Separation of Anionic Surfactants in a Sequential Ultrafiltration – Ion Exchange Purification System

Efficiency of a sequential ultrafiltration – ion exchange purification system was studied by testing separation of an anionic surfactant (SDBS) from aqueous solutions. Commercially available ultrafiltration membranes with cut-off values of 5, 10, and 30 kDa were used for the tests. The ion exchange processes were carried out on five types of ion-exchange resins – both macroporous and gel-based. Overall efficiency of the integrated purification system was determined by numerous parameters, including quality of the solution to be purified, membrane material type, membrane cut-off value, the type of ion-exchange resin, its dose, and solution contact time of the ion-exchange resin. It was shown that the application of ion exchange constitutes a highly effective final purification stage after the membrane process. The obtained results allowed for listing the integrated systems in the following descending efficiency order depending on the resin being used: MIEX > SBW > A400 > A200 > A100.