A novel three dimensional carbon nanotube-polyethylene glycol-polyvinyl alcohol nanocomposite for cu(II) removal from water

Abstract

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.