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dc.contributor.authorBock, Emily Maclaurenen_US
dc.date.accessioned2015-12-04T07:00:21Z
dc.date.available2015-12-04T07:00:21Z
dc.date.issued2014-06-11en_US
dc.identifier.othervt_gsexam:3037en_US
dc.identifier.urihttp://hdl.handle.net/10919/64278
dc.description.abstractThe global nitrogen cycle has been disrupted by large anthropogenic inputs of reactive nitrogen to the environment. Excess nitrogen underlies environmental problems such as eutrophication, and can negatively affect human health. Managing the natural microbial process of denitrification is advocated as a promising avenue to reduce excess nitrogen, and denitrifying bioreactors (DNBRs) are an emerging technology harnessing this biochemical process. Previous DNBR research has established successful nitrate removal, whereas this study examines the potential to expand DNBR functionality to address excess phosphorus and mitigate the production of nitrous oxide, a potent greenhouse gas. Results from a laboratory experiment supported the hypothesis that the addition of biochar, a charcoal-like soil amendment and novel organic carbon source in DNBR research, would increase nitrate and phosphorus removal as well as decrease the accumulation of nitrous oxide, an intermediate product of microbial denitrification. In order more closely examine the ratio of the products nitrous oxide and inert dinitrogen, development of a novel analytical method to quantify dissolved gases in environmental water samples using gas chromatography mass spectrometry was undertaken. Although static headspace analysis is a common technique for quantifying dissolved volatiles, the variation in sample preparation has recently been revealed to affect the determination of dissolved concentrations of permanent gases and convolute comparison between studies. This work demonstrates the viability of internal calibration with gaseous standard addition to make dissolved gas analysis more robust to variable sample processing and to correct for matrix effects on gas partitioning that may occur in environmental samples.en_US
dc.format.mediumETDen_US
dc.publisherVirginia Techen_US
dc.rightsThis Item is protected by copyright and/or related rights. Some uses of this Item may be deemed fair and permitted by law even without permission from the rights holder(s), or the rights holder(s) may have licensed the work for use under certain conditions. For other uses you need to obtain permission from the rights holder(s).en_US
dc.subjectdenitrifying bioreactoren_US
dc.subjectnitrous oxideen_US
dc.subjectbiocharen_US
dc.subjectstatic headspace analysisen_US
dc.subjectgaseous standard addition methoden_US
dc.titleGreenhouse Gas Production and Nutrient Reductions in Denitrifying Bioreactorsen_US
dc.typeThesisen_US
dc.contributor.departmentBiological Systems Engineeringen_US
dc.description.degreeMaster of Scienceen_US
thesis.degree.nameMaster of Scienceen_US
thesis.degree.levelmastersen_US
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen_US
thesis.degree.disciplineBiological Systems Engineeringen_US
dc.contributor.committeechairEaston, Zacharyen_US
dc.contributor.committeememberEick, Matthew J.en_US
dc.contributor.committeememberHession, William Cullyen_US


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