Desalination of saline water with single and combined adsorbents

Due to high expenses of energy, desalination of saline waters by low-cost methods is important. To investigate the ability of five adsorbents (peat, activated carbon, zeolite, anionic resin, and cationic resin) in single and combined forms to remove salinity ions from aqueous solutions, 21 treatments were prepared for a batch experiment. This study was conducted using 1 g of each adsorbent in 50 cc of saline drainage water with total dissolved solids of 13.32 g L-1. The ratios of adsorbents in 1 g of each combined adsorbents were the same. Study results showed that among the single adsorbents, peat and activated carbon with adsorption of 255.5 and 253.7 mg of salinity ions had the highest and lowest adsorption rate, respectively. Zeolite, anionic resin, and cationic resin had the same adsorption rate of salinity ions. Between two and three combined adsorbents, all treatments containing cationic resin had the highest adsorption rate. All adsorbents adsorbed anions about 1.7 times of cations. The main finding of this study was that the highest salinity adsorption occurred in combination of cationic resin with peat, zeolite, activated carbon, and anionic resin. Therefore, application of cationic resin with another adsorbent is much more effective in adsorption of salinity ions as compared to single form or combination of three adsorbents.