Mohamed Abdennouri

Title : Experimental and computational study of the adsorption mechanisms of heavy metals and industrial effluents by the monte carlo method, the molecular dynamics and density functional theory

Abstract:

This work is a part of the general framework of basic and applied research aimed at finding environmentally friendly and low-cost adsorbents. Afterwards, test their performance in the adsorption of heavy metals and various liquids and gaseous industrial effluents. We started with the synthesis of titanium dioxide by ground-freezing method and chitosan was extracted from waste shrimp shells, then the resulting powder experienced a set of unit operations to extract chitosan. These materials were then characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and point of zero charge (pH_PZC). The effect of pH, contact time, initial adsorbate concentration, temperature, protonation and solvent were investigated. The Monte Carlo simulation method, molecular dynamics (MD) and density functional theory (DFT) were used to optimize, predict and understand the interaction mechanisms and parameters affecting the adsorption process. The performance of different adsorbents was tested on the adsorption of eriochrome black T (EBT), anionic dye on the (110) chitosan polymer surface [1]. The methylene blue (MB), cationic dye on the (110) titanium dioxide surface and (001) zeolite. The (111) graphite carbon surface was used to theoretically study the adsorption of gases (SiF₄, HF, SO₂ and CO₂) [2] and heavy metals (Ag, Cd, Hg, Pd and Zn) [3].

The obtained results show that:

• The adsorption of eriochrome black T by chitosan and methylene blue by both titanium dioxide and zeolite is best described by the Langmuir isotherm;
• The adsorbed quantities of the two studied dyes were proportional to the initial mass of the adsorbent;
• The adsorption kinetics has been well described by the pseudo-second order kinetic model;
•  The solution pH, the initial adsorbate concentrations and the temperature of the media are the factors that influence the most the adsorption phenomenon;
• The maximum adsorption capacity of methylene blue was found in alkaline media and in acidic media for eriochrome black T;
• The adsorption of methylene blue and eriochrome T black is exothermic and spontaneous;
• Protonated forms of methylene blue adsorb better than neutral forms;
• Mercury has more affinity to the graphite surface than other heavy metals;
• The obtained results by Monte Carlo calculations show that the SiF₄ and SO₂ molecules adsorb better on the graphite surface than HF and CO₂ in aqueous medium;
• The adsorption of SiF₄, SO₂, HF and CO₂ at the graphite surface is also exothermic and spontaneous.

Keywords: Adsorption, Heavy metals, Gas, Dyes, Monte Carlo Simulation, MM, DM, DFT.

Biography:

Dr Mohamed ABDENNOURI is a Professor of Higher Education at the Polydisciplinary Faculty of Khouribga, Sultan Moulay Slimane University, Beni Mellal, Morocco, Major chemistry and physics. Holder of a doctoral thesis in sciences option chemistry specialty Materials, Processes and Catalysis in the Faculty of Sciences, Chouaib Doukkali University, El Jadida, Morocco in the 30^th October, 2010 ; University qualification to direct research works in the 7^th November,  2015 at the Polydisciplinary Faculty of Khouribga, Hassan First University, Settat, Morocco, and the rank of Professor of Higher Education in the 13^th December,  2022 at the Sultan Moulay Slimane University, Beni Mellal, Morocco. I have published more than 86 articles in internationally renowned journals and supervised many doctoral theses in this field.