活性炭对头孢氨苄吸附的热力学与动力学研究

从热力学和动力学角度研究了活性炭对水溶液中头孢氨苄的吸附行为。热力学研究表明:活性炭对头孢氨苄的吸附符合Freundlich等温吸附方程,ΔH25.24 kJ.mol-1,且40 kJ.mol-1,说明该吸附是一个物理吸附且过程中吸热。同时测得吉布斯自由能ΔG0,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:该吸附过程比较符合伪二级动力学描述,其表观活化能Ea为21.75 kJ.mol-1。

Study on the Kinetics and the Therm Odynamics for Adsorption of Cephalexin by Activate Carbon

The kinetic and thermodynamic parameters for the absorption of Cephalexin aqueous solution by activated carbon fiberwere studied.Research on the thermodynamic behavior indicated tha t the absorption of Cephalexin obeyed the Freundlich isotherm model.The heat of absorption ΔH was 25.24 kJ·mol^-1,which indicated that the absorption was an exothermic process,and ｜ΔH｜40 kJ·mol^-1 demonstrated that the absorption process was mostly physical adsorption.Meanwhile,Gibbs free energyΔG 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 Cephalexin by activated carbon fiber was best described by pseudo second-order rate model,and the apparent activation energy Ea was detected to be 21.75 kJ·mol^-1.