基于煤矸石制备的聚合氯化铝铁钛及其在二沉池出水处理中的应用  

Preparation of polyaluminum iron titanium chloride from coal gangue and its application in the treatment of effluent from secondary sedimentation tank

作　　者：丁舒航 周建民 张梦瑶 刘义青 付永胜 DING Shuhang;ZHOU Jianmin;ZHANG Mengyao;LIU Yiqing;FU Yongsheng(Faculty of Geosciences&Environmental Engineering,Southwest Jiaotong University,Chengdu 611756,China)

机构地区：[1]西南交通大学地球科学与环境工程学院,成都611756

出　　处：《环境工程学报》2021年第1期43-56,共14页Chinese Journal of Environmental Engineering

基　　金：四川省科技厅重点研发项目(2017SZ0175);国家重大科技专项(2018SZDZX0026);中央高校基本科研业务费科技创新项目(2682018CX32)。

摘　　要：以煤矸石酸浸液为原料,经过钛掺杂、聚合、熟化和浓缩干燥等过程,制备了高效无机高分子混凝剂聚合氯化铝铁钛(PTAFC)。分别考察了钛投加量、pH、聚合温度、聚合时间对PTAFC混凝性能的影响,同时研究了PTAFC对城镇污水处理厂二沉池出水浊度、COD、总磷和氨氮的去除效果,并与聚合氯化铝铁(PAFC)进行了对比。结果表明:在钛铁摩尔比0.3、pH=1.5、聚合温度60℃、聚合时间3 h、常温熟化24 h时,所制得的PTAFC性能最佳;在投加量70 mg·L^(-1)、pH=7、反应温度20℃、慢速搅拌速度40 r·min-1的混凝条件下,对自配水的浊度、COD和UV254的去除效果最好,去除率分别为99.13%、37.25%和39.9%。PTAFC对城镇污水处理厂二沉池出水的浊度和总磷有极好的去除效果,同时对COD和氨氮有一定去除能力,污染物去除能力明显优于PAFC。上述研究成果对有效减少煤矸石的堆存量、拓宽煤矸石利用渠道,实现混凝剂的低成本、高效率工业化生产和应用具有重要的意义。In this study,acid leaching solution of coal gangue was taken as a raw material to prepare polyaluminum iron titanium chloride(PTAFC),a highly efficient coagulant,through titanium doping,polymerization,curing,concentration and drying process.The effects of preparation conditions of PTAFC(titanium dosage,pH,polymerization temperature,and polymerization time)on turbidity removal were investigated.Besides,the turbidity,COD,TP and NH3-N removal effects from the effluent of secondary sedimentation tank of urban wastewater treatment plant by PTAFC were studied and compared with those by traditional polyaluminum iron chloride(PAFC).The results showed that the prepared PTAFC possessed the best performance under the preparation conditions of Ti-Fe molar ratio of 0.3,pH 1.5,polymerization temperature of 60℃,3 h polymerization and 24 h curing at room temperature.When the coagulation conditions were set as follows:PTAFC dosage of 70 mg·L^(-1),pH 7,reaction temperature of 20℃and slow stirring speed of 40 r·min-1,the best removal effects of turbidity,COD and UV254 of laboratory-made wastewater occurred with the removal rates of 99.13%,37.25%and 39.9%,respectively.For the effluent of secondary sedimentation tank of urban wastewater treatment plant,PTAFC had an excellent removal effect on turbidity and total phosphorus,while a certain removal effect on COD and NH3-N,which were significantly better than PAFC.This study is of great significance for effectively reducing the stockpiling of coal gangue and expanding its utilization channel,as well as realizing the low-cost and high-efficiency industrial production and application of coagulant.

关 键 词：煤矸石 酸浸 聚合氯化铝铁钛 浊度去除率 

分 类 号：X703[环境科学与工程—环境工程]