碱法草浆中段水絮凝脱色

Decolorization of Intermediate Wastewater from Alkali Straw Pulping with Flocculants

研究絮凝剂的搭配使用对碱法草浆中段废水进行脱色,并确定絮凝剂的投放量。实验结果表明:(1)Ca(OH)2和Al2(SO4)3混合处理废水,当Al2(SO4)3用量为200mg·L-1,Ca(OH)2用量为90mg·L-1时,废水的CODCr去除率达59.0%,脱色率达81.49%,pH为8.29。(2)Al2(SO4)3和PAM混合处理废水,当Al2(SO4)3用量为300mg·L-1,PAM用量为3mg·L-1时,CODCr去除率达90.5%,脱色率达94.47%,pH为7.51。(3)PAC和PAM混合处理废水,当PAC用量为25mg·L-1,PAM用量为4mg·L-1时,CODCr去除率达88.5%,脱色率达92.94%,pH为8.11。处理后废水的各项指标均达到国家一级排放标准。

This paper studied decolorization for intermediate wastewater of alkali straw pulp with mixed flocculants, and fixed the dosage of used flocculants.The results of this experiment was： 1） Al2（SO4）3 and Ca（OH）2 were mixed to treat wastewater. The optimum process condition was that Al2（SO4）3 added was 200mg·L^-1 and Ca（OH）2 added was 90mg·L^-1. Under this condition, the removal rate of CODer reached 59.0%, the decolorization rate was 81.49% and pH value was 8.29. 2） Al2（SO4）3 and PAM were mixed to treat wastewater. The optimum process condition was that Al2（SO4）3 added was 300mg·L^-1 and PAM added was 3mg·L^-1. Under this condition, the removal rate of CODer reached 90.5%, the decolorization rate was 94.47% and pH value was 7.51. 3） PAC and PAM were mixed to treat wastewater. The optimum process condition was that PAC added was 25mg·L^-1 and PAM added was 4mg·L^-1. Under this condition, the removal rate of CODCr reached 88.5%, the decolorization rate was 92.94% and pH value was 8.11. The treated wastewater could meet the First Grade Discharge Standard.