Method for direct observation of biofilm formation during operation on forward osmosis membranes

The purpose of this study is to describe a method for direct visual observation of biofilm formation on membranes used in a forward osmosis flow cell. Until recently biofouling research has focused on biofouling during reverse osmosis, and generally examined biofilms after, not during, operation. Direct observation allows for more sensitive measurements of fouling than flux data and membrane autopsies alone. The flow cell proposed here can be used to examine the mechanism of membrane fouling and to systematically examine the effects of surface coatings, membrane materials, and cleaning methods on biofouling using a broad range of process conditions.