(77c) Bio-Inspired Low Biofouling Nanocomposite Membranes: From Batch-Scale to Continuous-Scale Membrane Fabrication

According to the International Water Management Institute (IWMI), one in three people globally endures some form of water scarcity, one-quarter of the world's population lives in areas where water is physically scarce, and over a billion people live where water is economically scarce. Existing water supplies may be limited in quantity or quality for meeting the increasing demands from population growth and industry expansion. In many arid and semi-arid areas, providing the large volume of water required for industrial, agricultural, recreational and potable applications is especially difficult. The search for new technologies for water treatment is an increasingly important research topic. Depending on the application, water is desired in varying degrees of purity. For some applications, such as desalination, a very high degree of purification is desired.

Membrane processes are now a proven and reliable method of providing high-quality, cost-effective water. Membrane technologies have immediate applications to treatment of fresh, brackish and seawaters, as well as wastewater reclamation. With innovative module design and engineering, micro- and ultra-filtrations have become effective and economical for drinking water production, particularly for removal of microorganisms. Desalination is becoming more and more a commodity to satisfy the growing demand for water. This study shows the results of low-biofouling nanocomposite membranes, when using batch-scale fabrication and testing techniques, and when using continuous-scale fabrication and testing techniques. This holistic study begins with nanoparticle manufacturing and selection, then focuses on nanocomposite membrane synthesis and fabrication, and ends with testing and characterization. Nanocomposite membranes loaded with casein-coated silver nanoparticles (Casein-AgNPs) were cast using two approaches, doctor-blade extrusion (batch-scale) and slot-die casting (continuous-scale), to determine their biofouling control properties. Overall, filtration experiments and membrane testing following biofouling tests showed that laboratory-scale composite membranes operated for 24 hr were effective in mitigating biofouling formation. Conversely, continuous-scale nanocomposite membranes operated for 26 days did not show clear improvement in biofouling control, however there was visible damage to cells accumulated on the membrane.