Bioaccumulation of nickel by intercalation into polycrystalline hydrogen uranyl phosphate deposited via an enzymatic mechanism

Journal Article · Wed May 01 00:00:00 EDT 1996 · Bio/Technology

DOI:https://doi.org/10.1038/nbt0596-635· OSTI ID:577022

Bonthrone, K M; Basnakova, G; Lin, F; Macaskie, L E ^[1]

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1. Univ. of Birmingham (United Kingdom)

A Citrobacter sp. accumulates uranyl ion (UO{sub 2}{sup 2+}) as crystalline HUO{sub 2}PO{sub 4}{center_dot}4H{sub 2}O (HUP), using enzymatically generated inorganic phosphate. Ni was not removed by this mechanism, but cells already loaded with HUP removed Ni{sup 2+} by intercalative ion-exchange, forming Ni(UO{sub 2}PO{sub 4}){sub 2}{center_dot}7H{sub 2}O, as concluded by x-ray diffraction (XRD) and proton induced x-ray emission (PIXE) analyses. The loaded biomass became saturated with Ni rapidly, with a molar ratio of Ni:U in the cellbound deposit of approx. 1:6; Ni penetration was probably surface-localized. Cochallenge of the cells with Ni{sup 2+} and UO{sub 2}{sup 2+}, and glycerol 2-phosphate (phosphate donor for phosphate release and metal bioprecipitation) gave sustained removal of both metals in a flow through bioreactor, with more extensively accumulated Ni. We propose `Microbially Enhanced Chemisorption of Heavy Metals` (MECHM) to describe this hybrid mechanism of metal bioaccumulation via intercalation into preformed, biogenic crystals, and note also that MECHM can promote the removal of the transuranic radionuclide neptunium, which is difficult to achieve by conventional methods. 42 refs., 1 fig., 1 tab.

• OSTI ID: 577022
• Journal Information: Bio/Technology, Vol. 14, Issue 5; Other Information: PBD: May 1996
• Country of Publication: United States
• Language: English

Related Subjects

56 BIOLOGY AND MEDICINE
APPLIED STUDIES
32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
29 ENERGY PLANNING AND POLICY
55 BIOLOGY AND MEDICINE
BASIC STUDIES
CHEMISORPTION
ION EXCHANGE
NEPTUNIUM
NICKEL
X-RAY DIFFRACTION
BIOLOGICAL ACCUMULATION
URANYL PHOSPHATES
X-RAY EMISSION ANALYSIS
BIOLOGICAL RECOVERY
CLATHRATES
UPTAKE
PHOSPHATASES
DECONTAMINATION
ENZYME ACTIVITY
WASTE WATER
CALCINATION
WASTE PROCESSING
REMEDIAL ACTION