Solar-powered and self-guided floating electrochemical treatment platform for improving water quality of animal wastewater lagoons

The management of livestock wastewater remains a major environmental challenge, as concentrated animal feeding operations (CAFOs) release nutrients, solids, and pathogens that can degrade surface waters. Lagoon-based systems are widely used but often require substantial infrastructure and have limited adaptability in decentralized settings. This study presents a solar-powered, self-guided floating electrocoagulation (EC) platform that integrates renewable energy, autonomous navigation, and in situ treatment for dairy lagoon wastewater. Bench-scale electrocoagulation performance was validated using real lagoon wastewater, while autonomous navigation and solar-powered operation of the floating platform were independently confirmed under field conditions. Bench-scale optimization using a central composite design identified current (reported as current density) and reaction time as key factors controlling removal performance and energy use. Under optimized conditions, the system achieved up to 83.9% total solids (TS), 69.8% chemical oxygen demand (COD), and 96.7% total nitrogen (TN) removal, with quadratic models (R 2 ≥ 0.964) capturing nonlinear responses. A desirability-based configuration provided balanced removals of 83.9% TS, 69.3% COD, and 94.3% TN at 27.4 min and 35.8 mA/cm 2 , while an energy-minimized mode maintained 90.9% TN removal with 45% lower energy demand. Prototype field trials confirmed obstacle avoidance, path-following, and stable operation using a 15 W solar module, with daily solar input comparable to the estimated energy demand under favorable conditions. This work demonstrates a scalable, solar-autonomous EC approach for improving lagoon water quality and supporting decentralized agricultural wastewater management. • A solar-powered autonomous electrocoagulation platform is designed for dairy lagoon waste. • Bench-scale electrocoagulation using lagoon wastewater achieves up to 96.7% TN and 83.9% TS removal. • Response surface modeling enables precise multi-objective optimization. • Field trials confirm reliable autonomous and off-grid operation. • The platform provides a scalable solution for decentralized wastewater treatment.