寨上金矿矿区河流沉积物中砷的形态分析

在野外调查和样品采集的基础上,对寨上金矿矿区河流沉积物中砷的质量分数进行了测定,并采用Tessier连续提取法对砷在沉积物中的存在形态进行了提取分析。结果表明,砷在该区水系沉积物中质量分数较高（55.0~189.0μg.g-1）,说明金矿的开采已经对该区的环境造成了影响。运用Tessier连续提取法研究发现,沉积物样品中砷的提取率为89.87%~110.54%,样品沉积物中砷的形态分布基本一致,以残渣态为主,占其总量的85%以上,其他各形态相对含量较少,但相对活泼形态（水溶态、离子交换态和碳酸盐结合态）绝对质量分数较高（2.029~4.942μg.g-1）,说明该区水系沉积物中大部分砷在自然条件下相对比较稳定,小部分砷（1.10%~5.55%）易释放至环境中,但由于其绝对质量分数较高,将对环境产生较大危害。

Speciation of arsenic in sediment of the river around Zhaishang goldmine

Based on outdoor research and sampling,the concentration range of arsenic in the sediment of the River around Zhaishang goldmine was determined.The chemical partitioning of Arsenic in the sediment were determined by the Tessier sequential extraction method.Results showed that the concentration of Arsenic in the sediment of this area is high（55.0-189.0 μg？g-1）,and the environment is changed by gold mining.The extraction percentages of As with Tessier＇s sequential extraction procedures are between 89.87% and 110.54%,and the fractions of Arsenic in these samples are almost the same.Arsenic mainly existed in residual fraction,account-ing for more than 85% of its total content,and the content of other fractions are very low,but the absolute content of the relative ac-tive fractions（water soluble fraction,exchangeable fraction and carbonate bounds） is high（2.029-4.942 μg？g-1）.It showed that most Arsenic in the sediment of this area is relatively stable in natural condition,small part of the Arsenic（1.10%-5.55%） is easy to move into the environment,but its absolute content is high,so it does great harm to the environment.