混凝深度处理造纸废水的试验研究

Experimental study on advanced treatment of paper-making wastewater by coagulation

为了提高造纸废水二级生化处理后出水的水质,采用混凝技术对该废水进行深度处理,考察pH值、混凝剂和絮凝剂种类及投加量等对处理性能的影响。结果表明,最佳运行参数:聚合氯化铝(PAC)投加量为140mg/L,pH值为8,COD去除率和脱色率分别为29.1%和60%;复合絮凝剂阳离子聚丙烯酰胺(CPAM)最优投加量为2mg/L,COD去除率和脱色率分别为35.7%和67.1%;复合脱色剂最优投加量为4mg/L,COD去除率和脱色率分别为44.1%和77.2%。最终出水COD和色度达到了造纸行业水污染物排放标准,为混凝深度处理造纸废水的工艺优化提供了理论依据,有利于该技术的推广应用。

An advanced treatment of paper-making wastewater using PAC as coagulation CPAM and decoloration reagent as flocculation reagent respective was employed, and the effects of pH, kinds and dosage of chemicals on the treated effluent quality and the advanced treatment efficiency were discussed. The results indicated that the COD removal and decoloration rate are 29.1% and 60% while the optimial dosage of PAC is 140 mg/L with the optimal pH of 8. Meanwhile, the optimal dosage of CPAM is 2 mg/L, which improves COD removal and the decoloration rate to 35.7% and 67.1%, respectively. Furthermore, the optimal dosage of decoloration reagent is 4 mg/L, which further increases COD removal and decoloration rate to 44. 1% and 77. 2%, and the corresponding effluent concentrations meets discharge standard of water pollutants for pulp and paper industry. The optimal control strategy for the advanced treatment of paper-making wastewater by coagulation process proposed will be beneficial to engineering application.