Efficient removal of organic pollutants from aqueous environments using activated carbon derived from biomass waste of Calotropis procera fruit: Characterization, kinetics, isotherm, and thermodynamic investigation

Abstract

In this research, a powder derived from the biomass of the Calotropis Procera fruit (FCP) was utilized to produce an activated carbon (AC). The H3PO4 was the activator agent. After the adsorption test, the AC (AC-FCP1–1) impregnated with a ratio of 1:1 was chosen as the most suitable and efficient for methylene blue (MB) removal in aqueous environments at high rates. The characterization of AC-FCP1–1 and its efficient adsorption of MB was confirmed through various methods and analyses. The SEM image shows and confirms the micropores and mesopores. EDX analysis reveals the elemental composition and then BET analysis using N2 at 77 K indicates a high surface area of 1025.0628 m2.g-1 and prominent microporosity. FT-IR analysis confirmed functional groups such as OH, CO, CH (aromatic), phosphorus bands, and CO bonds. The amorphous structure was confirmed by XRD analysis. Conversely, the batch study, adsorption modeling, and adsorption mechanism were also carried out. The Adsorption of MB onto AC-FCP1–1 follows a pseudo-second-order kinetic and Freundlich isotherm, indicating that the adsorption process of MB onto AC-FCP1–1 was performed in a multilayer with a physisorption process. The interactions between AC and MB were fast, irreversible, and favorable. The thermodynamic parameters show that this adsorption is exothermic. At equilibrium, under optimal conditions, the adsorption rate of MB onto AC-FCP1–1 reaches 99.24 % with a maximum adsorption capacity of 158.98 mg.g−1.