In situ coagulation-electrochemical oxidation of leachate concentrate: A key role of cathodes

• DOI: 10.1016/j.ese.2023.100267
• Publication Date: 2023-03-17T07:46:07Z
• Authors: Huankai Li; Qian Zeng; Feixiang Zan; Sen Lin; Tianwei Hao
• Keywords: Metal hydroxide

To efficiently remove organic and inorganic pollutants from leachate concentrate, an in situ coagulation-electrochemical oxidation (CO-EO) system was proposed using Ti/Ti4O7 anode Al cathode, coupling the "super-Faradaic" dissolution of Al. The evaluated terms removal efficiencies organics, nutrients, metals, underlying cathodic mechanisms were investigated compared with Ti/RuO2-IrO2 graphite cathode systems. After a 3-h treatment, Al-cathode removed 89.0% COD 36.3% total nitrogen (TN). TN primarily ascribed to both ammonia organic-N N2. In comparison, achieved 3-10-fold phosphorus (TP) (62.6%) metal removals (>80%) than increased TP metals coagulation Al(OH)3, hydroxide precipitation, electrodeposition. With reduced scaling on surface, formation Al3+ electrified Al(OH)3 lessened requirement for cleaning bulk conductivity, resulting instantaneous current production (38.9%) operating cost (48.3 kWh kgCOD-1). present study indicated that CO-EO process could be potentially used treating persistent wastewater containing high levels ions.