酸析法和碱析法处理草浆造纸黑液的效果对比  

Comparative Study on the Treatment of Straw Pulping Black Liquid by Acid-Precipitation and Alkali-Precipitation

作　　者：荣少鹏[1] 孙亚兵[1] 赵泽华[1] 

机构地区：[1]南京大学环境学院污染控制与资源化国家重点实验室,江苏南京210046

出　　处：《化工环保》2013年第3期221-225,共5页Environmental Protection of Chemical Industry

基　　金：污染控制与资源化研究国家重点实验室开放课题(PCRRF10016)

摘　　要：对比了酸析法和碱析法对碱法草浆造纸黑液中木质素的去除效果,并分析了聚合氯化铝(PAC)絮凝剂对酸析和碱析后木质素的絮凝效果。实验结果表明:酸析法和碱析法都能有效析出造纸黑液中的木质素,酸析法对色度的去除效果要优于碱析法;当造纸黑液pH为3时,COD去除率达到72.0%,色度去除率为97.7%;当造纸黑液pH为13时,COD去除率达到55.0%,色度去除率为22.3%;PAC对于酸析后木质素有较好的絮凝效果,当废水温度为55℃、PAC加入量为45 mL/L时,COD去除率可以达到79.5%,色度去除率为98.5%;PAC絮凝剂对于碱析后的造纸黑液色度的去除效果较差。The effects of acid-precipitation and alkali-precipitation on the removal of lignin from straw alkaline pulping black liquor were compared.The flocculating effects of poly aluminium chloride（PAC） on lignin after acid-precipitation and alkali-precipitation were analyzed.The experimental results show that： Both acid-precipitation and alkali-precipitation can effectively separate lignin from the black liquor,but the removal of chroma by acid-precipitation is better than that by alkali-precipitation;When the black liquor pH is 3,the removal rates of COD and chroma are 72.0% and 97.7% respectively;When the black liquor pH is 13,the removal rates of COD and chroma are 55.0% and 22.3% respectively;The PAC has a better effect on the flocculation of lignin after acid-precipitation,and when the wastewater temperature is 55 ℃ and the PAC dosage is 45 mL/L,the removal rates of COD and chroma are 79.5% and 98.5% respectively;The effect of PAC on the removal of lignin after alkali-precipitation is bad.

关 键 词：造纸黑液 木质素 酸析 碱析 絮凝 

分 类 号：X793[环境科学与工程—环境工程]