化学混凝对两级曝气生物滤池出水的除磷效果研究

Study on Chemical Coagulation Process for Phosphorus Removal from Effluent of Two-stage Biological Aerated Filter

为解决两级曝气生物滤池处理城市污水时除磷效果欠佳的问题，采用化学混凝工艺对其出水进行处理，以聚合硫酸铁（PFS）为絮凝剂，通过烧杯试验考察了PFS投量及助凝剂聚丙烯酰胺（PAM）对除磷效果的影响，并通过中试考察了混凝、沉淀、过滤工艺的除磷效果。结果表明，PAM的助凝作用并不明显，单独投加130mg／L的PFS即可使出水TP〈1mg／L。在生物处理单元稳定运行的情况下，中试工艺的PFS投量在90-95mg／L时可使出水TP〈1mg／L，总铁〈0．5mg／L。

To solve low ting municipal wastewater, the phosphorus removal efficiency of two-stage biological aerated filter in treachemical coagulation process was used to treat its effluent. Polyferric sulfate （PFS） and polyacrylamide （PAM） were chosen as coagulant and coagulant aid respectively in jar tests, and the effects of dosages of PFS and PAM on chemical phosphorus removal were studied. The phosphorus removal efficiencies of coagulation, sedimentation and filtration processes were investigated through pilot-scale test. The results show that dosing PAM can not improve coagulation efficiency of PFS ; the effluent TP is less than 1 mg/L when using PFS of 130 mg/L alone in jar tests. Under the condition of stable operation of the biological treatment unit, the effluent TP and total iron are less than 1 mg/L and 0.5 mg/L respectively when the dosage of PFS is 90 mg/L in the pilot-scale test.