sources of contaminated wood in waste stream feedstocks is crucial before large-scale application of biochar or wood ash to soil is considered.

  11. Increased bioavailability of metals in two contrasting agricultural soils treated with waste wood-derived biochar and ash.

    PubMed

    Lucchini, P; Quilliam, R S; Deluca, T H; Vamerali, T; Jones, D L

    2014-03-01

    Recycled waste wood is being increasingly used for energy production; however, organic and metal contaminants in by-products produced from the combustion/pyrolysis residue may pose a significant environmental risk if they are disposed of to land. Here we conducted a study to evaluate if highly polluted biochar (from pyrolysis) and ash (from incineration) derived from Cu-based preservative-treated wood led to different metal (e.g., Cu, As, Ni, Cd, Pb, and Zn) bioavailability and accumulation in sunflower (Helianthus annuus L.). In a pot experiment, biochar at a common rate of 2 % w/w, corresponding to ∼50 t ha(-1), and an equivalent pre-combustion dose of wood ash (0.2 % w/w) were added to a Eutric Cambisol (pH 6.02) and a Haplic Podzol (pH 4.95), respectively. Both amendments initially raised soil pH, although this effect was relatively short-term, with pH returning close to the unamended control within about 7 weeks. The addition of both amendments resulted in an exceedance of soil Cu statutory limit, together with a significant increase of Cu and plant nutrient (e.g., K) bioavailability. The metal-sorbing capacity of the biochar, and the temporary increase in soil pH caused by adding the ash and biochar were insufficient to offset the amount of free metal released into solution. Sunflower plants were negatively affected by the addition of metal-treated wood-derived biochar and led to elevated concentration of metals in plant tissue, and reduced above- and below-ground biomass, while sunflower did not grow at all in the Haplic Podzol. Biochar and ash derived from wood treated with Cu-based preservatives can lead to extremely high Cu concentrations in soil and negatively affect plant growth. Identifying sources of contaminated wood in waste stream feedstocks is crucial before large-scale application of biochar or wood ash to soil is considered. PMID:24217969

  12. Experimental study of the relationship between formation factor, porosity, and cementation

    SciTech Connect

    Harig, M.D.; Chaney, R.C.

    1999-07-01

    Cemented granular soils are classified based on the size and distribution of the individual grains and qualitatively on the basis of cementation. To uniquely classify these types of soils, information about the fabric (pore geometry and/or level of cementation) of the specimen needs to be quantified. Electrical resistivity, or its reciprocal, conductivity, methods have been extensively used both in situ and in the laboratory to provide a means for determining a variety of soil index, structural, erosional, and cyclic properties. The objective of this study was to determine the relationship between formation factor (F), porosity (n), and cementation factor (m) of remolded sand-cement specimens. This relationship is shown to provide a mechanism for estimating the level of cementation in undisturbed specimens. The formation factor is the ratio of the electrical resistivity of the sand-water-cement mixture to that of the interstitial water.

  13. Infiltration and Erosion in Soils Treated with Dry PAM of Two Molecular Weights and Phosphogypsum

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil surface application of dissolved linear polyacrylamide (PAM) of high molecular weight (MW) can mitigate seal formation, runoff and erosion, especially when added with a source of electrolytes (e.g., gypsum). Practical difficulties associated with PAM solution application prohibited commercial u...

  14. EXPERIMENTS WITH A RESIN-IN-PULP PROCESS FOR TREATING LEAD-CONTAMINATED SOIL

    EPA Science Inventory

    This paper presents the results of experiments to evaluate the potential for using a resin-in-pulp process to remove lead contamination from soil. These experiments examined the kinetics and equilibrium partitioning of lead, lead carbonate, lead oxide, and lead sulfate in resin-s...

  15. Nitrate and phosphate leaching in a Phaeozem soil treated with biosolids, composted biosolids and inorganic fertilizers.

    PubMed

    Esteller, M V; Martínez-Valdés, H; Garrido, S; Uribe, Q

    2009-06-01

    The use of organic wastes in agriculture may increase the production of crops by incorporating organic matter and nutrients into the soil, and by improving its physical characteristics; however, this use may cause environmental problems such as the leaching of certain ions. The objective of this study was to establish possible nitrogen and phosphorus leaching under real field conditions in Phaeozem soils. The experimental work was performed in a corn (Zea mays L.) field where three plots were conditioned with inorganic fertilizer, three plots with 4.5 Mgha(-1) of biosolids on dry basis, and three plots with the same amount of composted biosolids. The quality of biosolids and composted biosolids complied with the Mexican Official Standards. Soil water samples were collected with suction cups during two agricultural cycles and were analysed. Soil samples were also taken and analysed. The N-NO(3) concentrations in soil water fluctuated between 0.9 and 98mgL(-1) in the composted biosolid treatment, between 0.7 and 64 mgL(-1) in the biosolid treatment, and between 1 and 61 mgL(-1) in the inorganic fertilizer treatment. The maximum concentration of N-NO(2) and N-NH(3) in soil water was 1.02 and 2.65 mgL(-1), respectively. The greatest percentage of nitrogen leached is produced when inorganic fertilizer is used (37.4% and 24.0% N leached in the first and second years, respectively), followed by composted biosolids (17.1% and 13.5% N leached in the first and second years, respectively) and last by biosolids (11% for both years). This difference could be related to the form in which nitrogen is present in the fertilizers, while commercial fertilizer is as inorganic nitrogen, organic wastes are basically presented as organic nitrogen. The maximum PO(4)(3-) concentration in soil water was 1.9 mgL(-1) in the composted biosolid treatment, 1.7mgL(-1) in the biosolid treatment and 0.9 mgL(-1) in the inorganic fertilizer treatment. The estimated percentage of leached phosphorus

  16. Nitrate and phosphate leaching in a Phaeozem soil treated with biosolids, composted biosolids and inorganic fertilizers.

    PubMed

    Esteller, M V; Martínez-Valdés, H; Garrido, S; Uribe, Q

    2009-06-01

    The use of organic wastes in agriculture may increase the production of crops by incorporating organic matter and nutrients into the soil, and by improving its physical characteristics; however, this use may cause environmental problems such as the leaching of certain ions. The objective of this study was to establish possible nitrogen and phosphorus leaching under real field conditions in Phaeozem soils. The experimental work was performed in a corn (Zea mays L.) field where three plots were conditioned with inorganic fertilizer, three plots with 4.5 Mgha(-1) of biosolids on dry basis, and three plots with the same amount of composted biosolids. The quality of biosolids and composted biosolids complied with the Mexican Official Standards. Soil water samples were collected with suction cups during two agricultural cycles and were analysed. Soil samples were also taken and analysed. The N-NO(3) concentrations in soil water fluctuated between 0.9 and 98mgL(-1) in the composted biosolid treatment, between 0.7 and 64 mgL(-1) in the biosolid treatment, and between 1 and 61 mgL(-1) in the inorganic fertilizer treatment. The maximum concentration of N-NO(2) and N-NH(3) in soil water was 1.02 and 2.65 mgL(-1), respectively. The greatest percentage of nitrogen leached is produced when inorganic fertilizer is used (37.4% and 24.0% N leached in the first and second years, respectively), followed by composted biosolids (17.1% and 13.5% N leached in the first and second years, respectively) and last by biosolids (11% for both years). This difference could be related to the form in which nitrogen is present in the fertilizers, while commercial fertilizer is as inorganic nitrogen, organic wastes are basically presented as organic nitrogen. The maximum PO(4)(3-) concentration in soil water was 1.9 mgL(-1) in the composted biosolid treatment, 1.7mgL(-1) in the biosolid treatment and 0.9 mgL(-1) in the inorganic fertilizer treatment. The estimated percentage of leached phosphorus

  17. Effect of eugenol and non-eugenol containing temporary cement on permanent cement retention and microhardness of cured composite resin.

    PubMed

    Bayindir, Funda; Akyil, M Samil; Bayindir, Yusuf Ziya

    2003-12-01

    This present study had three aims: 1) to evaluate the bond strengths of carboxylate and resin cements in cementing cast Co-Cr crowns to pretreatment of composite resin cores with eugenol and non-eugenol containing temporary cements, 2) to determine the microhardness of composite resin treated with temporary cement, 3) to view the surface differences of composite resin with SEM. The composite cores were divided into three experimental groups for the following pretreatments: Group 1, No treatment was provided, Group 2, The external walls of the composite cores were covered with eugenol-containing temporary cement, Group 3, The external walls of the composite cores were covered with non-eugenol containing temporary cement. Analysis of variance results showed that there was a significant difference between all three groups. Temporary cement with eugenol was significantly reduced the bond strength of full crown casting with resin cement compared with non-eugenol. The resin specimens treated with the eugenol-containing temporary cement showed the lowest microhardness values, the non-eugenol-containing temporary cement was not significantly different from those of the control groups. PMID:15005235

  18. Survival, Pb-uptake and behaviour of three species of earthworm in Pb treated soils determined using an OECD-style toxicity test and a soil avoidance test.

    PubMed

    Langdon, Caroline J; Hodson, Mark E; Arnold, Rebecca E; Black, Stuart

    2005-11-01

    Mature (clitellate) Eisenia andrei Bouché (ultra epigeic), Lumbricus rubellus Hoffmeister (epigeic), and Aporrectodea caliginosa (Savigny) (endogeic) earthworms were placed in soils treated with Pb(NO(3))(2) to have concentrations in the range 1,000 to 10,000 mg Pb kg(-1). After 28 days LC50(-95%confidence limit)(+95%confidence limit) values were E. andrei 5824(-361)(+898) mg Pb kg(-1), L. rubellus 2867(-193)(+145) mg Pb kg(-1) and A. caliginosa2747(-304)(+239) mg Pb kg(-1) and EC50s for weight change were E. andrei2841(-68)(+150) mg Pb kg(-1), L. rubellus1303(-201)(+240) mg Pb kg(-1) and A. caliginosa1208(-206)(+212) mg Pb kg(-1). At any given soil Pb concentration, Pb tissue concentrations after 28 days were the same for all three earthworm species. In a soil avoidance test there was no difference between the behaviour of the different species. The lower sensitivity to Pb exhibited by E. andrei is most likely due to physiological adaptations associated with the modes of life of the earthworms, and could have serious implications for the use of this earthworm as the species of choice in standard toxicological testing. PMID:15951078

  19. Valorization of a treated soil via amendments: fractionation and oral bioaccessibility of Cu, Ni, Pb, and Zn.

    PubMed

    Zagury, Gerald J; Rincon Bello, Jhony A; Guney, Mert

    2016-04-01

    The present study aims to transform a treated soil (TS) into a more desirable resource by modifying physico-chemical properties via amendments while reducing toxic metals' mobility and oral bioaccessibility. A hydrocarbon-contaminated soil submitted to treatment (TS) but still containing elevated concentrations of Cu, Ni, Pb, and Zn has been amended with compost, sand, and Al2(SO4)3 to render it usable for horticulture. Characterization and sequential extraction were performed for TS and four amended mixtures (AM1-4). P and K availability and metal bioaccessibility were investigated in TS and AM2. Amendment improved soil properties for all mixtures and yielded a usable product (AM2 20 % TS, 49 % compost, 30 % sand, 1 % Al2(SO4)3) satisfying regulatory requirements except for Pb content. In particular, AM2 had improved organic matter (OM) and cation exchange capacity (CEC), highly increased P and K availability, and reduced total metal concentrations. Furthermore, amendment decreased metal mobile fraction likely to be plant-available (in mg kg(-1), assumed as soluble/exchangeable + carbonates fractions). For AM2, estimated Pb bioavailability decreased from 1.50 × 10(3) mg kg(-1) (TS) to 238 mg kg(-1) (52.4 % (TS) to 34.2 %). Bioaccessible concentrations of Cu, Ni, and Zn (mg kg(-1)) were lower in AM2 than in TS, but there was no significant decrease for Pb. The results suggest that amendment improved soil by modifying its chemistry, resulting in lower metal mobile fraction (in %, for Cu and Zn) and bioaccessibility (in %, for Cu only). Amending soils having residual metal contamination can be an efficient valorization method, indicating potential for reducing treatment cost and environmental burden by rendering disposal/additional treatment unnecessary. Further studies including plant bioavailability are recommended to confirm results. PMID:26969154

  20. Valorization of a treated soil via amendments: fractionation and oral bioaccessibility of Cu, Ni, Pb, and Zn.

    PubMed

    Zagury, Gerald J; Rincon Bello, Jhony A; Guney, Mert

    2016-04-01

    The present study aims to transform a treated soil (TS) into a more desirable resource by modifying physico-chemical properties via amendments while reducing toxic metals' mobility and oral bioaccessibility. A hydrocarbon-contaminated soil submitted to treatment (TS) but still containing elevated concentrations of Cu, Ni, Pb, and Zn has been amended with compost, sand, and Al2(SO4)3 to render it usable for horticulture. Characterization and sequential extraction were performed for TS and four amended mixtures (AM1-4). P and K availability and metal bioaccessibility were investigated in TS and AM2. Amendment improved soil properties for all mixtures and yielded a usable product (AM2 20 % TS, 49 % compost, 30 % sand, 1 % Al2(SO4)3) satisfying regulatory requirements except for Pb content. In particular, AM2 had improved organic matter (OM) and cation exchange capacity (CEC), highly increased P and K availability, and reduced total metal concentrations. Furthermore, amendment decreased metal mobile fraction likely to be plant-available (in mg kg(-1), assumed as soluble/exchangeable + carbonates fractions). For AM2, estimated Pb bioavailability decreased from 1.50 × 10(3) mg kg(-1) (TS) to 238 mg kg(-1) (52.4 % (TS) to 34.2 %). Bioaccessible concentrations of Cu, Ni, and Zn (mg kg(-1)) were lower in AM2 than in TS, but there was no significant decrease for Pb. The results suggest that amendment improved soil by modifying its chemistry, resulting in lower metal mobile fraction (in %, for Cu and Zn) and bioaccessibility (in %, for Cu only). Amending soils having residual metal contamination can be an efficient valorization method, indicating potential for reducing treatment cost and environmental burden by rendering disposal/additional treatment unnecessary. Further studies including plant bioavailability are recommended to confirm results.

  1. ULTRA-LIGHTWEIGHT CEMENT

    SciTech Connect

    Fred Sabins

    2002-04-29

    The objective of this project is to develop an improved ultra-lightweight cement using ultra-lightweight hollow glass spheres (ULHS). This report includes results from laboratory testing of ULHS systems along with other lightweight cement systems, including foamed and sodium silicate slurries. During this project quarter, comparison studies of the three cement systems examined several properties: tensile strength, Young's modulus, and shear bond. Testing to determine the effect of temperature cycling on the shear bond properties of the cement systems was also conducted. In addition, the stress-strain behavior of the cement types was studied. This report discusses a software program that is being developed to help design ULHS cements and foamed cements.

  2. ULTRA-LIGHTWEIGHT CEMENT

    SciTech Connect

    Fred Sabins

    2001-07-18

    The objective of this project is to develop an improved ultra-lightweight cement using ultra-lightweight hollow glass spheres (ULHS). Work reported herein addresses Task 1: Assess Ultra-Lightweight Cementing Issues, Task 2: Review Russian Ultra-Lightweight Cement Literature, Task 3: Test Ultra-Lightweight Cements, and Task 8: Develop Field ULHS Cement Blending and Mixing Techniques. Results reported this quarter include: preliminary findings from a literature review focusing on problems associated with ultra-lightweight cements; summary of pertinent information from Russian ultra-lightweight cement literature review; laboratory tests comparing ULHS slurries to foamed slurries and sodium silicate slurries for two different applications; and initial laboratory studies with ULHS in preparation for a field job.

  3. Cytotoxicity evaluation of five different dual-cured resin cements used for fiber posts cementation.

    PubMed

    Dioguardi, M; Perrone, D; Troiano, G; Laino, L; Ardito, F; Lauritano, F; Cicciù, M; Muzio, L Lo

    2015-01-01

    Custom-cast posts and cores are usually used to treat endodontically treated teeth. However, several researches have underlined how these devices may be a much higher elastic modulus than the supporting dentine and the difference in the modulus could lead to stress concentrating in the cement lute, leading to failure. The role of the cement seems to play a fundamental role in order to transfer the strength during the chewing phases. Aim of this research is to record the rate of cytotoxicity of five different dual-cured resin cements used for fiber posts cementation. We tested the cytotoxicity of this five materials on MG63 osteoblast-like cells through two different methods: MTT ([3-4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide succinate) assay which tests for mitochondrial enzyme activity(6) and xCELLigence® system.

  4. Cytotoxicity evaluation of five different dual-cured resin cements used for fiber posts cementation.

    PubMed

    Dioguardi, M; Perrone, D; Troiano, G; Laino, L; Ardito, F; Lauritano, F; Cicciù, M; Muzio, L Lo

    2015-01-01

    Custom-cast posts and cores are usually used to treat endodontically treated teeth. However, several researches have underlined how these devices may be a much higher elastic modulus than the supporting dentine and the difference in the modulus could lead to stress concentrating in the cement lute, leading to failure. The role of the cement seems to play a fundamental role in order to transfer the strength during the chewing phases. Aim of this research is to record the rate of cytotoxicity of five different dual-cured resin cements used for fiber posts cementation. We tested the cytotoxicity of this five materials on MG63 osteoblast-like cells through two different methods: MTT ([3-4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide succinate) assay which tests for mitochondrial enzyme activity(6) and xCELLigence® system. PMID:26309592

  5. Cytotoxicity evaluation of five different dual-cured resin cements used for fiber posts cementation

    PubMed Central

    Dioguardi, M; Perrone, D; Troiano, G; Laino, L; Ardito, F; Lauritano, F; Cicciù, M; Muzio, L Lo

    2015-01-01

    Custom-cast posts and cores are usually used to treat endodontically treated teeth. However, several researches have underlined how these devices may be a much higher elastic modulus than the supporting dentine and the difference in the modulus could lead to stress concentrating in the cement lute, leading to failure. The role of the cement seems to play a fundamental role in order to transfer the strength during the chewing phases. Aim of this research is to record the rate of cytotoxicity of five different dual-cured resin cements used for fiber posts cementation. We tested the cytotoxicity of this five materials on MG63 osteoblast-like cells through two different methods: MTT ([3-4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide succinate) assay which tests for mitochondrial enzyme activity6 and xCELLigence® system. PMID:26309592

  6. Multi-bioindicators to assess soil microbial activity in the context of an artificial groundwater recharge with treated wastewater: a large-scale pilot experiment.

    PubMed

    Michel, Caroline; Joulian, Catherine; Ollivier, Patrick; Nyteij, Audrey; Cote, Rémi; Surdyk, Nicolas; Hellal, Jennifer; Casanova, Joel; Besnard, Katia; Rampnoux, Nicolas; Garrido, Francis

    2014-06-28

    In the context of artificial groundwater recharge, a reactive soil column at pilot-scale (4.5 m depth and 3 m in diameter) fed by treated wastewater was designed to evaluate soil filtration ability. Here, as a part of this project, the impact of treated wastewater filtration on soil bacterial communities and the soil's biological ability for wastewater treatment as well as the relevance of the use of multi-bioindicators were studied as a function of depth and time. Biomass; bacterial 16S rRNA gene diversity fingerprints; potential nitrifying, denitrifying, and sulfate-reducing activities; and functional gene (amo, nir, nar, and dsr) detection were analyzed to highlight the real and potential microbial activity and diversity within the soil column. These bioindicators show that topsoil (0 to 20 cm depth) was the more active and the more impacted by treated wastewater filtration. Nitrification was the main activity in the pilot. No sulfate-reducing activity or dsr genes were detected during the first 6 months of wastewater application. Denitrification was also absent, but genes of denitrifying bacteria were detected, suggesting that the denitrifying process may occur rapidly if adequate chemical conditions are favored within the soil column. Results also underline that a dry period (20 days without any wastewater supply) significantly impacted soil bacterial diversity, leading to a decrease of enzyme activities and biomass. Finally, our work shows that treated wastewater filtration leads to a modification of the bacterial genetic and functional structures in topsoil.

  7. Effect of endomycorrhizae on the bioavailability of bound sup 14 C residues to onion plants from an organic soil treated with ( sup 14 C)fonofos

    SciTech Connect

    Nelson, S.D.; Khan, S.U. )

    1990-03-01

    Uptake of bound {sup 14}C residues from an organic soil treated with radiolabeled fonofos (O-ethyl S-phenyl ethylphosphonodithioate) by selected Glomus endomycorrhiza and onion roots was studied. The hyphae of endomycorrhizal associations were capable of removing {sup 14}C residues from the soil and transporting them to onion plants. Bioavailability of soil-bound {sup 14}C residues, as measured by {sup 14}C residue content in onion, was increased 32 and 40% over that of nonmycorrhizal plants by hyphae of Glomus intraradices and Glomus vesiculiferium, respectively. The data suggest that under field conditions endomycorrhizal infection may greatly increase the bioavailability of soil-bound pesticide residues to plants.

  8. False positive identification of E. coli in treated municipal wastewater and wastewater-irrigated soils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    With the growth in use of treated wastewater for municipal and agricultural irrigation, accurate monitoring of water quality parameters, including Escherichia coli (E. coli), increases in importance. Chromogenic media, because they are easy to use and provide rapid sample analysis, are often used fo...

  9. Abyssal seep site cementation

    SciTech Connect

    Neumann, A.C.; Paull, C.K.; Commeau, R.; Commeau, J.

    1988-01-01

    The deepest submarine cements known so far occur along the 3,300-m deep base of the Florida escarpment and are associated with methane-bearing brine seeps, which emanate there. These deep Holocene carbonates, which occur as surficial and buried crusts, burrow fillings, and friable horizons, were sampled via ALVIN. The carbonates form irregular halos extending up to 20 m from seeps colonized by chemosynthetic fauna. Mussels, gastropods, and clams, the carbonate components of the community, produce a shell hash that is locally cemented by coarsely crystalline low-Mg calcite. Halos of palisade calcite are reminiscent of ancient examples of marine cements. Also present are carbonate hemipelagics cemented by micrite into crusts and burrow fillings. The degree of cementation varies from pervasive to light. Slabs of cemented crust up to 30 cm thick contrast with typical shallow crusts and exhibit irregular tops and smooth bottoms indicating different chemical gradients and pathways.

  10. Effects of Pseudomonas species on the release of bound sup 14 C residues from soil treated with ( sup 14 C)atrazine

    SciTech Connect

    Khan, S.U.; Behki, R.M. )

    1990-11-01

    The release of bound (nonextractable) {sup 14}C residues from soil previously treated with ({sup 14}C)atrazine was investigated by incubation of the solvent-extracted soil with two species of Pseudomonas capable of metabolizing atrazine. The two species, 192 and 194, released bound {sup 14}C residues from the soil. Addition of glucose, known to increase microbiological activities, to the incubated soil appeared to enhance the release of soil-bound {sup 14}C residues, in particular in the presence of Pseudomonas species 192. The {sup 14}C bound residues in soil, mainly present as the parent compound and its hydroxy and monodealkylated analogues, were released into the incubation mixture and were subsequently metabolized by the two species involving dechlorination and dealkylation.

  11. Cementation of indirect restorations: an overview of resin cements.

    PubMed

    Stamatacos, Catherine; Simon, James F

    2013-01-01

    The process of ensuring proper retention, marginal seal, and durability of indirect restorations depends heavily on effective cementation. Careful consideration must be made when selecting an adhesive cement for a given application. This article provides information on resin cements that can guide clinicians in determining which type of cement is best suited to their clinical needs regarding cementation of indirect restorations. Emphasis is placed on successful cementation of all-ceramic restorations.

  12. ULTRA-LIGHTWEIGHT CEMENT

    SciTech Connect

    Fred Sabins

    2003-01-31

    The objective of this project is to develop an improved ultra-lightweight cement using ultra-lightweight hollow glass spheres (ULHS). This report discusses testing that was performed for analyzing the alkali-silica reactivity of ULHS in cement slurries. DOE joined the Materials Management Service (MMS)-sponsored joint industry project ''Long-Term Integrity of Deepwater Cement under Stress/Compaction Conditions.'' Results of the project contained in two progress reports are also presented in this report.

  13. Determination of fluoroquinolone antibacterial agents in sewage sludge and sludge-treated soil using accelerated solvent extraction followed by solid-phase extraction.

    PubMed

    Golet, Eva M; Strehler, Adrian; Alder, Alfredo C; Giger, Walter

    2002-11-01

    A method for the quantitative determination of humanuse fluoroquinolone antibacterial agents (FQs) ciprofloxacin and norfloxacin in sewage sludge and sludge-treated soil samples was developed. The accelerated solvent extraction was optimized with regard to solvents and operational parameters, such as temperature, pressure, and extraction time. A 50 mM aqueous phosphoric acid/ acetonitrile mixture (1:1) was found to be optimum in combination with an extraction temperature of 100 degrees C at 100 bar, during 60 and 90 min for sewage sludge and sludge-treated soil samples, respectively. A cleanup step using solid-phase extraction substantially improved the selectivity of the method. Overall recovery rates for FQs ranged from 82 to 94% for sewage sludge and from 75 to 92% for sludge-treated soil, with relative standard deviations between 8 and 11%. Limits of quantification were 0.45 and 0.18 mg/kg of dry matter for sewage sludge and sludge-treated soils, respectively. The presented method was successfully applied to untreated and anaerobically digested sewage sludges and sludge-treated soils. Ciprofloxacin and norfloxacin were determined in sewage sludges from several wastewater treatment plants with concentrations ranging from 1.40 to 2.42 mg/kg of dry matter. Therefore, contrary to what may be expected for human-use pharmaceuticals, FQs may reach the terrestrial environment as indicated by the occurrence of FQs in topsoil samples from experimental fields, to which sewage sludge had been applied. PMID:12433073

  14. Impacts of Long-Term Irrigation of Domestic Treated Wastewater on Soil Biogeochemistry and Bacterial Community Structure.

    PubMed

    Wafula, Denis; White, John R; Canion, Andy; Jagoe, Charles; Pathak, Ashish; Chauhan, Ashvini

    2015-10-01

    Freshwater scarcity and regulations on wastewater disposal have necessitated the reuse of treated wastewater (TWW) for soil irrigation, which has several environmental and economic benefits. However, TWW irrigation can cause nutrient loading to the receiving environments. We assessed bacterial community structure and associated biogeochemical changes in soil plots irrigated with nitrate-rich TWW (referred to as pivots) for periods ranging from 13 to 30 years. Soil cores (0 to 40 cm) were collected in summer and winter from five irrigated pivots and three adjacently located nonirrigated plots. Total bacterial and denitrifier gene abundances were estimated by quantitative PCR (qPCR), and community structure was assessed by 454 massively parallel tag sequencing (MPTS) of small-subunit (SSU) rRNA genes along with terminal restriction fragment length polymorphism (T-RFLP) analysis of nirK, nirS, and nosZ functional genes responsible for denitrification of the TWW-associated nitrate. Soil physicochemical analyses showed that, regardless of the seasons, pH and moisture contents (MC) were higher in the irrigated (IR) pivots than in the nonirrigated (NIR) plots; organic matter (OM) and microbial biomass carbon (MBC) were higher as a function of season but not of irrigation treatment. MPTS analysis showed that TWW loading resulted in the following: (i) an increase in the relative abundance of Proteobacteria, especially Betaproteobacteria and Gammaproteobacteria; (ii) a decrease in the relative abundance of Actinobacteria; (iii) shifts in the communities of acidobacterial groups, along with a shift in the nirK and nirS denitrifier guilds as shown by T-RFLP analysis. Additionally, bacterial biomass estimated by genus/group-specific real-time qPCR analyses revealed that higher numbers of total bacteria, Acidobacteria, Actinobacteria, Alphaproteobacteria, and the nirS denitrifier guilds were present in the IR pivots than in the NIR plots. Identification of the nir

  15. Impacts of Long-Term Irrigation of Domestic Treated Wastewater on Soil Biogeochemistry and Bacterial Community Structure.

    PubMed

    Wafula, Denis; White, John R; Canion, Andy; Jagoe, Charles; Pathak, Ashish; Chauhan, Ashvini

    2015-10-01

    Freshwater scarcity and regulations on wastewater disposal have necessitated the reuse of treated wastewater (TWW) for soil irrigation, which has several environmental and economic benefits. However, TWW irrigation can cause nutrient loading to the receiving environments. We assessed bacterial community structure and associated biogeochemical changes in soil plots irrigated with nitrate-rich TWW (referred to as pivots) for periods ranging from 13 to 30 years. Soil cores (0 to 40 cm) were collected in summer and winter from five irrigated pivots and three adjacently located nonirrigated plots. Total bacterial and denitrifier gene abundances were estimated by quantitative PCR (qPCR), and community structure was assessed by 454 massively parallel tag sequencing (MPTS) of small-subunit (SSU) rRNA genes along with terminal restriction fragment length polymorphism (T-RFLP) analysis of nirK, nirS, and nosZ functional genes responsible for denitrification of the TWW-associated nitrate. Soil physicochemical analyses showed that, regardless of the seasons, pH and moisture contents (MC) were higher in the irrigated (IR) pivots than in the nonirrigated (NIR) plots; organic matter (OM) and microbial biomass carbon (MBC) were higher as a function of season but not of irrigation treatment. MPTS analysis showed that TWW loading resulted in the following: (i) an increase in the relative abundance of Proteobacteria, especially Betaproteobacteria and Gammaproteobacteria; (ii) a decrease in the relative abundance of Actinobacteria; (iii) shifts in the communities of acidobacterial groups, along with a shift in the nirK and nirS denitrifier guilds as shown by T-RFLP analysis. Additionally, bacterial biomass estimated by genus/group-specific real-time qPCR analyses revealed that higher numbers of total bacteria, Acidobacteria, Actinobacteria, Alphaproteobacteria, and the nirS denitrifier guilds were present in the IR pivots than in the NIR plots. Identification of the nir

  16. Impacts of Long-Term Irrigation of Domestic Treated Wastewater on Soil Biogeochemistry and Bacterial Community Structure

    PubMed Central

    Wafula, Denis; White, John R.; Canion, Andy; Jagoe, Charles; Pathak, Ashish

    2015-01-01

    Freshwater scarcity and regulations on wastewater disposal have necessitated the reuse of treated wastewater (TWW) for soil irrigation, which has several environmental and economic benefits. However, TWW irrigation can cause nutrient loading to the receiving environments. We assessed bacterial community structure and associated biogeochemical changes in soil plots irrigated with nitrate-rich TWW (referred to as pivots) for periods ranging from 13 to 30 years. Soil cores (0 to 40 cm) were collected in summer and winter from five irrigated pivots and three adjacently located nonirrigated plots. Total bacterial and denitrifier gene abundances were estimated by quantitative PCR (qPCR), and community structure was assessed by 454 massively parallel tag sequencing (MPTS) of small-subunit (SSU) rRNA genes along with terminal restriction fragment length polymorphism (T-RFLP) analysis of nirK, nirS, and nosZ functional genes responsible for denitrification of the TWW-associated nitrate. Soil physicochemical analyses showed that, regardless of the seasons, pH and moisture contents (MC) were higher in the irrigated (IR) pivots than in the nonirrigated (NIR) plots; organic matter (OM) and microbial biomass carbon (MBC) were higher as a function of season but not of irrigation treatment. MPTS analysis showed that TWW loading resulted in the following: (i) an increase in the relative abundance of Proteobacteria, especially Betaproteobacteria and Gammaproteobacteria; (ii) a decrease in the relative abundance of Actinobacteria; (iii) shifts in the communities of acidobacterial groups, along with a shift in the nirK and nirS denitrifier guilds as shown by T-RFLP analysis. Additionally, bacterial biomass estimated by genus/group-specific real-time qPCR analyses revealed that higher numbers of total bacteria, Acidobacteria, Actinobacteria, Alphaproteobacteria, and the nirS denitrifier guilds were present in the IR pivots than in the NIR plots. Identification of the nir

  17. Hydrothermal processing of new fly ash cement

    SciTech Connect

    Jiang, W.; Roy, D.M. )

    1992-04-01

    The recent Mount Pinatubo volcanic eruption in the Philippines, in which at least 268 people died, shows that volcanic eruptions can be highly destructive. The eruption shot ash and debris over the countryside; six towns near the volcano faced a high risk of devastating mudslides, and nearly 2000 U.S. service members and their families were evacuated from two nearby military bases. However, this paper reports that not all the consequences of volcanic eruptions are bad. Under hydrothermal conditions, volcanic ash can be transformed into zeolitic tuff and, eventually, into clay minerals that constitute agricultural soils. The Materials Research Laboratory (MRL) has recently used some artificial pozzolanas (fly ash) that when mixed with lime, under hydrothermal conditions, also produced a new type of cementitious material. This was categorized as a new fly ash cement. The formation of a new hydrothermally treated wood-fiber-reinforced composite has also been demonstrated. It is apparent, however, that with respect to concerns about detailed knowledge of the reactivity of calcium silicate-based materials under hydrothermal conditions, the application of the technology far outweighs the understanding of the underlying principles of reactivity. It would seem that an understanding of reactions on the molecular level is just beginning, and that work on hydrothermal reactions is still a potentially lucrative area of research.

  18. Protective effects of Glomus iranicum var. tenuihypharum on soil and Viburnum tinus plants irrigated with treated wastewater under field conditions.

    PubMed

    Gómez-Bellot, María José; Ortuño, María Fernanda; Nortes, Pedro Antonio; Vicente-Sánchez, Javier; Martín, Félix Fernández; Bañón, Sebastián; Sánchez-Blanco, María Jesús

    2015-07-01

    Currently, irrigation using recycled water is increasing, especially in semiarid environments, but a potential problem of using reclaimed wastewater is its elevated salt levels. The application of arbuscular mycorrhizal fungi (AMF) could be a suitable option to mitigate the negative effects produced by the salinity. In this work, the combined effect of Glomus iranicum var. tenuihypharum and two types of water: Control, C, with EC <0.9 dS m(-1) and reclaimed water (wastewater previously treated in a sewage treatment plant) with EC 4 dS m(-1) during a first saline period (11 weeks) and with EC 6 dS m(-1) during a second saline period (25 weeks), was evaluated for laurustinus (Viburnum tinus) plants under field conditions. This plant is a popular shrub very used for gardening. Chemical properties of soil as well as physiological behavior, leaf nutrition, and esthetic value of plants were evaluated. Due to the high salinity from wastewater at 6 dS m(-1), laurustinus plants decreased their stem water potential values and, to a lesser extent, the stomatal conductance. Also, the visual quality of the plants was diminished. The inoculated AMF satisfactorily colonized the laurustinus roots and enhanced the structure of the soil by increasing the glomalin and carbon contents. Furthermore, G. iranicum var. tenuihypharum inoculation decreased Na and Cl content, stimulated flowering and improved the stem water potential of the plants irrigated with both types of reclaimed water. The AMF also had a positive effect as a consequence of stimulation of plant physiological parameters, such as the stem water potential and stomatal conductance. Effective AMF associations that avoid excessive salinity could provide wastewater reuse options, especially when the plants grow in soils. PMID:25492808

  19. Protective effects of Glomus iranicum var. tenuihypharum on soil and Viburnum tinus plants irrigated with treated wastewater under field conditions.

    PubMed

    Gómez-Bellot, María José; Ortuño, María Fernanda; Nortes, Pedro Antonio; Vicente-Sánchez, Javier; Martín, Félix Fernández; Bañón, Sebastián; Sánchez-Blanco, María Jesús

    2015-07-01

    Currently, irrigation using recycled water is increasing, especially in semiarid environments, but a potential problem of using reclaimed wastewater is its elevated salt levels. The application of arbuscular mycorrhizal fungi (AMF) could be a suitable option to mitigate the negative effects produced by the salinity. In this work, the combined effect of Glomus iranicum var. tenuihypharum and two types of water: Control, C, with EC <0.9 dS m(-1) and reclaimed water (wastewater previously treated in a sewage treatment plant) with EC 4 dS m(-1) during a first saline period (11 weeks) and with EC 6 dS m(-1) during a second saline period (25 weeks), was evaluated for laurustinus (Viburnum tinus) plants under field conditions. This plant is a popular shrub very used for gardening. Chemical properties of soil as well as physiological behavior, leaf nutrition, and esthetic value of plants were evaluated. Due to the high salinity from wastewater at 6 dS m(-1), laurustinus plants decreased their stem water potential values and, to a lesser extent, the stomatal conductance. Also, the visual quality of the plants was diminished. The inoculated AMF satisfactorily colonized the laurustinus roots and enhanced the structure of the soil by increasing the glomalin and carbon contents. Furthermore, G. iranicum var. tenuihypharum inoculation decreased Na and Cl content, stimulated flowering and improved the stem water potential of the plants irrigated with both types of reclaimed water. The AMF also had a positive effect as a consequence of stimulation of plant physiological parameters, such as the stem water potential and stomatal conductance. Effective AMF associations that avoid excessive salinity could provide wastewater reuse options, especially when the plants grow in soils.

  20. Accumulation of Cr, Pb, Cu, Ni, Zn and Cd in soil following irrigation with treated urban effluent in Australia.

    PubMed

    Smith, C J; Hopmans, P; Cook, F J

    1996-01-01

    The effect of irrigation with secondary treated municipal effluent on the accumulation of heavy metals (Cd, Cr, Cu, Ni, Pb, and Zn) was investigated by monitoring sites that had been irrigated with effluent for 4 and 17 years. At Wodonga, seven tree species were sprinkler irrigated with effluent at an average application rate of 1347 mm per annum from 1980 to 1984. The other site at Canberra was a large grass playing field (9 ha), half of which had been effluent irrigated since 1977. The non-effluent irrigated area served as the control area and provided reference 'background' concentration to assess the extent of contamination due to 17 years of effluent irrigation. Archived soil samples collected before the commencement of effluent irrigation were compared with those taken in 1984 at Wodonga to assess the extent of contamination. The concentration of labile metals was determined by extraction with EDTA because this method provides a quantitative measure of bioavailable metals. Irrigation with effluent did not increase the EDTA-extractable metals concentration at either site. Furthermore, the EDTA-extractable metal values were within the natural 'back-ground' range reported for Australian soils. These data suggest that it may take between 50 and 100 years for heavy metal levels (mainly Cd) in effluent-irrigated soil to reach the currently proposed threshold values for environmental concern. The potentially harmful effects of long-term accumulation of heavy metals on plant growth cannot be ignored and could affect the sustainability of land-based disposal of effluent. PMID:15093492

  1. Bioavailability and influence of ¹⁴C-carbofuran on Eisenia andrei avoidance, growth and reproduction in treated natural tropical soils.

    PubMed

    Ferreira, Regina C B; Papini, Solange; de Andréa, Mara M

    2015-01-01

    The bioavailability of carbofuran to the compost worms Eisenia andrei and the influence of its residual amounts on the avoidance, reproduction and growth of this species were studied in two natural tropical soils: a Typic Humaquept (GM) and a Typic Hapludox (LVD), as indicated by the Brazilian environmental authorities for ecotoxicological tests. The worms avoided the soil LVD treated with different doses of carbofuran. The pesticide also affected the production of juvenile specimens in both soils, but cocoon production was reduced only in the GM soil. The earthworms' growth and weight loss were affected by carbofuran (2,2-dimethyl-2,3-dihydro-1-1-benzofuran-7-yl methylcarbamate. CAS number 1563-66-2) only in the LVD and the mortality detected at 56 days of contact with the treated soils was not statistically significant in both of them. Fourteen days after the soil treatment with(14) c-carbofuran, most residues detected in the soils were bound residues (approximately 36% and 30% in the GM and LVD, respectively) and neither mortality nor bioaccumulation was detected in the earthworms, even with absorptions of 13% and 43%, respectively. The LVD soil has lower organic matter content, and the effects of carbofuran on different aspects of the earthworms' life were more pronounced in this soil, most likely due to the higher bioavailability of the pesticide in the soil solution. The results for carbofuran clearly demonstrate that even small quantities of residues do not assure lack of toxicity. They also make evident the necessity of studying the effects of pesticides in natural agricultural soils. Furthermore, as the bound residues and the earthworm contamination are not detected by conventional techniques, they are not taken into account and may be underestimated on environmental risk assessments. PMID:25714458

  2. Bioavailability and influence of ¹⁴C-carbofuran on Eisenia andrei avoidance, growth and reproduction in treated natural tropical soils.

    PubMed

    Ferreira, Regina C B; Papini, Solange; de Andréa, Mara M

    2015-01-01

    The bioavailability of carbofuran to the compost worms Eisenia andrei and the influence of its residual amounts on the avoidance, reproduction and growth of this species were studied in two natural tropical soils: a Typic Humaquept (GM) and a Typic Hapludox (LVD), as indicated by the Brazilian environmental authorities for ecotoxicological tests. The worms avoided the soil LVD treated with different doses of carbofuran. The pesticide also affected the production of juvenile specimens in both soils, but cocoon production was reduced only in the GM soil. The earthworms' growth and weight loss were affected by carbofuran (2,2-dimethyl-2,3-dihydro-1-1-benzofuran-7-yl methylcarbamate. CAS number 1563-66-2) only in the LVD and the mortality detected at 56 days of contact with the treated soils was not statistically significant in both of them. Fourteen days after the soil treatment with(14) c-carbofuran, most residues detected in the soils were bound residues (approximately 36% and 30% in the GM and LVD, respectively) and neither mortality nor bioaccumulation was detected in the earthworms, even with absorptions of 13% and 43%, respectively. The LVD soil has lower organic matter content, and the effects of carbofuran on different aspects of the earthworms' life were more pronounced in this soil, most likely due to the higher bioavailability of the pesticide in the soil solution. The results for carbofuran clearly demonstrate that even small quantities of residues do not assure lack of toxicity. They also make evident the necessity of studying the effects of pesticides in natural agricultural soils. Furthermore, as the bound residues and the earthworm contamination are not detected by conventional techniques, they are not taken into account and may be underestimated on environmental risk assessments.

  3. Enhanced migration of polychlorodibenzo-p-dioxins and furans in the presence of pentachlorophenol-treated oil in soil around utility poles: screening model validation.

    PubMed

    Bulle, Cécile; Samson, Réjean; Deschênes, Louise

    2010-03-01

    Field samples were collected around six pentachlorophenol (PCP)-treated wooden poles (in clay, organic soil, and sand) to evaluate the vertical migration of polychlorodibenzo-p-dioxins and furans (PCDD/Fs). Soils were characterized, PCDD/Fs, C(10)-C(50), and PCP were analyzed for seven composite samples located at a depth from 0 to 100 cm and at a distance from 0 to 50 cm from each pole. Concentrations of PCDD/Fs measured in organic soils were the highest (maximum 1.2E + 05 pg toxic equivalent TEQ/g soil), followed by clay (maximum 3.8E + 04 pg TEQ/g soil) and sand (maximum 1.8E + 04 pg TEQ/g soil). Model predictions, including the influence of wood treatment oil, were validated using measured concentration values in soils around poles. The model predicts a migration of PCDD/Fs due to the migration of oil, which differs depending on the type of soil: in clay, 90% of PCDD/Fs are predicted to remain in the first 29 cm, whereas in sand, 80 to 90% of the emitted PCDD/Fs are predicted to migrate deeper than 185 cm. For the organic soil, the predicted migration depth varies from 90 to 155 cm. This screening model allows evaluating the danger of microcontaminated sites around PCP-treated wooden poles: from a risk assessment perspective, in the case of organic soil and clay, no PCDD/F contamination is to be expected below the pole, but high levels of PCDD/Fs can be found in the first 2 m below the surface. For sand, however, significantly lower levels of PCDD/Fs were predicted in the surface soil, while the migration depth remains elevated, posing an inherent danger of aquifer contamination under the pole.

  4. Characterization of novel linuron-mineralizing bacterial consortia enriched from long-term linuron-treated agricultural soils.

    PubMed

    Breugelmans, Philip; D'Huys, Pieter-Jan; De Mot, René; Springael, Dirk

    2007-12-01

    Linuron-mineralizing cultures were enriched from two linuron-treated agricultural soils in the presence and absence of a solid support. The cultures contained linuron-degrading bacteria, which coexisted with bacteria degrading either 3,4-dichloroaniline (3,4-DCA) or N,O-dimethylhydroxylamine (N,O-DMHA), two common metabolites in the linuron degradation pathway. For one soil, the presence of a solid support enriched for linuron-degrading strains phylogenetically related to but different from those enriched without support. Most linuron-degrading consortium members were identified as Variovorax, but a Hydrogenophaga and an Achromobacter strain capable of linuron degradation were also obtained. Several of the linuron-degrading isolates also degraded 3,4-DCA. Isolates that degraded 3,4-DCA but not linuron belonged to the genera Variovorax, Cupriavidus and Afipia. Hyphomicrobium spp. were involved in the metabolism of N,O-DMHA. Whereas several isolates degraded linuron independently, more efficient degradation was achieved by combining linuron and 3,4-DCA-degraders or by adding casamino acids. These data suggest that (1) linuron degradation is performed by a group of metabolically interacting bacteria rather than by individual strains, (2) there are other genera in addition to Variovorax that degrade linuron beyond 3,4-DCA, (3) linuron-degrading consortia of different origins have a similar composition, and (4) interactions between consortium members can be complex and can involve exchange of both metabolites and other nutrients. PMID:17991021

  5. Plant uptake of depleted uranium from manure-amended and citrate treated soil.

    PubMed

    Sevostianova, Elena; Lindemann, William C; Ulery, April L; Remmenga, Marta D

    2010-08-01

    Six plant species were tested for their ability to accumulate depleted uranium in their above-ground biomass from deployed munitions contaminated soil in New Mexico. In greenhouse experiments, Kochia (Kochia scoparia L. Schrad.) and pigweed (Amaranthus retroflexus L) were grown with steer manure added at rates of 22.4, 44.8, and 89.6 Mg ha(-1). Citric acid and glyphosate (N-(phosphonomethyl) glycine) applied at the end of the growing season increased DU concentrations from 2.5 to 17 times. Leaf and stem DU concentrations in kochia increased from 17.0 to 41.9 mg kg(-1) and from 3.5 to 18.0 mg kg(-1), respectively. In pigweed, leaf and stem DU concentrations increased from 1.0 to 17.3 and from 1.0 to 4.7 mg kg(-1), respectively. Manure generally decreased or had no effect on DU uptake. The effect of citric acid and ammonium citrate on DU uptake by kochia, sunflower (Helianthus annuus L), and sweet corn (Zea mays L) was also studied. Ammonium citrate was just as effective in enhancing DU uptake as citric acid. This implies that the citrate ion is more important in DU uptake and translocation than the solubilization of DU through acidification. In both experiments, leaves had higher DU concentrations than stems. PMID:21166280

  6. Valuation of efficacy and nonrepellency of indoxacarb and fipronil-treated soil at various concentrations and thicknesses against two subterranean termites (Isoptera: Rhinotermitidae).

    PubMed

    Hu, Xing Ping

    2005-04-01

    The efficacy and nonrepellency of indoxacarb (150 SC, 150 g [AI]/liter) and fipronil (Termidor SC, 9.1% [Al]) against field-collected eastern subterranean termite, Reticulitermes flavipes (Kollar), and the Formosan subterranean termite, Coptotermes formosanus Shiraki, were evaluated for mortality and penetration into treated soil in laboratory glass tube bioassays. Both insecticides were tested at five concentrations (0, 1, 10, 50, and 100 ppm) and two thicknesses (20 and 50 mm) of treated soil. Indoxacarb caused significantly greater mortality than controls at all treatment thicknesses of > or = 10 ppm, but not at 1 ppm. Concentration and treatment thickness of indoxacarb significantly affected termite mortality. Eastern subterranean termites were significantly more susceptible to indoxacarb than Formosan subterranean termites, but there were no intercolony differences in either species. Termites completely penetrated through all treatment thickness of indoxacarb-treated soil at all concentrations, except one of the six Formosan subterranean termite replicates of 50 mm at 50 ppm, when all termites were killed before tunneling through the treated soil. Fipronil resulted in significantly faster and greater termite mortality than indoxacarb at corresponding concentrations. Concentration and treatment thickness of fipronil also significantly affected termite mortality. There was no intercolony difference in susceptibility to either insecticide in either termite. Both termite species completely penetrated 20-mm treatments of all tested fipronil concentrations, as well as 50-mm soil treated with fipronil at < or = 10 ppm. At 50 and 100 ppm fipronil, termites tunneled only a mean of 87 +/- 0.21 and 47 +/- 0.18% deep into 50-mm treated soil, respectively, before death. Both insecticides demonstrated a delayed mode of activity and nonrepellency against the two termite species.

  7. ULTRA-LIGHTWEIGHT CEMENT

    SciTech Connect

    Fred Sabins

    2004-01-30

    The objective of this project is to develop an improved ultra-lightweight cement using ultra-lightweight hollow glass spheres (ULHS). This report discusses testing that was performed for analyzing the alkali-silica reactivity of ULHS in cement slurries.

  8. Desiccation-Induced Volumetric Shrinkage of Compacted Metakaolin-Treated Black Cotton Soil for a Hydraulic Barriers System

    NASA Astrophysics Data System (ADS)

    Moses, George; Peter, Oriola F. O.; Osinubi, Kolawole J.

    2016-03-01

    Black cotton soil treated with up to 24% metakaolin (MCL) content was prepared by molding water contents of -2, 0, 2, 4 and 6% of optimum moisture content (OMC) and compacted with British Standard Light (BSL) and West African Standard (WAS) or `Intermediate' energies. The specimens were extruded from the compaction molds and allowed to air dry in a laboratory in order to assess the effect of desiccation-induced shrinkage on the compacted mix for use as a hydraulic barrier in a waste containment application. The results recorded show that the volumetric shrinkage strain (VSS) values were large within the first 10 days of drying; the VSS values increased with a higher molding of the water content, relative to the OMC. The VSS generally increased with a higher initial degree of saturation for the two compactive efforts, irrespective of the level of MCL treatment. Generally, the VSS decreased with an increasing MCL content. Only specimens treated with a minimum 20% MCL content and compacted with the WAS energy satisfied the regulatory maximum VSS of 4% for use as a hydraulic barrier.

  9. ULTRA-LIGHTWEIGHT CEMENT

    SciTech Connect

    Fred Sabins

    2002-01-23

    The objective of this project is to develop an improved ultra-lightweight cement using ultra-lightweight hollow glass spheres (ULHS). This report includes results from laboratory testing of ULHS systems along with other lightweight cement systems: foamed and sodium silicate slurries. Comparison studies of the three cement systems examined several properties: tensile strength, Young's modulus, water permeability, and shear bond. Testing was also done to determine the effect that temperature cycling has on the shear bond properties of the cement systems. In addition, analysis was carried out to examine alkali silica reactivity of slurries containing ULHS. Data is also presented from a study investigating the effects of mixing and pump circulation on breakage of ULHS. Information is also presented about the field application of ULHS in cementing a 7-in. intermediate casing in south Texas.

  10. Feasibility of treating aged polycyclic aromatic hydrocarbons (PAHs)-contaminated soils using ethyl lactate-based Fenton treatment via parametric and kinetic studies.

    PubMed

    Yap, Chiew Lin; Gan, Suyin; Ng, Hoon Kiat

    2015-01-01

    This study focuses on the feasibility of treating aged polycyclic aromatic hydrocarbons (PAHs)-contaminated soils using ethyl lactate (EL)-based Fenton treatment via a combination of parametric and kinetic studies. An optimised operating condition was observed at 66.7 M H2O2 with H2O2/Fe(2+) of 40:1 for low soil organic carbon (SOC) content and mildly acidic soil (pH 6.2), and 10:1 for high SOC and very acidic soil (pH 4.4) with no soil pH adjustment. The desorption kinetic was only mildly shifted from single equilibrium to dual equilibrium of the first-order kinetic model upon ageing. Pretreatment with EL fc = 0.60 greatly reduced the mass transfer coefficient especially for the slow desorbed fraction (kslow) of high molecular weight (HMW) PAHs, largely contributed by the concentration gradient created by EL-enhanced solubility. As the major desorption obstacle was almost fully overcome by the pretreatment, the pseudo-first-order kinetic reaction rate constant of PAHs degradation of aged soils was statistically discernible from that of freshly contaminated soils but slightly reduced in high SOC and high acidity soil. Stabilisation of H2O2 by EL addition in combination with reduced Fe(2+) catalyst were able to slow the decomposition rate of H2O2 even at higher soil pH. PMID:25065478

  11. Feasibility of treating aged polycyclic aromatic hydrocarbons (PAHs)-contaminated soils using ethyl lactate-based Fenton treatment via parametric and kinetic studies.

    PubMed

    Yap, Chiew Lin; Gan, Suyin; Ng, Hoon Kiat

    2015-01-01

    This study focuses on the feasibility of treating aged polycyclic aromatic hydrocarbons (PAHs)-contaminated soils using ethyl lactate (EL)-based Fenton treatment via a combination of parametric and kinetic studies. An optimised operating condition was observed at 66.7 M H2O2 with H2O2/Fe(2+) of 40:1 for low soil organic carbon (SOC) content and mildly acidic soil (pH 6.2), and 10:1 for high SOC and very acidic soil (pH 4.4) with no soil pH adjustment. The desorption kinetic was only mildly shifted from single equilibrium to dual equilibrium of the first-order kinetic model upon ageing. Pretreatment with EL fc = 0.60 greatly reduced the mass transfer coefficient especially for the slow desorbed fraction (kslow) of high molecular weight (HMW) PAHs, largely contributed by the concentration gradient created by EL-enhanced solubility. As the major desorption obstacle was almost fully overcome by the pretreatment, the pseudo-first-order kinetic reaction rate constant of PAHs degradation of aged soils was statistically discernible from that of freshly contaminated soils but slightly reduced in high SOC and high acidity soil. Stabilisation of H2O2 by EL addition in combination with reduced Fe(2+) catalyst were able to slow the decomposition rate of H2O2 even at higher soil pH.

  12. The influence of ultrasound on removal of prefabricated metal post cemented with different resin cements

    PubMed Central

    Feiz, Atiyeh; Barekatain, Behnaz; Naseri, Roohollah; Zarezadeh, Hossein; Askari, Navid; Nasiri, Saman

    2013-01-01

    Background: Ultrasonic vibrations are used to remove a cemented post from a root canal requiring endodontic retreatment. Various results have been reported from the studies that evaluated the effect of ultrasonic instruments in removing the posts cemented with resin cements. The aim of this study was to evaluate the effect of ultrasonic energy on the retention of prefabricated metal post cemented with Panavia or Maxcem Elite cements. Materials and Methods: In this in vitro study, forty eight extracted single root premolars were decoronated with a diamond disc leaving a 13 mm long root and endodontically treated. The root canals were obturated by gutta-percha up to 5 mm with vertical condensation method and the 8 mm post-space was prepared to receive a no. 2 long Dentorama post. The roots were placed in an incubator for 48 h in 37°C and 100% humidity. After mounting the teeth in acrylic blocks, posts were cemented in the root canals using Panavia F2.0 in 24 specimens and Maxcem Elite in 24 others. For half of the specimens in each subgroup, an ultrasonic device was applied for 4 min. Universal testing machine was used to measure the force needed to remove the posts with a crosshead speed of 1 mm/min until the post came out of the canal. Kruskal-Wallis test was used for statistical analysis at 5% level of significance. Results: The removal force was not significantly different among the groups (P > 0.05). Conclusion: Ultrasonic energy did not decrease the retention of posts cemented with Panavia or Maxcem Elite cements. Furthermore, it seems that there is no significant difference between removal force of self-etch (Panavia) and the self-etch self-adhesive (Maxcem Elite) resin cements. PMID:24379864

  13. Assessment of intermittently loaded woodchip and sand filters to treat dairy soiled water.

    PubMed

    Murnane, J G; Brennan, R B; Healy, M G; Fenton, O

    2016-10-15

    Land application of dairy soiled water (DSW) is expensive relative to its nutrient replacement value. The use of aerobic filters is an effective alternative method of treatment and potentially allows the final effluent to be reused on the farm. Knowledge gaps exist concerning the optimal design and operation of filters for the treatment of DSW. To address this, 18 laboratory-scale filters, with depths of either 0.6 m or 1 m, were intermittently loaded with DSW over periods of up to 220 days to evaluate the impacts of depth (0.6 m versus 1 m), organic loading rates (OLRs) (50 versus 155 g COD m(-2) d(-1)), and media type (woodchip versus sand) on organic, nutrient and suspended solids (SS) removals. The study found that media depth was important in contaminant removal in woodchip filters. Reductions of 78% chemical oxygen demand (COD), 95% SS, 85% total nitrogen (TN), 82% ammonium-nitrogen (NH4N), 50% total phosphorus (TP), and 54% dissolved reactive phosphorus (DRP) were measured in 1 m deep woodchip filters, which was greater than the reductions in 0.6 m deep woodchip filters. Woodchip filters also performed optimally when loaded at a high OLR (155 g COD m(-2) d(-1)), although the removal mechanism was primarily physical (i.e. straining) as opposed to biological. When operated at the same OLR and when of the same depth, the sand filters had better COD removals (96%) than woodchip (74%), but there was no significant difference between them in the removal of SS and NH4N. However, the likelihood of clogging makes sand filters less desirable than woodchip filters. Using the optimal designs of both configurations, the filter area required per cow for a woodchip filter is more than four times less than for a sand filter. Therefore, this study found that woodchip filters are more economically and environmentally effective in the treatment of DSW than sand filters, and optimal performance may be achieved using woodchip filters with a depth of at least 1

  14. Assessment of intermittently loaded woodchip and sand filters to treat dairy soiled water.

    PubMed

    Murnane, J G; Brennan, R B; Healy, M G; Fenton, O

    2016-10-15

    Land application of dairy soiled water (DSW) is expensive relative to its nutrient replacement value. The use of aerobic filters is an effective alternative method of treatment and potentially allows the final effluent to be reused on the farm. Knowledge gaps exist concerning the optimal design and operation of filters for the treatment of DSW. To address this, 18 laboratory-scale filters, with depths of either 0.6 m or 1 m, were intermittently loaded with DSW over periods of up to 220 days to evaluate the impacts of depth (0.6 m versus 1 m), organic loading rates (OLRs) (50 versus 155 g COD m(-2) d(-1)), and media type (woodchip versus sand) on organic, nutrient and suspended solids (SS) removals. The study found that media depth was important in contaminant removal in woodchip filters. Reductions of 78% chemical oxygen demand (COD), 95% SS, 85% total nitrogen (TN), 82% ammonium-nitrogen (NH4N), 50% total phosphorus (TP), and 54% dissolved reactive phosphorus (DRP) were measured in 1 m deep woodchip filters, which was greater than the reductions in 0.6 m deep woodchip filters. Woodchip filters also performed optimally when loaded at a high OLR (155 g COD m(-2) d(-1)), although the removal mechanism was primarily physical (i.e. straining) as opposed to biological. When operated at the same OLR and when of the same depth, the sand filters had better COD removals (96%) than woodchip (74%), but there was no significant difference between them in the removal of SS and NH4N. However, the likelihood of clogging makes sand filters less desirable than woodchip filters. Using the optimal designs of both configurations, the filter area required per cow for a woodchip filter is more than four times less than for a sand filter. Therefore, this study found that woodchip filters are more economically and environmentally effective in the treatment of DSW than sand filters, and optimal performance may be achieved using woodchip filters with a depth of at least 1

  15. The effects of Paenibacillus polymyxa E681 on antifungal and crack remediation of cement paste.

    PubMed

    Park, Sung-Jin; Park, Seung-Hwan; Ghim, Sa-Youl

    2014-10-01

    This study investigated the antifungal effects of cement paste containing Paenibacillus polymyxa E681 against Aspergillus niger, a deleterious fungus commonly found in cement buildings and structures. To test the antifungal effects, cement paste containing P. polymyxa E681 was neutralized by CO2 gas, and the fungal growth inhibition was examined according to the clear zone around the cement specimen. In addition to the antifungal effects of the cement paste added with bacteria, calcium crystal precipitation of P. polymyxa E681 was examined by qualitative and quantitative analyses. The cement paste containing P. polymyxa E681 showed strong antifungal effects but fusA mutant (deficient in fusaricidin synthesis) showed no antifungal activity. Crack sealing of the cement paste treated with P. polymyxa E681 was captured by light microscope showed fungal growth inhibition and crack repairing in cement paste.

  16. The effects of Paenibacillus polymyxa E681 on antifungal and crack remediation of cement paste.

    PubMed

    Park, Sung-Jin; Park, Seung-Hwan; Ghim, Sa-Youl

    2014-10-01

    This study investigated the antifungal effects of cement paste containing Paenibacillus polymyxa E681 against Aspergillus niger, a deleterious fungus commonly found in cement buildings and structures. To test the antifungal effects, cement paste containing P. polymyxa E681 was neutralized by CO2 gas, and the fungal growth inhibition was examined according to the clear zone around the cement specimen. In addition to the antifungal effects of the cement paste added with bacteria, calcium crystal precipitation of P. polymyxa E681 was examined by qualitative and quantitative analyses. The cement paste containing P. polymyxa E681 showed strong antifungal effects but fusA mutant (deficient in fusaricidin synthesis) showed no antifungal activity. Crack sealing of the cement paste treated with P. polymyxa E681 was captured by light microscope showed fungal growth inhibition and crack repairing in cement paste. PMID:24824950

  17. A comparison of retentive strength of implant cement depending on various methods of removing provisional cement from implant abutment

    PubMed Central

    Keum, Eun-Cheol

    2013-01-01

    PURPOSE This study evaluated the effectiveness of various methods for removing provisional cement from implant abutments, and what effect these methods have on the retention of prosthesis during the definitive cementation. MATERIALS AND METHODS Forty implant fixture analogues and abutments were embedded in resin blocks. Forty cast crowns were fabricated and divided into 4 groups each containing 10 implants. Group A was cemented directly with the definitive cement (Cem-Implant). The remainder were cemented with provisional cement (Temp-Bond NE), and classified according to the method for cleaning the abutments. Group B used a plastic curette and wet gauze, Group C used a rubber cup and pumice, and Group D used an airborne particle abrasion technique. The abutments were observed using a stereomicroscope after removing the provisional cement. The tensile bond strength was measured after the definitive cementation. Statistical analysis was performed using one-way analysis of variance test (α=.05). RESULTS Group B clearly showed provisional cement remaining, whereas the other groups showed almost no cement. Groups A and B showed a relatively smooth surface. More roughness was observed in Group C, and apparent roughness was noted in Group D. The tensile bond strength tests revealed Group D to have significantly the highest tensile bond strength followed in order by Groups C, A and B. CONCLUSION A plastic curette and wet gauze alone cannot effectively remove the residual provisional cement on the abutment. The definitive retention increased when the abutments were treated with rubber cup/pumice or airborne particle abraded to remove the provisional cement. PMID:24049563

  18. Timing of syntaxial cement

    SciTech Connect

    Perkins, R.D.

    1985-02-01

    Echinodermal fragments are commonly overgrown in ancient limestones, with large single crystals growing in optical continuity over their skeletal hosts (i.e., syntaxial overgrowths). Such syntaxial cements are usually considered to have precipitated from meteoric pore waters associated with a later stage of subaerial exposure. Although several examples have been reported from ancient carbonates where petrographic relationships may indicate an early submarine formation of syntaxial cement, no occurrences have been noted in Holocene submarine-cemented rocks. Syntaxial cements of submarine origin have been found in Bermuda beachrock where isopachous high-magnesian calcite cements merge with large optically continuous crystals growing on echinodermal debris. Examination of other Holocene sediments cemented by magnesian calcite indicates that echinodermal fragments are not always overgrown syntaxially, but may be rimmed by microcrystalline calcite. The reason for this difference is not clear, although it may be a function of the spacing of nucleation sites and rates of crystal growth. A review of syntaxial cements from several localities in ancient carbonate sequences reveals that many are best interpreted as having formed in the submarine setting, whereas it is more clear that others formed from meteoric precipitation. These occurrences suggest that care should be exercised in inferring meteoric diagenesis from syntaxial overgrowths and that the possibility of submarine formation should be considered.

  19. ULTRA-LIGHTWEIGHT CEMENT

    SciTech Connect

    Fred Sabins

    2003-07-31

    The objective of this project is to develop an improved ultra-lightweight cement using ultra-lightweight hollow glass spheres (ULHS). This report discusses testing that was performed for analyzing the alkali-silica reactivity of ULHS in cement slurries. Laboratory testing during the eleventh quarter focused on evaluation of the alkali-silica reaction of eight different cement compositions, four of which contain ULHS. This report provides a progress summary of ASR testing. The original laboratory procedure for measuring set cement expansion resulted in unacceptable erosion of the test specimens. In subsequent tests, a different expansion procedure was implemented and an alternate curing method for cements formulated with TXI Lightweight cement was employed to prevent sample failure caused by thermal shock. The results obtained with the modified procedure showed improvement over data obtained with the original procedure, but data for some compositions were still questionable. Additional modification of test procedures for compositions containing TXI Lightweight cement were implemented and testing is ongoing.

  20. Addition of microbially-treated sugar beet residue and a native bacterium increases structural stability in heavy metal-contaminated Mediterranean soils.

    PubMed

    Carrasco, L; Caravaca, F; Azcón, R; Kohler, J; Roldán, A

    2009-10-15

    A mesocosm experiment was conducted to investigate the effect of the addition of Aspergillus niger-treated sugar beet waste, in the presence of rock phosphate, and inoculation with a native, metal-tolerant bacterium, Bacillus thuringiensis, on the stabilisation of soil aggregates of two mine tailings, with differing pH values, from a semiarid Mediterranean area and on the stimulation of growth of Piptatherum miliaceum. Bacterium combined with organic amendment enhanced structural stability (38% in acidic soil and 106% in neutral soil compared with their corresponding controls). Only the organic amendment increased pH, electrical conductivity, water-soluble C, water-soluble carbohydrates and plant growth, in both soils. While in neutral soil both organic amendment and bacterium increased dehydrogenase activity, only organic amendment had a significant effect in acidic soil. This study demonstrates that the use of P. miliaceum in combination with organic amendment and bacterium is a suitable tool for the stabilisation of the soil structure of degraded mine tailings, although its effectiveness is dependent on soil pH. PMID:19660785

  1. Microleakage of cements for stainless steel crowns.

    PubMed

    Shiflett, K; White, S N

    1997-01-01

    Microleakage is related to recurrent decay, inflammation of vital pulps, and reinfection of previously treated root canals. The purpose of this investigation was to compare the abilities of new adhesive cements and conventional nonadhesive controls to prevent microleakage under stainless steel crowns on primary anterior teeth. Standardized preparations were made, and stainless steel crowns were adapted. Specimens were assigned randomly to cement groups: zinc phosphate (ZP), polycarboxylate (PC), glass-ionomer (GI), resin-modified glass-ionomer (RMGI), RMGI with a dentin bonding agent (RMGI + DBA), adhesive composite resin (ACR) and zinc oxide eugenol (ZOE). Specimens were stored in water, aged artificially, stained, embedded, and sectioned, and the microleakage was measured. Group means and standard errors were calculated. ANOVA discerned differences among groups (P < 0.0001), and Turkey's multiple comparisons testing (P < 0.05) ranked the groups from least to most microleakage as follows: [RMGI + DBA, RMGI, ACR, GI], [ZP], and [PC, ZOE]. The adhesive cements significantly reduced microleakage.

  2. Stage cementing apparatus

    SciTech Connect

    Blamford, D.M.; Easter, J.H.

    1988-06-21

    A stage cementing apparatus for selectively passing cement from the interior passage of a casing to the annulus between the exterior of the casing and borehole, the casing having an upper portion and a lower portion, is described comprising: a barrel secured to the upper portion of the casing; a mandrel secured to the lower portion of the casing, and a stage cementing tool having a generally cylindrical configuration adapted for attachment to the lower end of the barrel about a portion of the mandrel.

  3. Bone cement implantation syndrome.

    PubMed

    Razuin, R; Effat, O; Shahidan, M N; Shama, D V; Miswan, M F M

    2013-06-01

    Bone cement implantation syndrome (BCIS) is characterized by hypoxia, hypotension, cardiac arrhythmias, increased pulmonary vascular resistance and cardiac arrest. It is a known cause of morbidity and mortality in patients undergoing cemented orthopaedic surgeries. The rarity of the condition as well as absence of a proper definition has contributed to under-reporting of cases. We report a 59-year-old woman who sustained fracture of the neck of her left femur and underwent an elective hybrid total hip replacement surgery. She collapsed during surgery and was revived only to succumb to death twelve hours later. Post mortem findings showed multiorgan disseminated microembolization of bone marrow and amorphous cement material. PMID:23817399

  4. Long-term applications of untreated and alum-treated poultry litter drive soil nitrogen concentrations and associated microbial community dynamics

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aluminum sulfate (alum)-treatment retains ammonia in poultry litter, potentially altering nitrogen cycling after application to soil. The objective of this research was to assess if eight and nine years of annual application of untreated or alum-treated poultry litters or ammonium nitrate have resul...

  5. Microbial biomass and soil carbon after 8 and 9 years of field applications of alum-treated and untreated poultry litter and inorganic nitrogen

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Amendment with aluminum sulfate (alum) is considered a best management practice for its benefits in poultry production and increased retention of nutrients in the litter. However, little is known about how long-term applications of alum-treated litter to soil will affect the microbial community and ...

  6. Assessment of sulfide production risk in soil during the infiltration of domestic wastewater treated by a sulfur-utilizing denitrification process.

    PubMed

    Ghorbel, L; Coudert, L; Gilbert, Y; Mercier, G; Blais, J F

    2016-10-01

    This study aimed to determine the potential of sulfide generation during infiltration through soil of domestic wastewater treated by a sulfur-utilizing denitrification process. Three types of soil with different permeability rates (K s = 0.028, 0.0013, and 0.00015 cm/s) were investigated to evaluate the potential risk of sulfur generation during the infiltration of domestic wastewater treated by a sulfur-utilizing denitrification system. These soils were thoroughly characterized and tested to assess their capacity to be used as drainages for wastewaters. Experiments were conducted under two operating modes (saturated and unsaturated). Sulfate, sulfide, and chemical oxygen demand (COD) levels were determined over a period of 100 days. Despite the high concentration of sulfates (200 mg/L) under anaerobic conditions (ORP = -297 mV), no significant amount of sulfide was generated in the aqueous (<0.2 mg/L) or gaseous (<0.15 ppm) phases. Furthermore, the soil permeability did not have a noticeable effect on the infiltration of domestic wastewater treated by a sulfur-utilizing denitrification system due to low contents of organic matter (i.e., dissolved organic carbon, DOC). The autotrophic denitrification process used to treat the domestic wastewater allowed the reduction of the concentration of biochemical oxygen demand (BOD5) below 5 mg/L, of DOC below 7 mg/L, and of COD below 100 mg/L.

  7. CHEMICAL CHARACTERIZATION OF A CHELATOR-TREATED SOIL HUMATE BY SOLUTION-STATE MULTINUCLEAR TWO-DIMENSIONAL NMR WITH FTIR AND PYROLYSIS-GCMS. (R825960)

    EPA Science Inventory

    A California forest soil used for contaminant bioavailability
    studies was extracted for humic substances (HS) and
    then treated with 4,5-dihydroxy-1,3-benzene disulfonate
    ("Tiron") to remove exchangeable metal ions. This yielded
    HS that was readily water-soluble at ...

  8. Assessment of sulfide production risk in soil during the infiltration of domestic wastewater treated by a sulfur-utilizing denitrification process.

    PubMed

    Ghorbel, L; Coudert, L; Gilbert, Y; Mercier, G; Blais, J F

    2016-10-01

    This study aimed to determine the potential of sulfide generation during infiltration through soil of domestic wastewater treated by a sulfur-utilizing denitrification process. Three types of soil with different permeability rates (K s = 0.028, 0.0013, and 0.00015 cm/s) were investigated to evaluate the potential risk of sulfur generation during the infiltration of domestic wastewater treated by a sulfur-utilizing denitrification system. These soils were thoroughly characterized and tested to assess their capacity to be used as drainages for wastewaters. Experiments were conducted under two operating modes (saturated and unsaturated). Sulfate, sulfide, and chemical oxygen demand (COD) levels were determined over a period of 100 days. Despite the high concentration of sulfates (200 mg/L) under anaerobic conditions (ORP = -297 mV), no significant amount of sulfide was generated in the aqueous (<0.2 mg/L) or gaseous (<0.15 ppm) phases. Furthermore, the soil permeability did not have a noticeable effect on the infiltration of domestic wastewater treated by a sulfur-utilizing denitrification system due to low contents of organic matter (i.e., dissolved organic carbon, DOC). The autotrophic denitrification process used to treat the domestic wastewater allowed the reduction of the concentration of biochemical oxygen demand (BOD5) below 5 mg/L, of DOC below 7 mg/L, and of COD below 100 mg/L. PMID:27343077

  9. Changes in Plant Nutrients, and Microbial Biomass in Different Soil Depths After Long-Term Surface Application of Secondary Treated Wastewater

    NASA Astrophysics Data System (ADS)

    Al-Rashidi, Radhi; Rusan, Munir; Obaid, Karem

    2013-12-01

    Long-term effects of surface application of secondary treated wastewater on plant nutrients dynamics, the cycling of C and N within the system through the determination of microbial biomass, and associated health hazards were studied in different soil locations. Sites that have been irrigated with wastewater for the last 1, 4, 10, and 17 years were identified and used as sampling locations for this study. Two other sites that have not been irrigated with wastewater were sampled as a control. Soil samples were taken from several sites within each location, and at the following depths: 0-20, 20-40, and 40-60 cm. Results obtained indicated that microbial biomass C and N were increased significantly with increasing application period of treated wastewater. Barley plant tissues analysis showed that plant nutrients content was significantly higher in sites which received wastewater for a long period than other sites. No significances in accumulation of lead (Pb) in barley plant tissues were observed with sites received wastewater for different periods. The bacteriological analysis showed that the total bacterial count of surface soil (0-20 cm) was higher in sites irrigated with wastewater for the last 10 and 17 years. The total coliforms ranged from 0.92x102 cfu/g soil to 3.3x102 cfu/g soil, while fecal coliform were less and detected only in top soils at sites irrigated with wastewater for the last 10 and 17 years.

  10. Modifications of sulfur polymer cement (SPC) stabilization and solidification (S/S) process

    SciTech Connect

    Lin, S.L.; Lai, J.S.; Chian, E.S.K.

    1995-12-31

    This paper addresses the effectiveness of using sulfur polymer cement (SPC) as a binder to stabilize/solidify lead-contaminated soils. SPC, which has been used as a construction material because of its excellent resistance to acid and salt environments and its superior water tightness as compared with Portland cement concrete, has recently emerged as a possible alternative binder to stabilize/solidify soils contaminated with hazardous, low-level radioactive and mixed wastes. However, it was found that the use of SPC alone could not satisfactorily stabilize/solidify lead-contaminated soils. Nevertheless, it was shown that additives, such as sodium sulfide or sodium sulfite, could be used to greatly enhance the ability of SPC to react chemically with lead contaminants, and physicochemically to bind these compounds. These enable us significantly to lower the leachability (e.g. from 77.8 mg Pb/l to 1.28 mg Pb/l in EPA TCLP extract) of the SPC-treated wastes to the point where they can be recycled as some form of construction material.

  11. Corrosion-resistant Foamed Cements for Carbon Steels

    SciTech Connect

    Sugama T.; Gill, S.; Pyatina, T., Muraca, A.; Keese, R.; Khan, A.; Bour, D.

    2012-12-01

    The cementitious material consisting of Secar #80, Class F fly ash, and sodium silicate designed as an alternative thermal-shock resistant cement for the Enhanced Geothermal System (EGS) wells was treated with cocamidopropyl dimethylamine oxide-based compound as foaming agent (FA) to prepare numerous air bubble-dispersed low density cement slurries of and #61603;1.3 g/cm3. Then, the foamed slurry was modified with acrylic emulsion (AE) as corrosion inhibitor. We detailed the positive effects of the acrylic polymer (AP) in this emulsion on the five different properties of the foamed cement: 1) The hydrothermal stability of the AP in 200 and #61616;C-autoclaved cements; 2) the hydrolysis-hydration reactions of the slurry at 85 and #61616;C; 3) the composition of crystalline phases assembled and the microstructure developed in autoclaved cements; 4) the mechanical behaviors of the autoclaved cements; and, 5) the corrosion mitigation of carbon steel (CS) by the polymer. For the first property, the hydrothermal-catalyzed acid-base interactions between the AP and cement resulted in Ca-or Na-complexed carboxylate derivatives, which led to the improvement of thermal stability of the AP. This interaction also stimulated the cement hydration reactions, enhancing the total heat evolved during cement’s curing. Addition of AP did not alter any of the crystalline phase compositions responsible for the strength of the cement. Furthermore, the AP-modified cement developed the porous microstructure with numerous defect-free cavities of disconnected voids. These effects together contributed to the improvement of compressive-strength and –toughness of the cured cement. AP modification of the cement also offered an improved protection of CS against brine-caused corrosion. There were three major factors governing the corrosion protection: 1) Reducing the extents of infiltration and transportation of corrosive electrolytes through the cement layer deposited on the underlying CS

  12. A kinetic study of trace element leachability from abandoned-mine-polluted soil treated with SS-MSW compost and red mud. Comparison with results from sequential extraction.

    PubMed

    Brunori, C; Cremisini, C; D'Annibale, L; Massanisso, P; Pinto, V

    2005-04-01

    The effect of adding treated red mud, a by-product of alumina production, to soil polluted by an abandoned mine and characterised by high concentrations of heavy metals, relatively low reaction grade, and low organic carbon content, was investigated. Also studied was addition of both red mud and compost (produced from source-separated municipal solid waste)--the synergistic action of red mud and compost could be exploited to achieve both metal trapping and an increase in organic carbon content. Leaching batch tests were performed on four different systems: soil, soil and treated red mud, soil and compost, soil and compost plus treated red mud. Dilute sulfuric acid and EDTA solution (liquid/solid ratio 10:1) were used in the tests--sulfuric acid to "mimic" acid rain and EDTA in accordance with general methods for estimating "plant-available" metals. Sequential extraction was also applied to the same samples. The use of relatively non-specific extractant reagents in the leaching tests led to a kinetic approach (already proposed in literature), because measurements of trace elements extracted at equilibrium cannot be related to their speciation. Comparison of information obtainable by the kinetic approach to evaluation of data from leaching tests with results from sequential extraction enabled evaluation whether the "kinetic fractionation method", a relatively rapid and simple procedure, furnishes adequate information about the mobility and bioavailability of trace elements. Especially interesting results were obtained for Mn, Zn, and Ni, present in large amounts in the soil studied--their leachability was significantly reduced by addition of red mud and compost, suggesting interesting perspectives in soil-remediation activity.

  13. Environmentally compatible spray cement

    SciTech Connect

    Loeschnig, P.

    1995-12-31

    Within the framework of a European research project, Heidelberger Zement developed a quickly setting and hardening binder for shotcrete, called Chronolith S, which avoids the application of setting accelerators. Density and strength of the shotcrete produced with this spray cement correspond to those of an unaccelerated shotcrete. An increased hazard for the heading team and for the environment, which may occur when applying setting accelerators, can be excluded here. Owing to the special setting properties of a spray cement, the process engineering for its manufacturing is of great importance. The treatment of a spray cement as a dry concrete with kiln-dried aggregates is possible without any problems. The use of a naturally damp pre-batched mixture is possible with Chronolith S but requires special process engineering; spray cement and damp aggregate are mixed with one another immediately before entering the spraying machinery.

  14. Thermodynamics and cement science

    SciTech Connect

    Damidot, D.; Lothenbach, B.; Herfort, D.; Glasser, F.P.

    2011-07-15

    Thermodynamics applied to cement science has proved to be very valuable. One of the most striking findings has been the extent to which the hydrate phases, with one conspicuous exception, achieve equilibrium. The important exception is the persistence of amorphous C-S-H which is metastable with respect to crystalline calcium silicate hydrates. Nevertheless C-S-H can be included in the scope of calculations. As a consequence, from comparison of calculation and experiment, it appears that kinetics is not necessarily an insuperable barrier to engineering the phase composition of a hydrated Portland cement. Also the sensitivity of the mineralogy of the AFm and AFt phase compositions to the presence of calcite and to temperature has been reported. This knowledge gives a powerful incentive to develop links between the mineralogy and engineering properties of hydrated cement paste and, of course, anticipates improvements in its performance leading to decreasing the environmental impacts of cement production.

  15. Effects of long-term irrigation with treated wastewater on the hydraulic properties, and the water and air regime in the root zone of a clayey soil.

    NASA Astrophysics Data System (ADS)

    Assouline, Shmuel

    2013-04-01

    With increasing water scarcity, treated wastewater (TW) appears as an attractive alternative source of water for irrigation, especially in arid and semi-arid regions where freshwater is naturally scarce. However, it seems that long-term use of TW for irrigation of orchards planted on heavy soils cause to yield reduction and crop damages. In terms of water quality, TW are characterized by higher concentrations of sodium and dissolved organic content (DOC) that affect soil exchangeable sodium percentage (ESP) on one hand and soil wettability, on the other hand. The working hypothesis of this study is that long-term use of TW for irrigation of clayey soils causes significant changes in the soil hydraulic properties. Such changes might affect the water and air regime in the root zone, and the hydrological balance components at the field scale. High-resolution field sampling determined the spatial distribution of chloride, ESP and DOC below the dripper, revealing higher salinity and sodicity, lower hydraulic conductivity, and possible preferential flow pattern linked to wettability in WW-irrigated soils. Laboratory experiments involving infiltration, evaporation, and swelling pressure measurements provide quantitative estimates of the impact of TW for irrigation on the soil hydraulic properties. The upper soil layer of TW-irrigated plots is more affected by the impact of DOC on soil wettability, while the lower layers are more affected by the impact of the increased ESP on soil hydraulic conductivity. Continuous monitoring of oxygen concentration at 10, 20 and 30 cm depths in the root zone near the trees and at mid-distance between trees revealed that the air regime in the root zone is significantly affected by the TW use as a consequence for the effect on the water regime.

  16. Different bacterial communities in heat and gamma irradiation treated replant disease soils revealed by 16S rRNA gene analysis - contribution to improved aboveground apple plant growth?

    PubMed

    Yim, Bunlong; Winkelmann, Traud; Ding, Guo-Chun; Smalla, Kornelia

    2015-01-01

    Replant disease (RD) severely affects apple production in propagation tree nurseries and in fruit orchards worldwide. This study aimed to investigate the effects of soil disinfection treatments on plant growth and health in a biotest in two different RD soil types under greenhouse conditions and to link the plant growth status with the bacterial community composition at the time of plant sampling. In the biotest performed we observed that the aboveground growth of apple rootstock M26 plants after 8 weeks was improved in the two RD soils either treated at 50°C or with gamma irradiation compared to the untreated RD soils. Total community DNA was extracted from soil loosely adhering to the roots and quantitative real-time PCR revealed no pronounced differences in 16S rRNA gene copy numbers. 16S rRNA gene-based bacterial community analysis by denaturing gradient gel electrophoresis (DGGE) and 454-pyrosequencing revealed significant differences in the bacterial community composition even after 8 weeks of plant growth. In both soils, the treatments affected different phyla but only the relative abundance of Acidobacteria was reduced by both treatments. The genera Streptomyces, Bacillus, Paenibacillus, and Sphingomonas had a higher relative abundance in both heat treated soils, whereas the relative abundance of Mucilaginibacter, Devosia, and Rhodanobacter was increased in the gamma-irradiated soils and only the genus Phenylobacterium was increased in both treatments. The increased abundance of genera with potentially beneficial bacteria, i.e., potential degraders of phenolic compounds might have contributed to the improved plant growth in both treatments.

  17. Different bacterial communities in heat and gamma irradiation treated replant disease soils revealed by 16S rRNA gene analysis - contribution to improved aboveground apple plant growth?

    PubMed

    Yim, Bunlong; Winkelmann, Traud; Ding, Guo-Chun; Smalla, Kornelia

    2015-01-01

    Replant disease (RD) severely affects apple production in propagation tree nurseries and in fruit orchards worldwide. This study aimed to investigate the effects of soil disinfection treatments on plant growth and health in a biotest in two different RD soil types under greenhouse conditions and to link the plant growth status with the bacterial community composition at the time of plant sampling. In the biotest performed we observed that the aboveground growth of apple rootstock M26 plants after 8 weeks was improved in the two RD soils either treated at 50°C or with gamma irradiation compared to the untreated RD soils. Total community DNA was extracted from soil loosely adhering to the roots and quantitative real-time PCR revealed no pronounced differences in 16S rRNA gene copy numbers. 16S rRNA gene-based bacterial community analysis by denaturing gradient gel electrophoresis (DGGE) and 454-pyrosequencing revealed significant differences in the bacterial community composition even after 8 weeks of plant growth. In both soils, the treatments affected different phyla but only the relative abundance of Acidobacteria was reduced by both treatments. The genera Streptomyces, Bacillus, Paenibacillus, and Sphingomonas had a higher relative abundance in both heat treated soils, whereas the relative abundance of Mucilaginibacter, Devosia, and Rhodanobacter was increased in the gamma-irradiated soils and only the genus Phenylobacterium was increased in both treatments. The increased abundance of genera with potentially beneficial bacteria, i.e., potential degraders of phenolic compounds might have contributed to the improved plant growth in both treatments. PMID:26635733

  18. Root-Zone Redox Dynamics - In Search for the Cause of Damage to Treated-Wastewater Irrigated Orchards in Clay Soils

    NASA Astrophysics Data System (ADS)

    Yalin, David; Shenker, Moshe; Schwartz, Amnon; Assouline, Shmuel; Tarchitzky, Jorge

    2016-04-01

    Treated wastewater (TW) has become a common source of water for agriculture. However recent findings raise concern regarding its use: a marked decrease (up to 40%) in yield appeared in orchards irrigated with TW compared with fresh water (FW) irrigated orchards. These detrimental effects appeared predominantly in orchards cultivated in clay soils. The association of the damage with clay soils rather than sandy soils led us to hypothesize that the damage is linked to soil aeration problems. We suspected that in clay soils, high sodium adsorption ratio (SAR) and high levels of organic material, both typical of TW, may jointly lead to an extreme decrease in soil oxygen levels, so as to shift soil reduction-oxidation (redox) state down to levels that are known to damage plants. Two-year continuous measurement of redox potential, pH, water tension, and oxygen were conducted in the root-zone (20-35 cm depth) of avocado trees planted in clay soil and irrigated with either TW or FW. Soil solution composition was sampled periodically in-situ and mineral composition was sampled in tree leaves and woody organs biannually. In dry periods the pe+pH values indicated oxic conditions (pe+pH>14), and the fluctuations in redox values were small in both TW and FW plots. Decreases in soil water tension following irrigation or rain were followed by drops in soil oxygen and pe+pH values. TW irrigated plots had significantly lower minimum pe+pH values compared with FW-irrigated plots, the most significant differences occurred during the irrigation season rather than the rain season. A linear correlation appeared between irrigation volume and reduction severity in TW-irrigated plots, but not in the FW plots, indicating a direct link to the irrigation regime in TW-irrigated plots. The minimum pe+pH values measured in the TW plots are indicative of suboxic conditions (9soil solution and in

  19. Novorossiysk agglomeration landscapes and cement production: geochemical impact assessment

    NASA Astrophysics Data System (ADS)

    Alekseenko, A. V.; Pashkevich, M. A.

    2016-09-01

    The article deals with assessing the environmental impact of marl mining and cement production in Novorossiysk city (Krasnodar krai, Russia). The existing methods of studying the environmental effects caused by the cement industry have been reviewed. Soil and aquatic vegetation sampling has been carried out and the gross concentration of metals in the samples has been defined. The research has been conducted in the certified and accredited laboratory using emission spectral analysis. The external control has been carried out via X-ray fluorescence analysis. Based on the collected data, main chemical pollutants in soil cover and water area near the cement plant have been identified. The contaminants released by urban enterprises and motor vehicle emissions, as well as fugitive dust from dumps and the cement factory, lead to multi-element lithogeochemical anomaly at geochemical barriers in soils. Accumulation of pollutants in soil depends on the type of land use and the area relief. The most contaminated aquatic landscapes have been identified in the inner bay. According to this information, the technical proposals can be prepared for environmental safety management in strongly polluted city areas, as well as for the reclamation design in the areas currently experiencing the negative impact of cement production.

  20. [Comparison of fixation effects of heavy metals between cement rotary kiln co-processing and cement solidification/stabilization].

    PubMed

    Zhang, Jun-li; Liu, Jian-guo; Li, Cheng; Jin, Yi-ying; Nie, Yong-feng

    2008-04-01

    Both cement rotary kiln co-processing hazardous wastes and cement solidification/stabilization could dispose heavy metals by fixation. Different fixation mechanisms lead to different fixation effects. The same amount of heavy metal compounds containing As, Cd, Cr, Cu, Pb, Zn were treated by the two kinds of fixation technologies. GB leaching test, TCLP tests and sequential extraction procedures were employed to compare the fixation effects of two fixation technologies. The leached concentration and chemical species distribution of heavy metals in two grounded mortar samples were analyzed and the fixation effects of two kinds of technologies to different heavy metals were compared. The results show the fixation effect of cement rotary kiln co-processing technology is better than cement solidification/stabilization technology to As, Pb, Zn. Calcinations in cement rotary kiln and then hydration help As, Pb, Zn contained in hazardous wastes transform to more steady chemical species and effectively dispose these heavy metals compounds. Cr3+ is liable to be converted to much more toxic and more mobile Cr6+ state in cement rotary kiln. And so Cr wastes are more fit for treatment by cement solidification/stabilization technology. The work could provide a basis when choosing disposal technologies for different heavy metals and be helpful to improve the application and development of cement rotary kiln co-processing hazardous wastes.

  1. Arthroscopic burring of exposed cement following curettage and cavity filling cementation for chondroblastoma of the proximal tibia.

    PubMed

    Park, Jong-Hoon; Chae, In-Jung; Han, Seung-Beom; Lee, Dae-Hee

    2015-03-01

    Chondroblastoma of the proximal tibia is difficult to treat because of its epiphyseal predilection. This condition can be treated by curettage, which results in immediate restoration of stability and a reduced recurrence rate, followed by cement filling of the bone defect. Nevertheless, contact with cement can damage articular cartilage, potentially leading to severe knee osteoarthritis. Most previous reports regarding this complication described patients with giant cell tumors of the proximal tibia. We present here a patient who underwent arthroscopic treatment for cement exposure caused by articular cartilage loss of the tibial plateau, which occurred after initial curettage and cementation for chondroblastoma of the proximal tibia. To our knowledge, this is the first report on arthroscopic treatment of this condition.

  2. Arthroscopic Burring of Exposed Cement Following Curettage and Cavity Filling Cementation for Chondroblastoma of the Proximal Tibia

    PubMed Central

    Park, Jong-Hoon; Chae, In-Jung; Han, Seung-Beom

    2015-01-01

    Chondroblastoma of the proximal tibia is difficult to treat because of its epiphyseal predilection. This condition can be treated by curettage, which results in immediate restoration of stability and a reduced recurrence rate, followed by cement filling of the bone defect. Nevertheless, contact with cement can damage articular cartilage, potentially leading to severe knee osteoarthritis. Most previous reports regarding this complication described patients with giant cell tumors of the proximal tibia. We present here a patient who underwent arthroscopic treatment for cement exposure caused by articular cartilage loss of the tibial plateau, which occurred after initial curettage and cementation for chondroblastoma of the proximal tibia. To our knowledge, this is the first report on arthroscopic treatment of this condition. PMID:25750896

  3. Arthroscopic burring of exposed cement following curettage and cavity filling cementation for chondroblastoma of the proximal tibia.

    PubMed

    Park, Jong-Hoon; Chae, In-Jung; Han, Seung-Beom; Lee, Dae-Hee

    2015-03-01

    Chondroblastoma of the proximal tibia is difficult to treat because of its epiphyseal predilection. This condition can be treated by curettage, which results in immediate restoration of stability and a reduced recurrence rate, followed by cement filling of the bone defect. Nevertheless, contact with cement can damage articular cartilage, potentially leading to severe knee osteoarthritis. Most previous reports regarding this complication described patients with giant cell tumors of the proximal tibia. We present here a patient who underwent arthroscopic treatment for cement exposure caused by articular cartilage loss of the tibial plateau, which occurred after initial curettage and cementation for chondroblastoma of the proximal tibia. To our knowledge, this is the first report on arthroscopic treatment of this condition. PMID:25750896

  4. Degradation of N,N'-dibutylurea (DBU) in soils treated with only DBU and DBU-fortified benlate fungicides.

    PubMed

    Lee, Linda S; Sassman, Stephen A; Bischoff, Marianne; Turco, Ronald F

    2004-01-01

    N,N'-dibutylurea (DBU) is a breakdown product of benomyl [methyl 1-(butylcarbamoyl)-2-benzimidazole carbamate], the active ingredient in Benlate fungicides, and has been proposed to cause crop damage after the use of Benlate 50 DF fungicide (DuPont, Wilmington, DE). Our research focused on DBU persistence after application into soil. We assessed DBU persistence on direct application of DBU (carbonyl-(14)C) at two concentrations (0.08 and 0.8 microg DBU kg(-1)) to seven soils and two potting mixes in soil microcosms incubated at various combinations of soil water potential (-0.03 or -0.1 MPa) and temperature (23, 33, 44 degrees C). For two soils at a subset of treatment variables we assessed DBU persistence in the presence of Benlate DF and SP fungicide formulations. Parent compounds, metabolites, and (14)CO(2) were tracked using chromatographic analysis with radioassay and UV detection, liquid scintillation counting, and post-extraction oxidation of the soil. DBU degradation was primarily microbial and for most soil-treatment combinations, half-lives were less than 2 wk. DBU degradation was retarded at the lower soil water potential and enhanced at 33 degrees C. In the presence of the formulation, DBU degradation was slower for one soil type. The longest half-life observed in any case was less than 7 wk; therefore, long-term persistence of DBU applied to soils through a Benlate application is very unlikely.

  5. Heavy metal accumulation in soils and grains, and health risks associated with use of treated municipal wastewater in subsurface drip irrigation

    NASA Astrophysics Data System (ADS)

    Asgari, Kamran; Najafi, Payam; Cornelis, Wim M.

    2014-05-01

    Constant use of treated wastewater for irrigation over long periods may cause buildup of heavy metals up to toxic levels for plants, animals, and entails environmental hazards in different aspects. However, application of treated wastewater on agricultural land might be an effective and sustainable strategy in arid and semi-arid countries where fresh water resources are under great pressure, as long as potential harmful effects on the environment including soil, plants, and fresh water resources, and health risks to humans are minimized. The aim of this study was to assess the effect of using a deep emitter installation on lowering the potential heavy metal accumulation in soils and grains, and health risk under drip irrigation with treated municipal wastewater. A field experiment was conducted according to a split block design with two treatments (fresh and wastewater) and three sub treatments (0, 15 and 30 cm depth of emitters) in four replicates on a sandy loam soil, in Esfahan, Iran. The annual rainfall is about 123 mm, mean annual ETo is 1457 mm, and the elevation is 1590 m a.s.l.. A two-crop rotation of wheat [Triticum spp.] and corn [Zea mays]) was established on each plot with wheat growing from February to June and corn from July to September. Soil samples were collected before planting (initial value) and after harvesting (final value) for each crop in each year. Edible grain samples of corn and wheat were also collected. Elemental concentrations (Cu, Zn, Cd, Pb, Cr, Ni) in soil and grains were determined using an atomic absorption spectrophotometer. The concentrations of heavy metals in the wastewater-irrigated soils were not significantly different (P>0.05) compared with the freshwater-irrigated soils. The results showed no significant difference (P>0.05) of soil heavy metal content between different depths of emitters. A pollution load index PLI showed that there was not substantial buildup of heavy metals in the wastewater-irrigated soils compared to

  6. ULTRA-LIGHTWEIGHT CEMENT

    SciTech Connect

    Fred Sabins

    2003-06-16

    The objective of this project is to develop an improved ultra-lightweight cement using ultra-lightweight hollow glass spheres (ULHS). This report discusses testing that was performed for analyzing the alkali-silica reactivity of ULHS in cement slurries. Laboratory testing during the tenth quarter focused on evaluation of the alkali-silica reaction of eight different cement compositions, four of which contain ULHS. The original laboratory procedure for measuring set cement expansion resulted in test specimen erosion that was unacceptable. A different expansion procedure is being evaluated. This report provides a progress summary of ASR testing. The testing program initiated in November produced questionable initial results so the procedure was modified slightly and the testing was reinitiated. The results obtained with the modified procedure showed improvement over data obtained with the original procedure, but questionable data were obtained from several of the compositions. Additional modification of test procedures for compositions containing TXI Lightweight cement are being implemented and testing is ongoing.

  7. ULTRA-LIGHTWEIGHT CEMENT

    SciTech Connect

    Fred Sabins

    2001-10-23

    The objective of this project is to develop an improved ultra-lightweight cement using ultra-lightweight hollow glass spheres (ULHS). Work reported herein addresses tasks performed in the fourth quarter as well as the other three quarters of the past year. The subjects that were covered in previous reports and that are also discussed in this report include: Analysis of field laboratory data of active cement applications from three oil-well service companies; Preliminary findings from a literature review focusing on problems associated with ultra-lightweight cements; Summary of pertinent information from Russian ultra-lightweight cement literature review; and Comparison of compressive strengths of ULHS systems using ultrasonic and crush methods Results reported from the fourth quarter include laboratory testing of ULHS systems along with other lightweight cement systems--foamed and sodium silicate slurries. These comparison studies were completed for two different densities (10.0 and 11.5 lb/gal) and three different field application scenarios. Additional testing included the mechanical properties of ULHS systems and other lightweight systems. Studies were also performed to examine the effect that circulation by centrifugal pump during mixing has on breakage of ULHS.

  8. Retention of crowns cemented on implant abutments with temporary cements.

    PubMed

    Nagasawa, Yuko; Hibino, Yasushi; Nakajima, Hiroshi

    2014-01-01

    This study was to examine the retentive force of crowns to implant abutments with commercial temporary cements. Six different temporary cements were investigated. Cast crowns were cemented to the abutments using each cement and their retentive forces to abutments were determined 7 or 28 days after cementing (n=10). The retentive force of the cements to abutments varied widely among the products [27-109 N (7-day), 18-80 N (28-days)]. The retentive force of all the cements was not reduced as the time elapsed, except for two products tested. The polycarboxylate cements and paste-mixing type eugenol-free cements revealed comparable retentive force after 28 days of storage. The powder-liquid type cements showed a positive correlation (p<0.05) between the retentive force and the shear strength, while a negative correlation (p<0.05) was obtained for paste-mixing type cement between the retentive force and compressive strength. Mechanical strength of temporary cements could not be a prominent predicting factor for retention of the crowns on the abutments.

  9. Mechanical and acoustic properties of weakly cemented granular rocks

    SciTech Connect

    Nakagawa, S.; Myer, L.R.

    2001-05-09

    This paper presents the results of laboratory measurements on the mechanical and acoustic properties of weakly cemented granular rock. Artificial rock samples were fabricated by cementing sand and glass beads with sodium silicate binder. During uniaxial compression tests, the rock samples showed stress-strain behavior which was more similar to that of soils than competent rocks, exhibiting large permanent deformations with frictional slip. The mechanical behavior of the samples approached that of competent rocks as the amount of binder was increased. For very weak samples, acoustic waves propagating in these rocks showed very low velocities of less than 1000 m/sec for compressional waves. A borehole made within this weakly cemented rock exhibited a unique mode of failure that is called ''anti-KI mode fracture'' in this paper. The effect of cementation, grain type, and boundary conditions on this mode of failure was also examined experimentally.

  10. Recycled rubber in cement composites

    SciTech Connect

    Raghavan, D.; Tratt, K.; Wool, R.P.

    1994-12-31

    Disposal of 200 million waste tires in the US each year has become a major problem. An environmentally sound innovative technology of recycling rubber in cement matrix was examined. Using silane coupling agent the rubber was bonded to the hydrating cement making a lighter composite, which absorbed more energy than ordinary Portland cement. The bonding information was obtained by peel strength analysis. SEM was used to understand the mode of fracture in pure cement paste, cement bonded rubber composite and rubber filled cement paste. It was found that cracks propagate through the rubber particle in rubber bonded cement composite while in unbonded rubber cement mix, the cracks propagate around the interface. The density and shrinkage measurements are also discussed.

  11. System for radioactive waste cementation

    SciTech Connect

    Dmitriev, S.A.; Barinov, A.S.; Varlakov, A.P.; Volkov, A.S.; Karlin, S.V.

    1995-12-31

    NPP, research reactors and radiochemical enterprises produce a great amount of liquid radioactive waste (LRW). One of the methods of LRW solidification is cementation. The recent investigations demonstrated possible inclusion of sufficient amount of waste in the cement matrix (up to 20--30 mass% on dry residue). In this case the cementation process becomes competitive with bituminization process, where the matrix can include 40--50 mass% and the solidified product volume is equal to the volume, obtained by cementation. Additionally, the cement matrix in contrast with the bituminous one is unburnable. Many countries are investigating the cementation process. The main idea governing technological process is the waste and cement mixing method and type of mixer. In world practice some principal types of cementation systems are used. The paper describes the SIA Radon industrial plant in Moscow.

  12. The hydration of dental cements.

    PubMed

    Wilson, A D; Paddon, J M; Crisp, S

    1979-03-01

    A study was made of the hydration of dental cements, water being classified as "non-evaporable" and "evaporable". The ratio of these two types of water was found to vary greatly among different cement types, being lesser in zinc oxide and ionic polymer cements and greater in ion-leachable glass and phosphoric acid cements. The cement with the least "non-evaporable" water, i.e., showing least hydration (the zinc polycarboxylate cement), had the lowest strength and modulus and the greatest deformation at failure. A linear relationship was found to exist between strength and the degree of hydration of dental cements. All the cements were found to become more highly hydrated and stronger as they aged. PMID:284040

  13. Small-particle-size cement

    SciTech Connect

    Ewert, D.P.; Almond, S.W.; Blerhaus, W.M. II )

    1991-05-01

    Successful remedial cementing has historically been difficult in wells with large-interval, multizone, gravel-packed completions. The reason is the inability of conventional oilfield cements to penetrate gravel packs adequately. Small-particle-size cement (SPSC) was developed to penetrate gravel packs and to provide the zonal isolation required. This paper details the laboratory work, job design, and field implementation of this new cement.

  14. Fate of antibiotic resistance genes and class 1 integrons in soil microcosms following the application of treated residual municipal wastewater solids.

    PubMed

    Burch, Tucker R; Sadowsky, Michael J; LaPara, Timothy M

    2014-05-20

    Substantial quantities of antibiotic resistance genes (ARGs) are discharged with treated residual municipal wastewater solids and subsequently applied to soil. The objective of this work was to determine the decay rates for ARGs and class 1 integrons following simulated land application of treated wastewater solids. Treated residual solids from two full-scale treatment plants were applied to sets of triplicate soil microcosms in two independent experiments. Experiment 1 investigated loading rates of 20, 40, and 100 g kg(-1) of residual solids to a sandy soil, while experiment 2 investigated a loading rate of 40 g kg(-1) to a silty-loamy soil. Five ARGs (erm(B), sul1, tet(A), tet(W), and tet(X)), the integrase of class 1 integrons (intI1), 16S rRNA genes, 16S rRNA genes of all Bacteroides spp., and 16S rRNA genes of human-specific Bacteroides spp. were quantified using real-time polymerase chain reaction. ARGs and intI1 quantities declined in most microcosms, with statistically significant (P < 0.05) half-lives varying between 13 d (erm(B), experiment 1, 100 g kg(-1)) and 81 d (intI1, experiment 1, 40 g kg(-1)). These kinetic rates were much slower than have been previously reported for unit operations used to treat wastewater solids (e.g., anaerobic digestion). This research suggests that the design and operation of municipal wastewater treatment facilities with the explicit goal of mitigating the release of ARGs should focus on using technologies within the treatment facility, rather than depending on attenuation subsequent to land application.

  15. CHEMICALLY BONDED CEMENTS FROM BOILER ASH AND SLUDGE WASTES. PHASE II REPORT, SEPT.1998-JULY 1999.

    SciTech Connect

    SUGAMA,T.YAGER,K.A.BLANKENHORN,D.

    1999-08-01

    Based upon the previous Phase I research program aimed at looking for ways of recycling the KeySpan-generated wastes, such as waste water treatment sludge (WWTS) and bottom ash (BA), into the potentially useful cementitious materials called chemically bonded cement (CBC) materials, the emphasis of this Phase II program done at Brookhaven National Laboratory, in a period of September 1998 through July 1999, was directed towards the two major subjects: One was to assess the technical feasibility of WWTS-based CBC material for use as Pb-exchange adsorbent (PEA) which remediates Pb-contaminated soils in the field; and the other was related to the establishment of the optimum-packaging storage system of dry BA-based CBC components that make it a promising matrix material for the steam-cured concrete products containing sand and coarse aggregate. To achieve the goal of the first subject, a small-scale field demonstration test was carried out. Using the PEA material consisting of 30 wt% WWTS, 13 wt% Type I cement and 57 wt% water, the PES slurry was prepared using a rotary shear concrete mixer, and then poured on the Pb-contaminated soil. The PEA-to-soil ratio by weight was a factor of 2.0. The placed PEA slurry was blended with soil using hand mixing tools such as claws and shovels. The wettability of soils with the PEA was very good, thereby facilitating the soil-PEA mix procedures. A very promising result was obtained from this field test; in fact, the mount of Pb leached out from the 25-day-aged PEA-treated soil specimen was only 0.74 mg/l, meeting the requirement for EPA safe regulation of < 5 mg/l. In contrast, a large amount (26.4 mg/l) of Pb was detected from the untreated soil of the same age. Thus, this finding demonstrated that the WWTS-based CBC has a potential for use as PEA material. Regarding the second subject, the dry-packed storage system consisting of 68.7 wt% BA, 13.0 wt% calcium aluminate cement (CAC), 13.0 wt% Type I portland cement and 5.3 wt

  16. Reducing cement's CO2 footprint

    USGS Publications Warehouse

    van Oss, Hendrik G.

    2011-01-01

    The manufacturing process for Portland cement causes high levels of greenhouse gas emissions. However, environmental impacts can be reduced by using more energy-efficient kilns and replacing fossil energy with alternative fuels. Although carbon capture and new cements with less CO2 emission are still in the experimental phase, all these innovations can help develop a cleaner cement industry.

  17. High temperature lightweight foamed cements

    DOEpatents

    Sugama, Toshifumi.

    1989-10-03

    Cement slurries are disclosed which are suitable for use in geothermal wells since they can withstand high temperatures and high pressures. The formulation consists of cement, silica flour, water, a retarder, a foaming agent, a foam stabilizer, and a reinforcing agent. A process for producing these cements is also disclosed. 3 figs.

  18. High temperature lightweight foamed cements

    DOEpatents

    Sugama, Toshifumi

    1989-01-01

    Cement slurries are disclosed which are suitable for use in geothermal wells since they can withstand high temperatures and high pressures. The formulation consists of cement, silica flour, water, a retarder, a foaming agent, a foam stabilizer, and a reinforcing agent. A process for producing these cements is also disclosed.

  19. Assessing Environmental Impacts of Treated Wastewater through Monitoring of Fecal Indicator Bacteria and Salinity in Irrigated Soils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    To assess the potential for bacterial persistence and/or growth in reclaimed water irrigation systems and in irrigated soils, and to quantify the effects of wastewater application on soil salinity, levels of fecal indicator bacteria (E. coli, Enterococcus) and environmental covariates were measured ...

  20. Cementing a wellbore using cementing material encapsulated in a shell

    DOEpatents

    Aines, Roger D.; Bourcier, William L.; Duoss, Eric B.; Spadaccini, Christopher M.; Cowan, Kenneth Michael

    2016-08-16

    A system for cementing a wellbore penetrating an earth formation into which a pipe extends. A cement material is positioned in the space between the wellbore and the pipe by circulated capsules containing the cement material through the pipe into the space between the wellbore and the pipe. The capsules contain the cementing material encapsulated in a shell. The capsules are added to a fluid and the fluid with capsules is circulated through the pipe into the space between the wellbore and the pipe. The shell is breached once the capsules contain the cementing material are in position in the space between the wellbore and the pipe.

  1. Salinity control in a clay soil beneath an orchard irrigated with treated waste water in the presence of a high water table: A numerical study

    NASA Astrophysics Data System (ADS)

    Russo, David; Laufer, Asher; Bardhan, Gopali; Levy, Guy J.

    2015-12-01

    A citrus orchard planted on a structured, clay soil associated with a high water table, irrigated by drip irrigation system using treated waste water (TWW) and local well water (LWW) was considered here. The scope of the present study was to analyze transport of mixed-ion, interacting salts in a combined vadose zone-groundwater flow system focusing on the following issues: (i) long-term effects of irrigation with TWW on the response of the flow system, identifying the main factors (e.g., soil salinity, soil sodicity) that control these effects, and (ii) salinity control aiming at improving both crop productivity and groundwater quality. To pursue this two-fold goal, 3-D numerical simulations of field-scale flow and transport were performed for an extended period of time, considering realistic features of the soil, water table, crop, weather and irrigation, and the coupling between the flow and the transport through the dependence of the soil hydraulic functions, K(ψ) and θ(ψ), on soil solution concentration C, and sodium adsorption ratio, SAR. Results of the analyses suggest that in the case studied, the long-term effect of irrigation with TWW on the response of the flow system is attributed to the enhanced salinity of the TWW, and not to the increase in soil sodicity. The latter findings are attributed to: (i) the negative effect of soil salinity on water uptake, and the tradeoff between water uptake and drainage flux, and, concurrently, solute discharge below the root zone; and, (ii) the tradeoff between the effects of C and SAR on K(ψ) and θ(ψ). Furthermore, it was demonstrated that a data-driven protocol for soil salinity control, based on alternating irrigation water quality between TWW and desalinized water, guided by the soil solution salinity at the centroid of the soil volume active in water uptake, may lead to a substantial increase in crop yield, and to a substantial decrease in the salinity load in the groundwater.

  2. Microbiological indicators for assessing ecosystem soil quality and changes in it at degraded sites treated with compost

    NASA Astrophysics Data System (ADS)

    Ancona, Valeria; Barra Caracciolo, Anna; Grenni, Paola; Di Lenola, Martina; Calabrese, Angelantonio; Campanale, Claudia; Felice Uricchio, Vito

    2014-05-01

    Soil quality is defined as the capacity of a soil to function as a vital system, within natural or managed ecosystem boundaries, sustain plant and animal health and productivity, maintain or enhance air and water environment quality and support human health and habitation. Soil organisms are extremely diverse and contribute to a wide range of ecosystem services that are essential to the sustainable functioning of natural and managed ecosystems. In particular, microbial communities provide several ecosystem services, which ensure soil quality and fertility. In fact, they adapt promptly to environmental changes by varying their activity and by increasing the reproduction of populations that have favourable skills. The structure (e.g. cell abundance) and functioning (e.g. viability and activity) of natural microbial communities and changes in them under different environmental conditions can be considered useful indicators of soil quality state. In this work we studied the quality state of three different soils, located in Taranto Province (Southern Italy), affected by land degradation processes, such as organic matter depletion, desertification and contamination (PCB and metals). Moreover, compost, produced from selected organic waste, was added to the soils studied in order to improve their quality state. Soil samples were collected before and after compost addition and both microbial and chemical analyses were performed in order to evaluate the soil quality state at each site at different times. For this purpose, the microbiological indicators evaluated were bacterial abundance (DAPI counts), cell viability (Live/Dead method), dehydrogenase activity (DHA) and soil respiration. At the same time, the main physico-chemical soil characteristics (organic carbon, available phosphorous, total nitrogen, carbonate and water content, texture and pH) were also measured. Moreover, in the contaminated soil samples PCB and inorganic (e.g. Pb, Se, Sn, Zn) contaminants were

  3. Kinetics of cobalt cementation on zinc powder

    SciTech Connect

    Polcaro, A.M.; Palmas, S.; Dernini, S.

    1995-09-01

    The cementation process may be considered an interesting method to treat dilute solutions containing metal ions. The aim of the process may be either the removal of pollutant metals or the recovery of economically valuable metals such as Ag from spent photographic liquors. The kinetics of cobalt cementation on Zn powder from zinc sulfate concentrated solutions in the presence of copper and antimony ions was investigated in stirred tank reactors. The composition of the solutions was in the range usually utilized in industrial zinc electrowinning plants. The results showed that the reaction occurs by means of the formation of crystallization nuclei of noble metals on the zinc powder, followed by the cementation of cobalt ions on these newly-formed nuclei. Mass transfer to the reaction surface is shown to be the controlling step in copper and antimony reduction, and an equation correlating mass transfer coefficients has been determined. A kinetic equation, which interprets the influence of stirring speed and solution composition on cobalt cementation, has also been proposed.

  4. Determination of acute Zn toxicity in pore water from soils previously treated with sewage sludge using bioluminescence assays

    SciTech Connect

    Chaudri, A.M.; Knight, B.P.; Barbosa-Jefferson, V.L.

    1999-06-01

    The effects of increasing concentrations of Zn and Cu in soil pore water from soils of a long-term sewage sludge field experiment on microbial bioluminescence were investigated. Concentrations of total soluble Zn, free Zn{sup 2+}, and soluble Cu increased sharply in soil pore water with increasing total soil metal concentrations above 140 mg of Zn kg{sup {minus}1} or 100 mg of Cu kg{sup {minus}1}. Two luminescence bioassays were tested, based on two bacteria (Escherichia coli and Pseudomonas fluorescens) with the lux genes encoding bacterial luminescence inserted into them. The bioluminescence response of the two microorganisms declined as total soil Zn, soil pore water soluble Zn, and soil pore water free Zn{sup 2+} concentrations increased. The EC{sub 25} values for E. coli and P. fluorescens were 1.3 {+-} 0.2 and 4.3 {+-} 0.5 mg L{sup {minus}1} on a free Zn{sup 2+} basis, respectively. The EC{sub 50} values were 2.5 {+-} 0.2 and 9.6 {+-} 0.9 mg of free Zn{sup 2+} L{sup {minus}1}, respectively. Copper had no significant effect on bioluminescence in the two assays, even at the largest soil pore water concentration of about 620 {micro}g L{sup {minus}1}, corresponding to a total Cu concentration in bulk soil of about 350 mg kg{sup {minus}1}. Thus, the decline in bioluminescence of the two assays was ascribed to increasing soil pore water free Zn{sup 2+} and not soluble Cu.

  5. Retention of posts cemented with various dentinal bonding cements.

    PubMed

    Mendoza, D B; Eakle, W S

    1994-12-01

    This investigation evaluated the retention of preformed posts with four different cements: C & B Metabond, Panavia, All-Bond 2, and Ketac-Cem. Sixty intact maxillary canines were selected for the study. The clinical crowns were removed and endodontic therapy done on each root, which was then prepared to receive prefabricated posts. The 60 samples were divided into four groups of 15, and the posts in each group were cemented with one of the four cements. The roots were mounted in acrylic resin blocks and the posts were separated from the canals with an Instron testing machine. Analysis of the forces needed to dislodge the posts with analysis of variance and Student-Newman-Keuls test disclosed that C & B Metabond cement was the most retentive (p < 0.05). No difference in retention was recorded between Ketac-Cem and Panavia cements. All-Bond 2 cement was the least retentive of cements. PMID:7853255

  6. Osteotransductive bone cements.

    PubMed

    Driessens, F C; Planell, J A; Boltong, M G; Khairoun, I; Ginebra, M P

    1998-01-01

    Calcium phosphate bone cements (CPBCs) are osteotransductive, i.e. after implantation in bone they are transformed into new bone tissue. Furthermore, due to the fact that they are mouldable, their osteointegration is immediate. Their chemistry has been established previously. Some CPBCs contain amorphous calcium phosphate (ACP) and set by a sol-gel transition. The others are crystalline and can give as the reaction product dicalcium phosphate dihydrate (DCPD), calcium-deficient hydroxyapatite (CDHA), carbonated apatite (CA) or hydroxyapatite (HA). Mixed-type gypsum-DCPD cements are also described. In vivo rates of osteotransduction vary as follows: gypsum-DCPD > DCPD > CDHA approximately CA > HA. The osteotransduction of CDHA-type cements may be increased by adding dicalcium phosphate anhydrous (DCP) and/or CaCO3 to the cement powder. CPBCs can be used for healing of bone defects, bone augmentation and bone reconstruction. Incorporation of drugs like antibiotics and bone morphogenetic protein is envisaged. Load-bearing applications are allowed for CHDA-type, CA-type and HA-type CPBCs as they have a higher compressive strength than human trabecular bone (10 MPa).

  7. Gentamicin in bone cement

    PubMed Central

    Chang, Y.; Tai, C-L.; Hsieh, P-H.; Ueng, S. W. N.

    2013-01-01

    Objectives The objective of this study is to determine an optimal antibiotic-loaded bone cement (ALBC) for infection prophylaxis in total joint arthroplasty (TJA). Methods We evaluated the antibacterial effects of polymethylmethacrylate (PMMA) bone cements loaded with vancomycin, teicoplanin, ceftazidime, imipenem, piperacillin, gentamicin, and tobramycin against methicillin-sensitive Staphylococcus aureus (MSSA), methicillin-resistant Staph. aureus (MRSA), coagulase-negative staphylococci (CoNS), Escherichia coli, Pseudomonas aeruginosa, and Klebsiella pneumoniae. Standardised cement specimens made from 40 g PMMA loaded with 1 g antibiotics were tested for elution characteristics, antibacterial activities, and compressive strength in vitro. Results The ALBC containing gentamicin provided a much longer duration of antibiotic release than those containing other antibiotic. Imipenem-loading on the cement had a significant adverse effect on the compressive strength of the ALBC, which made it insufficient for use in prosthesis fixation. All of the tested antibiotics maintained their antibacterial properties after being mixed with PMMA. The gentamicin-loaded ALBC provided a broad antibacterial spectrum against all the test organisms and had the greatest duration of antibacterial activity against MSSA, CoNS, P. aeruginosa and E. coli. Conclusion When considering the use of ALBC as infection prophylaxis in TJA, gentamicin-loaded ALBC may be a very effective choice. Cite this article: Bone Joint Res 2013;2:220–6. PMID:24128666

  8. Effect of climatic conditions on the development of soil water repellency in soils treated with the wastewater of the olive oil production

    NASA Astrophysics Data System (ADS)

    Schaumann, Gabriele E.; Peikert, Benjamin; Tamimi, Nesreen; Steinmetz, Zacharias; Fischer, Jonas; Bibus, Daniel; Marei Sawalha, Amer; Dag, Arnon

    2014-05-01

    The disposal of untreated wastewater on soil can induce severe water repellency. The final degree of water repellency may strongly depend on the environmental conditions prevailing during and after disposal. Also unpolluted soil can develop severe water repellency upon exposure to extreme heat or draught events. The induced water repellency can be either persistent or of transient nature. However, the underlying mechanisms are not yet completely understood. The objective of this study was to investigate how climatic conditions determine the development and persistence of water repellency following wastewater disposal. Our hypothesis was that amphiphilic organic wastewater compounds physically sorb onto surfaces, which renders them hydrophobic. Depending on temperature and moisture, those compounds are degraded, chemically incorporated into SOM, or irreversibly sorbed to soil particles during the time after the first waste water-soil contact. According to our hypothesis, biological communities favor degradation and transformation of OM of waste water into SOM under moist soil conditions. This would reduce the initial hydrophobization. In contrast, drying irreversibly renders soil hydrophobic and phytotoxic due to immobilization of OMW OM in the soil. To test these hypotheses, we investigated effects of olive mil wastewater (OMW), the effluent originating from olive oil production, directly applied to soil. In Israel and Palastine, olive oil production generates large amounts of OMW within a short period of time between November and January. As sewage facilities do not accept OMW, it is often disposed onto soil, which leads to severe soil and groundwater pollution. If the above mentioned hypotheses match, pollution and hydrophobization might be minimized if the wastewater is discharged at the right time of the year. In order to test this, we conducted field (2-3 years) and laboratory (60 days) experiments in Israel (Gilat, arid climate) and in the West Bank (Bait

  9. Effect of Reagents Concentration on Biocementation of Tropical Residual Soil

    NASA Astrophysics Data System (ADS)

    Chiet, K. T. P.; Kassim, K. A.; Chen, K. B.; Martula, U.; Yah, C. S.; Arefnia, A.

    2016-07-01

    This study explores the feasibility of Bacillus subtilis and optimum reagents concentration used in Microbial-Induced Calcite Precipitation (MICP) treatment of tropical residual soil. Experiment was conducted to investigate the effect of cementation reagents concentration toward MICP treatment. The performance of MICP treatment was assessed by measurement of the soil shear strength and calcite content. Based on the experimental results, it is discovered that the cementation reagent concentration has significantly affected on the performance of MICP treatment. The results suggested that the most preferable MICP treatment reagents concentration is 0.25M with the presence of Bacillus subtilis; using these treatment parameters, both UCS value and calcite content of treated soil had increased about 38% and 65.6% respectively. However, the reduction in UCS value was manifested for those samples treated at higher reagents concentration (0.35M); this phenomenon is attributed to the salinity of reagents where high salinity is not favourable to the bacteria growth and microbial activity; subsequently, this resulted in a consequential decrease in shear strength of the treated soil.

  10. Cross-Contamination of Residual Emerging Contaminants and Antibiotic Resistant Bacteria in Lettuce Crops and Soil Irrigated with Wastewater Treated by Sunlight/H2O2.

    PubMed

    Ferro, Giovanna; Polo-López, María I; Martínez-Piernas, Ana B; Fernández-Ibáñez, Pilar; Agüera, Ana; Rizzo, Luigi

    2015-09-15

    The sunlight/H2O2 process has recently been considered as a sustainable alternative option compared to other solar driven advanced oxidation processes (AOPs) in advanced treatment of municipal wastewater (WW) to be reused for crop irrigation. Accordingly, in this study sunlight/H2O2 was used as disinfection/oxidation treatment for urban WW treatment plant effluent in a compound parabolic collector photoreactor to assess subsequent cross-contamination of lettuce and soil by contaminants of emerging concern (CECs) (determined by QuEChERS extraction and LC-QqLIT-MS/MS analysis) and antibiotic resistant (AR) bacteria after irrigation with treated WW. Three CECs (carbamazepine (CBZ), flumequine (FLU), and thiabendazole (TBZ) at 100 μg L(-1)) and two AR bacterial strains (E. coli and E. faecalis, at 10(5) CFU mL(-1)) were spiked in real WW. A detection limit (DL) of 2 CFU mL(-1) was reached after 120 min of solar exposure for AR E. coli, while AR E. faecalis was more resistant to the disinfection process (240 min to reach DL). CBZ and TBZ were poorly removed after 90 min (12% and 50%, respectively) compared to FLU (94%). Lettuce was irrigated with treated WW for 5 weeks. CBZ and TBZ were accumulated in soil up to 472 ng g(-1) and 256 ng g(-1) and up-taken by lettuce up to 109 and 18 ng g(-1), respectively, when 90 min treated WW was used for irrigation; whereas no bacteria contamination was observed when the bacterial density in treated WW was below the DL. A proper treatment time (>90 min) should be guaranteed in order to avoid the transfer of pathogens from disinfected WW to irrigated crops and soil.

  11. Heavy metal accumulation in soils and grains, and health risks associated with use of treated municipal wastewater in subsurface drip irrigation.

    PubMed

    Asgari, Kamran; Cornelis, Wim M

    2015-07-01

    Constant use of treated wastewater (TWW) for irrigation over prolonged periods may cause buildup of heavy metals up to toxic levels for plants and animals, and entails environmental hazards in different aspects. However, application of TWW on agricultural land might be an effective and sustainable strategy in arid and semi-arid countries where fresh water resources are under great pressure, as long as potential harmful effects on the environment including soil, plants, and fresh water resources, and health risks to humans are minimized. The aim of this study was to assess the effect of deep emitters on limiting potential heavy metal accumulation in soils and grains, and health risk under drip irrigation with treated municipal wastewater. A field experiment was conducted according to a split block design with two treatments (fresh and wastewater) and three sub-treatments (0, 15, and 30 cm depth of emitters) in four replicates on a sandy loam Calcic Argigypsids, in Esfahan, Iran. The annual rainfall is about 123 mm, mean annual ETo is 1457 mm, and the elevation is 1590 m above sea level. A two-crop rotation of wheat (Triticum spp.) and corn (Zea mays) was established on each plot with wheat growing from February to June and corn from July to September. Soil samples were collected before planting and after harvesting for each crop in each year. Edible grain samples of corn and wheat were collected at harvest. Elemental concentrations (Cu, Zn, Cd, Pb, Cr, Ni) in soil and grains were determined using an atomic absorption spectrophotometer. Results showed that the concentrations of heavy metals in the wastewater-irrigated soils were not significantly different (P > 0.05) compared with the freshwater-irrigated soils. No significant difference (P > 0.05) in heavy metal content in soil between different depths of emitters was found. A pollution load index (PLI) showed that there was no substantial buildup of heavy metals in the wastewater-irrigated soils

  12. Heavy metal accumulation in soils and grains, and health risks associated with use of treated municipal wastewater in subsurface drip irrigation.

    PubMed

    Asgari, Kamran; Cornelis, Wim M

    2015-07-01

    Constant use of treated wastewater (TWW) for irrigation over prolonged periods may cause buildup of heavy metals up to toxic levels for plants and animals, and entails environmental hazards in different aspects. However, application of TWW on agricultural land might be an effective and sustainable strategy in arid and semi-arid countries where fresh water resources are under great pressure, as long as potential harmful effects on the environment including soil, plants, and fresh water resources, and health risks to humans are minimized. The aim of this study was to assess the effect of deep emitters on limiting potential heavy metal accumulation in soils and grains, and health risk under drip irrigation with treated municipal wastewater. A field experiment was conducted according to a split block design with two treatments (fresh and wastewater) and three sub-treatments (0, 15, and 30 cm depth of emitters) in four replicates on a sandy loam Calcic Argigypsids, in Esfahan, Iran. The annual rainfall is about 123 mm, mean annual ETo is 1457 mm, and the elevation is 1590 m above sea level. A two-crop rotation of wheat (Triticum spp.) and corn (Zea mays) was established on each plot with wheat growing from February to June and corn from July to September. Soil samples were collected before planting and after harvesting for each crop in each year. Edible grain samples of corn and wheat were collected at harvest. Elemental concentrations (Cu, Zn, Cd, Pb, Cr, Ni) in soil and grains were determined using an atomic absorption spectrophotometer. Results showed that the concentrations of heavy metals in the wastewater-irrigated soils were not significantly different (P > 0.05) compared with the freshwater-irrigated soils. No significant difference (P > 0.05) in heavy metal content in soil between different depths of emitters was found. A pollution load index (PLI) showed that there was no substantial buildup of heavy metals in the wastewater-irrigated soils

  13. Escherichia coli contamination and health aspects of soil and tomatoes (Solanum lycopersicum L.) subsurface drip irrigated with on-site treated domestic wastewater.

    PubMed

    Forslund, A; Ensink, J H J; Markussen, B; Battilani, A; Psarras, G; Gola, S; Sandei, L; Fletcher, T; Dalsgaard, A

    2012-11-15

    Faecal contamination of soil and tomatoes irrigated by sprinkler as well as surface and subsurface drip irrigation with treated domestic wastewater were compared in 2007 and 2008 at experimental sites in Crete and Italy. Wastewater was treated by Membrane Bio Reactor (MBR) technology, gravel filtration or UV-treatment before used for irrigation. Irrigation water, soil and tomato samples were collected during two cropping seasons and enumerated for the faecal indicator bacterium Escherichia coli and helminth eggs. The study found elevated levels of E. coli in irrigation water (mean: Italy 1753 cell forming unit (cfu) per 100 ml and Crete 488 cfu per 100 ml) and low concentrations of E. coli in soil (mean: Italy 95 cfu g(-1) and Crete 33 cfu g(-1)). Only two out of 84 tomato samples in Crete contained E. coli (mean: 2700 cfu g(-1)) while tomatoes from Italy were free of E. coli. No helminth eggs were found in the irrigation water or on the tomatoes from Crete. Two tomato samples out of 36 from Italy were contaminated by helminth eggs (mean: 0.18 eggs g(-1)) and had been irrigated with treated wastewater and tap water, respectively. Pulsed Field Gel Electrophoresis DNA fingerprints of E. coli collected during 2008 showed no identical pattern between water and soil isolates which indicates contribution from other environmental sources with E. coli, e.g. wildlife. A quantitative microbial risk assessment (QMRA) model with Monte Carlo simulations adopted by the World Health Organization (WHO) found the use of tap water and treated wastewater to be associated with risks that exceed permissible limits as proposed by the WHO (1.0 × 10(-3) disease risk per person per year) for the accidental ingestion of irrigated soil by farmers (Crete: 0.67 pppy and Italy: 1.0 pppy). The QMRA found that the consumption of tomatoes in Italy was deemed to be safe while permissible limits were exceeded in Crete (1.0 pppy). Overall the quality of tomatoes was safe for human

  14. Modification of catalase and MAPK in Vicia faba cultivated in soil with high natural radioactivity and treated with a static magnetic field.

    PubMed

    Haghighat, Nazanin; Abdolmaleki, Parviz; Ghanati, Faezeh; Behmanesh, Mehrdad; Payez, Atefeh

    2014-03-01

    The effects of a static magnetic field (SMF) and high natural radioactivity (HR) on catalase and MAPK genes in Vicia faba were investigated. Soil samples with high natural radioactivity were collected from Ramsar in north Iran where the annual radiation absorbed dose from background radiation is higher than 20mSv/year. The specific activity of the radionuclides of (232)Th, (236)Ra, and (40)K was measured using gamma spectrometry. The seeds were planted either in the soil with high natural radioactivity or in the control soils and were then exposed to a SMF of 30mT for 8 days; 8h/day. Levels of expression of catalase and MAPK genes, catalase activity and H2O2 content were evaluated. The results demonstrated significant differences in the expression of catalase and MAPK genes in SMF- and HR-treated plants compared to the controls. An increase in catalase activity was accompanied by increased expression of its gene and accumulation of H2O2. Relative expression of the MAPK gene in treated plants, however, was lower than those of the controls. The results suggest that the response of V. faba plants to SMF and HR may be mediated by modification of catalase and MAPK.

  15. Redistribution of fractions of zinc, cadmium, nickel, copper, and lead in contaminated calcareous soils treated with EDTA.

    PubMed

    Jalali, Mohsen; Khanlari, Zahra V

    2007-11-01

    Effect of ethylene diamine tetraacetic acid (EDTA) on the fractionation of zinc (Zn), cadmium (Cd), nickel (Ni), copper (Cu), and lead (Pb) in contaminated calcareous soils was investigated. Soil samples containing variable levels of contamination, from 105.9 to 5803 mg/kg Zn, from 2.2 to 1361 mg/kg Cd, from 31 to 64.0 mg/kg Ni, from 24 to 84 mg/kg Cu, and from 109 to 24,850 mg/kg Pb, were subjected to EDTA treatment at different dosages of 0, 1.0, and 2.0 g/kg. Metals in the incubated soils were fractionated after 5 months by a sequential extraction procedure, in which the metal fractions were experimentally defined as exchangeable (EXCH), carbonate (CARB), Mn oxide (MNO), Fe oxide (FEO), organic matter (OM), and residual (RES) fractions. In contaminated soils without EDTA addition, Zn, Ni, Cu, and Pb were predominately present in the RES fraction, up to 60.0%, 32.3%, 41.1%, and 36.8%, respectively. In general, with the EDTA addition, the EXCH and CARB fractions of these metals increased dramatically while the OM fraction decreased. The Zn, Ni, Cu, and Pb were distributed mostly in RES, OM, FEO, and CARB fractions in contaminated soils, but Cd was found predominately in the CARB, MNO, and RES fractions. The OM fraction decreased with increasing amounts of EDTA. In the contaminated soils, EDTA removed some Pb, Zn, Cu, and Ni from MNO, FEO, and OM fractions and redistributed them into CARB and EXCH fractions. Based on the relative percent in the EXCH and CARB fractions, the order of solubility was Cd > Pb > Ni > Cu > Zn for contaminated soils, before adding of EDTA, and after adding of EDTA, the order of solubility was Pb > Cd > Zn > Ni > Cu. The risk of groundwater contamination will increase after applying EDTA and it needed to be used very carefully.

  16. Arsenic Accumulation by Pteris vittata L. in Two Chemically Variant Soils Treated with Arsenical Pesticides - Greenhouse Study

    NASA Astrophysics Data System (ADS)

    Therapong, C.; Datta, R.; Sarkar, D.; Pachanoor, D.

    2006-05-01

    Arsenic (As) is one of the most toxic elements present in the environment. Over the years, arsenic has found its way to the environment due to its extensive use in agriculture and in industrial practices as pesticides, fertilizers, wood preservatives, smelter wastes and coal combustion ash, all of which are of great environmental concern. Arsenic contamination affects biological activities because it is a carcinogen and a mutagen, which has detrimental effects on the immune system of animals. Remediation of arsenic-contaminated soils has become a major environmental issue in the recent years. Several physical and chemical treatment methods, such as soil washing, co-precipitation, and excavation, have used to remediate As, but all of these methods are rather expensive and can disturb soil physiology and ecology. Phytoremediation, a plant based technology for the removal of toxic contaminants from soil and water is an attractive approach. Of late, this technology has received a high degree of attention from the scientific community because it is environment-friendly and also because of its tremendous cost efficiency compared to the conventional methods. Chinese Brake Fern (Pteris vittata L.) is a known arsenic hyperaccumulator that is being used extensively at present to remove As from soils. However, the degree of efficiency of this plant in accumulating As is likely to be a function of the soil properties. The objective of the reported study was to investigate arsenic uptake by Chinese Brake Fern in As-contaminated soils from the Immokalee (acid sand with minimal As-retention potential) and Millhopper series (sandy loam with high Fe/Al content, hence, high As-retention potential). A greenhouse experiment was designed to evaluate the effects on As uptake by Chinese Brake Fern at two pesticide application rates: 225 mg/kg and 500 mg/kg As in two chemical forms, namely sodium arsenate (AsV) and dimethylarsinic acid (DMA). Each treatment was replicated three times in

  17. Comparison of soil amendments to decrease high strength in SE USA Coastal Plain soils using fuzzy decision-making analyses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cemented subsurface layers restrict root growth in many southeastern USA Coastal Plain soils. Though cementation is usually reduced by tillage, soil amendments can offer a more permanent solution if they develop aggregation. To increase aggregation, we amended 450 g of a Norfolk soil blend of 90% E ...

  18. Mineral resource of the month: hydraulic cement

    USGS Publications Warehouse

    van Oss, Hendrik G.

    2012-01-01

    Hydraulic cements are the binders in concrete and most mortars and stuccos. Concrete, particularly the reinforced variety, is the most versatile of all construction materials, and most of the hydraulic cement produced worldwide is portland cement or similar cements that have portland cement as a basis, such as blended cements and masonry cements. Cement typically makes up less than 15 percent of the concrete mix; most of the rest is aggregates. Not counting the weight of reinforcing media, 1 ton of cement will typically yield about 8 tons of concrete.

  19. Preliminary systems design study assessment report. [Evaluation of using specific technologies, system concepts for treating the buried waste and surrounding contaminated soil

    SciTech Connect

    Mayberry, J.L.; Feizollahi, F.; Del Signore, J.C.

    1992-01-01

    The System Design Study (SDS), part of the Waste Technology Development Department at the Idaho National Engineering Laboratory (INEL), examined techniques available for the remediation of hazardous and transuranic waste stored at the Radioactive Waste Management Complex's Subsurface Disposal Area at the INEL. Using specific technologies, system concepts for treating the buried waste and the surrounding contaminated soil were evaluated. Evaluation included implementability, effectiveness, and cost. The SDS resulted in the development of technology requirements including demonstration, testing, and evaluation activities needed for implementing each. This volume contains the descriptions and other relevant information of the four subsystems required for most of the ex situ processing systems. This volume covers the metal decontamination and sizing subsystem, soils processing subsystem, low-level waste subsystem, and retrieval subsystem.

  20. Cement Kiln Flue Gas Recovery Scrubber Project

    SciTech Connect

    National Energy Technology Laboratory

    2001-11-30

    The Cement Kiln Flue Gas Recovery Scrubber Project was a technical success and demonstrated the following: CKD can be used successfully as the sole reagent for removing SO2 from cement kiln flue gas, with removal efficiencies of 90 percent or greater; Removal efficiencies for HCl and VOCs were approximately 98 percent and 70 percent, respectively; Particulate emissions were low, in the range of 0.005 to 0.007 grains/standard cubic foot; The treated CKD sorbent can be recycled to the kiln after its potassium content has been reduced in the scrubber, thereby avoiding the need for landfilling; The process can yield fertilizer-grade K2SO4, a saleable by-product; and Waste heat in the flue gas can provide the energy required for evaporation and crystallization in the by-product recovery operation. The demonstration program established the feasibility of using the Recovery Scrubber{trademark} for desulfurization of flue gas from cement kilns, with generally favorable economics, assuming tipping fees are available for disposal of ash from biomass combustion. The process appears to be suitable for commercial use on any type of cement kiln. EPA has ruled that CKD is a nonhazardous waste, provided the facility meets Performance Standards for the Management of CKD (U.S. Environmental Protection Agency 1999d). Therefore, regulatory drivers for the technology focus more on reduction of air pollutants and pollution prevention, rather than on treating CKD as a hazardous waste. Application of the Recovery Scrubbe{trademark} concept to other waste-disposal operations, where pollution and waste reductions are needed, appears promising.

  1. US cement industry

    SciTech Connect

    Nisbet, M.A.

    1997-12-31

    This paper describes the cement and concrete industry, and provides data on energy use and carbon dioxide emissions. The potential impact of an energy tax on the industry is briefly assessed. Opportunities identified for reducing carbon dioxide emissions include improved energy efficiency, alternative fuels, and alternative materials. The key factor in determining CO{sub 2} emissions is the level of domestic production. The projected improvement in energy efficiency and the relatively slow growth in domestic shipments indicate that CO{sub 2} emissions in 2000 should be about 5% above the 1990 target. However, due to the cyclical nature of cement demand, emissions will probably be above target levels during peak demand and below target levels during demand troughs. 7 figs., 2 tabs.

  2. Short-term effects of irrigation with treated domestic wastewater on microbiological activity of a Vertic xerofluvent soil under Mediterranean conditions.

    PubMed

    Kayikcioglu, Huseyin Husnu

    2012-07-15

    Approximately 70% of the world water use, including all the water diverted from rivers and pumped from underground, is used for agricultural irrigation, so the reuse of treated domestic wastewater (TWW) for purposes such as agricultural and landscape irrigation reduces the amount of water that needs to be extracted from natural water sources as well as reducing discharge of wastewater to the environment. Thus, TWW is a valuable water source for recycling and reusing in arid and semi-arid regions which are frequently confronting water shortages. In this regard, this study was planned to reveal the short-term effects of advanced-TWW irrigation on microbial parameters of Vertic xerofluvent soil. For this purpose, certain parameters were measured in the study, including soil total organic carbon (C(org)), N-mineralization (N(min)), microbial biomass carbon (C(mic)), soil microbial quotient (C(mic)/C(org)) and the activities of the enzymes dehydrogenase (DHG), urease (UA), alkaline phosphatase (ALKPA), β-glucosidase (GLU) and aryl sulphatase (ArSA) in soils irrigated with TWW and fresh water (FW). All of the microbial parameters were negatively affected by TWW irrigation. Microbial parameters decreased by 10.1%-54.1% in comparison with the FW plots. This decrease especially in enzymatic activities of soil irrigated with TWW, presumably due to some heavy metals inhibited their activity associated with the soil types and the concentrations of heavy metals in wastewater. In contrast, C(mic)/C(org) was found higher in the plots irrigated with TWW at the end of the experiment. The addition of organic matter to soil by irrigation with TWW is cause for the increase in this ratio. The dose of irrigation should be modified to reduce the quantity and to increase the frequency of application to avoid the loss of aggregation and salt accumulation. TWW irrigation is a strategy with many benefits to agricultural land management; however, long-term studies should be implemented to

  3. Preliminary Systems Design Study assessment report. [Evaluation of using specific technologies, system concepts for treating the buried waste and the surrounding contaminated soil

    SciTech Connect

    Mayberry, J.L.; Feizollahi, F.; Del Signore, J.C.

    1991-11-01

    The System Design Study (SDS), part of the Waste Technology Development Department at the Idaho National Engineering Laboratory (INEL), examined techniques available for the remediation of hazardous and transuranic waste stored at the Radioactive Waste Management Complex's Subsurface Disposal Area at the INEL. Using specific technologies, system concepts for treating the buried waste and the surrounding contaminated soil were evaluated. Evaluation included implementability, effectiveness, and cost. The SDS resulted in the development of technology requirements including demonstration, testing, and evaluation activities needed for implementing each concept.

  4. DETAILED ANALYSIS OF THE MOST PROMISING ALTERNATIVES TO USING GRANULAR ACTIVATED CARBON TO TREAT 200-ZP-1 GROUNDWATER AND 200-PW-1 SOIL VAPOR

    SciTech Connect

    BYRNES ME, KALMAR JA

    2007-11-26

    This document presents a detailed evaluation of selected alternative treatment options to granular activated carbon (GAC) for removing carbon tetrachloride generated from the groundwater pump-and-treat system at the 200-ZP-I Operable Unit (OU) in the 200 West Area of the Hanford Site. This evaluation of alternative treatment options to GAC is also applicable to the vadose zone soil vapor extraction (SVE) system at the 200-PW-l OU, which is also located in the Hanford Site's 200 West Area.

  5. Comparison of the fixation effects of heavy metals by cement rotary kiln co-processing and cement based solidification/stabilization.

    PubMed

    Zhang, Junli; Liu, Jianguo; Li, Cheng; Jin, Yiying; Nie, Yongfeng; Li, Jinhui

    2009-06-15

    Cement rotary kiln co-processing of hazardous wastes and cement based solidification/stabilization could both immobilize heavy metals. The different retention mechanisms of the two technologies lead to different fixation effects of heavy metals. The same amount of heavy metal compounds were treated by the two types of fixation technologies. Long-term leaching test (160 days), the maximum availability leaching test (NEN 7341) and a modified three-step sequential extraction procedure, proposed by the Commission of the European Communities Bureau of Reference (BCR) were employed to compare the fixation effects of the two fixation technologies. The leaching concentrations in NEN 7341 and long-term leaching tests were compared with identification standard for hazardous wastes (GB5085.3-1996) and drinking water standard (GB5749-2005). The results indicate that the leaching concentrations of the long-term leaching test and NEN 7341 test were lower than the regulatory limits and the leached ratios were small. Both cement based solidification/stabilization and cement rotary kiln co-processing could effectively fix heavy metals. Calcination in a cement rotary kiln and the following hydration that follows during cement application could fix As, Cd, Pb and Zn more effectively and decrease the release to the environment. Cement solidification/stabilization technology has better effect in immobilizing Cr and Ni. Cr wastes are more fitful to be treated by cement solidification/stabilization.

  6. Recovery of MSWI and soil washing residues as concrete aggregates.

    PubMed

    Sorlini, Sabrina; Abbà, Alessandro; Collivignarelli, Carlo

    2011-02-01

    The aim of the present work was to study if municipal solid waste incinerator (MSWI) residues and aggregates derived from contaminated soil washing could be used as alternative aggregates for concrete production. Initially, chemical, physical and geometric characteristics (according to UNI EN 12620) of municipal solid waste incineration bottom ashes and some contaminated soils were evaluated; moreover, the pollutants release was evaluated by means of leaching tests. The results showed that the reuse of pre-treated MSWI bottom ash and washed soil is possible, either from technical or environmental point of view, while it is not possible for the raw wastes. Then, the natural aggregate was partially and totally replaced with these recycled aggregates for the production of concrete mixtures that were characterized by conventional mechanical and leaching tests. Good results were obtained using the same dosage of a high resistance cement (42.5R calcareous Portland cement instead of 32.5R); the concrete mixture containing 400 kg/m(3) of washed bottom ash and high resistance cement was classified as structural concrete (C25/30 class). Regarding the pollutants leaching, all concrete mixtures respected the limit values according to the Italian regulation. PMID:20537523

  7. Recovery of MSWI and soil washing residues as concrete aggregates.

    PubMed

    Sorlini, Sabrina; Abbà, Alessandro; Collivignarelli, Carlo

    2011-02-01

    The aim of the present work was to study if municipal solid waste incinerator (MSWI) residues and aggregates derived from contaminated soil washing could be used as alternative aggregates for concrete production. Initially, chemical, physical and geometric characteristics (according to UNI EN 12620) of municipal solid waste incineration bottom ashes and some contaminated soils were evaluated; moreover, the pollutants release was evaluated by means of leaching tests. The results showed that the reuse of pre-treated MSWI bottom ash and washed soil is possible, either from technical or environmental point of view, while it is not possible for the raw wastes. Then, the natural aggregate was partially and totally replaced with these recycled aggregates for the production of concrete mixtures that were characterized by conventional mechanical and leaching tests. Good results were obtained using the same dosage of a high resistance cement (42.5R calcareous Portland cement instead of 32.5R); the concrete mixture containing 400 kg/m(3) of washed bottom ash and high resistance cement was classified as structural concrete (C25/30 class). Regarding the pollutants leaching, all concrete mixtures respected the limit values according to the Italian regulation.

  8. Cement penetration after patella venting.

    PubMed

    Jones, Christopher W; Lam, Li-On; Butler, Adam; Wood, David J; Walsh, William R

    2009-01-01

    There is a high rate of patellofemoral complications following total knee arthroplasty. Optimization of the cement-bone interface by venting and suction of the tibial plateau has been shown to improve cement penetration. Our study was designed to investigate if venting the patella prior to cementing improved cement penetration. Ten paired cadaver patellae were allocated prior to resurfacing to be vented or non-vented. Bone mineral density (BMD) was measured by DEXA scanning. In vented specimens, a 1.6 mm Kirschner wire was used to breach the anterior cortex at the center. Specimens were resurfaced with standard Profix instrumentation and Versabond bone cement (Smith and Nephew PLC, UK). Cement penetration was assessed from Faxitron and sectioned images by a digital image software package (ImageJ V1.38, NIH, USA). Wilcoxon rank sum test was used to assess the difference in cement penetration between groups. The relationship between BMD and cement penetration was analyzed by Pearson correlation coefficient. There was a strong negative correlation between peak BMD and cement penetration when analyzed independent of experimental grouping (r(2)=-0.812, p=0.004). Wilcoxon rank sum testing demonstrated no significant difference (rank sum statistic W=27, p=0.579) in cement penetration between vented (10.53%+/-4.66; mean+/-std dev) and non-vented patellae (11.51%+/-6.23; mean+/-std dev). Venting the patella using a Kirschner wire does not have a significant effect on the amount of cement penetration achieved in vitro using Profix instrumentation and Versabond cement.

  9. Cement penetration after patella venting.

    PubMed

    Jones, Christopher W; Lam, Li-On; Butler, Adam; Wood, David J; Walsh, William R

    2009-01-01

    There is a high rate of patellofemoral complications following total knee arthroplasty. Optimization of the cement-bone interface by venting and suction of the tibial plateau has been shown to improve cement penetration. Our study was designed to investigate if venting the patella prior to cementing improved cement penetration. Ten paired cadaver patellae were allocated prior to resurfacing to be vented or non-vented. Bone mineral density (BMD) was measured by DEXA scanning. In vented specimens, a 1.6 mm Kirschner wire was used to breach the anterior cortex at the center. Specimens were resurfaced with standard Profix instrumentation and Versabond bone cement (Smith and Nephew PLC, UK). Cement penetration was assessed from Faxitron and sectioned images by a digital image software package (ImageJ V1.38, NIH, USA). Wilcoxon rank sum test was used to assess the difference in cement penetration between groups. The relationship between BMD and cement penetration was analyzed by Pearson correlation coefficient. There was a strong negative correlation between peak BMD and cement penetration when analyzed independent of experimental grouping (r(2)=-0.812, p=0.004). Wilcoxon rank sum testing demonstrated no significant difference (rank sum statistic W=27, p=0.579) in cement penetration between vented (10.53%+/-4.66; mean+/-std dev) and non-vented patellae (11.51%+/-6.23; mean+/-std dev). Venting the patella using a Kirschner wire does not have a significant effect on the amount of cement penetration achieved in vitro using Profix instrumentation and Versabond cement. PMID:19010682

  10. Mineral of the month: cement

    USGS Publications Warehouse

    van Oss, Hendrik G.

    2006-01-01

    Hydraulic cement is a virtually ubiquitous construction material that, when mixed with water, serves as the binder in concrete and most mortars. Only about 13 percent of concrete by weight is cement (the rest being water and aggregates), but the cement contributes all of the concrete’s compressional strength. The term “hydraulic” refers to the cement’s ability to set and harden underwater through the hydration of the cement’s components.

  11. Hypoplastic model for simulation of compressibility characteristics of cement-admixed Bangkok soft clay at high water content

    NASA Astrophysics Data System (ADS)

    Chattonjai, Piyachat

    2016-06-01

    The developed hypoplastic model for simulation of compressibility characteristics of cement-admixed Bangkok soft clay at high water content was proposed in this paper. By using unique equation, the model is able to predict the relationship between void ratio and vertical effective stress of different water and cement content of soil cement. For practically convenient utilization and understanding, the parameters of Q1 which represented to initial cement bonding of soil (the initial value of structure tensor at time = 0) and C2 which effected to the model stiffness on isotropic consolidation direction, at 45° for loading and 225° for unloading of stress response envelope, were proposed as the function of cement and water content by comparing with dry weight of soil. By numerical integration that satisfied one-dimensional settlement, the simulation results were directly compared with fifteen experimental results to verify the accuracy of the proposed model.

  12. Temporal changes in chlorantraniliprole and indoxacarb in four midwestern soils and bioefficacy against the eastern subterranean termite (Isoptera: Rhinotermitidae).

    PubMed

    Spomer, Neil A; Kamble, Shripat T

    2011-06-01

    Temporal changes in indoxacarb and chlorantraniliprole were determined in four midwestern soils by simulating commercial field applications of termiticides. Indoxacarb (0.0625 and 0.125%) and chlorantraniliprole (0.05 and 0.10%) were applied to each soil type in a rotating cement mixer to ensure uniform distribution of active ingredient (AI). Temporal and spatial changes in termiticide concentrations were determined by sampling soil cores subdivided at different depths (0-20, 20-40, and 40-61 cm) at various intervals up to 705 d after application. Percentage loss of indoxacarb was initially greater (0-180 d) than losses after 180 d. The lowest indoxacarb extractable concentrations were detected in soils closest to the surface. Chlorantraniliprole losses with time from all soils were slower than indoxacarb, with no differences observed with soil type or depth. Bioefficacy was evaluated in laboratory glass tube bioassays that monitored the distance of termite penetration into treated soils and resulting eastern subterranean termite, Reticulitermes flavipes (Kollar) (Isoptera: Rhinotermitidae), worker mortality. Bioassay data revealed that R. flavipes termites were unable to completely penetrate 50 mm of indoxacarb- and chlorantraniliprole treated soils at 0 d after treatment; however, termites were not deterred from foraging in these soils indicating no repellency to these termiticides. Termites completely penetrated (50 mm) soils treated with indoxacarb (0.0625%) by 360 d and complete penetration occurred in all soils treated with indoxacarb (0.0625 and 0.125%) by 705 d. Termites were unable to completely penetrate chlorantraniliprole-treated soils at 705 d. Mortality of termite workers was high in all chlorantraniliprole-treated soils at all sampling intervals. These data confirm that vertical differences in termiticide persistence occur in various soils. PMID:21735921

  13. Removal of Ni(II) and Cu(II) ions using native and acid treated Ni-hyperaccumulator plant Alyssum discolor from Turkish serpentine soil.

    PubMed

    Bayramoglu, Gulay; Arica, M Yakup; Adiguzel, Nezaket

    2012-09-01

    Alyssum discolor biomass was collected from serpentine soil and was used for removal of metal ions. The plant species grown on serpentine soils are known to be rich with metals ions and thus have more capability for accumulating heavy metals. Native and acid-treated biomass of A. discolor (A. discolor) were utilized for the removal of Ni(II) and Cu(II) ions from aqueous solutions. The effects of contact time, initial concentration, and pH on the biosorption of Ni(II) and Cu(II) ions were investigated. Biosorption equilibrium was established in about 60 min. The surface properties of the biomass preparations were varied with pH, and the maximum amounts of Ni(II) and Cu(II) ions on both A. discolor biomass preparations were adsorbed at pH 5.0. The maximum biosorption capacities of the native, and acid-treated biomass preparations for Ni(II) were 13.1 and 34.7 mgg(-1) and for Cu(II) 6.15 and 17.8 mgg(-1) dry biomass, respectively. The biosorption of Ni(II) and Cu(II) ions from single and binary component systems can be successfully described by Langmuir and Freundlich isotherms. When the heavy metal ions were in competition, the amounts of biosorbed metal ions on the acid treated plant biomass were found to be 0.542 mmolg(-1) for Ni(II) and 0.162 mmolg(-1) for Cu(II), the A. discolor biomass was significantly selective for Ni(II) ions. The information gained from these studies was expected to indicate whether the native, and acid-treated forms can have the potential to be used for the removal and recovery of Ni(II) ions from wastewaters. PMID:22608134

  14. Technogenic Magnetic Particles in Alkaline Dusts from Power and Cement Plants.

    PubMed

    Magiera, Tadeusz; Gołuchowska, Beata; Jabłońska, Mariola

    2013-01-01

    most dangerous to the environment. Stoichiometric analysis of micro-particles confirmed the presence of heavy metals such as Pb, Mn, Cd, and Zn connected with TMPs, which are carriers of magnetic signals in atmospheric dust. Therefore, in some cases, their presence in topsoil when detected by magnetic measurement can be treated as an indicator of inorganic soil contamination. PMID:23325986

  15. Degradation of atrazine by a novel Fenton-like process and assessment the influence on the treated soil.

    PubMed

    Cheng, Min; Zeng, Guangming; Huang, Danlian; Lai, Cui; Xu, Piao; Zhang, Chen; Liu, Yang; Wan, Jia; Gong, Xiaomin; Zhu, Yuan

    2016-07-15

    This is the premier study reporting the remediation of atrazine contaminated soil with steel converter slag (SCS) catalyzed Fenton-like process. The effects of various operating parameters, such as SCS loads and H2O2 concentrations were evaluated with respect to the removal efficiency of atrazine. Results show the optimal SCS load and H2O2 concentration were 80gkg(-1) and 10%, respectably. The graded modified Fenton's oxidation with a 3-time addition of 10% H2O2 was able to remove 93.7% of total atrazine in the contaminated soil and maintain soil temperature within 50°C. In contrast to traditional Fenton treatment, a slight pH increase has been observed due to the addition of SCS. More importantly, experiment conducted at natural conditions with SCS gave the similar atrazine removal to the experiments with the other catalysts (e.g., FeSO4 and Fe2O3). One thing should be noted that after the treatment, dissolved organic carbon (DOC) content increased to 1.206gkg(-1) from an initial value of 0.339gkg(-1). PMID:27037472

  16. Injection of Dicyandiamide-Treated Pig Slurry Reduced Ammonia Volatilization without Enhancing Soil Nitrous Oxide Emissions from No-Till Corn in Southern Brazil.

    PubMed

    Aita, Celso; Gonzatto, Rogério; Miola, Ezequiel C C; B, Daniela; Santos, Dos; Rochette, Philippe; Angers, Denis A; Chantigny, Martin H; Pujol, Stefen B; Giacomini, Diego A; Giacomini, Sandro J

    2014-05-01

    There is a lack of information on how placement in soil and nitrification inhibitors affects nitrous oxide (NO) and ammonia (NH) emissions from pig slurry (PS) applied under no-till (NT) conditions. Our objective was to determine the impact of injecting PS and treating it with the nitrification inhibitor dicyandiamide (DCD) on NH and NO emissions from soils under NT in subtropical southern Brazil. The emissions of these gases were compared for shallow (∼ 10 cm) injection and surface broadcasting of PS with and without DCD (8.1-10.0 kg ha; 6.5-8.4% of applied NH-N). Measurements were made at two sites during two summer growing seasons under NT corn crops. Injection reduced NH volatilization by 70% but increased NO emissions 2.4-fold (from 2628 to 6198 g NO N ha) compared with surface broadcast application. Adding DCD to PS inhibited nitrification and reduced NO emissions by an average of 28% (730 g NO-N ha) for surface broadcast and 66% (4105 g NO-N ha) for injection but did not increase NH volatilization. Consequently, NO emission factors were much higher for injection (3.6%) than for surface broadcast (1.3%) application and were reduced (0.9%) when DCD was added to injected PS. In conclusion, the injection of DCD-treated slurry is a recommendable practice for reducing NH and NO emissions when applying PS on NT corn in southern Brazil.

  17. Thermal Shock-resistant Cement

    SciTech Connect

    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 -water 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

  18. Soil stabilization using oil shale solid wastes: Laboratory evaluation of engineering properties

    SciTech Connect

    Turner, J.P.

    1991-01-01

    Oil shale solid wastes were evaluated for possible use as soil stabilizers. A laboratory study was conducted and consisted of the following tests on compacted samples of soil treated with water and spent oil shale: unconfined compressive strength, moisture-density relationships, wet-dry and freeze-thaw durability, and resilient modulus. Significant increases in strength, durability, and resilient modulus were obtained by treating a silty sand with combusted western oil shale. Moderate increases in strength, durability, and resilient modulus were obtained by treating a highly plastic clay with combusted western oil shale. Solid waste from eastern shale can be used for soil stabilization if limestone is added during combustion. Without limestone, eastern oil shale waste exhibits little or no cementation. The testing methods, results, and recommendations for mix design of spent shale-stabilized pavement subgrades are presented. 11 refs., 3 figs., 10 tabs.

  19. Effect of kiln dust from a cement factory on growth of Vicia faba L.

    PubMed

    Uysal, Ismet; Ozdilek, Hasan Göksel; Oztürk, Münir

    2012-04-01

    This study was undertaken to study the effects of different amounts of kiln dust mixed with soil on the seed germination, plant growth, leaf area and water content of Vicia faba cv. Eresen. The reason for this was that cement kiln dust generated as a by-product from the cement factories is rich in potassium, sulfate and other compounds. This product becomes a serious problem when it comes in contact with water. The dust was collected from a cement factory located in Canakkale. Various elements such as Al, Co, Mo, Ca, B, Cd, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, P, Pb, S, Se and Zn were determined both in soil as well as kiln dust. Kiln dust was mixed with soil in pots (20 cm diameter) to make seven different treatments varying from 15 to 105 g kiln dust kg(-1) of soil. The experiment lasted for 4 months. Seeds of V faba were sown in the pots filled with mixtures of preanalysed kiln dust and soil. Germination was high in the pots with a lower treatment of cement kiln dust. However, lower germination rates were observed in the pots mixed with the highest and the medium amounts of cement kiln dust. Plants growing in the soil including 15 g kiln dust showed better performance in length as compared to control. Leaf area increased with increase in cement kiln dust content up to 60 g kiln dust kg(-1) of soil, but declined after 75 g kg(-1). Water content of leaves (mg cm(-2) leaf area) was found to be constantly decreasing with respect to increasing cement kiln content in the pots. Differences between the averages were evaluated by Tukey test and results were found to be significant.

  20. An ice block: a novel technique of successful prevention of cement leakage using an ice ball.

    PubMed

    Uri, Ishaq Fahmi; Garnon, Julien; Tsoumakidou, Georgia; Gangi, Afshin

    2015-04-01

    We report three cases of painful bone metastases with extraosseous invasion treated with cementoplasty and cryoablation. Due to significant cortical loss in all cases, the ice ball was used simultaneously during cementoplasty to deter potential cement leakage. This was achieved by direct application of the ice ball against the cortical surface, resulting in adequate consolidation and successful containment of the cement within the treated bones. To the authors' knowledge, this is the first report to describe such a combined technique.

  1. An Ice Block: A Novel Technique of Successful Prevention of Cement Leakage Using an Ice Ball

    SciTech Connect

    Uri, Ishaq Fahmi; Garnon, Julien Tsoumakidou, Georgia Gangi, Afshin

    2015-04-15

    We report three cases of painful bone metastases with extraosseous invasion treated with cementoplasty and cryoablation. Due to significant cortical loss in all cases, the ice ball was used simultaneously during cementoplasty to deter potential cement leakage. This was achieved by direct application of the ice ball against the cortical surface, resulting in adequate consolidation and successful containment of the cement within the treated bones. To the authors’ knowledge, this is the first report to describe such a combined technique.

  2. Prediction of zeolite-cement-sand unconfined compressive strength using polynomial neural network

    NASA Astrophysics Data System (ADS)

    MolaAbasi, H.; Shooshpasha, I.

    2016-04-01

    The improvement of local soils with cement and zeolite can provide great benefits, including strengthening slopes in slope stability problems, stabilizing problematic soils and preventing soil liquefaction. Recently, dosage methodologies are being developed for improved soils based on a rational criterion as it exists in concrete technology. There are numerous earlier studies showing the possibility of relating Unconfined Compressive Strength (UCS) and Cemented sand (CS) parameters (voids/cement ratio) as a power function fits. Taking into account the fact that the existing equations are incapable of estimating UCS for zeolite cemented sand mixture (ZCS) well, artificial intelligence methods are used for forecasting them. Polynomial-type neural network is applied to estimate the UCS from more simply determined index properties such as zeolite and cement content, porosity as well as curing time. In order to assess the merits of the proposed approach, a total number of 216 unconfined compressive tests have been done. A comparison is carried out between the experimentally measured UCS with the predictions in order to evaluate the performance of the current method. The results demonstrate that generalized polynomial-type neural network has a great ability for prediction of the UCS. At the end sensitivity analysis of the polynomial model is applied to study the influence of input parameters on model output. The sensitivity analysis reveals that cement and zeolite content have significant influence on predicting UCS.

  3. Solidification and stabilization of asbestos waste from an automobile brake manufacturing facility using cement.

    PubMed

    Chan, Y M; Agamuthu, P; Mahalingam, R

    2000-10-01

    Currently, the generated brake lining waste dust, which contains asbestos as its major component, is disposed of into a secure landfill without any additional treatment. As an alternative to this, solidification/stabilization (S/S) disposal of the dust was investigated using Portland cement alone and Portland cement mixed with activated carbon (AC), as the binders. Toxicity Characteristics Leaching Procedure (TCLP) results on the solidified matrix showed that cement was able to immobilize the heavy metals, Ba, Zn, Cr, Pb, Cu and Fe, to within the limits set by the US EPA for TCLP. Addition of AC to the cement reduced the leaching of heavy metals by an additional 4-24% compared to cement alone. The pH of the TCLP leachate extracted from virgin cement, and from dust treated with cement with or without AC was found to increase to 10.9-12.5 as opposed to an initial value of 4.93 for the TCLP extract for the untreated dust. Results of ANS 16.1 (modified) leach protocol revealed that Ba in cement-treated samples showed the highest leach rate, followed by Zn, Pb, Cr, Cu and Fe. The leach rate of heavy metals decreased with progress in time. Cement mixed with AC exhibited similar leach characteristics, however, the leach rate was lower. The linear relationship between the cumulative fraction leached (CFL) and the square root of leaching time in all cement-based samples indicate that a diffusional process is the controlling transport mechanism for the leaching of the heavy metals. The obtained Leachability Indices (L(i)) of 7.6-9.1 and 8.3-9.5 for cement and cement with AC, respectively, were low but exceeded the guidance value of 6, which clearly indicates that all the heavy metals studied are retained well within solid matrices. Cement-based S/S hardening times increased from 30 to 96 h as the dust content increased from 40 to 70 wt.%. The resulting solid matrices exhibited a compressive strength ranging from 1 to 12 MPa, which was well above the specified limit of 414 k

  4. Escherichia coli contamination and health aspects of soil and tomatoes (Solanum lycopersicum L.) subsurface drip irrigated with on-site treated domestic wastewater.

    PubMed

    Forslund, A; Ensink, J H J; Markussen, B; Battilani, A; Psarras, G; Gola, S; Sandei, L; Fletcher, T; Dalsgaard, A

    2012-11-15

    Faecal contamination of soil and tomatoes irrigated by sprinkler as well as surface and subsurface drip irrigation with treated domestic wastewater were compared in 2007 and 2008 at experimental sites in Crete and Italy. Wastewater was treated by Membrane Bio Reactor (MBR) technology, gravel filtration or UV-treatment before used for irrigation. Irrigation water, soil and tomato samples were collected during two cropping seasons and enumerated for the faecal indicator bacterium Escherichia coli and helminth eggs. The study found elevated levels of E. coli in irrigation water (mean: Italy 1753 cell forming unit (cfu) per 100 ml and Crete 488 cfu per 100 ml) and low concentrations of E. coli in soil (mean: Italy 95 cfu g(-1) and Crete 33 cfu g(-1)). Only two out of 84 tomato samples in Crete contained E. coli (mean: 2700 cfu g(-1)) while tomatoes from Italy were free of E. coli. No helminth eggs were found in the irrigation water or on the tomatoes from Crete. Two tomato samples out of 36 from Italy were contaminated by helminth eggs (mean: 0.18 eggs g(-1)) and had been irrigated with treated wastewater and tap water, respectively. Pulsed Field Gel Electrophoresis DNA fingerprints of E. coli collected during 2008 showed no identical pattern between water and soil isolates which indicates contribution from other environmental sources with E. coli, e.g. wildlife. A quantitative microbial risk assessment (QMRA) model with Monte Carlo simulations adopted by the World Health Organization (WHO) found the use of tap water and treated wastewater to be associated with risks that exceed permissible limits as proposed by the WHO (1.0 × 10(-3) disease risk per person per year) for the accidental ingestion of irrigated soil by farmers (Crete: 0.67 pppy and Italy: 1.0 pppy). The QMRA found that the consumption of tomatoes in Italy was deemed to be safe while permissible limits were exceeded in Crete (1.0 pppy). Overall the quality of tomatoes was safe for human

  5. Development of the Use of Alternative Cements for the Treatment of Intermediate Level Waste

    SciTech Connect

    Hayes, M.; Godfrey, I.H.

    2007-07-01

    This paper describes initial development studies undertaken to investigate the potential use of alternative, non ordinary Portland cement (OPC) based encapsulation matrices to treat historic legacy wastes within the UK's Intermediate Level Waste (ILW) inventory. Currently these wastes are encapsulated in composite OPC cement systems based on high replacement with blast furnace slag of pulverised fuel ash. However, the high alkalinity of these cements can lead to high corrosion rates with reactive metals found in some wastes releasing hydrogen and forming expansive corrosion products. This paper therefore details preliminary results from studies on two commercial products, calcium sulfo-aluminate (CSA) and magnesium phosphate (MP) cement which react with a different hydration chemistry, and which may allow wastes containing these metals to be encapsulated with lower reactivity. The results indicate that grouts can be formulated from both cements over a range of water contents and reactant ratios that have significantly improved fluidity in comparison to typical OPC cements. All designed mixes set in 24 hours with zero bleed and the pH values in the plastic state were in the range 10-11 for CSA and 5-7 for MP cements. In addition, a marked reduction in aluminium corrosion rate has been observed in both types of cements compared to a composite OPC system. These results therefore provide encouragement that both cement types can provide a possible alternative to OPC in the immobilisation of reactive wastes, however further investigation is needed. (authors)

  6. Metal/cement interface strength in cemented stem fixation.

    PubMed

    Ahmed, A M; Raab, S; Miller, J E

    1984-01-01

    To characterize the strength of the interface between stem-type metal implants and bone cements, a fracture mechanics parameter was used. This parameter, the critical strain energy release rate (Gc), was determined from "push-out" tests of cylindrical specimens. The specimens, formed using molds of bone, were maintained and tested at body temperature. The strength of interfaces formed with cancellous bone surrounding the cement mantle was significantly less than the strength of those formed in apposition to cortical bone. A marked degradation of strength was found with saline immersion for SS316LVM/cement interfaces formed with Zimmer regular, Simplex-P, and Zimmer LVC cements. After 60 days of immersion the interface Gc was only 10-20% of the value for bulk cement. Interfaces formed with thin-film polymethylmethacrylate-precoated metals (SS316LVM, Co-Cr-Mo, and Ti-6A1-4V) yielded "dry" Gc values one order of magnitude greater than those measured with interfaces formed with uncoated metals. Moreover, the strength of precoated SS316LVM/cement interfaces formed with all three brands of cement did not change after saline immersion for 60 days. PMID:6491806

  7. Radioactive bone cement for the treatment of spinal metastases: a dosimetric analysis of simulated clinical scenarios

    NASA Astrophysics Data System (ADS)

    Kaneko, T. S.; Sehgal, V.; Skinner, H. B.; Al-Ghazi, M. S. A. L.; Ramsinghani, N. S.; Marquez Miranda, M.; Keyak, J. H.

    2012-07-01

    Vertebral metastases are a common manifestation of many cancers, potentially leading to vertebral collapse and neurological complications. Conventional treatment often involves percutaneous vertebroplasty/kyphoplasty followed by external beam radiation therapy. As a more convenient alternative, we have introduced radioactive bone cement, i.e. bone cement incorporating a radionuclide. In this study, we used a previously developed Monte Carlo radiation transport modeling method to evaluate dose distributions from phosphorus-32 radioactive cement in simulated clinical scenarios. Isodose curves were generally concentric about the surface of bone cement injected into cadaveric vertebrae, indicating that dose distributions are relatively predictable, thus facilitating treatment planning (cement formulation and dosimetry method are patent pending). Model results indicated that a therapeutic dose could be delivered to tumor/bone within ∼4 mm of the cement surface while maintaining a safe dose to radiosensitive tissue beyond this distance. This therapeutic range should be sufficient to treat target volumes within the vertebral body when tumor ablation or other techniques are used to create a cavity into which the radioactive cement can be injected. With further development, treating spinal metastases with radioactive bone cement may become a clinically useful and convenient alternative to the conventional two-step approach of percutaneous strength restoration followed by radiotherapy.

  8. Effects of composition and exposure on the solar reflectance of Portland Cement Concrete

    SciTech Connect

    Levinson, Ronnen; Akbari, Hashem

    2002-06-01

    Increasing the solar reflectance (albedo) of a paved surface keeps it cooler in the sun, reducing convection of heat from pavement to air and thereby decreasing the ambient air temperature. Lower air temperatures decrease demand for cooling energy and slow the formation of urban smog. Variations with composition and environmental exposure of the albedos of portland cement concrete pavements were investigated through laboratory fabrication and exposure of 32 mixes of concrete. Concrete albedo generally correlated with cement albedo and sand albedo and, after abrasion, with rock albedo. Cement albedo had a disproportionately strong influence on the reflectance of concrete. Simulated weathering, soiling, and abrasion each reduced average concrete albedo, though some samples became slightly more reflective through weathering or soiling. Concrete albedo grew as the cement hydration reaction progressed, but stabilized within six weeks of casting.

  9. Germination and Seedling Growth of Perennial Ryegrass in Acid Sulfate Soil Treated by Pyrite Nano-Encapsulation

    NASA Astrophysics Data System (ADS)

    Lee, J.; Kim, J.; Yi, J.; Kim, T.

    2007-05-01

    The trial pot experiment was conducted to validate the effect of encapsulation in reduction of acid rock drainage. Six different treatments were performed: A = control, four times spraying of distilled water; B = four times of 0.01 M H2O2; C = once-encapsulated and three times spraying of distilled water; D = twice-encapsulated and twice spraying of distilled water; E = three times-encapsulated and once spraying of distilled water and F = four times-encapsulated for the acid sulfate soil with pyrite bearing andesite powder and sand. After the encapsulation treatment, the perennial ryegrass (Loium perenne) was sowed to evaluate germination rate and growth for three months. The leachate was examined for the chemical properties. The leachate from the A pot (control) is characterized as acidic (pH below 3) and high concentrations of SO4-2: 12,022 mg/L, Al: 85.8 mg/L and Mn: 34.1 mg/L which can be toxic effect to the plant growth. However, the leachate from encapsulated pots showed near neutral (pH 6 to 7) and low concentrations of SO4-2 (below 3,000 mg/L), Al (below 45mg/L) and Mn (24 gm/L). The frequency of encapsulation treatment is related to reduction of acidic drainage. It was hard to identify the significant difference of the seed germination rate of ryegrass between the treatments, although root and shoot growth showed three times difference between the control (1.90g/pot) and four times encapsulated treatment (6.33g/pot) after 2 month growth. It is suggested that encapsulation of pyrite in acid sulfate soil causes the reduction of acidic drainage resulting in the higher growth of herbaceous plants.

  10. 21 CFR 888.4200 - Cement dispenser.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cement dispenser. 888.4200 Section 888.4200 Food... DEVICES ORTHOPEDIC DEVICES Surgical Devices § 888.4200 Cement dispenser. (a) Identification. A cement dispenser is a nonpowered syringe-like device intended for use in placing bone cement (§ 888.3027)...

  11. 21 CFR 888.4200 - Cement dispenser.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Cement dispenser. 888.4200 Section 888.4200 Food... DEVICES ORTHOPEDIC DEVICES Surgical Devices § 888.4200 Cement dispenser. (a) Identification. A cement dispenser is a nonpowered syringe-like device intended for use in placing bone cement (§ 888.3027)...

  12. In vivo Dentin Microhardness beneath a Calcium-Phosphate Cement

    PubMed Central

    Bresciani, E.; Wagner, W.C.; Navarro, M.F.L.; Dickens, S.H.; Peters, M.C.

    2010-01-01

    A minimally invasive caries-removal technique preserves potentially repairable, caries-affected dentin. Mineral-releasing cements may promote remineralization of soft residual dentin. This study evaluated the in vivo remineralization capacity of resin-based calcium-phosphate cement (Ca-PO4) used for indirect pulp-capping. Permanent carious and sound teeth indicated for extraction were excavated and restored either with or without the Ca-PO4 base (control), followed by adhesive restoration. Study teeth were extracted after 3 months, followed by sectioning and in vitro microhardness analysis of the cavity floor to 115-µm depth. Caries-affected dentin that received acid conditioning prior to Ca-PO4 basing showed significantly increased Knoop hardness near the cavity floor. The non-etched group presented results similar to those of the non-treated group. Acid etching prior to cement application increased microhardness of residual dentin near the interface after 3 months in situ. PMID:20511564

  13. Resin cementation of zirconia ceramics with different bonding agents

    PubMed Central

    Tanış, Merve Çakırbay; Akay, Canan; Karakış, Duygu

    2015-01-01

    The aim of this study was to evaluate the effects of sandblasting and different chemical bonding agents on shear bond strength of zirconia and conventional resin cement. In this study, 35 zirconia specimens were treated as follows: Group I: control; Group II: sandblasting; Group III: sandblasting + Monobond S; Group IV: sandblasting + Monobond Plus; Group V: sandblasting + Z-Prime Plus. The specimens in each group were bonded with conventional composite resin cement Variolink II. After cementation, specimens were stored in distilled water (at 37 °C) for 24 h and shear test was performed. The highest shear bond strength values were observed in Groups IV and V. The lowest shear bond strength values were observed in Group I. Using 10-methacryloyloxy-decyl dihydrogenphosphate monomer-containing priming agents, e.g. Monobond Plus and Z-PRIME Plus, combined with sandblasting can be an effective method for resin bonding of zirconia restorations. PMID:26019653

  14. Pesticide tolerant and phosphorus solubilizing Pseudomonas sp. strain SGRAJ09 isolated from pesticides treated Achillea clavennae rhizosphere soil.

    PubMed

    Rajasankar, R; Manju Gayathry, G; Sathiavelu, A; Ramalingam, C; Saravanan, V S

    2013-05-01

    In this study, an attempt was made to identify an effective phosphate solubilizing bacteria from pesticide polluted field soil. Based on the formation of solubilization halo on Pikovskaya's agar, six isolates were selected and screened for pesticide tolerance and phosphate (P) solubilization ability through liquid assay. The results showed that only one strain (SGRAJ09) obtained from Achillea clavennae was found to tolerate maximum level of the pesticides tested and it was phylogenetically identified as Pseudomonas sp. It possessed a wide range of pesticide tolerance, ranging from 117 μg mL(-1) for alphamethrin to 2,600 μg mL(-1) for endosulfan. The available P concentrations increased with the maximum and double the maximum dose of monocrotophos and imidacloprid, respectively. On subjected to FT-IR and HPLC analysis, the presence of organic acids functional group in the culture broth and the production of gluconic acid as dominant acid aiding the P solubilization were identified. On comparison with control broth, monocrotophos and imidacloprid added culture broth showed quantitatively high organic acids production. In addition to gluconic acid production, citric and acetic acids were also observed in the pesticide amended broth. Furthermore, the Pseudomonas sp. strain SGRAJ09 possessed all the plant growth promoting traits tested. In presence of monocrotophos and imidacloprid, its plant growth promoting activities were lower than that of the pesticides unamended treatment. PMID:23512438

  15. Pesticide tolerant and phosphorus solubilizing Pseudomonas sp. strain SGRAJ09 isolated from pesticides treated Achillea clavennae rhizosphere soil.

    PubMed

    Rajasankar, R; Manju Gayathry, G; Sathiavelu, A; Ramalingam, C; Saravanan, V S

    2013-05-01

    In this study, an attempt was made to identify an effective phosphate solubilizing bacteria from pesticide polluted field soil. Based on the formation of solubilization halo on Pikovskaya's agar, six isolates were selected and screened for pesticide tolerance and phosphate (P) solubilization ability through liquid assay. The results showed that only one strain (SGRAJ09) obtained from Achillea clavennae was found to tolerate maximum level of the pesticides tested and it was phylogenetically identified as Pseudomonas sp. It possessed a wide range of pesticide tolerance, ranging from 117 μg mL(-1) for alphamethrin to 2,600 μg mL(-1) for endosulfan. The available P concentrations increased with the maximum and double the maximum dose of monocrotophos and imidacloprid, respectively. On subjected to FT-IR and HPLC analysis, the presence of organic acids functional group in the culture broth and the production of gluconic acid as dominant acid aiding the P solubilization were identified. On comparison with control broth, monocrotophos and imidacloprid added culture broth showed quantitatively high organic acids production. In addition to gluconic acid production, citric and acetic acids were also observed in the pesticide amended broth. Furthermore, the Pseudomonas sp. strain SGRAJ09 possessed all the plant growth promoting traits tested. In presence of monocrotophos and imidacloprid, its plant growth promoting activities were lower than that of the pesticides unamended treatment.

  16. Nutrient, metal and microbial loss in surface runoff following treated sludge and dairy cattle slurry application to an Irish grassland soil.

    PubMed

    Peyton, D P; Healy, M G; Fleming, G T A; Grant, J; Wall, D; Morrison, L; Cormican, M; Fenton, O

    2016-01-15

    Treated municipal sewage sludge ("biosolids") and dairy cattle slurry (DCS) may be applied to agricultural land as an organic fertiliser. This study investigates losses of nutrients in runoff water (nitrogen (N) and phosphorus (P)), metals (copper (Cu), nickel (Ni), lead (Pb), zinc (Zn), cadmium (Cd), chromium (Cr)), and microbial indicators of pollution (total and faecal coliforms) arising from the land application of four types of treated biosolids and DCS to field micro-plots at three time intervals (24, 48, 360 h) after application. Losses from biosolids-amended plots or DCS-amended plots followed a general trend of highest losses occurring during the first rainfall event and reduced losses in the subsequent events. However, with the exception of total and faecal coliforms and some metals (Ni, Cu), the greatest losses were from the DCS-amended plots. For example, average losses over the three rainfall events for dissolved reactive phosphorus and ammonium-nitrogen from DCS-amended plots were 5 and 11.2 mg L(-1), respectively, which were in excess of the losses from the biosolids plots. When compared with slurry treatments, for the parameters monitored biosolids generally do not pose a greater risk in terms of losses along the runoff pathway. This finding has important policy implications, as it shows that concern related to the reuse of biosolids as a soil fertiliser, mainly related to contaminant losses upon land application, may be unfounded. PMID:26410697

  17. Nutrient, metal and microbial loss in surface runoff following treated sludge and dairy cattle slurry application to an Irish grassland soil.

    PubMed

    Peyton, D P; Healy, M G; Fleming, G T A; Grant, J; Wall, D; Morrison, L; Cormican, M; Fenton, O

    2016-01-15

    Treated municipal sewage sludge ("biosolids") and dairy cattle slurry (DCS) may be applied to agricultural land as an organic fertiliser. This study investigates losses of nutrients in runoff water (nitrogen (N) and phosphorus (P)), metals (copper (Cu), nickel (Ni), lead (Pb), zinc (Zn), cadmium (Cd), chromium (Cr)), and microbial indicators of pollution (total and faecal coliforms) arising from the land application of four types of treated biosolids and DCS to field micro-plots at three time intervals (24, 48, 360 h) after application. Losses from biosolids-amended plots or DCS-amended plots followed a general trend of highest losses occurring during the first rainfall event and reduced losses in the subsequent events. However, with the exception of total and faecal coliforms and some metals (Ni, Cu), the greatest losses were from the DCS-amended plots. For example, average losses over the three rainfall events for dissolved reactive phosphorus and ammonium-nitrogen from DCS-amended plots were 5 and 11.2 mg L(-1), respectively, which were in excess of the losses from the biosolids plots. When compared with slurry treatments, for the parameters monitored biosolids generally do not pose a greater risk in terms of losses along the runoff pathway. This finding has important policy implications, as it shows that concern related to the reuse of biosolids as a soil fertiliser, mainly related to contaminant losses upon land application, may be unfounded.

  18. Preliminary Systems Design Study assessment report. [Evaluation of using specific technologies, system concepts for treating the buried waste and the surrounding contaminated soil

    SciTech Connect

    Mayberry, J.L.; Feizollahi, F.; Del Signore, J.C.

    1992-01-01

    The System Design Study (SDS), part of the Waste Technology Development Department at the Idaho National Engineering Laboratory (INEL), examined techniques for the remediation of hazardous and transuranic waste stored at Radioactive Waste Management Complex's Subsurface Disposal Area at the INEL. Using specific technologies, system concepts for treating the buried waste and the surrounding contaminated soil were evaluated. Evaluation included implementability, effectiveness, and cost. The SDS resulted in the development of technology requirements including demonstration, testing, and evaluation activities needed for implementing each concept. This volume contains introduction section containing a brief SDS background and lists the general assumptions and considerations used during the development of the system concepts. The introduction section is followed by sections describing two system concepts that produce a waste form in compliance with the Waste Isolation Pilot Plant (WIPP) Waste Acceptance Criteria (WAC) and transportation package (TRAMPAC) requirements. This system concept category is referred to as Waste Form 4, WIPP and TRAMPAC Acceptable.'' The following two system concepts are under this category: Sort, Treat, and Repackage System (4-BE-2); Volume Reduction and Packaging System (4-BE-4).

  19. Graphite-reinforced bone cement

    NASA Technical Reports Server (NTRS)

    Knoell, A. C.

    1976-01-01

    Chopped graphite fibers added to surgical bone cement form bonding agent with mechanical properties closely matched to those of bone. Curing reaction produces less heat, resulting in reduced traumatization of body tissues. Stiffness is increased without affecting flexural strength.

  20. Durability of Cement Composites Reinforced with Sisal Fiber

    NASA Astrophysics Data System (ADS)

    Wei, Jianqiang

    understanding of degradation mechanisms, two approaches are proposed to mitigate the degradation of sisal fiber in the cement matrix. In order to relieve the aggressive environment of hydrated cement, cement substitution by a combination of metakaolin and nanoclay, and a combination of rice husk ash and limestone are studied. Both metakaolin and nanoclay significantly optimize the cement hydration, while the combination of these two supplementary cementitious materials validates their complementary and synergistic effect at different stages of aging. The presented approaches effectively reduce the calcium hydroxide content and the alkalinity of the pore solution, thereby mitigating the fiber degradation and improving both the initial mechanical properties and durability of the fiber-cement composites. The role of rice husk ash in cement modification is mainly as the active cementitious supplementary material. In order to improve the degradation resistance of sisal fiber itself, two novel, simple, and economical pretreatments of the fibers (thermal and sodium carbonate treatment) are investigated. Both thermal treatment and Na 2CO3 treatment effectively improve the durability of sisal fiber-reinforced concrete. The thermal treatment achieves improvement of cellulose's crystallization, which ensures the initial strength and improved durability of sisal fiber. A layer consisting of calcium carbonate sediments, which protects the internals of a fiber from the strong alkali pore solution, is formed and filled in pits and cavities on the Na2CO3 treated sisal fiber's surface.

  1. Cement pulmonary embolism after vertebroplasty.

    PubMed

    Sifuentes Giraldo, Walter Alberto; Lamúa Riazuelo, José Ramón; Gallego Rivera, José Ignacio; Vázquez Díaz, Mónica

    2013-01-01

    In recent years, the use of vertebral cementing techniques for vertebroplasty and kyphoplasty has spread for the treatment of pain associated with osteoporotic vertebral compression fractures. This is also associated with the increased incidence of complications related with these procedures, the most frequent being originated by leakage of cementation material. Cement can escape into the vertebral venous system and reach the pulmonary circulation through the azygous system and cava vein, producing a cement embolism. This is a frequent complication, occurring in up to 26% of patients undergoing vertebroplasty but, since most patients have no clinical or hemodynamical repercussion, this event usually goes unnoticed. However, some serious, and even fatal cases, have been reported. We report the case of a 74-year-old male patient who underwent vertebroplasty for persistent pain associated with osteoporotic L3 vertebral fracture and who developed a cement leak into the cava vein and right pulmonary artery during the procedure. Although he developed a pulmonary cement embolism, the patient remained asymptomatic and did not present complications during follow-up.

  2. Epigeal fauna of a degraded soil treated with mineral fertilizer and compound cellulose cultivated of tree species

    NASA Astrophysics Data System (ADS)

    Giácomo, R. G.; de Arruda, O. G.; Souto Filho, S. N.; Alves, M. C.; Pereira, M. G.; Frigério, G. C.

    2012-04-01

    The aim of this study was to investigate the behavior of the epigeal fauna in a degraded soil in the recovery process after one year of cultivated with tree species. The experiment was established in February 2010 in Mato Grosso do Sul, Brazil. The experimental design was randomized blocks in split plots with five treatments and four replications. In the main plots, pure cultivation of Eucalyptus urograndis (exotic species - hybrids) and Mabea fistulifera Mart. (native species) and the subplot treatments: Control; D0 - without fertilization; DM - mineral fertilizer according to crop need; DC - with compost manure according to crop need (10 t ha-1); D15 - 15 t ha-1 and D20 - 20 t ha-1 of the compound. In February of the years 2010 and 2011 were installed in the central region of each treatment two traps "pitt fall" which remained for seven days in the field. We calculated Shannon diversity and Pielou evenness indices, and richness of wildlife activity groups. The results were analyzed by ANOVA and Scott Knott test at 5% significance level. In 2010, the area with M. fistulifera, was captured a total of 2697 organisms distributed mainly in: Hymenoptera with 45.83% of the total collected, Collembola (36.93%), Hemiptera Heteroptera (6.56%). In the area with E. urograndis, 1938 organisms were captured, being 50.67% of the order Hymenoptera, Collembola 26.83%, 7.59% Hemiptera Heteroptera. It was found that there was no significant difference between treatments and between species for all variables. Collected in 2011 were 4970 organisms in 56.22% of the order Hymenoptera, Collembola 18.49% and 7.12% beetle in the area of M. fistulifera. In the area of E. urograndis were 4200 organisms, 55.29% (Hymenoptera), 23.79% (Collembola) and 5.86% (Coleoptera). It appears that the activity values and richness of the fauna groups were significantly higher in treatments with organic fertilization in both cultive. It is concluded that after one year there was a variation of the dominant

  3. Arsenic encapsulation using Portland cement with ferrous sulfate/lime and Terra-Bond™ technologies - Microcharacterization and leaching studies.

    PubMed

    Randall, Paul M

    2012-03-15

    This work reports the results of an investigation on the treatment and encapsulation of arsenic-containing materials by Portland cement with ferrous sulfate and lime (PFL) and Terra-Bond™, a commercially available patented technology. The arsenic materials included: chromated copper arsenate (CCA)-treated wood materials; scorodite-rich mine tailings from the La Trinidad Mine in California; and a soil/smelter dust mixture from the Anaconda Superfund site spiked with monosodium methyl arsenate (MSMA) to simulate an organoarsenic soil material. SEM/EDS and XRD spectra of PFL treated samples showed similarity across all three waste materials while Terra-Bond treated samples showed predominance of elemental sulfur. SEM/EDS of PFL treated samples showed that calcium was imbedded in the structure while micrographs of Terra-Bond treated samples showed the appearance of an epoxy material on the surface. The epoxy material appears to be responsible for encapsulating and reducing the leachability of arsenic. XANES spectra for the PFL treatment of CCA-containing samples showed that arsenic has a predominant pentavalent form (As +5), and the PFL treatment process did not alter the arsenic oxidation state. But, distinct differences were observed for XANES spectra of untreated and PFL treated scorodite-rich mine tailing which changed the arsenic coordination structure from a mixture of As (+3/+5) to exclusively As (+5). Both S/S techniques reduced the amount of arsenic released in the leaching tests. Most cases show lower amounts of arsenic released from wastes treated by the Terra-Bond™ technique when compared to the PFL technique. The pH of the solution significantly affected the leachability, with the amount of arsenic released increasing with pH. Sequential extraction results indicate that sodium hydroxide was favorable in releasing arsenic in the mine tailings. This is due to ligand displacement reactions of hydroxyl ions with arsenic species and high pH conditions that

  4. Quality improvement of photopolimerizable-cement root canal obturation

    NASA Astrophysics Data System (ADS)

    Lupato Conrado, Luis A.; Frois, Iris M.; Amaro Zangaro, Renato; Munin, Egberto; Kuranaga, Carlos; Dias da Silva, Marcos; do Carmo de Andrade Nono, Maria; Cerquiera Rezende, Mirabel

    2003-06-01

    The sealing cements commonly used for endodontic applications are of the type cured through chemical reactions. During the polymerization process, mechanical contractions are not uncommon, leading to a non-perfect sealing. Photopolymerizable cements usually presents superior performance as compared to those chemically activated. However, difficulties in carrying the light to difficult-to-reach regions like the dental apex preclude those material of being accepted in the dental office routine. This work reports on a novel technique which allow the light curing of photopolymerizable cements in endodontic applications. A special light guide had been developed to allow the curing light to reach and polymerize the sealing cement in the apex region. The technique was tested by using single-root human teeth with normal canal morphology. The Ultradent EndoREZ root canal sealer and a resin-based photopolymerizable filler specially developed for the current application had been used. The cone-shaped light guide was introduced into treated canals filled with the photopolymerizable material, up to the apical region. Light from an argon laser was launched onto the light guide for polymerization. All test samples were immersed in methylene-blue solution for microleakage testing. All samples treated with the self-polymerizable material presented dye penetration to some extent. No sample within the group which had the filling material polymerized by using the light guide presented dye penetration through the canal wall.

  5. Effects of Using Pozzolan and Portland Cement in the Treatment of Dispersive Clay

    PubMed Central

    Vakili, A. H.; Selamat, M. R.; Moayedi, H.

    2013-01-01

    Use of dispersive clay as construction material requires treatment such as by chemical addition. Treatments to dispersive clay using pozzolan and Portland cement, singly and simultaneously, were carried out in this study. When used alone, the optimum amount of pozzolan required to treat a fully dispersive clay sample was 5%, but the curing time to reduce dispersion potential, from 100% to 30% or less, was 3 month long. On the other hand, also when used alone, a 3% cement content was capable of reducing dispersion potential to almost zero percent in only 7 days; and a 2% cement content was capable of achieving similar result in 14 days. However, treatment by cement alone is costly and could jeopardize the long term performance. Thus, a combined 5% pozzolan and 1.5% cement content was found capable of reducing dispersion potential from 100% to zero percent in 14 days. The results indicate that although simultaneous treatment with pozzolan and cement would extend the required curing time in comparison to treatment by cement alone of a higher content, the task could still be carried out in a reasonable period of curing time while avoiding the drawbacks of using either pozzolan or cement alone. PMID:23864828

  6. Effects of using pozzolan and Portland cement in the treatment of dispersive clay.

    PubMed

    Vakili, A H; Selamat, M R; Moayedi, H

    2013-01-01

    Use of dispersive clay as construction material requires treatment such as by chemical addition. Treatments to dispersive clay using pozzolan and Portland cement, singly and simultaneously, were carried out in this study. When used alone, the optimum amount of pozzolan required to treat a fully dispersive clay sample was 5%, but the curing time to reduce dispersion potential, from 100% to 30% or less, was 3 month long. On the other hand, also when used alone, a 3% cement content was capable of reducing dispersion potential to almost zero percent in only 7 days; and a 2% cement content was capable of achieving similar result in 14 days. However, treatment by cement alone is costly and could jeopardize the long term performance. Thus, a combined 5% pozzolan and 1.5% cement content was found capable of reducing dispersion potential from 100% to zero percent in 14 days. The results indicate that although simultaneous treatment with pozzolan and cement would extend the required curing time in comparison to treatment by cement alone of a higher content, the task could still be carried out in a reasonable period of curing time while avoiding the drawbacks of using either pozzolan or cement alone.

  7. Influence of Thermal Treatment Conditions on the Properties of Dental Silicate Cements.

    PubMed

    Voicu, Georgeta; Popa, Alexandru Mihai; Badanoiu, Alina Ioana; Iordache, Florin

    2016-01-01

    In this study the sol-gel process was used to synthesize a precursor mixture for the preparation of silicate cement, also called mineral trioxide aggregate (MTA) cement. This mixture was thermally treated under two different conditions (1400 °C/2 h and 1450 °C/3 h) followed by rapid cooling in air. The resulted material (clinker) was ground for one hour in a laboratory planetary mill (v = 150 rot/min), in order to obtain the MTA cements. The setting time and mechanical properties, in vitro induction of apatite formation by soaking in simulated body fluid (SBF) and cytocompatibility of the MTA cements were assessed in this study. The hardening processes, nature of the reaction products and the microstructural characteristics were also investigated. The anhydrous and hydrated cements were characterized by different techniques e.g., X-ray diffraction (XRD), scanning electron microscopy (SEM), infrared spectroscopy (FT-IR) and thermal analysis (DTA-DTG-TG). The setting time of the MTA cement obtained by thermal treatment at 1400 °C/2 h (MTA1) was 55 min and 15 min for the MTA cement obtained at 1450 °C/3 h (MTA2). The compressive strength values were 18.5 MPa (MTA1) and 22.9 MPa (MTA2). Both MTA cements showed good bioactivity (assessed by an in vitro test), good cytocompatibility and stimulatory effect on the proliferation of cells. PMID:26901185

  8. Effects of using pozzolan and Portland cement in the treatment of dispersive clay.

    PubMed

    Vakili, A H; Selamat, M R; Moayedi, H

    2013-01-01

    Use of dispersive clay as construction material requires treatment such as by chemical addition. Treatments to dispersive clay using pozzolan and Portland cement, singly and simultaneously, were carried out in this study. When used alone, the optimum amount of pozzolan required to treat a fully dispersive clay sample was 5%, but the curing time to reduce dispersion potential, from 100% to 30% or less, was 3 month long. On the other hand, also when used alone, a 3% cement content was capable of reducing dispersion potential to almost zero percent in only 7 days; and a 2% cement content was capable of achieving similar result in 14 days. However, treatment by cement alone is costly and could jeopardize the long term performance. Thus, a combined 5% pozzolan and 1.5% cement content was found capable of reducing dispersion potential from 100% to zero percent in 14 days. The results indicate that although simultaneous treatment with pozzolan and cement would extend the required curing time in comparison to treatment by cement alone of a higher content, the task could still be carried out in a reasonable period of curing time while avoiding the drawbacks of using either pozzolan or cement alone. PMID:23864828

  9. Cytokine responses of human lung cells (BEAS-2B) treated with micron-sized and nanoparticles of metal oxides compared to soil dusts

    PubMed Central

    Veranth, John M; Kaser, Erin G; Veranth, Martha M; Koch, Michael; Yost, Garold S

    2007-01-01

    Background The induction of cytokines by airway cells in vitro has been widely used to assess the effects of ambient and occupational particles. This study measured cytotoxicity and the release of the proinflammatory cytokines IL-6 and IL-8 by human bronchial epithelial cells treated with manufactured nano- and micron-sized particles of Al2O3, CeO2, Fe2O3, NiO, SiO2, and TiO2, with soil-derived particles from fugitive dust sources, and with the positive controls LPS, TNF-α, and VOSO4. Results The nano-sized particles were not consistently more potent than an equal mass of micron-sized particles of the same nominal composition for the induction of IL-6 and IL-8 secretion in the in vitro models used in this study. The manufactured pure oxides were much less potent than natural PM2.5 particles derived from soil dust, and the cells were highly responsive to the positive controls. The nano-sized particles in the media caused artifacts in the measurement of IL-6 by ELISA due to adsorption of the cytokine on the high-surface-area particles. The potency for inducing IL-6 secretion by BEAS-2B cells did not correlate with the generation of reactive oxygen species in cell-free media. Conclusion Direct comparisons of manufactured metal oxide nanoparticles and previously studied types of particles and surrogate proinflammatory agonists showed that the metal oxide particles have low potency to induce IL-6 secretion in BEAS-2B cells. Particle artifacts from non-biological effects need to be considered in experiments of this type, and the limitations inherent in cell culture studies must be considered when interpreting in vitro results. This study suggests that manufactured metal oxide nanoparticles are not highly toxic to lung cells compared to environmental particles. PMID:17326846

  10. Application of Bacillus subtilis 168 as a multifunctional agent for improvement of the durability of cement mortar.

    PubMed

    Park, Sung-Jin; Park, Jong-Myong; Kim, Wha-Jung; Ghim, Sa-Youl

    2012-11-01

    Microbiological calcium carbonate precipitation (MCCP) has been investigated for its ability to improve the durability of cement mortar. However, very few strains have been applied to crack remediation and strengthening of cementitious materials. In this study, we report the biodeposition of Bacillus subtilis 168 and its ability to enhance the durability of cement material. B. subtilis 168 was applied to the surface of cement specimens. The results showed a new layer of deposited organic-inorganic composites on the surface of the cement paste. In addition, the water permeability of the cement paste treated with B. subtilis 168 was lower than that of non-treated specimens. Furthermore, artificial cracks in the cement paste were completely remediated by the biodeposition of B. subtilis 168. The compressive strength of cement mortar treated with B. subtilis 168 increased by about 19.5% when compared with samples completed with only B4 medium. Taken together, these findings suggest that the biodeposition of B. subtilis 168 could be used as a sealing and coating agent to improve the strength and water resistance of concrete. This is the first paper to report the application of Bacillus subtilis 168 for its ability to improve the durability of cement mortar through calcium carbonate precipitation.

  11. Performance study and influence of radiation emission energy and soil contamination level on γ-radiation shielding of stabilised/solidified radionuclide-polluted soils.

    PubMed

    Falciglia, Pietro P; Puccio, Valentina; Romano, Stefano; Vagliasindi, Federico G A

    2015-05-01

    This work focuses on the stabilisation/solidification (S/S) of radionuclide-polluted soils at different (232)Th levels using Portland cement alone and with barite aggregates. The potential of S/S was assessed applying a full testing protocol and calculating γ-radiation shielding (γRS) index, that included the measurement of soil radioactivity before and after the S/S as a function of the emission energy and soil contamination level. The results indicate that setting processes are strongly dependent on the contaminant concentration, and for contamination level higher than 5%, setting time values longer than 72 h. The addition of barite aggregates to the cement gout leads to a slight improvement of the S/S performance in terms of durability and contaminant leaching but reduces the mechanical resistance of the treated soils samples. Barite addition also causes an increase in the γ-rays shielding properties of the S/S treatment up to about 20%. Gamma-ray measurements show that γRS strongly depends on the energy, and that the radioactivity with the contamination level was governed by a linear trend, while, γRS index does not depend on the radionuclide concentration. Results allow the calculated γRS values and those available from other experiments to be applied to hazard radioactive soil contaminations. PMID:25710096

  12. Performance study and influence of radiation emission energy and soil contamination level on γ-radiation shielding of stabilised/solidified radionuclide-polluted soils.

    PubMed

    Falciglia, Pietro P; Puccio, Valentina; Romano, Stefano; Vagliasindi, Federico G A

    2015-05-01

    This work focuses on the stabilisation/solidification (S/S) of radionuclide-polluted soils at different (232)Th levels using Portland cement alone and with barite aggregates. The potential of S/S was assessed applying a full testing protocol and calculating γ-radiation shielding (γRS) index, that included the measurement of soil radioactivity before and after the S/S as a function of the emission energy and soil contamination level. The results indicate that setting processes are strongly dependent on the contaminant concentration, and for contamination level higher than 5%, setting time values longer than 72 h. The addition of barite aggregates to the cement gout leads to a slight improvement of the S/S performance in terms of durability and contaminant leaching but reduces the mechanical resistance of the treated soils samples. Barite addition also causes an increase in the γ-rays shielding properties of the S/S treatment up to about 20%. Gamma-ray measurements show that γRS strongly depends on the energy, and that the radioactivity with the contamination level was governed by a linear trend, while, γRS index does not depend on the radionuclide concentration. Results allow the calculated γRS values and those available from other experiments to be applied to hazard radioactive soil contaminations.

  13. Method for treating materials for solidification

    DOEpatents

    Jantzen, Carol M.; Pickett, John B.; Martin, Hollis L.

    1995-01-01

    A method for treating materials such as wastes for solidification to form a solid, substantially nonleachable product. Addition of reactive silica rather than ordinary silica to the material when bringing the initial molar ratio of its silica constituent to a desired ratio within a preselected range increases the solubility and retention of the materials in the solidified matrix. Materials include hazardous, radioactive, mixed, and heavy metal species. Amounts of other constituents of the material, in addition to its silica content are also added so that the molar ratio of each of these constituents is within the preselected ranges for the final solidified product. The mixture is then solidified by cement solidification or vitrification. The method can be used to treat a variety of wastes, including but not limited to spent filter aids from waste water treatment, waste sludges, combinations of spent filter aids and waste sludges, combinations of supernate and waste sludges, incinerator ash, incinerator offgas blowdown, combinations of incinerator ash and offgas blowdown, cementitious wastes and contaminated soils.

  14. Amelioration of acidic soil using various renewable waste resources.

    PubMed

    Moon, Deok Hyun; Chang, Yoon-Young; Ok, Yong Sik; Cheong, Kyung Hoon; Koutsospyros, Agamemnon; Park, Jeong-Hun

    2014-01-01

    In this study, improvement of acidic soil with respect to soil pH and exchangeable cations was attempted for sample with an initial pH of approximately 5. Acidic soil was amended with various waste resources in the range of 1 to 5 wt.% including waste oyster shells (WOS), calcined oyster shells (COS), Class C fly ash (FA), and cement kiln dust (CKD) to improve soil pH and exchangeable cations. Upon treatment, the soil pH was monitored for periods up to 3 months. The exchangeable cations were measured after 1 month of curing. After a curing period of 1 month, a maize growth experiment was conducted with selected-treated samples to evaluate the effectiveness of treatment. The treatment results indicate that in order to increase the soil pH to a value of 7, 1 wt.% of WOS, 3 wt.% of FA, and 1 wt.% of CKD are required. In the case of COS, 1 wt.% was more than enough to increase the soil pH value to 7 because of COS's strong alkalinity. Moreover, the soil pH increases after a curing period of 7 days and remains virtually unchanged thereafter up to 1 month of curing. Upon treatment, the summation of cations (Ca, Mg, K, and Na) significantly increased. The growth of maize is superior in the treated samples rather than the untreated one, indicating that the amelioration of acidic soil is beneficial to plant growth, since soil pH was improved and nutrients were replenished.

  15. Amelioration of acidic soil using various renewable waste resources.

    PubMed

    Moon, Deok Hyun; Chang, Yoon-Young; Ok, Yong Sik; Cheong, Kyung Hoon; Koutsospyros, Agamemnon; Park, Jeong-Hun

    2014-01-01

    In this study, improvement of acidic soil with respect to soil pH and exchangeable cations was attempted for sample with an initial pH of approximately 5. Acidic soil was amended with various waste resources in the range of 1 to 5 wt.% including waste oyster shells (WOS), calcined oyster shells (COS), Class C fly ash (FA), and cement kiln dust (CKD) to improve soil pH and exchangeable cations. Upon treatment, the soil pH was monitored for periods up to 3 months. The exchangeable cations were measured after 1 month of curing. After a curing period of 1 month, a maize growth experiment was conducted with selected-treated samples to evaluate the effectiveness of treatment. The treatment results indicate that in order to increase the soil pH to a value of 7, 1 wt.% of WOS, 3 wt.% of FA, and 1 wt.% of CKD are required. In the case of COS, 1 wt.% was more than enough to increase the soil pH value to 7 because of COS's strong alkalinity. Moreover, the soil pH increases after a curing period of 7 days and remains virtually unchanged thereafter up to 1 month of curing. Upon treatment, the summation of cations (Ca, Mg, K, and Na) significantly increased. The growth of maize is superior in the treated samples rather than the untreated one, indicating that the amelioration of acidic soil is beneficial to plant growth, since soil pH was improved and nutrients were replenished. PMID:24078235

  16. Radioactive wastes dispersed in stabilized ash cements

    SciTech Connect

    Rubin, J.B.; Taylor, C.M.V.; Sivils, L.D.; Carey, J.W.

    1997-12-31

    One of the most widely-used methods for the solidification/stabilization of low-level radwaste is by incorporation into Type-I/II ordinary portland cement (OPC). Treating of OPC with supercritical fluid carbon dioxide (SCCO{sub 2}) has been shown to significantly increase the density, while simultaneously decreasing porosity. In addition, the process significantly reduces the hydrogenous content, reducing the likelihood of radiolytic decomposition reactions. This, in turn, permits increased actinide loadings with a concomitant reduction in disposable waste volume. In this article, the authors discuss the combined use of fly-ash-modified OPC and its treatment with SCCO{sub 2} to further enhance immobilization properties. They begin with a brief summary of current cement immobilization technology in order to delineate the areas of concern. Next, supercritical fluids are described, as they relate to these areas of concern. In the subsequent section, they present an outline of results on the application of SCCO{sub 2} to OPC, and its effectiveness in addressing these problem areas. Lastly, in the final section, they proffer their thoughts on why they believe, based on the OPC results, that the incorporation of fly ash into OPC, followed by supercritical fluid treatment, can produce highly efficient wasteforms.

  17. {sup 29}Si solid state NMR investigation of pozzolanic reaction occurring in lime-treated Ca-bentonite

    SciTech Connect

    Pomakhina, Elena; Deneele, Dimitri; Gaillot, Anne-Claire; Paris, Michael; Ouvrard, Guy

    2012-04-15

    Lime is widely used as additive to improve the mechanical properties of natural soil used in earthworks. However, the physico-chemical mechanisms involved are yet not well understood. In order to develop and optimize this treatment method, a better understanding of the interaction between lime and the minerals of the soils, in particular clay minerals, is required. In this study, Ca-bentonite was treated with 2, 5 and 10 wt.% of lime during 1 to 98 days. Modifications in the Si local environment were then monitored by solid state nuclear magnetic resonance to investigate the pozzolanic reaction. All the soil mineral phases contribute to the release of Si and to the pozzolanic reaction, with a rapid and total consumption of Si-polymorph and an exacerbated dissolution of montmorillonite. Mechanism of C-S-H formation, function of the Ca content in the system, was found to match the sorosilicate-tobermorite model described in cement systems.

  18. Experimental Calcium Silicate-Based Cement with and without Zirconium Oxide Modulates Fibroblasts Viability.

    PubMed

    Slompo, Camila; Peres-Buzalaf, Camila; Gasque, Kellen Cristina da Silva; Damante, Carla Andreotti; Ordinola-Zapata, Ronald; Duarte, Marco Antonio Hungaro; de Oliveira, Rodrigo Cardoso

    2015-01-01

    The aim of this study was to verify whether the use of zirconium oxide as a radiopacifier of an experimental calcium silicate-based cement (WPCZO) leads to cytotoxicity. Fibroblasts were treated with different concentrations (10 mg/mL, 1 mg/mL, and 0.1 mg/mL) of the cements diluted in Dulbecco's modified Eagle's medium (DMEM) for periods of 12, 24, and 48 h. Groups tested were white Portland cement (WPC), white Portland cement with zirconium oxide (WPCZO), and white mineral trioxide aggregate Angelus (MTA). Control group cells were not treated. The cytotoxicity was evaluated through mitochondrial-activity (MTT) and cell-density (crystal violet) assays. All cements showed low cytotoxicity. In general, at the concentration of 10 mg/mL there was an increase in viability of those groups treated with WPC and WPCZO when compared to the control group (p<0.05). A similar profile for the absorbance values was noted among the groups: 10 mg/mL presented an increase in viability compared to the control group. On the other hand, smaller concentrations presented a similar or lower viability compared to the control group, in general. A new dental material composed of calcium silicate-based cement with 20% zirconium oxide as the radiopacifier showed low cytotoxicity as a promising material to be exploited for root-end filling.

  19. A MODIFIED PMMA CEMENT (SUB-CEMENT) FOR ACCELERATED FATIGUE TESTING OF CEMENTED IMPLANT CONSTRUCTS USING CADAVERIC BONE

    PubMed Central

    Race, Amos; Miller, Mark A.; Mann, Kenneth A.

    2008-01-01

    Pre-clinical screening of cemented implant systems could be improved by modeling the longer-term response of the implant/cement/bone construct to cyclic loading. We formulated bone cement with degraded fatigue fracture properties (Sub-cement) such that long-term fatigue could be simulated in short-term cadaver tests. Sub-cement was made by adding a chain-transfer agent to standard polymethylmethacrylate (PMMA) cement. This reduced the molecular weight of the inter-bead matrix without changing reaction-rate or handling characteristics. Static mechanical properties were approximately equivalent to normal cement. Over a physiologically reasonable range of stress intensity factor, fatigue crack propagation rates for sub-cement were higher by a factor of 25 ± 19. When tested in a simplified 2 1/2D physical model of a stem-cement-bone system, crack growth from the stem was accelerated by a factor of 100. Sub-cement accelerated both crack initiation and growth rate. Sub-cement is now being evaluated in full stem/cement/femur models. PMID:18774136

  20. A modified PMMA cement (Sub-cement) for accelerated fatigue testing of cemented implant constructs using cadaveric bone.

    PubMed

    Race, Amos; Miller, Mark A; Mann, Kenneth A

    2008-10-20

    Pre-clinical screening of cemented implant systems could be improved by modeling the longer-term response of the implant/cement/bone construct to cyclic loading. We formulated bone cement with degraded fatigue fracture properties (Sub-cement) such that long-term fatigue could be simulated in short-term cadaver tests. Sub-cement was made by adding a chain-transfer agent to standard polymethylmethacrylate (PMMA) cement. This reduced the molecular weight of the inter-bead matrix without changing reaction-rate or handling characteristics. Static mechanical properties were approximately equivalent to normal cement. Over a physiologically reasonable range of stress-intensity factor, fatigue crack propagation rates for Sub-cement were higher by a factor of 25+/-19. When tested in a simplified 2 1/2-D physical model of a stem-cement-bone system, crack growth from the stem was accelerated by a factor of 100. Sub-cement accelerated both crack initiation and growth rate. Sub-cement is now being evaluated in full stem/cement/femur models.

  1. Cytotoxicity and biocompatibility of Zirconia (Y-TZP) posts with various dental cements

    PubMed Central

    Shin, Hyeongsoon; Ko, Hyunjung

    2016-01-01

    Objectives Endodontically treated teeth with insufficient tooth structure are often restored with esthetic restorations. This study evaluated the cytotoxicity and biological effects of yttria partially stabilized zirconia (Y-TZP) blocks in combination with several dental cements. Materials and Methods Pairs of zirconia cylinders with medium alone or cemented with three types of dental cement including RelyX U200 (3M ESPE), FujiCEM 2 (GC), and Panavia F 2.0 (Kuraray) were incubated in medium for 14 days. The cytotoxicity of each supernatant was determined using 3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays on L929 fibroblasts and MC3T3-E1 osteoblasts. The levels of interleukin-6 (IL-6) mRNA were evaluated by reverse transcription polymerase chain reaction (RT-PCR), and IL-6 protein was evaluated by enzyme-linked immunosorbent assays (ELISA). The data were analyzed using one-way ANOVA and Tukey post-hoc tests. A p < 0.05 was considered statistically significant. Results The MTT assays showed that MC3T3-E1 osteoblasts were more susceptible to dental cements than L929 fibroblasts. The resin based dental cements increased IL-6 expression in L929 cells, but reduced IL-6 expression in MC3T3-E1 cells. Conclusions Zirconia alone or blocks cemented with dental cement showed acceptable biocompatibilities. The results showed resin-modified glass-ionomer based cement less produced inflammatory cytokines than other self-adhesive resin-based cements. Furthermore, osteoblasts were more susceptible than fibroblasts to the biological effects of dental cement. PMID:27508157

  2. Effects of Silicon on Osteoclast Cell Mediated Degradation, In Vivo Osteogenesis and Vasculogenesis of Brushite Cement

    PubMed Central

    Vahabzadeh, Sahar; Roy, Mangal; Bose, Susmita

    2015-01-01

    Calcium phosphate cements (CPCs) are being widely used for treating small scale bone defects. Among the various CPCs, brushite (dicalcium phosphate dihydrate, DCPD) cement is widely used due to its superior solubility and ability to form new bone. In the present study, we have studied the physical, mechanical, osteoclast-like-cells differentiation and in vivo osteogenic and vasculogenic properties of silicon (Si) doped brushite cements. Addition of Si did not alter the phase composition of final product and regardless of Si level, all samples included β-tricalcium phosphate (β-TCP) and DCPD. 1.1 wt. % Si addition increased the compressive strength of undoped brushite cement from 4.78±0.21 MPa to 5.53±0.53 MPa, significantly. Cellular activity was studied using receptor activator of nuclear factor κβ ligand (RANKL) supplemented osteoclast-like-cells precursor RAW 264.7 cell. Phenotypic expressions of the cells confirmed successful differentiation of RAW264.7 monocytes to osteoclast-like-cells on undoped and doped brushite cements. An increased activity of osteoclast-like cells was noticed due to Si doping in the brushite cement. An excellent new bone formation was found in all cement compositions, with significant increase in Si doped brushite samples as early as 4 weeks post implantation in rat femoral model. After 4 weeks of implantation, no significant difference was found in blood vessel formation between the undoped and doped cements, however, a significant increase in vasculgenesis was found in 0.8 and 1.1 wt. % Si doped brushite cements after 8 weeks. These results show the influence of Si dopant on physical, mechanical, in vitro osteoclastogenesis and in vivo osteogenic and vasculogenic properties of brushite cements. PMID:26855779

  3. Moulded cement-prosthesis for osteosarcoma of the proximal humerus.

    PubMed

    Pan, K L; Ong, G B; Potukuchi, A P

    2006-12-01

    We report a case of an 11-year-old boy with osteosarcoma of the proximal humerus treated with wide excision and reconstruction with a cement spacer-prosthesis. After seven years of follow-up, the patient is now almost a young adult. We present his current physical and functional status, which seems to defray the initial doubts regarding long-term problems when we chose this method of reconstruction. PMID:17600994

  4. Different bacterial communities in heat and gamma irradiation treated replant disease soils revealed by 16S rRNA gene analysis – contribution to improved aboveground apple plant growth?

    PubMed Central

    Yim, Bunlong; Winkelmann, Traud; Ding, Guo-Chun; Smalla, Kornelia

    2015-01-01

    Replant disease (RD) severely affects apple production in propagation tree nurseries and in fruit orchards worldwide. This study aimed to investigate the effects of soil disinfection treatments on plant growth and health in a biotest in two different RD soil types under greenhouse conditions and to link the plant growth status with the bacterial community composition at the time of plant sampling. In the biotest performed we observed that the aboveground growth of apple rootstock M26 plants after 8 weeks was improved in the two RD soils either treated at 50°C or with gamma irradiation compared to the untreated RD soils. Total community DNA was extracted from soil loosely adhering to the roots and quantitative real-time PCR revealed no pronounced differences in 16S rRNA gene copy numbers. 16S rRNA gene-based bacterial community analysis by denaturing gradient gel electrophoresis (DGGE) and 454-pyrosequencing revealed significant differences in the bacterial community composition even after 8 weeks of plant growth. In both soils, the treatments affected different phyla but only the relative abundance of Acidobacteria was reduced by both treatments. The genera Streptomyces, Bacillus, Paenibacillus, and Sphingomonas had a higher relative abundance in both heat treated soils, whereas the relative abundance of Mucilaginibacter, Devosia, and Rhodanobacter was increased in the gamma-irradiated soils and only the genus Phenylobacterium was increased in both treatments. The increased abundance of genera with potentially beneficial bacteria, i.e., potential degraders of phenolic compounds might have contributed to the improved plant growth in both treatments. PMID:26635733

  5. High temperature well bore cement slurry

    SciTech Connect

    Nahm, J.J.W.; Vinegar, H.J.; Karanikas, J.M.; Wyant, R.E.

    1993-07-13

    A low density well bore cement slurry composition is described suitable for cementing well bores with high reservoir temperatures comprising: (a) a high alumina cement in an amount of about 40 pounds per barrel of slurry or greater: (b) graphite in an amount greater than about one quarter, by volume, of the solids in the cement slurry; and (c) and a carrier fluid comprising drilling mud.

  6. Neutron Scattering Studies of Cement

    NASA Astrophysics Data System (ADS)

    Allen, Andrew

    2010-03-01

    Despite more than a century of research, basic questions remain regarding both the internal structure and the role of water in Ordinary Portland cement (OPC) concrete, the world's most widely used manufactured material. Most such questions concern the primary hydration product and strength-building phase of OPC paste, the calcium silicate hydrate (C-S-H) gel. When cement and water are mixed, this phase precipitates as clusters of nanoscale (nearly amorphous) colloidal particles with an associated water-filled inter-particle pore system. Most attempts to characterize the C-S-H gel and the behavior of the associated water involve drying or other processes that, themselves, change the bound water content within and around the gel. Neutron scattering methods do not suffer from this disadvantage. Furthermore, the neutron isotope effect and the neutron's sensitivity to molecular motion have enabled considerable progress to be made in recent years by: (i) determining the C-S-H composition, density and gel structure in small-angle neutron scattering (SANS) H/D contrast variation studies; (ii) elucidating the changing state of water within cement as hydration progresses using quasielastic neutron scattering (QENS); and (iii) measuring the production and consumption of nanoscale calcium hydroxide (CH), a by-product of cement hydration that co-exists with the C-S-H gel, using inelastic neutron scattering (INS). These experiments have provided new insights into the physics and chemistry of cement hydration, and have implications for the design of new concretes with pozzolanic cement additions that are intended to address environmental concerns and sustainability issues.

  7. Performance evaluation of cement stabilized fly ash-GBFS mixes as a highway construction material.

    PubMed

    Singh, S P; Tripathy, D P; Ranjith, P G

    2008-01-01

    Fly ash and granulated blast furnace slag (GBFS) are major by-products of thermal and steel plants, respectively. These materials often cause disposal problems and environmental pollution. Detailed laboratory investigations were carried out on cement stabilized fly ash-(GBFS) mixes in order to find out its suitability for road embankments, and for base and sub-base courses of highway pavements. Proctor compaction test, unconfined compressive strength (UCS) test and California Bearing Ratio (CBR) test were conducted on cement stabilized fly ash-GBFS mixes as per the Indian Standard Code of Practice. Cement content in the mix was varied from 0% to 8% at 2% intervals, whereas the slag content was varied as 0%, 10%, 20%, 30% and 40%. Test results show that an increase of either cement or GBFS content in the mixture, results in increase of maximum dry density (MDD) and decrease of optimum moisture content (OMC) of the compacted mixture. The MDD of the cement stabilized fly ash-GBFS mixture is comparably lower than that of similarly graded natural inorganic soil of sand to silt size. This is advantageous in constructing lightweight embankments over soft, compressible soils. An increase in percentage of cement in the fly ash-GBFS mix increases enormously the CBR value. Also an increase of the amount of GBFS in the fly ash sample with fixed cement content improves the CBR value of the stabilized mix. In the present study, the maximum CBR value of compacted fly ash-GBFS-cement (52:40:8) mixture obtained was 105%, indicating its suitability for use in base and sub-base courses in highway pavements with proper combinations of raw materials.

  8. ADVANCED CEMENTS FOR GEOTHERMAL WELLS

    SciTech Connect

    SUGAMA,T.

    2007-01-01

    Using the conventional well cements consisting of the calcium silicate hydrates (CaO-SiO{sub 2}-H{sub 2}O system) and calcium aluminum silicate hydrates (CaO-Al{sub 2}O{sub 3}-SiO{sub 2}-H{sub 2}O system) for the integrity of geothermal wells, the serious concern confronting the cementing industries was their poor performance in mechanically supporting the metallic well casing pipes and in mitigating the pipe's corrosion in very harsh geothermal reservoirs. These difficulties are particularly acute in two geological regions: One is the deep hot downhole area ({approx} 1700 m depth at temperatures of {approx} 320 C) that contains hyper saline water with high concentrations of CO{sub 2} (> 40,000 ppm) in conjunction with {approx} 100 ppm H{sub 2}S at a mild acid of pH {approx} 5.0; the other is the upper well region between the well's surface and {approx} 1000 m depth at temperatures up to 200 C. The specific environment of the latter region is characterized by highly concentrated H{sub 2}SO{sub 4} (pH < 1.5) brine containing at least 5000 ppm CO{sub 2}. When these conventional cements are emplaced in these harsh environments, their major shortcoming is their susceptibility to reactions with hot CO{sub 2} and H{sub 2}SO4, thereby causing their deterioration brought about by CO{sub 2}-catalyzed carbonation and acid-initiated erosion. Such degradation not only reduced rapidly the strength of cements, lowering the mechanical support of casing pipes, but also increased the extent of permeability of the brine through the cement layer, promoting the rate of the pipe's corrosion. Severely carbonated and acid eroded cements often impaired the integrity of a well in less than one year; in the worst cases, casings have collapsed within three months, leading to the need for costly and time-consuming repairs or redrilling operations. These were the reasons why the geothermal well drilling and cementing industries were concerned about using conventional well cements, and further

  9. Considerations for proper selection of dental cements.

    PubMed

    Simon, James F; Darnell, Laura A

    2012-01-01

    Selecting the proper cement for sufficient bond strength has become progressively complicated as the number of different materials for indirect restorations has increased. The success of any restoration is highly dependent on the proper cement being chosen and used. The function of the cement is not only to seal the restoration on the tooth but also, in some cases, to support the retention of the restoration. This ability to strengthen retention varies by the cement chosen by the clinician; therefore, careful consideration must precede cement selection.

  10. Acetabular liner fixation by cement.

    PubMed

    Jiranek, William A

    2003-12-01

    Many situations in revision THA require the exchange of a PE liner in the setting of a well-fixed cementless acetabular shell. Unfortunately, a replacement liner is not always available, the locking mechanism of the metal shell may be damaged or incompatible with the desired liner, or the shell is malpositioned. Revision of a well-fixed cementless acetabular shell has been associated with considerable morbidity. This raises several questions: can a new PE liner be fixed in the existing shell using bone cement, and if so, which techniques can improve the end result, and in which patients should they be used? Biomechanical testing of cemented PE liners has shown initial fixation strengths that exceed conventional locking mechanisms. It is not known during what period this initial fixation will fail, but clinical reports with followup of as many as 6 years have shown survival in approximately 90% of cases. These studies have shown the importance of proper patient selection, accurate sizing of the PE liner, careful preparation of the substrate of the liner and the shell, and good cement technique. The potential advantages of this technique are less surgical morbidity, more rapid surgery and patient recovery, the ability to incorporate antibiotics in the cement, and more liner options.

  11. Process for cementing geothermal wells

    DOEpatents

    Eilers, Louis H.

    1985-01-01

    A pumpable slurry of coal-filled furfuryl alcohol, furfural, and/or a low molecular weight mono- or copolymer thereof containing, preferably, a catalytic amount of a soluble acid catalyst is used to cement a casing in a geothermal well.

  12. Surface treatment of injectable strontium-containing bioactive bone cement for vertebroplasty.

    PubMed

    Zhao, F; Lu, W W; Luk, K D K; Cheung, K M C; Wong, C T; Leong, J C Y; Yao, K D

    2004-04-15

    A novel injectable bioactive bone-bonding cement (SrHAC) composed of strontium-containing hydroxyapatite (Sr-HA) as the inorganic filler and bisphenol A diglycidylether dimethacrylate (Bis-GMA) as the organic matrix for vertebroplasty was developed previously. In this study, the Sr-HA powders were surface treated with methyl methacrylate (MMA) to improve the interface integration of the two phases. After surface treatment, the compression strength and Young's modulus, which were tested after immersion in distilled water at 37 degrees C for 24 h according to ISO 5833, were increased by 68.65 % (p <.001) and 31.02% (p <.001), respectively. The bending strength and bending stiffness of the bioactive bone cement were significantly improved by 54.44% (p <.001) and 83.90% (p <.001). In addition, the handling property of the cement was also enhanced. In vitro biomechanical testing showed that the stiffness of the fractured spine recovered to 82.5% (p <.01) of the intact condition after cementation with surface-treated SrHAC. The failure load of the spine cemented with original and MMA-treated SrHAC improved by 14.25% (p <.05) and 46.91% (p <.05) in comparison with the fractured spines. Results from this study revealed that the MMA-treated SrHAC has a better mechanical effect for orthopedic applications.

  13. Effects of composition and exposure on the solar reflectance of Portland cement concrete

    SciTech Connect

    Levinson, Ronnen; Akbari, Hashem

    2001-12-21

    Increasing the solar reflectance (albedo) of a paved surface keeps it cooler in the sun, reducing convection of heat from pavement to air and thereby decreasing the ambient air temperature. Simulations of the influence of pavement albedo on air temperature in Los Angeles predict that increasing the albedo of 1,250 km2 of pavement by 0.25 would save cooling energy worth $15M yr-1, and reduce smog-related medical and lost-work expenses by $76M yr-1. Most sidewalks and a small fraction of roads and parking areas are paved with portland cement concrete, which can be made quite reflective through suitable choice of cement and aggregate. Variations with composition and environmental exposure of the albedos of portland cement concrete pavements were investigated through laboratory fabrication and exposure of 32 mixes of concrete. Twenty-four mixes yielded substandard, ''rough'' concretes due to high, unmet aggregate water demand. The albedos of the remaining eight ''smooth'' concrete mixes ranged from 0.41 to 0.77 (mean 0.59). Simulated weathering, soiling, and abrasion each reduced average concrete albedo (mean decreases 0.06, 0.05, and 0.19, respectively), though some samples became slightly more reflective through weathering or soiling. Simulated rain (wetting) strongly depressed the albedos of concretes (mean decrease 0.23) until their surfaces were dried. Concrete albedo grew as the cement hydration reaction progressed (mean increase 0.08), but stabilized within six weeks of casting. White-cement concretes were on average significantly more reflective than gray-cement concretes. The albedo of the most-reflective white-cement concrete was 0.18 to 0.39 higher than that of the most-reflective gray-cement concrete, depending on state of exposure. Concrete albedo generally correlated with cement albedo and sand albedo, and, after abrasion, with rock albedo. Cement albedo had a disproportionately strong influence on the reflectance of concrete. Efflorescence and surface

  14. Lightweight Cement Slurries based on vermiculite

    NASA Astrophysics Data System (ADS)

    Minaev, K.; Gorbenko, V.; Ulyanova, O.

    2014-08-01

    The main purpose of the research is to study the lightweight cement slurry based on vermiculite and its parameters in accordance with GOST 1581-96 requirements as well as improvement of its formulation by polymer additives. Analysis of vermiculite-containing mixture providing the lowest density while maintaining other required parameters was conducted. As a cement base, cement PTscT-I-G-CC-1, cement PTscT - 100 and vermiculite M200 and M150 were used. Vermiculite content varied from 10 to 15 %; and water-to-cement-ratio ranged from 0.65 to 0.8. To sum up, despite the fact that lightweight cement slurry based on vermiculite satisfies GOST 1581-96 requirements under laboratory conditions, field studies are necessary in order to make a conclusion about applicability of this slurry for well cementing.

  15. Shear bond strength of two resin cements to human root dentin using three dentin bonding agents.

    PubMed

    Gogos, C; Stavrianos, C; Kolokouris, I; Economides, N; Papadoyannis, I

    2007-01-01

    This study compared the bond strength of two resin cements to human root dentin when used with three bonding agents. The materials used were Rely X ARC and Perma Cem, two one-bottle bonding agents (Single Bond, Bond-1) and one self-etching bonding agent (Clearfil SE Bond). The dentin was obtained from single rooted human teeth, and the specimens were treated with either 15% EDTA or 37% phosphoric acid to remove the smear layer, except in groups where the self-etching bonding agent was used. The resin cements were placed on dentin surfaces with the use of bonding agents. Shear bond strength (SBS) was tested using a single plane shear test assembly. The dentin specimens were divided into 10 groups. Eight groups were pre-treated with EDTA or phosphoric acid to remove the smear layer, followed by a bonding agent (Bond-1 or Single Bond) and resin cement (Rely X or Perma Cem). In the two remaining groups, the smear layer was left intact, and the two resins cements were used in combination with the self-etching bonding agent (Clearfil SE Bond). No statistically significant differences were observed among the eight groups treated with one-bottle bonding agents. The mean bond strengths of the two groups treated with the self-etching bonding agent did not differ significantly from each other but were both significantly greater than the bond strengths of all the other groups. The results of this study also showed that EDTA can be used as an alternative to phosphoric acid in bonding procedures for resin cements. However, the bond strengths of resin cements, in combination with a self-etching bonding agent, were significantly greater than those of the same cements when used with one-bottle bonding agents.

  16. Mesoscale texture of cement hydrates.

    PubMed

    Ioannidou, Katerina; Krakowiak, Konrad J; Bauchy, Mathieu; Hoover, Christian G; Masoero, Enrico; Yip, Sidney; Ulm, Franz-Josef; Levitz, Pierre; Pellenq, Roland J-M; Del Gado, Emanuela

    2016-02-23

    Strength and other mechanical properties of cement and concrete rely upon the formation of calcium-silicate-hydrates (C-S-H) during cement hydration. Controlling structure and properties of the C-S-H phase is a challenge, due to the complexity of this hydration product and of the mechanisms that drive its precipitation from the ionic solution upon dissolution of cement grains in water. Departing from traditional models mostly focused on length scales above the micrometer, recent research addressed the molecular structure of C-S-H. However, small-angle neutron scattering, electron-microscopy imaging, and nanoindentation experiments suggest that its mesoscale organization, extending over hundreds of nanometers, may be more important. Here we unveil the C-S-H mesoscale texture, a crucial step to connect the fundamental scales to the macroscale of engineering properties. We use simulations that combine information of the nanoscale building units of C-S-H and their effective interactions, obtained from atomistic simulations and experiments, into a statistical physics framework for aggregating nanoparticles. We compute small-angle scattering intensities, pore size distributions, specific surface area, local densities, indentation modulus, and hardness of the material, providing quantitative understanding of different experimental investigations. Our results provide insight into how the heterogeneities developed during the early stages of hydration persist in the structure of C-S-H and impact the mechanical performance of the hardened cement paste. Unraveling such links in cement hydrates can be groundbreaking and controlling them can be the key to smarter mix designs of cementitious materials. PMID:26858450

  17. Mesoscale texture of cement hydrates

    PubMed Central

    Ioannidou, Katerina; Krakowiak, Konrad J.; Bauchy, Mathieu; Hoover, Christian G.; Masoero, Enrico; Yip, Sidney; Ulm, Franz-Josef; Levitz, Pierre; Pellenq, Roland J.-M.; Del Gado, Emanuela

    2016-01-01

    Strength and other mechanical properties of cement and concrete rely upon the formation of calcium–silicate–hydrates (C–S–H) during cement hydration. Controlling structure and properties of the C–S–H phase is a challenge, due to the complexity of this hydration product and of the mechanisms that drive its precipitation from the ionic solution upon dissolution of cement grains in water. Departing from traditional models mostly focused on length scales above the micrometer, recent research addressed the molecular structure of C–S–H. However, small-angle neutron scattering, electron-microscopy imaging, and nanoindentation experiments suggest that its mesoscale organization, extending over hundreds of nanometers, may be more important. Here we unveil the C–S–H mesoscale texture, a crucial step to connect the fundamental scales to the macroscale of engineering properties. We use simulations that combine information of the nanoscale building units of C–S–H and their effective interactions, obtained from atomistic simulations and experiments, into a statistical physics framework for aggregating nanoparticles. We compute small-angle scattering intensities, pore size distributions, specific surface area, local densities, indentation modulus, and hardness of the material, providing quantitative understanding of different experimental investigations. Our results provide insight into how the heterogeneities developed during the early stages of hydration persist in the structure of C–S–H and impact the mechanical performance of the hardened cement paste. Unraveling such links in cement hydrates can be groundbreaking and controlling them can be the key to smarter mix designs of cementitious materials. PMID:26858450

  18. CBL evaluation of foam-cemented and synthetic-cemented casings

    SciTech Connect

    Burckdorfer, R.; Jacobs, W.R.; Masson, J.P.

    1983-10-01

    Cement Bond Log (CBL) studies on foam-cemented and synthetic-cemented wells were initiated to determine the feasibility of, as well as to develop technologies for, evaluating these novel cementing services. Early CBL's on these cementing systems showed little effect on the log amplitude curve. Hence, CBL evaluations were difficult to obtain and interpret. A special sonde with a 1.3-ft (0.4-m) transmitter-to-receiver spacing was developed for this study. Sonic signal amplitudes were determined using cemented short-casing test sections. Sonic attenuation rates were correlated to compressive strengths for a range of cement densities. Experimental details of the cementing operation and logging studies are discussed. Data relating attenuation rates to compressive strengths and cement densities are also presented. Field results are discussed.

  19. Treatment of a Vertical Root Fracture Using Dual-Curing Resin Cement: A Case Report

    PubMed Central

    Moradi Majd, Nima; Akhtari, Farshid; Araghi, Solmaz; Homayouni, Hamed

    2012-01-01

    Introduction. Vertical root fracture (VRF) is one of the most frustrating complications of root canal treatment. The prognosis of the root with VRF is poor therefore tooth extraction and root amputation are usually the only treatment options. However, bonding of the fracture line with adhesive resin cement during the intentional replantation procedure was recently suggested as an alternative to tooth extraction. Methods. A vertically fractured left maxillary incisor was carefully extracted, fracture line was treated with adhesive resin cement, a retrograde cavity was produced and filled with calcium-enriched mixture (CEM) cement, and tooth was replanted. Results. After 12 months the tooth was asymptomatic. The size of periapical radiolucency was noticeably reduced and there was no clinical sign of ankylosis. Conclusion. Using adhesive resin cement to bond the fracture lines extraorally in roots with VRF and intentional replantation of the reconstructed teeth could be considered as an alternative to tooth extraction, especially for anterior teeth. PMID:23316397

  20. The 3Rs and cement kiln dust: Opportunities for reduction, reuse and recycling

    SciTech Connect

    Nisbet, M.

    1997-12-31

    Cement kiln dust (CKD) is a by-product of the cement manufacturing process. This material which is captured in cement kiln dust control equipment consists primarily of raw and partly calcined kiln feed. Factors which contribute to the generation of CKD are described. Cases of successful reduction of CKD generation are presented. Technologies for treating CKD so that it can be reused as a raw material for cement production are discussed. Applications where CKD can be used alone or with other by-products are also presented. Opportunities for developing new uses for CKD are identified and discussed in terms of the drivers behind such applications as well as the economic, technical and regulatory barriers to their development.

  1. Treatment of a vertical root fracture using dual-curing resin cement: a case report.

    PubMed

    Moradi Majd, Nima; Akhtari, Farshid; Araghi, Solmaz; Homayouni, Hamed

    2012-01-01

    Introduction. Vertical root fracture (VRF) is one of the most frustrating complications of root canal treatment. The prognosis of the root with VRF is poor therefore tooth extraction and root amputation are usually the only treatment options. However, bonding of the fracture line with adhesive resin cement during the intentional replantation procedure was recently suggested as an alternative to tooth extraction. Methods. A vertically fractured left maxillary incisor was carefully extracted, fracture line was treated with adhesive resin cement, a retrograde cavity was produced and filled with calcium-enriched mixture (CEM) cement, and tooth was replanted. Results. After 12 months the tooth was asymptomatic. The size of periapical radiolucency was noticeably reduced and there was no clinical sign of ankylosis. Conclusion. Using adhesive resin cement to bond the fracture lines extraorally in roots with VRF and intentional replantation of the reconstructed teeth could be considered as an alternative to tooth extraction, especially for anterior teeth. PMID:23316397

  2. The effectiveness of arbuscular-mycorrhizal fungi and Aspergillus niger or Phanerochaete chrysosporium treated organic amendments from olive residues upon plant growth in a semi-arid degraded soil.

    PubMed

    Medina, A; Roldán, A; Azcón, R

    2010-12-01

    Arbuscular mycorrhizal (AM) fungi and a residue from dry olive cake (DOC) supplemented with rock phosphate (RP) and treated with either Aspergillus niger (DOC-A) or Phanerochaete chrysosporium (DOC-P), were assayed in a natural, semi-arid soil using Trifolium repens or Dorycnium pentaphyllum plants. The effects of the AM fungi and/or DOC-A were compared with P-fertilisation (P) over eleven successive harvests to evaluate the persistence of the effectiveness of the treatments. The biomass of dually-treated plants after four successive harvests was greater than that obtained for non-treated plants or those receiving the AM inoculum or DOC-A treatments after eleven yields. The AM inoculation was critical for obtaining plant growth benefit from the application of fermented DOC-A residue. The abilities of the treatments to prevent plant drought stress were also assayed. Drought-alleviating effects were evaluated in terms of plant growth, proline and total sugars concentration under alternative drought and re-watering conditions (8th and 9th harvests). The concentrations of both compounds in plant biomass increased under drought when DOC-A amendment and AM inoculation were employed together: they reinforced the plant drought-avoidance capabilities and anti-oxidative defence. Water stress was less compensated in P-fertilised than in DOC-A-treated plants. DOC-P increased D. pentaphyllum biomass, shoot P content, nodule number and AM colonisation, indicating the greater DOC-transforming ability of P. chrysosporium compared to A. niger. The lack of AM colonisation and nodulation in this soil was compensated by the application of DOC-P, particularly with AM inoculum. The management of natural resources (organic amendments and soil microorganisms) represents an important strategy that assured the growth, nutrition and plant establishment in arid, degraded soils, preventing the damage that arises from limited water and nutrient supply.

  3. The effect of sodium hypochlorite and resin cement systems on push-out bond strength of cemented fiber posts

    PubMed Central

    Alkhudhairy, Fahad I.; Bin-Shuwaish, Mohammed S.

    2016-01-01

    Objective: This study investigated the effect of different endodontic irrigant solutions and resin cement systems on the bond strength of cemented fiber posts. Methods: Sixty human single-rooted anterior teeth were sectioned transversely at 2 mm incisal to the cemento-enamel junction (CEJ). The roots were treated endodontically, and teeth were distributed into six groups: group A, includes 5.25%NaOCl irrigant with MultiCore Flow Core Build-Up material; group B, includes 5.25%NaOCl irrigant with RelyX-Unicem Self-Adhesive Universal Resin Cement; group C, includes 2.5% NaOCl irrigant with MultiCore Flow; group D, includes 2.5%NaOCl irrigant with RelyX-Unicem; group E, includes NaCl, irrigant with MultiCore Flow; and group F, includes NaCl irrigant with RelyX-Unicem. Universal tapered fiber posts (No. 3 RelyX Fiber Post) were cemented, and roots were sectioned into cervical and apical segments. Samples were then subjected to a push-out bond strength test and failure modes were examined. Results: The mean push-out bond strength for group D showed the highest mean value (20.07 MPa), while the lowest value was found in group A. There was a significant difference between groups with regard to the irrigants used (p<0.001), however, no significant difference was found between groups with regard to resin systems (p>0.05). The total mean push-out bond strength of the cervical segments was found to be significantly higher than the apical segments (p<0.001). Conclusion: The irrigant solution have a clear influence on the push-out bond strength of the fiber posts regardless of the cement used. Both adhesive resin systems showed similar bonding strength.

  4. The effect of sodium hypochlorite and resin cement systems on push-out bond strength of cemented fiber posts

    PubMed Central

    Alkhudhairy, Fahad I.; Bin-Shuwaish, Mohammed S.

    2016-01-01

    Objective: This study investigated the effect of different endodontic irrigant solutions and resin cement systems on the bond strength of cemented fiber posts. Methods: Sixty human single-rooted anterior teeth were sectioned transversely at 2 mm incisal to the cemento-enamel junction (CEJ). The roots were treated endodontically, and teeth were distributed into six groups: group A, includes 5.25%NaOCl irrigant with MultiCore Flow Core Build-Up material; group B, includes 5.25%NaOCl irrigant with RelyX-Unicem Self-Adhesive Universal Resin Cement; group C, includes 2.5% NaOCl irrigant with MultiCore Flow; group D, includes 2.5%NaOCl irrigant with RelyX-Unicem; group E, includes NaCl, irrigant with MultiCore Flow; and group F, includes NaCl irrigant with RelyX-Unicem. Universal tapered fiber posts (No. 3 RelyX Fiber Post) were cemented, and roots were sectioned into cervical and apical segments. Samples were then subjected to a push-out bond strength test and failure modes were examined. Results: The mean push-out bond strength for group D showed the highest mean value (20.07 MPa), while the lowest value was found in group A. There was a significant difference between groups with regard to the irrigants used (p<0.001), however, no significant difference was found between groups with regard to resin systems (p>0.05). The total mean push-out bond strength of the cervical segments was found to be significantly higher than the apical segments (p<0.001). Conclusion: The irrigant solution have a clear influence on the push-out bond strength of the fiber posts regardless of the cement used. Both adhesive resin systems showed similar bonding strength. PMID:27648037

  5. Research of magnesium phosphosilicate cement

    NASA Astrophysics Data System (ADS)

    Ding, Zhu

    Magnesium phosphosilicate cement (MPSC) is a novel phosphate bonded cement, which consists mainly of magnesia, phosphate and silicate minerals. The traditional magnesium phosphate cements (MPCs) usually composed by ammonium phosphate, and gaseous ammonia will emit during mixing and in service. There is no noxious ammonia released from MPSC, furthermore, it can recycle a large volume of the non-hazardous waste. The goal of this research is to investigate the composition, reaction products, reaction mechanism, microstructure, properties, durability and applications of the MPSC. MPSC sets rapidly and has high early strength. It reacts better with solid industrial waste when compared to Portland cement. Many solid industrial wastes, such as fly ash, steel slag, coal gangue, red coal gangue, red mud, barium-bearing slag, copper slag, silica fume, and ground granulated blast furnace slag, have been used as the main component (40% by weight) in MPSC. The research has found that these aluminosilicate (or ironsilicate, or calciumsilicate) minerals with an amorphous or glass structure can enhance the performance of MPSC. The disorganized internal structure of amorphous materials may make it possess higher reactivity compared to the crystalline phases. Chemical reaction between phosphate and these minerals may form an amorphous gel, which is favorable to the cementing. Borax, boric acid and sodium tripolyphosphate have been used as retardants in the MPSC system. It is found that boric acid has a higher retarding effect on the setting of cement, than borax does. However, sodium polyphosphate accelerates the reaction of MPSC. The hydration of MPSC is exothermic reaction. The heat evolution may prompt hydrates formation, and shorten the setting process. Modern materials characterization techniques, XRD, DSC, TG-DTA FTIR, XPS, MAS-NMR, SEM, TEM, MIP, etc. were used to analyze the phase composition, micro morphology, and microstructure of hardened MPSC. The main hydration product

  6. Performance of volcanic ash and pumice based blended cement concrete in mixed sulfate environment

    SciTech Connect

    Hossain, K.M.A. . E-mail: ahossain@ryerson.ca; Lachemi, M.

    2006-06-15

    The deterioration of concrete structures due to the presence of mixed sulfate in soils, groundwater and marine environments is a well-known phenomenon. The use of blended cements incorporating supplementary cementing materials and cements with low C{sub 3}A content is becoming common in such aggressive environments. This paper presents the results of an investigation on the performance of 12 volcanic ash (VA) and finely ground volcanic pumice (VP) based ASTM Type I and Type V (low C{sub 3}A) blended cement concrete mixtures with varying immersion period of up to 48 months in environments characterized by the presence of mixed magnesium-sodium sulfates. The concrete mixtures comprise a combination of two Portland cements (Type I and Type V) and four VA/VP based blended cements with two water-to-binder ratio of 0.35 and 0.45. Background experiments (in addition to strength and fresh properties) including X-ray diffraction (XRD), Differential scanning calorimetry (DSC), mercury intrusion porosimetry (MIP) and rapid chloride permeability (RCP) were conducted on all concrete mixtures to determine phase composition, pozzolanic activity, porosity and chloride ion resistance. Deterioration of concrete due to mixed sulfate attack and corrosion of reinforcing steel were evaluated by assessing concrete weight loss and measuring corrosion potentials and polarization resistance at periodic intervals throughout the immersion period of 48 months. Plain (Type I/V) cement concretes, irrespective of their C{sub 3}A content performed better in terms of deterioration and corrosion resistance compared to Type I/V VA/VP based blended cement concrete mixtures in mixed sulfate environment.

  7. Evaluation of amendments to decrease high strength in southeastern USA Coastal Plain soils using fuzzy multi-attributive comparison of alternatives

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Productivity of many southeastern USA Coastal Plain soils is reduced by cemented subsurface layers that restrict root growth. Though tillage is the usual way to reduce cementation, if soil amendments can develop aggregation, they offer a more permanent solution. To improve soil physical properties a...

  8. Cement bond log evaluation of foam- and synthetic-cemented casings

    SciTech Connect

    Bruckdorfer, R.A.; Jacobs, W.R.; Masson, J.P.

    1984-11-01

    Cement bond log (CBL /SUP TM/ ) studies on foam- and synthetic-cemented wells were initiated to determine the feasibility of, as well as to develop technologies for, evaluating these novel cementing services. Early CBL's on these cementing systems showed little effect on the log amplitude curve. Hence, CBL evaluations were difficult to obtain and interpret. A special sonde with a 1.3-ft (0.4-m) transmitter-toreceiver spacing was developed for this study. Sonic signal amplitudes were determined by using cemented shortcasing test sections. Sonic attenuation rates were correlated to compressive strengths for a range of cement densities. Experimental details of the cementing operation and logging studies are discussed. Data relating attenuation rates to compressive strengths and cement densities also are presented. Field results are discussed.

  9. Importance of microscopy in durability studies of solidified and stabilized contaminated soils

    USGS Publications Warehouse

    Klich, I.; Wilding, L.P.; Drees, L.R.; Landa, E.R.

    1999-01-01

    Solidification/stabilization (S/S) is recognized by the U.S. EPA as a best demonstrated available technology for the containment of contaminated soils and other hazardous wastes that cannot be destroyed by chemical, thermal, or biological means. Despite the increased use of S/S technologies, little research has been conducted on the weathering and degradation of solidified and stabilized wastes once the treated materials have been buried. Published data to verify the performance and durability of landfilled treated wastes over time are rare. In this preliminary study, optical and electron microscopy (scanning electron microscopy [SEM], transmission electron microscopy [TEM] and electron probe microanalyses [EPMA]) were used to evaluate weathering features associated with metal-bearing contaminated soil that had been solidified and stabilized with Portland cement and subsequently buried on site, stored outdoors aboveground, or achieved in a laboratory warehouse for up to 6 yr. Physical and chemical alteration processes identified include: freeze-thaw cracking, cracking caused by the formation of expansive minerals such as ettringite, carbonation, and the movement of metals from waste aggregates into the cement micromass. Although the extent of degradation after 6 yr is considered slight to moderate, results of this study show that the same environmental concerns that affect the durability of concrete must be considered when evaluating the durability and permanence of the solidification and stabilization of contaminated soils with cement. In addition, such evaluations cannot be based on leaching and chemical analyses alone. The use of all levels of microscopic analyses must be incorporated into studies of the long-term performance of S/S technologies.Solidification/stabilization (S/S) is recognized by the U.S. EPA as a best demonstrated available technology for the containment of contaminated soils and other hazardous wastes that cannot be destroyed by chemical

  10. A novel, multi-barrier, drug eluting calcium sulfate/biphasic calcium phosphate biodegradable composite bone cement for treatment of experimental MRSA osteomyelitis in rabbit model.

    PubMed

    Mistry, Surajit; Roy, Subhasis; Maitra, Nilendu Jyoti; Kundu, Biswanath; Chanda, Abhijit; Datta, Someswar; Joy, Mathew

    2016-10-10

    This article discloses the development of an effective and versatile technology to prepare a novel antibiotics-loaded biodegradable composite bone cement to treat methicillin-resistant Staphylococcal (MRSA) osteomyelitis and reports its detail in vitro characterization, drug loading efficiency, physico-mechanical properties, drug elution in simulated body fluid (SBF) and human plasma, merits and demerits over poly-methyl methacrylate (PMMA) cement. Chronic osteomyelitis in rabbit tibia (42) was induced by MRSA and composite cement was implanted to evaluate its safety and efficacy over PMMA cement and parenteral treated animals with histopathology, radiographs, bone/plasma drugs concentration, and SEM for 90days. The composite cement showed higher setting time, degradability, pH rise, injectability, in vitro drug elution but lesser mechanical strength than PMMA cement. Antibiotics release from cement beads was faster in SBF than plasma. Further, in vivo antibiotics elution from composite (42days) showed effective concentration against MRSA without eliciting drug-toxicity. Platelets activation by composite was an extraordinary feature. The in vivo studies also proved the superiority of composite cement than other treatment methods in terms of faster infection control and osteosynthesis. Based particularly on drug elution and in vivo results, this newly developed cement can successfully be used in clinical cases of chronic osteomyelitis.

  11. A novel, multi-barrier, drug eluting calcium sulfate/biphasic calcium phosphate biodegradable composite bone cement for treatment of experimental MRSA osteomyelitis in rabbit model.

    PubMed

    Mistry, Surajit; Roy, Subhasis; Maitra, Nilendu Jyoti; Kundu, Biswanath; Chanda, Abhijit; Datta, Someswar; Joy, Mathew

    2016-10-10

    This article discloses the development of an effective and versatile technology to prepare a novel antibiotics-loaded biodegradable composite bone cement to treat methicillin-resistant Staphylococcal (MRSA) osteomyelitis and reports its detail in vitro characterization, drug loading efficiency, physico-mechanical properties, drug elution in simulated body fluid (SBF) and human plasma, merits and demerits over poly-methyl methacrylate (PMMA) cement. Chronic osteomyelitis in rabbit tibia (42) was induced by MRSA and composite cement was implanted to evaluate its safety and efficacy over PMMA cement and parenteral treated animals with histopathology, radiographs, bone/plasma drugs concentration, and SEM for 90days. The composite cement showed higher setting time, degradability, pH rise, injectability, in vitro drug elution but lesser mechanical strength than PMMA cement. Antibiotics release from cement beads was faster in SBF than plasma. Further, in vivo antibiotics elution from composite (42days) showed effective concentration against MRSA without eliciting drug-toxicity. Platelets activation by composite was an extraordinary feature. The in vivo studies also proved the superiority of composite cement than other treatment methods in terms of faster infection control and osteosynthesis. Based particularly on drug elution and in vivo results, this newly developed cement can successfully be used in clinical cases of chronic osteomyelitis. PMID:27582374

  12. How to obtain good primary cement jobs

    SciTech Connect

    Kundert, D.P. ); Vacca, H.L. ); Smink, D.E

    1990-04-01

    A review of 23 primary cementing jobs performed over an 11-year period in four states has shown improved success with attention having been directed to low- cost means of improving displacement of drilling muds by cement slurries. The most important factors appear to be placement of centralizers and scratchers, conditioning of the drilling mud and pipe movement (reciprocation) while conditioning mud and while placing cement. Confidence gained in the use of these methods has resulted in a job technique wherein the top cementing plug is pumped down with 10% acetic acid or other desired perforating fluid followed by 2% KCI water. This technique permits lower-cost completions. The theory and application of cement bond logging is reviewed with five example CBL-VDL logs presented and discussed. Several examples are shown under applied surface pressure conditions. An example of a CBL-VDL log for an offset well where the principles of primary cementing were not observed is shown for comparison.

  13. Sustainable cement production-present and future

    SciTech Connect

    Schneider, M.; Romer, M.; Tschudin, M.; Bolio, H.

    2011-07-15

    Cement will remain the key material to satisfy global housing and modern infrastructure needs. As a consequence, the cement industry worldwide is facing growing challenges in conserving material and energy resources, as well as reducing its CO{sub 2} emissions. According to the International Energy Agency, the main levers for cement producers are the increase in energy efficiency and the use of alternative materials, be it as fuel or raw materials. Accordingly, the use of alternative fuels has already increased significantly in recent years, but potential for further increases still exists. In cement, the reduction of the clinker factor remains a key priority: tremendous progress has already been made. Nevertheless, appropriate materials are limited in their regional availability. New materials might be able to play a role as cement constituents in the future. It remains to be seen to what extent they could substitute Portland cement clinker to a significant degree.

  14. Zirconia: cementation of prosthetic restorations. Literature review

    PubMed Central

    GARGARI, M.; GLORIA, F.; NAPOLI, E.; PUJIA, A.M.

    2011-01-01

    SUMMARY Aim of the work Aim of the work was to execute a review of the international literature about the cementation of zirconia restorations, analyzing the properties of the cements most commonly used in clinical activities. Materials and methods It was performed, through PubMed, a bibliographic search on the international literature of the last 10 years using the following limits: studies in English, in vitro studies, randomized clinical trial, reviews, meta-analysis, guide-lines. Were excluded from the search: descriptive studies, case reports, discussion articles, opinion’s leader. Results From studies results that common surface treatments (silanization, acid etching) are ineffective on zirconia because it has an inert surface without glassy component (on which this surface treatments act primarily), instead the sandblasting at 1atm with aluminium oxide (Al2O3) results significantly effective for the resulting roughening that increase the surface energy and the wettability of the material. Furthermore it has been shown that zinc phosphate-based cements, Bis-GMA-based and glass-ionomer cements can’t guarantee a stable long-term adhesion, instead resin cements containing phosphate monomer 10-methacryloyloxyidecyl-dihyidrogenphosphate (MDP) have shown higher adhesion and stability values than the other cements. In particular, it has seen that bond strength of zirconia copings on dentin, using MDP-based cement, is about 6,9MPa; this value is comparable to that obtained with gold copings cementation. Conclusions Analyzed studies have led to the following conclusions: sandblasting with aluminium oxide (Al2O3) is the best surface treatment to improve adhesion between resin cements and zirconia; resin cements containing phosphate ester monomers 10-methacryloyloxyidecyl-dihyidrogenphosphate (MDP) have shown in the studies an higher bond strength and stability after ageing treatment; the best procedure for cementing zirconia restorations results the combination of

  15. Water dynamics in glass ionomer cements

    NASA Astrophysics Data System (ADS)

    Berg, M. C.; Jacobsen, J.; Momsen, N. C. R.; Benetti, A. R.; Telling, M. T. F.; Seydel, T.; Bordallo, H. N.

    2016-07-01

    Glass ionomer cements (GIC) are an alternative for preventive dentistry. However, these dental cements are complex systems where important motions related to the different states of the hydrogen atoms evolve in a confined porous structure. In this paper, we studied the water dynamics of two different liquids used to prepare either conventional or resin-modified glass ionomer cement. By combining thermal analysis with neutron scattering data we were able to relate the water structure in the liquids to the materials properties.

  16. Strength and Stiffness Development in Soft Soils: A FESEM aided Soil Microstructure Viewpoint

    NASA Astrophysics Data System (ADS)

    Wijeyesekera, D. C.; Ho, M. H.; Bai, X.; Bakar, I.

    2016-07-01

    This paper opens with an overview of the debatable definition of soft soil that goes beyond a (CH) organic / inorganic clay and OH peat to include weakly cemented periglacial deposits of loess and alike. It then outlines the findings obtained from stiffness test on cement-stabilised soft clay. The findings are complemented with a microstructure viewpoint obtained using field emission scanning electron microscope (FESEM). Research also comprised of making cylindrical stabilised clay samples, prepared in the laboratory with various rubber chips contents and cement, and then aged for 28 days. The samples were then subjected to unconfined compressive strength (UCS) test and observations were also made of its microstructure using the FESEM. The impact of the soil microstructure on the stiffness result was studied both with the stabilized soil and also of some of the natural undisturbed loess soils. Sustainability aspect and the potential of the use of rubber chips and sand as additives to cement stabilisation are also discussed. The overall test results indicated that rubber chips and sand contributed to the improvement in unconfined compressive strength (qu). The derogatory influence of moisture on the stiffness of the stabilised clay was studied simultaneously. SEM micrographs are presented that show bonding of cement, rubber chips/ sand and soft clay, granular units and aggregated / agglomerated units in loess. The paper concludes with observations on the dependence of soil microstructure on the soil strength and deformability and even collapsibility of the loess. Current practices adopted as engineering solutions to these challenging soils are outlined.

  17. Immunotoxicological response of the earthworm Lumbricus terrestris following exposure to cement kiln dusts.

    PubMed

    Massicotte, R; Robidoux, P-Y; Sauvé, S; Flipo, D; Mathiot, A; Fournier, M; Trottier, B

    2004-09-01

    Cement kiln dusts are made of a complex mixture of elements. We have evaluated the potential negative impact of those dusts on the immune system of the earthworm Lumbricus terrestris. We specifically studied cell viability and phagocytic activity of coelomocytes extruded during electrical stimulation. We used two modes of exposures: in vitro, and soil incubation using OECD artificial soil media. Extruded coelomocytes were exposed 18 h in vitro to 10, 100, and 500 mg L(-1) of cement kiln dust particles. The phagocytosis and the cell viability were determined using a double-laser-flow acquisition cytometry system. Using the double laser allows us to use a dichlorofluorescein diacetate (DCFDA) marker to discriminate the biological cells from the cement kiln dusts. Dead cells are marked using propidium iodide (PI). All three exposure levels showed highly significant impacts on cell viability and phagocytic activity. The in vivo soil incubation was performed using 10, 100, and 1000 mg kg(-1) of cement kiln dusts incorporated into the OECD media. Here, to discriminate the biological cells from the mineral dusts we only needed to use PI. The day-to-day variability of the in vivo assay was high and although we can observe an overall reduction in cell viability at the highest concentration tested, no statistically significant effects could be observed on either cell viability or phagocytosis.

  18. Pressurization of bioactive bone cement in vitro.

    PubMed

    Fujita, H; Iida, H; Kawanabe, K; Okada, Y; Oka, M; Masuda, T; Kitamura, Y; Nakamura, T

    1999-01-01

    We have developed a bioactive bone cement consisting of MgO-CaO-SiO2-P2O5-CaF2 glass-ceramic powder (AW glass-ceramic powder), silica glass powder as an inorganic filler, and bisphenol-a-glycidyl methacrylate (bis-GMA) based resin as an organic matrix. The efficacy of this bioactive bone cement was investigated by evaluating its pressurization in a 5-mm hole and small pores using a simulated acetabular cavity. Two types of acetabular components were used (flanged and unflanged sockets) and a commercially available polymethylmethacrylate (PMMA) bone cement (CMW 1 Radiopaque Bone Cement) was selected as a comparative control. Bioactive bone cement exerted greater intrusion volume in 5-mm holes than PMMA bone cement in both the flanged and unflanged sockets 10 minutes after pressurization (p < 0.05). In the small pores the bioactive and PMMA bone cements exerted almost identical intrusion volumes in flanged and unflanged sockets 10 min after pressurization. The intrusion volume in the flanged socket 10 minutes after pressurization was greater than that in the unflanged socket in all groups (p < 0.05). These results show that bioactive bone cement intrudes deeper into anchor holes than PMMA bone cement.

  19. Proper selection of contemporary dental cements.

    PubMed

    Yu, Hao; Zheng, Ming; Chen, Run; Cheng, Hui

    2014-03-01

    Today proper selection of dental cements is a key factor to achieve a successful restoration and will greatly increase the chances of long-term success of the restoration. In recent years, many newly formulated dental cements have been developed with the claim of better performance compared to the traditional materials. Unfortunately, selection of suitable dental cement for a specific clinical application has become increasingly complicated, even for the most experienced dentists. The purpose of this article is to review the currently existing dental cements and to help the dentists choose the most suitable materials for clinical applications.

  20. Importance of microscopy in durability studies of solidified and stabilized contaminated soils

    SciTech Connect

    Klich, I.; Wilding, L.P.; Drees, L.R.; Landa, E.R.

    1999-10-01

    Solidification/stabilization (S/S) is recognized by the US EPA as a best demonstrated available technology for the containment of contaminated soils and other hazardous wastes that cannot be destroyed by chemical, thermal, or biological means. Despite the increased use of S/S technologies, little research has been conducted on the weathering and degradation of solidified and stabilized wastes once the treated materials have been buried. Published data to verify the performance and durability of landfilled treated wastes over time are rare. In this preliminary study, optical and electron microscopy (scanning electron microscopy [SEM], transmission electron microscopy [TEM] and electron probe microanalyses [EPMA]) were used to evaluate weathering features associated with metal-bearing contaminated soil that had been solidified and stabilized with Portland cement and subsequently buried on site, stored outdoors aboveground, or archived in a laboratory warehouse for up to 6 yr. Physical and chemical alteration processes identified include: freeze-thaw cracking, cracking caused by the formation of expansive minerals such as ettringite, carbonation, and the movement of metals from waste aggregates into the cement micromass. Although the extent of degradation after 6 yr is considered slight to moderate, results of this study show that the same environmental concerns that affect the durability of concrete must be considered when evaluating the durability and permanence of the solidification and stabilization of contaminated soils with cement. In addition, such evaluations cannot be based on leaching and chemical analysis alone. The use of all levels of microscopic analyses must be incorporated into studies of the long-term performance of S/S technologies.

  1. Percutaneous Extraction of Cement Leakage After Vertebroplasty Under CT and Fluoroscopy Guidance: A New Technique

    SciTech Connect

    Amoretti, Nicolas Huwart, Laurent

    2012-12-15

    Purpose: We report a new minimally invasive technique of extraction of cement leakage following percutaneous vertebroplasty in adults. Methods: Seven adult patients (five women, two men; mean age: 81 years) treated for vertebral compression fractures by percutaneous vertebroplasty had cement leakage into perivertebral soft tissues along the needle route. Immediately after vertebroplasty, the procedure of extraction was performed under computed tomography (CT) and fluoroscopy guidance: a Chiba needle was first inserted using the same route as the vertebroplasty until contact was obtained with the cement fragment. This needle was then used as a guide for an 11-gauge Trocar t'am (Thiebaud, France). After needle withdrawal, a 13-gauge endoscopy clamp was inserted through the cannula to extract the cement fragments. The whole procedure was performed under local anesthesia. Results: In each patient, all cement fragments were withdrawn within 10 min, without complication. Conclusions: This report suggests that this CT- and fluoroscopy-guided percutaneous technique of extraction could reduce the rate of cement leakage-related complications.

  2. Try-in Pastes Versus Resin Cements: A Color Comparison.

    PubMed

    Vaz, Edenize Cristina; Vaz, Maysa Magalhães; Rodrigues Gonçalves de Oliveira, Maria Beatriz; Takano, Alfa Emília; de Carvalho Cardoso, Paula; de Torres, Érica Miranda; Gonzaga Lopes, Lawrence

    2016-05-01

    This study aimed to compare the color of ceramic veneer restorations using different shades of try-in pastes and resin cement. Researchers found no differences between try-in pastes and resin cements after cementation. PMID:27213935

  3. Utilization of flotation wastes of copper slag as raw material in cement production.

    PubMed

    Alp, I; Deveci, H; Süngün, H

    2008-11-30

    Copper slag wastes, even if treated via processes such as flotation for metal recovery, still contain heavy metals with hazardous properties posing environmental risks for disposal. This study reports the potential use of flotation waste of a copper slag (FWCS) as iron source in the production of Portland cement clinker. The FWCS appears a suitable raw material as iron source containing >59% Fe(2)O(3) mainly in the form of fayalite (Fe(2)SiO(4)) and magnetite (Fe(3)O(4)). The clinker products obtained using the FWCS from the industrial scale trial operations over a 4-month period were characterised for the conformity of its chemical composition and the physico-mechanical performance of the resultant cement products was evaluated. The data collected for the clinker products produced using an iron ore, which is currently used as the cement raw material were also included for comparison. The results have shown that the chemical compositions of all the clinker products including those of FWCS are typical of a Portland cement clinker. The mechanical performance of the standard mortars prepared from the FWCS clinkers were found to be similar to those from the iron ore clinkers with the desired specifications for the industrial cements e.g. CEM I type cements. Furthermore, the leachability tests (TCLP and SPLP) have revealed that the mortar samples obtained from the FWCS clinkers present no environmental problems while the FWCS could act as the potential source of heavy metal contamination. These findings suggest that flotation wastes of copper slag (FWCS) can be readily utilised as cement raw material due to its availability in large quantities at low cost with the further significant benefits for waste management/environmental practices of the FWCS and the reduced production and processing costs for cement raw materials.

  4. Vertebroplasty Using Calcium Triglyceride Bone Cement (Kryptonite™) for Vertebral Compression Fractures

    PubMed Central

    Guarnieri, Gianluigi; Tecame, Mario; Izzo, Roberto; Vassallo, Pasquale; Sardaro, Angela; Iasiello, Francesca; Cavaliere, Carlo; Muto, Mario

    2014-01-01

    Summary This study assessed the one-year clinical and radiographic outcomes, in terms of pain-relief, vertebral re-fracture and complications, after vertebroplasty (VP) using a new osteoconductive cement (calcium triglyceride bone cement - Kryptonite™ bone cement, Doctors Research Group Inc., Southbury, CT, USA) to treat osteoporotic vertebral compression fractures. Sixteen consecutive osteoporotic patients (12 women and four men, mean age 68+/-10.5) were treated with VP using Kryptonite™ bone cement for a total of 20 vertebral fractures. All the patients complained of a pain syndrome resistant to medical therapy and all procedures were performed under fluoroscopy control with neuroleptoanalgesia using a monopedicular approach in 12 patients and bipedicular approach in four patients. All patients were studied by MR and MDCT and were evaluated with the visual analogue scale (VAS) and the Oswestry disability index (ODI) before treatment and at one and 12 months after the procedure. A successful outcome was observed in 80% of patients, with a complete resolution of pain. Differences in pre and post treatment VAS and ODI at one-year follow-up were significant (P<0.0001). We observed a disk and venous leakage in 66% of patients but only in one case did an asymptomatic pulmonary embolism occur during cement injection. Two cases of vertebral re-fractures at distant metamers were observed during follow-up. VP using Kryptonite bone cement is a helpful procedure that allows complete and long-lasting resolution of painful vertebral symptoms. The cost of the material is very high and the rate of disk and venous leakage is too high compared to standard cement. PMID:25363260

  5. Total and available soil trace element concentrations in two Mediterranean agricultural systems treated with municipal waste compost or conventional mineral fertilizers.

    PubMed

    Baldantoni, Daniela; Leone, Anna; Iovieno, Paola; Morra, Luigi; Zaccardelli, Massimo; Alfani, Anna

    2010-08-01

    The temporal dynamics of some trace elements in two different types of Mediterranean soils were studied in order to evaluate the possible long-term contamination following compost amendments. Total and available (DTPA-extractable) concentrations of Cd, Cu, Pb and Zn were determined. The study was carried out on two agricultural soils in Campania region (southern Italy), a Sandy Loam Calcaric Cambisol (SG) and a Clay Gleyc Luvisol (CO), during 3 years of organic amendment with compost. The compost, produced from the organic fraction of municipal solid waste and urban yard trimmings, in accordance with the Italian law for agricultural use, was applied at annually rates of 15, 30, and 45 t ha(-1) (on dry weight basis). Wide variations in total and available Cd, Cu, Pb and Zn concentrations were observed over time, but appeared to be in many cases unrelated to the treatments, occurring also in control plots. After 3 years of compost application the amended SG soil showed the highest and significant increase in total Cd and Zn concentrations; in addition, the available Cd, Pb and Zn concentrations increased in accordance with the compost rates. The CO soil, characterized by a higher clay content, lower organic matter content and lower cation exchange capacity, exhibited a lower increase in available metal fractions. Our findings show that compost amendment affects more the available than the total metal concentrations in the two types of soils studied and thus it is important into legislation that metal "bioavailability" may be considered in defining threshold metal values.

  6. Quantitative determination of octylphenol, nonylphenol, alkylphenol ethoxylates and alcohol ethoxylates by pressurized liquid extraction and liquid chromatography-mass spectrometry in soils treated with sewage sludges.

    PubMed

    Andreu, Vicente; Ferrer, Emilia; Rubio, José Luís; Font, Guillermina; Picó, Yolanda

    2007-05-25

    Surfactants have one of the highest production rates of all organic chemicals. Non-ionic surfactants, especially alkylphenol ethoxylates, received most attention as precursors of estrogenic metabolic products generated during wastewater treatment. Alkylphenols (octyl and nonylphenol), alkylphenol polyethoxylates (APEOs), and alcohol ethoxylates (AEOs) have been determined in a Mediterranean forest soil (Mediterranean Rendzic Leptosol) amended with sludges from six waste water treatment plants (WWTPs) located in the Valencian Community. These compounds were isolated from soil by pressurized liquid extraction (PLE) using a mixture acetone-hexane (50:50 v/v), the extracts were cleaned up by solid-phase extraction (SPE) with C(18), and determined by liquid chromatography atmospheric pressure chemical ionization-mass spectrometry (LC-APCI-MS) using analytical standards for quantification. The method enabled high-reliable identification by monitoring the corresponding ammonium adduct [M+NH(3)](+) for AEOs and APEOs, and the deprotonated molecule [M-H](-) for octyl and nonylphenol. Recoveries, determined spiking soil samples at different concentrations, ranged from 89 to 94%, with limits of quantification from 1 to 100 microg kg(-1). Data obtained from a soil sample mixed with biosolids in the laboratory showed that these compounds are present at concentrations ranging from 0.02 to 5 mg kg(-1). According to these concentrations, levels of possible risk can be concluded for the presence of non-ionic surfactants in soil. However, further assessment will be necessary to establish the relationship between exposure and effect findings. PMID:17306341

  7. Microbial analysis of biofilms on cement surfaces: An investigation in cement-associated peri-implantitis.

    PubMed

    Korsch, Michael; Walther, Winfried; Marten, Silke-Mareike; Obst, Ursula

    2014-09-05

    The cementation of implant-supported restorations always poses the risk of excess cement retained in the peri-implant sulcus despite careful clinical control. Excess cement can become the basis of colonization by oral microorganisms. As a result of the biofilm formation peri-mucositis or peri-implantitis may develop. Complications were observed in the routine prosthetic restoration of implants when a methacrylate-based cement was used. These developed a few weeks after cementation of the suprastructure and caused bleeding on probing as well as suppuration from the peri-implant tissue. In the revision therapy, excess cement in the peri-implant sulcus was found in many cases. This excess cement was sampled from ten patients and investigated for biofilm formation. For this purpose, the cement samples were collected and analyzed for bacterial in situ colonization by 16S rDNA-based methods. In laboratory experiments, the methacrylate-based cement and two other dental cements were then investigated for their proneness to form biofilm. The results of the in situ and in vitro investigations revealed a strong tendency towards bacterial invasion of the methacrylate-based cement by opportunistic species and pathogens.

  8. Hydration products and thermokinetic properties of cement-bentonite and cement-chalk mortars

    SciTech Connect

    Klyusov, A.A.

    1988-08-20

    Bentonite and chalk are the most popular auxiliary additives to portland cement for borehole cementation. The authors studied by physicochemical analysis methods (x-ray phase, derivatographic, and scanning and electron microscopy in combination with microdiffraction) the newly formed solid-phase composition of cement-bentonite and cement-chalk mortars (binder-additive ratio 9:1) prepared from portland cement for cold boreholes and 8% calcium chloride solution at a water-mixing ratio of 0.9. The mechanism of the influence of Ca-bentonite and chalk additives on the portland cement hydration rate was ascertained from the heat evolution rate curves. It was found that the phase compositions of the hydration products are represented in the studied systems by newly formed substances typical for portland cement. It has been noted that Ca-bentonite interacts with the calcium hydroxide of hydrated cement with the formation of hexagonal and cubic calcium hydroaluminates. Unlike Ca-bentonite, chalk does not react with portland cement at normal and reduced temperatures, does not block hydrated cement particles, which, in turn, ensures all other conditions remaining equal, a higher initial rate of hydration of cement-chalk mortar.

  9. Treating the Aging Spine.

    PubMed

    Choma, Theodore J; Rechtine, Glenn; McGuire, Robert A; Brodke, Darrel S

    2016-01-01

    Demographic trends make it incumbent on orthopaedic spine surgeons to recognize the special challenges involved in caring for older patients with spine pathology. Unique pathologies, such as osteoporosis and degenerative deformities, must be recognized and treated. Recent treatment options and recommendations for the medical optimization of bone health include vitamin D and calcium supplementation, diphosphonates, and teriparatide. Optimizing spinal fixation in elderly patients who have osteoporosis is critical; cement augmentation of pedicle screws is promising. In the management of geriatric odontoid fractures, nonsurgical support with a collar may be considered for low-demand patients, whereas surgical fixation is favored for high-demand patients. Management of degenerative deformity must address sagittal plane balance, which includes consideration of pelvic incidence. Various osteotomies may prove helpful in this setting. PMID:27049195

  10. Basic Chemistry for the Cement Industry.

    ERIC Educational Resources Information Center

    Turner, Mason

    This combined student workbook and instructor's guide contains nine units for inplant classes on basic chemistry for employees in the cement industry. The nine units cover the following topics: chemical basics; measurement; history of cement; atoms; bonding and chemical formulas; solids, liquids, and gases; chemistry of Portland cement…

  11. A note on cement in asteroids

    NASA Astrophysics Data System (ADS)

    Bilalbegović, G.

    2016-09-01

    Cement mineral tobermorite was formed in hydrothermal experiments on alternation of calcium-aluminum-rich inclusions (CAIs) in carbonaceous chondrite meteorites. Unidentified bands at 14 μm were measured for CAIs and the matrix of the Allende meteorite sample, as well as for Hektor and Agamemnon asteroids. The presence of cement nanoparticles may explain the feature at 14 μm.

  12. 21 CFR 872.3275 - Dental cement.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Dental cement. 872.3275 Section 872.3275 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3275 Dental cement. (a) Zinc oxide-eugenol—(1)...

  13. 21 CFR 872.3275 - Dental cement.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Dental cement. 872.3275 Section 872.3275 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3275 Dental cement. (a) Zinc oxide-eugenol—(1)...

  14. Tires fuel oil field cement manufacturing

    SciTech Connect

    Caveny, B.; Ashford, D.; Garcia, J.G.; Hammack, R.

    1998-08-31

    In a new process, waste automobile tires added to the fuel mix of gas, coal, and coke help fire kilns to produce API-quality oil field cement. Capital Cement uses this process in its cement-manufacturing plant in San Antonio, in which it also produces construction cement. The tires provide a lower-cost fuel and boost the temperature at a critical stage in the kiln burn process. Also, steel-belted tires add iron content to the mix. According to lab results, tire-burned cement slurries will perform the same as conventionally burned cement slurries. Actual field applications have proven that cement produced by burning tires performs no different than conventionally produced slurries. Capital`s plant uses both dry and wet processes, with separate kilns running both processes at the same time. Cement clinker is partially fired by waste tires in both kiln processes. The tires represent 12% of the fuel consumed by the plant, a number that is expected to increase. Capital burns about 200 tires/hr, or about 1.6 million tires/year.

  15. TECHNOLOGICAL CHANGES IN THE CEMENT MANUFACTURING INDUSTRY.

    ERIC Educational Resources Information Center

    WESSON, CARL E.

    THE PURPOSE OF THIS STUDY IS TO PRESENT A PRELIMINARY PICTURE OF OCCUPATIONAL CHANGES BROUGHT ABOUT IN THE MANUFACTURE OF CEMENT AS A RESULT OF INTRODUCING AUTOMATED EQUIPMENT. ONE AUTOMATED AND SEVERAL CONVENTIONAL TYPE CEMENT PLANTS WERE STUDIED. ANALYSIS OF DATA OBTAINED THROUGH RESEARCH AND DATA COLLECTED DURING THE STUDY REVEALED THAT…

  16. Remediation of a heavy metal-contaminated soil by means of agglomeration.

    PubMed

    Polettini, Alessandra; Pomi, Raffaella; Valente, Mattia

    2004-01-01

    The feasibility of treating a heavy metal-contaminated soil by means of a solidification/stabilization treatment consisting of a granulation process is discussed in the present article. The aim of the study was to attain contaminant immobilization within the agglomerated solid matrix. The soil under concern was characterized by varying levels of heavy metal contamination, ranging from 50 to 500 mg kg(-1) dry soil for chromium. from 300 to 2000 mg kg(-1) dry soil for lead and from 270 to 5000 mg kg(-1) dry soil for copper. An artificially contaminated soil with contaminant concentrations corresponding to the upper level of the mentioned ranges was prepared from a sample of uncontaminated soil by means of spiking experiments. Pure soluble species of chromium, copper and lead. namely CrCl3.6H2O, CuCl2.2H2O and Pb(NO3)2, were selected for the spiking experiments, which were arranged according to a 2(3) full factorial design. The solidification/stabilization treatment was based on an agglomeration process making use of hydraulic binders including Portland cement, hydrated lime and sodium methasilicate, which were selected on the basis of preliminary test runs. It was found that after 7 days of curing the applied treatment was able to efficiently immobilize the investigated heavy metals within the hydrated matrix. Good acid neutralization behavior was also observed, indicating improved matrix resistance to acid attack and decreased potential for metal leaching. PMID:15137715

  17. Chemical stabilization of subgrade soil for the strategic expeditionary landing field

    NASA Astrophysics Data System (ADS)

    Conaway, M. H.

    1983-06-01

    The Strategic Expeditionary Landing Field (SELF) is a military expeditionary-type airfield with an aluminum matted surface that is designed for sustained tactical and cargo airlift operations in an amphibious objective area. Because of the operational traffic parameters such as loads of the various types of aircraft, tire pressures and volume of traffic, a base layer must be constructed over subgrade soil support conditions which may be only marginal. The base layer could be constructed with conventional soil construction techniques (compaction) and yield the required strength. It would be difficult, however, to maintain this strength for the required one-year service life under many climatic conditions due to the degrading effects of water on the support capacity of many soils. Chemical soil stabilization with lime, portland cement and asphalt stabilizing agents could be used to treat the soil. These additives, when properly mixed with certain types of soils, initiate reactions which will increase soil support strength and enhance durability (resistance to the degrading effects of water). Technically, this procedure is quite viable but logistically, it may not be feasible.

  18. Effect of different surface treatments on shear bond strength of zirconia to three resin cements

    NASA Astrophysics Data System (ADS)

    Dadjoo, Nisa

    Statement of problem: There are no standard guidelines for material selection to obtain acceptable bonding to high-strength zirconium oxide ceramic. Studies suggest resin cements in combination with MDP-containing primer is a reasonable choice, however, the other cements cannot be rejected and need further investigation. Objective: The purpose of this in vitro study was the evaluation of the shear bond strength of three composite resin cements to zirconia ceramic after using different surface conditioning methods. Materials and methods: One hundred and twenty sintered Y-TZP ceramic (IPS e.max ZirCAD) squares (8 x 8 x 4 mm) were embedded in acrylic molds, then divided into three groups (n=40) based on the type of cement used. Within each group, the specimens were divided into four subgroups (n=10) and treated as follows: (1) Air abrasion with 50microm aluminum oxide (Al2O 3) particles (ALO); (2) Air abrasion + Scotchbond Universal adhesive (SBU); (3) Air abrasion + Monobond Plus (MBP); (4) Air abrasion + Z-Prime Plus (ZPP). Composite cylinders were used as carriers to bond to conditioned ceramic using (1) RelyX Ultimate adhesive resin cement (RX); (2) Panavia SA self-adhesive resin cement (PSA); (3) Calibra esthetic cement (CAL). The bonded specimens were submerged in distilled water and subjected to 24-hour incubation period at 37°C. All specimens were stressed in shear at a constant crosshead speed of 0.5 mm/min until failure. Statistical analysis was performed by ANOVA. The bond strength values (MPa), means and standard deviations were calculated and data were analyzed using analysis of variance with Fisher's PLSD multiple comparison test at the 0.05 level of significance. The nature of failure was recorded. Results: The two-way ANOVA showed Panavia SA to have the highest strength at 44.3 +/- 16.9 MPa (p<0.05). The combination of Scotchbond Universal surface treatment with Panavia SA cement showed statistically higher bond strength (p=0.0054). The highest bond

  19. Rheological Characterization of Oil Cement Suspensions

    NASA Astrophysics Data System (ADS)

    Abderrahmane, Mellak; Moh-Amokrane, Aitouche

    2015-04-01

    This study is a contribution to the study of the rheological behavior of cement suspensions. An oil well is drilled, cased, cemented and set completion. The well drilling is done in several phases then at various diameters to isolate the following problems like land fragile subsidence and poorly consolidated aquifer formations, loss of the movement in the porous and permeable formations. Therefore, it would go down a casing and cementing to work safely. The materials studied were chosen to satisfy the requirements and the problems encountered in real applications in the oil field (casing cementing wells). So it was used an oil hydraulic binder "G". This systematic study of rheological properties of cement Class "G" standardized API (American Petroleum Institute) deal with a formulation which is compatible with the surrounding environment taking account an optimal efficiency.

  20. Early Complications Following Cemented Modular Hip Hemiarthroplasty

    PubMed Central

    Sullivan, Niall P.T; Hughes, Andrew W; Halliday, Ruth L; Ward, Abigail L; Chesser, Tim J.S

    2015-01-01

    Introduction : Hemiarthroplasty is the recommended treatment for displaced, intracapsular, femoral neck fractures. This study aimed to evaluate the early complications following insertion of the JRI Furlong cemented hemiarthroplasty, a contemporary, modular, double tapered, polished prosthesis. Method : A series of 459 consecutive patients (May 2006 - June 2009) treated with a JRI hemiarthroplasty with a minimum of one-year (1-4years) follow-up were evaluated. Data collected retrospectively from clinical records and hospital databases included patient demographics, mortality, deep infection, dislocation, periprosthetic fracture, and any requirement for revision or complications related to the prosthesis. Results : Full data were available for 429 of 459 (93%), partial data for 30 (7%). Average age was 83 years (52-100), 76% were female. One-year mortality was 24%. Intraoperative fractures occurred in 17 patients (3.7%). There were two intraoperative deaths. There were nine early deep wound infections (2%). There were two revisions to total hip replacement (THR), four patients required conversion to THR and one underwent an excision arthroplasty procedure. Discussion : Early surgical outcomes for the JRI hemiarthroplasty prosthesis are equivalent or superior to other major hemiarthroplasty prostheses previously reported however, there was a high intraoperative fracture rate of 3.7%. We recommend using a stem one size smaller than the final broach in fragile, osteoporotic bone. No patients re-presented with aseptic loosening or stem failure. PMID:25685248

  1. Biomonitoring of airborne particulate matter emitted from a cement plant and comparison with dispersion modelling results

    NASA Astrophysics Data System (ADS)

    Abril, Gabriela A.; Wannaz, Eduardo D.; Mateos, Ana C.; Pignata, María L.

    2014-01-01

    The influence of a cement plant that incinerates industrial waste on the air quality of a region in the province of Córdoba, Argentina, was assessed by means of biomonitoring studies (effects of immission) and atmospheric dispersion (effects of emission) of PM10 with the application of the ISC3 model (Industrial Source Complex) developed by the USEPA (Environmental Protection Agency). For the biomonitoring studies, samples from the epiphyte plant Tillandsia capillaris Ruíz & Pav. f. capillaris were transplanted to the vicinities of the cement plant in order to determine the physiological damage and heavy metal accumulation (Ca, Mn, Fe, Co, Ni, Cu, Zn, Cd and Pb). For the application of the ISC3 model, point and area sources from the cement plant were considered to obtain average PM10 concentration results from the biomonitoring exposure period. This model permitted it to be determined that the emissions from the cement plant (point and area sources) were confined to the vicinities, without significant dispersion in the study area. This was also observed in the biomonitoring study, which identified Ca, Cd and Pb, pH and electric conductivity (EC) as biomarkers of this cement plant. Vehicular traffic emissions and soil re-suspension could be observed in the biomonitors, giving a more complete scenario. In this study, biomonitoring studies along with the application of atmospheric dispersion models, allowed the atmospheric pollution to be assessed in more detail.

  2. Studies on the reuse of waste printed circuit board as an additive for cement mortar.

    PubMed

    Ban, Bong-Chan; Song, Jong-Yoon; Lim, Joong-Yeon; Wang, Soo-Kyoon; An, Kwang-Guk; Kim, Dong-Su

    2005-01-01

    The recent development in electronic industries has generated a drastic increase in production of printed circuit boards (PCB). Accordingly, the amount of waste PCB from electronic productions and waste electronics and its environmental impact such as soil and groundwater contamination have become a great concern. This study aims to propose a method for reuse of waste PCB as an additive for cement mortar. Although the expansibility of waste PCB powder finer than 0.08 mm in water was observed to be greater than 2.0%, the maximum expansion rates in water for 0.08 to approximately 0.15 and 0.15 to approximately 0.30 mm sized PCB powders were less than 2.0%, which satisfied the necessary condition as an alternative additive for cement mortar in place of sand. The difference in the compressive strength of standard mortar and waste PCB added mortar was observed to be less than 10% and their difference was expected to be smaller after prolonged aging. The durability of waste PCB added cement mortar was also examined through dry/wet conditioning cyclic tests and acidic/alkaline conditioning tests. From the tests, both weight and compressive strength of cement mortar were observed to be recovered with aging. The leaching test for heavy metals from waste PCB added mortar showed that no heavy metal ions such as copper, lead, or cadmium were detected in the leachate, which resulted from fixation effect of the cement hydrates.

  3. Cements with low Clinker Content

    NASA Astrophysics Data System (ADS)

    García-Lodeiro, I.; Fernández-Jiménez, A.; Palomo, A.

    2015-11-01

    Hybrid alkaline cements are multi-component systems containing a high percentage of mineral additions (fly ash, blast furnace slag), low proportions (<30%) of Portland clinker and scarce amounts of alkaline activators. The substantially lower amount of clinker needed to manufacture these binders in comparison to ordinary Portland cement is both economically and ecologically beneficial. Their enormous versatility in terms of the raw materials used has made them the object of considerable interest. The present study explored the mechanical strength of binary blends mixes; B1= 20% clinker (CK) + 80% fly ash (FA) and B2=20% clinker + 80% blast furnace slag (BFS), both hydrated in the presence and absence of an alkaline activator specifically designed for this purpose. The use of the activator enhanced the development of early age strength considerably. All the hydrated matrices were characterised with XRD, SEM/EDX and (29Si and 27Al) NMR. The use of the alkaline activator generated reaction products consisting primarily of a mix of gels ((N,C)-A-S-H and C-A-S-H) whose respective proportions were found to depend upon system composition and initial reactivity.

  4. Pack cementation coatings for alloys

    SciTech Connect

    He, Yi-Rong; Zheng, Minhui; Rapp, R.A.

    1996-08-01

    The halide-activated pack cementation process was modified to produce a Ge-doped silicide diffusion coating on a Cr-Cr{sub 2}Nb alloy in a single processing step. The morphology and composition of the coating depended both on the composition of the pack and on the composition and microstructure of the substrate. Higher Ge content in the pack suppressed the formation of CrSi{sub 2} and reduced the growth kinetics of the coating. Ge was not homogeneously distributed in the coatings. In cyclic and isothermal oxidation in air at 700 and 1050{degrees}C, the Ge-doped silicide coating protected the Cr-Nb alloys from significant oxidation by the formation of a Ge-doped silica film. The codeposition and diffusion of aluminum and chromium into low alloy steel have been achieved using elemental Al and Cr powders and a two-step pack cementation process. Sequential process treatments at 925{degrees}C and 1150{degrees}C yield dense and uniform ferrite coatings, whose compositions are close to either Fe{sub 3}Al or else FeAl plus a lower Cr content, when processed under different conditions. The higher content of Al in the coatings was predicted by thermodynamic calculations of equilibrium in the gas phase. The effect of the particle size of the metal powders on the surface composition of the coating has been studied for various combinations of Al and Cr powders.

  5. Bond Strength of Resin Cements to Noble and Base Metal Alloys with Different Surface Treatments

    PubMed Central

    Raeisosadat, Farkhondeh; Ghavam, Maryam; Hasani Tabatabaei, Masoomeh; Arami, Sakineh; Sedaghati, Maedeh

    2014-01-01

    Objectives: The bond strength of resin cements to metal alloys depends on the type of the metal, conditioning methods and the adhesive resins used. The purpose of this study was to evaluate the bond strength of resin cements to base and noble metal alloys after sand blasting or application of silano-pen. Materials and Method: Cylinders of light cured Z 250 composite were cemented to “Degubond 4” (Au Pd) and “Verabond” (Ni Cr) alloys by either RelyX Unicem or Panavia F2, after sandblasting or treating the alloys with Silano-Pen. The shear bond strengths were evaluated. Data were analyzed by three-way ANOVA and t tests at a significance level of P<0.05. Results: When the alloys were treated by Silano-Pen, RelyX Unicem showed a higher bond strength for Degubond 4 (P=0.021) and Verabond (P< 0.001). No significant difference was observed in the bond strength of Panavia F2 to the alloys after either of surface treatments, Degubond 4 (P=0.291) and Verabond (P=0.899). Panavia F2 showed a higher bond strength to sandblasted Verabond compared to RelyX Unicem (P=0.003). The bond strength of RelyX Unicem was significantly higher to Silano-Pen treated Verabond (P=0.011). The bond strength of the cements to sandblasted Degubond 4 showed no significant difference (P=0.59). RelyX Unicem had a higher bond strength to Silano-Pen treated Degubond 4 (P=0.035). Conclusion: The bond strength of resin cements to Verabond alloy was significantly higher than Degubond 4. RelyX Unicem had a higher bond strength to Silano-Pen treated alloys. Surface treatments of the alloys did not affect the bond strength of Panavia F2. PMID:25628687

  6. Total and available soil trace element concentrations in two Mediterranean agricultural systems treated with municipal waste compost or conventional mineral fertilizers.

    PubMed

    Baldantoni, Daniela; Leone, Anna; Iovieno, Paola; Morra, Luigi; Zaccardelli, Massimo; Alfani, Anna

    2010-08-01

    The temporal dynamics of some trace elements in two different types of Mediterranean soils were studied in order to evaluate the possible long-term contamination following compost amendments. Total and available (DTPA-extractable) concentrations of Cd, Cu, Pb and Zn were determined. The study was carried out on two agricultural soils in Campania region (southern Italy), a Sandy Loam Calcaric Cambisol (SG) and a Clay Gleyc Luvisol (CO), during 3 years of organic amendment with compost. The compost, produced from the organic fraction of municipal solid waste and urban yard trimmings, in accordance with the Italian law for agricultural use, was applied at annually rates of 15, 30, and 45 t ha(-1) (on dry weight basis). Wide variations in total and available Cd, Cu, Pb and Zn concentrations were observed over time, but appeared to be in many cases unrelated to the treatments, occurring also in control plots. After 3 years of compost application the amended SG soil showed the highest and significant increase in total Cd and Zn concentrations; in addition, the available Cd, Pb and Zn concentrations increased in accordance with the compost rates. The CO soil, characterized by a higher clay content, lower organic matter content and lower cation exchange capacity, exhibited a lower increase in available metal fractions. Our findings show that compost amendment affects more the available than the total metal concentrations in the two types of soils studied and thus it is important into legislation that metal "bioavailability" may be considered in defining threshold metal values. PMID:20561670

  7. Presence and survival of Escherichia coli O157:H7 on lettuce leaves and in soil treated with contaminated compost and irrigation water.

    PubMed

    Oliveira, M; Viñas, I; Usall, J; Anguera, M; Abadias, M

    2012-05-15

    Escherichia coli O157:H7 outbreaks associated with produce consumption have brought attention to contaminated compost manure, and polluted irrigation water as potential sources of pathogens for the contamination of these crops. The aim of this study was to determine the potential transfer of E. coli O157:H7 from soil fertilized with contaminated compost or irrigated with contaminated water to edible parts of lettuce together with its persistence in soil under field conditions in two different seasons (fall and spring). Moreover, its survival on lettuce sprinkled with contaminated irrigation water was evaluated, as well as the prevalence of aerobic mesophilic, Enterobacteriaceae and Pseudomonadaceae in control lettuce samples. Four treatments, contaminated compost, surface and sprinkle irrigation with contaminated water and uninoculated pots, were used in this work. Contaminated compost was applied to soil in the pots before lettuce was transplanted and contaminated irrigation water was applied twice and three times on the plants after the seedlings were transplanted, for sprinkle and surface irrigation, respectively. E. coli O157:H7 survived in soil samples for 9 weeks at levels, 4.50 log cfu gdw(-1) (dw, dry weight) in fall and 1.50 log cfu gdw(-1) in spring. The pathogen survives better in fall, indicating an important influence of environmental factors. E. coli O157:H7 population in lettuce leaves after sprinkle irrigation was very high (between 10(3) and 10(6) cfu g(-1)), but decreased to undetectable levels at field conditions. There was also transfer of E. coli O157:H7 from soil contaminated with compost or irrigated with contaminated water to lettuce leaves, mainly to the outer ones. The mean counts for aerobic mesophilic, Enterobacteriaceae and Pseudomonadaceae populations were also influenced by environmental conditions; higher levels were observed under fall conditions than in spring conditions. Contamination of lettuce plants in the field can occur

  8. Nanotechnology for treating osteoporotic vertebral fractures

    PubMed Central

    Gao, Chunxia; Wei, Donglei; Yang, Huilin; Chen, Tao; Yang, Lei

    2015-01-01

    Osteoporosis is a serious public health problem affecting hundreds of millions of aged people worldwide, with severe consequences including vertebral fractures that are associated with significant morbidity and mortality. To augment or treat osteoporotic vertebral fractures, a number of surgical approaches including minimally invasive vertebroplasty and kyphoplasty have been developed. However, these approaches face problems and difficulties with efficacy and long-term stability. Recent advances and progress in nanotechnology are opening up new opportunities to improve the surgical procedures for treating osteoporotic vertebral fractures. This article reviews the improvements enabled by new nanomaterials and focuses on new injectable biomaterials like bone cements and surgical instruments for treating vertebral fractures. This article also provides an introduction to osteoporotic vertebral fractures and current clinical treatments, along with the rationale and efficacy of utilizing nanomaterials to modify and improve biomaterials or instruments. In addition, perspectives on future trends with injectable bone cements and surgical instruments enhanced by nanotechnology are provided. PMID:26316746

  9. Nanotechnology for treating osteoporotic vertebral fractures.

    PubMed

    Gao, Chunxia; Wei, Donglei; Yang, Huilin; Chen, Tao; Yang, Lei

    2015-01-01

    Osteoporosis is a serious public health problem affecting hundreds of millions of aged people worldwide, with severe consequences including vertebral fractures that are associated with significant morbidity and mortality. To augment or treat osteoporotic vertebral fractures, a number of surgical approaches including minimally invasive vertebroplasty and kyphoplasty have been developed. However, these approaches face problems and difficulties with efficacy and long-term stability. Recent advances and progress in nanotechnology are opening up new opportunities to improve the surgical procedures for treating osteoporotic vertebral fractures. This article reviews the improvements enabled by new nanomaterials and focuses on new injectable biomaterials like bone cements and surgical instruments for treating vertebral fractures. This article also provides an introduction to osteoporotic vertebral fractures and current clinical treatments, along with the rationale and efficacy of utilizing nanomaterials to modify and improve biomaterials or instruments. In addition, perspectives on future trends with injectable bone cements and surgical instruments enhanced by nanotechnology are provided. PMID:26316746

  10. Push-out bond strength of quartz fibre posts to root canal dentin using total-etch and self-adhesive resin cements

    PubMed Central

    Mohammadi, Narmin; Navimipour, Elmira J.; Shakerifar, Maryam

    2012-01-01

    Objectives: Several adhesive systems are available for cementation of fibre posts into the root canal. The aim of the present study was to investigate the push-out bond strengths of quartz fibre posts to root dentin with the use of different total-etch and self-adhesive resin cements. Study Design: Ninety single-rooted human premolars were endodontically treated and standardized post-spaces were prepared. Fibre posts were cemented with different luting agents: total-etch (Nexus NX3, Duo-Link, and RelyX ARC) and self-adhesive resin cements (Maxcem Elite, BisCem, and RelyX Unicem). Three post/dentin sections (coronal, middle and apical) were obtained from each specimen, and push-out bond strength test was performed in each section at a cross-head speed of 0.5 mm/min. Data was analyzed with two-factor and one-way analysis of variance and a post-hoc Tukey test at a significance level of p < 0.05. Results: Cement type, canal region, and their interaction significantly influenced bond strength. Significantly higher bond strength values were observed in the apical region of self-adhesive cements. Only Duo-Link and RelyX ARC cements resulted in homogeneous bond strengths. Conclusions: Cementation of quartz fibre posts using self-adhesive cements provided higher push-out bond strengths especially in the apical region, while total-etch cements resulted in more uniform bond strengths in different regions of the root canal. Key words: Push-out bond strength; quartz fibre post; total-etch resin cement; self-adhesive resin cement. PMID:22143695

  11. Microscale investigation of arsenic distribution and species in cement product from cement kiln coprocessing wastes.

    PubMed

    Yang, Yufei; Xue, Jingchuan; Huang, Qifei

    2013-01-01

    To improve the understanding of the immobilization mechanism and the leaching risk of Arsenic (As) in the cement product from coprocessing wastes using cement kiln, distribution and species of As in cement product were determined by microscale investigation methods, including electron probe microanalysis (EPMA) and X-ray absorption spectroscopy. In this study, sodium arsenate crystals (Na3AsO412H2O) were mixed with cement production raw materials and calcined to produce cement clinker. Then, clinker was mixed water to prepare cement paste. EPMA results showed that As was generally distributed throughout the cement paste. As content in calcium silicate hydrates gel (C-S-H) was in low level, but higher than that in other cement mineral phases. This means that most of As is expected to form some compounds that disperse on the surfaces of cement mineral phases. Linear combination fitting (LCF) of the X-ray absorption near edge structure spectra revealed that As in the cement paste was predominantly As(V) and mainly existed as Mg3(AsO4)2, Ca3(AsO4)2, and Na2HAsO4. PMID:24223030

  12. Microscale investigation of arsenic distribution and species in cement product from cement kiln coprocessing wastes.

    PubMed

    Yang, Yufei; Xue, Jingchuan; Huang, Qifei

    2013-01-01

    To improve the understanding of the immobilization mechanism and the leaching risk of Arsenic (As) in the cement product from coprocessing wastes using cement kiln, distribution and species of As in cement product were determined by microscale investigation methods, including electron probe microanalysis (EPMA) and X-ray absorption spectroscopy. In this study, sodium arsenate crystals (Na3AsO412H2O) were mixed with cement production raw materials and calcined to produce cement clinker. Then, clinker was mixed water to prepare cement paste. EPMA results showed that As was generally distributed throughout the cement paste. As content in calcium silicate hydrates gel (C-S-H) was in low level, but higher than that in other cement mineral phases. This means that most of As is expected to form some compounds that disperse on the surfaces of cement mineral phases. Linear combination fitting (LCF) of the X-ray absorption near edge structure spectra revealed that As in the cement paste was predominantly As(V) and mainly existed as Mg3(AsO4)2, Ca3(AsO4)2, and Na2HAsO4.

  13. Cement oscillation increases interlock strength at the cement-bone interface, with commentary.

    PubMed

    Wang, Yi; Han, Pengfei; Gu, Wenguang; Shi, Zuowei; Li, Dabin; Wang, Changli

    2009-05-01

    Modern cementing techniques aim to improve the interlock between bone and cement and to establish a durable interface. Cement penetration is generally believed to influence interface failure, but current methods for improving the cement-bone interface are inadequate. Oscillation is the reciprocated movement of an object through its balanced position, or the quantum physics of systematic fluctuation back and forth near an average value (or trimmed value). To increase the interlock strength at the cement-bone interface, we designed a cement oscillator according to the principles of vibrational mechanics. To evaluate the effect of oscillation on the quality of interlock strength at the cement-bone interface, we randomly divided 156 femoral bones of adult pigs into 2 groups, oscillated and control, and performed mechanical tests to assess interlock strength at the cement-bone interface. The filling effect of bone cement was observed and analyzed under a stereomicroscope, and then each oscillated femur was compared with a control femur. The interlock strength at the cement-bone interface in the oscillated group was significantly greater than in the control group (P<.05), and the filling effect in the oscillated group was also better than that in the control group (P<.05). Our findings show that oscillation of bone cement significantly increases interlock strength at the cement-bone interface, point the way for clinicians to develop a high-performance and pragmatic fixation technique for prostheses to increase interlock strength, and will be of considerable practical importance in helping to prevent aseptic loosening of cemented prostheses.

  14. Extraoral Cementation Technique to Minimize Cement-Associated Peri-implant Marginal Bone Loss: Can a Thin Layer of Zinc Oxide Cement Provide Sufficient Retention?

    PubMed

    Frisch, Eberhard; Ratka-Krüger, Petra; Weigl, Paul; Woelber, Johan

    2016-01-01

    This report describes the use of laboratory-fabricated crown intaglio replicas for extraorally prepared cementation of fixed restorations to implants. This technique minimizes excess cement and may therefore reduce the risk of cement-related marginal peri-implant bone loss. It is unclear whether the remaining thin layer of luting agent provides sufficient retention if low-adhesive zinc oxide (ZnO) cement is used. In 85 consecutive patients, 113 single crowns were cemented to implants using extraoral cementation technique (ECT) and ZnO cement. All patients were followed for 6 months and investigated for decementation. Seven events of decementation (incidence: 6.19%) were found in 7 patients (8.24%). ECT may represent a viable cementation technique for implant-supported single crowns, even using low-adhesion cements.

  15. Extraoral Cementation Technique to Minimize Cement-Associated Peri-implant Marginal Bone Loss: Can a Thin Layer of Zinc Oxide Cement Provide Sufficient Retention?

    PubMed

    Frisch, Eberhard; Ratka-Krüger, Petra; Weigl, Paul; Woelber, Johan

    2016-01-01

    This report describes the use of laboratory-fabricated crown intaglio replicas for extraorally prepared cementation of fixed restorations to implants. This technique minimizes excess cement and may therefore reduce the risk of cement-related marginal peri-implant bone loss. It is unclear whether the remaining thin layer of luting agent provides sufficient retention if low-adhesive zinc oxide (ZnO) cement is used. In 85 consecutive patients, 113 single crowns were cemented to implants using extraoral cementation technique (ECT) and ZnO cement. All patients were followed for 6 months and investigated for decementation. Seven events of decementation (incidence: 6.19%) were found in 7 patients (8.24%). ECT may represent a viable cementation technique for implant-supported single crowns, even using low-adhesion cements. PMID:27479343

  16. Bone cement with a modified polyphosphate network structure stimulates hard tissue regeneration.

    PubMed

    Lee, Byung-Hyun; Hong, Min-Ho; Kim, Min-Chul; Kwon, Jae-Sung; Ko, Yeong-Mu; Choi, Heon-Jin; Lee, Yong-Keun

    2016-09-01

    In this study, a calcium polyphosphate cement (CpPC) consisting of basic components was investigated to assess its potential for hard tissue regeneration. The added basic components for improving the structural stability, which controlled the setting time, where the setting reaction resulted in the formation of amorphous structure with a re-constructed polyphosphate. Moreover, the characteristics were controlled by the composition, which determined the polyphosphate structure. CpPC exhibited outstanding dissolution rate compared with the common biodegradable cement, brushite cement (2.5 times). Despite high amounts of dissolution products, no significant cytotoxicity ensued. Induction of calcification in MG-63 cells treated with CpPC, the level of calcification increased with increasing CpPC dissolution rate. Induced calcification was observed also in CpPC-treated ST2 cells, in contrast with MG-63 and ST2 treated with brushite cement, for which no calcification was observed. In vivo tests using a rat calvarial defect model showed that resorbed CpPC resulted in favorable host responses and promoted bone formation. Additionally, there was a significant increase in defect closure, and new bone formation progressed from CpPC mid-sites as well as defect margins. From these results, CpPC exhibits significant potential as biodegradable bone substitute for bone regeneration. PMID:27511981

  17. Thermal diffusivity of glass-ionomer cements.

    PubMed

    Tay, W M; Braden, M

    1987-05-01

    Thermal diffusivity, a property related to the thermal insulative efficiency of a material, was measured in nine glass-ionomer cements and compared with results from a silicate and a polycarboxylate cement. Each cement was mixed at various powder-liquid ratios (P/L) and moulded into a rectangular prism of approximate dimensions 2 cm cube with a thermocouple embedded in it. The prism was immersed in a constant-temperature bath at 1 degree C, and the fall in temperature was observed over a period of three min. Except for the initial and later stages, the plot of the logarithmic difference between external and internal temperatures of each block of cement against time showed a straight line in accord with theoretical prediction. From the slope, the thermal diffusivity of the material was calculated. The values for the silicate, polycarboxylate, and glass-ionomer-metal (cermet) showed a marked rise with increasing P/L, whereas at higher P/L, glass ionomer cements showed gradual change, with values being only slightly higher than the thermal diffusivity of dentin. Glass-ionomer cements are good thermal insulators over a wide range of P/L, and close agreement between experimental and theoretical data shows that glass-ionomer cements are homogenous isotropic materials.

  18. Thermal diffusivity of glass-ionomer cements.

    PubMed

    Tay, W M; Braden, M

    1987-05-01

    Thermal diffusivity, a property related to the thermal insulative efficiency of a material, was measured in nine glass-ionomer cements and compared with results from a silicate and a polycarboxylate cement. Each cement was mixed at various powder-liquid ratios (P/L) and moulded into a rectangular prism of approximate dimensions 2 cm cube with a thermocouple embedded in it. The prism was immersed in a constant-temperature bath at 1 degree C, and the fall in temperature was observed over a period of three min. Except for the initial and later stages, the plot of the logarithmic difference between external and internal temperatures of each block of cement against time showed a straight line in accord with theoretical prediction. From the slope, the thermal diffusivity of the material was calculated. The values for the silicate, polycarboxylate, and glass-ionomer-metal (cermet) showed a marked rise with increasing P/L,