Li Huankai, Zeng Qian, Zan Feixiang, Lin Sen, Hao Tianwei
Department of Civil and Environmental Engineering, Faculty of Science and Technology, University of Macau, Macau, China.
Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China.
Environ Sci Ecotechnol. 2023 Mar 17;16:100267. doi: 10.1016/j.ese.2023.100267. eCollection 2023 Oct.
To efficiently remove organic and inorganic pollutants from leachate concentrate, an coagulation-electrochemical oxidation (CO-EO) system was proposed using Ti/TiO anode and Al cathode, coupling the "super-Faradaic" dissolution of Al. The system was evaluated in terms of the removal efficiencies of organics, nutrients, and metals, and the underlying cathodic mechanisms were investigated compared with the Ti/RuO-IrO and graphite cathode systems. After a 3-h treatment, the Al-cathode system removed 89.0% of COD and 36.3% of total nitrogen (TN). The TN removal was primarily ascribed to the oxidation of both ammonia and organic-N to N. In comparison, the Al-cathode system achieved 3-10-fold total phosphorus (TP) (62.6%) and metal removals (>80%) than Ti/RuO-IrO and graphite systems. The increased removals of TP and metals were ascribed to the coagulation of Al(OH), hydroxide precipitation, and electrodeposition. With the reduced scaling on the Al cathode surface, the formation of Al and electrified Al(OH) lessened the requirement for cathode cleaning and increased the bulk conductivity, resulting in increased instantaneous current production (38.9%) and operating cost efficiencies (48.3 kWh kg ). The present study indicated that the CO-EO process could be potentially used for treating persistent wastewater containing high levels of organic and inorganic ions.
为了有效去除渗滤液浓缩液中的有机和无机污染物，提出了一种使用Ti/TiO阳极和Al阴极的混凝-电化学氧化（CO-EO）系统，该系统耦合了Al的“超法拉第”溶解。通过有机物、营养物和金属的去除效率对该系统进行了评估，并与Ti/RuO-IrO和石墨阴极系统相比，研究了其潜在的阴极机制。经过3小时的处理，Al阴极系统去除了89.0%的化学需氧量（COD）和36.3%的总氮（TN）。TN的去除主要归因于氨和有机氮都被氧化为N。相比之下，Al阴极系统的总磷（TP）（62.6%）和金属去除率（>80%）比Ti/RuO-IrO和石墨系统高3至10倍。TP和金属去除率的提高归因于Al(OH)₃的混凝、氢氧化物沉淀和电沉积。随着Al阴极表面结垢的减少，Al和带电Al(OH)₃的形成减少了对阴极清洗的需求，并提高了整体电导率，导致瞬时电流产量增加（38.9%）和运行成本效率提高（48.3 kWh/kg）。本研究表明，CO-EO工艺可能潜在地用于处理含有高浓度有机和无机离子的持久性废水。
