Department of Civil Engineering, Malaviya National Institute of Technology, Jaipur, India.
Department of Chemical Engineering, Malaviya National Institute of Technology, Jaipur, India.
Water Environ Res. 2024 Sep;96(9):e11118. doi: 10.1002/wer.11118.
Textile wastewater, laden with persistent dyes and non-biodegradable organics, poses a challenge for treatment in common effluent treatment plants (CETPs) using conventional methods. Pre-treatment of textile effluents is essential to ensure compatibility with CETPs. The present study employed three-dimensional (3D) aluminum and graphite electrodes for a sequential electro-coagulation and electro-Fenton (EC + EF) process. An experimental plan of 25 experiments was constructed using Taguchi method. The combination resulted in high removal efficiencies: 99.91% for color, 93.20% for chemical oxygen demand (COD), and 91.75% for total organic carbon (TOC) for the operating parameters; for EC, current density (J): 20 mA/cm, time (t): 45 min, speed of rotation (N): 55 rpm; and for EF, current density (J): 25 mA/cm, time (t): 50 min, iron concentration: 40 mg/L. Post-treatment, the wastewater exhibited an enhanced biodegradability index of 0.875, rendering it suitable for CETPs. There was an increase of 11% in the total energy consumption when energy spent during rotation and aeration at the time of EC and EF, respectively, were considered. This energy increases the cost and is not accounted for, in previous research. The energy consumption in kWh per g of COD removed at optimum condition for the hybrid treatment was 0.0314, which is lower than the energy consumption by other electrochemical processes employing plate electrodes. This indicates that 3D electrodes are more energy efficient than plate electrodes. PRACTITIONER POINTS: Hybrid electrochemical processes can be used as pre-treatment method for textile effluents. Three-dimensional electrodes improve removal rates with lower energy consumption. Significant color, COD, and TOC abatement were noted post-hybrid treatment of textile wastewater. Biodegradability of the textile effluent improves after the hybrid treatment.
纺织废水含有持久性染料和难生物降解的有机物，使用常规方法在常规污水处理厂（CETP）进行处理具有挑战性。纺织废水的预处理对于确保与 CETP 的兼容性至关重要。本研究采用三维（3D）铝和石墨电极进行顺序电凝聚和电芬顿（EC+EF）处理。使用 Taguchi 方法构建了 25 个实验的实验计划。该组合的结果是，对于操作参数，去除效率很高：颜色为 99.91%，化学需氧量（COD）为 93.20%，总有机碳（TOC）为 91.75%；对于 EC，电流密度（J）：20 mA/cm，时间（t）：45 分钟，转速（N）：55 rpm；对于 EF，电流密度（J）：25 mA/cm，时间（t）：50 分钟，铁浓度：40 mg/L。后处理后，废水的可生化性指数提高到 0.875，适合 CETP。当分别考虑 EC 和 EF 时旋转和曝气所消耗的能量时，总能耗增加了 11%。与之前的研究相比，这增加了成本，并且没有考虑到这一点。在最佳条件下，混合处理每去除 1g COD 的千瓦时消耗量为 0.0314，低于使用板式电极的其他电化学过程的能量消耗。这表明 3D 电极比板式电极更节能。从业者要点： 混合电化学工艺可作为纺织废水的预处理方法。三维电极可提高去除率，同时降低能耗。在对纺织废水进行混合处理后，发现其显著减少了颜色、COD 和 TOC。混合处理后，纺织废水的可生化性得到改善。
