We developed thin, superhydrophobic ceramic anodic alumina membranes and evaluated them in vacuum membrane distillation (VMD) using a highly permeable support. The ceramic membranes have a thickness of 55 μm and pore size of 200 nm. The highly permeable support is 3 mm thick with a pore size of 1 mm. The superhydrophobic ceramic membranes displayed water contact angles and liquid entry pressure values higher than 150° and 4 bar, respectively. During VMD at 80 °C, a very high water flux of 400 kg/(m2·h) was observed, much higher than previously reported for ceramic membranes in the literature. For comparison, a commercial PTFE membrane with a similar thickness (76 μm) and pore size (220 nm) was evaluated at the same conditions using the same support and an almost identical water flux of 416 kg/(m2·h) was observed, again much higher than previously reported for this type of membrane. For a hydrophobic alumina membrane with a thickness of 21 μm and pore size of 200 nm on a traditional alumina support with a thickness of 3 mm and pore size of 2.5 μm, a quite low water flux of 29 kg/(m2·h) was observed. Consequently, we have shown that a thin membrane in combination with a highly permeable support is necessary to arrive at high flux in VMD.
Keywords: Superhydrophobic ceramic membranes; Vacuum membrane distillation; Desalination; Highly permeable support; High flux.
Authors:Nadin Al-Jariry*, Liang Yu and Jonas Hedlund Chemical Technology, Luleå University of Technology, SE-971 87 Luleå, Sweden *Corresponding author email address: nadin.al-jariry@ltu.se; Tel.: +46 920 492871
Nadin Al-Jariry*, Liang Yu and Jonas Hedlund Chemical Technology, Luleå University of Technology, SE-971 87 Luleå, Sweden
*Corresponding author email address: nadin.al-jariry@ltu.se; Tel.: +46 920 492871