Predictions of the nature and strength of soil sorption of organic pollutants by molecular topology
Predictions of the nature and strength of soil sorption of organic pollutants by molecular topology
复制标题
通过分子拓扑预测土壤对有机污染物吸附的性质和强度
DOI：
10.1021/jf00122a016
复制
发表时间：
1984
影响因子：
6.1
通讯作者：
A. Sabljic
中科院分区：
文献类型：
--
作者：
A. Sabljic
This study was undertaken to find a simple and accurate structural parameter for the prediction of the soil sorption coefficients (K^’s) of organic pollutants and to help resolve controversyabout the mechanism of soil sorption. The methods used are molecular topology and quantitativestructure-activity relationship analysis. We obtained extremely good linear correlation between thefirst-order molecular connectivity indexes) and Kom'a for a large group of nonionic organic compounds. In addition, the correlation equation successfully predicts soil sorption data of seven experimentally uncertain halogenated hydrocarbons. The* index also correlates very well with the molecular van der Waals surface area. Our results support the postulate that soil sorption is a surface area dependent adsorption process.The widespread use of organic pesticides led to extensive interest (Hance, 1980; Kenaga and Goring, 1980; Chiou, 1981) in the adsorption of such solutes from aqueous so-lution by soils because of the influenceof this process on pesticide performance, mobility in the soil, and residue problems. The soil sorption coefficient (Kom), defined as the ratio between the concentrations of a given chemical sorbed by the soil and dissolved in the soilwater nor-malized to the total organic carbon content of the soil, is currently used as a quantitative measure of the soil sorp-tion (Kenaga and Goring, 1980). The experimental de-termination of Kom values is often a costly and time-consuming process. It is also very inaccurate (Chiou et al., 1979; Kenaga and Goring, 1980) for compounds of low water solubility, such as DDT, lindane, and PCB’s. Water solubility (WS) and 1-octanol/water partition coefficients (KoJ have been proposed (Chiou et al., 1979; Karickhoff et al., 1979; Kenaga and Goring, 1980; Chiou, 1981) as alternative, more accurate estimates of Kom. Unfortu-nately, it is impossible to determine these parameters accurately for compoundswhose WS is below 1 ppm (Biggar et al., 1967; Haque and Schmedding, 1975), ie, the same pollutants whose Kom's cannot be measured ac-curately. In addition, several investigators have reported no or poor correlation between WS (Harris and Warren, 1964; Talbert and Fletchall, 1965; Hance, 1965; Briggs, 1969) or Kov/(Briggs, 1969) and soil sorption coefficients. Thus, a convenient, accurate way to predict soil sorption coefficients of a large numbers of chemical compounds is urgently needed, especially since the implication of the “Toxic Substances Control Act” is that all classes of chemicals must be assessed as to their environmental hazard.
