Redouane Mghaiouini

Safe drinking water remains an issue all around the world, especially in arid countries that require seawater desalination to obtain safe water. This research seeks to analyze water quality at the major stages of an SWRO plant, i.e., raw seawater intake, RO permeate, reject brine, and distribution network water. For the study, conventional physicochemical methods of water quality analysis, as well as electrochemical impedance spectroscopy, were used. Four water samples were taken at different stages of the treatment process: raw seawater (feed water), RO permeate, reject brine, and distribution network water. Physicochemical parameters, such as pH, electrical conductivity, total dissolved solids (TDS), major ions (Na⁺, Cl⁻, Ca²⁺, and Mg²⁺), and heavy metals (Zn, Cu, Cr, and Hg) concentrations, were evaluated. Electrochemical impedance spectroscopy was used to investigate ionic transport, dielectric relaxation, and interfacial polarization mechanisms within the tested solutions. It has been shown that RO membranes are capable of rejecting major ions up to 95–99%, as can be seen in the low values of conductivity and TDS of RO permeate. EIS analysis also allowed for identifying specific electrochemical characteristics of all four types of water, with brine being characterized by the highest polarization rates and relaxation times.

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Seawater desalination has become a critical approach to mitigating the global scarcity of freshwater resources. This study aims to comprehensively review desalination methods based on thermal and electromagnetic methods, examining their processes, benefits, and limitations. Thermal methods include multi-stage flash distillation, multi-effect distillation, thermal vapor compression, and mechanical vapor compression. These techniques rely on evaporation and distillation to remove salts and are effective in treating highly saline water. However, they consume large amounts of energy and are prone to problems such as limescale and corrosion. In contrast, electromagnetic-based technologies represent a novel, promising approach for enhancing desalination performance. Electromagnetic fields contribute to improved membrane performance and equipment longevity by modulating ionic behavior and mitigating surface fouling. Empirical studies suggest that such interventions can lead to reduced energy usage and lower rates of mineral deposition. The findings reviewed here suggest that integrating thermal and electromagnetic techniques may offer a viable pathway toward more sustainable, efficient, and reduced environmental impacts.

This work focuses on the preparation and characterization of chitosan (CS) at different degrees of deacetylation (CS 74%, CS 86%, CS 90% and CS 95%) in order to use them as adsorbents to remove fluoride ions. The characterization of the materials was carried out by X-ray diffraction, Infrared spectroscopy and determination the degrees of deacetylation (DD) by conductometric titration. The influence of various physico-chemical parameters such as adsorbent dose, contact time, pH, initial fluoride concentration and temperature were studied. The adsorption kinetics was studied using pseudo-first order and pseudo-second order kinetic equations. The adsorption isotherm was investigated by Langmuir and Freundlich models.