Abstract
The simultaneous anammox and denitrification granular process effectively removes nitrogen and organic matter, but its optimization for variable nitrogen loading rates (NLRs) is challenging due to regulatory complexities and delays. This study developed and evaluated a modified model to determine an effective operational strategy, using data from batch tests and long-term experiments. Simulations revealed a spatial cross-distribution of anammox bacteria and heterotrophic denitrification bacteria (HDB) within the granules, and HDB tended to grow on the surface. Higher NLRs (from 0.35 to 14.06 kg N (m3·d)−1) extended the time to reach steady state, limiting the treatment capacity to 7.73 kg N (m3·d)−1 at NH4+-N/NO2−-N/COD = 1:1.32: 0.5. At different influent NH4+-N concentrations (NH4+-NInf: 40, 150, and 300 g N m−3), single-factor simulations showed that optimal nitrogen removal and granular stability were achieved at specific NO2−-N/NH4+-N ratios (1.2–1.3), C/N ratios (1.2–0.8), and particle sizes (500–1000 μm). Adjusting the NO2−-N/NH4+-N (1.0–1.6) and C/N ratios (0.2–1.2) zones synergistically improved the operational efficiency (TN removal efficiency >90 %). Notably, elevated NH4+-NInf amplified single-factor effects, complicating efficient optimization. These insights significantly inform the process design and operation in varying NLR wastewater contexts.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
