Mercury and methyl mercury in the Great Salt Lake: overview and analysis

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Publication Type thesis
School or College College of Engineering
Department Civil & Environmental Engineering
Author Karra, Udayarka
Title Mercury and methyl mercury in the Great Salt Lake: overview and analysis
Date 2010-04-01
Description Mercury is one of the most toxic trace elements that is found in the environment, and has no recognized biological functions. Nevertheless, it is being introduced at profoundly alarming rates through various anthropogenic activities. The global cycle of Mercury (Hg) is a result of slow and complex bio-physiochemical transformations, involving various environmental pathways, and influencing its speciatiation into the highly toxic methylated form known as methyl mercury. This has resulted in bioaccumulation and biomagnification of mercury in the various water bodies of The United States, including the Great Salt Lake (GSL), Utah. The GSL watershed and the surrounding wetlands are of critical importance, and are instrumental in the sustenance of the regional ecosystem. Recent studies have reported alarmingly high concentrations of mercury in the Great Salt Lake (GSL), posing serious questions on its ecological viability. Bacteria-mediated methylation of mercury in wetland sediments has come to be an issue of recent concern and this is the focus of interest in this study. The research approach employed involved the synoptic analysis of the Total Mercury (THg) and Methyl Mercury (MeHg) concentration in the water column and sediments of the Farmington Bay (FB) in GSL, Utah Lake, and upper and lower sections of the Jordan River. Further, sediment samples were collected at three locations from a site in the wetlands of FB duck clubs to evaluate (1) the rate of mercury methylation, and (2) the ecology of sulfate reducers, which possibly participated in mercury methylation. The total and methyl mercury concentrations in the water column of Farmington Bay analyzed were 19.05±9.48 ng/L and 1.49±1.19 ng/L, respectively; the Utah Lake water column and the corresponding sediments total and methyl mercury concentrations were 2.74±0.393ng/L, 0.0536±0.024 ng/L and 27.13±2.58 ug/Kg, 0.0717±0.0235 ^ig/Kg, respectively. In the upper section of the Jordan River, mercury concentrations in the water column and the sediments estimated were 19.95±0.78 ng/L, 0.18±0.08 ng/L and 18.5±0.282 fig/Kg, 0.021 ±0.0 (Jg/Kg, respectively while, in the lower sections were 26.9±0.78 ng/L, 0.64±0.07 ng/L and 79.05±29.63 |ng/Kg, 0.15±0.023 ug/Kg, respectively. The average mercury methylation rates for the three sites in the FB duck clubs were estimated to be 0.018±0.001 /day. The phylogenetic analysis and diversity of the sulfate reducers has been analyzed and reported. The majority of the clones belong to the family of Desulfobacteraceae, signifying that the acetate-utilizing family of Sulfate Reducing Bacteria (SRB) may be more prevalent and the phylogenetic study established diversity within the sulfate reducers belonging to the four major genuses of Desulfovibrio, Desulfobacter, and Desulfonema.
Type Text
Publisher University of Utah
Subject Great Salt Lake watershed
Dissertation Institution University of Utah
Dissertation Name MS
Language eng
Relation is Version of Digital reproduction of "Mercury and methyl mercury in the Great Salt Lake: overview and analysis" J. Willard Marriott Library Special Collections TD7.5 2010 .K37
Rights Management © Udayarka Karra, To comply with copyright, the file for this work may be restricted to The University of Utah campus libraries pending author permission.
Format Medium application/pdf
Format Extent 98,430 bytes
Identifier us-etd2,162078
Source Original: University of Utah J. Willard Marriott Library Special Collections
Conversion Specifications Original scanned on Epson GT-30000 as 400 dpi to pdf using ABBYY FineReader 9.0 Professional Edition.
ARK ark:/87278/s68s54h6
Setname ir_etd
Date Created 2012-04-23
Date Modified 2017-09-21
ID 193382
Reference URL https://collections.lib.utah.edu/ark:/87278/s68s54h6