To aggrandize membrane flux during micro-polluted surface water ultrafiltration process, TiO2 photocatalytic oxidation pretreatment was conducted to mitigate the ultrafiltration membrane fouling. The single-factor experiments and membrane resistance analysis methods have shown that the water throughput performance in the hybrid process is affected by TiO2 concentration, aeration rate, transmembrane pressure, and crossflow velocity. Subsequently, the orthogonal methodology was further conducted to optimize the overriding variables using membrane flux as the response value. Simultaneously, parallel of UF ceramic membrane performance between chemical coagulation and TiO2 photocatalytic pretreatment was implemented and the excellent chemical washing method was determined. The results manifested that i) the impact on permeate flux was demonstrated following the order of the transmembrane pressure, crossflow velocity, aeration rate, and TiO2 concentration. The statistical optimum operating condition was acquired at 0.5 g/L additional TiO2, an aeration rate of 2 L/min, a transmembrane pressure of 0.15 MPa, and a crossflow velocity of 2.0 m/s; ii) TiO2 photocatalytic oxidation buttressed UF flux was superior to chemical coagulation pretreatment; iii) The best cleaning performance in permeability recovery was exhibited in citric acid solution after 40 minutes cycle-cleaning.

Zhou Zhen, Yu Yaqin, Yao Jilun, Zhang Xing and Ding Zhaoxia