Author(s): Yafei Jia; Tingting Zhu
Linked Author(s):
Keywords: Chemical fate and transport; Numerical modeling; PCB; Rhine River; Hudson River
Abstract: Chemicals accidentally released by acute spills will have negative environmental and ecological impacts. The polluted water can directly do harm to human health; the water quality and associated ecological systems will be affected by contaminated sediment for a long time to come. Because this environmental problem is complicated and involves many factors, it is essential to have a capable tool for assessing these impacts on water, sediments and overall environment so that comprehensive mitigation measures can be taken. For this purpose, a modeling frame work for simulating water quality, contaminant transport and cohesive sediment transport was developed based on a depth-averaged two-dimensional hydrodynamic and sediment transport model, CCHE2D. The cohesive sediment transport module is for freshwater, capable of handling flocculation, settling of flocs and the effects of erosion and deposition over multiple sediment bed layers for taking into account the consolidation process. The water quality and contaminant transport modules include physical and chemical processes such as transport, fate, absorption, desorption, volatilization, hydrolysis, photolysis and biodegradation, etc. With the model enhanced, users are allowed to predict the fate and transport of chemicals and associated environmental impacts. The model has been verified using a chemical spill case, an accident of chemical spill on the Rhine River in Nov., 1986 which caused a massive fish kill; it was also applied to a study of the Upper Hudson River PCBs. Simulation results of unsteady flow, cohesive sediment transport, fate and transport of PCBs are reported.
Year: 2007