Chloride reduction from brackish water by supported liquid membranes using ionic liquids as carriers

Abstract

The desalinization of the continental waters is one of the actual challenges on supplying water requirements. Water with high contents in salts is inadequate for drinking water and irrigation uses. In the industry this water involves additional conditioning steps. Salinity in water can determine the aquatic ecosystem and the life of the pants. High concentration of chloride in continental water is a great problem for the exploitation of these natural resources. In general, Cl- in water can be reduced by conventional water treatment processes, like ion exchange or reverse osmosis, but for long scale production these techniques could be very expensive due to resins regeneration or energy costs. This work proposes an alternative solution to chloride reduction from brackish water. The possibility to exchange Cl- to HCO3- anion on a supported liquid membrane using Aliquat 336, Cyphos IL 101 and Cyphos IL 167 as a carriers have been demonstrated. Experimental liquid liquid extraction process has been taken into account to determinate the stability and the easiness of the anion exchange. Alternating HCO3- 1M, and 1000 mg/L of Cl- contacts with the organic phase during fifteen extraction-regeneration cycles, no change in the results have been observed.