College of Environmental Science and Engineering, Taiyuan University of Technology, Taiyuan, 030024, China; Innovation Center for Postgraduate Education in Municipal Engineering of Shanxi Province, Taiyuan, 030024, China.
College of Environmental Science and Engineering, Taiyuan University of Technology, Taiyuan, 030024, China; Innovation Center for Postgraduate Education in Municipal Engineering of Shanxi Province, Taiyuan, 030024, China.
Chemosphere. 2020 Jan;238:124649. doi: 10.1016/j.chemosphere.2019.124649. Epub 2019 Aug 23.
Electro-Fenton (EF) with peroxi-coagulation (PC) as an emerging electro-chemical advanced oxidation method has been extensively applied to treat refractory wastewater. However, the studies on the pretreatment of the raw coke plant wastewater by EF process were still lacking. In this study, a lab-scale EF system (Fe as anode and graphite as cathode) achieved the highest COD removal of 69.2% based on the preliminary experiments. The process parameters and corresponding COD removal performance were further optimized using response surface methodology (RSM) combined with Box-Behnken experimental design (BBD). The optimal conditions were obtained as: 3.2 mA cm of current density, 2 h of the reaction time and 2.6 of the initial pH value, with the COD removal reaching 70.0%. Fourier infrared (FTIR), fluorescence excitation-emmission matrix (EEM) and gas chromatography-mass spectrometry (GC-MS) also revealed the degradation behaviors of dissolved organic matters (DOMs) by characterizing their structures and compositions before and after EF pretreatment, thus greatly improving the biodegradability of the wastewater. Moreover, the EF process for COD removal well followed third-order kinetics model. These findings give helpful guidance to design, optimize and control the EF process as a favourable pretreatment for actual refractory coking wastewater in practice.
电芬顿（EF）结合过氧凝聚（PC）作为一种新兴的电化学高级氧化方法，已广泛应用于处理难处理的废水。然而，关于 EF 工艺预处理原始焦化废水的研究仍很少。在这项研究中，实验室规模的 EF 系统（Fe 作为阳极和石墨作为阴极）根据初步实验实现了最高 69.2%的 COD 去除率。利用响应面法（RSM）结合 Box-Behnken 实验设计（BBD）进一步优化了工艺参数和相应的 COD 去除性能。最佳条件为：电流密度 3.2 mA·cm-2、反应时间 2 h 和初始 pH 值 2.6，COD 去除率达到 70.0%。傅里叶变换红外（FTIR）、荧光激发-发射矩阵（EEM）和气相色谱-质谱（GC-MS）也揭示了 EF 预处理前后溶解有机物（DOMs）的降解行为，通过表征其结构和组成，从而大大提高了废水的生物降解性。此外，COD 的去除符合三级动力学模型。这些发现为 EF 工艺作为实际难处理焦化废水的有利预处理方法的设计、优化和控制提供了有益的指导。
