Effects of fill modes on N2O emission from the SBR treating domestic wastewater

2001 ◽  
Vol 43 (3) ◽  
pp. 147-150 ◽  
Author(s):  
K. Y. Park ◽  
J. W. Lee ◽  
Y. Inamori ◽  
M. Mizuochi ◽  
K. H. Ahn
Keyword(s):  
Sequencing Batch Reactor ◽  
Emission Rate ◽  
Batch Reactor ◽  
Domestic Wastewater ◽  
N2o Emission ◽  
Ammonia Nitrogen ◽  
High Concentration ◽  
N2o Production ◽  
Initial Stage ◽  
Biological Nitrogen

Nitrous oxide (N2O) gas is emitted as an intermediate in the biological nitrogen removal process. A track study was performed to investigate the characteristics of N2O emission depending on the cyclic mode of a sequencing batch reactor (SBR). A major emission of N2O took place at the aerobic phase, while N2O emission at the anoxic phase was insignificant. Especially, the highest N2O emission rate was observed at the initial stage of aerobic phase under the limited dissolved oxygen (DO) condition. Under such a condition, nitrite (NO2-) was transiently accumulated along with significant N2O emission due to incomplete nitrification. In addition, N2O production at the aerobic phase was strongly related with incomplete denitrification by nitrifiers. N2O emission could be reduced by change in fill modes in the SBR. A significant conversion to N2O took place in the SBR with the anoxic fill mode, while only small amount of N2O was conversed in the SBR with the aerobic fill mode. Relatively high concentration of ammonia nitrogen (NH4+) accelerated N2O production at the aerobic phase in the SBR with the anoxic fill compared to the aerobic fill. For control of N2O emission in the SBR, the aerobic fill mode could be an effective method even if denitrification efficiency may be reduced at the anoxic phase.

Performance characterization of anaerobic sequencing batch reactor process for digestion of night soil

2001 ◽  
Vol 43 (1) ◽  
pp. 27-34 ◽  
Author(s):  
J. G. Lee ◽  
J. M. Hur ◽  
D. Chang ◽  
T. H. Chung
Keyword(s):  
Sequencing Batch Reactor ◽  
Batch Reactor ◽  
Ammonia Nitrogen ◽  
Gas Production ◽  
High Concentration ◽  
Anaerobic Sequencing Batch Reactor ◽  
Mixed Control ◽  
Volatile Solids ◽  
Equivalent Loading

Laboratory experiments were conducted to investigate the performance of an anaerobic sequencing batch reactor (ASBR) process for night soil treatment. Performances of the reactors were evaluated at an equivalent hydraulic retention time (HRT) of 10 days with an equivalent loading rate of 2.6 kgVS/m3/d (3.1 kgCOD/m3/day) at 35°C. Digestion of a night soil was possible using the ASBR at an HRT of 10 days in spite of high concentration of ammonia nitrogen and settleable solids. Solids were accumulated rapidly in the ASBRs, and their concentrations were 2.3∼2.4 times higher than that in a completely mixed control reactor. Remarkable increases in gas production were observed in the ASBRs compared with the control reactor. Average increases in equivalent daily gas production from the ASBRs were 205∼220% compared with that from the control run. The ASBR with reaction period/thickening period ratio (R/T ratio) of 1 showed a little higher gas production and organic removal efficiency than that with R/T ratio of 3. Volatile solids removals based on supernatant of the ASBRs were 12∼14% higher than that of the control reactor. Thus, the ASBR was a stable and effective process for the treatment of night soil having high concentration of settleable organics and ammonia nitrogen.

Nitrite accumulation followed by denitrification using sequencing batch reactor

2004 ◽  
Vol 49 (5-6) ◽  
pp. 47-55 ◽  
Author(s):  
C.S. Gee ◽  
J.S. Kim
Keyword(s):  
Sequencing Batch Reactor ◽  
Batch Reactor ◽  
Ammonia Nitrogen ◽  
Nitrite Accumulation ◽  
Nitrite Oxidation ◽  
High Concentration ◽  
Solid Retention Time ◽  
Factors Affecting ◽  
Nitrification And Denitrification ◽  
Ammonia Source

Biological ammonia-nitrogen removal utilizes two distinct processes, nitrification and denitrification. In nitrification, ammonia oxidizes to nitrite then to nitrate. In this study, elimination of nitrite oxidation to nitrate step was attempted in order to directly remove nitrite to nitrogen gas by denitrification. For this study the supernatant from an anaerobic digester was used as an ammonia source and a sequencing batch reactor (SBR) was employed. Emphasis was given to the evaluation of the operational factors affecting nitrite accumulation and the elucidation of kinetics for biological nitrification and denitrification. Accumulation of nitrite in the nitrification process was achieved by suppressing the growth of Nitrobacter, a nitrite oxidizer, by loading high concentration ammonia supernatant immediately after all ammonia in the previous loading was oxidized to nitrite. Nitrite oxidation was taking place as the solid retention time (SRT) was increased from 2.5 days to 3.0 days in a continuously aerated SBR mode with daily feeding. However, nitrite accumulation was achieved even at longer SRT of 5 days when the aeration and non-aeration periods were appropriately combined and the non-aeration period can be used for denitrification of the accumulated nitrite with a carbon source supplied.

scholarly journals Nitrite build-up effect on nitrous oxide emissions in a laboratory-scale anaerobic/aerobic/anoxic/aerobic sequencing batch reactor

2021 ◽  
Vol 16 (2) ◽  
pp. 1
Author(s):  
Larissa Coelho Auto Gomes ◽  
Barbara Costa Pereira ◽  
Renato Pereira Ribeiro ◽  
Jaime Lopes da Mota Oliveira
Keyword(s):  
Nitrous Oxide ◽  
Nitrogen Removal ◽  
Sequencing Batch Reactor ◽  
Batch Reactor ◽  
Mitigation Strategies ◽  
Nitrous Oxide Emissions ◽  
Biological Nitrogen Removal ◽  
N2o Emissions ◽  
N2o Production ◽  
Biological Nitrogen

Biological wastewater treatment processes with biological nitrogen removal are potential sources of nitrous oxide (N2O) emissions. It is important to expand knowledge on the controlling factors associated with N2O production, in order to propose emission mitigation strategies. This study therefore sought to identify the parameters that favor nitrite (NO2-) accumulation and its influence on N2O production and emission in an anaerobic/aerobic/anoxic/aerobic sequencing batch reactor with biological nitrogen removal. Even with controlled dissolved oxygen concentrations and oxidation reduction potential, the first aerobic phase promoted only partial nitrification, resulting in NO2- build-up (ranging from 29 to 57%) and consequent N2O generation. The NO2- was not fully consumed in the subsequent anoxic phase, leading to even greater N2O production through partial denitrification. A direct relationship was observed between NO2- accumulation in these phases and N2O production. In the first aerobic phase, the N2O/NO2- ratio varied between 0.5 to 8.5%, while in the anoxic one values ranged between 8.3 and 22.7%. Higher N2O production was therefore noted during the anoxic phase compared to the first aerobic phase. As a result, the highest N2O fluxes occurred in the second aerobic phase, ranging from 706 to 2416 mg N m-2 h-1, as soon as aeration was triggered. Complete nitrification and denitrification promotion in this system was proven to be the key factor to avoid NO2- build-up and, consequently, N2O emissions.

scholarly journals Removal of Nitrogen and Phosphorus from Wastewater by Modified Pyrite in a Sequencing Batch Reactor (SBR)

2019 ◽  
Vol 136 ◽  
pp. 06027
Author(s):  
Hou-Yun Yang ◽  
Pei Xu ◽  
Hua-Yuan Wang ◽  
Wei-Hua Li ◽  
Shu-Guang Zhu
Keyword(s):  
Removal Efficiency ◽  
Phosphorus Removal ◽  
Sequencing Batch Reactor ◽  
Batch Reactor ◽  
Ammonia Nitrogen ◽  
Nitrogen And Phosphorus ◽  
Nitrogen And Phosphorus Removal ◽  
Removal Efficiencies ◽  
Removal Processes ◽  
Biological Nitrogen

The removal efficiency of nitrogen and phosphorus is challenging in the conventional biological nitrogen and phosphorus removal processes. In this study, the modified pyrite was used as the fillings of se-quencing batch reactor (SBR) in order to improve the efficiencies of nitrogen and phosphorus removal from wastewater. The results showed that SBR with the modified pyrite could significantly improve the removal efficiencies of nitrogen and phosphorus when compared with that in SBR without fillings (control SBR). The average influent ammonia nitrogen (NH4+-N) and total phosphorus (TP) were 6.96±0.17 mg L-1 and 6.94±0.01 mg L-1, respectively. The average NH4+-N and TP removals of modified pyrite constructed SBR were 49.65±19.49% with 3.54±1.31 mg L-1 of average effluent NH4+-N and 76.20±6.55% with 1.84±0.46 mg L-1 of average effluent TP, respectively. While the average NH4+-N and TP removal efficiencies of con-trol SBR were only 34.76±11.28% and 56.28±0.11%. The mechanisms of the SBR with enhanced simulta-neous nitrogen and phosphorus removals might be anaerobic and aerobic oxidations of modified pyrite, and phosphorus retained in the SBR of modified pyrite was mostly in the form of Fe-bound-P.

Advanced Treatment of Domestic Wastewater Using Sequencing Batch Reactor Activated Sludge Process

1993 ◽  
Vol 28 (10) ◽  
pp. 267-274 ◽  
Author(s):  
M. Imura ◽  
E. Suzuki ◽  
T. Kitao ◽  
S. Iwai
Keyword(s):  
Activated Sludge ◽  
Sequencing Batch Reactor ◽  
Batch Reactor ◽  
Domestic Wastewater ◽  
Experimental Period ◽  
Small Scale ◽  
Experimental Plant ◽  
Activated Sludge Process ◽  
Nitrogen And Phosphorus ◽  
Experimental Apparatus

In order to apply a sequencing batch reactor activated sludge process to small scale treatment facilities, various experiments were conducted by manufacturing an experimental apparatus made of a factory-produced FRP cylinder transverse tank (Ø 2,500mm). Results of the verification test conducted for one year by leading the wastewater discharged from apartment houses into the experimental apparatus were as follows. Excellent performance was achieved without any addition of carbon source, irrespective of the organic compound concentration and the temperature of raw wastewater. Organic substances, nitrogen and phosphorus were removed simultaneously. Due to the automated operation format, stable performance was obtained with only periodic maintenance. Though water depth of the experimental plant was shallow, effective sedimentation of activated sludge was continued during the experimental period. Regarding the aerobic and anaerobic process, nitrification and denitrification occurred smoothly.

Performance of family-size sequencing batch reactor and rotating biological contactor units treating sewage at various operating conditions

2000 ◽  
Vol 41 (1) ◽  
pp. 97-104 ◽  
Author(s):  
J.C. Akunna ◽  
C. Jefferies
Keyword(s):  
Total Phosphorus ◽  
Sequencing Batch Reactor ◽  
Batch Reactor ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Ammonia Nitrogen ◽  
Operating Conditions ◽  
The Other ◽  
Rotating Biological Contactor ◽  
Effluent Quality

Field trials were carried out using two types of package units designed for the treatment of domestic sewage from individual households. One of the units was a commercially available rotating biological contactor (RBC) system. The other was a newly developed sequencing batch reactor (SBR) system. Trials were carried at the site of a local sewage treatment plant where degritted raw sewage from a combined sewerage network was fed to the two units for a period of four months. Both units produced good effluent quality, well below 20/30 (BOD/SS) during steady-state performance. However, shorter start-up time was observed with the SBR unit together with better effluent quality (up to BOD<10 mg/l and SS<15 mg/l). Furthermore, the SBR unit produced effluents with ammonia nitrogen and total phosphorus levels of 3 mg/l and 2 mg/l respectively, for influent levels that varied from 20 to 60 mg N-NH3/l and from 15 to 17 mg/l of total phosphorus. On the other hand, significant nutrient removal did not seem tohave occurred in the RBC unit. During testing to meet the requirements of British Standard (BS 6297), it was observed that the SBR can tolerate shockloads and periods following zero flow better than the RBC unit.

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