Cryosectioning diagnosis and enzymatic cleaning of reverse osmosis membrane biofouling: Part I

Biofouling of reverse osmosis membranes is one of the main reasons for the flux decline in water reuse applications in the filtration industry. A simple screening approach to evaluate such membranes for their propensity to biofouling and a means of removing biofoulants, without changing surface physicochemical properties, would be of benefit to this sector. The objectives of this research are to investigate the mode of action of Subtilisin protease- and lipase-based enzymatic cleaning of thin-film composite reverse osmosis membrane biofoulants, and characterise the effects of the biofilm-resistant membrane surfaces by using cryosectioning of the membrane with biofilm on its surface. The first instalment of this article, which appears here, provides an introduction to the research, the materials and methods used and the first part of the results, which discusses biofilm formation, and quantitative measurements and visualisation of biofoulants on reverse osmosis membranes. Part II will be published in the September 2020 issue of Membrane Technology.