Evaluation of heavy metal and cyanide pollution of the shallow groundwater in a gold mining area

The shallow groundwater in a gold mining area was taken as the research object and elements in 112 water samples were collected and analyzed, including Hg, Pb, Cd, Cr6+, As, Cu, Zn and CN-. The characteristics of heavy metal and cyanide element concentrations in the shallow groundwater were analyzed, and the storage law of heavy metal and cyanide element concentrations in shallow groundwater were preliminarily ascertained. On such a basis, the environmental quality related to heavy metal and cyanide pollution in the shallow groundwater was assessed by using the method of monomial and composite pollution index. The results indicated that the heavy metal and cyanide pollution of the shallow groundwater in a gold mining area was on the whole within the standard except for the elements Cr6+ and Hg, Pb, CN- in the local area. The element Cr6+ was inherent and the elements Hg, Pb, CN- in the shallow groundwater were influenced by the mining activities of industries in the lower reaches of the Shuangqiao River valley. The results obtained by the authors are important for the prevention and treatment of the shallow groundwater resources.