Determination of Adsorption Characteristics of Orange Peel Activated with Potassium Carbonate for Chromium(III) Removal

Abstract

In this study, Cr(III) removal from aqueous solutions was investigated by using the batch adsorption method. Orange peel activated with potassium carbonate (OPAPC) was used as the adsorbent because of the fact that adsorption capacity was higher when orange peel was activated with potassium carbonate, instead of both original orange peel and orange peel activated with phosphoric acid adsorbents. In order to determine optimum adsorption conditions, adsorbent concentration (2-15 g/L), pH (3-7), temperature (298-318 K), contact time (10-240 min) and initial concentration of Cr(III) (5-50 mg/L) were investigated for Cr(III) removal from aqueous solutions using OPAPC. The equilibrium data were evaluated using the Langmuir and Freundlich model equations and the kinetic data were evaluated with pseudo first and second order kinetic models. In addition, the adsorption thermodynamics of the proposed method in optimum conditions was investigated.