Extraction and characterization of ß-chitin from sardine’s scales Sardina pilchardus (Walbaum, 1792)

Sardine (Sardina pilchardus) is a common Mediterranean pelagic fish known as an important source of marine products in Morocco. In parallel, the high processing of sardines produces a huge quantity of sardine scales that causes environmental problem. Using the sardine scales for the production of chitin can enhance the economic value of sardine factories, and can reduce their adverse impact on nature. This study aimed to extract and characterize chitin for the first time from sardine scales basing on demineralization and deproteinization. The physicochemical structure of chitin extracted from sardine scales was determined by FT-IR, TGA, XRD, SEM, and EDAX. FTIR analysis revealed the β-form of the chitin extracted. The molecular weight (Mw) and the degree of Acetylation (DA) obtained were about 145KDA and 76% respectively. TGA determined thermal stability for the obtained chitin, which ranged between 150 to 250°C. XRD showed the amorphous structure of ß-chitin extracted and the crystalline index value of the chitin extracted (CrI) was 68%. While SEM and EDAX exposed that the chitin extracted has characterized by long chains and high purity. The results obtained in this current study showed that Sardina pilchardus can be used as a new alternative source of chitin

Textile wastewater discoloration by Fenton oxidation process

Treating industrial wastewater by advanced oxidation processes, is a recent interest primarily for decolorization of aqueous solutions containing dyes. The application of the Fenton reaction is one of these processes, bleaching liquid discharges after a textile dyeing unit in the city of Marrakech, Morocco, which are non-biodegradable, using oxidation by Fenton's reagent has shown its ability to degrade the dyes in water to carbon dioxide, water, and other harmless products. In this study a serie of pure dyes mineralization experiments used in the dyeing process, such as: the Bezaktiv BLUE-SR, the NOVACRON® Red FN-R, and the NOVACRON®SCALE TFN-6G, and a global liquid discharge containing dyes and chemical additives. Fenton's method is effective at pH = 3, as a result, we had a total discoloration for the three pure colors, and up to 47% to the overall rejection for 60 minutes at room temperature, and 100%  when the temperature was increased to 60 °C. The presence of chemical additives disadvantage Fenton oxidation

Comparative sorption isotherms of conserved Thymus satureioides

Thymus satureioides is an endemic plant of Morocco used for its virtues in traditional medicine. This natural plant in comparison with the preserved one by gamma irradiation and thermal-biochemical treatment using a solar dryer, were investigated at various temperatures and water activity using a saturated salt solution method. Thus, it was necessary to study the effect of preservation processes on the storage conditions. The sorption curves of thyme decreased with the increase in temperature at constant relative humidity and the hysteresis effects were observed. The experimental data of sorption were described by six equations. The Enderby’s model was found to be the most suitable for describing the sorption curves for untreated and irradiated thyme. In opposition, treated thyme was approached by Peleg’s model. Moreover, the optimum water activity of storage was investigated.

"Mouillage" partiel du graphite par SF

Les propriétés thermodynamiques du film de SF6 adsorbé sur graphite (0001) ont été déterminées par volumétrie à partir d'isothermes d'adsorption.Il ne se forme qu'une seule couche monomoléculaire dans tout le domaine étudié (120-180 K). En dessous de 150 K, cette couche est sans doute un solide 2D à son complément. Sa densité est alors voisine de celle d'un plan de densité maximale du cristal 3D ; toutefois, sa structure en diffère certainement étant donné que le film se limite à cette seule couche. Aux taux de recouvrement inférieurs à 0,75 il se formerait un liquide 2D entre environ 131 et 164 K, températures définissant respectivement un point triple (ou une zone de fusion) et un point critique

Propriétés du film de krypton adsorbé sur la face (0001) du graphite préalablement recouverte d'hexafluorure de soufre

Physisorption of krypton on the graphite (0001) face previously covered with sulfur hexafluoride (SF6) has been studied between 70 and 80 K by a volumetric method. Krypton adsorption is strongly hindered by pre-adsorbed SF6 and becomes significant only under pressures definitively higher than on naked graphite. It probably implies the displacement of the SF 6 film.La physisorption de krypton sur la face (0001) du graphite recouverte d'hexafluorure de soufre (SF6) également physisorbé a été étudiée par volumétrie entre 70 et 80 K. La présence de SF6 contrarie fortement l'adsorption du krypton qui ne s'adsorbe de façon importante qu'à des pressions nettement plus élevées que sur graphite nu en déplaçant probablement le film de SF 6

Optimization of Preparation Conditions of Novel Adsorbent from Sugar Scum Using Response Surface Methodology for Removal of Methylene Blue

A novel and inexpensive adsorbent was prepared from sugar scum for the removal of methylene blue as an organic pollutant from aqueous solutions. The response surface methodology was used to study the effects of the calcination temperature and time on the yield and the methylene blue adsorption. In order to determine the optimal conditions of the preparation, the Doehlert design and desirability function were applied. The increase in calcination temperature increases the methylene blue adsorption and induces a reduction in yield. The optimal conditions have been identified to be a calcination temperature of 986°C and calcination time of 61 min. The characteristics of the obtained adsorbent were determined using SEM/EDX, and surface functions were obtained based on FTIR and pHpzc. The produced adsorbent had a porous structure and a pHpzc of 12.5. The results showed that the yield was 49.74% and the adsorption of methylene blue was 24.52 mg·g−1 with a contact time of 10 h determined by kinetic test. The sugar scum was found to be an effective material for the preparation of appropriate adsorbent for dye removal from wastewater

Activated Carbon from Prickly Pear Seed Cake: Optimization of Preparation Conditions Using Experimental Design and Its Application in Dye Removal

In the present study, the experimental design method was used to optimize the preparation conditions of an activated carbon from prickly pear seed cake by phosphoric acid activation. The parameters studied include impregnation ratio, carbonization temperature, and carbonization time. The optimal conditions for the preparation of the activated carbon with high adsorption capacity for methylene blue were identified to be an impregnation ratio of 2.9, carbonization temperature of 541°C, and carbonization time of 88 min. The obtained activated carbon was characterized by SEM/EDX, FTIR, pHpzc, and its capacity to adsorb methylene blue. FTIR analysis and pHPZC showed the acidic character of the activated carbon surface. The adsorption capacity of the optimal activated carbon was found to be 260 mg·g−1 for methylene blue. The adsorption equilibrium of methylene blue was well explained by the pseudo-second-order model and Freundlich isotherm. Furthermore, the performance of the produced activated carbon was examined by the methyl orange removal