{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/116023"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/116023","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Nitrous oxide and methane emissions from denitrifying bioreactors with and without a soil cover","abstract":"Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2024-08-01","abstract_html":"Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2024-08-01","abstract_has_math":false,"creators":["Brunton, Ann Marie"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"M.S.","degree_level":"Thesis","degree_discipline":"Agricultural & Biological Engr","degree_department":null,"school":null,"contributors":["Christianson, Laura E","Cooke, Richard A","Zilles, Julie L"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2022,"date_issued":"2022-08","date_published":"2022-08","updated_at":"2026-07-22T22:24:55Z","subjects":["Denitrifying Bioreactor","greenhouse gas","nitrous oxide","methane","nitrate","water quality"],"languages":["en","eng"],"rights":["Copyright 2022 Ann Brunton"],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://hdl.handle.net/2142/116023","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Christianson, Laura E","Cooke, Richard A","Zilles, Julie L"]},{"key":"dc:creator","label":"Author","values":["Brunton, Ann Marie"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2022-08","2022-05-17"]},{"key":"dc:type","label":"Dc Type","values":["text","Thesis"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Agricultural & Biological Engr"]},{"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":["Denitrifying Bioreactor","greenhouse gas","nitrous oxide","methane","nitrate","water quality"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["en","eng"]},{"key":"dc:rights","label":"Dc Rights","values":["Copyright 2022 Ann Brunton"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://hdl.handle.net/2142/116023"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2024-08-01","The student, Ann Brunton, accepted the attached license on 2022-05-12 at 11:02.","The student, Ann Brunton, submitted this Thesis for approval on 2022-05-12 at 11:19.","This Thesis was approved for publication on 2022-05-17 at 14:03.","DSpace SAF Submission Ingestion Package generated from Vireo submission #18026 on 2022-11-15 at 19:16:10","Denitrifying woodchip bioreactors reduce nitrate loads in subsurface agricultural drainage water, thus reducing agriculture’s impact on water quality. However, bioreactors can emit the greenhouse gases nitrous oxide (N2O) and methane (CH4) as unwanted byproducts both through the bioreactor surface and as dissolved gas in the liquid outflow. The current United States Department of Agriculture design standard for denitrifying bioreactors allows flexibility as to whether a bioreactor is built with or without a soil cover, but it is unknown how greenhouse gases vary with or without a soil cover at the field-scale in real-world conditions. The objective of this study was to compare both surface and dissolved N2O and CH4 emissions at three full-scale bioreactors with a soil cover versus three without a soil cover in Illinois, USA to determine the impact of a soil cover on bioreactor greenhouse gas emissions. Each of the six bioreactors were monitored at least five times over March to August 2021 for: surface N2O and CH4 emissions; bioreactor flow rate; inflow and outflow dissolved N2O and CH4 and nitrate-nitrogen; and inflow and outflow temperature, dissolved oxygen (DO), and oxidation reduction potential. Hydraulic retention times varied widely between sites (means 1.8 to 21.6 h) but did not equally span the two treatments, preventing meaningful comparison of the covered vs. uncovered treatments and resolution of the stated objective; other trends outside of the two treatments were instead analyzed. Across all six sites, combined (surface and dissolved) mean nitrous oxide emissions (-1.57 to 14.5 mg N2O-N/m3-d) were 1-3 orders of magnitude lower than mean nitrate mass removal (0.291 to 2.97 g NO3-N/m3-d). Methane emissions (mean -1.16 to 412 mg CH4-C/m3-d) were nearly negligible from bioreactor surfaces, and like N2O, were mostly observed in the dissolved form. Methane and nitrous oxide approximately equally contributed to an impact on climate change, but methane was only released in noticeable quantities at half the bioreactors. Bioreactor #4 – No Cover consistently removed both N2O and CH4 due to low loading as well as possible young age impacts. Inducing low inflow DO levels or targeting a mid-range design HRT could mitigate climate change impacts from greenhouse gas emissions at subsurface drainage denitrifying bioreactors."]},{"key":"dc:format","label":"Dc Format","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["Nitrous oxide and methane emissions from denitrifying bioreactors with and without a soil cover"]}]}],"canonical_facts":{"dc:contributor":["Christianson, Laura E","Cooke, Richard A","Zilles, Julie L"],"dc:creator":["Brunton, Ann Marie"],"dc:date":["2022-08","2022-05-17"],"dc:description":["Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2024-08-01","The student, Ann Brunton, accepted the attached license on 2022-05-12 at 11:02.","The student, Ann Brunton, submitted this Thesis for approval on 2022-05-12 at 11:19.","This Thesis was approved for publication on 2022-05-17 at 14:03.","DSpace SAF Submission Ingestion Package generated from Vireo submission #18026 on 2022-11-15 at 19:16:10","Denitrifying woodchip bioreactors reduce nitrate loads in subsurface agricultural drainage water, thus reducing agriculture’s impact on water quality. However, bioreactors can emit the greenhouse gases nitrous oxide (N2O) and methane (CH4) as unwanted byproducts both through the bioreactor surface and as dissolved gas in the liquid outflow. The current United States Department of Agriculture design standard for denitrifying bioreactors allows flexibility as to whether a bioreactor is built with or without a soil cover, but it is unknown how greenhouse gases vary with or without a soil cover at the field-scale in real-world conditions. The objective of this study was to compare both surface and dissolved N2O and CH4 emissions at three full-scale bioreactors with a soil cover versus three without a soil cover in Illinois, USA to determine the impact of a soil cover on bioreactor greenhouse gas emissions. Each of the six bioreactors were monitored at least five times over March to August 2021 for: surface N2O and CH4 emissions; bioreactor flow rate; inflow and outflow dissolved N2O and CH4 and nitrate-nitrogen; and inflow and outflow temperature, dissolved oxygen (DO), and oxidation reduction potential. Hydraulic retention times varied widely between sites (means 1.8 to 21.6 h) but did not equally span the two treatments, preventing meaningful comparison of the covered vs. uncovered treatments and resolution of the stated objective; other trends outside of the two treatments were instead analyzed. Across all six sites, combined (surface and dissolved) mean nitrous oxide emissions (-1.57 to 14.5 mg N2O-N/m3-d) were 1-3 orders of magnitude lower than mean nitrate mass removal (0.291 to 2.97 g NO3-N/m3-d). Methane emissions (mean -1.16 to 412 mg CH4-C/m3-d) were nearly negligible from bioreactor surfaces, and like N2O, were mostly observed in the dissolved form. Methane and nitrous oxide approximately equally contributed to an impact on climate change, but methane was only released in noticeable quantities at half the bioreactors. Bioreactor #4 – No Cover consistently removed both N2O and CH4 due to low loading as well as possible young age impacts. Inducing low inflow DO levels or targeting a mid-range design HRT could mitigate climate change impacts from greenhouse gas emissions at subsurface drainage denitrifying bioreactors."],"dc:format":["application/pdf"],"dc:identifier":["https://hdl.handle.net/2142/116023"],"dc:language":["en","eng"],"dc:rights":["Copyright 2022 Ann Brunton"],"dc:subject":["Denitrifying Bioreactor","greenhouse gas","nitrous oxide","methane","nitrate","water quality"],"dc:title":["Nitrous oxide and methane emissions from denitrifying bioreactors with and without a soil cover"],"dc:type":["text","Thesis"],"thesis:degree_discipline":["Agricultural & Biological Engr"],"thesis:degree_level":["Thesis"],"thesis:degree_name":["M.S."],"thesis:institution_name":["University of Illinois at Urbana-Champaign"]},"updated_at":"2026-07-22T22:24:55Z"}