XUELei,ZENGLing-cong,LIZheng-hao,et al.Nitrogen Removal Performance through Synergistic Operation of Aerobic Granular Sludge and Anaerobic Ammonium Oxidation Granular Sludge[J].China Water & Wastewater,2025,41(23):132-140.
Nitrogen Removal Performance through Synergistic Operation of Aerobic Granular Sludge and Anaerobic Ammonium Oxidation Granular Sludge
China Water & Wastewater[ISSN:1000-4062/CN:12-1073/TU]
volume:
第41卷
Number:
第23期
Page:
132-140
Column:
Date of publication:
2025-12-01
- Keywords:
- aerobic granular sludge; anaerobic ammonium oxidation granular sludge; continuous flow reactor; expanded granular sludge blanket; sequencing batch reactor; autotrophic nitrogen removal
- Abstract:
- A coupled system integrating aerobic granular sludge (AGS) and anaerobic ammonium oxidation granular sludge (AnGS) was developed to provide technical support for autotrophic denitrification of wastewater from ionic rare earth mines in Southern Jiangxi Province. During operation, the morphologies of AGS in the continuous flow reactor (CFR), as well as those of AnGS in the expanded granular sludge blanket (EGSB) and sequencing batch reactor (SBR), remained largely stable, with granulation rates consistently exceeding 95% throughout the experimental period. Through oxygen- limited aeration, combined with the regulation of influent ammonia nitrogen and alkalinity, the ratio of ammonia nitrogen to nitrite nitrogen in the CFR effluent gradually stabilized between 1∶1.01 and 1∶1.36 after day 35. The nitrite accumulation rate (NAR) consistently remained within the range of 80.27% to 98.59%, while the total inorganic nitrogen (TIN) removal efficiency gradually stabilized at approximately 25% to 35%. The selective inhibition of nitrite-oxidizing bacteria (NOB) by free ammonia (FA) was crucial for achieving stable partial nitrification. The nitrogen removal performance of the EGSB reactor was highly unstable. After the 64th day, the TIN removal efficiency declined below 10%, leading to significant fluctuations in the overall TIN removal efficiency within the CFR-EGSB system, ranging from 24.84% to 78.83%. The contribution rates of the CFR and EGSB to TIN removal varied between 28.35% and 96.79%, and 3.32% and 71.65%, respectively. The rise in free nitrous acid (FNA) between day 61 and day 80 might be the primary factor contributing to the deterioration of nitrogen removal performance in the EGSB. The TIN removal efficiency of the SBR exhibited a consistent upward trend from day 81 to day 90 and remained relatively stable between 60% and 70% thereafter. In contrast, the TIN removal efficiency of the CFR-SBR coupled process gradually increased, reaching a maximum of 80.36%. Concurrently, the contribution rate of SBR unit to TIN removal rose progressively to about 60%.
Last Update:
2025-12-01