Adsorption of Cr (VI) from Aqueous Solution by Cetylpyridinium Bromide (CPB) Modified ZeoLite: Kinetic, Equilibrium and Thermodynamics Study

Abstract

The kinetic, equiLibrium and thermodynamics of Cr(VI) adsorption from aqueous solution on cetylpyridinium bromide (CPB) modified zeoLite were investigated. CPB modified zeoLite displayed a good affinity to Cr(VI) in aqueous solution, and its Cr(VI) adsorption capacity decreased with the increase of the temperature. The kinetics of adsorption of Cr(VI) were discussed using the pseudo-first-order and pseudo-second-order kinetic models, and the experimental data agreed very well with the pseudo-second-order kinetic model. The adsorption isotherms were analyzed by the Langmuir, FreundLich and Dubinin-Redushkevich (D-R) isotherm models, and the experimental data were well described by all these isotherm models. Thermodynamic parameters such as Gibbs free energy change, enthalpy change and entropy change were calculated and the results showed that the adsorption of Cr(VI) on CPB modified zeoLite was spontaneous and exothermic in nature.