TCLP法评价贵州六枝某矿区煤矸石山周围土壤重金属的生态环境风险

Ecological Risks of Heavy Metal Contamination in Soils Around the Coal Gangue Dump in the Coal Mining Area by Toxicity Characteristic Leaching Procedure

为了解六枝某矿区煤矸石山周围土壤重金属的污染现状,采用生态环境风险评价(TCLP)法提取重金属和内梅罗综合污染指数对六枝某矿区煤矸石山周围土壤重金属生态环境风险进行评价。结果表明:煤矸石山周围土壤Cd、Cu、Zn和Pb的总含量分别在2.85～10.01mg/kg、28.6～97.2mg/kg、248.3～1 476.9mg/kg和91.2～189.4mg/kg,有效态含量分别在0.1～3.2mg/kg、1.7～17.4mg/kg、20.3～150.7mg/kg和4.8～15.4mg/kg,重金属有效态含量分别与其全量之间存在显著的相关关系。18个土壤样品中达警戒水平、轻污染水平、中污染水平和重污染水平的所占比重分别为5.56%、22.22%、16.67%和55.56%。结论:该煤矿煤矸石山周围土壤重金属污染存在着较为严重的生态环境风险。

The contents of heavy metals （Cd, Cu, Zn and Pb） in soils around the coal gangue dump from the coal mining area, Guizou Province, China, were analyzed by toxicity characteristic leaching procedure （TCLP）. The results showed that the total content of As,Cd, Cu, Zn and Pb was 2.85-10.01 mg/kg, 28.6-97.2 mg/kg, 248.3-1476.9 mg/kg and 91.2-189.4 mg/kg and the level of available Cd, Cu, ZnandPb extracted by TCLP was 0. 1-3.2 mg/kg, 1.7-17.4 mg/kg, 20.3-150. 7 mg/kg and 4.8-15.4 mg/kg respectively. The contents of available heavy metals extracted by TCLP were correlated with total contents of heavy metals. The ratio at alert level, light pollution level, medium pollution level and heavy pollution level in 18 soil samples was 5.56%, 22.22%, 16. 67% and 55. 56% separately. In conclusion, pollution of heavy metals in soil samples around the coal gangue dump of the coal miming area is serious.