污水处理厂出水的聚硅硫酸铝铁混凝除磷研究

STUDY ON PHOSPHORUS REMOVAL OF EFFLUENT FROM MUNICIPAL WASTEWATER TREATMENT PLANT BY POLYALUMINUM FERRIC SULFATE SILICATE

研究新型混凝剂聚硅硫酸铝铁(PSFA)对城市污水处理厂出水中磷的混凝去除效果,考察了混凝剂投加量、原水pH、与聚丙烯酰胺(PAM)复配等因素对混凝除磷效果的影响,同时进行了聚合氯化铝(PAC)、聚合硫酸铁(PFS)和Al2(SO4)3混凝除磷效果的比较试验。结果表明,PSFA可有效降低城市污水处理厂出水TP含量,当投加量为36mg·L-1时,可以使出水TP的质量浓度从1.51mg·L-1下降到0.32mg·L-1,出水达到上海市地方标准DB31/199-2009规定的TP排放一级标准;PSFA混凝除磷适宜pH为6～10;PAM可以有效提高PSFA混凝除浊和除磷效果,减少混凝剂投加量;PSFA比PAC、PFS、Al2(SO4)3具有更好的混凝除磷效果,具有很好的应用前景。

The phosphorus of effluent from municipal wastewater treatment plant coagulation removal efficiency, which was treated by a novel coagulant polyaluminum ferric sulfate silicate and the variation of it with the change of dosage, pH of raw water was investigated. The effects of polyacrylamide （PAM） in improving phosphorus removal was also studied. In addition, the phosphorus removal efficiency of four coagulant such as polyaluminum ferric sulfate silicate, polyaluminum chloride （PAC）, poly ferric sulfate （PFS） and aluminum sulfate （Al2（SO4）3） had been compared. The results showed that the total phosphorus concentration of effluent from municipal wastewater treatment plant could be reduced effectively, when the dosage was 36 rag-L^-1, the total phosphorus concentration of effluent decreased from 1.51 mg.L^-1 to 0.32 mg·L^-1, which could meet the class one discharge standard of total phosphorus in Shanghai City; the optimum pH range for polyaluminum ferric sulfate silicate to remove phosphosphorus were 6-10; PAM had good perforrnance in improving turbidity and phosphorus removal efficiency and reduced coagulant dosage; the total phosphorus removal efficiency by polyaluminum ferric sulfate silicate was evidently higher than those by PAC, PFS, Al2（SO4）3. Polyaluminum ferric sulfate silicate has very good application prospect.