Résumé:
The release of dyes into aquatic environments is a serious environmental and health problem in
recent years. Therefore, the development of potential adsorbents for the effective removal of malachite
green (MG) of aqueous media is of great importance. In this study, new alginate beads were
successfully prepared by encapsulation of montmorillonite (Na-Mt) and Nickel oxide modified
montmorillonite (NiO-Mt) in alginate using CaCl2 solution (Alg/Na- Mt and Alg/NiO-Mt). The
obtained beads were utilized as a well adsorbents for the removal of MG dye from aqueous solutions
by batch adsorption procedure. The characteristics of the synthesized beads were investigated using
FTIR and pHPZC. The effects of various operation factors such as adsorbent dose, pH of the solution,
contact time, dye initial concentration and temperature on the removal of MG were studied. Moreover,
adsorption isotherm results showed that the Freundlich model fitted well for the adsorption of MG onto
Alg/Na-Mt and Alg/NiO-Mt beads. Kinetic and thermodynamic studies also indicated that the MG
adsorption were found to be well fitted with a pseudo-second-order kinetic model, feasible,
endothermic, and spontaneous in nature. In addition, the Alg/Na-Mt and Alg/NiO-Mt beads showed
excellent reusability for the removal of the dye after seven adsorption cycles. Overall, the obtained
results suggest that Alg/Na-Mt and Alg/NiO-Mt beads could be considered as a low- cost and eco
friendly adsorbents for dye contaminants removal from aquatic media
