Dye wastewater, as a kind of refractory wastewater (with a ratio of biochemical oxygen demand (BOD) and chemical oxygen demand (COD) of less than 0.3), still needs advanced treatments in order to reach the discharge standard. In this work, the recycling-flow three-dimensional (3D) electro-reactor system was designed for degrading synthetic rhodamine B (RhB) wastewater as dye wastewater (100 mg/L). After 180 min of degradation, the removal of total organic carbon (TOC) and chemical oxygen demand (COD) of RhB wastewater were both approximately double the corresponding values in the recycling-flow two-dimensional (2D) electro-reactor system. Columnar granular activated carbon (CGAC), as micro-electrodes packed between anodic and cathodic electrodes in the recycling-flow 3D electro-reactor system, generated an obviously characteristic peak of anodic catalytic oxidation, increased the mass transfer rate and electrochemically active surface area (EASA) by 40%, and rapidly produced 1.52 times more hydroxyl radicals (·OH) on the surface of CGAC electrodes, in comparison to the recycling-flow 2D electro-reactor system. Additionally, the recycling-flow 3D electro-reactor system can maintain higher current efficiency (CE) and lower energy consumption (Es).

中文翻译：

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循环流二维和三维电反应器系统对罗丹明B废水TOC和COD降解机理的比较

染料废水作为难处理废水（生化需氧量（BOD）与化学需氧量（COD）之比小于0.3），仍需深度处理才能达标排放。在这项工作中，设计了循环流三维 (3D) 电反应器系统，用于将合成罗丹明 B (RhB) 废水降解为染料废水 (100 mg/L)。降解 180 分钟后，RhB 废水的总有机碳 (TOC) 和化学需氧量 (COD) 的去除量均约为循环流二维 (2D) 电反应器系统中相应值的两倍。柱状颗粒活性炭 (CGAC)，作为填充在循环流 3D 电反应器系统中阳极和阴极电极之间的微电极，产生了明显的阳极催化氧化特征峰，使传质速率和电化学活性表面积（EASA）提高了 40%，并在 CGAC 电极表面迅速产生了 1.52 倍的羟基自由基（·OH）。循环流二维电反应器系统。此外，循环流 3D 电反应器系统可以保持更高的电流效率 (CE) 和更低的能耗 (Es)。