Green synthesis of polypyrrole/nanoscale zero valent iron nanocomposite and use as an adsorbent for hexavalent chromium from aqueous solution

Abstract

Green synthesis of polypyrrole/nanoscale zero valent iron nanocomposite (Ppy/Fe0 NC) fabricated by a simple in-situ oxidative polymerization method was reported. The structure and the properties of Ppy/Fe0 NC were confirmed using various analytical techniques. The as-prepared Ppy/Fe0 NC was used as an adsorbent for the adsorption of hexavalent chromium (Cr(VI)) through batch experiments. The effect of initial pH, adsorbent dose, contact time, equilibrium concentration and co-existing ions were studied. It was deduced that adsorption data followed the pseudo-second-order rate model and Langmuir isotherm model with a maximum adsorption capacity of 202.02 mg/g at 25°C. Furthermore, high selectivity of Ppy/Fe0 nanocomposite for the removal Cr(VI) was observed even in the presence of co-existing ions. These findings suggest that the green synthesized adsorbent can be used for treatment of wastewater containing Cr(VI).

Keywords

• Polypyrrole
• Iron zero nanoparticles
• Green synthesis
• Adsorption
• Hexavalent chromium