Physical Sciences and Mathematics Commons^™

Immobilization Of Uranium And Iodine By Calcium Phosphate Minerals, Angel L. Jimenez-Arroyo

Theses and Dissertations

This dissertation is comprised of three independent but interconnected studies with the scope of further understanding uranium and iodine partitioning between apatite and fluid. The studies herein presented investigated: 1) brushite to apatite crystallization method; 2) the degree of uranium incorporation into apatite; 3) the degree of iodine incorporation into apatite. The importance of this work is assessing the role of apatite in immobilizing these elements, where uranium is a major component of spent nuclear fuel and iodine is a chemical analog of its radioactive isotope (¹²⁹I). Once we understand the incorporation mechanisms, we will provide data that …

Rock-Fluid Interaction And The Incorporation Of Cations Into Calcite During Recrystallization In Multiple Hydrothermal Systems., Van Anh Nguyen

Theses and Dissertations

Fluid-rock interaction causes an exchange of isotopes or elements through various reactions. The rate of these reactions strongly depends on temperature. The interaction involves dissolution precipitation, chemical exchange reactions, redox reactions, diffusion, and their combinations. The goal of studying fluid-rock interaction is to understand the change in mineral chemistry of the rock materials when in contact with an aqueous solution. These processes occur in all regions of the Earth where aqueous solutions are found. This work is comprised of three independent studies which provide an understanding about crystallization processes under multiple hydrothermal conditions with geological and environmental applications.

In the …

Determining The Effects Of Elevated Carbon Dioxide On Soil Acidification, Cation Depletion, And Soil Inorganic Carbon And Mapping Soil Carbons Using Artificial Intelligence, Jannatul Ferdush

Theses and Dissertations

Soil carbon is the largest sink and source of the global carbon cycle and is disturbed by several natural, anthropogenic, and environmental factors. The global increase of atmospheric CO₂ affects soil carbon cycling through varied biogeochemical processes. The first chapter is a compilation of current information on potential factors triggering soil acidification and weathering mechanisms under elevated CO₂ and their consequences on soil inorganic carbon (SIC) pool and quality. Soil water content and precipitation were critical factors influencing elevated CO₂ effects on the SIC pool. The second chapter examines a detailed column experiment in which six soils …

Identifying Biogeochemical Factors Responsible For The Cyclical Precipitation Of Sphalerite And Galena In Low Temperature Mississippi Valley Type Ore Deposits, Daniel John Makowsky

Theses and Dissertations

Mississippi Valley Type (MVT) lead and zinc deposits provide a significant source of sedimentary galena and sphalerite. However, geochemical characteristics and genesis including the source and production of hydrogen sulfide required for galena and sphalerite ore formation and the reasoning for quick, episodic mineralization is not fully understood. By simulating regional MVT brines, the input and effect of biological by-products during the development of these ores as well as the cause of cyclicity within MVT deposits have been observed. Experiments using compositions from MVT fluid inclusions were conducted over two-week periods. Variables during the experiments included temperature, CO2, hydrogen sulfide …