焦家金矿土壤中汞的形态分布特征研究

采用改进的Tessier连续提取法分析了焦家金矿土壤中不同赋存形态汞的含量，阐述了金矿水平剖面土壤中不同形态汞的分布特征及相互转化规律。结果表明，土壤中汞主要以残渣态存在，不同形态汞平均含量依次为：残渣态＞腐殖酸结合态＞强有机结合态＞水溶态＞铁锰氧化物结合态＞碳酸盐结合态＞离子交换态；金矿对土壤中不同形态汞的影响显著，除碳酸盐结合态外，其他各形态汞都有在金矿附近富集的现象；非残渣态汞占总汞的27％左右，金矿土壤中的汞具有较大的生物可利用性；金矿附近土壤中活性较高的形态（离子交换态、水溶态、碳酸盐结合态及铁锰氧化物结合态）占总汞比例较低，活性较低的形态（腐植酸结合态及强有机结合态）占总汞比例较高。金矿开采活动可能对土壤中汞形态的分布造成影响。

Distribution Features of Mercury Speciation in the Soil of Jiaojia Gold Mine

Using an improved Tessier sequential extraction method to analyze the concentration of different speciation of mercury in the soil of Jiaojia Gold Mine, this article elaborated the distribution characteristics of different mercury speciation in the soil of horizontal spatial of the mine. The result indicated that firstly, mercury in soil existed mainly in residue speciation, and the descending order of the average concentration of different speciation of mercury as follow: residual＞humic acid＞strong organic＞water-soluble＞Fe\Mn oxide＞carbonate＞ion exchangeable. Secondly, the gold mine had significant effects on different speciation of mercury in soil and in addition to a carbonate combined state, a variety of speciation of mercury enriched near the gold mine. Thirdly, the non-residual mercury accounted for about 27% of the total mercury, the mercury in the soil of the gold mine had greater bioavailability. The speciation of mercury with high biological effectiveness in the soil near the gold mine(ion exchangeable, water-soluble, carbonate and Fe\Mn oxide) accounted for lower ratio of the total mercury. However, the speciation of mercury with low biological effectiveness（humic acid and strong organic）accounted for higher ratio of the total mercury. The activities of gold mining may affect the distribution of mercury speciation in the soil.