A paradigm shift is underway in wastewater treatment as the industry heads toward ~3% of global electricity consumption and contributes ~1.6% of greenhouse gas emissions. Although incremental improvements to energy efficiency and renewable energy recovery are underway, studies considering wastewater for carbon capture and utilization are few. This Review summarizes alternative wastewater treatment pathways capable of simultaneous CO2 capture and utilization, and demonstrates the environmental and economic benefits of microbial electrochemical and phototrophic processes. Preliminary estimates demonstrate that re-envisioning wastewater treatment may entirely offset the industry’s greenhouse gas footprint and make it a globally significant contributor of negative carbon emissions.

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L.L. and Z.J.R. were supported by the US National Science Foundation under award CEBT-1834724.

Author information


  1. Department of Civil and Environmental Engineering, Princeton University, Princeton, NJ, USA

    • Lu Lu
    • , Catherine A. Peters
    •  & Zhiyong Jason Ren
  2. Andlinger Center for Energy and the Environment, Princeton University, Princeton, NJ, USA

    • Lu Lu
    •  & Zhiyong Jason Ren
  3. Department of Civil, Environmental and Architectural Engineering, University of Colorado Boulder, Boulder, CO, USA

    • Lu Lu
    •  & Zhiyong Jason Ren
  4. Department of Civil and Environmental Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, USA

    • Jeremy S. Guest
  5. Department of Civil and Environmental Engineering, Louisiana State University, Baton Rouge, LA, USA

    • Xiuping Zhu
  6. Institute of Marine Sciences, University of California, Santa Cruz, CA, USA

    • Greg H. Rau


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Z.J.R. and L.L. designed the study. L.L, J.S.G. and Z.J.R. performed data analysis. L.L., J.S.G., C.A.P., X.Z., G.H.R. and Z.J.R. wrote the manuscript.

Competing interests

The authors declare no competing interests.

Corresponding author

Correspondence to Zhiyong Jason Ren.

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    Supplementary Analysis, Supplementary Tables 1, 2 and Supplementary References 1–9

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