251
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Vilanova RM, Fernandez P, Grimalt JO. Polychlorinated biphenyl partitioning in the waters of a remote mountain lake. THE SCIENCE OF THE TOTAL ENVIRONMENT 2001; 279:51-62. [PMID: 11712605 DOI: 10.1016/s0048-9697(01)00725-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The dissolved-particulate phase distribution of polychlorobiphenyls (PCBs) in the waters of a high mountain lake (Redó Lake, Pyrenees) has been studied. The lake is oligotrophic and its water hydrology is dominated by atmospheric precipitation; inputs from catchment or other sources are not significant. Samples were collected in several periods encompassing the summer and winter seasons. The PCB congener concentrations were rather uniform both in terms of water depth and seasonality showing steady state conditions. Seventy percent of the variation of the PCB particulate-dissolved phase coefficient (Kd) was correlated with temperature and log octanol-water (Kow)). Lower temperatures and hydrophobicity involved a higher association with the particulate phase. This behavior is consistent with the predominance of plankton among suspended particles following a two compartment model. Thus, temperature dependence seems mainly related to a rapid phase transfer mechanism such as surface adsorption to the cell membranes and log Kow influence could reflect steric restrictions for the uptake of these compounds upon algal ingestion.
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Affiliation(s)
- R M Vilanova
- Department of Environmental Chemistry, Institute of Chemical and Environmental Research (C.S.I.C.), Barcelona, Catalonia, Spain
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252
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Boyd SA, Sheng G, Teppen BJ, Johnston CT. Mechanisms for the adsorption of substituted nitrobenzenes by smectite clays. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2001; 35:4227-4234. [PMID: 11718335 DOI: 10.1021/es010663w] [Citation(s) in RCA: 93] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
To more fully understand the potential for transport of nitroaromatic compounds in soils and subsoils,the adsorption of a series of para- and meta-substituted nitrobenzenes (SNBs) by K-smectite clay was measured. Adsorption isotherms were fit to the Freundlich equation, and the resultant Freundlich adsorption coefficients (log(Kf) were positively correlated with the Hammett substituent constant (r2 = 0.80). This relationship and a positive reaction constant (p = 1.15) indicate that the adsorption reaction is favored by electron-withdrawing substituents. These results are consistent with an electron donor (smectite)-acceptor (substituted nitrobenzene) mechanism offered previously. However, quantum calculations did not reveal any systematic relationship between the Hammett constant and the electron density on the aromatic ring, which would explain a donor-acceptor relationship. Rather, electron density donated by a second substituent on nitrobenzene appears to be appropriated by the nitro group leaving ring electron density unchanged. Fourier transform infrared spectroscopy revealed shifts in the -NO2 vibrational modes of 1,3,5-trinitrobenzene (TNB) upon adsorption to K+-smectite that were consistent with the complexation of K+ by -NO2 groups. Such TNB vibrational shifts were not observed for SWy-1 saturated with more strongly hydrated cations (i.e., Na+, Mg2+, Ca2+, and Ba2+). The simultaneous interaction of multiple -NO2 groups with exchangeable K+ was indicated by molecular dynamic simulations. Adsorption of SNBs by smectite clays appears to result from the additive interactions of -NO2 groups and secondary substituents with interlayer K+ ions. Adsorption occurs to a greater or lesser extent depending on the abilities of substituents to complex additional interlayer cations and the water solubilities of SNBs. We conclude that the adsorption trends of SNBs on K-SAz-1 can be explained without recourse to hypothetical electron donor-acceptor complexes.
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Affiliation(s)
- S A Boyd
- Department of Crop and Soil Sciences, Michigan State University, East Lansing 48824, USA.
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253
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Huttenloch P, Roehl KE, Czurda K. Sorption of nonpolar aromatic contaminants by chlorosilane surface modified natural minerals. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2001; 35:4260-4264. [PMID: 11718339 DOI: 10.1021/es010131f] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The efficacy of the surface modification of natural diatomite and zeolite material by chlorosilanes is demonstrated. Chlorosilanes used were trimethylchlorosilane (TMSCI), tert-butyldimethylchlorosilane (TBDMSCI), dimethyloctadecylchlorosilane (DMODSCI), and diphenyldichlorosilane (DPDSCI) possessing different headgroups and chemical properties. Silanol groups of the diatomite and zeolite were modified by chemical reaction with the chlorosilanes resulting in a stable covalent attachment of the organosilanes to the mineral surface. The alteration of surface properties of the modified material was proved by measurements of water adsorption capacity, total organic carbon (TOC) content, and thermoanalytical data. The surface modified material showed great stability even when exposed to extremes in ionic strength, pH, and to pure organic solvents. Sorption of toluene, o-xylene, and naphthalene from water was greatly enhanced by the surface modification compared to the untreated materials which showed no measurable sorption of these compounds. The enhanced sorption was dependent on the organic carbon content as well as on chemical characteristics of the chlorosilanes used. Batch sorption experiments showed that the phenyl headgroups of DPDSCI have the best affinity for aromatic compounds. Removal from an aqueous solution of 10 mg/L of naphthalene, o-xylene, and toluene was 71%, 60%, and 30% for surface modified diatomite and 51%, 30%, and 16% for modified clinoptilolite, respectively. Sorption data were well described by the Freundlich isotherm equation, which indicated physical adsorption onto the lipophilic surface rather than partitioning into the surface organic phase. The chlorosilane modified materials have an apparent potential for application in environmental technologies such as permeable reactive barriers (PRB) or wastewater treatment.
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Affiliation(s)
- P Huttenloch
- Department of Applied Geology, University of Karlsruhe, Germany.
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254
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Rao BH, Asolekar SR. QSAR models to predict effect of ionic strength on sorption of chlorinated benzenes and phenols at sediment-water interface. WATER RESEARCH 2001; 35:3391-3401. [PMID: 11547860 DOI: 10.1016/s0043-1354(01)00053-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
It is hypothesised that the experimental sorption coefficient normalised to the organic carbon fraction of sediment (K(oc)exp) for non-ionic, hydrophobic, organic pollutant depends upon the molecular properties as well as background ionic strength of the aquatic system. The utility of this concept has been demonstrated by incorporating ionic strength as a parameter in the three quantitative structure activity relationships (QSARs) namely octanol-water partitioning coefficient model (Kow model), the linear solvation energy model (LSE model), and molecular connectivity indices theory (MCI model). Four chlorinated benzenes and two chlorinated phenols were employed in the present study. Sorption experiments using sediment from the Patalganga River were conducted in laboratory (bottle point method) at different ionic strengths (viz. 0.01, 0.05, and 0.10 M). The K(oc)cat values predicted using Kow model incorporating ionic strength compare reasonably well with the K(oc)exp values (r2 = 0.60 and standard error of estimator i.e. SEE = 0.35). The LSE model incorporating ionic strength too, was found to be equally good (r2 = 0.67, SEE = 0.33). An attempt has also been made to validate the QSARs developed in the present study utilising the sorption parameters experimentally measured by Dewulf et al. (1996) (Water Res. 30, 3130-3138) for sorption of toluene, ethylbenzenes, and xylenes onto the sediments from Belgian Continental Shelf and North Sea, as well as Mader et al. (1997) (Environ. Sci. Technol. 27, 1524-1531) for sorption of di-, tri-, tetra chlorobenzenes on pure mineral oxides namely Al2O3 and Fe2O3.
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Affiliation(s)
- B H Rao
- Centre for Environmental Science and Engineering, Indian Institute of Technology, Bombay
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255
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Totten LA, Brunciak PA, Gigliotti CL, Dachs J, Glenn TR, Nelson ED, Eisenreich SJ. Dynamic air-water exchange of polychlorinated biphenyls in the New York-New Jersey Harbor Estuary. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2001; 35:3834-3840. [PMID: 11642441 DOI: 10.1021/es010791k] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Simultaneous measurements of polychlorinated biphenyls (PCBs) in the air and water over Raritan Bay and New York Harbor were taken in July 1998, allowing the first determinations of air-water exchange fluxes for this heavily impacted system. Average gas-phase concentrations of sigmaPCBs were 1.0 ng m(-3) above Raritan Bay and 3.1 ng m(-3) above New York Harbor. A similar gradient was observed for dissolved water concentrations (1.6 and 3.8 ng L(-1), respectively). Shallow slopes of log K(oc) vs log K(ow) plots indicated a colloidal contribution to the dissolved concentrations, and a three-phase partitioning model was therefore applied. PCBs associated with colloids ranged from 6% to 93% for trichloro- to nonachlorobiphenyls, respectively. Air-water gas exchange fluxes of sigmaPCBs exhibited net volatilization for both Raritan Bay at +400 ng m(-2) day(-1) and New York Harbor at +2100 ng m(-2) day(-1). The correction for the colloidal interactions decreased the volatilization flux of sigmaPCBs by about 15%. Net air-water exchange fluxes of PCBs are expected to remain positive throughout the year due to the large water-air fugacity gradient and relatively constant seasonal water concentrations. The volatilization fluxes are approximately 40 times greater than atmospheric deposition of PCBs via both wet and dry particle deposition, suggesting that the estuary acts as a net source of PCBs to the atmosphere year-round.
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Affiliation(s)
- L A Totten
- Department of Environmental Sciences, Rutgers University, New Brunswick, New Jersey 08901, USA
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256
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Ma Q, Gan J, Becker JO, Papiernik SK, Yates SR. Evaluation of propargyl bromide for control of barnyardgrass and Fusarium oxysporum in three soils. PEST MANAGEMENT SCIENCE 2001; 57:781-786. [PMID: 11561402 DOI: 10.1002/ps.355] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
With the scheduled phasing out of methyl bromide, there is an urgent need for alternatives. We evaluated the efficacy of propargyl bromide as a potential replacement for methyl bromide for the control of barnyardgrass (Echinochloa crus-galli) and Fusarium oxysporum in an Arlington sandy loam, a Carsitas loamy sand and a Florida muck soil. Soil was mixed with barnyardgrass seeds or F oxysporum colonized on millet seeds, and treated with propargyl bromide at a range of concentrations. The mortality of the fungi and weed seeds was determined after 24 h of exposure at 30 degrees C. The concentrations required to inhibit 50% barnyard seed germination (LC50) were 2.8, 2.4 and 48.5 micrograms g-1 in the sandy loam, loamy sand and muck soil, respectively. In contrast, the LC50 values for F oxysporum were 11.2, 10.8 and 182.1 micrograms g-1 in the sandy loam, loamy sand and muck soil, respectively. The low efficacy of propargyl bromide in the muck soil was a result of the rapid degradation and high adsorption of the compound in the soil. The degradation half-life (t1/2) was only 7 h in the muck soil at an initial concentration of 6.8 micrograms g-1, compared to 60 and 67 h in the sandy loam and loamy sand, respectively. The adsorption coefficients (Kd) were 0.96, 0.87 and 5.6 cm3 g-1 in the sandy loam, loamy sand and muck soil, respectively. These results suggest that registration agencies should consider site-specific properties in recommending application rates for propargyl bromide.
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Affiliation(s)
- Q Ma
- George E Brown Jr Salinity Laboratory, USDA-ARS, 450 West Big Springs Road, Riverside, CA 92507, USA
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257
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Bhandari A, Xu F. Impact of peroxidase addition on the sorption-desorption behavior of phenolic contaminants in surface soils. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2001; 35:3163-3168. [PMID: 11505995 DOI: 10.1021/es002063n] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The impact of peroxidase addition on sorption-desorption of phenol, o-cresol, 2,4-dichlorophenol (DCP), and 1-naphthol was evaluated using two surface soils. Target chemicals were added to soils as single solutes or binary mixtures. Seven-day adsorption studies were followed by sequential fill-and-draw extractions with synthetic groundwater. Addition of horseradish peroxidase (HRP) with H2O2 was the primary treatment evaluated. HRP-mediated sorption enhancementwas related to contaminant solubility and increased in the order: naphthol < DCP < cresol < phenol. Little or no competition was observed in the presence of cosolutes. Contaminant desorption from soils was dramatically reduced upon HRP addition. Reduction in desorption was quantified using the Hysteresis Index and interpreted as attenuation of contaminant mobility. Desorption data predicted that mobility reductions followed the order: naphthol < DCP < cresol < phenol. It is believed that enzyme addition resulted in the production of hydrophobic polymers that, due to their low aqueous solubilities, readily partitioned on to the solid-phase. The adsorbed polymers were less likely to partition into the aqueous phase than the parent phenols resulting in a reduced risk to the environment.
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Affiliation(s)
- A Bhandari
- Department of Civil Engineering, Kansas State University, Manhattan 66506-5000, USA.
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258
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Li H, Lee LS, Fabrega JR, Jafvert CT. Role of pH in partitioning and cation exchange of aromatic amines on water-saturated soils. CHEMOSPHERE 2001; 44:627-635. [PMID: 11482650 DOI: 10.1016/s0045-6535(00)00511-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Predicting the reversible interactions between aromatic amines and soil is essential for assessing the mobility, bioavailability and exposure from contaminated sites. Reversible sorption mechanisms of aniline and alpha-naphthylamine were investigated by using single and binary solute sorption to five soils at several pH values, and by applying a distributed parameter (DP) model. The DP model assumes linear partitioning of the neutral species into soil organic matter domains and organic cation binding on negative-charged sites with the exchange coefficients represented by a Gaussian probability distribution. Sorption nonlinearity was attributed to cation exchange with varying site affinities, which was adequately simulated using the DP model. Greater uptake by hydrophobic partitioning and selectivity for cation exchange sites was observed for alpha-naphthylamine compared to aniline. Sorption of alpha-naphthylamine was not impacted quantitatively by aniline under those conditions examined; however, aniline sorption was reduced by alpha-naphthylamine with the largest reduction occurring in the soil with the lowest pH. DP model simulations showed that although hydrophobic partitioning increases with soil-solution pH, cation exchange still contributes significantly to the total sorption even at soil-solution pH values greater than pKa + 2.
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Affiliation(s)
- H Li
- Department of Agronomy, Purdue University, West Lafayette, IN 47907-1150, USA
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259
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Krauss M, Wilcke W. Predicting soil-water partitioning of polycyclic aromatic hydrocarbons and polychlorinated biphenyls by desorption with methanol-water mixtures at different temperatures. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2001; 35:2319-2325. [PMID: 11414039 DOI: 10.1021/es001616r] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
We evaluated a method to determine organic carbon-normalized soil-water partition coefficients (Koc) of 20 PAHs and 12 PCBs by desorption in the presence of a cosolvent (methanol fractions of 0.1-0.9) and at different temperatures (20-80 degrees C). The Koc values, the deviation factor from ideal sorption alpha, and the desorption enthalpies delta Hdes were estimated by nonlinear regression of log Koc on the methanol fractions and on T. The Koc values of individual compounds varied up to a factor of 100 among the studied 11 urban soils. The calculated alpha and delta Hdes of individual compounds varied considerably among the soils (coefficients of variation 5-20% and 20-30%, respectively), alpha increased with increasing hydrophobicity of the compounds. A sequential extraction with four temperature/methanol fraction combinations followed by a nonlinear regression allowed for the direct determination of the Koc, alpha, and delta Hdes. The use of less temperature/methanol fraction combinations requires a suitable estimation of alpha and delta Hdes, as their choice may change the obtained Koc values by up to a factor of 10. The proposed method is suitable for a routine determination of Koc values of PAHs and PCBs for small soil samples (2-6 g) and low concentrations (down to 0.3 mg kg-1 of sigma 20 PAHs and 1.2 micrograms kg-1 of sigma 12 PCBs).
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Affiliation(s)
- M Krauss
- Institute of Soil Science and Soil Geography, University of Bayreuth, D-95440 Bayreuth, Germany.
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260
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Sheng G, Johnston CT, Teppen BJ, Boyd SA. Potential contributions of smectite clays and organic matter to pesticide retention in soils. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2001; 49:2899-2907. [PMID: 11409985 DOI: 10.1021/jf001485d] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Soil organic matter (SOM) is often considered the dominant sorptive phase for organic contaminants and pesticides in soil-water systems. This is evidenced by the widespread use of organic-matter-normalized sorption coefficients (K(OM)) to predict soil-water distribution of pesticides, an approach that ignores the potential contribution of soil minerals to sorption. To gain additional perspective on the potential contributions of clays and SOM to pesticide retention in soils, we measured sorption of seven pesticides by a K-saturated reference smectite clay (SWy-2) and SOM (represented by a muck soil). In addition, we measured the adsorption of atrazine by five different K-saturated smectites and Ca-saturated SWy-2. On a unit mass basis, the K-SWy-2 clay was a more effective sorbent than SOM for 4,6-dinitro-o-cresol (DNOC), dichlobenil, and carbaryl of the seven pesticides evaluated, of which, DNOC was sorbed to the greatest extent. Atrazine was sorbed to a similar extent by K-SWy-2 and SOM. Parathion, diuron, and biphenyl were sorbed to a greater extent by SOM than by K-SWy-2. Atrazine was adsorbed by Ca-SWy-2 to a much lesser extent than by K-SWy-2. This appears to be related to the larger hydration sphere of Ca(2+) (compared to that of K(+)) which shrinks the effective size of the adsorption domains between exchangeable cations, and which expands the clay layers beyond the apparently optimal spacing of approximately 12.2 A for sorption of aromatic pesticide structures. Although a simple relation between atrazine adsorption by different K-smectites and charge properties of clay was not observed, the highest charge clay was the least effective sorbent; a higher charge density would result in a loss of adsorption domains. These results indicate that for certain pesticides, expandable soil clays have the potential to be an equal or dominant sorptive phase when compared to SOM for pesticide retention in soil.
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Affiliation(s)
- G Sheng
- Department of Crop, Soil, and Environmental Sciences, University of Arkansas, Fayetteville, AR 72701, USA
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261
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Gao B, Wang X, Zhao J, Sheng G. Sorption and cosorption of organic contaminant on surfactant-modified soils. CHEMOSPHERE 2001; 43:1095-1102. [PMID: 11368225 DOI: 10.1016/s0045-6535(00)00187-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Three kinds of soils were modified with the cationic surfactants, hexadecyltrimethylammonium (HDTMA) bromide and tetramethylammonium (TMA) bromide to increase their sorptive capabilities. Sorption of chlorobenzene in simulated groundwater by these soils was investigated. HDTMA-modified soil has a higher ability to sorb chlorobenzene from simulated groundwater than unmodified soil. TMA-modified soil did not show the superiority. HDTMA thus can be used to modify soil to improve its sorption capability. Cosorption of chlorobenzene in simulated groundwater in the absence or presence of nitrobenzene and dichloromethane on HDTMA-modified soil was also investigated. Nitrobenzene facilitated sorption of chlorobenzene on all HDTMA-modified soil. Dichloromethane did not influence the sorption of chlorobenzene by HDTMA-modified soil. The results suggest that HDTMA-modified soil is a highly effective sorbent for chlorobenzene and multiple organic compounds did not impede the uptake of chlorobenzene.
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Affiliation(s)
- B Gao
- Department of Environmental Science and Engineering, Nanjing University, People's Republic of China
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262
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Severtson SJ, Banerjee S. Dual Reactive Domain Model for Sorption of Aqueous Organics by Wood Fiber. J Colloid Interface Sci 2001; 236:362-368. [PMID: 11401384 DOI: 10.1006/jcis.2000.7420] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
An experimental study of 2,4,5-trichlorophenol (2,4,5-TCP) sorption to kraft papermaking fiber demonstrates that the dual reactive domain model (DRDM) effectively characterizes the process over a broad concentration region. Isotherm data were deconvoluted into linear partitioning and nonlinear adsorption contributions in accordance with the model demonstrating the importance of both mechanisms to the overall process. DRDM accurately fit concentration-dependent distribution coefficient, K(d)(C), data that could not be characterized with the Freundlich or Langmuir equations, and the model predicts the asymptotic movement toward a limiting K(d)(C) value at high solute or cosolute concentrations observed in experiments. Competitive effects were accounted for by modifying the adsorption portion of the model. With its limitations understood, the extended Langmuir equation was utilized and provided an effective fit of data. Langmuir fitting parameters for competitive data with five different n-alcohol homologs allowed estimates of free energy values per methylene linkage, which were in agreement with previously reported values. Also obtained from competitive data were relative sorption values for various benzene analogs, indicating that interactions in addition to those stemming from solute hydrophobicity often contribute in driving the overall sorption process. These results have implications for papermaking given the ubiquitous nature and importance of sorption in the process. Copyright 2001 Academic Press.
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Affiliation(s)
- Steven J. Severtson
- Department of Wood and Paper Science, Kaufert Laboratory, University of Minnesota, 2004 Folwell Avenue, St. Paul, Minnesota, 55108
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263
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Chiou CT, Sheng G, Manes M. A partition-limited model for the plant uptake of organic contaminants from soil and water. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2001; 35:1437-44. [PMID: 11348082 DOI: 10.1021/es0017561] [Citation(s) in RCA: 219] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
In dealing with the passive transport of organic contaminants from soils to plants (including crops), a partition-limited model is proposed in which (i) the maximum (equilibrium) concentration of a contaminant in any location in the plant is determined by partition equilibrium with its concentration in the soil interstitial water, which in turn is determined essentially by the concentration in the soil organic matter (SOM) and (ii) the extent of approach to partition equilibrium, as measured by the ratio of the contaminant concentrations in plantwater and soil interstitial water, alphapt (< or = 1), depends on the transport rate of the contaminant in soil water into the plant and the volume of soil water solution that is required for the plant contaminant level to reach equilibrium with the external soil-water phase. Through reasonable estimates of plant organic-water compositions and of contaminant partition coefficients with various plant components, the model accounts for calculated values of alphapt in several published crop-contamination studies, including near-equilibrium values (i.e., alphapt approximately equals 1) for relatively water-soluble contaminants and lower values for much less soluble contaminants; the differences are attributed to the much higher partition coefficients of the less soluble compounds between plant lipids and plant water, which necessitates much larger volumes of the plant water transport for achieving the equilibrium capacities. The model analysis indicates that for plants with high water contents the plant-water phase acts as the major reservoir for highly water-soluble contaminants. By contrast, the lipid in a plant, even at small amounts, is usually the major reservoir for highly water-insoluble contaminants.
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Affiliation(s)
- C T Chiou
- U.S. Geological Survey, Denver Federal Center, Colorado 80225, USA.
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264
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Gullick RW, Weber WJ. Evaluation of shale and organoclays as sorbent additives for low-permeability soil containment barriers. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2001; 35:1523-1530. [PMID: 11348096 DOI: 10.1021/es0015601] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
A natural shale and four synthetic organoclays were compared as potential sorbent additives to containment barriers at hazardous waste sites. Trimethylphenyl ammonium bentonite (TMPA-bent) was shown in batch experiments to have the greatest sorption capacities for 1,2,4-trichlorobenzene, trichloroethylene, and methyl isobutyl ketone, followed by the shale and a commercial organoclay. Sorption capacities were lowest for hexadecyltrimethyl ammonium bentonite (HDTMA-bent) and hexadecyl pyridinium bentonite (HDP-bent). Operative sorption mechanisms for the organoclays depended on the size of the organic modifier, i.e., uptake by the TMPA-bent occurred via adsorption onto mineral surfaces, while that for the HDTMA-bent and HDP-bent took place by absorption into organic phases formed by their long hydrocarbon tails. The shale was found to be by far the most cost-effective sorbent, an important factor for large scale applications. Solids concentration effects (i.e., higher apparent sorption capacities at lower experimental sorbent concentrations) were exhibited by HDTMA-bent and HDP-bent. This can be attributed to aggregation of sorbent particles as a result of interactions among their hydrocarbon chains. Solids effects were observed to decline and eventually disappear as sorbent concentrations were increased. Such effects must be considered in applying batch sorption results to flow-through systems.
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Affiliation(s)
- R W Gullick
- Environmental and Water Resources Engineering, Department of Civil and Environmental Engineering, The University of Michigan, Ann Arbor 48109-2125, USA
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265
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Ahmad R, Kookana RS, Alston AM, Skjemstad JO. The nature of soil organic matter affects sorption of pesticides. 1. Relationships with carbon chemistry as determined by 13C CPMAS NMR spectroscopy. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2001; 35:878-884. [PMID: 11351530 DOI: 10.1021/es001446i] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The structural composition of soil organic matter (SOM) was determined in twenty-seven soils with different vegetation from several ecological zones of Australia and Pakistan using solid-state CPMAS 13C NMR. The SOM was characterized using carbon types derived from the NMR spectra. Relationships were determined between Koc (sorption per unit organic C) of carbaryl(1-naphthylmethylcarbamate) and phosalone (S-6-chloro-2,3-dihydro-2-oxobenzoxazol-3-ylmethyl O,O-diethyl phosphorodithioate) and the nature of organic matter in the soils. Substantial variations were revealed in the structural composition of organic matter in the soils studied. The variations in Koc values of the pesticides observed for the soils could be explained only when variations in the aromatic components of SOM were taken into consideration. The highly significant positive correlations of aromaticity of SOM and Koc values of carbaryl and phosalone revealed that the aromatic component of SOM is a good predictor of a soil's ability to bind such nonionic pesticides.
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Affiliation(s)
- R Ahmad
- Department of Soil and Water, University of Adelaide, Waite Campus, PMB 1, Glen Osmond, SA 5064, Australia.
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266
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267
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Kibe K, Takahashi M, Kameya T, Urano K. Adsorption equilibriums of principal herbicides on paddy soils in Japan. THE SCIENCE OF THE TOTAL ENVIRONMENT 2000; 263:115-125. [PMID: 11194146 DOI: 10.1016/s0048-9697(00)00671-9] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Herbicides used in paddy fields during the flooding season can easily cause pollution by run-off into rivers or by other routes. It is very important to know the adsorption characteristics that influence their fate in the soil. The adsorption equilibriums have often been expressed by Henry equations, and the values of equilibrium constant, Kd, are estimated from the adsorption constants, K(OC), based on organic carbon contents of soils. There is little information concerning the equilibrium values expressed by the Freundlich equations, and insufficient information on the actual concentration levels in the paddy field. Therefore, adsorption equilibriums of the five principal herbicides: esprocarb, mefenacet, pretilachlor, simetryn and thiobencarb, on five kinds of paddy soil in Japan were investigated. It was found that their equilibrium values were better expressed by the Freundlich equation for concentration levels for the paddy fields, and that the values for the adsorption coefficient, n, varied from 1.0 to 1.6. Values for the coefficient, k, were in the range of 29-420 mg(1 - 1/n) l(1/n)/kg-dry, and the values were poorly related to solubilities in water or to the octanol-water partition coefficients of the herbicides. For each herbicide, except for simetryn, the values of k among the soils differed by 2-3 times, and no correlation could be found with the organic carbon contents, specific surface areas, pH, cation exchange capacity or major minerals of the soils. The adsorption equilibriums calculated from the values of adsorption constant Kd by the values of K(OC) in the literature were found to be very different from the experimental equilibriums. From the experimental values of coefficient k and n of the Freundlich equation, the maximum runoff concentrations of the herbicides were preliminarily estimated by a simple equilibrium model.
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Affiliation(s)
- K Kibe
- Laboratory of Environmental Safety Engineering, Faculty of Engineering, Yokohama National University, Japan.
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268
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Kirso U, Alumaa P, Irha N, Petersell V, Teinemaa E, Slet J, Steinnes E. Sorption of Pyrene to Two Estonian Soils. Polycycl Aromat Compd 2000. [DOI: 10.1080/10406630008034775] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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269
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Sanchez-Camazano M, Sanchez-Martin MJ, Rodriguez-Cruz MS. Sodium dodecyl sulphate-enhanced desorption of atrazine: effect of surfactant concentration and of organic matter content of soils. CHEMOSPHERE 2000; 41:1301-1305. [PMID: 10901262 DOI: 10.1016/s0045-6535(99)00503-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
A study was made of the adsorption-desorption of atrazine in aqueous medium in five soils with organic matter (OM) contents in the range 1.4-10.3% and also of the desorption of the herbicide in aqueous solutions of the anionic surfactant sodium dodecyl sulphate (SDS) at critical micelle concentrations (cmc) of 0.75, 1.50, 5 and 10. The adsorption and desorption isotherms in water together with the desorption isotherms in SDS solutions with concentrations of 0.75 and 1.50 cmc fit the Freundlich adsorption equation. All the desorption isotherms displayed hysteresis. The increase or reduction in hysteresis of the desorption isotherms in SDS solutions with respect to those of desorption in water depend on the SDS concentration and on the OM content of the soils. Below the cmc, SDS only increases the desorption of atrazine in the soil with the highest OM content (10.3%). However, above the cmc (5 and 10 cmc) the desorption of atrazine increases in all soils, the efficiency of desorption increasing with the OM content of the soils.
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Affiliation(s)
- M Sanchez-Camazano
- Instituto de Recursos Naturales, y Agrobiología de Salamanca, C.S.I.C., Spain.
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270
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Krauss M, Wilcke W, Zech W. Polycyclic aromatic hydrocarbons and polychlorinated biphenyls in forest soils: depth distribution as indicator of different fate. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2000; 110:79-88. [PMID: 15092858 DOI: 10.1016/s0269-7491(99)00280-8] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/1999] [Accepted: 10/15/1999] [Indexed: 05/21/2023]
Abstract
We determined 20 polycyclic aromatic hydrocarbons (PAHs) and 12 polychlorinated biphenyls (PCBs) in Oi, Oe, and Oa horizons and at 0-5 and 15-20 cm mineral soil depth of 16 Norway spruce (Picea abies) stands in north Bavaria. The sum of PAH concentrations increased along the line Oi (mean+/-SD: 841+/-330 microg kg(-1))<Oe (4117+/-3093)<Oa (9272+/-5721) while that of PCBs was higher in Oe (39.1+/-19.4 microg kg(-1)) than in Oi (12.1+/-6.5) but similar in Oe and Oa (46.0+/-39.4). The sum of both PAH (0-5 cm: 666+/-707/15-20 cm: 95+/-165) and PCB concentrations (1.7+/-1.5/0.28+/-0.20) decreased sharply in the mineral soil. The concentration ratios of an individual compound in the Oe to that in the Oi (enrichment factor, e(Oe/Oi)) and the analogously calculated e(Oa/Oe) correlated significantly (p<0.001) with the octanol-water partition coefficient (K(ow), r=0.94 and 0.93 for PAHs; r=0.91 and 0.83 for PCBs, respectively). The enrichment factors of PAHs were consistently higher than those of PCBs with comparable K(ow). This may be explained by a higher volatilisation rate of the PCBs or a stronger sorption of PAHs to soil. In the mineral soil, the concentrations of most PAHs and PCBs decreased with increasing depth, except those of naphthalene and the PCBs 8, 20, 28, and 52. In the mineral soil, the enrichment factors e(0-5/Oa) and e(15-20/0-5) of the PCBs 8, 20, 28, and 52 were, on average, 10 times higher than those of PAHs with similar K(ow) values indicating a more pronounced leaching of PCBs than of PAHs. The results demonstrate that the fate of PAHs in forest soils is markedly different from that of PCBs.
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Affiliation(s)
- M Krauss
- Institute of Soil Science and Soil Geography, University of Bayreuth, D-95440 Bayreuth, Germany.
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271
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Gao B, Yang L, Wang X, Zhao J, Sheng G. Influence of modified soils on the removal of diesel fuel oil from water and the growth of oil degradation micro-organism. CHEMOSPHERE 2000; 41:419-426. [PMID: 11057604 DOI: 10.1016/s0045-6535(99)00287-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Three soils were modified with two kinds of cationic surfactants in order to increase their sorptive capabilities for organic contaminants. Sorption of diesel fuel oil in water by these modified soils had been investigated. Modified soils can effectively sorb diesel fuel oil from water. The sorption capability of modified soils is: HDTMA-black soil > HDTMA-yellow brown soil > HDTMA-red soil > TMA-black soil > TMA-yellow brown soil > TMA-red soil. Sorption of diesel fuel oil by natural soils and HDTMA modified soils is via partition, the sorption isotherms can be expressed by Henry equation, and logK(SOM) is 2.42-2.80, logK(HDTMA) is 3.37-3.60. Sorption isotherms of TMA modified soils can be expressed by Langmuir equation, the saturation sorption capacities are 1150 (TMA-black soil), 750 (TMA-yellow-brown soil), 171 mg/kg (TMA-red soil), respectively. A diesel fuel oil degradation micro-organism (Pseudomonas sp.) was isolated in the lab. To test the influence of the modified soils on the micro-organism, various growth curves of Pseudomonas in different conditions were drawn. Pseudomonas can grow very well with natural soils and TMA modified soils. The acclimation period of Pseudomonas is reduced. As to HDTMA modified soils, HDTMA loading amount is very important. When HDTMA loading amount is no higher than 0.5 CEC, the micro-organism can grow very well after a long acclimation period.
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Affiliation(s)
- B Gao
- State Key Laboratory of Pollution Control and Resource Reuse, Department of Environmental Science and Engineering, Nanjing University, People's Republic of China
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272
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Shen L, Jaffé R. Interactions between dissolved petroleum hydrocarbons and pure and humic acid-coated mineral surfaces in artificial seawater. MARINE ENVIRONMENTAL RESEARCH 2000; 49:217-231. [PMID: 11285727 DOI: 10.1016/s0141-1136(99)00066-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The adsorption of total petroleum hydrocarbons (TPHs) on suspended particles in the marine environment is an important process affecting the fate of oils spilled in the ocean. Adsorption kinetics and adsorption isotherms of the water-soluble fraction of Fuel Oil No. 6 were performed on pure and humic acid-modified montmorillonite, alumina and kaolinite. The rates of adsorption on all sorbents are very fast and a pseudo-equilibrium is reached within 0.5 h. Linear adsorption isotherms were obtained for TPH and individual aromatic hydrocarbons on all sorbents. Higher sorption coefficients (Kd) were obtained for the humic acid-coated clays compared to the pure clays. However, a great contribution of mineral surface to overall adsorption was found on humic acid-modified particles in this study. A linear relationship between the log K and log Kow was also found for individual compounds on both pure alumina (log Km) and humic acid-coated alumina (log Koc).
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Affiliation(s)
- L Shen
- Environmental Geochemistry Group, Southeast Environmental Research Center and Department of Chemistry, Florida International University, Miami, FL 33199, USA
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273
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Ying GG, Williams B. Laboratory study on the interaction between herbicides and sediments in water systems. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2000; 107:399-405. [PMID: 15092986 DOI: 10.1016/s0269-7491(99)00178-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/1999] [Accepted: 06/01/1999] [Indexed: 05/24/2023]
Abstract
Interaction between herbicides and sediments in water systems is an important process occurring in water, which influences the behaviour of the herbicides in water. This paper reports on the sorption of herbicides norflurazon, oxadiazon and trifluralin on soil and the interaction between the herbicides and sediments under stirred and non-stirred conditions. The sorption coefficients of the herbicides on soils are 3.58 and 5.41 for norflurazon, 23.43 and 28.07 for oxadiazon and 890.73 and 1217.20 for trifluralin. The sorption of the herbicides is related to the organic carbon content in the soils. This study shows a greater sorption of the herbicides on stirred sediments than on non-stirred sediments due to more significant contact under stirred conditions. The relative concentrations of the herbicides in water systems containing sediments were higher than those in pure water 6 and 13 days after treatment. When these herbicides were sorbed on sediments, their persistence in water increased. Sorption of herbicides on sediments in aquatic systems could protect them from degradation in water.
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Affiliation(s)
- G G Ying
- Department of Environmental Science and Management, The University of Adelaide, Roseworthy Campus, Roseworthy, SA 5371, Australia
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274
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Mayer P, Vaes WH, Hermens JL. Absorption of hydrophobic compounds into the poly(dimethylsiloxane) coating of solid-phase microextraction fibers: high partition coefficients and fluorescence microscopy images. Anal Chem 2000; 72:459-64. [PMID: 10695129 DOI: 10.1021/ac990948f] [Citation(s) in RCA: 143] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The use of solid-phase microextraction with poly(dimethylsiloxane) (PDMS)-coated glass fibers for the extraction and analysis of hydrophobic organic analytes is increasing. The literature on this topic is characterized by large discrepancies in partition coefficients and an uncertainty of whether highly hydrophobic analytes are retained by absorption into the fiber coating or by adsorption to the fiber surface. We applied a new method, which minimizes the impact of experimental artifacts, to determine PDMS water partition coefficients of 17 hydrophobic analytes including chlorinated benzenes, PCBs, PAHs, and p,p'-DDE. These partition coefficients are several orders of magnitude higher than some reported values. Two observations strongly suggest that the retention of hydrophobic organic substances is governed by partitioning into the PDMS coating. (1) The partition coefficients are proportional with octanol/water partition coefficients. (2) The fluorescence of fluoranthene was observed to be homogeneously distributed within the polymer coating when studied by means of fluorescence microscopy. Implications of these findings for the application of solid-phase microextraction with respect to potential detection limits, with respect to biomimetic extraction, and with respect to measurements in multicompartment systems are discussed.
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Affiliation(s)
- P Mayer
- RITOX, Utrecht University, The Netherlands.
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275
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Prosen H, Zupančič-Kralj L. The interaction of triazine herbicides with humic acids. Chromatographia 2000. [DOI: 10.1007/bf02492799] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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276
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Weber WJ, Huang W, LeBoeuf EJ. Geosorbent organic matter and its relationship to the binding and sequestration of organic contaminants. Colloids Surf A Physicochem Eng Asp 1999. [DOI: 10.1016/s0927-7757(98)00820-6] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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277
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Lee JF, Liao PM, Tseng DH, Wen PT. Behavior of organic polymers in drinking water purification. CHEMOSPHERE 1998; 37:1045-1061. [PMID: 9722968 DOI: 10.1016/s0045-6535(98)00102-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Synthetic organic polymers used to purify drinking water are severely limited in that their impurities and by-products harm human health. In this study, the undesired effects resulted from chlorination and the enhanced attenuation of toxic organic compounds in drinking water from using synthetic organic polymer coagulants were investigated. In the simulated drinking water purification processes, synthetic organic polymers were used as coagulant aids, reacted with a disinfectant(chlorine) and formed a large number of volatile organic compounds (VOCs). Chloroform and benzene which, are carcinogenic compounds, had the maximum formation potential. Experimental results indicated that the total formation potential of these disinfection by-products significantly increased in the presence of turbidity. On the other hand, adding organic polymers to the coagulation systems resulted in more extensive remove of toxic organic compounds and turbidity. In coagulation and flocculation processes, the formation of clay/polymer complexes can facilitate the removal of toxic organic compounds in contaminated water.
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Affiliation(s)
- J F Lee
- Graduate Institute of Environmental Engineering, National Central University, Chung Li, Taiwan, R.O.C
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278
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Abuzaid NS, Al-Malack MH, El-Mubarak AH. Separation of colloidal polymeric waste using a local soil. Sep Purif Technol 1998. [DOI: 10.1016/s1383-5866(97)00069-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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279
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Tomy GT, Fisk AT, Westmore JB, Muir DC. Environmental chemistry and toxicology of polychlorinated n-alkanes. REVIEWS OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 1998; 158:53-128. [PMID: 9751033 DOI: 10.1007/978-1-4612-1708-4_2] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Polychlorinated-n-alkanes (PCAs) or chlorinated paraffins consist of C10 to C30 n-alkanes with chlorine content from 30% to 70% by mass. PCAs are used as high-temperature lubricants, plasticizers, flame retardants, and additives in adhesives, paints, rubber, and sealants. This review presents the existing data on the environmental chemistry and toxicology of PCAs and a preliminary exposure and risk assessment. There is limited information on the levels, fate, or biological effects of PCAs in the environment. This results both from the difficulty associated with quantifying PCAs, because of the complexity inherent to commercial formulations, and from the limited knowledge of their physicochemical properties and biodegradation rates. There are indications that PCAs are widespread environmental contaminants at ng/L levels in surface waters and ng/g (wet wt) levels in biota. However, environmental measurements of PCAs are very limited in the U.S. and Canada, and are only slightly more detailed in western Europe. Assuming that reported water concentrations are mainly caused by the short chain (C10-C13) compounds, aquatic organisms may be at risk from exposure to PCAs. Fugacity level II modeling for two representative PCAs, using the best available physicochemical property data and estimated degradation rates, suggested that C16C24Cl10 would achieve higher concentrations in biota, sediment, and soil than C12H20Cl6 because of slower degradation rates and lower water solubility. Environmental residence time of C16H24Cl10 is estimated to be 520 d compared to 210 d for C12H20Cl6. Future studies will require better analytical methods and reference materials certified for PCA content. Additional data are needed to evaluate exposure of biota to PCAs in the environment, particularly in light of their continued production and usage around the globe.
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Affiliation(s)
- G T Tomy
- Freshwater Institute, Department of Fisheries and Oceans, Winnipeg, Canada
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280
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Becnel JM, Dooley KM. Supercritical Fluid Extraction of Polycyclic Aromatic Hydrocarbon Mixtures from Contaminated Soils. Ind Eng Chem Res 1998. [DOI: 10.1021/ie9704105] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- James M. Becnel
- Department of Chemical Engineering, Louisiana State University, Baton Rouge, Louisiana 70808
| | - Kerry M. Dooley
- Department of Chemical Engineering, Louisiana State University, Baton Rouge, Louisiana 70808
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281
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Arocha MA, Jackman AP, McCoy BJ. Numerical analysis of sorption and diffusion in soil micropores, macropores, and organic matter. Comput Chem Eng 1997. [DOI: 10.1016/s0098-1354(96)00288-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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282
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Yang GP, Zhang ZB. Adsorption of Dibenzothiophene on Marine Sediments Treated by a Sequential Procedure. J Colloid Interface Sci 1997; 192:398-407. [PMID: 9367562 DOI: 10.1006/jcis.1997.4998] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The sorption behavior of dibenzothiophene on marine sediments treated by a sequential procedure was investigated. Sorption isotherms for dibenzothiophene on both no treatment and NaOAc-HOAc treatment sediments were all linear. Differences in Kp's between no-treatment and NaOAc-HOAc treatment sediments were mainly the result of differences in organic carbon content. Nonlinear adsorption isotherms of dibenzothiophene were observed on the sediments treated with H2O2 and could be described by the Freundlich equation. Nonlinear isotherms suggested that the sorption mechanism was a heterogenous adsorption process occurring on the surfaces of the residual organic matter and the bare inorganic minerals in the sediment. A linear correlation was found between the Freundlich constant K and the residual organic carbon. In addition, the clay content in the sediment also had a significant effect on the residual organic carbon content and the Freundlich constant K. Differences in the isotherms of dibenzothiophene between the H2O2 treatment sediments and the no or NaOAc-HOAc treatment sediments indicated that the sorption was strongly influenced by the change in composition as well as by the percentage of organic matter in the sediments. Copyright 1997Academic Press
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Affiliation(s)
- GP Yang
- College of Chemistry and Chemical Engineering, Ocean University of Qingdao, Qingdao, 266003, People's Republic of China
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283
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Singh R. Influence of cosolvent (acetone) on the adsorption and movement of cypermethrin on soils. Colloids Surf A Physicochem Eng Asp 1997. [DOI: 10.1016/s0927-7757(96)03839-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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284
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Dias RF, Freeman KH. Carbon Isotope Analyses of Semivolatile Organic Compounds in Aqueous Media Using Solid-Phase Microextraction and Isotope Ratio Monitoring GC/MS. Anal Chem 1997; 69:944-50. [DOI: 10.1021/ac960635+] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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285
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Poerschmann J, Zhang Z, Kopinke FD, Pawliszyn J. Solid Phase Microextraction for Determining the Distribution of Chemicals in Aqueous Matrices. Anal Chem 1997. [DOI: 10.1021/ac9609788] [Citation(s) in RCA: 196] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Juergen Poerschmann
- Department of Chemistry, University of Waterloo, Waterloo, Ontario, Canada N2L 3G1, and Center for Environmental Research, Permoserstrasse 15, D-04318 Leipzig, Germany
| | - Zhouyao Zhang
- Department of Chemistry, University of Waterloo, Waterloo, Ontario, Canada N2L 3G1, and Center for Environmental Research, Permoserstrasse 15, D-04318 Leipzig, Germany
| | - Frank-Dieter Kopinke
- Department of Chemistry, University of Waterloo, Waterloo, Ontario, Canada N2L 3G1, and Center for Environmental Research, Permoserstrasse 15, D-04318 Leipzig, Germany
| | - Janusz Pawliszyn
- Department of Chemistry, University of Waterloo, Waterloo, Ontario, Canada N2L 3G1, and Center for Environmental Research, Permoserstrasse 15, D-04318 Leipzig, Germany
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286
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The efficiency of modified bentonite clays for removal of aromatic organics from oily liquid wastes. ACTA ACUST UNITED AC 1997. [DOI: 10.1016/s1353-2561(98)00012-7] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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287
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Tanaka S, Oba K, Fukushima M, Nakayasu K, Hasebe K. Water solubility enhancement of pyrene in the presence of humic substances. Anal Chim Acta 1997. [DOI: 10.1016/s0003-2670(96)00422-9] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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288
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Zeng EY, Khan AR. Extraction of municipal wastewater effluent using 90-mm C-18 bonded disks. ACTA ACUST UNITED AC 1995. [DOI: 10.1002/mcs.1220070514] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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289
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Beck AJ, Jones KC. Kinetic constraints on theIn-situ remediation of soils contaminated with organic chemicals. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 1995; 2:244-252. [PMID: 24234698 DOI: 10.1007/bf02986778] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Cleanup of contaminated soils to comply with soil quality limits currently receives much interest.In-situ remediation of contaminated soils relies on the ability of the techniques employed to enhance the rate of release of contaminants from the soil-sorbed and nonaqueous phase liquid (NAPL) phases into the aqueous or gaseous phases from which they can be more readily removed and treated. Contaminant concentrations in these "environmentally mobile" forms usually decline over time so that the economic efficiency and the overall success of remediation technologies are subject to the "law of diminishing returns". In this paper we consider the "state of the art" in our understanding of NAPL dissolution and transport, desorption of soilsorbed contaminants and fluid flow in porous media. The extent to which these processes may constrain the success of bioremediation, pump-and-treat remediation and soil venting in relation to established soil quality limits is addressed. Finally, we suggest directions for future research and comment on legislative considerations.
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Affiliation(s)
- A J Beck
- Division of Environmental Sciences, Institute of Environmental and Biological Sciences, Lancaster University, LA1 4YQ, Lancaster, UK
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290
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Szabó G, Bulman RA. Comparison of Adsorption Coefficient (KOC) for Soils and HPLC Retention Factors of Aromatic Hydrocarbons Using a Chemically Immobilized Humic Acid Column in RP-HPLC. ACTA ACUST UNITED AC 1994. [DOI: 10.1080/10826079408013399] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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291
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292
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Schrap SM, Sleijpen GL, Seinen W, Opperhuizen A. Sorption kinetics of chlorinated hydrophobic organic chemicals : Part II: Desorption experiments. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 1994; 1:81-92. [PMID: 24234209 DOI: 10.1007/bf02986511] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/1993] [Accepted: 11/09/1993] [Indexed: 06/02/2023]
Abstract
This is the second of a two-part series describing the sorption kinetics of hydrophobic organic chemicals. Part I "The Use of First-Order Kinetic Multi-Compartment Models" is published in issue 1 of this journal, pp. 21-28. Sorption kinetics of chlorinated benzenes from a natural lake sediment have been investigated in gas-purge desorption experiments. Biphasic desorption curves, with an initial "fast" part and a subsequent "slow" part, were found for all tested chlorobenzenes. From these results first-order sorption uptake and desorption rate constants were calculated with a two-sediment compartment model, which is presented in the first paper.In three sets of experiments the sorption uptake period and sediment/water ratio were varied. Rate constants are not influenced by these experimental conditions, which supports the partitioning concept for the sorption of hydrophobic organic chemicals in sediments.
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Affiliation(s)
- S M Schrap
- Research Institute of Toxicology, Environmental Chemistry Group, University of Utrecht, P.O. Box 80.058, 3508, TB Utrecht, The Netherlands
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293
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Dyke MI, Gulley SL, Lee H, Trevors JT. Evaluation of microbial surfactants for recovery of hydrophobic pollutants from soil. ACTA ACUST UNITED AC 1993. [DOI: 10.1007/bf01583718] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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294
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O'Neill MW, Symons JM, Lazaridou ME, Park JB. In situ treatment of soil for the extraction of organic contaminants. ACTA ACUST UNITED AC 1993. [DOI: 10.1002/ep.670120105] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Booij K, Achterberg EP, Sundby B. Release rates of chlorinated hydrocarbons from contaminated sediments. ACTA ACUST UNITED AC 1992. [DOI: 10.1016/0077-7579(92)90070-u] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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297
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Murray MW, Andren AW. Precipitation scavenging of polychlorinated biphenyl congeners in the great lakes region. ACTA ACUST UNITED AC 1992. [DOI: 10.1016/0960-1686(92)90247-i] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Bodor N, Huang MJ. An extended version of a novel method for the estimation of partition coefficients. J Pharm Sci 1992; 81:272-81. [PMID: 1640367 DOI: 10.1002/jps.2600810317] [Citation(s) in RCA: 93] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Using the semi-empirical AM1 method, 302 compounds have been studied and equilibrium properties calculated. Functions based on linear combinations of subsets of calculated properties have been fit to the 1-octanol-water partition coefficients. The best such semi-empirical approach function has 18 parameters, has a standard deviation of 0.306, and seems to describe the partition coefficients of the 302 compounds. The predictive power of the function was tested and found to be good. Since this new version is based on a much larger number of, and structurally more varied, compounds and uses an improved, new function, we expect it to be a very useful method to predict partition properties of a wide variety of compounds.
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Affiliation(s)
- N Bodor
- Center for Drug Discovery, College of Pharmacy, University of Florida, Gainesville 32610
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299
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Sorption of hydrophobic organic contaminants and trace metals on phytoplankton and implications for toxicity assessment. ACTA ACUST UNITED AC 1992. [DOI: 10.1007/bf00044714] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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300
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