钢铁厂周边土壤重金属污染特征及风险评价——以闽西三明钢铁厂周边农田为例

为了明确闽西三明钢铁厂周边农田土壤重金属污染情况及其风险,于2019年5月在钢铁厂周边采集10个表层(0~20 cm)土壤样品,测定Pb、Cu、Zn、Cd、Hg和Ni的全量,利用单项污染指数法、内梅罗污染指数法和Hk?nson潜在生态危害指数法,评价重金属的污染水平和风险。结果表明,调查区域土壤重金属含量（除Hg超标率为80%外）均超过了福建省土壤背景值。相关性分析表明,土壤Pb、Cu、Zn、Cd、Ni具有同源性。评价结果表明,钢铁厂周边土壤重金属污染程度为Cd>Pb>Ni>Zn>Cu>Hg,调查区域所有土壤均达重度污染,处于很强和极强生态风险水平。因此,该钢铁厂周边农田土壤存在的重金属污染而产生的生态环境问题需引起高度重视,应优先开展Cd和Pb元素的防控,降低其生态风险。

Heavy Metals in Farmland Surrounding the Sanming Steel Plant in Western Fujian: Pollution Characteristics and Risk Assessment

The paper aims to clarify the heavy metal pollution and risk in the farmland surrounding the Sanming Steel Plant in western Fujian. We collected 10 surface soil samples (0-20 cm) in May, 2019, determined the contents of Pb, Cu, Zn, Cd, Hg and Ni, and evaluated the levels and risks of heavy metals by the methods of the single pollution index, the Nemero pollution index, and Hk?nson potential ecological hazard index. The results showed that: the contents of heavy metals in the studied area exceeded the background value of soil environment in Fujian, except that Hg exceeded the standard rate by 80%; correlation analysis demonstrated that: Pb, Cu, Zn, Cd, Ni in soil were homologous; the evaluation results demonstrated that: the pollution degree of heavy metals in the soil surrounding the Sanming Steel Plant was: Cd>Pb>Ni>Zn>Cu>Hg; all the soils in the studied area were heavily polluted, reaching very strong and extremely strong ecological risk level. Therefore, more attention should be paid to the ecological environment problems caused by heavy metal pollution in the farmland surrounding the Sanming Steel Plant, the prevention and control of Cd and Pb in soil should be the priority to reduce their ecological risks.