珠江三角洲农业土壤重金属含量特征研究

The Heavy Metal Content Character of Agricultural Soil in the Pearl River Delta

调查研究了珠江三角洲农业土壤中重金属的分布规律,在研究区域采集了212个表层土壤样品,分析了其中8种重金属元素(Cu,Pb,Zn,Cr,Ni,Cd,As和Hg)的全量与有效态含量。结果表明:在珠江三角洲农业土壤中,8种重金属元素的含量均有超标现象,其中以Zn,Cd和Hg的超标率较高;在所有重金属元素中,Cd的有效态占全量的比率最高,平均为45 58%;而Hg所占的比率最低,平均仅为0 41%。重金属的有效态含量与全量存在正相关关系。交通、污水灌溉、工业污染、垃圾和城市污泥是造成珠江三角洲土壤重金属污染的主要原因。

The distribution of heavy metals in agricultural soils in the Pearl River Delta was investigated. 212 topsoil samples were collected in the research area. The total content and available content of 8 heavy metals (Cu, Pb, Zn, Cr, Ni, Cd, As, Hg) in the soils were determined. The results show that: the contents of all the eight heavy metals are over the national and local soil standard, with the largest three being Zn, Cd and Hg. Among the 8 heavy metals, Cd has the highest ratio of available content to total content while Hg has the lowest. The average ratios of Cd and Hg are respectively 45.58% and 0.41%. The available content of heavy metals has positive relationship with the total content. The heavy metals pollution in soil of the Pearl River Delta is mainly caused by traffic, sewage irrigation, industries pollution, municipal garbage and sludge sewage.