Characterization of dye wastewater in advanced oxidation process and biological treatment

Abstract

In this study, advanced oxidation process (AOP) has been conducted in laboratory scale ozonation/H2O2 treatment train to investigate the characteristic change in azo dye. The experiments set up is designed base on the following matrices: Effect of H2O2/O3 ratio, effect of pH and effect of ozonation time. Advanced Oxidation Process (AOP) completely removing colour of azo dye solution. In AOP hydrogen peroxide accelerates the decomposition of ozone and enhanced the production of the hydroxyl radical. The radical quickly oxidize colour impacting functional group in azo dye, and consequently the azo dye is completely decolorized. COD value was slightly decreased after AOP, with the optimum H2O2/O3 ratio was obtained at 1 mg H2O2/ mg O3. The removal efficiency of COD were varied for different value of pH, with the optimum COD removal was achieved at pH 7AOP transformed the structure of benzene ring, N=N double bond and C-O single bond, which eventually resulted on decolourization of azo dye solution. As for COD removal for H2O2/O3 ratio at 1 mg shows the removal percentage at 26%. For pH, the COD removal at pH 7 is 53%. At pH 7 and 1 mg H2O2, the COD removal is optimum at 80 minutes with the removal percentage is 60.5%. BOD removal shows no huge different with AOP alone. This process must be continued with biological treatment to gain the maximum value. The result indicated that AOP was effective in transforming the functional groups present in Reactive Red 120 producing biodegradable product.