宁东能源化工基地固体废物中汞含量分布及对环境影响

通过分析宁东能源化工基地各大燃煤电厂以及煤化工厂固体废物样品,研究了固体废物中的汞分布规律及环境影响。结果表明:汞易在脱硫石膏、粉煤灰和气化粗渣中富集,汞浓度分别为0.16、0.24、0.15 mg/kg,而炉渣和气化细渣中的汞含量则相对较低,分别为0.05、0.03 mg/kg。通过化学组成及汞含量数据分析发现,出现这种情况的原因与汞本身易挥发的性质和固体废物的物化性质有关。此外,通过固体废物浸出毒性实验发现,脱硫石膏、粉煤灰、气化粗渣的浸出汞浓度小于浓度限值(0.1 mg/L),而气化细渣因锅炉回用,不参与填埋,汞又不易在炉渣中富集,故总体上宁东能源化工基地的固体废物无汞环境污染倾向。

Distribution and Environmental Impacts of Mercury in Solid Wastes from Energy and Chemical Industry Base of Ningdong

Distribution and environmental impact of mercury in solid wastes were studied by analyzing samples of each big coal-fired power plants and coal chemical plants in energy and chemical industry base of Ningdong. The results showed that mercury was concentrated easily in the desulfurization gypsum, fly ash and gasification of coarse slag, concentrations of mercury were 0.16, 0.24, 0.15 mg/kg, respectively, and the mercury contents in the slag and gasification of fine slag were lower with 0.05, 0.03 mg/kg, respectively. The reason for this situation is the volatility of mercury and the physical and chemical properties of solid wastes by analyzing the chemical composition and mercury contents in solid wastes. In addition, through the test on leaching toxicity of solid wastes found that mercury contents in desulfurization gypsum, fly ash and gasification of coarse slag were lower than concentration limits of 0.1mg/L. Furthermore, gasification of fine slag can be recycled for boiler, was not dumped in landfill, and mercury was difficult to enrich in the slag. So overall, the mercury in solid wastes from energy and chemical industry base of Ningdong will not tend to pollute the environment.