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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.

  3. Effects of Ground Conditions on Microbial Cementation in Soils

    PubMed Central

    Kim, Daehyeon; Park, Kyungho; Kim, Dongwook

    2014-01-01

    The purpose of this study is to understand the effect of ground conditions on microbial cementation in cohesionless soils. Since the method of microbial cementation is still at the experimental stage, for its practical use in the field, a number of laboratory experiments are required for the quantification of microbial cementation under various ground conditions, such as relative densities, relative compactions and particle size distributions. In this study, in order to evaluate the effectiveness of microbial cementation in treated sands and silts, an experiment was performed for different relative densities of silica sands, for different relative compactions of silts and for different particle size distributions of weathered soils sampled from the field. Scanning electron microscope (SEM), X-ray diffraction (XRD), energy dispersive X-ray (EDX) spectroscopy and mapping analyses were implemented for the quantification of the levels of microbial cementations for sand, silt and weathered soil specimens. Based on the test results, a considerable microbial cementation was estimated depending on the soil conditions; therefore, an implementation of this new type of bio-grouting on a weak foundation may be possible to increase the strength and stiffness of weak ground. PMID:28788446

  4. Laboratory Electrical Resistivity Studies on Cement Stabilized Soil

    PubMed Central

    Lokesh, K. N.; Jacob, Jinu Mary

    2017-01-01

    Electrical resistivity measurement of freshly prepared uncured and cured soil-cement materials is done and the correlations between the factors controlling the performance of soil-cement and electrical resistivity are discussed in this paper. Conventional quality control of soil-cement quite often involves wastage of a lot of material, if it does not meet the strength criteria. In this study, it is observed that, in soil-cement, resistivity follows a similar trend as unconfined compressive strength, with increase in cement content and time of curing. Quantitative relations developed for predicting 7-day strength of soil-cement mix, using resistivity of the soil-cement samples at freshly prepared state, after 1-hour curing help to decide whether the soil-cement mix meets the desired strength and performance criteria. This offers the option of the soil-cement mix to be upgraded (possibly with additional cement) in its fresh state itself, if it does not fulfil the performance criteria, rather than wasting the material after hardening. PMID:28540364

  5. Treating cement burns in the emergency department.

    PubMed

    Summers, Anthony

    2013-03-01

    Use of cement is widespread in the UK and warnings about burns caused by contact with the material are usually printed on bags and delivery dockets. Nevertheless, about 2 per cent of people admitted to burns units have injuries, many serious, caused by prolonged contact with wet cement. This article explores the pathophysiology of cement burns, and outlines the best forms of treatment and prevention.

  6. 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.

  7. 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

  8. 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.

  9. 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.

  10. 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.

  11. Immobilization of lead in shooting range soils by means of cement, quicklime, and phosphate amendments.

    PubMed

    Cao, Xinde; Dermatas, Dimitris; Xu, Xuanfeng; Shen, Gang

    2008-03-01

    Lead (Pb) contamination at shooting range sites is increasingly under environmental concern. Controlling Pb leachability from shooting range soil media is an important step to minimize Pb exposure to the surrounding environment. This study investigated stabilization of Pb in shooting range soils treated with cement, quicklime, and phosphate. Two soils were used and collected from two shooting ranges, referred to as SR1 and SR2. The treatment additives were applied to the soils at rates from 2.5% to 10% (w/w). The effectiveness of each treatment was evaluated by Pb (w/w). The effectiveness of each treatment was evaluated by Pb leachability, measured by the Toxicity Characteristic Leaching Procedure (TCLP). The possible mechanisms for Pb immobilization were elucidated using X-ray powder diffraction (XRPD). Cement and quicklime treatments were effective in immobilizing Pb in SR1 soil, with reduction of Pb concentration in TCLP leachate (TCLP-Pb) to be below the U.S. EPA non-hazardous regulatory limit of 5 mg L(-1) at application rates of > or =5% and 28-d incubation. By contrast, cement and quicklime amendments were less effective for Pb stabilization in SR2 soil because the TCLP-Pb levels in the treated soil were still higher than the limit of 5 mg L(-1) at all application rates, although they were significantly reduced in comparison with the untreated soil. Phosphate application was most effective in reducing Pb leach ing in both soils. Even at an application rate as low as 5% and 1-d incubation, phosphate could reduce TCLP-Pb to be below the limit of 5 mg L(-1) in both soils. Immobilization of Pb in the SR1 soil amended with cement and quicklime was attributed to the formation of pozzolanic minerals (e.g., calcium silicate hydrate C-S-H and ettringite) that could encapsulate soil Pb. The pozzolanic reaction was limited in the SR2 soil upon the application of cement and quicklime. Reduction of the TCLP-Pb might result from complexation of Pb on the surface of the

  12. 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.

  13. 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.

  14. 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.

  15. Apatite cement containing antibiotics: efficacy in treating experimental osteomyelitis.

    PubMed

    Sasaki, S; Ishii, Y

    1999-01-01

    Osteomyelitis is generally treated by the systemic administration of antibiotics and continuous irrigation after curettage of the lesion, and bone graft is performed secondarily to treat any bone defect. This treatment is associated with major invasion, and also has adverse effects on other organs. If a superior bone filling material were to be developed that allowed high concentrations of antibiotics that acted only locally, and allowed bone formation at the same time, an ideal method of treating osteomyelitis would become available. We created an implant composed of calcium phosphate cement, gentamicin, and poly-L-lactic acid. The results of sustained-release testing in vivo and in vitro demonstrated the release of effective antibiotic concentrations over a 2-month period. Further, when an experimental model of osteomyelitis was produced in rabbits and the implant was inserted after bone marrow curettage, the implant proved effective in preventing the progression of osteomyelitis and in achieving local bone formation.

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

    NASA Astrophysics Data System (ADS)

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

    2004-03-01

    Cemented volcanic crusts are studied to learn about their composition, formation processes, and implications for climate interactions with the surface on Mars. Such carbonate, sulfate and opal crusts may be present in cemented soil units on Mars.

  17. 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

  18. 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

  19. Iron filings cement engineered soil mix

    USDA-ARS?s Scientific Manuscript database

    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 ...

  20. 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. Copyright 2010 Elsevier Ltd. All rights reserved.

  1. 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

  2. Strengthening of Weakly-Cemented Gravelly Soil with Curing Period

    NASA Astrophysics Data System (ADS)

    Lohani, Tara Nidhi; Tatsuoka, Fumio; Tateyama, Masaru; Shibuya, Satoru

    A series of drained triaxial compression (TC) tests were conducted on a lightly cement-mixed gravelly soil (CMG) compacted at three different water contents (w), on a dry side, at the optimum (w opt) and at a wet side. The specimens were cured at constant water content under atmospheric pressure for periods of 7, 28 and 180 days. The TC tests performed under 20 kPa confining pressure by measuring local strains showed that the compressive strength, q max, and the initial Young's modulus, E 0, in particular the former, became the respective maximum value when compacted at w=w opt regardless of curing period (t c). Each of the q max and E 0 value increased at a rather constant rate with respect to log (t c) even after t c= 28 days, at which the design strength is determined in the usual design practice. Such an increasing trend for CMG specimens is close enough to the conclusion drawn for cement-mixed sand specimens but differs largely from that of ordinary cement concrete, found in the existing literatures. The stress-strain behavior became more linear with t c irrespective to their molding water content.

  3. 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

  4. Infected total elbow arthroplasty treated by cemented arthrodesis.

    PubMed

    Lui, Tun Hing

    2014-03-22

    A lady had suffered from deep infection of the GSB III prosthesis of her right elbow. The infection could not be controlled by repeated debridement. Finally, cemented arthrodesis was performed and the infection was eradicated.

  5. 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

  6. 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.

  7. 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.

  8. 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. Copyright © 2011 Elsevier B.V. All rights reserved.

  9. Integrated system for treating soil contaminated with wood treating wastes

    SciTech Connect

    Acheson, C.M.; Brenner, R.C.; Khodadoust, A.P.

    1995-10-01

    Approximately 20% of the hazardous waste sites undergoing bioremediation are contaminated with wood treating wastes, primarily compounds such as pentachlorophenol (PCP), creosote, polycyclic aromatic hydrocarbons (PAHs), and other hydrocarbons. A process that combines soil washing with sequential anaerobic and aerobic biotreatment is being integrated to remediate soil contaminated with these wood treating wastes. By extracting the target compound from the soil, soil washing facilitates degradation by mobilizing the target compound and expanding the range of feasible remediation technologies. Additional flexibility is possible since soil washing can be conducted in an in-situ or ex-situ format. In this process, the wash solution is initially bioremediated in an anaerobic environment. Mineralization of the target compound is completed aerobically. Based on preliminary results, the integrated process could meet the target cleanup level for PCP in approximately 45% of the bioremediation sites. Process development began by independently evaluating soil washing and target compound degradation. PCP contaminated soils were the initial focus, but this work is currently being extended to include soils contaminated with both PCP and PAHs. In addition, based on promising results from the soil washing and degradation evaluations, these individual unit operations are being integrated to form a complete process to remediate soils contaminated with wood treating wastes. This complete process incorporates soil washing, soil wash solution recycling, and biodegradation of the target compounds and is outlined.

  10. Fracture resistance of endodontically treated teeth restored with glass fiber reinforced posts and cast gold post and cores cemented with three cements.

    PubMed

    Torres-Sánchez, Carlos; Montoya-Salazar, Vanessa; Córdoba, Paola; Vélez, Claudia; Guzmán-Duran, Andrés; Gutierrez-Pérez, José-Luis; Torres-Lagares, Daniel

    2013-08-01

    Dental fractures can occur in endodontically treated teeth restored with glass fiber reinforced posts and cast gold posts. The objective of this study was to record the fracture strength of endodontically treated teeth restored with glass fiber reinforced or cast gold post and cores cemented with 3 cements. Forty-two single-rooted premolars with standardized weakened roots were endodontically treated and allocated to 6 experimental groups (n=7) defined by the 2 factors investigated: post system and cement. Three groups were restored with glass fiber posts and resin-modified glass ionomer cement, dual-polymerizing resin cement, or chemically active autopolymerizing resin cement. The other 3 groups were restored with cast gold post and cores and the same 3 cements. The cores of the glass fiber post groups were fabricated with composite resin core material. Metal crowns were cemented on the cores in the 6 groups. The entire system was subjected to continuous compression in a universal testing machine, and fracture limit and location (cervical third, middle third, or apical third) were noted. Two-way ANOVA and the Scheffé test were used to analyze the data and compare the groups (α=.05). Two-way ANOVA showed significant differences in the post type (P<.001) and the cements (P<.001). The interaction between them (P<.001) was statistically significant in the fracture resistance of the endodontically treated teeth. The greatest interaction between post and cement was the glass fiber post with resin-modified glass ionomer cement, followed by the cast gold post and core with resin-modified glass ionomer cement. The use of a glass fiber reinforced post and resin-modified glass ionomer cement increased the fracture resistance of endodontically treated teeth. Copyright © 2013 The Editorial Council of the Journal of Prosthetic Dentistry. Published by Mosby, Inc. All rights reserved.

  11. 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. Copyright © 2013 Elsevier Ltd. All rights reserved.

  12. Interrelationships among geotechnical and leaching properties of a cement-stabilized contaminated soil.

    PubMed

    Kogbara, Reginald B

    2017-01-28

    Relationships among selected performance properties have been established using experimental data from a cement-stabilized mixed contaminated soil. The sandy soil was spiked with 3,000 mg/kg each of Cd, Cu, Pb, Ni and Zn, and 10,000 mg/kg of diesel. It was then treated with 5%, 10%, 15%, and 20% dosages of Portland cement. Different water contents were considered for lower dosage mixes. Selected geotechnical and leaching properties were determined on 28-day old samples. These include unconfined compressive strength (UCS), bulk density, porosity, hydraulic conductivity, leachate pH and granular leachability of contaminants. Interrelationships among these properties were deduced using the most reasonable best fits determined by specialized curve fitting software. Strong quadratic and log-linear relationships exist between hydraulic conductivity and UCS, with increasing binder and water contents, respectively. However, the strength of interrelationships between hydraulic conductivity and porosity, UCS and porosity, and UCS and bulk density varies with binder and water contents. Leachate pH and granular leachability of contaminants are best related to UCS and hydraulic conductivity by a power law and an exponential function, respectively. These results suggest how the accuracy of not-easily-measurable performance properties may be constrained from simpler ones. Comparisons with some published performance properties data support this.

  13. 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.

  14. Incorporation of bitumen and calcium silicate in cement and lime stabilized soil blocks

    NASA Astrophysics Data System (ADS)

    Kwan, W. H.; Cheah, C. B.; Ramli, M.; Al-Sakkaf, Y. K.

    2017-04-01

    Providing affordable housing is the most critical problem in many of the developing countries. Using earth materials in building construction is one of the feasible methods to address this issue and it can be a way towards sustainable construction as well. However, the published information on the stabilized soil blocks is limited. Therefore, the present study is conducted to examine the characterization of the soils and engineering properties of the stabilized soil blocks. Four types of stabilizer were used in the study, namely; cement, slaked lime, bitumen emulsion and calcium silicate. Cement and slaked lime were added at different percentages in the range of 5% to 15%, with interval of 2.5%. The percentage was determined based on weight of soil. Meanwhile, bitumen emulsion and calcium silicate were incorporated at various percentages together with 10% of cement. Dosage of bitumen emulsion is in the range of 2% to 10% at interval of 2% while calcium silicate was incorporated at 0.50%, 0.75%, 1.00%, 1.25%, 1.50% and 2.00%. Results show that cement is the most viable stabilizer for the soil block among all stabilizers in this study. The bulk density, optimum moisture content and compressive strengths were increased with the increasing cement content. The most suitable cement content was 10% added at moisture content of 12%. Lime, bitumen and calcium contents were recommended at 5.0%, 6.0% and 1.25%, respectively.

  15. SEM analysis of microstructure of adhesive interface between resin cement and dentin treated with self-etching primer.

    PubMed

    Hirabayashi, Shigeru; Yoshida, Eiji; Hayakawa, Tohru

    2011-01-01

    The purpose of this study was to examine the microstructure of the adhesive interface between resin cement and dentin treated with a self-etching primer by SEM in order to clarify the adhesive efficiencies of four self-etch type resin cement systems, Bistite II (BII), Linkmax (LM), Panavia F2.0 (PF), and ResiCem (RC) to dentin. The fluidity and inorganic filler content of these cements were also determined to examine their influences on the adhesion. A hybrid layer with 0.5-1.5 µm thickness and many resin tags could be confirmed clearly at the interface between BII cement and dentin, but was not observed distinctly for the other resin cements. It was suggested that the hybrid layer and resin tags might contribute to the high adhesive efficiency for BII. As the fluidity of cement had been adjusted to be suitable for luting in all cements, it did not significantly influence the adhesive efficiency of cement.

  16. 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.

  17. [Histopathological studies of periodontal tissue reactions to perforations in the furcation of dogs' teeth treated with cyanoacrylate cement (FH Cement)].

    PubMed

    Morinaga, K; Furusawa, M; Kitamura, M; Sato, H; Watanabe, H; Yokoya, S; Nakagawa, K; Asai, Y

    1989-06-01

    In the previous study (Shikwa Gakuho, 85: 413-451, 1985.), Morinaga reported on the histopathology of furcation perforations treated with ethyl cyanoacrylate and showed that, because of its properties, this material cannot be expected to effect a permanent blockade. It did not, however, irritate the wound. The purpose of this study is to investigate the effects of a new cyanoacrylate cement (FH Cement) when applied to furcation perforations. Subjects were 25 mandibular and maxilla premolars and molars obtained from 3 adult dogs. The method used in the study was as follows. After administration of pentobarbital-sodium general anesthesia, the pulp chamber was opened by means of a high-speed air turbine fitted with a diamond point. According to usual procedures, the pulp was removed, and the main root canal was filled. Next the floor of the pulp chamber was deliberately perforated by means of a 1mm round bur that had been previously sterilized in advance pouring a physiological sodium chloride solution at the same time. The perforated areas were then washed with a same solution, wiped, and dried with aseptic cotton pellets. They were then stuffed with cyanoacrylate cement. The cavity was lined with gutta-percha temporary stopping, and the remainder of the cavity was filled with silver amalgam. At periods of 1, 2, 4, 8 and 12 weeks after the operation, the animals were sacrificed by means of electricity under general anesthesia. The jaw bones were removed, fixed, decalcified, and embedded in celloidin. Longitudinal sections were stained with hematoxylin-eosin. Results 1. Periodontal tissues around perforated sites were healed by means of scar tissue, though suppuration occurred in a few cases. 2. Hard tissue was appended to the teeth in a small number of cases. 3. Repair of the alveolar bone was observed in the damaged site in about half of all cases. From the result mentioned above, cyanoacrylate cement (FH Cement) was seemed to did not close the site perforation for

  18. Bond strength of self-adhesive resin cements to different treated indirect composites.

    PubMed

    Fuentes, M Victoria; Ceballos, Laura; González-López, Santiago

    2013-04-01

    The objective of this study was to determine microtensile bond strength (μTBS) to dentin of three self-adhesive and a total-etch resin cements used for luting different treated indirect composites. Composite overlays (Filtek Z250) were prepared. Their intaglio surfaces were ground with 600-grit SiC papers and randomly assigned to three different surface treatments: no treatment, silane application (RelyX Ceramic Primer), and silane agent followed by a bonding agent (Adper Scotchbond 1 XT). The composite overlays were luted to flat dentin surfaces of extracted human third molars using the following self-adhesive resin cements: RelyX Unicem, Maxcem Elite and G-Cem, and a total-etch resin cement, RelyX ARC. The bonded assemblies were stored in water (24 h, 37 °C) and subsequently prepared for μTBS testing. Beams of approximately 1 mm(2) were tested in tension at 1 mm/min in a universal tester (Instron 3345). Data were analyzed by two-way ANOVA and Student-Newman-Keuls tests (α = 0.05). A significant influence of the resin cement used was detected. Composite surface treatment and the interaction between the resin cement applied and surface treatment did not affect μTBS. Surface treatment of indirect resin composite did not improve the μTBS results of dentin/composite overlay complex. Self-adhesive resin cements tested obtained lower μTBS than the total-etch resin cement RelyX ARC. Specimens luted with Maxcem Elite exhibited the highest percentage of pretesting failures. Surface treatment of indirect resin composite with silane or silane followed by a bonding agent did not affect bond strength to dentin.

  19. 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.

  20. Assessment of Physical and Mechanical Properties of Cement Panel Influenced by Treated and Untreated Coconut Fiber Addition

    NASA Astrophysics Data System (ADS)

    Abdullah, Alida; Jamaludin, Shamsul Baharin; Anwar, Mohamed Iylia; Noor, Mazlee Mohd; Hussin, Kamarudin

    This project was conducted to produce a cement panel with the addition of treated and untreated coconut fiber in cement panel. Coconut fiber was added to replace coarse aggregate (sand) in this cement panel. In this project, the ratios used to design the mixture were 1:1:0, 1:0.97:0.03, 1:0.94:0.06, 1:0.91:0.09 (cement: sand: coconut fiber). The water cement ratio was constant at 0.55. The sizes of sample tested were, 160 mm x 40 mm x 40 mm for compression test, and 100 mm x 100 mm x 40 mm for density, moisture content and water absorption tests. After curing samples for 28 days, it was found that the addition of coconut fiber, further increase in compressive strength of cement panel with untreated coconut fiber. Moisture content of cement panel with treated coconut fiber increased with increasing content of coconut fiber whereas water absorption of cement panel with untreated coconut fiber increased with increasing content of coconut fiber. The density of cement panel decreased with the addition of untreated and treated coconut fiber.

  1. 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.

  2. In Situ Evaluation of Unsurfaced Portland Cement-Stabilized Soil Airfields

    DTIC Science & Technology

    2009-07-01

    interparticle friction within the soil mass, and reduce the moisture susceptibility of the parent material. Stabilization with Portland cement can be used...Materials underlying a bound surface layer can be tested by first drilling or coring an access hole. The typical apparatus is composed of a handle, two...methods for the determination of the modulus and damping properties of ERDC/GSL TR-09-20 15 soils using the cyclic triaxial apparatus .” In this

  3. Comparative Study of Bipolar Hemiarthroplasty for Femur Neck Fractures Treated with Cemented versus Cementless Stem

    PubMed Central

    Choi, Jung-Yun; Kim, Joo-Hyung

    2016-01-01

    Purpose To compare and analyze clinical and radiologic outcomes of cemented versus cementless bipolar hemiarthroplasty for treatment of femur neck fractures. Materials and Methods A total of 180 patients aged 65 years and over older who underwent bipolar hemiarthroplasty for treatment of displaced femur neck fractures (Garden stage III, IV) from March 2009 to February 2014 were included in this study. Among the 180 patients, 115 were treated with cemented stems and 65 patients with cementless stems. Clinical outcomes assessed were: i) postoperative ambulatory status, ii) inguinal and thigh pain, and iii) complications. The radiologic outcome was femoral stem subsidence measured using postoperative simple X-ray. Results The cemented group had significantly lower occurrence of complications (postoperative infection, P=0.04) compared to the cementless group. There was no significant difference in postoperative ambulatory status, inguinal and thigh pain, and femoral stem subsidence. Conclusion For patients undergoing bipolar hemiarthroplasty, other than complications, there was no statistically significant difference in clinical or radiologic outcomes in our study. Selective use of cemented stem in bipolar hemiarthroplasty may be a desirable treatment method for patients with poor bone quality and higher risk of infections. PMID:28097110

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. The Estimation of Compaction Parameter Values Based on Soil Properties Values Stabilized with Portland Cement

    NASA Astrophysics Data System (ADS)

    Lubis, A. S.; Muis, Z. A.; Pasaribu, M. I.

    2017-03-01

    The strength and durability of pavement construction is highly dependent on the properties and subgrade bearing capacity. This then led to the idea of the selection methods to estimate the density of the soil with the proper implementation of the system, fast and economical. This study aims to estimate the compaction parameter value namely the maximum dry unit weight (γd max) and optimum moisture content (wopt) of the soil properties value that stabilized with Portland Cement. Tests conducted in the laboratory of soil mechanics to determine the index properties (fines and liquid limit) and Standard Compaction Test. Soil samples that have Plasticity Index (PI) between 0-15% then mixed with Portland Cement (PC) with variations of 2%, 4%, 6%, 8% and 10%, each 10 samples. The results showed that the maximum dry unit weight (γd max) and wopt has a significant relationship with percent fines, liquid limit and the percentation of cement. Equation for the estimated maximum dry unit weight (γd max) = 1.782 - 0.011*LL + 0,000*F + 0.006*PS with R2 = 0.915 and the estimated optimum moisture content (wopt) = 3.441 + 0.594*LL + 0,025*F + 0,024*PS with R2 = 0.726.

  9. [Bone cement dry prosthetic with internal fixation treat senile osteoporotic femoral fractures].

    PubMed

    Jiang, Y; Rong, X X; Chen, P; Xu, Y J; Zhu, G X

    2017-03-01

    Objective: To explore the treatment of senile osteoporotic femoral fractures after using internal fixation of bone cement dry prosthetic. Methods: Twelve patients aged from 74 to 94 years with mean age of (84.0±2.5) years with internal fixation of bone cement dry prosthetic surgery who were treated at Department of Orthopaedics in Nanjing Medical University Affiliated Wuxi Second Hospital between May 2013 and May 2015 were retrospectively analyzed. There were 8 male and 4 female, 10 cases of tumble and 2 cases of traffic injury. The fracture types with AO type included 1 case of A1 type, 5 cases of A2 type, 3 cases of A3 type, 1 case of B1 type, 2 cases of B2 type. The steel plate internal fixation with bone cement dry prosthetic method was chosen to treat senile severe femoral fracture. Postoperative observation of postoperative pain assessment, hip joint activity and walking ability were evaluated. Paired simple t test and Wilcoxon rank sum test were used to compare the differences of pain score and the ability to walk. Results: Twelve cases received an average of (16.0±3.6) months follow-up. The average hospitalization days are (9.0±1.4) days and average of intraoperative time was (68.0±10.6) minutes. Intraoperative blood loss compared to normal was (106.0±24.2) ml. Patients began walking load and activities in two weeks. The gait and joint activities gradually restored and there were no obvious deformity and no loose internal fixation. All of the patients didn't have fracture shift with breaking plates or screws deformation and have no bone cement reaction. The walking ability was (4.1±0.9) points, the hip joint activities were 98.5°±7.7° and pain scores were 1.22±0.58 by Holden grading standards. The differences of walking ability (Z=-3.126, P<0.05) and pain scores (t=23.047, P<0.001) between pre- and post-operative were statistically significant. One patient had contralateral hip pain, 2 patients had lateral thigh pain, 10 patients returned to

  10. 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.

  11. Leachability of Arsenic (As) Contaminated Landfill Soil Stabilised by Cement and Bagasse Ash

    NASA Astrophysics Data System (ADS)

    Azhar, A. T. S.; Azim, M. A. M.; Aziman, M.; Nabila, A. T. A.

    2016-11-01

    Contaminated soil with heavy metals, especially Arsenic (As) has become a major issue worldwide. As is reported to be a metal that affects human health and is related to have caused serious diseases that interrupts the nervous system, blood vessels and kidneys. However, proper treatment techniques such as Stabilization/Solidification (S/S) method can be employed and is capable of controlling these heavy metals from contaminating the soil strata and groundwater resources. This study is to investigate the leachability of Arsenic (As) in S/S method when bagasse ash (BA) is added to remedy contaminated Landfill soil. Cement is added at a proportion of 5%, 10%, 15% and 20% in sample weights without BA while in another sample; the cement replaces BA at a proportion of 2.5%, 5%, 7.5%. and 10%. All samples were allowed to harden and cured at room temperature for 7, 14 and 28 days. The effectiveness of the treatment was assessed by conducting Synthetic Precipitation Leaching Procedure (SPLP). Results indicate that pH and leachability are found to have major influence on metal release. The final pH after leaching tests showed improvements especially samples containing BA. In addition, the concentration of As in the SPLP test after the curing period of 28 days were detected to be below the leachability limit as regulated by WHO's Guidelines for Drinking-water Quality. As a whole, the results obtained from testing showed that sample containing 10% cement with 10% BA is the most effective and is the optimum mix since this proportion succeeded in minimising the leachability of As at total reduction by 100%, In conclusion, partial replacement of cement with BA in the binder system has been successful in reducing the leachability.

  12. The effect of portland cement for solidification of soils contaminated by mine tailings containing heavy metals

    NASA Astrophysics Data System (ADS)

    Jian-Jun, Chen; Zheng-Miao, Xie

    2010-05-01

    Portland cement(PC) was used to solidify the lead-zinc mine tailings contaminated soils(CS) in this work. The soils were heavily polluted by heavy metals with lead(up to 19592 mg/kg), zinc(up to 647mg/kg), Cd(up to 14.65mg.kg) and Cu(up to 287mg/kg). Solidified/stabilized(s/s)forms with a range of cement contents, 40-90 wt%, were evaluated to determine the optimal binder content. Unconfined compression strength test(UCS), Chinese solid waste-extraction procedure for leaching toxicity - Horizontal vibration method, toxicity characteristic leaching procedures(TCLP) were used for physical and chemical characterization of the s/s forms. The procedure of Tessier et al.(1979) was used to separate S/S forms Pb, Zn, Cd, Cu into different fractions. The results show that addition of 50% cement was enough for the s/s forms to satisfy the MU10 requirements (0.10 MPa). Under the 50% addition, the content of the water-exchangeable fraction of Pb reduced from 2.25% to 0.2%, the carbonate-bound fraction and organic-bound fraction reduced by about half, while the Fe-Mn oxide-bound fraction was more than doubled. The residual fraction decreased 8% on the contrary. For Zn, except for the carbonate-bound fraction increased slightly, the features of other items were same as that of Pb. For Cd, the water-exchangeable fraction was reduced largely, the residual fraction and Fe-Mn oxide-bound fraction increased 2-3%. For Cu, A distinct feature is the organic-bound fraction reduced with the reduction in consumption of cement, at the same time, the residual fraction increased corresponding. Leaching test results indicate that the leaching contents of Pb2+ of the six specimens are quite different at low pH value(

  13. 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.

  14. Bond strengths and patterns of failure of a zinc polycarboxylate cement on surface-treated gold alloys.

    PubMed

    Ogunyinka, A

    2000-08-01

    The study investigated the shear strengths and fracture characteristics of a zinc polycarboxylate cement on three sets of type III gold alloy bars whose surfaces were modified by alumina blasting, heat treatment and tin plating respectively. Each set comprised 20 bars with similarly treated surfaces, cemented in pairs with the polycarboxylate cement and stored in water at 37 degrees C for 48 hours. The cement bond was then stressed to failure by application of forces in shear mode and the bond strength was determined. The mean bond strength for each type of treated gold alloy surface was calculated and then compared with the others by way of statistical analysis. The failed surfaces were observed and photographed with a stereophotomicroscope for subjective evaluation of the character of the failed surfaces. The strongest bonds were formed on the alumina-blasted surfaces where 70% of the bonds failed in an adhesive-cohesive fashion. The weakest bonds were formed on the tin-plated surfaces where cement failure was entirely adhesive. Bond strengths on the heat-treated surfaces were intermediate and a cohesive failure pattern was observed on 80% of the specimens. The differences in bond strengths on the three surfaces were statistically significant.

  15. 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.

  16. 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.

  17. 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. Copyright © 2014 Elsevier B.V. All rights reserved.

  18. Wheat Growth in Soils Treated by Ex Situ Thermal Desorption.

    PubMed

    O'Brien, Peter L; DeSutter, Thomas M; Casey, Francis X M; Wick, Abbey F; Khan, E

    2017-07-01

    Successful remediation of oil-contaminated agricultural land may include the goal of returning the land to prespill levels of agricultural productivity. This productivity may be measured by crop yield, quality, and safety, all of which are influenced by soil characteristics. This research was conducted to determine if these metrics are affected in hard red spring wheat ( L. cultivar Barlow) when grown in soils treated by ex situ thermal desorption (TD) compared with wheat grown in native topsoil (TS). Additionally, TD soils were mixed with TS at various ratios to assess the effectiveness of soil mixing as a procedure for enhancing productivity. In two greenhouse studies, TD soils alone produced similar amounts of grain and biomass as TS, although grain protein in TD soils was 22% (±7%) lower. After mixing TS into TD soils, the mean biomass and grain yield were reduced by up to 60%, but grain protein increased. These trends are likely the result of nutrient availability determined by soil organic matter and nutrient cycling performed by soil microorganisms. Thermal desorption soil had 84% (±2%) lower soil organic carbon than TS, and cumulative respiration was greatly reduced (66 ± 2%). From a food safety perspective, grain from TD soils did not show increased uptake of polycyclic aromatic hydrocarbons. Overall, this research suggests that TD soils are capable of producing safe, high-quality grain yields. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  19. Ecological evaluation of artificial soils treated with phosphogypsum

    NASA Astrophysics Data System (ADS)

    Yakovlev, A. S.; Kaniskin, M. A.; Terekhova, V. A.

    2013-06-01

    An attempt to set up ecologically acceptable concentrations of toxic components contained in phosphogypsum was made for soils of different land uses. For this purpose, an experimental ecological evaluation of a standard soil mixture (model artificial soil ISO 11268-1) treated with phosphogypsum was performed. Both positive and negative effects of the phosphogypsum components were found. Thus, a significant increase in the biomass of lawn grasses was observed in the model soil with the phosphogypsum content of less than 3.3%. In the soil containing more than 6.8% phosphogypsum, the concentrations of Sr and F exceeded the maximum permissible values and adversely affected the living organisms. According to the basic ecological norms, the allowable content of phosphogypsum should be ≤2.0% for the soils of specially protected natural areas; ≤6.8% for agricultural and urban soils; and ≤9.6% for the soils of forest, water management, and transport lands.

  20. Fracture Resistance of Endodontically Treated Roots Restored with Fiber Posts Using Different Resin Cements- An In-vitro Study

    PubMed Central

    Irodi, Sujatha; Mehta, Deepak; Subramanya, Shankar; Govindaraju, Vinay Kumar

    2017-01-01

    Introduction The influence of the remaining coronal tooth structure along with intra-radicular esthetic posts increases fracture resistance of fractured teeth especially in the anterior region. The advent of resin based luting cements improves the adhesion of fiber posts. Aim To evaluate the fracture resistance of endodontically treated roots restored with fiber posts using different resin cements – Calibra (etch and rinse), PermaFlo® DC (self-etch primer) and SmartCem2 (self-adhesive). Materials and Methods Extracted human maxillary central incisors having similar dimensions were decoronated at the Cemento-Enamel Junction (CEJ) to create 16mm long specimens and endodontically treated. A total of 45 teeth were divided into three groups with 15 teeth each for cementation of easy fiber posts (size1, 0.8mm diameter). Post spaces were prepared to a depth of 10mm. Group 1 – Caulk 34% phosphoric acid gel, dual cure adhesive Prime and Bond NT followed by luting of post with Calibra cement. Group 2 – Ultra – etch then Primer A and Primer B, and PermaFlo® DC was used to cement the post. Group 3 – SmartCem2 [1:1 ratio] was used to cement the post. The excess lengths of posts were seared and teeth were mounted on acrylic blocks and loaded under compressive force to the long axis of the tooth which increased in periodic pattern of 1mm/min. The value of the force at which each root section gets fractured was noted. The data were statistically analysed using ANOVA and Tukey’s Test. Results The mean fracture load (and SD) were as follows Group 1 – 762.400 (251.490); Group 2 – 662.933 (206.709); Group 3 – 657.800 (57.372). No statistically significant differences were seen among all three Groups, p-value (0.228). Conclusion Posts cemented using self -adhesive resin cement SmartCem2 have highest fracture resistance and bonding efficacy of self-adhesive technique showed reliably better results but was comparable to total–etch and self–etch techniques. PMID

  1. 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

  2. Treating osteoporotic vertebral compression fractures with intraosseous vacuum phenomena using high-viscosity bone cement via bilateral percutaneous vertebroplasty.

    PubMed

    Guo, Dan; Cai, Jun; Zhang, Shengfei; Zhang, Liang; Feng, Xinmin

    2017-04-01

    Osteoporotic vertebral compression fractures with intraosseous vacuum phenomena could cause persistent back pains in patients, even after receiving conservative treatment. The aim of this study was to evaluate the efficacy of using high-viscosity bone cement via bilateral percutaneous vertebroplasty in treating patients who have osteoporotic vertebral compression fractures with intraosseous vacuum phenomena.Twenty osteoporotic vertebral compression fracture patients with intraosseous vacuum phenomena, who received at least 2 months of conservative treatment, were further treated by injecting high-viscosity bone cement via bilateral percutaneous vertebroplasty due to failure of conservative treatment. Treatment efficacy was evaluated by determining the anterior vertebral compression rates, visual analog scale (VAS) scores, and Oswestry disability index (ODI) scores at 1 day before the operation, on the first day of postoperation, at 1-month postoperation, and at 1-year postoperation.Three of 20 patients had asymptomatic bone cement leakage when treated via percutaneous vertebroplasty; however, no serious complications related to these treatments were observed during the 1-year follow-up period. A statistically significant improvement on the anterior vertebral compression rates, VAS scores, and ODI scores were achieved after percutaneous vertebroplasty. However, differences in the anterior vertebral compression rate, VAS score, and ODI score in the different time points during the 1-year follow-up period was not statistically significant (P > 0.05).Within the limitations of this study, the injection of high-viscosity bone cement via bilateral percutaneous vertebroplasty for patients who have osteoporotic vertebral compression fractures with intraosseous vacuum phenomena significantly relieved their back pains and improved their daily life activities shortly after the operation, thereby improving their life quality. In this study, the use of high-viscosity bone

  3. Adsorption of radiostrontium by soil treated with alkali metal hydroxides

    SciTech Connect

    Spalding, B.P.

    1980-07-01

    Twelve soils from areas used for the disposal of low-level radioactive solid waste at the Oak Ridge National Laboratory were examined for their ability to adsorb trace levels of Sr. Radiostrontium adsorption, in the presence of normal soil Ca levels, was determined following the addition of LiOH, NaOH, KOH, NaCl, and Na-polyacrylate. With soils from C horizons, the average thermodynamic equilibrium constant for the Na-Ca(Sr) exchange reaction decreased from 0.063 to 0.00041 after treatment with 0.4 meq/g of NaOH, indicating a large increase in the selectivity for Ca(Sr) adsorption. With samples from A or B horizons, this effect was not observed due to the dissolution of soil organic matter; Na-polyacrylate interfered with the adsorption of Ca(Sr) in the same manner as the NaOH-solubilized soil organic matter. Selectivity differences between trace levels of Sr and the macroamounts of soil Ca were quite small (<5%) in both the treated and untreated soils. A multiple regression analysis indicated that three soil properties (percent organic matter, exchangeable Ca + Mg, and exchangeable acidity) explained 77% of the variation in Sr adsorption by alkali-treated soils. In untreated soils, the exchangeable Ca + Mg and exchangeable acidity explained 70% of the variation in the adsorption of Sr. The response of the soils to alkali treatment generally followed the lyotropic series: Li > Na > K.

  4. 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

  5. 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.

  6. 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.

  7. Analysis of the Feasibility of Using Soil from the Municipality of Goytacazes/RJ for Production of Soil-Cement Brick

    NASA Astrophysics Data System (ADS)

    Alexandre, J.; Azevedo, A. R. G.; Theophilo, M. M. D.; Xavier, C. G.; Paes, A. L. C.; Monteiro, S. N.; Margem, F. M.; Azeredo, N. G.

    The use of bricks of soil-cement is proving to be an important constructive methodology due to low environmental impact in the production process of these blocks comparing with conventional bricks are burnt, besides being easy to produce. However during the process of production of bricks, which are compressed, knowledge of the properties of the soil used is critical to the quality and durability of the blocks. The objective of this work is to evaluate the feasibility of using soil from the municipality of Goytacazes for the production of soil-cement bricks. Assays were performed the compaction, liquid limit, plastic limit, particle size analysis, EDX and X-Ray diffraction for later pressed blocks and analyze their compressive strength and water absorption.

  8. Leaching of arsenic, copper and chromium from thermally treated soil.

    PubMed

    Kumpiene, Jurate; Nordmark, Désirée; Hamberg, Roger; Carabante, Ivan; Simanavičienė, Rūta; Aksamitauskas, Vladislovas Česlovas

    2016-12-01

    Thermal treatment, if properly performed, is an effective way of destroying organic compounds in contaminated soil, while impact on co-present inorganic contaminants varies depending on the element. Leaching of trace elements in thermally treated soil can be altered by co-combusting different types of materials. This study aimed at assessing changes in mobility of As, Cr and Cu in thermally treated soil as affected by addition of industrial by-products prior to soil combustion. Contaminated soil was mixed with either waste of gypsum boards, a steel processing residue (Fe3O4), fly ash from wood and coal combustion or a steel abrasive (96.5% Fe(0)). The mixes and unamended soil were thermally treated at 800 °C and divided into a fine fraction <0.125 mm and a coarse fraction >0.125 mm to simulate particle separation occurring in thermal treatment plants. The impact of the treatment on element behaviour was assessed by a batch leaching test, X-ray absorption spectroscopy and dispersive X-ray spectrometry. The results suggest that thermal treatment is highly unfavourable for As contaminated soils as it increased both the As leaching in the fine particle size fraction and the mass of the fines (up to 92%). Soil amendment with Fe-containing compounds prior to the thermal treatment reduced As leaching to the levels acceptable for hazardous waste landfills, but only in the coarse fraction, which does not justify the usefulness of such treatment. Among the amendments used, gypsum most effectively reduced leaching of Cr and Cu in thermally treated soil and could be recommended for soils that do not contain As. Fly ash was the least effective amendment as it increased leaching of both Cr and As in majority of samples. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. 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.

  10. Five to thirteen year results of a cemented dual mobility socket to treat recurrent dislocation.

    PubMed

    Hamadouche, Moussa; Ropars, Mickael; Rodaix, Camille; Musset, Thierry; Gaucher, François; Biau, David; Courpied, Jean Pierre; Huten, Denis

    2017-03-01

    Dual mobility (DM) socket has been associated with a low rate of dislocation following both primary and revision total hip arthroplasty (THA). However, little is known about the long-term efficiency of DM in the treatment of THA instability. The purpose of this retrospective study was to evaluate the outcome of a cemented DM socket to treat recurrent dislocation after a minimum of five year follow-up. The series included 51 patients with a mean age of 71.3 ± 11.5 (range, 41-98) years presenting with recurrent dislocation (mean 3.3). A single DM socket design was used consisting of a stainless steel outer shell with grooves with a highly polished inner surface articulating with a mobile polyethylene component. The femoral head was captured in the polyethylene component using a snap-fit type mechanism, the latter acting as a large unconstrained head inside the metal cup. At the minimum five year follow-up evaluation, 18 of the 51 patients deceased at a mean of 4.8 ± 2.3 years, three were lost to follow-up at a mean of 1.4 years, seven had been revised at a mean of 4.7 ± 3.1 years (range, 1.5-9.1), and the remaining 23 were still alive and did not have revision at a mean of 8.2 ± 2.4 years (range, 5-13 years). Of the seven revision, three were performed for further episodes of dislocation (at the large bearing for one patient and intra-prosthetic for two patients) after a mean 5.9 ± 2.9 years (range, 2.7-9.1), whereas two were performed for late sepsis and two for aseptic loosening of the acetabular component. Radiographic analysis did not reveal any further loosening on the acetabular side. The survival rate of the cup at ten years, using re-dislocation as the end-point, was 86.1 ± 8.4% (95% confidence interval, 69.7-100%). The survival rate of the cup at ten years, using revision for any reason as the end-point, was 75.2 ± 9.3% (95% confidence interval, 56.9-93.5%). A cemented dual mobility cup was able to restore hip

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

    PubMed Central

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

    2014-01-01

    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. PMID:24556955

  12. 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.

  13. Pathological fracture after migration of cement used to treat distal femur physeal arrest.

    PubMed

    Shea, Kevin G; Rab, George T; Dufurrena, Magen

    2009-07-01

    Treatment of physeal arrest with bar removal and placement of interposition materials in young patients has been shown to restore physeal growth. Among the various materials that have been used to prevent early reformation of the physeal bar (fat, silastic, cartilage), Peterson recommended the use of Cranioplast, as this material can prevent bar reformation, and it is radiolucent because it does not contain barium. Peterson suggested steps be taken to prevent migration of the Cranioplast, as migration of the interposition material might allow for reformation of the physeal bar. Although Peterson had not observed cement migration leading to pathologic fracture, he felt that this was a potential concern. We describe the case of cement migration from the epiphysis into the diaphysis, leading to a pathological femur fracture. Despite migration of the Cranioplast, the physeal bridge did not reform, and the patient had nearly normal growth 7 years after the initial physeal arrest procedure.

  14. 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

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

    PubMed

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

    2014-11-01

    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. 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). 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. 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.

  16. 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.

  17. 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

  18. 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. Copyright 2010 Elsevier B.V. All rights reserved.

  19. 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. Copyright © 2014 Elsevier GmbH. All rights reserved.

  20. Soil enzyme dynamics in chlorpyrifos-treated soils under the influence of earthworms.

    PubMed

    Sanchez-Hernandez, Juan C; Notario Del Pino, J; Capowiez, Yvan; Mazzia, Christophe; Rault, Magali

    2017-09-08

    Earthworms contribute, directly and indirectly, to contaminant biodegradation. However, most of bioremediation studies using these annelids focus on pollutant dissipation, thus disregarding the health status of the organism implied in bioremediation as well as the recovery of indicators of soil quality. A microcosm study was performed using Lumbricus terrestris to determine whether earthworm density (2 or 4individuals/kg wet soil) and the time of exposure (1, 2, 6, 12, and 18wk) could affect chlorpyrifos persistence in soil initially treated with 20mg active ingredientkg(-1) wet soil. Additionally, selected earthworm biomarkers and soil enzyme activities were measured as indicators of earthworm health and soil quality, respectively. After an 18-wk incubation period, no earthworm was killed by the pesticide, but clear signs of severe intoxication were detected, i.e., 90% inhibition in muscle acetylcholinesterase and carboxylesterase (CbE) activities. Unexpectedly, the earthworm density had no significant impact on chlorpyrifos dissipation rate, for which the measured half-life ranged between 30.3d (control soils) and 44.5d (low earthworm density) or 36.7d (high earthworm density). The dynamic response of several soil enzymes to chlorpyrifos exposure was examined calculating the geometric mean and the treated-soil quality index, which are common enzyme-based indexes of microbial functional diversity. Both indexes showed a significant and linear increase of the global enzyme response after 6wk of chlorpyrifos treatment in the presence of earthworms. Examination of individual enzymes revealed that soil CbE activity could decrease chlorpyrifos-oxon impact upon the rest of enzyme activities. Although L. terrestris was found not to accelerate chlorpyrifos dissipation, a significant increase in the activity of soil enzyme activities was achieved compared with earthworm-free, chlorpyrifos-treated soils. Therefore, the inoculation of organophosphorus-contaminated soils with

  1. 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.

  2. 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

  3. Assessment of polycyclic aromatic hydrocarbons (PAHs) in soil of a Natural Reserve (Isola delle Femmine) (Italy) located in front of a plant for the production of cement.

    PubMed

    Orecchio, Santino

    2010-01-15

    Isola delle Femmine Natural Reserve is a very little isle about 15 km from the centre of Palermo, in front of a plant for the production of cement and about 600 m from coast. In the present research, profiles soil PAHs were obtained for 16 sites within the reserve and for 8 stations on the rural soil taken as reference. summation Sigma PAHs, in the soil of investigated area, ranged from 35 to 545 microg/kg. With the aim to find the origin of PAHs in the soil of Isola delle Femmine, we compare the distribution of single analytes in the investigated area with those of the reference rural area (Monte Raffo Rosso), with those of atmospheric urban particulate collected at Palermo along with reported of emissions of some cement plants. The island's investigated area showed a high amount of 4- and 5-rings PAHs, whereas 3-ring PAHs are present mainly in the emission of cement plants (from literature). The percentage of 3-, 4-, 5- and 6-rings PAHs determined in samples of Isola delle Femmine are similar to those of the reference rural soils and to those of urban atmospheric particulate. Cement plant activity has a negligible weight on the presence of PAHs in the soil of Isola delle Femmine.

  4. 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.

  5. Water quality improvement of treated wastewater by intermittent soil percolation.

    PubMed

    Castillo, G; Mena, M P; Dibarrart, F; Honeyman, G

    2001-01-01

    Our research aimed to evaluate intermittent soil infiltration of treated sewage for reuse in the north of Chile. Aerated lagoon effluent was infiltrated in columns packed with native soils (sandy-lime, lime-gravel and limey-sand). Columns were operated for more than a year under different cycles of filling and drying, depths and load pressures depending on soil characteristics. The efficiency of the system was determined through influent-effluent microbiological indicators level (faecal coliforms, E. coli, Salmonella spp, MS2 phage, and protozoan cysts), physicochemical characterisation (TOC, COD, BOD, nitrogen), and hydraulic flow measurement. Results showed: (a) high reduction of enteric bacteria (5-7 log10), some inactivation of phage (2-4 log10) and complete removal of intestinal cyst; (b) stable removal of organic matter (80-90% reduction of TOC, COD, BOD); and (c) partial ammonia reduction through adsorption and nitrification with denitrification mainly occurring in sandy soil. Preliminary data from pilot plant working in the field showed better results that those obtained in the laboratory especially removal of microbiological indicators. Microbiological quality of effluent met Class A regulations for agricultural reuse (WHO, 1989) and the system looks like an attractive alternative to cope with water shortage in the region.

  6. Treated wastewater effects on water repellency and soil hydraulic properties of soil aquifer treatment infiltration basins

    NASA Astrophysics Data System (ADS)

    Arye, Gilboa; Tarchitzky, Jorge; Chen, Yona

    2011-01-01

    SummaryIrrigation with treated wastewater (TWW) has been reported to induce low to moderate hydrophobicity in soils of different texture with or without vegetation cover. Additional potential sites for adverse effects of TWW are infiltration basins, where TWW undergoes tertiary treatment, known as soil aquifer treatment (SAT). The annual organic matter (OM) loads in SAT are a hundred fold higher than those applied in irrigation with TWW. Therefore, we initially presumed that in the sandy soils of SAT infiltration basins, hydrophobicity would be expressed to a higher extent and would further affect the hydraulic properties of these soils. This hypothesis was tested in the Dan Region Wastewater Reclamation Project, Tel-Aviv, Israel. In terms of water drop penetration time (WDPT) test, the results obtained exhibited similar hydrophobicity levels (0 ⩽ WDPT ⩽ 238 s) to those obtained in the TWW irrigated fields and in a similar manner, soil hydrophobicity was only exhibited in the surface soil layer. It is suggested that the low to moderate hydrophobicity obtained under TWW irrigation and recharge into the SAT basins, may primarily stem from the drying and wetting cycle regimes employed. Under these conditions, hydrophobic compounds, which may impart hydrophobicity to the soil particles, are likely to detach and dissolve into the soil solution at the subsequent irrigation or recharge event. Furthermore, the frequent displacement of the resident TWW derived OM by repeatedly flooding events, prevents maturation and humification of the resident OM. Further investigations on the hydraulic properties of the basin soils were conducted in conjunction with the solid-liquid contact angle ( ω) and the surface tension ( γL) of the soil solution. The results obtained imply that the dependence of the hydraulic properties on ω and/or γL, can be attributed to the hydrophobic nature of both the solid and dissolved OM originating from the recharged TWW.

  7. 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.

  8. Mobility, longevity and activity of chlorfenapyr in soils treated at a termiticidal rate.

    PubMed

    Peterson, Chris J; Davis, Robert W

    2013-01-01

    The mobility, longevity and termiticidal activity of chlorfenapyr applied to soils at the termiticidal labeled rate was evaluated for 30 months after treatment (MAT) in a greenhouse study. There was little dissipation of chlorfenapyr in soil treated at the labeled rate for perimeter treatments for the prevention and control of termite infestations. Chlorfenapyr was detected in soil immediately below the initially treated soil in the packed soil columns. This was likely due to settling of soil. The treated soil remained toxic to subterranean termites in 3 and 7 day bioassays over the duration of the study. The treated soil displayed slow-acting properties regarding toxicity to termites. Trace amounts of chlorfenapyr were detected in the eluates of packed soil cones. The commercial formulation of chlorfenapyr used in this study (21.45% concentrate diluted to 0.125% prior to application) killed 100% of the tested subterranean termites for at least 30 months. Copyright © 2012 Society of Chemical Industry.

  9. 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 Central

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

    2014-01-01

    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. PMID:25498806

  10. Magnetic properties and heavy metal pollution of soils in the vicinity of a cement plant, Xuzhou (China)

    NASA Astrophysics Data System (ADS)

    Wang, Xue Song

    2013-11-01

    This study characterized the magnetic property and levels of heavy metals of the topsoils near a cement plant. The concentrations of five selected heavy metals (Pb, Cu, Zn and Cd) were measured on 32 topsoil samples (0-20 cm) collected near a cement plant via inductively coupled plasma/mass spectroscopy (ICP-MS). The orders of enrichment factors (EF), on average, were Cd (7.3) > Cu (3) > Zn (2.9) > Pb (2.1), respectively. A self-organizing map (SOM) was applied to the concentrations of heavy metals for “correlation hunting”. Mineral magnetic concentration parameters, such as the specific magnetic susceptibility (χ), susceptibility of anhysteretic remanent magnetization (χARM), saturation isothermal remanent magnetization (SIRM), together with interparametric ratios (such as IRM- 100mT/SIRM, SIRM/χ, χARM/SIRM) show that ferrimagnetic, superparamagnetic (SP) and multi-domain (MD) minerals dominated the soils. The results of correlation analysis indicate that copper showed a significant correlation with χ, χARM and SIRM but such a relationship with χ, χARM and SIRM was only weakly identified for Zn, Cd and Pb.

  11. 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.

  12. 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

  13. Dynamics of soil organic carbon and microbial activity in treated wastewater irrigated agricultural soils along soil profiles

    NASA Astrophysics Data System (ADS)

    Jüschke, Elisabeth; Marschner, Bernd; Chen, Yona; Tarchitzky, Jorge

    2010-05-01

    Treated wastewater (TWW) is an important source for irrigation water in arid and semiarid regions and already serves as an important water source in Jordan, the Palestinian Territories and Israel. Reclaimed water still contains organic matter (OM) and various compounds that may effect microbial activity and soil quality (Feigin et al. 1991). Natural soil organic carbon (SOC) may be altered by interactions between these compounds and the soil microorganisms. This study evaluates the effects of TWW irrigation on the quality, dynamics and microbial transformations of natural SOC. Priming effects (PE) and SOC mineralization were determined to estimate the influence of TWW irrigation on SOC along soil profiles of agricultural soils in Israel and the Westbank. The used soil material derived from three different sampling sites allocated in Israel and The Palestinian Authority. Soil samples were taken always from TWW irrigated sites and control fields from 6 different depths (0-10, 10-20, 20-30, 30-50, 50-70, 70-100 cm). Soil carbon content and microbiological parameters (microbial biomass, microbial activities and enzyme activities) were investigated. In several sites, subsoils (50-160 cm) from TWW irrigated plots were depleted in soil organic matter with the largest differences occurring in sites with the longest TWW irrigation history. Laboratory incubation experiments with additions of 14C-labelled compounds to the soils showed that microbial activity in freshwater irrigated soils was much more stimulated by sugars or amino acids than in TWW irrigated soils. The lack of such "priming effects" (Hamer & Marschner 2005) in the TWW irrigated soils indicates that here the microorganisms are already operating at their optimal metabolic activity due to the continuous substrate inputs with soluble organic compounds from the TWW. The fact that PE are triggered continuously due to TWW irrigation may result in a decrease of SOC over long term irrigation. Already now this could be

  14. A resin-modified glass ionomer cement barrier for treating degree II furcation defects: a pilot study in dogs.

    PubMed

    Miranda, Letícia Algarves; Gomes, Sabrina Carvalho; Soares, Ilson José; Oppermann, Rui Vicente

    2006-02-01

    The aim of this study was to evaluate in an animal model the healing of degree II furcation defects treated with: an experimental barrier of resin-modified glass-ionomer cement (GIC), a polylactic acid barrier (GUI), and flap surgery (CTR). In 3 beagles, 18 class II furcation defects were surgically produced in mandibular and maxillary premolars and exposed to plaque accumulation for 21 days. Following a full flap, notches were made at the base to the bone defect. GIC barriers were prepared immediately before use from a commercial product and fit to place with the same product. The GIC barriers were removed after 30 days and the dogs euthanized after 120 days. Histologic sections were analyzed in a computer-assisted microscope. Epithelium, new cementum with inserting fibers, and connective tissue lining the root surface in-between notches were measured and medians of percentage values calculated. In the GIC, epithelium constituted 3.5% (median values) of the notch-to-notch root area; new cementum was 83.6% and connective tissue 12.9%. These values were 0%, 73.6%, and 26.4% for the GUI group and 35.6%, 43.2%, and 0% for the CTR group. Bone fill median values were 54.3% for GIC, 20.6% for GUI, and 24.6% for CTR. GIC and GUI prevented epithelial migration and promoted the formation of new periodontal tissues in experimentally induced class II furcation defects in dogs.

  15. Petroleum sludge treatment and reuse for cement production as setting retarder

    NASA Astrophysics Data System (ADS)

    Aeslina, A. K.; Ali, B.

    2017-05-01

    Petroleum sludge is a dangerous waste that needs to be treated to avoid any contamination of soil and groundwater due to its disposal. As an attempt to treat this waste, it has been incorporated into cement production as substitution for gypsum. As results, 5% of petroleum sludge has shown effective results and could play the same role of gypsum in delaying the flash setting of cement clinker.

  16. 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.

  17. Phenanthrene removal from soil slurries with surfactant-treated oxides

    SciTech Connect

    Park, J.W.; Jaffe, P.R.

    1995-06-01

    A soil-slurry washing technique to decontaminate soils containing low-solubility nonionic organic pollutants was investigated, using phenanthrene as a model pollutant. The technique is based on first transferring the sorbed phenanthrene from the soil to anionic surfactant-coated oxide particles, and then separating these anionic surfactant-coated oxide particles with the sorbed phenanthrene from the soil slurry via a magnetic separation technique. The decontamination of two soils with different particle sizes and soil organic matter content was investigated. The proposed soil-slurry washing technique was effective in removing a strongly sorbing nonionic organic contaminant from soil slurries. Various operational scenarios of multistage soil-slurry reactors were evaluated with a mathematical model.

  18. High abundance and role of antifungal bacteria in compost-treated soils in a wildfire area.

    PubMed

    Kim, Yong-Hak; Kim, In Sung; Moon, Eun Young; Park, Jeong Soo; Kim, Sang-Jong; Lim, Joo-Hoon; Park, Byung Tae; Lee, Eun Ju

    2011-10-01

    Compost has been widely used in order to promote vegetation growth in post-harvested and burned soils. The effects on soil microorganisms were scarcely known, so we performed the microbial analyses in a wildfire area of the Taebaek Mountains, Korea, during field surveys from May to September 2007. Using culture-dependent and -independent methods, we found that compost used in burned soils influenced a greater impact on soil fungi than bacteria. Compost-treated soils contained higher levels of antifungal strains in the genera Bacillus and Burkholderia than non-treated soils. When the antifungal activity of Burkholderia sp. strain O1a_RA002, which had been isolated from a compost-treated soil, was tested for the growth inhibition of bacteria and fungi isolated from burned soils, the membrane-filtered culture supernatant inhibited 19/37 fungal strains including soil fungi, Eupenicillium spp. and Devriesia americana; plant pathogens, Polyschema larviformis and Massaria platani; an animal pathogen, Mortierella verticillata; and an unidentified Ascomycota. However, this organism only inhibited 11/151 bacterial strains tested. These patterns were compatible with the culture-independent DGGE results, suggesting that the compost used in burned soils had a greater impact on soil fungi than bacteria through the promotion of the growth of antifungal bacteria. Our findings indicate that compost used in burned soils is effective in restoring soil conditions to a state closer to those of nearby unburned forest soils at the early stage of secondary succession.

  19. 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...

  20. 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...

  1. 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. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. 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…

  3. 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…

  4. Vegetation on the Soil Infiltration System Treating Livestock Wastewater

    NASA Astrophysics Data System (ADS)

    Sakurai, Shinji; Fujikawa, Yoko; Fukui, Masami; Hamasaki, Tastuhide; Sugahara, Masataka

    In the overland flow wastewater treatments and the constructed wetlands, the purification by soil infiltration units is enhanced using vegetation. However, wetland plants (i.e. cattail (Typha latifolia)) and trees, rather than agronomic crops, have been used in conventional systems. We carried out laboratory-scale soil infiltration experiments using two forage crops, tall fescue (Festuca araundinacea) and white clover (Trifolium repens) while using livestock wastewater for irrigation. The purpose of the study was to clarify the amount of accumulation of available phosphorus and exchangeable cations in the soil and its effect on the plant growth. The application of livestock wastewater increased available phosphorus, and exchangeable potassium and sodium in the upper soil. The soil sodification, examined based on exchangeable sodium ratio and plant growth, was not very significant after 10 months of livestock wastewater application. Growing forage crops on the soil infiltration system may be a promising technology to improve crop production and treatment efficacy.

  5. 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.

  6. 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.

  7. Bond Strength of Resin Cement and Glass Ionomer to Nd:YAG Laser-Treated Zirconia Ceramics.

    PubMed

    Asadzadeh, Nafiseh; Ghorbanian, Foojan; Ahrary, Farzaneh; Rajati Haghi, Hamidreza; Karamad, Reza; Yari, Amir; Javan, Abdollah

    2017-09-05

    To investigate the effect of neodymium-doped yttrium aluminum garnet (Nd:YAG) laser irradiation on the surface properties and bond strength of zirconia ceramics. Forty-eight zirconia ceramic pieces (4 × 4 × 1 mm(3) ) were divided into four groups according to surface treatment as follows: two control groups (no treatment) for resin bonding (CRC) and glass ionomer (GI) bonding (CGC); two laser treatment groups (Nd:YAG irradiation, 3 W, 200 MJ, 10 Hz, 180 μs) for resin bonding (LRC) and GI bonding (LGC). The ceramics in the control groups and the laser groups were distinguished by the application of different cements (resin cement and GI). Following surface treatments, the specimens were cemented to human dentin with resin cement and GI. After bonding, the shear bond strength (SBS) of the ceramic to dentin was measured, and the failure mode of each specimen was analyzed using a stereomicroscope. A one-way ANOVA compared the average bond strength of the four groups. Pairwise comparisons among the groups were performed using the Games-Howell test. The level of significance was set at 0.05. The means (± standard deviation) of SBS values in the CRC, CGC, LRC, and LGC groups were 3.98 ± 1.10, 1.66 ± 0.59, 10.24 ± 2.46, and 2.21 ± 0.38 MPa, respectively. Data showed that the application of the Nd:YAG laser resulted in a significantly greater SBS of the resin cement to the zirconia ceramics (p < 0.001). The highest bond strength was recorded in the LRC group. In the CRC group, 75% of the failures were of the adhesive type, compared with 66.7% and 83.3% in the LRC and LGC groups, respectively. In the CGC group, all failures were adhesive. Pretreatment of zirconia ceramic via Nd:YAG laser improves the bond strength of the resin cement to the zirconia ceramic. GI cement does not provide sufficient bond strength of zirconia ceramics to dentin. © 2017 by the American College of Prosthodontists.

  8. 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

  9. 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.

  10. Effects of compost and phosphate on plant arsenic accumulation from soils near pressure-treated wood.

    PubMed

    Cao, Xinde; Ma, Lena Q

    2004-12-01

    Leaching of arsenic (As) from chromated copper arsenate (CCA)-treated wood may elevate soil arsenic levels. Thus, an environmental concern arises regarding accumulation of As in vegetables grown in these soils. In this study, a greenhouse experiment was conducted to evaluate As accumulation by vegetables from the soils adjacent to the CCA-treated utility poles and fences and examine the effects of soil amendments on plant As accumulation. Carrot (Daucus carota L.) and lettuce (Lactuca sativa L.) were grown for ten weeks in the soil with or without compost and phosphate amendments. As expected, elevated As concentrations were observed in the pole soil (43 mg kg(-1)) and in the fence soil (27 mg kg(-1)), resulting in enhanced As accumulation of 44 mg kg(-1) in carrot and 32 mg kg(-1) in lettuce. Addition of phosphate to soils increased As accumulation by 4.56-9.3 times for carrot and 2.45-10.1 for lettuce due to increased soil water-soluble As via replacement of arsenate by phosphate in soil. However, biosolid compost application significantly reduced plant As uptake by 79-86%, relative to the untreated soils. This suppression is possibly because of As adsorbed by biosolid organic mater, which reduced As phytoavailability. Fractionation analysis showed that biosolid decreased As in soil water-soluble, exchangeable, and carbonate fraction by 45%, whereas phosphate increased it up to 2.61 times, compared to the untreated soils. Our results indicate that growing vegetables in soils near CCA-treated wood may pose a risk of As exposure for humans. Compost amendment can reduce such a risk by reducing As accumulation by vegetables and can be an important strategy for remediating CCA-contaminated soils. Caution should be taken for phosphate application since it enhances As accumulation.

  11. 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....

  12. Considerations in Deciding to Treat Contaminated Unsaturated Soils In Situ

    EPA Pesticide Factsheets

    The purpose of this Issue Paper is to assist the user in deciding if in situ treatment of contaminated soil is a potentially feasible remedial alternative and to assist in the process of reviewing and screening in situ technologies.

  13. 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....

  14. 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.

  15. Treat PCB-laden soils with acetone and polystyrene beads

    SciTech Connect

    1995-11-01

    In a typical solvent-extraction process, polychlorinated biphenyls (PCBs), polyaromatic hydrocarbons (PAHs) and other nonvolatile organic compounds are transferred from a solid medium (i.e., soil) to a liquid medium. The solvent is then distilled, and the contaminant-free sludge is disposed. However, capital and operating costs can be steep because solvent-extraction systems require several processing steps, and the solvent must ultimately be distilled or reclaimed for reuse in the system. To overcome these drawbacks, Envirogen, Inc. (Lawrenceville, N.J.) has recently developed a two-step, solvent-extraction process, which uses a small amounts of solvent to extract organic contaminants from soil, and then adsorbs these contaminants onto a solid, polystyrene substrate, for cheaper recovery. To date, the technology, dubbed Solid Organic Phase Extraction (SOPE) has been field tested on PCB-laden soils, and has achieved a removal efficiency of 99%, says the firm, adding that it is suitable for any hydrophobic contaminants.

  16. 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.

  17. Soil chemistry adjacent to roads treated with dust control products at Squaw Creek National Wildlife Refuge

    USGS Publications Warehouse

    Kunz, Bethany K.

    2016-01-01

    The health of soils along roadways is critical for maximizing habitat quality and minimizing negative ecological effects of roads. Adjacent to unpaved roads, soil chemistry may be altered by the deposition of dust, as well as by road treatment with dust suppressants or soil stabilizer products. If present in roadside soils, these product residues may be available to plants, terrestrial invertebrates, or small mammals. Unfortunately, very few studies have attempted to track the transport of dust suppressants after application. As part of a larger ongoing study on the environmental effects of dust suppressant products on roadside plants and animals, we sampled roadside soils at Squaw Creek National Wildlife Refuge (NWR). Replicated road sections at Squaw Creek NWR had been previously treated with two road products—calcium chloride-based durablend-C™ and synthetic iso-alkane EnviroKleen®. In order to quantify the effect of dust suppressant treatment on roadside soils, we took replicated composite soil samples one year after treatment at 1m and 4m from the road’s edge, and analyzed samples for a suite of soil chemistry variables (pH, conductivity, NO3-N, P, K, Ca, Mg, Na and S). We also assessed dust suppressant product residues in the soil. For durablend-C™, we used soil conductivity as an indicator. For EnviroKleen®, we developed a method for extraction and isolation, followed by analysis with gas chromatography/mass spectrometry to look for a specific EnviroKleen® signature. Surprisingly, soil conductivity was not elevated adjacent to road sections treated with durablend-C™, relative to other sections. EnviroKleen® was detectable at both 1m and 4m from treated sections at concentrations from 1 to 1500 mg/kg, and was non-detectable in soils adjacent to the untreated section. The most notable characteristic of soils across all treated and untreated sections at 1m was elevated calcium (up to 30,000 mg/kg), likely as a result of dust deposition from the

  18. 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.

  19. 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.

  20. 1-D Compression Behaviour of Acid Sulphate Soils Treated with Alkali-Activated Slag

    PubMed Central

    Islam, Shahidul; Haque, Asadul; Bui, Ha Hong

    2016-01-01

    Improvements of soft soils by mechanically mixing cementitious additives have been widely practised for construction of infrastructure. Mixing of additives improves strength and compressibility properties of soils through the development of soil structure. This study investigates the 1-D compression behaviour of alkali-activated slag treated acid sulphate soils (ASS) cured up to 365 days. The void ratio-logarithm of pressure (e-logσ′) behaviour of treated ASS, including the destructuration behaviour, with additive contents and curing time have been analysed. X-ray diffraction (XRD) and scanning electron microscopy (SEM) analyses have been undertaken to explain the observed variations of the 1-D compression behaviour. This paper presents the results of these analyses in view of obtaining an insight into the 1-D compression behaviour of treated ASS with the help of mineralogical analysis. PMID:28773415

  1. Soil surface colonization by phototrophic indigenous organisms, in two contrasted soils treated by formulated maize herbicide mixtures.

    PubMed

    Joly, Pierre; Misson, Benjamin; Perrière, Fanny; Bonnemoy, Frédérique; Joly, Muriel; Donnadieu-Bernard, Florence; Aguer, Jean-Pierre; Bohatier, Jacques; Mallet, Clarisse

    2014-11-01

    Soil phototrophic microorganisms, contributors to soil health and food webs, share their particular metabolism with plants. Current agricultural practices employ mixtures of pesticides to ensure the crops yields and can potentially impair these non-target organisms. However despite this environmental reality, studies dealing the susceptibility of phototrophic microorganisms to pesticide mixtures are scarce. We designed a 3 months microcosm study to assess the ecotoxicity of realistic herbicide mixtures of formulated S-metolachlor (Dual Gold Safeneur(®)), mesotrione (Callisto(®)) and nicosulfuron (Milagro(®)) on phototrophic communities of two soils (Limagne vertisol and Versailles luvisol). The soils presented different colonizing communities, with diatoms and chlorophyceae dominating communities in Limagne soil and cyanobacteria and bryophyta communities in Versailles soil. The results highlighted the strong impairment of Dual Gold Safeneur(®) treated microcosms on the biomass and the composition of both soil phototrophic communities, with no resilience after a delay of 3 months. This study also excluded any significant mixture effect on these organisms for Callisto(®) and Milagro(®) herbicides. We strongly recommend carrying on extensive soil studies on S-metolachlor and its commercial formulations, in order to reconsider its use from an ecotoxicological point of view.

  2. Soil water repellency induced by long-term irrigation with treated sewage effluent.

    PubMed

    Wallach, R; Ben-Arie, O; Graber, E R

    2005-01-01

    This study describes soil water repellency developed under prolonged irrigation with treated sewage effluent in a semiarid environment. Soil surface layer (0-5 cm) and soil profile (0-50 cm) transects were sampled at a high resolution at the close of the irrigation season and rainy winter season. Samples from 0- to 5-cm transects were subdivided into 1-cm slices to obtain fine scale resolution of repellency and organic matter distribution. Extreme to severe soil water repellency in the 0- to 5-cm soil surface layer persisted throughout the 2-yr study period in the effluent-irrigated Shamouti orange [Citrus sinensis (L.) Osbeck cv. Shamouti] orchard plot. Nearby Shamouti orange plots irrigated with tap water were either nonrepellent or only somewhat repellent. Repellency was very variable spatially and with depth, appearing in vertically oriented "repellency tongues." Temporal and spatial variability in repellency in the uppermost 5-cm soil surface layer was not related to seasonality, soil moisture content, or soil organic matter content. Nonuniform distribution of soil moisture and fingered flow were observed in the soil profile after both seasons, demonstrating that the repellent layer had a persistent effect on water flow in the soil profile. A lack of correlation between bulk density and volumetric water content in the soil profile demonstrates that the observed nonuniform spatial distribution of moisture results from preferential flow and not heterogeneity in soil properties. Soil water repellency can adversely affect agricultural production, cause contamination of underlying ground water resources, and result in excessive runoff and soil erosion.

  3. Long-term soil accumulation of chromium, copper, and arsenic adjacent to preservative-treated wood.

    Treesearch

    S. Lebow; D. Foster; J. Evans

    2004-01-01

    Chromated copper arsenate (CCA) treated wood has been used extensively in outdoor applications. The Environmental Protection Agency (EPA) and CCA producers recently reached an agreement to limit future use of CCA for some types of applications. One area of concern is the long-term accumulation of leached CCA in soil adjacent to treated wood structures. Interpreting...

  4. 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.

  5. Bone cement

    PubMed Central

    Vaishya, Raju; Chauhan, Mayank; Vaish, Abhishek

    2013-01-01

    The knowledge about the bone cement is of paramount importance to all Orthopaedic surgeons. Although the bone cement had been the gold standard in the field of joint replacement surgery, its use has somewhat decreased because of the advent of press-fit implants which encourages bone in growth. The shortcomings, side effects and toxicity of the bone cement are being addressed recently. More research is needed and continues in the field of nanoparticle additives, enhanced bone–cement interface etc. PMID:26403875

  6. 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.

  7. 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.

  8. Bioventing to treat hydrocarbon contaminated soils in Alaska

    SciTech Connect

    Marlow, H.J. Jr.; Muniz, H.R.; Geyer, D.J.

    1995-12-31

    Hart Crowser has designed or is currently operating 9 in situ and 6 ex situ bioventing systems in various locations throughout the state of Alaska. The objective of these projects was to design, install, and operate a remediation system capable of reducing the existing petroleum hydrocarbon levels to below the Alaska Department of Environmental Conservation clean-up action levels. Prior to the design of the bioventing systems, Hart Crowser initiated site investigations including soil borings and installation of monitoring wells to determine site geological characteristics, and the extent of the hydrocarbon impacted soils. Laboratory biofeasibility testing or in situ respirometry testing was accomplished to determine the biological activity at the sites and provide information to optimize the remedial design. Degradation rates for the various sites ranged from 0.92 mgkg{sup -1}d{sup -1} to 17.6 mgkg{sup -1}d{sup -1}. Three in situ bioventing case studies will be presented. The results of treatability testing, considerations for the design of the bioventing systems, systems installation, and the results from two years of operation will be outlined.

  9. 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

  10. 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.

  11. Biodegradability of pharmaceutical compounds in agricultural soils irrigated with treated wastewater.

    PubMed

    Grossberger, Amnon; Hadar, Yitzhak; Borch, Thomas; Chefetz, Benny

    2014-02-01

    Pharmaceutical compounds (PCs) are introduced into agricultural soils via irrigation with treated wastewater (TWW). Our data show that carbamazepine, lamotrigine, caffeine, metoprolol, sulfamethoxazole and sildenafil are persistent in soils when introduced via TWW. However, other PCs, namely diclofenac, ibuprofen, bezafibrate, gemfibrozil and naproxen were not detected in soils when introduced via TWW. This is likely due to rapid degradation as confirmed in our microcosm studies where they exhibited half-lives (t1/2) between 0.2-9.5 days when soils were spiked at 50 ng/g soil and between 3 and 68 days when soils were spiked at 5000 ng/g soil. The degradation rate and extent of PCs observed in microcosm studies were similar in soils that had been previously irrigated with TWW or fresh water. This suggests that pre-exposure of the soils to PCs via irrigation with TWW does not enhance their biodegradation. This suggests that PCs are probably degraded in soils via co-metabolism. Copyright © 2013 Elsevier Ltd. All rights reserved.

  12. 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. Copyright © 2012 Wiley Periodicals, Inc.

  13. 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

  14. Nitrous oxide fluxes and soil oxygen dynamics of soil treated with cow urine

    USDA-ARS?s Scientific Manuscript database

    Ruminant urine deposition onto pastures creates hot-spots where emissions of nitrous oxide (N2O) are produced by aerobic and anaerobic microbial pathways. However, limited measurements of in situ soil oxygen (O2)-N2O relationships hinder the prediction of N2O emissions from urine-affected soil. This...

  15. 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.

  16. In vitro gastrointestinal bioavailability of arsenic in soils collected near CCA-treated utility poles.

    PubMed

    Pouschat, Priscilla; Zagury, Gerald J

    2006-07-01

    Because of the potentially high arsenic concentrations found in soils immediately adjacent to chromated copper arsenate (CCA)-treated wood structures and utility poles, CCA-contaminated soil ingestion may be a significant exposure route to arsenic for children. Therefore, a strong need exists to provide accurate data on oral relative bioavailability (RBA) of arsenic (in vivo or in vitro) in field-collected CCA-contaminated soils. The objectives of this study were (1) to assess arsenic bioaccessibility in contaminated soils collected near in-service CCA-treated utility poles, (2) to determine the influence of soil properties and arsenic fractionation on arsenic bioaccessibility, and (3) to estimate an average daily arsenic intake from incidental soil ingestion. Arsenic bioaccessibility (in vitro gastrointestinal (IVG) method) was determined on surface soil samples collected immediately adjacent to 12 CCA-treated utility poles after 18 months of service. Bioaccessible arsenic was also determined in 3 certified reference materials. Total arsenic concentrations in soils (<300 microm) varied from 37 +/- 2 to 251 +/- 12 mg/kg, irrespective of soil organic matter contentwith the major soil-bound arsenic species being As(V). Arsenic bioaccessibility ranged between 25.0 +/- 2.7 and 66.3 +/- 2.3% (mean value 40.7 +/- 14.9%). The mean value was in agreement with the in vivo arsenic RBA reported by Casteel et al. (2003) in soil near CCA-treated utility poles. Bioaccessible arsenic was positively correlated with total organic carbon content (r2 = 0.36, p < 0.05) and with water-soluble arsenic (2 = 0.51, p < 0.01), and was negatively correlated with clay content (r2 = 0.43, p < 0.05). Using conservative exposure parameters, the mean daily arsenic intake from incidental ingestion of contaminated soil near CCA-treated utility poles was 0.18 +/- 0.09 microg As kg(-1) d(-1). This arsenic intake appeared negligible compared to the daily intake of inorganic arsenic from water and food

  17. 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.

  18. 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. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Soil organic carbon of degraded wetlands treated with freshwater in the Yellow River Delta, China.

    PubMed

    Wang, Hui; Wang, Renqing; Yu, Yue; Mitchell, Myron J; Zhang, Lianjun

    2011-10-01

    Supplying freshwater is one of the important methods to help restore degraded wetlands. Changes in soil properties and plant community biomass were evaluated by comparing sites with freshwater treatment versus reference sites following freshwater addition to wetlands of the Yellow River Delta for 7 years. The results indicated that soil organic carbon (SOC) was significantly increased in all wetland sites that were treated with freshwater compared to the reference sites. The treatment wetlands had greater total nitrogen (TN), lower pH and electrical conductivity and higher water content in the soil compared to the reference wetlands. In general, the upper soil layer (0-20 cm) had greater SOC than the lower soil layer (20-40 cm). The increase of SOC in the freshwater reintroduction wetlands was higher in the Suaeda salsa plant community (mean ± standard error) (6.89 ± 0.63 g/kg) and Phragmites communis plant community (4.11 ± 0.12 g/kg) than in the Tamarix chinensis plant community (1.40 ± 0.31 g/kg) in the upper soil layer. The differences were especially marked between the treated and reference wetlands for SOC and TN in the P. communis plant communities. The C:N ratio of the soil was significantly greater in the treated compared to the reference wetlands for the S. salsa plant community. Although the C: N ratios increased after treatment, they were all <25 suggesting that N availability was not limiting soil organic matter decomposition. Our results indicate that freshwater addition and the concomitant increase in soil moisture content enhances the accumulation of SOC in the Yellow River Delta. Copyright © 2011 Elsevier Ltd. All rights reserved.

  20. Irrigation with treated wastewater: effects on soil, lettuce (Lactuca sativa L.) crop and dynamics of microorganisms.

    PubMed

    Mañas, Pilar; Castro, Elena; de Las Heras, Jorge

    2009-10-01

    The aim of this study was to evaluate the applicability of treated wastewater for horticultural crops, assess the effects of continuous use of treated water on soil and crops, and analyse the physical, chemical and biological effects of irrigation with recycled water. Two lettuce plots watered with drinking water and treated wastewater were monitored over a three year period. Nutrients, heavy metal and the dynamics of pathogen and indicator microorganism content in soil and foliar tissues were analysed. Wastewater irrigation had a high influence on soil parameters: organic matter, N, P, Ca, Al, Fe, Pb and Zn. Indicator and pathogenic microorganisms were detected in soil and plants grown in the wastewater-irrigated plot, and persisted in the soil for 27 days during the study under humid conditions. N, P, Pb and Al content were significantly higher in plant tissues of wastewater-irrigated plots than in the control after 3 years of irrigation. Harvest was significantly higher in the wastewater-irrigated plot. Wastewater can be a resource for agricultural irrigation. In any case, the possible heavy metal accumulation in soils and presence of pathogenic organisms require careful management of this alternative resource: use of a drip irrigation system, previous wastewater disinfection and a limited irrigation period are recommended.

  1. Leachate Properties and Cadmium Migration Through Freeze-thaw Treated Soil Columns.

    PubMed

    Xu, Meng; Zheng, Yue; Chen, Weiwei; Mao, Na; Guo, Ping

    2017-01-01

    Soil column leaching experiments were conducted to study the effects of multiple freeze-thaw cycles on the vertical migration of cadmium (Cd). Three Cd-spiked leaching solutions of different properties were derived from snowmelt, sludge, and straw, designated as B, W and J, respectively. The leaching solutions varied in dissolved organic matter (DOM) concentrations in the order of J > W > B. Changes in leachate properties and Cd concentration were observed. The results showed that pH values of all the leachate solutions through freeze-thaw treated soil columns were higher than those of leachates through unfrozen soils. However, electrical conductivity (EC) values decreased compared with leachates in unfrozen treated soil columns. Although the concentrations of DOM in leachate solutions had no evident differences between the freeze-thaw and unfrozen treated soil columns, the concentrations of DOM in the leachate solutions B, W and J were different. Freeze-thaw cycles resulted in increased concentrations of Cd in the leachate solutions in the order J > W > B, and promoted a deeper migration of Cd in the soil columns. Thus, it was shown that freeze-thaw cycles may increase the risk of groundwater pollution by Cd.

  2. Effects of treated wastewater irrigation on contents and dynamics of soil organic carbon and microbial activity

    NASA Astrophysics Data System (ADS)

    Jüschke, E.; Marschner, B.; Chen, Y.; Tarchitzky, J.

    2009-04-01

    In many arid and semi-arid regions, the demand for freshwater as drinking water and other domestic uses is constantly growing due to demographic growth and increasing standard of living. Therefore, less freshwater is available for agricultural irrigation and new water sources are needed. Treated wastewater (TWW) already serves as an important water source in Jordan, the Palestinian Territories and Israel. Related to its high loads with nutrients, salts and organic materials within its use as irrigation water major effects on the soil physical and chemical properties can occur, in the worst case leading to soil degradation. In an ongoing study we are investigated in the effects of TWW irrigation on agricultural soils in the region. Here we present results from analyses of total soil carbon contents and qualities in soils irrigated with freshwater and TWW. Furthermore microbiological parameters were investigated as microbial biomass, microbial activities and enzyme activities. In several sites, subsoils (50-160 cm) from TWW irrigated plots were depleted in soil organic matter with the largest differences occurring in sites with the longest TWW irrigation history. Laboratory incubation experiments with additions of 14C-labelled compounds to the soils showed that microbial activity in freshwater irrigated soils was much more stimulated by sugars or amino acids than in TWW irrigated soils. The lack of such "priming effects" (Hamer & Marschner 2005) in the TWW irrigated soils indicates that here the microorganisms are already operating at their optimal metabolic activity due to the continuous substrate inputs with soluble organic compounds from the TWW. Apparently, this higher microbial activity is causing an increased depletion of soil organic matter, which may have negative long-term effects on soil quality.

  3. 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. Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. Physiological traits and antioxidant metabolism of leaves of tropical woody species challenged with cement dust.

    PubMed

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

    2017-10-01

    Tropical woody species occurring in limestone outcrops are frequently exposed to particulate material from cement factories. The effects of 60-day cement dust exposure on physiological traits and enzymatic antioxidant system of young plant leaves of Guazuma ulmifolia Lam., Myracrodruon urundeuva Allemão and Trichilia hirta L. were investigated. Cement dust (2.5 or 5mgcm(-2)) was applied to the leaf surface or soil or both (leaf plus soil) and plants were maintained at greenhouse. Cement dust barely affected the mineral nutrient levels, except for iron whose content was decreased in leaves/leaflets of all species studied. The incident light was partly blocked in cement dust-treated leaves, regardless of the plant species, causing a decrease in the photosynthetic pigments in M. urundeuva. The chlorophyll b content, however, increased in G. ulmifolia and T. hirta leaves upon cement dust treatment. The potential quantum yield of photosystem II in challenged leaves of G. ulmifolia was 3.8% lower than that of control plants, while such trait remained unaffected in the leaves of the other species. No changes in leaf stomatal conductance and antioxidant enzymes activities were observed, except for M. urundeuva, which experienced a 31% increment in the superoxide dismutase activity upon 5mgcm(-2) cement dust (leaf plus soil treatment), when compared with control plants. Overall, the mild changes caused by cement dust in the in physiological and biochemical traits of the species studied indicate that such species might be eligible for further studies of revegetation in fields impacted by cement factories. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. 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

    2012-05-09

    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.

  6. 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.

  7. The effect of glass ionomer cement or composite resin bases on restoration of cuspal stiffness of endodontically treated premolars in vitro.

    PubMed

    Hofmann, N; Just, N; Haller, B; Hugo, B; Klaiber, B

    1998-06-01

    The purpose of the present study was to decide whether composite resin or conventional glass ionomer cement should be preferred as a base material in endodontically treated premolars. Twelve extracted human maxillary premolars were mounted in a universal testing machine at a 35 degrees angle. Cuspal stiffness was determined by applying a load of 75 N to the buccal cusp and recording the displacement of the cusp using inductive displacement transducers. In the same teeth, different cavity preparations and restorations were performed sequentially. Standard MOD cavities were enlarged to allow endodontic access. In addition, the cusps were undermined. Half of the teeth were restored to the level of the previous shallow cavities using conventional glass ionomer cement (Ketac Fil), in the rest of the teeth dentine bonding agent (Syntac) and composite resin (Tetric) were used instead. Finally, composite resin fillings (Tetric) were placed. All restorations were removed and the experiments were repeated twice. For each replication, the assignment of the base materials to the experimental groups was reversed, and ceramic inlays (Empress) were used as final restorations for the last replication. Improvement of cuspal stiffness achieved by conventional glass ionomer bases was very small, whereas composite resin bases increased cuspal stability by more than a factor of two. After placement of the final restorations, however, there was no longer a difference between teeth with different base materials. Nevertheless, composite resin bases might be preferred for two reasons. Firstly, deterioration of adhesive restorations will probably start at the cavosurface margins. The incidence of margin gaps, however, will not only compromise marginal seal but also the stabilizing effect of the restoration. In this situation, the resin base may still stabilize the tooth. Moreover, resin bases may reduce the risk of cusp fracture during the time between cavity preparation and the insertion

  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. Shear bond strength of resin-modified glass ionomer cements to Er:YAG laser-treated tooth structure.

    PubMed

    de Souza-Gabriel, Aline Evangelista; do Amaral, Flávia Lucisano Botelho; Pécora, Jesus Djalma; Palma-Dibb, Regina Guenka; Corona, Silmara Aparecida Milori

    2006-01-01

    This study evaluated the effect of Er:YAG laser irradiation of enamel and dentin on the shear bond strength of resin-modified glass ionomer cements (RMGIC). Twenty molars were selected and the roots removed. The crowns were bisected, embedded in polyester resin and ground to plane the enamel or expose the dentin. The bonding site was delimited, and samples were randomly assigned according to the cavity preparation device: I--Er.YAG laser (350mJ/2Hz); II--Carbide bur (control group). They were subdivided according to the restorative material employed: A) Fuji II LC (GC); B) Vitremer (3M). Samples were then fixed to a metallic device where ionomer cylinders were prepared. Sequentially, the molars were stored for 24 hours and subjected to a shear bond strength test (50Kgf at 0.5 mm/minute). Means in MPa were: Enamel--IA) 4.77 (+/- 1.12); IB) 4.36 (+/- 1.50); IIA) 7.70 (+/- 1.53); IIB) 7.34 (+/- 1.52) and Dentin--IA) 3.13 (+/- 1.15); IB) 2.67 (+/- 0.74); IIA) 6.38 (+/- 1.44); IIB) 5.58 (+/-2.09). Data were submitted to statistical analysis by ANOVA. Adhesion for enamel was more efficient than for dentin (p < 0.01). The cavities prepared with a conventional bur (control group) presented higher bond strength values than those recorded for Er:YAG laser (p < 0.01). No significant differences were observed between the restorative materials. Based on these results, it was concluded that Er:YAG laser adversely affected the shear bond strength of RMGIC for both enamel and dentin.

  10. Cu, Cr and As distribution in soils adjacent to pressure-treated decks, fences and poles.

    PubMed

    Chirenje, Tait; Ma, L Q; Clark, C; Reeves, M

    2003-01-01

    Chromated copper arsenate (CCA)-treated wood has been widely used in the Southeastern United States to protect wood products from microbial and fungal decay. The aims of this study were to (1). determine the distribution of arsenic (As), chromium (Cr), and copper (Cu), in soils surrounding CCA-treated wood structures such as decks, fences and poles; and (2). evaluate the impacts of these structures on As, Cr and Cu loading of the soils. Profile and lateral soil samples were collected under CCA-treated decks and adjacent to poles and fences. The results showed elevation of As, Cr and Cu concentrations close to and under the structures, with mean As concentrations as high as 23 mg x kg(-1) close to utility poles compared with less than 3 mg x kg (-1) at distances of about 1.5 m away. Concentrations of As, Cr, and Cu decreased with depth in areas close to CCA-treated poles. However, these results were only apparent in relatively new structures. A combination of weathering and leaching with time may have reduced the impact in older poles. Increased concentrations of As, Cu and Cr were also observed close to CCA-treated decks and fences, with age showing a similar impact. These results are helpful for CCA-treated wood product users to determine the safe use of these structures.

  11. Phenanthrene adsorption by soils treated with humic substances under different pH and temperature conditions.

    PubMed

    Ping, Lifeng; Luo, Yongming; Wu, Longhua; Qian, Wei; Song, Jing; Christie, Peter

    2006-01-01

    The mobility of phenanthrene (PHE) in soils depends on its sorption and is influenced by either the existing soil humus or exogenous humic substances. Exogenous humic acids (HAs) were added to soil to enhance the amount of soil organic carbon (SOC) by 2.5, 5.0, and 10.0 g kg(-1). PHE desorption of the treated soils was determined at two pH levels (3.0 and 6.0) and temperatures (15 and 25 degrees C). Soil PHE adsorption was related to pH and the type and quantity of added HAs. Humic acid (HA) and fulvic acid (FA) derived from peat had different effects on adsorption of PHE. Adsorption increased at first and then decreased with increasing quantity of exogenous FA. When the soil solution pH (in 0.005 M CaCl(2)) was 4.5 or 3.0, the turning points were 2.5 g FA kg(-1) at pH 3.0 and 5 g FA kg(-1) at pH 4.5. When soil solution pH was 6, the amount of adsorbed PHE was enhanced with increasing exogenous HAs (HA or FA) and amount of adsorption by soil treated with FA was higher than with HA. Adsorption of PHE in the FA treatment at 10.0 g kg(-1) was lower than the controls (untreated soil or treatment with HAs at 0 g kg(-1)) when the soil solution pH was 3.0. This suggests that FA adsorbed by soil was desorbed at low pH and would then increase PHE solubility, and PHE then combined with FA. PHE adsorption was usually higher under lower pH and/or lower temperature conditions. PHE sorption fitted the Freundlich isotherm, indicating that exogenous humic substances influenced adsorption of phenanthrene, which in turn was affected by environmental conditions such as pH and temperature. Thus, exogenous humic substances can be used to control the mobility of soil PAHs under appropriate conditions to decrease PAH contamination.

  12. 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

  13. 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. Copyright © 2015. Published by Elsevier B.V.

  14. 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)

  15. 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...

  16. 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...

  17. Humic acid toxicity in biologically treated soil contaminated with polycyclic aromatic hydrocarbons and pentachlorophenol.

    PubMed

    Nieman, J K C; Sims, R C; Sorensen, D L; McLean, J E

    2005-10-01

    Contaminated soil from a land treatment unit at the Libby Groundwater Superfund Site in Libby, MT, was amended with 14C pyrene and incubated for 396 days to promote biodegradation and the formation of soil-associated bound residues. Humic and fulvic acids were extracted from the treated soil microcosms and analyzed for the presence of pyrene residues. Biologic activity promoted 14C association with the fulvic acid fraction, but humic acid-associated 14C did not increase with biologic activity. The Aboatox flash toxicity assay was used to assess the toxicity of humic and fulvic acid fractions. The fulvic acid gave no toxic response, but the humic acid showed significant toxicity. The observed toxicity was likely associated with pentachlorophenol, a known contaminant of the soil that was removed by solvent extraction of the humic acid and that correlated well with toxicity reduction.

  18. 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

  19. Bacterial community structure and activity in different Cd-treated forest soils.

    PubMed

    Lazzaro, Anna; Hartmann, Martin; Blaser, Peter; Widmer, Franco; Schulin, Rainer; Frey, Beat

    2006-11-01

    In this study we compared indicators of Cd bioavailability (water extracts, Lakanen extracts, free ions) and ecotoxicity in forest soils with contrasting physico-chemical characteristics. Soil samples were treated with CdCl(2) solutions (0, 0.1, 1, 10 and 100 mM) and incubated for 30 days. Microbial activity indexes (acid phosphatase, beta-glucosidase, basal respiration) and changes in bacterial community structure using terminal restriction fragment length polymorphism (T-RFLP) fingerprinting were investigated. The Cd concentrations measured ranged from 1% to 37% of the total additions in water extracts, to higher levels in Lakanen extracts. Effects of Cd were observed at bioavailable concentrations exceeding United Nations/European Economic Commission UN/ECE guidelines for total Cd in the soil solution. Basal respiration was the most affected index, while enzymatic activities showed variable responses to the Cd treatments. We also noticed that soils with pH higher than 6.7 and clay content higher than 50% showed inhibition of basal respiration but no marked shift in bacterial community structure. Soils with lower pH (pH <5.8) with less clay content (<50%) showed in addition strong changes in the bacterial community structure. Our results provide evidence for the importance of relating the effects of Cd on the soil communities to soil properties and to bioavailability.

  20. Salmonella survival in manure-treated soils during simulated seasonal temperature exposure.

    PubMed

    Holley, Richard A; Arrus, Katia M; Ominski, Kimberly H; Tenuta, Mario; Blank, Gregory

    2006-01-01

    Addition of animal manure to soil can provide opportunity for Salmonella contamination of soil, water, and food. This study examined how exposure of hog manure-treated loamy sand and clay soils to different simulated seasonal temperature sequences influenced the length of Salmonella survival. A six-strain cocktail of Salmonella serovars (Agona, Hadar, Heidelberg, Montevideo, Oranienburg, and Typhimurium) was added to yield 5 log cfu/g directly to about 5 kg of the two soils and moisture adjusted to 60 or 80% of field capacity (FC). Similarly, the Salmonella cocktail was mixed with fresh manure slurry from a hog nursery barn and the latter added to the two soils at 25 g/kg to achieve 5 log cfu/g Salmonella. Manure was mixed either throughout the soil or with the top kilogram of soil and the entire soil volume was adjusted to 60 or 80% FC. Soil treatments were stored 180 d at temperature sequences representing winter to summer (-18, 4, 10, 25 degrees C), spring to summer (4, 10, 25, 30 degrees C), or summer to winter (25, 10, 4, -18 degrees C) seasonal periods with each temperature step lasting 45 d. Samples for Salmonella recovery by direct plating or enrichment were taken at 0, 7, and 15 d post-inoculation and thereafter at 15-d intervals to 180 d. Salmonella numbers decreased during application to soil and the largest decreases occurred within the first week. Higher soil moisture, manure addition, and storage in the clay soil increased Salmonella survival. Salmonella survived longest (> or = 180 d) in both soils during summer-winter exposure but was not isolated after 160 d from loamy sand soil exposed to other seasonal treatments. For all but one treatment decimal reduction time (DRT45d) values calculated from the first 45 d after application were < or = 30 d and suggested that a 30-d delay between field application of manure in the spring or fall and use of the land would provide reasonable assurance that crop and animal contamination by Salmonella would be

  1. 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

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

    PubMed

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

    1998-03-01

    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.

  3. 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.

  4. Fate of carbamazepine and anthracene in soils watered with UV-LED treated wastewaters.

    PubMed

    Chevremont, A-C; Boudenne, J-L; Coulomb, B; Farnet, A-M

    2013-11-01

    Water disinfection technologies based on ultraviolet (UV) radiations emitted by Light-Emitting Diodes (LED), as a wastewater tertiary treatment, have been shown to be promising for water reuse. Here, we assessed the fate of two ubiquitous pollutants, carbamazepine and anthracene, in soil watered with either UV-LED treated wastewaters or irrigation water. After 3 months, anthracene and carbamazepine were transformed two and three times faster respectively, in soils watered with UV-LED wastewater than in soils watered with tap water (probably because of the addition of organic matter by the effluent). Laccase activity was induced in the presence of the pollutants and anthraquinone was found as anthracene product of oxidation by laccases. Moreover, the addition of these pollutants into soil did not affect the functional diversity of autochthonous microbial communities assessed by Ecolog plates. Cellulase, protease and urease activities increased in soils watered with UV-LED treated wastewaters (UV-LED WW), showing transformation of organic matter from the effluent and lipase activity increased by anthracene addition, confirming the potential role of these enzymes as indicators of hydrocarbon contamination.

  5. 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.

  6. Temperature and moisture effects on selected properties of wood fiber-cement composites

    SciTech Connect

    Blankenhorn, P.R.; Silsbee, M.R.; Blankenhorn, B.D.; DiCola, M.; Kessler, K.

    1999-05-01

    The effects of moisture cycling on the dimensional stability and temperature cycling on the compressive strength of treated wood fiber-cement composites were investigated. The Kraft softwood fibers and the hardwood fibers were treated with an aqueous acrylic emulsion or alkylalkoxysilane prior to manufacturing into wood fiber-cement composites. Moisture cycling results indicated that the treated fiber-cement composites were more resistant to deterioration than the neat cement specimens. The alkylalkoxysilane-treated fiber-cement composites resisted deterioration more than the acrylic emulsion-treated fiber-cement composites. Treated hardwood fiber-cement composites were more resistant than the treated Kraft fiber-cement composites. The effects of temperature cycling on the compressive strength values produced similar results. The treated fibers were more resistant to deterioration than the neat element. The alkylalkoxysilane-treated Kraft and hardwood fiber-cement composites had higher average compressive strength values than the acrylic emulsion-treated wood fiber-cement composites.

  7. 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.

  8. Response of microbial activities to heavy metals in a neutral loamy soil treated with biosolid.

    PubMed

    Kao, Po-Hsu; Huang, Cheng-Chieh; Hseu, Zeng-Yei

    2006-06-01

    Application of biosolid on land has been widespread in numerous countries for last several decades. This study performed incubation experiments by mixing a neutral loamy soil and biosolid enriched in Cu, Pb and Zn to explore how heavy metal affects soil mineralization and microbial biomass. The experimental results indicated that large nutrient, microorganism and C sources from biosolid were beneficial to microbial respiration. However, compared to the biosolid alone treatment, the supplemented Cu, Pb and Zn in biosolid reduced the mineralized C by roughly 36%. This phenomenon was probably caused by a portion of the Cu, Pb and Zn being complexed with organic matter to prevent decomposition of organic carbon by microorganisms. Equally, soil treated with biosolid increased the quantity of mineralized N by approximately five-fold and accelerated the rate of N mineralization by about one-fold compared to untreated soil. Notably, addition of heavy metals impaired the mineralization process, particularly when Pb reached about 64%. The reduced N mineralization occurred for similar reasons to the microbial respiration. The addition of biosolid in soil considerably increased the amount of mineralizable N; however, the increase was lower in biosolid-treated soil spiked by heavy metals. The addition of heavy metals in the soil-biosolid mixture clearly reduced the microbial biomasses C (MBC) and N (MBN), indicating that the microbial activities had been disrupted by the heavy metals. The microbial biomass C/N ratio had changed initially from 8 to 13 at the end of incubation period, owing to various groups of microbes expressing different mechanisms of metabolism, indicating that the microbial population had changed from bacteria to fungi, which had higher metal tolerance.

  9. 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.

  10. 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

  11. 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.

  12. 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

  13. 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

  14. 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

  15. The effect of glass ionomer cement Fuji IX on the hard tissues of teeth treated by sparing methods (ART and CMCR).

    PubMed

    Marczuk-Kolada, G; Waszkiel, D; Luczaj-Cepowicz, E; Kierklo, A; Pawińska, M; Mystkowska, J

    2006-01-01

    The aim of the study was to assess the effect of glass ionomer fillings Fuji IX on the mineral content of the hard dental tissues of carious teeth treated by sparing methods. The study material consisted of 4 deciduous teeth lost due to physiological resorption. The teeth had glass ionomer fillings Fuji IX inserted after treatment of caries by means of sparing methods (ART and CMCR). Chemical analysis of enamel and dentin was performed by means of energy dispersive spectroscopy (EDS) with X-ray analysis QUEST system at a distance of 20 um (point C) and 120 um (point D), respectively. The content of the following elements was evaluated in weight percent: oxygen (O), fluoride (F), sodium (Na), magnesium (Mg), aluminum (Al), silicon (Si), phosphorus (P), calcium (Ca), strontium (Sr). The Ca/P ratio was calculated. T-student test for pairs, with the level of significance p < 0.05, was used for statistical analysis of the results. We found significantly higher levels of fluoride, aluminum and silicon and lower concentrations of calcium and phosphorus in the dentine adjacent to the filling (point C). However, no statistically significant differences were observed in the levels of the elements between these two sites of measurement. Our results indicate that mineralization of the calcified dentine may involve elements released from glass ionomer cement Fuji IX.

  16. The performance of constructed wetlands treating primary, secondary and dairy soiled water in Ireland (a review).

    PubMed

    Healy, M G; O' Flynn, C J

    2011-10-01

    In Ireland, no database detailing the design, influent loading rates or performance of constructed wetlands (CWs) exists. On account of this, they are designed without any protocol based on empirical data. The aim of this paper was to provide the first published data on the performance of free-water surface flow (FWSF) CWs treating primary and secondary-treated municipal wastewater, and agricultural dairy soiled water (DSW) in Ireland. In total, the performance of thirty-four FWSF CWs, comprising fourteen CWs treating primary-treated municipal wastewater, thirteen CWs treating secondary-treated municipal wastewater, and seven CWs treating DSW, were examined. In most CWs, good organic, suspended solids (SS) and nutrient removal was measured. At an average organic loading rate (OLR) of 10 and 9 g biochemical oxygen demand (BOD) m(-2) d(-1), CWs treating primary and secondary wastewater removed 95 and 84% of influent BOD. Constructed wetlands treating DSW had an average BOD removal of 98%. At average SS loading rates of 6 and 14 g m(-2) d(-1), CWs treating primary and secondary wastewater had a 96 and an 82% reduction, and produced a final effluent with a concentration of 14 and 13 mg L(-1). Constructed wetlands treating DSW produced a final effluent of 34 mg L(-1) (94% reduction). Similar to other studies, all CWs examined had variable performance in ammonium-N (NH(4)(+)-N) removal, with average removals varying between 37% (for CWs treating secondary wastewater) and 88% (for CWs treating DSW). Variable ortho-phosphorus (PO(4)(3-)-P) removal was attributable to different durations of operation, media types and loading rates.

  17. A new approach to treat discontinuities in multi-layered soils

    NASA Astrophysics Data System (ADS)

    Berardi, Marco; Difonzo, Fabio; Caputo, Maria; Vurro, Michele; Lopez, Luciano

    2017-04-01

    The water infiltration into two (or more) layered soils can give rise to preferential flow paths at the interface between different soils. The deep understanding of this phenomenon can be of great interest in modeling different environmental problems in geosciences and hydrology. Flow through layered soils arises naturally in agriculture, and layered soils are also engineered as cover liners for landfills. In particular, the treatment of the soil discontinuity is of great interest from the modeling and the numerical point of view, and is still an open problem.% (see, for example, te{Matthews_et_al,Zha_vzj_2013,DeLuca_Cepeda_ASCE_2016}). Assuming to approximate the soils with different porous media, the governing equation for this phenomenon is Richards' equation, in the following form: {eq:different_Richards_1} C_1(ψ) partial ψ/partial t = partial /partial z [ K_1(ψ) ( partial ψ/partial z - 1 ) ], \\quad if \\quad z < \\overline{z}, C_2(ψ) partial ψ/partial t = partial /partial z [ K_2(ψ) ( partial ψ/partial z - 1 ) ], \\quad if \\quad z > \\overline{z}, where \\overline{z} is the spatial threshold that identifies the change in soil structure, and C1 C_2, K_1, K_2, the hydraulic functions that describe the upper and the lower soil, respectively. The ψ-based form is used, in this work. Here we have used the Filippov's theory in order to deal with discontinuous differential systems, and we handled opportunely the numerical discretization in order to treat the abovementioned system by means of this theory, letting the discontinuity depend on the state variable. The advantage of this technique is a better insight on the solution behavior on the discontinuity surface, and the no-need to average the hydraulic conductivity field on the threshold itself, as in the existing literature.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. Potential exposure to clothianidin and risk assessment of manual users of treated soil.

    PubMed

    Ren, JingXia; Tao, ChuanJiang; Zhang, LiYing; Ning, Jun; Mei, XiangDong; She, DongMei

    2017-09-01

    Treated soil is the second most prevalent application technique for all registered pesticides in China. Some developing countries also adopt this method. However, the safety of this scenario has not been reported in the literature. Experiments were therefore conducted to assess exposure using standard whole-body dosimetry and air sampling methodologies. Dermal deposition was the main route of exposure in this scenario. The total dermal unit exposure (UE) of operators to clothianidin-treated soil was 51.7 mg kg(-1) AI handled (SD = 20.59, n = 16), and hands accounted for 36%. Inhalation UE was 0.04 mg kg(-1) AI handled (SD = 0.02, n = 4), negligible compared with dermal exposure. Using an NOAEL (no observed adverse effect level) of 10 mg kg(-1) day(-1) , the margin of exposure was 773, i.e. greater than 100. For the first time, the scenario of treated soil exposure was assessed and was found to pose less risk than conventional pesticide application. These results can be used as a reference in pesticide management. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  3. 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

    2015-04-09

    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. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. 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.

  5. Impact of treated wastewater irrigation on antibiotic resistance in the soil microbiome.

    PubMed

    Gatica, Joao; Cytryn, Eddie

    2013-06-01

    The reuse of treated wastewater (TWW) for irrigation is a practical solution for overcoming water scarcity, especially in arid and semiarid regions of the world. However, there are several potential environmental and health-related risks associated with this practice. One such risk stems from the fact that TWW irrigation may increase antibiotic resistance (AR) levels in soil bacteria, potentially contributing to the global propagation of clinical AR. Wastewater treatment plant (WWTP) effluents have been recognized as significant environmental AR reservoirs due to selective pressure generated by antibiotics and other compounds that are frequently detected in effluents. This review summarizes a myriad of recent studies that have assessed the impact of anthropogenic practices on AR in environmental bacterial communities, with specific emphasis on elucidating the potential effects of TWW irrigation on AR in the soil microbiome. Based on the current state of the art, we conclude that contradictory to freshwater environments where WWTP effluent influx tends to expand antibiotic-resistant bacteria (ARB) and antibiotic-resistant genes levels, TWW irrigation does not seem to impact AR levels in the soil microbiome. Although this conclusion is a cause for cautious optimism regarding the future implementation of TWW irrigation, we conclude that further studies aimed at assessing the scope of horizontal gene transfer between effluent-associated ARB and soil bacteria need to be further conducted before ruling out the possible contribution of TWW irrigation to antibiotic-resistant reservoirs in irrigated soils.

  6. 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.

  7. Squeeze cementing

    SciTech Connect

    Ewert, D.P.; Kundert, D.P.; Dahl, J.A.; Dalrymple, E.D.; Gerke, R.R.

    1992-06-16

    This patent describes a method for terminating the flow of fluid from a portion of a subterranean formation into a wellbore. It comprises: placing within the wellbore adjacent the portion a volume of a slurry of hydraulic cement, permitting the volume to penetrate into the portion; and maintaining the slurry in the portion for a time sufficient to enable the slurry to form a rigid mass of cement in the portion.

  8. Long-term irrigation with treated wastewater: effects on the hydraulic properties of a clay soil

    NASA Astrophysics Data System (ADS)

    Bardhan, Gopali; Russo, David; Levy, Guy

    2017-04-01

    Treated wastewater (TWW) is an important water resource, especially in semiarid and arid regions. However, there are some concerns that irrigation with TWW could lead to degradation of soil physical and hydraulic properties. Our objective was to evaluate the effects of long-term (≥15 y) irrigation with secondary TWW on some basic and hydraulic soil properties of a clay soil. Undisturbed soil samples (cores) were taken to a depth of 4.5 m (in sections of 0.5 m) over a diagonal cross section of a five year old orchard irrigated with TWW. Samples were taken from five sites within the tree rows (i.e., representing soil directly affected by TWW; referred to as "within rows") and four sites between the rows of trees (i.e., the control treatment representing soil that was not directly subjected to the irrigation water; referred to as "between rows"). Soil analyses included an array of basic properties, determination of a continuous particle size distribution and measurement of the saturated hydraulic conductivity (HC). The latter two were used for the computation of soil characteristic curve, Θ(ψ), and the unsaturated HC curve, K(ψ). The results showed that irrigation with TWW had insignificant effects on bulk density, moisture content, cation exchange capacity, pH and exchangeable sodium percentage (ESP), but caused a reduction in the saturated HC, Ks. The computed Θ(ψ) curve at a given soil depth, averaged over the different sites, was similar for the TWW-irrigated samples and the control ones. On the contrary, the computed K(ψ) curve at a given soil depth, averaged over the different sites, for the TWW-irrigated samples were lower than those for the control samples at matric potential > -100 cm (=pF< 2); similar K(ψ) values were noted at pF>2 for the two treatments. Possible reasons for the observed differences in the hydraulic properties between the TWW-irrigated samples and the control ones are discussed.

  9. Acute Delayed or Late Infection of Revision Total Hip Arthroplasty Treated with Debridement/Antibiotic-loaded Cement Beads and Retention of the Prosthesis

    PubMed Central

    Chang, Jun-Dong; Kim, In-Sung; Lee, Sang-Soo

    2017-01-01

    Purpose The treatment of infected revision total hip arthroplasty (THA) is very challenging due to retained revision prosthesis, poor bone stock and soft tissue condition derived from previous revision surgeries, and comorbidities. The purpose of this study was to investigate the effectiveness and short-term outcomes of aggressive debridement and use of antibiotic-loaded cement beads with retention of the prosthesis for acute delayed or late infection of revision THAs. Materials and Methods Ten consecutive patients with symptoms or signs of less than one-week evolution and well-fixed prostheses, were treated with this procedure and a postoperative course of organism-specific antibiotics for a minimum of 6 weeks. All hips presented with acute delayed or late infection of revision THAs. Patients with a mean age of 68.1 years (range, 59-78 years) underwent an average of 1.9 previous revision THAs (1-4) before the index surgery. The minimal follow-up was 2 years with a mean of 46.2 months (range, 24-64 months). Results There were 8 cures (80.0%) and 2 failures with no mortality during the study period. The 2 failures involved the same and resistant bacteria implicated in the primary infection (methicillin-resistant Staphylococcus aureus and Prevotella oralis, respectively). The mean Harris hip score was 65.2 (range, 26-83) and the mean visual analogue scale was 2.6 (range, 1-4) at final follow-up. Conclusion With a favorable success rate and no mortality, our procedure may be considered a safe and effective alternative for the treatment of acute delayed or late infection of revision THAs with well-fixed prostheses. PMID:28316961

  10. 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

  11. Chlortetracycline and tylosin runoff from soils treated with antimicrobial containing manure.

    PubMed

    Hoese, A; Clay, S A; Clay, D E; Oswald, J; Trooien, T; Thaler, R; Carlson, C G

    2009-05-01

    This study assessed the runoff potential of tylosin and chlortetracycline (CTC) from soils treated with manure from swine fed rations containing the highest labeled rate of each chemical. Slurry manures from the swine contained either CTC at 108 microg/g or tylosin at 0.3 microg/g. These manures were surface applied to clay loam, silty clay loam, and silt loam soils at a rate of 0.22 Mg/ha. In one trial, tylosin was applied directly to the soil surface to examine runoff potential of water and chemical when manure was not present. Water was applied using a sprinkler infiltrometer 24-hr after manure application with runoff collected incrementally every 5 min for about 45 min. A biofilm crust formed on all manure-treated surfaces and infiltration was impeded with > 70% of the applied water collected as runoff. The total amount of CTC collected ranged from 0.9 to 3.5% of the amount applied whereas tylosin ranged from 8.4 to 12%. These data indicate that if surface-applied manure contains antimicrobials, runoff could lead to offsite contamination.

  12. Irrigating okra with secondary treated municipal wastewater: Observations regarding plant growth and soil characteristics.

    PubMed

    Kumar, Vinod; Chopra, A K; Srivastava, Sachin; Singh, Jogendra; Thakur, Roushan Kumar

    2017-05-04

    The present study was carried out to probe the agronomic response of hybrid cultivar of okra (Hibiscus esculentus L. var. JK 7315) grown in secondary treated municipal wastewater irrigated soil with field investigations. The concentrations of the municipal wastewater viz., 10%, 20%, 40%, 60%, 80%, and 100% along with the control (groundwater) were used for the irrigation of the H. esculentus. The study revealed that the concentrations of the municipal wastewater showed significant (p < 0.05/p < 0.01) effect on the soil parameters after wastewater fertigation in comparison to groundwater in both the seasons. The maximum agronomic performance of the H. esculentus was recorded with 60% concentration of the municipal wastewater in both the seasons. The contamination factor of heavy metals varied in the H. esculentus plants and soils. In the H. esculentus plants, following fertigation with municipal wastewater, the contamination factor of manganese was the highest, while that of chromium was the lowest. Intermediate contamination factor were observed for zinc, copper, and cadmium. Therefore, secondary treated municipal wastewater can be used as an agro-fertigant after appropriate dilution (up to 60%) to achieve the maximum yield of the H. esculentus.

  13. Cement Burns

    PubMed Central

    Alam, Munir; Moynagh, M.; Lawlor, C.

    2007-01-01

    Objective: Cement burns account for relatively few admissions to a burn unit; however, these burns deserve separate consideration because of special features of diagnosis and management. Cement burns, even though potentially disabling, have rarely been reported in literature. Methods: A retrospective review was performed of all patients admitted with cement burns injuries to the national burns unit at the St James's Hospital in Dublin, Ireland, over a 10-year period for the years 1996–2005. Results: A total of 46 patients with cement burns were admitted. The majority of patients were aged 16–74 years (mean age = 32 years). Eighty-seven percent of injuries occurred in an industrial and 13% in a domestic setting. The upper and lower extremities were involved in all the patients, and the mean total body surface area affected was 6.5%. The mean length of hospital stay was 21 days with a range of 1–40 days. Thirty-eight (82%) were surgically managed involving debridement and split-thickness skin graft (SSG) and four (9%) were conservatively managed. A further four did not have data available. Conclusion: Widespread inexperience in dealing with this group of cement burns patients and delays in referral to burns unit highlights the potential for greater levels of general awareness and knowledge in both prevention and treatment of these burns. As well, early debridement and split-thickness skin grafting at diagnosis constitutes the best means of reducing the high socioeconomic costs and allows for early return to work. PMID:18091981

  14. Statistical analysis of influence of soil source on leaching of arsenic and copper from CCA-C treated wood

    Treesearch

    Patricia Lebow; Richard Ziobro; Linda Sites; Tor Schultz; David Pettry; Darrel Nicholas; Stan Lebow; Pascal Kamdem; Roger Fox; Douglas Crawford

    2006-01-01

    Leaching of wood preservatives affects the long-term efficacy and environmental impact of treated wood. Soil properties and wood characteristicscan affectleaching of woad preservatives, but these effects are not well understood. This paper reports a statistical analysis of the effects of soil and wood properties on leaching of arsenic (As) and copper (Cu) from southern...

  15. Metagenomes of Soils Samples from an Established Perennial Cropping System of Asparagus Treated with Biostimulants in Southern France

    PubMed Central

    Crovadore, Julien; Asaff Torres, Ali; Rodríguez Heredia, Raúl; Cochard, Bastien; Chablais, Romain

    2017-01-01

    ABSTRACT We report here the metagenomes of soils samples from a perennial cropping system of asparagus that was treated with two biostimulants. Two treatments were compared to an untreated control. Control soils samples were taken at the beginning and at end of the experiment. PMID:28619798

  16. False-positive identification of Escherichia coli in treated municipal wastewater and wastewater-irrigated soils.

    PubMed

    McLain, Jean E T; Rock, Channah M; Lohse, Kathleen; Walworth, James

    2011-10-01

    The increasing use of treated wastewater for irrigation heightens the importance of accurate monitoring of water quality. Chromogenic media, because they are easy to use and provide rapid results, are often used for detection of Escherichia coli in environmental samples, but unique levels of organic and inorganic compounds alter the chemistry of treated wastewater, potentially hindering the accurate performance of chromogenic media. We used MI agar and molecular confirmatory methods to assess false-positive identification of E. coli in treated wastewater samples collected from municipal utilities, an irrigation holding pond, irrigated soils, and in samples collected from storm flows destined for groundwater recharge. False-positive rates in storm flows (4.0%) agreed closely with USEPA technical literature but were higher in samples from the pond, soils, and treatment facilities (33.3%, 38.0%, and 48.8%, respectively). Sequencing of false-positive isolates confirmed that most were, like E. coli, of the family Enterobacteriaceae, and many of the false-positive isolates were reported to produce the β-D-glucuronidase enzyme targeted by MI agar. False-positive identification rates were inversely related to air temperature, suggesting that seasonal variations in water quality influence E. coli identification. Knowledge of factors contributing to failure of chromogenic media will lead to manufacturer enhancements in media quality and performance and will ultimately increase the accuracy of future water quality monitoring programs.

  17. Effect of Strength Enhancement of Soil Treated with Environment-Friendly Calcium Carbonate Powder

    PubMed Central

    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

  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.

  19. Predictors of excess cement and tissue response to fixed implant-supported dentures after cementation.

    PubMed

    Korsch, Michael; Robra, Bernt-Peter; Walther, Winfried

    2015-01-01

    The cementation of fixed implant-supported restorations involves the risk of excess cement remaining in the peri-implant tissue that may cause a peri-implant tissue response with attachment loss. The aim was to study the peri-implant tissue response after cementation and to detect potential predictors of excess cement. Clinical complications after cementation in several index cases led to a recall of all patients treated with a special methacrylate cement (one hundred five patients with one hundred eighty-eight implants) and systematic reevaluation of 71 patients (68%) with one hundred twenty-six implants (67%). In all cases, suprastructures including abutments were removed, and findings were documented. Implant diameter was significantly associated with the frequency of excess cement. Implant location or system had no significant effect. Excess cement in turn was associated with bleeding on probing, suppuration, and peri-implant attachment loss. In the absence of excess cement 58.8% of implants had no peri-implant attachment loss versus 37.3% when excess cement was present. With increasing retention time of the methacrylate cement, more peri-implant attachment loss was detected. However, the latter association was not significant. Larger diameters are significantly associated with excess cement in peri-implant tissue. Consequences of excess cement may be increased bleeding on probing, suppuration, and possibly peri-implant attachment loss. © 2013 Wiley Periodicals, Inc.

  20. 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.

  1. 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.

  2. Influence of Alveolar Bone Loss and Cement Layer Thickness on the Biomechanical Behavior of Endodontically Treated Maxillary Incisors: A 3-dimensional Finite Element Analysis.

    PubMed

    Dal Piva, Amanda Maria de Oliveira; Tribst, João Paulo Mendes; Souza, Rodrigo Othávio de Assunção E; Borges, Alexandre Luiz Souto

    2017-05-01

    In order to understand the mechanical behavior of a weakened incisor, this study aimed to evaluate the stress distribution caused by different alveolar bone heights and cement layer thickness. A finite element analysis was conducted for this investigation. An intact maxillary central incisor was initially modeled, and the bone of the models was modified in order to simulate 4 levels of bone height: BL0 (no bone loss), BL1 (1/3 bone loss), BL2 (1/2 bone loss), and BL3 (2/3 bone loss). These teeth models were remodeled with a fiber post at 2 different cement thicknesses and restored with a ceramic crown; "A" refers to the well-adapted fiber post (0.3 mm) and "B" to the nonadapted fiber post (1 mm), resulting in 12 models. RelyX ARC (3M ESPE, St Paul, MN) cement was simulated for the cementation of the crowns and fiber posts for all groups. Numeric models received a load of 100 N on the lingual surface. All materials and structures were considered linear elastic, homogeneous, and isotropic. Numeric models were plotted and meshed with isoparametric elements, and results were expressed in maximum principal stress. For fiberglass posts, cement, and dentin, the highest stress concentration occurred in the groups with increased bone loss. For cortical bone, the highest values were for the groups with 1/3 bone loss. A greater thickness of cement layer concentrates more stress. More bone loss and greater CLT were the influential factors in concentrating the stress. Copyright © 2017 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  3. 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.

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

    PubMed

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

    2005-08-15

    This study deals with 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 degrees 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 degrees C and 40% at 60 degrees 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(ll) hydroxide and Cu(ll) 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.

  5. 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

  6. 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.

  7. Managed aquifer recharge: the fate of pharmaceuticals from infiltrated treated wastewater investigated through soil column experiments

    NASA Astrophysics Data System (ADS)

    Silver, Matthew; Selke, Stephanie; Balsaa, Peter; Wefer-Roehl, Annette; Kübeck, Christine; Schüth, Christoph

    2017-04-01

    The EU FP7 project MARSOL addresses water scarcity challenges in arid regions, where managed aquifer recharge (MAR) is an upcoming technology to recharge depleted aquifers using alternative water sources. Within this framework, column experiments were conducted to investigate the fate of pharmaceuticals when secondary treated wastewater (TWW) is infiltrated through a natural soil (organic matter content 6.8%) being considered for MAR. Three parallel experiments were run under conditions of continuous infiltration (one column) and wetting-drying cycles (two columns, with different analytes) over a 16 month time period. The pharmaceuticals diclofenac, ibuprofen, carbamazepine, naproxen, gemfibrozil, and fenoprofen, as well as the antibiotics doxycycline, sulfadimidine, and sulfamethoxazole, are commonly present in treated wastewater in varying concentrations. For the experiments, concentration variability was reduced by spiking the column inflow water with these compounds. Concentrations were periodically analyzed at different depths in each column and the mass passing each depth over the duration of the experiment was calculated. At the end of the experiments, sorbed pharmaceuticals were extracted from soil samples collected from different depths. A pressurized liquid extraction method was developed and resulted in recoveries from spiked post-experiment soil samples ranging from 64% (gemfibrozil) to 82% (carbamazepine) for the six non-antibiotic compounds. Scaling results by these recovery rates, the total mass of pharmaceuticals sorbed to the soil in the columns was calculated and compared to the calculated attenuated mass (i.e. mass that left the water phase). The difference between the attenuated mass and the sorbed mass is considered to be mass that degraded. Results for continuous infiltration conditions indicate that for carbamazepine and diclofenac, sorption is the primary attenuation mechanism, with missing (i.e. degraded) mass lying within the propagated

  8. 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.

  9. 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. Crown Copyright © 2011. Published by Elsevier Ltd. All rights reserved.

  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. Effects of treated sewage sludge levels on temporal variations of some soil properties of a Typic Xerofluvent soil in Menemen Plain, Western Anatolia, Turkey.

    PubMed

    Delibacak, S; Okur, B; Ongun, A R

    2009-01-01

    The aim of this study is to determine effects of treated sewage sludge (TSS) levels as an organic matter (OM) resource on temporal variations of some soil properties of a Typic Xerofluvent soil. The experiment was conducted in Menemen Plain, in the Western Anatolia Region of Turkey (latitudes 38 degrees 34'48.22''-38 degrees 34'49.24'' N; longitudes 27 degrees 1'23.05-27 degrees 1'24.14'' E) in the years of 2003 and 2004. Moist TSS was added to the soil at the rates of 0, 30, 60 and 90 t ha(-1) on May 1, 2003. Peanut (Arachis hypogaea) was planted as first crop. On the other hand, mixture of green barley (Hordeum vulgare) and common vetch (Vicia sativa L.) was planted as second crop. During the experiment, soil samples were taken in five different periods (1st, June 18, 2003; 2nd, November 13, 2003; 3rd, April 30, 2004; 4th, October 10, 2004 and 5th, May 12, 2004). The results showed that increasing TSS application to Typic Xerofluvent soil was significantly increased total salt, OM, total porosity, micro porosity, macro porosity, field capacity, wilting point, available water content, structure stability index and aggregation percentage values of soil when compared with control. Meanwhile, particle density, dry bulk density and nonaggregated silt + clay values of soil decreased. On the other hand, soil reaction (pH), lime content and total silt + clay values of soil did not significantly change. In the course of time, depending on decomposing of TSS organic materials in soil, effect of TSS levels on soil properties decreased particularly in the last periods. For this reason, it can be recommended that 90 t ha(-1) moist TSS can be added once in 2 years for improving soil properties of Typic Xerofluvent soil, which are characterized by low OM content.

  12. 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

    2017-09-01

    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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. Cryogenics with cement microscopy redefines cement behavior

    SciTech Connect

    Mehta, S.; Jones, R. ); Caveny, B. )

    1994-10-03

    Cement microscopy (CM), cryogenics, environmental scanning microscopy (ESM), scanning electron microscopy (SEM), and other technologies are leading investigators to change their views on cement gelation, hydration, and retardation. Cement samples frozen in a nitrogen slush and viewed with an SEM present a more accurate picture of the setting process. Observations made through this technique have revolutionized ARCO Exploration and Production Technology's and Halliburton Energy Services' oil field cement procurement and slurry design. Findings from this joint study are expected to lead to: optimized waiting on cement (WOC) times; reduced planning and design time; optimized slurry retarder additions; optimized gel times to fit given situations; especially applicable to squeeze operations; improved cement selection (from vendors) for peak performance; and improved cement manufacture. The paper discusses the measuring methods and the findings on the following: cement voids, cement gelation, and retardation mechanisms. It also briefly discusses the impact these discoveries have on operations.

  20. Long-Term Exposure of Tropical Soils to Pressure Treated Lumber, Barro Colorado Island, Panama: Impacts on Soil Metal Mobility and Microbial Community Structure

    NASA Astrophysics Data System (ADS)

    Marietta, M. L.; Fowle, D. A.; Roberts, J. A.

    2008-12-01

    Pressure treated lumber (CCA) has been used in a variety of structures for over seven decades, but recent concerns have been raised about leaching of metals such as chromium (Cr) and arsenic (As) into proximal soils and water supplies. Pressure treated lumber abundance and its continued use necessitate a thorough understanding of metal release and sequestration in the subsurface. To date, no long-term, in situ study on the migration of CCA compounds from lumber has been performed. Barro Colorado Island, Panama is the site of several previous CCA studies and provides an opportunity to investigate the long-term (>70 years) effects of pressure treated lumber in oxisols, where high rainfall and warm temperatures may represent an end-member condition for the leaching and mobility of these metals. Soil samples from CCA and control sites were measured for Cr, As, Cu, Zn, and Fe abundances, microbial biomass and community structure via phospholipid fatty acid analysis, along with basic soil properties. CCA lumber samples were also characterized for their metal abundance. Lumber treated with zinc meta-arsenite displayed advanced decay with elevated As, Cu, and Zn concentrations observed in the adjacent soil. Increased soil organic matter and microbial biomass correlate to decreases in Fe and Fe-associated metals compared to the control. High As concentrations persist to <1 m of the source. Lumber treated with potassium dichromate contained high chromium concentrations and displayed little decay, however, soil concentrations of Cr, Fe, and Cu were generally less than control soils. Over these same intervals, soil organic matter and microbial biomass increased, particularly the fraction of metal reducing bacteria (MRB). We hypothesize that organic carbon loading from lumber stimulates MRB, leading to mobilization of Fe and Fe-associated metals from these oxide-rich soils. Principal component analysis of PLFA data confirms a distinction between controls and samples with

  1. 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

  2. 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)

  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. 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. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. Production of micro- and nanosilica from soil inhabiting Folsomia candida fed with treated rice husk.

    PubMed

    Moreno-Murguía, Barbara; Soto-Mercado, Jorge R; Morales-Malacara, Juan B; Castaño, Victor M

    2015-08-01

    Rice husk was employed as a source for producing silica micro- and nanoparticles through its digestion by soil fauna. Although many physicochemical methods for producing nanostructures have been studied, the biological processes remain mostly unexplored. Alkaline hydrogen peroxide with continuous control of reaction pH allowed removal of lignin bonds while preserving most of the cell wall and the silica present in the rice husk. The accessibility of lignocellulose was achieved without removing appreciable amounts of lignin, so this agricultural byproduct can be employed as feeding material for microarthropods Folsomia candida (Collembola). When these microarthropods are placed on a substrate of treated rice husk, more than 85% of degraded material is obtained, as compared to the untreated rice husk substrate, while the silica particles obtained show a slight decrease in average size.

  6. Development of a feasible method to extract somatic coliphages from sludge, soil and treated biowaste.

    PubMed

    Guzmán, Carolina; Jofre, Juan; Blanch, Anicet R; Lucena, Francisco

    2007-09-01

    Extraction of viruses and bacteriophages from sludge, soil and treated biowaste requires homogenization, elution, clarification and detoxification-decontamination steps. Seeding these matrixes with bacteriophages does not reproduce what happens in nature. Therefore, naturally occurring matrixes, raw sludge, digested and dewatered sludge and compost, containing high numbers of somatic coliphages, and soils contaminated with wastewater or raw sludge were used in the extraction assays. Based on eluting the bacteriophages with beef extract, a feasible method in which the different steps had been optimized has been established. The method is feasible, repeatable, robust and applicable in routine laboratories. Digested and dewatered sludge has been probed to be useful as a reference material for validation studies and for "in lab" quality control. The established method includes homogenization by magnetic stirring, elution (which is performed at the same time that homogenization) with 10% beef extract at neutral pH, clarification by centrifuging at 4000 x g and decontamination by filtration through low protein binding 0.22 microm diameter pore size membrane filters.

  7. Characterizing the physio-chemical properties and release kinetics of dissolved organic carbon from thermally treated soils in arid climates.

    NASA Astrophysics Data System (ADS)

    Retuta, A.; Webster, J.; McKay, G.; Rosario-Ortiz, F.

    2016-12-01

    The soil matrix contains a significant portion of the global terrestrial carbon reservoir. Potential shifts in dissolved organic carbon (DOC) concentrations from incoming raw water sources have severe implications for downstream water treatment facilities and, ultimately, for public health. The process through which DOC desorbs from the soil surface is a topic that lacks widespread consensus; understanding the structural and chemical properties is a crucial step to obtaining both consensus and consistency in this field. The aim of this study is two-fold: to thoroughly profile the physical and chemical properties of DOC from both unperturbed and thermally treated soils and to assess the release kinetics of DOC from the soil surface into solution. The goal was to attempt to systematically, carefully, and fundamentally characterize the soil-solution transference of carbon to inform future studies of this phenomena in a changing and perturbed environment. To accomplish the first objective of this study, soil from three different geographical locations in the Western United States were sampled, processed, and partitioned with portions of it undergoing thermal treatment. Both unperturbed and thermally treated samples were leached in simulated a rain water solution prior to filtration and analyzed for ultra-violet (UV) absorbance and fluorescence spectra to evaluate the physical and chemical properties of the desorbed carbon. The photochemical reactivity of the desorbed DOC in solution was also analyzed by measuring the production of reactive intermediates (RI). To accomplish the second objective, both unperturbed and thermally treated soil samples were leached in a sufficient volume of solution in order to extract 40 mL of leachate in timed increments of 5, 15, 30, 60, and 120 minutes. These leachates were analyzed for total organic carbon (TOC) content and the release kinetics of both soil types were assessed. The results of this study served as critical information in

  8. Influence of loading rate and modes on infiltration of treated wastewater in soil-based constructed wetland.

    PubMed

    Bisone, Sara; Gautier, Mathieu; Masson, Matthieu; Forquet, Nicolas

    2017-01-01

    Over the last 10 years soil-based constructed wetlands for discharge of treated wastewater (TWW) are commonly presented as a valuable option to provide tertiary treatment. The uncomplete knowledge in soil modifications and a lack of clear design practices laid the foundation of this work. The aim of this study was to determine optimal hydraulic loads and to observe the main critical parameters affecting treating performances and hydraulic loads acceptance. For this purpose, a soil rich in clay and backfill was chosen to perform column infiltration tests with TWW. Two loading rates and two loading modes were compared to study the influence of an intermittent feeding. Inlet and outlet waters were periodically analysed and columns were instrumented with balances, tensiometers, O2 and temperature probes. Soil physico-chemical characteristics were also taken into account to better understand the modification of the soil. One of the main expectations of tertiary treatment is to improve phosphate removal. A particular attention was thus given to phosphorus retention. The interest of an intermittent feeding in presence of a soil with high clay content was showed. This study highlighted that an intermittent feeding could make possible the use of a clay-rich soil for water infiltration.

  9. 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

  10. Cementing multilateral wells with latex cement

    SciTech Connect

    1997-08-01

    A multilateral well is a well with one or more branches or lateral sections extending from its main wellbore. The laterals can be openhole or cased hole. When laterals are cased hole, the cement integrity for casing support and zonal isolation is very important. When cementing the lateral sections of multilateral wells, it is important to use a cement with high strength and durability to support the liner throughout the life of the well and to support the lateral section. The cement column is subjected to various stresses when the cemented inner stub is cut. High tensile strength, flexural strength, and crack resistance are required. These properties are necessary to make a clean cut through the cement sheath that does not induce cracks in the cement column. Latex cement is commonly used for its gas-migration-control property.

  11. Well cementing in permafrost

    SciTech Connect

    Wilson, W.N.

    1980-01-01

    A process for cementing a string of pipe in the permafrost region of a borehole of a well wherein aqueous drilling fluid actually used in drilling the wellbore in the permafrost region of a wellbore is employed. The drilling fluid contains or is adjusted to contain from about 2 to about 16 volume percent solids. Mixing with the drilling fluid (1) an additive selected from the group consisting of ligno-sulfonate, lignite, tannin, and mixtures thereof, (2) sufficient base to raise the pH of the drilling fluid into the range of from about 9 to about 12, and (3) cementitious material which will harden in from about 30 to about 40 hours at 40/sup 0/F. The resulting mixture is pumped into the permafrost region of a wellbore to be cemented and allowed to harden in the wellbore. There is also provided a process for treating an aqueous drilling fluid after it has been used in drilling the wellbore in permafrost, and a cementitious composition for cementing in a permafrost region of a wellbore.

  12. Simplified urban soil bioaccessible Pb test correlated with bioavailability of soil-Pb to humans in untreated and phosphate-treated Joplin soils

    USDA-ARS?s Scientific Manuscript database

    Urban soils are commonly contaminated with Pb from multiple sources. Total Pb levels commonly exceed 500 mg/kg in center city soils, ranging to above 10,000 where paint residue was incorporated in soils. Many persons seek to grow garden crops in cities, but obtaining useful soil analyses needed to p...

  13. Expansive Cements

    DTIC Science & Technology

    1970-10-01

    sulfate (C), and free lime (C) as well as other known portland cement compounds. 9. Etiite (C6AS3H3 2 ) is the phase formed during the hydration of...hydroxide (CH), required for chemical combination originates by hydration of alite (C3 S), belite (C2 S), and hydration of free lime in both the... shrinkage was also observed when the specimens were moist cured to full exparn-on for a pericd of 33 days. The data regarding the effect of aggregate size on

  14. Assessing environmental impacts of treated wastewater through monitoring of fecal indicator bacteria and salinity in irrigated soils.

    PubMed

    McLain, Jean E T; Williams, Clinton F

    2012-03-01

    To assess the potential for treated wastewater irrigation to impact levels of fecal indicator bacteria (FIB) and salinity in irrigated soils, levels of Escherichia coli, Enterococcus, and environmental covariates were measured in a treated wastewater holding pond (irrigation source water), water leaving the irrigation system, and in irrigated soils over 2 years in a municipal parkland in Arizona. Higher E. coli levels were measured in the pond in winter (56 CFU 100 mL(-1)) than in summer (17 CFU 100 mL(-1)); however, in the irrigation system, levels of FIB decreased from summer (26 CFU 100 mL(-1)) to winter (4 CFU 100 mL(-1)), possibly related to low winter water use and corresponding death of residual bacteria within the system. For over 2 years, no increase in FIB was found in irrigated soils, though highest E. coli levels (700 CFU g(-1) soil) were measured in deeper (20-25 cm) soils during summer. Measurements of water inputs vs. potential evapotranspiration indicate that irrigation levels may have been sufficient to generate bacterial percolation to deeper soil layers during summer. No overall increase in soil salinity resulting from treated wastewater irrigation was detected, but distinct seasonal peaks as high as 4 ds m(-1) occurred during both summers. The peaks significantly declined in winter when surface ET abated and more favorable water balances could be maintained. Monitoring of seasonal shifts in irrigation water quality and/or factors correlated with increases and decreases in FIB will aid in identification of any public health or environmental risks that could arise from the use of treated wastewater for irrigation.

  15. 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.

  16. 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

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

    USDA-ARS?s Scientific Manuscript database

    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...

  18. The dynamics of nitrogen derived from a chemical nitrogen fertilizer with treated swine slurry in paddy soil-plant systems

    PubMed Central

    Lee, Joonhee

    2017-01-01

    A well-managed chemical nitrogen (N) fertilization practice combined with treated swine slurry (TSS) is necessary to improve sustainability and N use efficiency in rice farming. However, little is known about the fate of N derived from chemical N fertilizer with and without TSS in paddy soil-plant systems. The objectives of this study were (1) to estimate the contribution of applied N fertilizer to N turnover in rice paddy soil with different N fertilization practices that were manipulated by the quantity of treated swine slurry and chemical N fertilizer (i.e., HTSS+LAS, a high amount of TSS with a low amount of ammonium sulfate; LTSS+HAS, a low amount of TSS with a high amount of ammonium sulfate; AS, ammonium sulfate with phosphorus and potassium; C, the control) and (2) to compare the rice response to applied N derived from each N fertilization practice. Rice biomass yield, 15N recovery in both rice grain and stems, soil total N (TN), soil inorganic N, and soil 15N recovery were analyzed. Similar amounts of 15N uptake by rice in the TSS+AS plots were obtained, indicating that the effects of the different quantities of TSS on chemical fertilizer N recovery in rice during the experimental period were not significant. The soil 15N recoveries of HTSS+LAS, LTSS+HAS, and AS in each soil layer were not significantly different. For the HTSS+LAS, LTSS+HAS and AS applications, total 15N recoveries were 42%, 43% and 54%, respectively. Because the effects of reducing the use of chemical N fertilizer were attributed to enhancing soil quality and cost-effectiveness, HTSS+LAS could be an appropriate N fertilization practice for improving the long-term sustainability of paddy soil-plant systems. However, N losses, especially through the coupled nitrification-denitrification process, can diminish the benefits that HTSS+LAS offers. PMID:28339491

  19. The dynamics of nitrogen derived from a chemical nitrogen fertilizer with treated swine slurry in paddy soil-plant systems.

    PubMed

    Lee, Joonhee; Choi, Hong L

    2017-01-01

    A well-managed chemical nitrogen (N) fertilization practice combined with treated swine slurry (TSS) is necessary to improve sustainability and N use efficiency in rice farming. However, little is known about the fate of N derived from chemical N fertilizer with and without TSS in paddy soil-plant systems. The objectives of this study were (1) to estimate the contribution of applied N fertilizer to N turnover in rice paddy soil with different N fertilization practices that were manipulated by the quantity of treated swine slurry and chemical N fertilizer (i.e., HTSS+LAS, a high amount of TSS with a low amount of ammonium sulfate; LTSS+HAS, a low amount of TSS with a high amount of ammonium sulfate; AS, ammonium sulfate with phosphorus and potassium; C, the control) and (2) to compare the rice response to applied N derived from each N fertilization practice. Rice biomass yield, 15N recovery in both rice grain and stems, soil total N (TN), soil inorganic N, and soil 15N recovery were analyzed. Similar amounts of 15N uptake by rice in the TSS+AS plots were obtained, indicating that the effects of the different quantities of TSS on chemical fertilizer N recovery in rice during the experimental period were not significant. The soil 15N recoveries of HTSS+LAS, LTSS+HAS, and AS in each soil layer were not significantly different. For the HTSS+LAS, LTSS+HAS and AS applications, total 15N recoveries were 42%, 43% and 54%, respectively. Because the effects of reducing the use of chemical N fertilizer were attributed to enhancing soil quality and cost-effectiveness, HTSS+LAS could be an appropriate N fertilization practice for improving the long-term sustainability of paddy soil-plant systems. However, N losses, especially through the coupled nitrification-denitrification process, can diminish the benefits that HTSS+LAS offers.

  20. Soil and sediment concentrations of chromium, copper, and arsenic adjacent to a chromated copper arsenate-treated wetland boardwalk

    Treesearch

    Stan Lebow; Daniel Foster

    2010-01-01

    Environmental accumulation of preservative adjacent to a chromated copper arsenate (type C)–treated wetland boardwalk was evaluated. The site is considered a realistic ‘‘worst case’’ because of the large volume of treated wood, low current speeds, high annual rainfall, and environmental sensitivity. Soil and sediment samples were collected before construction and 0.5,...

  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.

  2. [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.

  3. Effects of domestic wastewater treated by anaerobic stabilization on soil pollution, plant nutrition, and cotton crop yield.

    PubMed

    Uzen, Nese; Cetin, Oner; Unlu, Mustafa

    2016-12-01

    This study has aimed to determine the effects of treated wastewater on cotton yield and soil pollution in Southeastern Anatolia Region of Turkey during 2011 and 2012. The treated wastewater was provided from the reservoir operated as anaerobic stabilization. After treatment, suspended solids (28-60 mg/l), biological oxygen demand (29-30 mg/l), and chemical oxygen demand (71-112 mg/l) decreased significantly compared to those in the wastewater. There was no heavy metal pollution in the water used. There were no significant amounts of coliform bacteria, fecal coliform, and Escherichia coli compared to untreated wastewater. The cottonseed yield (31.8 g/plant) in the tanks where no commercial fertilizers were applied was considerably higher compared to the yield (17.2 g/plant) in the fertilized tanks where a common nitrogenous fertilizer was utilized. There were no significant differences between the values of soil pH. Soil electrical conductivity (EC) after the experiment increased from 0.8-1.0 to 0.9-1.8 dS/m. Heavy metal pollution did not occur in the soil and plants, because there were no heavy metals in the treated wastewater. It can be concluded that treated domestic wastewater could be used to grow in a controlled manner crops, such as cotton, that would not be used directly as human nutrients.

  4. 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.

  5. 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.

  6. 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.

  7. Cement design based on cement mechanical response

    SciTech Connect

    Thiercelin, M.J.; Dargaud, B.; Baret, J.F.; Rodriquez, W.J.

    1998-12-01

    The disappearance of cement bond log response as a result of variations of downhole conditions has been observed in numerous wells. This observation has led to concern about the loss of proper zonal isolation. Stresses induced in the cement, through deformation of the cemented casing resulting from the variation of downhole conditions, are the cause of this damage. The authors present an analysis of the mechanical response of set cement in a cased wellbore to quantify this damage and determine the key controlling parameters. The results show that the thermo-elastic properties of the casing, cement, and formation play a significant role. The type of failure, either cement debonding or cement cracking, is a function of the nature of the downhole condition variations. This analysis allows one to propose appropriate cement mechanical properties to avoid cement failure and debonding. The authors show that the use of high compressive strength cement is not always the best solution and, in some cases, flexible cements are preferred.

  8. Disposal of metal treated Salvinia biomass in soil and its effect on growth and photosynthetic efficiency of wheat.

    PubMed

    Dhir, Bhupinder; Srivastava, Sheela

    2012-01-01

    Phytoremediation technologies generate huge quantities of biomass, the disposal of which is a serious concern. Wastewater samples collected from electroplating industries were treated with Salvinia biomass. The effect of application of metal loaded Salvinia plant biomass in soil on growth and physiological indices of 10-day-old seedlings of Triticum aestivum was evaluated. Controls (A) consisted of soil supplemented with untreated plant biomass. Seed germination, seedling height, total chlorophyll, glucose and protein levels, photosynthetic efficiency (Fv/Fm), photochemical quenching (qP), non-photochemical quenching (qn), quantum yield (Y), and electron transport rate (ETR) were not significantly affected in seedlings raised in soils supplemented with metal loaded biomass from most of the samples (B-F) in comparison to control. However, significant decline was noted in total chlorophyll, glucose, and quantum yield in plants grown in soil supplemented with biomass from sample E. Among elemental levels, C(%) remained largely unaffected, N(%) showed slight enhancement but a decrease in H(%) was noted in plants grown in soil supplemented with biomass from sample E. Our results, therefore, suggest that metal accumulated Salvinia biomass obtained after phytoremediation of heavy metal contaminated wastewater can be supplemented in soil. Further studies are required to assess long-term effects of disposal of metal loaded Salvinia plant biomass in soil.

  9. Impact of watering with UV-LED-treated wastewater on microbial and physico-chemical parameters of soil.

    PubMed

    Chevremont, A-C; Boudenne, J-L; Coulomb, B; Farnet, A-M

    2013-04-15

    Advanced oxidation processes based on UV radiations have been shown to be a promising wastewater disinfection technology. The UV-LED system involves innovative materials and could be an advantageous alternative to mercury-vapor lamps. The use of the UV-LED system results in good water quality meeting the legislative requirements relating to wastewater reuse for irrigation. The aim of this study was to investigate the impact of watering with UV-LED treated wastewaters (UV-LED WW) on soil parameters. Solid-state ¹³C NMR shows that watering with UV-LED WW do not change the chemical composition of soil organic matter compared to soil watered with potable water. Regarding microbiological parameters, laccase, cellulase, protease and urease activities increase in soils watered with UV-LED WW which means that organic matter brought by the effluent is actively degraded by soil microorganisms. The functional diversity of soil microorganisms is not affected by watering with UV-LED WW when it is altered by 4 and 8 months of watering with wastewater (WW). After 12 months, functional diversity is similar regardless of the water used for watering. The persistence of faecal indicator bacteria (coliform and enterococci) was also determined and watering with UV-LED WW does not increase their number nor their diversity unlike soils irrigated with activated sludge wastewater. The study of watering-soil microcosms with UV-LED WW indicates that this system seems to be a promising alternative to the UV-lamp-treated wastewaters.

  10. 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.

  11. Runoff and interrill erosion in sodic soils treated with dry PAM and phosphogypsum

    USDA-ARS?s Scientific Manuscript database

    Seal formation at the soil surface during rainstorms reduces rain infiltration and leads to runoff and erosion. An increase in soil sodicity increases soil susceptibility to crusting, runoff, and erosion. Surface application of dissolved polyacrylamide (PAM) mixed with gypsum was found to be very ef...

  12. 210Po and major ions in drainage water from soil treated with various types of fertilizers.

    PubMed

    Jiménez, Fernando; López, Raúl; Debán, Luis; Pardo, Rafael; García-Talavera, Marta

    2007-07-01

    The levels of (210)Po, nutrients (NH(4)(+), NO(3)(-), PO(4)(3 -)) and major ions (Na(+), K(+), Mg(2 +), Ca(2 +), F(-), NO(2 -), Br(-), Cl(-), SO(4)(2 -)) were determined, by means of lysimeter experiences, in drainage waters for agricultural soils untreated and treated with different types of fertilizers (animal manure, sewage sludge and NPK synthetic fertilizer) applied at several rates. Analytical determinations were performed by using alpha -spectrometry in the case of (210)Po, or Ion Exchange liquid chromatography for the other ionic species. Statistical uni and multivariate analysis of the results shown significant differences among lixiviates according to the different fertilizer treatments. Sewage sludge and manure applications resulted in similar compositions of lixiviates with low (210)Po levels, whereas synthetic fertilizers produced higher (210)Po concentrations and different concentration patterns of ionic species when applied at or above the recommended rates. All (210)Po levels were well below the limits proposed by the 2001/928/ Euratom Recommendation. The concentrations of the rest of the ionic species, exception made from NH(4)(+) and NO(3)(-), were also below the limits proposed by Spanish regulations.

  13. 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*).

  14. Application of a γRS index-based method and techno-economic analysis for in situ treatment of (137)Cs-contaminated soils by cement-barite based stabilisation/solidification.

    PubMed

    Falciglia, Pietro P; Romano, Stefano; Vagliasindi, Federico G A

    2017-07-15

    This paper examines the application of cement (C)-barite (Ba) based-Stabilisation/Solidification (S/S) for the remediation of (137)Cs-contaminated soils, investigating the influence of soil: grout and C: Ba ratios on the shielding performance of the S/S mix assessed as gamma radiation shielding (γRS) index variation. Results from experiments were used to perform a novel approach and an economic analysis in order to calculate the effective dose reduction achievable by S/S and to assess the optimum quantities and costs of selected mixes, respectively. Gamma ray spectrometer measurements indicate that γRS index increases with increasing barite percentage up to a maximum level of 50%; however a further increase results in a worsening of the shielding performances. A maximum γRS variation of 46.5% was recorded with grout percentage increasing from 16.6 to 50%. At the photon energy of 662 keV ((137)Cs), the maximum grout amount results in the possibility to shield up to 24.1% of γ-rays emitted. The effective dose reduction achievable by the investigated S/S allows a maximum (137)Cs-soil contamination in the range 2.94-14.55 kBq kg(-1) successfully treatable employing a soil: grout ratio of 1: 1 (C: Ba = 1:1). Technical data, jointly with economic analysis findings, make cement-barite based-S/S very competitive in cost-effectiveness and could provide a basis for decision-making of (137)Cs-contaminated site remediation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. The survival of pathogens in soil treated with wastewater sludge and in potatoes grown in such soil.

    PubMed

    Chale-Matsau, J R B; Snyman, H G

    2006-01-01

    The prevalence of pathogens on potatoes (Solanum tuberosum) grown in soil amended with a pathogen rich wastewater sludge was investigated. Bacteria of the family Enterobacteriaceae are important pathogens causing intestinal and systemic illness of humans and other animals. Type B sludge was used. Sludges investigated are the high metal and the low metal sludges. Microorganisms in the sludge-amended soil were using culture-based technique. Salmonella and E. coli were observed in tested soil samples. No microorganisms were isolated from control samples taken throughout the process of the experiment. At harvest time, some of the potato samples from LMS soil were contaminated. These potatoes were subjected to further investigation using molecular techniques (polymerase chain reaction) with fD1 and rP2 as primers. Organisms identified from the sequenced potato peel samples with the BLAST search tool included Enterobacter agglomerans (Pantoea agglomerans), several Buttiauxella spp., Pectobacterium spp., Erwinia spp. and a few Pantoea spp. Other than the E. agglomerans, which is commonly found in the gut and upper respiratory tract of humans and in the environment, all the other species identified were found to be mainly either plant or soil pathogens. The E. agglomerans are not primary pathogens but secondary opportunistic pathogens particularly in immunocompromised individuals. These results suggest that growing high risk crops using wastewater sludge contaminated soil may lead to limited infestation of produce with primary pathogens. It appears that the use of HMS due to early pathogen die-off provides less risk of infection than the LMS. However, proper treatment of wastewater sludge to reduce pathogen load is essential prior to its use as soil conditioner.

  16. 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

  17. 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.

  18. Effectiveness of an anaerobic granular activated carbon fluidized-bed bioreactor to treat soil wash fluids: a proposed strategy for remediating PCP/PAH contaminated soils.

    PubMed

    Koran, K M; Suidan, M T; Khodadoust, A P; Sorial, G A; Brenner, R C

    2001-07-01

    An integrated system has been developed to remediate soils contaminated with pentachlorophenol (PCP) and polycyclic aromatic hydrocarbons (PAHs). This system involves the coupling of two treatment technologies, soil-solvent washing and anaerobic biotreatment of the extract. Specifically, this study evaluated the effectiveness of a granular activated carbon (GAC) fluidized-bed reactor to treat a synthetic-waste stream of PCP and four PAHs (naphthalene, acenaphthene, pyrene, and benzo(b)fluoranthene) under anaerobic conditions. This waste stream was intended to simulate the wash fluids from a soil washing process treating soils from a wood-preserving site. The reactor achieved a removal efficiency of greater than 99.8% for PCP with conversion to its dechlorination intermediates averaging 46.5%. Effluent, carbon extraction, and isotherm data also indicate that naphthalene and acenaphthene were removed from the liquid phase with efficiencies of 86 and 93%, respectively. Effluent levels of pyrene and benzo(b)fluoranthene were extremely low due to the high-adsorptive capacity of GAC for these compounds. Experimental evidence does not suggest that the latter two compounds were biochemically transformed within the reactor.

  19. Effects of adhesive liner and provisional cement on the bond strength of nickel/chrome/beryllium alloy cemented to dentin.

    PubMed

    Latta, Mark A; Kelsey, W Patrick; Murdock, Carol M

    2005-01-01

    Treating teeth with adhesive agents before placing a provisional restoration can prevent tooth sensitivity. This study evaluated the bond strength of resin cements to dentin treated with 2 adhesive agents and 2 provisional cements. Extracted human molars were prepared by exposing dentin and were treated with either Prime & Bond NT or Clearfil SE Bond. After a simulated impression technique, the teeth were provisionalized with either a eugenol or noneugenol temporary cement. Teeth were cleaned for bonding by either mechanical removal of the cement or use of an acid conditioner. Panavia F and Calibra resin cements were used to cement nickel/chrome/beryllium alloy to the tooth surfaces, and the specimens were debonded. Mean shear bond strengths for each group were calculated. Mean shear bond strengths ranged from 26.6 +/- 5.8 MPa for Calibra bonded to dentin treated with Prime & Bond NT, a noneugenol cement, and mechanically cleaned, to 10.6 +/- 4.4 MPa for Panavia F bonded to unlined (no adhesive) dentin treated with a eugenol cement and mechanically cleaned. Of the 14 groups tested, significant differences were observed related to the adhesives and resin cements. Both temporary cements reduced the bond to dentin not treated with a resin adhesive. Use of an acid conditioner for cleaning the temporary cement also reduced bond strengths in all groups. Placement of a dentin adhesive before provisionalization may prevent the temporary cement from affecting the bond of the final resin cement to the tooth. For the products used in this study, use of phosphoric acid to clean the tooth surface is not recommended.

  20. 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

  1. The performance of enhanced coagulation for treating slightly polluted raw water combining polyaluminum chloride with variable charge soil.

    PubMed

    Zhang, Z L; Wu, C D; Wang, Y J; Tang, J C; Liu, Y P

    2014-01-01

    The feasibility and effectiveness of treating pollutants in slightly polluted raw water by variable charge soil and polyaluminum chloride (PAC) was investigated. Removal efficiencies of turbidity, phenol, aniline, algae and heavy metals (Cu(2+), Zn(2+) and Pb(2+)) were used to evaluate the coagulation performance. The results indicated that the addition of variable charge soil as a coagulant aid is advantageous due to the improvement of removal efficiencies. The tests also demonstrated that the presence of variable charge soil increased the removal of turbidity rather than adding residuary turbidity. The use of variable charge soil produced settleable flocs of greater density and bigger size. The main mechanism involved in the PAC coagulation was supposed to be sweep flocculation as well as charge-neutralization. Variable charge soil played a promoted aid role by adsorption in the enhanced coagulation process. It is concluded that the enhanced coagulation by PAC and variable charge soil, as coagulant and adsorbent, is more effective and efficient than traditional coagulation.

  2. Petroleum Sludge as gypsum replacement in cement plants: Its Impact on Cement Strength

    NASA Astrophysics Data System (ADS)

    Benlamoudi, Ali; Kadir, Aeslina Abdul; Khodja, Mohamed

    2017-08-01

    Due to high cost of cement manufacturing and the huge amount of resources exhaustion, companies are trying to incorporate alternative raw materials or by-products into cement production so as to produce alternative sustainable cement. Petroleum sludge is a dangerous waste that poses serious imparts on soil and groundwater. Given that this sludge contains a high percentage of anhydrite (CaSO4), which is the main component of gypsum (CaSO4.2H2O), it may play the same gypsum role in strength development. In this research, a total replacement of gypsum (100%) has been substituted by petroleum sludge in cement production and has led to an increase of 28.8% in UCS values after 28 curing days. Nevertheless, the burning of this waste has emitted a considerable amount of carbon monoxide (CO) gas that needs to be carefully considered prior to use petroleum sludge within cement plants.

  3. Cadmium contamination of wood ash and fire-treated coniferous humus: Effect on soil respiration

    SciTech Connect

    Fritze, H.; Kapanen, A.; Vanhala, P.

    1995-05-01

    Atmospheric acidic deposition is known to affect soil fertility and in many countries, liming has been used to counteract anthropogenic soil acidification in coniferous forest soils. Other measures used to improve the acid neutralization capacity of forest soils are wood ash application and prescribed burning. In both cases, ash is deposited on the forest floor, resulting in a pH increase in the humus layer. Currently, application of forests with wood ash is under discussion in Finland, since the naturally occurring cadmium of forest trees is concentrated into the wood ash which then contains between 4 and 20 {mu} g{sup {minus}1} of dry matter. Microbes are essential for maintaining soil fertility and plant growth because they play a fundamental role in nutrient availability. Soil respiration rate, which is an indicator of the microbially-mediated nutrient turnover rate, is decreased by addition of cadmium to the soil environment. In this paper we report on the effects of cadmium addition on the soil respiration rate of forest humus having received wood ash or fire treatments. The underlying objectives of this study were: (i) to determine the cadmium level which decreases the soil respiration of a Vaccinium site type forest humus to half of its original value (EC{sub 50}), (ii) to estimate how the forest treatments influence the EC{sub 50}, and (iii) to discuss the effect of Cd addition provided by wood ash on the nutrient mineralization rate. 17 refs., 2 figs., 2 tabs.

  4. Cement mixing with vibrator

    SciTech Connect

    Allen, T.E.

    1991-07-09

    This patent describes a method of cementing a casing string in a bore hole of a well. It comprises introducing water and dry cement material into a mixing vessel; mixing the water and dry cement material in the mixing vessel to form a cement slurry, the slurry including lumps of the dry cement material, the mixing including steps of: agitating the slurry; and while agitating the slurry, transmitting vibrational energy into the slurry and thereby aiding disintegration and subsequent wetting of the lumps of the dry cement material in the slurry; and pumping the slurry into an annulus between the casing string and the bore hole.

  5. Two-stage soil infiltration treatment system for treating ammonium wastewaters of low COD/TN ratios.

    PubMed

    Lei, Zhongfang; Wu, Ting; Zhang, Yi; Liu, Xiang; Wan, Chunli; Lee, Duu-Jong; Tay, Joo-Hwa

    2013-01-01

    Soil infiltration treatment (SIT) is ineffective to treat ammonium wastewaters of total nitrogen (TN) > 100 mg l(-1). This study applied a novel two-stage SIT process for effective TN removal from wastewaters of TN>100 mg l(-1) and of chemical oxygen demand (COD)/TN ratio of 3.2-8.6. The wastewater was first fed into the soil column (stage 1) at hydraulic loading rate (HLR) of 0.06 m(3) m(-2) d(-1) for COD removal and total phosphorus (TP) immobilization. Then the effluent from stage 1 was fed individually into four soil columns (stage 2) at 0.02 m(3) m(-2) d(-1) of HLR with different proportions of raw wastewater as additional carbon source. Over the one-year field test, balanced nitrification and denitrification in the two-stage SIT revealed excellent TN removal (>90%) from the tested wastewaters.

  6. Instability improvement of the subgrade soils by lime addition at Borg El-Arab, Alexandria, Egypt

    NASA Astrophysics Data System (ADS)

    El Shinawi, A.

    2017-06-01

    Subgrade soils can affect the stability of any construction elsewhere, instability problems were found at Borg El-Arab, Alexandria, Egypt. This paper investigates geoengineering properties of lime treated subgrade soils at Borg El-Arab. Basic laboratory tests, such as water content, wet and dry density, grain size, specific gravity and Atterberg limits, were performed for twenty-five samples. Moisture-density (compaction); California Bearing Ratio (CBR) and Unconfined Compression Strength (UCS) were conducted on treated and natural soils. The measured geotechnical parameters of the treated soil shows that 6% lime is good enough to stabilize the subgrade soils. It was found that by adding lime, samples shifted to coarser side, Atterberg limits values of the treated soil samples decreased and this will improve the soil to be more stable. On the other hand, Subgrade soils improved as a result of the bonding fine particles, cemented together to form larger size and reduce the plastiCity index which increase soils strength. The environmental scanning electron microscope (ESEM) is point to the presence of innovative aggregated cement materials which reduce the porosity and increase the strength as a long-term curing. Consequently, the mixture of soil with the lime has acceptable mechanical characteristics where, it composed of a high strength base or sub-base materials and this mixture considered as subgrade soil for stabilizations and mitigation the instability problems that found at Borg Al-Arab, Egypt.

  7. Comparing the reinforcing effects of a resin modified glassionomer cement, Flowable compomer, and Flowable composite in the restoration of calcium hydroxide-treated immature roots in vitro.

    PubMed

    Prathibha, Rani S

    2011-01-01

    One hundred and sixty human permanent central incisors were enlarged to a 120 file size after crown removal procedure to simulate immature teeth. The root canals were filled with calcium hydroxide and stored for 15 days (phase I), 30 days (phase II), 90 days (phase III), and 180 days (Phase IV). At the end of these selected time periods, calcium hydroxide was cleaned off the root canals of forty teeth that were randomly selected and obturated with gutta-percha points in the apical 2 mm of the root canals with a sealer. The specimens were further equally divided into four groups. Unrestored Group I served as control and the root canals of teeth in the other three group specimens were reinforced with resin modified glassionomer cement (RMGIC) (Group II), Flowable Compomer (Group III), and Flowable Composite (Group IV), respectively, using a translucent curing post. All specimens were subjected to compressive force using an Instron Testing machine, until fracture occurred. All the materials evaluated substantially reinforced the root specimens compared to the control. At the end of 180 days, Flowable composites showed maximum reinforcement compared to the other groups; however, no significant differences were found between the reinforcement capabilities of Flowable Compomer and RMGIC.

  8. 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...

  9. 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...

  10. Variation in herbaceous vegetation and soil moisture under treated and untreated oneseed juniper trees

    Treesearch

    Hector Ramirez; Alexander Fernald; Andres Cibils; Michelle Morris; Shad Cox; Michael Rubio

    2008-01-01

    Clearing oneseed juniper (Juniperus monosperma) may make more water available for aquifer recharge or herbaceous vegetation growth, but the effects of tree treatment on soil moisture dynamics are not fully understood. This study investigated juniper treatment effects on understory herbaceous vegetation concurrently with soil moisture dynamics using vegetation sampling...

  11. 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.

  12. 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.

  13. 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.

  14. Leaching of PAHs from agricultural soils treated with oil shale combustion ash: an experimental study.

    PubMed

    Jefimova, Jekaterina; Adamson, Jasper; Reinik, Janek; Irha, Natalya

    2016-10-01

    The present study focuses on the fate of polycyclic aromatic hydrocarbons (PAHs) in soils amended with oil shale ash (OSA). Leachability studies to assess the release of PAHs to the environment are essential before the application of OSA in agriculture. A quantitative estimation of the leaching of PAHs from two types of soil and two types of OSA was undertaken in this study. Two leaching approaches were chosen: (1) a traditional one step leaching scheme and (2) a leaching scheme with pretreatment, i.e.., incubation of the material in wet conditions imitating the field conditions, followed by a traditional leaching procedure keeping the total amount of water constant. The total amount of PAHs leached from soil/OSA mixtures was in the range of 15 to 48 μg/kg. The amount of total PAHs leached was higher for the incubation method, compared to the traditional leaching method, particularly for Podzolic Gleysols soil. This suggests that for the incubation method, the content of organic matter and clay minerals of the soil influence the fate of PAHs more strongly compared to the traditional leaching scheme. The amount of PAHs leached from OSA samples is higher than from soil/OSA mixtures, which suggests soils to inhibit the release of PAHs. Calculated amount of PAHs from experimental soil and OSA leaching experiments differed considerably from real values. Thus, it is not possible to estimate the amount of PAHs leached from soil/OSA mixtures based on the knowledge of the amount of PAHs leached from soil and OSA samples separately.

  15. Asphalt cement poisoning

    MedlinePlus

    ... petroleum material that hardens when it cools. Asphalt cement poisoning occurs when someone swallows asphalt. If hot ... found in: Road paving materials Roofing materials Tile cements Asphalt may also be used for other purposes.

  16. 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.

  17. Induced heterogeneity of soil water content and chemical properties by treated wastewater irrigation and its reclamation by freshwater irrigation

    NASA Astrophysics Data System (ADS)

    Rahav, Matan; Brindt, Naaran; Yermiyahu, Uri; Wallach, Rony

    2017-06-01

    The recognition of treated wastewater (TWW) as an alternative water resource is expanding in areas with a shortage of freshwater (FW) resources. Today, most orchards in Israel are irrigated with TWW. While the benefits of using TWW for irrigation are apparent, evidence of its negative effects on soil, trees, and yield is accumulating. This study, performed in a commercial TWW-irrigated citrus orchard in central Israel, examined the effects of (1) soil-wettability decrease due to prolonged TWW irrigation on the spatial and temporal distribution of water content and associated chemical properties in the root zone; (2) the conversion of irrigation in half of the TWW-irrigated research plot to FW (2012) for soil reclamation. Electrical resistivity tomography surveys in the substantially water repellent soils revealed that water flow is occurring along preferential flow paths in both plots, leaving behind a considerably nonuniform water-content distribution. This was despite the gradual relief in soil water repellency measured in the FW plots. Four soil-sampling campaigns (spring and fall, 2014-2016), performed in 0-20 and 20-40 cm layers of the research plot, revealed bimodal gravimetrically measured water-content distribution. The preferential flow led to uneven chemical-property distribution, with substantially high concentrations in the dry spots, and lower concentrations in the wet spots along the preferential flow paths. The average salt and nutrient concentrations, which were initially high in both plots, gradually dispersed with time, as concentrations in the FW plots decreased. Nevertheless, the efficiency of reclaiming TWW soil by FW irrigation appears low.

  18. 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.

  19. 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.

  20. 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...

  1. 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...

  2. Detrimental effects of boric-acid-treated soil against foraging subterranean termites (Isoptera: Rhinotermitidae)

    Treesearch

    Bradford M. Kard

    2001-01-01

    111 laboratory bioassays, boric acid (BA) mixed with soil caused significant subterranean termite mortality. In clloice tests, eastern subterranean and Formosan subterranean tennites were exposed to boric acid mixed with soil at concentrations of 0.05, 0.25, 0.50, 1.00, 2.00, and 4.00 percent Al (wt:wt). Termites could choose to remain in their main nests wit13 non-...

  3. 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.

  4. Laboratory persistence in soil of thiacloprid, pendimethalin and fenarimol incubated with treated wastewater and dissolved organic matter solutions. Contribution of soil biota.

    PubMed

    Rodríguez-Liébana, José Antonio; ElGouzi, Siham; Peña, Aránzazu

    2017-08-01

    Reutilization of treated wastewater (TWW) in agriculture has continued to grow, especially in areas prone to frequent drought periods. One of the major aspects derived from this practice is the addition of important amounts of organic carbon (OC) that could interfere with the fate of organic contaminants in soils. This study has evaluated the impact of irrigation with a secondary TWW and dissolved OC (DOC) solutions from sewage sludge in the dissipation of thiacloprid (THC), pendimethalin (PDM) and fenarimol (FEN) in an OC-poor agricultural soil under laboratory conditions. The effect on soil microbial activity was also assessed through the measurement of dehydrogenase activity. Biotic processes were the main responsible for the degradation of the three compounds. Results showed that while THC was rapidly degraded (DT50 ≤ 5.5 d), PDM and FEN were moderately persistent in soil (DT50 ≥ 93 d). Incubation with TWW did not modify the decay rate of the three pesticides, but initially inhibited soil biota. Solutions of DOC did not alter the dissipation of FEN, but contrasting effects were observed for THC and PDM. Low DOC concentrations (30 mg L(-1)) accelerated THC disappearance, a fact explained by stimulation of endogenous biota rather than by the presence of exogenous microorganisms from the solution. On the other hand, high DOC concentrations (300 mg L(-1)) had more influence on the activity of microorganisms at longer times, and showed a trend to enhance the disappearance of the moderately persistent PDM. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. 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.

  6. The activation energy of stabilised/solidified contaminated soils.

    PubMed

    Chitambira, B; Al-Tabbaa, A; Perera, A S R; Yu, X D

    2007-03-15

    Developing an understanding of the time-related performance of cement-treated materials is essential in understanding their durability and long-term effectiveness. A number of models have been developed to predict this time-related performance. One such model is the maturity concept which involves use of the 'global' activation energy which derives from the Arrhenius equation. The accurate assessment of the activation energy is essential in the realistic modelling of the accelerated ageing of cement-treated soils. Experimentally, this model is applied to a series of tests performed at different elevated temperatures. Experimental work, related to the results of a time-related performance on a contaminated site in the UK treated with in situ stabilisation/solidification was carried out. Three different cement-based grouts were used on two model site soils which were both contaminated with a number of heavy metals and a hydrocarbon. Uncontaminated soils were also tested. Elevated temperatures up to 60 degrees C and curing periods up to 90 days were used. The resulting global activation energies for the uncontaminated and contaminated soils were compared. Lower values were obtained for the contaminated soils reflecting the effect of the contaminants. The resulting equivalent ages for the uncontaminated and contaminated mixes tested were 5.1-7.4 and 0.8-4.1 years, respectively. This work shows how a specific set of contaminants affect the E(a) values for particular cementitious systems and how the maturity concept can be applied to cement-treated contaminated soils.

  7. 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.

  8. ULTRA-LIGHTWEIGHT CEMENT

    SciTech Connect

    Fred Sabins

    2001-04-15

    The objective of this project is to develop an improved ultra-lightweight cement using ultralight hollow glass spheres (ULHS). Work reported herein addresses Task 1: Assess Ultra-Lightweight Cementing Problems and Task 3: Test Ultra-Lightweight Cements. Results reported this quarter include a review and summary of Halliburton Energy Services (HES) and BJ Services historical performance data for lightweight cement applications. These data are analyzed and compared to ULHS cement and foamed cement performances. Similar data is expected from Schlumberger, and an analysis of this data will be completed in the following phases of the project. Quality control testing of materials used to formulate ULHS cements in the laboratory was completed to establish baseline material performance standards. A testing protocol was developed employing standard procedures as well as procedures tailored to evaluate ULHS and foamed cement. This protocol is presented and discussed. Results of further testing of ULHS cements are presented along with an analysis to establish cement performance design criteria to be used during the remainder of the project. Finally, a list of relevant literature on lightweight cement performance is compiled for review during the next quarter.

  9. 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

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

    PubMed

    Singleton, David R; Richardson, Stephen D; Aitken, Michael D

    2011-11-01

    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.

  11. 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.

  12. ULTRA-LIGHTWEIGHT CEMENT

    SciTech Connect

    Fred Sabins

    2002-10-31

    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 will be performed for analyzing the alkali-silica reactivity of ULHS in cement slurries, as well as the results of Field Tests 1 and 2.

  13. 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.

  14. C and N accumulations in soil aggregates determine nitrous oxide emissions from cover crop treated rice paddy soils during fallow season.

    PubMed

    Pramanik, Prabhat; Haque, Md Mozammel; Kim, Sang Yoon; Kim, Pil Joo

    2014-08-15

    Combination of leguminous and non-leguminous plant residues are preferably applied in rice paddy soils to increase the rate of organic matter mineralization and to improve plant growth. However, organic matter addition facilitates methane (CH4) emission from rice paddy soil. Mineralization of organic nitrogen (N) increases NO3-N concentrations in soil, which are precursors for the formation of nitrous oxide (N2O). However, N2O is a minor greenhouse gas emitted from submerged rice field and hence is not often considered during calculation of total global warming potential (GWP) during rice cultivation. The hypothesis of this study was that fluxes of N2O emissions might be changed after removal of flooded water from rice field and the effect of cover crops on N2O emissions in the fallow season might be interesting. However, the effects of N-rich plant residues on N2O emission rates in the fallow season and its effect on annual GWP were not studied before. In this experiment, combination of barley (non-leguminous) and hairy vetch (leguminous) biomasses were applied at 9 Mg ha(-1) and 27 Mg ha(-1) rates in rice paddy soil. Cover crop application significantly increased CH4 emission flux while decreased N2O emissions during rice cultivation. The lowest N2O emission was observed in 27 Mg ha(-1) cover crop treated plots. Cover crop applications increased N contents in soil aggregates especially in smaller aggregates (<250 μm), and that proportionately increased the N2O emission potentials of these soil aggregates. Fluxes of N2O emissions in the fallow season were influenced by the N2O emission potentials of soil aggregates and followed opposite trends as those observed during rice cultivation. Therefore, it could be concluded that the doses of cover crop applications for rice cultivation should not be optimized considering only CH4, but N2O should also be considered especially for fallow season to calculate total GWP. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. 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.

  16. 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).

  17. 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.

  18. 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

  19. 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

    Kumar, Lalit; 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.

  20. The influence of temporary cements on dental adhesive systems for luting cementation.

    PubMed

    Ribeiro, José C V; Coelho, Paulo G; Janal, Malvin N; Silva, Nelson R F A; Monteiro, André J; Fernandes, Carlos A O

    2011-03-01

    This study tested the hypothesis that bond strength of total- and self-etching adhesive systems to dentine is not affected by the presence of remnants from either eugenol-containing (EC) or eugenol-free (EF) temporary cements after standardized cleaning procedures. Thirty non-carious human third molars were polished flat to expose dentine surfaces. Provisional acrylic plates were fabricated and cemented either with EC, EF or no temporary cements. All specimens were incubated for 7 days in water at 37°C. The restorations were then taken out and the remnants of temporary cements were mechanically removed with a dental instrument. The dentine surfaces were cleaned with pumice and treated with either total-etching (TE) or self-etching (SE) dental adhesive systems. Atomic force microscopy was used to examine the presence of remnants of temporary cements before and after dentine cleaning procedures. Composite resin build-ups were fabricated and cemented to the bonded dentine surfaces with a resin luting cement. The specimens were then sectioned to obtain 0.9mm(2) beams for microtensile bond strength testing. Fractographic analysis was performed by optical and scanning electron microscopy. ANOVA showed lower mean microtensile bond strength in groups of specimens treated with EC temporary cement than in groups treated with either no cement or an EF cement (p<0.05). Mean microtensile bond strength was lower in groups employing the SE rather than the TE adhesive system (p<0.001). SE samples were also more likely to fail during initial processing of the samples. There was no evidence of interaction between cement and adhesive system effects on tensile strength. Fractographic analysis indicated different primary failure modes for SE and TE bonding systems, at the dentine-adhesive interface and at the resin cement-resin composite interface, respectively. The use of eugenol-containing temporary cements prior to indirect bonding restorations reduce, to a statistically similar

  1. 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.

  2. Tooth surface treatment strategies for adhesive cementation.

    PubMed

    Rohr, Nadja; Fischer, Jens

    2017-04-01

    The aim of this study was to evaluate the effect of tooth surface pre-treatment steps on shear bond strength, which is essential for understanding the adhesive cementation process. Shear bond strengths of different cements with various tooth surface treatments (none, etching, priming, or etching and priming) on enamel and dentin of human teeth were measured using the Swiss shear test design. Three adhesives (Permaflo DC, Panavia F 2.0, and Panavia V5) and one self-adhesive cement (Panavia SA plus) were included in this study. The interface of the cement and the tooth surface with the different pre-treatments was analyzed using SEM. pH values of the cements and primers were measured. The highest bond strength values for all cements were achieved with etching and primer on enamel (25.6 ± 5.3 - 32.3 ± 10.4 MPa). On dentin, etching and priming produced the highest bond strength values for all cements (8.6 ± 2.9 - 11.7 ± 3.5 MPa) except for Panavia V5, which achieved significantly higher bond strengths when pre-treated with primer only (15.3 ± 4.1 MPa). Shear bond strength values were correlated with the micro-retentive surface topography of enamel and the tag length on dentin except for Panavia V5, which revealed the highest bond strength with primer application only without etching, resulting in short but sturdy tags. The highest bond strength can be achieved for Panavia F 2.0, Permaflo DC, and Panavia SA plus when the tooth substrate is previously etched and the respective primer is applied. The new cement Panavia V5 displayed low technique-sensitivity and attained significantly higher adhesion of all tested cements to dentin when only primer was applied.

  3. Tooth surface treatment strategies for adhesive cementation

    PubMed Central

    2017-01-01

    PURPOSE The aim of this study was to evaluate the effect of tooth surface pre-treatment steps on shear bond strength, which is essential for understanding the adhesive cementation process. MATERIALS AND METHODS Shear bond strengths of different cements with various tooth surface treatments (none, etching, priming, or etching and priming) on enamel and dentin of human teeth were measured using the Swiss shear test design. Three adhesives (Permaflo DC, Panavia F 2.0, and Panavia V5) and one self-adhesive cement (Panavia SA plus) were included in this study. The interface of the cement and the tooth surface with the different pre-treatments was analyzed using SEM. pH values of the cements and primers were measured. RESULTS The highest bond strength values for all cements were achieved with etching and primer on enamel (25.6 ± 5.3 - 32.3 ± 10.4 MPa). On dentin, etching and priming produced the highest bond strength values for all cements (8.6 ± 2.9 - 11.7 ± 3.5 MPa) except for Panavia V5, which achieved significantly higher bond strengths when pre-treated with primer only (15.3 ± 4.1 MPa). Shear bond strength values were correlated with the micro-retentive surface topography of enamel and the tag length on dentin except for Panavia V5, which revealed the highest bond strength with primer application only without etching, resulting in short but sturdy tags. CONCLUSION The highest bond strength can be achieved for Panavia F 2.0, Permaflo DC, and Panavia SA plus when the tooth substrate is previously etched and the respective primer is applied. The new cement Panavia V5 displayed low technique-sensitivity and attained significantly higher adhesion of all tested cements to dentin when only primer was applied. PMID:28435616

  4. Soils

    Treesearch

    Emily Moghaddas; Ken Hubbert

    2014-01-01

    When managing for resilient forests, each soil’s inherent capacity to resist and recover from changes in soil function should be evaluated relative to the anticipated extent and duration of soil disturbance. Application of several key principles will help ensure healthy, resilient soils: (1) minimize physical disturbance using guidelines tailored to specific soil types...

  5. 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.

  6. Legacy Chlordane in Soils from Housing Areas Treated with Organochlorine Pesticides

    DTIC Science & Technology

    2009-12-01

    because of concern about cancer risks and canceled all uses after 1988 (USEPA/IRIS 2008). There- fore, all chlordane present in soil in Air Force housing...and T. F. Meiller. 2004. Fungal biofilms and drug resistance. Emerging Infectious Diseases (www.cdc.gov/eid) 10:14–19. Johannes, C., and A

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

    USDA-ARS?s Scientific Manuscript database

    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...

  8. Evaluation of PAH contamination in soil treated with solid by-products from shale pyrolysis.

    PubMed

    Nicolini, Jaqueline; Khan, Muhammad Y; Matsui, M; Côcco, Lílian C; Yamamoto, Carlos I; Lopes, Wilson A; de Andrade, Jailson B; Pillon, Clenio N; Arizaga, Gregorio G Carbajal; Mangrich, Antonio S

    2015-01-01

    The aim of this work was to evaluate the concentrations of polycyclic aromatic hydrocarbons (PAHs) in soils to which solid shale materials (SSMs) were added as soil conditioners. The SSMs were derived from the Petrosix pyrolysis process developed by Petrobras (Brazil). An improved ultrasonic agitation method was used to extract the PAHs from the solid samples (soils amended with SSMs), and the concentrations of the compounds were determined by gas chromatography coupled to mass spectrometry (GC-MS). The procedure provided satisfactory recoveries, detection limits, and quantification limits. The two-, three-, and four-ring PAHs were most prevalent, and the highest concentration was obtained for phenanthrene (978 ± 19 μg kg(-1) in a pyrolyzed shale sample). The use of phenanthrene/anthracene and fluoranthene/pyrene ratios revealed that the PAHs were derived from petrogenic rather than pyrogenic sources. The measured PAH concentrations did not exceed national or international limit values, suggesting that the use of SSMs as soil conditioners should not cause environmental damage.

  9. 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...

  10. 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...

  11. Ectomycorrhizal formation in herbicide-treated soils of differing clay and organic matter content

    Treesearch

    Matt D. Busse; Gary O. p Fiddler; Alice W. Ratcliff

    2004-01-01

    Herbicides are commonly used on private timberlands in the western United States for site preparation and control of competing vegetation. How non-target soil biota respond to herbicide applications, however, is not thoroughly understood. We tested the effects of triclorpyr, imazapyr, and sulfometuron methyl on ectomycorrhizal formation in a greenhouse study. Ponderosa...

  12. Treating soil-washing fluids polluted with oxyfluorfen by sono-electrolysis with diamond anodes.

    PubMed

    Vieira Dos Santos, E; Sáez, C; Cañizares, P; Martínez-Huitle, C A; Rodrigo, M A

    2017-01-01

    This works is focused on the treatment by sono-electrolysis of the liquid effluents produced during the Surfactant-Aided Soil-Washing (SASW) of soils spiked with herbicide oxyfluorfen. Results show that this combined technology is very efficient and attains the complete mineralization of the waste, regardless of the surfactant/soil radio applied in the SASW process (which is the main parameter of the soil remediation process and leads to very different wastes). Both the surfactant and the herbicide are completely degraded, even when single electrolysis is used; and only two intermediates are detected by HPLC in very low concentrations. Conversely, the efficiency of single sonolysis approach, for the oxidation of pollutant, is very low and just small changes in the herbicides and surfactant concentrations are observed during the tests carried out. Sono-electrolysis with diamond electrodes achieved higher degradation rates than those obtained by single sonolysis and/or single electrolysis with diamond anodes. A key role of sulfate is developed, when it is released after the electrochemical degradation of surfactant. The efficient catalytic effect observed which can be explained by the anodic formation of persulfate and the later, a sono-activation is attained to produce highly efficient sulfate radicals. The effect of irradiating US is more importantly observed in the pesticide than in the surfactant, in agreement with the well-known behavior of these radicals which are known to oxidize more efficiently aromatic compounds than aliphatic species. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. Operations Guide and Modification Analysis for Use of the CE (Corps of Engineers) Concrete Quality Monitor on Roller-Compacted Concrete and Soil Cement.

    DTIC Science & Technology

    1985-07-01

    ly produced washing machine that was specified for which has a water pump and stirrer motor. The tank the original KV and USA-CERL/KV methods. A is...set up by (1) placing it on the base stand, (2) at- cement suspension tank was chosen for the Generation taching the tube connecting the water pump to...uncrate (or crate) and set up (or more versatile , rugged (and expensive) digital scale. take down) all the CE CQM equipment. Also, if the CE CQM is

  14. 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

  15. 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.

  16. Coupled effects of treated effluent irrigation and wetting-drying cycles on transport of triazines through unsaturated soil columns.

    PubMed

    Seol, Y; Lee, L S

    2001-01-01

    The physical and chemical parameters controlling the movement of atrazine (6-chloro-N2-ethyl-N4-isopropyl-l,3,5-triazine-2,4-diamine; 98.8%) and prometryn [N,N'-bis(1-methylethyl)-6-(methylthio)-l,3,5triazine-2,4-diamine; 99.5%] were investigated in columns infiltrated with treated effluent under unsaturated transient conditions and subjected to drying events at 22 or 60 degrees C followed by rewetting. Three soils varying in soil pH and texture and three solutions were used. The infiltrating solutions consisted of either a CaCl2 matrix (CC), a swine waste-derived lagoon effluent (SW), or a simulated buffer solution (SB) representative of the element composition and pH of the SW but with no dissolved organic matter. Several parameters were monitored including leachate triazine concentrations, pH, dissolved organic carbon (DOC), inorganic carbon, and flow rates. Compared with CC, application of SW and SB increased column leachate pH, enhanced dissolution of organic carbon and particle dispersion, and decreased average flow rates, which allowed for increased desorption time. The coupled effect of these processes enhanced movement of triazines in some cases, with SW generally having the greatest effect. The individual effect of increased pH was more pronounced for prometryn (pKa=4.05) versus atrazine (pKa=1.66), and most dramatic for the soil with the lowest initial pH. High-temperature drying, which simulated intensive evaporation, further enhanced the dissolution of soil organic matter and the reduction in leachate flow rates with SW and SB applications; however, the net effect under the experimental conditions employed varied with soil type. Relative to low-temperature drying, high-temperature drying in the silty clay loam-packed columns reduced pesticide migration.

  17. Effects of sewage sludges contaminated with chlorinated aromatic hydrocarbons on sludge-treated areas (soils and sediments).

    PubMed

    Eljarrat, Ethel

    2002-06-22

    The fate of PCDDs, PCDFs, and PCBs in sewage sludges after different management techniques--such as agricultural application, land restoration, and marine disposal--was studied. Changes observed in the concentrations, in the ratio between PCDD and PCDF levels, and in the isomeric distribution suggest the influence of the sewage sludge on the sludge-treated areas (soils and sediments). Whereas land application techniques seem to produce no serious environmental consequences, marine disposal practices produce considerable increases in the levels of contamination in marine sediments.

  18. 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

  19. Soil

    USDA-ARS?s Scientific Manuscript database

    Soil is a diverse natural material characterized by solid, liquid, and gas phases that impart unique chemical, physical, and biological properties. Soil provides many key functions, including supporting plant growth and providing environmental remediation. Monitoring key soil properties and processe...

  20. Improvement of casing cementation of deep and ultradeep wells. Part 2: Oilfield cements and cement additives

    NASA Astrophysics Data System (ADS)

    Arens, K. H.; Akstinat, M.

    1982-07-01

    Oilfield cements and cement additives were investigated in order to improve the casing cementation of deep and ultradeep wells. Characterization and evaluation of the main oil field cements commercially available were studied. The testing was carried out according to American Petroleum Institute API standards and nonstandardized test methods (dynamic modulus of elasticity, expansion/shrinkage), especially the rheology, thickening time and the influence of pressure, temperature and water-cement ratio, were considered. The main emphasis in the field of cement additives was on the evaluation of cement retarders for high temperatures, accelerators, and additives for cement expansion. Furthermore oil field cements were tested, and their properties are described.

  1. Manufactured Soil Field Demonstration for Constructing Wetlands to Treat Acid Mine Drainage on Abandoned Minelands

    DTIC Science & Technology

    2007-11-01

    constructing the wetlands including dredged material, residual waste paper fiber, sawdust, mush- room compost , cow manure, processed cow manure, and...Bony + Waste Paper Fiber + Mushroom Compost + BionsoilTM The RSMT procedures (Sturgis and Lee 1999) were applied in a randomized complete block design...than 100 percent Bony, 100 percent Donora, 3BD, and the 4 ERDC TN-DOER-D9 November 2007 fertile commercial potting soil. Blend 1BD was selected for

  2. Land application of chemically treated sewage sludge. II. Effects on soil and plant heavy metal content

    SciTech Connect

    Soon, Y.K.; Bates, T.E.; Moyer, J.R.

    1980-07-01

    Anaerobically digested sewage sludges resulting from treatment of sewage with Ca(OH)/sub 2/, Al/sub 2/(SO/sub 4/)/sub 3/, or FeCl/sub 3/ for phosphorus precipitation were applied to corn (Zea mays L.) and bromegrass (Bromus inermis Leyess) grown on a soil having an initial pH of 7.3. Rates of sludge supplied 200, 400, 800, and and 1,600 kg N/ha each year for 5 years. Treatments with NH/sub 4/NO/sub 3/ supplying 0, 100, 20, and 400 kg N/ha were included for comparison. Plant tissue was analyzed for Cu, Zn, Mn, Cd, Ni, Cr, and Pb. No toxicity or deficiency symptoms were noted. Soil Zn, Cd, and Ni extracted by NTA (nitrilotriacetic acid) were increased by continued sludge application. The NTA-extractable Zn and Cd were positively correlated with the Zn and Cd concentrations in corn stover. Soil pH was reduced by the Fe-sludge application, slightly affected by the Al-sludge, and increased by the Ca-sludge. Increases in Cu concentrations in bromegrass and corn stover were associated with increases in the N content rather than the source of N, and plant Cu concentrations remained relatively constant across years. Sewage sludge application increased Zn, Cd, and Ni concentrations in bromegrass and corn stover, and Zn and Ni concentrations in corn grain, particularly at the higher metal loadings from sludge application. Zinc and Cd concentrations, especially in corn stover, increased with continued sludge application during the 5-year period. The inclusion of soil pH as a factor, in addition to cummulative amounts of Zn or Cd added as a constituent of sludge, improved the regression equations predicting Zn or Cd uptake.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. ENGINEERING CHARACTERISTICS OF SOME SOUTHEAST ASIAN SOILS.

    DTIC Science & Technology

    soil samples were mostly sandy soils and lateritic soils, composed mainly of quartz, perthite, kaolinite, illite, and goethite, or some combination of...mainly on gradation of the soils and was not affected adversely by the sesquioxides in the lateritic soils. Additional tests are required to more accurately delineate the most beneficial soil gradations for soil-cements. (Author)

  8. Effects of different irrigation practices using treated wastewater on tomato yields, quality, water productivity, and soil and fruit mineral contents.

    PubMed

    Demir, Azize Dogan; Sahin, Ustun

    2017-09-15

    Wastewater use in agricultural irrigation is becoming a common practice in order to meet the rising water demands in arid and semi-arid regions. The study was conducted to determine the effects of the full (FI), deficit (DI), and partial root-zone drying (PRD) irrigation practices using treated municipal wastewater (TWW) and freshwater (FW) on tomato yield, water use, fruit quality, and soil and fruit heavy metal concentrations. The TWW significantly increased marketable yield compared to the FW, as well as decreased water consumption. Therefore, water use efficiency (WUE) in the TWW was significantly higher than in the FW. Although the DI and the PRD practices caused less yields, these practices significantly increased WUE values due to less irrigation water applied. The water-yield linear relationships were statistically significant. TWW significantly increased titratable acidity and vitamin C contents. Reduced irrigation provided significantly lower titratable acidity, vitamin C, and lycopene contents. TWW increased the surface soil and fruit mineral contents in response to FW. Greater increases were observed under FI, and mineral contents declined with reduction in irrigation water. Heavy metal accumulation in soils was within safe limits. However, Cd and Pb contents in fruits exceeded standard limits given by FAO/WHO. Higher metal pollution index values determined for fruits also indicated that TWW application, especially under FI, might cause health risks in long term.

  9. 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.

  10. Urine from Treated Cattle Drives Selection for Cephalosporin Resistant Escherichia coli in Soil

    PubMed Central

    Subbiah, Murugan; Shah, Devendra H.; Besser, Thomas E.; Ullman, Jeffrey L.; Call, Douglas R.

    2012-01-01

    The U.S. Food and Drug Administration recently issued new rules for using ceftiofur in food animals in part because of an increasing prevalence of enteric bacteria that are resistant to 3rd-generation cephalosporins. Parenteral ceftiofur treatment, however, has limited effects on enteric bacteria so we tested the hypothesis that excreted ceftiofur metabolites exert significant selection pressure for ceftiofur-resistant Escherichia coli in soil. Test matrices were prepared by mixing soil with bovine feces and adding urine containing ceftiofur metabolites (CFM) (0 ppm, ∼50 ppm and ∼100 ppm). Matrices were incubated at 23°C or 4°C for variable periods of time after which residual CFM was quantified using a bioassay. BlaCMY-2 plasmid-bearing ceftiofur resistant (cefR) E. coli and one-month old calves were used to study the selection effects of CFM and transmission of cefR bacteria from the environment back to animals. Our studies showed that urinary CFM (∼13 ppm final concentration) is biologically degraded in soil within 2.7 days at 23°C, but persists up to 23.3 days at 4°C. Even short-term persistence in soil provides a >1 log10 advantage to resistant E. coli populations, resulting in significantly prolonged persistence of these bacteria in the soil (∼two months). We further show that resistant strains readily colonize calves by contact with contaminated bedding and without antibiotic selection pressure. Ceftiofur metabolites in urine amplify resistant E. coli populations and, if applicable to field conditions, this effect is far more compelling than reported selection in vivo after parenteral administration of ceftiofur. Because ceftiofur degradation is temperature dependent, these compounds may accumulate during colder months and this could further enhance selection as seasonal temperatures increase. If cost-effective engineered solutions can be developed to limit ex vivo selection, this may limit proliferation for ceftiofur resistant enteric bacteria

  11. Urine from treated cattle drives selection for cephalosporin resistant Escherichia coli in soil.

    PubMed

    Subbiah, Murugan; Shah, Devendra H; Besser, Thomas E; Ullman, Jeffrey L; Call, Douglas R

    2012-01-01

    The U.S. Food and Drug Administration recently issued new rules for using ceftiofur in food animals in part because of an increasing prevalence of enteric bacteria that are resistant to 3(rd)-generation cephalosporins. Parenteral ceftiofur treatment, however, has limited effects on enteric bacteria so we tested the hypothesis that excreted ceftiofur metabolites exert significant selection pressure for ceftiofur-resistant Escherichia coli in soil. Test matrices were prepared by mixing soil with bovine feces and adding urine containing ceftiofur metabolites (CFM) (0 ppm, ∼50 ppm and ∼100 ppm). Matrices were incubated at 23°C or 4°C for variable periods of time after which residual CFM was quantified using a bioassay. Bla(CMY-2) plasmid-bearing ceftiofur resistant (cef(R)) E. coli and one-month old calves were used to study the selection effects of CFM and transmission of cef(R) bacteria from the environment back to animals. Our studies showed that urinary CFM (∼13 ppm final concentration) is biologically degraded in soil within 2.7 days at 23°C, but persists up to 23.3 days at 4°C. Even short-term persistence in soil provides a >1 log(10) advantage to resistant E. coli populations, resulting in significantly prolonged persistence of these bacteria in the soil (∼two months). We further show that resistant strains readily colonize calves by contact with contaminated bedding and without antibiotic selection pressure. Ceftiofur metabolites in urine amplify resistant E. coli populations and, if applicable to field conditions, this effect is far more compelling than reported selection in vivo after parenteral administration of ceftiofur. Because ceftiofur degradation is temperature dependent, these compounds may accumulate during colder months and this could further enhance selection as seasonal temperatures increase. If cost-effective engineered solutions can be developed to limit ex vivo selection, this may limit proliferation for ceftiofur resistant enteric

  12. Enhanced bioremediation process: A case study of effectiveness on PAH contamination in soils at a former wood-treating site

    SciTech Connect

    Mills, W.F.; Matens, B.L.; Buchalter, D.S.; Montgomery, D.N.

    1997-12-31

    The Enhanced Bioremediation Process (EBP) technology is an exsitu biodegradation process that utilizes bacterial and fungal inoculants to effectively oxidize and bioremediate persistent hard to degrade organics in contaminated soils. The EBP fungal inoculants produce highly reactive extracellular peroxidase enzymes that can oxidize and degrade lignin, a complex, natural polymer composed of phenylpropane units that is resistant to decay. The lignin peroxidase enzymes are highly nonspecific because of their ability to oxidize the heterogenic lignin molecule, and are capable of degrading a wide variety of complex organic compounds. Because the chemical sub-structure of lignin (1,2-aryl diethers, alkyl sidechains and connected aryl systems) resembles that of many persistent organic compounds, the EBP inoculants are very effective in biodegrading similar hazardous organic pollutants in contaminated soils. As an inadvertent by-product of these biochemical processes, the EBP organisms reduce the organic constituents to a soluble form. In a soluble form, the indigenous organisms can further degrade the contaminants. The technology is applied in such a manner as to maximize the activity of the indigenous organisms by establishing optimum growth conditions. The efficacy of the EBP technology in degrading persistent environmental pollutants has been documented at both the bench scale and pilot demonstration levels. A recently completed field pilot demonstration was conducted at a creosote contaminated site. The demonstration entailed the treatment of approximately 700 tons of soil contaminated with PAH constituents. Laboratory analyses of pre and post-treated soils indicate that total average PAH concentrations in many samples were reduced by greater than 91 percent over a two month treatment period.

  13. Population Dynamics of Heterodera glycines and Soybean Response in Soils Treated with Selected Nematicides and Herbicides.

    PubMed

    Schmitt, D P; Corbin, F T; Nelson, L A

    1983-07-01

    Two field experiments were conducted in two locations to determine the effects of the nematicides aldicarb, phenamiphos, and ethoprop and/or the herbicides alachlor, linuron, or metribuzin on the population dynamics of Heterodera glycines and soybean growth and yield. Population densities of H. glycines were greater, at some time during the growing season, in several treatments with alachlor alone and in combination with nematicides. Numbers of H. glycines at harvest were greater in plots treated with aldicarb than in those treated with ethoprop or phenamiphos. The numbers in aldicarb treated plots were generally reduced when plots also received a herbicide. Soybean yields were negatively correlated with numbers of H. glycines eggs and juveniles in early to mid season but positively correlated with late season population densities.

  14. Assessment of soil and groundwater impacts by treated urban wastewater reuse. A case study: application in a golf course (Girona, Spain).

    PubMed

    Candela, Lucila; Fabregat, Salvador; Josa, Alejandro; Suriol, Josep; Vigués, Núria; Mas, Jordi

    2007-03-01

    Starting in July 2000, treated wastewater of urban origin has been used for the "Serres de Pals" golf course irrigation (Girona, Spain). To evaluate if the soil and the aquifer underneath are affected by the utilization of this type of water, samples have been taken along a period of several months from the wastewater treatment plant, the stabilization lagoon, groundwater and soil profiles. Analyses have been performed for total coliforms and aerobic bacteria, soil water pressure and soil water content as well as chemical analyses of the irrigation water, aquifer and water of the vadose zone. Soil profiles taken at several times during the study indicate the absence of coliforms except for a short period during summer. In the vadose zone an increase of more than 1000 mg kg(-1) of NaO(2) in the top 60 cm of soil was observed while Cl(-) concentration in the aquifer reached up to 1200 mg l(-1) ten months after starting the irrigation.

  15. 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.

  16. Gelatin powders accelerate the resorption of calcium phosphate cement and improve healing in the alveolar ridge.

    PubMed

    Matsumoto, Goichi; Sugita, Yoshihiko; Kubo, Katsutoshi; Yoshida, Waka; Ikada, Yoshito; Sobajima, Satoshi; Neo, Masashi; Maeda, Hatsuhiko; Kinoshita, Yukihiko

    2014-05-01

    The aim of this study was to show the effectiveness of combining calcium phosphate cement and gelatin powders to promote bone regeneration in the canine mandible. We mixed gelatin powders with calcium phosphate cement to create a macroporous composite. In four beagle dogs, two saddle-type bone defects were created on each side of the mandible, and calcium phosphate cement alone or calcium phosphate cement containing composite gelatin powders was implanted in each of the defects. After a healing period of six months, mandibles were removed for µCT and histological analyses. The µCT and histological analyses showed that at experimental sites at which calcium phosphate cement alone had been placed new bone had formed only around the periphery of the residual calcium phosphate cement and that there had been little or no ingrowth into the calcium phosphate cement. On the other hand, at experimental sites at which calcium phosphate cement containing composite gelatin powders had been placed, we observed regenerated new bone in the interior of the residual calcium phosphate cement as well as around its periphery. The amount of resorption of calcium phosphate cement and bone regeneration depended on the mixing ratio of gelatin powders to calcium phosphate cement. New bone replacement was significantly better in the sites treated with calcium phosphate cement containing composite gelatin powders than in those treated with calcium phosphate cement alone.

  17. Soil bacterial communities in constructed wetlands treated with swine wastewater using PCR-DGGE technique.

    PubMed

    Dong, Xiuli; Reddy, Gudigopuram B

    2010-02-01

    Marsh-pond-marsh (MPM) constructed wetlands were designed for the treatment of swine wastewater. The goal of this study was to characterize bacterial communities in these wetlands and determine the nutrient removal from influent to effluent. Surface soil samples were collected and analyzed by culture-dependent and culture-independent techniques. The results showed that the bacterial colony forming units (CFU) and the average concentrations of total nitrogen, NH(4)(+), total phosphorous (TP) and PO(4)(3-) from the influent to the effluent decreased. The NH(4)(+) and the PO(4)(3-) concentrations showed the most dramatic changes, with decreases of 39.97% and 16.92%, respectively. Data of culture-independent samples produced by using PCR-denaturing gradient gel electrophoresis (DGGE) technique showed that the Shannon diversity index and richness decreased significantly (P<0.05) from influent to effluent. Bacterium species distributions strongly correlated with the concentrations of TP, NH(4)(+) and the PO(4)(3-). Sequencing of partial 16S rRNA genes fragments revealed that the total bacterial community composition was dominated by Pseudomonas sp., Arthrobacter sp., Bacillus sp. and other soil bacteria. Anammox (anaerobic ammonium oxidation) stains were detected. Phylogenetic analysis demonstrated that some of the partial 16S rRNA gene sequences had close relationships with unculturable denitrification bacteria. The activities of these bacteria might contribute to the nutrient removal in the wetlands.

  18. Herbicide residues in leaves of Erythroxylum coca var. coca plants treated with soil-applied tebuthiuron and hexazinone.

    PubMed

    Lydon, J; Darlington, L

    1998-09-01

    The herbicide residue levels in leaves of Erythroxylum coca var. coca Lam. plants treated with soil applications of tebuthiuron and hexazinone at 3.36 and 6.72 kg a.i. ha-1 were determined in order to estimate the potential for human exposure to these residues from consuming the leaves or cocaine produced from them. Field-grown plants were treated with a commercial formulation of tebuthiuron or hexazinone and leaves were harvested at the first indication of herbicide injury (i.e. chlorosis and/or necrosis) and at the onset of leaf abscission. Herbicide residues were detected by HPLC in leaf samples from both harvests of all plants treated with tebuthiuron or hexazinone. At 3.36 kg ha-1, herbicide residues in the leaves were less than 2 micrograms g-1 dry wt. for both harvests of both experiments. The highest residue levels detected were 5.90 micrograms g-1 dry wt. for tebuthiuron and 7.17 micrograms g-1 dry wt. for hexazinone in leaves from plants treated with the herbicide at the rate of 6.72 kg ha-1 and harvested at the onset of leaf drop. Based on published toxicity data and estimates of leaf consumption, the herbicide residues in leaves of E. coca var. coca plants treated with tebuthiuron or hexazinone at twice the recommended control rates or less would have a negligible contribution to the health risks of individuals who chew coca leaves. Furthermore, based on the most conservative estimates of cocaine yield and herbicide carry over, death by cocaine overdose would occur long before the NOEL for either herbicide was reached.

  19. Factors affecting the cement-post interface.

    PubMed

    Zicari, F; De Munck, J; Scotti, R; Naert, I; Van Meerbeek, B

    2012-03-01

    To evaluate the effect of different factors on the push-out bond strength of glass fiber posts luted in simulated (standard) root canals using different composite cements. Three types of glass-fiber root-canal posts with a different matrix, namely an epoxy resin (RelyX post, 3M ESPE), a proprietary composite resin (FRC-Plus post, Ivoclar-Vivadent), and a methacrylate resin (GC post, GC), and three types of composite cements, namely an etch-and-rinse Bis-GMA-based (Variolink II, Ivoclar-Vivadent), a self-etch 10-MDP-based (Clearfil Esthetic Cement, Kuraray) and a self-adhesive (RelyX Unicem, 3M ESPE) cement, were tested. Posts were either left untreated (control), were treated with silane, or coated with silicated alumina particles (Cojet system, 3M ESPE). Posts were inserted up to 9-mm depth into composite CAD-CAM blocks (Paradigm, 3M ESPE) in order to solely test the strength of the cement-post interface, while excluding interference of the cement-dentin interface. After 1-week storage at 37 °C, three sections (coronal, middle, apical) of 2-mm thickness were subjected to a push-out bond-strength test. All three variables, namely the type of post, the composite cement and the post-surface pre-treatment, were found to significantly affect the push-out bond strength (p<0.001). Regarding the type of post, a significantly lower push-out bond strength was recorded for the FRC-Plus post (Ivoclar-Vivadent); regarding the composite cement, a significantly higher push-out bond strength was recorded for the self-adhesive cement Unicem (3M ESPE); and regarding the post-surface treatment, a significantly higher push-out bond strength was recorded when the post-surface was beforehand subjected to a Cojet (3M ESPE) combined sandblasting/silicatization surface pre-treatment. Many interactions between these three variables were found to be significant as well (p<0.001). Finally, the push-out bond strength was found to significantly reduce with depth from coronal to apical

  20. Contrasting effects of EDTA applications on the fluxes of methane and nitrous oxide emissions from straw-treated rice paddy soils.

    PubMed

    Pramanik, Prabhat; Kim, Pil Joo

    2017-01-01

    Submerged rice paddy soils are the major anthropogenic source of methane (CH4 ) emission to the atmosphere. Straw incorporation for sustaining soil organic C pool increases CH4 emission flux from rice paddy soils. Though the rate of nitrous oxide (N2 O) emission is much less than CH4 , the former has 298 times higher global warming potential (GWP) than equivalent quantity of carbon dioxide. The effect of chelating agents, such as EDTA, on N2 O emission and on GWP due to CH4 and N2 O emissions has not been evaluated before. The emission of CH4 gas from submerged soil may be mitigated by EDTA application; however, it also increases concentration of nitrate-N in soil, the precursor of N2 O gas formation under anaerobic condition. In this experiment, irrespective of straw application, EDTA-treated soils emitted less CH4 to the atmosphere than the corresponding control. Though N2 O emission was increased from soil due to EDTA applications, total GWP was at least 15% reduced in EDTA treated soils during rice cultivation. The plant growth and rice grain yield was not affected by EDTA application. EDTA application at 5.0 ppm might be used to reduce total global warming potential during rice cultivation. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  1. 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.

  2. Well treating process and composition

    SciTech Connect

    Holland, A.C.

    1984-09-11

    A process is disclosed for treating a subterranean zone by emplacing therein a hardenable aqueous slurry and then permitting the slurry to harden, where the slurry comprises a hydraulic cement, water, sodium bentonite, sodium metasilicate, and a hydroxyethyl cellulose. The composition and process employing same is particularly useful in the treatment of oil and gas wells where cementing of a weak formation of very long string cementing, in a single stage, is desired.

  3. 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

  4. 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.

  5. 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.

  6. Impact of anaerobically treated and untreated (raw) distillery effluent irrigation on soil microflora, growth, total chlorophyll and protein contents of Phaseolus aureus L.

    PubMed

    Chandra, Ram; Kumar, Kishan; Singh, Jaswant

    2004-10-01

    Impact of distillery effluent (untreated and treated) irrigation on soil microflora of the pots used for growing Phaseolus aureus L. was investigated. The growth of the P. aureus plants as affected by distillery effluent irrigation was also evaluated. The irrigation of the pots by 1-10% distillery effluent (anaerobically treated) stimulated the growth of the soil microflora (increased number of bacteria, fungi and actinomycetes) and P. aureus plants (increased shoot and root lengths, biomass, chlorophyll and protein contents). Further, 15-20% distillery effluent (anaerobically treated) had toxic effect on soil micro flora as indicated by reduced number of bacteria, fungi and actinomycetes. Reduction in shoot, root, lengths, biomass, chlorophyll, protein contents of P. aureus was also observed when irrigated by 15-20% treated distillery effluent. All the concentrations of raw distillery effluent reduced the bacterial population. However, the treated distillery effluent concentrations <10% had stimulatory effect on fungal and actinomycetes population. However, raw effluent concentrations >5% reduced the same. Raw distillery effluent was more toxic to P. aureus than treated distillery effluent as concentrations >5%, had reduced the growth (shoot, root length and biomass) of the test plant. Raw distillery effluent had adverse effect to total chlorophyll contents and all the test concentrations reduced the total chlorophyll level. However, untreated (raw) distillery effluent stimulated the protein content initially. It has been concluded from-present study that lower concentrations of the raw distillery effluent (1-5%) and treated distillery effluent (1-10%) had stimulated the growth of P. aureus and soil microflora except soil bacteria (inhibited by all the concentration of the raw effluent). However, higher concentrations (raw effluent: 10-20%; treated effluent 15-20%) had toxicity to test parameters.

  7. Spatial and temporal variability of plant-available water in calcium carbonate-cemented soils and consequences for arid ecosystem resilience

    USDA-ARS?s Scientific Manuscript database

    Increased variability in precipitation, including frequency of drought, is predicted for many arid and semiarid regions of the world. The ability of soils to retain water can increase resilience by buffering vegetation communities against precipitation extremes. Little is known, however, about water...

  8. Leaching behavior of Cr(III) in stabilized/solidified soil.

    PubMed

    Jing, Chuanyong; Liu, Suqin; Korfiatis, George P; Meng, Xiaoguang

    2006-06-01

    The leaching behavior of chromium was studied using batch leaching tests, surface complexation modeling and X-ray absorption near edge structure (XANES) spectroscopy. A contaminated soil sample containing 1330 mg-Cr kg(-1) and 25600 mg-Fe kg(-1) of dry soil was stabilized/solidified (S/S) with 10% cement, 25% cement, 10% lime and a mixture of 20% flyash and 5% lime. The XANES analysis showed that Cr(III) was the only Cr species in untreated soil and S/S-treated samples. The leachate Cr concentration determined using the toxicity characteristic leaching procedure (TCLP) was reduced from 5.18 mg l(-1) for untreated soil to 0.84 mg l(-1) for the sample treated with 25% cement. The Cr leachability in untreated and treated soil samples decreased dramatically as the pH increased from 3 to 5, remained at similar levels in the pH range between 5 and 10.5, and further decreased at pH>10.5. Modeling results indicated that the release of Cr(III) was controlled by adsorption on iron oxides at pH<10.5, and by precipitation of Ca(2)Cr(2)O(5).6H(2)O at pH>10.5.

  9. Capillary effect in salt-cemented media of particle sizes

    NASA Astrophysics Data System (ADS)

    Yoon, Hyung-Koo; Hung Truong, Q.; Byun, Yong-Hoon; Lee, Jong-Sub

    2015-01-01

    Natural cementation such as salt cementation may significantly affect the geotechnical properties of soils at low confining pressures. Capillary force plays a key role in the distribution patterns of salt cementation resulting from dehydration. The aim of this study is to investigate the effect of capillary force on salt cementation through cone penetration testing, electrical conductivity measurements, photographic imaging technique, and nondestructive elastic wave scanning. Granular media is modeled using glass beads which are saturated in salt water and cemented by oven drying. The cone tip resistance profiles, electrical conductivity profiles, and amplitudes of the scanned elastic waves are high at the top of the specimen with small-sized particles, in the middle of the specimen in medium-sized particles, and at the bottom of the specimen in the large-sized particles. Differences in the distribution of salt in the cemented specimens are confirmed from photographic images. The calculated capillary heights are associated with the areas of high salt concentration in the cemented specimens. The four investigation methods used in this study show that the behavior of salt-cemented granular media depends on capillary force in a shallow depth.

  10. 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.

  11. Influence of farmyard manure on some morphological and biochemical parameters of cowpea (Vigna unguiculata) seedling grown in cadmium-treated soil.

    PubMed

    Asagba, Samuel Ogheneovo; Ezedom, Theresa; Kadiri, Helen

    2017-09-01

    The present study aims to assess the effects of the two kinds of farmyard manure (poultry and pig manures) as amendments for soil on cadmium (Cd) toxicity in plants using cowpea seedlings as plant model. Cd toxicity was evaluated by assessing the effect of the metal on the growth rate and antioxidant status as well as the ability of the plant to metabolise xenobiotic. There was a significantly (p < 0.05) increased concentration of Cd in the root, stem and leaves of cowpea seedlings grown in all the treated soils relative to control. Addition of poultry manure to the soil significantly (p < 0.05) decreased the level of Cd in these component parts of the seedlings and their corresponding bioaccumulation factor in a dose-dependent manner as compared with treatments with Cd pollution without manure addition and Cd pollution with pig manure addition. There was restoration of Cd-induced effect on growth rate parameters to levels comparable to controls in cowpea seedlings grown in Cd-treated soil augmented with poultry manure but not in cowpea seedlings in cadmium-treated soil with pig manure amendments. Similarly, augmentation of Cd-treated soil with pig manure did not alter the Cd-induced effect on the levels of superoxide dismutase (SOD) and lipid peroxidation (LPO) in leaf, stem and roots, as SOD remained significantly (p < 0.05) decreased and LPO increased relative to control. On the other hand, the levels of SOD and LPO in these parts of cowpea seedlings grown in Cd-treated soils amended with poultry manure were restored to a level not significantly (p > 0.05) different from control. Like in the case of SOD, the Cd-induced inhibition of the activity of xenobiotic metabolising enzymes, aldehyde oxidase and sulphite oxidase remained significantly (p < 0.05) decreased in the organs of seedling grown in Cd-treated soil amended with pig manure. Conversely, the Cd-induced effect on the activities of these enzymes was reversed in the organs of seedlings exposed

  12. 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.

  13. 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.

  14. 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

  15. [Mitigation of nitrous oxide emissions in vegetable system by treating soil with dicyandiamide, a nitrification inhibitor].

    PubMed

    Qiu, Wei-Hong; Liu, Jin-Shan; Hu, Cheng-Xiao; Tan, Qi-Ling; Sun, Xue-Cheng; Hu, Zhen-Lan

    2011-11-01

    Undisturbed soil monolith lysimeter was used to investigate the effectiveness of DCD (dicyandiamide) in reducing N2O emissions in vegetable (Chinese cabbage and pepper) field. Results showed that DCD significantly reduced total N2O emission in vegetable field. Total N2O emissions from the urea treatment without DCD reached 0.215 kg x hm(-2) for Chinese cabbage, and it reduced to 0.109 kg x hm(-2), equivalent to a 49.3% reduction. The total N2O emissions for pepper were much higher compared with those for Chinese cabbage. The total N2O emitted from the urea treatment was 2.32 kg x hm(-2) (without DCD) and it was reduced to 1.14 kg x hm(-2) with DCD application, representing a 50.9% reduction. In the control treatments where no urea was applied, the daily N2O flux was very low and it never exceeded 9 microg x (m2 x h) (-1) for Chinese cabbage and 22 microg x (m2 x h) (-1) for pepper, respectively, but DCD also reduced N2O emissions (33.5% for Chinese cabbage and 33.4% for pepper). In addition, the urea-N emission factor (EF) was 0.15%, 0.99% for Chinese cabbage and pepper without DCD, respectively, and it was reduced to 0.07%, 0.52% when DCD was applied. These results demonstrated the potential of using nitrification inhibitors (DCD) to mitigate N2O emissions in vegetable system.

  16. 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.

  17. 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

  18. 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

  19. 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.

  20. Using Natural Cementation Systems to Control Corrosion Dust on Un-surfaced Roads

    DTIC Science & Technology

    2010-02-01

    metallurgical slags), volcanic glass, fly ash and low-fired clays • Can use waste alkali from manufacturing operations • No Portland cement is involved Soil...Conventional Cement? • Glass can be both the aggregate and form the cementing phase • Waste glass (slag, fly ash ) can be used • More alkaline solution is...Materials: Suitable raw materials are available almost everywhere ( fly ash , slag, calcined clays) • Economical: Uses waste materials or low-fired clay

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. Iron oxide nanoparticles significantly enhances the injectability of apatitic bone cement for vertebroplasty.

    PubMed

    Vlad, María Daniela; del Valle, Luis J; Barracó, Marc; Torres, Ricardo; López, José; Fernández, Enrique

    2008-10-01

    Experimental study to characterize the setting and the cytocompatibility properties of apatitic bone cement. To investigate the setting, flowing, and biocompatibility properties of new iron-modified calcium phosphate bone cements. Vertebroplasty and kyphoplasty are efficient procedures for the treatment of painful vertebral compression fractures. Nowadays, calcium phosphate cements are used to treat these fractures mainly due to the similar bone apatitic phase formed after setting. However, clinicians have reported great difficulties in filling the vertebral bodies due to the high pressures needed to inject these materials. Thus, new approaches are needed to improve the initial flowing properties of these cements without affecting or even improving their short-term mechanical stability and their long-term in vivo cement transformation into bone tissue. Cement setting times were measured by the Gillmore needles method. The evolution of the compressive strength accounted for the cement hardening process. Scanning Electron Microscopy followed the evolution of the cement microstructure with hardening. Radiograph diffraction analysis confirmed the evolution of the crystalline phases underlying the setting and the hardening processes. Injectability tests were performed by using syringes filled with bone cement and recording the evolution of the injection force needed to empty the syringe. Finally, the cytocompatibility was analyzed by culturing human epithelial cells onto the cements and evaluating both the relative cell viability and the adhesion cell density. The modification of the powder phase of an alpha-tricalcium phosphate cement with iron oxide nanopar-ticles significantly enhanced, at constant liquid to powder cement mixing ratio, the resulting cement injectability by lowering the extrusion force required for cement delivery. For example, 24 wt% iron oxide addition resulted in 83% of cement injected with an extrusion force lower than 25 N. In fact, the setting

  6. 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 ...

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

    USDA-ARS?s Scientific Manuscript database

    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...

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

    USDA-ARS?s Scientific Manuscript database

    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 ...

  9. 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 ...

  10. 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.

  11. 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.

  12. Soils

    Treesearch

    John R. Jones; Norbert V. DeByle

    1985-01-01

    Edaphic and climatic characteristics of a site quite well define the quality of that site for plant growth. The importance of soil characteristics to the growth and well-being of aspen in the West is apparent from observations by many authors, from inferences resulting from work with other trees and agricultural crops, and from detailed study of aspen soils and site...

  13. 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

  14. Porcelain inlays cemented with composite resin cement: an in vivo investigation of pulpal reaction one year following cementation.

    PubMed

    Vigolo, Paolo; Graiff, Lorenzo; Mutinelli, Sabrina; Fonzi, Fulvio

    2007-01-01

    This in vivo study was designed to verify the presence of pulpal inflammation on teeth after 1 year of function from cementation of porcelain inlays. Thirty-two vital, healthy, caries-free and previously untreated maxillary and mandibular first premolars in eight patients needing extraction for orthodontic reasons were included in this study. For each patient three first premolars were randomly chosen and treated with porcelain MOD inlays. One first premolar served as the control group with no restorations. The porcelain inlays were cemented with dental adhesive and composite resin cement without pulpal protection. The same dentist, following standardized preparation, impression, and cementation techniques, accomplished all clinical phases. The teeth were extracted 1 year later. The condition of the pulp tissues of the 24 teeth with porcelain inlays was compared with the pulpal tissues of the eight teeth of the control group. The data relating to the number of inflammatory cells were evaluated by one-way analysis of variance to assess quantitative differences between the group of teeth with porcelain inlays and the group without porcelain inlays (p < 0.05). Means and standard deviations were calculated for each group. The microscopic analysis revealed the absence of pulpal inflammation of the teeth with porcelain inlays when compared with the teeth of the control group. The analysis of variance revealed no statistical differences between the two groups compared. Within the limitations of this study, the cementation of porcelain inlays with dental adhesive and composite cement on healthy premolars did not result in any inflammatory reaction of the pulpal tissues 1 year after placement.

  15. [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.

  16. Some heavy metals in soils treated with sewage sludge, their effects on yield, and their uptake by plants

    SciTech Connect

    Valdares, J.M.A.S.; Gal, M.; Mingelgrin, U.; Page, A.L.

    1983-01-01

    The possible use of sludge with high heavy metal concentrations and at high rates in calcareous soil was demonstrated in this study. Mixtures of two sludges were added to soils in various proportions up to 4% sludge content. One sludge was rich in Ni and Cd, while the other was relatively poor in heavy metals. Three soils varying in pH from 7.7 to 5.5 were tested. The concentrations of Cd, Ni, Cu and Zn in the DTPA and saturation extracts of the soil-sludge mixtures were determined and correlated with their uptake by plants and the yield of Swiss chard (Beta vulgaris L., cv. Ford Hook Giant) grown on these mixtures. The metal-poor sludge hardly affected the yield of the relatively salt-resistant Swiss chard. The metal-rich sludge reduced the yield drastically in noncalcareous soils after a critical amount of that sludge (1.5%) was added to the soils. Yet, even 4% of this metal-rich sludge increased the yield of Swiss chard, as compared with the sludge-free control in a calcareous soil. The best fit to yield was obtained by multiple regression with metal content in the soil saturation extract. The solubility in soil solution of Cd, Ni and Zn was strongly affected by the pH. The uptake of Ni and Zn by plants was significantly larger in the acid soil than in the calcareous soil. The difference in the uptake of Cd and Cu between the soils was smaller. Plant uptake of the metals was generally predicted better by the total metal addition or concentration in the DPTA extract than by metal concentration in the soil saturation extract. In noncalcaeous soils the total metal addition correlated as well as metal content in the DTPA extracts with the metal concentration in the soil solution, with the uptake by plants and with the yield.

  17. 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.

  18. 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.

  19. FTIR Evidence of Changes in Carbon Associated with Hydrophobicity in Wildfire Affected Soils Treated with Elevated Temperature, Acid Snow Melt, or UV-Light

    NASA Astrophysics Data System (ADS)

    Jacobson, A. R.; Anderson, A. J.; van Miegroet, H.

    2009-12-01

    In a wild fire, organic volatile compounds from vegetation condense on soil particles forming a hydrophobic layer several centimeters below the soil surface. We studied the degradation of the hydrophobic layer in soils from two fire sites. One site is located in a montane woodland (Wood Camp, Logan Canyon, UT) that burned in 2006. The second site is located in an arid pinyon pine/juniper stand in Milford Flats, Beaver County, UT that burned in 2007. Both sites were sampled in 2008. In situ measurements of hydrophobicity demonstrated highly hydrophobic layers a few centimeters below the surface at both sites in contrast with unburned control sites, where hydrophobicity was observed at the surface but fell off sharply with depth. Samples of surface and subsurface soil were collected from the burned and unburned areas at both sites. Subsamples of all the soils were placed in microlysimeters, treated with acid snowmelt, elevated temperatures (30°C - 47°C), and UV light. After the treatments, the soils were air-dried and the surfaces analyzed for evidence of change in hydrophobicity using the drop test, oxidation of aromatic functional groups by cation exchange capacity (CEC), and the selective degradation of aliphatic functional groups associated with hydrophobicity by FTIR-ATR. Although results of the water drop penetration test suggest that simply wetting and air-drying the soils resulted in complete loss of hydrophobicity, the CEC results suggest that carbon oxidation occurred in the organic matter rich Wood Camp Soils. CEC results for the low carbon content Milford Flats soils were less clear. Analyses of peak heights in the range 4000 - 400 cm-1 demonstrate clear differences between the controlled and burned soils from the two sites and effects of all the treatments, particularly in the regions from 3020 to 2800 cm-1, corresponding to asymmetric and symmetric stretching vibrations of methyl and methylene groups associated with hydrophobicity. Peak height in this

  20. 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

  1. Recycling stabilised/solidified drill cuttings for forage production in acidic soils.

    PubMed

    Kogbara, Reginald B; Dumkhana, Bernard B; Ayotamuno, Josiah M; Okparanma, Reuben N

    2017-10-01

    Stabilisation/solidification (S/S), which involves fixation and immobilisation of contaminants using cementitious materials, is one method of treating drill cuttings before final fate. This work considers reuse of stabilised/solidified drill cuttings for forage production in acidic soils. It sought to improve the sustainability of S/S technique through supplementation with the phytoremediation potential of plants, eliminate the need for landfill disposal and reduce soil acidity for better plant growth. Drill cuttings with an initial total petroleum hydrocarbon (TPH) concentration of 17,125 mg kg(-1) and low concentrations of metals were treated with 5%, 10%, and 20% cement dosages. The treated drill cuttings were reused in granular form for growing a forage, elephant grass (Pennisetum purpureum), after mixing with uncontaminated soil. The grasses were also grown in uncontaminated soil. The phytoremediation and growth potential of the plants was assessed over a 12-week period. A mix ratio of one part drill cuttings to three parts uncontaminated soil was required for active plant growth. The phytoremediation ability of elephant grass (alongside abiotic losses) reduced the TPH level (up to 8795 mg kg(-1)) in the soil-treated-drill cuttings mixtures below regulatory (1000 mg kg(-1)) levels. There were also decreased concentrations of metals. The grass showed better heights and leaf lengths in soil containing drill cuttings treated with 5% cement dosage than in uncontaminated soil. The results suggest that recycling S/S treated drill cuttings for forage production may be a potential end use of the treated waste. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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

  8. Cementing a wellbore using cementing material encapsulated in a shell

    DOEpatents

    Aines, Roger D.; Bourcier, William L.; Duoss, Eric B.; Floyd, III, William C.; Spadaccini, Christopher M.; Vericella, John J.; Cowan, Kenneth Michael

    2017-03-14

    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.

  9. 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.

  10. Comparison of soil amendments to decrease high strength in SE USA Coastal Plain soils using fuzzy decision-making analyses

    USDA-ARS?s Scientific Manuscript database

    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 ...

  11. 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.

  12. Materials Evaluated as Potential Soil Stabilizers

    DTIC Science & Technology

    1977-09-01

    21.0 168 270 +153 Lithium hydroxide 0.59 20.8 168 198 +85 Sodium sulfite 1.0 21.2 168 322 +200 Sodium carbonate 1.0 20.5 168 375 +250 Sodium bicarbonate...fluoride, sodium 1.0, and 2.0% rates fluoborate , and sodium tetraborate Mixing Material Form* Type of Soil Treated Capability Powder Silt Good Effective...used (sodiun fluosilicate, sodium fluoride, sodium fluoborate , ET-218, and sodium tetraborate) were either detrimental when added to the cement or no

  13. Effect of some biotic factors on microbially-induced calcite precipitation in cement mortar.

    PubMed

    Al-Salloum, Yousef; Abbas, H; Sheikh, Q I; Hadi, S; Alsayed, Saleh; Almusallam, Tarek

    2017-02-01

    Sporosarcina pasteurii, a common soil bacterium has been tested for microbial treatment of cement mortar. The present study also seeks to investigate the effects of growth medium, bacterial concentration and different buffers concerning the preparation of bacterial suspensions on the compressive strength of cement mortar. Two growth media, six different suspensions and two bacterial concentrations were used in the study. The influence of growth medium on calcification efficiency of S. pasteurii was insignificant. Significant improvement in the compressive as well as the tensile strength of cement mortar was observed. Microbial mineral precipitation visualized by Scanning Electron Microscopy (SEM) shows fibrous material that increased the strength of cement mortar. Formation of thin strands of fillers observed through SEM micrographs improves the pore structure, impermeability and thus the compressive as well as the tensile strengths of the cement mortar. The type of substrate and its molarity have a significant influence on the strength of cement mortar.

  14. Meteoric calcite cementation: diagenetic response to relative fall in sea-level and effect on porosity and permeability, Las Negras area, southeastern Spain

    NASA Astrophysics Data System (ADS)

    Li, Zhaoqi; Goldstein, Robert H.; Franseen, Evan K.

    2017-03-01

    A dolomitized Upper Miocene carbonate system in southeast Spain contains extensive upper and lower zones of calcite cementation that cut across the stratigraphy. Cement textures including isopachous and circumgranular, which are consistent with phreatic-zone cementation. Cements in the upper cemented zone are non-luminescent, whereas those in the lower cemented zone exhibit multiple bands of luminescent and non-luminescent cements. In the upper cemented zone, isotopic data show two meteoric calcite lines (MCL) with mean δ18O at - 5.1‰ and - 5.8‰ VPDB, whereas no clear MCL is defined in the lower cemented zone where mean δ18O for calcite cement is at - 6.7‰ VPDB. δ13C values in both cement zones are predominantly negative, ranging from - 10 to + 2‰ VPDB, suggestive of carbon from soil gas or decayed organics. Measurements of Tm ice in primary fluid inclusions yield a mode of 0.0 °C in both zones, indicating calcite cementation from fresh water. These two zones define the positions of two different paleo-water tables that formed during a relative sea-level fall and erosional downcutting during the Plio-Pleistocene. The upper cemented zone pre-dated the lower cemented zone on the basis of known relative sea-level history. Meteoric calcite cementation reduced porosity and permeability, but measured values are inconsistent with simple filling of open pore space. Each texture, boundstone, grainstone, packstone, wackestone, produces a different relationship between percent calcite cement and porosity/permeability. Distribution of cements may be predictable on the basis of known sea-level history, and the effect of the cementation can be incorporated into subsurface geomodels by defining surfaces of rock boundaries that separate cemented zones from uncemented zones, and applying texture-specific relationships among cementation, porosity and permeability.

  15. Cement-in-cement stem revision for Vancouver type B periprosthetic femoral fractures after total hip arthroplasty. A 3-year follow-up of 23 cases.

    PubMed

    Briant-Evans, Toby W; Veeramootoo, Darmaraja; Tsiridis, Eleftherios; Hubble, Matthew J

    2009-10-01

    Revision surgery for periprosthetic femoral fractures around an unstable cemented femoral stem traditionally requires removal of existing cement. We propose a new technique whereby a well-fixed cement mantle can be retained in cases with simple fractures that can be reduced anatomically when a cemented revision is planned. This technique is well established in femoral stem revision, but not in association with a fracture. We treated 23 Vancouver type B periprosthetic femoral fractures by reducing the fracture and cementing a revision stem into the pre-existing cement mantle, with or without supplementary fixation. 3 patients died in the first 6 months for reasons unrelated to surgery. In addition, 1 was too frail to attend follow-up and was therefore excluded from the study, and 1 patient underwent revision surgery for a nonunion. The remaining 18 cases all healed with radiographic union after an average time of 4.4 (2-11) months. There was no sign of loosening or subsidence of the revision stems within the old cement mantle in any of these cases at the most recent follow-up after an average of 3 (0.3-9) years. Our results support the use of the cement-in-cement revision in anatomically reducible periprosthetic fractures with a well-preserved pre-existing cement mantle. This technique is particularly useful for the elderly patient and for those who are not fit for prolonged surgical procedures.

  16. Evaluation of adhesive and compressive strength of glass ionomer cements.

    PubMed

    Ramashanker; Singh, Raghuwar D; Chand, Pooran; Jurel, Sunit Km; Tripathi, Shuchi

    2011-12-01

    The aim of the study was to assess, compare and evaluate the adhesive strength and compressive strength of different brands of glass ionomer cements to a ceramometal alloy. (A) Glass ionomer cements: GC Fuji II (GC Corporation, Tokyo), Chem Flex (Dentsply DeTrey, Germany), Glass ionomer FX (Shofu-11, Japan), MR dental (MR dental suppliers Pvt Ltd, England). (B) Ceramometal alloy (Ni-Cr: Wiron 99; Bego, Bremen, Germany). (C) Cold cure acrylic resin. (E) Temperature cum humidity control chamber. (F) Instron Universal Testing Machine. Four different types of Glass ionomer cements were used in the study. From each type of the Glass ionomer cements, 15 specimens for each were made to evaluate the compressive strength and adhesive strength, respectively. The 15 specimens were further divided into three subgroups of five specimens. For compressive strength, specimens were tested at 2, 4 and 12 h by using Instron Universal Testing Machine. To evaluate the adhesive strength, specimens were surface treated with diamond bur, silicone carbide bur and sandblasting and tested under Instron Universal Testing Machine. It was concluded from the study that the compressive strength as well as the adhesive bond strength of MR dental glass ionomer cement with a ceramometal alloy was found to be maximum compare to other glass ionomer cements. Sandblasting surface treatment of ceramometal alloy was found to be comparatively more effective for adhesive bond strength between alloy and glass ionomer cement.

  17. 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.

  18. Lower leaf gas-exchange and higher photorespiration of treated wastewater irrigated Citrus trees is modulated by soil type and climate.

    PubMed

    Paudel, Indira; Shaviv, Avi; Bernstein, Nirit; Heuer, Bruria; Shapira, Or; Lukyanov, Victor; Bar-Tal, Asher; Rotbart, Nativ; Ephrath, Jhonathan; Cohen, Shabtai

    2016-04-01

    Water quality, soil and climate can interact to limit photosynthesis and to increase photooxidative damage in sensitive plants. This research compared diffusive and non-diffusive limitations to photosynthesis as well as photorespiration of leaves of grapefruit trees in heavy clay and sandy soils having a previous history of treated wastewater (TWW) irrigation for >10 years, with different water qualities [fresh water (FW) vs TWW and sodium amended treated wastewater (TWW + Na)] in two arid climates (summer vs winter) and in orchard and lysimeter experiments. TWW irrigation increased salts (Na(+) and Cl(-) ), membrane leakage, proline and soluble sugar content, and decreased osmotic potentials in leaves of all experiments. Reduced leaf growth and higher stomatal and non-stomatal (i.e. mesophyll) limitations were found in summer and on clay soil for TWW and TWW + Na treatments in comparison to winter, sandy soil and FW irrigation, respectively. Stomatal closure, lower chlorophyll content and altered Rubisco activity are probable causes of higher limitations. On the other hand, non-photochemical quenching, an alternative energy dissipation pathway, was only influenced by water quality, independent of soil type and season. Furthermore, light and CO2 response curves were investigated for other possible causes of higher non-stomatal limitation. A higher proportion of non-cyclic electrons were directed to the O2 dependent pathway, and a higher proportion of electrons were diverted to photorespiration in summer than in winter. In conclusion, both diffusive and non-diffusive limitations contribute to the lower photosynthetic performance of leaves following TWW irrigation, and the response depends on soil type and environmental factors. © 2015 Scandinavian Plant Physiology Society.

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

    USDA-ARS?s Scientific Manuscript database

    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. 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

  1. Cement composition and sulfate attack

    SciTech Connect

    Shanahan, Natalya; Zayed, Abla . E-mail: zayed@eng.usf.edu

    2007-04-15

    Four cements were used to address the effect of tricalcium silicate content of cement on external sulfate attack in sodium sulfate solution. The selected cements had similar fineness and Bogue-calculated tricalcium aluminate content but variable tricalcium silicates. Durability was assessed using linear expansion and compressive strength. Phases associated with deterioration were examined using scanning electron microscopy and X-ray diffraction. Mineralogical phase content of the as-received cements was studied by X-ray diffraction using two methods: internal standard and Rietveld analysis. The results indicate that phase content of cements determined by X-ray mineralogical analysis correlates better with the mortar performance in sulfate environment than Bogue content. Additionally, it was found that in cements containing triclacium aluminate only in the cubic form, the observed deterioration is affected by tricalcium silicate content. Morphological similarities between hydration products of high tricalcium aluminate and high tricalcium silicate cements exposed to sodium sulfate environment were also observed.

  2. 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.

  3. 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

  4. Evaluating changes in cellulolytic bacterial population to explain methane emissions from air-dried and composted manure treated rice paddy soils.

    PubMed

    Pramanik, Prabhat; Kim, Pil Joo

    2014-02-01

    Compost application recorded ~20% reduction in methane (CH4) emission during rice cultivation as compared to air-dried manure treatment. The objective of this study was to evaluate the dependence of methanogens on cellulolytic bacteria (CB) to produce CH4 in organic-amended rice paddy soils. The presence of more decomposable organic C in manure was probably the key factor for higher CH4 emission from manure-treated soils as compared to compost application. Manure application facilitated anaerobic CB abundance in rice paddy soils, and that in turn increased concentrations of dissolved organic C compounds like carbohydrates in soil. Soluble organic C compounds are converted into acetate and/or carbon dioxide, which act as initial energy source for methanogens. Therefore, it could be concluded that CB positively influenced methanogen activity and methanogenesis and stabilized organic substrates like compost are more rational treatment to mitigate CH4 emission from rice paddy soil than cattle manure application. Copyright © 2013 Elsevier B.V. All rights reserved.

  5. New cement formulation helps solve deep cementing problems

    SciTech Connect

    Brothers, L.E.; DeBlanc, F.X.

    1989-06-01

    Invert-emulsion muds are used in most deep, hot wells. The internal aqueous phase of these muds frequently contains high concentrations of salts. It is desirable to complete these wells with a cement slurry containing salt concentrations up to and including saturation to minimize compatibility problems between cement slurry and mud. Above their effective temperature range, however, saturated salt cements - though still considered desirable for their other properties - pose design difficulties regarding thickening time, fluid loss, and rheology. High salt concentrations tend to decrease the effectiveness of most common cement additives - e.g., retarders, fluid-loss additives, and dispersants. At high temperatures, concentrations of these additives can become unacceptably large, while the additives themselves are not as effective under these conditions. Development of and field experience with a new cementing formulation for deep, high-temperature, saturated-salt applications have helped resolve the cement design problems encountered in south Texas and southern and offshore Louisiana. A single synthetic-polymer additive provides cement retardation, fluid-loss control, and dispersant properties with normal design considerations as opposed to the lengthy design requirements of other cement systems. A particular benefit derived from use of the new cement system involves cementing of long liners. Such liners frequently require squeeze cementing at the liner top because the cement is designed for conditions at the bottom of the liner and is thus frequently over-retarded for the cooler temperatures encountered at the top of the liner. This over-retardation tendency is alleviated greatly by use of the new saturated-salt cement additive.

  6. Reduction of root-knot nematode, Meloidogyne javanica, and ozone mass transfer in soil treated with ozone.

    PubMed

    Qiu, Jinya Jack; Westerdahl, Becky B; Pryor, Alan

    2009-09-01

    Ozone gas (O₃) is a reactive oxidizing agent with biocidal properties. Because of the current phasing out of methyl bromide, investigations on the use of ozone gas as a soil-fumigant were conducted. Ozone gas was produced at a concentration of 1% in air by a conventional electrical discharge O₃ generator. Two O₃ dosages and three gas flow rates were tested on a sandy loam soil collected from a tomato field that had a resident population of root knot nematodes, Meloidogyne javanica. At dosages equivalent to 50 and 250 kg of O₃/ha, M. javanica were reduced by 24% and 68%, and free-living nematodes by 19% and 52%, respectively. The reduction for both M. javanica and free-living nematodes was dosage dependent and flow rate independent. The rates of O₃ mass transfer (OMT) through three soils of different texture were greater at low and high moisture levels than at intermediate ones. At any one soil moisture level, the OMT rate varied with soil texture and soil organic matter content. Results suggest that soil texture, moisture, and organic matter content should be considered in determining O₃ dosage needed for effective nematode control.

  7. Reduction of Root-Knot Nematode, Meloidogyne javanica, and Ozone Mass Transfer in Soil Treated with Ozone

    PubMed Central

    Qiu, Jinya Jack; Pryor, Alan

    2009-01-01

    Ozone gas (O3) is a reactive oxidizing agent with biocidal properties. Because of the current phasing out of methyl bromide, investigations on the use of ozone gas as a soil-fumigant were conducted. Ozone gas was produced at a concentration of 1% in air by a conventional electrical discharge O3 generator. Two O3 dosages and three gas flow rates were tested on a sandy loam soil collected from a tomato field that had a resident population of root knot nematodes, Meloidogyne javanica. At dosages equivalent to 50 and 250 kg of O3/ha, M. javanica were reduced by 24% and 68%, and free-living nematodes by 19% and 52%, respectively. The reduction for both M. javanica and free-living nematodes was dosage dependent and flow rate independent. The rates of O3 mass transfer (OMT) through three soils of different texture were greater at low and high moisture levels than at intermediate ones. At any one soil moisture level, the OMT rate varied with soil texture and soil organic matter content. Results suggest that soil texture, moisture, and organic matter content should be considered in determining O3 dosage needed for effective nematode control. PMID:22736821

  8. 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. Copyright © 2010 Elsevier Ltd. All rights reserved.

  9. 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.

  10. Cement from magnesium substituted hydroxyapatite.

    PubMed

    Lilley, K J; Gbureck, U; Knowles, J C; Farrar, D F; Barralet, J E

    2005-05-01

    Brushite cement may be used as a bone graft material and is more soluble than apatite in physiological conditions. Consequently it is considerably more resorbable in vivo than apatite forming cements. Brushite cement formation has previously been reported by our group following the mixture of nanocrystalline hydroxyapatite and phosphoric acid. In this study, brushite cement was formed from the reaction of nanocrystalline magnesium-substituted hydroxyapatite with phosphoric acid in an attempt to produce a magnesium substituted brushite cement. The presence of magnesium was shown to have a strong effect on cement composition and strength. Additionally the presence of magnesium in brushite cement was found to reduce the extent of brushite hydrolysis resulting in the formation of HA. By incorporating magnesium ions in the apatite reactant structure the concentration of magnesium ions in the liquid phase of the cement was controlled by the dissolution rate of the apatite. This approach may be used to supply other ions to cement systems during setting as a means to manipulate the clinical performance and characteristics of brushite cements.

  11. Cement Leakage in Percutaneous Vertebral Augmentation for Osteoporotic Vertebral Compression Fractures: Analysis of Risk Factors.

    PubMed

    Xie, Weixing; Jin, Daxiang; Ma, Hui; Ding, Jinyong; Xu, Jixi; Zhang, Shuncong; Liang, De

    2016-05-01

    The risk factors for cement leakage were retrospectively reviewed in 192 patients who underwent percutaneous vertebral augmentation (PVA). To discuss the factors related to the cement leakage in PVA procedure for the treatment of osteoporotic vertebral compression fractures. PVA is widely applied for the treatment of osteoporotic vertebral fractures. Cement leakage is a major complication of this procedure. The risk factors for cement leakage were controversial. A retrospective review of 192 patients who underwent PVA was conducted. The following data were recorded: age, sex, bone density, number of fractured vertebrae before surgery, number of treated vertebrae, severity of the treated vertebrae, operative approach, volume of injected bone cement, preoperative vertebral compression ratio, preoperative local kyphosis angle, intraosseous clefts, preoperative vertebral cortical bone defect, and ratio and type of cement leakage. To study the correlation between each factor and cement leakage ratio, bivariate regression analysis was employed to perform univariate analysis, whereas multivariate linear regression analysis was employed to perform multivariate analysis. The study included 192 patients (282 treated vertebrae), and cement leakage occurred in 100 vertebrae (35.46%). The vertebrae with preoperative cortical bone defects generally exhibited higher cement leakage ratio, and the leakage is typically type C. Vertebrae with intact cortical bones before the procedure tend to experience type S leakage. Univariate analysis showed that patient age, bone density, number of fractured vertebrae before surgery, and vertebral cortical bone were associated with cement leakage ratio (P<0.05). Multivariate analysis showed that the main factors influencing bone cement leakage are bone density and vertebral cortical bone defect, with standardized partial regression coefficients of -0.085 and 0.144, respectively. High bone density and vertebral cortical bone defect are

  12. Pharmaceuticals and personal care products in untreated and treated sewage sludge: Occurrence and environmental risk in the case of application on soil - A critical review.

    PubMed

    Verlicchi, P; Zambello, E

    2015-12-15

    This review is based on 59 papers published between 2002 and 2015, referring to about 450 treatment trains providing data regarding sludge concentrations for 169 compounds, specifically 152 pharmaceuticals and 17 personal care products, grouped into 28 different classes. The rationale of the study is to provide data to evaluate the environmental risk posed by the spreading of treated sludge in agriculture. Following discussion of the legislative scenario governing the final disposal of treated sludge in European countries and the USA, the study provides a snapshot of the occurrence of selected compounds in primary, secondary, mixed, digested, conditioned, composted and dried sludge originating in municipal wastewater treatment plants fed mainly with urban wastewater as well as in sludge-amended soil. Not only are measured values reported, but also predicted concentrations based on Kd values are reported. It emerges that in secondary sludge, the highest concentrations were found for fragrances, antiseptics and antibiotics and an attenuation in their concentrations occurs during treatment, in particular anaerobic digestion and composting. An in-depth literature survey of the (measured and predicted) Kd values for the different compounds and treated sludge are reported and an analysis of the influence of pH, redox conditions, sludge type was carried out. The data regarding measured and predicted concentrations of selected compounds in sludge-amended soil is then analyzed. Finally an environmental risk assessment posed by their occurrence in soil in the case of land application of sludge is examined, and the results obtained by different authors are compared. The most critical compounds found in the sludge-amended soil are estradiol, ciprofloxacin, ofloxacin, tetracycline, caffeine, triclosan and triclocarban. The study concludes with a focus on the main issues that should be further investigated in order to refine the environmental risk assessment. Copyright © 2015

  13. Foamed well cementing compositions and methods

    SciTech Connect

    Bour, D.L.; Childs, J.D.

    1992-07-28

    This patent describes a method of cementing a well penetrating a salt containing subterranean formation. It comprises: forming a foamed cement composition; placing the foamed cement composition in contact with the salt containing formation; and permitting the foamed cement composition to set in contact with the salt containing formation to form a hardened mass of cement.

  14. Arsenic extractability and uptake by velvetgrass Holcus lanatus and ryegrass Lolium perenne in variously treated soils polluted by tailing spills.

    PubMed

    Karczewska, Anna; Lewińska, Karolina; Gałka, Bernard

    2013-11-15

    Phytostabilization should be considered as an appropriate phytoremediation technique to restore the area affected by tailing spills in Zloty Stok, where arsenic ores were mined and processed for several centuries. The study aimed to compare the suitability of velvetgrass (Holcus lanatus L.) and ryegrass (Lolium perenne L.) for development of plant cover in that area. Various treatments commonly applied to support phytostabilization were examined. A pot experiment was carried out to assess the effects of soil amendment with phosphate (P), sewage sludge (SS) and iron salts (Fe) on arsenic extractability and its uptake by grass. Four kinds of soil material, containing 356-5350 mg kg(-1) As, were examined. Velvetgrass proved to be more resistant than ryegrass to the toxicity of soil arsenic. Ammonium sulphate extractability of As in soils correlated well with As concentrations in the biomass of both grass species. In three of four tested soils, application of Fe failed to decrease As extractability and to reduce its concentrations in the aboveground parts of grasses. Application of P and SS resulted in increased As solubility in soils, but their effects on plant biomass and As uptake were ambiguous. SS had a strong beneficial influence on the growth of velvetgrass, while such an effect was not observed for ryegrass.

  15. Bioconcentration factor estimates of polycyclic aromatic hydrocarbons in grains of corn plants cultivated in soils treated with sewage sludge.

    PubMed

    Paraíba, Lourival Costa; Queiroz, Sônia Cláudia Nascimento; Maia, Aline de Holanda Nunes; Ferracini, Vera Lúcia

    2010-07-15

    This study presents a model to simulate the organic substance concentrations in corn grains assuming that the substances in soil solution are absorbed via the transpiration stream by plants growing in soils fertilized with sewage sludge (SS). The model was applied and validated using soil and corn grain samples from a long-term field experiment with six successive yearly applications of SS to the soil. The following polycyclic aromatic hydrocarbons (PAHs) were simulated and evaluated in soil and grain samples: acenaphthene, acenaphthylene, anthracene, benz(a)anthracene, benz(a)pyrene, benz(b)fluoranthene, benz(g,h,i)perylene, benz(k)fluoranthene, chrysene, dibenz(a,h)anthracene, fluoranthene, fluorene, indeno(1,2,3-c,d)pyrene, naphthalene, phenanthrene and pyrene. The PAH bioconcentration factors (BCF) in corn grains ranged from 1.57 to 10.97 L kg(-1). Polycyclic aromatic hydrocarbons with low soil distribution coefficients and high values of transpiration stream concentration factors (TSCF) are more likely to be absorbed by corn plants and accumulated in grains. It was possible to estimate and observe that highly lipophilic PAH molecules (heavy PAHs) show lower accumulative potential in corn grains than the less lipophilic ones (light PAHs). Sewage sludges containing significant concentrations of light PAHs with two, three or four benzene rings should be avoided as fertilizers in alimentary field crops.

  16. 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.

  17. 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

  18. Release of metals from metal-amended soil treated with a sulfosuccinamate surfactant: effects of surfactant concentration, soil/solution ratio, and pH.

    PubMed

    Hernández-Soriano, Maria del Carmen; Peña, Aránzazu; Dolores Mingorance, Ma

    2010-01-01

    Anionic surfactants, mainly sulfosuccinamates, can be found in soils as the result of sludge application, wastewater irrigation, and remediation processes. Relatively high concentrations of surfactants together with multimetals can represent an environmental risk. A study was performed to assess the potential of the anionic surfactant Aerosol 22 (A22) for release of Cd, Cu, Pb, and Zn from a metal-amended soil representative of a Mediterranean area. Metal desorption was performed by batch experiments and release kinetics were assessed. Response surface methodology was applied to determine the influence of A22 concentration and the surfactant/soil ratio, as extraction key factors. An increase in solution/soil ratio to 100 (mL g(-1)) caused higher metal release. Leaching predictions found Pb to have the lowest and Cd the highest hazard. Metal release was highly dependent on pH. When extraction was made at pH less than 7, low or negligible amounts of metals were leached, whereas an increase to pH 7 caused desorption rates of 50 to 55% for Cd, Cu, and Zn but only 35% for Pb. Complexed metal-carboxylic groups from A22 were mainly responsible for its higher extractive capacity, especially of Cd and Cu.

  19. 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.

  20. Comparison of properties of traditional and accelerated carbonated solidified/stabilized contaminated soils.

    PubMed

    Liu, Jiangying; Xu, Dimin; Xiong, Lan; Hills, Colin; Carey, Paula; Gardner, Kevin

    2008-01-01

    The investigation of the long-term performance of solidified/stabilized (S/S) contaminated soils was carried out in a trial site in southeast UK. The soils were exposed to the maximum natural weathering for four years and sampled at various depths in a controlled manner. The chemical properties (e.g., degree of carbonation (DOC), pH, electrical conductivity (EC)) and physical properties (e.g., moisture content (MC), liquid limit (LL), plastic limit (PL), plasticity index (PI)) of the samples untreated and treated with the traditional and accelerated carbonated S/S processes were analyzed. Their variations on the depths of the soils were also studied. The result showed that the broad geotechnical properties of the soils, manifested in their PIs, were related to the concentration of the water soluble ions and in particular the free calcium ions. The samples treated with the accelerated carbonation technology (ACT), and the untreated samples contained limited number of free calcium ions in solutions and consequently interacted with waters in a similar way. Compared with the traditional cement-based S/S technology, e.g., treatment with ordinary portland cement (OPC) or EnvirOceM, ACT caused the increase of the PI of the treated soil and made it more stable during long-term weathering. The PI values for the four soils ascended according to the order: the EnvirOceM soil, the OPC soil, the ACT soil, and the untreated soil while their pH and EC values descended according to the same order.

  1. Cement evaluation tool: a new approach to cement evaluation

    SciTech Connect

    Froelich, B.; Dumont, A.; Pittman, D.; Seeman, B.

    1982-08-01

    Cement bond logging achieves its greatest utility when it provides the production engineer with precise indications of cement strength and distribution around the casing. Zone isolation is of critical importance in production. Previous logging systems have yielded measures of cement bond that were circumferential averages of cement quality. These were difficult to interpret. Additionally, they were sensitive to the degree of shear coupling between pipe, cement, and formation and thus were affected by microannulus. The cement evaluation tool (CET) described here overcomes these difficulties. It provides a measurement of cement presence and strength, which is largely insensitive to microannulus. Its log output is interpreted easily. Tool design allows examination of the casing circumferentially at each depth. Impedance behind casing is measured. Laboratory calibration measurements allow this to be presented in terms of cement compressive strength. Cement channels are distinguished easily, and a zone isolation indicator can be presented. Additionally, casing internal diameter and distortion are displayed. European and North American field tests have been completed, and performance for a variety of well conditions is discussed. The ability of the tool to identify channels is confirmed. Sequential runs with and without excess pressure demonstrate immunity to microannulus in cases where CBL is affected but where microannulus is small enough to prohibit hydraulic communication. Geometrical measurements have been good indicators of casing deformation and have identified casing corrosion and wear.

  2. 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.

  3. 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.

  4. Speciation and bioaccessibility of lead and cadmium in soil treated with metal-enriched Indian mustard leaves.

    PubMed

    Cui, Yanshan; Fu, Jin; Chen, Xiaochen

    2011-01-01

    Indian mustard (Brassica juncea (L.) Czern.) has shown good potential for the phytoremediation of soil contaminated with heavy metals. However, there is little information about the speciation and bioaccessibility of heavy metals in soil during the decomposition of metal-rich Indian mustard leaves. Incubation experiments (1-, 3-, and 6-month) were carried out in Beijing and Hunan soil with metal-rich Indian mustard leaves addition (1% and 3%) and the effects of mustard leaves addition on the speciation and bioaccessibility of heavy metals were studied. The results showed that the addition of mustard leaves led to significant increases in pH and DOC in the Hunan soil. Both 1% and 3% of mustard leaf amendment caused the percentage of the exchangeable (F1), precipitated with carbonates (F2), bound to Fe/Mn oxides (F3) and bound to organic matter (F4) fractions of Pb and Cd to increase dramatically, while the percentage of the residual fraction (F5) of Cd and Pb significantly dropped in both Beijing and Hunan soils. Mustard leaf addition caused the bioaccessibility of Pb to decrease in the gastric phase, whereas the values increased in the small intestinal phase. The Cd bioaccessibility increased with mustard leaf addition in both the gastric and small intestinal phases. In conclusion, the metal-enriched mustard leaves addition induces Pb and Cd concentrations and their mobility increasing in the Beijing and Hunan soils. Therefore, heavy metal risk in metal-enriched plant leaves should be considered in phytoremediation system in which heavy metal might be brought back to soil and changed over time.

  5. 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.

  6. 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.

  7. 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

  8. 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.

  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.

  10. [Haemotoxicity of dental luting cements].

    PubMed

    Anders, A; Welker, D

    1989-06-01

    A glass ionomer luting cement (AquaCem) shows a relatively low haemolytic activity in comparison with two zinc phosphate cements. Especially the initial irritation by this cement is smaller. Although it is possible that AquaCem particularly, in unfavourable cases, may damage the pulpa dentin system; this is due to the slowly decrease of the haemolytic activity with increasing of the probes. We found that Adhesor showed in dependence of the batches a varying quality.

  11. Abrasive wear of cemented carbides

    SciTech Connect

    Hawk, Jeffrey A.; Wilson, Rick D.

    2003-10-01

    Cemented carbides are used for a wide variety of applications where wear is a problem. Usually the wear of the cemented carbides is a combination of metal-to-metal and abrasion. Wear can occur at room or elevated temperatures. This research summarizes initial research to understand the abrasive wear of various cemented carbides (various grain sizes, carbide types, carbide grain sizes and binder compositions) in terms of absolute material removal rates and material removal mechanisms.

  12. Microtensile bond strength of glass fiber posts cemented with self-adhesive and self-etching resin cements.

    PubMed

    Zaitter, Suellen; Sousa-Neto, Manoel D; Roperto, Renato C; Silva-Sousa, Yara T; El-Mowafy, Omar

    2011-02-01

    To evaluate the bond strength of glass fiber posts to intraradicular dentin when cemented with self-etching and self-adhesive resin cements. Forty-eight single-rooted human teeth were decoronated, endodontically treated, post-space prepared and divided into 8 groups (n = 6). The glass fiber posts used were: Exacto (EA) (Angelus) and everStick (ES) (StichTeck), which were cemented with two self-adhesive resin cements: BisCem (BIS) (Bisco) and Rely-X Unicem (UNI) (3M/ESPE), and two self-etching resin cements: Esthetic Cementing System NAC100 (NAC) (Kuraray) and Panavia-F (PAN) (Kuraray). Specimens were thermocycled between 5°C and 55 °C for 1000 cycles and stored in water at 37°C for 1 month. Four 1-mm-thick (in cross section) rods were obtained from the cervical region of the roots. Specimens were then subjected to microtensile testing in a special machine (BISCO; Schaumburg, IL, USA) or a crosshead speed of 0.5 mm/min. Microtensile bond strength (μTBS) data were analyzed with two-way ANOVA and Tukey's tests. Means (and SD) of μTBS (MPa) were: EA/PAN: 10.3 (4.1), EA/NAC: 14 (5.1) EA/BIS: 16.4 (4.8), EA/UNI: 19.8 (5.1), ES/PAN: 25.9 (6.1), ES/NAC: 29.1 (7), ES/BIS: 28.9 (6), ES/UNI: 30.5 (6.6). ANOVA indicated significant differences among the groups (p < 0.001). Mean μTBS values obtained with ES post were significantly higher than those obtained with EA (p < 0.001). For EA, Tukey's test indicated that higher μTBS means were obtained with the self-adhesive resin cements (BIS and UNI), which were statistically significantly different (p < 0.05) from values obtained with the self-etching resin cements (PAN and NAC). Different cements had no significant effects on the bond strength values of ES post (p > 0.05). μTBS values obtained with ES post were significantly higher than those obtained with EA post irrespective of the resin cement used. everStick posts resulted in the highest mean μTBS values with all cements. Self-adhesive cements performed well in terms

  13. Inspection program improves bulk cement system delivery

    SciTech Connect

    O'Bannion, T. ); Guidroz, B.; Morris, G. )

    1993-12-20

    A recently implemented survey of pneumatically operated bulk cement-handling equipment offshore has improved bulk cement deliverability on several Gulf of Mexico rigs. The 30-point survey helps ensure an adequate rate of bulk cement delivery throughout the cement job. The inspection survey was developed because the source of many cement job failures was a lack of adequate, steady delivery of bulk cement to the cementing unit during the job. The job failures caused by flow interruptions, plugging of tools by chunks of set cement, and erratic flow resulted in poor primary cement jobs, many of which required remedial cementing jobs. A better-controlled flow of cement may help prevent these types of failure, thereby reducing the number of remedial cement operations. The paper describes the inspection procedures.

  14. 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.

  15. 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.

  16. 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.

  17. Pressable feldspathic inlays in premolars: effect of cementation strategy and mechanical cycling on the adhesive bond between dentin and restoration.

    PubMed

    Feitosa, Sabrina Alves; Corazza, Pedro Henrique; Cesar, Paulo Francisco; Bottino, Marco Antonio; Valandro, Luiz Felipe

    2014-04-01

    To evaluate the effect of the cementation strategy and mechanical cycling (MC) on the microtensile bond strength (MTBS) of feldspathic inlays cemented to premolars. Forty-eight human premolars were prepared and porcelain inlays were produced. Specimens were allocated into 3 groups, based on the cementation strategy: 1) conventional adhesive cementation (RelyX ARC, 3M ESPE): application of etch-and-rinse single bottle adhesive to dentin / ceramic surface treated with hydrofluoric acid (HF) and silane (S) / cementation with resin cement; 2) simplified cementation using a self-adhesive resin cement (RelyX U100, 3M ESPE); 3) modified simplified cementation using a self-adhesive resin cement (RelyX U100, 3M ESPE) with HF+S treatment. Half of the specimens from each group were submitted to MC (2x106 pulses, frequency = 4 Hz, load = 100 N). Each specimen was serially sliced for MTBS and the failures were classified. The stress distribution analysis using FEA was verified. All of the bar-samples from G2 were lost during cutting of the specimens. Mechanical-cycling had no significant effect on bond strength, whereas cementation strategy significant affected MTBS results. The most common type of failure was cohesive of cement. FEA showed that stresses were concentrated mainly at the loading region going up to the root fixation. Porcelain inlays cemented with conventional resin cement or self-adhesive resin cement should be associated with ceramic surface treatment. FEA showed the most critical zone for failure is located in the cement region close to the marginal crest.

  18. 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.

  19. ADSORPTION OF LEAD FROM A CONTAMINATED SOIL TREATED WITH PHOSPHORUS AND MANGANESE OXIDES BY APRAGUE-DAWLEY RATS

    EPA Science Inventory

    In addition to the formation of insoluble lead (Pb) compounds as a mean of reducing Pb bioavalability, adsorption is another potentially important process controlling the bioavailability of Pb in soils. Less attention has been given to manganese (Mn) oxides, even though they are ...

  20. 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.

  1. Phosphate based oil well cements

    NASA Astrophysics Data System (ADS)

    Natarajan, Ramkumar

    The main application of the cement in an oil well is to stabilize the steel casing in the borehole and protect it from corrosion. The cement is pumped through the borehole and is pushed upwards through the annulus between the casing and the formation. The cement will be exposed to temperature and pressure gradients of the borehole. Modified Portland cement that is being used presently has several shortcomings for borehole sealant. The setting of the Portland cement in permafrost regions is poor because the water in it will freeze even before the cement sets and because of high porosity and calcium oxide, a major ingredient it gets easily affected by the down hole gases such as carbon dioxide. The concept of phosphate bonded cements was born out of considerable work at Argonne National Laboratory (ANL) on their use in stabilization of radioactive and hazardous wastes. Novel cements were synthesized by an acid base reaction between a metal oxide and acid phosphate solution. The major objective of this research is to develop phosphate based oil well cements. We have used thermodynamics along with solution chemistry principles to select calcined magnesium oxide as candidate metal oxide for temperatures up to 200°F (93.3°C) and alumina for temperatures greater than 200°F (93.3°C). Solution chemistry helped us in selecting mono potassium phosphate as the acid component for temperatures less than 200°F (93.3°C) and phosphoric acid solution greater than 200°F (93.3°C). These phosphate cements have performance superior to common Portland well cements in providing suitable thickening time, better mechanical and physical properties.

  2. 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

  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. [Association between allergy to benzoyl peroxide, vitiligo and implantation of a cemented total knee joint prosthesis: Is there a connection?].

    PubMed

    Gothner, M; Ozokyay, L; Godau, P; Kälicke, T; Muhr, G; Schildhauer, T A; Dudda, M

    2011-09-01

    Allergies against bone cement or bone cement components have been well-described. We report on a 63-year-old patient who presented with progressive vitiligo all over the body after implantation of a cemented total knee replacement. A dermatological examination was performed and an allergy to benzoyl peroxide was found. A low-grade infection was diagnosed 5 months after implantation of the total knee replacement and the prosthesis was replaced with a cement spacer. After treating the infection of the knee replacement non-cemented arthrodesis of the knee was performed. In cases of new, unknown skin efflorescence, urticaria and periprosthetic loosening of cemented joint replacement, the differential diagnosis should include not only infections but also possible allergies against bone-cement and components such as benzoyl peroxide or metal components.

  6. Alumina as a filler for bone cement: a feasibility study.

    PubMed

    Ackley, M A; Monroe, E

    1980-10-01

    A composite bone cement of Alcoa A-10 Alumina and very finely ground poly(methyl methacrylate) beads (PMMA) was fabricated. It was tested in an attempt to improve on the conventionally used pure PMMA bone cement. By knowing the densities of the powders and their volumes, the mass of each was calculated for the most efficient packing of PMMA and Al2O3 powders and a 65% PMMA: 35% Al2O3 ratio by weight composition was determined. This was tested, as well as the pure cement so comparisons could be made. Cylinders for the strength tests were also made of silane treated Al2O3. The compositions were tested for compressive and tensile strengths. The pure PMMA, composite and silane treated composite had compressive strengths of 79.64 +/- 13.0, 83.17 +/- 4.8, and 71.52 +/- 8.6 MPa and the tensile strengths were 6.69 +/- 0.6, 5.12 +/- 0.3, and 7.12 +/- 0.5 MPa respectively. Also the 65%-35% PMMA-Al2O3 composite required 64% less monomer for mixing than did the pure cement which is thought to be better for tissue healing. The maximum temperature attained from room temperature was 110 degrees-115 degrees C for both cements. The composite took 6.5 min longer to reach its peak temperature than did the pure cement. The bone cements were implanted for one week in a rabbit and both compositions seemed acceptable by the tissue.

  7. Calcium sulfate cement in contained traumatic metaphyseal bone defects.

    PubMed

    Drosos, Georgios I; Ververidis, Athanasios; Babourda, Eleni C; Kakagia, Despoina; Verettas, Dionisios-Alexandros

    2012-12-01

    The aim of this study was to evaluate prospective patients with periarticular fractures where a meta physeal bone defect was grafted with high compressive calcium sulfate cement. The calcium sulfate cement MIIG X3, (Wright Medical Technology, Inc, Arlington, TN) was used in 45 patients with periarticular fractures--distal radial, tibial plateau, humeral head, and calcaneal fractures--to fill the metaphyseal defect. All fractures were treated either with open or closed reduction, fracture fixation, and the cement was applied openly or closed. Radiographs were evaluated for fracture reduction, joint line gap, and step, as well as for rate of graft replacement by bone. All fractures united without an additional procedure. There were no wound infections or other complications attributed to the graft. At three-month follow-up, a complete graft replacement by bone was observed in all fractures. Joint line step was not developed in any patient, but a joint line gap of 3 mm was observed postoperatively in one patient with a tibial plateau fracture. Loss of reduction occurred in one patient with an extra-articular distal radial fracture treated with closed reduction and k-wire fixation. Cement that escaped into the joint or the surrounding soft tissues was not visible at the six-week follow-up. In conclusion, the results of this study confirm the safety and the efficacy of this cement when it is used as graft with the appropriate fixation method in traumatic metaphyseal bone defects.

  8. Microleakage in ceramic inlays luted with different resin cements.

    PubMed

    Mota, Cristiane Soares; Demarco, Flávio Fernando; Camacho, Guilherme Brião; Powers, John M

    2003-01-01

    The objective of this in vitro study was to evaluate the microleakage in ceramic inlays using different resin cements with margins in enamel and cementum/dentin interfaces. Standard Class II MOD inlay cavities were prepared in 32 noncarious human premolars. The cavities were randomly divided into 4 groups (n = 8): cavities were treated with Single Bond and incrementally filled with a composite resin (P60); Enforce group: feldspathic ceramic inlays were luted using Prime & Bond 2.1 and Enforce; RelyX group: inlays were cemented with Single Bond and RelyX ARC; Resin Cement group: ceramic inlays were bonded using Single Bond and Resin Cement. Ceramic inlays were previously treated with 10% hydrofluoric acid for 2 min, followed by silane application. After 7 days of storage in distilled water, teeth were submitted to thermocycling. After applying nail varnish, specimens were immersed in 2% aqueous solution of methylene blue for 8 h. After washing, teeth were cut into three sections through the restorations, and the leakage was assessed using a standardized score. Data were submitted to statistical analysis using nonparametric tests (Mann-Whitney and Kruskal-Wallis). Dye leakage at margins in enamel was statistically lower (p < 0.01) than at cementum/dentin interfaces. RelyX ARC performed better (p < 0.05) than resin cement (enamel) and composite restorations (cementum/dentin). No other statistical differences were observed. Both the material and the substrate interface influenced microleakage of the ceramic inlays.

  9. Arsenic leachability and speciation in cement immobilized water treatment sludge.

    PubMed

    Jing, Chuanyong; Liu, Suqin; Meng, Xiaoguang

    2005-06-01

    Arsenic leachability and speciation in cement immobilized water treatment sludge were investigated with leaching tests and X-ray absorption near edge structure (XANES) spectroscopy. The As leachability in the sludge determined with the toxicity characteristic leaching procedure (TCLP) and the waste extraction test (WET) was 283 and 7490 microgl(-1), respectively. Extractions with a lower liquid to solid ratio, under anaerobic conditions, and using citric acid buffer solution dramatically increased the leachate As concentration. XANES results showed that the As(III) composition was reduced from 51.1% of the total As content in the sludge to 16.3% in the cement treated sample with 28 days of cure. When the cement treated sample was cured for two years, the As(III) composition was decreased to 7.4%. The cement treatment reduced the As leachability. The leachate As(III) and total As concentrations were of the same order of magnitude in the samples cured for 28 days as for 2yr. However, consistently lower concentrations were detected in samples with longer cure time. The results of this study improve our understanding of arsenic speciation and leachability in the cement matrix after long cure times.

  10. [Toxicity of glass ionomer cement].

    PubMed

    Lübben, B; Geyer, G

    2001-04-01

    The hybrid bone substitute ionomeric cement achieves a stable and durable space-free bond to adjacent bone during hardening. Clinical studies have evaluated the material differently: Fully hardened ionomeric cement showed in middle ear surgery, e.g. as an ossicular prosthesis, good biocompatibility with outstanding functional results. In a few cases, freshly mixed ionomeric cement led to severe complications after contact with CSF in skull base surgery. Therefore we intended to evaluate the influence of early fluid contact on the quality of cement and to define the interval for a safe application of the material, using a cell culture model. Further we intended to investigate whether combining cement with homologous and alloplastic materials influenced its quality. 1) Ionomeric cement (Ionocem) test bodies were placed in Ringer's solution at different times after the mixing phase. 2) Ionomeric cement (Ionocem) test bodies were coated with different clinically used homologous and alloplastic materials during the setting and hardening phase. The concentrations of released cement-forming ions and the toxic effects on mouse fibroblasts within cell cultures were measured. Cytotoxic effects were observed when ionomeric cement was not carefully protected from fluid contact for the first two hours after mixing. This was due to forced fast elution of large amounts of cement-constituting fluoride ions and aluminium ions and to the development of acid valences and their interactions. A total hardening time of less than 25 min had an especially unfavourable influence on cell behaviour. Cell impairments could be reduced significantly by coating the 30-minute cured cement with PDS sheeting and significantly by covering it with viscous collagene. On the other hand, cement toxicity was intensified in part by combinations with some other coating materials. Ionomeric cement should be kept dry and protected from any fluid contact for at least 30 minutes after mixing. Contact with soft

  11. 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.

  12. Solidification and stabilization of asbestos waste from an automobile brake manufacturing facility using cement.

    PubMed

    Chan, Y M; Agamuthu, P; Mahalingam, R

    2000-10-02

    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

  13. Significance of treated agrowaste residue and autochthonous inoculates (Arbuscular mycorrhizal fungi and Bacillus cereus) on bacterial community structure and phytoextraction to remediate soils contaminated with heavy metals.

    PubMed

    Azcón, Rosario; Medina, Almudena; Roldán, Antonio; Biró, Borbála; Vivas, Astrid

    2009-04-01

    In this study, we analyzed the impact of treatments such as Aspergillus niger-treated sugar beet waste (SB), PO4(3-) fertilization and autochthonous inoculants [arbuscular mycorrhizal (AM) fungi and Bacillus cereus], on the bacterial community structure in a soils contaminated with heavy metals as well as, the effectiveness on plant growth (Trifolium repens). The inoculation with AM fungi in SB amended soil, increased plant growth similarly to PO4(3-) addition, and both treatments matched in P acquisition but bacterial biodiversity estimated by denaturing gradient gel electrophoresis of amplified 16S rDNA sequences, was more stimulated by the presence of the AM fungus than by PO4(3-) fertilization. The SB amendment plus AM inoculation increased the microbial diversity by 233% and also changed (by 215%) the structure of the bacterial community. The microbial inoculants and amendment used favoured plant growth and the phytoextraction process and concomitantly modified bacterial community in the rhizosphere; thus they can be used for remediation. Therefore, the understanding of such microbial ecological aspects is important for phytoremediation and the recovery of contaminated soils.

  14. Corrosion resistant cemented carbide

    SciTech Connect

    Hong, J.

    1990-10-16

    This paper describes a corrosion resistant cemented carbide composite. It comprises: a granular tungsten carbide phase, a semi-continuous solid solution carbide phase extending closely adjacent at least a portion of the grains of tungsten carbide for enhancing corrosion resistance, and a substantially continuous metal binder phase. The cemented carbide composite consisting essentially of an effective amount of an anti-corrosion additive, from about 4 to about 16 percent by weight metal binder phase, and with the remaining portion being from about 84 to about 96 percent by weight metal carbide wherein the metal carbide consists essentially of from about 4 to about 30 percent by weight of a transition metal carbide or mixtures thereof selected from Group IVB and of the Periodic Table of Elements and from about 70 to about 96 percent tungsten carbide. The metal binder phase consists essentially of nickel and from about 10 to about 25 percent by weight chromium, the effective amount of an anti-corrosion additive being selected from the group consisting essentially of copper, silver, tine and combinations thereof.

  15. 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.

  16. 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)

  17. 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.

  18. 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.

  19. 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)...

  20. 21 CFR 888.4200 - Cement dispenser.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 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) into...

  1. 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) into...

  2. 21 CFR 888.4200 - Cement dispenser.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 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) into...

  3. 21 CFR 888.4200 - Cement dispenser.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 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) into...

  4. High-viscosity cement significantly enhances uniformity of cement filling in vertebroplasty: an experimental model and study on cement leakage.

    PubMed

    Baroud, Gamal; Crookshank, Meghan; Bohner, Marc

    2006-10-15

    Experimental study using a laboratory leakage model. To examine the working hypothesis that high-viscosity cements will spread uniformly, thus significantly reducing the risk of leakage. In vertebroplasty, forces that govern the flow of bone cement in the trabecular bone skeleton are an essential determinant of the uniformity of cement filling. Extraosseous cement leakage has been reported to be a major complication of this procedure. Leakage occurs due to the presence of a path of least resistance caused by irregularities in the trabecular bone or shell structure. Ideally, cement uniformly infiltrates the trabecular bone skeleton and does not favor specific paths. Cement viscosity is believed to affect the infiltration forces and flow during the procedure. Clinically, altering the time between cement mixing and delivery modifies the viscosity of bone cement. An experimental model of the leakage phenomenon of vertebroplasty was developed. A path, simulating a blood vessel, was created in the model to perturb the forces underlying cement flow and to favor leakage. Cement of varying viscosities was injected in the model, and, thereafter, the filling pattern, cement mass that has leaked, time at which leakage occurred, and injection pressure were measured. A strong relationship was found between the uniformity of the filling pattern and the elapsed time from cement mixing and viscosity, respectively. Specifically, 3 distinct cement leakage patterns were observed: immediate leakage was observed when cement was injected 5-7 minutes following mixing. The cement was of a low viscosity and more than 50% of the total cement injected leaked. Moderate leakage was observed when injection occurred 7-10 minutes following mixing. Less than 10% of the cement leaked, and the viscosity was at a transient state between the low viscosity of immediate leakage and a higher viscosity, doughy cement. Cement leakage ceased completely when cement was delivered after 10 minutes. The

  5. Furcal perforation repair using calcium enriched mixture cement

    PubMed Central

    Asgary, Saeed

    2010-01-01

    This case describes a furcal perforation in a mandibular first molar accompanied by furcal lesion which has been managed after one month. Root canal treatment was performed; subsequently, the defect was repaired with calcium enriched mixture (CEM) cement. The endodontically treated tooth was restored with amalgam. A 24-month recall showed no evidence of periodontal breakdown, no symptoms, in addition to completes healing of furcal lesion. According to physical and biological properties of the newly introduced CEM cement, this novel material may be suitable for sealing and repairing the perforations. The present case report supports this hypothesis. PMID:21116393

  6. 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

  7. Mild acid and alkali treated clay minerals enhance bioremediation of polycyclic aromatic hydrocarbons in long-term contaminated soil: A (14)C-tracer study.

    PubMed

    Biswas, Bhabananda; Sarkar, Binoy; Rusmin, Ruhaida; Naidu, Ravi

    2017-04-01

    Bioremediation of polycyclic aromatic hydrocarbon (PAH)-contaminated soils requires a higher microbial viability and an increased PAH bioavailability. The clay/modified clay-modulated bacterial degradation could deliver a more efficient removal of PAHs in soils depending on the bioavailability of the compounds. In this study, we modified clay minerals (smectite and palygorskite) with mild acid (HCl) and alkali (NaOH) treatments (0.5-3 M), which increased the surface area and pore volume of the products, and removed the impurities without collapsing the crystalline structure of clay minerals. In soil incubation studies, supplements with the clay products increased bacterial growth in the order: 0.5 M HCl ≥ unmodified ≥ 0.5 M NaOH ≥ 3 M NaOH ≥ 3 M HCl for smectite, and 0.5 M HCl ≥ 3 M NaOH ≥ 0.5 M NaOH ≥ 3 M HCl ≥ unmodified for palygorskite. A(14)C-tracing study showed that the mild acid/alkali-treated clay products increased the PAH biodegradation (5-8%) in the order of 0.5 M HCl ≥ unmodified > 3 M NaOH ≥ 0.5 M NaOH for smectite, and 0.5 M HCl > 0.5 M NaOH ≥ unmodified ≥ 3 M NaOH for palygorskite. The biodegradation was correlated (r = 0.81) with the bioavailable fraction of PAHs and microbial growth as affected particularly by the 0.5 M HCl and 0.5 M NaOH-treated clay minerals. These results could be pivotal in developing a clay-modulated bioremediation technology for cleaning up PAH-contaminated soils and sediments in the field.

  8. 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

  9. Resin cementation of zirconia ceramics with different bonding agents.

    PubMed

    Tanış, Merve Çakırbay; Akay, Canan; Karakış, Duygu

    2015-03-04

    The aim of this study was to evaluate the effects of sandblasting and different chemical bonding agents on shear bond strength