Enhanced performance of a macroporous ceramic support for nanofiltration by using α-Al2O3 with narrow size distribution

Abstract Enhanced performance of a macroporous disk alumina support was fabricated through colloidal filtration route, by using α-Al 2 O 3 powder with an average particle size of 1.1 μm. The support, sintered at 1250 °C, showed relative high permeances towards water (101 L h −1 m −2 bar −1 ) and nitrogen (∼2×10 −6 mol m −2 s −1 Pa −1 ), with an average surface roughness of ∼175 nm and a high mechanical strength of 61.1 MPa. Titania supported γ-Al 2 O 3 mesoporous layers were deposited onto this promising disk α-Al 2 O 3 support through dip-coating. The disk membrane A1100/TiO 2 /γ-Al 2 O 3 , with pore size of ca. 4.4 nm, showed a pure water flux as high as 4.5 L m −2 h −1 bar −1 , which is four times higher than that of γ-Al 2 O 3 membrane reported in literature. This mesoporous membrane showed relative high retention rate (∼80%) towards di-valent cations like Ca 2+ , Mg 2+ , but not for the mono-valent cation (Na + ).