基于改进的水质标识指数法垃圾填埋场地下水评价

GROUNDWATER EVALUATION OF INFORMAL LANDFILLS BASED ON WATER QUALITY IDENTIFICATION INDEX METHOD

非正规生活垃圾填埋场产生的渗滤液易对地下水环境造成严重污染,为了精准评价劣Ⅴ类水质和同类水质间的差异,引入水质标识指数法对典型非正规垃圾填埋场地下水水质进行评价。结果表明:由于浅层地下水与生活垃圾渗滤液直接接触,导致各监测点地下水中氨氮、高锰酸盐指数、氯化物指标单因子水质评价结果分别为66.362~255.3251、13.89~40.036、15.111~21.417;各监测点地下水综合水质评价结果为9.645~25.9521,均为劣Ⅴ类;最小值出现在2005年以前垃圾填埋区。受隔水层对污染物的有效阻隔作用,微承压水水质较潜水层水质显著好转,各监测点地下水综合水质评价结果为3.100~3.700。从空间分布特征看,不同填埋区潜水或微承压水单因子水质评价结果均存在显著差异;不同填埋区潜水水质综合评价结果存在显著差异,而微承压水综合水质评价结果差异不显著。研究成果对于今后我国垃圾填埋场地下水水质评价和环境管理具有借鉴作用。

In order to accurately evaluate the difference between poor Class V water quality and similar water quality,the water quality identification index method was introduced to evaluate the groundwater quality of typical informal landfill.The results showed that the single factor water quality evaluation results of ammonia nitrogen,permanganate index and chloride index were from 66.362 to 255.3251,13.89 to 40.036 and 15.111 to 21.417,respectively,due to the direct contact between shallow groundwater and domestic garbage leachate.The comprehensive evaluation results of groundwater quality at each monitoring point are 9.645~25.9521,all of which are inferior category V.The lowest values were found in the pre-2005 landfill area.Due to the effective barrier effect of the water barrier layer on the pollutants,the water quality of the microconfined water is significantly better than that of the diving layer,and the comprehensive evaluation results of groundwater quality at each monitoring point are 3.100~3.700.From the spatial distribution characteristics,there are significant differences in the single factor water quality evaluation results of submersible or microconfined water in different landfills.There are significant differences in the comprehensive evaluation results of diving water quality in different landfill areas,but there is no significant difference in the comprehensive evaluation results of microconfined water.The research results can be used as reference for groundwater quality assessment and environmental management of landfill sites in China.