Spectral Analysis of Catalytic Oxidation and Degradation of Bromophenol Blue at Low pH with Potassium Dichromate

Abstract This research investigated the efficacy of potassium dichromate (K2Cr2O7), ultraviolet (UV) solar irradiation and UV in combination with two diprotic acid i-e sulphuric and oxalic acid (UV chromate/carbonate), for decolorizing bromophenol blue (BPB). The results suggested that alone UV and solar exposure was the poor decolorizer of the dye waste water. Up to 10% color removal with alone UV and solar treatment were achieved which indicated that, only solar and UV were not effective for dye removal even though UV was slightly more effective as compared to solar one. The decline reaction rate was observed as a result of increased concentration of dye. Increase in concentration of dichromate showed two peaks at 592 and 515 which showed that bromophenol degraded into two smaller components through complex formation. Addition of sodium carbonate as a catalyst in dye chromate-oxalate system found to be effective in degradation of BPB with reduced time period. The reaction was rapid and almost maximum of the dye converted into CO2. Research outcome suggests that chromate-oxalate system is very effective techniques for reducing color of dye waste water for safety of aquatic environment. Reaction pathway of oxidation of BPB is discussed in the relevant section of the paper.