Regeneration of used Ironoxide nanoparticles (A-Fe2O3) in reduction of Chromium (VI) and Cadmium (II)

The present study examines the photo catalytic reduction of Chromium (VI) and Cadmium (II) from aqueous solution by recycling used hematite (a-Fe2O3) nanoparticles. a-Fe2O3 nanoparticles which were successfully synthesized by sol gel method. Predetermined IONP had crystalline size of 11.5 nm and flower shape. The photocatalytic reduction studies were earlier carried out for Chromium (VI) and Cadmium (II) solution using Ironoxide nanoparticles (IONP) in aqueous solution. Different parameters like metal concentration, dosage of nanoparticles, contact time and pH were studied. Best five results obtained in the experiments carried out while optimizing variable parameters using Response surface methodology were taken for regeneration study. Combination of 2ppm,4pH,150mg gave 92.27% Reduction :10ppm,4pH,150mg gave 81.25% Reduction: 2ppm,4pH,50mg gave 61.96% reduction:6ppm,4pH,100mg gave 59.42% reduction:6ppm,7pH,150mg gave 59.25% reduction These values were obtained for reduction of Chromium (VI) and were taken for regeneration study. Similarly for Cadmium (II) reduction, following best five results was taken for regeneration studies. 2ppm,4pH,150mg gave 94.43% reduction: 2ppm,10pH,150mg gave 75.52% reduction:2ppm,7pH,100mg gave 67.92% reduction:6ppm,7pH,150mg gave 65.02% reduction: 10ppm,7pH,100mg gave 58.65% reduction were taken for regeneration study. The regeneration and reusable experiments were performed and it was observed that the prepared a-Fe2O3 was stable and regenerable using strong acid (HCl) as desorbing agent.