响应面法优化絮凝处理造纸法烟草薄片废水

摘要

A coagulation–flocculation process was used to treat papermaking-reconstituted tobacco slice wastewater with polyaluminium chloride (PAC) as coagulant and cationic polyacrylamide (CPAM) as flocculants. To minimize chemical oxygen demand (COD) and color of the wastewater, the experiments were carried out using jar tests and response surface methodology (RSM) was applied to optimize this process. A central composite design, which is the standard design of RSM, was used to evaluate the effects and interactions of three factors, i.e. PAC dosage, CPAM dosage and pH on the treating efficiency. The optimal conditions obtained from the compromise of the two desirable responses, COD removal rate and color removal rate, were PAC dosage of 715 mg/L, CPAM dosage of 4.8 mg/L and pH 6.6, respectively. Under the optimal conditions, the maximal COD removal rate (67.8%) and the maximal color removal rate (77.7%) could be achieved. The RSM was demonstrated as an appropriate approach for the optimization of the coagulation–flocculation process by confirmation experiments.%　　以聚合氯化铝(PAC)和聚丙烯酰胺(CPAM)为絮凝剂,对造纸法烟草薄片废水进行絮凝预处理.以絮凝剂用量和p H值为影响因素,以COD和色度去除率为响应值,采用中心组合实验设计和响应面法建立了COD和色度去除率的响应面方程.通过对数学模型进行求解,可知在PAC用量为715mg/L、CPAM用量为4.8mg/L和pH值为6.5的条件下,COD和色度去除率可同时达到最大值,分别为67.8%和77.7%.验证实验结果表明,响应面法的预测值与实验值吻合较好,建立的模型具有较高的可信度,响应面法是一种有效的优化废水絮凝条件的方法,为烟草薄片废水的优化絮凝处理提供了一定的理论依据.