“…The nanofiltration process is a simple and very efficient way of separating ions from water solutions. Nanofiltration, which is a relatively new pressure-driven filtration process with separation properties between reverse osmosis (RO) and ultrafiltration (UF) processes, has several advantages including higher permeability for monovalent ions, low permeability for multivalent ions, lower operating pressure, higher flux, lower energy consumption compared to RO, and lower molecular weight cut-off (200–1000 Da) compared to UF [ 25 , 26 , 27 , 28 , 29 , 30 , 31 ]. The mass transport process in NF involves a combination of different mechanisms including steric exclusion (sieving), Donnan (charge effects) interactions, dielectric exclusion, and solute-membrane affinity [ 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 ].…”