INTERACTIONS BETWEEN THE IRON, MANGANESE, AND OXYGEN CYCLES IN THE MARINE ENVIRONMENT
| Author(s) | Coffey, Nicole | |
| Date Accessioned | 2018-09-27T15:45:05Z | |
| Date Available | 2018-09-27T15:45:05Z | |
| Publication Date | 2018-05 | |
| Abstract | The speciation of dissolved Mn (dMnT) in oxygenated systems has typically been assumed to be dominated by soluble Mn(II) in addition to Mn(IV) existing as solid MnO2. Work in the last few decades has shown that the intermediate state, Mn(III), is stabilized by organic ligands (L) in oxygen depleted waters, making up to 78% of dMnT in the oceanic-type surface waters of the Delaware Bay and up to 99% of dMnT in surface waters of salt marsh creeks feeding the Broadkill River in Delaware. These values were obtained using a known method involving spectrophotometric determination of the kinetics of Mn(II) complexation with porphyrin (POR). The higher percentage of Mn(III) in creek waters as opposed to the bay was attributed to greater influence of the salt marsh in the form of an influx of humic material as unknown ligands. The complexation of Mn(III) and humic materials to form Mn(III)-L allows for increased transport of Mn and organic material to the oceans or, in this case, the Delaware Bay. Unexpected oxidation of environmental samples was observed, prompting laboratory experiments that uncovered a strong interaction between iron, manganese, and oxygen in a somewhat saline matrix (S = 14 ppt). The interaction observed was due to a series of reactions, beginning with the oxidation of Fe(II) producing superoxide. This superoxide was then able to react with Mn(II) to generate MnOx. This previously unconsidered reaction series implies an interaction between iron, manganese, and oxygen cycling in the environment with relevance in not only surface water systems but also in hydrothermal vent systems and banded iron formations. More work is needed to determine the extent to which this interaction is occurring in natural systems. | en_US |
| Advisor | George Luther | |
| Program | Marine Science | |
| URL | http://udspace.udel.edu/handle/19716/23842 | |
| Publisher | University of Delaware | en_US |
| Keywords | Marine Science, iron, manganese, oxygen, marine environment | en_US |
| Title | INTERACTIONS BETWEEN THE IRON, MANGANESE, AND OXYGEN CYCLES IN THE MARINE ENVIRONMENT | en_US |
| Type | Thesis | en_US |