Optimization and Modeling of Hexavalent Chromium Removal From Aqueous Solution Via Adsorption on Multiwalled Carbon Nanotubes

Mina Gholipour ； Hassan Hashemipour Rafsanjani ； Ataollah Soltani Goharrizi

《Research Journal of Applied Sciences, Engineering and Technology》 3卷9期 (2011/09) Pp. 880-886

並列摘要

Hexavalent chromium and its derivatives are potential pollutant due to their mortal affects. Therefore, It is essential to remove these components from wastewaters before disposal. Adsorption can be effective and versatile method for removing of hexavalent chromium. In this article, removal of hexavalent chromium via adsorption on multiwalled carbon nanotubes was investigated as a function of adsorbent dosage, initial solution pH, initial Cr (VI) concentrations, contact time and temperature. The batch experiments were conducted at 3 different temperatures (17, 27 and 37°C) and shows that Cr (VI) removal obeys pseudo-second order rate equation. Rate constant (K) values in 3 temperatures, pre-exponential factor and adsorption activation energy (E) was also obtained. The sorption data fitted well with Freundlich isotherm adsorption model. Thermodynamic parameters such as Gibbs free energy (ΔG°), enthalpy (ΔH°) and entropy (ΔS°) for Cr (VI) adsorption were estimated and Results suggest that the adsorption process is a spontaneous and endothermic.

並列關鍵字

Adsorption ； adsorption isotherm ； adsorption kinetics ； hexavalent chromium ； multiwalled carbon nanotubes ； thermodynamic parameters