Abstract:

This study investigates the sorption kinetics of organochlorine pesticides on three typical types of solids involving biofilms, suspended particles and surface sediments sampled from natural waters. Results indicated that the process of sorption kinetics of organochlorine pesticides on the three solids could be divided into two stages: fast sorption and slow sorption. Pseudo-second-order model could provide a more satisfactory fitting performance in this work. Equilibrium sorbed amount of organochlorine pesticides by the three solids showed the order: biofilms>suspended particles>surface sediments, which is consistent with the order of contents of organic matters in these solids. However, during the initial sorption stage, the rate of organochlorine pesticides sorbed by the surface sediments, which contain the least organics, was the fastest and the extent of variation of sorbed amount was the greatest, followed by suspended particles and biofilms.

Key words: Biofilm, Suspended particles, Sediments, Organochlorine pesticide, Sorption, Kinetics