PAC、PFS混凝剂去除微污染水体中PCBs效果研究

Removal of PCBs in micro-polluted water by PAC and PFS coagulants

以聚合氯化铝(PAC)、聚合硫酸铁(PFS)为混凝剂,采用强化混凝的水处理方法,完成对低浊度微污染水体中多氯联苯(PCBs)的去除,考察了2种混凝剂的投加量、水样初始浊度、水样pH值以及水力条件等因素对PAC、 PFS混凝剂去除低浊度水体中PCBs的效果影响。研究得出,当PAC投加量为7 mL/L,水样初始浊度为62NTU,慢速搅拌时间为15 min, pH值为5.0时, PAC强化混凝效果最佳,其对水样中PCBs的去除率为68.42%～76.02%,剩余浊度为1.01 NTU;当PFS投加量为5.5 mL/L,水样初始浊度为62 NTU,慢速搅拌时间为15 min,p H值为6.5时, PFS强化混凝效果最佳,其对水样中PCBs的去除率为70.30%～77.52%,剩余浊度为4.14 NTU。研究得出, PAC、 PFS均能有效去除微污染水体中的PCBs,且与PAC相比, PFS的去除效果更佳。

Polychlorinated biphenyls(PCBs)in micro-polluted water was removed by enhanced coagulation process with poly aluminum chloride(PAC)and poly ferric sulfate(PFS)as coagulants,the influences of two kinds of coagulants dosage,initial turbidity and pH value of water samples,hydraulic condition and some other factors on PCBs removal from low-turbidity water were investigated.The results of the test showed that,the optimal enhanced coagulation performance of PAC which showed a PCBs removal rate of 68.42%-76.02%was obtained under the condition that the PAC dosage was 7 mg/L,the initial turbidity of water sample was 62 NTU,the low-speed stirring time was 15 min,and the pH value was 5.0.However,for PFS,the optimal enhanced coagulation condition was:the residual turbidity was 1.01 NTU,the PFS dosage was 5.5 mL/L,the initial turbidity of water sample was 62 NTU,the low-speed stirring time was 15 min,and the pH value was 6.5.Under the above condition,the removal rate of PCBs was 70.30%-77.52%,the residual turbidity was 4.14 NTU.It could draw a conclusion that,both PAC and PFS could remove PCBs from micro-polluted water effectively,and compared to PAC,PFS has a better removal effect.