References of "Crine, Michel"
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See detailPhotocatalytic decolorization of Gentian Violet with Na-doped (SnO2 and ZnO)
Benhebal, Hadj; Chaib, Messaoud; Crine, Michel ULg et al

in Chiang Mai Journal of Sciences (2016), 42

Photocatalysis is a technique used for the purification and decolorization of water. In this work, the photocatalytic decolorization of aqueous solutions of Gentian Violet has been investigated. The ... [more ▼]

Photocatalysis is a technique used for the purification and decolorization of water. In this work, the photocatalytic decolorization of aqueous solutions of Gentian Violet has been investigated. The photocatalysts used for the study are tin dioxide (SnO2) and zinc oxide (ZnO) doped with sodium and prepared by sol-gel process. Photocatalysts were synthesised by sol-gel process and characterized by several techniques such as X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Brunauer, Emmett and Teller (BET) method and UV-vis Spectroscopy. The results of photocatalytic activity of gentian violet degradation under ultraviolet irradiation, indicated that the synthesised photocatalyst exhibit good photocatalytic performance. [less ▲]

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See detailSludge dewatering and drying: about the difficulty of making experiments with a non-stabilized material
Pambou, Yvon-Bert ULg; Fraikin, Laurent ULg; Salmon, Thierry ULg et al

in Desalination and Water Treatment (2016), 57(30), 13841-13856

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See detailEuler–Lagrange approach to model heterogeneities in stirred tank bioreactors – Comparison to experimental flow characterization and particle tracking
Delafosse, Angélique ULg; Calvo, Sébastien ULg; Collignon, Marie-Laure ULg et al

in Chemical Engineering Science (2015), 134

The aim of this work is the validation of an Euler–Lagrange modeling approach coupling a CFD-based compartment model (Eulerian approach) and a stochastic model based on a Continuous-Time Markov Chain ... [more ▼]

The aim of this work is the validation of an Euler–Lagrange modeling approach coupling a CFD-based compartment model (Eulerian approach) and a stochastic model based on a Continuous-Time Markov Chain (Lagrangian approach). The turbulent flow structure and the mixing process in a bioreactor stirred by an axial Mixel TT impeller is characterized by PIV and tracer experiments. Comparison between experimental and numerical data shows that the CFD-based compartment model is able to reproduce accurately the spatial heterogeneities inside the bioreactor. The trajectory of a small tracer particle which perfectly follows the fluid flow is measured by optical trajectography. It is then simulated by a stochastic model which is either based on an homogeneous or on an inhomogeneous Continuous Time Markov Chain (CTMC). Comparison of residence and circulation time distributions in three zones defined inside the bioreactor shows that the inhomogeneous CTMC model predicts with an excellent accuracy the particle trajectories inside the bioreactor. The modeling approach proposed here could be an useful tool to design scale-down bioreactors in order to reproduce at lab-scale the stress levels encountered in large-scale production bioreactors and to characterize and compare different bioreactor configurations. [less ▲]

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See detailUSING OF AN EXPERIMENTAL DESIGN TO CHARACTERIZE THE CONVECTIVE DRYING BEHAVIOR OF DIFFERENT SLUDGES
Fraikin, Laurent ULg; Salmon, Thierry ULg; Herbreteau, Benjamin et al

in Drying Technology (2015, August 18), 33(11), 1302-1308

Drying appears as a major step prior to valorization of sludge from wastewater treatment plant. This study uses an experimental design on different sludges to highlight the drying behavior according to ... [more ▼]

Drying appears as a major step prior to valorization of sludge from wastewater treatment plant. This study uses an experimental design on different sludges to highlight the drying behavior according to drying conditions, storage and extrusion. This research is performed with industrial view, but on a single cylinder sample, and focuses on five responds: maximum drying flux, time to reach 95% of dry matter, final volume, critical moisture and slowing-down coefficient. [less ▲]

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See detailHighly efficient, long life, reusable and robust photosynthetic hybrid core-shell beads for the sustainable production of high value compounds
Desmet, Jonathan; Meunier, Christophe; Danloy, Emeric et al

in Journal of Colloid & Interface Science (2015), 448

An efficient one-step process to synthesize highly porous (Ca-alginate–SiO2–polycation) shell: (Na-alginate– SiO2) core hybrid beads for cell encapsulation, yielding a reusable long-life ... [more ▼]

An efficient one-step process to synthesize highly porous (Ca-alginate–SiO2–polycation) shell: (Na-alginate– SiO2) core hybrid beads for cell encapsulation, yielding a reusable long-life photosynthetically active material for a sustainable manufacture of high-value metabolites is presented. Bead formation is based on crosslinking of an alginate biopolymer and mineralisation of silicic acid in combination with a coacervation process between a polycation and the silica sol, forming a semi-permeable external membrane. The excellent mechanical strength and durability of the monodispersed beads and the control of their porosity and textural properties is achieved by tailoring the silica and alginate loading, polycation concentration and incubation time during coacervation. This process has led to the formation of a remarkably robust hybrid material that confers exceptional protection to live cells against sheer stresses and contamination in a diverse range of applications. Dunaliella tertiolecta encapsulated within this hybrid core–shell system display high photosynthetic activity over a long duration (>1 year). This sustainable biotechnology could find use in high value chemical harvests and biofuel cells to photosynthetic solar cells (energy transformation, electricity production, water splitting technologies). Furthermore the material can be engineered into various forms from spheres to variable thickness films, broadening its potential applications. 2015 Elsevier Inc. All rights reserved. [less ▲]

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See detailHYDRODYNAMICS IN A DISPOSABLE RECTANGULAR PARALLELEPIPED STIRRED BIOREACTOR WITH ELLIPTIC PENDULUM MOTION PADDLE
Collignon, Marie-Laure ULg; Droissart, Laurent; Delafosse, Angélique ULg et al

in Biochemical Engineering Journal (2015), 93

Stainless steel bioreactors increasingly fall behind to their disposable counterparts in pharma research as they do not require cleaning or sterilization. This led company ATMI LifeSciences to develop the ... [more ▼]

Stainless steel bioreactors increasingly fall behind to their disposable counterparts in pharma research as they do not require cleaning or sterilization. This led company ATMI LifeSciences to develop the “Nucleo™”. Original in design, this disposable bioreactor comprises a rectangular parallelepiped plastic bag stirred by a paddle revolving in elliptic pendulum motion. Studies covering this bioreactor showed good homogeneity of culture medium as well as good productivity for animal cell cultures. To further explain these good performances, the flow inside the “Nucleo™” had to be resolved. This paper focuses on the mean flow description, computed from stereo-PIV measurements performed in 20 verticals covering the whole volume of a 50 dm3 Nucleo™ bioreactor. As the flow is already turbulent in the chosen agitation conditions, its dimensionless mean velocity field does not vary with the paddle rotational speed. Mean flow pattern exhibits an axial symmetry – same flow is observed in opposite quarters of the tank – and can be described as a three-dimensional helix coiled on itself to form a distorted horizontal torus which covers the whole tank volume. Mean velocity value is on average doubled in the cone swept by the paddle, and its two horizontal components are twice higher than its vertical ones. However, mean velocity remains significant everywhere and, in particular, no stagnant area is observed in tank corners. Our results thus confirm previous studies observations. [less ▲]

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See detailInfluence of viscosity on Liquid Flow Inside Structured Packings
Bradttmöller, Christian; Janzen, Anna; Crine, Michel ULg et al

in Industrial & Engineering Chemistry Research (2015), 54

In this study, X-ray computer tomography and light-induced fluorescence were applied to investigate the morphology of liquid flow inside structured packings. Fluid dynamic parameters such as liquid holdup ... [more ▼]

In this study, X-ray computer tomography and light-induced fluorescence were applied to investigate the morphology of liquid flow inside structured packings. Fluid dynamic parameters such as liquid holdup and wetted surface were determined to study the effect of the variation of viscosity and liquid load. Flow patterns inside the packing were identified and categorized. Liquid film thickness and its distribution were analyzed on single sheets. For both methods, the measured holdup values are in good agreement, despite differences in the techniques of measurement. For the flow patterns and their relative contribution, as well as mean liquid film thickness, a strong dependency on the varied parameters was found. Furthermore, the density function of film thickness distribution changed characteristically with liquid load and viscosity. The complementary use of tomography and optical assessment allowed an improved insight into flow phenomena and the observed interdependency of physical, geometric, and operational parameters. [less ▲]

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See detailInvestigation of the links between mass transfer conditions, dissolved hydrogen concentration and biohydrogen production by the pure strain Clostridium butyricum CWBI1009
Beckers, L.; Masset, J.; Hamilton, C. et al

in Biochemical Engineering Journal (2015), 98

Fermentative hydrogen production has often been described as inhibited by its own gas production. In this work, hydrogen production by Clostridium butyricum was investigated in batch Biochemical Hydrogen ... [more ▼]

Fermentative hydrogen production has often been described as inhibited by its own gas production. In this work, hydrogen production by Clostridium butyricum was investigated in batch Biochemical Hydrogen Potential (BHP) tests and in a 2.5L anaerobic sequenced batch reactor (AnSBR) under different operating conditions regarding liquid-to-gas mass transfer. Through the addition of both stirring up to 400rpm and nitrogen sparging, the yields were enhanced from 1.6 to 3.1molH2molglucose -1 and the maximum hydrogen production rates from 140 to 278mLh-1. These original results were achieved with a pure Clostridium strain. They showed that hydrogen production was improved by a higher liquid-to-gas hydrogen transfer resulting in a lower dissolved hydrogen concentration in the culture medium and therefore in a lower bacterial inhibition. In addition, biohydrogen partitioning between the gas and the liquid phase did not conform to Henry's Law due to critical supersaturation phenomena up to seven-fold higher than the equilibrium conditions. Therefore, dissolved hydrogen concentration should be systematically measured instead of the headspace hydrogen partial pressure. A model was proposed to correlate H2 production yield and rate by the pure C. butyricum strain CWBI1009 with mass transfer coefficient KLa. [less ▲]

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See detailEnhanced sludge dewatering and drying comparison of two linear polyelectrolytes co-conditioning with Polyaluminium chloride
Pambou, Yvon-Bert ULg; Fraikin, Laurent ULg; Salmon, Thierry ULg et al

Poster (2014, October 23)

Annual production of sewage sludge in Europe is estimated at more than ten million tons of dry matter. Use in agriculture and incineration are the main ways of valorization. In this context, sludge drying ... [more ▼]

Annual production of sewage sludge in Europe is estimated at more than ten million tons of dry matter. Use in agriculture and incineration are the main ways of valorization. In this context, sludge drying appears as an essential step after mechanical dewatering. It reduces the costs of storage and transport, allows the stabilization and the hygienization of sludge while increasing its calorific value. However, this process is highly energy consuming and still needs to be optimized as it constitutes an important economic and environmental issue. This implies the improvement of knowledge about sludge drying, including the impact of the mechanical dewatering step. Before studying experimentally the influence of polymers type and dosage use for dewatering on the rheological properties and the drying process, it is necessary to assess the stability of the sludge during of the storage. Because sludge is a living material that can rapidly change, we use the method of experimental design in order to get maximum information with minimal testing, regarding sludge stability during storage. [less ▲]

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See detailCFD Comparison of hydrodynamics between BIOSTAT® Cultibag STR and standard Stirred Cell Culture Bioreactors
Calvo, Sébastien ULg; Delafosse, Angélique ULg; Crine, Michel ULg et al

Poster (2014, September 10)

Single-use bioreactors have been increasingly used for animal cell cultures on microcarriers in screening experiments. Because of their manufacturing process, the shape of these kinds of vessels such as ... [more ▼]

Single-use bioreactors have been increasingly used for animal cell cultures on microcarriers in screening experiments. Because of their manufacturing process, the shape of these kinds of vessels such as the BIOSTAT® Cultibag STR one, is limited. For example, technical constraints on weld seams limit angles to 30° and no baffle may be installed. The shape of standard re-usable vessels may thus not be exactly reproduced and the flow structure may thus significantly differs from the flow structure in standard bioreactors. [less ▲]

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See detailINFLUENCE OF SLUDGE TREATEMENT ON ITS CONVECTIVE DRYING BEHAVIOR
Fraikin, Laurent ULg; Herbreteau, Benjamin; Salmon, Thierry ULg et al

Conference (2014, August 27)

Drying appears as a major step prior to valorization of sludge from wastewater treatment plant. This study uses an experimental design on different sludges to highlight the drying behavior according to ... [more ▼]

Drying appears as a major step prior to valorization of sludge from wastewater treatment plant. This study uses an experimental design on different sludges to highlight the drying behavior according to drying conditions, storage and extrusion. This research is performed with industrial view, but on a single cylinder sample, and focuses on five responds: maximum drying flux, time to reach 95% of dry matter, final volume, critical moisture and slowing-down coefficient. [less ▲]

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See detailIMPACT OF A HIGH LINEAR WEIGHT POLYMER CO-CONDITIONING WITH POLYALUMINIUM CHLORIDE ON DEWATERING AND CONVECTIVE DRYING OF URBAN RESIDUAL SLUDGE
Pambou, Yvon-Bert ULg; Fraikin, Laurent ULg; Salmon, Thierry ULg et al

Poster (2014, August)

This paper investigated the influence of Polyaluminium chloride (PAX) co-conditioning with a high linear weight polymer on the dewatering performance and the drying behavior of sludge. The CT linear ... [more ▼]

This paper investigated the influence of Polyaluminium chloride (PAX) co-conditioning with a high linear weight polymer on the dewatering performance and the drying behavior of sludge. The CT linear polymer with a high molecular weight was used combined with PAX for sludge flocculation prior to mechanical dewatering and drying. It was found that sludge conditioned with the couple PAX/ CT led to better flocculation/dewatering process regarding size flocs and specific resistance to filtration. Concerning drying, it appeared that this chemicals combination led to improved drying rates with effect of a reduction of the drying time, when compared to polyelectrolyte used without PAX adding. [less ▲]

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See detailEnhanced sludge dewatering and drying comparison of two linear polyelectrolytes co-conditioning with Polyaluminium chloride
Pambou, Yvon-Bert ULg; Fraikin, Laurent ULg; Salmon, Thierry ULg et al

Poster (2014, May 26)

Annual production of sewage sludge in Europe is estimated at more than eleven million tons of dry matter content [1]. Use in agriculture and incineration are the main ways of valorization. In this context ... [more ▼]

Annual production of sewage sludge in Europe is estimated at more than eleven million tons of dry matter content [1]. Use in agriculture and incineration are the main ways of valorization. In this context, drying of residual sludge appears as an essential step after mechanical dewatering. It reduces the costs of storage, transport and allows the sludge stabilization. However, this process is highly energy consuming and still needs to be optimized as it constitutes an important economic and environmental issue [2]. Polymers are usually employed in the conditioning step in order to promote particle aggregation, making the dewatering easier. The past decades, the application of pre-hydrolized polyaluminium chlorides (PACls) as coagulant has increased, particularly in China, Japan, Russia and Western Europe [3]. As a consequence, PACls are extensively investigated for their coagulation performance, characterization and speciation [3]. In this work, the influence of Polyaluminium chloride (PAX-14) co-conditioning with linear polyelectrolytes on sludge dewatering and drying performances was investigated. Experiments were conducted on activated sludge samples collected after thickening from the wastewater treatment plant of the Grosses- Battes (Belgium). Two cationic polymers were tested, each of them in combination with PAX for sludge flocculation prior to mechanical dewatering and their effects on sludge convective drying. The one referenced as 640 LH was a linear polymer with a low molecular weight, whereas the 640 CT was a linear one with a high molecular weight. After conditioning, the dewatering step was realized by using a normalized filtration-expression cell (AFNOR 1979) under 5 bar of pressure. Then, the specific resistance to filtration was determined from the follow-up of filtrate mass with time, using the Carman-Kozeny equation [4]. Figure 1 shows the experimental design. For convective drying experiments, the cake recovered after filtration was extruded through a circular die of 14 mm diameter and cut at a height of 14 mm, yielding cylindrical samples with mass of approximately 2.5 g, as used in several industrial belt dryers. Individual extrudates have been dried in a specially designed convective micro-dryer. Results reported in this paper were obtained with the following operating conditions: air temperature of 130 °C, at ambient humidity (absolute humidity ~ 0.005 kgwater/ kgdry air) and a superficial velocity of 1 m/ s. Results show that, the dry solids content of the dewatering cake increases with increasing Polyaluminium chloride dosage for both series of experiments. It supposes that PAX contributed to improve solids capture, depicted on Fig. 2. Concerning drying, it appeared that the samples treated by the dual PAX/ polymers combination showed higher drying rates than samples conditioned by polymer without PAX addition, allowing a reduction of the drying time (see Fig. 3). Table 1 shows the drying characteristics of the samples. The drying time decreases and the average drying rate increases with the dual conditioners addition, while the initial water content decreases as well as the total amount water to be removed. [less ▲]

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See detailPreparation of polyaniline-modified local clay and study of its sorption capacity
Benhebal, Hadj; Chaid, Messaoud; Léonard, Angélique ULg et al

in Journal of Nanostructure in Chemistry (2014), 4(98), 6

Clay minerals are frequently used in adsorption processes with aqueous solution; it was found that the adsorption properties of clays change when the samples are modified. In this context, polyaniline ... [more ▼]

Clay minerals are frequently used in adsorption processes with aqueous solution; it was found that the adsorption properties of clays change when the samples are modified. In this context, polyaniline-modified clay nanocomposite (at 10 %) was prepared by in situ polymerization processes. The structural and morphological characteristics of the synthesized material are systematically examined by X-ray diffraction, scanning electron microscopy, thermo-gravimetry, differential scanning calorimetry and infrared spectroscopy techniques. The adsorption property of the modified clay was evaluated for the removal of a reactive dye (methylene blue) from aqueous solution at room temperature (25 C) via batch adsorption. [less ▲]

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See detailCFD-based Compartment model for description of mixing in bioreactors
Delafosse, Angélique ULg; Calvo, Sébastien ULg; Collignon, Marie-Laure ULg et al

in Chemical Engineering Science (2014), 106

In most bioprocesses, it is fundamental to accurately predict the hydrodynamics behavior of bioreactors of different size and its interaction with the biological reaction. Computational Fluid Dynamics can ... [more ▼]

In most bioprocesses, it is fundamental to accurately predict the hydrodynamics behavior of bioreactors of different size and its interaction with the biological reaction. Computational Fluid Dynamics can provide detailed modeling about hydrodynamics and mixing. However, it is computationally intensive, especially when reactions are taken into account. Another way to predict hydrodynamics is the use of “Compartment” or “Network-of-zones” model which are much less demanding in computation time than CFD. However, compartments and fluxes between them are often defined by considering global quantities not representative of the flow complexity. To overcome the limitations of these two methods, a solution is to combine compartment modeling and CFD simulations. The aim of this study is to propose a compartment model where the flow rates between two adjacent compartments are easily computed from the velocity fields obtained by CFD. The mixing evolution predicted by the CFD-based compartment model have been then compared with mixing experiment results. Unlike a CFD mixing simulation and a classical compartment model, the CFD-based compartment model proposed in this work reproduces with a good accuracy the spatial distribution of concentrations during the mixing process and this, without any adjustable parameters. [less ▲]

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See detailAnalysis of electrical resistance tomography measurements obtained in a bubble column: Dynamics aspects, first results
Fransolet, Emmanuelle; Crine, Michel ULg; L'Homme, Guy ULg et al

in Mann, R.; Mewes, D.; Ronson, P. (Eds.) Proceedings of 2nd World Congress on Industrial Process Tomography, Hanovre, Germany, 29-31 août 2001 (2014)

Detailed reference viewed: 19 (8 ULg)