乌鲁木齐市米东污灌区农田土壤重金属污染评价

Assessment of Farmland Soil Heavy Metal Pollution in Urumqi Midong Sewage Irrigation Region

对米东污灌区农田土壤重金属含量进行监测分析,利用不同的评价方法和标准对土壤重金属的环境质量进行评价。结果表明:米东污灌区农田土壤重金属含量分别为Cd(0.12±0.06)mg/kg,Cu(40.43±5.30)mg/kg,Zn(78.38±11.04)mg/kg,Pb(11.66±11.79)mg/kg,Ni(20.24±8.05)mg/kg,Cr(75.81±8.05)mg/kg。以国家土壤环境质量标准(二级)为标准评价,各元素的污染指数排序为Cu>Ni>Cr>Zn>Cd>Pb,综合污染指数为0.337,污染程度为安全。以食用农产品产地土壤环境质量要求为标准评价,各元素的污染指数排序为Cu>Ni>Cr>Zn>Cd>Pb,综合污染指数为0.343,污染程度为安全。表明米东污灌区农田土壤重金属含量尚能达到食用农产品产地土壤环境质量要求。Pb、Cu、Zn的平均含量超过乌鲁木齐市土壤背景值,这说明污灌区土壤重金属Pb、Cu、Zn近年来已有所累积,存在一定的污染风险。

Monitored and analyzed farmland soil heavy metal content in the Midong sewage irrigation region,evaluated environmental quality of soil heavy metals using different evaluation methods and criteria.The results showed that： the Midong sewage irrigation area soil heavy metals were Cd（0.12± 0.06）mg/kg,Cu（40.43±5.30）mg/kg,Zn（78.38±11.04）mg/kg,Pb（11.66±11.79）mg/kg,Ni（20.24±8.05）mg/kg,and Cr（75.81±8.05）mg/kg,refer to National Soil Environmental Quality Standards（Grade 2） the pollution index of each element the order Cu Ni Cr Zn Cd Pb,the integrated pollution index is 0.337,the degree of pollution for safety.Requirements for edible agricultural products of soil environmental quality criteria evaluate the pollution index of each element the order Cu Ni Cr Zn Cd Pb,the comprehensive pollution index of 0.343,the degree of pollution for safety.The results in Midong sewage irrigation region farmland soil heavy metal content can still reach the consumption of agricultural produce soil environmental quality requirements.Pb,Cu and of Zn average content of more than soil background values Urumqi,indicating that Pb and Cu and Zn cumulated in recent years,there is a certain risk of contamination.