Carbon reduction measures-based life cycle assessment of the photovoltaic-supported sewage treatment system

This study developed a photovoltaic (PV)-supported wastewater treatment system (WWTS) and conducted a combined experimental and simulation-based life cycle assessment (LCA). The system's energy demand and greenhouse gas (GHG) emissions were predicted through data analysis from manufacturers and the Ecoinvent databases. The energy payback time (EPBT) and GHG payback time (GPBT) were assessed. Additionally, the life cycle cost (LCC) based economic analysis was performed. The result showed that the EPBT and GPBT of the PVsupported WWTS were 11.31 years and 8.3 years, respectively, while the EPBT and GPBT of the PV-supported wastewater treatment plant (WWTP) were 9.7 years and 7.1 years, respectively. Differences in treatment scale, equipment size, and electrical stability between the PV-supported WWTS and the PV-supported WWTP necessitate independent LCA assessments to ensure environmental consistency. Based on the LCA results, recommendations for further system optimization were proposed to reduce carbon emissions. Moreover, the analysis and comparison of the PV-supported WWTS under different scenarios revealed positive investment returns. These results provide the foundation for the system's expansion, which include different energy structures and various sewage types.