响应面法优化混凝处理造纸法再造烟叶生产废水

Optimization of Coagulation-flocculation Process Using Response Surface Methodology to Treat Effluent from Papermaking Reconstituted Tobacco Production

关键词:  造纸法再造烟叶  响应面法  废水  混凝

Key Words:papermaking reconstituted tobacco  response surface methodology  effluent  coagulation-flocculation

摘要:以聚合硫酸铁(PFS)为絮凝剂,阳离子聚丙烯酰胺(CPAM)为助凝剂,絮凝处理造纸法再造烟叶生产废水,并采用响应面法考察了絮凝剂用量、助凝剂用量及pH值对絮凝效果的影响。结果表明,通过单因素实验确定响应曲面设计的自变量中心点为：PFS用量3150 mg/L、CPAM用量11 mg/L、pH值7.5。采用中心复合设计方法(CCD),建立了以PFS用量、CPAM用量及pH值为自变量的两个二次回归模型,两个模型均显著(P<0.0001)；对絮凝率和电导率影响最大的因素均为pH值,其与PFS用量、CPAM用量的交互作用都显著。最优工艺参数为PFS用量2859 mg/L、CPAM用量14.9 mg、pH值8.0,该条件下絮凝率为67.6%,电导率为6.18 mS/cm。验证实验结果表明,响应面法的预测值与实际值吻合较好,是一种优化废水絮凝的有效方法,建立的模型可用于优化工艺参数。

Abstract:In order to treat papermaking reconstituted tobacco effluent, a coagulation-flocculation process was used with PFS as coagulant and CPAM as flocculant. Response surface methodology (RSM) was utilized to optimize this process. The results showed that, PFS dosage of 3150 mg/L, CPAM dosage of 11 mg/L and pH value of 7.5 were chosen to be the center point of the response surface design and to investigate the effects on coagulation-flocculation rate and electrical conductivity. Two quadratic regression models with PFS dosage, CPAM dosage and pH value as independent variables were developed based on acentral composite design (CCD). And the analysis of variance indicated that both the two models were significant (P<0.0001). pH value had a greater effect on both coagulation-flocculation rate and electrical conductivity than the other two factors. Moreover, the interaction between pH value and PFS dosage and the interaction between pH value and CPAM dosage both were significant. The optimal PFS dosage, CPAM dosage and pH value were 2859 mg/L, 14.9 mg/L and 8.0 respectively, the coagulation-flocculation rate and electrical conductivity were 67.6% and 6.18 mS/cm respectively under the optimal conditions. The experimental data agreed well with the model predicted values, and also showed that the regression equations could be used as the theoretical basis for using coagulation-flocculation process to treat papermaking reconstituted tobacco effluent.