Aerobic granulation for nitrogen removal via nitrite in a sequencing batch reactor and the emission of nitrous oxide

2011 ◽  
Vol 102 (3) ◽  
pp. 2536-2541 ◽  
Author(s):  
Yi-Jing Shi ◽  
Xin-Hua Wang ◽  
Hai-Bo Yu ◽  
Hui-Jun Xie ◽  
Shao-Xiang Teng ◽  
...  
Keyword(s):  
Nitrous Oxide ◽  
Nitrogen Removal ◽  
Sequencing Batch Reactor ◽  
Batch Reactor ◽  
Aerobic Granulation

Enhanced aerobic granulation and nitrogen removal by the addition of zeolite powder in a sequencing batch reactor

2012 ◽  
Vol 97 (20) ◽  
pp. 9235-9243 ◽  
Author(s):  
Dong Wei ◽  
Xiaodong Xue ◽  
Shuwei Chen ◽  
Yongfang Zhang ◽  
Liangguo Yan ◽  
...  
Keyword(s):  
Nitrogen Removal ◽  
Sequencing Batch Reactor ◽  
Batch Reactor ◽  
Aerobic Granulation

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.

Excess nitrogen accumulation in activated sludge in sequencing batch reactor with a single-stage oxic process

2009 ◽  
Vol 59 (3) ◽  
pp. 573-582 ◽  
Author(s):  
Xiao-ming Li ◽  
Dong-bo Wang ◽  
Qi Yang ◽  
Wei Zheng ◽  
Jian-bin Cao ◽  
...  
Keyword(s):  
Activated Sludge ◽  
Nitrogen Removal ◽  
Sequencing Batch Reactor ◽  
Ph Value ◽  
Batch Reactor ◽  
Nitrogen Loss ◽  
Single Stage ◽  
Synthetic Wastewater ◽  
Nitrogen Accumulation ◽  
Excess Nitrogen

It was occasionally found that a significant nitrogen loss in solution under neutral pH value in a sequencing batch reactor with a single-stage oxic process using synthetic wastewater, and then further studies were to verify the phenomenon of nitrogen loss and to investigate the pathway of nitrogen removal. The result showed that good performance of nitrogen removal was obtained in system. 0–7.28 mg L−1 ammonia, 0.08–0.38 mg L−1 nitrite and 0.94–2.12 mg L−1 nitrate were determined in effluent, respectively, when 29.85–35.65 mg L−1 ammonia was feeding as the sole nitrogen source in influent. Furthermore, a substantial nitrogen loss in solution (95% of nitrogen influent) coupled with a little gaseous nitrogen increase in off-gas (7% of nitrogen influent) was determined during a typical aerobic phase. In addition, about 322 mg nitrogen accumulation (84% of nitrogen influent) was detected in activated sludge. Based on nitrogen mass balance calculation, the unaccounted nitrogen fraction and the ratio of nitrogen accumulation in sludge/nitrogen loss in solution were 14.6 mg (3.7% of nitrogen influent) and 0.89, respectively. The facts indicated that the essential pathway of nitrogen loss in solution in this study was excess nitrogen accumulation in activated sludge.

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