(636e) Alternative Membrane Chromatography for Water Treatment

In contrast to resin column chromatography, membrane chromatography (MC) has high mass transfer rate and small operating pressure, thus finding important applications in bioseparation to purify and recover high value products such as proteins and antibodies. However, it is barely used for removal of small concentration metal ions for water treatment because of low performance/cost ratio. The effective use of membrane chromatography can still be compromised by mass transfer, ligand chemistry for adsorption, as well as poly-distribution of fluid flow across the membrane bed. In this talk, alternative membrane chromatography constructed with fibrous biopolymeric membranes will be discussed. These alternatives have high throughput and minimal pressure drop. The materials used to fabricate these membranes were carefully designed using nano-engineered technologies such as TiO₂ nanocrystals growing in situ on cellulose fibers, electrospun chitosan nanofibers. They were used to remove Pb (II) and Cr (VI) in small concentration from water, respectively. Static stirred tank adsorption was investigated first before dynamic membrane bed experiments were conducted. Adsorption of these metals all fitted Freundlich isotherm. The MC was very effective in capturing these metals in a single pass flow mode, the shape of the breakthrough curves was dependent of a number of parameters such as membrane packing style, bed length and flow distribution. It is concluded that these alternative MC is advantageous over traditional MC for water treatment.