BIOACCUMULATION OF NICKEL BY MICROBIALLY-ENHANCED CHEMISORPTION INTO POLYCRYSTALLINE HYDROGEN URANYL PHOSPHATE

Ni2+ was removed quantitatively, from aqueous solution into a microbia lly-created crystalline deposit of hydrogen uranyl phosphate (HUP). Th e mechanism of Ni2+ removal is an ion-exchange intercalation of Ni2+ i nto the interlayer space of HUP. The Ni2+-removing capacity of a colum n was proportional to the mass of HUP deposited and the Ni/HUP-loaded column was regenerated by washing with uranyl solution containing citr ate/MOPS buffer and glycerol-2-phosphate, or with citrate buffer alone . Regeneration in the presence of UO22+ increased the Ni2+-removing ca pacity of the column. A new mechanism for the removal of heavy metals via microbially enhanced chemisorption is proposed.