Membrane fouling is a major issue impeding the application of membrane technology to water treatment processes. In our lab, complex mechanisms of combined colloidal and organic fouling of nanofiltration (NF) and reverse osmosis (RO) membranes are studied via experimental measurement and mathematical modeling, and the cationic species are crucial on organic foulant adsorption.
Previous studies investigated the interactions between foulants in solution, the adsorption of the foulants on the membrane surface, and effective cleaning protocols for removing combined fouling. The roles of various membrane surface chemical funcationalities are investigated using self-assembled monolayers (SAMs), and the differential adsorption of common wastewater and seawater organic foulants is quantified using quartz crystal microbalance with dissipation monitoring (QCM-D). A membrane surface chemistry parameter is being developed as an indicator for adsorptive fouling by organic foulants and the effectiveness of subsequent chemical cleaning. The effects of important cationic species on organic foulant adsorption are determined.