Institute Scientifique Of Service Public Issep

Colfontaine, Belgium

Institute Scientifique Of Service Public Issep

Colfontaine, Belgium
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Grippa T.,Free University of Colombia | Lennert M.,Free University of Colombia | Beaumont B.,Free University of Colombia | Beaumont B.,Institute Scientifique Of Service Public Issep | And 3 more authors.
Remote Sensing | Year: 2017

This study presents the development of a semi-automated processing chain for urban object-based land-cover and land-use classification. The processing chain is implemented in Python and relies on existing open-source software GRASS GIS and R. The complete tool chain is available in open access and is adaptable to specific user needs. For automation purposes, we developed two GRASS GIS add-ons enabling users (1) to optimize segmentation parameters in an unsupervised manner and (2) to classify remote sensing data using several individual machine learning classifiers or their prediction combinations through voting-schemes. We tested the performance of the processing chain using sub-metric multispectral and height data on two very different urban environments: Ouagadougou, Burkina Faso in sub-Saharan Africa and Liège, Belgium inWestern Europe. Using a hierarchical classification scheme, the overall accuracy reached 93% at the first level (5 classes) and about 80% at the second level (11 and 9 classes, respectively). © 2017 by the authors.

Zebracki M.,Center National Of Recherches Sur Les Sites Et Sols Pollues Cnrssp | Zebracki M.,Institute for Radiological Protection and Nuclear Safety | Alary C.,Center National Of Recherches Sur Les Sites Et Sols Pollues Cnrssp | Lefevre I.,CEA Saclay Nuclear Research Center | And 4 more authors.
Journal of Soils and Sediments | Year: 2016

Purpose: Contamination of river sediment reaches problematic levels in industrialised regions. This study investigates the relevance of using beryllium-7 (7Be), a short-lived environmental radionuclide (53 days half-life), for quantifying the deposition and resuspension of sediment and associated metallic contaminants in a heavily polluted channelized river of Northern France (The Lower Scarpe River). Materials and methods: Activities in 7Be were measured in bed and suspended sediments collected each month over a hydrological year. Suspended sediments were analysed for metal contents (Pb, Zn, Cd, Cu). The determination of short-term sediment dynamics is based on the variation of total 7Be inventory between two successive samplings. Total inventory of 7Be consists of two components, i.e., the residual inventory and the new inventory. Results and discussion: Inventories of 7Be in sediment varied from 1 to 135 mBq cm−2. Observed spatial and temporal variations reflected the dynamic behaviour of sediment in the studied channel section. The succession of sediment deposition and resuspension periods was demonstrated during the study, with maximum deposition and erosion rates of 0.3 ± 0.2 and −0.46 ± 0.05 g cm−2 month−1, respectively. A sediment resuspension rate of 0.06 g cm−2 month−1 supplied to the water column a flux of 12, 13, 23 and 145 μg cm−2 month−1 of Cd, Cu, Pb and Zn, respectively. During this 15-month study, 28 to 50 % of Pb that was deposited in the riverbed sediment was resuspended, thereby contributing to the (short term) degradation of water quality. Conclusions: The present work provides a useful tool for examining the role of sediment as a sink or source of contamination for the water column. It produces knowledge of how sediment processes affect the fate and the transport of contaminants and the implications for future downstream fluxes. © 2015, Springer-Verlag Berlin Heidelberg.

Meus P.,Service Public de Wallonie SPW | Moureaux P.,Institute Scientifique Of Service Public Issep | Gailliez S.,Service Public de Wallonie SPW | Flament J.,Institute Scientifique Of Service Public Issep | And 2 more authors.
Environmental Earth Sciences | Year: 2014

The implementation of the Water Framework Directive, as well as the forthcoming entry into force of other European water policies focusing on water resources, require a thorough reorganization of groundwater resources monitoring in most European countries. In Wallonia, monitoring programs were initiated in 2005 to control the quantitative and chemical statuses of groundwater bodies, as well as the effectiveness of management plans aimed at achieving environmental objectives. In karst aquifers, springs are preferential monitoring targets even if, as a result of the high heterogeneity of this type of aquifer, the interpretation of time series and spatial data remains a challenge. Since 2006, a “springs” monitoring network has been progressively set up in the southern part of Belgium. Currently, in situ measurements of discharge, temperature, conductivity, turbidity and fluorescence of water are conducted at nine karstic outlets in the Devonian and the Carboniferous limestone aquifers of Wallonia. The main objective of this ongoing research is to evaluate the suitability and the robustness of such standard measurements to discriminate anthropogenic impacts from natural variations, at both short- and long-term scales. Discharge and temperature data revealed being useful in the assessment of regional hydro-climatic trends. Groundwater proved to be a better natural filter for the assessment of long-term climatic changes than mathematical filtering of noisy surface signals. Investigations of such data at a European scale could therefore give additional insight into the impacts of climate change on groundwater resources. Conductivity, turbidity and fluorescence data characterize the particulate, mineral and organic health of water and a better understanding of their natural dynamics could help in the early detection of anthropogenic deviations. However, the current reproducibility of these measurements is too low to ascertain observed trends and fluctuations, and further research is still needed. © 2013, Springer-Verlag Berlin Heidelberg.

Font O.,CSIC - Institute of Environmental Assessment And Water Research | Moreno N.,CSIC - Institute of Environmental Assessment And Water Research | Querol X.,CSIC - Institute of Environmental Assessment And Water Research | Izquierdo M.,CSIC - Institute of Environmental Assessment And Water Research | And 9 more authors.
Fuel | Year: 2010

The relevance of Al-Si glass in a number of fly ash applications, such as use as a pozzolanic material, zeolite synthesis, and geopolymer production, necessitated research towards investigation of methods for an easy and consistent determination of the glass content in this coal (co)-combustion by-products. A glass standard-addition X-ray powder diffraction (XRD)-based method is proposed in this study as an alternative to the non straightforward procedure of conventional methods for determining the amorphous components, mainly by difference of the total mass and the addition of quantified crystalline species. A >99% Al-Si glass slag sample was selected as a standard for glass. A number of glass standard/fly ash mixtures were performed on Fluidized Bed Combustion (FBC) and pulverized coal combustion (PCC) fly ashes and subsequently analyzed by XRD. The method provides results closer to quantitative proportions of the Al-Si amorphous material of this (co)-combustion by-product, with a range of values <3% when compared with those obtained by the conventional Reference Intensity Method (RIM) method, demonstrating suitability and consistence of the procedure. Furthermore, by the proposed method, the requirement of previous determination of the mineral phases of conventional techniques is avoided. Coupled with the easy calculations, this allowed a fast determination of the glass content of (co)-combustion fly ash. The mineralogy of FBC and PCC fly ash was also investigated using the RIM method. The occurrence and proportions of the crystalline components in fly ash are in line with the combustion technology and their inherent operational parameters, especially the (co)-combustion temperature. The FBC fly ash shows the highest content of relic phases from feed coal (quartz, illite, calcite, and feldspars) and lower contents of amorphous components. The PCC fly ash are characterized by the highest proportions of mullite and Al-Si glass and low contents of quartz an other relict phases. The occurrence and distribution of anhydrite and Fe-oxide species appears to be related to the content of Ca and Fe in the feed fuels, showing slightly higher contents in FBC than in PCC fly ash. © 2009 Elsevier Ltd. All rights reserved.

Bergmans B.,Institute Scientifique Of Service Public Issep | Dormann M.,Center for Research in Metallurgy | Idczak F.,Institute Scientifique Of Service Public Issep | Petitjean S.,Institute Scientifique Of Service Public Issep | And 2 more authors.
WIT Transactions on Ecology and the Environment | Year: 2011

Ever stricter air quality standards force all activity sectors to take measures to reduce the emission of particles. In the past, dust measurements at stack mostly referred to Total Suspended Particles (TSP), but nowadays there are more and more concerns about the finest fractions. Indeed, when inhaled, small particles can go deeply into the lungs and are thus the most toxic ones. Particulate Matters (PMs) are generally classified in different fractions regarding their size (PM10/PM2.5/PM1/UFP). A new European standard (ISO 23210) dealing with PM measurements in stacks has been released in 2009 and abatement impositions are expected within short delays. In the framework of various research projects the Centre for Research in Metallurgy (CRM) and its partners are studying the possibility to comply with stricter PM regulation by improving the collection efficiency of existing dedusting systems, in order to avoid expensive investments in additional abatement means. One idea is to agglomerate fine dust particles together or onto coarser ones by applying ultrasounds to the dust laden waste gas flow, upstream of the dedusting unit. This should facilitate the fine dust collection, whatever the considered dedusting technique. The feasibility of this concept has been studied at laboratory scale on a specific pilot for different industrial processes. Specific measurement techniques have also been developed to measure in real time the effects of ultrasounds on the various size fractions. For the moment the abatement reaches already up to 40% for the smallest particles (PM2.5 and PM1), making this system very attractive. Optimization of the method is still under progress. Present activities deal with ultrasounds frequency, acoustic chamber design and up-scaling modelling. © 2012 WIT Press.

Izquierdo M.,CSIC - Institute of Environmental Assessment And Water Research | Izquierdo M.,University of Limerick | Querol X.,CSIC - Institute of Environmental Assessment And Water Research | Phillipart C.,Institute Scientifique Of Service Public Issep | And 2 more authors.
Journal of Hazardous Materials | Year: 2010

This study deals with the synthesis of geopolymers from co-fired fly ash and blast furnace slags. Geopolymer bodies were simultaneously synthesized in open and closed curing conditions in order to elucidate the role of this parameter on their resultant properties. Open curing conditions produce solid bodies characterized by high porosity, low compressive strength and exacerbated leaching of certain oxyanionic metalloids. By contrast, protected curing promotes the binder development, giving rise to higher strength and less porous systems. This imposes physical restrictions to leaching which decreases and/or retards releases of oxyanionic metalloids in comparison to open curing conditions. Fly ash-slag-based geopolymers may immobilize a number of trace pollutants such as Be, Bi, Cd, Co, Cr, Cu, Nb, Ni, Pb, REE, Sn, Th, U, Y and Zr, regardless of the curing conditions. Due to geopolymers displaying weak assimilation capacity for oxyanionic species, their successful regarding oxyanionic retention is strongly dependent on porosity and therefore on curing conditions applied. © 2009 Elsevier B.V. All rights reserved.

Fourneau C.,University of Mons | Delvosalle C.,University of Mons | Breulet H.,Institute Scientifique Of Service Public Issep | Brohez S.,University of Mons
Chemical Engineering Transactions | Year: 2013

The ISO 5660-1 Cone Calorimeter is commonly used for the measurement of main fire properties of products and materials, such as the heat release rate, the effective heat of combustion, the mass loss rate or the time to ignition. The standard Cone Calorimeter has been designed with an 'open configuration', allowing to test specimens through use of freely driven room air for combustion. For testing specimens in oxygen depleted atmospheres (air vitiation effect) or in fuel rich combustion (ventilation effect) a modified apparatus working under controlled atmosphere can be used. A Cone Calorimeter fitted with a controlled atmosphere device has been further modified to improve the air tightness of the combustion chamber, and reduce the biasing post-combustion phenomena. This experimental setup gives promising results regarding the characterization of fire properties of materials under highly under-ventilated conditions, among them the production of toxic and unburned species. © 2013, AIDIC Servizi S.r.l.

Fourneau C.,University of Mons | Delvosalle C.,University of Mons | Breulet H.,Institute Scientifique Of Service Public Issep | Brohez S.,University of Mons
Fire and Materials | Year: 2016

The cone calorimeter, originally designed with an 'open configuration', may be used in combination with a closed-combustion chamber in order to test specimens in oxygen-depleted atmospheres (air vitiation effect) or in fuel-rich combustion (ventilation effect). However, highly under-ventilated conditions are not achievable, as a consequence of an overconsumption of oxygen due to the incomplete confinement of the flame and imperfections in the air tightness of the combustion volume. In this work, these issues were solved by lowering the combustion zone, in order to fit a 600 mm chimney on the top of the controlled-atmosphere chamber, and further improving the sealing of the whole setup. n-Heptane was used as a reference fuel, and its combustion properties were determined in under-ventilated conditions. The yields of main combustion species correlated well with the global equivalence ratio, for values of Φ up to three. The use of a Fourier-transform infrared spectrometer allowed further refinement of the total unburned-fraction composition. The relative concentration of species like methane, ethylene, or acetylene was shown to be relatively constant over the range of under-ventilated conditions. © Copyright 2015 John Wiley & Sons, Ltd.

Merbitz H.,RWTH Aachen | Detalle F.,Institute Scientifique Of Service Public Issep | Ketzler G.,RWTH Aachen | Schneider C.,RWTH Aachen | Lenartz F.,Institute Scientifique Of Service Public Issep
International Journal of Environment and Pollution | Year: 2012

In the framework of the Interreg-IV 'PM-Lab' project a local-scale exercise was set up to evaluate air pollution in terms of particulate matter (PM) within the centre of Liège, Belgium (pop. 190,000). Sixteen sites distributed on a boulevard and its side streets were selected to determine the spatio-temporal variation of PM concentration in this traffic-dominated area. In addition to the in situ measurements numerical simulations were performed by means of AUSTAL2000. The performance of this Lagrangian dispersion model was checked through some basic qualitative and quantitative comparisons. As the model was able to detect highest PM concentrations both in space and time, test scenarios of emission reductions were also run in order to examine the impact of different traffic related measures. © 2012 Inderscience Enterprises Ltd.

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