Department of Environmental Engineering, Chulalongkorn University, Phayathai Road, Bangkok 10330, Thailand.
J Environ Sci (China). 2009;21(11):1491-6. doi: 10.1016/s1001-0742(08)62445-6.
The production of biodiesel through a transesterification method produces a large amount of wastewater that contains high levels of chemical oxygen demand (COD) and oil and grease (O&G). Currently, flotation is the conventional primary treatment for O&G removal prior to biological treatments. In this study, electrocoagulation (EC) was adopted to treat the biodiesel wastewater. The effects of initial pH, applied voltage, and reaction time on the EC process for the removal of COD, O&G, and suspended solids (SS) were investigated using one factor at a time experiment. Furthermore, the Box-Behnken design, an experimental design for response surface methodology (RSM), was used to create a set of 15 experimental runs needed for optimizing of the operating conditions. Quadratic regression models with estimated coefficients were developed to describe the pollutant removals. The experimental results show that EC could effectively reduce COD, O&G, and SS by 55.43%, 98.42%, and 96.59%, respectively, at the optimum conditions of pH 6.06, applied voltage 18.2 V, and reaction time 23.5 min. The experimental observations were in reasonable agreement with the modeled values.
通过酯交换法生产生物柴油会产生大量含有高浓度化学需氧量 (COD) 和油和油脂 (O&G) 的废水。目前，浮选是在进行生物处理之前去除 O&G 的常规主要处理方法。在这项研究中，采用电化学混凝 (EC) 处理生物柴油废水。通过单因素实验考察了初始 pH 值、施加电压和反应时间对 EC 过程去除 COD、O&G 和悬浮固体 (SS) 的影响。此外，还使用 Box-Behnken 设计（响应面法 (RSM) 的实验设计）来创建一组 15 个实验运行，以优化操作条件。开发了具有估计系数的二次回归模型来描述污染物的去除情况。实验结果表明，在最佳条件下（pH 值为 6.06、施加电压为 18.2 V 和反应时间为 23.5 min），EC 可以有效地分别将 COD、O&G 和 SS 降低 55.43%、98.42%和 96.59%。实验观察结果与模型值吻合良好。
