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.