(604d) Fouling Prevention in Rotating Reactive Membrane Filtration

Current trends of water stress and scarcity worldwide necessitate the development of effective and efficient technologies for water reuse and recycle. Membrane filtration becomes an essential technique for water reuse and recycle of low-quality sources. However, biofouling and biofilm growth are major obstacles for membrane filtration because they cause dramatic losses in efficiency and system flux. By coating ceramic ultrafiltration membranes with titanium dioxide photocatalysts, we have created a multifunctional reactive membrane that resists fouling and biofilm growth by improving hydrophilicity, inactivating microorganisms, and degrading organics. In previous work we have identified Degussa P25 as a strong candidate for biofilm prevention based on its excellent bacterial cell attachment resistance and high organic degradation activity, and long-term biofilm growth prevention and reduced flux decline in experiments with Pseudomonas putida on ceramic membrane discs coated with the Degussa P25 photocatalyst. In this presentation, I will report on further work elucidating the mechanisms by which this reactive coating prevents attachment, and comparing the importance of surface hydrophilicity, photocatalytic activity, and photolysis by UV illumination in the system.

Furthermore, this reactive coating has been incorporated into a rotating cylindrical geometry to take advantage of Taylor-Couette flow for enhanced biofouling prevention. By combining the physical action of Taylor-Couette flow and the chemical action of TiO2, we have created a highly effective system. I will report the latest results from this experimental setup, with a description of our system design, and preliminary results on the overall flux decline and biofilm growth reduction.