四种混凝剂复配处理造纸黑液的实验研究

通过单一混凝剂的最佳pH和最佳用量的混凝实验,对四种混凝剂逐级进行复配,并研究了在优选pH和pH不变两种情况下,复配混凝剂对造纸黑液的处理效果.实验表明:四种混凝剂的最佳复配比例为:硫酸铁∶硫酸铝∶聚氯化铝铁∶硫酸铝钾=1∶0.4∶1.4∶1.4(体积比),且优选pH为6.pH=6时,投加用量分别为硫酸铁、硫酸铝、聚氯化铝铁、硫酸铝钾=0.95 g/L、0.4 g/L、1.35 g/L、0.65 g/L的复配混凝剂溶液,CODcr和色度去除率分别为97.78%和97.74%.当黑液pH不变(即pH=7.8)时,CODcr和色度去除率均不大,说明pH对复配混凝剂的处理效果有较大的影响.

Experimental Study on the Treatment of Papermaking Black Liquor by the Complicating of Four Coagulants

In the experiment of flocculation-sedimentation,four kinds of coagulant were mixed gradually after optimization of pH and dosage flocculation experiments of a single coagulant.Besides,the effect of complex coagulant on the treatment of black liquor was studied under the premise of optimum pH and original pH.The results showed that the optimum mixture ratio of coagulants was 1(Fe(2SO4)3)∶0.4(Al(2SO4)3)∶1.4(PAFC)∶1.4(KA(l SO4)2),and the preferred pH was 6.The CODcr and Chroma removal rates were 97.78% and 97.74% respectively when pH value was 6 and dosage were Fe(2SO4)3=0.95 g/L,Al(2SO4)3=0.4 g/L,PAFC=1.35 g/L,KA(l SO4)2=0.65 g/L.Under the premise of original pH,black liquor CODcr and chroma didn’t change significantly.This showed that pH had a greater impact on the treatment effect of complex coagulant.