Research article
Comparison of 4-chloro-2-nitrophenol adsorption on single-walled and multi-walled carbon nanotubes
1 Ph.D Student, Department of Chemistry, Science and Research Branch, Islamic Azad University, Tehran, Iran
2 Faculty of Chemistry, North Tehran Branch, Islamic Azad University, Tehran, Iran
3 Department of Chemistry, Ahar Branch, Islamic Azad University, Ahar, Iran
4 Biotechnology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
5 School of Pharmacy, Tabriz University of Medical Sciences, Tabriz, Iran
6 Department of Chemistry, Science and Research Branch, Islamic Azad University, Tehran, Iran
Iranian Journal of Environmental Health Science & Engineering 2012, 9:5 doi:10.1186/1735-2746-9-5
Published: 3 September 2012Abstract
The adsorption characteristics of 4-chloro-2-nitrophenol (4C2NP) onto single-walled and multi-walled carbon nanotubes (SWCNTs and MWCNTs) from aqueous solution were investigated with respect to the changes in the contact time, pH of solution, carbon nanotubes dosage and initial 4C2NP concentration. Experimental results showed that the adsorption efficiency of 4C2NP by carbon nanotubes (both of SWCNTs and MWCNTs) increased with increasing the initial 4C2NP concentration. The maximum adsorption took place in the pH range of 2–6. The linear correlation coefficients of different isotherm models were obtained. Results revealed that the Langmuir isotherm fitted the experimental data better than the others and based on the Langmuir model equation, maximum adsorption capacity of 4C2NP onto SWCNTs and MWCNTs were 1.44 and 4.42 mg/g, respectively. The observed changes in the standard Gibbs free energy, standard enthalpy and standard entropy showed that the adsorption of 4C2NP onto SWCNTs and MWCNTs is spontaneous and exothermic in the temperature range of 298–328 K.
