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

Enhanced performance of a macroporous disk alumina support was fabricated through colloidal filtration route, by using α-Al2O3 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-Al2O3 mesoporous layers were deposited onto this promising disk α-Al2O3 support through dip-coating. The disk membrane A1100/TiO2/γ-Al2O3, 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-Al2O3 membrane reported in literature. This mesoporous membrane showed relative high retention rate (∼80%) towards di-valent cations like Ca2+, Mg2+, but not for the mono-valent cation (Na+).