SORPTION BEHAVIOURS OF POLYCYCOC AROMATIC HYDROCARBONS ON WHOLE SOIL AND HUMIN FRACTION

Using Phenanthrene and pyrene as the model compounds, the sorption experiments by eight whole soil samples with different organic carbon contents and the corresponding humin fractions were performed. Different sorption models were employed to fit the experimental data for studying the influence of organic carbon content on soil sorption behaviours. The results demonstrated that, all values of the nonlinearity index n in Freundlich model were lower than 1, indicating the nonlinear properties of sorption procedures of the whole soils and residues after alkaline extration. Sorption characteristics of phenanthrene and pyrene were dependent on the levels of soil organic matters, and the sorption capacities of residual fractions, normalized by organic carbon content, were higher than those of whole soils, and the different sorption behaviours were mainly due to the differences in contents and nature of soil organic matters.