广州郊区土壤重金属污染程度及潜在生态危害评价

The assessments of polluted degree and potential ecological hazards of heavy metals in suburban soil of Guangzhou city

以广州市南沙区土壤为研究对象,研究了广州远郊土壤中Zn、Pb、Ni、Cu、Cr、As、Hg 7种重金属含量特征,并对该地区土壤重金属污染程度和潜在生态危害进行评价.结果表明,该地区26个土壤样品中重金属平均含量均高于广东省背景值,部分采样点的Zn、Pb、Ni、Cu、As含量超过国家土壤二级标准,且土壤中重金属含量空间分布不均匀;土壤重金属平均内梅罗综合指数为0.82,处于警戒级,污染程度不均匀;现阶段土壤重金属潜在生态危害尚轻,潜在生态危害主要来自于Cu、Hg.

Investigation and assessments of pollutions of heavy metals such as Zn、Pb、Ni、Cu、Cr、As and Hg in outer suburbs of Guangzhou City were carried out. The present polluted degree and potential ecological hazards of heavy metals were evaluated by the nemerow index and the potential ecological risk index(RI). The heavy metal concentrations of 26 soil samples were higher than the local background value, some indicators exceed the national recommended environmental quality secondary standard for soils, and with the uneven of space distribution. The mean nemerow synthesis index of heavy metal in soils was 0.82, the degree of pollution was alert level. The soil of Nansha Guangzhou City was of the slightly ecological hazard, Cu and Hg were primary ecological hazard factors.