Characterization and applicability of the natural Iraqi bentonite clay for toxic cationic dye removal: Adsorption kinetic and isotherm study

Abstract

This research targets to adsorb the organic dye (methylene blue, MB) from aqueous media using natural Iraqi bentonite clay (NIBC). Several analytical methods (e.g., XRD, FTIR, SEM-EDX, XRF, pHpzc, and BET) analysis were conducted to inspect the physicochemical characteristics of the NIBC. Adsorption key variables, including dosage of adsorbent (0.02–0.1 g), pH (2–10), and initial concentrations (10–150 mg/L) were inspected for determining their impacts on MB dye removal. The Redlich-Peterson isotherm demonstrated the best account for the equilibrium adsorption of MB. The NIBC's highest adsorption capacity (qmax) for MB was 256 mg/g. The kinetics of the adsorption of MB by NIBC matched the pseudo-second-order model. This study demonstrates that the NIBC could be utilized to successfully remove MB from aqueous environments.

Keywords

• Bentonite clay
• Adsorption
• Methylene blue dye
• Isotherm
• Kinetics