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Published on: December 25, 2015
[Rapid Achievement of Nitrifying Micro-granular Sludge and Its Nitritation Function]
Wen-Ru Liu1,2,3,4, Jia-Jun Song2, Jian-Fang Wang1,2,3,4
1National and Local Joint Engineering Laboratory of Municipal Sewage Resource Utilization Technology, Suzhou 215009, China.
Nitrifying micro-granular sludge was rapidly achieved in three weeks using an airlift reactor. This sludge quickly developed a nitritation function, crucial for wastewater treatment, reaching a 90% nitrite accumulation ratio.
Area of Science:
- Environmental Microbiology
- Biotechnology
- Wastewater Treatment
Context:
- Developing efficient nitrification and nitritation processes is vital for advanced wastewater treatment.
- Micro-granular sludge offers improved settleability and activity compared to traditional floccular sludge.
- Internal-loop airlift reactors are effective for cultivating specialized microbial consortia.
Purpose:
- To investigate the rapid formation of nitrifying micro-granular sludge in a continuously operated internal-loop airlift reactor.
- To assess the development and efficiency of the nitritation function in the micro-granular sludge.
- To identify key operational parameters influencing the speed of micro-granulation and nitritation.
Summary:
- Micro-granular sludge was successfully formed within three weeks by reducing hydraulic retention time in an airlift reactor, achieving an average size of 134 μm with homogeneous distribution.
- The nitritation function was rapidly established in the micro-granular sludge within one week, with influent ammonia concentrations increased progressively.
- The study achieved a high nitrite accumulation ratio (90%) and nitritation loading rate (1.34 kg·(m³·d)⁻¹), attributing rapid nitritation to residual ammonia and low dissolved oxygen to ammonia-nitrogen ratios.
Impact:
- Demonstrates a highly efficient method for rapidly generating nitrifying micro-granular sludge.
- Highlights the potential for accelerated implementation of nitritation processes in wastewater treatment.
- Provides insights into operational strategies for optimizing micro-granule formation and function in bioreactors.
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