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The anticorrosive performance of two acrylic polymers (PANa) and (PAA) on smild steel in the 0.1 M hydrochloric acid medium was investigated using numerous techniques, such as weight loss, potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), Scanning electron spectroscopy (SEM), Energy-dispersive X-ray Analysis (EDAX), and DFT simulation. The obtained results through all tested methods are in good agreement. The polarization curves revealed that PANa and PAA belonged to mixed-type inhibitors. The influence of temperature on the corrosion of mild steel in 1.0 M HCl was also studied. The adsorption of PANa and PAA on mild steel surface in the studied medium follows the Langmuir isotherm. Scanning electron spectroscopy and Energy-dispersive X-ray analyses were carried out in order to study the mechanism which controls the corrosion inhibition of mild steel. Theoretical calculations realized using density functional theory (DFT), molecular dynamic (MD), and Monte Carlo (MC) simulations explored the most reactive sites of the investigated polymers.

The adsorption of methyl orange (MO) dye by artificial zeolites beads, used previously in the removal of heavy metal through the ionic exchange process, has been studied. The effect of several parameters such as temperature, MO concentration, and zeolite mass on MO adsorption was tested in order to determinate optimal conditions. All results have shown that the adsorption process was influenced by the studied parameters. The kinetic data concerning the study of temperature effect was modeled through pseudo-first-order and pseudo-second-order to determinate the adsorption mechanism. Thermodynamic parameters were calculated using the Van’t Hoff equation. Also, they have shown that the studied process has an endothermic, stable and spontaneous nature.

The present work aims the elimination of an organic dye Methylene Blue (MB) by adsorption on the polyacrylamide (PAAM) hydrogel. Several experiments series were then carried out in order to study the influence on the adsorption capacity of certain parameters such as the mass of the adsorbent, the pH, the contact time, the initial dye concentration and the temperature. The maximal capacity is 1620 mg/g it was obtained at T = 25°C, pH = 6, [BM] = 200 ppm and 0.013g of the adsorbent. The adsorption kinetics of the dye on the support is well described by the first-order model. The adsorption isotherms of the adsorbent/adsorbate systems studied are satisfactorily described by the Langmuir mathematical model. On the other hand, the thermodynamic study revealed that adsorption is spontaneous and endothermic.

Coriandrum Sativum seeds (CSS), were tested as a new eco-friendly adsorbent of copper ions from aqueous solutions. Hence, the effect of the most influencing experimental parameters such as initial concentration of Cu (II) and the temperature was studied upon the adsorption process in order to use its results in following studies. Lagergren pseudo-first-order, pseudo-second-order, and Intraparticle diffusion models were used to describe the biosorption kinetics. The adsorption process was also analyzed by Langmuir, Freundlich and Temkin models and the maximum monolayer biosorption capacity of CSS was found to be 33,5 mg. g −1 by using the Langmuir model. So as to investigate the thermodynamic properties of the adsorption process, the Gibbs free energy ( Δ G°), enthalpy ( Δ H°), and entropy ( Δ S°) values in the temperature range of 25-55 C ° were also calculated in order to conclude the process characteristics. SEM and EDAX analysis were effectuated in order to study the surface morphology of CSS before and after the adsorption process.

Coriandrum sativum seeds (CSS) were investigated as a new eco-friendly and economic biosorbent for the removal of methylene blue (MB) dye from synthetic solutions. First, the spectroscopic analyses were effectuated using FTIR and SEM to confirm the possibility of CSS to remove MB dye from aqueous solutions. The study of the influence of different parameters, such as contact time, CSS mass, solution pH, MB concentration, and temperature was realized and proved the rapid and efficient power adopted by CSS as a removal of the studied dye. Also, the regeneration study was effectuated for four cycles with excellent adsorption rates. The modeling studies revealed that the studied process obeys the pseudo-second-order model and Langmuir isotherm model. The adsorption amount was found to be 107.53 mg/g. Finally, the determination of thermodynamic parameters indicated the exothermic and spontaneous type of the removal process of MB onto CSS.

In the present study, the performance of sodium polyacrylate beads on the removal of trivalent chromium Cr (III) from aqueous solutions was evaluated using several techniques such as Fourier Transformed Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray Analysis (EDAX), Inductively Coupled Plasma (ICP) and Atomic Adsorption Spectroscopy (AAS). On one hand, the characterization of dry PANa beads was carried out through FTIR and the surface morphology was analyzed by SEM and EDAX methods in order to show the loading of heavy metal on PANa beads. On the other hand, the effect of contact time, initial pH solution, initial Cr(III) concentration, adsorbent mass and temperature on the adsorption capacity of PANa was studied. All results have shown that the adsorption equilibrium was reached at about 60 minutes with an adsorption efficiency close to 90 %. Also, the study of the reliability of PANa beads was effectuated using 0.01 M nitric acid solution through six cycles of adsorption/desorption which were determined in order to study the reliability of PANa over time and to test their efficiency in industrial applications. Finally, the obtained thermodynamic parameters (ΔG°, ΔH° and ΔS°) indicate that the adsorption process is spontaneous and endothermic.