Year Established: 2013 Start Date: 2013-03-01 End Date: 2015-02-28
Total Federal Funds: $17,992 Total Non-Federal Funds: $37,041
Principal Investigators: Paula Mouser, Hendrik Verweij, Linda Weavers
Abstract: Inorganic membranes contain porous oxides, or metals, and can be present in multi-layer supporting structures, or be self-supporting. Compared to polymeric membranes, inorganic membranes can be more selective and permeable, retain a more stable pore structure, hold higher mechanical strength and Young’s modulus, maintain a longer life, withstand more extreme conditions during use and cleaning, and have a wider variety surface properties of importance for biofouling. This translates to a more sustainable and energy efficient form of water filtration in a wide range of treatment applications. To make inorganic membranes fully competitive, their cost price must be reduced by improvements in processing, introduction of rapid fabrication methods, and possibly incorporation in hybrid, polymeric structures. There also remains a significant knowledge gap in our understanding of the fundamental mechanisms contributing to the reduction of flux during operation of these membranes, and in particular biological fouling. This research proposes to investigate the biophysical characteristics of biofilm growth on subset of ceramic membranes, and to investigate how efficiently these films are removed using sonication techniques. Experiments will be conducted using inorganic ceramic membranes that vary in their morphology (pore size, porosity) and surface chemistry. Membranes will be used to filter secondary effluent from a domestic wastewater facility until they are biologically fouled. Biofilms and associated membrane surfaces will be characterized for physical/morphological/chemical changes using a multianalytical approach consisting of spectroscopic and ellipsometry analyses, and electron microscopy with focused ion beam cross-sections. The associated microbial community will further be characterized using a molecular genetic approach targeting the 16S rRNA gene. Biofouling reversibility will be assessed by the application of sonication to the membrane surface for varying durations. These data will be used to better understand the physical and biological mechanisms associated with biofilm formation and the potential for using sonication for in-situ fouling control. This knowledge is critical for optimizing ceramic membrane efficiency, ensuring the design life of the membrane and lowering overall energy consumption in water and wastewater treatment applications.