نوع مقاله : مقاله پژوهشی

نویسندگان

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

چکیده

در پژوهش حاضر، مقاومت‌­های انتقال جرمی مراحل مختلف جذب ­زیستی اورانیم توسط جاذب ­زیستی
Pseudomonas putida @ Chitosan درون ستون بستر ثابت محاسبه شد. تشریح پارامترهای دینامیکی در قالب اعداد بدون بعد نشان داد که عدد بایوت در تمامی آزمایش‌­ها بزرگ­‌تر از 30 است که تأییدکننده نرخ بالای انتقال جرم از فیلم مایع در مقایسه با نفوذ درون­ذره­ای می‌­باشد. افزایش نیروی محرکه انتقال جرم در عرض فیلم مایع از طریق افزایش در غلظت خوراک و کاهش ضخامت فیلم مایع از طریق کاهش اندازه جاذب موجب کاهش مقاومت انتقال جرم فیلم مایع شد. هم‌­چنین افزایش ارتفاع بستر و کاهش اندازه جاذب موجب افزایش عدد پکلت شد که به ­معنی کوتاه شدن ضخامت ناحیه انتقال جرمی درون ستون و کاهش مقاومت پراکندگی محوری می‌­باشد. ساختار جاذب ­زیستی باعث شد تا شار نفوذ حفره­ای در مقایسه با شار نفوذ سطحی قابل صرف ­نظر کردن باشد و عملاً فرایند نفوذ درون ­ذره­ای از نوع نفوذ سطحی باشد. نتایج ثابت کرد که مقاومت نفوذ درون ذره­ای در تمامی آزمایش‌­ها چندین برابر مقاومت فیلم مایع و مقاومت پراکندگی محوری بوده و مرحله­ کنترل ­کننده فرایند می‌­باشد. به دلیل تأثیرپذیری کم نفوذ درون ­ذره­ای از تغییر شرایط عملیاتی، بازدهی ستون تنها با زمان ماند فرایند و در محدوده صفر تا 00/53­% تغییر کرد.

کلیدواژه‌ها

عنوان مقاله [English]

Investigation of U(VI) biosorption dynamic in fixed bed column: calculation of mass transfer resistances and identification of rate-controlling step

نویسندگان [English]

  • H. Sohbatzadeh
  • A.R. Keshtkar
  • J. Safdari

Nuclear Fuel Cycle Research School, Nuclear Science and Technology Research Institute, AEOI, P.O.Box: 11365-8486, Tehran – Iran

چکیده [English]

In the present research, mass transfer resistances of various steps of uranium biosorption using Pseudomonas putida @ Chitosan biosorbent in a fixed bed column were calculated. The description process dynamic parameters using dimensionless numbers showed that the Biot number was greater than 30 in all experiments which confirms the high mass transfer rate of the liquid film in comparison with intra-particle diffusion. Increment of the mass transfer driving force across the liquid film via enhancement in the inlet concentration along with a decrease in the liquid film thickness through a reduction in the sorbent particle size caused a decline in the mass transfer resistance of the liquid film. Furthermore, the Peclet number was found to be increased with increment of the bed height and decrement of the sorbent particle size which indicates a shortening in the mass transfer region thickness and reduction in the axial dispersion resistance. The biosorbent structure caused the pore diffusion flux to be negligible in comparison with the surface diffusion flux. The surface diffusion was the dominant intraparticle diffusion mechanism. The obtained results showed that intraparticle diffusion resistances were several times greater than liquid film resistances and axial dispersion resistances in all experiments, and also were the rate-controlling step. Since the change in operational conditions has a small effect on the intraparticle diffusion, the column efficiency was only proportional to the process residence time, varying between 0.00% to 53.00%.

کلیدواژه‌ها [English]

  • Dynamic
  • U(VI) Biosorption
  • Fixed Bed Column
  • Mass Transfer Resistance
  • Rate-Controlling Step
1. B. Hayati, et al, Heavy metal adsorption using PAMAM/CNT nanocomposite from aqueous solution in batch and continuous fixed bed systems, Chem. Eng. J. 346, 258-270 (2018).
 
2. K. Vijayaraghavan, Y.-S. Yun, Bacterial biosorbents and biosorption, Biotechnol. Adv. 26, 266-291 (2008).
 
3. D. Bulgariu, L. Bulgariu, Sorption of Pb(II) onto a mixture of algae waste biomass and anion exchanger resin in a packed-bed column, Bioresource Technol. 129, 374-380 (2013).
 
4. M. Zheng, et al, Adsorption desulfurization performance and adsorption-diffusion study of B2O3 modified Ag-CeOx/TiO2-SiO2, J. Hazard. Mater. 362, 424-435 (2019).
 
5. C. Yao, T. Chen, A new simplified method for estimating film mass transfer and surface diffusion coefficients from batch adsorption kinetic data, Chem. Eng. J. 265, 93-99 (2015).
 
6. L. Denise Fiorentin, et al, Biosorption of the Reactive Blue 5G Dye in a Fixed Bed Column Packed with Orange Bagasse: Experimental and Mathematical Modelling, Sep. Sci. Technol. 50, 2267-2275 (2015).
 
7. Y. Shao, H. Zhang, Y. Yan, Adsorption dynamics of p-nitrophenol in structured fixed bed with microfibrous entrapped activated carbon, Chem. Eng. J. 225, 481-488 (2013).
 
8. A. Hethnawi, et al, Fixed-bed column studies of total organic carbon removal from industrial wastewater by use of diatomite decorated with polyethylenimine- functionalized pyroxene nanoparticles, J. Colloid. Interf. Sci. 513, 28-42 (2018).
 
9. H. Sohbatzadeh, et al, U(VI) biosorption by bi-functionalized Pseudomonas putida @ chitosan bead: Modeling and optimization using RSM, Int. J. Biol. Macromol. 89, 647-658 (2016).
 
10. H. Sohbatzadeh, et al, Insights into the biosorption mechanisms of U(VI) by chitosan bead containing bacterial cells: A supplementary approach using desorption eluents, chemical pretreatment and PIXE–RBS analyses, Chem. Eng. J. 323, 492-501 (2017).
 
11. J. Choi, J.Y. Lee, J.-S. Yang, Biosorption of heavy metals and uranium by starfish and Pseudomonas putida, J. Hazard. Mater. 161, 157-162 (2009).
 
12. W.S. Wan Ngah, M.A.K.M. Hanafiah, S.S. Yong, Adsorption of humic acid from aqueous solutions on crosslinked chitosan–epichlorohydrin beads: Kinetics and isotherm studies, Colloid. Surface. B. 65, 18-24 (2008).
 
13. M.S. Podder, C.B. Majumder, Fixed-bed column study for As(III) and As(V) removal and recovery by bacterial cells immobilized on Sawdust/MnFe2O4 composite, Biochem. Eng. J. 105, 114-135 (2016).
 
14. N. Sonetaka, et al, Simultaneous determination of intraparticle diffusivity and liquid film mass transfer coefficient from a single-component adsorption uptake curve, J. Hazard. Mater. 164, 1447-1451 (2009).
 
15. V.M. Esquerdo, et al, Kinetics and mass transfer aspects about the adsorption of tartrazine by a porous chitosan sponge, Reac. Kinet. Mech. Cat. 116(1), 105-117 (2015).
 
16. J. Fujiki, Experimental determination of fluid-film mass transfer coefficient from adsorption uptake curve, Chem. Eng. J. 173, 49-54 (2011).
 
17. A. Sperlich, Predicting anion breakthrough in granular ferric hydroxide (GFH) adsorption filters, Water R. 42, 2073-2082 (2008).
 
18. T. Gu, Mathematical Modeling and Scale-Up of Liquid Chromatography, Second ed., Springer (2015).
19. G. Naja, B. Volesky, Behavior of the Mass Transfer Zone in a Biosorption Column, Environ. Sci. Technol. 40, (2006) 3996-4003.
 
20. T. Salmi, et al, Application of film theory on the reactions of solid particles with liquids: Shrinking particles with changing liquid films, Chem. Eng. Sci. 160(16), 161-170 (2017).
 
21. G.L. Dotto, C. Buriol, L.A.A. Pinto, Diffusional mass transfer model for the adsorptionof food dyes on chitosan films, Chem. Eng. Res. Des. 92(11), 2324-2332 (2014).
 
22. W. Zou, L. Zhao, L. Zhu, Adsorption of uranium(VI) by grapefruit peel in a fixed-bed column: experiments and prediction of breakthrough curves, J. Radioanal. Nucl. Ch. 295, 717-727 (2013).
 
23. H. Cui, et al, Exceptional arsenic (III,V) removal performance of highly porous, nanostructured ZrO2 spheres for fixed bed reactors and the full-scale system modeling, Water res. 47(16), 6258-6268 (2013).
 
24. Y. Zhang, C. Banks, A comparison of the properties of polyurethane immobilised Sphagnum moss, seaweed, sunflower waste and maize for the biosorption of Cu, Pb, Zn and Ni in continuous flow packed columns, Water Res. 40, 788-798 (2006).
 
25. I. Nuic, M. Trgo, N.V. Medvidovic, The application of the packed bed reactor theory to Pb and Zn uptake from the binary solution onto the fixed bed of natural zeolite, Chem. Eng. J. 295, 347-357 (2016).
 
26. G. Hodaifa, Iron removal from liquid effluents by olive stones on adsorption column: breakthrough curves, Ecol. Eng. 73, 270-275 (2014).
 
27. P. Marin, et al, A. Dimitrov Kroumov, Determination of the mass transfer limiting step of dye adsorption onto commercial adsorbent by using mathematical models, Environ. Technol. 35(18), 2356-2364 (2014).