无机混凝剂影响因素及其混凝效果对比研究

以生活污水为研究对象,考察了3类无机混凝剂(铁盐、铝盐、钙盐)的影响因素,同时考察了投加量对出水pH值的影响,并进一步比较了在相同投加量及最佳pH值下,各混凝剂的混凝效果。结果表明:TP和CODCr的去除率随着混凝剂投加量的增加先快速升高而后趋于稳定;FeCl_3、Fe_2(SO_4)_3、FeSO_4、PFS以及AlCl_3、Al_2(SO_4)_3、PAC和CaO的最佳pH值分别为5、6、8、6、7、6、7、10;出水pH值随着混凝剂投加量的增加而降低,其中AlCl_3、CaO对pH值影响最为显著;在相同投加量及最佳pH值下,FeCl_3、PAC对TP和CODCr的去除效果最好,综合考虑2个指标,AlCl_3的去除效果最佳。

Coagulation efficiency of inorganic coagulants and influencing factors thereof

Take domestic sewage as the research object, the influencing factors of its treatment by 3 kinds of inorganic coagulants: ferric salt, aluminium salt and calcium salt, were investigated, meanwhile, the effect of coagulants dosage on pH value of the effluent water was also studied. The coagulation efficiency of the above three kinds of coagulants with the same dosage at the optimal pH condition were compared. The results showed that, with the coagulants dosage increasing, the removal rates of TP and CODCr increased rapidly at first and then tend to be stable, the optimal pH value for FeCl3, Fe2(SO4)3, FeSO4, PFS, AlCl3, Al2(SO4)3, PAC and CaO were 5, 6, 8, 6, 7, 6, 7 and 10 respectively. The pH value of the effluent water decreased with the increasing of the coag-ulants dosage. It could be seen that, AlCl3 and CaO had the most significant effect on pH value of the effluent water; with the same dosage at the optimal pH condition, the removal effect of TP and CODCr by FeCl3 was the best, therefore, based on the overall consideration, AlCl3 was the optimal choice.