Naslov
Reduced sulfur and iron species in anoxic water column of Lake Pavin

Autori
Bura-Nakić, Elvira ; Viollier, Eric ; Jézéquel, Didier ; Thiam, Alassane ; Ciglenečki, Irena

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, ostalo

Izvornik
International Meeting Lake Pavin and Other Meromictic Lakes / Amblard, Christian - Besse-et-Saint-Anastaise : Clermont Ferrad University, 2009, 35-35

Skup
International Meeting on Lake Pavin and Other Meromictic Lakes

Mjesto i datum
Besse-et-Saint-Anastaise, Francuska, 14.05.2009. - 16.05.2009

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
reduced sulfur ; iron species ; voltammetry ; Pavin Lake

Sažetak
The vertical distribution of reduced sulfur species (RSS including H2S/HS-, S0, electroactive FeS) and dissolved Fe (II) were studied in the anoxic water column of meromictic Lake Pavin. Sulfide concentrations were determined by two different analytical techniques, i.e. spectophotometry (methylene blue technique) and voltammetry (HMDE electrode). Total sulfide concentrations determined with methylene blue method (∑ H2SMBRS) were in the range from 0.6 µ ; M to 16.7 µ ; M and were substantially higher than total reduced sulfur species (RSSV) concentrations determined by voltammetry, which ranged from 0.1 to 5.6 μ M. The observed difference in the sulfide concentrations between the two methods can be assigned to the presence of electroactive FeS colloidal species. Dissolved Fe was high (>1000 µ ; M), whereas dissolved Mn was only 25 µ ; M, in the anoxic water column. This indicates that Fe is the dominant metal involved in sulfur redox cycling and precipitation. Consequently, in the anoxic deep layer of Lake Pavin, “ free” sulfide, H2S/HS-, was low ; and about 80 % of total sulfide detected was in the electroactive FeS colloidal form. IAP calculations showed that the Lake Pavin water column is saturated with respect to FeSam phase. The upper part of monimolimnion layer is characterized by higher concentrations of S(0) (up to 3.4 µ ; M) in comparison to the bottom of the lake. This behavior is probably influenced by sulfide oxidation with Fe(III) oxyhydroxide species and pyrite formation at the lake bottom.

Izvorni jezik
Engleski

Znanstvena područja
Geologija

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