SULFUTOPES · Isotope Studies of the Sulfur Cycling using the Four Sulfur Isotopes: Developing Tools to Investigate the Flow of Sulfur through Biogeochemical Systems
FP7 — People (Marie Curie Actions)
- Duration
- 2008-08-01 → 2011-07-31
- EU contribution
- €238,026
- Participants
- 1
- Scheme
- MC-IOF
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Results in brief
Periodic Report Summary - SULFUTOPES (Isotope Studies of the Sulfur Cycling using the Four Sulfur Isotopes: Developing Tools to Investigate the Flow of Sulfur through Biogeochemical Systems)
During last 12 months of the project execution, Wadden Sea sediments and tidal flat sulfide-rich water pools were sampled for studying their biogeochemistry by combination of quantitative and isotopic techniques. Concentrations of sulfate, sulfide, elemental sulfur and thiosulfate as well as quadruple sulfur isotope composition of both, main (sulfate and sulfide) and intermediate (zero-valent sulfur) species were measured. Analyses of quadruple sulfur isotope composition of samples acquired in the first two years of the project execution (Yellowstone National Park hydrothermal springs and Delaware Great Marsh pore-waters) were continued during two visits to the University of Maryland, 7 - 10 days each. Unexpected detection of high concentrations of hydrogen cyanide (up to 1.92 µmol l-1 of free and 6.94 µmol l-1 of strong metallo-complexed cyanide) and thiocyanate (up to 2.28 µmol l-1 of free thiocyanate) in the Delaware Great Marsh pore waters led to a collateral research. This research resulted in clarification of cyanide source and sinks in the salt marsh. I found that hydrogen cyanide is produced by the roots of cord grass Spartina alterniflora. The main sinks of free hydrogen cyanide were found to be complexation with Fe(II), adsorption on sediment and especially the reaction with zero-valent sulfur species. This reaction results in formation of thiocyanate, which is less toxic than hydrogen cyanide. Four papers based on results obtained during previous years were submitted to international peer-reviewed journals. One paper was published in Geochimica et Cosmochimica Acta, two of them were accepted for publication in Marine Chemistry and one was accepted for publication in International Journal of Environmental Analytical Chemistry. Significant part of the work time in the last 12 months of project period was focused on acquiring of academic position. From 1 August 2011 I was received tenure-track senior lecturer position at the Ben-Gurion University of the Negev, Beer Sheva, Israel.
Data: CORDIS, © European Union
Project objective
New developments in isotope ratio mass spectrometry have made possible the use of both traditional and rare sulfur isotopes in biogeochemical systems studies and open new ways to explore natural sulfur cycle. The project will focus on the detection of the abundances of four sulfur isotopes in reduced and intermediate sulfur compounds such as sulfide, dispersed particulate elemental sulfur, polysulfides, thiosulfate and polythionates in natural aquatic and sedimentary systems. Quantitative detection of these compounds together with determination of four sulfur isotopes abundances will allow development of the method, which answers the following long-standing questions: a) how to differentiate between the systems, where production of hydrogen sulfide from sulfate is due to sulfate reduction to sulfide, and the systems, where disproportionation of intermediate compounds like sulfur occurs; b) how to differentiate between the systems, where intermediate sulfur compounds, especially dissolved (polysulfidic) and non-soluble (elemental) zero-valent sulfur, are produced by oxidation of hydrogen sulfide by biotic and abiotic routes. Various systems with different rates (from minutes to thousands of years), microbial activities, pH and mechanisms of reduced and intermediate sulfur compounds cycling will be studied. Systems may include: Black Sea, North Sea, salt marshes, meromictic lakes, monomictic lakes, acidic pools (i.e. at Yellowstone National Park) and soda lakes. The samples from both water column and sediment will be analyzed in order to reconstruct the flow of sulfur through the complex biogeochemical system. Bacterial cultures will be studied to explain the role of microbial processes in sulfur isotopes fractionation.
Original text from CORDIS.
Participants
- MAX-PLANCK-GESELLSCHAFT ZUR FORDERUNG DER WISSENSCHAFTEN EV · MUNCHENCoordinatorGermany
Links
Data: CORDIS, © European Union