Membrane Separation - Photocatalytic Study Of The Combined Process

This study focuses on photocatalysis-membrane filtration integrated process. By testing the particle size, the appropriate hollow fiber membrane is chosen for microfiltration. Then the membrane is used to filtrate titanium dioxide aqueous suspensions under different conditions. The systematic studies have shown that the separation performance of titanium dioxide particles is strongly affected by the particle size, suction pressure, aeration intensity, temperature, pH of the suspension and the ionic strength. When the feed concentration range from 1g/L to 4g/L, which is the widely adopted concentration range in slurry photocatalytic reactor systems, the flux doesn't change much.The membrane fouling resistance is divided into two parts: reversible fouling resistance and irreversible fouling resistance, based on the effects of hydraulic cleaning. Studies show that the reversible fouling resistance is the main reason causing membrane fouling. Decreasing suction pressure, increasing aeration intensity and periodic running can greatly alleviate membrane reversible fouling. The optimum operation parameters are suction pressure of 0.02MPa, aeration rate of 0.4m~3/h and 13 minutes of suction time, 2 minutes of suction suspended time. Ultrasonic and chemical cleaning was used to eliminate membrane irreversible fouling.The continuous operation for thirty days is described. It is discovered a completed separation of titanium dioxide from water can be carried out.