Modelling transport phenomena for the decontamination of porous and absorbent surfaces - Julien Landel (LMFA, Université Claude Bernard, Lyon)

In this presentation I will discuss problems associated with the decontamination of surfaces. Typical scenarios are found in the decontamination of harmful chemicals spilled onto a solid surface after an accident or a terrorist attack, or in military context. The basic scenario considers the interaction between a cleansing liquid shear flow applied onto the surface to remove an unwanted miscible liquid substance. The substance is deposited onto the surface in the form of a drop. After reviewing briefly the case of impermeable surfaces, I will focus on the more challenging cases or porous and absorbent surfaces. As the cleansing liquid flows over the surface, a convective mass transfer enables transport of the substance away from the original contamination spot. However, in the case of porous and absorbent surfaces, the transport processes are limited by the permeability of the material, as the substance generally absorbs in the bulk of the material. In addition, the washing flow can potentially increase the contaminated area through bulk spreading or redistribution via the washing flow. I will present some models of the transport processes for low and high permeability porous material, as well as for non-porous but absorbent media such as swelling hydrogel layers. To validate these models, I will show our latest progress in developing laboratory techniques to probe transport processes in situ and in real time in the bulk of porous or absorbent material.

Contact: Lionel Bureau