Diffusion and Osmotic Permeability of Ion Exchange Membrane MK-40 Using Sodium Chloride Solution

Abstract

Cation exchange membrane (MK-40) is a commercial membrane with a fixed group that is an important part of the electrodialysis (ED) process. Sodium chloride (NaCl) diffusion and osmotic permeability for MK-40 was studied. A cell containing two compartments was used to analyse the properties of the MK-40 membrane fixed between them. Furthermore, the influence of temperature, NaCl concentration, and operating time on MK-40 properties was investigated. The results showed that the highest diffusion permeability coefficient of NaCl was 7.37×10-9 (m2/s), and the maximum osmotic permeability coefficient of distilled water was 43.8×10-9 (m2/s) at NaCl solution concentration of 0.1 M and 50oC. Generally, the permeability was constant beyond 60 min of operational time. Additionally, the minimum diffusion permeability coefficients of the MK-40 membrane fell by about 22% over time when the concentration of NaCl solution was 1 M at 25oC. To conclude, membrane properties in the ED process depend on the two electrodes (a cathode and an anode), without the diffusion of salts particles. Meanwhile, the most important properties of cation exchange membranes (CEMs) used in electrodialysis are increased membrane efficiency when water and salts transport decrease through CEMs, which leads to a decrease in energy consumption. Thus, the MK-40 membrane showed a good properties due to its low diffusion permeability for concentrated NaCl solution at elevated temperatures and minimum reduction in diffusion permeability of concentrated NaCl solution over time.