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Electrochemically and Bioelectrochemically Induced Ammonium Recovery
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Electrochemical In Situ pH Control Enables Chemical-Free Full Urine Nitrification with Concomitant Nitrate
Jolien De Paepe1,2,3, Peter Clauwaert1,3, Maria Celeste Gritti1
1Center for Microbial Ecology and Technology (CMET), Department of Biotechnology, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, 9000 Gent, Belgium.
Environmental Science & Technology
|June 4, 2021
Summary
This study integrates an electrochemical cell for on-demand hydroxide production, enabling full nitrification of urine. This stabilizes nutrients for recovery, offering a chemical-free alternative for applications on Earth and in space.
Area of Science:
- Environmental Science
- Electrochemistry
- Biotechnology
Background:
- Urine stabilization is crucial for nutrient recovery, preventing ammonia loss and odor.
- Current methods like alkalinization have limitations, including insufficient alkalinity for full nitrification.
- Uncontrolled urine processing leads to nutrient loss and malodor.
Purpose of the Study:
- To explore the feasibility of an integrated electrochemical cell for on-demand hydroxide production.
- To enable full nitrification of urine by compensating for acidification during nitritation.
- To provide a reliable, chemical-free alternative to traditional base addition for urine stabilization.
Main Methods:
- An electrochemical cell was integrated with a bioreactor to produce hydroxide via water reduction.
- A controller modulated the electrochemical cell's current based on real-time pH monitoring.
- The system was tested to assess its ability to enable full nitrification and concentrate nitrate.
Main Results:
- The integrated electrochemical cell successfully enabled full nitrification of urine.
- On-demand hydroxide production compensated for acidification, overcoming alkalinity limitations.
- The system offered a chemical-free, reliable method for urine stabilization and nutrient recovery.
- The electrochemical cell also functioned as an in situ extraction technology, producing a concentrated nitrate stream.
Conclusions:
- Integrating an electrochemical cell is a feasible and innovative approach for urine stabilization and nutrient recovery.
- This method avoids chemical addition, associated logistics, and increased salinity.
- The system's versatility allows for tailored end-product composition for diverse applications, including space exploration.
Keywords:
MELiSSAmoving bed biofilm reactornitrogen recoveryregenerative life support systemresource recoveryMore Related Videos
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