Water solubility enhancement of some organic pollutants and pesticides by dissolved humic and fulvic acids

Chiou, Cary T.; Malcolm, Ronald L.; Brinton, Terry I.; Kile, Daniel E.

doi:10.1021/es00147a010

Cited by 1,006 publications

(658 citation statements)

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“…A negative correlation was also observed between the DOC contents and the amounts of p,p 0 -DDT desorption (R = 0.805, p < 0.05). The DOC in soil can enhance the dissolution of organic compounds in soil (Chiou et al, 1986;Seol and Lee, 2000;Tao et al, 2004a). The most likely reason for this negative relationship between the DOC and the DDT desorption is due to the dynamic equilibrium between SOC and DOC in soils (Antoniadis and Alloway, 2002;Ben-Hur et al, 2003), indeed, a positive correlation between SOC and DOC was found in this study (R = 0.895, p < 0.01).…”

Section: Abiotic Pp 0 -Ddt Desorption and Its Relationship With Soilsupporting

confidence: 52%

“…SOC includes both soluble and insoluble fractions of organic carbon, and the proportion of dissolved organic carbon (DOC) in a soil is usually very small. Both solid organic carbon and dissolved organic carbon have to be taken into account for a proper description of the distribution of hydrophobic compounds in sediment or soil/water system (Chiou et al, 1986;Ben-Hur et al, 2003;Tao et al, 2004a). A negative correlation was also observed between the DOC contents and the amounts of p,p 0 -DDT desorption (R = 0.805, p < 0.05).…”

Section: Abiotic Pp 0 -Ddt Desorption and Its Relationship With Soilmentioning

confidence: 99%

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Oxalate and root exudates enhance the desorption of p,p′-DDT from soils

et al. 2006

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The abiotic desorption of p,p 0 -DDT from seven Chinese soils spiked with p,p 0 -DDT and the effects of oxalate at 0.001-0.1 M and the root exudates of maize, wheat, and ryegrass were evaluated using batch experiments. Soil organic carbon played a predominant role in the retention of DDT. Oxalate significantly increased the desorption of p,p 0 -DDT, with the largest increments ranging from 11% to 54% for different soils. Oxalate addition also resulted in the increased release of dissolved organic carbon and inorganic ions from soils. Root exudates had similar effects to those of oxalate. Root exudates significantly increased DDT desorption from the soils, and the general trend was similar among the plant species studied for all the soils (p > 0.05). Low molecular weight dissolved organic carbon amendments caused partial dissolution of the soil structure, such as the organo-mineral linkages, resulting in the release of organic carbon and metal ions and thus the subsequent enhanced desorption of DDT from the soils. The enhancing effects of oxalate and root exudates on DDT desorption were influenced by the contents of soil organic carbon and dissolved organic carbon in soils.

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Section: Abiotic Pp 0 -Ddt Desorption and Its Relationship With Soilsupporting

confidence: 52%

Section: Abiotic Pp 0 -Ddt Desorption and Its Relationship With Soilmentioning

confidence: 99%

Oxalate and root exudates enhance the desorption of p,p′-DDT from soils

et al. 2006

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“…Hydrophobic organic contami- nants, such as naphthalene etc., have strong affinity toward the hydrophobic groups of the humic substances, and their adsorption onto the natural particles acts mainly on the organic layers of the natural particles. Therefore, earlier investigations [10,11,[42][43][44][45] showed that sorption of hydrophobic organic contaminants (HOCs) by soils and sediments is dominated by partitioning into relatively homogeneous, lipophilic, gel-like humic matrices, which can be recognized as a partition or dissolution process and has the linear adsorption features. A number of more recent studies [12][13][14][15][46][47][48][49][50][51][52][53][54][55] , however, have indicated that such sorption often manifests substantial deviations from a linear partition model, provided that very low concentrations of HOCs are studied.…”

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AFM study on the adsorption and aggregation behavior of dissolved humic substances on mica

Zhou

Lü

et al. 2006

SCI CHINA SER B

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Humic substances constitute the major organic fractions of soils, sediments and natural waters, and play a dominant role in the binding, mobilization, transport and ultimate fate of organic contaminants in subsurface systems. In this paper, two humic acid samples, Guanting and Tianjin, with different origin and chemical compositions have been investigated with AFM imaging for their adsorption and aggregation behaviors on mica. While the Tianjin humic sample is found to form small spheres with 250 to 330 nm in diameter at lower concentrations, irregular loop-chain assemblies of hundreds of nanometer in diameter with the chain width of about 40 nm are dominant for the Guanting humic sample, which may attribute to the more polar aliphatic fractions in the chemical composition in the latter. The heterogeneous and polydisperse nature of humic substances with multiple structural features, such as sponge-like structures, perforated sheets, aggregate of spheres, branches and chain-like assemblies etc., is apparent at higher concentrations for both humic samples, showing morphologically new evidence for the dominant view of the humic dual-mode sorption model. With naphthalene introduced, the assemblies of Guanting humic substances clearly become more compact with significantly narrowed branches and less porous the perforated sheet-like structures. It is indicative of that smaller nanometer scale rings present along the perforated assemblies could potentially represent hydrophobic domains, which may facilitate the adsorption and aggregation of naphthalene onto the natural particle surfaces and therefore lead to an important role of dissolved humic substances in the sorption of environmental pollutants.Keywords: atomic force microscopy (AFM), dissolved humic substances, morphology, aggregation, adsorption.Humic substances (HS) are a category of naturally occurring, biogenic, heterogeneous organic materials found in or extracted from soils, sediments, and natural waters that can generally be characterized as being yellow-to-black in color, of highly variable relative molecular masses, and refractory [1,2] . Derived from a variety of organic precursors (plant biopolymers such as lignin etc.), plant residues and animal debris via both transformation and synthesis processes [3] under the profound geochemical alteration, including the microbiological and chemical degradation, sedimentation and diagenesis as well, humic substances com-AFM study on the adsorption and aggregation behavior of dissolved HS on mica 257 prise highly complex composites of partially or completely degraded biomolecules, carbohydrates, lipids, and proteins etc. However, they cannot be classified into any of the normal, easily defined categories of discrete materials such as proteins, polysaccharides, and polynucleotides. As the major organic constituents of soils, sediments and waters, humic substances are ubiquitous in all terrestrial and aquatic environments. They can form molecular aggregates, dispersed in different colloidal states in solutio...

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“…Ces composés étant peu solubles dans les eaux, les risques de pollution par ruissellement ou drainage sont donc limités. Leurs associations avec les substances humiques (Khan, 1972) peut cependant modifier leur activité entraînant notamment une augmentation de leur solubilité et donc de la pollution des eaux (WERSHAW et ai, 1969 ;CHIOU et al, 1986 ;CHIOU et al, 1987 ;AYELE et al, 1989 ;FABRE étal., 1990).…”

Section: Introductionunclassified

Influence de l'origine et de la nature des substances humiques sur l'adsorption de l'atrazine sur charbon actif en poudre

Ayele¹,

Fabre²,

Mazet³

2005

rseau

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Les essais d'adsorption sur charbon actif en poudre, de sept acides humiques (H) ou fulviques (F) et pour trois pH (5,6 ; 7,0 ; 8,8) marquent que ces acides ont un comportement différent suivant leur origine.Lorsque le pH de la suspension de charbon est basique, l'adsorption des différentes fractions humiques diminue, ce qui est en relation avec l'augmentation de leur solubilité. Pour un même pH de la suspension, les acides humiques et fulviques d'origine aqueuse s'adsorbent mieux que ceux d'origine commerciale ou que ceux extraits de sol.La capacité maximale d'adsorption de l'atrazine sur charbon actif en poudre : 260 mg.g-1 (Langmuir), est plus fortement diminuée en présence d'acides fulviques que d'acides humiques d'une part, et plus inhibée (jusqu'à 40 %) par les acides fulviques extraits d'eau (F1, F2) que par ceux extraits de sol (F3) d'autre part.Par contre, les acides humiques provenant de substances commerciales (H4, H5) influencent moins l'adsorption de l'atrazine.L'ensemble des essais montre que l'origine et la nature des substances humiques joue un rôle prépondérant sur l'adsorption de l'atrazine sur charbon actif, le pH ayant une influence limitée.Enfin l'étude de l'influence de l'atrazine sur l'adsorption des substances humiques sur charbon actif en poudre indique également une différence de comportement entre les acides fulviques, pour lesquels on note peu de variation, et les acides humiques, pour lesquels on note à la fois une promotion de l'adsorption et une meilleure affinité d'adsorption sur le charbon actif en poudre en présence d'atrazine.Ce travail met en évidence l'importance du choix des substances humiques pour des essais d'évaluation des interactions substances humiques - pesticides lors de l'adsorption sur charbon actif en poudre.Though the subject was copiously and oldly studied, this work is bringing a new contribution to the study of the influence of the origin and the nature upon their properties and in particular with atrazine, the more used herbicide these fast years.In order to study this influence of the origin and nature of various humic substances upon the removal of atrazine by adsorption onto powdered activated carbon (PAC), humic substances were obtained from different sources :- Natural aquatic fulvic (F1) and humic (H1) acids isolated from Beaune Lake (Limoges, France).- Natural aquatic fulvic (F2) and humic (H2) acids extracted from hydroxyde sludges of the water treatment plant of La Bastide (Limoges, France).- Soil fulvic acids (F3) extracted from a canadian top soil horizon.- Commercial humic acids (Aldrich. H4 and Jansen H5) obtained from commercial sodium humates.The results of adsorption test of humic acids, fulvic acids and atrazine (alone or together) onto powdered activated carbon (PAC) at three different pH (5,6 ; 7,0 ; 8,8) were expressed by Freundlich's and Langmuir’s models and permitted us to note that :- According to the increasing of water solubility of humic substances with basic pH, their adsorption was better in acidic medium.- Natural aquatic humic s...

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Water solubility enhancement of some organic pollutants and pesticides by dissolved humic and fulvic acids

Cited by 1,006 publications

References 26 publications

Oxalate and root exudates enhance the desorption of p,p′-DDT from soils

Oxalate and root exudates enhance the desorption of p,p′-DDT from soils

AFM study on the adsorption and aggregation behavior of dissolved humic substances on mica

Influence de l'origine et de la nature des substances humiques sur l'adsorption de l'atrazine sur charbon actif en poudre

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