Author/Authors :
Mehrizad، Ali نويسنده Department of Chemistry, Science and Research Branch, Islamic Azad University, Tehran, Iran , , Aghaie، Mehran نويسنده Faculty of Chemistry, North Tehran Branch, Islamic Azad University, Tehran, Iran , , Gharbani، Parvin نويسنده Department of Chemistry, Ahar Branch, Islamic Azad University, Ahar, Iran Gharbani, Parvin , Dastmalchi، Siavoush نويسنده , , Monajjemi، Majid نويسنده Department of Chemistry, Science and Research Campus, Tehran, Iran , , Zare، Karim نويسنده Department of Chemistry, Science and Research Branch, Islamic Azad University, Tehran, Iran ,
Abstract :
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.
