Electrochemical technologies for sustainable agricultural water treatment and resource recovery

Electrochemical technologies are emerging as modular, low-chemical, and energy-efficient solutions for treating and valorizing agricultural water streams. This review synthesizes the state-of-the-art in six core electrochemical processes—electrocoagulation, electroflotation, electrodialysis, capacitive deionization, electrochemical advanced oxidation, and electro-reductive pathways—and evaluates their effectiveness for removing sediments, nutrients, salts, organic micropollutants, and pathogens. We compare removal efficiencies, resource-recovery yields, energy consumption, and operational challenges across bench-, pilot-, and field-scale studies. Key insights include the high phosphorus recovery (>99 %) achievable via electrocoagulation, selective nitrate concentration by electrodialysis for fertilizer reuse, sub-kWh m⁻³ energy footprints of capacitive deionization for brackish irrigation water, and > 99 % degradation of persistent pesticides using advanced oxidation anodes. Looking ahead, we identify three critical research priorities: (1) development of low-cost, fouling-resistant electrode materials tailored for complex agricultural matrices; (2) integration of electrochemical units with renewable energy sources and biological polishing to maximize circularity; and (3) techno-economic assessments and long-term field demonstrations to validate performance under variable on-farm conditions. Addressing these gaps will accelerate deployment of decentralized electrochemical water treatment systems—advancing nutrient circularity, safeguarding water resources, and enhancing resilience of agricultural landscapes.