A study on heavy metal partitioning in sediments from Poyang Lake in China

Abstract

The partitioning of heavy metals in sediment from Poyang Lake, the largest freshwater lake in China, was studied. The majority of the heavy metals, copper, lead and zinc, were found to be bound to the organic matter and iron oxide phases. The distribution of the metals among the different geochemical phases in sediments was controlled by the abundance of the geochemical phases. An equilibrium adsorption model developed by Oakley et al. (1981) and Davies-Colley et al. (1984) was applied to predict the partitioning of copper among different geochemical phases in the sediments of Poyang Lake. The conditional equilibrium constants (slopes of the linear portions of the adsorption isotherms) were determined using an artificial water-sediment system at various pH's. This model was used to describe the heavy metal partitioning in sediment samples from Poyang Lake and the predicted results were consistent with those measured in the laboratory.