Performance studies of heterogeneous ion exchange membranes in the removal of bivalent metal ions in an electrodialysis stack

Abstract

AbstractHeterogeneous anion and cation exchange membranes have been prepared by solution casting technique with poly(vinyl chloride) as inert binder and anion/cation exchange resins (−300 + 400 mesh) in a blend ratio of 60 : 40. The membranes were characterized with respect to their physical, mechanical, and electrochemical behavior. Anion and cation exchange membranes (10 cell pairs) were packed in an electrodialysis stack in a parallel plus series flow pattern. Desalting experiments were carried out with four different salt solutions, such as calcium chloride, magnesium chloride, cupric chloride, and nickel chloride (varying in their total dissolved solid from 500 to 1000 ppm), at different applied potentials and flow rates. The resultant current, percentage reduction in total dissolved solid, current efficiency, and energy consumption were calculated. The maximum current density in the electrodialysis stack was observed for calcium chloride solution and at any applied potential and flow rate the percentage reduction in total dissolved solid for Ca++ > Cu++ > Ni++ > Mg++. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009