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Updated: Jun 1, 2026
08:13
A Novel Bioreactor for High Density Cultivation of Diverse Microbial Communities
Published on: December 25, 2015
Microbial community structure and dynamics in a mixotrophic nitrogen removal process using recycled spent caustic
Sora Park1, Jaecheul Yu, Imgyu Byun
1Department of Civil and Environmental Engineering, Pusan National University, Jangjeon-Dong, Geumjung-Gu, Busan, Republic of Korea.
Bioresource Technology
|May 24, 2011
Summary
Modified spent caustic (MSC) can be used in the Bardenpho process for nitrogen removal. To meet water quality standards, the nitrogen loading rate (NLR) should not exceed 0.15 kg N/m(3)d when using MSC.
Area of Science:
- Environmental Engineering
- Microbiology
- Wastewater Treatment
Background:
- The Bardenpho process is a key technology for nitrogen removal in wastewater treatment.
- Modified spent caustic (MSC) offers potential as an electron donor and alkalinity source for denitrification.
- Optimizing nitrogen loading rate (NLR) is crucial for efficient and compliant wastewater treatment.
Purpose of the Study:
- To determine the optimal nitrogen loading rate (NLR) for denitrification using modified spent caustic (MSC) in a laboratory-scale Bardenpho process.
- To investigate the impact of MSC on microbial communities involved in nitrogen removal.
- To establish safe operating limits for MSC application in wastewater treatment.
Main Methods:
- Implementation of a laboratory-scale Bardenpho process.
- Application of modified spent caustic (MSC) as the primary electron donor and alkalinity source.
- Monitoring of nitrogen removal rate (NRR) and effluent nitrogen concentrations.
- Characterization of microbial communities in anoxic reactors using 16S rRNA gene pyrosequencing.
Main Results:
- MSC facilitated both autotrophic and heterotrophic denitrification pathways.
- Nitrogen removal rate (NRR) did not scale linearly with increasing nitrogen loading rate (NLR).
- Elevated MSC dosage led to reduced microbial diversity and an increase in sulfur-oxidizing bacteria (SOB) of the genus Thiobacillus.
Conclusions:
- The optimal nitrogen loading rate (NLR) for MSC in the Bardenpho process should not exceed 0.15 kg N/m(3)d to ensure effluent quality.
- MSC application influences microbial community structure, promoting specific sulfur-denitrifying bacteria.
- Careful control of MSC dosage is necessary to balance denitrification efficiency and microbial community health.
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