Levich Institute Seminar Announcement, 10/25/2016
Steinman Hall, Room #312
(Chemical Engineering Conference Room)
Dr. Christine Lafforgue-Baldas
CNRS Laboratory LISBP
"In situ 3D Analysis of Cake Formation During Filtration on Microsieves Using Confocal Laser Scanning Microscopy"
During filtration operations, a cake layer composed of the compounds retained by the membrane, modifies productivity and selectivity and thereby the separation performances. The aim of this study is, in the case of particle suspension filtration, to analyze the deposit mechanism and the resulting cake characteristics under different operating conditions. This approach could be useful to improve the models that predict the filtration performances. Pure and mixed suspensions of inert and biological particles are filtrated on microsieves membranes that are observed in situ using Confocal Laser Scanning Microscopy (CLSM). The morphological characteristics of the cake (particle arrangement, thickness, porosity, microsieve coverage ratio) are determined by image processing and correlated with the permeability reduction. The analysis of the effects of several parameters such as: particles size, microsieve geometry (pore size, pore pitch) and particles characteristics, leads to the following conclusions: (i) the initial filtration of large particles before the filtration of the smaller ones could maintain a higher flux, (ii) for high particles size to pores size ratio, the first deposited particles protect surrounding pores, (iii) inert and biological cakes behave similarly under the experimental conditions of this study, (iiii) three regions can be identified in a cake: a germination region in contact with the membrane, a central high particle concentration region and a superficial capture region.
BRIEF ACADEMIC/EMPLOYMENT HISTORY
1985 : Master of Biochemical Engineering at INSA Toulouse France
1988 : PHD "Alcoholic fermentation in membrane bioreactor"
1991-2007 : Reseacher at CNRS, Enhancement of fermentation and bioprocesses performances by improved control of operating conditions
2007-present : Associate professor in Biological Engineering at INSA Toulouse (main courses: microbiology, bioprocesses)
RECENT RESEARCH INTERESTS
In situ and local analysis of concentration and separation mechanisms of micro-particles and microorganisms by filtration or by inertial focusing