Assessing membrane aerated biofilm reactor configurations in mainstream anammox applications

Abstract

Partial nitritation anammox (PNA) membrane aerated biofilm reactors (MABR) have the potential to be employed in mainstream wastewater treatment and can drastically decrease the energy and carbon requirements for nitrogen removal. Previous PNA MABR studies have looked at 1-stage systems, but no study has holistically compared the performance of different MABR configurations. In this study, a PNA MABR was mechanistically modelled to determine the impact of the reactor configuration (1-stage, hybrid, or 2-stage system) on the location of the preferred niche for anammox bacteria and the overall nitrogen removal performance. Results from this study show that the 2-stage configuration which used an MABR with a thin biofilm for nitritation and a moving bed biofilm reactor for anammox had a 20% larger nitrogen removal rate than the 1-stage or hybrid configurations. This suggests that an MABR should focus on maximizing nitrite production with anammox implemented in a second-stage biofilm reactor to achieve the most cost-effective nitrogen removal. However, the optimal configuration will likely be facility specific, as each facility differs in operating costs, construction costs, footprint, and effluent limits. Additional experimentation is required to confirm these results, but this work narrows the number of viable configurations that need to be tested. The results of this study will inform researchers and engineers how to best implement PNA MABRs in mainstream nitrogen removal at larger scales.

Advancements in biofilm carriers and gas-permeable membranes: assessment of zeolite technologies for shortcut nitrogen removal applications in wastewater

“…14 Many studies have shown that biofilm technologies work well for shortcut nitrogen removal processes, but that there is still room for improvement, particularly with respect to enhancing the colonization and retention of anammox biomass. 10,13,[15][16][17] Because of their ability to sorb and therefore concentrate ammonium, zeolite-coated membranes and biofilm carriers could improve current biofilm technologies for shortcut nitrogen removal by enriching the local environment for ammonium. 18,19 It is thought that if ammonium is present at a higher concentration, it could improve both the rate at which anammox bacteria colonize solid supports and their retention.…”

“…14 Many studies have shown that biofilm technologies work well for shortcut nitrogen removal processes, but that there is still room for improvement, particularly with respect to enhancing the colonization and retention of anammox biomass. 10,13,15–17…”

Modelagem matemática do processo de nitritação parcial/anammox em reatores de biofilme aerado por membrana (MABR).

“…Não há registro de estudos experimentais utilizando o MABR no póstratamento de reatores UASB, com a maior parte dos estudos avaliando-o para tratamento de efluentes sintéticos (WAGNER et al, 2022). Para efeito de comparação, Bunse et al (2020), aplicando o MABR para tratamento de esgoto doméstico bruto (sem remoção prévia de matéria orgânica), obteve resultados ligeiramente piores: 40% de remoção de NT operando um reator com taxa de aplicação superficial de N de 2,0 g N/m 2 /dia e TDH médio de 15,8 h. Por outro lado, Augusto et al (2018), operando um MABR em escala de bancada para um efluente sintético com concentração de nitrogênio amoniacal 50 mg N/L e sem carbono orgânico, obteve remoção média NT de 78% para um TDH de 24h (taxa de aplicação de nitrogênio por área de membrana não reportada).…”