【摘要】 讨论了2种氨羧类络合剂EDTA和DTPA对MSW(城市固体废物)焚烧炉飞灰中Zn,Pb,Cu 3种有害重金属的络合萃取过程,分析了影响络合萃取效率的主要因素——萃取反应时间、溶液pH和络合剂浓度。结果表明,在溶液pH 3~10范围内用浓度为1.5%的EDTA和DTPA处理飞灰20 h时,大约90%的Zn,80%的Pb和60%的Cu被萃取。络合萃取的飞灰残渣溶出试验表明,残渣中重金属含量远低于指导值。络合剂处理后的飞灰能满足填埋的要求,络合剂对MSW焚烧炉飞灰中重金属的去除是有效的。更多还原

【Abstract】 An extraction process has been studied for the pretreatment of municipal solid waste(MSW) incinerator fly ash to remove Cu,Pb and Zn by ethylenediaminetetraacetate(EDTA) or diethylene triaminepentacetate(DTPA).The main factors influencing complexing extraction efficiency,known as extraction time,solution pH and chelating agent concentration have been analyzed.The result showed that it is effective to remove three typs of heavy metals from incinerator for about 20 hours when the solution in the pH rang 3～10 and EDTA or DTPA concentration was 1.5%.By the treatment with 1.5% EDTA or DTPA,about 90% Zn,80% Pb and 60% Cu were extracted.The leaching text on the residues after the treatment with chelating agents showed that the heavy metals content of residues is far below the guideline for landfilling.The fly ashes after the treatment with chelating agents meet the requirement for landfilling.The chelating agents is effective to remove the heavy metals from MSW incinerator fly ashes.更多还原