基于环境风险的危险废物填埋场安全寿命周期评价

通过系统分析危险填埋场的设计功能,结合安全寿命周期的定义,对危险废物填埋场的安全寿命周期进行了定义.在此基础上,通过文献查阅和理论推导确定了描述危险废物填埋场主要单元性能衰减的老化模型,并结合课题组开发的渗漏环境风险分析模型,建立了危险废物填埋场的安全寿命评估模型,并选择中部某危险废物填埋场进行了案例研究.结果表明:随着防渗材料老化以及导排层淤堵,渗滤液渗漏量将逐渐增加,其安全贮存功能将逐渐丧失,并逐渐达到其安全寿命周期.仅就本案例而言,该填埋场的安全寿命周期为385a;对安全寿命周期相关参数的敏感性分析表明,浸出浓度与填埋场安全寿命周期呈负相关,包气带厚度和含水层厚度与安全寿命周期呈正相关,相关系数分别为-0.79、0.99和0.72,这说明包气带厚度对安全寿命周期影响更大,其次为浸出浓度,最后为含水层厚度;应加强填埋场相关单元老化模型研究,开展其他因素对填埋场安全寿命周期的影响,进一步完善危险废物填埋场安全寿命周期评价理论和方法.

Risk-based method to assess the safe life of hazardous waste landfill

Through systematic analysis on hazardous waste landfill's (HWL) design function, the definition of Safety Life Cycle (SLC) of HWL was given with reference on the traditional definition of SLC. Base on this, the models describing the degradation process of HWL's main functional units were determined by literature reviewing and theoretical analyzing. This models were then coupled with the ERAMLL (Environmental risk assessment model for the leachate leakage) to assess the SLC for HWL. A HWL in central area in China was selected as a case study, and the result reveals that: with the aging of geomembrane and clogging of drainage system, the leakage rate of leachate in HWL will increase with time. Its environment risk will increase, and the HWL will reach to its SLC. As far as this case is concerned, its SLC is about 385a; sensitivity analysis on relevant parameters indicates that the parameter of leaching concentration has negative relation with the SLC, while the thickness of vandose and aquifer has the positive relation with the SLC. Among them, parameter that has the greatest influence on SLC is vandose thickness with the coefficient of correlation equal to 0.99, and then are the limit value of leaching concentration and aquifer thickness with the coefficient of correlation equal to -0.79 and 0.72, correspondingly. Finally, this paper suggested that more effort should be paid to strengthen the research on aging models and the factors that influence the SLC in order to consummate the theory and method of SLC assessment.