Conversion of Phaseolus vulgaris into chemically functionalized biocomposites for efficient methylene blue removal: kinetics, isothermal, and thermodynamics analysis

Abstract

Herein, green beans “Phaseolus vulgaris” have been successfully converted into polypyrrole-modified and polyethylene glycol-based magnetic nanocomposites for efficient removal of methylene blue (MB) dye removal from wastewater. The physicochemical properties including morphologies and functionalities were also examined. Comparative analysis of all designed nanocomposites toward MB dye removal demonstrated that under optimized batch adsorption experimental conditions (pH 9, dosage 0.05 g, contact time 90 min, and initial MB concentration 50 mg L⁻¹ at 28 °C) the Ppy/BB magnetic nanocomposites exhibited excellent removal efficacy with values of 47.09 mg g⁻¹ and 97.96%. Isothermal and kinetic dynamic analysis revealed that the best-fit models were the Freundlich isothermal model and the Pseudo-2nd-order model with R² > 0.991 and R² > 0.999, respectively. The synthesized nanocomposites demonstrated a high affinity for the adsorption of dyes in the context of the present analysis, and this innovative class of biomass-derived materials can be employed for the eco-friendly remediation of polluted water containing MB toxic dye.