(486c) Monitoring Biofouling Dynamics on Foward Osmosis (FO) Membranes Using a Clsm-Compatible Microfluidic Biofilm Flow Cell

In membrane biofouling studies, the current method for examining the growth of biofilms on water-purifying membranes in membrane testing flow cells has been a â??membrane autopsyâ? followed by microscopic observations. However, during the preparation of membrane samples, uncontrollable and unpredictable disturbances to the biofilms on the membrane surfaces may occur, resulting in artifacts that may lead to misinterpretation of experimental results. Furthermore, the autopsy approach can only provide a snapshot of and the dynamically changing biofouling conditions over time. This limitation is mainly due to the lack of tools that allow us to monitor dynamics of biofouling without the need of dissembling the membrane testing systems. In this study, we developed a novel multichannel microfluidic membrane flow cell that enables non-destructive, real-time monitoring of biofouling dynamics using confocal laser scanning microscopy (CLSM). As a proof of concept, we examined the development of green florescent protein (GFP)-tagged bacterial biofilms on forward osmosis (FO) membranes. The temporal profiles of quantitative biofouling parameters including surface coverage, biovolume and biofilm thickness were obtained without disrupting the continuous operation of the membrane testing system. The microfluidic membrane flow cell developed in this study can be readily applied to evaluate anti-biofouling activities of FO membranes and allows direct comparison of biofouling dynamics between FO membranes with different surface modifications.