Startup strategies for mainstream anammox polishing in moving bed biofilm reactors

Abstract

This study evaluated startup strategies for mainstream polishing anammox moving bed biofilm reactors (MBBRs) without anammox bacterial (AMX) biomass inoculation. Two types of startups were tested: anammox only (no external carbon addition) and partial denitrification/anammox (PdNA) with glycerol addition. Reactors were started with either virgin carriers or carriers with a preliminary biofilm from a mainstream aerobic integrated fixed‐film activated sludge (IFAS) process. Three pilot‐scale startups were completed under the following conditions: anammox‐only with preliminary biofilm carriers, PdNA with preliminary biofilm carriers, and PdNA with virgin carriers. AMX presence was confirmed via quantitative polymerase chain reaction (qPCR) after 57, 57, and 77 days, respectively. Prior to AMX detection, average influent concentrations of ammonia and nitrite ranged from 1.7–2.7 mg/L and 0.98–1.8 mg/L, respectively. This study demonstrated that AMX can be grown on carriers without AMX seeding under mainstream conditions (temperature 17–29°C, low ammonia and nitrite), regardless of whether nitrite came from upstream or partial denitrification within the reactor. This study also showed that using preliminary biofilm carriers can decrease startup time by approximately 1 month. These results address critical questions for moving mainstream anammox processes to full‐scale implementation, and suggest that PdNA MBBRs are feasible and sustainable for full‐scale ammonia, nitrate, and nitrite polishing to meet stringent total nitrogen requirements. Practitioner Points This research will help utilities develop methods for starting up mainstream anammox MBBRs without the barrier of anammox biomass seeding. Preliminary biofilm carriers accelerated startup time in a PdNA MBBR, but a virgin carrier reactor started up in a similar timeframe, contrary to expectations. Also, contrary to expectations, high concentrations of ammonia and nitrite are not necessary for startup of an anammox or PdNA MBBR.

Nitrogen removal capacity and carbon demand requirements of partial denitrification/anammox MBBR and IFAS processes

“…The PdNA MBBR contained media that already had anammox established on it during a prior anammox startup study (without seed) in the same MBBR (Figure S1). The second anoxic MBBR in the series contained media with anammox already established on it from a prior anammox MBBR startup experiment at HRSD's Chesapeake‐Elizabeth Treatment Plant BNR Pilot (Schoepflin et al, 2020).…”

“…PdNA has been implemented in hybrid granular/suspended growth processes (Le et al, 2019b), deep bed filters (Cui et al, 2020; Fofana et al, 2020; Klaus et al, 2020), upflow anaerobic sludge bed reactors (Xu et al, 2020), moving bed biofilm reactors (MBBRs, Campolong et al, 2019; Schoepflin et al, 2020), and integrated fixed‐film activated sludge (IFAS, Forney et al, 2020) configurations. All of these are pilot‐scale processes except for Klaus et al (2020), which describes the full‐scale implementation of a PdNA deep‐bed denitrification filter operating at the Hampton Roads Sanitation District's (HRSD) York River Wastewater Treatment Plant since 2018.…”

Full‐scale transition from denitrification to partial denitrification–anammox (PdNA) in deep‐bed filters: Operational strategies for and benefits of PdNA implementation

“…Only one genus of AnAOB was found in the filters, Candidatus Brocadia, which has been frequently identified in PdNA systems (Cui et al, 2020; Du et al, 2019; Fofana, Huynh et al, 2022; Lu et al, 2021; Schoepflin et al, 2022; Wang et al, 2020; Wang, Xu et al, 2020; Zhan et al, 2020; Zheng, et al, 2020). The relative abundance of Candidatu s Brocadia (2–5%) obtained in the filters was significantly higher than other one‐stage PdNA filters (0.7–1.0%) (Cao et al, 2020; Lu et al, 2021), most likely due to the higher loading rates at full‐scale.…”

“…Integrated refers to PdNA occurring within the mixed liquor in either a pre-or post-anoxic zone of the biological nutrient removal (BNR) process with some mechanism for AnAOB retention (e.g., screens, hydrocyclones, or integrated fixed film activated sludge [IFAS]) (Ali et al, 2020;Bachmann et al, 2021;Cui et al, 2021;Ladipo-Obasa et al, 2022;Le et al, 2019a). Polishing refers to PdNA occurring in a separate reactor downstream of secondary clarification such as in moving bed biofilm reactors (MBBRs) (Bachmann et al, 2021;Campolong et al, 2019;Schoepflin et al, 2022;, sequencing batch reactors Sharp et al, 2017;Zhang et al, 2019), upflow anaerobic sludge blanket reactors Zhang et al, 2019), and deep-bed filters (Cao et al, 2019;Cui et al, 2020;Lu et al, 2021;Ma et al, 2020). Implementation of PNA or PdNA reduces aeration, alkalinity, and supplemental COD addition Lackner et al, 2014;Siegrist et al, 2008;Trinh et al, 2021).…”

Concept development of a mainstream deammonification and comparison with conventional process in terms of energy, performance and economical construction perspectives

“…Since the last decades, there have been many studies conducted on the determination of optimal conditions for deammonification, the effect of reactor technologies such as moving bed biofilm reactor (MBBR) and configurations such as integrated fixed-film activated sludge (IFAS), the impact of different biofilm carriers and additives such as salts and polymers for the process stability, the identification of the diversity and distribution of involved microorganisms and examination of their growth conditions ( Liu et al, 2021 ; Feng et al, 2022 ; Jiang et al, 2022 ; Ladipo-Obasa et al, 2022 ; Schoepflin et al, 2022 ; Zhang et al, 2022 ). So far, most of the studies have been carried out on a laboratory scale with artificial wastewater.…”