Environmental Risk Assessment For Municipal Solid Waste Sanitary Landfill

Urban garbage disposal project is a public municipal engineering which can protect the urban city scape, construct a clean and civilized city and benefit the future generations. However, because of design flaws or management oversight, municipal solid waste sanitary landfill may also bring about a certain degree of environmental risk during its operation. Once the risk accidents occur, the environment surrounding the landfill will be damaged seriously. Therefore, it is very necessary to carry on environmental risk assessment studies for municipal solid waste sanitary landfill and propose appropriate risk management measures to alleviate the pollution risk of the landfill on the surrounding environment.The environmental risk assessment for Fuxin landfill was studied in this paper. By on-site survey and profile analysis to Fuxin landfill, the principal risk materials and the potential environmental risk accident types were recognized, and the Analytic Hierarchy Process method was used to select that leachate polluting groundwater was the maximum credible accident. Then, the Fault Tree Analysis method was used to carry qualitative and quantitative analysis on the maximum credible accident, which found the minimum cut-set, analyzed the structure importance of the basic event and calculated the occurrence probability of the accident. On this basis, a mathematical model was established according to the scenarios hypothesis of leachate polluting groundwater and the Matlab soft was used to solve the model; the solution results show that, in the study target point, the maximum concentrations of ammonia nitrogen, mercury, iron and manganese are in excess of Gradeâ…¢standard of groundwater, and that of other pollutants do not exceed. Finally, according to the characteristics of leachate polluting groundwater, the health risk assessment model was adopted to calculate the risk values and carry on risk assessment. The evaluation results indicate that the risk of leachate polluting groundwater in Fuxin landfill is an acceptable risk. Whereas, leachate is a kind of high concentration organic wastewater with complicated composition and strong toxicity and there are many uncertainties in the evaluation process, so it is very necessary to take appropriate risk management measures.