Uranium removal by sulfate reducing biofilms in the presence of carbonates

• Published in: Water Science & Technology Vol. 52; no. 7; pp. 49 - 55
• Main Authors: MARSILI, E, BEYENAL, H, DI PALMA, L, MERLI, C, DOHNALKOVA, A, AMONETTE, J. E, LEWANDOWSKI, Z
• Format: Conference Proceeding Journal Article
• Language: English
• Published: Oxford Pergamon 01.01.2005; IWA Publishing
• Subjects: Applied sciences; Bacteria; Bicarbonate; Bicarbonates; Biofilms; Biological and medical sciences; Biological treatment of waters; Bioreactors; Biotechnology; Carbonates; Cell membranes; DESULFOVIBRIO; Desulfovibrio desulfuricans; Environment and pollution; Environmental Molecular Sciences Laboratory; Exact sciences and technology; Fundamental and applied biological sciences. Psychology; General purification processes; Industrial applications and implications. Economical aspects; Influents; Lactate; Lactic acid; Membranes; Microorganisms; Periplasmic space; Plates (structural members); Pollution; RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY; Reactors; REMOVAL; Sulfate reduction; Sulfate-reducing bacteria; Sulfates; UPTAKE; Uranium; URANIUM COMPOUNDS; Wastewaters; Water treatment and pollution
• ISBN: 9781843395522; 1843395525
• ISSN: 0273-1223; 1996-9732
• DOI: 10.2166/wst.2005.0180

Hexavalent uranium [U(VI)] was immobilized in biofilms composed of the sulfate reducing bacteria (SRB), Desulfovibrio desulfuricans G20. The biofilms were grown in two flat-plate, continuous-flow reactors using lactate as the electron donor and sulfate as the electron acceptor. The growth medium contained uranium U(VI) and the pH was maintained constant using bicarbonate buffer. The reactors were operated for 5 months, and during that time biofilm activity and uranium removal were evaluated. The efficiency of uranium removal strongly depended on the concentration of uranium in the influent, and was estimated to be 30.4% in the reactor supplied with 3 mg/L of U(VI) and 73.9% in the reactor supplied with 30 mg/L of U(VI). TEM and SAED analysis showed that uranium in both reactors accumulated mostly on microbial cell membranes and in the periplasmic space. The deposits had amorphous or poor nanocrystalline structures.