AWWA MTC64581

The objective of this work is to study the influence of hydrodynamics using a direct microscopic observation technique and biofilm initiation and cleaning mechanisms using an annular biofilm reactor. Initial microbial adhesion onto nanofiltration (NF) and reverse osmosis (RO) membranes was investigated through systematic adjustment of physical and chemical conditions. An optically clear cross-flow membrane filter mounted on a microscope stage coupled with a CCD camera allowed direct observation of the initial attachment of stained deposited microorganisms. Post-filtration image analysis enabled quantification of net particle deposition rates for different microbial cells, solution/suspension properties, membrane properties, and operating conditions. The experimental set up used for the DOB experiments is provided, and the computational fluid dynamics (CFD) modeling technique used for this study has been described in detail by Subramani et al. A commercial finite element solver (FEMLAB 3.0, Comsol, Inc., Sweden) was used to solve the differential transport equations. Includes 8 references, figures.