کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4700202 1637701 2009 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Reduced sulfur and iron species in anoxic water column of meromictic crater Lake Pavin (Massif Central, France)
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات ژئوشیمی و پترولوژی
پیش نمایش صفحه اول مقاله
Reduced sulfur and iron species in anoxic water column of meromictic crater Lake Pavin (Massif Central, France)
چکیده انگلیسی

The vertical distribution of reduced sulfur species (RSS including H2S/HS−, S0, electroactive FeS) and dissolved Fe(II) was 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 µM to 16.7 µM and were substantially higher than total reduced sulfur species (RSSV) concentrations determined by voltammetry, which ranged from 0.1 to 5.6 μM. The observed difference in the sulfide concentrations between the two methods can be assigned to the presence of FeS colloidal species.Dissolved Fe was high (> 1000 µM), whereas dissolved Mn was only 25 µM, 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 µM) in comparison to the bottom of the lake. This behavior is probably influenced by sulfide oxidation with Fe(III) oxyhydroxide species.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Chemical Geology - Volume 266, Issues 3–4, 30 August 2009, Pages 311–317
نویسندگان
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