Effect of Sediment Suspension Duration on Release of Organochlorine Pesticides at Static State

Organochlorine pesticides belong to organic pollutant that exist widely in the environment. Their characteristics include low solubility, high hydrophobicity, high absorbability on particles, and then accumulation in the sediments with the particles. The accumulated organochlorine pesticides in the sediments will be re-released into the water with re-suspended sediments leading to secondary pollution. In order to study the effect of sediment suspension duration on the release of organochlorine pesticides, a simulative sediment releasing device was operated for 80 days using the sediment of Weishan Lake. The result showed that with the lasting disturbance time, the concentration of organochlorine pesticides in overlying water increased rapidly during day 0～20. It increased until day 60 when the content trended to a stable level. The release rate of organochlorine pesticides depended on disturbance and the higher the pesticides water-soluble, the easier the release.