污泥在土地利用中的潜在生态风险评价

Assessment of Potential Ecological Risk of Sludge in Land Use

为评估污泥在土地利用中的潜在生态环境风险,笔者对比分析了污泥施用区和对照区土壤样品中As、Cd、Cr、Cu、Ni、Pb、Zn共7种重金属的含量,并采用地积累指数法和潜在生态危害指数法对污泥施用区重金属污染进行了分析和评价。研究结果表明:除Ni和Pb外,其他重金属平均含量较背景值均有所增加;污泥施用区重金属含量与对照区存在显著差异,但其平均值含量均在土壤环境质量II级范围内;从平均地积累指数来看,土壤环境总体上处于无污染状态;重金属元素的潜在生态危害指数除Cd外均处于低度污染,元素Cd有部分处于中度以上污染。可得出结论:潜在生态危害指数由于考虑外源重金属富集和不同重金属生物毒性系数的影响,其评价结果更加精确。

In order to assess the potential ecological environmental risk of sludge use on soil, the authoranalyzed 7 kinds of heavy metal（As、Cd、Cr、Cu、Ni、Pb and Zn） in sludge application area and control area,analyzed and evaluated heavy metal contamination in sludge application area through the methods of geo-accumulation index and potential ecological risk index. The results showed that： the heavy metal contents werelarger than background value except Ni and Pb; there was significant difference of heavy metal content betweensludge application area and control area, but the average content was within the range of soil environmentalquality level II. According to the geo-accumulation index, soil environment quality was in no pollution state;heavy metals＇ potential ecological risk was in low pollution status except Cd, Cd was in moderate or abovepollution status in some areas. In conclusion, considering the impact of enrichment and biological toxicity ofheavy metal, the potential ecological risk index was more accurate.