Thermodynamics and Kinetics of Adsorption of Dyes from Aqueous Media onto Alumina

Abstract

Use of alumina for the removal of industrially important dyes namely, methylene blue, methyl blue, bromophenol blue, malachite green, eriochrome black-T, phenol red and methyl violet from aqueous media at different shaking times, temperatures and pH values has been investigated. The adsorption data was fitted to both the pseudo-first-order and pseudo-second-order kinetic models and calculated values of amount adsorbed at equilibrium (qe) by pseudo-second-order equations were found to be in good agreement with the experimental values. The negative values of ΔH and ΔG indicates that the adsorption is exothermic and spontaneous, respectively. The adsorption data was fitted to Freundlich, B.E.T., Dubinin-Radushevich (D-R) and Langmuir isotherms and their corresponding adsorption parameters for each were calculated. The dyes were found to be chemisorbed onto alumina.