Characterization of a Dialdehyde Chitosan Generated by Periodate Oxidation

This article reports the oxidation of Chitosan by using periodate and the characterization of the dialdehyde chitosan (DAC) generated by the reaction. Oxidised chitosan were further characterised by FTIR analysis, 1HNMR and TGA. The morphological analyses of oxidized chitosan by SEM confirmed the non change of elongated and fibrous network of chitosan. FTIR and TGA show no significant change on chemical structure and thermal properties successively. 1H NMR study confirmed the presence of imines generated by the reaction between dialdehyde chitosan and amino groups of chitosan (spontaneous assembling)

Effects of Phenol Addition on Oil Extraction from Moroccan Oil Shale by Supercritical Toluene

In the present work, the effect of phenol on the supercritical extraction of the organic matter from Tarfaya's oil shale with toluene was evaluated. The experimental results showed clearly that phenol had a significant effect on the yield and the composition of the oils obtained. Moreover, it was shown that phenol was a very efficient modifier for oil shale, giving a good yield of recovery and a suitable maturation of the organic matter. The pitches prepared by mixing phenol and toluene contain more aromatics and have a high char yield at 950 °C compared to those obtained by extraction with supercritical toluene alone

Comparison of chemical and physical activation processes at obtaining adsorbents from moroccan oil shale

Within the Moroccan natural resources valorisation scheme, new adsorbents have been prepared from oil shale by chemical and physical activation processes. The activation process the authors have developed in this study give effective adsorbent materials. In view of the physico-chemical properties of these materials and application to the treatment of water loaded with a metal (Cr6+ ion) or organic (methylene blue (MB)) pollutant, it is concluded that the chemical activation process of oil shale at low temperature (250 °C) affords the best material. The material’s yield is good in comparison with the physical activation at the same temperature and the process is energy saving differently from that at 450 °C. Moreover, the chemical activation of oil shale with phosphoric acid at 250 °C produces a material with a good yield (about 70%), a high specific surface area (approximately 600 m2 /g) and a highly porous structure, which gives it a high retention of methylene blue and the Cr6+ ion

Elaboration and characterization of a new activated carbon obtained from oregano residue: Application in environmental field

This study focuses on the valorization of extraction residues of medicinal plants which represent approximately 80% of the gross weight of the plant. In this context we proceeded to the transformation of “marc oregano” to a material adsorbent type activated carbon. The oregano marc, obtained after extraction of essential oils and organic compounds, has undergone a chemical activation using the phosphoric acid 85% (H3PO4). It is well known as precursors of lignocellulosic activating agent, allows the development of a large porosity in the activated material. The activated product has subsequently underwent heat treatment in the temperature range from 200 to 350 °C. The optimum temperature for development was set at 300 °C. The results obtained showed that the adsorbent material O300 has developed the interesting textural properties. It is an adsorbent material like activated carbon, which presents, according to the BET method, a specific surface of 1200 m2·g−1 (specific surface area of commercial activated carbon is of about 905 m2·g−1). The application of adsorbent material developed O300 in microbial decontamination of urban waste water, has revealed its effectiveness and its important adsorptive properties against pathogens pollutants from wastewater

Characterization of Chitosan and fabrication of Chitosan hydrogels matrices for biomedical applications

The development of injectable hydrogels for drug delivery is a major challenge. Chitosan is a copolymer of N-acetylglucosamine and glucosamine units and is represented as a copolymer. Chitosan occurs in nature in the cell walls of some fungi, exoskeletons of insects and marine animals such as crabs and prawns. Chitosan and its derivatives possess a wide range of useful properties. They are biodegradable, and biocompatible with antibacterial and antioxidant activities. They are useful in drug delivery formulations and tissue engineering. The objective of the present study was to characterize chitosan, prepare chitosan hydrogels and study the gelation of this hydrogels over time. Chitosan with DDA% ∼ 80%–90% were characterized by infrared spectroscopy, conductimetry and pH-metry. In addition, chitosan hydrogels were prepared using an ionic gelation method making it suitable for biomedical applications

Effect of temperature and clay addition on the thermal behavior of phosphate sludge

The aim of the present work is to characterize the phosphate sludge from the area of Youssoufia (rich in CaO ~ 31%) and to study its thermal behavior alone and when mixed with clay from Safi (Morocco). This may contribute to its valorization as an alternative raw material for ceramic industries. The evolution of phases during the thermal treatment of phosphate sludge, clay and sludge–clay mixtures at different mass ratios (25 wt%, 50 wt%, and 75 wt%) was performed at different levels of temperatures from 600 to 1120 °C. Mineralogical analysis by X-ray diffraction (XRD) showed that the sludge mainly consisted of quartz, calcite, dolomite, and francolite. Dolomite and calcite vanished after sludge heating and two new phases were formed, namely akermanite and monticellite. For clay, it mainly consisted of illite, kaolinite, quartz, calcite, and dolomite. After clay sintering at high temperature, a new phase was formed, i.e. anorthite. The effects of the MO/SiO2 ratio (MO = CaO + MgO) in mixtures (clay + sludge) on the crystallization behavior of diopside and fluorapatite, and the disappearance of the akermanite were investigated. The results showed that the crystallization of diopside–fluorapatite increased when the MO/SiO2 ratio increased. Resumen: El objetivo del presente trabajo es caracterizar un lodo de fosfato del área de Youssoufia (rico en CaO ~ 31%) y estudiar su comportamiento térmico tras su mezcla con una arcilla de Safi (Marruecos). Este estudio puede contribuir a su valorización como materia prima alternativa para la industria cerámica. La evolución de las fases minerales durante el tratamiento térmico de lodos de fosfato, arcilla y mezclas de lodos y arcilla en diferentes proporciones de masa (25, 50 y 75% de peso) se realizó a diferentes temperaturas, desde 600 a 1.120 °C. El análisis por difracción de rayos X (DRX) permitió conocer la composición mineralógica del lodo formado principalmente por cuarzo, calcita, dolomita y francolita. La dolomita y la calcita desaparecieron tras el calentamiento del lodo y se formaron 2 nuevas fases, a saber, akermanita y monticellita. En cuanto a la arcilla, el análisis mineralógico evideció la presencia de illita, caolinita, cuarzo, calcita y dolomita como fases mayoritarias. Tras la descomposicón de la arcilla se formó anortita como fase de alta temperatura. Se investigaron los efectos de la relación MO/SiO2 (MO = CaO + MgO) en mezclas (arcilla + lodo) sobre la cristalización de diópsido y fluorapatita y la desaparición de la akermanita. Los resultados mostraron que la cristalización de diopsido-fluorapatita aumentó cuando creció el cociente MO/SiO2

Extraction and Recovery of Bioactive Metabolites from Marine Spongeand#8220;Ircinia spinulosaand#8221;

Oceans cover more than 75% of our planet. In some ecosystems, such as coral reefs, experts believe that biodiversity is greater than that of tropical forests. Morocco, with its double facade Atlantic and Mediterranean, long of more than 3500 km, is a country deeply influenced by the sea, which implies the existence of thousands of marine species by reports in other countries. Currently, marine organisms are a very important source of new molecules in pharmacology and thus in the development of new bioactive products. Sponges, in particular, given their very primitive origin and persistence during evolution, have developed a chemical defense system. This study aims the biological valorization of crude extract from a marine sponge collected in Atlantic coastal El Jadida: Ircinia spinulosa. The chemical study of Ircinia spinulosa, marine sponge was realized for the first time in Morocco, and revealed that this sponge contains different levels of primary and secondary metabolites. Analysis of fatty acids in the lipid extract of Ircinia spinulosa is performed by gas chromatography coupled with mass spectrometry (GC-MS) was used to determine the predominance of acid Palmitic. This molecular diversity of sponges has a large deposit of biological and biomedical potential. What pushed us to continue the research to isolate new and original molecules

Thermal and mechanical properties of cordierite refractory ceramic produced from stevensite-rich clay, kaolin and alumina

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