Temperature dependence of membrane transport parameters in hyperfiltration

Abstract

Using three homogeneous (CA/F-700, K-700, L-700) and two asymmetric flat sheet membranes (B-9 and SOLROX SC-200) as well as a homogeneous strong ion exchange (CK-1) and a composite membrane (Teijin PBIL), the temperature dependence (0°C ⩽ T⩽ 40°C) of the transport parameters of the phenomenological relationships of the thermodynamics of irreversible processes such as the hydrodynamic and osmotic permeability, ℓp and ℓ π, and the asymptotic solute rejection, r∞, was determined from hyperfiltration experiments with 0.1 M NaCl brine solution. The activation energies of water and salt transport, Eℓ p and Ep s, for the different membranes used were then evaluated from the experimental data. Using aqueous KCl, MgCl 2, K 2SO 4, MgSO 4 solutions, the data were supplemented by the experimentally determined enthalpies of dissolution at infinite dilution of the salt, ΔH O s, in homogeneous CA membranes.