The Research Of Environmental Risk Assessment Technology Of The Old Dump

With the speeding up of urbanization, the municipal solid waste production is growing fast. But our government did not form a complete set of relevant laws and garbage disposal measures and old dump is generated accordingly. The old dump was only natural pilling up with no necessary measure taken and it may cause a series of problem such as fire, landfill gas explosion, groundwater pollution etc. Therefore, it is necessary to evaluate the risk of existing old dump and the corresponding risk prevention measures should be given. In this paper, the writer establish the old dump risk assessment index system by researching paper, investigating typical old dump, sampling analysis, evaluates the risk of three typical old dump in some county, and put forward the preventive measures and suggestions on the basis of large amounts of data.Through the analysis of the literature research, the risk of the old dump mainly includes:rubbish fire risk, landfill gas explosion risk, groundwater pollution risk, surface water pollution risk, garbage body collapse risk and the heavy metal poisoning risk.Through the investigation and garbage samples component analysis of the old dump, This paper identified possible risk categories of three typical old dump in some county.The main types of risk of landfill A include groundwater pollution risk, surface water pollution risk, garbage body collapse risk and the heavy metal poisoning risk;the main types of risk of landfill B are rubbish fire risk, landfill gas explosion risk, groundwater pollution risk, garbage body collapse risk and the heavy metal poisoning risk; the main types of risk of landfill C are rubbish fire risk, landfill gas explosion risk, groundwater pollution risk, surface water pollution risk, garbage body collapse risk and the heavy metal poisoning risk.The writer use the analytic hierarchy process (AHP) to establish the old dirt risk evaluation index system depending on the complexity, systematic and comprehensive of the old dump risk. This system contains 18 indexes, three risk levels which can be defined high, medium and low and use the improved analytic hierarchy process (method G1) to determine the weight of each index. Through the risk evaluation of three landfill, the writer get the same evaluation results of risk level high (in the "high"). Landfill C has the most types of possible environmental risk, followed by landfill B, and landfill A. The old dump risk prevention measures such as the pile body shaping, layout guide gas well, sealing cover and vegetation greening, leachate guide row collection, and set the intercepting ditch flood are given according to the results of the analysis and evaluation correspondingly.