Nitrous oxide emissions from aerobic granular sludge

Abstract The emissions of climate-relevant nitrous oxides from wastewater treatment with aerobic granular sludge (AGS) are of special interest due to considerable structural as well as microbiological differences compared with flocculent sludge. Due to the compact and large structures, AGS is characterised by the formation of zones with different dissolved oxygen (DO) and substrate gradients, which allows simultaneous nitrification and denitrification (SND). N2O emissions from AGS were investigated using laboratory-scale SBR fed with municipal wastewater. Special attention was paid to the effects of different organic loading rates (OLR) and aeration strategies. Emission factors (EF) were in a range of 0.54% to 4.8% (gN2O/gNH4-Nox.) under constant aerobic conditions during the aerated phase and different OLR. Higher OLR and SND were found to increase the N2O emissions. A comparative measurement of two similarly operated SBR with AGS showed that the reactor operated under constant aerobic conditions (DO of 2 mg L−1) emitted more N2O than the SBR with an alternating aeration strategy. Total nitrogen (TN) removal was significantly higher with the alternating aeration since non-aerated periods lead to increased anoxic zones inside the granules. The constant aerobic operation was found to promote the accumulation of NO2-N, which could explain the differences in the N2O levels.

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Performance of aerobic granular sludge at variable circulation rate in anaerobic–aerobic conditions

Water Science & Technology ◽

10.2166/wst.2014.156 ◽

2014 ◽

Vol 69 (11) ◽

pp. 2252-2257 ◽

Cited By ~ 3

Author(s):

Hasnida Harun ◽

Aznah Nor Anuar ◽

Zaini Ujang ◽

Noor Hasyimah Rosman ◽

Inawati Othman

Keyword(s):

Municipal Wastewater ◽

Granular Sludge ◽

Ammonia Removal ◽

Soy Sauce ◽

Volume Index ◽

Aerobic Granular Sludge ◽

Circulation Rate ◽

Anaerobic Conditions ◽

Aerobic Conditions ◽

Mixed Liquor

Aerobic granular sludge (AGS) has been applied to treat a broad range of industrial and municipal wastewater. AGS can be developed in a sequencing batch reactor (SBR) with alternating anaerobic–aerobic conditions. To provide anaerobic conditions, the mixed liquor is allowed to circulate in the reactor without air supply. The circulation flow rate of mixed liquor in anaerobic condition is the most important parameter of operation in the anaerobic-AGS processes. Therefore, this study investigates the effect of circulation rate on the performance of the SBR with AGS. Two identical reactors namely R1 and R2 were operated using fermented soy sauce wastewater at circulation rate of 14.4 and 36.0 l/h, respectively. During the anaerobic conditions, the wastewater was pumped out from the upper part of the reactor and circulated back into the bottom of the reactor for 230 min. A compact and dense AGS was observed in both reactors with a similar diameter of 2.0 mm in average, although different circulation rates were adopted. The best reactor performance was achieved in R2 with chemical oxygen demand removal rate of 89%, 90% total phosphorus removal, 79% ammonia removal, 10.1 g/l of mixed liquor suspended solids and a sludge volume index of 25 ml/g.

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Analysis of nitrous oxide emissions from aerobic granular sludge treating high saline municipal wastewater

The Science of The Total Environment ◽

10.1016/j.scitotenv.2020.143653 ◽

2021 ◽

Vol 756 ◽

pp. 143653

Author(s):

Benjamin J. Thwaites ◽

Richard Stuetz ◽

Michael Short ◽

Petra Reeve ◽

Juan-Pablo Alvarez-Gaitan ◽

...

Keyword(s):

Nitrous Oxide ◽

Municipal Wastewater ◽

Granular Sludge ◽

Nitrous Oxide Emissions ◽

Aerobic Granular Sludge

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Aerobic granular sludge reactor treating anaerobically pretreated brewery wastewater at different loading rates

Proceedings of the Water Environment Federation ◽

10.2175/193864718825137115 ◽

2018 ◽

Vol 2018 (13) ◽

pp. 2295-2298

Author(s):

A. di Biase ◽

S.F Corsino ◽

T.R Devlin ◽

M Torregrossa ◽

G Munz ◽

...

Keyword(s):

Granular Sludge ◽

Aerobic Granular Sludge ◽

Brewery Wastewater ◽

Loading Rates

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Performance and Characteristics of Aerobic Granular Sludge Degrading 2,4,6-Trichlorophenol at Different Volumetric Organic Loading Rates

CLEAN - Soil Air Water ◽

10.1002/clen.201500127 ◽

2016 ◽

Vol 44 (6) ◽

pp. 615-623 ◽

Cited By ~ 7

Author(s):

Stefano Milia ◽

Roberta Porcu ◽

Simona Rossetti ◽

Alessandra Carucci

Keyword(s):

Granular Sludge ◽

Aerobic Granular Sludge ◽

Organic Loading ◽

Loading Rates

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Managing Municipal Wastewater Treatment to Control Nitrous Oxide Emissions from Tidal Rivers

Water ◽

10.3390/w11061255 ◽

2019 ◽

Vol 11 (6) ◽

pp. 1255

Author(s):

Chandra Sekhar Akella ◽

S. Murty Bhallamudi

Keyword(s):

Nitrous Oxide ◽

Municipal Wastewater ◽

High Tide ◽

Tidal River ◽

Nitrous Oxide Emissions ◽

N2o Emissions ◽

Municipal Wastewater Treatment ◽

Water Release ◽

Decision Variables ◽

Waste Load

Waste load allocation management models were developed for controlling nitrous oxide emissions from a tidal river. The decision variables were treatment levels at wastewater discharging stations and the rate of upstream water release. The simulation model for N2O emissions from the river was embedded in the optimization model and the problem was solved using the simulated annealing technique. In two of the models, the total cost was minimized, while in the third model, emissions from the river were minimized for a specified constraint on the available money. Proof-of-concept studies, with hypothetical scenarios for contaminant loading but realistic flow conditions corresponding to the Tyne River, UK, were carried out. It was found that the treatment cost could be reduced by 36% by treating wastewater discharges in the upper reaches more during the high tide as compared to during low tide. For the same level of N2O emissions, approximately 16.7% lesser costs could be achieved by not only treating the wastewater but also inducing dilution by releasing more water from the upstream side. It was also found that beyond a limit, N2O emissions cannot be reduced significantly by spending more money on treatment and water release.

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Formation and properties of pure-oxygen aerobic granular sludge (POAGS) at high organic loading rates (HOLR)

10.5004/dwt.2020.25024 ◽

2020 ◽

Vol 179 ◽

pp. 45-53

Author(s):

Fanghui Pan ◽

Youbao Wang ◽

Yongbin Jiang ◽

Xinxi Zhang ◽

Kunxiao Huang ◽

...

Keyword(s):

Granular Sludge ◽

Pure Oxygen ◽

Aerobic Granular Sludge ◽

Organic Loading ◽

Loading Rates

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Biological degradation of a mixture of municipal wastewater and organic garbage leachate in expanded bed anaerobic reactors and a zeolite filter

Water Science & Technology ◽

10.2166/wst.2009.019 ◽

2009 ◽

Vol 59 (4) ◽

pp. 723-728 ◽

Cited By ~ 2

Author(s):

P. Castilla ◽

L. Aguilar ◽

M. Escamilla ◽

B. Silva ◽

Z. Milán ◽

...

Keyword(s):

Suspended Solids ◽

Municipal Wastewater ◽

Total Suspended Solids ◽

Granular Sludge ◽

Biological Degradation ◽

Organic Loading ◽

Methanogenic Activity ◽

Loading Rates ◽

Anaerobic Reactors ◽

Removal Efficiencies

Municipal wastewater was amended with organic garbage leachates at a concentration around 700 mgCODsoluble/L and fed to three different anaerobic systems to compare their performance: a down flow fluidized bed (DFFB), an expanded granular sludge bed (EGSB) and a zeolite-packed anaerobic filter reactor (ZPF). The DFFB and EGSB reactors were operated at HRT of 6 and 4 h and the ZPF reactor at 12 and 36 h. Organic loads rate for the DFFB reactor were 2.3±0.9 and 4.8±1.8 gCOD/L·d, with removal efficiencies around 40% and a methane productivity of 0.2±0.03 L/Lreactor·d. For the EGSB reactor, organic loads tested were 2.1±0.9 and 4.3±1.3 gCOD/L·d, removal efficiencies attained were of 77.6±12.7% and 84.4±4.9%, respectively at both conditions and total suspended solids were removed in 54.6±19.3%, while methane productivity at 4 h HRT was of 1.29±0.4 L/Lreactor·d. The ZPF reactor was operated at lower organic loading rates, 1.4±0.27 and 0.42±0.13 gCOD/L·d and attained removal efficiencies of 48±18% and 83±8%, respectively, reaching a methane productivity of 0.21±0.09 and 0.12±0.04 L/Lreactor·d, 83±8.0% of total suspended solids were retained in the reactor and as HRT was increased ammonium concentrations increased in 39%. Specific methanogenic activity in all systems was around 0.2 gCOD-CH4/gVSS d.

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