A transport model for heavy metals in sediments

In this study, we develop an integrated model of hydrodynamic-sediment-heavy metal transport, which includes physical and chemical dynamics during the process of heavy metal adsorption in sediments. For this model, the traditional surface complexation model is modified to include sediment surface discharge, and then applied to represent the chemical bonding activities between heavy metals and sediment surface groups. In addition, according to the conditions of chemical reactions, two layers (aerobic layer and anaerobic layer) are included to considering topography evolution. The model is finally calibrated by simulating the transport of Ni, a trace metal, in a flume experiment. A comparison between observed data and the simulated results indicates that the integrated model is rational and can properly describe the complex process of heavy metal transport in sediments.