通过试验,研究了地下水除铁除锰水厂反冲洗废水混凝处理的效果、影响因素以及混凝机理。结果表明,CPF和PAM的混凝效果最好,氯化铁次之,PAC较差,硫酸铝最差;含铁量为100mg/L左右的冲洗废水自然沉淀效果较差,而投加少量混凝剂后,这种冲洗废水可在较短的时间内获得很好的沉淀效果;在混凝后的最初的10￣30min内,废水上清液的含铁量急剧下降,此后随着沉淀时间的增加,上清液含铁量缓慢降低;当pH值为7.5左右时,硫酸铝、氯化铁和PAC的混凝机理可能以电性中和作用与吸附架桥作用为主,PAM可能主要是吸附架桥作用,而CPF的混凝机理除了吸附架桥作用以外,还可能存在一定的电性中和作用。

By experiment, the coagulation effect, influence factors of the backwashing wastewater in the groundwater works for iron and manganese removal have been investigated, and its coagulation mechanism has been discussed. The results show that the CPF and PAM coagulation effect is the best, the ferric chloride is the second best, the PAC is worse, and the aluminum sulfate is the worst. When the iron content of the backwashing wastewater is about 100 mg/L, the natural settling effect is not good, but if some coagulant is added to the backwashing wastewater, the backwashing wastewater has good sedimentation effect in a short time. In the initial 10 - 30 min after the coagulation, the iron content of the clear supernatant is lowered quickly, and with the increase of the sedimentation time, its iron content decreases slowly. When pH value is about 7.5, the coagulation mechanism of the aluminum sulfate, polychlorinated aluminum and ferric chloride may mainly have electrical neutralization and adsorption bridging action, and the PAM coagulation mechanism may be mainly adsorption bridging action, and the CPF may have some electrical neutralization besides adsorption bridging action.