[Application of equilibrium partitioning approach to establish sediment quality criteria for heavy metals in Hengyang section of Xiangjiang River].

Twenty-nine surface sediment samples were collected from Hengyang sections of Xiangjiang River to detect concentrations and speciation percentage of heavy metals (Cu, Pb, Zn and Cd) in sediment and pore water. According to the Equilibrium Partitioning (EqP) approach, the sediment-water partition coefficients (Kp) of heavy metals in Hengyang section of Xiang River were revised by the bioavailable fraction, and the USEPA Criterion Continuous Concentration(CCC) which was based on aquatic toxicity of the final chronic level and GB3838-2002 I ,water quality standard were introduced to establish two types of sediment quality criteria (SQC) for heavy metals (Cu, Pb, Zn and Cd) in Hengyang section of Xiangjiang River for comparison. The better SQCs (base on CCC) of Cu, Pb, Zn and Cd were 64.62, 55.57, 1 360.40 and 2.34 microg x g(-1), and they can protect benthic organism from being poisoned by heavy metal chronic aquatic toxicity. The ratio of heavy metal concentration and SQC was used to assess sediment quality in Hengyang section of Xiangjiang River, the result showed that concentration levels of Cd, Pb in sediment in Hengyang section of Xiangjiang River had strong chronic toxic effects, Cd pollution could not be ignored.