Removal of copper (II)‎ from wastewater using modified carbon nanotubes

Abstract EN

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.