Fenton’s reagent-initiated modification of plantain (Musa paradisiaca) peel biomass – mechanisms of chain propagation and dyes removal from simulated wastewaters

This report describes the mechanisms of Fenton’s reagent-initiated graft-copolymerization of plantain peel biomass (PPB) and that of the polymer-dyes interactions. Methacrylic acid (MAA) was grafted onto the PPB backbone. Optimization of the process was accomplished by varying the [Fe۲+]/[H۲O۲] ratio in the Fenton’s reagent, grafting temperature, grafting time, PPB mass and monomer mass. The resulting copolymer was characterized by FTIR, SEM, XRD, TGA/DTA and BET isotherm. Adsorption of methylene blue and malachite green was performed by varying the pH of the solution of each dye, as well as investigating the kinetics, isothermal behaviors and thermodynamics of the process. Optimum %yield was established at ۱:۱۰۰ (w/w) [Fe۲+]/[H۲O۲] combination, ۴۰℃, ۳۰ min grafting time, ۱ g PPB mass and ۲ g monomer mass. At optimum condition, about ۷۰% yield was obtained. Characterization results confirmed the effective grafting of poly(MAA) on the PPB backbone. Both dyes had good adsorption at pH ۶. The kinetic and equilibrium data followed the pseudo-second-order (R^۲ > ۰.۹۹), and Freundlich isotherm (R^۲ ≥ ۰.۹۳) models, respectively. The process was spontaneous, exothermic, and predicted to have occurred by physico-chemical adsorption. A study of the mechanism of the process predicted the involvement of electrostatic attraction, dipole-dipole H-bonding, Yoshida H-bonding, n→π, and π→π interactions.

کلیدواژه ها:

Active site ، Fenton’s Reagent ، graft copolymerization ، Adsorption