复配混凝剂强化处理生活污水试验研究

择优选取对TP及COD去除效果均较优的3种混凝剂AlCl_3、FeCl_3、Fe_2(SO_4)_3,以依次投加的方式进行复配,考察了复配混凝剂对生活污水中TP和COD的去除效果及影响因素。研究结果表明,当复配混凝剂按m(AlCl_3)∶m(FeCl_3)∶m〔Fe_2(SO_4)〕=5∶6∶7投加时,对污染物的去除效果最好;pH是影响污染物去除效果的关键因素;在最佳配比条件下,当复配混凝剂投加量为160 mg/L时,出水TP可达0.402 mg/L,达到《城镇污水处理厂污染物排放标准》(GB 18918—2002)的一级A标准,COD去除率比单一混凝剂高12.9%~20.1%。

Experimental study on the composite coagulant for the enhanced treatment of domestic sewage

Three kinds of coagulants,AlCl3,FeCl3,and Fe2(SO4)3 ,which are excellent in the removal of TP and COD have been preferentially selected,and combined by adding them in turn. The effect of the composite coagulant on the removal of TP and COD from domestic sewage,and the influential factors are investigated. The results show that when the composite coagulant dosage is at the ratio of m(AlCl3)∶m(FeCl3)∶m(Fe2(SO4)3)=5∶6∶7,the pollutant removing effect is perfect,and pH is the key factor affecting the pollutant removing effect. Under the optimum ratio condition,when the total dosage of the composite coagulant is 160 mg/L,the effluent TP concentration is 0.402 mg/L,achieving the First Level?A standard of the Pollutant Discharge Standard for Urban Sewage Treatment Plants(GB 18918—2002). Its COD removing rate is 12.9%-20.1% higher than that of single coagulant(AlCl3,FeCl3 or Fe2(SO4)3).