AWWA WQTC71423

Microfiltration (MF) membranes are increasingly becoming critical components of treatment systems, including water reuse applications. In water reuse, MF typically acts as pretreatment to downstream reverse osmosis (RO) and advanced oxidation process. While numerous advances have been made, membrane fouling and the development of effective membrane cleaning protocols persist as challenges. New chemical clean-in-place (CIP) formulations were evaluated in pilot tests at the Edward C. Little Water Recycling Facility (ECLWRF) for their ability to improve the performance restoration for the Phase III continuous MF (CMF) membranes. Membrane autopsies found that the primary fouling mechanisms for the CMF membranes were biological and organic in origin. The cleaning test results found that the current CIP regime for the Phase III system performed better than the four commercially available cleaning solutions evaluated here. However, improved results were obtained when hydrogen peroxide was added to the current CIP regime consisting of caustic soda and the commercially available Memclean C™ cleaning solution. The effects of the addition of hydrogen peroxide to the standard cleaning procedure shows some promise; however, further research is needed to understand the cleaning mechanisms and long-term effects of using hydrogen peroxide as a cleaning additive. Includes 35 references, tables, figures.