Indanthrene Blue Dye Degradation by UV/H2O2 Process: H2O2 as a Single or Fractioned Aliquot?

Organic dyes are relatively resistant to conventional treatment methods and some of them produce carcinogenic by-products, making necessary the development of technologies for the removal of dyes and their breakdown products in wastewater. In this study, the influence of the addition of single or fractionated aliquots of H2O2 on the removal of indanthrene blue dye contained in aqueous solutions through the UV/H2O2 system was studied. Experimental parameters studied were temperature, pH, and H2O2 concentration, using single and fractional H2O2 additions. Maximum efficiency was observed at the highest H2O2 concentration in acid media. Fractional addition of H2O2 has a positive influence on the overall efficiency of the oxidative processes. Treatment carried out at 40 degrees C, pH 5, and 1,500mg/L of H2O2 (fractional addition) resulted in a drastic enhancement of the dye degradation/mineralization rate, reducing 98.6% chemical oxygen demand, 100% color, 92% total organic carbon, and 99% H2O2, demonstrating that this system was effective in the treatment of effluent containing indanthrene blue dye.