Removal of Chromium from Aqueous Solution Using Two Kinds of Polyaniline

Absorptive characteristics of polyaniline synthesized with two different oxidants including potassium iodate and ammonium persulfate was studied. Synthesized polyanilines in powder shape is used as an adsorbent to remove toxic hexavalent chromium from aqueous solutions. Experiments were conducted in batch mode with different variables such as agitation time, solution pH and initial concentration of hexavalent chromium. Removal mechanism involving polyaniline is the combination of surface adsorption and reduction reaction. Synthesized polyaniline with potassium iodate had the good performance for total chromium removal, while synthesized polyaniline with ammonium persulfate had the good performance for hexavalent chromium removal. The equilibrium times for total and hexavalent chromium removal were occurred at 30 and 5 minutes respectively for polyanilines. The optimum pH for total chromium removal occurred at pH 3, 11 for synthesized polyaniline with potassium iodate and ammonium persulfate respectively. The maximum hexavalent chromium removal took place under acidic condition at pH 1 for polyanilines. Investigating the isothermal characteristics showed that the equilibrium adsorption data for polyanilines fitted both Freundlich’s and Langmuir’s isotherms.