Sarah Conrad

MetTrans Photo1sara

I finished my academic studies in spring 2012 at the Christian-Albrechts-University Kiel (Germany) with a diploma in geology and paleontology. During my studies I was focused on paleoceanography and magmatic petrology.  In October 2012 I started my Ph.D “Trace metal transport across suboxic zones” at the Luleå University of Technology. I am part of the Geosciences and Environmental Engineering division under the supervision of Prof. Johan Ingri. During my Ph.D I will study the role of freshwater input of iron and manganese for the phosphorus cycling in the Gulf of Bothnia. The idea behind these studies is, that the coupled redox chemistry of Fe and Mn is a major driver in the oligotrophication and therefore could explain the difference in phosphorus sequestering between the different basins of the Baltic Sea. My current focus is the riverine transport of Fe(II) to the Baltic Sea. Therefore I am analyzing the Fe(II) content along the Kalix River and Råne River (northern Sweden), and the Fe(II) concentration of the Bothnia Bay. For the analyzes of the Fe(II) concentration I use different methods: 1) In situ I measure the concentration with a so called Flow Injection Analyzer, which measures the oxidation rate of Fe(II) and allows the calculation of the initial Fe(II) concentration. 2) Water samples are spiked in situ with different reagents for the ferrozine method. The samples will be measured with a photospectrometer in the lab.  This allows the determination of Fe(II)/Fe(III) speciation in natural waters. 3) Diffusive Gradient in Thin Films (DGT) samplers for water and sediment are deployed for a certain amount of time in the water. The DGT´s will be analyzed for iron and phosphorus concentration in a commercial lab.

Next to the Fe(II) content we are analyzing major and trace elements, CDOM, H2O2 and O2 of the samples.