Removal of chromium from aqueous solution using polyaniline - Poly ethylene glycol composite

The adsorption of chromium compounds from solutions by a composite of polyaniline/poly ethylene glycol (PANi/PEG) was investigated in this study. Experiments were conducted in batch mode under various operational conditions including agitation time, solution pH, PANi/PEG dose and initial concentration of chromium salts. Results showed that concentration of PEG at synthesizing stage has a significant effect on the capacity of produced composite for removal of chromium. Morphologically, PANi/PEG composite is closely dependent on the concentration of PEG. Maximum removal of hexavalent chromium was experienced when 2 g/L of PEG was used in synthesis of PANi/PEG. Removal of hexavalent chromium by PANi/PEG composite included surface adsorption and reduction reaction. The optimum pH was 5 and the equilibrium time for hexavalent chromium removal was about 30 min. Investigation of the isothermal characteristics showed that chromium adsorption by PANi/PEG composite was in high accordance with Langmuir's isotherm.