Optimizing Carbon Addition to a Polishing Partial Denitrification/Anammox MBBR using Online Control

Self Cite

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.

Section: Establishment Of Amx Without Seedcontrasting

confidence: 72%

Section: Introductionmentioning

confidence: 99%

Startup strategies for mainstream anammox polishing in moving bed biofilm reactors

Schoepflin

Justin

Long

et al. 2022

Self Cite

“…The difficulty to demonstrate that significant amounts of ammonium (NH 4 + -N) are being consistently routed through the anammox pathway and the lack of stability and reliability of NOB out-selection limit the full-scale adoption of PNA processes. Partial denitrification-anammox (PdNA) has emerged as a more stable approach to shortcut nitrogen removal as it does not depend on NOB out-selection (Campolong et al, 2018;Le et al, 2019a). PdNA requires that part of the influent ammonium be oxidized aerobically upstream prior to an anoxic zone where partial denitrification (PdN) and anammox (AnAOB) reactions occur simultaneously.…”

Section: Introductionmentioning

confidence: 99%

“…Recent pilot research has shown that, with stable influent loading, PdN can be effectively controlled simply by maintaining a nitrate (NO 3 − ‐N) residual through feedback carbon dosing control (Campolong et al, 2018; Le et al, 2019a), making requirements for PdN selection compatible with current instrumentation present in polishing filters. With more variable diurnal loading consistent with full‐scale plants, the PdN processes likely require feedforward–feedback control.…”

Section: Introductionmentioning

confidence: 99%

“…Partial denitrification–anammox (PdNA) has emerged as a more stable approach to shortcut nitrogen removal as it does not depend on NOB out‐selection (Campolong et al, 2018; Du et al, 2019; Le et al, 2019a). PdNA requires that part of the influent ammonium be oxidized aerobically upstream prior to an anoxic zone where partial denitrification (PdN) and anammox (AnAOB) reactions occur simultaneously.…”

Section: Introductionmentioning

confidence: 99%

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

Fofana

Parsons

Long

et al. 2022

Self Cite

This study shows for the first time more than 2 years of operation of a mainstream anammox application at full-scale under temperate climate. This implementation of partial denitrification-anammox (PdNA) in deep bed filters at the HRSD York River treatment plant was demonstrated to achieve the benefits of shortcut nitrogen removal without nitrite oxidizing bacteria (NOB) out-selection. The transition from denitrification to PdNA filters required bleeding ammonium to the filters using an optimized ammonium versus NOx (AvN) control in the upstream aeration tanks and maintaining a nitrate residual in the filter effluent through feedforward/feedback control. The latter actions led to savings of 85% in methanol, 100% in alkalinity, and 35% in capacity enhancement. Up to 6 mg NH 4 + -N/L with an average of 2.2 ± 0.98 mg NH 4 + -N/L was removed through the anammox pathway, which accounted for about 15% of the overall plant nitrogen removal. Anammox enrichment was confirmed by activity testing and molecular analysis. The large excess of AnAOB capacity present in the filters (5-10 times more than normal operation) resulted in stable and reliable operation through winter conditions and showed potential for further intensification. Practitioner Points• For the first time, long-term mainstream anammox was established fullscale through PdNA implementation in deep-bed filters. • PdNA implementation required upstream aeration control optimization to provide a blend of ammonium and nitrate to the filters.• Efficient anammox enrichment and retention resulted in reliable PdNA performance under different seasonal and influent conditions.All authors are members of the Water Environment Federation (WEF).

Impact of instrumentation reliability on mainstream suspended partial denitrification–anammox (PdNA)

Ladipo‐Obasa

Forney

Foster

et al. 2023

This study successfully revealed the importance of probe reliability and sensitivity with ion sensitive electrode (ISE) probes on achieving high partial denitrification (PdN) efficiency; and decreasing carbon overdosing events that cause the decline of microbial populations and performance of PdNA. In a mainstream integrated hybrid granule–floc system, an average PdN efficiency of 76% was achieved with acetate as the carbon source. Thauera was identified as the dominant PdN species; its presence in the system was analogous to instrumentation reliability and PdN selection and was not a consequence of bioaugmentation. Up to 27–121 mg total inorganic nitrogen/L/d, an equivalent of 18–48% of the overall total inorganic nitrogen removed, was achieved through the PdNA pathway. Candidatus Brocadia was the main anoxic ammonium oxidizing bacteria species that was seeded from sidestream and enriched and retained in the mainstream system with observed growth rates of 0.04–0.13 day−1. Moreover, there was no direct negative impact of methanol's use for post‐polishing on anoxic ammonium oxidizing bacteria activity and growth. Practitioner Points Stress testing with ISE sensors revealed the importance of probe reliability and sensitivity on PdN selection and PdNA performance. Up to 121 mg TIN/L/d was achieved via PdNA in a mainstream suspended hybrid granule–floc partial denitrification–anammox (PdNA) system. Candidatus Brocadia was the dominant AnAOB species with observed growth rates of 0.04–0.13 day–1. There was no direct negative impact of methanol's use for post‐polishing on AnAOB activity and growth.