文档介绍：摘 要
赣南是中国钨业的发祥地,并有“世界钨都”之称。境内四大钨矿经过几十年的开采, 在一定程度上给我国社会经济带来快速发展的同时,也给矿区当地的自然环境和人类的生存健康产生了一定的影响。As 是引起矿山环境污染主要的重金属元素之一,尾矿砂中的***会通过孔隙下渗和地表径流等方式进入到土壤当中,而土壤中的 As 经过一系列的迁移转化后能够被生物体所吸收,最终危害到人类的健康。
本文通过二乙基二硫代氨基甲酸银分光光度法对赣南某钨矿开采所产生的尾矿砂和矿区周围土壤中的 As 进行了全量分析,了解了矿区周围土壤的基本理化性质和 As 的富集特
征。结果发现矿区周围土壤呈偏酸性;另外尾矿砂和土壤中***的含量明显高于当地土壤中***的背景值,并且土壤中的***含量在离尾矿砂堆积处越近的地方富集效果越明显。
论文通过静态释放试验,研究了尾矿砂和土壤中 As 的释放特征以及影响 As 释放的主
要因素。结果表明样品的振荡处理、温度的升高以及土壤 pH 的增大都会提高 As 的释放量, 另外,***在酸性条件下的释放迁移能力小于碱性条件下的迁移释放能力,而且释放量会随 pH 的升高而逐渐增加,到 pH 为 10-11 时达到最大值。
不同形态的 As 对环境的危害大小不一,论文采用 Tessier 连续提取法对尾矿砂和土壤中的 As 进行提取与分析。结果表明:在尾矿砂中 As 主要以残渣态的形式存在,其比例占到了总***的 %;而在土壤中以铁锰氧化物结合态存在的 As 最多,其占总***的比例为
% ~ %。在 As 的五种形态当中,残渣态***的释放迁移能力最弱,在尾矿砂中释放能力最强的是可交换态和铁-锰氧化物结合态,释放量分别占到了各自形态***总含量的 78%和 %;而在土壤中,由于铁-锰氧化物结合态***的总含量大,释放量的平均百分比
达到了 %,因此在***的释放迁移过程中占主导地位。
关键词:尾矿砂;矿区土壤;***(As);释放迁移
I
Abstract
Gannan is the birthplace of Chinese tungsten industry, and is famous as “tungsten world ”.There are four tungsten ores after decades of exploitation, brings in the social economic development to our country, but at the same time, there are also impact on the local natural environment and human survival health. Arsenic is one of the major heavy metal elements caused by mine environment pollution, arsenic in the mine tailings can through the pore of infiltration and surface runoff into the soil, and these arsenic after a series of migration and transformation can be absorbed anisms, and eventually harm to human health.
The paper through analyze the arsenic from mine tailings produced by tungsten ore of Gannan and the surrounding soil to mining area in full amount by silver diethyl dithiocarbamate spectrophotometry method, to understand the basic physical and chemical properties of soil around mining area and enrichment characteristics of the of the research showed that the soil around mining area are skew acidic; In addition, the content of arsenic in tailings and surrounding soil are significantly higher than that