Study On Integrated Process Of Photocatalytic Oxidation With Inorganic Membrane Enhanced By Ultrasound Field

In the reactor of ultrasonic-enhanced photocatalysis with inorganic membrane separation, we coupled ultrasound field, photocatalysis and membrane separation for photocatalytic oxidative degradation of low concentration phenol solution and polyacrylamide solution, using inorganic membrane to separate TiO2 particles from slurry system.Photocatalysis degradation of phenol was investigated. The pH value, reaction temperature, the initial concentration of the phenol Solution ultrasound power, ultrasound frequency on the integrated process was investigated. We fixed pH value of 9.0, temperature of 308 K, phenol concentration of 14 mg.L-1,ultrasonic power of 150 w and frequency of 45 kHz. Ultrasound can greatly improve the photocatalytic reaction rate and phenol degradation rate. We Studied dynamic model of ultrasound enhanced photocatalytic oxidative degradation of low concentration phenol solution, the results showed that ultrasound can enhance photocatalytic oxidation.Photocatalysis degradation of PAM solution was investigated. The effect of ultrasound power, ultrasound frequency was investigated. We fixed ultrasonic power of 150 w and frequency of 45 kHz. Ultrasound enhanced photocatalytic degradation, showing superior performance compared to only photocatalytic oxidation degradation process or only ultrasonic degradation process. We investigated the mechanism and kinetic model of ultrasonic-enhanced photocatalytic oxidation degradation, the result show that the ultrasonic enhance photocatalytic oxidation degradation polyacrylamide solution was first order reaction kinetics.In the reactor of ultrasonic-enhanced inorganic membrane separation, the ultrasound power, ultrasound frequency was investigated. We fixed the operation pressure of 0.1-0.15 MPa,cross-flow velocity of 0.8 m·s-1, solution concentration 1000-1500 mg·L-1, solution temperature of 298-303 K, pH value of 2.0-4.0, ultrasonic power of 100 w and frequency of 45 kHz for TiO2 particles slurry system. The increment of the permeation flux was 12 %-15 % under optimized conditions. We fixed the operating pressure 0.1 MPa, cross-flow velocity1.0 m·s-1, solution concentration 1000 mg·L-1, solution temperature303 K, pH value of 11.0,,ultrasonic power of 100 w and frequency of 45 kHz for PAM solution system. The increment of the permeation flux was 12 %-15 % under optimized conditions. Model to describe the ultrasound-enhanced inorganic membrane separation of polyacylamide (PAM) suspension was proposed based upon the experimental results and analysis of forces acted upon particles.