Naslov
Distribution of redox-sensitive elements in bottom, porewater and sediment of seawater lake (Rogoznica lake, Croatia) considering oxic and anoxic conditions

Autori
Ciglenečki, Irena ; Pichler, Srdjan ; Prohić, Esad ; Ćosović, Božena

Izvornik
Marine chemistry (0304-4203) 6 (2006); 537-545

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
anoxia ; geochemistry ; Fe ; Mn ; Mo ; porewater ; sulfide ; sediment ; Rogoznica Lake.

Sažetak
Geochemical, mineralogical and sedimentological analyses have been made to view the difference between two contrasting sediment locations in a small, meromictic, seawater lake, Rogoznica Lake regarding its oxic and anoxic bottom water conditions. Due to relatively high organic matter content, and delicate exchange of water, the lake has almost permanent anoxic conditions below the depth of 12 m, and can be characterized as anoxic-sulfidic sedimentation environment. Changes in redox conditions of the water column as well as in sediments with depth affect the distribution and speciation of major redox-sensitive metals (Fe, Mn, Mo), reduced sulfur species (RSS) and dissolved organic C (DOC). Distribution of trace metals between porewater and sediments showed their larger quantities in sediments especially for those metals which accumulate in anoxic-sulfidic environment (Fe, Mo). Low solubility of investigated sulfides in turn results in their low pore water concentrations. Relatively high sedimentary enrichment of Mo (up to 81 mg/l) indicates that Rogoznica lake is a typical anoxic basin. Obtained results clearly show that chemical species within the sediments will tend towards equilibrium between porewater and solid phase according the prevailing environment conditions such as redox, pH, salinity, DOC.

Izvorni jezik
Engleski

Znanstvena područja
Geologija

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