Application of Kinetics, Thermodynamics and Activation Energy inAdsorption of Pb2+ by Peanut Shell
LIN Chen-Xi1, FENG Yang1, LI Qing1, REN Yan-Mei1, LI Yin-Hui1,2,3**
1.School of Chemical Engineering and Technology, Hebei University of Technology, Tianjin 300130, China;
2.China Engineering Research Center of Seawater Utilization Technology, Ministry of Education, Tianjin 300130, China;
3.National-Local Joint Engineering Laboratory for Energy Conservation of Chemical Process Integration and Resources Utilization, Tianjin 300130, China
Abstract The adsorption process of solid surface in physical chemistry was studied with peanut shell as the adsorbent and Pb2+ as the simulated pollutant. The effects of Pb2+ initial concentration and adsorption temperature were investigated. The kinetics, thermodynamics and activation energy of adsorption reaction on solid surface were studied. The results showed that the adsorption kinetics of Pb2+ on peanut shell surface was in accordance with the pseudo-second-order kinetic model at different Pb2+ initial concentration. It is shown that the adsorption process was an adsorption process in which chemical adsorption was the control step. Thermodynamics results showed that Pb2+ adsorption on peanut shell surface was a spontaneous exothermic process and the entropy of the system decreased because Pb2+ changed from three-dimensional motion to two-dimensional motion. Activation energy Ea=31.35 kJ·mol-1 proved again that the adsorption of Pb2+ on the surface of peanut shell was a chemical adsorption process. These results verified the adsorption behavior of solid surface in physical chemistry teaching well. Students’ understanding of solid surface adsorption process was deepened through the expansion experiment. At the same time, the ability of scientific and technological innovation of students was cultivated.
LIN Chen-Xi, FENG Yang, LI Qing, REN Yan-Mei, LI Yin-Hui. Application of Kinetics, Thermodynamics and Activation Energy inAdsorption of Pb2+ by Peanut Shell[J]. Chinese Journal of Chemical Education, 2020, 41(8): 53-57.
