Removal of Chromium (VI) from Aqueous Solution using a Low Cost Activated Carbon Prepared from Prosopis juliflora by Adsorption

This paper presents the feasibility for the removal of chromium (VI) from aqueous solution using an activated carbon prepared from Prosopis juliflora bark. Batch adsorption experiments were carried out as a function of contact time, adsorbent dosage, pH, adsorbate concentration, and temperature. A comparison of adsorption capacity and adsorption intensity were examined in Freundlich and Langmuir isotherms. The nature of adsorption and feasibility were evaluated with thermodynamic parameters like the change in enthalpy (ΔH⁰), change in entropy (ΔS⁰) and change in Gibbs free energy (ΔG⁰). The negative ΔG⁰and ΔH⁰ values indicates the adsorption process was spontaneous and exothermic in nature. The kinetics of adsorption process was analyzed with Pseudo second order and intraparticle diffusion equations.