Effects of combined ozone and PAC pretreatment on ultrafiltration membrane fouling control and mechanisms

This work investigates the effects of combined ozone and powered activated carbon (PAC) pretreatment on ultrafiltration (UF) performance. High performance size exclusion chromatography (HPSEC) combined with peak-fitting prediction and fluorescence excitation-emission matrix spectroscopy coupled with parallel factor analysis (EEM-PARAFAC) were used to analyze membrane fouling and organic removal. We conclude that combined ozone and PAC pretreatment can significantly inhibit an increase in transmembrane pressure (TMP) whereby ozone plays a predominant role in delaying TMP increases. Ozone and activated carbon can greatly improve the removal efficiency of organic matter, especially that of macromolecular biopolymers, medium molecules of humic-like substances and small molecular acids and neutrals; however, the removal efficiency of aromatic proteins containing tyrosine is limited. Macromolecular biopolymers show high correlations with TMP/TMP0, followed by that of building blocks of low molecular acids and neutrals, while humic-like substances have a minor influence on UF membrane fouling. Fluorescence EEM is not valid for use as an indicator of membrane fouling after combined ozone and PAC treatment according to this study.