| In this paper HCHs and DDTs, listed as'priority persisten organic pollutants'by the US EPA and China, were selected as representative contaminations. Transport behaviours of them between water and sediment were studied by field monitoring of Haihe river and Jingye lake such as water eutrophication index, particulate material fluxes, concentrations of HCHs and DDTs in surface sediment.The results showed that phytoplankton thrived in spring and autumn, algal bloom was easily happened in autumn, and concentrations of chlorophyll reached peak values at the beginning of September and October, respectively. Sanchakou of Haihe and Jingye lake were in eutrophic status, and the eutrophic status of Sanchakou of Haihe was more serious. The growth of phytoplankton was limited by phosphorus at the two places.From March to October 2006, concentrations of∑HCH and∑DDT in surface sediment of Sanchakou of Haihe ranged from 1.92-10.07 ng/g (mean 4.00 ng/g) and 3.24-43.39 ng/g (mean 13.55 ng/g), respectively. Jingye lake ranged from 2.19-20.16 ng/g (mean 7.68 ng/g) and 1.79-29.11 ng/g (mean 12.57 ng/g), respectively. The results showed that the seasonal change of concentrations of OCPs in surface sediment of Sanchakou of Haihe was unconspicuous but obvious in surface sediment of Jingye lake. Concentrations of OCPs were down in spring, fluctuated in summer, were from high to low and then rebound in autumn.Transport behaviours of organochlorine pesticides between water and sediment were significantly influenced by eutrophication. Concentrations of∑HCH in surface sediment were most influnced by particulate material fluxes, not directly by phytoplankton which was possibly attributed to retarding in settlement of phytoplankton, and indirectly by alkaline phosphatase activity.The results of Haihe river showed that contamination of OCPs was serious in Sanchakou and Guangming Bridge. Composition of HCH isomers was dominant byβ-HCH in surface sediment of Haihe river and Jingye lake.
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