Partial-nitritation of low-strength anaerobic effluent: A moderate-high dissolved oxygen concentration facilitates ammonia-oxidizing bacteria disinhibition and nitrite-oxidizing bacteria suppression

2021 ◽  
Vol 770 ◽  
pp. 145337
Author(s):  
Zhen Lei ◽  
Lianxu Wang ◽  
Jun Wang ◽  
Shuming Yang ◽  
Zhaoyang Hou ◽  
...  
Keyword(s):  
Dissolved Oxygen ◽  
Oxygen Concentration ◽  
Ammonia Oxidizing Bacteria ◽  
Dissolved Oxygen Concentration ◽  
Partial Nitritation ◽  
Nitrite Oxidizing Bacteria ◽  
Low Strength

Effect of Physicochemical Variables on Algal Autoflotation

1992 ◽  
Vol 26 (7-8) ◽  
pp. 1769-1778 ◽  
Author(s):  
S.-I. Lee ◽  
B. Koopman ◽  
E. P. Lincoln
Keyword(s):  
Dissolved Oxygen ◽  
Oxygen Concentration ◽  
Retention Time ◽  
Contact Time ◽  
Pilot Scale ◽  
Dissolved Oxygen Concentration ◽  
Physicochemical Variables ◽  
Rise Rate ◽  
Mixing Intensity ◽  
Maximum Rise

Combined chemical flocculation and autoflotation were examined using pilot scale process with chitosan and alum as flocculants. Positive correlation was observed between dissolved oxygen concentration and rise rate. Rise rate depended entirely on the autoflotation parameters: mixing intensity, retention time, and flocculant contact time. Also, rise rate was influenced by the type of flocculant used. The maximum rise rate with alum was observed to be 70 m/h, whereas that with chitosan was approximately 420 m/h. The efficiency of the flocculation-autoflotation process was superior to that of the flocculation-sedimentation process.

scholarly journals Gas–liquid mass transfer characteristics of aviation fuel scrubbing in an aircraft fuel tank

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Li Chaoyue ◽  
Feng Shiyu ◽  
Xu Lei ◽  
Peng Xiaotian ◽  
Yan Yan
Keyword(s):  
Mass Transfer ◽  
Dissolved Oxygen ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Oxygen Concentration ◽  
Gas Holdup ◽  
Aviation Fuel ◽  
Volumetric Mass Transfer Coefficient ◽  
Dissolved Oxygen Concentration ◽  
Liquid Mass Transfer

AbstractDissolved oxygen evolving from aviation fuel leads to an increase in the oxygen concentration in an inert aircraft fuel tank ullage that may increase the flammability of the tank. Aviation fuel scrubbing with nitrogen-enriched air (NEA) can largely reduce the amount of dissolved oxygen and counteract the adverse effect of oxygen evolution. The gas–liquid mass transfer characteristics of aviation fuel scrubbing are investigated using the computational fluid dynamics method, which is verified experimentally. The effects of the NEA bubble diameter, NEA superficial velocity and fuel load on oxygen transfer between NEA and aviation fuel are discussed. Findings from this work indicate that the descent rate of the average dissolved oxygen concentration, gas holdup distribution and volumetric mass transfer coefficient increase with increasing NEA superficial velocity but decrease with increasing bubble diameter and fuel load. When the bubble diameter varies from 1 to 4 mm, the maximum change of descent rate of dissolved oxygen concentration is 18.46%, the gas holdup is 8.73%, the oxygen volumetric mass transfer coefficient is 81.45%. When the NEA superficial velocities varies from 0.04 to 0.10 m/s, the maximum change of descent rate of dissolved oxygen concentration is 146.77%, the gas holdup is 77.14%, the oxygen volumetric mass transfer coefficient is 175.38%. When the fuel load varies from 35 to 80%, the maximum change of descent rate of dissolved oxygen concentration is 21.15%, the gas holdup is 49.54%, the oxygen volumetric mass transfer coefficient is 44.57%. These results provide a better understanding of the gas and liquid mass transfer characteristics of aviation fuel scrubbing in aircraft fuel tanks and can promote the optimal design of fuel scrubbing inerting systems.

scholarly journals Control of Dissolved Oxygen Concentration in Deep Hydroponic Culture of Spinach Using Pressurized Oxygen Gas.

2003 ◽  
Vol 15 (1) ◽  
pp. 27-32 ◽  
Author(s):  
Eiji GOTO ◽  
Daisuke SUGAWARA ◽  
Ying-der LEE ◽  
Tadashi TAKAKURA
Keyword(s):  
Dissolved Oxygen ◽  
Oxygen Concentration ◽  
Hydroponic Culture ◽  
Dissolved Oxygen Concentration ◽  
Oxygen Gas

Control of dissolved oxygen concentration using neural network in a batch bioreactor

2010 ◽  
Vol 20 (4) ◽  
pp. 619-628 ◽  
Author(s):  
Tufan Mete ◽  
Gulay Ozkan ◽  
Hale Hapoglu ◽  
Mustafa Alpbaz
Keyword(s):  
Neural Network ◽  
Dissolved Oxygen ◽  
Oxygen Concentration ◽  
Dissolved Oxygen Concentration ◽  
Batch Bioreactor
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