Application of ceramic microfiltration membrane modified by nano-TiO2 coating in separation of a stable oil-in-water emulsion

Hydrophilic modification of the commercial ceramic microfiltration membranes is processed by the nano-TiO2 coating. The nano-coating does not form a separation layer but increases the hydrophilic character of membrane surface. The modified microfiltration membranes are used to treat stable oil-in-water emulsions. The results show that the ceramic membrane modified by 2 mol/L Ti(SO4)2 solution is the more suitable in the MF process. Under the following operation conditions: cross-flow velocity of 5 m/s, trans-membrane pressure of 0.16 MPa, feed temperature of 40 °C, the modified membrane has the better stable flux, which is higher than that of the unmodified one. The oil concentration of the filtrate is no more than 10 mg/L if the oil concentration of the feed is not higher than 4 g/L due to the existence of the hydrophilic nano-TiO2 coating, indicating the modified ceramic microfiltration membrane can be directly applied in the treatment of a stable oil–water emulsion.