Department of Environmental Engineering, Sivas Cumhuriyet University, 58140, Sivas, Turkey.
Chemosphere. 2022 Mar;290:133172. doi: 10.1016/j.chemosphere.2021.133172. Epub 2021 Dec 13.
Nowadays, the decrease in useable water resources day by day necessitates studies on the protection of resources by treating wastewater. It is also one of the best options for reusing the water to be treated, and electrochemical technologies can be an alternative to existing technologies, because of the easy operation and effectiveness of pollutants treatment. The study evaluated the treatment of domestic wastewater by Electrocoagulation-Electrooxidation successive processes in continuous and batch modes. The effects of the operational parameters on the Electrocoagulation and Electrooxidation processes were determined for removals of chemical oxygen demand, ammonium-nitrogen, nitrate-nitrogen, turbidity, phosphate-phosphorus, nitrite-nitrogen, and Escherichia coli. The experiments revealed that the Electrocoagulation process effectively removed all pollutants but not ammonium-nitrogen. After the Electrocoagulation process was completed, ammonium-nitrogen from domestic wastewater treatment was removed with the Electrooxidation process for further treatment. The optimum operational conditions in the Electrocoagulation process were electrode type iron anode-carbon felt cathode, current density 100 A m, initial pH original, and operation time 20 min. Under these conditions, removal efficiencies of chemical oxygen demand, turbidity, phosphate-phosphorus, nitrate-nitrogen, nitrite-nitrogen, and Escherichia coli were found to be 90.2%, 96%, 88.2%, 73.6%, and 97.9%, respectively. The removal efficiencies for the optimum operating conditions of the Electrooxidation process using Ti/SbO anode and stainless steel cathode were obtained as 95.4% (chemical oxygen demand), 89.4% (ammonium-nitrogen), and 99.99% (Escherichia coli) at 100 A m, 5 mm electrode distance, and 30 min operation time. Finally, the EC process is an effective process for removing chemical oxygen demand, phosphate-phosphorus, turbidity, nitrite-nitrogen, and nitrate-nitrogen. However, the Electrooxidation process is a successful process for the treatment of ammonium-nitrogen and Escherichia coli. This research revealed that the sequential processes effectively removed organic, inorganic, and Escherichia coli from domestic wastewater.
如今，可用水资源的日益减少使得对废水进行资源保护的研究成为必要。这也是处理后再利用水的最佳选择之一，而电化学技术可以作为现有技术的替代方案，因为其操作简单且对污染物处理有效。本研究评估了连续和批量模式下电凝聚-电氧化连续工艺处理生活污水的效果。确定了操作参数对电凝聚和电氧化过程的影响，以去除化学需氧量、氨氮、硝酸盐氮、浊度、磷酸盐磷、亚硝酸盐氮和大肠杆菌。实验表明，电凝聚过程有效地去除了所有污染物，但不能去除氨氮。电凝聚过程完成后，用电氧化法去除生活污水中的氨氮进行进一步处理。电凝聚过程的最佳操作条件为电极类型为铁阳极-碳纤维阴极、电流密度 100 A m、初始 pH 值为 7、操作时间为 20 min。在这些条件下，化学需氧量、浊度、磷酸盐磷、硝酸盐氮、亚硝酸盐氮和大肠杆菌的去除效率分别为 90.2%、96%、88.2%、73.6%和 97.9%。使用 Ti/SbO 阳极和不锈钢阴极的电氧化过程的最佳操作条件下的去除效率分别为 95.4%（化学需氧量）、89.4%（氨氮）和 99.99%（大肠杆菌），电流密度为 100 A m、电极间距为 5mm，操作时间为 30 min。最后，EC 工艺是去除化学需氧量、磷酸盐磷、浊度、亚硝酸盐氮和硝酸盐氮的有效工艺。然而，电氧化工艺是处理氨氮和大肠杆菌的成功工艺。本研究表明，连续工艺能有效去除生活污水中的有机、无机和大肠杆菌。
