Ultrasonic treatment of biologically treated baker’s yeast effluent

The aim of this study was to examine the removal of color and chemical oxygen demand COD of biologically treated baker’s yeast effluent with ultrasonic irradiation. An ultrasonic homogenizator with 20 kHz frequency was used for this purpose. TiO2/ZnO composite was used as a sonocatalyst. The effect of the amount of catalyst on color and COD removal was investigated. According to results, by using ultrasound and TiO2/ZnO composite, decolorization increases until the optimum of the catalyst amount. The highest decolorization was obtained at 0.15 g/L of catalyst concentration. COD removal was 17% with ultrasonic irradiation and increased to 33% when using ultrasound along with the catalyst at the optimum amount. The effect of the solution pH on ultrasonic decolorization was also investigated in this stud