As one of the most representative hard-to-biodegrade industrial wastewater, coking wastewater is poor in biodegradability and has a high concentration of organic matter. Consequently, even after treatment using biochemical technology, the discharge standards cannot be reached. We used the self-developed Fe-loaded needle coke electrodes (Fe-NCPEs) as particle electrodes and established a three-dimensional electro-Fenton (3DEF) system for the treatment of bio-treated coking wastewater (BTCW) in this study. The 3DEF system's conditions for treating BTCW were optimized using Response Surface Method (RSM). When the initial pH was 4.69, the applied voltage was 11.1 V, the Fe-NCPE dosage was 11.63 g L−1, and the COD was reduced from 387 to 57.3 mg L−1 and the colour removal rate reached 99 % after 3 h of reaction, meeting local coking wastewater discharge standards. The power consumption is only 15 kWh per ton of BTCW, indicating that this system can treat the BTCW with high efficiency and low energy consumption. UV-Vis, FTIR, and GC-MS analysis illustrated that cyclic aromatic compounds, esters, and ethers can be efficiently degraded to alkanes and olefins by the 3DEF system. The ·OH quenching experiments showed that in the 3DEF system, the ·OH is the main reactive group, which can oxidize the large hard-to-degrade organic compounds in BTCW to small organic compounds, and even to CO2 and H2O. Dynamic experiments showed that the 3DEF system can successfully remove pollutants from BTCW under continuous flow conditions with an HRT of 3 h, allowing it to meet emission standards.

中文翻译：

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在3DEF系统中使用负载铁的针状焦粒电极处理生物处理焦化废水


焦化废水作为最具代表性的难生物降解工业废水之一，生物降解性差，有机物浓度高。因此，即使使用生化技术处理后，也无法达到排放标准。本研究采用自主研发的带铁针状焦电极 （Fe-NCPEs） 作为颗粒电极，建立了用于处理生物处理焦化废水 （BTCW） 的三维电芬顿 （3DEF） 系统。使用响应面法 （RSM） 优化 3DEF 系统处理 BTCW 的条件。当初始 pH 值为 4.69 时，外加电压为 11.1 V，Fe-NCPE 用量为 11.63 g L−1，反应 3 h 后 COD 从 387 降低到 57.3 mg L−1，颜色去除率达到 99 %，满足当地焦化废水排放标准。每吨 BTCW 的功耗仅为 15 kWh，表明该系统可以高效、低能耗地处理 BTCW。UV-Vis、FTIR 和 GC-MS 分析表明，3DEF 系统可以有效地将环状芳香族化合物、酯和醚降解为烷烃和烯烃。的 ·OH 淬灭实验表明，在 3DEF 系统中， ·OH 是主要的反应基团，可将 BTCW 中难以降解的大有机化合物氧化成小分子有机化合物，甚至氧化成 CO2 和 H2O。动态实验表明，3DEF 系统可以在连续流动条件下以 3 h 的 HRT 成功去除 BTCW 中的污染物，使其达到排放标准。