▎ 摘　　要

The hexavalent chromium in water is extremely toxic to most living organisms and can cause many diseases. In this work, we developed Polypyrrole (PPy), Polypyrrole/graphene oxide (PPy/ GO) nanocomposite, and Polypyrrole/graphene oxide/zerova-lent iron nanoparticles (PPy/GO/n-ZVI) nanocomposite for adsorption of Cr (VI) from water. PPy/GO nanocomposite showed the highest Cr (VI) removal capacity for 10% (weight) loading of GO. PPy/GO/n-ZVI nanocomposite showed the highest Cr (VI) adsorption capacity for 50 % iron nanoparticle loading. Chemical kinetics data showed that Cr (VI) adsorption occurred with pseudo-second-order. The maximum adsorption capacity (q(max)) was found to be 64.29 mg/g, 129.09 mg/g, and 171.04 mg/g on PPy, PPy/GO nanocomposite, and PPy/GO/n-ZVI nanocomposite respectively. The thermodynamic study showed a positive value of delta S, and a negative value of delta G indicated rise in the disorder at the adsorbate-adsorbent interface and spontaneous nature of Cr (VI) adsorption. delta H was close to 21 kJ/mole indicating adsorption process occurred via physisorption. The recycling of the adsorbent was carried out by washing with sodium hydroxide and Cr (VI) removal efficiency decreased by around twenty % in the fifth cycle. The present study suggests that the PPy/GO/n-ZVI nanocomposite is an environment-friendly magnetic material and provides a simple, low-cost strategy for the adsorption of Cr (VI) from wastewater.