This study investigates the possibility of applying an adsorption process using two abundant natural minerals M1 and M2. Without pretreatment or activation, the adsorbents were used to treat real textile wastewater samples (collected from Fez city, Morocco). As a cost-effective alternative, these materials were characterized by different analyses, including X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and X-ray fluorescence (XRF). Chemical oxygen demand (COD) and biological oxygen demand (BOD) were used to characterize the textile wastewater. Additionally, the influence of operating conditions (contact time, adsorbent dosages, and pH) was evaluated. Results show that the adsorption process takes place quickly, reaching the equilibrium at 90 and 160 min for M1 (88% COD) and M2 (79% COD). Both materials show a higher affinity to Cr (39%) and lower affinity to Cu (28%). A pseudo-second-order kinetic model provides the best fit to the experimental adsorption data. Germination tests indicate a low toxicity after the adsorption process. Performance of both materials was compared with that of other literature studies.

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Adsorption Studies on the Removal of Textile Effluent over Two Natural Eco-Friendly Adsorbents

This research aims to assess the employability of fava bean peels (FBP) as low-cost adsorbents in the removal of Brilliant Green (BG) and Eriochrome Black T (EBT) from aqueous solutions and therefore in colored wastewater treatment. Scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR), and pHPZC were used to characterize these materials. The constants of Langmuir, Freundlich, and Dubinin-Radushkevich have all been determined. The adsorption capacity of BG and EBT was 28.14 and 7.91 mg g–1, respectively, at 5 g L–1 FBP dose, 40 mg L–1 initial dye concentration, temperature 20°C, and contact time BG (80 min) and EBT (40 min). The calculated thermodynamic parameters indicated that adsorption of BG was endothermic and exothermic for EBT. The isotherm studies show that the adsorption experimental data of both dyes are fitted well by the Freundlich isotherm model. The adsorption of the two dyes studied on fava bean peels is perfectly described by a pseudo-second-order kinetic model. Cyclic experiments have indicated that the current bio-adsorbent can be effectively reused to remove BG and EBT from aqueous solutions. Removal efficiencies remained above 84% and 10% for BG and EBT respectively even after four adsorption–desorption cycles. As a consequence of these relevant results, our inexpensive and environmentally friendly material could provide enormous application prospects in large-scale wastewater treatment in the industrial level.

Assessment of Brilliant Green and Eriochrome Black T dyes adsorption onto fava bean peels: kinetics, isotherms and regeneration study

Copper nickel co-impregnation of Moroccan yellow clay as promising catalysts for the catalytic wet peroxide oxidation of caffeine.

Solution combustion synthesis of β-Cu2V2O7 nanoparticles: photocatalytic degradation of crystal violet under UV and visible light illumination

In this study, natural Algerian kaolin was used as a support and impregnated with nickel at different loading amounts (2 wt.%, 5 wt.%, and 7 wt.%) in order to prepare a supported catalyst. The wet impregnation technique was used in this preparation; nickel oxide (NiO) was the active phase precursor of the catalyst, and the catalysts were designated as follows: 2%, 5%, and 7% Ni/kaolin. These catalysts were put to the test in catalytic wet peroxide oxidation (CWPO) for degrading the organic contaminant malachite green dye (MG). Analytical techniques such as FTIR spectroscopy, X-ray diffraction, BET, and X-fluorescence were used to examine the structure, morphology, and chemical composition of the support and the produced catalysts. Several parameters, including temperature, catalytic dose, metal loading, hydrogen peroxide volume, and kinetic model were systematically investigated. The combination of improved parameters resulted in a significant increase in the catalytic activity, achieving a high removal rate of MG dye of 98.87%.

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Removal of Malachite Green Dye from Aqueous Solution by Catalytic Wet Oxidation Technique Using Ni/Kaolin as Catalyst

The aim of this study is to find an effective and inexpensive natural material used as an adsorbent for the textile dyes removal. Indeed, we have been interested in testing the effectiveness of sugarcane bagasse (SB) as a biosorbent to remove brilliant green (BG) and eriochrome black T (EBT). In our experiments, different parameters such as initial dye concentration, contact time, adsorbent dose and solution temperature have been analyzed in a batch system. Similarly, the studies of thermodynamic, kinetic and adsorption isotherm have been evaluated. The sugarcane bagasse (SB) without any modification has been characterized by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The maximum adsorption capacity of BG and EBT on the SB adsorbent has been 37.58 and 12.30 mg.g -1 respectively, for a concentration of 40mg.g -1 at a temperature of 20°C and 1g.L -1 of adsorbent. The results of the adsorption kinetics have proved that the pseudo-second order model correctly describes the adsorption phenomenon of the two dyes studied. The Langmuir and Freundlich isotherms have been applied to experimental equilibrium data. The various thermodynamic parameters such as Gibbs free energy (ΔG°), enthalpy (ΔH°) and standard entropy (ΔS°) have indicated that the adsorption is spontaneous and endothermic in brilliant green and exothermic in eriochrome black T.

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Kinetic and thermodynamicstudy of the adsorption of twodyes:brilliant green and eriochrome black T using a natural adsorbent "sugarcane bagasse".

Promising catalyst of cooper impregnated on natural material (CT) synthesized via wet impregnation method, in order to enhance the catalytic wet peroxide oxidation during the degradation of organic matter in a batch reactor under mild conditions. Three different percentages of copper metal (2.5, 5 and 7.5 %) incorporated into CT material which are referred as follows 2.5% Cu-CT, 5% Cu-CT and 7.5% Cu-CT were investigated in the oxidation catalytic of methyl green (MG) dye. The chemical composition, the morphology and the structure of raw CT and all prepared samples, were investigated by X-ray fluorescence, Fourier transform infrared spectroscopy, X-ray diffraction (XRD) and scanning electron microscopy (SEM) to get a better understand concerning the catalytic activity behavior of Cu-CT catalyst. Different variable examined the catalytic activity of the samples obtained such as initial concentrations of dye, copper (Cu) loading, temperature and H 2 O 2 effect was investigated to enhance the MG conversion. CWPO experiments showed that 2.5% Cu-CT catalysts have the maximum catalytic activity during the degradation of MG dye. The presence of copper on CT support ameliorates the hydroxyl radicals in the reaction medium after the contact with H 2 O 2 thus enhanced the catalytic conversion of the CT pristine. The optimum conditions showing an important catalytic conversion of MG dye (95 %) at 2.5% of copper loading, 139.10 -3 mol.L -1 H 2 O 2, temperature of 40 °C and at pH 6.0 during  30 min as a reaction time.

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B. El Khazzan

Papers

Kinetic and thermodynamicstudy of the adsorption of twodyes:brilliant green and eriochrome black T using a natural adsorbent "sugarcane bagasse".

Copper-impregnated on natural material as promising catalysts for the wet hydrogen peroxide catalytic oxidation of Methyl Green