Sediment-controlled radionuclide transport: Mathematical modeling and field application.

摘要

The contamination of soil is a major concern of environmentalists. The soil contamination can easily be transferred into our body through water and plants. In major accidents, where cleaning up is not an option it is vital to confine the polluted area or to track down the path, through which the contamination is transported and to estimate the rate of transport. The focus of this research is to develop a model to define the transport of radionuclides over the soil surface by erosion and sedimentation induced by rain.; The local equilibrium concept has been used to develop a 2D depth-averaged contaminant transport model to estimate the removal of radionuclides from the soil surface due to erosion and sedimentation process. A 2D depth-averaged surface flow model has been coupled with a 2D depth-averaged sediment transport model. The flow is extremely shallow (about 1–5 cm) and does not have enough energy to detach and roll the relatively bigger soil grains on the soil surface. Therefore the sediment transport takes place in suspension mode. The results of this coupling have then been used in a 2D depth-averaged contaminant transport model to estimate the rate of radioactive removal by erosion and sedimentation in water.; The model has been applied to a 20 m x 20 m plot in Ukraine, where a one-year experiment was conducted by the Center for Water Resources and Environmental Research in CUNY. The results were compared to the collected field data. It was concluded that the model results were statistically in an acceptable range.