Hydrophilic composite membranes for simultaneous separation and photocatalytic degradation of organic pollutants

Abstract

TiO2/Al2O3 composite membranes were prepared using a sol–gel technique. After membrane characterization, six layers as optimal number of coatings was chosen (0.2μm homogenous thin film). Filtration and photodegradation were coupled by using TiO2/Al2O3 membranes in a photocatalytic membrane reactor under UV light. Experimental results clearly showed that TiO2 thin film under UV irradiation enhanced the wettability of the ceramic membrane, were higher and more stable water flux were reached rapidly. Acid Orange 7 (AO7) were used as model pollutant. Dye was not completely degraded, 25% of degradation was obtained for only one pass corresponding to a contact time of several milliseconds. Photonic efficiency equal to 0.29 was reached. Evolution of the kinetic degradation versus the initial concentration of AO7 were consistent with the Langmuir Hinselwood model. The photodegradation allows to increase significantly composite membrane flux and to strongly prevent flux decrease when AO7 solutions were filtrated. Membrane cleaning was performed without chemicals by irradiating membrane surface under static conditions.