贵州典型重金属高背景区耕地土壤重金属生态风险评价

Ecological risk assessment of cultivated land in typical areas with high heavy metal background values in Guizhou Province

耕地土壤重金属污染问题是热点也是要点问题,开展小尺度土壤重金属生态风险调查,能够更精准地掌握重金属的污染状况及机理。对贵州威宁县盐仓—炉山一带典型重金属高背景区的耕地土壤和主要农作物进行重金属生态风险调查,采用地累积指数和Hakanson潜在生态风险指数法对土壤重金属的污染状况和生态风险进行评价,结果显示:耕地土壤存在重金属复合污染,其中Cd的污染程度和生态风险最高;农作物马铃薯和玉米存在Cd超标情况,与水溶态和离子交换态Cd密切相关,今后应更加重视土壤污染监测与修复中重金属污染与形态的研究。

The heavy metal pollution in cultivated land is a hot and key issue,and the pollution status and mechanisms can be accu-rately grasped through small-scale ecological risk surveys of heavy metals in soil.In this study,the heavy metal ecological risk survey of cultivated land and major crops was carried out in Yancang and Lushan towns,Weining County,Guizhou Province.Meanwhile,the pollution status and ecological risks of heavy metals in soil were assessed using the geoaccumulation index and the potential ecological risk index proposed by Hakanson.The results are as follows.The compound pollution of heavy metals exists in the soil of the cultivated land,with Cd showing the highest pollution level and ecological risks.Meanwhile,Cd exceeds the standard in some potato and maize samples,which is closely related towater-soluble and exchangeable Cd.Therefore,more attention should be paid to the studies on the pollution and speciation of heavy metals in the monitoring and remediation of soil pollution in cultivated land in the future.