含重金属水处理污泥的固化和浸出毒性研究

工业危险固体废物在进行安全填埋前需要进行固化稳定处理。针对电镀厂和皮革厂含重金属的水处理污泥 ,用不同比例的水泥、粉煤灰进行固化稳定处理。考虑酸雨环境 ,浸出实验采用TCLP标准。电镀厂污泥单独固化时 ,其浸出液中铜离子浓度由 78 0mg/L下降到 1 5mg/L ;镍离子浓度由 2 2 4 5mg/L下降到 2 2 2mg/L ,高于危险废物允许进入填埋区 15mg/L的控制限值。电镀厂污泥与皮革厂污泥混合后固化 ,浸出液毒性明显降低。铜离子的浸出浓度降低到1 98mg/L ,镍离子降低到 4 10mg/L ,总铬降低到 0 4 0mg/L ,各项指标均低于国家危险废物允许进入填埋区的控制限值 ,可安全填埋。

Experimental study on solidification and soaking test of sewage sludge containing heavy metal ion

Industrial hazardous solid wastes should be stabilized/solidified before landfilling to minimize toxicity. Solidification and leaching tests of sewage sludge containing heavy metal ion from wastewater treatment process of electroplating factory and leather works were conducted. The cement and fly ash were used as stabilizing agents. To simulate acid raining environment, TCLP method was used in soaking test. When sludge of electroplating factory was solidated alone, concentration of copper ion in leaching solution reduced from 78.0 mg/L to 1.5 mg/L, concentration of nickle ion reduced from 224.5 mg/L to 22.2 mg/L, which was still higher than the permitted superior limit of landfill, 15 mg/L. When sludge of electroplating factory was solidated together with sludge of leather works, concentration of copper ion in leaching solution decreased to 1.98 mg/L, nickle ion decreased to 4.10 mg/L, and total chromium to 0.40 mg/L. All of hazardous components' concentrations were much lower than the permitted superior limit of landfill.