Étude du séchage et de la fixation des colorants réactifs par rayonnement infrarouge

La première partie de ce travail consiste en une revue de la littérature traitant des différents points étudiés notamment les travaux relatifs au séchage des textiles et à leur teinture. Le deuxième chapitre consacré à l'étude du séchage et du chauffage de différents textiles par rayonnement infrarouge, se scinde en deux parties: la première est une étude théorique basée sur l'évaluation de l'énergie absorbée par ces textiles à partir de leurs spectres de réflexion diffuse. la deuxième est une étude expérimentale du séchage et du chauffage de ces mêmes textiles de différentes couleurs. Cette étude présentée dans ce chapitre est conduite afin de déterminer l'impact de la couleur des tissus sur leur séchage et chauffage dans un four à infrarouge mettant en oeuvre des émetteurs de rayonnement infrarouge moyen et court. Le troisième chapitre est consacré à l'étude de la fixation des colorants réactifs par rayonnement infrarouge. De cette étude, on ressort les conditions opératoires pour lesquelles le rendement de fixation des colorants est optimal. Dans ce chapitre est présentée aussi une étude de l'influence de l'extraction sous vide sur ce procédé de teinture par foulardage - séchage et fixation par rayonnement infrarouge. Enfin, le quatrième chapitre traite d'une simulation de ce procédé de teinture par foulardage afin d'élucider les différents facteurs de perturbation du bain de teinture

Étude du séchage et de la fixation des colorants réactifs par rayonnement infrarouge

La première partie de ce travail consiste en une revue de la littérature traitant des différents points étudiés notamment les travaux relatifs au séchage des textiles et à leur teinture. Le deuxième chapitre consacré à l'étude du séchage et du chauffage de différents textiles par rayonnement infrarouge, se scinde en deux parties: la première est une étude théorique basée sur l'évaluation de l'énergie absorbée par ces textiles à partir de leurs spectres de réflexion diffuse. la deuxième est une étude expérimentale du séchage et du chauffage de ces mêmes textiles de différentes couleurs. Cette étude présentée dans ce chapitre est conduite afin de déterminer l'impact de la couleur des tissus sur leur séchage et chauffage dans un four à infrarouge mettant en oeuvre des émetteurs de rayonnement infrarouge moyen et court. Le troisième chapitre est consacré à l'étude de la fixation des colorants réactifs par rayonnement infrarouge. De cette étude, on ressort les conditions opératoires pour lesquelles le rendement de fixation des colorants est optimal. Dans ce chapitre est présentée aussi une étude de l'influence de l'extraction sous vide sur ce procédé de teinture par foulardage - séchage et fixation par rayonnement infrarouge. Enfin, le quatrième chapitre traite d'une simulation de ce procédé de teinture par foulardage afin d'élucider les différents facteurs de perturbation du bain de teinture

Efficient Photocatalytic Degradation of Aqueous Atrazine over Graphene-Promoted g-C₃N₄ Nanosheets

Atrazine is a systemic herbicide widely used in weed control. In recent years, it has been largely detected in surface and groundwater in several locations all over the world. Photocatalysis is a green and sustainable technology with huge application prospects in pollution control and the degradation of organic water pollutants. In this work, photodegradation of aqueous atrazine was investigated over pristine graphitic carbon nitride (g-C3N4) synthesized via urea pyrolysis and graphene/g-C3N4 composite synthesized via the in situ growth method involving direct deposition of g-C3N4 nanosheets on the graphene surface. The obtained photocatalysts were characterized using transmission and scanning electron microscopy, Fourier-transformed infrared spectroscopy, UV-visible spectroscopy, photoluminescence spectroscopy, X-ray diffraction, and surface area measurements. It was demonstrated that the composite material exhibited remarkable photocatalytic properties for the efficient degradation of aqueous atrazine under visible light at ambient temperature. After 5 h of reaction, atrazine conversion reached 100% in the presence of graphene/g-C3N4 composite, while the pristine g-C3N4 allowed 40% conversion under the same conditions, thus demonstrating the positive effect of graphene on the photocatalytic activity of g-C3N4. Moreover, graphene/g-C3N4 was shown to keep its activity even when it was recycled five times, thus proving its stability and its potential to be used at the industrial scale

Palladium and Graphene Oxide Doped ZnO for Aqueous Acetamiprid Degradation under Visible Light

Acetamiprid is a neonicotinoid insecticide widely used in pest control. In recent years, it has been considered as a contaminant in groundwater, lakes, and rivers. Photocatalysis under visible light radiation proved to be an effective process for getting rid of several organic pollutants. In the present work, photodegradation of aqueous acetamiprid was investigated over bare zinc oxide (ZnO) photocatalyst as well as ZnO doped with either palladium or palladium combined with graphene oxide. Both ZnO and doped-ZnO were synthesized via a microwave-assisted hydrothermal procedure. The obtained photocatalysts were characterized using different techniques. After 5 h of reaction at ambient temperature under visible light irradiation, acetamiprid conversions attained ca. 38, 82, and 98% in the presence of bare ZnO, Pd-doped ZnO and Pd-GO-doped ZnO photocatalysts, respectively, thus demonstrating the positive effect of Pd- and GO-doping on the photocatalytic activity of ZnO. In addition, Pd-GO-doped ZnO was shown to keep its activity even when it is recycled five times, thus proving its stability in the reaction medium

Palladium and Graphene Oxide Doped ZnO for Aqueous Acetamiprid Degradation under Visible Light

Acetamiprid is a neonicotinoid insecticide widely used in pest control. In recent years, it has been considered as a contaminant in groundwater, lakes, and rivers. Photocatalysis under visible light radiation proved to be an effective process for getting rid of several organic pollutants. In the present work, photodegradation of aqueous acetamiprid was investigated over bare zinc oxide (ZnO) photocatalyst as well as ZnO doped with either palladium or palladium combined with graphene oxide. Both ZnO and doped-ZnO were synthesized via a microwave-assisted hydrothermal procedure. The obtained photocatalysts were characterized using different techniques. After 5 h of reaction at ambient temperature under visible light irradiation, acetamiprid conversions attained ca. 38, 82, and 98% in the presence of bare ZnO, Pd-doped ZnO and Pd-GO-doped ZnO photocatalysts, respectively, thus demonstrating the positive effect of Pd- and GO-doping on the photocatalytic activity of ZnO. In addition, Pd-GO-doped ZnO was shown to keep its activity even when it is recycled five times, thus proving its stability in the reaction medium

Biological Activity of the Mentha spicata L. and Salvia officinalis L. (Lamiaceae) Essential Oils on Sytophilusgranarius L. and Triboliumconfusum Jac. Du Val. Infested Stored Wheat

This work is part of the development and enhancement of natural substances and the search for effective, non-polluting and beneficial control methods for human health against insect pests of stored cereals. For this purpose, the essential oils extracted by hydro-distillation from two aromatic plants, i.e., Mentha spicata L. and Salvia officinalis L., were tested for their bio-insecticide effect against two different insect pest species affecting stored cereals: wheat weevil Sytophilusgranarius Linnaeus, 1758 (Coleoptera; Curculionidae (https://www.google.com/search?rlz=1C1RLNS_frDZ794DZ794&sxsrf=ALeKk02kJGWNyk9IHmU4edt2WofGTjHQjQ:1599765637919&q=Curculionidae&stick=H4sIAAAAAAAAAONgVuLUz9U3MDTNNs9ZxMrrXFqUXJqTmZ-XmZKYCgAlNltqHQAAAA&sa=X&ved=2ahUKEwjSqsm0p9_rAhVGxoUKHT7qDkEQmxMoATAkegQIDhAD)) and confused flour beetle Triboliumconfusum Jacquelin du Val, 1863 (Coleoptera; Tenebrionidae (https://en.wikipedia.org/wiki/Darkling_beetle)). A batch of adult insect individuals was introduced into each petri dish and placed in their respective oven. The test results showed that the aerial part of Sage and Spearmint have a toxic effect on adults of Weevil (60% mortality for Spearmint and 90% for Sage) and Tribolium (70% mortality for spearmint and 90% for sage). In conclusion, these two aromatic and medicinal plantsare naturally occurring substances that act as insecticides to control effectively the stored cereals insect pest species

Synthesis of Gold Catalysts Supported on Mesoporous Silica Materials: Recent Developments

Mesoporous silica materials (MSM) with ordered and controllable porous structure, high surface area, pore volume and thermal stability are very suitable catalyst supports, because they provide high dispersion of metal nanoparticles and facilitate the access of the substrates to the active sites. Since the conventional wet-impregnation and deposition-precipitation methods are not appropriate for the incorporation of gold nanoparticles (AuNPs) into MSM, considerable efforts have been made to develop suitable methods to synthesize Au/MSM catalysts, because the incorporation of AuNPs into the channel system can prevent their agglomeration and leaching. In this review, we summarize the main methods to synthesize active gold catalysts supported on MSM. Examples and details of the preparative methods, as well as selected applications are provided. We expect this article to be interesting to researchers due to the wide variety of chemical reactions that can be catalyzed by gold supported catalysts

Bioremediation of Polluted Soil Sites with Crude Oil Hydrocarbons Using Carrot Peel Waste

The biostimulation potentials of carrot peel waste and carob kibbles for bioremediation of crude petroleum-oil polluted soil were investigated. Temperature, pH, moisture, total petroleum hydrocarbon (TPH), and changes in microbial counts during 45 days were monitored when 4 mL of carrot peel waste or carob kibbles media were added to 200 g of crude oil polluted soil samples. Gas chromatography-flame ionization detection (GC-FID) was used to compare hydrocarbon present in the crude oil polluted soil and in pure fuel, composition of crude oil polluted soil was analyzed by X-ray diffraction (XRD), and the TPH was measured by distillation using distiller mud. The results showed that, at the end of experiments, the concentration of TPH decreased in crude oil polluted soil containing carrot peel waste with a percentage of 27 ± 1.90% followed by crude oil polluted soil containing carob kibbles (34 ± 1.80%) and in the unamended control soil (36 ± 1.27%), respectively. The log [Colony Forming Unit (CFU)/g] of total heterotrophic bacteria in the crude oil polluted soil increased from 10.46 ± 0.91 to 13.26 ± 0.84 for carrot peel waste, from 11.01 ± 0.56 to 11.99 ± 0.77 for carob kibbles and from 8.18 ± 0.39 to 8.84 ± 0.84 for control, respectively. Such results demonstrated that carrot peel could be used to enhance activities of the microbial hydrocarbon-degrading bacteria during bioremediation of crude petroleum-oil polluted soil