Influence of Adsorbent Nature on Metal Retention: Application to Water Treatment

The increasing contamination of water resources by dissolved metals has become a major environmental concern. In this context, the present study investigates the ability of two adsorbent materials, sodium bentonite and activated carbon, to remove Fe²⁺ and Ni²⁺ metal ions from aqueous solutions. The main objective is to compare their adsorption performance and to identify the mechanisms involved in the immobilization of these contaminants within solid matrices.

The adsorption process was evaluated by examining several physicochemical parameters likely to influence metal ion retention, including solution pH, initial metal concentration, agitation mode and speed, and temperature. The experimental data obtained were used to establish adsorption isotherms and to characterize the behavior of the adsorbents toward the investigated metals.

The results indicate that the observed retention phenomena are satisfactorily described by the Langmuir and Freundlich isotherm models, suggesting strong interactions between the adsorbates and the adsorbent surfaces. The analysis also reveals a greater affinity of activated carbon for metal ions, with iron exhibiting higher adsorption than nickel. Compared with sodium bentonite, activated carbon demonstrated superior removal efficiency for both studied elements.

These findings highlight the potential of highly adsorptive materials for the design of containment barriers aimed at reducing the dispersion of metallic micropollutants and enhancing the protection of water resources