Enhanced antibiofouling properties of chitosan-based membranes by coating and blending of Moringa Oleifera L extracts

During application of ultrafiltration membrane for fruit juice clarification, biofouling occurred as the process deals with food substances. Chitosan-based membrane has potential to reduce membrane biofouling, however the performance is still requiring improvement. Natural antibiotics such as Moringa oleifera leaves and nuts extracts might be used to improve the antibiofouling properties of ultrafiltration membrane. We investigated the method to adhere Moringa oleifera extracts into chitosan-based ultrafiltration membranes. Two methods were investigated, i.e. coating and blending. The modified membranes were then immersed in Escherichia coli solution to test the anti-biofouling effect, alongside clean water flux test. The results show that by increasing Moringa oleifera extract concentration from 0%, 2.5% and 5% by using coating method, the mean clean water fluxes are similar in ? 5000-6000 L/m2h, while blending method provide less clean water fluxes, i.e. ? 6.000 L/m2h, 2.150 L/m2h, 4.462 L/m2h, for blending Moringa oleifera extract concentration from 0%, 2,5% and 5%, respectively. The lower clean water flux for blending method is due to smaller pore sizes of chitosan membrane which was filled by Moringa oleifera extract. With regards to bacteria adhesion, by observing 200μm membrane area under microscope, and analyzing the images, the total area of Escherichia coli attachment onto membrane surface are 38.07%, 4.57%, 0.57% for coating Moringa oleifera extract concentration of 0%, 2,5% and 5%, respectively. This result is better than blending methods that promotes 38.7%, 11.22% and 32.87% total area of Escherichia coli attachment onto membrane surface, by increasing blending concentration of 0%, 2,5% and 5%, respectively.