Abstract

The paper presents a hybrid matrix form of Kedem–Katchalsky equations that contains Peusner’s coefficients $$H_{ij}^{*}\;(i, j = 1, 2)$$ for the conditions of concentration polarization and $$H_{ij}$$ for homogeneous solutions. The aqueous glucose solutions were analyzed in Nephrophan membrane system with membrane in horizontal plane. The calculations of coefficients $$H_{ij}^{*}$$ were made for the A and B configurations of the membrane system. In the A configuration glucose solution with higher concentration was located below and the solution with lower concentration above the membrane. In configuration B locations of the solutions were reversed. Non-diagonal coefficients of matrix $$[H^{*}]$$ (concentration polarization conditions) were shown to be linearly dependent on average concentration of glucose solution in the membrane. $$H_{12}^{*}$$ in A configuration was lower than in B configuration. Non-diagonal coefficients of matrix $$[H^{*}]$$ were lower than appropriate coefficients of matrix [H] (homogeneous solutions). For diagonal coefficients of matrix $$[H^{*}]$$ coefficient $$H_{11}^{*}$$ is constant and equal to $$H_{11}$$ , whereas $$H_{22}^{*}$$ and $$H_{22}$$ are nonlinearly dependent on average concentration of glucose solution in the membrane. Value of $$H_{22}^{*}$$ in A was lower than in B configuration of the membrane system. Additionally, $$H_{22}^{*}$$ were lower than $$H_{22}$$ . For both A and B configurations and concentration polarization conditions, the coefficients $$H_{12}^{*}$$ and $$H_{22}^{*}$$ of matrix $$[H^{*}]$$ are different for average solution concentrations $${>}5.41\,\hbox {mol}\,\hbox {m}^{-3}$$ due to convective mixing of solutions in B configuration.

Highlights

  • Peusner’s Network Thermodynamics (Peusner’s NT) is one of the methods used to describe transport in membrane systems that enables symmetrical and/or hybrid transformation of classical Kedem–Katchalsky equations to network forms (Peusner 1970, 1983, 1985, 1986).For homogeneous binary non-electrolyte solutions there are two symmetrical and two hybrid forms of network K–K equations

  • In our previous papers (Slezak et al 2012a, b; Batko et al 2014a, b, 2015) we used the coefficients of concentration polarization and membrane transport parameters (L p, σ, ω) to calculate the matrices [R∗], [L∗] and [P∗]

  • The coefficients of concentration polarization and membrane transport parameters are contained in the Kedem–Katchalsky formalism

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Summary

Introduction

Peusner’s Network Thermodynamics (Peusner’s NT) is one of the methods used to describe transport in membrane systems that enables symmetrical and/or hybrid transformation of classical Kedem–Katchalsky equations to network forms (Peusner 1970, 1983, 1985, 1986). In our previous papers (Slezak et al 2012a, b; Batko et al 2014a, b, 2015) network forms of the Kedem–Katchalsky equations were applied to interpret the transport of binary nonelectrolyte solutions through horizontally mounted membrane in concentration polarization cationondndsPitoii∗jof nwgsle.urTceohcseoecmoapnefadfirecpdioelntyotmstheLrei∗jmv,aRelmui∗jebsarnaodnfePc.oi∗Aje(fdifi,dcijitei∈onnt{sa1l,Lly2i,j},)thRweiejvreaalncudaelscPuiojlfactceaodlcefufofilractaieeqdnutefsoorLusci∗jos,onRldui∗ij--. Kedem–Katchalsky equations were transformed into hybrid matrix form and applied to interpret the membrane transport of non-electrolyte solutions in conditions of concentration polarization. We assessed the influence of the concentration polarization on the value of Peusner’s coefficients Hi∗j , for aqueous solutions of glucose and a Nephrophan hemodialysis membrane. The values of these coefficients were compared to the values of coefficients Hi j calculated for the same concentrations of homogeneous solutions and different configurations of the membrane. To find new coefficients better describing the membrane transport in concentration polarization conditions for both configurations of the membrane system, we analyzed other combinations of coefficients of matrixes [H ∗] and [H ] for A and B configurations

Theory
H11 H12 H21 H22
Results and Discussion
12 B 12 A
Conclusions
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