In this study, the factors affecting the rate of chemical oxygen demand (COD) of a synthetic waste
solution containing a water soluble basic dye [Methylene Blue] were investigated.Decolorization of the
dye was achieved by ozonation.The research was conducted using a batch bubble column to take the
advantage of the intensive back-mixing that prevails in bubble columns. As a result, the COD of basic
dyestuff wastewater was reduced to 64.96% and decolorization was observed under basic conditions (pH
12), complete MB degradation occurring in 12 min.