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 alpha-Al2O3 powder with an average particle size of 1.1 mu m. The support, sintered at 1250 degrees C, showed relative high permeances towards water (101 L h(-1) m(-2) bar(-1)) and nitrogen (similar to 2 x 10(-6) mol m(-2) s(-1) Pa-1), with an average surface roughness of similar to 175 nm and a high mechanical strength of 61.1 MPa. Titania supported gamma-Al2O3 mesoporous layers were deposited onto this promising disk alpha-Al2O3 support through dip-coating. The disk membrane A1100/TiO2/gamma-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 gamma-Al2O3 membrane reported in literature. This mesoporous membrane showed relative high retention rate (similar to 80%) towards di-valent cations like Ca2+, Mg2+, but not for the mono-valent cation (Na+). (c) 2012 Elsevier Ltd and Techna Group S.r.l. All rights reserved.