Degradation Kinetics of Dye SF Blue in UV/TiO_2 Suspension System

The degradation efficiency,effect factors(such as reaction time,TiO2 dosage,dye concentration,initial pH value and temperature)and kinetics of dye SF Blue in UV/TiO2 suspension system are investigated.The results show that UV/TiO2 has a high activity on degradation of dye SF Blue in solution,and the photodecomposition reaction of the dye is concurrent besides the photocatalytic degradation.The results also show that the photocatalytic degradation of the dye in UV/TiO2 system is a second-order reaction apparently,with activation energy 50.1 kJ·mol-1 and pre-exponential factor 4.47×105 L·mg-1·min-1,while the photodecomposition of the dye in UV system is a first-order reaction apparently,with activation energy 14.8 kJ·mol-1 and pre-exponential factor 1.67 min-1.In addition,the adsorption of the dye on TiO2 surface becomes very strong when the initial pH value of dye solution being and below 3.