某矿区农田土壤重金属潜在生态风险评价及形态分析研究

Potential Ecological Risk Assessment and Forms Analysis of Heavy Metals in Farmland Soil of a Lead-Zinc Mining Area

对广西某矿区农田土壤中的Cd、Pb、Zn、Hg进行潜在生态风险评价及存在形态分析。结果表明,研究区域Cd为极强危害程度,Pb和Hg为很强危害程度,Zn为中等危害程度,所有采样点位均处于很强危害程度,其中主要的贡献来自于Cd。形态分析结果表明,Cd以可交换态为主,Pb以碳酸盐态和铁锰氧化态为主,Zn以残渣态、有机结合态和铁锰氧化态为主,Hg以残渣态和有机结合态为主。次生相与原生相分布比值法与潜在生态风险评价法评价结果存在差异,两种方法的评价结果均应加以考虑。

This paper made a potential ecological risk assessment and forms analysis of heavy metals( Cd,Pb,Zn,Hg) in farmland soil in a lead- zinc mining area in Guangxi. Results showed that Cd have reached a extremely harmful degree,and strongly harmful degree for Pb and Hg,while moderate degree for Zn. All sampling points were in a strongly harmful degree,and Cd was the main contributor. Forms analysis results showed that Cd was dominated by exchangeable form,Pb was mostly in the carbonate and Fe- Mn oxides forms,Zn existed mainly in residual,organic and Fe- Mn oxides forms,while the residual and organic forms was most for Hg. There were some differences between the ratio of secondary phrase to primary phrase and potential ecological risk assessment,and two methods should be considered in the ecological risk assessment process.