兰州市安宁区蔬菜地土壤酸度及重金属的测定和评价

Investigation and evaluation of the acidity and heavy metals pollution in the vegetable field in Lanzhou City

以甘肃省兰州市安宁区的5块菜地土壤为研究对象,采用电位法测定了土壤pH及土壤中Cu、Pb、As、Zn、Cr和Ni的含量,并根据GB 15618-1995土壤环境质量二级标准通过单项质量指数与综合质量指数相结合的方法对土壤重金属的环境质量状况进行了评价.结果表明:兰州市安宁区蔬菜土壤环境质量等级为1～2级,属于尚清洁水平,符合无公害蔬菜生产的土壤环境质量要求.但土样之间重金属含量存在较大的变异性,反映了人为活动已对土壤重金属含量产生了明显的影响,需加强监测和预防.

A survey was conducted to investigate the soil of 5 different vegetable field in Anning District of Lanzhou City.The pH values of the samples were measured using potentiometry,the heavy metals such as Cu,Pb,As,Zn,Cr and Ni in soils were measured using inductive coupled plasma-optical emission spectrometry（ICP）.According to the soil environment quality standard（GB 15618-1995）,the determined results were further assessed using methods of combining single quality index and comprehensive quality index.The results indicated that the soil quality of vegetable fields in Anning District of Lanzhou City belonged to the first to second class,which was considered to be clean,indicating that they met the requirements of soil environment for producing pollution free food.But the heavy metal concentrations among samples were much different,this indicated that human activities obviously effected the heavy metal concentrations in soil,so we should tighten the screw on environmental protection.