Frontiers of Chemical Science and Engineering
Kinetics and thermodynamics of the phosphine adsorption on the modified activated carbon
1. School of Chemical and Environmental Engineering, China University of Mining and Technology (Beijing), Beijing 100083, China; 2. College of Environment and Safety, Taiyuan University of Science and Technology, Taiyuan 030024, China
The kinetics and the thermodynamics of phosphine (PH ) adsorption on the modified activated carbon have been explained for the adsorption process of PH . This study investigated the kinetic and thermodynamic properties of PH adsorption on the activated carbon impregnated with 5% HCl solution. The thermodynamic properties including PH adsorption isotherm and adsorption heat were separately investigated at 20°C, 70°C, 90°C. The results showed that the Freundlich-type isotherm equation described the isotherms well. The adsorption capacity increased with increasing temperature between 20°C and 70°C. Between 70°C and 90°C, the adsorption capacity decreased obviously with increasing temperature. The adsorption capacity reached the maximum at 70°C. By analyzing the results of the kinetics and the thermodynamics, we found that the adsorption of PH was dominated by physical adsorption at the lower temperature (20°C). Then with increasing temperature, chemical adsorption gradually dominated in the adsorption process. The adsorption capacity decreased at above 70°C is due to the exothermic effects in the process of adsorption.