Accumulation of zirconium and nickel by Citrobacter sp

✍ Scribed by Gabriela Basnakova; Lynne E Macaskie

• Publisher: Wiley (John Wiley & Sons)
• Year: 1999
• Tongue: English
• Weight: 98 KB
• Volume: 74
• Category: Article
• ISSN: 0268-2575
• DOI: 10.1002/(sici)1097-4660(199906)74:6<509::aid-jctb68>3.0.co;2-d

✦ Synopsis

Zirconium in aqueous ¯ows was moderately biomineralized by immobilized Citrobacter N14 cells, in the form of gel-like deposits, probably comprising a mixture of zirconium hydrogen phosphate (Zr(HPO 4 ) 2 ) and hydrated zirconia (ZrO 2 ). The simultaneous presence of uranyl ion (UO P P ) did not facilitate zirconium deposition and the biomineralization of uranium itself as HUO 2 PO 4 was repressed by zirconium in the presence of excess inorganic phosphate, liberated enzymatically. Nickel (Ni 2+ ) was not signi®cantly removed from aqueous ¯ows by sorption into cell-bound zirconium deposits, although cell-bound hydrogen uranyl phosphate (HUP) facilitated nickel removal via intercalative ion exchange into its polycrystalline lattice. A preformed layer of HUP also promoted zirconium removal, at 100% ef®ciency at pH 2.6, maintained over 38 column ¯uid-volumes before saturation.