Achieving single‐stage partial nitritation and anammox (PN/A) using a submerged dynamic membrane sequencing batch reactor (DM‐SBR)

Abstract

Single‐stage partial nitration and anammox (PN/A) process was achieved in a sequencing batch reactor (SBR) using a submerged dynamic membrane (DM) in this study. The reactor was stably operated for 200 days, and the nitrogen removal efficiency (NRE) was sustained at 70.3 ± 7.2% at a nitrogen loading rate (NLR) ranging from 0.1 to 0.3 kgNm−3 day−1 with a hydraulic retention time (HRT) of 24 hr. When the NLR was 0.2 kgN m−3day−1, the NRE achieved was high as 80% with a low concentration of dissolved oxygen (DO) of 0.13 mg/L. In addition, the specific activity of anammox bacteria and ammonia‐oxidizing bacteria (AOB) reached was 2.72 and 16.80 gN gVSS−1day−1, respectively. The DM intercepted the biomass due to the lamellar, intact, dense biofilm self‐generated on the surface of the supporting material, which had an effluent turbidity of 10 NTU. The enriched anammox functional bacteria were Candidatus Jettenia (11.06%) and the AOB‐like functional bacteria consisted primarily of Nitrosomonas, with a relative abundance of 2.76%, which ensured the PN/A process proceeding. This study provides a novel reactor configuration of the single‐stage PN/A process in the view of practical applications. Practitioner points Single‐stage partial nitration and anammox (PN/A) process was achieved using a submerged dynamic membrane (DM) in this study. The reactor was stably operated for 200 days, and the nitrogen removal efficiency was sustained at 70.3 ± 7.2%. The feasibility of the PN/A system with DM is evaluated. The main objective is to provide a control strategy of the DM‐SBRs for practical applications.

Extracellular polymeric substances and microbial community shift during the start‐up of a single‐stage partial nitritation/anammox process

“…Analysis of the data at the SPN/A stage revealed that with the higher NRE in each stage, the corresponding above ratio was nearly 0.11, which was compatible with the finding of Chen et al (2019). A previous study reported that the performance of the SPN/A system in a dynamic membrane SBR with intermittent aeration, at influent NH 4 + ‐N of 300.00 mg/L, the NRE reached 70.31 ± 7.20% (Yang et al, 2021). In this research, an SBR was used to start and create a steady operation of an SPN/A system and obtained high activity of AOB and anammox bacteria with a NRE reaching 77.11% under intermittent aeration mode.…”

“…Therefore, it is necessary to develop more feasible strategies for the start-up of the SPN/A process. Previously, researchers found some strategies to inhibit NOB, such as manipulation of aeration duration (Li et al, 2021), increase of temperature (Malovanyy et al, 2015), increase of free ammonia (FA) concentration (Wang, Li, et al, 2020), as well as limitation of dissolved oxygen (DO) concentration (Yang et al, 2021). Moreover, the repetitive and alternating operations of the aeration system were an effective way to suppress NOB activity and achieve nitritation process stability (Miao et al, 2018).…”