Thermally Induced Changes in Metal Solubility of Contaminated Soils Is Linked to Mineral Recrystallization and Organic Matter Transformations

2001 ◽  
Vol 35 (5) ◽  
pp. 908-916 ◽  
Author(s):  
Carmen Enid Martínez ◽  
Astrid Jacobson ◽  
Murray B. McBride
Keyword(s):  
Organic Matter ◽  
Contaminated Soils ◽  
Thermally Induced ◽  
Metal Solubility ◽  
Induced Changes

scholarly journals Study of the Effects of Heating on Organic Matter and Mineral Phases in Limestones

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
J. May-Crespo ◽  
P. Martínez-Torres ◽  
P. Quintana ◽  
J. J. Alvarado-Gil ◽  
L. Vilca-Quispe ◽  
...  
Keyword(s):  
Organic Matter ◽  
Thermal Treatment ◽  
Effective Porosity ◽  
Thermally Induced ◽  
Mineral Phases ◽  
Induced Changes ◽  
Degree Of Degradation ◽  
Partial Release

Color-induced changes in stones due to heating can be useful in determining the degree of degradation generated in their components and structure. We evaluate the effect of heating in three types of limestones, useful in building and restoration, corresponding to biomicrite (BC), biosparite (BS), and intramicrite (IM), in the range of temperature from 100°C to 600°C. Our analyses indicate that the strongest changes in reflectance occur in the samples of intramicrite, followed by biomicrite, being biosparite showing the smallest ones. Additionally, IM samples suffer the largest modifications in effective porosity due to the thermal treatment; in contrast, BS and BC samples show smaller temperature-induced alterations associated with smaller changes in reflectance. Moreover, we reveal that most of the thermally induced variations are associated, in this range of temperature, to the dehydroxylation of goethite that transforms into hematite, as well as by the burning and partial release of the organic matter present in the rock. Colorimetry analyses show that the sequence of thermally induced changes can be followed by the evolution of the three coordinates, L ∗ (lightness), a ∗ (red-green), and b ∗ (yellow-blue), of the CIE 1976 L ∗ a ∗ b ∗ space.

scholarly journals Fractionation of Heavy Metals in Multi-Contaminated Soil Treated with Biochar Using the Sequential Extraction Procedure

Biomolecules ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 448
Author(s):  
Mahrous Awad ◽  
Zhongzhen Liu ◽  
Milan Skalicky ◽  
Eldessoky S. Dessoky ◽  
Marian Brestic ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Organic Matter ◽  
Soil Organic Matter ◽  
Soil Ph ◽  
Contaminated Soil ◽  
Contaminated Soils ◽  
Extraction Procedure ◽  
Sequential Fractionation ◽  
Relationship Of ◽  
The Relationship

Heavy metals (HMs) toxicity represents a global problem depending on the soil environment’s geochemical forms. Biochar addition safely reduces HMs mobile forms, thus, reducing their toxicity to plants. While several studies have shown that biochar could significantly stabilize HMs in contaminated soils, the study of the relationship of soil properties to potential mechanisms still needs further clarification; hence the importance of assessing a naturally contaminated soil amended, in this case with Paulownia biochar (PB) and Bamboo biochar (BB) to fractionate Pb, Cd, Zn, and Cu using short sequential fractionation plans. The relationship of soil pH and organic matter and its effect on the redistribution of these metals were estimated. The results indicated that the acid-soluble metals decreased while the fraction bound to organic matter increased compared to untreated pots. The increase in the organic matter metal-bound was mostly at the expense of the decrease in the acid extractable and Fe/Mn bound ones. The highest application of PB increased the organically bound fraction of Pb, Cd, Zn, and Cu (62, 61, 34, and 61%, respectively), while the BB increased them (61, 49, 42, and 22%, respectively) over the control. Meanwhile, Fe/Mn oxides bound represents the large portion associated with zinc and copper. Concerning soil organic matter (SOM) and soil pH, as potential tools to reduce the risk of the target metals, a significant positive correlation was observed with acid-soluble extractable metal, while a negative correlation was obtained with organic matter-bound metal. The principal component analysis (PCA) shows that the total variance represents 89.7% for the TCPL-extractable and HMs forms and their relation to pH and SOM, which confirms the positive effect of the pH and SOM under PB and BB treatments on reducing the risk of the studied metals. The mobility and bioavailability of these metals and their geochemical forms widely varied according to pH, soil organic matter, biochar types, and application rates. As an environmentally friendly and economical material, biochar emphasizes its importance as a tool that makes the soil more suitable for safe cultivation in the short term and its long-term sustainability. This study proves that it reduces the mobility of HMs, their environmental risks and contributes to food safety. It also confirms that performing more controlled experiments, such as a pot, is a disciplined and effective way to assess the suitability of different types of biochar as soil modifications to restore HMs contaminated soil via controlling the mobilization of these minerals.

Thermally induced changes in cluster-assembled carbon nanocluster films observed via photoelectron spectroscopy

2003 ◽  
Vol 212-213 ◽  
pp. 879-884 ◽  
Author(s):  
E. Magnano ◽  
C. Cepek ◽  
M. Sancrotti ◽  
F. Siviero ◽  
S. Vinati ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Thermally Induced ◽  
Induced Changes

Formation process of interface states at grain boundaries in sputtered polycrystalline Si films

1999 ◽  
Vol 14 (2) ◽  
pp. 371-376 ◽  
Author(s):  
Yoshitaka Nakano ◽  
Jiro Sakata ◽  
Yasunori Taga
Keyword(s):  
Energy Levels ◽  
Columnar Structure ◽  
Systematic Investigation ◽  
Defect States ◽  
Electron Microscopic ◽  
Thermally Induced ◽  
Transmission Electron ◽  
Transmission Electron Microscopic ◽  
Si Films ◽  
Induced Changes

A systematic investigation has been made on surface defect states of crystallites in the crystallization process of sputtered amorphous silicon films by isothermal annealing. Transmission electron microscopic observations indicate a pronounced vertical columnar structure in the upper part of the films, where the crystallization is delayed. Admittance spectroscopy reveals that two newly generated energy levels with the crystallization are attributed to the crystallites in the lower and upper parts of the films in view of the anisotropic crystallization. These thermally induced changes can be well explained by Si–Si shearing modes at the interfaces of crystallites through the process of crystallization.

scholarly journals Temperature-dependent nanomechanics and topography of bacteriophage T7

2018 ◽  
Author(s):  
Zsuzsanna Vörös ◽  
Gabriella Csík ◽  
Levente Herényi ◽  
Miklós Kellermayer
Keyword(s):  
Structural Changes ◽  
Mechanical Stability ◽  
Genetic Material ◽  
Heat Inactivation ◽  
Infectious Agents ◽  
Temperature Dependent ◽  
Thermally Induced ◽  
Partial Denaturation ◽  
Induced Changes ◽  
T7 Bacteriophage

AbstractViruses are nanoscale infectious agents which may be inactivated by heat treatment. Although heat inactivation is thought to be caused by the release of genetic material from the capsid, the thermally-induced structural changes in viruses are little known. Here we measured the heat-induced changes in the properties of T7 bacteriophage particles exposed to two-stage (65 °C and 80 °C) thermal effect by using AFM-based nanomechanical and topographical measurements. We found that exposure to 65 °C caused the release of genomic DNA due to the loss of the capsid tail which leads to a destabilization of the T7 particles. Further heating to 80 °C surprisingly led to an increase in mechanical stability due to partial denaturation of the capsomeric proteins kept within the global capsid arrangement.

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