宝鸡长青镇铅锌冶炼厂周边土壤重金属污染研究

Heavy Metals Pollution in Soil Around the Lead-zinc Smelting Plant in Changqing Town of Baoji City, China

通过野外采样和实验室分析,在分析土壤基本理化性质的基础上,重点研究宝鸡长青镇铅锌冶炼厂周边土壤中重金属元素的含量和形态特征,并进行了污染评价。结果表明,宝鸡长青镇铅锌冶炼厂周边土壤中Cu、Pb、Zn、Mn、Co、Ni、Cr的平均含量分别为31.8、41.3、102.6、704.6、14.4、37.4、83.2mg·kg-1,均高于陕西省和全国土壤元素背景值,尤其是Cu、Pb和Zn。土壤中Cu、Zn、Ni和Cr主要以残余态的形式存在,Pb、Mn和Co主要以可还原态和残余态的形式存在,重金属的迁移顺序为Mn（63.91%）〉Pb（60.08%）〉Co（51.70%）〉N（i37.12%）〉Zn（32.09%）〉C（r30.58%）〉Cu（19.95%）,其中,Mn、Pb和Co有50%~65%可以发生迁移,易被生物体利用,危害较大。评价结果表明,宝鸡长青镇铅锌冶炼厂周边土壤主要受到了Pb的轻度污染。

According to the methods of field sampling and experimental analysis, the content, speciation and pollution assessment of heavy metals in soil around the lead-zinc smelting plant in Changqing Town of Baoji City were studied based on physiochemical analysis of soil. The results showed that the contents ofCu, Pb, Zn, Mn, Co, Ni and Cr were 31.8, 41.3, 102.6, 704.6, 14.4, 37.4 mg·kg-1 and 83.2 mg·kg-1, respectively. They were higher than that of element background values in soils of Shannxi Province and China, especially for Cu, Pb and Zn. In soil, Cu, Zn, Ni and Cr were rich in the residual part, Pb, Mn and Co were controlled by the reducible and residual parts, and the order of transfer of heavy metals was Mn（ 63.91% ）〉Pb（ 60.O8% ）〉Co（ 51.70% ）〉Ni（ 37.12% ）〉Zn（ 32.09% ）〉Cr（ 30.58% ）〉Cu（19.95% ）. Among all analyzed heavy metals, Mn, Pb and Co were easy to transfer, which had higher potential harm. The results of pollution assessment showed that the soil around the lead-zinc smelting plant in Changqing town of Baoji City was slightly contaminated by Pb.