Wastewater treatment meets artificial photosynthesis: Solar to green fuel production, water remediation and carbon emission reduction

Highlights

• Mitigating energy utilization and carbon emission is urgent for wastewater treatment.

• MPEC integrates both solar energy storage and wastewater organics removal.

• Energy self-sustaining MPEC allows to mitigate the fossil carbon emission.

• MPEC is able to convert CO₂ into storable carbon fuel using renewable energy.

• MPEC would inspire photoelectrochemistry by employing a novel oxidation reaction.

Abstract

Current wastewater treatment (WWT) is energy-intensive and leads to vast CO₂ emissions. Chinese pledge of “double carbon” target encourages a paradigm shift from fossil fuels use to renewable energy harvesting during WWT. In this context, hybrid microbial photoelectrochemical (MPEC) system integrating microbial electrochemical WWT with artificial photosynthesis (APS) emerges as a promising approach to tackle water-energy-carbon challenges simultaneously. Herein, we emphasized the significance to implement energy recovery during WWT for achieving the carbon neutrality goal. Then, we elucidated the working principle of MPEC and its advantages compared with conventional APS, and discussed its potential in fulfilling energy self-sustaining WWT, carbon capture and solar fuel production. Finally, we provided a strategy to judge the carbon profit by analysis of energy and carbon fluxes in a MPEC using several common organics in wastewater. Overall, MPEC provides an alternative of WWT approach to assist carbon-neutral goal, and simultaneously achieves solar harvesting, conversion and storage.

Graphical abstract

Keywords

Wastewater treatment / Artificial photosynthesis / Microbial photoelectrochemical (MPEC) system / Carbon neutral / Renewable energy

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Acknowledgements

This work was financially supported by the State Key Laboratory of Urban Water Resource and Environment (Harbin Institute of Technology, China) (No. 2021TS13), the National Natural Science Foundation of China (No. 22176046) and Shenzhen Science and Technology Program (China) (KQTD20190929172630447 and JCYJ20210324124-209025).

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2022 Higher Education Press