青藏高原典型金属矿山河流重金属污染对比

为研究青藏高原金属矿山勘探、开采、闭坑阶段不同开发阶段河流重金属污染的严重程度,通过野外调查,室内测试分析,对比5个金属矿山河流重金属元素含量、污染指数沿程变化,得出以下结果:(1)勘探阶段和闭坑后河流水质污染较小,开采阶段矿业活动对河水水质污染较大。(2)As、Pb、Cd、Cu和Zn五种元素是金属矿山的特征污染物。开采矿区中德尔尼铜矿区、下柳沟铅锌矿、甲玛矿区河流均有重金属元素污染,微碱性环境中德尔尼铜矿区,主要污染物为As,单项污染指数为0～10.6;下柳沟铅锌矿Pb、Cd、Cu和Zn元素单项污染指数分别为0.2～2.1、0～55、0.4～24、0.3～1550;偏酸性环境中甲玛矿区的特征污染物主要为Cu、Cd。其中Cu、Cd单项污染指数为0～4174、0～4;勘探矿区大场金矿、闭坑矿区罗布莎铬铁矿区河流未出现污染元素。(3)青藏高原5处典型的高海拔山地矿山河流由于稀释作用重金属流经2km后达到安全水平,研究结果可为青藏高原矿山开采中河流水环境保护提供参考依据。

A comparative study of the content of heavy metals in typical metallic mine rivers of the Tibetan Plateau

In order to study the severity of heavy metal pollution in the exploration, exploitation and closure of metal mines in the Tibetan Plateau, the authors made a comparative study of the heavy metal content and pollution index variation along the rivers in five metal mines. The results show that the water quality of the river is relatively insignificantly affected during the exploration stage and the closure of the pit, whereas the mining activities cause more pollution to the river water quality. (2)As, Pb, Cd, Cu and Zn are the characteristic pollutants of metal mines. Rivers in Deerni copper mine, Xialiugou lead-zinc mine and Jiama mine show heavy metals pollution; in the slightly alkaline environment of Deerni copper mining area, the main pollutant is As, with single pollution index being 0~10.6; the single pollution indexes of Pb, Cd, Cu and Zn elements of Xialiugou lead and zinc deposit are 0.2~2.1, 0~55, 0.4~24, and 0.3~1550 respectively. The characteristic pollutants of the Jiama mining area in an acidic environment are Cu and Cd. The single pollution indexes of Cu and Cd are 0~4174 and 0~4 respectively. There is no pollution element in the river of Rolosa chromium iron ore mining area. (3)The heavy metals of five typical high altitude mountain mine rivers in the Tibetan Plateau reach the safety level after the rivers flow a distance of 2km. The results obtained by the authors provide a reference basis for water environmental protection.