LAUSR

Abstract Desalinated water reduces salt load and water needs in irrigation but lack hardness and sulfate ions required for optimal plant growth. Mixing with groundwater adds hardness but raises chloride and sodium levels limiting the amount of groundwater that can be used in the blend. Monovalent selective electrodialysis (SED) allows reducing chloride and sodium while preserving most of the hardness ions. This study examined under what conditions monovalent selective membranes are effective in treating groundwater for irrigation. All monovalent selective anion exchange membranes tested showed excellent selectivity for sulfate over chloride. Monovalent selective cation exchange membranes worked less well at the lower conductivities typical of brackish water, with only CSO membrane showing significant monovalent permselectivity (Pdm