During the experiments, the current, voltage, and electrical conductivity (EC) were monitored using the inbuilt software of the ED system, and an external pH meter and thermometer (Orion Dual Star, Thermo Fisher Scientific, USA) were used for pH and temperature measurements. Concentrations of major cations (Ca 2+ , Mg 2+ , K + , Na + ) and total P, S, and Cl -were determined by inductively coupled plasmaatomic emission spectroscopy (ICP-AES; SPECTRO ARCOS, SPECTRO Analytical Instruments GmbH, Germany). The Cl -and F -concentrations were determined by ion chromatography (IC; Dionex IonPac AS19 4 x 250 mm column, Thermo Fisher Scientific, USA). Three sets of experiments were undetaken. Experiments 1-3 and 4-6 were carried out using initial pH values of 1.5 and 2.0, respectively. Diluate and concentrate Solutions were prepared using the salts and acids specified above, totalling 1 L volumes (for 50% diluate recovery). In all of the experiments, 0.25 M Na2SO4 was used as an electrode-rinse solution. The initial concentrations are listed in Table . The third set of experiments (7-8) was undertaken with >80% higher recovery ratio (diluate to concentrate volume ratio) by circulating 2.2 L flouride-free solution in the diluate compartment and 0.4 L 10 mM H2SO4 in the concentrate compartment (Table ). The applied voltages in all experiments were in the range of 4-30 V; flow rate and pressure ranges were 20-35 L h -1 and 50-100 mbar, respectively (barring 360-390 mbar in experiment 1 and 300-360 mbar in experiments 7 and 8); the temperature was maintained at 25°C ± 1.5°C using an external chiller. Based on EC reduction, samples were collected according to desalination degree (0%-50%; experiments 2, 7, 8: 52%-55%). The experimental conditions are summarized in Table .