Ahmad Gholamalizadeh Ahangar - Department of Soil Science, College of Agriculture, University of Zabol, Zabol, Iran

Removal of soil lipids using accelerated solvent extraction (ASE) increased the sorption affinity of the remaining organic matter for both diuron and phenanthrene, by an average of 31% and 29%, respectively. Extractable lipids accounted for 3-13% of organic C. The organic carbon-normalized sorption coefficients (KOC) for diuron and phenanthrene were consistently higher for the lipid-extracted soils than for the whole soils (average of 31% for diuron and 29% for phenanthrene), indicating that lipids compete for or block sorption sites on the organic matter. Sorption experiments on one pair of HF-treated soils indicated that the blocking effects of minerals and lipids are independent, since lipid extraction and HF-treatment combined increased KOC by more than either treatment alone.

sorption, phenanthrene, diuron, Lipid