Journal of
Soil Science and Environmental Management

  • Abbreviation: J. Soil Sci. Environ. Manage.
  • Language: English
  • ISSN: 2141-2391
  • DOI: 10.5897/JSSEM
  • Start Year: 2010
  • Published Articles: 311

Full Length Research Paper

Optimization of key parameters for chromium (VI) removal from aqueous solutions using activated charcoal

M. Seyf-laye Alfa-Sika, Fei Liu* and Honghan Chen
Beijing Key Laboratory of Water Resources and Environmental Engineering, China University of Geosciences, Beijing 100083, China.
Email: [email protected]

  •  Accepted: 31 March 2010
  •  Published: 31 May 2010

Abstract

Commercial activated charcoal was investigated for removal of Cr(VI) from aqueous solutions. The effects of altering the initial Cr(VI) concentration, pH, contact time and amount of activated charcoal were studied. Maximum adsorption of Cr(VI) was achieved between pH 1 - 3 and after a contact time of 120 min. The percentage of Cr(VI) removed decreased from 99.99 - 90.83% when the initial Cr(VI) concentration was increased from 0.05 - 0.5 mg ml-1 at pH 2 and 26 ± 2°C. Various kinetic models such as pseudo first-order, pseudo second-order and Elovich models were used to evaluate the mechanism of Cr(VI) adsorption on activated charcoal. The Cr(VI) removal process was found to be governed by second-order kinetics and the rate constant of the adsorption (k2) was 0.1800 g kg-1 min-1 for an initial Cr(VI) concentration of 0.1 mg ml-1. The adsorption of Cr(VI) was evaluated using Langmuir, Freundlich, and Temkin isotherms and their constants were determined. The maximum adsorption capacity obtained using the Langmuir isotherm model was 45.24 g kg-1 at pH 2.

 

Key wordsKey parameters, activated charcoal, adsorption, aqueous solutions, Cr(VI).