Abstract:
Polypyrrole (PPy) coated oxidized multi-walled carbon nanotube (PPy-OCNT NC) based nanocomposites were successfully synthesized. They were used as novel adsorbent for the removal of hexavalent chromium Cr (VI) from aqueous solution. Effects of various parameters that include pH, dose of PPy-OCNT NC, initial concentration of Cr (VI) and percentage loading of PPy on OCNTs were explored. The optimum pH for Cr (VI) removal was found to be 2. Cr (VI) adsorption followed Langmuir isotherm with maximum adsorption capacity of 555.56 mg/g while the sorption kinetics followed the pseudo second order kinetic model. Ion exchange mechanism was found to be the predominant mechanism in the removal of Cr (VI) from aqueous solution where the doped Cl- on polypyrrole exchanged with either monovalent bichromate, HCrO4-ordivalent dichromate Cr2O72- ions, as these ions are dominating species at pH <6. Keywords: Carbon nanotubes, nanocomposite, Heavy metals, isotherms, Pollution
