Adsorption of boron from aqueous solutions by activated carbon impregnated with salicylic acid: equilibrium, kinetic and thermodynamic studies

Abstract

Abstract The adsorption of boron from aqueous solution containing boron by activated carbon impregnated with salicylic acid (ACISA) was studied in a batch system. In order to investigate the effect of initial boron concentration and temperature on boron adsorption capacity of ACISA; the equilibrium, kinetic and thermodynamic parameters were calculated. The adsorption capacity data were obtained by using Langmuir and Freundlich isotherm models and both models fitted well. The pseudo-first-order, pseudo-second-order and the intraparticle diffusion models were used to describe the kinetic parameters and the rate constants were evaluated. The experimental data fitted very well the pseudo-second-order kinetic model. The activation energy (Ea ) calculated using the Arhenius equation was found to be 58.25 kJ mol−1. Various thermodynamic parameters such as Gibbs free energy (ΔG o), enthalpy (ΔH o) and entropy (ΔS o) changes were computed and the results showed that the adsorption of boron onto ACISA was spontaneo...