湖南省矿山尾砂土壤污染现状分析

Characteristics of Soils Contaminated by Tailings in Mining Areas of Hunan Province, China

对湖南省 10个矿区的尾砂土壤进行了采样调查 ,分析了尾砂土壤的pH值、烧失量、阳离子交换容量、重金属含量以及重金属各种化学形态的含量。结果显示大部分土样中的Pb、Cd、Cu和Zn都超过了土壤中植物正常生长的最高容许浓度。各种重金属在土样中主要以残留态、硫化物和有机物结合态、或是Fe/Mn氧化物结合态存在 ,可交换态与碳酸盐结合态的含量极少。对各矿区尾砂土壤的污染指数 (PI)与危险指数 (DI)的计算表明 ,土样的PI与DI值分析显示 1号永州铜矿、5号宝山铜铅锌矿、10号湘潭锰矿和 7号冷水江铅锌矿需要尽快得到治理。

Tailing soil samples have been taken for study from ten mining areas in Hunan Province. The pH value, loss on ignition, cation exchange capacity, the concentration of heavy metals and each chemical form of heavy metal have been investigated. The results show that the concentration of Pb, Cd, Cu and Zn in the most of soil samples exceed the maximum tolerable concentration for plants to normally grow. A large proportion of heavy metals in the soil samples mainly existed in the form of residual fraction, combination of sulfides and organic substance, or the combination of Fe/Mn oxide fractions, less in the exchangeable form and combination of carbonate. Based on the calculation of pollution index (PI) and danger index (DI) for tailing soil in each mining area, the analysis on the PI and DI of soil indicates that some measures should be taken as soon as possible to improve the soil quality in 1# Yongzhou Copper Mine, 5# Baoshan Copper-lead-zinc Mine, 10# Xiangtan Manganese Mine and 7# Lengshuijiang Lead-zinc Mine.