Hazards of Heavy Metal Contamination at L’ubietová Cu-Deposit (Slovakia)

AbstractThe dump-fields Podlipa and Reiner at L’ubietová abandoned Cu-(Ag) deposit is situated at the boundary of the village settlement. The heavy metal contamination of the technogenous sediments and soils at the investigated dump-field show irregular planar distribution. Also the heavy metal content in the surface water, drainage water and in the groundwater was studied both in the dry as well as during the rainy periods. The speciation of As and Sb showed that there are present both As3+, Sb3+ as well as the less toxic As5+ and Sb5+ species. In the sediments prevail As5+ and Sb5+ species while in the water is dominant the As3+ and Sb3+ form. The article also presents results of the plant tissue degradation study in heavy metal contaminated conditions and compares them with those from reference sites. The cementation process causes substitution of iron by copper. The technogenous sediments and the contaminated soil of the dump show only very limited acidification potential. The installation of the Fe0-barrier seems to an acceptable solution for cleaning of the underground water

Mineralogical controls on antimony and arsenic mobility during tetrahedrite-tennantite weathering at historic mine sites Špania Dolina-Piesky and Ľubietová-Svätodušná, Slovakia

The legacy of copper (Cu) mining at Spania Dolina-Piesky and Lubietova-Svatodusna (central Slovakia) is waste rock and soil, surface waters, and groundwaters contaminated with antimony (Sb), arsenic (As), Cu, and other metals. Copper ore is hosted in chalcopyrite (CuFeS2) and sulfosalt solid solution tetrahedrite-tennantite {Cu-6[Cu-4(Fe,Zn)(2)]Sb4S13-Cu-6[Cu-4(Fe,Zn)(2)]As4S13} that show wide-spread oxidation characteristic by olive-green color secondary minerals. Tetrahedrite-tennantite can be a significant source of As and Sb contamination. Synchrotron-based mu-XRD, mu-XRF, and mu-XANES combined with electron microprobe analyses have been used to determine the mineralogy, chemical composition, element distribution, and Sb speciation in tetrahedrite-tennantite oxidation products in waste rock. Our results show that the mobility of Sb is limited by the formation of oxidation products such as tripuhyite and romeite group mineral containing 36.54 wt% Sb for samples where the primary mineral chemical composition is close to tetrahedrite end-member. Antimony K-edge mu-XANES spectra of these oxidation products indicate that the predominant Sb oxidation state is 5(+). Arsenic and Cu are also hosted by amorphous phases containing 6.23 wt% Sb on average and these are intergrown with tripuhyite and romeite. Antimony in this environment is not very mobile, meaning it is not easily released from solid phases to water, especially compared to As, Cu, and S. For samples where the primary sulfosalt is close to tennantite composition, the oxidation products associated with tennantite relicts contain 2.43 wt% Sb and are amorphous. The variable solubility of the secondary minerals that have been identified is expected to influence mobility of Sb and As in near-surface environment.Web of Science10251100109

Mineralogy of neutral mine drainage in the tailings of siderite-Cu ores in Eastern Slovakia

This work presents the results of investigation of the primary minerals and their weathering products of two tailing ponds near the villages of Rudňany and Slovinky in eastern Slovakia. The tailings are near-neutral or slightly alkaline (pH = 7.2–8.8) because the acidity generated by the decomposition of the sulfides is efficiently neutralized by the abundant carbonate minerals. The most frequent primary gangue minerals are siderite, quartz, barite, and muscovite. The prevailing primary sulfide minerals in both tailing ponds are pyrite and chalcopyrite; less common are tetrahedrite and arsenopyrite. The most frequent secondary and tertiary (i.e., formed in the tailings, not in the oxidation zone of the deposits) minerals at both localities are iron oxides, either goethite or poorly crystalline hydrous ferric oxide. Other minerals (cuprite, malachite, delafossite; identified by X-ray microdiffraction or Raman spectroscopy) are minor or rare and occur only in Slovinky. The iron oxide minerals are enriched in a suite of elements, including Cu, Si, Ca, Zn, As, Mg, and Mn. The transformations of the poorly crystalline hydrous ferric oxide to goethite and maturation of goethite is controlled by both high-valence tetrahedral cations (Si, As, P) and lower-valence octahedral cations (Cu), as shown by the measurements of the size of coherently diffracting domains in goethite and the chemical composition of goethite. The iron oxide minerals, by virtue of their adsorption capacity, prevent separate minerals of many metals and metalloids (Cu, Ca, As, Sb) from nucleating and growing, and therefore control the entire neutral mine drainage (NMD) system. Geochemical modeling of the discharged waters shows that all common Cu and ferric arsenate minerals are strongly undersaturated, confirming the central role of iron oxide phases in the NMD system.Web of Science52579877

Stratigraphic, sedimentological, geochemical, mineralogical and geochronological data characterizing the Upper Miocene sequence of the Turiec Basin, Western Carpathians (Central Europe)

International audienceThe data included in this article specify the characteristicsof the Upper Miocene fill of the Turiec Basin and servedfor reconstruction of temporal evolution of depositional systems in this intermontane basin located within the Western Carpathians (Central Europe). The borehole lithologicallog data were used to describe the stratigraphy of the TuriecBasin in geological sections and were gained in the Geofond archive of the State Geological Institute of Dionýz Štúr.The sedimentological data were acquired by field researchapplying facies analysis to nine outcrop sites. The outcropsserved for grain size analyzes performed by sieving and laser diffraction, for geochemical analyzes using ICP-ES, ICP-MSand XRF, and for mineralogical analyzes of whole rock andclay fraction by XRD. Moreover, the muddy layers on outcrops served for collection of 31 samples for the authigenic10Be/9Be dating. The geochronological data are presented byusing five different initial ratios for calculation, determinedwithin the Turiec Basin at the Late Pleistocene alluvial fanand river terrace sites as well as at two Holocene muddyfloodplain sites. Another initial ratio data are gained from anUpper Miocene lacustrine succession dated independentlyby magnetostratigraphy in previous research. Finally, asummary of previously published strontium isotope datafrom the Turiec Basin is included. The interpretations of thedata are provided in Šujan et al., (2023) Palaeogeography,Palaeoclimatology, Palaeoecology 628, 111746

Innovative in situ remediation of mine waters using a layered double hydroxide-biochar composite

International audienceThe current demand for alternative water sources requires the incorporation of low-cost composites in remediation technologies; these represent a sustainable alternative to more expensive, commercially used adsorbents. The main objective of this comprehensive field-scale study was to incorporate the layered double hydroxides (LDHs) into the hybrid biochar-based composites and apply an innovative material to remediate As/Sb-rich mine waters. The presence of hydrous Fe oxides (HFOs) within the composite enhanced the total adsorption efficiency of the composite for As(V) and Sb(V). The kinetic data fitted to a pseudo-second order model. Equilibrium experiments confirmed that the composite had a stronger interaction with As(V) than with Sb(V). The efficient removal of As(V) from mine water was achieved in both batch and continuous flow column systems, reaching up to 98% and 80%, respectively. Sb(V) showed different behavior to As(V) during mine water treatment, reaching adsorption efficiencies of up to 39% and 26% in batch and column experiments, respectively. The migration of Sb(V) in mine water was mostly attributed to its dispersion before it was able to show affinity to the composite. In general, the proposed column technology is suitable for the field remediation of small volumes of contaminated water, and thus has significant commercial potential

Application of the authigenic 10Be/9Be dating to constrain the age of a long-lived lake and its regression in an isolated intermontane basin: The case of Late Miocene Lake Turiec, Western Carpathians

International audienceThe depositional record of intermontane basins provides a valuable archive of the temporal evolution of orogenic belts; their common isolated nature may, however, hinder the efficient usage of standard approaches to constrain the age of a basin fill. In this paper the authigenic 10Be/9Be dating method is employed and tested to construct an age model of the existence and regression of Lake Turiec, which appeared during the Late Miocene in the intermontane Turiec Basin, Central Western Carpathians (Central Europe). The initial authigenic 10Be/9Be ratio, essential for the dating method, was analyzed on five sites of the Pleistocene-Holocene age, and back-calculation of the paleo-initial ratio was performed using lacustrine succession dated by magnetostratigraphy. Noteworthy, the initial ratio appears to be affected mainly by (post)depositional settings, and not by different provenance of the analyzed sediment. The sedimentological analysis of the Upper Miocene outcrops allowed the definition of the facies associations of an alluvial fan, a braided river, a fan delta and an open lake. The distribution of facies associations in the basin fill implies an increase in sediment supply to accommodation rate ratio due to the replacement of the open lake environment by the interconnected alluvial fan-braided river-fan delta system. Authigenic 10Be/9Be dating yielded ages of the lacustrine succession reaching ∼10.7–7.8 Ma, while the age of the fan delta succession, considered as the timing of the regression, was established to ∼6.7 Ma. The deposition of alluvial fans dominated the basin after the regression of the lake, possibly up to ∼4.0 Ma. The abrupt increase in sediment supply to the accommodation ratio at ∼6.7 Ma was caused by the uplift of the Malá Fatra Mts. at the western margin of the Turiec Basin, which had previously formed a moderate topography. The timing of this process generally coincides with the overall decrease in accommodation rates in the region due to the inversion of the Pannonian Basin System. The endorheic character of the basin before ∼6.7 Ma prevented the transport of the sediment denudated from the recently most uplifted parts of the Western Carpathians and carried towards the Pannonian Basin System, while the present-day source-to-sink system could only be formed later. This implies a low sediment supply and restricted denudation rate not only from the morphostructures surrounding the basin, but also from the Tatra Mts. and Nízke Tatry Mts. during the period ∼10.7–6.7 Ma. The research supports the suitability of intermontane basins for authigenic 10Be/9Be dating in a setting of high accommodation rates and limited redeposition of older muddy sediment. However, a special attention has to be paid to the depositional settings during determination of initial 10Be/9Be ratio