危险废物填埋场营运前初期地下水质评价

GROUNDWATER QUALITY ASSESSMENT OF A HAZARDOUS WASTE LANDFILL AT ORIGINAL OPERATION STAGE

对某刚投入运营的危险废物填埋场的地下水和渗滤液进行采样分析,选取14个污染指标作为评价因子,以《地下水质量标准》中推荐的方法和改进综合评价法对水质进行评价,并分析了水质成因。结果表明,研究区地下水氨氮超标,主要受临近鱼塘和养猪场的排泄物影响。渗滤液挥发酚超标,与初期填埋废物成分相关。地下水样中氨氮浓度高于渗滤液,说明填埋场投入前初期附近地下水补充源氨氮指标贡献值高于渗滤液入渗。14项评价因子监测数据表明,渗滤液对填埋场地下水收集系统水质量的影响不明显,总体水质较好。由于改进综合评价法同时考虑了污染最大值和最大与次大权重单项因子,其得出的地下水质评价结果能更客观地反映评价区地下水的实际质量状况。

Samples of groundwater and leachate were collected from a beginning hazardous waste landfill and analyzed at three different times.Fourteen pollution factors in these water samples were used to evaluate water quality by the method recommended by national quality standard for groundwater and its improved method respectively.The results showed that ammonia nitrogen concentration in the groundwater exceeded the limit,which was mainly caused by the infiltration of pollutants discharged from the surrounding fish ponds and pig farms.The higher concentration of volatile phenol in the leachate samples,was related to the composition of initial landfill waste.The ammonia nitrogen concentrations in the groundwater samples were higher than those in the leachate samples,indicating that the contribution of nearby supplementary source to ammonia nitrogen in groundwater was greater than leachate infiltration at the original operation stage.The monitoring data of 14 evaluation factors revealed that the effect of landfill leachate on the quality of water in groundwater collection system was not obvious,and the overall water quality was good.The improved comprehensive evaluation method could reflect groundwater quality better,due to its simultaneous consideration of the biggest pollution factor and various weight values for different pollution factors.