基于随机-模糊耦合的填埋场地下水污染风险评价方法

A fuzzy-stochastic coupled method to assess groundwater pollution risk in a landfill

为分析参数不确定性对填埋场渗漏风险评估结果的影响,构建了填埋场地下水污染风险评价的物理过程模型,在此基础上,分别采用模糊理论和概率理论刻画模糊不确定性参数和随机不确定性参数,同时采用基于随机理论的Monte Carlo方法模拟模糊不确定参数,最终构建了基于模糊随机耦合的填埋场地下水污染风险评价方法。采用该模型对东北某一般工业固废填埋场进行案例研究,结果表明,实测浓度在模型模拟的的浓度区间（10%～90%分位值浓度）之内。说明本模型构建的模糊-随机耦合的地下水污染风险评价模型能较准确地预测地下水中污染物实际浓度,可以用于填埋场地下水污染风险评价.风险评估结果表明,该填埋场地下水的潜在污染物为As和Mn,其中As为主要健康风险物质,其非致癌风险值超过风险可接受水平的概率为22%,致癌风险超过10-4的概率为33%,超过10-5的概率为86%,应该采取措施控制含As填埋废物中As的溶出,降低其环境风险;Mn的非致癌风险值小于风险可接受水平的概率为100%,无风险。

To consider the influence of the uncertainty of parameters in assessing the risk of landfill leachate leakage,a physical-process-based conception model for leachate leakage＇s risk to groundwater has been constructed. Based on this,the fuzzy set theory and probability theory were used to describe the fuzzy uncertainty parameters and random uncertainty parameters. In addition,the Monte Carlo simulation method based on random theory was used to simulate the fuzzy uncertainty parameters. Finally,a fuzzy-stochastic coupled method based on random theory was constructed to asses the groundwater pollution risk in a landfill. An industry solid waste landfill was selected as case study. The case study result indicates that the measured value of contaminant concentration fell in the range of the predicted 10 th and 90 th percentile value,which means the constructed model was accurate enough to simulate the actual concentration distribution in the groundwater around the landfill. Risk assessment showed that the potential contaminants were arsenic（ As） and manganese（ Mn）. As was the main contaminant with noticeable toxic effects on human health. The probability that its hazard quotient exceeded the acceptable value is 22%. Furthermore,the probability that its cancer risk value exceeds the acceptable value of 10- 5and 10- 4are 33% and 86%,respectively,which means that its potential health risk was high and measurement should be taken to control the present risks. Mn has a non-carcinogenic effect and the probability that its hazard quotient exceeded the acceptable risk level is zero,which means its environmental effect can be ignored.