一种修复Pb-Cd污染污泥的复合淋洗剂的研究

以某自来水厂污泥为背景泥样,人工添加重金属后泥样为研究对象,考察了葡萄糖酸、氯化钠、六偏磷酸钠复配溶液对污泥中重金属的洗脱效果.研究发现,复配淋洗剂对污泥中Pb和Cd有较好的萃取效果.形态分析表明,葡萄糖酸对污泥中的水溶态、离子交换态、碳酸盐结合态及部分弱有机结合态形式的重金属Pb、Cd有较好的萃取效果；六偏磷酸钠主要...

Treating Pb-Cd Polluted Sludge Using a Kind of Complex Leaching Agent

A kind of complex agent constituted by gluconic acid,sodium chloride and sodium hexametaphosphate was used to remove lead and cadmium from sludge.Influence including pH value and concentration of leaching agent on the extraction efficiency was investigated.It was found that the complex leaching agent had high removal efficiency for Pb and Cd from sludge.Analysis of species distribution showed that gluconic acid had good extraction effect on the heavy metals with water soluble,ion exchange,carbonated and part of weak organic,while sodium hexametaphosphate had complex effect on the heavy metals with water soluble,ion exchange,weak organic and part of strong organic.In the condition of 0.1 mol/L gluconic acid,0.2 mol/L sodium chloride,0.01 mol/L sodium hexametaphosphate and pH 5,the extraction efficiency of Pb and Cd are 65% and 70% respectively,which is the optimal choice.During the process,the extraction efficiency increased gradually with increasing of concentration and decreasing of pH value.