Multiwall carbon nanotube-polyethylene glycol and poly vinyl
alcohol (MWCNTs-PEG-PVA) nanocomposite hydrogel was fabricated
and used for the Cu(II) ions removal from water with high efficiency. The
prepared nanocomposite hydrogel was characterized using Scanning
electron microscope (SEM), Fourier transform infrared spectroscopy
FTIR, X-ray diffraction (XRD), thermogravimetric analyzer TGA and
mechanical properties. A series of systematic batch adsorption
experiments were conducted to study the adsorption property of
MWCNTs-PEG-PVA hydrogels prepared with different concentrations of
MWCNTs. Studying the effects of adsorption parameters such as pH,
contact time, and initial concentration were evaluated in a batch system.
The high adsorption capacity, easy regeneration and effective adsorption–
desorption results proved that the prepared MWCNTs-PEG-PVA
composite hydrogel could be an effective adsorbent in removing Cu(II) ion
from its aqueous solution. The maximum adsorption capacities were found
to be 645.1, 334.4, 238.09 and 185.09 mg g–1 for MWCNTs-PEG-PVA
hydrogel with 0.05, 0.10, 0.15, and 0.2 % MWCNTs, respectively at pH 6.
Isotherm studies revealed that Langmuir model well described the
equilibrium data of Cu(II) compared with Freundlich isotherm model.
Kinetics studies of Cu(II) adsorption followed pseudo-second order model.
The removal efficiency of the recycled MWCNTs-PEG-PVA hydrogel
was 79.3, 76.4, 73.8, 70.1 and 65.5 % for five cycles, which demonstrated
efficient reusability.
INTRODUCTION