Izvorni znanstveni članak

https://doi.org/10.4154/gc.2019.09

Macroscopic, optical and diffraction assessment of encrustations and SEM analyses of phototrophic microbial mats from wellheads and select zones of emergence of mineral water in Serbia

Vladimir Šaraba ; Univerzitet u BeograduRudarsko-geološki fakultet
Slađana Popović ; University of Belgrade, Institute of Chemistry, Technology and Metallurgy, Department of Ecology and Technoeconomics
Vesna Obradović ; Institute for Water Management “Jaroslav Černi“, Belgrade
Jana Štrbački ; University of Belgrade, Faculty of Mining and Geology, Department of Hydrogeology
Violeta Gajić ; University in Belgrade, Faculty of Mining and Geology, Department of Mineralogy, Crystallography, Petrology and Geochemistry
Predrag Vulić ; University in Belgrade, Faculty of Mining and Geology, Department of Mineralogy, Crystallography, Petrology and Geochemistry
Gordana Subakov Simić ; University of Belgrade, Faculty of Biology, Department of Algology, Mycology and Lichology
Olivera Krunić ; University of Belgrade, Faculty of Mining and Geology, Department of Hydrogeology

Sažetak

Investigations focusing on wellhead encrustations within select zones of emergence of mineral water, in different hydrogeological provinces, were conducted from 2014 to 2017 in Serbia. They included: well BB-1 in Bogatić (Inner Dinaric Alps of western Serbia), wells LB-4 and LB-5 in Lukovska Banja (Šumadija-Kopaonik-Kosovo Province), and wells VG-2 and VG-3 in Vranjska Banja (Serbian Crystalline Core). The studied occurrences belong to the group of hot mineral waters, with temperatures ranging from 62°C to 93.9°C, and total dissolved solids (TDS) from 600 to 1267 mg/L. They are mildly acidic to mildly alkaline (pH 6.6 – 8.0) and their genetic types are HCO₃-_-Na++K+ (Bogatić and Lukovska Banja) and SO42-, HCO₃--Na++K+ (Vranjska Banja). Macroscopic, optical and diffraction assessment revealed that the encrustations comprised calcite and aragonite minerals, along with some local quartz, muscovite, albite and clinochlore. The conclusion was that there was a predominant presence of calcium carbonate in all the occurrences, represented by crystalline calcite grains, characteristically birefractive, and dark, semitranslucent grains in the form of microcrystalline calcite highly stained by iron hydroxides (Bogatić), as well as crystalline calcite with radially developed carbonate - aragonite (Lukovska Banja) and rod-like and filamentous aggregates of aragonite and calcite, highly translucent in places (Vranjska Banja).The texture of the samples exhibits alternating horizontal or wavy carbonate laminae. In Vranjska Banja, they include thin micritic to medium crystalline laminae and laminae composed of aggregates of aragonite needles in the form of bunch. In Bogatić and Lukovska Banja, there are thick micritic and highly porous laminae, 0.025 to 1 mm thick, or interlayers of a coarser crystalline structure. Apart from encrustations, all the occurrences exhibit phototrophic microbial mats, which were analyzed by scanning electron microscopy. The onset and progress of encrustation are primarily influenced by the physical and chemical composition of the mineral water (T, pH, TDS, HCO₃-, Ca2+, CO₂, etc.), as corroborated by hydrogeochemical modeling software PHREEQC 3.4.0. In addition, phototrophic biofilms might be contributing to the creation and accumulation of minerals in the encrustations.

Ključne riječi

Hrčak ID:

224690

URI

https://hrcak.srce.hr/224690

Datum izdavanja:

5.6.2019.

Posjeta: 1.331 *