Coking wastewater is a major challenge in wastewater treatment because of its complex composition, high pollutant concentrations, and poor biodegradability. In this study, a novel electro-Fenton cathode was prepared from needle coke loaded with ferrous ions (Fe/NC/Ti) for use in a heterogeneous electro-Fenton system for coking wastewater treatment. The optimum preparation conditions of the electrode and the main factors affecting the treatment of coking wastewater were investigated. An effective method to reduce the energy consumption of the electro-Fenton system was sought by constructing variable current systems, and scale-up experiments were performed. When the catalyst-to-binder ratio was 3:1, Fe loading was 2.5 %, and the calcination temperature was 400 °C, the Fe/NC/Ti cathode had the best catalytic effect. The chemical oxygen demand (COD) removal rate of the coking wastewater reached 97.7 %, and UV decreased from 0.163 to 0.037 under optimal conditions. The water was clarified and made transparent after the reaction. A series of characterizations confirmed that the Fe/NC/Ti cathode had good stability and electrochemical performance, and the electro-Fenton system constructed using the cathode degraded aromatic compounds in coking wastewater, such as phenols and cyclic macromolecular organic compounds, to small molecules and even caused full mineralization. The results of the scale-up experiment showed that the system had low energy consumption while maintaining high COD removal efficiency. Therefore, the Fe/NC/Ti cathode could be used as a potential solution to address the limitations of the traditional electro-Fenton process for coking wastewater degradation.

中文翻译：

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新型针状焦非均相电芬顿阴极的制备用于焦化废水处理


焦化废水成分复杂、污染物浓度高、可生化性差，是废水处理的一大挑战。在本研究中，采用负载亚铁离子（Fe/NC/Ti）的针状焦制备了一种新型电芬顿阴极，用于焦化废水处理的非均相电芬顿系统。研究了电极的最佳制备条件以及影响焦化废水处理的主要因素。通过构建变电流系统，寻求降低电芬顿系统能耗的有效方法，并进行了放大实验。当催化剂与粘结剂的比例为3:1、Fe负载量为2.5%、焙烧温度为400℃时,Fe/NC/Ti正极的催化效果最好。最佳条件下焦化废水化学需氧量（COD）去除率达到97.7%，UV由0.163下降到0.037。反应后水澄清并变得透明。一系列表征证实Fe/NC/Ti阴极具有良好的稳定性和电化学性能，利用该阴极构建的电Fenton体系可将焦化废水中的苯酚、环状大分子有机化合物等芳香族化合物降解为小分子和有机物。甚至引起完全矿化。放大实验结果表明，该系统在保持较高COD去除效率的同时，能耗较低。因此，Fe/NC/Ti阴极可以作为解决传统电芬顿工艺降解焦化废水局限性的潜在解决方案。