Reduction of Hexavalent Chromium Present in Wastewater by Steel Wool in a Continuous Flow System

Continuous reduction of hexavalent chromium Cr(VI) in aqueous solution by commercial steel wool was investigated using glass column over the pH range of 3–7. Nearly 100% reduction took place within the first 10 minutes. The maximum reduction was obtained at pH 3, and the rate decreased with increasing initial pH of Cr(VI) solution. The initial substrate concentration was varied as 50 mg/L, 80 mg/L and 100 mg/L respectively. There was a gradual decrease in the extent of reduction as the initial substrate concentration increased. The breakthrough of the column was observed generally at 10 minutes whereas the complete exhaustion took 120 minutes. Results of this experiment may be utilized for modelling, simulation and scale-up in future.