1. Efficiency of hybrid systems enhanced with different sludge ratios in improving resistance to short-term low temperatures.
- Author
-
Tian, Mengyuan, Wang, Heng, Li, Xiang, Li, Dongqing, Zhou, Zhi, and Li, Bolin
- Subjects
- *
LOW temperatures , *HYBRID systems , *WASTEWATER treatment , *BIOFORTIFICATION , *AMMONIA - Abstract
Complete autotrophic nitrogen removal over nitrite (CANON) is used in wastewater treatment. However, the performance of the CANON system significantly decreases at low temperatures; thus, a new strategy to improve the resistance of the CANON system is required. To investigate the impact of sludge ratio control (high-granule, equivalent, and high-floc systems) on the resistance of CANON to low temperatures, and their recovery after restoring to normal temperature, the nitrogen removal performance of hybrid systems with different ratios was evaluated. The equivalent system had the lowest nitrite accumulation rate and highest nitrogen removal rate. Anaerobic ammonia oxidation was the rate-limiting step of each system, and hzs was the rate-limiting gene. The higher anaerobic ammonium oxidizing bacteria (AAOB) abundance and hzs expression levels resulted in an equivalent system with better resistance and recovery to short-term low temperatures at the gene level. [Display omitted] • Nitrogen removal performance of CANON system with different sludge ratios studied. • Resistance to low temperature and recovery of CANON system was evaluated. • Systems with different sludge ratios have varied resistance to low temperatures. • Biofortification has a positive effect on the gene transcription process. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF