Synergizing resource recovery and net-zero emissions in China’s wastewater sector

Abstract Wastewater management is undergoing a paradigm shift from pollution control towards resource recovery. However, techno-economically feasible pathways to synergize resource recovery with net-zero emissions in the wastewater sector remain underexplored. Targeting municipal and industrial wastewater across Chinese provincial regions, we design a transformative life cycle wastewater treatment system integrating energy recovery and conversion, wastewater reclamation, biofertilizer production, and carbon capture. The system delivers net energy output and reduces net greenhouse gas emissions from 99.8 to −10.0 million tonnes carbon dioxide equivalent, but raises total cost by varying amounts across scenarios. Economically and technically feasible pathway for synergistically enhancing resource recovery while delivering lower residual greenhouse gas emissions are identified. Large scale deployment of wastewater source heat pumps for secondary effluent and lower anaerobic membrane bioreactor costs are identified as key levers to enable net-negative greenhouse gas emissions while avoiding cost increases and potentially delivering net economic gains.