References of "Léonard, Angélique"
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See detailDetermination and modeling of the isotherms of adsorption/desorption and thermodynamic properties of obeche and lotofa using nelson’s sorption model
Simo-Tagne, Merlin; Bennamoun, Lyes; Léonard, Angélique ULiege et al

in Heat and Mass Transfer (in press)

Equilibrium moisture content (EMC), net isosteric heat of sorption (NIHS), net entropy of sorption (NES) and standard free energy of Gibbs (SFEG) of Triplochiton scleroxylon (obeche) and Sterculia ... [more ▼]

Equilibrium moisture content (EMC), net isosteric heat of sorption (NIHS), net entropy of sorption (NES) and standard free energy of Gibbs (SFEG) of Triplochiton scleroxylon (obeche) and Sterculia rhinopetala (lotofa) are modeled using Nelson’s sorption isotherm model. Experimental data are determined using a dynamic vapor sorption apparatus. Air relative humidity is ranged from 0 to 90% and two air temperatures (20 °C and 40 °C) are used. Experimental data of EMCs obtained from adsorption and desorption for the mentioned woods were compared with the predicted results using Nelson’s sorption model by the application of the same operating conditions (i.e. temperatures and relative humidity conditions). The results showed that the predicted ones were in good agreement with the experimental data, when the relative humidity varied from 1.2 to 90%. Both adsorption and desorption phase presented a mean relative errors value inferior to 6.3%. The parameters that define the sorption isotherm varied with the wood type and the sorption mode. Thus, Nelson’s sorption isotherm model is a useful tool that can be used for prediction of the moisture change in wood under different environmental conditions and for predicting indirectly the thermodynamic parameters such as NIHS, NES and SFEG. In adsorption and desorption mode, the NIHS are estimated using Clausius-Clapeyron’s equation. The desorption values were higher than the adsorption ones. NIHS versus EMC varied exponentially and the parameters of the function were presented variable with the sorption mode and the wood type. The total energy that we needed to extract and evaporate all bounded water is 12,398.6 J/mol for obeche and 11,627.7J/mol for lotofa. The total energy that we needed to condense and fix all bounded water taken from the state vapour is 11,829.34 J/mol for obeche and 11,379.39 J/mol for lotofa. Water molecules are more mobile during desorption than adsorption in the case of obeche. In the case of lotofa, these molecules are more mobile during adsorption. SFEG is higher in desorption than adsorption and it is influenced by species and less by the temperature. When the temperature increased, the SFEG increased as well. At low values of EMC, NIHS and SFEG are higher and decreased with the increase of EMC until reaching the fibre saturation point. © 2019, Springer-Verlag GmbH Germany, part of Springer Nature. [less ▲]

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See detailModeling of coupled heat and mass transfer during drying of ebony wood using indirect natural convection solar dryer
Simo-Tagne, Merlin; Bonoma, B.; Bennamoun, L. et al

in Drying Technology (in press)

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See detailLe casse-tête de l’emballage : Comment s’orienter vers des solutions durables ?
Léonard, Angélique ULiege

Conference given outside the academic context (2019)

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See detailLife cycle externalities versus external costs: the case of inland freight transport in Belgium
Merchan Arribas, Angel ULiege; Léonard, Angélique ULiege; Limbourg, Sabine ULiege et al

in Transportation Research. Part D, Transport and Environment (2019), 67

This paper proposes a case study on Belgium in which externalities and external costs of inland freight transport modes in Belgium are compared for the year 2012. The well-known Life Cycle Assessment ... [more ▼]

This paper proposes a case study on Belgium in which externalities and external costs of inland freight transport modes in Belgium are compared for the year 2012. The well-known Life Cycle Assessment methodology is used to identify the updated specific Belgian externalities related to three categories of negative impacts: climate change, photochemical ozone formation and particulate matter formation. The obtained values of externalities are then compared to the related external cost values. The objective is to determine if these two tools can be used interchangeably. We find that road transport has the maximum impact for every environmental impact indicator, with rail freight transport presenting the minimum one. We identify that each category of negative impact on the environment does not represent the same percentage of global externalities and external costs. In the analysis of the environmental impact per mode, it is observed that, when external costs are considered instead of externalities, the impact of road transport is slightly increased compared to both impacts of rail and inland waterways. Using externalities and average external costs interchangeably for estimating the impact of specific transport categories on the environment may thus lead to different results and different related policies. [less ▲]

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See detailImpact of heavy metals on human toxicity using LCA: The case study of Walloon corn
Gerbinet, Saïcha ULiege; Van Stappen, Florence; Belboom, Sandra ULiege et al

in Materiaux et Techniques (2019), 107(1),

This paper focuses on potential errors when assessing the human toxicity of corn farming in Wallonia, Belgium. The USEtox method is applied to the farming of 1 hectare of corn. Local data are used for ... [more ▼]

This paper focuses on potential errors when assessing the human toxicity of corn farming in Wallonia, Belgium. The USEtox method is applied to the farming of 1 hectare of corn. Local data are used for farming data and GaBi datasets for background data. Field emissions due to farming are calculated by the most prevailing models. The results in human toxicity, cancer effect, underline the large contribution of chromium (Cr) emissions. But when characterizing fertilizer composition, only the total chromium is measured and therefore unspecified chromium is used as emissions. However, it is known that chromium in the natural environment is mostly the non-toxic form Cr (III), which would greatly decrease the impact as the characterization factor for unspecified chromium is, in USEtox, the average of Cr (III) and the toxic form Cr (VI). The impact for human toxicity, non-cancer effect is mostly related to zinc emissions even if zinc is relatively harmless. The impact of pesticides is negligible in both cases. These results show that caution must be taken when examining/interpreting toxicity categories. © 2019 EDP Sciences. [less ▲]

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See detailLoss of stromal galectin-1 enhances multiple myeloma development: Emphasis on a role in osteoclasts
Muller, Joséphine; Duray, Elodie ULiege; Plougonven, Erwan ULiege et al

in Cancers (2019), 11(2),

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See detailStudying the effect of desiccation cracking on the hydraulic behaviour of a Luvisol–from an experimental and numerical approach
Tran, Duc Kien ULiege; Ralaizafisoloarivony, Njaka Andriamanantena ULiege; Charlier, Robert ULiege et al

in Soil and Tillage Research (2019)

Cracking formation due to desiccation of the soil surface is a common phenomenon related to the interaction between soil and the atmosphere. Indeed, during dry seasons, high evaporation of pore water near ... [more ▼]

Cracking formation due to desiccation of the soil surface is a common phenomenon related to the interaction between soil and the atmosphere. Indeed, during dry seasons, high evaporation of pore water near the soil surface leads to a more significant soil suction in this region. The suction results in compressive effective stress on the soil structure and produces shrinkage including cracking. As the crack network forms, the initial soil structure is strongly modified, which provides preferential flow pathways for solute-water and influences the soil hydraulic behaviour in general. The work aims to study the formation of cracks during evaporation process of a Cutanic Luvisol and evaluate how cracking affects the soil hydraulic behaviour. Laboratory experiments were performed on undisturbed soil samples. To do that, a small-scale environmental chamber was designed and equipped with sensors for measuring the ambient temperature and relative humidity, and a digital camera for investigating the initiation and propagation of cracks on the soil surface. By combining with a HYPROP device (UMS GmbH, Munich, Germany), the hydraulic properties and the kinetics of evaporation of soil samples were also determined through the tests. Finally, numerical simulations were carried out by using the finite element code LAGAMINE developed at the University of Liege to emphasize the effect of desiccation cracking on the soil hydraulic conductivity and the moisture transport mechanisms in the soil, as well as exchanges with ambient atmosphere. [less ▲]

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See detailInvestigation of the evaporation process of a Luvisol–from an experimental and numerical approach
Tran, Duc Kien ULiege; Ralaizafisoloarivony, Njaka Andriamanantena ULiege; Degré, Aurore ULiege et al

in Geoderma (2019)

As a consequence of global warming and climate change, higher ambient air temperatures during dry seasons lead to a greater soil water evaporation fluxes, therefore, to a more rapid reduction of soil ... [more ▼]

As a consequence of global warming and climate change, higher ambient air temperatures during dry seasons lead to a greater soil water evaporation fluxes, therefore, to a more rapid reduction of soil moisture contents in agricultural land. An assessment of the kinetic of evaporation and the soil behaviour are essential in order to help farmers to identify an appropriate tillage method and management practices to improve the soil structure and the water retention capacity of the soil. This paper presents a study of the evaporation process of a Cutanic Luvisol in Gembloux-Belgium from both experimental analysis and numerical modelling. First, we developed a small-scale environmental chamber and carried out a series of evaporation tests. The chamber dryer is equipped with sensors to monitor the temperature and relative humidity, and a digital camera placed at 0.5 m above the sample to study the evolution of the soil surface. The soil sample is placed on a HYPROP device (UMS GmbH, Munich, Germany) during the test to characterise soil hydraulic properties and drying curve. Three evaporation tests were carried out to provide data for further numerical analysis. Four distinct periods of soil water evaporation were observed in the experiments instead of three as the classical concept. Second, we proposed a thermo-hydro-mechanical framework for modelling the drying behaviour of the Luvisol. Numerical simulations were performed by using the finite element code LAGAMINE developed at the University of Liège to emphasise the moisture transport mechanisms between the soil and the surrounding atmosphere. The results showed that the drying was mainly achieved by the Darcean flow during the whole process. The vapour diffusion took place when the soil surface started to desaturate but only made a minor contribution. [less ▲]

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See detailEffect of desiccation cracking on the fluid transfer process in agricultural soil
Tran, Duc Kien ULiege; Ralaizafisoloarivony, Njaka; Charlier, Robert ULiege et al

Poster (2018, October)

The natural soil structure can be strongly modified and generate heterogeneities during wetting and drying processes. This significantly affects the transfer of fluids and nutrients between the atmosphere ... [more ▼]

The natural soil structure can be strongly modified and generate heterogeneities during wetting and drying processes. This significantly affects the transfer of fluids and nutrients between the atmosphere, the subsoil, the hydrosphere and the biosphere. Experimental observations on a Cutanic Luvisol from agricultural field in Gembloux, Belgium, by using X-ray microtomography coupled with 3D image analysis have shown the cracking phenomenon occurring and leading to preferential flows in the soil sample during a drainage process. In order to better understand the impact of cracks on the behaviour of this soil type, in this study, we have proposed a numerical modelling of soil evaporation process by using the constitutive models implemented in the finite element code LAGAMINE. Considering that the soil we study is a loamy soil, we have chosen to fit the dual model of Durner (Durner, 1994) for the water retention capacity. The drying kinetics is modelled using the boundary layer model (Gerard et al., 2010), assuming that the vapour and heat transfers take place in a boundary layer at the surface of the porous medium. The embedded fracture model is chosen to represent the development of the fractures in porous medium in which fracture opening is activated by a threshold strain parameter (Olivella et Alonso, 2008). The results obtained have shown that an increase in permeability in the fracture zones makes the permeability tensor anisotropic up to one order and thus strongly modifies the drying kinetics of the soil core (e.g., evaporation rate). The results also have suggested that using a simple concept of cracking development, a continuum model is capable of modelling preferential flows developed in a fractured porous medium such as agricultural soil. [less ▲]

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See detailOrganic or conventional wheat: what is the better choice to limit the environmental impact, especially human toxicity?
Gerbinet, Saïcha ULiege; Van Stappen, Florence; Belboom, Sandra ULiege et al

Conference (2018, September 26)

In the context of biobased materials, the accurate assessment of the environmental impact of the agricultural raw materials is crucial. In this study, the environmental impact of traditional or ... [more ▼]

In the context of biobased materials, the accurate assessment of the environmental impact of the agricultural raw materials is crucial. In this study, the environmental impact of traditional or conventional wheat produced in Wallonia (Belgium) is evaluated. The system boundaries are from field to farm gates and the functional unit is the production of 1 kg of wheat. The ILCD recommended methods are used. Surprisingly, the organic wheat has a higher impact on the environment in all the categories. This is due to its smaller yield and to the higher organic fertilizers used: These organic fertilizers result in higher field emissions because the nutritive elements are less available for plants. A detailed analysis of the human toxicity categories underlines that most of the impact is due to heavy metal emissions: most of the impact in human toxicity, cancer effect, is due to chromium (Cr) emissions due to the use of fertilizers. But during fertilizers composition characterization only the total chromium is measured and therefore, unspecified chromium is used as emissions. However, the chromium in natural environment is most probably Cr (III) and this could decrease the impact as the characterization factor for unspecified chromium, is, the average of the one of Cr (III) (non-toxic) and Cr (VI) (toxic). The chromium emissions are in the same order on magnitude for organic and conventional wheat for one hectare, but, due to the smaller yield are larger for conventional wheat on a mass basis. The impact for human toxicity, non-cancer effect is mostly related to zinc emissions in soil from organic fertilizer, especially pig manure. As more organic fertilizers are used for organic wheat, its impact is more than 10 time higher than the impact of conventional wheat. Nevertheless, the real toxicity of zinc is questionable, indeed, zinc is an important trace element in the human body. Surprisingly, for both toxicity categories, the contribution of pesticide is negligible: this also contributes to the worst results of organic wheat. As this study is from field to farm gate, the potential impact wheat consumption on human health is not included. Moreover, the Belgian case study is not favorable to organic agriculture as the conventional agriculture has very good practice and high yields. This case study also underlines the limitation of the existing tool to asses to toxicity impact. [less ▲]

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See detailINFLUENCE OF DRYING ON THE RECOVERY OF PHOSPHORUS FROM WASTEWATER SLUDGE
Fraikin, Laurent ULiege; Shariff, Zaheer Ahmed ULiege; Pfennig, Andreas ULiege et al

Poster (2018, September 13)

The North West Europe (NWE) Interreg Phos4You (P4Y) project addresses the phosphorus (P) challenge. P is a nutrient essential for all living organisms. Though it is a finite resource on earth, P is ... [more ▼]

The North West Europe (NWE) Interreg Phos4You (P4Y) project addresses the phosphorus (P) challenge. P is a nutrient essential for all living organisms. Though it is a finite resource on earth, P is largely wasted today. The EU acknowledged this by adding phosphate rock to its list of critical raw materials in 2014. There is a need to boost the use of secondary raw P. The project addresses rural, urban and port areas in NWE. P is needed in rural areas as fertilizer or feed additive (often produced in port areas). P is transferred within food to urban areas where 82% of NWE-citizens live in (World Bank, 2015), and wasted there, via sewage and waste. P4Y specifically targets recovery from municipal waste water treatment plants. In 2015 NWE imported 100% of its mineral P-needs. 45% of the demand could be supplied by circular economy. The project will exploit the recovery potential of P in municipal sewage water (113,000 t/y P), estimated to cover 26% of the mineral P-demand in NWE. To achieve this change, P4Y supports 44 enterprises by producing demonstrators in real life conditions of 6 P-recovery technologies for municipal sewage water. One of these new technologies for P recovery will be developed at ULiège. The novelty of this process is that it treats directly the raw sludge instead of ashes obtained from incineration, as encountered in many processes. The idea is to directly leach the sludge with acids and to remove the solid residue. Afterwards, the aqueous liquor is purified thanks to an organic extraction to remove the heavy metals. Finally, the phosphorus is precipitated in calcium salts. For the development of this process one key issue is to find the optimal water content at which sludge will be leached. Indeed, the water present in the sludge will dilute the acid and reduce the leaching capacity while increasing the consumption of raw acids. On another side, a dried sludge has other properties such as wettability or porosity developed during the drying. However, dry sludge may need an additional grinding step and request other technologies to handle the so formed powder. The first leaching tests performed on sludge with different levels of dryness obtained by a combination of dewatering and convective drying are running. The influence of the drying step on the whole P recovery process will be illustrated during the presentation. [less ▲]

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See detailKinetics of water adsorption on activated carbons
Boutillara, Yasmine; Lodewyckx, Peter; Richelet, Lucas et al

Poster (2018, July)

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See detailEnhancement of dewatering and drying behavior of activated sludge when using PAX coagulant for conditioning
Fraikin, Laurent ULiege; Pambou, Yvon-Bert; Salmon, Thierry ULiege et al

Conference (2018, May 24)

This paper investigated the influence of dual conditioning of waste water treatment sludge on the evolution of sludge internal structure during convective drying. Results showed clearly an impact of ... [more ▼]

This paper investigated the influence of dual conditioning of waste water treatment sludge on the evolution of sludge internal structure during convective drying. Results showed clearly an impact of chemical conditioners on the evolution of the created porosity. For sludge flocculated by single conditioning, a centred porosity delimiting by external crust was shown, while for dual conditioning, a porosity structured in lamellae, was identified. [less ▲]

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See detailPhos4You: a NW Europe Interreg project aiming at recovering phosphorus from wastewater and wastewater sludge
Fraikin, Laurent ULiege; Léonard, Angélique ULiege

Poster (2018, May 23)

This paper presents the overview and the goals of the North West Europe Interreg project named Phos4You.

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See detailEfficiency of biobased coagulant for the conditioning urban residual wastewater sludge
Fraikin, Laurent ULiege; Clermont, Quentin; Salmon, Thierry ULiege et al

Conference (2018, May 23)

This paper focuses on the dewatering efficiency of activated sludge from waste water treatment plant using biobased coagulants in addition with classical flocculant and compares the results with those ... [more ▼]

This paper focuses on the dewatering efficiency of activated sludge from waste water treatment plant using biobased coagulants in addition with classical flocculant and compares the results with those obtained with a classical coagulant. For this work, a standard compression-expression cell is used and an experimental design is develop to highlight the effect of the biobased coagulants. [less ▲]

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See detailIMPACT OF HEAVY METALS ON HUMAN TOXICITY USING LCA: A CASE STUDY FOR WALLOON CORN
Gerbinet, Saïcha ULiege; Van Stappen, Florence; Belboom, Sandra ULiege et al

Conference (2018, May 22)

This paper aims to focus on surprising results when assessing the human toxicity of corn farming in Wallonia, Belgium. The USEtox method is applied to the farming of 1 hec-tare of corn. Local data are ... [more ▼]

This paper aims to focus on surprising results when assessing the human toxicity of corn farming in Wallonia, Belgium. The USEtox method is applied to the farming of 1 hec-tare of corn. Local data are used for farming data and GaBi datasets are used for back-ground data. The field emissions due to farming are calculated by the most used models. The results in human toxicity, cancer effect, underline the large contribution of chromi-um (Cr) emissions due to the use of organic and mineral fertilizers. But during fertilizers composition characterization only the total chromium is measured and therefore, unspeci-fied chromium is used as emissions. However, it is known that the chromium in natural environment is most probably Cr (III) and this could really decrease the impact as the characterization factor for unspecified chromium, is, in USEtox, the average of the one of Cr (III) (non-toxic) and Cr (VI) (toxic), therefore really larger than the one of Cr (III). Therefore, a test is realized where 95% of the Chromium is Cr (III) and the rest is Cr (VI). In this case, score in human toxicity cancer effect is divided by 7, whereas this has no in-fluence on the other results. The impact for human toxicity, non-cancer effect is mostly related to zinc emissions in soil due to the use of organic fertilizer, especially pig manure. However, zinc is abundant and is an important trace element in the human body. It is useful for growth, bone and brain development, etc. and the European Commission recommends the consumption of 7- 10 mg of zinc by person and per day. Moreover, mammals are able to eliminate zinc, therefore they are able to maintain a constant level of zinc independently of the exposure level. Consequently, only the exposure to high doses can have toxic effects. A test was made with the characterization factor of zinc equal to 0 in the USEtox model. In this case, the corn cropping obtains a human toxicity, non-cancer effect divided by 12 compared to the base case and mostly related to lead and mercury emissions in the soil. In both case, the contribution of pesticide is negligible. In conclusion, although the uncertainties about toxicity categories are well-known, this case study underlines the impact of the user hypotheses and shows that a detailed analy-sis of the results is essential for a critical view on the toxicity results. [less ▲]

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