A novel approach for producing low cost and highly efficient activated carbon for removing cationic dyes

Abstract

Chemical activation was used to prepare a low-cost activated carbon (AC) from an agricultural waste material: sugarcane bagasse. It was used as a green biosorbent for the removal of two cationic dyes from aqueous solutions (Methylene blue (MB) and Malachite Green (MG)). Central composite design (CCD) using response surface methodology (RSM) was applied in this work in order to run a limited number of experiments. The possibility of revealing the interaction of three selected factors: activation temperature, activation time, and chemical impregnation ratios at different levels for the process of preparing the AC were studied. Two-second order quadratic regression models for a yield of AC and capacity of adsorption were developed using JMP Software.

The results of the process of optimization were carried out; it showed a good agreement between the predictive response of RSM model and the obtained experimental values with high correlation coefficients (R²) which indicates the efficacy of the model. The optimal activated carbon was obtained using 400°C activation temperature, 36 min activation time, and 2 impregnation ratio, resulting in 63.12 % of AC yield and 99.86 % for MB removal and 400°C activation temperature, 90 min activation time and 2 impregnation ratio, resulting in 45.69 % of AC yield and 99.75 % for MG removal. Moreover, the comparison between the experimental and the predicted values at optimum conditions was in good agreement with relatively small errors.

This work showed the effectiveness and the performance of preparing activated carbon from sugarcane bagasse, and it recommended as an effective and green biosorbent for the removal of cationic dyes from aqueous solutions.