Adsorption of Chromium Ions by Acid Activated Low Cost Carbon-Kinetic,Thermodynamic and Equilibrium Studies

B R Venkatraman,S Arivoli,S Parthasarathy,A Kasthuri,P Pandian

doi:10.1155/2009/134010

Abstract

A carbonaceous adsorbent prepared from an indigenous waste, by acid treatment was tested for its efficiency in removing metal ions. The process parameters studied include agitation time, initial metal ions concentration, carbon dose, pH and temperature. The adsorption followed first order reaction equation and the rate is mainly controlled by intra-particle diffusion. Freundlich and Langmuir isotherm models were applied to the equilibrium data. The adsorption capacity (Qm) obtained from the Langmuir isotherm plot were found to around 30 mg/g at an initial pH of 7.0. The temperature variation study showed that the metal ions adsorption is endothermic and spontaneous with increased randomness at the solid solution interface. Significant effect on adsorption was observed on varying the pH of the metal ion solutions. The Langmuir and Freundlich adsorption isotherms obtained, positive ΔH0value, pH dependent results and desorption of metal ions in mineral acid suggest that the adsorption of metal ions on BBC involves chemisorption as well as physisorption mechanism.

Highlights

The problems of the ecosystem are increasing with developing technology
We have reported the applicability of kinetic and mass-transfer models for the adsorption of chromium ion onto activated carbon
The experiments carried out at different pH shows that there was a change in the percent removal of metal ion over the entire pH range of 3 to 9 shown in the Figure 5, This indicates the strong force of interaction between the metal ion and the activated carbon that, either H+ or OH - ions could influence the adsorption capacity

Summary

Introduction

The problems of the ecosystem are increasing with developing technology. Heavy metal pollution is one of the main problems. The present study undertaken to evaluate the efficiency of a carbon adsorbent prepared form acid activated Borassus Bark for the removal of metal ion aqueous solution.

Results

Conclusion