scholarly journals Effects of the Food-to-Microorganism (F/M) Ratio on N2O Emissions in Aerobic Granular Sludge Sequencing Batch Airlift Reactors

Water ◽  
2017 ◽  
Vol 9 (7) ◽  
pp. 477 ◽  
Author(s):  
Ning Guo ◽  
Jian Zhang ◽  
Hui-Jun Xie ◽  
Lin-Rui Tan ◽  
Jie-Ning Luo ◽  
...  
Keyword(s):  
Granular Sludge ◽  
Aerobic Granular Sludge ◽  
N2o Emissions ◽  
Airlift Reactors

Effect of COD/N ratio on N2O production during nitrogen removal by aerobic granular sludge

2017 ◽  
Vol 76 (12) ◽  
pp. 3452-3460 ◽  
Author(s):  
V. F. Velho ◽  
B. S. Magnus ◽  
G. C. Daudt ◽  
J. A. Xavier ◽  
L. B. Guimarães ◽  
...  
Keyword(s):  
Nitrogen Removal ◽  
Operating Cost ◽  
Granular Sludge ◽  
N2o Emission ◽  
Nitrogen Loading ◽  
Partial Nitrification ◽  
Aerobic Granular Sludge ◽  
Nitrite Accumulation ◽  
N2o Emissions ◽  
N2o Production

Abstract N2O-production was investigated during nitrogen removal using aerobic granular sludge (AGS) technology. A pilot sequencing batch reactor (SBR) with AGS achieved an effluent in accordance with national discharge limits, although presented a nitrite accumulation rate of 95.79% with no simultaneous nitrification–denitrification. N2O production was 2.06 mg L−1 during the anoxic phase, with N2O emission during air pulses and the aeration phase of 1.6% of the nitrogen loading rate. Batch tests with AGS from the pilot reactor verified that at the greatest COD/N ratio (1.55), the N2O production (1.08 mgN2O-N L−1) and consumption (up to 0.05 mgN2O-N L−1), resulted in the lowest remaining dissolved N2O (0.03 mgN2O-N L−1), stripping the minimum N2O gas (0.018 mgN2O-N L−1). Conversely, the carbon supply shortage, under low C/N ratios, increased N2O emission (0.040 mgN2O-N L−1), due to incomplete denitrification. High abundance of ammonia-oxidizing and low abundance of nitrite-oxidizing bacteria were found, corroborating the fact of partial nitrification. A denitrifying heterotrophic community, represented mainly by Pseudoxanthomonas, was predominant in the AGS. Overall, the AGS showed stable partial nitrification ability representing capital and operating cost savings. The SBR operation flexibility could be advantageous for controlling N2O emissions, and extending the anoxic phase would benefit complete denitrification in cases of low C/N influents.

scholarly journals Nitrous oxide emissions from aerobic granular sludge

2019 ◽  
Vol 80 (7) ◽  
pp. 1304-1314 ◽  
Author(s):  
Lydia Jahn ◽  
Karl Svardal ◽  
Jörg Krampe
Keyword(s):  
Municipal Wastewater ◽  
Granular Sludge ◽  
Nitrous Oxide Emissions ◽  
Aerobic Granular Sludge ◽  
N2o Emissions ◽  
Nitrous Oxides ◽  
Aerobic Conditions ◽  
Loading Rates ◽  
Large Structures ◽  
Anoxic Zones

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.

An Attempt to Develop Aerobic Granular Sludge in Continuous Airlift Reactors

2021 ◽  
Vol 1025 ◽  
pp. 265-272
Author(s):  
Muhammad Syafiq Mohd Shafei ◽  
Zulkifly Jemaat
Keyword(s):  
Wastewater Treatment ◽  
Operation Mode ◽  
Treatment Plant ◽  
Granular Sludge ◽  
Cod Removal ◽  
Aerobic Granular Sludge ◽  
Organic Loading Rate ◽  
Aerobic Granules ◽  
Reactor Performance ◽  
Airlift Reactors

Recent advancement on biological wastewater treatment is via granular sludge technology. It is widely known that, aerobic granular sludge has been developed in a batch operation since its discovery. Yet, most of the wastewater treatment plant (WWTP) is operated in continuous mode. Now, the real challenge is how to adopt the granular technology while maintaining present operation mode of WWTP. Thus, this study attempts to evaluate the feasibility of developing aerobic granular sludge in continuous airlift reactors feed with two different substrates, namely glucose and acetate. Two identical airlift reactors (6 L) were employed and operated at room temperature (30°C). Prior to the substrate feeding, both reactors were inoculated with seed sludge obtained from a palm oil mill anaerobic pond. One of the reactors was fed with 2000 mg COD L-1 of glucose (ALR1) and the other reactor with 2000 mg COD L-1 of acetate (ALR2). The hydraulic retention time (HRT) and organic loading rate (OLR) for both reactors were maintained at 4 days and between 0.2 to 0.5 kg m-3day-1 respectively. Dissolved oxygen was maintained between 5.0 and 6.0 mg O2L-1 and supplied by air compressor. The reactor performance was monitored based on COD removal. Aerobic granules developed throughout the study period was evaluated based on granules size and morphology, sludge volumetric index (SVI30) and SVI5/SVI30 ratio analysis. Results showed that ALR1 demonstrated the formation of filamentous-type aerobic granules with most of the SVI30 average at 100 to 190 mL g-1. Ratio SVI5/SVI30 analysis was evaluated at 0.2 and 0.5. The largest granules size obtained during the experiment was about 600 μm on day-136 and average granules size obtained at 200 to 400 μm. ALR1 able to achieve 95% COD removal. For ALR2, round shaped aerobic granules were developed with average SVI30 from 100 to 1000 mLg-1. SVI5/SVI30 analysis indicated an average ratio between 0.7 and 0.9. The average granules size was between 30 to 50 μm and the largest was 78 μm on day-60. 90% of COD removal efficiency was obtained in ALR2. In conclusion, ALR fed with acetate had indicated better aerobic granules characteristics as compared to glucose fed reactor. Furthermore, the study demonstrated that to develop aerobic granules in continuous reactors is feasible.

Impact of Substrate Profile on BNR Performance in Aerobic Granular Sludge Pilots at the Lawrence, KS WWTP

2016 ◽  
Vol 2016 (9) ◽  
pp. 5470-5478 ◽  
Author(s):  
Belinda Sturm ◽  
Rasha Faraj ◽  
Theresa Amante ◽  
Shashikiran Kambhampati ◽  
Jennifer Warren
Keyword(s):  
Granular Sludge ◽  
Aerobic Granular Sludge

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

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

An Innovative Approach for Modeling Aerobic Granular Sludge Processes

2017 ◽  
Vol 2017 (16) ◽  
pp. 129-140
Author(s):  
Oliver Schraa ◽  
Jens Alex ◽  
Leiv Rieger ◽  
Ivan Miletic
Keyword(s):  
Granular Sludge ◽  
Innovative Approach ◽  
Aerobic Granular Sludge

Alginate-like exopolysaccharide extracted from aerobic granular sludge as biosorbent for methylene blue: Thermodynamic, kinetic and isotherm studies

2019 ◽  
Vol 7 (3) ◽  
pp. 103081 ◽  
Author(s):  
Sebastian Ladnorg ◽  
Nelson Libardi Junior ◽  
Patricia Dall´ Agnol ◽  
Dayane Gonzaga Domingos ◽  
Bruna Scandolara Magnus ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Granular Sludge ◽  
Aerobic Granular Sludge
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