Trace analysis: soils

1990 ◽  
Vol 333 (1628) ◽  
pp. 160-161
Keyword(s):  
Trace Elements ◽  
Manganese Oxides ◽  
Soil Extract ◽  
Water Soluble ◽  
Plant Availability ◽  
Soil Solutions ◽  
Freshwater Biota ◽  
Solute Chemistry ◽  
Trace Concentrations ◽  
Iron And Manganese

Determinations of constituents present in soils and soil solutions at trace concentrations are conducted primarily because of interest in soil as a medium for plant growth or because of its influence upon the solute chemistry of fresh waters and ground waters. Interest may arise from concern over potential toxicity effects or over adverse effects of deficiency of trace nutrient elements essential to soil or freshwater biota. In the above context, total amounts of elements present in soil are generally of less interest than water-soluble or labile, plant available forms (Marr & Cresser 1983). Rhizosphere soil may be more relevant than bulk soil in assessing plant availability. Over recent decades, optimal chemical extractants (such as EDTA or DTPA for Zn and Cu) have been selected which reflect plant availability of trace elements in terms of high correlations between plant tissue and soil extract concentrations. Occasionally full speciation is conducted. M. S. Cresser & E. El-Sayad (unpublished results), for example, have measured water-soluble, exchangeable and organically bound trace elements, and those in carbonate and amorphorus and crystalline iron and manganese oxides, and residual sand, silt and clay minerals. Such detailed analysis is valuable in elucidation of soil pedogenesis (El-Sayad et al . 1988).

Kinetics of the Natural Wolframite Interaction with Sodium and Potassium Carbonates

2020 ◽  
Vol 989 ◽  
pp. 440-447
Author(s):  
E.N. Selivanov ◽  
K.V. Pikulin ◽  
R.I. Gulyaeva ◽  
L.I. Galkova
Keyword(s):  
Manganese Oxides ◽  
Atomic Ratio ◽  
Water Soluble ◽  
Isothermal Kinetics ◽  
X Ray ◽  
Unit Cells ◽  
Subsequent Phase ◽  
Kinetics Of ◽  
Sodium And Potassium ◽  
Iron And Manganese

The kinetics and mechanism of the natural wolframite interaction with sodium and potassium carbonate, when they are heated in the air, are studied. Using X-ray phase and X-ray structure microanalysis, it was established that the initial single crystal wolfram consists of Fe0.5Mn0.5WO4 and Fe0.3Mn0.7WO4. The method of differential thermal and subsequent phase analysis of products has shown that the interaction of wolframite with sodium and potassium carbonates begins above 450-470 °C with the formation of tungstate and ferrites of sodium and potassium, iron and manganese oxides. Conducting the model experiments on sintering with the subsequent removal of water-soluble compounds (alkalization) made it possible to follow the change in the structure of wolframite. Unit cells parameters of wolframites in solid products (cakes) of leaching do not change if sintering is carried out in the range up to 600 °С. In samples, the preparation of which is coupled with heating to 700–800 °C, the atomic ratio of Fe/Mn in wolframite decreases to 0.2. This allows to specify the mechanism of the process and judge the greater reactivity of wolframites with an increased proportion of iron. Thermal analysis with data processing using the methods of non-isothermal kinetics has established that the studied interactions proceed according to a two-stage mechanism, which in the first stage is limited by diffusion. The appearance of a low-melting eutectic Na2WO4 – Na2CO3 и K2WO4 – K2CO3 in the system contributes to the process transition to the autocatalytic mode.

Trace element speciation in water and bottom sediments of the Pirogov water reservoir

2020 ◽  
pp. 59-68
Author(s):  
O. A. Lipatnikova ◽  
T. N. Lubkova ◽  
N. A. Korobova
Keyword(s):  
Trace Elements ◽  
Surface Water ◽  
Bottom Sediments ◽  
Manganese Oxides ◽  
Maximum Permissible Concentration ◽  
Solid Phase ◽  
Metal Speciation ◽  
Water Reservoir ◽  
Element Speciation ◽  
Iron And Manganese

The composition and speciation of trace elements (Cu, Pb, Zn, Cd, Ni, Co, Mn, Fe, Ba, and Sr) in surface water and bottom sediments of the Pirogov water reservoir have been studied. It was found that the metal content in surface water does not exceed the maximum permissible concentration (MPC) for fishery water reservoir excluded Zn (2–9 MPC) and Cu (up to 2 MPC). According to results of thermodynamic calculations, the predominant metal speciation in water is the free ion (Sr, Ba, Zn, Ni, Co, Cd), fulvate (Cu) and carbonate (Pb) complex. The interstitial water is characterized by an increase in the content of sulfate complex of trace elements in loams, the solid phase of which is also characterized by slightly anomalous contents of Zn, Cd, Co, and Ni. According to data of sequential selective procedure, metals are predominantly immobilized in solid phase of bottom sediments in the crystal structure of silicates or bounded to iron and manganese oxides. Only for Cd and Mn exchangeable and bound to carbonates fractions are characterized by considerable relative contents.

scholarly journals The filamentous bacteria Sphaerotilus, Leptothrix, Cladothrix , and their relation to iron and manganese

1949 ◽  
Vol 233 (605) ◽  
pp. 453-482 ◽  
Keyword(s):  
Related Species ◽  
Manganese Oxides ◽  
Soil Extract ◽  
Filamentous Bacteria ◽  
Sterile Soil ◽  
Meat Extract ◽  
Sphaerotilus Natans ◽  
Cultural Conditions ◽  
Microscopic Inspection ◽  
Iron And Manganese

The Chlamydobacteriaceae are a family of filamentous bacteria varying extremely with environmental conditions. The tacit assumption that species can be distinguished by mere microscopic inspection has led to the creation of numerous genera, species, and varieties of doubtful validity. In order to detect reversible modifications and hereditary differences cultures were undertaken. Threads of Sphaerotilus natans, Cladothrix dichotoma and Leptothrix ochracea were washed in sterile soil extract and transferred to agar plates with a low concentration of meat extract. By repeated plating several strains of each form were obtained in pure culture. All of these were identical, despite their origin from the various ‘species’ mentioned. By modifying the cultural conditions each strain could be made to change into the three original forms, as well as into certain others generally believed to belong to distinct genera. Since Sphaerotilus natans Kütz. is the oldest name it must be retained for all these forms. Schwers’s Megalothrix discophora , which was later referred to other genera and has been grown in culture by various authors, was not obtained from the cultures of Sphaerotilus natans . It represents a second related species of Sphaerotilus which may be named S. discophorus . Further species of Sphaerotilus have been described under the name of Leptothrix , but of the remaining socalled genera of the Chlamydobacteriaceae Crenothrix alone seems to be well founded. Conclusions are also reached on the colour of iron-containing deposits. If these appear brown, it is due to admixture of manganese oxides. Otherwise the colour is only slightly yellowish under the microscope and orange-ochre in larger accumulations. The envelopes produced by various organisms may contain much iron without its presence being revealed by their colour, although it can be recognized by the very refractive and brittle character of the envelopes and by micro-chemical reactions.

Plant availability of boron doped on iron and manganese oxides and its effect on soil acidosis

Geoderma ◽  
2009 ◽  
Vol 151 (3-4) ◽  
pp. 401-406 ◽  
Author(s):  
Liying Ren ◽  
Duanwei Zhu ◽  
Jingzhen Cui ◽  
Shuijiao Liao ◽  
Mingjian Geng ◽  
...  
Keyword(s):  
Manganese Oxides ◽  
Plant Availability ◽  
Boron Doped ◽  
Iron And Manganese

Ultrasound-Assisted Citric Acid Extraction of Zinc in Plateau Red Soil and Tessier Speciation Study

2013 ◽  
Vol 726-731 ◽  
pp. 4464-4467
Author(s):  
Wei Wei ◽  
Xue Jin Zhou ◽  
Yun Tao Gao
Keyword(s):  
Heavy Metal ◽  
Citric Acid ◽  
Manganese Oxides ◽  
Red Soil ◽  
Extraction Rate ◽  
Acid Extraction ◽  
Speciation Study ◽  
Ultrasonic Assisted ◽  
Ultrasound Assisted ◽  
Iron And Manganese

Taking plateau red soil as research object, using the ultrasonic-assisted organic acid extraction the heavy metal zinc in it, and analyze the form of zinc. Results showed that the extraction rate can reach 68%, with the increase of time, the extraction effect of zinc is obviously enhanced in this method. Ultrasonic-assisted citric acid extraction soil can increase the extraction rate of exchangeable, bound to carbonates and bound to iron and manganese oxides relatively.

Strategies for EELS Data Analysis. Introducing UMAP and HDBSCAN for Dimensionality Reduction and Clustering

2021 ◽  
pp. 1-14
Author(s):  
Javier Blanco-Portals ◽  
Francesca Peiró ◽  
Sònia Estradé
Keyword(s):  
Dimensionality Reduction ◽  
Clustering Analysis ◽  
Manganese Oxides ◽  
Spatial Clustering ◽  
State Of The Art ◽  
Core Loss ◽  
Nonnegative Matrix ◽  
Case Scenario ◽  
Electron Energy Loss ◽  
Iron And Manganese

Hierarchical density-based spatial clustering of applications with noise (HDBSCAN) and uniform manifold approximation and projection (UMAP), two new state-of-the-art algorithms for clustering analysis, and dimensionality reduction, respectively, are proposed for the segmentation of core-loss electron energy loss spectroscopy (EELS) spectrum images. The performances of UMAP and HDBSCAN are systematically compared to the other clustering analysis approaches used in EELS in the literature using a known synthetic dataset. Better results are found for these new approaches. Furthermore, UMAP and HDBSCAN are showcased in a real experimental dataset from a core–shell nanoparticle of iron and manganese oxides, as well as the triple combination nonnegative matrix factorization–UMAP–HDBSCAN. The results obtained indicate how the complementary use of different combinations may be beneficial in a real-case scenario to attain a complete picture, as different algorithms highlight different aspects of the dataset studied.

Enhancing Cd(II) Adsorption on Rice Straw Biochar by Modification of Iron and Manganese Oxides

2021 ◽  
Author(s):  
Wen-Tao TAN ◽  
Hang ZHOU ◽  
Shang-Feng TANG ◽  
Peng ZENG ◽  
Jiao-Feng GU ◽  
...  
Keyword(s):  
Rice Straw ◽  
Manganese Oxides ◽  
Rice Straw Biochar ◽  
Iron And Manganese

scholarly journals Chemical characterization of fine particular matter in Changzhou, China and source apportionment with offline aerosol mass spectrometry

2016 ◽  
Author(s):  
Zhaolian Ye ◽  
Jiashu Liu ◽  
Aijun Gu ◽  
Feifei Feng ◽  
Yuhai Liu ◽  
...  
Keyword(s):  
Trace Elements ◽  
Organic Matter ◽  
Organic Carbon ◽  
Source Apportionment ◽  
Major Ions ◽  
Chemical Properties ◽  
Chemical Characterization ◽  
Water Soluble ◽  
Traffic Emissions ◽  
Aerosol Mass

Abstract. Knowledge on aerosol chemistry in densely populated regions is critical for reduction of air pollution, while such studies haven't been conducted in Changzhou, an important manufacturing base and polluted city in the Yangtze River Delta (YRD), China. This work, for the first time, performed a thorough chemical characterization on the fine particular matter (PM2.5) samples, collected during July 2015 to April 2016 across four seasons in Changzhou city. A suite of analytical techniques were employed to characterize organic carbon / elemental carbon (OC / EC), water-soluble organic carbon (WSOC), water-soluble inorganic ions (WSIIs), trace elements, and polycyclic aromatic hydrocarbons (PAHs) in PM2.5; in particular, an Aerodyne soot particle aerosol mass spectrometer (SP-AMS) was deployed to probe the chemical properties of water-soluble organic aerosols (WSOA). The average PM2.5 concentrations were found to be 108.3 μg m−3, and all identified species were able to reconstruct ~ 80 % of the PM2.5 mass. The WSIIs occupied about half of the PM2.5 mass (~ 52.1 %), with SO42−, NO3− and NH4+ as the major ions. On average, nitrate concentrations dominated over sulfate (mass ratio of 1.21), indicating influences from traffic emissions. OC and EC correlated well with each other and the highest OC / EC ratio (5.16) occurred in winter, suggesting complex OC sources likely including both secondarily formed and primarily emitted OA. Concentrations of eight trace elements (Mn, Zn, Al, B, Cr, Cu, Fe, Pb) can contribute up to 6.0 % of PM2.5 during winter. PAHs concentrations were also high in winter (140.25 ng m−3), which were predominated by median/high molecular weight PAHs with 5- and 6-rings. The organic matter including both water-soluble and water-insoluble species occupied ~ 20 % PM2.5 mass. SP-AMS determined that the WSOA had an average atomic oxygen-to-carbon (O / C), hydrogen-to-carbon (H / C), nitrogen-to-carbon (N / C) and organic matter-to-organic carbon (OM / OC) ratios of 0.36, 1.54, 0.11, and 1.74, respectively. Source apportionment of WSOA further identified two secondary OA (SOA) factors (a less oxidized and a more oxidized OA) and two primary OA (POA) factors (a nitrogen enriched hydrocarbon-like traffic OA and a cooking-related OA). On average, the POA contribution overweighed SOA (55 % vs. 45 %), indicating the important role of local anthropogenic emissions to the aerosol pollution in Changzhou. Our measurement also shows the abundance of organic nitrogen species in WSOA, and the source analyses suggest these species likely associated with traffic emissions, which warrants more investigations on PM samples from other locations.

scholarly journals Contents, distribution, and fractionation of soil organic carbon and trace elements in soils under a green manure application

2020 ◽  
Vol 16 (No. 1) ◽  
pp. 50-58
Author(s):  
Yana Timofeeva ◽  
Lyudmila Purtova ◽  
Alexey Emelyanov ◽  
Maxim Burdukovskii ◽  
Irina Kiseleva ◽  
...  
Keyword(s):  
Trace Elements ◽  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Green Manure ◽  
Mineral Soil ◽  
Water Soluble ◽  
Household Waste ◽  
Nickel Ions ◽  
Low Degree ◽  
Soluble Components

We quantified the soluble fractions of the soil organic carbon (SOC) concentrations and the total and water-soluble trace elements in soils contaminated by household waste and remediated via the addition of green manure over 13 years and identified the main factors controlling the vertical distribution and accumulation of the trace elements. Green manure favoured the active formation of soil organic matter. The SOC of the examined soils was characterised by the active stabilisation by mineral soil compounds, but by a low degree of humification. The soils showed increased concentrations of Cr and Ni ions. The SOC and different soil compounds enriched by Si, Ca, and Mn ions were the important determinant for the distribution of Sr, V and Cu ions, as well as for the distribution of Pb and Cr ions bound to the water-soluble components of the soils. The low degree of SOC humification may be one of the main reasons of the high concentrations of Cu and Pb ions in the composition of the water-soluble soil compounds. The nickel ions were mainly associated with compounds enriched by the Al and Fe ions. The extremely high percentage concentration of the Ni ions in the water-soluble components of the soils may be result of the absence of the Ni ions adsorption by humic substances.

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