Adsorption of di-butyl phosphate on activated alumina: equilibrium and kinetics

摘要

The rate of removal of di-n-butyl phosphate (DBP) by sorption on activated alumina (AA) has been studied in batch conditions. The rate of adsorption of DBP is initially rapid for about 10-20 min and reaches a maximum in about two hours. The Langmuir and Freundlich isotherm equations have been used to describe the partitioning behavior of the system. Kinetic modeling analysis of the pseudo-first-order, pseudo-second-order, and pore diffusion model, coupled with the observed Langmuir or Freundlich isotherm equations showed that pseudo-second-order equation and pore diffusion model to be the most appropriate models for the description of transport of DBP within AA particles. The agreement between the model predictions and experimental data indicated that adsorption and diffusion of DBP can be simulated by the proposed models. From analysis of the experimental kinetic data, effective diffusivity has also been estimated and is found to be in the range of 10(-9 )cm(2)/s.