LEIXue-yan,ZHUYi-chun,ZHANGChao,et al.Secondary Start-up and Nitrogen Removal Performance of Anammox under Room Temperature, Aerobic, and Low Concentration Substrate Conditions[J].China Water & Wastewater,2025,41(1):16-24.
Secondary Start-up and Nitrogen Removal Performance of Anammox under Room Temperature, Aerobic, and Low Concentration Substrate Conditions
China Water & Wastewater[ISSN:1000-4062/CN:12-1073/TU]
volume:
第41卷
Number:
第1期
Page:
16-24
Column:
Date of publication:
2025-01-01
- Keywords:
- Anammox; secondary start-up; room temperature; aerobic condition; low concentration substrate
- Abstract:
- Anammox is currently the most economical and efficient biological nitrogen removal process. However, the temperature and nitrogen concentration of domestic sewage are low, and it contains a certain amount of dissolved oxygen (DO). Moreover, the seed sludge of Anammox is scarce and difficult to obtain in large quantities, which limits its application in domestic sewage treatment. Hence, the feasibility of the secondary start-up of Anammox under room temperature, aerobic and low concentration substrate conditions was explored, and the nitrogen removal efficiency was evaluated. When the influent DO was 4.20-7.50 mg/L, ammonia nitrogen was 27.13-35.64 mg/L, nitrite nitrogen was 36.35-44.80 mg/L, and the temperature was 20.8-31.8 ℃, the removal efficiencies of ammonia nitrogen, nitrite nitrogen, and total nitrogen reached 92.63%, 81.61%, and 68.41% respectively after 79 days of operation. The ratio of ΔNO2--N/ΔNH4+-N was close to the theoretical value of 1.32, indicating the successful secondary start?up of Anammox. The DO in the effluent declined, ΔNO3--N/ΔNH4+-N was higher than the theoretical value, indicating nitrification took place within the system. The sludge possessed excellent settling performance and its color transformed from reddish brown and grayish black to brown. The extracellular polymeric substances of sludge was mainly tightly bounded, and the content of polysaccharides was higher than that of proteins. There were many hydrophilic functional groups such as hydroxyl and amino groups on the surface of the sludge, enabling the sludge particle size to be maintained within an appropriate range, which was beneficial for resisting the damage of external adverse factors to Anammox bacteria. High-throughput sequencing results revealed that the relative abundances of Candidatus_Anammoxoglobus and Candidatus_Kuenenia were 16.39% and 3.43%, and they interacted with other nitrogen-removal bacteria to achieve an efficient and stable nitrogen removal efficiency.
Last Update:
2025-01-01