LIUWen-long,YINGQian-hong,WANGJia-ming,et al.Achieving Deep Nitrogen Removal via Two-stage PN-SAED Process from Low C/N Ratio Wastewater[J].China Water & Wastewater,2025,41(1):1-8.
Achieving Deep Nitrogen Removal via Two-stage PN-SAED Process from Low C/N Ratio Wastewater
China Water & Wastewater[ISSN:1000-4062/CN:12-1073/TU]
volume:
第41卷
Number:
第1期
Page:
1-8
Column:
Date of publication:
2025-01-01
- Keywords:
- partial nitrification; Anammox; endogenous denitrification; deep nitrogen removal; microbial community structure
- Abstract:
- To address the issue of instability and nitrate accumulation in the effluent of the mainstream anaerobic ammonia oxidation (Anammox) process treating municipal wastewater, this study established a two-stage process combining partial nitrification/Anammox with endogenous denitrification (PN-SAED) process for low carbon to nitrogen (C/N) ratio wastewater treatment, and the deep nitrogen removal performance and changes in microbial community structure were evaluated. The results indicated that, with an influent C/N ratio of 2.60 ± 0.11, the PN-SAED process achieved an effluent total inorganic nitrogen (TIN) concentration of (2.6 ± 0.5) mg/L, corresponding to a TIN removal efficiency of (94.6 ± 1.0)%. Nitrogen balance analysis during a typical cycle showed that the contributions of the PN and SAED systems to nitrogen removal were 7.3% and 92.7%, respectively, with the Anammox pathway accounting for the majority of nitrogen removal (82.2%) in the SAED system. High-throughput sequencing data revealed that the addition of hydroxylamine led to a rapid decline in the abundance of nitrite- oxidizing bacteria (Nitrospira, from 3.1% to 0.6%) in the PN system, while enriching ammonia-oxidizing bacteria (Nitrosomonas, from 0.13% to 0.92%), achieving stable partial nitrification. In the SAED system, Candidatus Brocadia (12.3%) and Candidatus Jettenia (2.83%) emerged as the dominant Anammox bacteria, coexisting synergistically with endogenous denitrifying bacteria of Candidatus Competibacter (17.5%) and Denitratisoma (7.15%), thereby accomplishing deep nitrogen removal from municipal wastewater with a low C/N ratio.
Last Update:
2025-01-01