Desalination 177 (2005) 51–57 0011-9164/05/$– See front matter © 2005 Elsevier B.V. All rights reserved Fluoride removal by Donnan dialysis with anion exchange membranes F. Durmaz * , H. Kara, Y. Cengeloglu, M. Ersoz Department of Chemistry, Selcuk University, Kampus, Konya 42031,Turkey Tel. +90 (332) 2232796; e-mail: fdurmaz@selcuk.edu.tr Received 15 June 2004; accepted: 22 November 2004 Abstract The removal of fluoride from diluted solution with Neosepta AHA anion exchange membrane has been studied by Donnan dialysis. The effects of concentration, pH, and accompanying anion on feed phase and receiving phase composition were investigated. Neosepta AHA anion exchange membrane was used for the removal of fluoride and the flux of fluoride with respect to the concentration, pH, and the effect of the counter-ions (HCO 3 - , Cl - , SO 4 -2 ) were obtained between 34–136.10 -7 (m.mol.cm -2 .s -1 ). The effect of the fluoride flux in- creased with increasing of concentration on the feed phase. The flux of fluoride was found to be higher at higher pH in the feed phase. In addition, the accompanying counter-anions also influenced the flux of fluoride and the order of flux was founded as HCO 3 - >Cl - >SO 4 -2 . The results obtained for AHA membrane were compared with Neosepta AFN and polysulfone SB-6407 membranes. The transport efficiencies of the membranes were found to be in the order AFN>AHA>SB-6407. Keywords: Donnan dialysis; AHA; Ion exchange membrane; Flux 1. Introduction Increased industrialization and human popu- lation have led to a progressive degeneration of the existing environment. Pollutants in the physical and biological environment are subject to redistribution, deterioration and transforma- tion. The fluoride pollution in water is a serious _____________________ *Corresponding author problem and can occur due to both natural rea- sons and human activity. Excess or lack of levels of fluoride in drinking water is harmful to human health, causing dental or skeletal fluorosis [1,2]. The acceptable standard limit of fluoride con- centration ranges between 0.5–1.5 mgL -1 for drinking water [3]. However the amount of fluoride ion in groundwater for some places in the world ex- ceeds the acceptable values. Therefore, various