活性炭对恩诺沙星吸附的热力学与动力学研究

Study on the Kinetics and the Thermodynamics for Adsorption of Enrofloxacin by activate carbon

从热力学和动力学角度,研究了活性炭对水溶液中恩诺沙星的吸附行为。热力学研究表明:活性炭对恩诺沙星的吸附符合Freundlich等温吸附方程。测得ΔH=-16.02 kJ.mol-1,说明活性炭对恩诺沙星的吸附过程为放热过程,且|ΔH|<20 kJ.mol-1,表明吸附过程为物理吸附。同时测得吉布斯自由能ΔG<0,受温度影响不大,表明吸附质从溶液到吸附剂表面的吸附过程是自发过程。动力学研究表明:活性炭对恩诺沙星的吸附更好地符合伪二级动力学描述,测得其表观活化能Ea为105.72 kJ.mol-1。

The kinetic and thermodynamic parameters for the absorption of enrofloxacin in aqueous solution by activated carbon fiber were studied. Research on the thermodynamic behavior indicated that the absorption of enrofloxacin obeyed the Freundlinch isotherm model. The heat of absorption AH was - 16.02 kJ · mol^-1, which indicated that the absorption was an exothermic process, and ｜ △H｜ 〈 20 kJ · mol^-1 demonstrated that the absorption process was mostly physical adsorption. Meanwhile, Gibbs free energyAG was determined to be below 0 and free from the influence of temperature, which indicated that the absorption was a spontaneous process. Research on kinetic parameters showed that absorption of enrofloxacin by activated carbon fiber was best described by pseudo second - order rate model, and the apparent activation energy Ea was detected to be 105.72 kJ · mol^-1.