Study of the Interaction of Heavy Metals (Cu(II), Zn(II)) Ions with a Clay Soil of the Region of Naima-Tiaret-Algeria

The RM (RM stands for the pristine clay) collected from sites in the Naima-Tiaret-Algeria and its purified phase TM (TM stands for the treated clay) were characterized using XRF, XRD, FT−IR, SEM−EDX, and DC electrical conductivity techniques. The as-prepared clays were used as potential adsorbents for the removal of Cu2+ and Zn2+ metals ions. Highly purified clay TM, exhibiting a basal, spacing of 25.83 Å and CEC of 51 meq/100 g, was obtained. The type of interstratified I/M in the studied sites is S=1, based on the calculation method of Watanabe. The percentage of illite type S=1 is between 80−85% illite. The adsorption equilibrium was established in 60 min with the capacities of 28.57 and 24.39 mg/g for Cu2+ onto RM, 32.25 and 4.95 mg/g for Zn2+ in the presence of TM. D-R isotherm model was more suitable with the adsorption process than Freundlich and Langmuir models suggesting the ion exchange nature of the retention mechanism in most cases (E > 8 kJ/mol). Pseudo second-order model best described the kinetics of adsorption process. The adsorption mechanism was mainly monitored by ion exchange mechanism between exchangeable interlayer cations (Na) in the interstratified I/M and Cu2+ or Zn2+ metals from aqueous matrix. Further, the release of H+ ions from the edge of the layer structure in acidic environments promote the adsorption of heavy metals onto the surfaces interstratified I/M clay soils via electrostatic attraction. Copyright © 2021 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

Mobilite Du Plomb Et Du Zinc Issus De Retombees Atmospheriques Dans Le Sol : Cas De La Zone Industrielle De Tiaret, Algerie

Study of heavy metals mobility in soil is a necessary step for making an accurate appraisal and quantitative evaluation of the extent of contamination, indeed, wet and dry atmospheric deposits, plays an important role in the cycle of semi-volatile contaminants (Vinogradova, 2000). Metallurgical industries release heavy metals into the atmosphere, these last, clump together to form fines particles suspended in the air, these metals can be transported by wind via aerosol or aqueous pathway and deposited in the soil. The main aim of this work was to study the mobility and fate of lead and zinc from atmospheric deposits in a contaminated soil from the foundry (ALFET) in the industrial zone of Tiaret (Western Algeria) and to determine the effect of physicochemical parameters of the soil on their mobility in the topsoil. The physicochemical analysis of soil samples have shown that zinc and lead levels contents in the surface layer soil (0-30cm) vary depending on the pH, total limestone (CaCO3). The obtained results clearly show the major effect of soil texture, the fine fraction (clay and sand)

Mapping Real Time Applications on NoC Architecture with Hybrid Multi-objective Algorithm

International audienceThe work presented in this paper is a contribution to solving a widespread problem in the field of system design, embedded the placement of a large application on an architecture (NOC). Application is represented by a set of tasks that communicate with each other by sending message via bus on a heterogeneous architecture. Our role is to place the tiles (task) on different elements (core) of architecture with the objectives of minimizing time execution and the energy consumption under the constraints of load balancing, bandwidth, available memory and size of the queue waiting processors. To solve this problem, we used in the context of our present work, a new meta-heuristic algorithm Particle Swarm. it has proved its effectiveness in many fields such as optimization of networks, image processing and even control of industrial systems but it was never applied in our domain

Reactivite physico-chimique, fonctionnement physiologique et microbiologique en conditions salines

*ENSA/INRA;Rennes (FRA) Diffusion du document : ENSA/INRA;Rennes (FRA) Diplôme : Dr. Ing

Impact de la céréaliculture en pluvial sur l'érosion éolienne à Laghouat (Steppe algérienne°

Limitée au nord par l’isohyète 400 mm et au sud par l’isohyète 100 mm, la steppe algérienne est soumise à des pressions anthropiques croissantes. Pendant plusieurs décennies, ces espaces ont été le siège de céréaliculture en pluvial, soumettant leurs sols à un émiettement durant les travaux aratoires et facilitant en conséquence leur dégradation par érosion éolienne. Notre travail a été réalisé dans une région modèle de la steppe Algérienne, dans le périmètre agricole de Mokrane, région de Laghouat. Des capteurs de sables de type BSNE placés sur une parcelle de 1.35 ha cultivée à l’orge (Hordeum Vulgare) en pluvial ont été utilisé pour mesurer les flux éoliens en 2009, 2010, et 2011. Une station météo (Campell Scientific) équipée de quatre anémomètres, d’une girouette, d’un pluviomètre et d’un saltiphone a servi à la caractérisation des événements éoliens. Les résultats de mesures montrent que les tempêtes de sable à Laghouat durent parfois plusieurs jours. Les événements érosifs sont quant à eux de durées très variables allant de quelques minutes à plusieurs heures et entrecoupés par des périodes de calme de durées similaires. Les directions des vents érosifs oscillent entre l’ouest et le nord. Les vitesses moyennes du vent pendant la saltation sont comprises entre 6,2 et 7,3 m/s. La vitesse seuil de saltation varie entre 5,7 m/s et 7,6 m/s et ne montre pas de tendance saisonnière claire. Les bilans de masse mesurés sont généralement négatifs mais peuvent occasionnellement prendre des valeurs positives. Des pertes en terre totales de -118 t/ha ont été mesurées sur une période de 25 mois. Ceci illustre le fort potentiel de dégradation des sols en cas de mise en culture en pluvial. Des mesures devraient être prises pour limiter ce mode de mise en valeur des sols steppiques

R action du riz @ la salure en relation avec la dynamique des quilibres ioniques Nitrification et d gagement de CO2 en sol sal

BSE B224637H / UCL - Université Catholique de LouvainSIGLEBEBelgiu

Bending examination of advanced generation of composite structures with specific properties exposed to different loads

Introduction/purpose: This article presents the bending examination of advanced-generation composite structures with specific properties exposed to different loads. Methods: This paper thus proposes and introduces a new generalized five-variable shear strain theory for calculating the static response of functionally graded rectangular plates made of ceramic and metal. Notably, our theory eliminates the need for a shear correction factor and ensures zero-shear stress conditions on both the upper and lower surfaces. Numerical investigations are introduced to interpret the influences of loading conditions and variations of power of functionally graded material, modulus ratio, aspect ratio, and thickness ratio on the bending behavior of FGPs. These analyzes are then compared to the results available in the literature. Results: Preliminary results include a comparative analysis with standard higher-order shear deformation theories (PSDPT, ESDPT, SSDPT), as well as Mindlin and Kirchhoff theories (FSDPT and CPT). Conclusion: Our theory contributes alongside established theories in the field, providing valuable insights into the static thermomechanical response of functionally graded rectangular plates. This encompasses the influence of volume fraction exponent values on non-dimensional displacements and stresses, the impact of aspect ratios on deflection, and the effects of the thermal field on deflection and stresses. Numerical examples of the bending examination of advanced-generation composite structures with specific properties exposed to different loads demonstrate the accuracy of the present theory

Effect of rainfed cereal crops on the wind erosion in the Algerian steppe (Case study in Laghouat)

The Algerian steppe 20 million ha, bounded on the north by the 400 mm isohyets and south by the 100 mm isohyets. This territory is subject to increasing human pressure. For several decades, this area has been home to rainfed cereal cropping subjecting soils to a strong fragmentation during seedbed preparation, thereby facilitating the degradation of soil by wind erosion. This study was conducted within the agricultural area of Mokrane (Laghouat), a region of the Algerian steppe. In 2009 and 2010, sediment mass flux densities were measured using BSNE sand-traps on a plot of 1.35 ha cropped with rainfed barley (Hordeum vulgare). A weather station equipped with anemometers, a wind vane and a saltiphone was used to acquire the data needed to characterize erosive events. The results show that in Laghouat sandstorms can last for several days. However, the actual erosive periods were highly variable in terms of duration, ranging from a few minutes to several hours interspersed with calm periods. Erosive winds originated from the west and north. The average wind speeds during saltation were between 6.2 and 7.3 m/s. The threshold velocity had low seasonality and varied between 5.7 m/s and 7.6 m/s. The measured mass balances were negative and fluctuated between -74.5 t/ha -2.8 t/ha depending on the measurement periods. The total soil loss measured over a period of two years confirms that rainfed cultivation induces severe degradation of soil by wind erosion in the Algerian steppe and should be discouraged