Superfiltration (SF) membranes are a class of membrane that falls between ultrafiltration and nanofiltration. SF membranes demonstrate high NF-like organic rejection and low UF-like salt rejection. Membranes in this class may be described as “tight UF”, “open NF”, and “thin-film UF” and commonly have a molecular weight cut-off (MWCO) between 500 – 3,500 Daltons and low monovalent ion rejection (< 15%). 

ZwitterCo’s zwitterionic SF membranes are even more versatile due to their unprecedented fouling resistance, wide pH tolerance, and ability to clean with chlorine. 

With these separation characteristics, SF membranes are a great option for fractionating dissolved components, like capturing protein while passing inorganic molecules. Additionally, SF is tight enough to remove all fats, oils, and grease (FOG) and common dissolved foulants, making SF membranes an excellent candidate for pre-treatment to reverse osmosis in wastewater treatment or reuse.