Desalination 158 (2003) 95–100 0011-9164/03/$– See front matter © 2003 Elsevier Science B.V. All rights reserved Presented at the European Conference on Desalination and the Environment: Fresh Water for All, Malta, 4–8 May 2003. European Desalination Society, International Water Association. *Corresponding author. Effect of feed characteristics on the separation performances of monovalent and divalent salts by electrodialysis N. Kabay a *, M. Arda b , I. Kurucaovali a , E. Ersoz a , H. Kahveci a , M. Can a , S. Dal a , S. Kopuzlu a , M. Haner a , M. Demircioglu a , M. Yuksel a a Department of Chemical Engineering, Faculty of Engineering, Ege University, 35100 Izmir, Turkey Tel/Fax +90 (232) 3887600; e-mail: kabay@eng.ege.edu.tr b Department of Chemistry, Faculty of Science, Ege University, 35100 Izmir, Turkey Received 12 December 2002; accepted 30 December 2002 Abstract In this study, separation performance for monovalent salts (NaCl, KCl) and divalent salts (CaCl 2, MgCl 2 ) was investigated by electrodialysis at pH 6.0–6.5, 4.0 and 2.0 using constant voltage mode of operation. TS-1-10 electrodialysis equipment (Tokuyama) modified with rotameters was employed in experimental studies. The effect of electrical potential, pH and ion valency on separation performance was studied at room temperature using a constant flow rate. The efficiencies of each run were evaluated as specific power consumption with the electrical energy consumed only in stack. Keywords: Electrodialysis; Monovalent salts; Divalent salts; Desalination; Feed characteristics; Specific power consumption 1. Introduction Water is the most important natural resource in the world since without it life cannot exist and most industries could not operate. The presence of a safe and reliable source of water is thus an essential prerequisite for the establishment of a stable community. Electrodialysis and reverse osmosis have been widely applied for many years for the production of drinking and process water in order to reduce the salinity. In electrodialysis process, ion ex- change membranes are employed to separate ions