【摘要】 对金昌矿区不同区域土壤5~20 cm层中重金属各化学形态及活性态的迁移行为进行了研究,结果表明:土壤中重金属不同化学形态迁移率不同,弱酸提取态、可还原态、可氧化态和残渣态平均迁移率分别为0.13、0.51、0.30和0.54。重金属总量和活性态(包括弱酸提取态、可还原态、可氧化态)迁移率也表现出很大差异,尾矿区土壤Cr总量迁移率较高为0.65,而其活性态迁移率较低为0.26,Ni与Cr迁移特征完全相反,总量迁移率为0.26,而活性态迁移率为0.67;农田土壤中Pb总量迁移率低而活性态迁移率高,Ni与Zn特征相似,总量迁移率高而活性态迁移率相对较低;大棚地土壤中重金属迁移率均较低,Cu和Ni活性态几乎未发生向下迁移。可见,重金属的迁移与其化学形态分布关系密切,与重金属总量的迁移率相比,活性态迁移率能够更有效地反映出土壤中重金属的迁移特征和潜在危害性。更多还原

【Abstract】 Transport behavior of various speciation and each chemical form of heavy metals in soil from the different field around Cu-Ni mining area in Jinchang were assessed.The results show that the mean transfer coefficient of acid-soluble/exchangeable,reducible,oxidisable and residual fraction is 0.13,0.51,0.30 and 0.54,respectively.Furthermore,transfer coefficient between total content and variable speciation including acid-soluble/exchangeable,reducible,oxidisable fraction of heavy metals are different.Transfer coefficient of total Cr is 0.65 in tailings area,but that of variable speciation is 0.26.In contrast with Cr,transfer coefficient of total Ni is 0.26,but that of variable speciation is 0.67.The similar characteristics on Pb and Zn in cultivated soil,namely,transfer coefficient of total Zn is high,but low for variable speciation,which is reversed for Pb.Transfer coefficient of total content and variable speciation in abandoned soil are low compared with above two fields soil,especially,variable speciation of Cu and Ni are not transported almost down soil profile.The transport behavior of heavy metals in soil is closely related to the distribution of chemical forms of heavy metals.The transfer coefficient of variable speciation can effectively reflect transport feature of heavy metals in soil and its potential harmfulness.更多还原