24 research outputs found
Enhanced Cadmium Removal by Raw Argan Shell Adsorbent: Experimental and Theoretical Investigations for Ecological Applications
No full textThe removal of cadmium ions (Cd2+) using raw argan shells (ArS) was optimized through experimental and theoretical studies. Adsorption experiments revealed optimal conditions at an adsorbent dose of 3.5 g, an initial Cd2+ concentration of 20 mg·L−1, and a pH of 8, achieving a maximum sorption capacity of 3.92 mg·g−1. The kinetic analysis showed that the adsorption followed a pseudo-second-order model (R2 = 0.98), and the Langmuir isotherm model predicted a maximum adsorption capacity of 4 mg·g−1. Thermodynamic analysis indicated an endothermic adsorption process, with ΔG° shifting from positive to negative as temperature increased, confirming that adsorption is favored at higher temperatures. Desorption studies demonstrated that HCl was the most effective eluting agent, achieving a desorption efficiency of 90.02%, followed by HNO3 (76.65%) and CH3COOH (71.59%). The varying desorption efficiencies were attributed to differences in acid strength and ionic interactions with Cd2+. This study demonstrates the potential of raw argan shells as an efficient, reusable, and sustainable biosorbent for cadmium removal, offering a promising solution for water treatment and environmental remediation
Constructed Wetland as a Low-Energy Technique for Wastewater Treatment – Seasonal Impact, Performance and Phytomanagement
No full textThis work aims to study the seasonal impact on pollutant removal efficiency of constructed wetland (CW) units which treat domestic wastewater in the region of Rabat, Morocco. In this context, four vertical flow-constructed wetlands (VFCWs) were investigated for one year. Each CW unit has a surface area of 1m² and a depth of 60 cm. The difference between the units is the vegetation. The experiments are conducted on a laboratory scale and outdoors, to investigate also the direct effect of the climate. The purpose is to investigate the CWs performances with two different plant species (Phragmites Australis and Arundo Donax) and plant arrangements (mono-culture and poly-cultures). Since the region of Rabat has a semi-arid climate, plants behave during seasonal changes was explored. The elimination of organic matters showed a seasonal variation in the CW systems, with higher rates during the hot season and lower rates during the cold ones. Planted systems outperformed the unplanted system and the polyculture system was the most effective, reaching removal rates of 99.47%, 99.58%, and 85.64%, for, COD, BOD5, and TSS in the summer season where the temperature reaches its maximum promoting plant growth as well as microbial activity. Anyhow, results showed that the VFCWs used in this study are a successful technology for the region that is cost-effective and requires low energy
Study of Temperature Effect on the Corrosion Inhibition of C38 Carbon Steel Using Amino-tris(Methylenephosphonic) Acid in Hydrochloric Acid Solution
No full textTafel polarization method was used to assess the corrosion inhibitive and adsorption behaviours of amino-tris(methylenephosphonic) acid (ATMP) for C38 carbon steel in 1 M HCl solution in the temperature range from 30 to . It was shown that the corrosion inhibition efficiency was found to increase with increase in ATMP concentration but decreased with temperature, which is suggestive of physical adsorption mechanism. The adsorption of the ATMP onto the C38 steel surface was found to follow Langmuir adsorption isotherm model. The corrosion inhibition mechanism was further corroborated by the values of kinetic and thermodynamic parameters obtained from the experimental data.</jats:p
Introducing Project-Based Climate Education in Moroccan Universities via a New Air Quality Monitoring Network in Rabat
No full textMorocco’s economy has recently seen an unprecedented growth, which made the country emerge into the 5th strongest economy of the African continent. As other countries at the same stage of development, Morocco is also undergoing rapid urbanization, which results in increased anthropogenic air-pollution levels. The geographical location of the country makes it vulnerable to both short and longterm impacts of climate change. Despite the elevated risk and vulnerability, the current air pollution and climate change monitoring strategy of the country needs improvement. The present paper introduces a novel strategy to improve the air quality monitoring system in the capital combined with developing a project-based climate education curriculum, and promises to raise public awareness to the risks related to air pollution and climate change. The sustainability of the project is guaranteed by the low cost of instruments and the educational aspect which ensures that future experts are well-trained for the maintenance of the system that we propose to install
Optimization of Organic Micropollutant Adsorption onto Granular Activated Carbon Using Response Surface Methodology
No full textWater pollution from pharmaceutical and textile industries urgently requires effective treatment solutions due to environmental and health risks. Effective treatment methods are desperately needed for water pollution from the textile and pharmaceutical industries because of the dangers to the environment and human health. To treat these micropollutants, the optimized granular activated carbon (OGAC) produced from olive fruit stones was utilized as an adsorbent in this study. The central composite design (CCD) of response surface methodology (RSM) was statistically used to optimize the operating factors for rhodamine B (RhB) and thiamphenicol (THI) removal efficiency on the optimized granular activated carbon. This study evaluated the influence of factors such as the solution’s pH, initial RhB and THI concentration, and OGAC dose, along with their interactions to model outcomes and determined optimal adsorption conditions on OGAC. The adsorption kinetic data will be analyzed using the intra-particle diffusion, pseudo-second-order, and pseudo-first-order models. Equilibrium data will be analyzed using the Langmuir, Freundlich, Temkin, and Dubinin–Radushkevich isotherms. The adsorption thermodynamics of the various systems under investigation will also be examined. Finally, a study on OGAC regeneration has been conducted. Results showed that THI and RhB removal is primarily influenced by pH, initial pollutant concentration, and dose. RSM indicated the optimal adsorption parameters for THI and RhB on OGAC as pH = 5.7, an initial concentration of C0 = 2.5 mg/L, and a dose of 6 g/L. The kinetic study revealed that THI and RhB retention on OGAC generally follows a pseudo-second-order kinetic model, indicating chemisorption as the primary mechanism controlling adsorption. The adsorption isotherm data analysis showed that chemisorption has a significant role in the THI and RhB adsorption process on OGAC. Furthermore, thermodynamic parameters suggest that THI adsorption on OGAC is exothermic, while RhB adsorption is endothermic. Activated carbon regeneration tests demonstrated its cost-effectiveness, and activated carbon was successfully regenerated over three cycles, achieving efficiencies of 62.39% for RhB and 59.6% for THI. These results demonstrate that the studied OGAC is an effective adsorbent for THI and RhB removal
Introducing Project-Based Climate Education in Moroccan Universities via a New Air Quality Monitoring Network in Rabat
No full textMorocco’s economy has recently seen an unprecedented growth, which made the country emerge into the 5th strongest economy of the African continent. As other countries at the same stage of development, Morocco is also undergoing rapid urbanization, which results in increased anthropogenic air-pollution levels. The geographical location of the country makes it vulnerable to both short and longterm impacts of climate change. Despite the elevated risk and vulnerability, the current air pollution and climate change monitoring strategy of the country needs improvement. The present paper introduces a novel strategy to improve the air quality monitoring system in the capital combined with developing a project-based climate education curriculum, and promises to raise public awareness to the risks related to air pollution and climate change. The sustainability of the project is guaranteed by the low cost of instruments and the educational aspect which ensures that future experts are well-trained for the maintenance of the system that we propose to install
Induced mutagenesis for improving water stress tolerance in durum wheat (Triticumturgidum L. subsp. durum)
No full textOver the Water deficit is considered to be one of the most important limiting factors for crop productivity worldwide. Thus, it is important to use water resources more efficiently. One of the ways to conserve water and respond to the climate change is by using appropriate crop species and cultivars, notably which have low requirements for water.Chemical mutagens have contributed immensely to the development of a wide range of genetic variability and the improvement of several crop plants, including durum wheat. This study has the aim of understanding the effect of water stress on some morpho-physiological parameters and identifying tolerant lines to water stress from an EMS-mutated population in durum wheat. The results, under moderate (T1) and severe (T2) conditions of water stress,show the positive effect of mutagenesis on the population resulting in tolerantmutated linesto water deficit. Compared to the non-mutated, 32.15% of lines have a higher specific leaf weight; 57.14% of lines have a better ability to maintain a high water content and 75% of all lines demonstrate a very high intensity of chlorophyll fluorescence .In sum, this study has revealed the improvement of water stress tolerance in some induced durum wheat mutants
Study of the Electronic, Optical, and Photovoltaic Properties of Lead-Free Double Perovskite Cs₂AgBiCl₆ Through DFT Calculations
No full textInternational audienc
Treatment of brilliant blue by plasma and combination plasma with photocatalysis process intensification
No full textInternational audienceVarious treatment methods are widely used to reduce water pollution. Among these techniques, heterogeneous photocatalysis and non-thermal plasma technologies, notably dielectric barrier discharges, are currently the most suitable for water treatment. However, the use of each of these processes alone presents certain limitations. In this study, the brilliant blue (BB) photo-degradation was investigated via the dielectric barrier discharge (DBD) method. The impact of certain process factors, including the model pollutant's initial concentration (from 5 to 10 mg/L), the airflow rate (240 L/h) as well as the frequency (from 230 to 400 Hz), upon the DBD's performance in terms of bright blue decomposition and mineralisation was assessed. The latter reached 49.5% for 120 minutes, assuming optimised operating parameters (BB initial concentration of 10 mg/L, airflow rated at 240 L/h, 21 kV as an applied voltage at 400 Hz). It could be said that DBD processing has a high ecological potential for the aqueous degradation of BB. Scavenger analysis indicated that the radicals O-2(-and DEG;), HO2 and DEG;, as well as and DEG;OH, represent the underlying oxygen reactive species in the process of brilliant blue decomposition. The study showed that both reactive nitrogen species and ROS contribute to the process of BB removal. For approximating real-life requirements, DBD tests were performed in both tap and synthetic water matrices. The degradation and mineralisation of BBs were significantly inhibited in tap water (% Degradation = 71.3, % Mineralisation = 31.6) and synthetic water (% Degradation = 65.41, % Mineralisation = 12), compared to BB degradation and mineralisation in ultrapure water (% Degradation and GE; 98, % Mineralisation = 49.5), after 120 min of irradiation. This proved that inorganic and organic molecules in tap and synthetic water reduce BB degradation efficiency. Thus, our pollutant was treated by the combination plasma-photocatalysis system using cellulose paper-supported titanium dioxide as a photocatalyst, which showed a significant improvement in BB decomposition efficiency versus considering either separate process
Effect of temperature on corrosion inhibition by ethanolic extract of Eriobotrya Japonica seeds in chloride medium 1M
No full textThis work investigated the effect of temperature on corrosion of C38 steel in a hydrochloric medium (1M) in the absence and presence of the ethanolic extract from Eriobotrya Japonica (ERJ) seeds treated by maceration. For a better understanding of the corrosion process, electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization techniques had applied by increasing the temperature from 303.15 K to 333.15 K. Moreover, studying adsorption isotherms and determining thermodynamic parameters to understand the mechanism adopted in the adsorption of ERJ molecules on the metal surface. The results reveal that the inhibition efficiency increases with higher inhibitor concentration and decreases slightly with increasing temperature. Thus, the Langmuir model is the best model to fit the data obtained, and the adsorption follows a spontaneous physisorption process. According to the evolution of enthalpy, entropy, and activation energy, the inhibition capacity decreases is associated with a slow endothermic dissolution due to forming an active complex on the surface of C38
