混凝-絮凝工艺处理水性油墨废水

Treatment of Water-based Ink Wastewater by Coagulation-flocculation Process

关键词:  混凝  PAC  CPAM  pH值  水性油墨废水  絮凝

Key Words:PAC  CPAM  pH value  water-based ink wastewater  flocculation

摘要:采用混凝-絮凝工艺处理水性油墨废水,探讨了油墨废水初始pH值、PAC用量和CPAM用量对COD^Cr去除率、色度去除率和浊度去除率的影响。采用中心组合设计(CCD)和响应曲面法(RSM)设计多因素实验并优化混凝-絮凝过程中的3个影响因素。单因素实验结果表明,混凝-絮凝工艺处理废水主要是通过电荷中和以及架桥作用完成的,降低废水初始pH值可以提高去除率。多因素实验结果表明,废水初始pH值为6.56,PAC最佳用量为126.5 mg/L,CPAM最佳用量为4.6 mg/L,COD^Cr去除率达到96.5%；废水初始pH值为6.78,PAC最佳用量为107.7 mg/L,CPAM最佳用量为3.0 mg/L,色度去除率接近100%；废水初始pH值为6.5,PAC最佳用量为107.8 mg/L,CPAM最佳用量为5.8 mg/L,浊度去除率达到99.97%。整合以上3个响应面的最佳条件,油墨废水的初始pH值为6.51,PAC最佳用量为128.7 mg/L,CPAM最佳用量为4.9 mg/L,处理效果最好。

Abstract:Treatment of water-based ink wastewater by coagulation-flocculation process with PAC as coagulant and CPAM as flocculant was studied. Single-factor experiment and multi-factor experiment were applied to study the effect of pH, PAC dosage and CPAM dosage on removal efficiency of COD^Cr, color and turbidity. A 23 full central composite design (CCD) and response surface methodology (RSM) were employed to design the multi-factor experiment and optimize the three factors for the coagulation-flocculation process. Single factor experiment result showed that the decrease of pH could improve the removal efficiency as the function of coagulation-flocculation process was mainly based on charge neutralization and bridging. Multi-factor experiment result showed that the RSM approach was appropriate to optimiz the coagulation-flocculation process and the optimal conditions for the best treatment result of water-based ink were as the follows: PAC dosage 128.7 mg/L, CPAM dosage 4.9 mg/L, and initial pH value 6.51.