AP-05: Alginate/montmorillonite beads for efficient removal of malachite green dye from aqueous solutions

Abstract

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