混凝气浮法处理造纸废水

Treatment of Papermaking Wastewater by Mixed flocclating and Air Floating Method

本文采用硫酸铝和聚丙烯酰胺(PAM)作为混凝剂的混凝气浮法处理造纸废水,探讨了混凝刺用量、气浮压力、体系的pH值、助留剂等对造纸废水处理的影响。结果表明,硫酸铝的最佳用量为80 mg·L-1,PAM的最佳用量为2．4 mg·L-1; 气浮压力控制在1．2MPa时对造纸废水的处理效果最好。实验得到当废水的pH为5-7时处理效果较好。助留剂RM-31 可以降低废水的纤维含量,结合考虑经济因素,确定了助留剂的最佳用量为3kg·t-1(对绝干浆)。应用本工艺得到的最佳条件处理造纸废水,废水的浊度去除率可达97％以上,COD去除率可达80％以上。

The paper aims to study on mixed flocclating and air floating process for treatment of papermaking wastewater. Some factors affecting treatment had been incorporated into the operation, inclusive of dosage of coagulant, the pressure of flotation, pH in system, retainer and etc. It has been indicated by the test that the aluminum sulfate, combining with polyacrylamide（PAM ）, can be used as coagulant. The optimal dosage of aluminum sulfate is 80 mg per liter, and PAM of 94 mg per liter. Under the conditions of the pressure of flotation of 1.2MPa and pH 5-7, the removal ratio of turbidity of 97% and COD of 80% are obtained, respectively. Retainer, RM-31, can reduce the content of fibre of wastewater. In general, the retainer dosage of 3kg per ton dry pulp should be used in the mixed flocclating and air floating process.