夹皮沟金矿区土壤汞的赋存形态及污染特征

Chemical Speciation and Pollution Characteristics of Hg in Soils from Jiapigou Gold Mining Area

使用改进的BCR连续提取法和电感耦合等离子质谱（ICP-MS）,测定夹皮沟金矿区土壤样品中汞元素的赋存形态及含量.结果表明,三个深度的土壤汞元素形态分布趋势相似,均以残渣态为主,其次为可氧化态和可还原态,酸溶/可交换态和水溶态所占比例较少,各形态汞的分配系数依次为：残渣态（48.28％）＞可氧化态（25.68％）＞可还原态（13.35％）＞酸溶/可交换态（838％）＞水溶态（433％）.垂直方向上,20 ～ 40 cm的中层土壤中的汞含量略高于0～ 20 cm的表层土壤,40～60 cm的下层土壤则含量最低.不同深度土壤中的有效态汞与总汞的含量具有较高的相关性,但三层土壤不具有相同的相关趋势.

Modified BCR extraction procedure and ICP-MS technique were applied to examine the content of Hg and chemical speciation.It was found that the trends of Hg chemical speciation in soil at 3 different depths were similar.The chemical speciation of Hg in soils was dominated by residual form,followed by the oxidizable and reducible forms,and the water-soluble form and acetic-acid-extractable form were less than them.The distribution coefficient of different Hg chemical speciation was residual form （48.28％） ＞ oxidizable form（25.68％） ＞ reducible form （13.35％） ＞ acetic-acid-extractable form （8.38％） ＞ water-soluble form （4.33％）.In soil profiles,Hg content in 20 ～40 cm was high than that in 0 ～20 cm,and the Hg content in 40 ～ 60 cm soil was the least.There was a significant correlation between the concentrations of Hg in available form and total Hg at 3 different depths,however,the related trends at 3 different depths were dissimilar.