scholarly journals ALTERACIONES FISICO-QUIMICAS DE LA COLUMNA DE AGUA, GENERADAS POR EL USO DEL BOLICHE (METODO DE PESCA ARTESANAL) EN LA CIENAGA GRANDE DE SANTA MARTA, CARIBE COLOMBIANO

2016 ◽  
Vol 24 ◽  
Author(s):  
Mario Enrique Rueda ◽  
José Ernesto Mancera P.
Keyword(s):  
Dissolved Oxygen ◽  
Water Column ◽  
Oxygen Concentration ◽  
Coastal Lagoon ◽  
Water Transparency ◽  
Dissolved Oxygen Concentration ◽  
Artisanal Fishing ◽  
Physical Chemical ◽  
Before And After ◽  
The Impact

With the purpose of assessing the impact generated by the use of an artisanal fishing method populary called "boliche", in the tropical coastal lagoon Ciénaga Grande de Santa Marta, different aspects were quantified; being one of them designed to analyze some physical-chemical alterations of the water column, produced during the fishing operations. The dissolved oxygen concentration, water transparency and seston composition and concentration, before and after of 70 boliche's thrusts were determinated. The results showthat fishing operations generate some momentary changes of little repercution to the ecosystem, such as particle resuspention principally inorganic an increase in seston concentration and a consequen water column transparency decrease. The dissolved oxygen concentration does not show appreciable alteration.

scholarly journals Kondisi Fisika-Kimia Perairan Pulau Kabaena Kabupaten Bombana Sulawesi Tenggara

2017 ◽  
Vol 4 (1) ◽  
pp. 29
Author(s):  
Roni Wardi ◽  
Musrifin Ghalib ◽  
Mubarak Mubarak
Keyword(s):  
Dissolved Oxygen ◽  
Water Temperature ◽  
Oxygen Concentration ◽  
Dissolved Oxygen Concentration ◽  
Chemical Parameters ◽  
Average Value ◽  
Physical Chemical ◽  
Chemical Conditions ◽  
Depth Water

This research was conducted in December 2016 at Kabaena Island, Bombana Southeast Sulawesi which refers to data taken in August 2016. The aim the research is to provide an overview and information on the physical-chemical conditions of Kabaena waters. The method used in this study is a survey and determining the point of sampling by purposive sampling. Sampling physical-chemical parameters of waters us done at a distance of 500 meters from the beach towards the sea and the sample was measured in situ. Physical-chemical parameters were observed i.e. depth, brightness, turbidity, dissolved oxygen, salinity, acidity (pH), temperature, and flow. The results of show that physical-chemical parameters measured were 3-41 meters depth, water temperature ranged from 27oC – 32oC, salinity obtained in waters between 31‰ - 34‰, brightness values waters between 3 meters to 13 meters, the value of the degree of acidity 8, 24, dissolved oxygen concentration from 3.81 to 4.43 mg/l or 5.44 to 6.33 mg/l, turbidity levels are high at 0.97 NTU, and the velocity of 0.04 m/sec to 0, 62 m/sec with an average value of 0.19 m/sec. 3.2. Based on the research results physical-chemical parameters of the waters of Kabaena by comparison with Kepmen LH 2004, the condition of physical-chemical parameters of waters Kabaena still quite good to support the continuity of the life of the organism.

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.

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