Fractionation of heavy metals in shallow marine sediments from Jinzhou Bay, China

This work investigated the distribution and speciation of Cd, Cu, Pb, Fe and Mn in the shallow sediments of Jinzhou Bay, Northeast China, which has been heavily contaminated by nonferrous smelting activities. The concentrations of Cd, Cu and Pb in sediments were found to be 100, 13 and 7 times higher than the national guideline (GB 18668-2002). Sequential extraction test showed that 39%-61% of Cd are exchangeable fractions, indicating that Cd in the sediments poses a high risk to local environments, While Cu and Pb are at moderate risk levels. According to the relationships between percentage of metal speciation and total metals concentration, it can be concluded that the distribution of Cd, Cu and Pb in some geochemical fractions were dynamic in the process of pollutants migration and the stability of metals in sediments of Jinzhou Bay decreased in the order of Pb > Cu > Cd.