eng URI http://hdl.handle.net/10795/2314 environmental protection biodegradability water pollution waste A pilot-scale system was established to examine the feasibility of in situ U(VI) immobilization at a highly contaminated aquifer (U.S. DOE Integrated Field Research Challenge site, Oak Ridge, TN). Ethanol was injected intermittently as an electron donor to stimulate microbial U(VI) reduction, and U(VI) concentrations fell to below the Environmental Protection Agency drinking water standard (0.03 mg liter_1). Microbial communities from three monitoring wells were examined during active U(VI) reduction and maintenance phases with GeoChip, a high-density, comprehensive functional gene array. The overall microbial community structure exhibited a considerable shift over the remediation phases examined. GeoChip-based analysis revealed that Fe(III)-reducing bacterial (FeRB), nitrate-reducing bacterial (NRB), and sulfate-reducing bacterial (SRB) functional populations reached their highest levels during the active U(VI) reduction phase (days 137 to 370), in which denitrification and Fe(III) and sulfate reduction occurred sequentially. A gradual decrease in these functional populations occurred when reduction reactions stabilized, suggesting that these functional populations could play an important role in both active U(VI) reduction and maintenance of the stability of reduced U(IV). These results suggest that addition of electron donors stimulated the microbial community to create biogeochemical conditions favorable to U(VI) reduction and prevent the reduced U(IV) from reoxidation and that functional FeRB, SRB, and NRB populations within this system played key roles in this process 11 pp. LOMv1.0 creator LOMv1.0 Project Final Beneficiary LOMv1.0 Project Executing Organisation 2011-06 LOMv1.0 training LOMv1.0 higher education 18+ Digital Library of the Operational Programme "Education and Lifelong Learning" abstract types Text Uranium Contaminants Bioremediation Bacteria Microbial communities Groundwater Ethanol 3046410 application/pdf http://repository.edulll.gr/edulll/bitstream/10795/2314/2/2314_Biostimulation%20Uranium.pdf Πανεπιστήμιο Θεσσαλίας. Σχολή Επιστημών Υγείας. Τμήμα Βιοχημείας και Βιοτεχνολογίας. Βιβλιογραφία διαλέξεων. Πρόγραμμα δια βίου μάθησης ΑΕΙ για την επικαιροποίηση γνώσεων αποφοίτων ΑΕΙ (ΠΕΓΑ) «Οι σύγχρονες τεχνικές βιο-ανάλυσης στην υγεία, τη γεωργία, το περιβάλλον και τη διατροφή» - Ενότητα 2. Σύγχρονες τεχνικές βιοανάλυσης στη γεωργία και το περιβάλλον URI http://hdl.handle.net/10795/2314 LOMv1.0creator 2016-03-15T07:46:03Z LOMv1.0validator 2016-03-15T07:46:03Z LOMv1.0 gre no no Copyright EYD-EPEDBM (Operational Programme "Education and Lifelong Learning")