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[Modified step-feed A/O biological nitrogen removal process for enhanced phosphorus removal]
Wei Wang1, Yong-zhen Peng, Fang-fang Yin
1Key Laboratory of Beijing for Water Quality Science and Water Environmental Recovery Engineering, Beijing University of Technology, Beijing 100124, China. wang_wei2005@emails.bjut.edu.cn
Huan Jing Ke Xue= Huanjing Kexue
|December 9, 2009
Summary
A modified step-feed A/O system significantly improved simultaneous nitrogen and phosphorus removal from municipal wastewater. This enhanced system boosts nutrient removal efficiency and promotes the growth of key microorganisms for better wastewater treatment.
Area of Science:
- Environmental Engineering
- Microbiology
- Wastewater Treatment
Context:
- Low C/N municipal wastewater presents challenges for conventional treatment systems.
- Achieving simultaneous nitrogen and phosphorus removal is crucial for meeting stringent effluent standards.
- Existing step-feed A/O systems may require optimization for enhanced nutrient removal.
Purpose:
- To develop and evaluate a modified step-feed A/O system for superior simultaneous nitrogen and phosphorus removal.
- To compare the efficiency of the modified system against the original configuration.
- To investigate the microbial community dynamics, specifically polyphosphate-accumulating organisms (PAOs) and denitrifying polyphosphate-accumulating organisms (DNPAOs).
Summary:
- The modified step-feed A/O system achieved a total nitrogen (TN) removal efficiency of 73.61% and a total phosphorus (TP) removal efficiency of 89.81% at an optimal feeding ratio.
- Compared to the original system (TN: 66.52%, TP: 29.24%), the modified configuration demonstrated a significant improvement in TP removal and a modest increase in TN removal.
- Batch tests confirmed the accumulation of PAOs and DNPAOs in the modified system, with increased aerobic and anoxic phosphorus uptake rates.
Impact:
- The enhanced system provides a cost-effective solution for simultaneous nitrogen and phosphorus removal, reducing the need for external carbon sources.
- The study contributes to a better understanding of microbial ecology in enhanced biological phosphorus removal processes.
- The findings support the implementation of optimized step-feed A/O systems for advanced municipal wastewater treatment.
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