Valorisation du marc du café : extraction de l’huile et évaluation de son activité antioxydante

The spent coffee grounds are considered as a solid waste generated by coffee consumers. The present work aims to enhance this co-product rich in high value-added molecules. Indeed, the spent coffee grounds are extracted by two methods, Soxhlet and decoction. The solvent used in both processes to extract the lipid fraction was n-hexane. Both extractions, Soxhlet and decoction, were conducted under the same operating conditions. The Soxhlet extract 11% (dray mass) of oil after three hours of extraction and decoction extract 8% (dry mass) of oil after only 30 minutes. Preliminary characterization of these extracts, by the Folin Ciocalteu protocol, provided 28 mg GAE/g of total phenolic compounds for the Soxhlet extract, and 30 mg GAE/g for the decoction extract. The antioxidant activity of different extracts was assessed by two methods, the test of free radical scavenging, using the diphenyl picrylhydrazyl (DPPH•), and Ferric Reducing Antioxidant Power (FRAP) test. The extracts showed significant antioxidant potential. 70% of inhibition of DPPH° free radicals were observed for 30 min decoction extract and a higher iron reducing power for Soxhlet and decoction extracts.Le marc du café est considéré comme un déchet solide généré par les consommateurs de café moulu. Le présent travail a pour but de valoriser ce coproduit riche en molécules de haute valeur ajoutée. En effet, le marc du café est soumis à une extraction par deux procédés, le Soxhlet et la décoction. Le solvant utilisé dans les deux procédés pour extraire la fraction lipidique est le n-hexane. Les deux extractions, par Soxhlet et par décoction, ont été conduites dans les mêmes conditions opératoires. Le procédé Soxhlet abouti à 11% (base sèche) de l’huile totale de marc de café après trois heures d’extraction et environ 8% (base sèche) d’huile après seulement 30 minutes d’extraction par décoction. La caractérisation préliminaire de ces extraits a fourni, selon la méthode de Folin Ciocalteu, une teneur en composés phénoliques totaux de 28 mg GAE/g pour l’extrait de trois heures par Soxhlet, et 30 mg GAE/g pour l’extrait d’une heure par décoction. L’activité antioxydante des différents extraits a été évaluée par deux méthodes. Le test de piégeage du radical libre DiPhényl Picryl Hydrazyl (DPPH•) et le teste de réduction des ions de fer Ferric Reducing Antioxidant Power (FRAP). Les extraits ont manifesté un important potentiel antioxydant. Un pourcentage d’inhibition de 70% du radical DPPH remarqué pour l’extrait de 30 minutes par décoction et un pouvoir réducteur de fer plus élevé pour l’extrait de 4 heures par Soxhlet et celui de 3 heures par décoction

REMOVAL OF PHENOL AND SURFACTANT FROM LANDFILL LEACHATE BY COAGULATION-FLOCCULATION PROCESS

Following the action of rainfall and natural fermentation, the stored waste produces a liquid fraction called leachate. This leachate is rich in organic matter (biodegradable but also refractory) and trace elements. There are many techniques of treating the leachate, in particular, biological, physicochemical, membrane processes. The choice of a technique instead of another depends on several parameters including: the age of the leachate, composition... In this work we applied a coagulation-flocculation process to treat intermediate landfill leachate of Rabat city with a combined ferric chloride coagulant and a polymer flocculant. We were inspired by full factorial design, including twenty five experiments, to determine optimal dosages of coagulant and flocculant. We operate at pH 8.4, the best removal efficiencies obtained were 88 % for Turbidity, 98 % for Phenol and 82 % for surfactant. The optimum dosages values determined by this study were 13.2 g∙L-1 of coagulant, 62 mL∙L-1 of flocculant

OPTIMIZATION OF A PROCESS FOR DISCOLORATION OF LOW-GRADE SYRUP

L'amélioration de la couleur du sirop industriel de qualité inférieure, sur le charbon actif, a été optimisée à l'aide d'une conception composite centrale et d'une méthodologie de surface de réponse. Cette étude vérifie l'effet de trois paramètres expérimentaux : masse d'adsorbant (charbon actif), temps de contact adsorbat-adsorbant (sirop - charbon actif), rapport de masses des farines constituant le gâteau de filtration (m w /m b ) , et leurs interactions sur la réponse : ICUMSA Color. L'exploitation du modèle établi dans l'espace des variables a permis de définir des conditions économiques optimales d'obtention de sirop de classe claire selon la Commission Internationale pour les Méthodes Uniformes d'Analyse du Sucre (ICUMSA)

Natural Phosphate K09 as a New Reusable Catalyst for the Synthesis of Dihydropyrano[2,3-c]Pyrazole Derivatives at Room Temperature

International audienceIn this study, we report a simple, efficient and green protocol for the synthesis of pyrano[2,3-c]pyrazole derivatives by the use of the natural phosphate K09 as a mild and efficient heterogeneous catalyst. The catalytic efficiency of K09 was compared with other heterogeneous catalysts to determine the best catalyst for said conversion. Easy recovery of the catalyst and its reusability, room temperature reaction conditions, short reaction time, excellent yields, are some of the important features of this protocol

Triage et valorisation des déchets solides à la décharge publique de la ville de Mohammedia

This work is part of the evaluation of solid waste in landfills in Morocco. It can first show, the importance of triage and valorization and help develop other opportunities in the various sectors of solid waste. The latter is relevant in overcoming the constraints identified and exploiting the opportunities      identified. The results obtained during the triage conducted showed that the dump of Mohammedia is a source of raw material (plastic, glass, paper ...). The study showed an estimated quantity  T/day between 10 and 16 tones of plastic to value, 10 to 6 tons of  paper... The activity of plastic recycling mainly responds to the demand and supply products with an annual deposit within a range from 30000 to 40000 tones (1). The circuit recovery and recycling of solid waste the plastic glassware ... knows a problem of organization and precarious working conditions of scavengers in particular:   hygiene and sanitation and health risk.Ce travail entre dans le cadre de la valorisation des déchets solides triés dans des décharges publiques au Maroc. Il peut d’une part montrer l’importance de triage et valorisation et d’autre part aider  au développement des débouchés des différentes filières de récupération des déchets. Ce dernier présente les actions pertinentes à même de dépasser les contraintes relevées et d’exploiter les opportunités identifiées. Les principaux résultats obtenu durant le triage réalisé a montré que la décharge publique de Mohammedia constitue une source de matière première (plastiques, verreries, papiers cartonnées….). L’étude réalisée a montré qu’on estime une quantité en T/ jour variant entre 10  et 16 tonnes de plastiques à valoriser, 10 à 6 tonnes de papiers,… L’activité de recyclage du plastique répond principalement à l’offre et la demande des produits dont le gisement annuel se situe dans une fourchette de 30 000 à 40 000 tonnes (1). Le circuit de récupération et de valorisation des déchets tel que le plastique la verrerie… connaît un véritable problème d’organisation et de précarité des conditions de travail en particulier des récupérateurs : manquement aux règles de base d’hygiène et de salubrité, risque pour la santé, etc

Advanced statistical optimization of parameters of synthesis process of oxygenated carbonated apatite

International audienceThe synthesis process of oxygenated carbonated apatite was optimized by an advanced statistical planning of experiments. Full factorial design of 24 experiments was used to find the effects of five principal parameters: pH of the reaction medium, atomic ratio Ca/P of the reagents, concentration of the calcium solution (Ca2+), temperature of the reaction medium (T) and duration of the reaction (D), with fixing the H2O2 composition at 30% and stirring to 600 turns/min. Studied responses were the atomic ratio Ca/P, % O2, % O2 2− and % CO3 2−. Optimum synthesis parameters were found to be pH = 7.38, Ca/P = 1.647, [Ca2+] = 0.636 M, T = 40°C and D = 1 h. The prediction responses were Ca/P = 1.575, % O2 = 0.76, % O2 2− = 0.50 and % CO3 2−= 1.84. The actual experimental results were in agreement with the prediction

Synthesis, characterization and thermal behaviour of a Phosphocalcic Oxygenated Apatite

A new route for preparing an antiseptic biomaterial has been described. An oxygenated apatite-based calcium phosphate powder that had a Ca/P ratio of 1.55 was synthesized from calcium nitrate and phosphoric acid in oxygenated water via a precipitation method. The X-ray diffraction and FTIR analysis of the as-dried powder reveals that the apatite is poorly crystalline and is converted into a biphasic calcium phosphate (HAP/beta TCP) when calcined at a temperature higher than 600°C. The chemical analysis of oxygenated species shows the disappearance of these species at 400°C

Analytical validation of potentiometric method for cetirizinium ion

Accuracy and reliability of the analytical results are crucial for ensuring quality, safety, and efficacy of pharmaceutical products. However, to ensure these criteria, analytical validation is required. In this matter, many official documents describing the criteria of validation are available. However, these concern mainly chromatography analysis and bio-analytical methods of pharmaceutical products, but they do not propose any experimental protocol for direct potentiometric methods using ion-selective electrodes applied in pharmaceutical analysis. In this work, we are proposing a validation strategy based on the normative and regulatory guidelines applied to a potentiometric method with a polymeric membrane selective to cetirizine dihydrochloride. The statistical analysis obtained from raw data is described for all steps of this protocol. Also this validated method was successfully applied to the determination of cetirizine in pharmaceutical preparations using direct potentiometry with a mean relative standard deviation of 0.57% and a mean recovery of 99.63%