Photocatalytic degradation of bisphenol A in a gas-liquid-solid circulating fluidized bed photoreactor with internal multi-layered lamps using Gd-doped TiO2 particles
多层光源内置式气-液-固循环流化床光催化降解双酚A

A new photocatalytic degradation process combining particle and gas-liquid-solid circulating fluidized bed photoreactor (GLSCFBPR) technologies is proposed, in order to take the advantage of suspended slurry photocatalytic systems that can maximize the efficiency of photon utilization, oxidation rates and reactor throughput, and to solve the separation problem of nanophotocatalysts from the slurry system. The performance of the proposed process was evaluated using Gd doped TiO2 microparticles as photocatalyst and bisphenol A as model pollutant. Photocatalyst concentration, superficial gas velocity and superficial liquid velocity all have a corresponding optimum value in the new reactor system. When the micrometer Gd-TiO2 was used, the optimum operation conditions were photocatalyst concentration 6 g·L-1, superficial gas velocity 8.34×10-3m·s-1 and superficial liquid velocity 1.11×10-2 m·s-1. Under the optimized operation conditions, the Gd-TiO2 fluidized system exhibited superior photocatalytic degradation and sedimentation separation performance to that of the P25-TiO2 slurry system. Therefore, the new photocatalytic reactor system combining easily separable microparticles and a gas-liquid-solid circulating fluidized bed reactor is highly suitable for large-scale industrial applications of photocatalysis for water treatment and purification.