Schematic representation of the experimental set for visualizing the diffusion of oxygen in liquid throug a planar interface in a Hele-Shaw cell.
Evolution of the oxygen concentration field as a function of the distance to the interface (x) and time when diffusion through a planar oxygen/water interface.
In direct connection with my work on Bubble and Wastewater , I developed a new technique for determining diffusion coefficients of gases in liquids through a planar gas/liquid interface. Again, the purpose of this work was to fully understand mass transfer mechanisms occurring in complex media such as those encountered in sewage plants. Visualization techniques involved for this study include PLIF (Planar Laser Induced Fluorescence) and PIV (Particle Image Velocimetry). Please refer to the Techniques section for further details. This work relied on the consideration of an Hele-Shaw cell, which is a cell with one of its dimension smaller than the other ones to assume a 2-dimensional approach. Using specific laser techniques, the transfer of the gas in the liquid phase can be visualized and quantified. Specific efforts have be undertaken to accurately determine diffusion coefficients from these concentration profiles.