Numerical Simulation Research On Groundwater Pollution Of Coke-oven Project Of Pingyao Coalification Group

With the improvement of people’s living standard and acceleration of urbanization and industrialization, city sewage, garbage and industrial waste caused the deterioration of groundwater environmental quality and pollution problems have become increasingly prominent, while the human society continues to increase the exploitation of groundwater resources. Coking project, as a more serious pollution work, has already became a principal contradiction of constraining environmental construction. So it is particularly important to control the pollution,which has been already one of the priorities of the new ’12th five-Year plan’.This article takes the coke-oven project of PingYao Coalification Group as an example, the data of meteorology, hydrology and geological conditions, hydrogeological conditions, and surface water was collected and sorted comprehensively and systematically, as well as the field pumping test and the surrounding groundwater quality-sample test. Based on these, hydrogeological conceptual model was established in Accordance with groundwater aquifer systems. According to the transport mechanism of pollutants in the groundwater environment and field trials, this paper made use of Visual Modflow software to set up a coupled dynamics mathematical model, which reflects the flow of pollutant migration in groundwater environment. Based on numerical simulation of pollutant migration by Visual Modflow software, this article analyzed the influence of the coking project pollutants to shallow groundwater qualitatively and quantitatively. On this foundation, this paper proposed pollution prevention and control measures with respond actively to 《Environmental Impact Assessment Technical Guidelines-Groundwater Environment》, which was issued by China’s Ministry of Environmental Protection. This paper has a very important practical significance to manage potential groundwater problem from the source in the planning and licensing phases of new project development.According to the results of numerical simulation on Modflow software, the main conclusions are:(1)The distance of solute transportation in vertical direction is different from that in horizontal direction. And the former generally is longer than the later. The pollution halo appears an oval or pinnate distribution.(2)The lateral migration distance depends on the dispersion of the pollution itself, while the longitudinal migration distance depends on the hydraulic gradient of the groundwater. Groundwater is a good carrier of pollution transportation, and the effect of water current is larger than the effect of dispersion. The larger the hydraulic gradient is, the faster the pollutions transport.(3) After the failure of making the accident pool impermeable, the excessive range of pollution factors occupies32%-36%of the coverage, the impact is small. While if the Tank farm sclerosis face is broken, the excessive range of pollution factors occupies84%-91%of the coverage, which has a serious influence on the environment of the groundwater.(4)The longitudinal migration distance of Pollution halo and the range of the influence in accident pool are greater than those in the tank, which indicates that the concentration of the pollution factors plays the crucial role in solute transportation when the hydraulic gradient is equal.