Fabrication of a silica ceramic membrane using the aerosol flame deposition method for pretreatment focusing on particle control during desalination

A silica membrane was fabricated using the aerosol flame deposition (AFD) method under different sintering temperatures. It was characterized, in terms of roughness, pure water permeability, contact angle, zeta potential, and effective pore size distribution. Membrane performance was evaluated with respect to removal of Suwannee River humic acids and polystyrene particles with different sizes. Both membrane thickness and pure water permeability decreased with increasing sintering temperature. The effective pore sizes of synthesized membranes ranged from 6.5 to 8.0 µm. Polystyrene particles with sizes higher than 7 µm were almost completely removed by the synthesized ceramic membranes; however, no removal for humic acids was measured with the ceramic membranes tested.

A new method, AFD, was developed to fabricate microporous silica membranes. The ceramic membranes, fabricated under different sintering temperatures, were characterized in terms of roughness, pure water permeability, contact angle, zeta potential, and effective pore size distribution. The membranes were also evaluated with respect to removal performance using Suwannee River humic acids and polystyrene latex particles with different sizes. Membrane thickness and PWP were found to decrease with increasing sintering temperatures due to aerosol melting under higher sintering temperatures. From these, sintering temperature for the AFD method was identified as an influencing factor for membrane properties. Fabricated ceramic silica membranes provided good removal efficiencies for micron-sized polystyrene particles but were not good for the removal of humic acids. Based on these results, the AFD method can fabricate microporous ceramic membranes which are efficient in micro- sized particle removal (for example, pre-treatment focusing particles control for desalination process).