Application of TiO_2 Dynamic Membrane in Separation of Oil-in-water Emulsions

Titanium dioxide dynamic membranes (DM) were formed on carbon tube support via crossflow microfiltration, and their performances in separation of oil-in-water emulsions were experimentally studied. The effects of pore size of the support on oil rejection efficiency and steady permeate flux were examined. Results show that oil rejection efficiency of the prepared DM is higher than 98% and oil concentration of permeate solution is less than 8.3 mg⋅L −1 , which meets the requirement of national drainage control regulations. The steady permeate flux increases at first then decreases with the increase of the support pore size. A novel concept, "steady flux decay ratio" (FDR) of DM was proposed, and types of DM were identified based on the concept. Analysis displays that the FDR increases at first then decreases with the increase of the support pore size, and microfiltration type of DM transits from full blocking filtration to intermediate blocking filtration during which the decline of permeate flux becomes slower as the support pore size is increased.