Microecology And Environmental Effect Of Coal Mine Sulfur-bearing Waste Dump

A large number of by-product in coal mining process is coal gangue, which generally contain sulfide minerals such as pyrite and marcasite, its oxidation would lead to the release of acid and heavy metals, then resulting in serious environmental pollution.In this study, through researching, sampling and testing the sulfur containing waste dump of the mining area in Tongling, Anhui Province and Sitai Shanxi Province, contrasted the content of the material and its environmental characteristics; studied the advantage microbial flora in the sulfur containing waste dump and its colony structure, optimum growth conditions, then isolated and determined 16S rDNA of the special microorganisms; studied the role of microorganisms and kinetic parameters in the weathering process of sulphide; studied the released of harmful elements under the role of microbial sulfide. Studies have shown that the pH values of leaching water in the yard of sulfur containing waste dump are around 2.5, the color of leaching filtrate are almost reddish-brown, with high concentration of harmful chemical pollutants such as Fe3+, Al3+, sulfate and heavy metals, it flowing into rivers and farmland, causing a certain degree damage of ecological; the 9 strains which isolated from the acid water are belonging to two species: Acidiphilium sp. and Acidithiobacillus ferrooxidans, they are the advantage microbial flora in this environment. Through simulated weathering experiments with the mining rocks in Xinqiao pyrite mine, the comparison of nonsterile and sterile system under different conditions,the leaching regularities of heavy metals, such as As, Cu, Zn, Ni, Pb, in were studied. The results showed that the initial pH of liquid phase, temperature, solid-liquid ratio and particle sizes of mining rocks would affect the behavior of microorganisms in the process of pyrite weathering. When microorganisms and culture medium were coexist, the pyrite oxidation rate reached0.71mmol.d-1.L-1, it was35.5times of the control group;the release regularities of As, Cu, Zn, Ni, Pb influenced obviously by microorganisms, pH, temperature, solid-liquid ratio, the release rate and quantity of As, Cu, Zn, Ni increased in the nonsterile system, but the release of Pb is unusual, the release rate and quantity were inhibitied in the nonsterile system.