High-Flux, Low-Fouling Membrane System for Wastewater Recycle in Space Missions

This study evaluates the use of microfiltration (MF), low pressure RO (LPRO) and nanofiltration (NF) membranes for use in a treatment train for recycled wastewater. Specifically, a MF membrane will act as pretreatment for RO/NF membranes. Contaminants of concern for the membrane system include biosolids and surfactant micelles for the MF membrane, and ammonium ions, urea, surfactant monomers, and salts for the RO/NF system. These contaminants will be reduced to meet existing EPA and NASA standards using these membrane systems. The goal is to achieve high removal rates (>95% for these contaminants) while maintaining high flux and low fouling of the membranes, as membrane treatment is the last treatment step before final disinfection of the recycled wastewater. This paper outlines the experimental plan for designing the integrated membrane system and explains the potential benefits of such a system.