In the present work, carbon nanotubes were prepared by Chemical Vapor
Deposition (CVD) method, acetylene gas was used as a carbon source. In CVD
system, a catalytic growth of CNTs is carried out by decomposition of acetylene
(C2H2 ) at a temperature of 750 0C for one hour ,argon is used as an oxidation
protection gas. The carbon nanotubes produced are purified to remove impurities
such as metal catalyst and then functionalized by treating with HNO3. Scanning
Electron Microscopy (SEM), FT-IR spectra and BET for Surface Area measurement
technique were used for characterization of CNTs. CNTs with about 30 nm in
diameter and with length of several microns were obtained. The effects of initial
concentration of metal (ppm), pH, carbon nanotube (CNT) dosage (mg) and contact
time (min) on the adsorption of Cu+2 ion were studied.
The results show that the pH of aqueous solution is one of the major parameters
that control the adsorption of ion at the solid-water interfaces. Maximum removal
percentage of Cu+2 species is achieved at pH 8, CNT dosage of 50 mg/L and initial
concentration of 50 mg/L and it is 98.39%. The constants of Langmuir and
Freundlich models are obtained from fitting the adsorption equilibrium data. The
correlation coefficients of Langmuir and Freundlich models are 0.75 and 1,
respectively, indicating that the Freundlich model is more appropriate to describe the
adsorption characteristics of Cu+2 onto CNTs.