Photovoltaic-Integrated Constructed Wetland System for Energy-Neutral Greywater Treatment and Reuse

Abstract

The increasing demand for sustainable water management and renewable energy integration has accelerated the development of energy-efficient wastewater treatment technologies. This study proposes a photovoltaic-integrated constructed wetland system for energy-neutral greywater treatment and reuse in decentralized environmental applications. The developed system combines natural wetland-based purification processes with photovoltaic energy generation to achieve continuous wastewater treatment with minimal external power dependency. A hybrid treatment model was designed to evaluate the interaction between hydraulic performance, pollutant removal efficiency, and renewable energy utilization under varying operational conditions. The constructed wetland unit facilitates the removal of suspended solids, organic contaminants, nutrients, and pathogenic microorganisms through physical, biological, and phytoremediation mechanisms, while the photovoltaic subsystem supplies the energy required for water circulation and auxiliary treatment operations. Key parameters, including hydraulic retention time, plant species effectiveness, solar energy conversion efficiency, and influent pollutant concentration, were analyzed to optimize system performance. Experimental and simulation results demonstrated substantial reductions in biochemical oxygen demand, chemical oxygen demand, turbidity, and nutrient levels, indicating effective greywater purification suitable for non-potable reuse applications. The photovoltaic integration successfully maintained energy-neutral operation by meeting the system’s electrical requirements through renewable solar power generation.