酸溶粉煤灰制备混凝剂及其处理污水效果  

Production of fly ash-based coagulant and its application in sewage treatment

作　　者：李亚强[1] 汤凤[1] 胡凯[1] 赵庆良[1] 崔福义[1] 刘志刚[1] 

机构地区：[1]哈尔滨工业大学市政环境工程学院,哈尔滨150090

出　　处：《哈尔滨工业大学学报》2008年第8期1238-1241,共4页Journal of Harbin Institute of Technology

基　　金：教育部“长江学者与创新团队发展计划”资助项目;哈尔滨市环境保护局科技攻关资助项目(2006)

摘　　要：为了提高粉煤灰的利用价值,采用酸溶法提取其中的铝、铁元素,制备粉煤灰基混凝剂.以硫酸为酸浸液,固定酸灰比为3:1,考查不同酸溶方式的溶出效果,并利用制得的混凝剂处理生活污水.实验结果表明:硫酸浓度或反应温度的提高有助于粉煤灰中铝、铁的溶出.添加NH4F为助溶剂,铝、铁的总溶出率可达63.42%,但存在F-的二次污染.经过高温焙烧后粉煤灰中铝、铁酸溶性降低,但添加碳酸钠且配比达到0.06以上时,熟料中铝酸溶性提高;由此制得的混凝剂处理污水时,适宜投量为1.2 mL/L,效果优于市售混凝剂,COD、TP的去除率分别为69%、95%,剩余SS低于20 mg/L.Fly ash （FA） was utilized as a raw material in producing an FA-based coagulant, which was a high value-added product, by acid leaching. The sulfuric acid was adopted as the leaching solution with a ratio of 3 ： 1 to FA, and different acid-leaching treatments on the extracting efficiencies of aluminum and ferrum were compared. The prepared coagulant was used to treat the domestic sewage. Results showed that the concentrations of aluminum and ferrum in the prepared coagulant increased with the increase of either sulfuric acid concentration or reaction temperature. The addition of NH4F improved the leaching efficiency to a value of 63.42% with the disadvantage of potential secondary F- pollution. Roasting FA under 850 ℃ would decrease the leaching efficiencies of aluminum and ferrum, but roasting FA by the addition of Na2CO3 with the mass ratio of 0. 06 of Na2CO3 to FA would increase the leaching efficiency of aluminum. The prepared FA-based coagulant was proved to be an effective agent for reducing COD, SS and TP from the domestic sewage compared with the commercial coagulants. When the dosage was applied at 1.2 mL/L, the residual SS was less than 20 mg/L and the removal efficiencies for COD and TP were 69% and 95%, respectively.

关 键 词：粉煤灰 酸溶 混凝剂 溶出率 污水处理 

分 类 号：X703[环境科学与工程—环境工程]