scholarly journals A Baseline Survey of The Geochemical Characteristics of the Arctic Soils of Alexandra Land Within the Franz Josef Land Archipelago (Russia)

Author(s):  
Dmitry Valerievich Moskovchenko ◽  
Evgeny Babkin ◽  
Maria Pogojeva ◽  
Ruslan Zhostkov ◽  
Aleksandr Ovsyuchenko ◽  
...  

Abstract The composition of soils and their parent materials were studied within one of the most northern land areas of the world – the island of Alexandra Land of the Franz Josef Land archipelago. Contents of 65 trace and major elements were determined using atomic emission spectrometry (ICP-AES) и inductively coupled plasma spectrometry (ICP-MS). Other analyzed characteristics included soil pH, particle-size distribution and contents of carbon and nitrogen. The mineralogical composition of rocks was determined in thin sections. The studied soils were formed on basalts with high contents of MgO, Fe2O3, TiO2, Сu, Co, V, Ni, Cr, Zn, and low contents of Pb and Hg. The composition of soils was generally similar to that of the bedrock. The median concentrations (mg kg-1) of trace elements in the soils were as follows: Cu - 160, Zn - 101, Ni - 74, Pb - 2.9, Cd - 0.14, and Hg - 0.031. The bedrock had an alkaline pH, whereas the soil pH ranged from weakly acid to alkaline. The textural class of the soils predominantly corresponded to sandy loam. The contents of clay and silt increased with depth due to the migration of these fractions with groundwater. The concentrations of ecologically hazardous Hg and Pb were slightly increased in the upper layer of soils and correlated with carbon contents, which was indicative of bioconcentration processes.

2017 ◽  
Vol 10 (2) ◽  
pp. 194-200
Author(s):  
Carlos Roberto Juchen ◽  
Cristiano Poleto ◽  
Marcio Antonio Vilas Boas ◽  
Rodrigo Trevisani Juchen

This study aimed to determine the granulometric and mineralogical composition and the contents of trace elements Cr, Ni and Pb in sediments collected in impermeable streets located in the urban perimeter of Toledo PR, Brazil. The mineralogical analyses were performed by a diffractometer, the granulometric by integrated sieving methods and laser diffraction, trace elements in sediment quartered fractions by optical emission spectrometry with inductively coupled plasma (ICP-OES). It was concluded that the sediments with an average granulometric greater than 0.09 mm and finer fractions represented by the clay. The mineralogy identified ferruginous substances characteristics of Distroferric Red Latosol - DRL with high presence of quartz and diopside. Statistically it was shown that the concentrations of the trace elements in sediment samples had a significant enrichment for Chromium and Nickel in the central area’s streets and the Lead in lower concentrations in the streets of the periphery areas. The sediments have an average particle size with diameters greater than 0.09 mm, represented by sand, and the fine sediments represent 2 to 6% of samples. The software indicated that the sediments are from different anthropogenic sources. The diffractograms show peaks for quartz and diopside. The enrichment for trace elements was significant for chromium and nickel on the downtown area streets.


2021 ◽  
Vol 9 ◽  
Author(s):  
Arthur Monhonval ◽  
Jens Strauss ◽  
Elisabeth Mauclet ◽  
Catherine Hirst ◽  
Nathan Bemelmans ◽  
...  

Ice-rich permafrost has been subject to abrupt thaw and thermokarst formation in the past and is vulnerable to current global warming. The ice-rich permafrost domain includes Yedoma sediments that have never thawed since deposition during the late Pleistocene and Alas sediments that were formed by previous thermokarst processes during the Lateglacial and Holocene warming. Permafrost thaw unlocks organic carbon (OC) and minerals from these deposits and exposes OC to mineralization. A portion of the OC can be associated with iron (Fe), a redox-sensitive element acting as a trap for OC. Post-depositional thaw processes may have induced changes in redox conditions in these deposits and thereby affected Fe distribution and interactions between OC and Fe, with knock-on effects on the role that Fe plays in mediating present day OC mineralization. To test this hypothesis, we measured Fe concentrations and proportion of Fe oxides and Fe complexed with OC in unthawed Yedoma and previously thawed Alas deposits. Total Fe concentrations were determined on 1,292 sediment samples from the Yedoma domain using portable X-ray fluorescence; these concentrations were corrected for trueness using a calibration based on a subset of 144 samples measured by inductively coupled plasma optical emission spectrometry after alkaline fusion (R2 = 0.95). The total Fe concentration is stable with depth in Yedoma deposits, but we observe a depletion or accumulation of total Fe in Alas deposits, which experienced previous thaw and/or flooding events. Selective Fe extractions targeting reactive forms of Fe on unthawed and previously thawed deposits highlight that about 25% of the total Fe is present as reactive species, either as crystalline or amorphous oxides, or complexed with OC, with no significant difference in proportions of reactive Fe between Yedoma and Alas deposits. These results suggest that redox driven processes during past thermokarst formation impact the present-day distribution of total Fe, and thereby the total amount of reactive Fe in Alas versus Yedoma deposits. This study highlights that ongoing thermokarst lake formation and drainage dynamics in the Arctic influences reactive Fe distribution and thereby interactions between Fe and OC, OC mineralization rates, and greenhouse gas emissions.


2021 ◽  
Author(s):  
Lucie Malard ◽  
David A Pearce

Abstract BackgroundGlobal dispersal of microorganisms primarily occurs through airborne transport. Airborne microorganisms can travel thousands of kilometres and be deposited in the most remote places on Earth, from the Arctic to Antarctica, with the potential of invasion and colonisation. The first stage of microbial colonisation is deposition into a new ecosystem. However, how and under what circumstances such deposited microorganisms might successfully colonise a new environment is yet to be determined. Using the Arctic snowpack as a model system, we investigated the colonisation potential of snow derived bacteria deposited onto Arctic soils during and after snowmelt using laboratory-based microcosm experiments set-up to mimic realistic environmental conditions. We tested different melting rate scenarios to evaluate the influence of increased precipitation (via the increase of bacterial inputs and ecosystem disturbance) as well as the influence of soil pH (as the key driver of soil diversity) on bacterial communities and on the colonisation potential.Results We observed several candidate colonisations in all experiments; however, the number of potentially successful colonisation was higher in acidoneutral soils, at the average snowmelt rate measured in the Arctic. While the higher melt rate increased the total number of potentially invading bacteria, it did not promote colonisation. Instead, persistence decreased with time and most potential colonists were not identified by the end of the experiments. On the other hand, soil pH appeared as a determinant factor impacting invasion and subsequent colonisation. In acidic and alkaline soils, bacterial persistence with time was lower than in acidoneutral soils, as was the number of potentially successful colonisations. ConclusionsThis is the first study to investigate bacterial colonisation using the snowpack as a model system, and to demonstrate the low rate of potentially successful colonisations of soil by invading bacteria. It suggests that local soil properties might have a greater influence on the colonisation outcome than increased precipitation or ecosystem disturbance.


2020 ◽  
Author(s):  
Irene Rocchi ◽  
Sergio Rocchi ◽  
Matteo Masotta

<p>The discovery of metals and how to extract and use them was a turning point in human history, because it changed the economy and socio-cultural structure of ancient civilisations and started to severely affect the impact of human activities on the environment. In fact, a lot of societies developed near extraction sites and founded their economy on the use and trade of metals.<br>In Tuscany (Italy) there has been a long history of mining and metal extraction. From archaeological studies it has been reconstructed that the earliest records of these activities date back to the Etruscan period (VII century B.C.). Exploitation continued intermittently until a few decades ago. This extended period of mining exploitation left a wealth of both iron and copper metallurgical slags that can usually be found as abandoned and unsupervised heaps.<br>These slags, apparently just a waste from the metallurgical process, actually carry information about the evolution of the metallurgical process through which they were generated. Information about the charge, flux and fuel can be inferred from chemical and mineralogical composition of the slags.<br>Slags from three different smelting districts, ranging from ancient Etruscan-Roman period to modern age (1900 A.D.)  were studied macroscopically, identifying distinctive features related to the smelting process in different time periods. Then, thin sections obtained from representative samples were examined, using optical microscopy and electron microscopy. Chemical analyses were performed for major and trace elements by X-ray fluorescence spectroscopy and by inductively coupled plasma mass spectrometry, respectively.<br>Leaching experiments on some carefully selected samples were also completed, to investigate the release of potentially toxic elements during the interaction of the slags with the surrounding environment.<br>This kind of investigation allows to reconstruct part of the history of metal utilisation as well as to predict the impact that these remains will have on the environment.</p>


2017 ◽  
Vol 10 (2) ◽  
pp. 194-200
Author(s):  
Carlos Roberto Juchen ◽  
Cristiano Poleto ◽  
Marcio Antonio Vilas Boas ◽  
Rodrigo Trevisani Juchen

This study aimed to determine the granulometric and mineralogical composition and the contents of trace elements Cr, Ni and Pb in sediments collected in impermeable streets located in the urban perimeter of Toledo PR, Brazil. The mineralogical analyses were performed by a diffractometer, the granulometric by integrated sieving methods and laser diffraction, trace elements in sediment quartered fractions by optical emission spectrometry with inductively coupled plasma (ICP-OES). It was concluded that the sediments with an average granulometric greater than 0.09 mm and finer fractions represented by the clay. The mineralogy identified ferruginous substances characteristics of Distroferric Red Latosol - DRL with high presence of quartz and diopside. Statistically it was shown that the concentrations of the trace elements in sediment samples had a significant enrichment for Chromium and Nickel in the central area’s streets and the Lead in lower concentrations in the streets of the periphery areas. The sediments have an average particle size with diameters greater than 0.09 mm, represented by sand, and the fine sediments represent 2 to 6% of samples. The software indicated that the sediments are from different anthropogenic sources. The diffractograms show peaks for quartz and diopside. The enrichment for trace elements was significant for chromium and nickel on the downtown area streets.


2018 ◽  
Vol 7 (2) ◽  
pp. 145-152 ◽  
Author(s):  
Medet Junussov ◽  
Ferenc Mádai ◽  
Bánhidi Olivér

Abstract The carbonaceous siltstone rock material is a disseminated sulfide-rich sedimentary rock from a sediment-hosted gold deposit of Bakyrchik. The Bakyrchik deposit is located in Eastern Kazakhstan, which includes in Qalba gold province. The main purpose of this paper is a demonstration on chemical extraction of heavy metals from the carbonaceous siltstone rock and detection of its elemental concentrations. In the work was used a rock sample from the deposit which is a sericizited carbonaceous-siltstone rock. In sequential extraction method was selected four stages such as water soluble fraction (reaction with deionized water) for extraction of water soluble metals, reducible metal fraction (reaction with hydroxyl ammonium chloride) for extracting all reducible metals, organics and sulfides (reaction with hydrogen peroxide) for dissolution of organics and copper sulfide, and extraction of metal oxides and residual fraction (reaction with aqua regia) for extracting of all remaining metals. The paper comprises analytical methods for research outlooks. They are X-Ray Diffraction (determination of mineralogical composition), X-Ray Fluorescence (determination of chemical composition) and Inductively Coupled Plasma – Optical Emission Spectrometry (determination of heavy metal concentrations).


2020 ◽  
Vol 86 (5) ◽  
pp. 16-21
Author(s):  
T. A. Karimova ◽  
G. L. Buchbinder ◽  
S. V. Kachin

Calibration by the concentration ratio provides better metrological characteristics compared to other calibration modes when using the inductively coupled plasma atomic emission spectrometry (ICP-AES) for analysis of geological samples and technical materials on their base. The main reasons for the observed improvement are: i) elimination of the calibration error of measuring vessels and the error of weighing samples of the analyzed materials from the total error of the analysis; ii) high intensity of the lines of base element; and iii) higher accuracy of measuring the ratio of intensities compared to that of measuring the absolute intensities. Calcium oxide is better suited as a base when using calibration by the concentration ratio in analysis of carbonate rocks, technical materials, slags containing less than 20% SiO2 and more than 20% CaO. An equation is derived to calculate the content of components determined in carbonate materials when using calibration by the concentration ratio. A method of ICP-AES with calibration by the concentration ratio is developed for determination of CaO (in the range of contents 20 – 100%), SiO2 (2.0 – 35%), Al2O3 (0.1 – 30%), MgO (0.1 – 20%), Fe2O3 (0.5 – 40%), Na2O (0.1 – 15%), K2O (0.1 – 5%), P2O5 (0.001 – 2%), MnO (0.01 – 2%), TiO2 (0.01 – 2.0%) in various carbonate materials. Acid decomposition of the samples in closed vessels heated in a HotBlock 200 system is proposed. Correctness of the procedure is confirmed in analysis of standard samples of rocks. The developed procedure was used during the interlaboratory analysis of the standard sample of slag SH17 produced by ZAO ISO (Yekaterinburg, Russia).


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