多环芳烃在全土及其碱提残余物上的吸附行为

以菲和芘为代表性化合物,采用8种有机质含量不同的天然全土样品及其碱提残余物进行吸附实验,并利用不同吸附模型进行数据拟合,藉以探讨有机质含量对土壤吸附行为的影响.结果表明,Freundlich吸附模型的非线性指数n都小于1,显示全土和碱提残余物在多环芳烃的吸附过程中表现出非线性特征.菲和芘的吸附行为随土壤有机质含量不同而变化,碱提残余物的吸附能力强于全土,两者吸附行为的差异主要归因于土壤有机质含量和性状的区别.

SORPTION BEHAVIOURS OF POLYCYCLIC 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.