Africa Center of Excellence for Water Management, Addis Ababa University, P.O.Box: 1176, Addis Ababa, Ethiopia.
Africa Center of Excellence for Water Management, Addis Ababa University, P.O.Box: 1176, Addis Ababa, Ethiopia.
Chemosphere. 2022 Sep;302:134706. doi: 10.1016/j.chemosphere.2022.134706. Epub 2022 May 3.
The hybrid electrocoagulation-electrooxidation (EC-EO) process was evaluated for its capability to remove color, total organic carbon (TOC), and chemical oxygen demand (COD). Aluminum (Al/Al) and iridium dioxide-coated onto titanium (IrO/Ti) electrodes were selected as anode/cathode for EC and EC-EO experiments, respectively. The box-Behnken statistical experimental design was used to optimize different operating conditions of the processes. The selected EC operating parameters are the concentrated dye concentration, applied current density, electrolysis time, and pH. The three chosen operating conditions for hybrid EC- EO processes are applied current density, pH, and electrolysis time. The results were evaluated based on the interaction effects of operating parameters of the treatment methods on the percentage of COD, TOC, and color removal. The EC process achieved 89% color and 76% COD removal rate at the optimum operating conditions. Likewise, the hybrid EC-EO process obtained 97% COD and color removal efficiency. FT-IR and H and C NMR spectroscopy combined approach was employed to analyze the dye degradation extent. Both analysis results confirm the complete degradation of the organic contaminants into carbon dioxide and water. Thus, this study discloses that the treatment method using mesh IrO/Ti electrodes is a promising technology that could reach the discharge limit for industrial effluents. In addition, the optimum operating conditions are tested for real industrial wastewater effluents and show excellent performance in removing pollutants. Furthermore, the treatment method's mineralization study and economic analysis were performed and compared to other studies.
混合电凝聚-电氧化（EC-EO）工艺用于去除颜色、总有机碳（TOC）和化学需氧量（COD）的能力进行了评估。选择铝（Al/Al）和涂覆在钛上的二氧化铱（IrO/Ti）电极分别作为 EC 和 EC-EO 实验的阳极/阴极。采用 Box-Behnken 统计实验设计优化了两种工艺的不同操作条件。选择的 EC 操作参数是浓缩染料浓度、施加电流密度、电解时间和 pH 值。混合 EC-EO 工艺的三个选择的操作条件是施加电流密度、pH 值和电解时间。结果基于处理方法的操作参数对 COD、TOC 和颜色去除率的相互作用效应进行了评估。EC 工艺在最佳操作条件下达到了 89%的颜色去除率和 76%的 COD 去除率。同样，混合 EC-EO 工艺获得了 97%的 COD 和颜色去除效率。采用傅里叶变换红外光谱（FT-IR）和氢核（1H）和碳核（13C）核磁共振光谱结合的方法分析染料的降解程度。两种分析结果都证实了有机污染物完全降解为二氧化碳和水。因此，这项研究表明，使用网孔 IrO/Ti 电极的处理方法是一种很有前途的技术，可以达到工业废水的排放标准。此外，对实际工业废水进行了最佳操作条件测试，显示出在去除污染物方面的优异性能。此外，还进行了处理方法的矿化研究和经济分析，并与其他研究进行了比较。
