Résumé: This study introduces α-FeOOH@Luffa, a novel composite for the adsorptive removal of methyl green (MG) from aqueous solutions. Utilizing fractional factorial design (FrFD) and response surface methodology (RSM), we optimized six parameters to enhance the adsorption process. The findings reveal a maximum adsorption capacity of 256.32 mg g⁻1 at an optimal pH of 9 within 60 min. The adsorption behavior aligns with the Langmuir isotherm and follows pseudo-second-order kinetics, indicating strong adsorption dynamics. The process is characterized as exothermic and spontaneous, supported by a high correlation between observed and predicted removal efficiencies (R2 = 98.03%). Furthermore, the composite exhibits excellent regeneration capabilities, maintaining adsorption efficiency across six consecutive cycles. These results underscore the potential of α-FeOOH@Luffa as a cost-effective and eco-friendly solution for wastewater treatment, paving the way for further investigations into its application for other persistent pollutants.

Résumé: This study focused on the synthesis and preparation of cationic and anionic biomaterials. These materials were used as adsorbents in waters polluted by various adsorbates likely to be present in the environment. Using a batch adsorption approach, this work interprets biomass Pumpkin Seed Shells (PS) as an inexpensive, environmentally benign, and promising adsorbent for 4-nitrophenol (4NP) adsorption from aqueous solution. X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, and Brunauer Emmett Teller (BET) spectroscopy were among the methods used to characterize the produced biosorbent. Batch experiments were conducted based on various process factors, such as temperature, pH, concentration, contact time, and material dose. Very excellent results were obtained with a pH of 6.5, a biosorbent dosage of 0.030 g, an initial 4-nitrophenol concentration of 30 mg/L, and a temperature of 25°C.and 298 K, which were ideal for removing 4NP. 97.95% sorption was the maximum. Adsorption data better fit the Freundlich, Temkin, Liu, and Langmuir isotherms. It was demonstrated that the biosorption process is spontaneous and exothermic and that the rate of sorption obeys the Elovich and pseudo-second-order kinetics.This article explains how to create inexpensive, environmentally friendly adsorbents and looks at how well they can remove 4-nitrophenol from wastewater. The unaltered biochar-based pumpkin seed shells were characterized using basic analysis, FTIR, SEM, and BET.

Résumé: The conversion of food and agro-industrial wastes to produce useful products is one of the goals of economic and sustainable development, as also evidenced in the 2030 Agenda for Sustainable Development, adopted by all United Nations Member States in 2015. This work aims to study the transformation of CaCO3 based eggshell waste (ES) into a face centered cubic oxide form (namely, CaO), followed by CuO coating to be used as photocatalytic material (ES@CuO) for fast removal of basic fuchsin (BF) dye from water under visible light. Different ES@CuO samples with different CuO amounts (2.5, 5 and 10%, respectively) and calcined at different temperatures (600, 800, and 1000 °C) were prepared by hydrothermal method. Samples with CuO from medium to high amounts (5 and 10%) demonstrated excellent photocatalytic activity, as compared to low CuO amount (2.5%). In addition, the samples calcined at higher temperature (800 and 1000 °C) exhibited superior degradation rates, reaching 88.11% and 88.33%, respectively. The effect of operating parameters was investigated to understand the behavior of ES@CuO under different conditions. ES@CuO shows rapid removal of BF which combines adsorption and photooxidation, wherein the removal rate reaches up 99% for a BF dye concentration of 100 ppm within 30 min using 75 mg/L of ES@CuO5%. ES@CuO exhibits superior adsorption ability and excellent photoproduced charges transfer which provide synergistic effects to boost the quick removal of dye from water. The finding of this investigation encourages valorizing food wastes into sustainable materials for water remediation. Graphical abstract

Résumé: Over the last decades, the valorization of agro-industrial wastes into adsorbents has received a lot of attention due to the low-cost, high performance and sustainability factors. This work aims to valorize Silybum marianum seed shells (SMSS) as biosorbent for the removal of basic fuchsin dye (BF) from water. The prepared biosorbent from SMSS was characterized to check the morphological and structural proprieties using several techniques including FTIR, XRD, SEM, TGA-DTA, and BET. It was found that SMSS has a fibrous semi-amorphous structure typical of lignocellulosic materials. The study also investigated the impact of numerous operational parameters on basic fuchsin biosorption efficiency, including particle size, biosorbent mass, stirring speed, initial dye concentration, temperature, and pH of solution. Additionally, the research explored the influence of natural water matrices on dye removal. The adsorption performance was found to be higher at basic pH values, reaching 97.50%. The adsorption process was analyzed using different kinetic models, and it was found that the process follows a pseudo-second-order model. The experimental data was thoroughly scrutinized using the Freundlich and Langmuir isotherm models. The results confirm that Langmuir model fits well the BF dye adsorption on SMSS surface. The thermodynamic study revealed that the adsorption process of BF dye onto SMSS was endothermic. Overall, SMSS shows great adsorption ability which might be a good candidate for real wastewater treatment, by considering low-cost and availability of the original waste

Résumé: The current study aims to investigate the elimination behavior of hexavalent chromium from aquatic media by using dry Pomegranate peel powders (PGPs). The pomegranate peels powder used was well prepared and then characterized using various techniques including FTIR, pHpzc , BET, XRD, and SEM–EDX microscopy. A Box–Behnken design was employed to study the influences of four operating factors including solution pH (1–7), PGPs quantity (20 mg–200 mg), Cr(VI) starting concentration (10 mg L− 1–100 mg L− 1) and media temperature (20 °C–50 °C) on the adsorption process, which allows satisfactory removal of Cr(VI) from water media. The highest elimination efficiency (100%) was achieved with an adsorbent amount of 152.08 mg in medium highly acid (pH 1) at a temperature of 50 °C and a Cr(VI) initial dose of 100 mg L− 1, with a maximum adsorbent loading of 25.74 mg g− 1. The non-linear kinetic modelling study showed that the adsorption kinetics of Cr(VI) obey a pseudo-second order model. The thermodynamic investigation shows that the removal process is exothermic, spontaneous and of a stable configuration. Keywords Cr(VI) · Experimental design · Optimization · Adsorption · Nonlinear kinetic modelling · Pomegranate peels

Résumé: Affordable bioadsorbents to eliminate medication, colorants, and heavy metals.

Résumé: Application des nanoparticules à base de kaolin pour l’élimination des colorants en milieu aqueux