Mise au point d’un procédé expérimental de quantification de la teneur totale en créosote dans les bois imprégnés

Organic preservatives like creosote are used to preserve wood from insects, fungi and water damage for many years. Poles for electric power or telephone and railroad sleepers are treated with this preservative and generate wood waste for which environmentally friendly treatment technologies need to be developed in the near future. These wood wastes which represent a large volume of material are classified as dangerous waste. These waste streams sum up to 100 000 ton of material per year in every major country of the European Community. While various types of creosotes have been extensively analysed as reported in various publications, a rapid method of evaluation of the quantity of creosote present in a given sample is not available. The present work is an attempt to validate such a protocol using Infrared spectroscopy, allowing the evaluation of the mass content of creosote in impregnated woods. La créosote est largement utilisée comme fongicide dans le traitement des bois d’extérieur (traverses de chemin de fer, poteaux électriques et téléphoniques) pour pallier aux effets climatiques (vent, pluie) et aux dégradations néfastes engendrées sur les insectes. Ces bois en fin de vie représentent actuellement un gisement de 100 000 tonnes de déchets par an sur l’ensemble de la Communauté européenne. Le retraitement et la valorisation de ces déchets dangereux monopolisent un grand nombre d’études. Si l’identification et la quantification de la totalité des molécules organiques aromatiques contenues dans une créosote sont largement décrites dans la littérature par l’utilisation de la chromatographie en phase gazeuse, la teneur globale en créosote d’un bois imprégné n’est en général pas connue. Cette étude expérimentale présente un protocole rapide de quantification de la teneur totale en créosote dans un bois imprégné par spectroscopie infrarouge

Filamentation and Pulse Self-compression in the Anomalous Dispersion Region of Glasses

International audienceThe propagation of near-infrared ultra-short laser pulses in the regime of anomalous dispersion of transparent solids is associated with a host of self-induced effects including a significant spectral broadening extending from the ultraviolet into the infrared region, pulse self-compression down to few-cycle pulse durations, free and driven third harmonic generation, conical emission and the formation of stable filaments over several cm showing the emergence of conical light bullets. We review measurements performed in different experimental conditions and results of numerical simulations of unidirectional propagation models showing that the interpretation of all these phenomena proceed from the formation of non-spreading conical light bullets during filamentation

Pulse-Jet Bag Filter Performances for Treatment of Submicronic and Nanosized Particles from Waste Incineration

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Caractérisation de l'émission particulaire de nanodéchets halogénés lors d'une incinération dans un four de laboratoire à 1100°C

International audienceL'élimination des déchets contenant des nanocharges (ceci incluant leur incinération) se doit d'être étudié pour en mesurer l'impact sur la santé humaine et l'environnement. Il y a peu de connaissances sur le sujet de l'incinération de déchets nanostructurés. Dans ce contexte, le projet NanoWet soutenu par l'ADEME a été mis sur pied. Il se focalise sur le traitement de déchets nanostructurés halogénés et soufrés dans les filières spécialisées à haute température (1100°C). L'objectif général du projet est triple, à savoir d'évaluer l'influence (i) de la haute température sur le processus d'incinération (ii) de la présence de gaz acide dans les fumées sur l'émission particulaire (iii) des tours de lavages installées dans l'usine de traitement sur la capture des particules

Lab-scale characterization of emissions from incineration of halogen- and sulfur-containing nanowastes by use of a tubular furnace

International audienceMany solid materials contain nanoparticles to enhance their functionalities. The question of whether they may release nanoparticles at different moments of their life cycle is raised. Lifecycle includes waste management. There is therefore a need to determine the fate of nanoparticles when the materials they are incorporated in are incinerated. The present study aims at shedding light on these issues. In this context, three real-life wastes selected for their specific compositions were combusted in a lab-scale furnace under incineration conditions. The first two wastes contained nanoparticles, namely silica and titanium dioxide. The third waste was purposely nanoparticle free. In addition, the waste containing titanium dioxide did contain chlorine and the nanoparticle-free material was partly made of sulfur. Disposal of halogen and sulfur-containing garbage implies an incineration temperature of 1100 °C. This complex waste composition was seen as an opportunity to assess possible interactions between nanoparticles and hazardous elements such as chlorine and sulfur during the combustion. Most of the analyses were supported by electronic microscopy imaging after having sampled particles in the fumes and in the bottom ashes. Eventually, three mechanistic scenarios were drawn from these experiments. Focus was made on the evolution of the nanostructure. It was observed to be preserved for the first waste. It disappeared both from the aerosol and the residue for the second waste. The third material, though not initially nanostructured, led to the formation of a nanostructure in the aerosol

Technico-economical assessment of MFI-type zeolite membranes for CO2 capture from postcombustion flue gases

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