The effectiveness of reverse osmosis (RO) membrane systems may be compromised due to fouling, of which biofouling (excessive growth of biomass) is the most troublesome. Effective control of biofouling is essential to improve membrane performance and reduce operating costs. The periodic application of chemical cleaning agents is possibly the most widely practiced method of biofouling control in RO membranes. This research investigated advanced chemical cleaning strategies for biofouling control. The first part of this study concluded that short-term accelerated biofouling studies using lab-scale membrane fouling simulators (MFSs) are a representative and suitable approach for the prediction of long-term biofouling development in membrane systems. Thereon, the superior efficiency of urea as an alternative to conventional chemical cleaning agents was demonstrated (i) at lab-scale using MFSs, (ii) for full-scale industrial spiral-wound membranes and (iii) for multiple cleaning cycles during long-term operation. Periodic chemical cleaning with urea resulted in better restoration of membrane performance, higher biomass inactivation, enhanced biofilm solubilization and removal, disintegration of extracellular polymeric substances (EPS) particularly proteins, and a considerable reduction of key biofilm-forming bacteria. This research presented enhanced chemical cleaning strategies aiming to increase the removal of biofilms, reduce biomass accumulation and its impact on membrane performance, and delay fresh biofilm formation.
Huma Sanawar is a Ph.D. candidate under the supervision of Professor Johannes Vrouwenvelder. She is an alumna of Limerick Institute of Technology, Ireland, and holds a B.Sc. in Pharmaceutical and Forensic Analysis, and M.Sc. in Analytical Chemistry. Her research at KAUST focuses on curative biofouling control strategies for reverse osmosis membrane systems. During the course of her Ph.D., she also collaborated with the Delft University of Technology and Evides Industriewater in the Netherlands to carry out research activities at both lab-scale and full-scale set-ups, investigating novel membrane cleaning strategies for enhanced biofilm removal.