Search

This article is part of the contribution to the development of two medicinal plants widely used by the Moroccan population: white wormwood (Artemisia herba-alba) andArâr (Juniperus phoenicea), species belonging to the Asteraceae and Cupressaceae families, respectively. The present work was conducted to investigate the chemical composition and anticorrosive properties of essential oils (EOs) extracted from these plants. The chemical analysis of the essential oils (EOs) was carried out by GC-MS/MS. Potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), and quantum chemical calculations by density-functional theory at B3lYP were used to study the anticorrosive effect of the researched oils on mild steel in 1 M hydrochloric acid solution. Moreover, SEM-EDX analysis was used to identify the surface morphology of mild steel surface. GC-MSMS results showed the presence of 32 potentially active compounds in the EOs of Artemisia herba-alba. The average yield of the EOs was about 1.39 ± 0.17 mL/100 g dry matter. Beta thujone (30.07%) and alpha thujone (13.32%) are the main components, while for the EOs of Juniperus phoenicea, the study showed the presence of 30 constituents, with alpha-pinene (43.61%) and manoyl oxide (11.5%) as the main components. The average yield of HE was 1.10 ± 0.03 mL/100 g dry matter. The findings demonstrated an important anticorrosive action of EOs from Artemisia herba-alba and Juniperus phoenicea. Notably, the experimental results showed good efficiency of the studied essential oils and correlated well with the density-functional theory (DFT) calculations. The results of potentiodynamic polarization measurements showed that hydrazone acted as a mixed-type inhibitor. The EIS results showed an increase in charge transfer resistance accompanied by a noticeable decrease in Cdl values, revealing that both studied oils were effective as reliable inhibitors for the protection of mild steel in 1 M HCl solution. Also, the efficiency decreased with decreasing inhibitor concentrations. Surface studies ensure the effectiveness of both investigated oils and the reduction of the surface roughness of mild steel. Furthermore, DFT results of the major constituents of Artemisia herba-alba and Juniperus phoenicea EOs revealed insights into the chemical reactivity of the tested oils while supporting the experimental conclusions and showed outstanding adsorption ability of both investigated EOs on the steel surface.

The present work aims to investigate the conditions for improving the containment of spent ion exchange resin (IER) as a radioactive waste, using powdered Callovo-Oxfordian clay (COx) as an addition to the cementitious matrix at different rates. The aim of this work was to investigate the influence of COx on the characteristics of cemented packages of spent (REI). In this context, a cemented pack was made using Portland class 45 cement, sand, resin and water. And others are prepared by replacing the sand with COx, in the following proportions: (2%, 4%, 6%, 8% and 10%). The packages obtained with and without COx were measured for their compressive strength and porosity.

In order to optimize the formulation of the conditioning matrix of the Ion Exchange Resins (IER) (MBD-15), considered as radioactive waste generated by the TRIGA MARK II nuclear reactor of the CENM, we carried out several tests by fixing the percentage of cement and by modifying the percentages of the resins to be confined (0 - 14%) and that of water. On the other hand, we performed another test to illustrate the role of an aggregate such as sand, in the cement matrix. The measured response of all the tests carried out is evaluated by the compressive strength of the matrix, after a time of 7, 14 and 28 days of confinement. The results obtained show that the maximum amount of IER that can be incorporated into a formulation without the package losing its strength is 12%. The addition of an aggregate (sand) in the cement matrix increases its compressive strength.

Une utilisation non raisonnée des engrais et des pesticides nuit à l’environnement et en particulier aux sources d’eau ainsi qu’à la santé de l’être humain à travers la nourriture. Dans le cadre de la surveillance des eaux de surface marocaine, on a réalisé une enquête auprès de 100 agriculteurs à El Gara, province de Berrechid (Région Casablanca-Settat). Tous les agriculteurs consultés utilisent les engrais et les pesticides. 75% des interviewés ignorent le mode d’emploi de ces produits. Les pesticides sont utilisés une fois par an par 44% des agriculteurs, 70% les appliquent par l’intermédiaire de pick up ou de tracteur, 3% les manipulent en mettant des habits spéciaux et 27% le font à mains nues. Pour les engrais, les agriculteurs les utilisent une fois par an à des proportions variables en ne se basant que sur leur propre expérience. Ainsi, l’Ammonitrate 33,5%N est utilisé par 98% des agriculteurs à une moyenne de 130,9 Kg/ha, le NPK 10-30-10 utilisé par 95% à une moyenne de 175 Kg/ha, le Sulfate d'ammoniaque 21%N est utilisé par 66% à une moyenne de 121,9 Kg/ha et finalement l’Urée 46%N est utilisée par 46% à une moyenne de 67,9 Kg/ha. Ces pratiques ne sont pas soutenables à long terme car elles vont nuire à l’équilibre des écosystèmes en provoquant des dommages à l’environnement et agir sur la santé humaine d’où l’intérêt des agricultures durables. Mots clés: Engrais, pesticides, agriculteurs, enquête

Cementitious materials are widely used in the nuclear industry for the conditioning of radioactive waste. In this context, a study of the cementation of the spent radioactive resins in the presence of an addition consisting of natural red clay was carried out. The essential goal is to increase the quantity of confined resins without altering the final cemented resins form. The materials used including the spent resins and local red clay were characterized, the cemented resins form were carried out by mixing 16.12 % of water, 53 % of Portland cement class 45, (16.504 %.- X %) of Sand, (X %) of red clay with X between 0 and 10 %, and 14.38 % of spent resins. The characterization of cemented resins forms were completed by X-ray fluorescence, by X-Ray diffraction spectrometry and by Scanning Electron Microscope. The mechanical quality of each cemented resins forms was determined after 28 days of curing, by measuring the compressive strength and analysing its porosity. The cemented waste forms made by substituting 2 % and 4 % of sand with local red clay gave interesting results. The value of their compressive strength being equal to 18.4 MPa. The porosity is 33.91 %, Moreover, the analysis of the XRD spectra showed that the formulation at 4 % is the richest in C-S-H. Compared to the reference cemented resins forms carried out in the absence of red clay, the two cemented waste forms have 45 % higher compressive strength, with an improvement in their porosity. Under these conditions, the quantity of confined resin recorded an increase of 14.4 %