Desalination efficiency of a novel bipolar membrane based on functionalized polysulfone

Abstract

Over the last few years, membrane technology has witnessed significant advances in the fabrication of ion-exchange membranes which have been used in various industrial processes such as desalination of saline water by electrodialysis and recovery of acid and alkali from solutions. In the present paper, we fabricated a functionalized polysulfone based bipolar membrane with PVA as the intermediate layer. The structure and characteristic properties of the membrane was studied by FTIR, 1H NMR, TGA and SEM. The membrane performance was evaluated using lab made bipolar membrane electrodialysis stack. Using sea water at a run time of 480min and 0.05N electrolytes, the process efficiency for the production of acid and alkali were 0.6M and 0.7M respectively for the synthesized membrane as compared with 0.4M and 0.5M respectively for the commercial membrane. The prepared membrane showed a current efficiency and energy consumption of 63% and 0.129kWh, respectively as against 45% and 0.14kWh as observed in the case of the procured membrane. The transport number of co-ions, conductivity of the solution and change in potential with respect to time at constant current density of about 5mA/cm2 were also recorded and compared for both the membranes.