ADSORPTION AND KINETICS OF HAZARDOUS DYE RHODAMINE-B FROM AQUEOUS SOLUTIONS WITH ACTIVATED CARBON-BASED LOW-RANK COAL

摘要

Activated carbon was prepared from Tuncbilek-Kiitahya (Turkey) lignite by chemical activation with KOH (impregnation ratio 1:2). Pore characteristics of the activated carbon, such as BET surface area, pore volume, size distribution and the diameter of pores, were determined. BET surface area was found to be 902 m~2/g, and other characteristic values are as follows: S_(micro): 560 m~2/g, V_(total): 0.50 cm~3/g, V_(micro): 0.30 cm~3/g and average pore diameter: 2.21 nm (4 V/A by BET). The prepared activated carbon was used to adsorb Rhodamine-B (RB) from aqueous solution in a batch reactor. The adsorption isotherm of process could be best identified using the Langmuir model since it gave a better fit and had a higher R2 value (0.9908) than Freundlich model. The kinetics of the adsorption of RB was tested using a pseudo-second order equation and an intraparticle diffusion model. Adsorption capacity was determined to be between 1.80-2.55 10 ~(-4) mol.g~(-1). It was found that the boundary layer thickness increased as the temperature increased (50.641 - 64.271).