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The aim of this work is to prepare and characterize activated carbons with good properties at lower cost from molasses, obtained as byproducts of the sugar industry. The samples were prepared by chemical activation with phosphoric acid (H3PO4). Their structural and textural characterization was effected by FT-IR, specific surface area, SEM, as well as functional group determination. The results showed that the H3PO4/molasses ratio, the activation temperature and the surrounding atmosphere affected the properties of the final activated carbons. The best product was obtained with a H3PO4/molasses ratio of 1.75 at 500°C in air. It presented a specific surface area of 1470 m2/g, a maximum adsorption capacity for methylene blue of 600 mg/g (Langmuir model) and an important quantity of surface functional groups. The study revealed that molasses, a by-product of food industry, could be used as raw material for the preparation of activated carbon under mild conditions and with good textural and structural properties., Applied Journal of Environmental Engineering Science, Vol 4, No 3 (2018)

In order to optimize the factors affecting the extraction of Moroccan oil shale of Timahdit area (Y layer) by sub-critical water extraction, we conducted a study by response surface design type faced central composite design (FCCD). The treatment of the results for experimental designs was carried out using software of experimental design JMP 10. After an appropriate choice of three variables, 20 experiments led to a mathematical second degree model relating the response function (extraction yield) to factors and allowing a good control of the extraction process. Our study proved the great efficiency to applying the experiments design methodology for optimizing the operational parameters affecting the sub-critical water extraction of Moroccan shale oil. The modeling extraction process create a mathematical model between extraction conditions (factors studied) and the response measured (propriety searched). The ANOVA test was used to identify the significant factors. Later than the realization of the experiments and data analysis, the study has allowed the knowledge of the optimal conditions necessary to obtain a better essential oil yield about 95.52%. The optimized parameters are: operating temperature of 315.1 °C, an extraction time of 117.4 min and 55.6 g of olive oil mill wastewater with 50 g of oil shale. It is about a relevant and economical way which allows obtaining the maximum of information in a short time with a minimum of experiments. However for a sustainable environment and to try to address environmental issues, we could develop these effluents (liquid wastes) as extraction solvent of Moroccan oil shale., Applied Journal of Environmental Engineering Science, Vol 3, No 4 (2017)

International audience

In Municipal sewer sludge production in EU is expected to rise to 13.0 million tons in 2020. Also in Algeria the estimated quantity of sludge produced in 2017 will exceed 2.0 million tons per year. Since there production, the treatment and disposal of sewage sludge is become an economically and environmentally sensitive problem. The challenge facing sludge managers is to find cost-effective and innovative solutions whilst responding to environmental, regulatory and public pressures. Methods were developed for reducing and disposal the quantities of generated sludge. The present paper is a contribution to valorizing the ashes sludge of wastewater treatment plants (WWTPs) for the production of a green-cement. Mineralogical and physic-chemical characterizations of ashes sludge were carried out. Ashes contain significant amounts of Al2O3 and SiO2 and can be used as a partial replacement of clinker. Four green-cement samples were prepared by substitute (5, 10, 15 and 20%) of ashes into cement standard. Mechanical tests (compressive strength and bending tensile strength) were carried out to the sample mortars (40x40x160mm3) made of green-cements at different curing times (2, 7 and 28 days). The results show that after 28 days of curing, the compressive strength exceeds 50 MPa. The same trend is observed with specimens tested in bending tensile strength exceeding 7 MPa. These results are encouraging for better management of sludge from Algerian plants in the field of cement industry. © 2017, University of Mohammed Premier Oujda Morocco.

National audience

The layered perovskite oxide, LaCaBiMn 2 O 7 , has been prepared by the conventional aqueous solution precipitation method. The powder X-ray diffraction studies suggest that the phase crystallizes with tetragonal unit cell in the space group I4/mmm. The magnetic properties suggest that the ferromagnetic interactions are dominant and manganese ion in the phase is present in mixed valence states Mn 3+ and Mn 4+ . The thermomagnetization curve is found to obey the Bloch law. Spin wave stiffness constant D and the approximate value for J MnMn exchange interaction were estimated from the experimental results.

We present a review on catalytic or electrical properties of materials based on rare earth (RE) oxides (CeO2 ,L a2O3, Lu2O3) or bismuth based composite systems CeO2-Bi2O3, susceptible to be integrated into catalytic microsystems or gas sensors. The polycrystalline solids can be used as catalysts allowing conversion of CO or CH4 traces in air-gas flows. Fourier Transform infrared spectroscopy is used to determine the conversion rate of CO or CH4 into CO2 through the variations versus time and temperature of vibrational band intensities. The time dependent reactivities are interpreted in terms of an adapted Avrami model. In these catalytic analyses the nature of surfaces of polycrystalline solids seems to play a prominent role in catalytic efficiency. Electrical impedance spectroscopy allows analyzing the variation of conductivity of the system CeO2-Bi2O3. In this system, the specific high ionic conduction of a Bi2O3 tetragonal phase might be linked to the high catalytic activity.

This paper reports electrokinetic phenomena of grafted Poyamide 6.6 multifilament yarns. These yarns is grafted with N-allyliminodiacetic acid for the purpose of removal of some heavy metal ions from their aqueous solutions, by forming its metal chelate especially with Cd2+ and Pb2+ ions. Electrokinetic potential was measured by streaming potential/current method using a Brookhaven-Paar electrokinetic analyzer (EKA), with a rectangular cell designed for textile material. This paper also discusses the spectrometric changes of grafted PA6.6, in UV and VIS spectrum by measuring UVA and UVB transmittance radiation and reflectance of visible spectrum. As yellowish grafted polyamide, the changes of Whiteness Degree and Yellowness Index and the thermo gravimetric analysis (TGA) by this modification will be discussed too.