Batch-Modified Janus Membranes via In-Membrane-Module Interfacial Polymerization for Robust Membrane Stripping of Ammonia from Coking Wastewater

Membrane stripping is a promising method for ammonia removal/recovery from industrial wastewater, whereas, its application in treating coking wastewater is restricted by severe membrane fouling and wetting problems. Aiming at the challenges on applying interfacial polymerization on batch modification of hollow fiber membrane, this study come up with a novel in-membrane-module interfacial polymerization method. By flowing the aqueous and oil phases into the shell and lumen sides respectively, a hydrophilic nanoporous layer was constructed on the outer surface of hollow fiber membranes, obtaining a fouling- and wetting-resistant Janus membrane. The optimized Janus membrane demonstrated strong anti-wetting performance against surfactants for 14 days. 3600 hollow fibers in a 2-inch commercial membrane contactor were successfully modified in batch, and showed excellent anti-fouling properties when treating actual coking wastewater for over 80 days. In summary, this Janus membrane is highly beneficial for promoting the practical application of membrane stripping of ammonia from industrial wastewater across various fields.