ORIGINAL PAPER Chloride behaviour in electromembrane treatment of brine issued from desalination plants M. Naimi • C. Innocent • D. E. Akretche Received: 13 September 2009 / Accepted: 4 January 2010 / Published online: 14 January 2010 Ó Springer Science+Business Media B.V. 2010 Abstract In this work, the chloride behavior through an electrochemical treatment of brines is examined using ion exchange membranes like in electrodialysis. All experi- ments have been performed using solutions of NaCl before an application on real brines issued from an Algerian desalination plant. After checking oxidation parameters of chloride oxidation by electrolysis, ion exchange membrane have been introduced to control both the pH and the species migrated. The effect of current density and the membrane nature has been studied. The electrochemical treatment described in this work allows transforming the brines in useful products as NaOH, HCl and Cl 2 . The pH and the salt concentration are varied and the products obtained at the electrodes were identified and analyzed. It was shown that we can get chlorates according to the current density applied and the fixed pH. This fact gives rise to an eco- nomical process where valuable products can be obtained using only the chloride oxidation current. Results were linked to the Pourbaix diagram and allow the prediction of the process efficiency. Keywords Brine  Chloride  Chlorate  Membrane  Electro-electrodialysis 1 Introduction In the output of a desalination plant, great quantities of brine are generated and cause an environmental problem. Effectively, brines cannot be rejected in the sea because it provokes an increase of the salt concentration which is hazardous to all marine life. It is a worried problem which is not well treated until now. On the other hand, the brine production gives rise to a real problem of storage like sludge in the output of surface industries. Although the possibility of electrochemical scale removal has long been recognized, industrial application of this technique is rather limited and technical information in the literature is not important. Electrolytic scale removal is based on the generation of a high pH environment around the cathode by the cathodic reactions which produce OH - . Thus, the alkaline environment promotes precipitation of both the calcium hardness in the form of CaCO 3 and the magnesium hardness in the form of Mg(OH) 2 . In the presence of chloride ions, authors [1] assume that only chlorine gas is released at the anode. Despite the commercial availability of such equipment, the use of electrolytic scale control methods is quite limited. The small number of laboratory studies [2–4] and the few publications dealing with commercial devices [5–7] pro- vide very limited information on parameters affecting the performance of electrolytic scale removal installations. Recent publications [8–11] indicate a revived interest in the study of electrochemical precipitation of CaCO 3 . Electrochemical treatment is also proposed by Van Hege et al. [12] as a novel treatment strategy for RO membrane concentrate. Electro-oxidation has been successfully implemented for the abatement of hard-to-treat wastes such as landfill leachate [13, 14], textile effluent [15] and wastewater containing polyaromatic organic pollutants M. Naimi L.E.C. – U.E.R.C.A. – EMP, BP101, Bordj El-Bahri, Algiers, Algeria C. Innocent IEM-UMR5635, Place Euge `ne Bataillon, 34095 Montpellier Cedex, France D. E. Akretche (&) Laboratory of Hydrometallurgy and Inorganic Molecular Chemistry, Faculty of Chemistry, USTHB, BP32 El-Alia, 16111 Bab ezzouar, Algiers, Algeria e-mail: dakretche@hotmail.com 123 J Appl Electrochem (2010) 40:1079–1083 DOI 10.1007/s10800-010-0070-5