Interaction of Hydrophobic Organic Compounds with Mineral-Bound Humic Substances

Murphy, Ellyn M.; Zachara, John M.; Smith, Steven C.; Phillips, J. E.; Wietsma, Thomas

doi:10.1021/es00056a017

Cited by 264 publications

(252 citation statements)

References 50 publications

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“…However, in this study, it was found that there was no fixed proportionality between the log K exp p values at different ionic strengths. Murphy et al (1994) studied the influence of ionic strength, pH and cation valence on to the structure of mineral bound humic material. They found that increase in ionic strength brings out curling of humic material due to reduction in electrostatic repulsion between adjacent functional groups.…”

Section: Estimation Of Experimental Sorption Coefficientsmentioning

confidence: 99%

QSAR Models To Predict Effect of Ionic Strength on Sorption of Chlorinated Benzenes and Phenols at Sediment–Water Interface

Rao

Asolekar

2001

Water Research

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Abstract}It is hypothesised that the experimental sorption coefficient normalised to the organic carbon fraction of sediment (K exp oc ) 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 cal oc values predicted using Kow model incorporating ionic strength compare reasonably well with the K exp oc values (r 2 ¼ 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 (r 2 ¼ 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)

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Section: Estimation Of Experimental Sorption Coefficientsmentioning

confidence: 99%

QSAR Models To Predict Effect of Ionic Strength on Sorption of Chlorinated Benzenes and Phenols at Sediment–Water Interface

Rao

Asolekar

2001

Water Research

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“…The presence of calcium significantly influences the configuration of dissolved humic substances, which may in turn affect the structure of organic matter on the surface of solid particles and the sorption of HOCs to sorbents [26][27][28][29][30][40][41][42]. Ca 2+ can neutralize the negative charge of humic molecules and reduce the electrostatic repulsion between humic molecules, which may induce aggregate formation and generate an expanded structure with hydrophobic interior voids [24,29,30],…”

Section: Influence Of Ca 2+ Concentration On Phenanthrene Sorptionmentioning

confidence: 99%

“…In addition, the configuration change of humic substances in solution subsequently influences the structure of humics on mineral surfaces. Murphy et al determined the relative molecule size of dissolved humic acids in various solution by high-performance size exclusion chromatography (HPSEC) and found that dissolved humic acids exhibit loosen configuration at low I but relatively condensed structure at high I and the sorption capacities of HOCs to mineral-associated humic acids were larger at low I than at high I [27].…”

Section: Influence Of Ca 2+ Concentration On Phenanthrene Sorptionmentioning

confidence: 99%

“…Furthermore, the extent of HOC sorption shows a strong dependence on the solution parameters, such as pH [24][25][26][27][28][29], ionic strength (I ) [23,[26][27][28], electrolyte cation valence [26,29,30], humic concentration [26,31], cosolute [32], and others. The cation, such as H + and Ca 2+ , can interact with carboxyl/hydroxyl functional groups on dissolved humic substances and mineral surfaces and reduce the negative electrostatic repulsion between the humic molecules and mineral interfaces.…”

Section: Introductionmentioning

confidence: 99%

“…A change in pH or ionic strength of the soil solution leads to different configuration of dissolved humics ("open" or "closed"), which may subsequently alter the structure of organic matter on the mineral surfaces [25,27,30]. Murphy et al [27] have reported that the sorption capacities of hydrophobic organic compounds to mineral-associated peat humic acid is larger at low I than at high I because the "open" configuration of adsorbed humic substances at low I facilitates the accessibility of hydrophobic sorption sites with HOCs.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Sorption interaction of phenanthrene with soil and sediment of different particle sizes and in various CaCl2 solutions

Zhou

Liu

Tang

2004

Journal of Colloid and Interface Science

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The objective of this investigation is to evaluate the influences of natural sorbent particle size and system Ca 2+ concentration on sorption of low-polarity organic chemicals. The physicochemical properties of the different particle size soil and sediment subsamples and the surface characters of the soil and sediment samples in various CaCl 2 concentrations were determined. The sorption behavior of phenanthrene (PHN) on the subsamples of different particle size and to the samples in various CaCl 2 solutions was examined. Batch experiments demonstrate that the sorption capacities increase with decreased particle size for both soil and sediment. It is presumably due to the higher total organic carbon (TOC) content for the finer particles. But the enhancements in sorption coefficients are not met with the equal increases in TOC contents. The effect of Ca 2+ on PHN uptake is strong in short contact time but slight in long contact time. With increasing Ca 2+ concentration, the sorption capacities for Beizhai soil increase first in the low Ca 2+ concentration range, and then decline. Nevertheless, the increase of Ca 2+ concentration greatly reduces the uptake of phenanthrene on Guanting sediment over the overall measured range. The different physicochemical properties, such as dissolved organic carbon (DOC) content, mineral and element composition, and surface characters, between soil and sediment may result in this discrepancy.

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Asymmetrical flow field-flow fractionation as a method to study the behavior of humic acids in solution

Schimpf

Wahlund

1997

J. Micro. Sep.

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Interaction of Hydrophobic Organic Compounds with Mineral-Bound Humic Substances

Cited by 264 publications

References 50 publications

QSAR Models To Predict Effect of Ionic Strength on Sorption of Chlorinated Benzenes and Phenols at Sediment–Water Interface

QSAR Models To Predict Effect of Ionic Strength on Sorption of Chlorinated Benzenes and Phenols at Sediment–Water Interface

Sorption interaction of phenanthrene with soil and sediment of different particle sizes and in various CaCl2 solutions

Asymmetrical flow field-flow fractionation as a method to study the behavior of humic acids in solution

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