Prospective for remediation and purification of wastes from Xikuangshan mine by using Si-based substances

Heavy metal mining includes several procedures producing water and solid wastes. These wastes may have high content of heavy metals and other pollutants. Usually, traditional technologies for purification of solid and liquid wastes are expensive and require a lot of special constructions. Recent investigations have shown that some Si-rich substances enable to regulate the mobility of pollutants in soil and water and enhance the plant resistance to its toxicity. Based on these findings, new way for purification of waste-waters and detoxification of pollutants can be elaborated. Laboratory test was conducted with contaminated solid and liquid wastes from Xikuangshan mine. In column and incubation tests, the contents and mobility of the following pollutants were evaluated in Si-treated and untreated samples: As, Cd, Co, Cr, Cu, Hg, Pb, Ni and Zn. The investigations have shown that the Si-rich substances can be used for filtration of contaminated waste-water. The concentrations of soluble pollutants were reduced by 5-10 times and more. The incubation tests with solid wastes and Si-rich compounds have demonstrated that some Si-based substances reduced the contaminant mobility by 2-4 times. The efficiency of tested substances depended on their solubility on Si. The data has demonstrated that some types of local materials including industrial wastes can be used for purification of waste-waters and detoxification of solid wastes.