For wastewater treatment (e.g. in activated sludge or membrane bioreactors), a supply of dissolved oxygen, e.g. by injecting air bubbles, is required to ensure the availability of microorganisms able to degrade specific pollutants. However the mechanisms of gas transfer from the bubble to the microorganism in such complex media is still poorly understood. The purpose of this work co-funded by SUEZ-Degremont was to locally visualize the impact of the liquid composition on these two phenomena (mass transfer & hydrodynamics) in the wake of oxygen bubbles. One of the main outcomes of this work was a better understanding of the impact of surfactants, which is of prime importance since massively encountered in wasterwater due to their daily use for all washing purposes.
- Oxygen mass transfer and hydrodynamic behaviour in wastewater: determination of local impact of surfactants by visualization techniques. M.Jimenez, N.Dietrich, J.R. Grace and G. Hebrard. Water Research, 58, 111-121 (2014)
- Mass Transfer in the wake of non-spherical air bubbles quantified by quenching of fluorescence. M. Jimenez, N. Dietrich and G. Hébrard. Chemical Engineering Science, 100, 160-171 (2013)
- Direct measurement of mass transfer around a single bubble by micro-PLIFI. J. Francois, N. Dietrich, P. Guiraud and A. Cockx. Chemical Engineering Science, 66(14), 3328–3338 (2011)