Chemistry Commons^™

Mercury Sulfide Dissolution In Environmental Conditions: Thermodynamic And Kinetic Approaches, Ping Jiang

FIU Electronic Theses and Dissertations

Mercury (Hg) is a global contaminant of ecosystems and human health risk, with complicated biogeochemical processes. Mercury sulfide (HgS) dissolution has been suggested as a key process in Hg cycling, as it could potentially increase the pool of inorganic Hg (iHg) for the production of methylmercury (MeHg). Despite previous sporadic observations of enhanced HgS dissolution under certain conditions, much remains unclear on mechanisms of HgS dissolution. The objective of my research was to advance the mechanistic understanding of HgS dissolution, concerning re-adsorption of released Hg, effects of thiol-ligands, and Hg speciation.

Considering the lack of feasible techniques to differentiate dissolution …

Characterizing The Molecular Structure And Reactivity Of Natural Organic Matter In The Everglades, Wenxi Huang

FIU Electronic Theses and Dissertations

Mangroves are the dominant vegetation in Everglades estuarine environment and are known to contain polyphenols such as tannins, which present similar fluorescence properties as some amino acid fluorophores. In the present study, gas chromatography–mass spectrometry (GC/MS) was used to quantify gallic acid, which is a normal monomer of polyphenols. The quantitative GC/MS analytical method was developed using gallic acid and tannic acid standards to quantify the false ‘protein-like’ fluorescence in DOM. The present study also compared the optical properties, reactive species (RS) production and radical scavenging ability of DOM from different regions of the Everglades and a correlation was observed …

Application Of Biomarkers And Compound Specific Stable Isotopes For The Assessment Of Hydrology As A Driver Of Organic Matter Dynamics In The Everglades Ecosystem, Ding He

FIU Electronic Theses and Dissertations

The Everglades is a sub-tropical coastal wetland characterized among others by its hydrological features and deposits of peat. Formation and preservation of organic matter in soils and sediments in this wetland ecosystem is critical for its sustainability and hydrological processes are important divers in the origin, transport and fate of organic matter. With this in mind, organic matter dynamics in the greater Florida Everglades was studied though various organic geochemistry techniques, especially biomarkers, bulk and compound specific δ¹³C and δD isotope analysis. The main objectives were focused on how different hydrological regimes in this ecosystem control organic matter …