Laboratory of Wastewater and Environment, Water Research and Technologies Centre (CERTE), Technopark Borj Cedria, BP 273-8020, Soliman, Tunisia.
Faculty of Sciences of Bizerte, University of Carthage, 7021, Jarzouna, Tunisia.
Environ Sci Pollut Res Int. 2019 Jul;26(19):18993-19011. doi: 10.1007/s11356-018-2657-z. Epub 2018 Jul 9.
The present paper investigates the efficiency of coagulation/flocculation process using aluminum sulfate as coagulant and CHT industrial flocculent as coagulant aid/flocculent in the treatment of vegetable oil refinery wastewater (VORW). The process optimization was conducted in two steps, jar test experiments for preliminary evaluation to identify the most influencing factors and response surface methodology using Box-Behnken design to investigate the effects of three major factors and their interactions. The variables involved were the coagulant concentration (X), flocculent dosage (X), and initial pH (X) of water samples, while the responses were COD removal (Y1) and residual turbidity (Y2). The optimal conditions obtained by solving the quadratic regression models, as well as by analyzing the response surface contour plots, were as follows: 2.4 g/L of coagulant (aluminum sulfate), 60.05 mg/L of flocculent, and about 9.23 as initial pH. Under these conditions, the coagulation/flocculation treatment was able to achieve 99% of COD removal with total turbidity elimination (100% removal). Analysis of variance showed high variance coefficient (R) values of 0.929 and 0.836 for COD and turbidity removals, respectively, thus ensuring a satisfactory adjustment of the second-order regression model with the experimental data. This statistical design methodology was demonstrated as an efficient and feasible approach for the optimization of coagulation/flocculation treatment.
本论文研究了硫酸铝作为混凝剂和 CHT 工业絮凝剂作为助凝剂/絮凝剂在处理植物油精炼废水（VORW）中的混凝/絮凝工艺的效率。该工艺优化分两步进行，通过烧杯试验初步评估来确定最有影响的因素，然后使用 Box-Behnken 设计来研究三个主要因素及其相互作用的影响。所涉及的变量是水样的混凝剂浓度（X）、絮凝剂用量（X）和初始 pH 值（X），而响应值为 COD 去除率（Y1）和残余浊度（Y2）。通过求解二次回归模型以及分析响应曲面等高线图，得到了最佳条件，即 2.4 g/L 的混凝剂（硫酸铝）、60.05 mg/L 的絮凝剂和初始 pH 值约为 9.23。在这些条件下，混凝/絮凝处理能够实现 99%的 COD 去除率和总浊度消除（100%去除）。方差分析显示，COD 和浊度去除的方差系数（R）值分别为 0.929 和 0.836，因此可以用实验数据对二次回归模型进行满意的调整。这种统计设计方法被证明是优化混凝/絮凝处理的一种有效且可行的方法。
