Degradation kinetics of azo dye by ozonation in water

Abstract

Decomposition of azo dye by ozonation was investigated. A methyl orange (MO) was used as a typical compound of azo dye. Concentration of MO in water was adjusted to 200 mg/L. 2.0% ozone in oxygen was introduced into the MO solution from the bottom of a bubble column reactor. The MO solution was decolorized rapidly by ozonation and the COD and TOC of MO solutions were also decreased with an increase in ozonation time. The color reduction rate of MO solution by ozonation was much faster than those of COD and TOC reduction. The decolorization and degradation were followed by pseudo-first-order kinetics independently