Please use this identifier to cite or link to this item:
http://hdl.handle.net/11375/22057
Full metadata record
DC Field | Value | Language |
---|---|---|
dc.contributor.advisor | Slater, Greg | - |
dc.contributor.author | Whaley Martin, Kelly Jane | - |
dc.date.accessioned | 2017-10-04T19:30:24Z | - |
dc.date.available | 2017-10-04T19:30:24Z | - |
dc.date.issued | 2017-11 | - |
dc.identifier.uri | http://hdl.handle.net/11375/22057 | - |
dc.description.abstract | Understanding how organic matter is microbially cycled through Bangladesh aquifers is a key component in understanding the spatial and temporal patterns of arsenic release into groundwater occurring on wide regional scales. There is a current gap in the literature for how overall microbial carbon cycles are functioning in Bangladesh aquifers, how these microbial metabolisms factor into arsenic release, including methodology as to approach these questions in situ. This research aimed to provide insight into carbon sources and cycling of the microbial communities in Bangladesh aquifers through a complimentary applied suite of lipidomic, isotopic and inorganic analytical approaches on in situ sediments and groundwater from Bangladesh aquifers. Through radiocarbon analyses of phospholipid fatty acids (PLFA's), bacterial populations in a shallow Holocene-aged and high arsenic aquifer were found to be predominantly utilizing younger organic matter as their carbon source rather than older sedimentary carbon. At the sites studied, the sources of younger organic matter that coincide with zones where increased reductive dissolution of iron and arsenic release is occurring were consistent with human and livestock waste identified through sedimentary sterol distributions (phytosterols and coprstonaol) and Cl/Br mass ratios in groundwater. Since poor sanitation is widespread across Bangladesh, sewage-derived waste should be considered a prevalent potential microbial carbon source is these systems. An examination of sediment- versus groundwater-associated microbial communities in Bangladesh aquifers (through PLFA analysis) suggested that the former is 5-6 orders of magnitude more abundant than the latter. Archaeal communities, examined through both groundwater methane and sedimentary archaeal lipid (archaeol and glycerol dialkyl glycerol tetraether (GDGT)) analysis, are suggested to be highly active (depths 5-240 m) but to varying degrees in Bangladesh aquifers. Methanogenesis, dominantly being carried out through CO2 reduction, appears to be spatially associated at some sites with zones of iron/arsenic reductive dissolution in the Bangladesh aquifers. The analytical approaches and conceptual frameworks applied throughout this dissertation have been demonstrated to be effective strategies to understand how microbial carbon cycling is occurring at a community level and intimately involved in arsenic release. | en_US |
dc.language.iso | en | en_US |
dc.title | Examining microbial carbon source cycling in arsenic contaminated Bangladesh aquifers through lipid and isotopic analyses | en_US |
dc.type | Thesis | en_US |
dc.contributor.department | Geography and Earth Sciences | en_US |
dc.description.degreetype | Thesis | en_US |
dc.description.degree | Doctor of Philosophy (PhD) | en_US |
Appears in Collections: | Open Access Dissertations and Theses |
Files in This Item:
File | Description | Size | Format | |
---|---|---|---|---|
Kelly Whaley Martin Final PhD Thesis Revisions.pdf | 9.64 MB | Adobe PDF | View/Open |
Items in MacSphere are protected by copyright, with all rights reserved, unless otherwise indicated.