麦草NH_4OH-KOH法蒸煮黑液的处理

Treatment of Black Liquid from NH 4OH-KOH Pulping of Wheat Straw

采用聚合氯化铝 聚丙烯酰胺在碱性 (pH值 9 2 5)条件下絮凝处理麦草NH4 OH KOH蒸煮黑液。适宜的絮凝条件为 :1 0 %聚合氯化铝用量 8mL/L ,0 1 %聚丙烯酰胺用量 1 2mL/L ,反应温度50℃ ,搅拌时间 1 0min ,澄清时间 45min。在此条件下 ,CODCr去除率为 66 % ,木素去除率为 91 %。分析表明 ,絮凝沉淀物中除含大量木素外 ,氮、钾等营养元素的含量分别为 2 2 1 1 %、 5 93 % ,为制备固体有机肥料创造了条件 ;上清液pH值 9 1 5、残碱 0 43mol/L、铵态氮 7 85g/L、木素 3 69g/L ,可部分作为工艺水循环使用。

The black liquor form NH 4OH-KOH pulping of wheat straw was treated with aluminium polyachlorid and polyacrylamide at pH 9.25.The suitable flocculating conditions were as follows:the dosage of aluminium polychlorid (10% concentration) 8mL/L and polyacrylamide(1% concentration) 12mL/L,reaction temperature 50℃,stirring time 10 min and clarification time 45 min.Removal of COD and delignification rate were 66% and 91% respectively on this conditions.It was found that 22.11%N,5.93% K and lots of lignin were contained in the flocculate mud which could be used as raw material to prepare organic solid fertilizer.Composition of the clarified black liquor was as follows:pH 9.15,residual alkali 0.43mol/L,NH 3-N 7.85g/L and lignin 3.69g/L,and it could be recycled as the process water.