Researchers at Peking University have designed a bioelectrochemical wastewater treatment process that generates electricity while capturing nutrients, according to a report in Nature Communications. The system achieves a net carbon emission rate of –0.413 kg-CO2 m–3 and yields a power density of 0.43 W m–2.
The process relies on a hybrid bioelectrochemical assembly (HBA) that combines abiotic and biotic cathodes to manage carbon metabolism in stages. Through this hierarchical carbon processing, the resulting effluent chemical oxygen demand directly satisfies Class Ⅲ surface water standards. To handle nitrogen, customized water-permeable biofilm separators construct distinct anaerobic, anoxic, and aerobic zones sequentially within the assembly, enabling complete nitrogen removal.
Once nitrogen is removed, the assembly channels phosphorus-rich tailwater into an integrated hydroponic irrigation system. This setup captures and uses the remaining phosphorus, ultimately leaving behind clean, reusable water. The authors described the assembly as a prototype for sustainable purification, aimed particularly at low-resource regions striving to meet carbon reduction and neutrality targets.
Chao Li and Yamei Ma contributed equally as lead authors on the research alongside Chengcheng Ji, Jing Zhang, Xiayu Yuan, Kexin Yi, and Wulin Yang. The team conducted the work at the Key Laboratory of Water and Sediment Sciences and the State Environmental Protection Key Laboratory of All Material Fluxes in River Ecosystems at Peking University. Funding was provided by the Ministry of Education of China, the National Natural Science Foundation of China, and the China Postdoctoral Science Foundation. Dr. Yan Tian assisted in editing the manuscript, which Nature Communications published on July 29, 2026.
