Comparison study of adsorbent produced from renewable resources: Oil palm empty fruit bunch and rice husk

Abstract

Rapid industrialization and growth of human population have led to the increase of water pollution. To preserve the water quality, adsorbents have been utilized to remove or mitigate pollutants from water bodies. Low cost adsorbents made from biomass waste have gained great interest. Rice husk and oil palm empty fruit bunches (OPEFBs) are two of the underutilised biomasses which potentially to be used as adsorbent resources in Malaysia. In this study, cellulose based adsorbents which extracted from OPEFB and rice husk were used to remove methylene blue dye from aqueous solution. OPEFB and rice husk were bleached and treated with alkaline treatment. Optimization of adsorption process of methylene blue was performed using response surface methodology (RSM). Solution pH and dye initial concentration have been considered as input and removal efficiency is assigned to be the response. OPEFB cellulose has optimum condition of pH 8.19 and dye initial concentration of 9.03 mg/L whereas rice husk cellulose at pH 8.61 and 8.11 mg/L initial concentration. Removal efficiency of 96.77% and 97.80% have been achieved for OPEFB and rice husk cellulose, respectively. Equilibrium study has been carried out and both cellulose was found fitted best in Langmuir isotherm model. The adsorption capacity of OPEFB and rice husk cellulose was calculated to be 185.19 mg/L and 58.48 mg/g respectively. Pseudo-second-order model has found to fit the obtained data best for both celluloses with value of R2 very close to unity. The characterization study using scanning electron microscopy (SEM) and Fourier transformation infrared (FT-IR) has proved that OPEFB and rice husk cellulose are the great adsorbents to remove methylene blue dye from aqueous solution.