关键词: 竹炭, 硝基苯, 吸附性能, 动力学参数, 热力学参数

Abstract:

The adsorption property， thermodynamic parameters and kinetic parameters of nitrobenzene with bamboo-charcoal were studied in this paper. The result shows that adsorption equilibrium time is 540 min and the bamboo-charcoal shows high adsorption ability for nitrobenzene at the pH of 5.6. Langmuir isotherm model is well obeyed. The studying kinetics shows that the adsorption kinetics of bamboo-charcoal on nitrobenzene can be described by pseudo first-order kinetics. The adsorption apparent rate constant k₂₉₈ is equal to 2.42×10^-4s^-1 and activation energy E_a is equal to 23.5 kJ·mol^-1 at the temperature of 298 K. The studying thermodynamic shows that the adsorption process of bamboo-charcoal on nitrobenzene is an exothermic process. The heat of adsorption （ΔH） is equal to －16.8 kJ·mol^-1， entropy change（ΔS） is equal to 37.9 J·K^-1mol^-1 and free energy change （ΔG） is equal to -28.1 kJ·mol^-1. The ΔG is a negative value shows that the adsorption process of adsorbate from solution to adsorbent surface is a spontaneous process.

Key words: bamboo-charcoal, nitrobenzene, adsorption property, kinetic parameters, thermodynamic parameters