Spectral, Isotherm, Kinetic, and Thermodynamic Studies of Malachite Green Dye Adsorption from Aqueous Solutions onto Low-cost Treated Kaolin

This study investigated the potential of Algerian kaolin clay exchanged with protons as an inexpensive adsorbent for malachite green (MG) dye elimination from colored effluents using batch equilibrium experiments. Before using the kaolin as an adsorbent, it was treated with HCl (0.1 M). The structural, compositional, and textural characteristics of the Tamazert kaolin (TK) and the treated Tamazert kaolin (tTK) were determined using physicochemical and mineralogical characterizations. The optimization of miscellaneous experimental parameters such as contact time, adsorbent dose, temperature, and initial pH solution was conducted through batch adsorption experiments. The findings of the experiment revealed that 30 min of contact time was adequate to achieve liquid-solid phase equilibrium. The highest adsorption capacity of MG dye was reached at 18.51 mg g-1. The adsorption kinetics followed the pseudo-first-order model. The adsorption isotherms showed a correlation between the Freundlich model and the experimental results. Enthalpy changes, Gibbs free energy, and entropy were computed.