CFD Simulation of UV Disinfection Reactor for Applesauce with a Low UV Absorption Coefficient

Document Type : Original Paper


1 Computational Fluid Dynamics (CFD) Research Laboratory, School of Chemical Engineering, Iran University of Science and Technology (IUST), Tehran, Iran

2 Department of Chemical and Biological Engineering, University of British Columbia, Vancouver, BC Canada


In this study, a Computational Fluid Dynamics (CFD) model was developed to evaluate ultraviolet disinfection applesauce reactor. To simulate UV reactors, three sets of equations, including hydrodynamics, radiation and species mass conservation were solved simultaneously. The Realizable k-e turbulence model and the discrete ordinate method were used to find the UV radiation profile through the reactor. Using the Chick-Watson kinetic model and the Eulerian framework, inactivation of applesauce microorganisms was simulated in the UV reactor. Simulation results for water disinfection in the UV reactor were evaluated by the reported experimental data. Simulation was extended for non-Newtonian fluid such as applesauce. Results show that the UV reactor is less effective in eliminating microorganisms from applesauce than from water because applesauce has a higher UV absorption rate. In order to achieve higher disinfection of the UV reactor for non-Newtonian fluids with high absorption, this study examined different parameters and makes suggestions for appropriate reactor design. Different designs for disinfection reactor were studied, due to higher UV absorption coefficient of applesauce, CFD simulations show that the inactivation of microorganisms in applesauce is less than water, consequently thin film or small radius reactors are appropriate design.


[1] Unluturk, S. K., Arastoopour, H. andKoutchma, T. (2004). "Modeling of UV dose distribution in a thin-film UV reactor for processing of apple cider."J. Food Eng., Vol. 65, pp. 125–136.
[2] Adhikari, C., Koutchma, T. and Beecham-Bowden, T. (2005). "Evaluation of HHEVC (4, 40, 400-tris-di-Bhydroxyethyl
amino triphenyl acetonitrile) dye as a chemical actinometer in model buffers for UV treatment of apple juice and cider."LWT-Food Sci. Technol., Vol.38, No. 7, pp. 717-725.
[3] Koutchma, T. and Parisi, B. (2004). "Biodosimetry of Escherichia coli UV inactivation in model juices with regard to dose distribution in annular UV reactors."J. Food Sci., Vol. 69, No. 1, FEP14-FEP22.
[4] Koutchma, T., Parisi, B. andUnluturk, S.K. (2006). "Evaluation of UV dose in flow-through reactors for fresh apple juice and cider."Chem. Eng. Commun., Vol. 193, pp. 715–728.
[5] Keyser, M., Műller, I.A., Cilliers, F.P., Nel, W. and Gouws, P.A. (2008). “Ultraviolet radiation as a nonthermal treatment for the inactivation of microorganisms in fruit juice."Innovative Food Sci. Emerging Technol., Vol. 9, pp. 348–354.
[6] Koutchma, T., Parisi, B. andPatazca, E. (2007). "Validation of UV coiled tube reactor for fresh fruit juices."J. Environ. Eng., Vol. 6, pp. 319–328.
[7] Oteiza, J.M., Giannuzzi, L. and Zaritzky, N. (2010). "Ultraviolet treatment of orange juice to inactivate E. coli O157:H7 as Affected by Native Microflora." Food Bioprocess Technol., Vol.3, No. 4, pp. 603-614.
[8] Unluturk, S., Atılgan, M.R., Handan Baysal, A. and Tarı, C. (2008). “Use of UV-C radiation as a non-thermal process for liquid egg products (LEP)."J. Food Eng., Vol. 85, pp. 561-568.
[9] Ducoste, J.J., Liu, D. and Linden, K. (2005). "Alternative approaches to modeling fluence distribution and microbial inactivation in Ultraviolet Reactors: Lagrangian versus Eulerian."Environ. Eng., Vol.131, No. 10, pp.1393–1403.
[10] Duran, J.E., Taghipour, F. andMohseni, M. (2009). "CFD modeling of mass transfer in annular reactors."Int. J. Heat Mass Transfer, Vol. 52, pp. 5390-5401.
[11] Elyasi, S. andTaghipour, F. (2006). "Simulation of UV photoreactor for water disinfection in Eulerian framework."Chem. Eng. Sci., Vol. 61, pp. 4741– 4749.
[12] Wols, B.A., Shao, L., Uijttewaal, W.S.J., Hofman, J.A.M.H., Rietveld, L.C. andVan Dijk, J.C. (2010). "Evaluation of experimental techniques to validate numerical computations of the hydraulics inside a UV
bench-scale reactor."Chem. Eng. Sci., Vol. 65, pp. 4491-4502.
[13] Liu, D., Wu, C., Linden, K. and Ducoste, J. (2007). "Numerical simulation of UV disinfection reactors: Evaluation of alternative turbulence models." Appl. Math. Model., Vol. 31, pp. 1753-1769.
[14] Sozzi, D. andTaghipour, F. (2006). "UV reactor performance modeling by Eulerian and Lagrangian methods."Environ. Sci. Technol., Vol. 40, No. 5, pp. 1609-1615.
[15] Chiu, K., Lyn, D.A., Savoye, P. and Blatchley, E.R. (1999). 'Integrated UV disinfection model based on particle tracking."Environ. Eng., Vol. 125, No. 1, pp. 7-16.
[16] Duran, J.E., Taghipour, F. and Mohseni, M. (2010). "Irradiance modeling in annular photoreactors using the finite-volume method."J. Photochem. Photobiol. A: Chemistry., Vol. 215, pp. 81-91.
[17] Stamnes, K., Tsay, S.C., Wiscombe, W. andJayaweera, K. (1988). "Numerically stable algorithm for discrete-ordinate-method radiative transfer in multiple scattering and emitting layered media." Appl. Optics, 27(12), pp. 2502-2509.
[18] Liou, B.T. and Wu, C.Y. (1996). "Radiative transfer in a multi-layer medium with Fresnel interfaces."Heat Mass Transfer, Vol. 32, No. (1-2), pp. 103-107.
[19] Patankar, S.V. (1980). Numerical Heat Transfer and Fluid Flow, Taylor and Francis.
[20] Versteeg, H. andMalalasekra, W. (2007). An Introduction to Computational Fluid Dynamics: The Finite Volume Method, 2nd Edition, Pearson Prentice Hall.
[21] Steff, J.F. (1996). Rheological Methods in Food Process Engineering, 2nd ed., Freeman Press, East Lansing, USA.
[22] Sozzi, A. andTaghipour, F. (2006). "Computational and experimental study of annular photo-reactor hydrodynamics."Int. J. Heat Fluid Flow, Vol. 27, pp. 1043–1053.
[23] Liu, D., Ducoste, J. and Linden, K. (2004). "Evaluation of alternative fluence rate distribution models."J. Water Supply, Res. Technol., Vol. 56, pp. 391-408.
[24] Bird, R.B., Armstrong, R.C. and Hassager, O. (1987). Dynamics of polymeric liquids: Vol. 1 Fluid Mechanics., 2nd ed., Wiley, New York.