نوع مقاله : مقاله پژوهشی

نویسندگان

1 دانشکده مهندسی شیمی، دانشگاه تهران، صندوق پستی: 4563-11155، تهران ـ ایران

2 پژوهشگاه علوم و فنون هسته‌ای، سازمان انرژی اتمی ایران، صندوق پستی: 8486-11365، تهران ـ ایران

چکیده

 از آن جا که ضریب انتقال جرم حجمی کل یکی از پارامترهای مهم در طراحی زیست رآکتور فرایند هوازی همراه با هم­زن مکانیکی است، در این مقاله ضریب انتقال جرم اکسیژن در محدوده­ی وسیعی از متغیرهای عملیاتی مورد بررسی قرار گرفت. متغیرهای عملیاتی مورد مطالعه در این تحقیق غلظت سلولی باکتری، توان مصرفی هم­زن و سرعت ظاهری جریان هوا بودند. نتایج تجربی به دست آمده نشان داد که اثر توان مصرفی هم­زن بیش­تر از سرعت ظاهری جریان هوا و اثر این آخری بیش­تر از غلظت سلولی باکتری است. محدوده­ی ضریب انتقال جرم حجمی کل اکسیژن در این آزمایش­‌ها، 36-84 hr-1  محاسبه شد. مقادیر به دست آمده برای ضریب انتقال جرم هم­چنین نشان داد که انتقال جرم اکسیژن در فرایند فروشویی میکروبی اورانیم از پارامترهای محدودکننده نیست. تطابق مدل­‌های ریاضی پیشنهادی برحسب پارامترهای عملیاتی برای ضریب انتقال جرم با نتایج تجربی نشان داد که معادلات ارایه شده برحسب دور هم­زن یا توان مصرفی و سرعت ظاهری جریان هوا از سازگاری نسبتاً خوبی برخوردار هستند و ضریب هم­بستگی R2 آن‌­ها برابر 94.2 و 93.4 تعیین شد. لذا، این مدل برای پیش­بینی ضریب انتقال جرم در فرایند فروشویی میکروبی اورانیم می­‌تواند استفاده شود.

تازه های تحقیق

  1. J.L. Casas Lopez, E.M. Rodriguez Porcel, I. Oller Alberola, M.M. Ballesteros Martin, J.A. Sanchez Perez, J.M. Fernandez Sevilla, Y. Chisti, Simultaneous determination of oxygen consumption rate and volumetric oxygen transfer coefficient in pneumatically agitated bioreactors, Ind. Eng. Chem. Res. 45 (2006) 1167-1171.

 2.   J. Petersen, D.G. Dixon, Modeling and optimisation of heap bioleach processes, In: Rawlings, D.E., Johnson, D.B. (Eds.), Biomining, Springer Verlag, Berlin (2006) 153–176.

 3.   Pierre-Alain Ruffieux, Urs von Stockar, Ian William Marison, Measurement of volumetric (OUR) and determination of specific (qO2) oxygen uptake rates in animal cell cultures, Journal of Biotechnology, 63 (1998) 85–95.

 4.   D. Tromans, Modeling oxygen solubility in water and electrolyte solutions. Ind. Eng. Chem. Res. 39(3) (2000) 805–812.

 5.   J. Petersen, Determination of oxygen gas–liquid mass transfer rates in heap bioleach reactors, Minerals Engineering, 23 (2010) 504–510.

 6.   S. Aiba, A.E. Humphrey, N.F. Millis, Biochemical Engineering, Academic Press, New York (1973) 183.

 7.   Y. Chisti, Mass transfer. In Encyclopedia of Bioprocess Technology: Fermentation, Biocatalysis, and Bioseparation; Flickinger, M. C. Drew, S. W., Eds.; Wiley: New York, 3 (1999) 1607-1640.

 8.   H. Taguchi, A.E. Humphrey, Dynamic measurement of the volumetric oxygen transfer coefficient in fermentation systems, J. Ferment. Technol. 44 (1966) 881-889.

 9.   M. Moo-Young, Ch.L. Cooney, A.E. Humphrey (Eds.), Comprehensive Biotechnology, 2, Pergamon Press, Oxford, (1985) 16.

 10. C.S. Ho, J.Y. Olshue (Eds.), Biotechnology Processes Scale-up and Mixing, American Institute of Chemical Engineering, (1987) 128.

 11. A.-I. Galaction, D. Cascaval, C. Oniscu, M. Turnea, Prediction of oxygen mass transfer coefficients in stirred bioreactors for bacteria, yeasts and fungus broths, Biochemical Engineering Journal, 20 (2004) 85-94.

12. M. Boon, T.A. Meeder, J.J. Heijnen, K.Ch. Luyben AM, Influence of Oxygen Adsorption on the Dynamics ka Measurement in Three-Phase Slurry Reactor, Biotechnology and Bioengineering, 40 (1992) 1097-1106.

 13. Van’t Riet K, Review of measuring methods and nonviscous gas–liquid mass transfer in stirred vessels, Ind Eng Chem Process Design Dev, 18 (1979) 357–364.

 14. CS Shin, MS Hong and J Lee, Oxygen transfer correlation in high cell density culture of recombinant E. Coli. Biotechnol Technol, 10 (1996) 679-682.

 15. D.R. Nielsen, A.J. Daugulis, P.J. McLellan, A novel method of simulating oxygen mass transfer in two-phase portioning bioreactors, Biotechnol Bioeng, 83 (2003) 735–742.

 16. Felix Garcia-Ochoa, Emilio Gomez, Bioreactor scale-up and oxygen transfer rate in microbial process: An overview, Biotechnology Advanced, 27 (2009) 153-176.

 17. A. Rashidi, S.J. Safdari, R. Roosta-Azad, M.F. Foroghian, B. Rafizadeh, H. Zare-Tarakoli, Isolation of native acidithiobacillus strains from gachin uranium mine and evaluation their effects on uranium bioleaching, Second National Conference of Applied Microbiology (2011).

 18. R.M. Atlas, Media for environmental Microbiology, 2th ed., Taylor & Francis (2005).

 19. JH. Rushton, EW. Costich, HJ. Everett, Power characteristics of mixing impellers: part I. Chem Eng. Prog, 46 (1950) 395-404.

 20. S. Katoh, F. Yoshida, Biochemical Engineering, Wily-VCH Velag, Germany (2009) 112-115.

 21. G.A. Hughmark, Power requirements and interfacial area in gas–liquid turbine agitated systems, Ind Eng Chem Process Design Dev, 19 (1980) 638–641.

 22. D.S. Savic, V.B. Veljkovic, M.L. Lazic, M.M. Vrvic, J.I. Vucetic, Effects of the oxygen transfer rate on ferrous iron oxidation by Thiobacillus ferrooxidans, Enzyme and Microbial Technology, 23 (1998) 427-431.

کلیدواژه‌ها

عنوان مقاله [English]

Study of Oxygen Mass Transfer Coefficient in Microbial Leaching of Uranium

نویسندگان [English]

  • S Zokaei Kadijani 1
  • S. J Safdari 2
  • S. M. A Mousavian 1
  • A Rashidi 2

چکیده [English]

Oxygen mass transfer coefficient is one of the most important parameters in the design of aerobic process bioreactor, which is represented by the overall volumetric oxygen mass transfer. The purpose of this article was the investigation of the mass transfer coefficient in the vast range of operational parameters in a stirred tank reactor. The effects of cell concentration, stirred power consumption and apparent air velocity on the mass transfer coefficient show that oxygen mass transfer in microbial leaching of uranium and in this range of parameter is not limited in these experiments. The overall volumetric oxygen mass transfer was determined in the range of 36-84 hr-1. Agreements of the suggested mathematical correlation for predicting the mass transfer were also evaluated. The results showed that the equation based on the rpm and/or power consumption and apparent air velocity specifies a good agreement with the experimental results with the coefficient of determination of R2=94.2 and 93.4. It was concluded that the introduced models are suitable for evaluation of the mass transfer coefficient in the microbial leaching of uranium.

کلیدواژه‌ها [English]

  • Mass Transfer Coefficient
  • Oxygen
  • Microbial Leaching
  • Uranium
  • Stirred Bioreactor
  1. J.L. Casas Lopez, E.M. Rodriguez Porcel, I. Oller Alberola, M.M. Ballesteros Martin, J.A. Sanchez Perez, J.M. Fernandez Sevilla, Y. Chisti, Simultaneous determination of oxygen consumption rate and volumetric oxygen transfer coefficient in pneumatically agitated bioreactors, Ind. Eng. Chem. Res. 45 (2006) 1167-1171.

 2.   J. Petersen, D.G. Dixon, Modeling and optimisation of heap bioleach processes, In: Rawlings, D.E., Johnson, D.B. (Eds.), Biomining, Springer Verlag, Berlin (2006) 153–176.

 3.   Pierre-Alain Ruffieux, Urs von Stockar, Ian William Marison, Measurement of volumetric (OUR) and determination of specific (qO2) oxygen uptake rates in animal cell cultures, Journal of Biotechnology, 63 (1998) 85–95.

 4.   D. Tromans, Modeling oxygen solubility in water and electrolyte solutions. Ind. Eng. Chem. Res. 39(3) (2000) 805–812.

 5.   J. Petersen, Determination of oxygen gas–liquid mass transfer rates in heap bioleach reactors, Minerals Engineering, 23 (2010) 504–510.

 6.   S. Aiba, A.E. Humphrey, N.F. Millis, Biochemical Engineering, Academic Press, New York (1973) 183.

 7.   Y. Chisti, Mass transfer. In Encyclopedia of Bioprocess Technology: Fermentation, Biocatalysis, and Bioseparation; Flickinger, M. C. Drew, S. W., Eds.; Wiley: New York, 3 (1999) 1607-1640.

 8.   H. Taguchi, A.E. Humphrey, Dynamic measurement of the volumetric oxygen transfer coefficient in fermentation systems, J. Ferment. Technol. 44 (1966) 881-889.

 9.   M. Moo-Young, Ch.L. Cooney, A.E. Humphrey (Eds.), Comprehensive Biotechnology, 2, Pergamon Press, Oxford, (1985) 16.

 10. C.S. Ho, J.Y. Olshue (Eds.), Biotechnology Processes Scale-up and Mixing, American Institute of Chemical Engineering, (1987) 128.

 11. A.-I. Galaction, D. Cascaval, C. Oniscu, M. Turnea, Prediction of oxygen mass transfer coefficients in stirred bioreactors for bacteria, yeasts and fungus broths, Biochemical Engineering Journal, 20 (2004) 85-94.

12. M. Boon, T.A. Meeder, J.J. Heijnen, K.Ch. Luyben AM, Influence of Oxygen Adsorption on the Dynamics ka Measurement in Three-Phase Slurry Reactor, Biotechnology and Bioengineering, 40 (1992) 1097-1106.

 13. Van’t Riet K, Review of measuring methods and nonviscous gas–liquid mass transfer in stirred vessels, Ind Eng Chem Process Design Dev, 18 (1979) 357–364.

 14. CS Shin, MS Hong and J Lee, Oxygen transfer correlation in high cell density culture of recombinant E. Coli. Biotechnol Technol, 10 (1996) 679-682.

 15. D.R. Nielsen, A.J. Daugulis, P.J. McLellan, A novel method of simulating oxygen mass transfer in two-phase portioning bioreactors, Biotechnol Bioeng, 83 (2003) 735–742.

 16. Felix Garcia-Ochoa, Emilio Gomez, Bioreactor scale-up and oxygen transfer rate in microbial process: An overview, Biotechnology Advanced, 27 (2009) 153-176.

 17. A. Rashidi, S.J. Safdari, R. Roosta-Azad, M.F. Foroghian, B. Rafizadeh, H. Zare-Tarakoli, Isolation of native acidithiobacillus strains from gachin uranium mine and evaluation their effects on uranium bioleaching, Second National Conference of Applied Microbiology (2011).

 18. R.M. Atlas, Media for environmental Microbiology, 2th ed., Taylor & Francis (2005).

 19. JH. Rushton, EW. Costich, HJ. Everett, Power characteristics of mixing impellers: part I. Chem Eng. Prog, 46 (1950) 395-404.

 20. S. Katoh, F. Yoshida, Biochemical Engineering, Wily-VCH Velag, Germany (2009) 112-115.

 21. G.A. Hughmark, Power requirements and interfacial area in gas–liquid turbine agitated systems, Ind Eng Chem Process Design Dev, 19 (1980) 638–641.

 22. D.S. Savic, V.B. Veljkovic, M.L. Lazic, M.M. Vrvic, J.I. Vucetic, Effects of the oxygen transfer rate on ferrous iron oxidation by Thiobacillus ferrooxidans, Enzyme and Microbial Technology, 23 (1998) 427-431.