The New Sludge-Free and Regenerative Methods of Treatment of Chromium Compounds Containing Water

Abstract

There were presented regenerative methods of solutions treatment from chromium compounds (VI) and chromium(III), which ensured water treatment to the required hygienic standards, without galvanic sludge formation. There was demonstrated that diluted (wash) solutions, containing chromium(VI) less than 100 mg/l, could be treat by reagentless method, by means of chemisorption Cr2O72- within keratin materials (hairs and/or wool). For concentrated solutions [Cr6+ > 100 mg/l] the best performance is achieved under joint recovery of chromium electroplating solution with pickle solutions containing sulfates or chlorides. All processes could be completely regenerate chromium as chromium oxide(III) or its mixtures with ferric oxides. Purified water contains only sodium sulfate.