Xia Yun-Sheng, Li Fang-Bai, Wan Hong-Fu, Ma Jin, Yang Guo-Yi, Zhang Tian-Bin, Luo Wei
Guangdong Institute of Eco-Environment and Soil Sciences, Guangdong Key Laboratory of Integrated Control of Agro-Environment, Guangzhou 510650, China.
J Environ Sci (China). 2004;16(6):912-8.
Distribution and speciation of heavy metals of agricultural soils(85 surface soil samples and 4 soil profiles) in Dongguan were investigated, while total Cr, Cu, Ni, Pb, Zn(abbreviated as Cr, Cu, Ni, Pb, Zn) and available Cu, Zn(Av-Cu, Av-Zn) were analyzed by a flame absorption spectrophotometer(AAS), and total Cd(Cd) was analyzed using graphite furnace AAS. The content of Cd, Cu and Ni was partially much more than the second grade of GB15618-1995 even though the mean contents of all heavy metal were less than the threshold value of the second grade and only the mean content of Pb was more than the value of national background. Results of descriptive statistic showed that the mean content of heavy metals should depend on land utilization and spatial location at some extent. The heavy metal contents were higher in the Southwest and Northwest than in the Central. In addition, the mean contents of Zn and Pb in Dongguan paddy soils were significantly higher than those of Pearl River Delta(PRD) and Taihu Lake region(TLR). Correlation analyses indicated that there existed significant correlation between Cr and Ni in orchard soils, and among Zn, Cd and Cu, between Av-Cu and Cu, between Av-Zn and Cr, Ni, pH value in vegetable soils, and a weak relationship between Cd, Cu and Pb, between Av-Zn and Zn. Principal component analyses(PCA) showed that the order of importance should be Zn > Pb > Cr > Ni > Cu.
对东莞农业土壤(85个表层土壤样本和4个土壤剖面)中的重金属分布及形态进行了研究,采用火焰吸收分光光度计(AAS)分析了总铬、铜、镍、铅、锌(分别简称为Cr、Cu、Ni、Pb、Zn)以及有效态铜、锌(Av-Cu、Av-Zn),采用石墨炉AAS分析了总镉(Cd)。尽管所有重金属的平均含量均低于GB15618-1995二级标准阈值,且只有铅的平均含量高于全国背景值,但镉、铜和镍的部分含量远超该标准二级标准。描述性统计结果表明,重金属的平均含量在一定程度上应取决于土地利用方式和空间位置。西南部和西北部的重金属含量高于中部地区。此外,东莞水稻土中锌和铅的平均含量显著高于珠江三角洲(PRD)和太湖地区(TLR)。相关性分析表明,果园土壤中铬和镍之间、蔬菜土壤中锌、镉和铜之间、有效态铜与铜之间、有效态锌与铬、镍、pH值之间存在显著相关性,镉、铜和铅之间以及有效态锌与锌之间存在较弱的相关性。主成分分析(PCA)表明,重要性顺序应为锌>铅>铬>镍>铜。