Physical Sciences and Mathematics Commons^™

Nitrate Transport In The Unsaturated Zone, Patience Bosompemaa

Theses and Dissertations

Abundance of nitrate in the soil is a basic issue in agricultural land-use regions, causing eutrophication and pollution of water bodies. The study focuses on the role of a saturated buffer zone (SBZ) to remove nitrate from the groundwater resulting from agricultural activities. The study area is herbaceous SBZ located in central Illinois (40.614382ºN, -89.023542ºW), which lies between a stream and a farm located upgradient. The SBZ has been outfitted with an agricultural runoff treatment system that diverts tile drainage into the subsurface of the SBZ rather than discharging into the stream. Within the SBZ three experimental areas composed of …

The Role Of Sediment Resuspension In Estuarine Inorganic Nutrient Cycling, Kirsten Jo Ayres

Theses and Dissertations

Time-scaling of estuarine inorganic nitrogen cycling contains many assumptions due to biogeochemical interactions. Nitrogen, often a limiting factor for primary production, is transformed and utilized by many estuarine organisms. Inorganic nitrogen is especially high in porewater. High nutrient pore water, contained within the interstitial spaces of sediment, has been assumed to influx high concentrations of inorganic nutrients into surface waters during resuspension events. These short-term resuspension events rapidly introducing high concentration of nutrients into the water column. In order to determine the internal time scale of inorganic nitrogen cycling, a box-model nutrient budget, horizontal in situ transects, and vertical nutrient …

Diurnal And Seasonal Variation In Groundwater Nitrate -N Concentration In A Saturated Buffer Zone, Joseph Miller

Theses and Dissertations

Surface water pollution by nitrate (NO3-) is identified as a critical problem in agricultural land-use areas. Excess NO3- loading causes eutrophication and hypoxia in near-shore marine waters such as the Gulf of Mexico. Diversion of agricultural runoff into saturated buffer zones reduces NO3- loading. Although the mechanisms responsible for NO3- reduction in saturated buffer zones are well characterized, little is known about how NO3- concentrations vary temporally and what factors control those changes. The objective of this study is to understand NO3- concentration and environmental factor variability in a saturated buffer zone on a diurnal scale within and among the …

Nutrient Loading Reduction In A Tile Drained Agricultural Watershed Through Watershed-Scale Cover Cropping: A High Resolution Analysis, Benjamin Gerald Bruening

Theses and Dissertations

Nutrient pollution originating from agricultural regions in the Midwest is a serious issue, leading to pollution of drinking water sources as well as large hypoxic zones in the Gulf of Mexico. The source of much of this contamination has been shown to be runoff from agricultural fields in the Upper Mississippi River Basin. One method that has been shown to reduce this pollution from the Upper Mississippi River Basin is the planting of winter cover crops. Winter cover crops such as rye and tillage radish have been shown to significantly reduce nitrate exported from agricultural fields, even in tile-drained watersheds …

Dynamics Of Nitrate, Phosphorus, And Suspended Sediment Transport In Two Agricultural Streams In Central Illinois, Luke W. Lampo

Theses and Dissertations

Nutrients such as nitrate and phosphorus are necessary for life, but excessive amounts can be detrimental. Large amounts of nutrients entering bodies of water can lead to hypoxic zones such as the one in the Gulf of Mexico. Nutrients are also problematic in drinking water reservoirs, as high concentrations of nitrate in drinking water can cause health conditions such as blue baby syndrome and high phosphorus concentrations can lead to algal blooms. Suspended sediment leads to reservoir sedimentation, habitat degradation, and is able to transport particulate nutrients. High nutrient and sediment concentrations are a recurring problem in the drinking water …

Reducing Nitrate Pollution By Redirecting Farm Runoff Into The Subsurface Of An Herbaceous Riparian Buffer Zone., Tamru Girma Taye

Theses and Dissertations

In areas dominated by agricultural land use, excess nitrate is one of the leading contributors to water pollution. Tile drains, installed to drain crop root zones for maximum yield, fast track the introduction of nitrate-laden water into a nearby stream. Due to the risks elevated levels of nitrate pose to an ecosystem and its inhabitants, the following project explores a method of reducing nitrate pollution. One that can do it as close to the source of the pollution as possible.

A tile draining a 60acre farm in central Illinois was redirected to discharge its contents through subsurface flow into an …

Stoichiometric Controls On Denitrification In High Nitrate Watersheds, Brian Grebliunas

Theses and Dissertations

Watershed biogeochemistry throughout Midwestern agroecosystems have been altered through hydrologic manipulation and over-application of nitrogenous fertilizers. As a result, nitrate (NO3-N) export from subsurface drainage has negative impacts on local and downstream ecosystem health. Wetland installation has proven to be a viable option for targeted management where a large proportion of NO3-N is removed through the bacterially mediated process denitrification. For denitrification to maintain high rates under prolonged NO3-N saturation, a stable supply of labile dissolved organic carbon (DOC) is required. The focus of this dissertation was to study how the stoichiometry of agricultural wetlands limits denitrification within a controlled …

Nitrate Uptake In Central Illinois Streams: A Comparison Along A Transient Storage Gradient, Kristen Lynn Theesfeld

Theses and Dissertations

Transient storage can be influenced by channel morphology. Anthropogenic activities can alter stream morphology by straightening channels, lining channels, or even restoration of previously altered channels. This study focused on whether relative transient storage (RTS) was related to stream type - modified lined, modified unlined, or natural. The study further sought to determine if a greater RTS is correlated to a decrease in percent nitrate-N.

Eight (8) sites, encompassing three (3) different stream types - modified lines, modified unlined, and natural - were studied. Chloride and nitrate tracers were added to streams, and samples were analyzed for tracer concentrations and …

First Order Analysis Of Nitrate Loading In The Upper Elbe River Basin, Czech Republic, Daniel J. Ritter

Theses and Dissertations

Nitrate contamination of water is a worldwide issue. Nitrate is especially dangerous for young children, and may result in potentially fatal blue baby syndrome when concentration in drinking water is > 10 mg/L N-NO3. Nitrate in surface water may also lead to eutrophication. Sources of NO3- contamination include nitrate fertilizers, wastewater treatment plants, individual domestic septic systems, runoff from animal feedlots, and natural soil nitrogen. Nitrate contamination in the Elbe River drainage, covering 148,270 km2 in Germany and the Czech Republic, has been a long-term issue. This study examines the upper one-third of the basin, located almost entirely in the Czech …