Comparing filtration performances of precoated and uncoated ceramic membranes used in photocatalytic process for humic acid removal

The photocatalytic membrane reactor simultaneously employed with Precoated Dyanmic Membranes (PDM) and Uncoated Flat Ceramic Membranes (UFCM) for humic acid removal were evaluated to enhance the membrane performances. The influences of TiO2 concentrations and membrane fluxes on the Transmembrane Pressures (TMPs), membrane specific fluxes (MSFS) and removal rates of pollutants were carried out in details. The resistance distributions and chemical cleaning methods were investigated and compared. The results showed that the PDM showed higher HA and DOC rates than UFCM at different conditions. The highest DOC removal rates of PDM and UFCM were 81.2% and 77.5% at TiO2 concentration of 0.6gꞏL-1, respectively. The PDM showed better anti-fouling properties than UFCM due to its lower membrane fouling resistances, especially its small irreversible membrane resistances. The NaClO represented the best cleaning efficiency at pH 11, in which the pure water flux restore rates of PDM and UFCM can amount to 98.8% and 96.7%, respectively. The pure water flux restore rates reached over 95% for a new ceramic membrane repeatedly used 8eight times in PDM and four times in UFCM.