title: Temporal change in the distribution patterns of hexachlorobenzene and dichlorodiphenyltrichloroethane among various soil organic matter fractions.
abstract: Residence time-dependent distribution patterns of hexachlorobenzene (HCB) and dichlorodiphenyltrichloroethane (DDT) among different soil organic matter fractions of three Chinese soils were investigated. Soil organic matter (SOM) was fractionated into fulvic acid (FA), humic acid (HA), bound-humic acid (BHA), lipid, and insoluble residue (IR) fractions using methyl isobutyl ketone (MIBK) method. Results revealed that as the residence time prolonged, the amounts of HCB and DDT in the FA, HA and BHA fractions decreased, while those in the lipid and IR fractions increased. One- and two-compartment first order, and one- and two-parameter pore-diffusion kinetic models were used to describe the mobility of HCB and DDT from the FA, HA and BHA fractions. The results suggest that excellent agreements were achieved between the experimental data and fits to the two-compartment first order kinetic model (R2>0.97). The transfer rates of HCB and DDT followed the order FA>HA>BHA.
authors: State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing 100085, China.
authors: Jing-Jing
authors: JJ
authors: Zhang
authors: Bei
authors: B
authors: Wen
authors: Xiao-Quan
authors: XQ
authors: Shan
authors: Shuzhen
authors: S
authors: Zhang
authors: Shahamat U
authors: SU
authors: Khan
mesh_terms: D000327:Adsorption; D001673:Biodegradation, Environmental; D005591:Chemical Fractionation; D002681:China; D003634:DDT / Q000032:analysis*; D004784:Environmental Monitoring / Q000379:methods*; D006581:Hexachlorobenzene / Q000032:analysis*; D006812:Humic Substances / Q000032:analysis*; D008962:Models, Theoretical; D010573:Pesticide Residues / Q000032:analysis*; D012989:Soil Pollutants / Q000032:analysis*; D013997:Time Factors
chemical_list: D006812:Humic Substances; D010573:Pesticide Residues; D012989:Soil Pollutants; D006581:Hexachlorobenzene; D003634:DDT