ZHANGBing,WULian,HUANGShu-chang,et al.Effect of Different Operational Modes and C/N Ratios on Enhanced Partial Nitrification and Denitrification of AGS[J].China Water & Wastewater,2023,39(1):9-18.
Effect of Different Operational Modes and C/N Ratios on Enhanced Partial Nitrification and Denitrification of AGS
China Water & Wastewater[ISSN:1000-4062/CN:12-1073/TU]
volume:
第39卷
Number:
第1期
Page:
9-18
Column:
Date of publication:
2023-01-01
- Keywords:
- aerobic granular sludge; partial nitrification and denitrification; operational mode; C/N ratio; microbial community structure
- Abstract:
- In order to enhance the partial nitrification and denitrification of aerobic granular sludge (AGS), the operational modes, including anaerobic/aerobic (R1) and anaerobic/aerobic+anaerobic/aerobic (R2)，and the influent C/N ratios (6, 7.5, 10) of the sequencing batch reactor (SBR) were optimized. The results showed that when the AGS in R2 was cultured to day 56, the filamentous bacteria seriously bulked, leading to the suspension of the reactor. However, granules in R1 had better settling performance and pollutant removal efficiency compared to R2. When C/N ratio of R1 was 6 and 7.5, the partial nitrification and denitrification occurred briefly. When the C/N ratio was increased to 10, NO2--N significantly accumulated, and NAR achieved 100%, the purpose of enhancing AGS partial nitrification and denitrification was successfully realized in R1, and the removal rates of COD, TIN and TP were above 95%,75% and 70%, respectively. The results of high?throughput sequencing showed that the microbial community structure in R1 system after granulation was significantly different from that of inoculated sludge. At the genus level, the genera Candidatus_Competibacter (0.28%) and Flavobacterium (0.03%) in the inoculated sludge had relative lower abundance. After the implementation of sludge granulation in R1, a variety of denitrifying bacteria such as Candidatus_Competibacter (13.53%) and Thauera (3.25%) were noticeably enriched. In addition, the genera Flavobacterium (13.66%) and Comamonas (2.23%) were the dominant ammonia oxidizing bacteria (AOB). It was speculated that these bacteria cooperated with each other to achieve efficient partial nitrification and denitrification in AGS system.
Last Update:
2023-01-01