A General Approach for Predicting the Filtration of Soft and Permeable Colloids: The Milk Example

Membrane filtration operations (ultra-, microfiltration) are now extensively used for concentrating or separating an ever-growing variety of colloidal dispersions. However, the phenomena that determine the efficiency of these operations are not yet fully understood. This is especially the case when dealing with colloids that are soft, deformable, and permeable. In this paper, we propose a methodology for building a model that is able to predict the performance (flux, concentration profiles) of the filtration of such objects in relation with the operating conditions. This is done by focusing on the case of milk filtration, all experiments being performed with dispersions of milk casein micelles, which are sort of ″natural″ colloidal microgels. Using this example, we develop the general idea that a filtration model can always be built for a given colloidal dispersion as long as this dispersion has been characterized in terms of osmotic pressure Π and hydraulic permeability k. For soft and permeable colloids, the major issue is that the permeability k cannot be assessed in a trivial way like in the case for hard-sphere colloids. To get around this difficulty, we follow two distinct approaches to actually measure k: a direct approach, involving osmotic stress experiments, and a reverse-calculation approach, that consists of estimating k through well-controlled filtration experiments. The resulting filtration model is then validated against experimental measurements obtained from combined milk filtration/SAXS experiments. We also give precise examples of how the model can be used, as well as a brief discussion on the possible universality of the approach presented here

Microfiltration tangentielle de lactosérum doux prétraité : mécanisme de colmatage et conduite opératoire

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Microfiltration tangentielle de lactosérum doux prétraité : mécanisme de colmatage et conduite opératoire

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Microfiltration tangentielle de lactoserum avec une membrane M14 carbosep: influence de la résistance hydraulique initiale

International audienc

Politic, way of life and sociability in a small rural society

The article describes the configuration and dynamics that takes politics in the Comisión Municipal de Yavi, interpreted as a small rural society. From identifying the meanings and practices that people associate and oppose to politic and observe interactions with processes occurring at the provincial and national level, it’s proposed a functioning model of politic in Yavi. The results shows that the political practices are encouraged by multiple motivations that go beyond what is considered strictly as political and overlap with other spheres of social life. The methodology articulates the ethnographic approach and the case study. The empirical observations were collected between 1997 and 2014

Stabilité de la microfiltration tangentielle de lait écrémé : impact sur le mode de conduite

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Stabilité de la filtration tangentielle : avancées récentes en microfiltration tangentielle (0,1 micro M) de lait écrémé

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Critical stability conditions in skimmed milk crossflow microfiltration : impact on operating modes (critical permeation flux)

National audienc

Stabilité de la filtration tangentielle : avancées récentes en microfiltration tangentielle (0,1 micro M) de lait écrémé

National audienc