Reduction of Cr(VI) Using Polyaniline–Polystirene-Divinyl Benzene Gels

Wastewaters generated by electroplating, Industry of Pigments, Tannins, etc. contain Cr(VI).The removal of Cr(VI)from wastewaters is necessary due to its toxicity; the admissible concentration being 10 ppm.This work studies quantitatively and qualitatively the possibility of treating waste waters that have a concentration of 0.1 g/l Cr(VI), by using DVB gels coated with Pani films.The Pani films were applied on the DVB's surface both by polymerization of aniline in acid medium, using ammonium peroxodisulphate as the oxidizing agent and by treating the DVB gels with Pani solutions in N,N-dimethylformamide.During reaction, the reduction rate of Cr(VI)decreases because the Pani films are degrading. This degradation is generated by over-oxidation, phenomenon that leads to a series of secondary hydrolysable products.