Enzymatically‐mediated uranium accumulation and uranium recovery using a Citrobacter sp. Immobilised as a biofilm within a plug‐flow reactor

TLDR: A modified integrated form of the Michaelis-Menten equation is proposed to describe the removal of metal ion by a columnar bioreactor, where the efficiency of metal removal is semi-quantitatively related to the input flow rate, the total enzyme loading and theBioreactor activity.

Abstract: Biofilm-immobilised Citrobacter sp removed uranyl ion from flows supplemented with glycerol 2-phosphate The metal uptake mechanism was mediated by the activity of a cell-surface bound phosphatase that precipitated liberated inorganic phosphate with uranyl ion as HUO 2 PO 4 4H 2 O at the bacterial surface A modified integrated form of the Michaelis-Menten equation is proposed to describe the removal of metal ion by a columnar bioreactor, where the efficiency of metal removal is semi-quantitatively related to the input flow rate, the total enzyme loading (E 0 ) and the bioreactor activity With biofilm immobilised bacteria, E 0 was further divisible (split) into subparameters of phosphatase titre per bacterium and total biomass surface area Varying the split E 0 and the reaction temperature modified the bioreactor performance The immobilised bacteria retained high metal loads without loss in steady-state activity Accumulated metal was recovered as a concentrated solution