佛山市城郊菜地土壤重金属污染状况调查与评价

对佛山市城郊9个调查点的菜地土壤Cu、Zn、Ni、Pb、Cr、Cd污染状况进行调查与分析,采用单因子污染指数法和内梅罗综合污染指数法对其污染程度进行评价。结果表明:Zn检测值100%,Cu、Ni、Pb、Cr和Cd检测值分别有87.3%、89.1%、74.5%、94.5%和34.5%超过了广东省土壤背景值,Cu、Ni、Cr和Cd检测值分别有3.6%、23.6%、30.9%和30.9%超过了国家土壤环境质量二级标准。全市土壤整体上受到了轻度重金属污染,Cd污染最严重,其次是Cr和Ni。9个调查点的综合污染程度依次为南庄>张槎>盐步>里水>罗村>桂城>澜石>黄岐>狮山。Cd的变异系数最大,达到强变异水平,预示着工厂等点源性污染的存在。Cu、Ni、Pb、Cr和Zn之间存在极显著或显著的正相关关系,它们具有明显的同源性。

Investigation and assessment on the pollution of vegetable field with heavy metals in the suburbs of Foshan

9 patches of vegetable field in the suburbs of Foshan were chosen to investigate and analyze their pollution with Cu,Zn,Ni,Pb,Cr and Cd.The pollution received an assessment by using the single factor and the Nemerow pollution index.The statistics of Zn,Cu,Ni,Pb,Cr and Cd were 100%,87.3%,89.1%,74.5%,94.5% and 34.5% respectively when the single factor method was used while those of Cu,Ni,Cr and Cd were 3.6%,23.6%,30.9%,and 30.9% respectively when the Nemerow pollution index was used.The former exceeded the background values of soil in Guangdong and the latter exceeded the National Secondary Standard for soil environment.The soil throughout the whole city of Foshan was heavily polluted with heavy metals among which Cd ranked first,Cr,second and Ni,last.Among the 9 chosen suburbs,Nanzhuang,followed by Zhangcha,Yanbu,Lishui,Luocun,Guicheng,Lanshi,Huangqi and Shishan,ranked first in pollution with heavy metals.The variation coefficient of Cd,which was the biggest and has reached the strong level,indicated the existence of pollution sources.There were very remarkable or remarkably positive relevant relation among Cu,Ni,Pb,Cr and Zn who obviously shared the same source.