Start-up strategy of single-stage partial nitrification-anammox process for anaerobic digestion effluent

• Published in: Bioresource technology 2024-09, Vol.408, p.131213, Article 131213
• Main Authors: Park, Jihye, Song, Minsu, Hwang, Kwanghyun, Bae, Hyokwan
• Format: Article
• Language: English
• Subjects: Aeration; Hydraulic retention time; Internal recirculation; Iron particle-integrated anammox granules; Nitrogen removal; Real wastewater; Single-stage system
• ISSN: 0960-8524; 1873-2976; 1873-2976
• DOI: 10.1016/j.biortech.2024.131213

[Display omitted] •Oxygen inhibition of anammox activity was prevented for single-stage application.•Anammox granules larger than 1 mm of EGSB showed high oxygen resistance.•Internal recirculation of IP-IAG is effective for AnAOB adaptation to oxygen.•Optimal SPNA conditions with IP-IAG were 0.01 vvm aeration and 24 h HRT.•The continuous SPNA showed TNRE and NRR of 86 % and 0.74 kg-N/m3·d, respectively. The objective of this study was to improve the nitrogen removal efficiency and reduce the start-up period of a single-stage partial nitritation-anammox (SPNA) system using iron particle-integrated anammox granules (IP-IAGs). Anammox granules were enriched in sequencing batch and expanded granular sludge bed (EGSB) reactors. The EGSB reactor produced larger and more uniform granules with higher specific anammox activity. IP-IAGs were then inoculated into a two-stage partial nitritation-anammox reactor treating anaerobic digestion (AD) effluent, followed by an internal recirculation strategy to acclimate the granules to oxygen exposure for SPNA. Finally, the SPNA process operated to treat real AD effluent under optimal conditions of 0.05 L/min aeration intensity (0.01 vvm) and 24 h of hydraulic retention time, achieving TNRE of 86.01 ± 2.64 % and nitrogen removal rate of 0.74 ± 0.04 kg-N/m3·d for 101 d.