Synergistic Electrochemical-Ce(IV) Redox Platform Enabling Dual Removal of Algae and Cyanotoxins: Mechanism-Resolved Evaluation

Ce(Ⅳ) markedly enhanced the electrochemical removal rate of M. aeruginosa . • Simultaneous removal of algae (92.5%) and MC-LR (94.1%) was achieved in 60 min. • Kinetic analysis indicates a strong synergistic effect in E-Ce (IV) system. • Multi-target cellular damage drives population-level algal inactivation. The frequent occurrence of cyanobacterial blooms poses severe challenges to aquatic environmental safety and conventional water treatment processes. While electrochemical oxidation is operationally simple, its efficiency in algal cells removal is often limited by low current efficiency and prevalent side reactions in conventional systems. This study developed a Ce(IV)-assisted electrochemical system, E-Ce(IV), incorporating Cerium(IV) (Ce(IV)) to boost the removal of Microcystis aeruginosa ( M. aeruginosa ). A synergistic effect between Ce(IV) chemical oxidation and direct electro-oxidation was identified, significantly improving algal removal performance. Under optimal conditions, the E-Ce(IV) system achieved a high removal rate of 92.5% within 60 min, markedly superior to the Ce(IV) alone system (4.68%) and direct electro-treatment (DET) system (57%). Mechanistic investigations revealed that the E-Ce(IV) system synergistically disrupted cellular membrane integrity, as well as their photosynthetic and antioxidant capacities. Concurrently, the system degraded algal organic matter, achieving a 94.1% degradation rate of the cyanotoxin microcystin-LR (MC-LR). Further assessment of different typical water matrices and bodies demonstrated the feasibility of the system for algal control under acidic conditions. As a proof-of-concept batch treatment process under acidic, sulfate-supported conditions, this work extended the E-Ce(IV) process from degrading organic pollutants to removing algal cells, offering preliminary insights into its multi-target synergistic inactivation mechanism. The simultaneous efficient degradation of cyanotoxins suggests that this approach may offer a potential strategy for algal bloom control when applied with mild pre-acidification and sulfate electrolyte supplementation. Download: Download high-res image (341KB) Download: Download full-size image