Radiochemistry Commons^™

O-Sulfonamidophenol Ligands And Derivatives For F-Element Sensing, Complexation, And Extraction From Alkaline High-Level Waste, Oluwaseun William Adedoyin

FIU Electronic Theses and Dissertations

The accumulated (>100 Mgal) alkaline high-level waste (HLW), which is a legacy of nuclear weapons manufacturing during the cold war era, is an issue of environmental concern that has presented reprocessing challenges, due to its complex physicochemical properties and the presence of ¹³⁷Cs, ⁹⁰Sr, and long-lived actinides.

This study is focused on o-sulfonamidophenol derivatives bearing electron-rich O- and N- donor sites (when deprotonated in alkaline conditions) for effective complexation, sensing, and extraction of f-elements from highly alkaline solutions. Using Ln(III) as experimental surrogates for An(III), a family of o-sulfonamidophenol ligands (L1H₂ – L4H_{2 …}

Ligands For Complexation, Extraction, And Sensing Of Mercury(Ii) For Application To High-Level Waste (Hlw) At The Savannah River Site (Srs), Adenike O. Fasiku

FIU Electronic Theses and Dissertations

Mercury (Hg) separation and sensing is of high significance due to Hg^(II) environmental mobility and toxicity. Furthermore, the use of Hg in nuclear applications has resulted in its accumulation in several DOE sites, such as in Oak Ridge and Savannah River reservations. Organic mercury species have been found in low activity waste (LAW) streams resulting from high-level waste (HLW) processing at the Savannah River Site (SRS), therefore posing a threat to humans and the environment. Mercury, being a soft Lewis acid, has a strong affinity for softer Lewis bases, such as S- or N-donor ligands. Therefore, we focus on …

Lanthanide Interactions With Ligands And Biomolecules: Spectroscopic And Extraction Studies, Setareh Sakhdari

FIU Electronic Theses and Dissertations

Lanthanides (Ln), also known as rare earth metals, have been utilized for industrial and biological purposes and are commonly encountered in the 3+ oxidation state as Ln³⁺. The presence of Ln in spent nuclear fuel introduces problems during the transmutation and partitioning of actinides (An) due to the Ln high neutron cross-sections. Therefore, designing ligands for Ln³⁺ complexation, can be helpful for their separation from An³⁺ in nuclear technology. Also, the biomimetic roles of Ln³⁺ could be suitable for studying the biological macromolecules, such as the Ca²⁺-binding EF-hand proteins that are otherwise inaccessible …

Uranium Fate And Mineral Transformations Upon Remediation With Ammonia (Nh3) Gas, Silvina A. Di Pietro

FIU Electronic Theses and Dissertations

The fission of uranium (U) for plutonium production was a major activity at the U.S. Department of Energy’s (DOE) Hanford Site in Washington State during World War II and Cold War. This endeavor resulted in the generation of over two million liters of high-level radioactive waste, most of which still remains in 177 underground storage tanks. Due to the improper storage and aging of these tanks in addition to other waste releases across the Site, approximately 200,000 kg of U have been released into the vadose zone. The objective of this study was to determine whether the application of the …

Dipicolinamide Ligands And Analogs For Lanthanides (Ln), Actinides (An) And Mercury (Hg) For Application To Nuclear Fuel Cycle Separations And Waste Management, Ingrid Lehman-Andino

FIU Electronic Theses and Dissertations

Spent nuclear fuel (SNF) – or used nuclear fuel (UNF) – contains long-lived minor actinides such as ²⁴¹Am, ²⁴⁵Cm, and ²³⁷Np, together with fission products that include lanthanides. Minor actinides are responsible for much of the radiotoxicity and heat generation that limits the capacity of geological repositories. Thus, removing minor actinides from UNF can reduce storage time required for decay to natural levels of activity by several orders of magnitude. Actinide(An)/Lanthanide(Ln) separation processes via solvent extraction by selective complexation with organic or aqueous ligands have to overcome difficulties due to similarities in their ionic radii for the …

Hydrogeochemical Modeling Of Saltwater Intrusion And Water Supply Augmentation In South Florida, Yonas T. Habtemichael

FIU Electronic Theses and Dissertations

The Biscayne Aquifer is a primary source of water supply in Southeast Florida. As a coastal aquifer, it is threatened by saltwater intrusion (SWI) when the natural groundwater flow is altered by over-pumping of groundwater. SWI is detrimental to the quality of fresh groundwater sources, making the water unfit for drinking due to mixing and reactions with aquifer minerals. Increasing water demand and complex environmental issues thus force water utilities in South Florida to sustainably manage saltwater intrusion and develop alternative water supplies (e.g., aquifer storage and recovery, ASR).

The objectives of this study were to develop and use calibrated …

Microspheres For Liver Radiomicrospheres Therapy And Planning, Alejandro Amor-Coarasa

FIU Electronic Theses and Dissertations

Liver cancer accounts for nearly 10% of all cancers in the US. Intrahepatic Arterial Radiomicrosphere Therapy (RMT), also known as Selective Internal Radiation Treatment (SIRT), is one of the evolving treatment modalities. Successful patient clinical outcomes require suitable treatment planning followed by delivery of the microspheres for therapy. The production and in vitro evaluation of various polymers (PGCD, CHS and CHSg) microspheres for a RMT and RMT planning are described. Microparticles with a 30±10 µm size distribution were prepared by emulsion method. The in vitro half-life of the particles was determined in PBS buffer and porcine plasma and their potential …