Membranes for efficient, large-scale water purification face the key challenges illustrated in the following diagram:
Specialized membranes, e.g. functional membranes, biocide resistant membranes (chlorine, bromine etc.), membranes selective to specific contaminants (such as estrogen-like chemicals), biofilm repealing membranes, and slow release membranes, require the additional criterion of selectivity to be met for a wide variety of chemical species. Water purification via membrane technology is a global challenge and a high impact area for innovation using functional/smart materials. The combined polymer and materials science expertise of BGU, ANL and UChicago is well-suited to devising new materials for this purpose.
The biological issues related to water relate both to purity with respect to biological pathogens, as well as to the formation of biofilms on membrane surfaces immersed in water, which degrade membrane performance over time. A Singapore success story and the pillar of Singapore’s water sustainability, NEWater is high-grade reclaimed water produced from treated used water that is further purified using advanced membrane technologies and ultra-violet disinfection, making it ultra-clean and safe to drink. Biofilms are ubiquitous. Nearly every species of microorganism, not only bacteria and archaea, have mechanisms by which they can adhere to surfaces and to each other. Biofilms will form on virtually every non-shedding surface in a non-sterile aqueous (or very humid) environment. Disinfectants such as chlorine can be used to inhibit biofilm formation but have adverse effects on many membrane materials. Omniphobic surfaces to which nothing can attach durably would be a desirable goal.