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Estimating Sediment Denitrification Rates Using Cores and N2O Microsensors
Published on: December 6, 2018
PHA based denitrification: municipal wastewater vs. acetate
Eli Krasnits1, Michael Beliavsky, Sheldon Tarre
1Faculty of Civil and Environmental Engineering, Technion, Haifa 32000, Israel.
Bioresource Technology
|February 12, 2013
Summary
Polyhydroxyalkanoates (PHA) enable effective wastewater denitrification without external carbon sources. This PHA-based denitrification is viable for real wastewater, especially with low COD/N ratios, achieving high nitrate removal.
Area of Science:
- Environmental Microbiology
- Wastewater Treatment Engineering
- Biotechnology
Background:
- Denitrification is crucial for municipal wastewater treatment to remove nitrogen.
- External carbon sources are often required for efficient denitrification, increasing operational costs.
- Bacterial storage polymers, like Polyhydroxyalkanoates (PHA), offer a potential internal carbon source.
Purpose of the Study:
- To investigate the efficacy of Polyhydroxyalkanoates (PHA) based denitrification (PBD) in real municipal wastewater.
- To compare PBD performance with acetate-based denitrification in a two-sludge system.
- To determine the feasibility of PBD as a standalone or supplementary treatment without external carbon addition.
Main Methods:
- Utilized biofilm sequencing batch reactors (BSBRs) for wastewater treatment.
- Investigated denitrification using bacterial PHA as the primary carbon source in real municipal wastewater.
- Compared performance against acetate-based synthetic wastewater under similar reactor conditions.
Main Results:
- PHA-based denitrification (PBD) proved viable for real municipal wastewater, particularly with low COD/N ratios.
- Achieved high nitrate removal capacities of 40-50 mg N/L with a low COD/N requirement of 4-5.
- Entrapped organic matter provided additional reducing power, enhancing nitrate reduction; daily removal rates comparable to extensive systems (0.24-0.31 g N/L reactor*d).
Conclusions:
- PBD is a cost-effective and sustainable alternative for municipal wastewater denitrification, minimizing the need for external carbon sources.
- The system demonstrates high efficiency, especially for nitrogen-rich wastewater streams.
- Significant differences in PHA storage yield and composition were observed between biomass grown on synthetic versus municipal wastewater.
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