Integrated Hydroponics-Microbial Electrochemical Technology for domestic wastewater recycling at point sources: Long-term performance and environmental impact assessment

The practical applicability and environmental impacts of the emerging integrated Hydroponics-Microbial Electrochemical Technology (iHydroMET) were assessed for decentralized domestic wastewater management through a yearlong field study. The towered-design iHydroMET system, comprising of modular reactors, achieved robust wastewater treatment, substantial leafy greens yield, and consistent power output, without showing any major indication of clogging. Enrichment of electrogens (e.g. Geobacter), denitrifiers (e.g. Dechloromonas and Hydrogenophaga), and organic degraders (e.g. Roseateles) was observed. Life cycle assessment revealed that plant cultivation contributes substantially to avoided impacts, while the plastic framework and electricity consumption were identified as the major contributors to environmental burdens. The findings validate the suitability of iHydroMET for recovering the key resources of domestic wastewater at point sources such as households and scattered establishments, aligning with the circular resource utilization paradigm.