Membranes were preconditioned by immersing them in deionised water for 24 h, followed by 2 h immersion in 0.5 M LiOH solution and rinsed in deionised water before use. Electrodialysis experiments were carried out by applying a current of 150 mA (ca. 1.5 kA m -2 electrode) between the counter and working electrodes at room temperature for 4 h. The applied current and resulting potential difference were recorded with a Biologic SP200 potentiostat. Acid-base titration of the resulting solutions was carried out using a Thermo Scientific Orion DUAL STAR pH meter at 25 o C to determine the free acid and free base concentrations in the anolyte and catholyte, respectively, with 0.5 M NaOH or 0.5 M HCl, from which recovered H 2 SO 4 or produced LiOH were indirectly quantified.