Evaluation of easily separated natural clay as an ultrafast adsorbent for cationic toxic dye

Abstract

Natural clay is considered one of the most attractive substances due to its broad applications and environmental benignity. In this work, Kurdistan montmorillonite clay (KMC) has been easily separated from the soil without any chemical treatment. It is employed as an efficient adsorbent for removing the cationic toxic dyes from the influent. Different methods, such as BET, FESEM, TEM, UV–VIS, XRD, XRF, XPS, and Zeta potential, have been applied to study how well clay works. In an effort to match the isothermal data, Langmuir, Freundlich, Temkin, and Dubinin–Radushkevich equations were used. The experimental findings have shown that a Langmuir isotherm equation provides a good fit for the equilibrium data (R² = 0.999). The rate parameters were assessed using pseudo-first-order, pseudo-second-order, intra-particle diffusion, and liquid film diffusion equations and were consistent with the pseudo-second-order kinetic model (R² = 0.999). Additionally, the results revealed that the clay exhibited a high adsorption capacity (2.45 mg/g) and removal for methylene blue (MB) dye (98%) in one minute. The outcomes show that KMC effectively adsorbs MB dye and may be used as a low-cost substitute in wastewater treatment to get rid of cationic dyes.