Optimization and kinetic evaluation of acid blue 193 degradation by UV/peroxydisulfate oxidation using response surface methodology

The op miza on of process condi ons for the degrada on of Acid Blue 193 byUV/peroxydisulfate was investigated using response surface methodology(RSM). The effects of four parameters namely initial K2S2O8concentration, UVirradiation, temperature, and initial dye concentration on two processresponses, color removal and the rate constants of the first-order kineticequations, were investigated using a second-order polynomial multipleregression model. The analysis of variance (ANOVA) explained a highdetermination coefficient (R2) value of 0.927-0.967, which ensures a good fit ofthe first-order regression model with the experimental data. The centralcomposite design (CCD) was used to optimize the process conditions, whichshowed that an initial K2S2O8concentra on of 5 mM, UV irradia on of 250 W,temperature of 50 °C, and the ini al dye concentra on of 40 mg/L were thebest conditions. Under optimum conditions, the maximum color removal fromthe wastewater and the rate constants of the first-order kinetic equation were100% and 0.086 min--1, respectively.