Evaluation of electroactive denitrifiers at different potentials, temperatures and buffers based on microcalorimetry
Long Chen1, Yanli Guo1, Shaohui Zhang2
1School of Civil Engineering and Architecture, Wuhan University of Technology, Wuhan 430070, PR China.
Journal of Microbiological Methods
|November 19, 2022
Summary
Microcalorimetry revealed optimal conditions for electroactive denitrifiers in bioelectrochemical systems. The study identified ideal cathode potential, temperature, and buffer for efficient nitrate removal and growth.
Area of Science:
- Environmental Microbiology
- Electrochemistry
- Biotechnology
Background:
- Electroactive denitrifiers are crucial for nitrate removal in bioelectrochemical systems.
- Understanding their metabolism and growth is vital for optimizing these systems.
Purpose of the Study:
- To evaluate metabolism and growth parameters of electroactive denitrifiers.
- To determine optimal conditions (cathode potential, temperature, buffer) for their activity.
Main Methods:
- Utilized microcalorimetry to assess metabolic and growth parameters.
- Tested various cathode potentials, temperatures, and buffer solutions.
Main Results:
- Optimal conditions identified: -100 mV cathode potential and 30°C.
- Phosphate buffer is suitable; bicarbonate buffer is a viable alternative.
- Achieved specific nitrate removal rate of 2.20 × 10-10 mg NO3--N·(min·cell)-1 with gaseous nitrogen as the end product.
Conclusions:
- Bioelectrochemical denitrification is a two-step process.
- Nitrite reduction to nitrogen gas is the rate-limiting step.
- Established optimal parameters for enhanced denitrification efficiency.
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