E-Locus - Institutional Repository of the University of Crete - Ειδοπροσδιορισμός σιδήρου σε δείγματα ατμοσφαιρικής εναπόθεσης στην Α. Μεσόγειο

Home Ειδοπροσδιορισμός σιδήρου σε δείγματα ατμοσφαιρικής εναπόθεσης στην Α. Μεσόγειο

Results - Details

[Add to Basket]

Identifier

000305032

Title

Ειδοπροσδιορισμός σιδήρου σε δείγματα ατμοσφαιρικής εναπόθεσης στην Α. Μεσόγειο

Alternative Title

iron speciation in atmospheric deposition in the eastern Mediterranean

Author

Θεοδόση, Χριστίνα Νικολάου

Thesis advisor

Μιχαλόπουλος, Νικόλαος

Abstract

Atmospheric transport is recognized as a potential source of trace elements of continental origin, such as Iron (Fe), to marine ecosystems. Of particular interest are the inputs of elements such as N, P, and Fe, which are essential for the biological growth of oceanic biota. The potential role of atmospheric deposition on the ocean’s productivity is expected to be particularly important for oligotrophic oceanic areas, such as the Mediterranean Sea and especially its eastern basin. Iron is present in environmental samples (rain, dry deposition samples and aerosols) as particulate and dissolved Fe and includes both Fe(II) and Fe(III) species. Model calculations and correlation analysis indicate that Fe(II)_(αq) occurs almost exclusively as the free ion whereas Fe(III)_(αq) occurs as both iron oxalate and Fe(OH)₂⁺_(αq) depending on the pH range. Iron speciation was studied in rainwater and dry deposition samples collected at two locations in the E. Mediterranean: Finokalia and Heraklion, a remote and an urban area respectively on the island of Crete - Greece during 11/2004 – 2/2007. Fe(II)_(αq)and Fe(III)_(αq) concentrations were determined using a modification of the ferrozine colorimetric method, while Particulate Fe was determined using ICP-MS. DSRFe and Fe(II) concentrations ranged from 0.01 to 5.13 μM (average 0.34 μM) and from 0.01 to 3.46 μM (average 0.27 μM) respectively, while Total Fe ranged from 0.07 to 244.96 μM (average 15.87 μM). The present work examines the factors controlling iron speciation in wet and dry depositions. More precisely the role of factors like: pH and dust content and their role on Fe speciation and solubility will be assessed. Finally, the temporal and annual variability of Fe deposition via the wet and dry pathways will be presented and its role on seawater productivity will be discussed.

Language

Greek

Subject

Biochemical implications

Iron speciation

Solubility

Wet and dry deposition

Βιογεωχημική σημασία

Διαλυτότητα

Προσδιορισμός σιδήρου

Υγρή και ξηρή εναπόθεση

Issue date