Hydrodynamics and Oxygen Transfer in Bubble Column Reactors Influence of Petroleum Contaminants and Surfactant

Document Type : Research Note

Authors

1 Department of Environmental Engineering, Environmental Research Institute of ACECR, Rasht, I.R. IRAN

2 School of Chemical Engineering, College of Engineering, University of Tehran, P.O. Box 11155-4563 Tehran, I.R. IRAN

Abstract

The purpose of the present study was investigation of effect petroleum contaminants and surfactants on hydrodynamics and oxygen transfer as important parameters for treatment of crude contaminated wastewaters. Gas hold-up (εg), bubble size distribution and oxygen transfer coefficient (kLa) were evaluated for petroleum contaminants (C13 and C16) in water at concentrations of 0.1 and 0.5 vol.% over the range of  superficial gas velocity (ug) of 1.18-23.52×10-3 m/s in bubble column reactor. A type of anionic surfactant (SDS) was utilized in the experiments for studying of surfactants on wastewater parameters. The bubble size distribution becomes bimodal with increasing of gas velocity and gas hold-up, mass transfer coefficient and Sauter mean diameter is increased. The petroleum contaminants and surfactants lead to delayed regime transition from the homogeneous to heterogeneous by decreased surface tension and by the coalescence inhibition, and also, Sauter mean diameter is decreased in the presence of petroleum contaminants. These changes increased in the presence of surfactants. Also, petroleum contaminants enhanced mass transfer coefficient and gas hold-up, especially at higher superficial gas velocity. Increasing of mass transfer and hold-up were more at higher concentrations of contaminants. Also, presence of surfactants on bubble surfaces, decreases oxygen transfer due to the enhanced mass transfer resistance. Empirical correlations were proposed for evaluating gas hold-up and mass transfer coefficient as a function of superficial gas velocity and interfacial surface tension.

Keywords

Main Subjects


[1] Jajuee B., Margaritis A., Karamanev D., Bergougnou M.A., Influence of Dissolved Hydrocarbons on Volumetric Oxygen Mass Transfer Coefficient in a Novel Airlift Contactor, Chemical Engineering Science, 61, p. 4111 (2006).
[2] Mehrnia M.R., Towfighi J., Bonakdarpour B., Akbarnegad M.M., Influence of Top Section Design and Draft-Tube Height on the Performance of Airlift Bioreactors Containing Water-in-Oil Microemulsion, Journal of Chemical Technology and Biotechnology, 79, p. 260 (2004).
[3] Bouaifi M., Hebrard G., Bastoul D., Roustan M., A Comparative Study of Gas Holdup, Bubble Size, Interfacial Area and Mass Transfer Coefficients in Stirred Gas-Liquid Reactors and Bubble Columns, Chemical Engineering Processing, 40, p. 97 (2001).
[4] Schafer R., Marten C., Eigenberger G., Bubble Size Distributions in a Bubble Column Reactor Under Industrial Conditions, Experimental Thermal and Fluid Science, 26, p. 595 (2002).
[5] Asgharpour M., Mehrnia M.R., Mostoufi N., Effect of Surface Contaminants on Oxygen Transfer in Bubble Column Reactors, Biochemical Engineering Journal, 49, p. 351 (2010). 
[6] Yoshida F., Yamane T., Miyamoto Y., Oxygen Absorption Into Oil-in-Water Emulsions: a Study on Hydrocarbon Fermentors, Industrial Engineering Chemistry Process Design & Development, 9, p. 570 (1970).
[7] Hassan I.T.M., Robinson C.W., Oxygen Transfer in Mechanically Agitated Aqueous Systems Containing Dispersed Hydrocarbon, Biotechnology and Bioengineering, 19, p. 661 (1977).
[8] Kundu A., Dumont E., Duquenne A.M., Delmas H., Mass Transfer Characteristics in Gas-Liquid-Liquid System, Canadian Journal of Chemical Engineering, 81, p. 640 (2003).
[9] Rols J.L., Condoret J.S., Fonade C., Goma G., Mechanism of Enhanced Ooxygen Transfer in ermentation Using Emulsified Oxygen-Vectors, Biotechnology and Bioengineering, 35, p. 427 (1990).
[10] MacMillan J.D., Wang D.I. C., Mechanisms of Oxygen Transfer Enhancement During Submerged Cultivation in Perfluorochemicalin-Water Dispersions, Anals New York Academy of Sciences, 589, p. 283 (1990).
[11] Painmanakul P., Loubière K., Hébrard G., Mietton-Peuchot M., Roustan M., Effect of Surfactants on Liquid-Side Mass Transfer Coefficients, Chemical Engineering Science, 60, p. 6480 (2005).
[12] Prakash A., Margaritis A., Li H., Hydrodynamics and Local Heat Transfer Measurements in a Bubble Column with Suspension of Yeast, Biochemical Engineering Journal, 9, p. 155 (2001).
[13] Ju L.K., Ho C.S., Oxygen Diffusion Coefficient and Solubility in N-Hexadecane, Biotechnology and Bioengineering, 34, p. 1221 (1989).
[14] Clarke K.G., Correia L.D.C., Oxygen Transfer in Hydrocarbon-Aqueous Dispersions and Its Applicability to Alkane Bioprocesses: A Review, Biochemical Engineering Journal, 39, p. 405 (2008).