ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Determination of diffusivity from mass transfer measurements in a batch dialyzer: numerical analysis of pseudo-steady state approximation

Zdeněk Palatý and Helena Bendová

Institute of Environmental and Chemical Engineering, Faculty of Chemical Technology, University of Pardubice, Studentská 573, 532 10 Pardubice, Czech Republic

E-mail: Zdenek.Palaty@upce.cz

Abstract: The presented paper deals with the numerical analysis of pseudo-steady state conditions used in the modelling of the batch dialysis process. First, under specified conditions, time dependences of component concentrations and liquid volumes in both compartments were generated using a rigorous model based on Fick’s second law. From these data, the diffusion coefficient of the component in the membrane was calculated using a simplified model based on Fick’s first law. The specified coefficient was then compared with the calculated one. Numerical analysis revealed that in case of not too thick membranes, sufficiently high values of the diffusion coefficient, high intensity of mixing and considering the concentration and volume data in compartments I and II, the pseudo-steady state conditions can be considered as a good approximation of the real state

Keywords: dialysis – batch dialyzer – mathematical modelling – diffusivity – numerical analysis

Full paper is available at www.springerlink.com.

DOI: 10.1515/chempap-2015-0070

Chemical Papers 69 (4) 560–568 (2015)