Magnetic resonance imaging and 3D simulation studies of biofilm accumulation and cleaning on reverse osmosis membranes

Reverse osmosis (RO) is one of the multiple pressure-driven membrane separation processes used primarily for the production of high purity water for various industries, including food processing. Biofilm growth in the spiral-wound membrane module, commonly referred to as biofouling, reduces the efficiency to produce water. Biofilm accumulation and removal using chemical cleaning on RO membranes were studied using magnetic resonance imaging (MRI) techniques. Additionally, a previously validated biofilm simulation model, which is based on a lattice Boltzmann platform, was modified to account for cleaning operations. The spatial and velocity MRI experimental results captured biofilm distribution and water flow within the fouled membrane modules and subsequent changes in the biofilm distribution and water flow due to cleaning. Cleaning was simulated by accounting for reductions in the biofilm cohesive strength in the numerical model. Qualitative and quantitative comparisons between the experimental and simulated images showed good agreement. (C) 2010 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.