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This work aimed to study the seasonal impact on the pollutant removal efficiency of constructed wetland (CW) units that 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 1 m² and a depth of 60 cm. The difference between the units is the vegetation. The experiments were conducted on a laboratory scale and outdoors to investigate the direct effect of climate. The purpose of this study was to investigate the performance of CWs with two different plant species (Phragmites australis and Arundo Donax) and plant arrangements (monoculture and polyculture). Since the region of Rabat has a semiarid climate, plants that behave during seasonal changes were explored. The elimination of organic matter showed seasonal variation in the CW systems, with higher rates occurring during the hot season and lower rates occurring during the cold season. The planted system 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, respectively, in the summer season where the temperature reached its maximum, promoting plant growth as well as microbial activity. The results showed that the VFCWs used in this study are a successful technology for regions that are cost-effective and require little energy.

Morocco, like other arid and semi-arid countries, faces a growing water shortage, necessitating the exploration of alternative solutions. This study investigates the potential use of untreated urban wastewater for irrigation and environmental impact mitigation, focusing on El Jadida as a case study. Throughout the year 2023, from January to December, a comprehensive characterization of physico-chemical, heavy metal, and biological parameters of this unconventional water source was conducted to account for seasonal variations, particularly between rainy and sunny periods. Samples were collected at the inlet of the El Jadida wastewater pre-treatment plant (WWTP) to assess the city's net pollution levels. Results indicate high values for chemical oxygen demand (COD = 741 mg/L), biological oxygen demand (BOD5 = 344 mg/L), organic load (BOD5/COD ratio = 2.2), and biodegradability, suggesting a strong need for biological treatment. Despite compliance with discharge standards, concentrations of heavy metals such as mercury (Hg), cadmium (Cd), aluminum (Al), manganese (Mn), and fluoride ions (F-) exceed Moroccan irrigation water quality thresholds by 90%, 66.7%, 21.8%, 33.3%, and 86.1%, respectively. Therefore, advanced chemical treatment is highly recommended to mitigate environmental impact and ensure safe reuse for irrigation. The novelty of this study lies in evaluating the suitability of El Jadida's wastewater for irrigation and environmental impact mitigation, underscoring the critical need for effective treatment solutions to enhance water sustainability in Morocco. Future research will focus on optimizing water treatment processes.

Calcium molybdate (CaMoO4) is of significant interest due to its unique properties and numerous industrial applications, such as catalysis, electrochemistry, and optoelectronics. In this study, we developed an economical and environmentally friendly method to synthesize calcium molybdate from Moroccan phosphogypsum (PG) industrial waste and sodium molybdate, all at room temperature. Comprehensive analysis through X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Raman vibrational spectroscopy, and scanning electron microscopy (SEM) revealed the high purity of the synthesized calcium molybdate, with particle sizes of only 12 nm. Additionally, optical characteristics were studied using ultraviolet-visible spectroscopy (UV-vis), which showed an optical band gap of Egap = 3.96 eV for CaMoO4. These results confirm the successful synthesis of calcium molybdate nanoparticles from Moroccan phosphogypsum, demonstrating an effective pathway to valorize this industrial waste into a valuable material. This approach contributes to environmental sustainability by reducing dependence on rare chemicals while offering innovative solutions for the industry’s sustainable development.

A novel synthesis process and characterization of nano-Calcium fluoride(n-CaF2) single crystal prepared from phosphogypsum waste. The phosphogypsum (CaSO4,•2H2O) powder has been mechanically mixed with NH4F in presence of a controlled amount of water. The mixture still sintered for 48 hours until the formation of nano Calcium fluoride particles. The n-CaF2 particles have been characterized by several techniques, The techniques utilized included X-ray diffraction (XRD), infrared spectroscopy (IR), and scanning electron microscopy (SEM).Therefore, it was confirmed that very pure n-CaF2 was obtained with a Ca / F ratio of 0.5 and an average crystalizing size measured according to the Debye-Scherrer equation of 11 nm. Based on the findings reached, The characterization data revealed successful synthesis of n-CaF2 from phosphogypsum. Additionally, the adsorption performance of the elaborated n-CaF2 was tested in Reactive Blue 21 (RB21) anionic dye removal, Adsorption tests were conducted in a batch reactor, focusing on key factors such as contact time, which can significantly influence the adsorption results. adsorption amount, pH, and dye concentration were tested. Hence results show an important adsorption performance of n-CaF2 with Reactive Blue 21 removal rate up to 90%.

A novel method has been explored based on the recovery of two industrial wastes V2O5 and phosphogypsum from the fertilizer production industry, which also provide a significant challenge due to their toxicity and environmental impact. To solve the problem of these two harmful wastes, these residues have been transformed into valuable resources, by the elaboration of Nanoparticles vanadate-hydroxyapatite (NPs-HAP/VAP) adsorbent, contributing a sustainable solution without requiring expensive or highly skilled work. This comprehensive investigation explores the adsorption of the reactive red 141 dye (RR 141) on Ca10(VO4) x(PO4)6−x(OH)2, with (xi = 0, 1.5, 3, 4.5, and 6). Using a Centered Composite Design (CCD), several parameters influencing the adsorption process were examined. The optimal adsorption capacity is 50 mg. g-1 under optimal conditions 57.5 mg of the adsorbent dose, 152.5 mgL-1 for the RR 141, pH 8, 92.5 minutes of contact time, and incorporation ratio of 4.5 with an R2 of 0.99. These results reinforce the effectiveness of our chosen CCD model. Kinetic analysis demonstrated a pseudo-order reaction model with an R2˃0.92, while the Sips isotherm describes the adsorption process. Thermodynamic studies revealed spontaneous adsorption, suggesting a physical character enhanced by a positive entropy variation.

Agricultural residue emerges as a cost-effective and readily available option for the adsorption of dyes, owing to its affordability and efficacy. The purpose of our study focuses on the methylene blue dye (MB) removal using chemically modified jujube stone (MJS) as an adsorbent. The MJS underwent characterization through multiple methodologies including scanning electron microscopy (SEM), Energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). The research systematically investigated contact time, PH, temperature, initial dye concentration, and adsorbent dosage impact to optimize the removal efficiency. Experimental findings demonstrated that the MJS adsorbent achieved a dye removal efficiency of approximately 94% under batch mode and room temperature conditions. Kinetic analysis revealed an equilibrium time of around 70 minutes. Remarkably, this study unveils the novel application of chemically customized jujube stone a highly effective adsorbent for removing methylene blue dye. Applying the pseudo-second-order model provides the most precise description for methylene blue (MB) adsorption onto MJS. The modeling of adsorption isotherms indicated conformity to the Langmuir model. The thermodynamic study shows a negative value of ΔG, which demonstrates spontaneous MB adsorption into MJS, while a positive value of ΔH implies an endothermic adsorption process.

This study investigates a controlled synthesis and particle size optimization of nanocalcite particles using phosphogypsum, a waste byproduct from the phosphate fertilizer industry, and cesium carbonate (Cs2CO3), a common carbonate source. The effects of synthesis parameters, including temperature and pH, on the size, morphology, and crystallinity of the synthesized nanocalcite particles were systematically examined. The optimized synthesis conditions for obtaining nanocalcite particles with desired properties are discussed. The synthesized nanocalcite particles were characterized using various techniques, such as XRD, FTIR, and SEM, to analyze their crystal structure, morphology, and elemental composition. Particle sizes were determined using the Debye–Scherrer method, and accordingly, nanometric sizes were achieved. The potential applications of the synthesized nanocalcite particles in cementitious materials, agriculture, and drug delivery are highlighted. This research provides valuable insights into the sustainable synthesis and size optimization of nanocalcite particles from phosphogypsum and Cs2CO3 at a controlled temperature and pH.

Au Maroc, La tuberculose sévit à l’état endémique, la localisation oculaire est une manifestation rare de la maladie. L’uvéite reste l’atteinte la plus fréquente au cours de la tuberculose oculaire. L’immunodépression d’origine infectieuse par le virus HIV ou d’origine iatrogène par corticothérapie au long cours sont parmi les raisons de la recrudescence de cette maladie. Le diagnostic Positif reste difficile en l’absence de lésions accessibles à une étude histologique, d’où l’intérêt d’y penser devant une uvéite. Il s’agit d’une étude rétrospective concernant 4 patients reçus dans notre service entre 2006 et 2010. Les principaux signes d’appel étaient la baisse d’acuité visuelle, la douleur et la rougeur oculaire. Sur les 4 cas de tuberculose oculaire on retrouve une notion de contage tuberculeux dans 1 cas et une tuberculose extra-oculaire dans 1 cas. Le diagnostic est posé sur l’aspect clinique et sur un faisceau d’arguments para cliniques. Le traitement anti bacillaire a été institué chez tous les malades avec un traitement anti-inflammatoire stéroïdien dans 2 cas. L’évolution a été favorable dans 3 cas. La tuberculose atteint au Maroc environ 30000 nouveaux cas par an. La localisation oculaire n’est pas exceptionnelle et peut se voir dans le cadre d’une primo-infection ou de lésions secondaires à une tuberculose générale. L’atteinte de l’uvée est la manifestation la plus fréquente. Le diagnostic de tuberculose oculaire se base sur des éléments de présomption que sont les critères anamnestiques, les lésions extra oculaires, la positivité de l’IDR, la positivité de la recherche du génome du BK par méthode de polymérase chain réaction (PCR) au niveau de l’humeur aqueuse. Le diagnostic différentiel se fait avec la sarcoïdose et la toxoplasmose. Le traitement des uvéites d’origine tuberculeuse comprend, en plus des anti bacillaires, un traitement à base de corticoïdes.

Introduction : La sarcoïdose est une granulomatose multisystémique d’étiologie inconnue. Ses manifestations ophtalmologiques sont polymorphes et toutes les structures du globe oculaire peuvent être atteintes. But du travail : Exposer les aspects épidémiologiques, cliniques, thérapeutiques et pronostiques des atteintes oculaires au cours de la sarcoïdose. Matériel et méthodes : Il s’agit d’une étude rétrospective concernant 31 globes oculaires (16 patients dont 15 présentant une atteinte bilatérale), suivis dans notre service de janvier 2007 à décembre 2011. Résultats : La moyenne d’âge était de 35 ans (extrêmes : 27 – 48ans) avec une prédominance féminine (78%). Tous les patients ont bénéficié d’un examen ophtalmologique complet, d’un examen général (collaboration avec l’interniste) et d’un bilan para clinique (bilan d’uvéite, IDR à la tuberculine, recherche de syndrome sec).L’acuité visuelle initiale était variable. L’examen au biomicroscope a trouvé des précipités rétrodésmetiques en graisse de mouton dans 43,7% des yeux, une pars planite dans 18,7% des yeux, un syndrome sec associé chez 25% des patients, une hypertrophie des glandes lacrymales dans 18,7% des cas, une vascularite rétinienne chez un patient et un oedème papillaire chez une patiente. Une tumeur conjonctivale a révélé la maladie chez une patiente. Le traitement était à base de corticoïdes systémiques et/ou topiques . Discussion : L’atteinte ophtalmologique survient dans 25 à 50 % au cours de la sarcoïdose systémique, elle peut être inaugurale ou précède de plusieurs années l’atteinte pulmonaire.Elle touche surtout l’adulte jeune entre 20 et 30 ans de sexe féminin.Toutes les structures oculaires peuvent être atteintes.L’uvéite antérieure est la plus fréquente (66 à 85 %). La conjonctive et la glande lacrymale sont deux localisations particulièrement fréquentes. L’atteinte du segment postérieur est rare (vascularite, granulome choroïdien, oedème maculaire, oedème papillaire…) et évolue sur un mode chronique et conditionne le pronostic visuel. Le diagnostic de présomption nécessite un faisceau d’arguments cliniques et para cliniques et le diagnostic de certitude sur la présence d’un granulome épithélioide gigantocellulaire non caséeux. Le traitement repose, selon les cas, sur la corticothérapie au long cours, les immunosuppresseurs ou l’abstention thérapeutique. Conclusion : Les atteintes oculaires au cours de la sarcoïdose sont polymorphes. Les atteintes conjonctivales et lacrymales sont bénignes et d’une grande aide diagnostique. Le pronostic fonctionnel est en rapport avec les uvéites et l’atteinte neuro-ophtalmologique.

Wood wastes have been widely studied for their adsorption properties in recent years. Researchers have mainly been interested in Atlas cedar sawdust. The present work studies four adsorbents after different extraction (hydrodistillation, soxhlet, maceration, and ultrasound) for methylene blue adsorption. The points discussed concern the operating conditions used during adsorption, thermodynamic, kinetic and other models describing the adsorbent-adsorbate system, and the effect of the main operating parameters (adsorbate concentration, treatment pH, and adsorbent concentration) was investigated using the full factorial design. The best adsorbent is the residue of sawdust generated after extraction via maceration: the yield of methylene blue adsorption is 98.42 % and the adsorbed quantity (Qads = 7.84 mg/g) is close to that of powdered activated carbon used for comparison (Qads = 9 mg/g). According to the kinetic result, the second order describes well the adsorption of MB onto the four types of Cedar Sawdust. The thermodynamic study confirms the physisorption process in which the enthalpy was found low to 40 kJ·mol−1.

A novel organometallic complex adsorbent was synthesized owing to a co-precipitation reaction of iron extracted from pyrrhotite ash residues of the mining activities, catechin extract from green tea, and propylene glycol. Hereafter, the adsorbent (catechin-PG-Fe) was characterized by X-ray diffraction, FTIR, SEM, PZC, and N2 adsorption–desorption. Catechin-PG-Fe shows spherical-like iron oxide nanoparticles of 80 nm dispersed on an amorphous surface, while the specific area was revealed to be significant (230.82 m2/g). Catechin-PG-Fe was then tested for adsorption of Reactive Yellow 145 Azo Dye. The uptake capacity was optimized by the central complex design and response surface methodology, where four adsorption parameters have been considered, including pH (1–5), adsorbent dose (0.6–1.4 g/L), dye concentration (20–260 mg/L) and time (50–250 min). Hence, the adsorbent shows an important capacity for Reactive Yellow 145 of 345.41 mg g−1 at optimum conditions of pH = 1, adsorbent dose = 0.6 g/L, dye concentration = 260 mg/L, and a contact time of 200 min. The experimental data are best fitted to the second-order model, while the equilibrium data fit well to the Freundlich model, which reflects multilayer adsorption on the heterogeneous surface. A comparison within intraparticle and Boyd’s diffusion models confirmed that film diffusion is the rate-limiting step.

This 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. [ABSTRACT FROM AUTHOR]

Morocco, like other arid and semi-arid countries, faces a growing water shortage, necessitating the exploration of alternative solutions. This study investigates the potential use of untreated urban wastewater for irrigation and environmental impact mitigation, focusing on El Jadida as a case study. Throughout the year 2023, from January to December, a comprehensive characterization of physico-chemical, heavy metal, and biological parameters of this unconventional water source was conducted to account for seasonal variations, particularly between rainy and sunny periods. Samples were collected at the inlet of the El Jadida wastewater pre-treatment plant (WWTP) to assess the city's net pollution levels. Results indicate high values for chemical oxygen demand (COD = 741 mg/L), biological oxygen demand (BOD5 = 344 mg/L), organic load (BOD5/COD ratio = 2.2), and biodegradability, suggesting a strong need for biological treatment. Despite compliance with discharge standards, concentrations of heavy metals such as mercury (Hg), cadmium (Cd), aluminum (Al), manganese (Mn), and fluoride ions (F-) exceed Moroccan irrigation water quality thresholds by 90%, 66.7%, 21.8%, 33.3%, and 86.1%, respectively. Therefore, advanced chemical treatment is highly recommended to mitigate environmental impact and ensure safe reuse for irrigation. The novelty of this study lies in evaluating the suitability of El Jadida's wastewater for irrigation and environmental impact mitigation, underscoring the critical need for effective treatment solutions to enhance water sustainability in Morocco. Future research will focus on optimizing water treatment processes. [ABSTRACT FROM AUTHOR]

Calcium molybdate (CaMoO4) is of significant interest due to its unique properties and numerous industrial applications, such as catalysis, electrochemistry, and optoelectronics. In this study, we developed an economical and environmentally friendly method to synthesize calcium molybdate from Moroccan phosphogypsum (PG) industrial waste and sodium molybdate, all at room temperature. Comprehensive analysis through X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Raman vibrational spectroscopy, and scanning electron microscopy (SEM) revealed the high purity of the synthesized calcium molybdate, with particle sizes of only 12 nm. Additionally, optical characteristics were studied using ultraviolet-visible spectroscopy (UV-vis), which showed an optical band gap of Egap = 3.96 eV for CaMoO4. These results confirm the successful synthesis of calcium molybdate nanoparticles from Moroccan phosphogypsum, demonstrating an effective pathway to valorize this industrial waste into a valuable material. This approach contributes to environmental sustainability by reducing dependence on rare chemicals while offering innovative solutions for the industry's sustainable development. [ABSTRACT FROM AUTHOR]

A novel synthesis process and characterization of nano-calcium fluoride (n-CaF2) single crystal prepared from phosphogypsum waste. The phosphogypsum (CaSO4·2H2O) powder has been mechanically mixed with NH4F in presence of a controlled amount of water. The mixture still sintered for 48 hours until the formation of nano calcium fluoride particles. The n-CaF2 particles have been characterized by several techniques, The techniques utilized included X-ray diffraction (XRD), infrared spectroscopy (IR), and scanning electron microscopy (SEM). Therefore, it was confirmed that very pure n-CaF2 was obtained with a Ca/F ratio of 0.5 and an average crystalizing size measured according to the Debye-Scherrer equation of 11 nm. Based on the findings reached, The characterization data revealed successful synthesis of n-CaF2 from phosphogypsum. Additionally, the adsorption performance of the elaborated n-CaF2 was tested in Reactive Blue 21 (RB21) anionic dye removal, Adsorption tests were conducted in a batch reactor, focusing on key factors such as contact time, which can significantly influence the adsorption results. adsorption amount, pH, and dye concentration were tested. Hence results show an important adsorption performance of n-CaF2 with Reactive Blue 21 removal rate up to 90%. [ABSTRACT FROM AUTHOR]

In this work, we investigate the electrical and the optical properties of a new series of four acceptor–donor-acceptor oligothiophenes. In particular, we study the optimized geometries, the natural bond orbital (NBO) analysis, the nonlinear optical (NLO) properties, the Mulliken atomic charges, absorption spectra, and the electronic properties of such molecules using time-dependent density functional theory (TD-DFT) computations at the B3LYP/6-31G(d,p) level. Among others, we find that the resulting low energy band gap (Egap) values from the computed HOMO and LUMO frontier orbital energies can be supported by the NBO evaluation and good NLO response, including the large values of the first-order hyperpolarizability (β).

Agricultural residue emerges as a cost-effective and readily available option for the adsorption of dyes, owing to its affordability and efficacy. The purpose of our study focuses on the methylene blue dye (MB) removal using chemically modified jujube stone (MJS) as an adsorbent. The MJS underwent characterization through multiple methodologies including scanning electron microscopy (SEM), Energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). The research systematically investigated contact time, PH, temperature, initial dye concentration, and adsorbent dosage impact to optimize the removal efficiency. Experimental findings demonstrated that the MJS adsorbent achieved a dye removal efficiency of approximately 94% under batch mode and room temperature conditions. Kinetic analysis revealed an equilibrium time of around 70 minutes. Remarkably, this study unveils the novel application of chemically customized jujube stone a highly effective adsorbent for removing methylene blue dye. Applying the pseudo-second-order model provides the most precise description for methylene blue (MB) adsorption onto MJS. The modeling of adsorption isotherms indicated conformity to the Langmuir model. The thermodynamic study shows a negative value of ΔG, which demonstrates spontaneous MB adsorption into MJS, while a positive value of ΔH implies an endothermic adsorption process. [ABSTRACT FROM AUTHOR]

In this work, vanadate-fluorapatite, V2O5/Ca10(PO4)6F2, nanocrystals were successfully synthesized through a straightforward one-step co-precipitation method. This method was based on two toxic solid wastes, which are mainly generated as by-products during sulfuric acid manufacturing and in the phosphate industry. The two solid wastes were mainly based on phosphogypsum as a source of calcium and vanadium pentoxide as a source of vanadate. In comparison to numerous conventional methods for FAP synthesis, this innovative method is not laborious, not complex, cost-effective, and environmentally friendly, thanks to the recovery of toxic solid wastes. Furthermore, it consists of mixing various contents of anhydrous gypsum with phosphoric acid, vanadium pentoxide, and ammonium fluoride at one time and at room temperature with no further adjustment of the pH. Several physicochemical characterization techniques were used, including X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FT-IR), and Ultraviolet-Visible Spectroscopy (UV-vis). Whereas SEM analysis of the crystals obtained showed a nanometer-scale fluorapatite crystallites was obtained. The obtained results offer exciting potential for applying the prepared nanomaterial in both photocatalysis and pollution removal. They hold great promise and are expected to generate significant interest in these fields. [ABSTRACT FROM AUTHOR]

In this work, we examine the performance of novel dyes as photosensitizers in dye-sensitized solar cells. We use density functional theory calculations to explore the energy levels, absorption wavelengths, and photovoltaic characteristics of these dyes. The calculated energy levels show appropriate alignment with electron transport layers, guaranteeing efficient charge injection and reducing energy losses. These dyes also exhibit absorption wavelengths in the visible range, indicating that they are capable of efficiently harnessing solar energy. Analysis of their photovoltaic properties has demonstrated their potential in terms of the open circuit voltage. The dyes show favorable properties, making them potential candidates for efficient light absorption and electron transfer in dye-sensitized solar cells. These results underline the need to include them in future dye-sensitized solar cells research and provide interesting pointers for the design and optimization of efficient photosensitizers. [ABSTRACT FROM AUTHOR]