scholarly journals Regularities of La distribution in humic psammozem profile of Transbaikalia and soil-root layer microzones of maize during the vegetation period

2014 ◽  
Vol 3 (2) ◽  
pp. 167-174
Author(s):  
Larisa Afanasyeva ◽  
Nina Kozhevnikova
Keyword(s):  
Rare Earth ◽  
Soil Profile ◽  
Maximum Concentration ◽  
Total Content ◽  
Vegetation Period ◽  
Selective Extraction ◽  
Water Soluble ◽  
Mobile Form ◽  
Field Approach ◽  
Mobile Forms

In Transbaikalia information about accumulation, distribution of rare earth elements (REEs) in soils, their transportation from soil to plants is very rare. The aim of this study was to assess the migration of lanthanum in a soil profile and soil-root layer microzones of maize during the vegetation period. The study is based on a field approach in non-polluted natural sites. Concentration of total content La and its mobile form (acid-soluble, exchangeable and water-soluble) in the soil and soil root layer of maize was determined using method of selective extraction Gobran and Glegg. Maximum concentration total La was founded in the upper part of the soil (0 to 15 cm depth). The content of the La mobile forms is 6.9-11.2% from the total amount. The distribution of the element mobile forms within the profile is relatively even. Results indicated that concentration La mobile forms changed in accordance with the phase of maize development. The higher concentration of mobile forms (17-120% from germination period) was founded in soil-root layer microzones in the blossom period. DOI: http://dx.doi.org/10.3126/ije.v3i2.10527 International Journal of the Environment Vol.3(2) 2014: 213-220

scholarly journals Mobile Forms of Gold and Pathfinder Elements in Surface Sediments at the Novye Peski Gold Deposit and in the Piilola Prospecting Area (Karelia Region)

Minerals ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 34 ◽  
Author(s):  
Vera Korshunova ◽  
Marina Charykova
Keyword(s):  
Organic Matter ◽  
Gold Deposit ◽  
Surface Sediments ◽  
Gold Mineralization ◽  
Total Content ◽  
Fulvic Acids ◽  
Water Soluble ◽  
Mobile Form ◽  
Mobile Forms ◽  
Pathfinder Elements

The success of prospecting for gold deposit in overburdened areas based on the using of secondary dispersion haloes mostly depends on the chosen method of geochemical survey (sampling horizon, sample preparation for analysis, etc.). At the same time, the geochemistry of gold in the supergene zone is insufficiently studied, especially it’s migration and concentration in association with other elements in surface sediments due to weathering of gold-bearing ore. The main aim of the study presented in this paper is the determination of mobile forms of gold and pathfinder elements (As, Cu, Ni, Ag, Zn, Pb, Se, Sb, Mo, Bi, and Te) in podzol soil and moraine in the areas of Karelia region with known gold mineralization. As a result of conducted experiments it was determined that the main mobile forms of gold are water-soluble and bound to organic matter, while pathfinder elements bound preferably to Fe and Mn(hydr)oxides and to organic matter. As gold and some pathfinders bind with organic matter, this form was considered in more detail, and the elements’ interaction with humic and fulvic acids was investigated. In addition, it was determined that the studied elements are quite “mobile” because the percentage of the mobile form in their total content was mostly more than 50%. The main features of the elements’ migration and concentration were identified in surface sediments of the study areas.

scholarly journals Landscape-geochemical preconditions and regularities of toxic elements distribution on “Oleshkivski pisky” military training site territory

2020 ◽  
pp. 34-43
Author(s):  
A. Splodytel
Keyword(s):  
Heavy Metals ◽  
Soil Profile ◽  
Military Training ◽  
Water Soluble ◽  
Soluble Form ◽  
Contamination Level ◽  
Training Site ◽  
Mobile Forms ◽  
Migration Dynamics ◽  
The Military

It is characterized main features of landscape-geochemical structure of “Oleshkivski pisky” military range. It is analysed special aspects of military training activity influence on the of soils and plants contamination level with heavy metals. Sampling scheme for studying of heavy metals migration features, with respect to landscape structure of the territory is substantiated. Special features of heavy metals distribution in soils at different distances from firing positions within military range have been determined. It is investigated distribution and accumulation of I and II danger class heavy metals in soil and vegetational cover of the military training site. The regularities of spatial distribution of mobile and potentially accessible forms of heavy metals are determined. It was defined that content of heavy metals in three movable forms are represented in the following geochemical units, mg/kg: in acid soluble form – Mn > Zn > Pb > Cu > V > Ni > Co > Cd; in exchangeable form – Mn > Zn > Pb > V > Co = Ni > Cu > Cd; in water soluble form – Mn > Zn > Pb = V > Co > Ni > Cd > Cu. It is presented studies results on accumulation intensity and the nature of distribution of gross and mobile heavy metals forms in soil space and on their migration in the soil profile. The dominant technogenic geochemical unit was extracted: Cd > Hg > Pb > Cu > Zn > Ni > V > Co > Mn. Landscapes with maximum polyelement contamination have been identified. Landscape-geochemical map of “Oleshkivski pisky” military training site territory was drawn, relying on own field and experimental materials. Migration dynamics of Ni, Zn, Cu, V, Pb and other heavy metals mobile forms in the soil profile of soddy underdeveloped sandy soil during 2015–2019 under impact contamination levels has been determinated. The peculiarities of heavy metals mobile forms absorption in typical plant species of the military range territory during 2015–2019 vegetation periods were clarified.

scholarly journals Rare earth elements in soils of saline agrolandscapes of the Baraba plain

2021 ◽  
Vol 51 (3) ◽  
pp. 5-14
Author(s):  
N. V. Semendyaeva ◽  
A. A. Morozova ◽  
N. I. Dobrotvorskaya ◽  
N. V. Elizarov
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Soil Profile ◽  
Humus Content ◽  
Total Content ◽  
Agricultural Landscapes ◽  
Earth’S Crust ◽  
Depth Study ◽  
Earth's Crust ◽  
Humus Horizons

The total content of rare earth elements in the soil profile of saline agricultural landscapes catena of the Baraba plain within Novosibirsk region was studied. The total content of zirconium, yttrium, scandium, gallium, including lanthanides - cerium, lanthanum and ytterbium was determined. Rare earth elements are extremely poorly analyzed. At present, their influence on plants, organisms of animals and humans is being actively studied, although the maximum permissible and tentatively permissible concentrations for them have not yet been developed. The total content of rare earth elements, determined in the soils of the catena, depends on the granulometric composition and the degree of humus content of the soil horizons. It was revealed that in the studied soils they are mainly contained in the number of clarkes of the earth's crust, with the exception of lanthanum in the humus horizons, where its content is almost 1.5 times (44-48 mg/kg) higher than the clarke in the earth's crust (29 mg/kg), and ytterbium (10 times higher than the clarke). Along the soil profile, an insignificant movement of rare earth elements in both vertical and horizontal directions was noted, which indicates a low mobility of their compounds. Zirconium predominates in the profile of the studied soils from the group of rare earth elements. Its content in the humus horizons of soils of eluvial positions is within the clarke of the earth's crust; variations along the profile are insignificant. Ytterbium is contained in large quantities - from 1.89 to 4.05 mg/kg of soil, which is significantly higher than the clarke of the earth's crust (0.3 mg/kg of soil). The role of lanthanides in the soil -plant - animal - human system requires further in-depth study.

scholarly journals To the Issue of the Presence of the Occurrence of Rare Earth Elements in the Structure of Chromium Pyrope Garnet

2021 ◽  
Vol 38 ◽  
pp. 71-87
Author(s):  
V. V. Lin ◽  
◽  
A. I. Turkin ◽  
A. A. Chepurov ◽  
◽  
...  
Keyword(s):  
High Pressure ◽  
Rare Earth ◽  
Rare Earth Elements ◽  
Total Content ◽  
Kimberlite Pipe ◽  
Distribution Coefficients ◽  
Water Soluble ◽  
Refractory Oxide ◽  
Mineral Association ◽  
Initial Charge

Rare earth elements (REE) in garnet are of interest in various fields of modern geology. The geochemistry of REEs in magmatic minerals is widely used in determining the distribution coefficients of crystal/melt and crystal/fluid, modeling the processes of melting and crystallization of magmatic rocks, studying deep mantle processes, age estimates and other issues of petrogenesis. The aim of the present work was a synthesis of a peridotite mineral association including the garnet containing REE at high pressure and high temperature. The initial sample consisted mainly of natural serpentine collected from ophiolites of the Eastern Sayan (Russia). As is known, the extreme stage of the regressive metamorphism of peridotites is serpentinization. It is depleted in calcium, but can recrystallize at high PT conditions into a harzburgite paragenesis, and at the initial stage of the experiment the chemical composition of the sample was a model harzburgite depleted in calcium and chromium, as well as a fluid of predominantly aqueous composition. As a source of chromium, chromite grains of 1–2 mm in size from peridotite xenoliths of the Udachnaya kimberlite pipe (Yakutia) were used. REE were added to the initial charge in the form of water-soluble salts. The experiment at a pressure of 5 GPa and temperature 1300 was performed on a multi-anvil high-pressure apparatus of the “split sphere” type (BARS) designed and developed at the V.S. Sobolev Institute of Geology and Mineralogy SB RAS. A container based on refractory oxide ZrO2 was used as a highpressure medium. The pressure in the cell before sample heating was estimated using the reference substances Bi and PbSe. The temperature was measured by a platinum-platinum-rhodium thermocouple PtRh30-PtRh6. The quenched was performed by switching off the voltage in the heater circuit. The experiment products contain an association of olivine + garnet + orthopyroxene + newly formed spinel. The predominant phase was olivine of a forsterite composition. A low-Fe orthopyroxene (1.49 – 1.68 wt% FeO) was found in elongated grains uniformly distributed throughout the sample. The newly formed spinel shows the faceted grains. The chromium content in the spinel significantly exceeds that of the initially added to the initial charge, 61.63 and 54.04 wt% Cr2O3, respectively. The garnet is characterized by a purple color, and was identified in the sample volume between olivine grains in the form of individual faceted crystals or their clusters. The largest garnets reached 0.5 mm in size. The synthesized garnet was determined as a high-Cr low-Ca pyrope variety. The contents of Cr2O3 and CaO are 10.15-11.21 and 0.06-0.11 wt%, respectively. The total content of REE in the garnet identified by the microprobe analysis is relatively high reaching 5-7 wt%. As a result of the work a mineral association corresponding to the peridotite paragenesis was obtained, including the subcalcic Crrich pyrope containing rare earth elements in significant amounts. It was estimated that their content in garnet mainly depends on the size of the ionic radius and, accordingly, on the atomic weight. This is consistent with the known facts about the preferable position of heavy REEs into the garnet structure compared to the light REEs.

scholarly journals Assessment of anthropogenic contamination in an urban territory by the example of Blagoveshchensk city

2019 ◽  
pp. 79-93
Author(s):  
V. I. Radomskaya ◽  
N. A. Borodina
Keyword(s):  
Heavy Metals ◽  
Urban Soils ◽  
Soil Cover ◽  
Soil Layer ◽  
Organic Matter Content ◽  
Total Content ◽  
Water Soluble ◽  
Biogenic Elements ◽  
Average Risk ◽  
Mobile Forms

The distribution of heavy metals (HM) was analyzed in soils of Blagoveshchensk. The main physicochemical features (pH, the content of organic substance, mobile forms of phosphorus and potassium, the exchangeable cations of calcium and magnesium, as well as the total content of Cu, Cr, Ni, Co, Pb, Mn, Cd, Zn) were studied in soil samples. The anthropogenic influence on the urban environment transforms the physicochemical properties of soils: alkalizes the soil cover, increases the organic matter content, exchangeable bases, and mobile forms of biogenic elements. The total content of studied HM in the soils of Blagoveshchensk exceeds their concentrations in soils of the Mukhinka background territory and shows the spatial heterogeneity of pollutants distribution in the upper soil layer. As proceeds from the comparison of the studied elements concentrations with their MPC/APC, the most polluted territories are confined to industrial zones. Four elements, i.e., Mn, Pb, Cd and Zn, are accumulated in urban soils. However, Cu, Ni, Co, Cr accumulation is not so important. The calculation results of total contamination index in the upper soil cover layer in Blagoveshchensk taking into account the HM toxicity coefficient prove that Blagoveshchensk soils are mainly classified as moderately hazardous and nonhazardous. The evidence on the total content of HM do not allow making conclusion about their geochemical behavior in soils and about possible transition to neighbor environment. That is why the most mobile and easily mobilized forms of heavy metals, i.e., water-soluble and specifically adsorbed forms, were extracted using the method of successive extractions. The mobility of metals was established to be higher in the urban soils as compared to the background soils. Among the studied elements, Cd, Pb and Zn proved to be the most hazardous, with their mobility being close to the average risk of being included in the nutrition chains. This may lead to the contamination of Amur cross-boundary river ecosystems with heavy metals in case the groundwater level rises in the Blagoveshchensk territory due to its waterlogging by the Zeya River water.

scholarly journals Influence of irrigated mineralized waters on properties of ordinary chernozem in the conditions of Prysamaria Dniprovske

2020 ◽  
Vol 31 (2) ◽  
pp. 93-98
Author(s):  
E. P. Pochernyaeva ◽  
V. O. Okata ◽  
O. V. Kotovych ◽  
V. M. Yakovenko
Keyword(s):  
Soil Profile ◽  
Physicochemical Parameters ◽  
Total Content ◽  
Research Area ◽  
Water Soluble ◽  
Ordinary Chernozem ◽  
Negative Consequences ◽  
Soluble Salts ◽  
Exchangeable Calcium ◽  
Irrigated Soils

Irrigation of lands in arid climates helps to solve the problem of water deficit of soils in order to increase their fertility.  However, under the influence of mineralized waters used for irrigation, there is a degradation of chemical, physico-chemical, water-physical and physical properties of soils. Soil monitoring is one of the effective mechanisms that allowsassessing the current state of soils and predicting the negative consequences of economic activity in the future. The area where the research was conducted is in the zone of insufficient moisture where there is an annual deficit of water balance of soils. Irrigation in the studied areas began in the mid-70s of the last century and lasted until 1992. The waters of the Samara River were used for this purpose. The total mineralization of water during the growing season reaches 3515 mg/dm3. It is possible to estimate the degree of transformation of soils that have been under the influence of irrigation waters for a long time in relation to the indicators of virgin soils. The zonal soils of the research area are CalcicChernozems.  The analysis of macromorphological indicators showed that irrigation soils differ from the reference ones by the thickness of the organogenic horizon, density and structure. The results of the analysis of the aqueous extract of the reference soils show the absence of salinization with water-soluble salts.  Their content varies in the range from 0.051 to 0.078 %. A maximum of one salt is observed in the soil profile, namely in the transitional horizon at a depth of 45–63 cm. Below this depth, the content of water-soluble salts progressively decreases. The total content and distribution of water-soluble salts in the soil profile of irrigated soils has some differences from the reference soils.  In the upper part of the humus horizon, the total amount of water-soluble salts is smaller, which can be attributed to the effects of machining and better aeration, as well as the intensive removal of their vegetation.  Below these horizons, the amount of water-soluble salts progressively increases and reaches a maximum in the soil-forming rock.  The nature of the distribution in the soil profile and the total amount of salts isnot typical for Calcic Chernozems and ismore similar to those of Gleyic Calcic Chernozems.  The maximum amount of water-soluble salts is concentrated in the parent rock.  Their percentage indicates the absence of salinity in both studied soils.  But guided by the method of calculating the content of toxic water-soluble salts in the soil, in the reference soils, this figure reaches 0.21 t/ha in a meter layer of soil, and in irrigation 0.42 t/ha. The results of studies of physicochemical parameters show that a higher content of metabolic calcium is characteristic of the reference soils, and its distribution in the soils along the profile of both options is relatively similar.  In contrast, the distribution of exchangeable magnesium in the soil profile varies greatly, especially in the reference soils.  In irrigated soils, the ratio of exchangeable calcium to magnesium is more stable and varies in the range from 4.2 to 7.9, which may be the result of prolonged irrigation. According to the obtained physicochemical parameters, irrigation soils have weak salinity in the lower part of the transition horizon.  This indicator, together with the ratio of exchangeable calcium to magnesium, indicates eluvial-illuvial processes that for some time contributed to the redistribution in the soil profile of both water-soluble salts and exchangeable cations. Evaluation of the degree of salinity of soils showed the absence of salinization in the reference soils, as well as in the upper part of the humus horizons of irrigated soils.  Given the buffering of irrigated soils, weak salinity is present only in the upper part of the transition horizon.

A NEW WELDING MATERIAL FOR REGENERATION IN THE WELDING TECHNOLOGY BASED ON NICKEL. ANALYSIS OF THE COMPOSITION AND PROPERTIES OF DEFORMABLE HEAT-RESISTANT HIGH-CHROMIUM NICKEL-BASED ALLOYS FOR WELDED PARTS. ANALYSIS OF EXISTING FUELLING STATIONS TYPES AND VEHICLES USING HYDROGEN, HYDROGEN PRODUCTION AND STORING METHODS

2019 ◽  
pp. 43-48
Author(s):  
Ben Nengjun ◽  
Zhou Pengfei ◽  
Oleksandr Labartkava ◽  
Mykhailo Samokhin
Keyword(s):  
Rare Earth ◽  
High Temperature ◽  
Nickel Alloys ◽  
Total Content ◽  
Operating Conditions ◽  
High Temperature Strength ◽  
High Chromium ◽  
Salt Corrosion ◽  
Tcp Phases ◽  
The Impact

This work involves an analysis of high-chromium high-temperature deformable wieldable nickel alloys for use in GTE repair assemblies. It is shown that the alloys EP868 (VZh98) and Haynes 230 can be used in welded assemblies with an operating temperature of 800-1100 °C. The alloys Nimonic 81, Nimonic 91, IN 935, IN 939, and Nicrotan 2100 GT also have a high potential for use in welded assemblies. They are characterized by a combination of good weldability, high-temperature strength, and resistance to scaling. There have been conducted studies on high-temperature salt corrosion of model nickel alloys. They allowed establishing the patterns of the impact of base metal alloying with chromium, aluminum, titanium, cobalt, tungsten, molybdenum, niobium, tantalum and rare earth metals on the critical temperature of the start of salt corrosion Tcor and the alloy mass loss. It has been established that alloys with a moderate concentration (13-16%) of chromium can possess satisfactory hightemperature corrosion resistance (HTC resistance) under the operating conditions of ship GTE. The HTC resistance of CrAl-Ti alloys improves upon reaching the ratio Ti/Al ˃ 1. Meanwhile, the ratio Ti/Al ˂ 1 promotes the formation of corrosion products with low protective properties. The positive effect of tantalum on the HTC resistance of alloys is manifested at higher test temperatures than that of titanium, and the total content of molybdenum and tungsten in alloys is limited by the condition 8Mo2 – 2W2 = 89. The presence of refractory elements stabilizes the strengthening phase and prevents formation of the ɳ-phase. However, their excess promotes formation of the embrittling topologically close packed (TCP) phases and boundary carbides of an unfavorable morphology. Based on the studies of the HTC resistance, there has been identified a class of model high-temperature corrosionresistant nickel alloys with a moderate or high chromium content (30%), Ti/Al ˃ 1, and a balanced content of refractory and rare-earth elements.

Selective Extraction of Thorium from Rare Earth Elements Using Wrinkled Mesoporous Carbon

2018 ◽  
Vol 140 (44) ◽  
pp. 14735-14739 ◽  
Author(s):  
Zijie Wang ◽  
Alexander T. Brown ◽  
Kui Tan ◽  
Yves J. Chabal ◽  
Kenneth J. Balkus
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Mesoporous Carbon ◽  
Selective Extraction

Selective Transport of Water-Soluble Proteins from Aqueous to Ionic Liquid Phase via a Temperature-Sensitive Phase Change of These Mixtures

2012 ◽  
Vol 65 (11) ◽  
pp. 1548 ◽  
Author(s):  
Yuki Kohno ◽  
Nobuhumi Nakamura ◽  
Hiroyuki Ohno
Keyword(s):  
Phase Change ◽  
Aqueous Phase ◽  
Selective Dissolution ◽  
Selective Extraction ◽  
Soluble Proteins ◽  
Water Soluble ◽  
Temperature Sensitive ◽  
Salting Out ◽  
Key Factor ◽  
The Difference

Mixtures of some ionic liquids (ILs) and water show reversible phase change between a homogeneous mixture and phase-separated state by a small change in temperature. Some water-soluble proteins have been migrated from the aqueous to the IL phase. When tetrabutylphosphonium 2,4,6-trimethylbenzenesulfonate was used as an IL, cytochrome c (Cyt.c) was found to be extracted from the water phase to the IL phase. Conversely, both horseradish peroxidase (HRP) and azurin remained in the aqueous phase. This selective extraction was comprehended to be due to the difference in solubility of these proteins in both phases. The separated aqueous phase contained a small amount of IL, which induced the salting-out of Cyt.c. On the other hand, condensed IL phase promoted the salting-in of Cyt.c. As a result, Cyt.c was preferably dissolved in the hydrated IL phase rather than aqueous phase. In the case of HRP, there was only a salting-out profile upon increasing the concentration of IL, which induced selective dissolution of HRP in the aqueous phase. These results clearly suggest that the profile of salting-out and salting-in for proteins is the key factor to facilitate the selective extraction of proteins from aqueous to the IL phase.

Study of the Radiation Resistance of Endohedral Fullerenes of Rare-Earth Elements and Their Water-Soluble Derivatives

2018 ◽  
Vol 63 (1) ◽  
pp. 132-138
Author(s):  
I. M. Dubovskii ◽  
V. T. Lebedev ◽  
V. A. Shilin ◽  
A. A. Szhogina ◽  
M. V. Suyasova ◽  
...  
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Radiation Resistance ◽  
Water Soluble ◽  
Endohedral Fullerenes
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