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This paper evaluates the ability of a natural rock found in Morocco to remove the pollutant properties of methylene blue (MB) dye. In this regard, the experiments were conceived to test the hypothesis that the rock native of the country’s region of Khenifra can be used as a new abundant adsorbent to remove cationic dyes from water through the adsorption technique in order to avoid extra cost and contribute to the valorization of this material. For this, several factors such as pH of the solution, granulometry, mass of adsorbent, initial dye concentration and stirring rate were tested. The adsorption kinetics process was tested through three models, namely, the pseudo-first-order model, pseudo-second-order model and the intraparticle diffusion model, to predict which type of adsorption is best suited in the removal of dye pollution.The batch study proves that only the granulometry (G ≤ 63µm = 91%, G ≤ 80µm = 88.4% and G ≤ 100µm=70.7%) and the adsorbent mass (the more the mass of the adsorbent increases the more the elimination is achieved) can influence the elimination rate of our rock. Meanwhile, the data of the adsorption kinetics test show that the experimental adsorption could be described by the mechanism of the pseudo-second-order model (correlation coefficients near the unit ‘R2 = 0.99’ ), confirming chemical sorption as a rate-limiting step of the intraparticle diffusion mechanism.According to the results of this study, the rock collected from the area of Khenifra can be used as a new and efficient adsorbent in the field of wastewater treatment.

A serious environmental disaster is looming on the horizon due to the indiscriminate release of heavy metals into the soil and wastewater from human industrial practices. In this study, waste mint (WM) was used to remove chromium(VI) from aqueous solution using batch experiments. The adsorbent material (WM) was characterized using scanning electron microscopy coupled with energy dispersive analysis of X-ray spectroscopy (SEM-EDS), Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and thermal gravimetric analysis (TGA). The adsorption parameters optimized were as follows: pH solution (2–11), initial concentration of Cr(VI) (10–50 mg/L), adsorbent dose (0.1–10 g/L), and temperature conditions (298 K, 308 K, and 318 K). The experimental data fitted well to the fractional power kinetic model (0.97≤R2≤ 0.99) and Langmuir isotherm (R2 = 0.984) with a maximum adsorption capacity Qmax = 172.41 mg/g. The thermodynamic parameters for Cr(VI) sorption were also calculated, confirming that the adsorption process was spontaneous and accompanied by an exothermic adsorption (−4.83 ≤ ΔG ≤ −3.22 kJ/mol and ΔH = −28.93 kJ/mol). The Cr(VI) removal percentage was within the range of 41–98%, and the highest removal was noted at pH = 2. The results of the present study suggest that WM is a potential low-cost adsorbent for the removal of chromium(VI) from aqueous solutions.

The objective of this study was to investigate the possibility of using mint waste as a bioadsorbent for the removal of dye (Methylen Blue) from aqueous solutions. Batch adsorption studies were carried out by monitoring the pH, the bio-adsorbent dose and the initial dye concentration. Attempts have also been made to monitor the adsorption process through Langmuir, Freundlich, Dubinin-Radushkevich, and Temkin adsorption isotherm models. These results have demonstrated the immense potential of mint waste as a bioadsorbent for dyes remediation in polluted water and wastewater. Finally followed by the process of adsorption phenomenon was achieved by fourier transform infrared spectrometer (FTIR), the results shows that the adsorption is mechanical trapping.

The effect of extract of brown alga Bifurcaria bifurcata (Bb) on the corrosion of steel in 1 M HCl solution was studied using weight loss, potentiodynamic, and polarization resistance measurements. Experimental data revealed that Bb extract acted as an inhibitor in the acid environment. The extract was a mixed-type inhibitor, predominating as an anodic inhibitor at higher concentration. It was found that the inhibition efficiency increased with an increase in Bb extract concentration. The corrosion inhibition of Bb extract on carbon steel in 1 M HCl solution was also investigated by infrared and UV-visible spectrophotometry to obtain information on bonding mechanism between the metallic surface and the inhibitor. The process of inhibition is attributed to the adsorption of the extract molecules, the precipitation of Fe-chelates, and/or formation of complex at the electrode surface.