Notice of RetractionExperimental Study on the Transporting Process Downwards of Organochlorine Pesticides in a Sediment Core from Honghu Lake, China

Abstract

The transporting process downwards of organ ochlorine pesticides in a sediment core from Honghu Lake was stuied expeimentally. The filtrate was collected at intervals. The concentrations of β-HCH in filtrate decreased gradually with the increase of time, which indicated that β-HCH in the sediments was being removed gradually with water. But the highest concentrations of HCB and p,p'-DDE in filtrate had obvious delay because of stronger absorbility of sediments. There were evident difference between the initial concentrations and the final concentrations of HCHs and DDTs in the sediment core. The concentrations of HCHs and DDTs decreased in the sediment with 0-5cm depth and those increased in the 5-15 cm sediments. However, the tendency that HCHs and DDTs in the sediment with 10-15 cm removed downwards was not obvious because of adsorption of TOC. HCHs in the sediments under 15 cm removed downwards and led to increase of HCHs concentration in the sediment with 25-30 cm depth, but the varieties of DDTs concentrations in the sediments under 15 cm depth were not obvious because of its hydrophobia.