Hybrid low-pressure submerged membrane photoreactor for the removal of bisphenol A Original Research Article

The efficiency of a hybrid system combining photocatalysis and membrane filtration in a single module was investigated. Low-pressure submerged hollow fibre membranes were used to retain the TiO2 particles in the system. Bisphenol A (BPA) was used as a model pollutant. Ninety-seven per cent photodegradation and more than 90% photomineralization of 10 ppm of BPA were achieved after 90 and 120 min of UV illumination, respectively. Aeration was applied in the submerged membrane photoreactor (SMPR) to provide mixing, dissolved oxygen, mechanical agitation to prevent agglomeration of TiO2 particles as well as providing shear forces to remove TiO2 particles from the membrane surface. The optimum aeration rate used in our 0.8-L reactor was 0.5 L/min. It was found that intermittent permeation enhanced the sustainability of the submerged membranes but showed no effect on the photoactivity of the system. An intermittence frequency (IF) of 0.1 was sufficient to reduce the fouling rate of the membrane under the experimental conditions. The SMPR appears to be very effective and can achieve removal of low-concentration organics (such as BPA) in a compact, low-energy system.