UV-LED induced bicontinuous microemulsions polymerisation for surface modification of commercial membranes - Enhancing the antifouling properties

Due to a worldwide growing population and the resulting rising demand for fresh water, the treatment of wastewater is becoming more and more important to meet the water demand in many countries that have limited access to freshwater sources. In several processes, as in textile industries, the produced wastewater is treated by membrane bioreactors (MBRs). However, the membrane life-time and performance are strongly influenced by the fouling issue and, for this reason innovative approaches have to be considered for producing antifouling membranes. In this work, a novel polymerisable bicontinuous microemulsion (PBM) with antimicrobial properties was coated onto a commercial polyethersulfone (PES) UF membrane by using a UV-LED polymerisation system. The energy efficient UV-LED based process allows curing within a shorter time by selecting the optimal photoinitiator, curing time, coating thickness and temperature. The improved anti-fouling propensity was verified by water permeability experiments with humic acid as model foulant. The stability of the novel PBM coating was proven by FTIR analysis subsequent to chemical cleaning at pH 1 and 13. The novel PBM surface modification technique can be considered as a great step forward in the scale-up of a process thanks to the possibility of integrating into existing membrane production plants.