耕层土壤重金属污染评价——以长治市为例  

Evaluation of Heavy Metal Pollution in Plough Layer:A Case Study of Changzhi City

作　　者：史晓宁 SHI Xiaoning(Changzhi Comprehensive Inspection and Testing Center,Changzhi 046000,China)

机构地区：[1]山西省长治市综合检验检测中心,山西长治046000

出　　处：《特产研究》2023年第3期81-87,共7页Special Wild Economic Animal and Plant Research

摘　　要：种植业易受土壤重金属的影响,综合评价耕层土壤重金属污染情况,有助于农业环境全面分析和污染防控。基于长治市耕层土壤重金属Cd、Hg、As、Pb和Cr的实测值,采用单因子污染指数、内梅罗污染指数、污染累积指数、污染负荷指数、地质积累指数和潜在生态风险指数法,对研究区域土壤重金属污染程度进行综合评价。耕层土壤中Cd、Hg、As、Pb和Cr的平均含量分别为0.123mg/kg、0.044 mg/kg、13.03 mg/kg、22.2 mg/kg和47.7 mg/kg;因地质特征,研究区域土壤Cd、Hg、As和Pb含量均高于山西省土壤元素背景值;分别以土壤质量标准值和元素地球化学背景值为参照,判断研究区域耕层土壤分别处于清洁状态、轻度和中度污染状态,或存在Hg的点状污染,重金属污染程度依次为Hg>Pb≈As>Cd>Cr;Cd和Hg生物毒性较强,表现出中-强潜在生态风险,研究区域最主要的土壤污染元素为Hg。基于全量分析和单一方法,潜在生态风险指数比较适用于土壤重金属污染评价,但复合型评价得出的结果更接近实际。Agriculture is easily affected by the heavy metal in soil.Multi-angle evaluation of heavy metal pollution in plough layer is helpful for comprehensive analysis of agricultural environment and pollution prevention and control.Based on the measured values of heavy metals Cd,Hg,As,Pb and Cr in topsoil of Changzhi green organic dry farming closed demonstration area in 2019,the single-factor pollution index,Nemerow pollution index,pollution accumulation index,pollution load index,geoaccumulation index and potential ecological risk index were used to comprehensively evaluate the heavy metal pollution degree of soil in the study area.The average contents of Cd,Hg,As,Pb and Cr in topsoil were 0.123 mg/kg,0.044 mg/kg,13.03 mg/kg,22.2 mg/kg and 47.7 mg/kg,respectively.Due to the geological characteristics,the contents of Cd,Hg,As and Pb in soil in the study area were all higher than the background values of soil elements in Shanxi Province.With the standard value of soil environmental quality and the background value of element geochemistry as reference,the soil in the topsoil of the study area was judged to be in clean state and mildly to moderately polluted state respectively.Under the combined action of exogenous inputs such As soil formation process and human activities,the heavy metal pollution degree is Hg>Pb≈As>Cd>Cr.The biological toxicity of Cd and Hg is strong,showing medium-strong potential ecological risks,or there is spot pollution of Hg.Based on the total analysis and single method,the potential ecological risk index is more suitable for the assessment of soil heavy metal pollution,but the results of the composite assessment are closer to the reality.

关 键 词：耕层土壤 重金属 污染评价 长治 

分 类 号：X53[环境科学与工程—环境工程]