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Full-Text Articles in Physical Sciences and Mathematics
Regulation Of Dissolved Arsenic Using Zero-Valent Iron With Gypsum And Sulfate Reducing Bacteria: Laboratory Microcosm And Column Studies, Ying Liu
Dissertations, Theses, and Capstone Projects
Bench scale microcosm incubation was first conducted in two stages to examine the removal of arsenic (As) by zero-valent iron (ZVI) in the presence of sulfate reducing bacteria, gypsum as well as organic substrates under anaerobic condition. About 98% of dissolved As was removed from solution within 20 days with concurrent decrease of dissolved sulfate and growth of bacterial population. Mineralogy analysis using SEM-EDS found the formation of iron sulfide and Fourier-transformed infrared (FTIR) spectroscopy analysis indicates that some As is associated with pyrite. The main iron corrosion product was found as ferrihydrite with traces of lepidocrocite. Sequential leaching shows …
Biogeochemistry Of Sulfur Isotopes In Crystal Lake, Clark County, West-Central Ohio, Amanda Lynn Meyer
Biogeochemistry Of Sulfur Isotopes In Crystal Lake, Clark County, West-Central Ohio, Amanda Lynn Meyer
Browse all Theses and Dissertations
Crystal Lake showed distinct biogeochemical patterns, which were governed by thermal stratification, photosynthesis, and sulfur redox processes. Field parameter measurements and water and Planktothrix rubescens samples were collected in May, August, and October, 2013 at the deepest point in the lake, to better understand these processes. At the metalimnion-hypolimnion boundary, P. rubescens produced chlorophyll and turbidity maxima. Photosynthesis produced oxygen-rich and nutrient-poor surface waters. The decay of organic matter produced anoxic, nutrient-rich water in the hypolimnion. Sulfate concentrations were high in the epilimnion and metalimnion, with a maximum at the layer of P. rubescens, and decreased with depth in the …
Denitrification By Sulfur-Oxidizing Bacteria In A Eutrophic Lake, Amy J. Burgin, Stephen K. Hamilton, Stuart E. Jones, Jay T. Lennon
Denitrification By Sulfur-Oxidizing Bacteria In A Eutrophic Lake, Amy J. Burgin, Stephen K. Hamilton, Stuart E. Jones, Jay T. Lennon
School of Natural Resources: Faculty Publications
Understanding the mechanistic controls of microbial denitrification is of central importance to both environmental microbiology and ecosystem ecology. Loss of nitrate (NO3 −) is often attributed to carbon-driven (heterotrophic) denitrification. However, denitrification can also be coupled to sulfur (S) oxidation by chemolithoautotrophic bacteria. In the present study, we used an in situ stable isotope (15NO3 −) tracer addition in combination with molecular approaches to understand the contribution of sulfur-oxidizing bacteria to the reduction of NO3 − in a eutrophic lake. Samples were incubated across a total dissolved sulfide (H2S) gradient (2 to …
Effect Of Sediment Slurry Application On Selected Aspects Of Sulfur, Iron, And Manganese Biogeochemistry In A Coastal Louisiana Marsh, Martin Kyle Maxwell
Effect Of Sediment Slurry Application On Selected Aspects Of Sulfur, Iron, And Manganese Biogeochemistry In A Coastal Louisiana Marsh, Martin Kyle Maxwell
LSU Master's Theses
Coastal wetlands, long recognized to be among the most productive ecosystems on the planet, are being lost at a disturbingly high rate in coastal Louisiana due to both eustatic sea-level rise and land subsidence. A number of approaches have been proposed for reducing wetland loss and restoring deteriorated wetlands, among which the addition of sediment to increase marsh surface elevation is promising. However, little is known about how the added sediment affects the biogeochemistry of marsh sediment. The objective of this study was to determine the effects of sediment slurry addition on sulfur, iron, and manganese biogeochemistry in a subsiding …
The Effect Of Water Level Management On The Soils And Vegetation Of Two Coastal Louisiana Marshes, Brian J. Wilsey, K. M. Flynn, I. A. Mendelssohn
The Effect Of Water Level Management On The Soils And Vegetation Of Two Coastal Louisiana Marshes, Brian J. Wilsey, K. M. Flynn, I. A. Mendelssohn
Brian J. Wilsey
Wetland degradation and loss is the result of a combination of natural causes and anthropogenic activities and is a serious problem in coastal Louisiana, where approximately 80% of the total US coastal wetland loss since the 1930’s has occurred. One method currently used to address this wetland loss problem is structural marsh management,which is the use of levees and water control structures to control hydroperiod. The effects of structural marsh management on two managed marshes in Southern Louisiana (Unit 4 of the Rockefeller Wildlife Refuge and the Fina LaTerre Mitigation Bank) were evaluated by comparing the soils and the dominant …
Accidental Releases Of Sour Gas From Wells And Collection Pipelines In The Overthrust Belt: Calculating And Assessing Potential Health And Environmental Risks, D. W. Layton, R. T. Cederwall, Y. E. Ricker, J. H. Shinn, K. D. O'Banion
Accidental Releases Of Sour Gas From Wells And Collection Pipelines In The Overthrust Belt: Calculating And Assessing Potential Health And Environmental Risks, D. W. Layton, R. T. Cederwall, Y. E. Ricker, J. H. Shinn, K. D. O'Banion
All U.S. Government Documents (Utah Regional Depository)
Parts of the Overthrust Belt of western Wyoming and adjoining areas in Utah and Idaho contain geologic formations with significant accumulations of oil and natural gas. Some of these formations, though, yield gas that is contaminated with toxic hydrogen sulfide. As a consequence, the development of these so-called sour-gas reservoirs requires special safety procedures and technologies in order to prevent accidental releases of gas to the atmosphere that could cause adverse occupational and public health effects. To improve the analysis and assessment of wells and collection pipelines completed on lands leased from the Federal Government, the Minerals Management Service, Onshore …