Preparation and Characterization of Activated Carbon Derived from Antidesma bunius L. in Methylene Blue Removal from Wastewater

Abstract

This study investigated the effect of contact time and methylene blue (MB) solution concentration on the adsorption capacity of granulated activated carbon derived from bignay (Antidesma bunius L.) seeds. The raw bignay seeds were subjected to physical activation via oven drying at 120°C and carbonization at 500°C for 30 min. The maximum adsorption capacity of both powdered and granulated activated carbon were determined. The alkyl functional groups of Bignay activated carbon (BAC) were determined using Fourier transform infrared (FTIR) analysis and the surface morphology and composition of the BAC were analyzed using scanning electron microscopy-energy dispersive x-ray (SEM-EDX). Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich isotherm models were used to analyze the adsorption of isotherm BAC. But the data best fitted with the Freundlich isotherm. The mean energy of the adsorption showed that the adsorption of MB by BAC was physical adsorption implying that MB molecules were trapped in the pores of the BAC. The maximum adsorption capacity was 1.60 mg g-1. The rate of adsorption was used to determine if the process is physisorption or chemisorption using pseudo-first order and pseudo-second order adsorption kinetics. The data showed best fit for pseudo-second order ,suggesting that the reaction depends on the concentration of both reactants