Pub Date : 2000-09-01DOI: 10.1080/10588330091134329
R. Singh, Raj Kumar
In this study, the effect of concentration (1/2 CMC, at CMC and 2 x CMC) of surfactants, cetyl trimethyl ammonium bromide (cationic), sodium dodecyl sulfate (anionic), and tween ‘20’ (non-ionic) on the movement of carbofuran, chlorpyrifos and en-dosulfan in soils was evaluated by using a soil thin-layer chromatographic technique. The movement of pesticides was detected by spray reagents and expressed in terms of Rf values. The penetrability K was found to increase by decreasing the plate angle and followed the order as: sandy loam > loam > silt loam soils. The penetrability K also decreases in surfactant-free and surfactant-amended soils when developed in distilled water and aqueous surfactant solutions of different CMCs, respectively. The higher movement of pesticides was observed in sandy loam soil followed by loam and silt loam soils. On the basis of Rf values, the movement of pesticides follows the order as: carbofuran > chlorpyrifos > endosulfan, both in surfactant-amended and surfactant-free soils when developed in distilled water and aqueous surfactant solutions of different CMCs. The movement is directly proportional to the aqueous solubilities, polarities, and carbon numbers and inversely related to the molecular weights of pesticides. A significant increase or decrease of pesticides movement in soils was discussed on the basis of adsorption of pesticides on soils, chemical nature of the surfactants, and its concentrations in terms of critical micelle concentrations (CMCs) in soils and eluents. Results obtained may provide insights pertaining to the use of surfactants for solving soil pollution problems posed by pesticides.
{"title":"Evaluation of the Effect of Surfactants on the Movement of Pesticides in Soils Using a Soil Thin-Layer Chromatography Technique","authors":"R. Singh, Raj Kumar","doi":"10.1080/10588330091134329","DOIUrl":"https://doi.org/10.1080/10588330091134329","url":null,"abstract":"In this study, the effect of concentration (1/2 CMC, at CMC and 2 x CMC) of surfactants, cetyl trimethyl ammonium bromide (cationic), sodium dodecyl sulfate (anionic), and tween ‘20’ (non-ionic) on the movement of carbofuran, chlorpyrifos and en-dosulfan in soils was evaluated by using a soil thin-layer chromatographic technique. The movement of pesticides was detected by spray reagents and expressed in terms of Rf values. The penetrability K was found to increase by decreasing the plate angle and followed the order as: sandy loam > loam > silt loam soils. The penetrability K also decreases in surfactant-free and surfactant-amended soils when developed in distilled water and aqueous surfactant solutions of different CMCs, respectively. The higher movement of pesticides was observed in sandy loam soil followed by loam and silt loam soils. On the basis of Rf values, the movement of pesticides follows the order as: carbofuran > chlorpyrifos > endosulfan, both in surfactant-amended and surfactant-free soils when developed in distilled water and aqueous surfactant solutions of different CMCs. The movement is directly proportional to the aqueous solubilities, polarities, and carbon numbers and inversely related to the molecular weights of pesticides. A significant increase or decrease of pesticides movement in soils was discussed on the basis of adsorption of pesticides on soils, chemical nature of the surfactants, and its concentrations in terms of critical micelle concentrations (CMCs) in soils and eluents. Results obtained may provide insights pertaining to the use of surfactants for solving soil pollution problems posed by pesticides.","PeriodicalId":433778,"journal":{"name":"Journal of Soil Contamination","volume":"27 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":"123513736","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: 10.1080/10588330091134338
L. R. Chevalier, Tim Morris, Charles B. Allen, V. Lazarowitz, Lars Fektenberg
Column experiments were conducted to compare the use of surfactants as a part of primary pumping to remove free phase NAPL to the use of surfactants to reduce or recover residual LNAPL in secondary treatment. Eight surfactant blends were tested, for a total of 48 column experiments. The column experiments show that the use of surfactants during primary pumping: (1) can potentially increase the amount of free product recovered; (2) can potentially reduce the amount of residual NAPL remaining after primary pumping; and (3) performs better than the use of surfactants to mobilize trapped residual NAPL.
{"title":"Comparison of Primary and Secondary Surfactant Flushing to Enhance LNAPL Recovery","authors":"L. R. Chevalier, Tim Morris, Charles B. Allen, V. Lazarowitz, Lars Fektenberg","doi":"10.1080/10588330091134338","DOIUrl":"https://doi.org/10.1080/10588330091134338","url":null,"abstract":"Column experiments were conducted to compare the use of surfactants as a part of primary pumping to remove free phase NAPL to the use of surfactants to reduce or recover residual LNAPL in secondary treatment. Eight surfactant blends were tested, for a total of 48 column experiments. The column experiments show that the use of surfactants during primary pumping: (1) can potentially increase the amount of free product recovered; (2) can potentially reduce the amount of residual NAPL remaining after primary pumping; and (3) performs better than the use of surfactants to mobilize trapped residual NAPL.","PeriodicalId":433778,"journal":{"name":"Journal of Soil Contamination","volume":"29 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":"129221280","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 : 2000-07-01DOI: 10.1080/10588330091134301
V. Puri
Contamination due to chemicals and oil spills can influence the engineering behavior of soils. The results of an investigation conducted to study the effects of oil contamination on compaction characteristics, shear strength, one-dimensional compression, and hydraulic conductivity of a sand are presented in this article. The test results indicate that the compaction characteristics are influenced by oil contamination. The angle of internal friction of sand based on total stress condition was found to decrease with the presence of oil in the pore spaces. One-dimensional compression characteristics of sand are significantly influenced by oil contamination, resulting in a decrease in the value of the constrained modulus with increase in the degree of oil saturation. Hydraulic conductivity was observed to be a function of the initial viscosity and the degree of oil saturation.
{"title":"Geotechnical Aspects of Oil-Contaminated Sands","authors":"V. Puri","doi":"10.1080/10588330091134301","DOIUrl":"https://doi.org/10.1080/10588330091134301","url":null,"abstract":"Contamination due to chemicals and oil spills can influence the engineering behavior of soils. The results of an investigation conducted to study the effects of oil contamination on compaction characteristics, shear strength, one-dimensional compression, and hydraulic conductivity of a sand are presented in this article. The test results indicate that the compaction characteristics are influenced by oil contamination. The angle of internal friction of sand based on total stress condition was found to decrease with the presence of oil in the pore spaces. One-dimensional compression characteristics of sand are significantly influenced by oil contamination, resulting in a decrease in the value of the constrained modulus with increase in the degree of oil saturation. Hydraulic conductivity was observed to be a function of the initial viscosity and the degree of oil saturation.","PeriodicalId":433778,"journal":{"name":"Journal of Soil Contamination","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129438744","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 : 2000-07-01DOI: 10.1080/10588330091134284
Katherine R. Weeks, C. Bruell, N. Mohanty
Fenton's reaction is comprised of hydrogen peroxide (H2O2) catalyzed by iron, producing the hydroxyl radical (·OH), a strong oxidant. ·OH in turn may react with H2O2 and iron and is capable of destroying a wide range of organic contaminants. In this laboratory study, Fenton's reaction was observed in aqueous and soil slurry systems using trichloroethylene (TCE) as the target contaminant, with the goal of maximizing TCE degradation while minimizing H2O2 degradation. Fenton's reaction triggers a complex matrix of reactions involving ·OH, H2O2, iron, TCE, and soil organics. In soil slurries with a high fraction of organic carbon (fOC), iron tends to sorb to soil organics and/or particles. In aqueous systems the optimal ratio of H2O2:Fe2+:TCE to degrade TCE in a timely fashion, minimize costs, and minimize H2O2 degradation is 300 mg/L: 25 mg/L: 60 mg/L (19:1:1 molar ratio), while soil slurries with a fOC up to approximately 1% and a soil:water ratio of 1:5 (weight ratio) require about ten times the amount of H2O2, the optimal ratio being 3000 mg/L: 5 mg/L: 60 mg/L (190:0.2:1 molar ratio). TCE degradation rates were observed to decrease in soil slurries with higher fOC because of competition by soil organic matter, which appears to act as a sink for ·OH. H2O2 degradation rates tended to increase in soil slurries with higher fOC, most likely due to increased demand for ·OH by soil organics, increased available iron and other oxidation processes.
{"title":"Use of Fenton's Reagent for the Degradation of TCE in Aqueous Systems and Soil Slurries","authors":"Katherine R. Weeks, C. Bruell, N. Mohanty","doi":"10.1080/10588330091134284","DOIUrl":"https://doi.org/10.1080/10588330091134284","url":null,"abstract":"Fenton's reaction is comprised of hydrogen peroxide (H2O2) catalyzed by iron, producing the hydroxyl radical (·OH), a strong oxidant. ·OH in turn may react with H2O2 and iron and is capable of destroying a wide range of organic contaminants. In this laboratory study, Fenton's reaction was observed in aqueous and soil slurry systems using trichloroethylene (TCE) as the target contaminant, with the goal of maximizing TCE degradation while minimizing H2O2 degradation. Fenton's reaction triggers a complex matrix of reactions involving ·OH, H2O2, iron, TCE, and soil organics. In soil slurries with a high fraction of organic carbon (fOC), iron tends to sorb to soil organics and/or particles. In aqueous systems the optimal ratio of H2O2:Fe2+:TCE to degrade TCE in a timely fashion, minimize costs, and minimize H2O2 degradation is 300 mg/L: 25 mg/L: 60 mg/L (19:1:1 molar ratio), while soil slurries with a fOC up to approximately 1% and a soil:water ratio of 1:5 (weight ratio) require about ten times the amount of H2O2, the optimal ratio being 3000 mg/L: 5 mg/L: 60 mg/L (190:0.2:1 molar ratio). TCE degradation rates were observed to decrease in soil slurries with higher fOC because of competition by soil organic matter, which appears to act as a sink for ·OH. H2O2 degradation rates tended to increase in soil slurries with higher fOC, most likely due to increased demand for ·OH by soil organics, increased available iron and other oxidation processes.","PeriodicalId":433778,"journal":{"name":"Journal of Soil Contamination","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131335725","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 : 2000-07-01DOI: 10.1080/10588330091134293
K. Haarstad, Marianne Fresvig
We have studied the concentrations of DDT in ground water samples at field locations with DDT-polluted topsoil and concentrations and solubility in samples prepared from deionized water with different types and concentration of organic acids. The solubility of DDT increased with increasing concentration of humic acid when the pH of the samples was low (adjusted to about 5.5). The effect flutters in the humic acid concentration range from 200 to 300 mg/L, in accordance with humic acid hydrophobicity, operationally measured as liquid surface tension. The findings correspond to trends previously reported in the literature. The trend of increasing solubility was not found using fulvic acid or low-molecular-weight aliphatic acids. No trend was found adding humic acid without adjusting the pH. The mechanism of enhanced solubility due to humic compounds can explain relatively high levels of DDT in ground water. The ground water samples, however, had a moderately high concentration of maximum 6 µg/L compared with a maximum of about 2300 µg/L in the water samples with humic acid in pure water.
{"title":"The Influence of Organic Matter and pH on DDT Aqueous Solubility","authors":"K. Haarstad, Marianne Fresvig","doi":"10.1080/10588330091134293","DOIUrl":"https://doi.org/10.1080/10588330091134293","url":null,"abstract":"We have studied the concentrations of DDT in ground water samples at field locations with DDT-polluted topsoil and concentrations and solubility in samples prepared from deionized water with different types and concentration of organic acids. The solubility of DDT increased with increasing concentration of humic acid when the pH of the samples was low (adjusted to about 5.5). The effect flutters in the humic acid concentration range from 200 to 300 mg/L, in accordance with humic acid hydrophobicity, operationally measured as liquid surface tension. The findings correspond to trends previously reported in the literature. The trend of increasing solubility was not found using fulvic acid or low-molecular-weight aliphatic acids. No trend was found adding humic acid without adjusting the pH. The mechanism of enhanced solubility due to humic compounds can explain relatively high levels of DDT in ground water. The ground water samples, however, had a moderately high concentration of maximum 6 µg/L compared with a maximum of about 2300 µg/L in the water samples with humic acid in pure water.","PeriodicalId":433778,"journal":{"name":"Journal of Soil Contamination","volume":"53 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115860075","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 : 2000-07-01DOI: 10.1080/10588330091134310
T. J. Moore, C. M. Rightmire, R. K. Vempati
This article discusses the results of efforts to reclaim As-contaminated soil from a former timber-treating plant. The study site, commonly referred to as the Rocker Timber Framing site, is located along Silver Bow Creek approximately 7 miles west of the Butte Mining District, MT, USA. The plant operations resulted in contamination of the soils with a highly caustic solution containing 5% As (III). Contaminated soil resulted in the groundwater plumes that contained up to 25 mg L−1 As, with As (V) being the predominant species. The objective of this study was to evaluate the effectiveness of Fe (II) treatment for remediation of As-contaminated soils. Laboratory-treatability studies were conducted on samples of saturated zone (AS1) and va-dose zone (AV1) soils. The AS1 soil was a mixture of coarse alluvium and potentially some mill tailings from adjacent mining operations. The AV1 soil consisted primarily of fill, including soil, construction debris, and timber fragments. Initial concentrations of total As in AS1 and AV1 soils were 683 and 4814 µg kg−1, respectively. Water-soluble As concentrations were 15.4 and 554 µg L−1, respectively, in a 20:1 solution to soil extract. Batch equilibration were performed by placing 10 g of soil into 20 vessels and adding increasing amounts of FeSO4.7H2O. Amendment increments were made as multiples of molar ratios of total As present in each soil. Treatability studies were run with and without a pH buffer of CaCO3 (added at a 2:1 molar ratio to the FeSO4.7H2O treatment). Solution concentrations of As in the AS1 and AV1 soils (without CaCO3) decreased from 554 to 15.4 µ L−1 and 3802 to 0.64 µ L−1, respectively, as the Fe:As molar ratios increased from 0 to 2, whereas for the AS1 soil the solution As concentration increased at the Fe:As molar ratios >2 and reverse trend was observed for the AV1 soils. The decrease in As solution concentration for the AS1 soil is attributable to the dramatic decrease in soil pH with increasing Fe:As molar ratios. In the case of soils treated with CaCO3, the solution concentrations decreased from 564 to 0.65 µg L−1 and 3790 to 0.79 µg L−1 for the AS1 and AV1 soils, respectively,as the Fe:As molar ratios increased from 0 to 50. Generally, in both the soils, the CaCO3-treated soil contained significantly more solution As compared with the non-CaCO3-treated soil at the comparable Fe:As molar ratios. This is attributable to higher solution pH on CaCO3 treatment. Our rapid engineering study indicates that treating both the soils with Fe:As molar ratio of 2 lowered the As water quality limit to <50 µL−1, whereas treating the AS1 and AV1 soils with Fe:As molar ratio of 2 and 3, respectively, lowered the As water quality limit to ≤15 µg L−1. The concentrations of the Cu and Zn were below the instrument detection limits for the AS1 and AV1 soils without CaCO3 treatment. Sequential extraction of Fe-treated soils illustrated that As was relatively stable. Less than 1% of the As was extractable
本文讨论了对原木材加工厂砷污染土壤进行治理的结果。研究地点，通常被称为Rocker木材框架地点，位于美国MT巴特矿区以西约7英里的银弓溪沿岸。工厂的操作导致土壤受到含有5% As (III)的高腐蚀性溶液的污染。污染的土壤导致地下水中含有高达25 mg L - 1 As，其中As (V)是主要物种。本研究的目的是评价铁(II)处理对砷污染土壤的修复效果。对饱和区(AS1)和va剂量区(AV1)土壤样品进行了实验室可处理性研究。AS1土壤是粗冲积物和可能来自邻近采矿作业的一些尾矿的混合物。AV1土壤主要由填充物组成，包括土壤、建筑碎片和木材碎片。AS1和AV1土壤中总砷的初始浓度分别为683和4814µg kg−1。水溶As浓度分别为15.4和554µg L−1，与土壤提取物的比例为20:1。将10 g土壤放入20个容器中，加入越来越多的FeSO4.7H2O进行批量平衡。修正增量为每种土壤中总砷的摩尔比的倍数。在有和没有CaCO3的pH缓冲液(以2:1的摩尔比加入FeSO4.7H2O处理)的情况下进行可处理性研究。随着Fe:As摩尔比从0增加到2,AS1和AV1土壤(不含CaCO3)中As溶液浓度分别从554µL−1和3802µL−1降低到15.4µL−1，而AS1土壤在Fe:As摩尔比>2时溶液浓度升高，AV1土壤则相反。AS1土壤中As溶液浓度的下降是由于土壤pH值随着Fe:As摩尔比的增加而急剧下降。在CaCO3处理的土壤中，随着Fe: as摩尔比从0增加到50,AS1和AV1土壤的溶液浓度分别从564µg L−1和3790µg L−1下降到0.79µg L−1。一般来说，在两种土壤中，caco3处理过的土壤在Fe:As摩尔比下的溶液As含量明显高于未caco3处理过的土壤。这是由于CaCO3处理的溶液pH值较高。我们的快速工程研究表明，当Fe:As摩尔比为2时，两种土壤的As水质限值均降低至<50µL−1，而当Fe:As摩尔比分别为2和3时，AS1和AV1土壤的As水质限值均降低至≤15µg L−1。未处理CaCO3的AS1和AV1土壤中Cu和Zn的浓度均低于仪器检测限。铁处理土壤的连续提取表明，砷相对稳定。使用改良的TCLP方法可提取的As不到1%，使用苛刻的酸修饰盐酸羟胺萃取法可提取的As <70%。
{"title":"Ferrous Iron Treatment of Soils Contaminated with Arsenic-Containing Wood-Preserving Solution","authors":"T. J. Moore, C. M. Rightmire, R. K. Vempati","doi":"10.1080/10588330091134310","DOIUrl":"https://doi.org/10.1080/10588330091134310","url":null,"abstract":"This article discusses the results of efforts to reclaim As-contaminated soil from a former timber-treating plant. The study site, commonly referred to as the Rocker Timber Framing site, is located along Silver Bow Creek approximately 7 miles west of the Butte Mining District, MT, USA. The plant operations resulted in contamination of the soils with a highly caustic solution containing 5% As (III). Contaminated soil resulted in the groundwater plumes that contained up to 25 mg L−1 As, with As (V) being the predominant species. The objective of this study was to evaluate the effectiveness of Fe (II) treatment for remediation of As-contaminated soils. Laboratory-treatability studies were conducted on samples of saturated zone (AS1) and va-dose zone (AV1) soils. The AS1 soil was a mixture of coarse alluvium and potentially some mill tailings from adjacent mining operations. The AV1 soil consisted primarily of fill, including soil, construction debris, and timber fragments. Initial concentrations of total As in AS1 and AV1 soils were 683 and 4814 µg kg−1, respectively. Water-soluble As concentrations were 15.4 and 554 µg L−1, respectively, in a 20:1 solution to soil extract. Batch equilibration were performed by placing 10 g of soil into 20 vessels and adding increasing amounts of FeSO4.7H2O. Amendment increments were made as multiples of molar ratios of total As present in each soil. Treatability studies were run with and without a pH buffer of CaCO3 (added at a 2:1 molar ratio to the FeSO4.7H2O treatment). Solution concentrations of As in the AS1 and AV1 soils (without CaCO3) decreased from 554 to 15.4 µ L−1 and 3802 to 0.64 µ L−1, respectively, as the Fe:As molar ratios increased from 0 to 2, whereas for the AS1 soil the solution As concentration increased at the Fe:As molar ratios >2 and reverse trend was observed for the AV1 soils. The decrease in As solution concentration for the AS1 soil is attributable to the dramatic decrease in soil pH with increasing Fe:As molar ratios. In the case of soils treated with CaCO3, the solution concentrations decreased from 564 to 0.65 µg L−1 and 3790 to 0.79 µg L−1 for the AS1 and AV1 soils, respectively,as the Fe:As molar ratios increased from 0 to 50. Generally, in both the soils, the CaCO3-treated soil contained significantly more solution As compared with the non-CaCO3-treated soil at the comparable Fe:As molar ratios. This is attributable to higher solution pH on CaCO3 treatment. Our rapid engineering study indicates that treating both the soils with Fe:As molar ratio of 2 lowered the As water quality limit to <50 µL−1, whereas treating the AS1 and AV1 soils with Fe:As molar ratio of 2 and 3, respectively, lowered the As water quality limit to ≤15 µg L−1. The concentrations of the Cu and Zn were below the instrument detection limits for the AS1 and AV1 soils without CaCO3 treatment. Sequential extraction of Fe-treated soils illustrated that As was relatively stable. Less than 1% of the As was extractable ","PeriodicalId":433778,"journal":{"name":"Journal of Soil Contamination","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133470895","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 : 2000-07-01DOI: 10.1080/10588330091134275
J. Sierra, G. Montserrat, E. Martí, M. Garau, R. Cruañas
This study examines the soils affected by the accidental spillage and subsequent flood of pyritic liquids and sludge (a total of 4.5 Hm3) from a flotation plant for complex sulfides in Aznalcóllar (Spain). Two samplings were taken, the first 15 days and the second 3 months after the flood. Potentially toxic elements (PTE) in aqua regia and aqueous extracts were analyzed by ICP. X-ray diffraction and electron microscopy techniques were also used. The objective of this work was to determine the degree of contamination of the soils, the depths and variations with time, as well as the factors determining the presence of contaminants in the soil. Generally speaking, the soils affected are contaminated by Zn, Cu, Pb, As, and Cd at different degrees and depths depending on their particular conditions. En este trabajo se realiza un estudio de los suelos afectados por el vertido accidental de aguas ácidas y lodos piríticos provenientes de una planta de flotación de sulfuros complejos en Aznalcóllar (España). Se realizaron dos muestreos, el primero al cabo de quince días y el segundo tres meses después del vertido. Se han determinado las concentraciones de elementos potencialmente tóxicos (EPT) presentes en extractos acuosos y en agua regia de las muestras. Asimismo se han utilizado técnicas de difracción de rayos X y microscopía electrónica con el fin de localizar la presencia de partículas de lodos contaminantes en los suelos muestreados. Los objetivos de este trabajo consisten en el determinación del grado de contaminación de los suelos, la profundidad y variaciones en el tiempo, así como los factores que determinan la presencia de contaminantes en el suelo. En general los suelos afectados están contaminados por Zn, Cu, Pb, As y Cd, en distintos grados y profundidades, en función de sus condiciones particulares.
本研究考察了在Aznalcóllar(西班牙)的一个复杂硫化物浮选厂意外溢出和随后的黄铁矿液体和污泥(总计4.5 Hm3)泛滥所影响的土壤。在洪水发生后的前15天和后3个月分别采集了两次样本。用ICP分析了王水和水提取物中的潜在有毒元素(PTE)。x射线衍射和电子显微镜技术也被使用。这项工作的目的是确定土壤的污染程度、深度和随时间的变化，以及决定土壤中存在污染物的因素。一般来说，受影响的土壤受Zn、Cu、Pb、As和Cd的污染程度和深度不同，取决于土壤的特定条件。En este trabajo se realizun estudio de los suelos afectados pel vertido accident de aguas ácidas y lodos piríticos provenentes de una plant de flotación de sulfide complexes En Aznalcóllar (España)。“我的梦想成真了”，“我的梦想成真了”，“我的梦想成真了”días“我的梦想成真了”，“我的梦想成真了”。硒离子浓度测定法测定元素电势tóxicos (EPT)表明，即使提取液中含有高浓度的铅离子，也能有效地去除铅离子。Asimismo将利用通讯通讯系统的通讯通讯系统的通讯通讯系统的通讯通讯系统的通讯通讯系统的通讯通讯系统的污染物的通讯通讯系统的污染物的存在。Los objtivos de este trabajo consisten en determinación del grado de contaminación de Los suelos, la profdidique variaciones en en time time, así como Los factores que determinan de污染物存在于Los suelo。一般情况下污染程度为están污染程度为Zn、Cu、Pb、As、Cd，深度程度为不同程度，个别情况为función。
{"title":"Contamination Levels in the Soils Affected by the Flood From Aznalcóllar (Spain)","authors":"J. Sierra, G. Montserrat, E. Martí, M. Garau, R. Cruañas","doi":"10.1080/10588330091134275","DOIUrl":"https://doi.org/10.1080/10588330091134275","url":null,"abstract":"This study examines the soils affected by the accidental spillage and subsequent flood of pyritic liquids and sludge (a total of 4.5 Hm3) from a flotation plant for complex sulfides in Aznalcóllar (Spain). Two samplings were taken, the first 15 days and the second 3 months after the flood. Potentially toxic elements (PTE) in aqua regia and aqueous extracts were analyzed by ICP. X-ray diffraction and electron microscopy techniques were also used. The objective of this work was to determine the degree of contamination of the soils, the depths and variations with time, as well as the factors determining the presence of contaminants in the soil. Generally speaking, the soils affected are contaminated by Zn, Cu, Pb, As, and Cd at different degrees and depths depending on their particular conditions. En este trabajo se realiza un estudio de los suelos afectados por el vertido accidental de aguas ácidas y lodos piríticos provenientes de una planta de flotación de sulfuros complejos en Aznalcóllar (España). Se realizaron dos muestreos, el primero al cabo de quince días y el segundo tres meses después del vertido. Se han determinado las concentraciones de elementos potencialmente tóxicos (EPT) presentes en extractos acuosos y en agua regia de las muestras. Asimismo se han utilizado técnicas de difracción de rayos X y microscopía electrónica con el fin de localizar la presencia de partículas de lodos contaminantes en los suelos muestreados. Los objetivos de este trabajo consisten en el determinación del grado de contaminación de los suelos, la profundidad y variaciones en el tiempo, así como los factores que determinan la presencia de contaminantes en el suelo. En general los suelos afectados están contaminados por Zn, Cu, Pb, As y Cd, en distintos grados y profundidades, en función de sus condiciones particulares.","PeriodicalId":433778,"journal":{"name":"Journal of Soil Contamination","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121795472","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 : 2000-05-01DOI: 10.1080/10588330091134239
R. Simons, G. Canali, G.T. Anderson-Newton, G. Cotton
Numerical modeling of sediment transport in fluvial and estuarine systems can be a reliable way of predicting sediment mobility. If approached naïvely, however, such modeling can produce results that do not have sufficient accuracy or reliability to be useful in decision making or design regarding a range of remediation or stabilization alternatives. It is important to recognize the numerical modeling process as merely one step toward a more complete and balanced understanding of the fluvial or estuarine system in question. Other steps include qualitative and quantitative geomorphic and engineering analyses used to evaluate the accuracy and reliability of numerical modeling as part of a three-level approach to analyze sediment mobility and overall channel behavior and trends. It must first be recognized that attempting to quantitatively analyze sediment mobility involves developing and applying simplified mathematical algorithms to the complexities of continually varying hydrodynamic and sediment transport processes through natural or modified bodies of water. Accuracy in sediment modeling can only be assessed by comparing measured data to model results with accuracy being defined as the model results matching the data within some acceptable band of uncertainty. Reliability of a sediment model is the concept of dependability in reproducing the processes one is attempting to model and implies that a model includes appropriate mathematical expressions that cover the pertinent physical processes of hydrodynamics and sediment mobility. The concept of reasonableness in sediment modeling is the evaluation of results, when compared with other independent analyses in the application of the three-level process, provide an acceptable level of consistency and consensus of conclusions. The importance of modeling software selection, data quality, model calibration, verification, validation, and reasonableness of results are discussed along with two case studies.
{"title":"Sediment Transport Modeling: Calibration, Verification, and Evaluation","authors":"R. Simons, G. Canali, G.T. Anderson-Newton, G. Cotton","doi":"10.1080/10588330091134239","DOIUrl":"https://doi.org/10.1080/10588330091134239","url":null,"abstract":"Numerical modeling of sediment transport in fluvial and estuarine systems can be a reliable way of predicting sediment mobility. If approached naïvely, however, such modeling can produce results that do not have sufficient accuracy or reliability to be useful in decision making or design regarding a range of remediation or stabilization alternatives. It is important to recognize the numerical modeling process as merely one step toward a more complete and balanced understanding of the fluvial or estuarine system in question. Other steps include qualitative and quantitative geomorphic and engineering analyses used to evaluate the accuracy and reliability of numerical modeling as part of a three-level approach to analyze sediment mobility and overall channel behavior and trends. It must first be recognized that attempting to quantitatively analyze sediment mobility involves developing and applying simplified mathematical algorithms to the complexities of continually varying hydrodynamic and sediment transport processes through natural or modified bodies of water. Accuracy in sediment modeling can only be assessed by comparing measured data to model results with accuracy being defined as the model results matching the data within some acceptable band of uncertainty. Reliability of a sediment model is the concept of dependability in reproducing the processes one is attempting to model and implies that a model includes appropriate mathematical expressions that cover the pertinent physical processes of hydrodynamics and sediment mobility. The concept of reasonableness in sediment modeling is the evaluation of results, when compared with other independent analyses in the application of the three-level process, provide an acceptable level of consistency and consensus of conclusions. The importance of modeling software selection, data quality, model calibration, verification, validation, and reasonableness of results are discussed along with two case studies.","PeriodicalId":433778,"journal":{"name":"Journal of Soil Contamination","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126601742","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 : 2000-05-01DOI: 10.1080/10588330091134257
P. Fuchsman, T. Barber
Many evaluations estimating safe levels of hydrophobic organic chemicals in sediments do not account for confounding factors such as physical habitat quality or covariance among chemicals. Controlled experiments demonstrating cause and effect can be conducted with spiked sediment toxicity tests, but application of this methodology has been limited in part by concerns about chemical bioavailability and challenges in achieving target concentrations. Relevant literature was reviewed to assess the utility of standardizing sediment equilibration times; hydrophobicity, complex sediment characteristics, and temperature were identified as potentially equally important factors. Disequilibrium appears likely following limited equilibration time but should yield conservative toxicity test results relative to aged field sediments. Nominal and measured concentrations in over 20 published studies were compared to assess spiked chemical recovery (i.e., measured concentration/nominal concentration). Recovery varied substantially among studies and was not readily predictable based on spiking or extraction method, chemical properties, or measured sediment characteristics, although unmeasured differences between sediments appeared to be important. Factors affecting specific studies included chemical adsorption to glassware, biodegradation, and volatilization. Pre- and post-toxicity test analyses are recommended to confirm exposure concentrations. Studies with 2,3,7,8-tetrachloro-dibenzo-p-dioxin (2,3,7,8-TCDD) and hexachlorobenzene (HCB) exemplify the utility of verifying results of field studies using spiked sediment tests. Sediments spiked with these chemicals at concentrations greatly exceeding those in associated field studies caused no adverse effects in test organisms, demonstrating that other chemicals co-occurring in test sediment samples caused toxicity initially attributed to 2,3,7,8-TCDD and HCB in the field studies. Another key application of spiked sediment tests has been the investigation of TOC as the primary factor affecting bioavailability of hydrophobic organic chemicals. A review of LC50s for nine chemicals reported in 12 studies shows that comparable LC50s derived in different sediments generally agree within a factor of five when concentrations are normalized to a constant TOC. Additionally, use of spiked sediment toxicity testing to investigate toxicological interactions among chemicals provides a promising approach to improving the ability to predict sediment toxicity in the field.
{"title":"Spiked Sediment Toxicity Testing of Hydrophobic Organic Chemicals: Bioavailability, Technical Considerations, and Applications","authors":"P. Fuchsman, T. Barber","doi":"10.1080/10588330091134257","DOIUrl":"https://doi.org/10.1080/10588330091134257","url":null,"abstract":"Many evaluations estimating safe levels of hydrophobic organic chemicals in sediments do not account for confounding factors such as physical habitat quality or covariance among chemicals. Controlled experiments demonstrating cause and effect can be conducted with spiked sediment toxicity tests, but application of this methodology has been limited in part by concerns about chemical bioavailability and challenges in achieving target concentrations. Relevant literature was reviewed to assess the utility of standardizing sediment equilibration times; hydrophobicity, complex sediment characteristics, and temperature were identified as potentially equally important factors. Disequilibrium appears likely following limited equilibration time but should yield conservative toxicity test results relative to aged field sediments. Nominal and measured concentrations in over 20 published studies were compared to assess spiked chemical recovery (i.e., measured concentration/nominal concentration). Recovery varied substantially among studies and was not readily predictable based on spiking or extraction method, chemical properties, or measured sediment characteristics, although unmeasured differences between sediments appeared to be important. Factors affecting specific studies included chemical adsorption to glassware, biodegradation, and volatilization. Pre- and post-toxicity test analyses are recommended to confirm exposure concentrations. Studies with 2,3,7,8-tetrachloro-dibenzo-p-dioxin (2,3,7,8-TCDD) and hexachlorobenzene (HCB) exemplify the utility of verifying results of field studies using spiked sediment tests. Sediments spiked with these chemicals at concentrations greatly exceeding those in associated field studies caused no adverse effects in test organisms, demonstrating that other chemicals co-occurring in test sediment samples caused toxicity initially attributed to 2,3,7,8-TCDD and HCB in the field studies. Another key application of spiked sediment tests has been the investigation of TOC as the primary factor affecting bioavailability of hydrophobic organic chemicals. A review of LC50s for nine chemicals reported in 12 studies shows that comparable LC50s derived in different sediments generally agree within a factor of five when concentrations are normalized to a constant TOC. Additionally, use of spiked sediment toxicity testing to investigate toxicological interactions among chemicals provides a promising approach to improving the ability to predict sediment toxicity in the field.","PeriodicalId":433778,"journal":{"name":"Journal of Soil Contamination","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131607938","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 : 2000-05-01DOI: 10.1080/10588330091134220
B. Finley, P. Scott, C. Kirman
Analytical results for Aroclor may contain a great deal of uncertainty if the relative ratios of certain PCB congeners are substantially altered following differential environmental degradation. Selective degradation of PCB congeners has been shown to occur in biological tissues, and recent studies have shown that Aroclor analyses may significantly underestimate PCB concentrations in fish. The purpose of this study is to assess whether a similar phenomenon can occur with PCB-impacted sediments. Five hundred and thirty-seven sediment samples from the Passaic River were analyzed for Aroclors and selected non-ortho (PCB #77, 126, and 169) and mono-ortho (PCB #105, 114, 118, 123, 156, 157, 167, and 189) coplanar PCB congeners. Aroclors 1248 and 1254 were detected in 67 and 53% of the samples, respectively; 54 samples (approximately 10%) did not contain detectable levels of any Aroclors. In these 54 samples, the sum of the detected PCB congener concentrations was significantly greater, on average, than the Aroclor limit of detection by approximately threefold. In individual samples the sum of the PCB congeners exceeded the Aroclor limit of detection by up to 36-fold. In those samples in which Aroclors were detected, the summed PCB congener concentrations exceeded the Aroclor 1248 and 1254 concentrations, on average, by 41 and 33%, respectively. Given the fact that only a fraction of the 209 PCB congeners were quan-titated, these findings indicate that Arocolor data may significantly underestimate total PCB concentrations in Passaic River sediments. Total PCB data obtained from total homologue analysis indicated that Aroclor results underestimated total PCB mass by up to 43-fold. These findings suggest that caution is required when comparing Aroclor sediment data from the Passaic River to total PCB sediment criteria.
{"title":"PCBs in Passaic River Sediments: Some Analytical Considerations","authors":"B. Finley, P. Scott, C. Kirman","doi":"10.1080/10588330091134220","DOIUrl":"https://doi.org/10.1080/10588330091134220","url":null,"abstract":"Analytical results for Aroclor may contain a great deal of uncertainty if the relative ratios of certain PCB congeners are substantially altered following differential environmental degradation. Selective degradation of PCB congeners has been shown to occur in biological tissues, and recent studies have shown that Aroclor analyses may significantly underestimate PCB concentrations in fish. The purpose of this study is to assess whether a similar phenomenon can occur with PCB-impacted sediments. Five hundred and thirty-seven sediment samples from the Passaic River were analyzed for Aroclors and selected non-ortho (PCB #77, 126, and 169) and mono-ortho (PCB #105, 114, 118, 123, 156, 157, 167, and 189) coplanar PCB congeners. Aroclors 1248 and 1254 were detected in 67 and 53% of the samples, respectively; 54 samples (approximately 10%) did not contain detectable levels of any Aroclors. In these 54 samples, the sum of the detected PCB congener concentrations was significantly greater, on average, than the Aroclor limit of detection by approximately threefold. In individual samples the sum of the PCB congeners exceeded the Aroclor limit of detection by up to 36-fold. In those samples in which Aroclors were detected, the summed PCB congener concentrations exceeded the Aroclor 1248 and 1254 concentrations, on average, by 41 and 33%, respectively. Given the fact that only a fraction of the 209 PCB congeners were quan-titated, these findings indicate that Arocolor data may significantly underestimate total PCB concentrations in Passaic River sediments. Total PCB data obtained from total homologue analysis indicated that Aroclor results underestimated total PCB mass by up to 43-fold. These findings suggest that caution is required when comparing Aroclor sediment data from the Passaic River to total PCB sediment criteria.","PeriodicalId":433778,"journal":{"name":"Journal of Soil Contamination","volume":"52 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121341646","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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