Preparation and application of TiO₂/Al₂O₃ microspherical photocatalyst for water treatment

Powder photocatalyst is difficult to be separated from treated water, and often contributes to membrane fouling when membrane filtration is employed to conserve photocatalyst, which limits the application of photocatalysis in practice. To solve these problems, TiO₂/Al₂O₃ microspheres consisting of nanosized crystals were fabricated by sol-spraying-calcination method. In humic acid (HA) photodegradation experiments, TiO₂/Al₂O₃ microspheres showed nice photocatalytic activity (removal efficiency nearly 80%), and the activity maintained at high level even after 20 cycles of reuse in durability test, which indicated good mechanical strength of the fabricated microspheres. In continuous operation of hybrid photocatalysis/membrane system, TiO₂/Al₂O₃ microspheres showed excellent pollutant removal ability, and controlled membrane fouling to a great extent.