Removal and recycle of heavy metals in sludge
- 化学化工－已发表论文 
［中文文摘］论述了利用离子交换技术循环使用柠檬酸去除污泥中重金属,并置换回收重金属的适宜工艺条件。经柠檬酸处理后,污泥中90%以上的重金属被去除;柠檬酸处理液中的重金属用离子交换法回收,考察了树脂种类、流速、操作方式等因素对离子交换、再生效果的影响;在适宜工艺条件下,重金属的交换率均为100%,而洗脱率均接近90%;柠檬酸及离子交换树脂循环使用,重金属也得到回收,降低了处理成本。［英文文摘］ Heavy metals in wastewater t reatment sludge were first ext racted by cit ric acid and subsequently re2 moved f rom the cit ric acid byion exchange. They were recovered f rom the ion exchange bed by dilute HCl and , final2 ly , were replaced in the spent HCl by Al to form valuable water t reatment coagulant and recycleable metals. The effects of resin types , flow rate and flow pattern on the IX t reatment and regeneration were determined. Using 0. 2 M citric acid at p H of 3. 0 , more than 90 % of the heavy metal content was ext racted in 24 hours ; the metal removed sludge could be used as a natural fertilizer. The least costly 732 cationic resin performed the best among the four cat2 ionic IX resins studied ; nearly 100 % of heavy metals in the cit ric acid feed were removed and that regeneration recov2 ered more than 90 % of those removed. The process employing cit ric acid for sludge ext raction , 732 cationic resin for removing the metal in the cit ric acid , 3 bed volumes of 5 % HCl for resin regeneration , and Al slices for replacing the recovered heavy metals in the spent HCl is a low cost method ( YMB ＄35/ ton dry sludge) for removal and recycle of heavy metals in the sludge.