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Full-Text Articles in Physical Sciences and Mathematics
Memory Response: Exposure History Dependence Of Microbial Mediated Transformations Of Substrates In Groundwater, Charles Joseph Paradis
Memory Response: Exposure History Dependence Of Microbial Mediated Transformations Of Substrates In Groundwater, Charles Joseph Paradis
Doctoral Dissertations
The flow, transport, and reactivity of dissolved-phase constituents in an unconfined and shallow aquifer were characterized, in situ, by utilizing the single-well push-pull test method. In the first study, the re-oxidation/mobility of uranium, in the presence of nitrate oxidant, was shown to be mitigated by preferential oxidation/mobilization of solid-phase, reduced, sulfur-bearing species. These results indicated that establishing conditions conducive to uranium reduction and the formation of reduced sulfur-bearing species can increase the efficacy of sustained uranium reduction/immobility in the presence of re-mobilizing oxidants. In the second study, the analytical solution to describe the one-dimensional displacement of the center of …
Global And Regional Assessments Of Unsustainable Groundwater Use In Irrigated Agriculture, Danielle S. Grogan
Global And Regional Assessments Of Unsustainable Groundwater Use In Irrigated Agriculture, Danielle S. Grogan
Doctoral Dissertations
Groundwater is an essential input to agriculture world-wide, but it is clear that current rates of groundwater use are unsustainable in the long term. This dissertation assesses both current use of groundwater for country- to global-scale agriculture, and looks at the future of groundwater. The focus is on 1) quantifying food directly produced as a result of groundwater use across spatially-varying agricultural systems, 2) projecting future groundwater demands with consideration of climate change and human decision-making, and 3) understanding the system dynamics of groundwater re-use through surface water systems. All three are addressed using a process-based model designed to simulate …