Pub Date : 2000-11-01DOI: 10.1080/10588330091134437
H. Park, C. S. Juan
This article presents the rationale for the mathematical fate and transport model, which has been provided in the accompanying spreadsheet (GWProt). This spreadsheet model may be used as a simple and scientifically defensible regulatory tool for determining the risk-based soil clean up level of petroleum release sites to protect groundwater quality. The model incorporates either a three- or four-phase partitioning equilibrium mechanism, depending on the detection of Non-Aqueous Phase Liquid phase presence mathematically, as well as Raoult's Law convention and default dilution and attenuation factors. A database of contaminant-specific parameters, including solubility and organic-carbon partition-coefficient, molecular weight, and Henry's Law constant, is assembled for benzene, toluene, ethylbenzene, xylenes, and 12 other TPH equivalent carbon fractions. In addition to distributing organic chemicals among aqueous, sorbed solid, air, and NAPL phases, according to traditional partitioning equations, the algorithm incorporates equations for the conservation of mass and volume. A unique solution is obtained by solving a series of mass balance equations simultaneously using the iterative spreadsheet routine built in MICROSOFT EXCELTM Solver — with the restrictions that the volume is conserved and the sum of the mole fractions is equal to one. Sample calculations are presented for a range of parameter values to illustrate the use of the model and the relative leach-ability of a wide range of representative fuels. Sensitivity analysis was also performed to quantify the effects of uncertainty in the estimates of the key model parameters on model results. Model predictions were compared with the results from a water-fuel experiment. The noncar-cinogenic Hazard Index (HI) for groundwater through direct ingestion was calculated using predetermined oral reference dose (Rfd) values. Applications and limitations of the model are also discussed.
{"title":"A Method for Assessing Leaching Potential for Petroleum Hydrocarbons Release Sites: Multiphase and Multisubstance Equilibrium Partitioning","authors":"H. Park, C. S. Juan","doi":"10.1080/10588330091134437","DOIUrl":"https://doi.org/10.1080/10588330091134437","url":null,"abstract":"This article presents the rationale for the mathematical fate and transport model, which has been provided in the accompanying spreadsheet (GWProt). This spreadsheet model may be used as a simple and scientifically defensible regulatory tool for determining the risk-based soil clean up level of petroleum release sites to protect groundwater quality. The model incorporates either a three- or four-phase partitioning equilibrium mechanism, depending on the detection of Non-Aqueous Phase Liquid phase presence mathematically, as well as Raoult's Law convention and default dilution and attenuation factors. A database of contaminant-specific parameters, including solubility and organic-carbon partition-coefficient, molecular weight, and Henry's Law constant, is assembled for benzene, toluene, ethylbenzene, xylenes, and 12 other TPH equivalent carbon fractions. In addition to distributing organic chemicals among aqueous, sorbed solid, air, and NAPL phases, according to traditional partitioning equations, the algorithm incorporates equations for the conservation of mass and volume. A unique solution is obtained by solving a series of mass balance equations simultaneously using the iterative spreadsheet routine built in MICROSOFT EXCELTM Solver — with the restrictions that the volume is conserved and the sum of the mole fractions is equal to one. Sample calculations are presented for a range of parameter values to illustrate the use of the model and the relative leach-ability of a wide range of representative fuels. Sensitivity analysis was also performed to quantify the effects of uncertainty in the estimates of the key model parameters on model results. Model predictions were compared with the results from a water-fuel experiment. The noncar-cinogenic Hazard Index (HI) for groundwater through direct ingestion was calculated using predetermined oral reference dose (Rfd) values. Applications and limitations of the model are also discussed.","PeriodicalId":433778,"journal":{"name":"Journal of Soil Contamination","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129490238","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2000-11-01DOI: 10.1080/10588330091134392
C. Axtell, C. G. Johnston, J. Bumpus
The explosives TNT, HMX, and RDX are integral components of many munitions. The wastes from the manufacture and the use of these and other explosives has resulted in substantial contamination of water and soil. White rot fungi have been proposed for use in the bioremediation of contaminated soil and water. Strains of Phanerochaete chrysosporium and Pleurotus ostreatus adapted to grow on high concentrations of TNT were studied with regard to their ability to degrade TNT in liquid cultures. Both strains were able to cause extensive degradation of TNT. Field bioremediation studies using P. ostreatus were performed on site at the Yorktown Naval Weapons Station Yorktown (Yorktown, VA). In two plots, 6 cubic yards of soil contaminated with TNT, HMX, and RDX were blended with 3 cubic yards of a substrate mixture containing nutrients that promote the growth of fungi. In soil amended with growth substrate and P. ostreatus, concentrations of TNT, HMX and RDX were reduced from 194.0±50, 61±20 mg/kg and 118.0±30 to 3±4, 18±7 and 5±3 mg/kg, respectively, during a 62-day incubation period. Interestingly, in soil that was amended with this substrate mixture, but not with P. ostreatus, the concentrations of TNT, HMX, and RDX were also reduced substantially from 283±100, 67±20, and 144±50 mg/kg to 10±10, 34±20, and 12±10 mg/kg, respectively, during the same period. Thus, it appears that addition of amendments that enhance the growth and activity of indigenous microorganisms was sufficient to promote extensive degradation of these compounds in soil.
{"title":"Bioremediation of Soil Contaminated with Explosives at the Naval Weapons Station Yorktown","authors":"C. Axtell, C. G. Johnston, J. Bumpus","doi":"10.1080/10588330091134392","DOIUrl":"https://doi.org/10.1080/10588330091134392","url":null,"abstract":"The explosives TNT, HMX, and RDX are integral components of many munitions. The wastes from the manufacture and the use of these and other explosives has resulted in substantial contamination of water and soil. White rot fungi have been proposed for use in the bioremediation of contaminated soil and water. Strains of Phanerochaete chrysosporium and Pleurotus ostreatus adapted to grow on high concentrations of TNT were studied with regard to their ability to degrade TNT in liquid cultures. Both strains were able to cause extensive degradation of TNT. Field bioremediation studies using P. ostreatus were performed on site at the Yorktown Naval Weapons Station Yorktown (Yorktown, VA). In two plots, 6 cubic yards of soil contaminated with TNT, HMX, and RDX were blended with 3 cubic yards of a substrate mixture containing nutrients that promote the growth of fungi. In soil amended with growth substrate and P. ostreatus, concentrations of TNT, HMX and RDX were reduced from 194.0±50, 61±20 mg/kg and 118.0±30 to 3±4, 18±7 and 5±3 mg/kg, respectively, during a 62-day incubation period. Interestingly, in soil that was amended with this substrate mixture, but not with P. ostreatus, the concentrations of TNT, HMX, and RDX were also reduced substantially from 283±100, 67±20, and 144±50 mg/kg to 10±10, 34±20, and 12±10 mg/kg, respectively, during the same period. Thus, it appears that addition of amendments that enhance the growth and activity of indigenous microorganisms was sufficient to promote extensive degradation of these compounds in soil.","PeriodicalId":433778,"journal":{"name":"Journal of Soil Contamination","volume":"53 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122467770","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2000-11-01DOI: 10.1080/10588330091134383
John E. Thomas, R. D. Rhue, W. Reve
Dipping vats were used routinely in the southeastern U.S. in the early 1900s to eradicate the cattle fever tick. The legacy is many dip vat sites with arsenic (As)-contaminated soil and ground water. Assessing the extent of these As plumes can be time consuming and expensive. We describe a quicker and less expensive, onsite test for soil As. It is a modification of a commercially available test designed for As in water, taking about 10 min to complete, allowing large plume areas to be delineated in a single day. An As contaminant plume in Alachua County, FL, was delineated using the quick test. Soil samples taken from a large grid encompassing the plume were analyzed in the laboratory for As to confirm the results obtained with the quick test. The comparison showed that the quick test very accurately delineated the outer boundary of the plume as well as zones of higher As concentration within the plume.
{"title":"A Quick, Onsite Test for Delineating Arsenic Contaminant Plumes in Soil","authors":"John E. Thomas, R. D. Rhue, W. Reve","doi":"10.1080/10588330091134383","DOIUrl":"https://doi.org/10.1080/10588330091134383","url":null,"abstract":"Dipping vats were used routinely in the southeastern U.S. in the early 1900s to eradicate the cattle fever tick. The legacy is many dip vat sites with arsenic (As)-contaminated soil and ground water. Assessing the extent of these As plumes can be time consuming and expensive. We describe a quicker and less expensive, onsite test for soil As. It is a modification of a commercially available test designed for As in water, taking about 10 min to complete, allowing large plume areas to be delineated in a single day. An As contaminant plume in Alachua County, FL, was delineated using the quick test. Soil samples taken from a large grid encompassing the plume were analyzed in the laboratory for As to confirm the results obtained with the quick test. The comparison showed that the quick test very accurately delineated the outer boundary of the plume as well as zones of higher As concentration within the plume.","PeriodicalId":433778,"journal":{"name":"Journal of Soil Contamination","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134448481","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2000-11-01DOI: 10.1080/10588330091134428
Y. Rong, Rueen-Fang Wang
Many vadose zone models are available for environmental remediation, but few offer the procedures for verifying model predictions with field data and for dealing with uncertainties associated with model input parameters. This article presents a modified model combining a one-dimensional vadose-zone transport model and a simple groundwater mixing model with a function of Monte Carlo simulation (MCS). The modified model is applied to determine soil remedial concentrations for methyl tertiary butyl ether (MTBE). The modified model generates a distribution of MTBE ground-water concentrations at the point of compliance. This distribution can be used to estimate the risk of exceeding groundwater quality standard given soil remedial concentrations. In a case study, soil remedial concentration for MTBE is established to be 5 µg/kg, with a 95% and 10 µg/kg with a 50% probability that groundwater concentration will not exceed the water quality objective of 13 µg/L. Furthermore, this study uses MCS to investigate uncertainties of model input parameter hydraulic conductivity (K). One set of data (K1) is based on the results of hydraulic conductivity laboratory tests, and the other (K2) is based on the results of slug tests conducted in the field. As expected, the laboratory data show smaller K values than the field data. The comparison of the MCS results obtained from the two sets of K data indicates that the MTBE groundwater concentrations calculated based on K1 are generally 160 to 625% greater than those calculated based on K2 at the same percentiles of the MCS distribution. A higher soil remedial concentration of9jig/kg is then calculated based on the MCS results from K2 at 95%ile and 19 µg/kg at 50%ile.
{"title":"Monte Carlo Vadose Zone Model for Soil Remedial Criteria","authors":"Y. Rong, Rueen-Fang Wang","doi":"10.1080/10588330091134428","DOIUrl":"https://doi.org/10.1080/10588330091134428","url":null,"abstract":"Many vadose zone models are available for environmental remediation, but few offer the procedures for verifying model predictions with field data and for dealing with uncertainties associated with model input parameters. This article presents a modified model combining a one-dimensional vadose-zone transport model and a simple groundwater mixing model with a function of Monte Carlo simulation (MCS). The modified model is applied to determine soil remedial concentrations for methyl tertiary butyl ether (MTBE). The modified model generates a distribution of MTBE ground-water concentrations at the point of compliance. This distribution can be used to estimate the risk of exceeding groundwater quality standard given soil remedial concentrations. In a case study, soil remedial concentration for MTBE is established to be 5 µg/kg, with a 95% and 10 µg/kg with a 50% probability that groundwater concentration will not exceed the water quality objective of 13 µg/L. Furthermore, this study uses MCS to investigate uncertainties of model input parameter hydraulic conductivity (K). One set of data (K1) is based on the results of hydraulic conductivity laboratory tests, and the other (K2) is based on the results of slug tests conducted in the field. As expected, the laboratory data show smaller K values than the field data. The comparison of the MCS results obtained from the two sets of K data indicates that the MTBE groundwater concentrations calculated based on K1 are generally 160 to 625% greater than those calculated based on K2 at the same percentiles of the MCS distribution. A higher soil remedial concentration of9jig/kg is then calculated based on the MCS results from K2 at 95%ile and 19 µg/kg at 50%ile.","PeriodicalId":433778,"journal":{"name":"Journal of Soil Contamination","volume":"36 1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131194361","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2000-11-01DOI: 10.1080/10588330091134400
Trine S. Jensen, E. Arvin, B. Svensmark, P. Wrang
Samples from a long-term bioremediation experiment contaminated with two crude oils, Arabian Heavy and Gullfax, was used to analyze the compositional change of petroleum hydrocarbons. A time course of five different homologous series of petroleum hydrocarbons were analysed by GC/FID and GC/MS. The homologous series were n-alkanes, acyclic isoprenoids, alkylated naphthalenes, alkylated phenanthrenes, and alkylated dibenzothiophenes. Several biomarker compounds were monitored during the experiment to evaluate the possible use as conserved reference compounds for the quantification of other oil compounds, that is, nor-hopanes, hopanes, methyl-hopanes, steranes, mono- og triaromatic steranes. The 17α(H),21β(H)-hopane was found to be stable toward biodegradation and was used as reference compound. The internal standard quantification method was used to quantify changes of the homologous series of oil compounds, and a graphic presentation was used to compare the decrease of the individual compounds. This was found to be an easy way of comparing relative changes in oil. The disappearance of the compounds was extensive and in 6 to 7 months less than 6% remained. The decrease of the n-alkanes (>C15) and acyclic isoprenoids was almost uniform within each homologous series and thus independent of physical-chemical characteristics. Evaporation affected compounds with boiling points lower than n-C15. The alkylated aromatic and sulfur-aromatic compounds decreased according to the degree of alkylation and the decrease showed to be delayed by 10 to 20% by each additional alkyl group. The lack of isomeric-specific degradation of most of the aromatic and sulfur-aromatic compounds, until extensive decrease in concentration had occurred, suggests these compounds have to be dissolved, before any biodegradation occurs.
{"title":"Quantification of Compositional Changes of Petroleum Hydrocarbons by GC/FID and GC/MS during a Long-Term Bioremediation Experiment","authors":"Trine S. Jensen, E. Arvin, B. Svensmark, P. Wrang","doi":"10.1080/10588330091134400","DOIUrl":"https://doi.org/10.1080/10588330091134400","url":null,"abstract":"Samples from a long-term bioremediation experiment contaminated with two crude oils, Arabian Heavy and Gullfax, was used to analyze the compositional change of petroleum hydrocarbons. A time course of five different homologous series of petroleum hydrocarbons were analysed by GC/FID and GC/MS. The homologous series were n-alkanes, acyclic isoprenoids, alkylated naphthalenes, alkylated phenanthrenes, and alkylated dibenzothiophenes. Several biomarker compounds were monitored during the experiment to evaluate the possible use as conserved reference compounds for the quantification of other oil compounds, that is, nor-hopanes, hopanes, methyl-hopanes, steranes, mono- og triaromatic steranes. The 17α(H),21β(H)-hopane was found to be stable toward biodegradation and was used as reference compound. The internal standard quantification method was used to quantify changes of the homologous series of oil compounds, and a graphic presentation was used to compare the decrease of the individual compounds. This was found to be an easy way of comparing relative changes in oil. The disappearance of the compounds was extensive and in 6 to 7 months less than 6% remained. The decrease of the n-alkanes (>C15) and acyclic isoprenoids was almost uniform within each homologous series and thus independent of physical-chemical characteristics. Evaporation affected compounds with boiling points lower than n-C15. The alkylated aromatic and sulfur-aromatic compounds decreased according to the degree of alkylation and the decrease showed to be delayed by 10 to 20% by each additional alkyl group. The lack of isomeric-specific degradation of most of the aromatic and sulfur-aromatic compounds, until extensive decrease in concentration had occurred, suggests these compounds have to be dissolved, before any biodegradation occurs.","PeriodicalId":433778,"journal":{"name":"Journal of Soil Contamination","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126829058","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2000-11-01DOI: 10.1080/10588330091134419
Sanjeev Kumar
One of the most important factors that affect the post-closure operation of a landfill is the settlement of refuse and foundation material. Prediction of settlement of refuse is complex because of the mechanisms of settlement and the heterogeneity of the refuse. The settlement of a landfill can be estimated using a simplified method, the Power Creep Law. Based on the analysis of published data measured in the field from four landfills, a correlation is proposed between two parameters, reference compressibility and rate of compression, required to predict the refuse settlement using the Power Creep Law. The settlement-time relationships of waste landfills predicted using the proposed correlation show better agreement with the measured settlements than the settlements predicted using average values or some arbitrary combination of the parameters.
{"title":"Settlement Prediction for Municipal Solid Waste Landfills Using Power Creep Law","authors":"Sanjeev Kumar","doi":"10.1080/10588330091134419","DOIUrl":"https://doi.org/10.1080/10588330091134419","url":null,"abstract":"One of the most important factors that affect the post-closure operation of a landfill is the settlement of refuse and foundation material. Prediction of settlement of refuse is complex because of the mechanisms of settlement and the heterogeneity of the refuse. The settlement of a landfill can be estimated using a simplified method, the Power Creep Law. Based on the analysis of published data measured in the field from four landfills, a correlation is proposed between two parameters, reference compressibility and rate of compression, required to predict the refuse settlement using the Power Creep Law. The settlement-time relationships of waste landfills predicted using the proposed correlation show better agreement with the measured settlements than the settlements predicted using average values or some arbitrary combination of the parameters.","PeriodicalId":433778,"journal":{"name":"Journal of Soil Contamination","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124289415","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2000-09-01DOI: 10.1080/10588330091134356
Y. Roh, S. Lee, S.-K. Choi, M. Elless, S. Y. Lee
Physicochemical and mineralogical properties of the contaminants should be taken into account to decide a remediation strategy for a given radionuclide because development and optimization of soil remedial technologies are based on physicochemical and mineralogical separation techniques. The objectives of this study are to (1) demonstrate how a priori physicochemical and mineralogical characterization of soil contaminants can direct the development of remediation strategies and their performance evaluation for soil treatments and (2) understand the nature of uranium contamination and its association with the soil matrix by chemical extractions. This study examined two U-contaminated sites (K311 and K1300) at the DOE K-25 site, presently located at East Tennessee Technology Park, Oak Ridge, Tennessee. Uranium concentrations of the soils ranged from 1499 to 216,413 Bq kg−1 at both sites. Scanning electron microscopy with backscattered electron spectroscopy and X-ray diffraction analysis showed that the dominant U phases are U oxides (schoepite), U-Ca-silicate (uranophane) and U silicate (coffinite) from the K311 site soils, whereas U-Ca-oxide and U-Ca-phosphate dominate in the K1300 site soils. Sodium carbonate/bicarbonate leaching was effective on the K1300 site soils, whereas citric acid leaching is effective on the K311 site soils. Sequential leaching showed that the majority of the uranium in the contaminated soils was contained in carbonate minerals (45%) and iron oxides (40%). Conventional leaching showed that citric acid treatment was most effective on the K311 site soils, whereas the sodium carbonate/ bicarbonate treatment was most effective on the K1300 site soils.
{"title":"Physicochemical and Mineralogical Characterization of Uranium-Contaminated Soils","authors":"Y. Roh, S. Lee, S.-K. Choi, M. Elless, S. Y. Lee","doi":"10.1080/10588330091134356","DOIUrl":"https://doi.org/10.1080/10588330091134356","url":null,"abstract":"Physicochemical and mineralogical properties of the contaminants should be taken into account to decide a remediation strategy for a given radionuclide because development and optimization of soil remedial technologies are based on physicochemical and mineralogical separation techniques. The objectives of this study are to (1) demonstrate how a priori physicochemical and mineralogical characterization of soil contaminants can direct the development of remediation strategies and their performance evaluation for soil treatments and (2) understand the nature of uranium contamination and its association with the soil matrix by chemical extractions. This study examined two U-contaminated sites (K311 and K1300) at the DOE K-25 site, presently located at East Tennessee Technology Park, Oak Ridge, Tennessee. Uranium concentrations of the soils ranged from 1499 to 216,413 Bq kg−1 at both sites. Scanning electron microscopy with backscattered electron spectroscopy and X-ray diffraction analysis showed that the dominant U phases are U oxides (schoepite), U-Ca-silicate (uranophane) and U silicate (coffinite) from the K311 site soils, whereas U-Ca-oxide and U-Ca-phosphate dominate in the K1300 site soils. Sodium carbonate/bicarbonate leaching was effective on the K1300 site soils, whereas citric acid leaching is effective on the K311 site soils. Sequential leaching showed that the majority of the uranium in the contaminated soils was contained in carbonate minerals (45%) and iron oxides (40%). Conventional leaching showed that citric acid treatment was most effective on the K311 site soils, whereas the sodium carbonate/ bicarbonate treatment was most effective on the K1300 site soils.","PeriodicalId":433778,"journal":{"name":"Journal of Soil Contamination","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115444762","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2000-09-01DOI: 10.1080/10588330091134374
S. Kaoser, S. Barrington, Maria Elektorowicz
Despite technological developments and improved liner-material applications, heavy metals in landfill leachate still penetrate the soil profile, polluting the soil and ground-water. An alternative approach therefore must be explored to reduce heavy-metal migration in soil-bentonite landfill liners. By considering the interaction of different heavy metals and their synergetic and antagonistics behaviors, such an approach could be developed. Low mobility metals such as Cu2+, and Pb2+ inhibit the adsorption of Cd2+ which is a moderate-mobility metal and Cu2+ sorption is decreased by the presence of Zn2+ and Cd2+. Therefore, Zn2+, a low-mobility metal, cannot be grouped with Cu2+. This way, four compatible metal groups have been identified: (1) low mobility: Pb2+, Cu2+, and Ag, (2) low mobility: Zn2+ and Cr3+; (3) moderate mobility: As2+, Fe2+, and Ni2+; (4) high mobility: Cd2+ and Hg2+. Cd2+ with a moderate mobility pattern is synergetic to Fe2+ and is more mobile with Ni2+. Therefore, Cd2+ is separated from the moderate-mobility group and is consigned with Hg, a high-mobility metal. The liner materials suitable for Hg2+ are assumed to be suitable for Cd2+ as well. Based on this concept, and to reduce heavy metal mobility, wastes should be segregated on compatibility basis according to their heavy metal contents before being disposed in different individual compartments. For wastes containing several incompatible heavy metals, sorting should be based on the heavy-metal with the highest concentration. Another solution is the manufacturing of products using compatible heavy metal combinations and then labeling them accordingly. Such waste segregation and landfill compartmentalization lowers risks of groundwater contamination and liner cost.
{"title":"Compartments for the Management of Municipal Solid Waste","authors":"S. Kaoser, S. Barrington, Maria Elektorowicz","doi":"10.1080/10588330091134374","DOIUrl":"https://doi.org/10.1080/10588330091134374","url":null,"abstract":"Despite technological developments and improved liner-material applications, heavy metals in landfill leachate still penetrate the soil profile, polluting the soil and ground-water. An alternative approach therefore must be explored to reduce heavy-metal migration in soil-bentonite landfill liners. By considering the interaction of different heavy metals and their synergetic and antagonistics behaviors, such an approach could be developed. Low mobility metals such as Cu2+, and Pb2+ inhibit the adsorption of Cd2+ which is a moderate-mobility metal and Cu2+ sorption is decreased by the presence of Zn2+ and Cd2+. Therefore, Zn2+, a low-mobility metal, cannot be grouped with Cu2+. This way, four compatible metal groups have been identified: (1) low mobility: Pb2+, Cu2+, and Ag, (2) low mobility: Zn2+ and Cr3+; (3) moderate mobility: As2+, Fe2+, and Ni2+; (4) high mobility: Cd2+ and Hg2+. Cd2+ with a moderate mobility pattern is synergetic to Fe2+ and is more mobile with Ni2+. Therefore, Cd2+ is separated from the moderate-mobility group and is consigned with Hg, a high-mobility metal. The liner materials suitable for Hg2+ are assumed to be suitable for Cd2+ as well. Based on this concept, and to reduce heavy metal mobility, wastes should be segregated on compatibility basis according to their heavy metal contents before being disposed in different individual compartments. For wastes containing several incompatible heavy metals, sorting should be based on the heavy-metal with the highest concentration. Another solution is the manufacturing of products using compatible heavy metal combinations and then labeling them accordingly. Such waste segregation and landfill compartmentalization lowers risks of groundwater contamination and liner cost.","PeriodicalId":433778,"journal":{"name":"Journal of Soil Contamination","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127145666","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2000-09-01DOI: 10.1080/10588330091134347
K. Reddy, S. Chinthamreddy
This article describes the removal of heavy metals from contaminated clayey soils by soil washing using various extractants. Two clayey soils, kaolin, a low buffering soil with pH of 5, and glacial till, a high buffering soil with pH of 8, were used to represent various soil conditions. These soils were spiked with chromium (Cr), nickel (Ni), and cadmium (Cd) to simulate improper disposal of typical electroplating waste constituents. The following extracting solutions were investigated for the removal of heavy metals from the soils: deionized water, distilled water, and tap water; acetic acid and phosphoric acid; chelating agents ethylenediaminetetraacetic acid (EDTA) and citric acid; and the oxidizing agents potassium permanganate and hydrogen peroxide. The effect of extractant concentration on removal of heavy metals was also investigated. Complete removal of Cr was achieved using 0.1 M potassium permanganate for kaolin, while a maximum of 54% was removed from glacial till. A maximum Ni removal of 80% was achieved using tapwater for kaolin, while a maximum removal of 48 to 52% was achieved using either 1 M acetic acid or 0.1 M citric acid for glacial till. A maximum Cd removal of 50% was achieved using any of the extractants for kaolin, while a maximum removal of 45 to 48% was obtained using either acids or chelating agents for glacial till. Overall, this study showed that complete removal of Cr, Ni, and Cd from clayey soils is difficult to achieve using the soil-washing process, and also the use of one extractant may not be effective in removing all metals. A sequential extraction using different extractants may be needed for the removal of multiple metal contaminants from clayey soils.
{"title":"Comparison of Extractants for Removing Heavy Metals from Contaminated Clayey Soils","authors":"K. Reddy, S. Chinthamreddy","doi":"10.1080/10588330091134347","DOIUrl":"https://doi.org/10.1080/10588330091134347","url":null,"abstract":"This article describes the removal of heavy metals from contaminated clayey soils by soil washing using various extractants. Two clayey soils, kaolin, a low buffering soil with pH of 5, and glacial till, a high buffering soil with pH of 8, were used to represent various soil conditions. These soils were spiked with chromium (Cr), nickel (Ni), and cadmium (Cd) to simulate improper disposal of typical electroplating waste constituents. The following extracting solutions were investigated for the removal of heavy metals from the soils: deionized water, distilled water, and tap water; acetic acid and phosphoric acid; chelating agents ethylenediaminetetraacetic acid (EDTA) and citric acid; and the oxidizing agents potassium permanganate and hydrogen peroxide. The effect of extractant concentration on removal of heavy metals was also investigated. Complete removal of Cr was achieved using 0.1 M potassium permanganate for kaolin, while a maximum of 54% was removed from glacial till. A maximum Ni removal of 80% was achieved using tapwater for kaolin, while a maximum removal of 48 to 52% was achieved using either 1 M acetic acid or 0.1 M citric acid for glacial till. A maximum Cd removal of 50% was achieved using any of the extractants for kaolin, while a maximum removal of 45 to 48% was obtained using either acids or chelating agents for glacial till. Overall, this study showed that complete removal of Cr, Ni, and Cd from clayey soils is difficult to achieve using the soil-washing process, and also the use of one extractant may not be effective in removing all metals. A sequential extraction using different extractants may be needed for the removal of multiple metal contaminants from clayey soils.","PeriodicalId":433778,"journal":{"name":"Journal of Soil Contamination","volume":"154 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127228613","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2000-09-01DOI: 10.1080/10588330091134365
J. L. Daniels, C. Chien, V. Ogunro, H. Inyang
Waste containment facilities are often composed of barriers such as liners, grout curtains, and slurry walls. The primary design objective for such systems is to mitigate against the release and transport of contaminants. It is often necessary to quantify barrier effectiveness in order to conduct risk and exposure assessments. The extent to which a barrier material is effective can be assessed using analytical methods, laboratory testing, and field monitoring. Obviously, there is a great deal of time and expense associated with both laboratory and field monitoring, making modeling an attractive first alternative. There are, however, numerous solutions to the well-known advection-dispersion equation that vary in accuracy and applicability, depending on initial and boundary conditions. Moreover, most of the equations formulated for transport through porous media were developed for use in aquifer rather than barrier material. Prudent model selection involves matching the conditions to be analyzed with the appropriate mathematical description. In this article, five transport equations are analyzed and compared with laboratory results and projected field conditions for the migration of Pb2+ through soil-bentonite. After 30 days of continuous source injection, measurable concentrations of lead were only detected in the first 0.5 cm of a column of soil-bentonite. All five solutions predicted approximately the same level of penetration for the column tests; however, significant differences emerged after extrapolation to field conditions. For barrier design purposes, the only equations recommended are Equation 3 (the complete solution from Ogata and Banks [1961]) and Equation 6 (Crank's [1956] solution to Fick's Second Law).
{"title":"A Comparative Analysis of Contaminant Migration Models Using Barrier Material Data","authors":"J. L. Daniels, C. Chien, V. Ogunro, H. Inyang","doi":"10.1080/10588330091134365","DOIUrl":"https://doi.org/10.1080/10588330091134365","url":null,"abstract":"Waste containment facilities are often composed of barriers such as liners, grout curtains, and slurry walls. The primary design objective for such systems is to mitigate against the release and transport of contaminants. It is often necessary to quantify barrier effectiveness in order to conduct risk and exposure assessments. The extent to which a barrier material is effective can be assessed using analytical methods, laboratory testing, and field monitoring. Obviously, there is a great deal of time and expense associated with both laboratory and field monitoring, making modeling an attractive first alternative. There are, however, numerous solutions to the well-known advection-dispersion equation that vary in accuracy and applicability, depending on initial and boundary conditions. Moreover, most of the equations formulated for transport through porous media were developed for use in aquifer rather than barrier material. Prudent model selection involves matching the conditions to be analyzed with the appropriate mathematical description. In this article, five transport equations are analyzed and compared with laboratory results and projected field conditions for the migration of Pb2+ through soil-bentonite. After 30 days of continuous source injection, measurable concentrations of lead were only detected in the first 0.5 cm of a column of soil-bentonite. All five solutions predicted approximately the same level of penetration for the column tests; however, significant differences emerged after extrapolation to field conditions. For barrier design purposes, the only equations recommended are Equation 3 (the complete solution from Ogata and Banks [1961]) and Equation 6 (Crank's [1956] solution to Fick's Second Law).","PeriodicalId":433778,"journal":{"name":"Journal of Soil Contamination","volume":"2004 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125790959","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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