{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/88079"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/88079","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Uranium isotopic fractionation induced by U(VI) adsorption onto common aquifer minerals","abstract":"Uranium groundwater contamination due to mining and processing affects numerous sites in the western United States. Bioreduction of soluble, mobile U(VI) to U(IV)-bearing solids is a common remediation strategy. Uranium isotopes (238U/235U) have been utilized to track the progress of microbial reduction, with laboratory and field studies finding a ~1‰ isotopic fractionation with the U(IV) product enriched in 238U. However, the isotopic fractionation produced by adsorption may complicate the use of 238U/235U to trace microbial reduction. A previous study found that adsorption of U(VI) onto Mn oxides produced a -0.2‰ fractionation with the adsorbed U(VI) depleted in 238U (Brennecka et. al. 2011b). The aqueous speciation of U(VI), and the characteristics of the sorbent surfaces may both produce variations in isotopic fractionation induced by adsorption. This study determined U isotopic fractionation induced by U(VI) adsorption onto goethite, birnessite, illite, quartz, and complex aquifer materials. The influence of U(VI) speciation on fractionation was also examined by measuring differences between fractionation factors accompanying the adsorption of uranyl, uranyl hydroxyl, uranyl carbonato, and calcium uranyl carbonato ions. To increase our ability to resolve fractionation, experiments were carried out with a multi-stage, batch approach, in which a U(VI)-bearing solution was exposed to three stages of adsorption. The dissolved U(VI) was analyzed by a double-spike MC-ICP-MS method. Adsorption to the studied solid phases induces an average isotopic fractionation of -0.17‰ with the adsorbed U(VI) isotopically lighter. U(VI) speciation can affect the magnitude of isotopic fractionation with uranyl carbonato and calcium uranyl carbonato complexes producing a greater isotopic fractionation than uranyl hydroxyl species. Studies using U isotope data to assess U(VI) reduction must consider adsorption as a lesser, but significant isotope-fractionating process.","abstract_html":"Uranium groundwater contamination due to mining and processing affects numerous sites in the western United States. Bioreduction of soluble, mobile U(VI) to U(IV)-bearing solids is a common remediation strategy. Uranium isotopes (238U/235U) have been utilized to track the progress of microbial reduction, with laboratory and field studies finding a ~1‰ isotopic fractionation with the U(IV) product enriched in 238U. However, the isotopic fractionation produced by adsorption may complicate the use of 238U/235U to trace microbial reduction. A previous study found that adsorption of U(VI) onto Mn oxides produced a -0.2‰ fractionation with the adsorbed U(VI) depleted in 238U (Brennecka et. al. 2011b). The aqueous speciation of U(VI), and the characteristics of the sorbent surfaces may both produce variations in isotopic fractionation induced by adsorption. This study determined U isotopic fractionation induced by U(VI) adsorption onto goethite, birnessite, illite, quartz, and complex aquifer materials. The influence of U(VI) speciation on fractionation was also examined by measuring differences between fractionation factors accompanying the adsorption of uranyl, uranyl hydroxyl, uranyl carbonato, and calcium uranyl carbonato ions. To increase our ability to resolve fractionation, experiments were carried out with a multi-stage, batch approach, in which a U(VI)-bearing solution was exposed to three stages of adsorption. The dissolved U(VI) was analyzed by a double-spike MC-ICP-MS method. Adsorption to the studied solid phases induces an average isotopic fractionation of -0.17‰ with the adsorbed U(VI) isotopically lighter. U(VI) speciation can affect the magnitude of isotopic fractionation with uranyl carbonato and calcium uranyl carbonato complexes producing a greater isotopic fractionation than uranyl hydroxyl species. Studies using U isotope data to assess U(VI) reduction must consider adsorption as a lesser, but significant isotope-fractionating process.","abstract_has_math":false,"creators":["Jemison, Noah Edward"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"M.S.","degree_level":"Thesis","degree_discipline":"Geology","degree_department":null,"school":null,"contributors":["Johnson, Thomas M."],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2015,"date_issued":"2015-09-29T20:38:38Z","date_published":"2015-09-29T20:38:38Z","updated_at":"2026-07-22T22:26:31Z","subjects":["U(VI) adsorption","isotopic fractionation"],"languages":["en"],"rights":["Copyright 2015 Noah Jemison"],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/2142/88079","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Johnson, Thomas M."]},{"key":"dc:creator","label":"Author","values":["Jemison, Noah Edward"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2015-09-29T20:38:38Z","2015-08","2015-07-17","2015-8"]},{"key":"dc:type","label":"Dc Type","values":["text"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Geology"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Thesis"]},{"key":"thesis:degree_name","label":"Degree Name","values":["M.S."]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["University of Illinois at Urbana-Champaign"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["U(VI) adsorption","isotopic fractionation"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["en"]},{"key":"dc:rights","label":"Dc Rights","values":["Copyright 2015 Noah Jemison"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["http://hdl.handle.net/2142/88079"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Uranium groundwater contamination due to mining and processing affects numerous sites in the western United States. Bioreduction of soluble, mobile U(VI) to U(IV)-bearing solids is a common remediation strategy. Uranium isotopes (238U/235U) have been utilized to track the progress of microbial reduction, with laboratory and field studies finding a ~1‰ isotopic fractionation with the U(IV) product enriched in 238U. However, the isotopic fractionation produced by adsorption may complicate the use of 238U/235U to trace microbial reduction. A previous study found that adsorption of U(VI) onto Mn oxides produced a -0.2‰ fractionation with the adsorbed U(VI) depleted in 238U (Brennecka et. al. 2011b). The aqueous speciation of U(VI), and the characteristics of the sorbent surfaces may both produce variations in isotopic fractionation induced by adsorption. This study determined U isotopic fractionation induced by U(VI) adsorption onto goethite, birnessite, illite, quartz, and complex aquifer materials. The influence of U(VI) speciation on fractionation was also examined by measuring differences between fractionation factors accompanying the adsorption of uranyl, uranyl hydroxyl, uranyl carbonato, and calcium uranyl carbonato ions. To increase our ability to resolve fractionation, experiments were carried out with a multi-stage, batch approach, in which a U(VI)-bearing solution was exposed to three stages of adsorption. The dissolved U(VI) was analyzed by a double-spike MC-ICP-MS method. Adsorption to the studied solid phases induces an average isotopic fractionation of -0.17‰ with the adsorbed U(VI) isotopically lighter. U(VI) speciation can affect the magnitude of isotopic fractionation with uranyl carbonato and calcium uranyl carbonato complexes producing a greater isotopic fractionation than uranyl hydroxyl species. Studies using U isotope data to assess U(VI) reduction must consider adsorption as a lesser, but significant isotope-fractionating process.","Submission original under an indefinite embargo labeled 'Open Access'. The submission was exported from vireo on 2015-09-29 without embargo terms","The student, Noah Jemison, accepted the attached license on 2015-07-17 at 14:42.","The student, Noah Jemison, submitted this Thesis for approval on 2015-07-17 at 14:43.","This Thesis was approved for publication on 2015-07-17 at 15:16.","DSpace SAF Submission Ingestion Package generated from Vireo submission #8541 on 2015-09-29 at 13:23:08","Made available in DSpace on 2015-09-29T20:38:38Z (GMT). No. of bitstreams: 2 JEMISON-THESIS-2015.pdf: 757713 bytes, checksum: bbd5cdcb6c394d1adda7bb00a28e9d32 (MD5) LICENSE.txt: 4209 bytes, checksum: eb8e9af957f5035106d563fc4014e09c (MD5) Previous issue date: 2015-07-17"]},{"key":"dc:format","label":"Dc Format","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["Uranium isotopic fractionation induced by U(VI) adsorption onto common aquifer minerals"]}]}],"canonical_facts":{"dc:contributor":["Johnson, Thomas M."],"dc:creator":["Jemison, Noah Edward"],"dc:date":["2015-09-29T20:38:38Z","2015-08","2015-07-17","2015-8"],"dc:description":["Uranium groundwater contamination due to mining and processing affects numerous sites in the western United States. Bioreduction of soluble, mobile U(VI) to U(IV)-bearing solids is a common remediation strategy. Uranium isotopes (238U/235U) have been utilized to track the progress of microbial reduction, with laboratory and field studies finding a ~1‰ isotopic fractionation with the U(IV) product enriched in 238U. However, the isotopic fractionation produced by adsorption may complicate the use of 238U/235U to trace microbial reduction. A previous study found that adsorption of U(VI) onto Mn oxides produced a -0.2‰ fractionation with the adsorbed U(VI) depleted in 238U (Brennecka et. al. 2011b). The aqueous speciation of U(VI), and the characteristics of the sorbent surfaces may both produce variations in isotopic fractionation induced by adsorption. This study determined U isotopic fractionation induced by U(VI) adsorption onto goethite, birnessite, illite, quartz, and complex aquifer materials. The influence of U(VI) speciation on fractionation was also examined by measuring differences between fractionation factors accompanying the adsorption of uranyl, uranyl hydroxyl, uranyl carbonato, and calcium uranyl carbonato ions. To increase our ability to resolve fractionation, experiments were carried out with a multi-stage, batch approach, in which a U(VI)-bearing solution was exposed to three stages of adsorption. The dissolved U(VI) was analyzed by a double-spike MC-ICP-MS method. Adsorption to the studied solid phases induces an average isotopic fractionation of -0.17‰ with the adsorbed U(VI) isotopically lighter. U(VI) speciation can affect the magnitude of isotopic fractionation with uranyl carbonato and calcium uranyl carbonato complexes producing a greater isotopic fractionation than uranyl hydroxyl species. Studies using U isotope data to assess U(VI) reduction must consider adsorption as a lesser, but significant isotope-fractionating process.","Submission original under an indefinite embargo labeled 'Open Access'. The submission was exported from vireo on 2015-09-29 without embargo terms","The student, Noah Jemison, accepted the attached license on 2015-07-17 at 14:42.","The student, Noah Jemison, submitted this Thesis for approval on 2015-07-17 at 14:43.","This Thesis was approved for publication on 2015-07-17 at 15:16.","DSpace SAF Submission Ingestion Package generated from Vireo submission #8541 on 2015-09-29 at 13:23:08","Made available in DSpace on 2015-09-29T20:38:38Z (GMT). No. of bitstreams: 2 JEMISON-THESIS-2015.pdf: 757713 bytes, checksum: bbd5cdcb6c394d1adda7bb00a28e9d32 (MD5) LICENSE.txt: 4209 bytes, checksum: eb8e9af957f5035106d563fc4014e09c (MD5) Previous issue date: 2015-07-17"],"dc:format":["application/pdf"],"dc:identifier":["http://hdl.handle.net/2142/88079"],"dc:language":["en"],"dc:rights":["Copyright 2015 Noah Jemison"],"dc:subject":["U(VI) adsorption","isotopic fractionation"],"dc:title":["Uranium isotopic fractionation induced by U(VI) adsorption onto common aquifer minerals"],"dc:type":["text"],"thesis:degree_discipline":["Geology"],"thesis:degree_level":["Thesis"],"thesis:degree_name":["M.S."],"thesis:institution_name":["University of Illinois at Urbana-Champaign"]},"updated_at":"2026-07-22T22:26:31Z"}