Multicomponent Kinetic Reactive Transport Modeling of Heavy Metals in Water and Sediment of Jiehe River.

This study investigated the reactive transport of trace elements (As,Cr,Cd,Cu,Zn,Pb) in heavyly polluted JieHe River and its tributaries in Zhaoyuan, Shandong. A reactive transport model was developed by incorporating multicomponent kinetic reaction modules into existing water quality model. The model have the capability of predicting fate and behavior of heavy metals in water and sediment under varying environmental conditions and has been used to support the scentific decision making for remediation and restoration of heavy metal contaminated streams and rivers. Data collection and field survey was carried out to establish the baseline hydrologic conditions of the studied watershed. Synoptic sampling and chemical speciation of water and sediments was performed at different sites along the stream reaches during critical low flow season. Response of stream water quality to heavy metal loading from various point and non-point sources in the watershed was analyzed based on the sampling results. Multicomponent kinetic reaction model was employed to describe the results of kinetic batch experiments and to quantify the retention and release rate of heavy metals from contaminated sediment at different pH and oxidation-reduction states. A one dimensional steady state reactive transport model of heavy metals in water-sediment of JieHe River and its tributaries has been developed based on the results from tracer experiment, synoptic sampling, and kinetic batch studies. The baseline numerical model has been used in combination with scenario analysis to establish management and remedaition plans for restoration of JieHe Watershed.