This study aimed at modelling the performance of a novel MBBR configuration, named A/O-MBBR, comprised of a pre-anoxic reactor, with an HRT of 4.5 h, coupled with an intermittent anoxic/aerobic MBBR (HRT = 6.8 h). The lab-scale system was fed with municipal wastewater with an average influent Total Ammonia Nitrogen (TAN) and total COD (TCOD) concentrations of 46 mg of TAN-N L-1 and 310 mg TCOD L-1. During the whole experimental period, TAN removal efficiency was always higher than 96%; denitrification was also very effective, achieving nitrate and nitrite concentrations in the effluent both lower than 5 mg NOx-N L-1 on average. Moreover, TCOD average removal efficiency was equal to 85%. Modelling was performed to investigate the nitrification efficacy enhancement; to this aim, a biofilm model was developed, adopting the equations for mixed-culture biofilms and the Activated Model Sludge n degrees 1 (ASM1) for the biological processes rates. The model allowed to determine the maximum uptake rate for autotrophic growth (mu(A) was 2.5 d(-1)) and the semisaturation constant (K-OA was 0.2 mg O-2 L-1), suggesting that the nitrification process was 3-fold faster than average and very effective at low oxygen concentrations. The model estimated that about 85% of TAN was removed by the biofilm and only the remaining part by suspended biomass in the bulk liquid. Finally, it was assessed that the A/O-MBBR configuration allowed for a 45-60% savings of the energy requirement compared to a Benchmark WWTP layout.

Mathematical Modelling of an Intermittent Anoxic/aerobic MBBR: Estimation of Nitrification Rates and Energy Savings / Montecchio, D.; Mattei, M. R.; Esposito, G.; Andreottola, G.; Ferrentino, R.. - In: JOURNAL OF ENVIRONMENTAL MANAGEMENT. - ISSN 1095-8630. - 321:(2022), p. 116026. [10.1016/j.jenvman.2022.116026]

Mathematical Modelling of an Intermittent Anoxic/aerobic MBBR: Estimation of Nitrification Rates and Energy Savings

Andreottola G.;Ferrentino R.
2022-01-01

Abstract

This study aimed at modelling the performance of a novel MBBR configuration, named A/O-MBBR, comprised of a pre-anoxic reactor, with an HRT of 4.5 h, coupled with an intermittent anoxic/aerobic MBBR (HRT = 6.8 h). The lab-scale system was fed with municipal wastewater with an average influent Total Ammonia Nitrogen (TAN) and total COD (TCOD) concentrations of 46 mg of TAN-N L-1 and 310 mg TCOD L-1. During the whole experimental period, TAN removal efficiency was always higher than 96%; denitrification was also very effective, achieving nitrate and nitrite concentrations in the effluent both lower than 5 mg NOx-N L-1 on average. Moreover, TCOD average removal efficiency was equal to 85%. Modelling was performed to investigate the nitrification efficacy enhancement; to this aim, a biofilm model was developed, adopting the equations for mixed-culture biofilms and the Activated Model Sludge n degrees 1 (ASM1) for the biological processes rates. The model allowed to determine the maximum uptake rate for autotrophic growth (mu(A) was 2.5 d(-1)) and the semisaturation constant (K-OA was 0.2 mg O-2 L-1), suggesting that the nitrification process was 3-fold faster than average and very effective at low oxygen concentrations. The model estimated that about 85% of TAN was removed by the biofilm and only the remaining part by suspended biomass in the bulk liquid. Finally, it was assessed that the A/O-MBBR configuration allowed for a 45-60% savings of the energy requirement compared to a Benchmark WWTP layout.
2022
Montecchio, D.; Mattei, M. R.; Esposito, G.; Andreottola, G.; Ferrentino, R.
Mathematical Modelling of an Intermittent Anoxic/aerobic MBBR: Estimation of Nitrification Rates and Energy Savings / Montecchio, D.; Mattei, M. R.; Esposito, G.; Andreottola, G.; Ferrentino, R.. - In: JOURNAL OF ENVIRONMENTAL MANAGEMENT. - ISSN 1095-8630. - 321:(2022), p. 116026. [10.1016/j.jenvman.2022.116026]
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11572/354362
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