Water Recovery Desalination of Non-Traditional Waters

This research describes the design of new materials and research into sustainable membrane treatment practices to reduce the energy demands of water purification processes, including inland desalination. These technologies can help California reach its sustainability goals for water treatment, by considering the energy demands required by advanced water treatment and targeting plant inefficiencies caused by fouling and redundant process requirements of traditional materials. Brine disposal, membrane fouling, and membranes’ sensitivity to chemical treatment contribute to high energy costs associated with membrane-based water treatment by increasing the pressure required for membrane operations or by causing the need for additional pre-treatment and/or post-treatment steps. This work addresses these problems by applying materials science. In particular, the research studied ways to modify commercial membranes to prevent membrane fouling and examined methods to make membranes that are highly chemically tolerant and can be tailored selectively. The research also reviewed existing technologies for the sustainable operation of membrane treatment facilities. A single-step process was developed for the photochemical treatment of commercial membranes to create hydrophilic surfaces that resist fouling by preventing surface adhesion of hydrophobic foulants and preventing biofilm propagation on membrane surfaces. Addressing the chemical intolerance of the materials used commercially to fabricate membranes, the research team developed a method for making composite membranes from materials with enhanced properties including chemical tolerance. These approaches were designed with scalability in mind. A roll-to-roll prototype was built for the photochemical modification of membranes, while robust chemistries and scalable methods were used and developed for each of the novel membrane designs. By focusing on specific problems and scalable methods, this research brings new solutions closer to real-world applications. Simulated water treatment scenarios suggest that these materials offer new ways to overcome common membrane treatment challenges.