Numerical Simulation And PRB Design Of Impact On Groundwater Environment By Waste Incineration Power Generation Project

With the deepening of the reform and opening up, China’s modernization and urbanization process accelerate and the accompanying is all kinds of environmental problems including groundwater environment quality deteriorating. At present, the degree of groundwater pollution is very serious. But compared with the surface water pollution and air pollution environmental pollution problems that is easy to be attention in domestic people, there is no enough attention on groundwater pollution. It is difficult for people to control groundwater pollution under the condition of existing technology because of the strong concealment, low velocity and poor Self-purification ability. This paper, taking a waste incineration for power generation project in Bazhou for example, selects CODcr as a simulation factor and establishes the solute transport model of the study area’s groundwater on the basis of sorting the relevant geological and hydrogeological data. By using the Visual MODFLOW, it adopts the method of numerical simulation to study the migration process of pollutants. Finally, assuming an accident that the garbage leachate infiltrates into the aquifer, the paper design a PRB system to repair the polluted water using the prediction of the movement of CODcr in groundwater system. The main conclusions are as follows:1. By collecting the geological, hydrogeological data of study area, the valleys in the study area north are defined as river boundary conditions and the surroundings are defined as confining boundary; It can be divided into two layers of structure through analysis of the mainly hydrogeological conditions. The first layer is quaternary silty clay and the 2nd is medium, strongly weathered sandstone aquifer. The groundwater flow numerical model is established and the paper was carried out on the model validation and recognition.2. Based on the groundwater flow numerical model. CODcr is selected as a simulation factor and the solute transport model is established. we uses the Visual MODFLOW to solve the model. From the point of prediction results, pollutants move from the pollution source to the north of model. The plume area of CODcr becomes bigger as time goes on. Ten years after the simulation, the whole plume has spread to the north side of the model and its average concentration reached 80 mg/L and the largest concentration is 150 mg/L3. Using the pollution plume and the hydrogeological data, the paper researches the PRB repair proposal. The PRB reaction medium mix with quartz sand, zero-valent iron and modified coal cinder and the wall chooses continuous structure. The main design parameters of the wall are as follows:the wall length is 40 m and height to 5.7 m; The paper determines the depth of 10.7 m and determines the thickness of 0.6 m; The Angle between the wall and the model of horizontal axis is 52°and the reaction layer permeability coefficient is 9.23 x 10-7 m/s. Finally, the paper uses the Visual MODFLOW to generalize related conditions and test repair effect on groundwater quality.