Rachid Mamouni

The objective of this study is to develop a calcium carbonate-based adsorbent derived from Cellana Tramoscrica seashells, incorporated into a sodium alginate matrix (Na-Alg@CTs) to form hydrogel beads, for the efficient removal of Cu (II) and Zn (II) heavy metals from aqueous solutions. XRD, SEM/EDS, and FTIR analysis confirm the successful synthesis and characterization of the fabricated adsorbent. The adsorption study of Cu (II) and Zn (II) onto Na-Alg@CTs hydrogel beads revealed that the Langmuir model was the most suitable for characterizing the adsorption isotherms, suggesting monolayer coverage. Na-Alg@CTs exhibited a maximum Langmuir adsorption capacity of 368.58 mg/g and 1075.67 mg/g for Cu (II) and Zn (II), respectively. Additionally, the kinetics followed the pseudo-second-order model, indicating that the adsorption process is primarily governed by chemisorption. The thermodynamic study suggests that the uptake of metal ions on Na-Alg@CTs hydrogel beads is spontaneous and endothermic. The exceptional adsorption capacity, eco-friendly nature, and low-cost characteristics of Na-Alg@CTs hydrogel beads make them an ideal adsorbent for the removal of Cu (II) and Zn (II) from wastewater.

This study focused on optimizing the fermentation-based production of Exopolysaccharides (EPS) from Enterococcus faecium F58 initially isolated from traditional Moroccan Jben, a fresh goat cheese. Using the central composite design, yeast extract, MnSO₄, and time affect EPS concentration. The highest experimental and predicted EPS production yields were 2.46 g/L ± 0.38 and 2.86 g/L, respectively. Optimal concentrations of yeast extract (4.46 g/L) and MnSO4 (0.011 g/L) were identified after 26 h at 30 °C. Characterization of EPS was conducted using SEM with EDX, XRD, and FTIR analyses. These tests revealed a specific morphology and an amorphous structure. Additionally, thermogravimetric analysis indicated adequate EPS stability up to 200 °C with anti-adhesion properties against different pathogens. This study offers valuable insights into the optimized production of EPS from Enterococcus faecium F58, which exhibits significant structural and functional properties for various applications in the food and biotechnology industries.

In arid environments, specifically in Africa, inadequate water sources have resulted in poor-quality water use in business and agricultural industries. This can also negatively impact the ecosystem, along with the industry’s water management. In solar power generation facilities, evaporating basins are usually used to release and store industrial contaminated wastewater. An examination of the environmental implications and concerns of this experience suggests such a form of wastewater discharge to reduce industrial effluents’ direct release into the environment. Unfortunately, this strategy could have far-reaching global environmental consequences and issues. In this research, we examined the evolution of the effluent’s physicochemical characteristics over a long period using a methodological approach for a power station located in Morocco; the findings of this practical study show a significant increase in the physicochemical characteristics of the wastewater released in the evaporating basins, which might be interpreted by an increase in water pollution. The primary objective of this study is to examine wastewater recycling and the generation of treated water in a solar still, utilizing renewable energy to minimize the environmental and ecological problems associated with wastewater discharged into evaporating basins.

In this paper, Cellana tramoserica (CT) shells were modified by copper and used as an adsorbent to remove thiabendazole (TBZ) from aqueous media. The removal efficiency of TBZ onto CT shells and modified Cellana tramoserica (CT-Cu) shells was investigated by considering the following parameters: initial pesticide concentration, solution pH, agitation time, temperature, and adsorbent mass. The experimental results show that the pseudo-first-order and Langmuir models well describe the adsorption process. The maximum adsorption amount for CT and CT-Cu is 319.68 mg/g and 376.12 mg/g, respectively. CT-Cu showed higher TBZ removal efficiency than CT, explained by the ligand exchange between the water and the pesticide molecules in the metal coordination sphere. Response surface methodology combined with central composite design (RSM-CCD) was used to optimize the adsorption conditions. Optimized values were obtained at 5 for pH, 50 ppm, 120 min, and 20 mg of CT-Cu adsorbent. Under these optimal conditions, 91% of TBZ was removed by adsorption onto CT-Cu. Graphical abstract