PREPARATION AND CHARACTERIZATION OF ACTIVATED CARBON FROM OIL-PALM FIBER AND ITS EVALUATION FOR METHYLENE BLUE ADSORPTION

A new type of activated carbon was produced from oil-palm fiber using steam activation. Scanning electron microscopy (SEM) was performed on the surface of oil-palm-fiber activated carbon (OPF-AC). The spectra of OPF-AC was investigated with Fourier-transform infrared (FTIR) spectroscopy. The effects of the temperature, adsorbent dose, adsorption time and pH on the adsorption properties of methylene blue on OPF-AC were discussed. The Langmuir adsorption model and Freundlich adsorption model were used to find the adsorption equilibrium isotherm. Adsorption kinetics were employed to explain the adsorption process and predict the adsorption efficiency. The Van't Hoff equation was used to assess the impact exerted by the adsorption temperature on the adsorbing process. According to the results, the data of the adsorption equilibrium of OPF-AC fit well the Langmuir adsorption model and the kinetics data can be gathered into a pseudo-second-order kinetic model. The adsorption behavior of methylene blue on OPF-AC was endothermic and spontaneous. The total pore volume and BET surface area of OPF-AC reached 0.7809 cm(3)/g and 1018.84 m(2)/g, respectively. The maximum adsorption capacity of OPF-AC was 862.07 mg/g at 323 K. Accordingly, the gratifying adsorption of OPF-AC endows it with a promising prospect in the application field of agricultural adsorbents.