Application of equilibrium partitioning approach to derive sediment quality guideline (SQG) values for heavy metals in the Dianbu River

The Dianbu River was taken as the study object, the normalized equilibrium partitioning approach was used to derive the sediment quality guideline (SQG) values of five heavy metals (Cr, Cu, Zn, Cd, Pb) in the sediments of the river, and the contribution of each metal binding phase to the SQG value for five different heavy metals was analyzed. The results showed that the SQG values of Cr, Cu, Zn, Cd, and Pb in the sediments of the Dianbu River were 318.80, 122.24, 1 326.99, 7.88 and 31.43 mg/kg, respectively. There were differences in the contribution of each metal binding phase to the SQG values of five heavy metals. The contribution rate of fine particulate material (particle size < 63 μm) to the SQG values of five heavy metals in the sediments of the Dianbu River was 24.49%-48.93%, and the contribution rate to the SQG values of Cr, Zn and Cu sediments were the largest. The contribution rate of acid volatile sulfide to the SQG values of Cu, Zn, Cd and Pb was 2.11%, 0.22%, 50.13% and 21.67%, respectively, which mainly determined the SQG value of Cd. Total organic carbon and residual state contributed less than 3% to the SQG values of these five heavy metals.