常规混凝沉淀工艺对阴离子表面活性剂的去除研究

Experimental research on removal of anion-surfactants by conventional coagulation-settlement process

随着阴离子表面活性剂(LAS)在民用和工业上的广泛应用,由此带来的水污染问题也日益加剧,对供水安全造成了很大威胁。针对目前大部分水厂仍采用混凝沉淀常规水处理工艺,考察了常规混凝沉淀工艺对LAS的去除效果。以Al2(SO4)3,PAC,FeCl3,PFS为混凝剂,非离子PAM为助凝剂进行了试验,结果表明混凝沉淀对LAS有一定的去除效果,而且有机物和LAS的去除有一定相关关系。但浊度与LAS的去除相关性较差。试验条件下对于LAS去除最佳混凝方案是投加量为40 mg/L的FeCl3。相同水质条件下铁盐混凝剂在除浊、除有机物和除LAS方面优于铝盐混凝剂。pH和水温对LAS的去除有一定影响,较低的pH和较高的水温均有利于LAS的去除。

Along with the broad application of anion-surfactants (LAS) for domestic and industrial purposes, water pollution problem becomes serious increasingly. Both the groundwater and surface water bodies, some of them possibly could be used as drinking water sources are contaminated by LAS in certain levels, which has threaten the safety of water supply. Now coagulation-sedimentation process is still adopted by most waterworks and further research will be helpful. In the experiment, the coagulants Al2(SO4)3, PAC, FeCl3, PFS and coagulant aid non-ion PAM are examined and the results indicate that LAS could be removed partially from water in coagulation-sedimentation process. Also certain correlation between the LAS and organism removals is observed but no evidential between LAS and SS removals. In this experiment the best coagulant dosage for LAS removal is 40 mg/L of FeCl3. For the same raw water, iron coagulants are much better than aluminum coagulants in removing turbidity, organism and LAS. Water temperature and pH have much effluence on LAS removal. Lower pH and higher temperature might be favorable for LAS removal.