Borassus aethiopum shell-based activated carbon as efficient adsorbent for carbofuran

Abstract

ABSTRACT. Carbofuran, a pesticide applied in farmlands, often gets washed away into water bodies due to heavy rainfall and renders the water toxic. In this study, Borassus aethiopum shells-based activated carbon (BAS-AC) was prepared using CO₂ and KOH as physical and chemical activating agents, respectively, which was employed as an adsorbent for the removal of carbofuran from an aqueous medium. The adsorbent was produced using the impregnation ratio of 3.28, activation temperature of 800 ^oC and activation time of 90 min. Textural properties and available functional groups in the adsorbent were determined using N₂ adsorption-desorption isotherm and Fourier transform infrared spectroscopy, respectively. The removal efficiency was performed after optimizing the adsorption parameters and kinetics of the adsorption process was examined using a batch system. The surface area, average pore diameter and adsorption capacity of the BAS-AC were obtained as 632 m²/g, 2.97 nm and 160 mg/g, respectively. Equilibrium adsorption isotherms were fitted better by the Langmuir model than the Temkin and Freundlich models. The adsorption kinetics follow the pseudo-second-order model and the adsorbent diffusion mechanism was further studied using the intraparticle diffusion model.

KEY WORDS: Borassus aethiopum, Carbofuran, Activated carbon, Adsorption isotherm, Adsorption kinetics

Bull. Chem. Soc. Ethiop. 2019, 33(3), 425-436.

DOI: https://dx.doi.org/10.4314/bcse.v33i3.4