Kinetics of Batch Adsorption of Iron (II) ions from Aqueous Solution using Activated Carbon from Glossocardia linearifolia Stem

Abstract

Glossocardia linearifolia Stem obtained from nearby area of pudukkottai district, was activated around 600^o C and the particle size (53–150 μm) was used as an adsorbent for the removal of Fe (II) ion from aqueous solution. The effect of various factors (temperature, adsorbent dose and Initial pH) on adsorption of Fe (II) on Glossocardia linearifolia Stem was investigated. The effect of pH shows that the amount adsorbed increased with the increase of pH of solution. The equilibrium adsorption isotherms were analyzed by Langmuir and Freundlich equations. Both Langmuir and Freundlich models can describe the adsorption equilibrium but the Langmuir model shows better agreement. The amount adsorbed increased with the increase of temperature suggests the formation of dimer in the contact region. SEM micrographs and differential molar isosteric heat of adsorption (ΔH) calculated at different surface coverage, indicate that the surface is heterogeneous having energetically different adsorption sites. Values of n calculated from Freundlich plots indicate that adsorption of Fe (II) on Glossocardia linearifolia Stem is spontaneous. At high surface coverage, the differential heat of adsorption versus surface coverage plot shows maximum value indicating the occurrence of structural rearrangement in the adsorbate. With the increase of adsorbent dose, amount adsorbed increased due to the increased surface area of adsorbent.