关键词: 活性炭, 热改性, 吸附动力学, 吸附能

Abstract: According to the TGA results, the temperature requirement of the activated carbons modifying process was discussed. Boehm titration, Fourier transformed infrared spectroscopy(FTIR) and BET surface area measurement were used in measuring surface physicochemical properties of these modified activated carbons. Then, Fixed-bed adsorption experiments were conducted under the same experimental conditions at 283K, with acetone, dichloroethane and methanol being as adsorbents, respectively. After the correlation analysis of experimental results and test result, the calculation of dynamics parameters and adsorption energy was conducted. The results show that the pore size distribution and surface functional groups of thermal-modified activated carbon are different from the unmodified one, and the relationship of adsorption capacity and effective pore volume is linear. The adsorption process of four absorbates on activated carbon can be described by the pseudo-first-order and pseudo-second-order kinetic equation. Also, intra-particle diffusion model shows that the rate of adsorbing the organic gases of activated carbon is greater than unmodified one. The adsorption energy of all the four chosen adsorbents is smaller than 20 kJ?mol-1, which indicating that the adsorption of the four adsorbents on activated carbon is dominated by physical adsorption.

Key words: activated carbon, thermal treatment, adsorption kinetics, adsorption energy