陈腐垃圾的重金属污染特征及其潜在风险评价

Polluted characteristics and potential risk assessment of heavy metals in refuse

以九江市生活垃圾填埋场陈腐垃圾为调查对象,分析了不同填埋结构不同回灌方式下陈腐垃圾中Cr、Cu、Zn、As、Cd、Hg和Pb的含量.结果表明:4个填埋体陈腐垃圾中Cr、Cu、Zn、As、Cd、Hg和Pb重金属平均含量均低于《土壤环境质量标准》(GB 15618-1995)三级标准,厌氧填埋体D(渗滤液回灌)陈腐垃圾中的Cr略微超标,2种填埋结构清水回灌方式陈腐垃圾中重金属的含量低于渗滤液回灌方式;准好氧填埋结构陈腐垃圾内梅罗综合污染指数处于清洁水平,厌氧填埋结构陈腐垃圾内梅罗综合污染指数处于轻微污染水平.潜在生态风险评价表明,不同填埋结构、不同回灌方式垃圾填埋场陈腐垃圾的重金属潜在生态风险指数(RI)均处于轻微生态风险水平,没有明显的级别差异.

Taking the different refuses from different landfill structures of Jiujiang city of Jiangxi province as the objects, the contents of heavy metals, such as Cr, Cu, Zn, As, Cd, Hg and Pb, were investigated. The results show that the concentrations of heavy metals are not beyond the three grades of Environmental Quality Standards for Soils （GB15618-1995） except Cr in anaerobic landfill D aged refuse. The concentrations of heavy metals of refuse from water recirculation are lower than leachate recirculation. Nemerow pollution index is at a clean level in semi-aerobic landfills, but is at a low ecological risk level in anaerobic landfills. The potential ecological risk assessment indicates the potential ecological risk index （RI） is at a low ecological risk level without distinct grade difference for different landfill structures and different leachate recirculation ways.