Modeling Ozonation and Chlorination in potable Water Treatment

This article presents SimOx, the new simulator being currently developed by Anjou Recherche / ENSCR for oxidation steps in potable water treatment works. Whereas designing this new prediction engine was originally motivated by difficulties encountered when simulating a plant under on-site conditions, an increasingly stringent legal context and the emergence of micropolluants of concern clearly confirmed the need for a performing and innovative tool. The experience gained with the development of previous simulators is of advantage and opens interesting possibilities, in particular calculation capabilities upon which SimOx partly bases. Nevertheless, given the very characteristics of the new simulator SimOx (capacity to deal with sparse on-site data under changing water matrixes and hydrodynamic conditions), special modelling and calculation procedures are being implemented

Improved growth model for two-stage continuous cultures of Lactobacillus helveticus

An unstructured model for growth and lactic acid production during two-stage continuous cultures of Lactobacillus helveticus was previously developed. The Verlhust model was considered to describe growth kinetics. Production models was based on modified Luedeking-Piret expressions involving an inhibitory effect for the first stage (seed culture) and a nutritional limitation effect for the second stage (culture). To account for the decrease of the biomass concentration observed in the second stage, the dilution rate Dc was replaced by an exponential term of the dilution rate \u3b1 exp (Dc/\u3b2 ) in the growth and product relations. Contrarily to the previous model, the important decrease of the biomass concentration observed at steady state in the second stage at high dilution rates, namely close to wash out, was correctly described by the new model. It also proved to satisfactory describes production data and volumetric productivity

Chromatographie à contre-courant simulé : développements et perspectives

Les applications industrielles et le principe de fonctionnement du procédé de séparation en lit mobile ou en contre-courant simulé sont brièvement rappelés. La réalisation pratique de trois unités pilotes fonctionnant selon ce principe mais employant une technologie innovante est présentée. Cette mise en oeuvre particulière permet de tester par un simple changement de paramètres de contrôle toutes les configurations possibles de l'unité. Cet appareillage particulièrement souple est donc véritablement multitâche, ce qui permet en plus des applications en pétrochimie son emploi dans les domaines de la pharmacie, de la chimie fine et des bioséparations, où existe un grand nombre d'applications potentielles très différentes les unes des autres. Deux exemples de séparations réalisées à l'Institut Français du Pétrole sont succinctement présentés. La conclusion de ces essais est que la modélisation de ces procédés est indispensable pour pouvoir opérer correctement ce type d'unité. Une comparaison entre la chromatographie d'élution et cette technique de séparation ainsi que quelques propositions d'amélioration du procédé permettront au lecteur de se faire une idée sur l'extension potentielle de ce type de séparation

Comment on "anomalous dielectric behavior of nanoconfined electrolytic solutions". Reply to comment.

International audienceA reply to the polemic of Gekle and Arnold, ibid., 089801. [on SciFinder(R)

REMOVED: Hindered Diffusion of Ions Confined in Nanopores: Molecular Dynamics Simulations Versus Continuum–Based Models

This article has been removed: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy).This article has been removed at the request of the Executive Publisher.This article has been removed because it was published without the permission of the author(s)