Electrode passivation is the most challenging technical problem in electrocoagulation (EC) water treatment process, but research on understanding and mitigating passivation evolution are still lacking. Herein, homogenization of current density (CD) distribution was found to be a critical factor in alleviating the anode passivation during EC process. Decreasing electrode area decelerated the growth of passivation layer on anode through homogenizing CD distribution, which was quantified by the ratios of CD distributed at the electrode edges and centers. When aluminum anode area decreased from 8 cm² to 2 cm² with a constant CD, the homogenization degree increased by 24.0%, and passivation was reduced by 24.3%. The depth profiles of passivated anodes confirmed the inhomogeneity of the anode passivation. Thicker passivation layers were observed at edges due to high CD distributions, which originated from the “edge effect” of electric field distribution between parallel plate electrodes. A facile strategy to homogenize CD distribution by splitting electrodes into smaller electrodes is then proposed for passivation mitigation, which can save energy consumption by 21.8% with unchanged removal efficiency. This study provides a unique insight into anode passivation mitigation and a feasible electrode design in EC.

电极钝化是电凝（EC）水处理过程中最具挑战性的技术问题，但仍缺乏了解和减缓钝化演变的研究。在此，电流密度 (CD) 分布的均匀化被发现是减轻 EC 过程中阳极钝化的关键因素。减小电极面积通过均匀CD分布减缓了阳极上钝化层的生长，这通过分布在电极边缘和中心的CD的比率来量化。当铝阳极面积从 8 cm ²减小到 2 cm ²CD不变时，均质化程度提高24.0%，钝化降低24.3%。钝化阳极的深度分布证实了阳极钝化的不均匀性。由于高 CD 分布，在边缘观察到较厚的钝化层，这源于平行板电极之间电场分布的“边缘效应”。然后提出了一种通过将电极分成更小的电极来均匀化 CD 分布的简便策略来缓解钝化，该策略可以在去除效率不变的情况下节省 21.8% 的能耗。本研究为缓解阳极钝化和 EC 中可行的电极设计提供了独特的见解。