Transport of NaCl, MgSO4, MgCl2 and Na2SO4 across DL type nanofiltration membrane

The separation of inorganic ions by membrane filtration of aqueous solutions through NF-membranes was investigated. The single and binary salt solutions of NaCl, MgCl2, Na2SO4 and MgSO4 were used in this study. These salts are the most commonly found in natural water resources. From the research literature it was stated that NaCl has a very low rejection range with NF membranes while MgCl2 is moderately rejected, Na2SO4 and MgSO4 are very highly rejected salts. Thus, these four salts provide a full range of rejection behavior for the NF system and hence constitute an ideal system. In addition, these salts have a very high solubility in water so there would not be any cake layer formed due to precipitation of salts at the surface of the membrane where a significantly higher concentration of salt can be developed due to concentration polarization