Decolorization of Reactive Yellow 17 in aqueous solution by ozonation in a semi-batch bubble column reactor

In this study, the factors influencing the rate of chemical oxygen demand (COD) of a synthetic waste solutions containing water soluble reactive dye [Reactive Yellow 17 (RY17)] by ozone gas was investigated. The research was conducted using a semi-batch bubble column to take the advantage of the intensive back-mixing that prevails in bubble columns. As a result, the COD of disperse dyestuff wastewater was reduced to 78.58%, and decolorization was remarkable under the basic condition of pH 12, complete each dye degradation occurs in 12 min, ozone consumption goes on for a further 30 min after which time most degradation reaction is completed. Kinetic studies were exhibited that direct ozonation of the aqueous dyes were a pseudo-first-order reaction with respect to the dyes. The apparent rate constant increased with both applied ozone dose and higher pH values, declined logarithmically with the initial dye concentration