[Kinetics model for photo-catalytic degradation of Rodamine B with TiO2 /SiO2 as catalyst].

A novel photo-catalytic reactor of three-phase internal circulation fluidized bed was employed to the photodegradation of Rhodamine B with TiO2/SiO2 carried on porous silica as photocatalyst. The degradation kinetics of Rodaming B is investigated in the reactor. It is found that the degradation of Rodaming B conform hyperbola model, the reciprocal of degradation rate 1/X is proportional to the reciprocal of time 1/t. The reaction rate constant has no relation with initial reactant concentration and is proportional to the light density and volumetric rate of energy absorption. The reaction rate conforms the experiment results quite well, the average relative error being less 3.25%.

[Radiation transformation mechanism in a photocatalytic reactor of three-phase internal circulating fluidized bed].

A novel three-phase internal circulating fluidized bed photocatalytic reactor was established and the radiation transformation in which was investigated. The experimental results indicate that with the interaction of gas and solid (gas flux > 0.3m3/h), the radiation transformation in the reactor along radial direction conforms to a definite exponential function, which agrees to formula Rose about the rules of light intensity distribution through evenly suspended particles. The value of radiation energy is affected by the initial light intensity, the concentration of photocatalyst and the thickness of liquid layer. The aerated gas amount only influence the state of the fluidized bed and has little effect on the distribution of light intensity along radical direction. Photocatalytic degradation of Rhodamine B indicate that the efficiency of three-phase internal circulating fluidized bed is much higher than slurry bed. The optimal catalyst concentration of this system is 10 - 12g/L.