Decolorization of azo dye by ozonation

Abstract

The decolourization and Chemical Oxygen Demand (COD) removal of azo dye solution in different ozonation time and biodegradation processes were evaluated to apply for reactive azo dye. Reactive Red 120 (RR120), Remazol Brilliant Blue R (RBBR), Reactive Green 19 (RG19) and Reactive Black 5 (RB5) have been selected amongst reactive azo dyes in performing ozonation process. Ozonation is effective for decolourization of reactive azo dye even with lower ozone dose. Ozonation time of 5 minutes, 10 minutes and 20 minutes are done to evaluate the performance of ozonation and biological treatment. Contrarily, significant decreased in COD concentration was only observed within higher range of ozone doses. Higher COD removal at high ozone dose was due to complete oxidation of azo dye. COD removals are increases as the increase of ozonation time and ozone dose. Biodegradation processes will decrease the COD value compare after the ozonation process. The performance of ozonation process in removal of color is 100% after 20 minutes ozonation.