Sorption of pyrene on two paddy soils and their particle-size fractions
In the present study, the sorption of pyrene on two kinds of bulk paddy soils, Gleyic Stagnic Anthrosols, and Ferric accumulic Stagnic Anthrosols as well as their particle-size fractions was investigated. The sorption isotherms fitted well with Freundlich equation. For both soils, the clay fraction (<2µm) and coarse sand fraction (2000-250µm) had higher sorption capacity than fine sand fraction (250-20µm) and silt fraction (20-2µm). The logKoc values obtained of each soil and its particle-size fractions were similar, proving that SOM content was a key factor affecting pyrene sorption. The Kmd values showed a significant correlation with contents of dithionite-extractable Fe in both paddy soils and a good relationship with CEC in Gleyic Stagnic Anthrosols, indicating possible effects of surface properties of particle-size fractions on the sorption of pyrene.