Abstract:

Aiming at the effluent of secondary bio-treatment domestic sewage, the removal efficient and factors affected by the poly-ferric sulfate (PFS) and poly-aluminum chloride (PAC) coagulation for the range of original total phosphorus (TP) of 1 mg/L to 6.5 mg/L have been studied. The pilot scale experiments results showthat the optimum pH of TP removal by PFS and PAC is 7.5～8 and 8～9 respectively. Ferric salt should be chosen when the original TP concentration is lower. The pH has more effect on the TP removal by PAC coagulation. At the basic conditions, it is feasible to choose PAC to deal with higher original TP influent. Results of full-scale demonstration project show that the PFS is a kind of effective and economic coagulant for phosphorus removal. As the TP concentration is in the range of 1.09～2.4 mg/Lafter bio-treatment, and the addition of PFS is 10 mg/L, the average removal efficiency of TP is about 75%, while the removal efficiency of dissolved orthophosphate is over 98%.

Key words: phosphorus removal, coagulation, domestic sewage

摘要：

以生活污水二级生物处理后的出水为研究对象，考察了聚合硫酸铁(PFS)及聚合氯化铝(PAC)对初始质量浓度在1～6.5mg/L范围内的总磷的混凝去除效果及影响因素。小试结果表明，PFS与PAC除磷的最佳pH范围分别为7.5～8和8～9；当总磷初始质量浓度较低时，宜采用铁盐除磷。PAC除磷效果受pH影响较大，对初始质量浓度较高的总磷，在碱性条件下宜采用PAC混凝除磷。示范工程应用结果表明，当生物处理后出水总磷质量浓度在1.09～2.4mg/L范围内时，投加聚合硫酸铁质量浓度为10mg/L，总磷平均去除率为75%，溶解性正磷酸盐的去除率可达98%以上，是较为经济有效的除磷混凝剂。

关键词: 除磷, 混凝, 生活污水

CLC Number: 

• X703.1