Research On Environmental Risk Assessment Model For Leakage Of Hazardous Waste Landfills

Large cardinal number of solid waste storage、fast production speed、low utilization rate and safety prevention&control level is limited and some problems need to be solved urgently.At present, the domestic and international mainly adopted landfill way for harmless treatment of solid waste. In the process of landfill use, there are different levels of leachate leakage, which cause some pollution to the nearby soil and groundwater, threatening the stability of ecosystem and the safety of people’s life and property. At this time, it is important to construct a set of risk assessment system for landfill site, which has great significance and social value.For hazardous waste landfill field leakage problems, this paper based on the theory of environmental risk assessment and control of hazardous waste landfill standard, to build a hazardous waste landfill leakage environmental risk assessment system, using advanced computer technology(WinForm development 、 XML data processing 、 Mixed programming 、MATLAB graphics, etc) 、 mathematical model(SCS Runoff Curve Model,etc) and related algorithm(Gauss integral algorithm,etc). Completed the development of hazardous waste landfill leakage environmental risk assessment system.First of all, discusses the five sub models(Surface infiltration model、Drainage- seepage control model、Heap leaching model、Leachate drainage- seepage control model、Vadose zone- groundwater model) involved in the process of building model in detail. The surface infiltration model selected classic runoff calculation model Soil Conservation service model as the theoretical foundation of the modeling. Provides two methods that the leachate characteristic parameters and garbage characteristic parameters to calculate the leachate concentration from pile leaching calculation. At the same time, the leachate through the hole into the vadose zone and in the capillary force, under the action of gravity into groundwater and solute in the underground water migration and diffusion process were introduced in this pape.Then, the typical algorithm used in the model are discussed. Respectively discusses the Monte Carlo method, distribution theory, Gauss integral algorithm and empirical cumulative probability statistics algorithm. Finally, introduces the key technique used in the process of model system. The parameters of the data storage and read calls, separation of WinForm unit thread and evaluation computation thread and the process of data visualization with the help of MATLAB,etc.The results of the model output interface, we achieved that cumulative probability distribution of concentration of pollutants in the water under the specified time and coordinates conditions,the concentration changes of pollutants with time under the specified coordinate position and the confidence interval conditions as well as the graphical interface of spatial distribution of pollutant concentration under the specified time and confidence interval conditions. For the landfill design and management personnel, the EIA department provides data support for the planning of hazardous waste landfill environmental risk potential.