Wavelength Dispersive X-ray Spectrometry Element Mapping and Mineralogy Based Manipulation: Assessment as a Method for Distinguishing Forensic Soil Samples

Four naturally occurring zeolites were examined to verify their assignments as chabazites AZLB-Ca and AZLB-Na (Bowie, Arizona) and clinoptilolites NM-Ca (Winston, New Mexico) and NV-Na (Ash Meadows, Nevada). Based on powder X-ray diffraction, NM-Ca was discovered to be mostly quartz with some clinoptilolite residues. Treatment with concentrated HCl (12.1 M) acid resulted in AZLB-Ca and AZLB-Na, the chabazite-like species, becoming amorphous, as confirmed by powder X-ray diffraction. In contrast, NM-Ca and NV-Na, which are clinoptilolite-like species, withstood boiling in concentrated HCl acid. This treatment removes calcium, magnesium, sodium, potassium, aluminum, and iron atoms or ions from the framework while leaving the silicon framework intact as confirmed via X-ray fluorescence and diffraction. SEM images on calcined and HCl treated NV-Na were obtained. BET surface area analysis confirmed an increase in surface area for the two zeolites after treatment, NM-Ca 20.0(1) to 111(4) m2/g and NV-Na 19.0(4) to 158(7) m2/g. 29Si and 27Al MAS NMR were performed on the natural and treated NV-Na zeolite, and the data for the natural NV-Na zeolite suggested a Si:Al ratio of 4.33 similar to that determined by X-Ray fluorescence of 4.55. Removal of lead ions from solution decreased from the native NM-Ca, 0.27(14), NV-Na, 1.50(17) meq/g compared to the modified zeolites, 30 min HCl treated NM-Ca 0.06(9) and NV-Na, 0.41(23) meq/g, and also decreased upon K+ ion pretreatment in the HCl modified zeolites.

Download Full-text

Use of Triple-Exposure X-ray Computed Tomography for Nondestructive Identification of Heavy Elements in Soil Samples

Soil and Sediment Contamination An International Journal ◽

10.1080/15320383.2021.1900068 ◽

2021 ◽

pp. 1-20

Author(s):

Yoshito Nakashima

Keyword(s):

Computed Tomography ◽

Soil Samples ◽

Heavy Elements ◽

X Ray ◽

X Ray Computed ◽

Nondestructive Identification

Download Full-text

Bacterial influence on the formation of hematite: implications for Martian dormant life

International Journal of Astrobiology ◽

10.1017/s1473550421000124 ◽

2021 ◽

pp. 1-15

Author(s):

Sudeera Wickramarathna ◽

Rohana Chandrajith ◽

Atula Senaratne ◽

Varun Paul ◽

Padmanava Dash ◽

...

Keyword(s):

Inductively Coupled Plasma ◽

Soil Layer ◽

Soil Samples ◽

Mineral Weathering ◽

Compositional Variation ◽

Rrna Gene ◽

Potential Candidate ◽

Metabolic Processes ◽

Extraterrestrial Life ◽

X Ray

Abstract Previous exploration missions have revealed Mars as a potential candidate for the existence of extraterrestrial life. If life could have existed beneath the Martian subsurface, biosignatures would have been preserved in iron-rich minerals. Prior investigations of terrestrial biosignatures and metabolic processes of geological analogues would be beneficial for identifying past metabolic processes on Mars, particularly morphological and chemical signatures indicative of past life, where biological components could potentially be denatured following continued exposure to extreme conditions. The objective of the research was to find potential implications for Martian subsurface life by characterizing morphological, mineralogical and microbial signatures of hematite deposits, both hematite rock and related soil samples, collected from Highland Complex of Sri Lanka. Rock samples examined through scanning electron microscopy-energy dispersive X-ray (SEM-EDX) spectroscopy. Analysis showed globular and spherical growth layers nucleated by bacteria. EDX results showed a higher iron to oxygen ratio in nuclei colonies compared to growth layers, which indicated a compositional variation due to microbial interaction. X-ray diffraction analysis of the hematite samples revealed variations in chemical composition along the vertical soil profile, with the top surface soil layer being particularly enriched with Fe2O3, suggesting internal dissolution of hematite through weathering. Furthermore, inductively coupled plasma-mass spectrometry analyses carried out on both rock and soil samples showed a possible indication of microbially induced mineral-weathering, particularly release of trapped trace metals in the parent rock. Microbial diversity analysis using 16S rRNA gene sequencing revealed that the rock sample was dominated by Actinobacteria and Proteobacteria, specifically, members of iron-metabolizing bacterial genera, including Mycobacterium, Arthrobacter, Amycolatopsis, Nocardia and Pedomicrobium. These results suggest that morphological and biogeochemical clues derived from studying the role of bacterial activity in hematite weathering and precipitation processes can be implemented as potential comparative tools to interpret similar processes that could have occurred on early Mars.

Download Full-text

Laboratory Sources for Soft-X-Ray Imaging of Hydrated Biological Material

Microscopy and Microanalysis ◽

10.1017/s1431927608088466 ◽

2008 ◽

Vol 14 (S2) ◽

pp. 664-665

Author(s):

JA Hunt ◽

PAC Takman ◽

B Frazer ◽

BC Gundrum ◽

A Abbott ◽

...

Keyword(s):

New Mexico ◽

Biological Material ◽

X Ray ◽

X Ray Imaging

Extended abstract of a paper presented at Microscopy and Microanalysis 2008 in Albuquerque, New Mexico, USA, August 3 – August 7, 2008

Download Full-text

X-ray fluorescence element-mapping spectrometer with improved spatial resolution

Measurement Science and Technology ◽

10.1088/0957-0233/2/2/018 ◽

1991 ◽

Vol 2 (2) ◽

pp. 183-184 ◽

Cited By ~ 5

Author(s):

Y Kobayashi ◽

N Fukumoto ◽

M Kurahashi

Keyword(s):

Spatial Resolution ◽

X Ray ◽

Element Mapping

Download Full-text

Macrostructural and Microstructural Properties of Residual Soils as Engineered Landfill Liner Materials

Environmental and Engineering Geoscience ◽

10.2113/eeg-d-20-00004 ◽

2021 ◽

Author(s):

Lee Li Yong ◽

Vivi Anggraini ◽

Mavinakere Eshwaraiah Raghunandan ◽

Mohd. Raihan Taha

Keyword(s):

Tap Water ◽

Chemical Precipitation ◽

Soil Samples ◽

Residual Soil ◽

Diffuse Double Layer ◽

Microstructural Properties ◽

Residual Soils ◽

Soil Leachate ◽

Landfill Liner ◽

X Ray

ABSTRACT This study assessed the performance of residual soils with regard to their macrostructural and microstructural properties and compatibility with leachate in pursuit of exploring alternative cost-effective and efficient landfill liner materials. A series of laboratory investigations was conducted on three residual soil samples by using tap water and leachate as permeation fluid to achieve the objectives of the study. The zeta potential measurements revealed that the presence of multivalent cations in the leachate decreased the diffuse double layer (DDL) thickness around the soil particles. The reduced DDL thickness caused a decrease in Atterberg limits of soil-leachate samples and changes in the classification of fine fractions. Additionally, the effects of pore clogging attributed to chemical precipitation and bioclogging were responsible for the reduction in measured hydraulic conductivities of soil-leachate samples. These effects can be clearly observed from the field-emission scanning electron microscopy images of soil-leachate samples with the appearance of less visible voids that led to a more compact and dense structure. The formation of new non-clay minerals and associated changes in the Al and Si ratio as reflected in the x-ray diffraction diffractograms and energy-dispersive x-ray analyses, respectively, were attributed to the effects of chemical precipitation. This study concluded that S1 and S2 residual soil samples are potential landfill liner materials because they possess adequate grading characteristics, adequate unconfined compressive strength, low hydraulic conductivity, and good compatibility with leachate. In contrast, the S3 sample requires further treatment to enhance its properties in order to comply with the requirements of landfill liner materials.

Download Full-text

Element mapping by X-ray fluorescence spectrometry.

Analytical Sciences ◽

10.2116/analsci.1.13 ◽

1985 ◽

Vol 1 (1) ◽

pp. 13-17 ◽

Cited By ~ 6

Author(s):

Yoshinori KOBAYASHI ◽

Akira KAWASE ◽

Akira UCHIUMI ◽

Susumu NAKAMURA ◽

Masaaki KUBOTA ◽

...

Keyword(s):

Fluorescence Spectrometry ◽

X Ray ◽

Element Mapping

Download Full-text

Evaluation of computer-controlled SEM in the study of metal-contaminated soils

Mineralogical Magazine ◽

10.1180/0026461036720096 ◽

2003 ◽

Vol 67 (2) ◽

pp. 219-231 ◽

Cited By ~ 10

Author(s):

H. W. Langmi ◽

J. Watt

Keyword(s):

Electron Microscopy ◽

Heavy Metals ◽

Contaminated Soils ◽

X Ray ◽

Computer Controlled ◽

Weathering Crusts ◽

Individual Particles ◽

Element Mapping ◽

Scanning Electron

Computer-controlled scanning electron microscopy (CCSEM) has been assessed for the determination of form and size distribution of heavy metals in urban contaminated soils. Metal distributions within individual particles were determined using X-ray element mapping. The sites selected for study were (1) around a landfill site, previously a colliery in Wolverhampton, UK and (2) a private garden adjacent to a railway in Nottingham, UK. Backscattered thresholding techniques were used to isolate the Pb-containing categories. The classification results for both Wolverhampton and Nottingham soils were generally similar but more Pb-containing classes were observed for the Nottingham samples when a comparison was made between results of the same size fractions. However, difficulties with the technique arose when particles showing chemically similar weathering crusts were assigned to the same class, despite having different internal compositions. The CCSEM data therefore need to be interpreted with caution and their application limited to situations in which particle internal complexity is not an issue.

Download Full-text

Determination of the content of heavy metals in soils and plants of urban ecosystems (Kaliningrad, Russia)

10.5194/egusphere-egu21-6610 ◽

2021 ◽

Author(s):

Nataliia Chupakhina ◽

Pavel Maslennikov ◽

Pavel Feduraev ◽

Luba Skrypnik ◽

Galina Chupakhina

Keyword(s):

Urban Environment ◽

Woody Plants ◽

Urban Soils ◽

Agricultural Landscape ◽

Fluorescence Analysis ◽

Soil Samples ◽

Soil Horizon ◽

X Ray ◽

Accumulation Of Metals ◽

Maximum Content

The purpose of this work is to investigate the accumulation of metals in urban soils of the main geochemical landscapes of the urban environment and in plants growing in these areas. The paper presents the results of a study of the accumulation of metals (Cu, Pb, As, Co, Cr, V, Zn, Mn, Sr, Ni, Ca, Fe) in the accumulative soil horizon of the main functional zones of Kaliningrad (agricultural landscape, residential, industrial and municipal). As a control, we used the landscape of recreation and recreation. The accumulation of elements in the soil and leaves of plants during the growing season and calendar period (year) was studied. The content of TM was determined in the leaves of woody, shrubby and herbaceous plants (22 species) of the urban environment of the city of Kaliningrad.The metal content in the samples was determined by X-ray fluorescence analysis on the Spectroscan Max-G device. Soil samples were taken from the upper accumulative horizon with a thickness of 0 to 10 cm by the envelope method. The content of TM in the samples was determined by X-ray fluorescence analysis on the device " Spectroscan Max-G "("Spektron", Russia). Soil samples for analysis were prepared in accordance with the M049-P/10 method.In urban soils, a significant excess of background concentrations of lead, manganese, zinc, copper, strontium and nickel (Pb>Cu>Zn>Mn>Sr>Ni) was found. The maximum content of pollutants in urban soils was observed in industrial and residential multi-storey areas with increased transport load. It is shown that the pH of the soil has the greatest influence on the distribution of metals in the accumulative horizon.The absorption of elements by plants is species-specific. The highest total level of metals (Mn, Fe, Zn, Sr, Br, Rb) was observed in the leaves of woody plants: holly maple, hanging birch and heart-shaped linden. Of the studied elements, the plants most accumulated manganese and iron. The accumulation of manganese in the leaves is more characteristic of woody plants than of shrubs or grasses. The maximum content of Mn was found in the leaves of holly maple (79.5%), in the leaves of other plants, manganese accumulated significantly less actively (2.7 - 35.6%). The predominant accumulation of iron was observed in the leaves of white clover, wrinkled rose and crowned chub, its content in the leaves was 81.0&#8212;83.8 %. Among woody species, the maximum concentration of iron was found in the leaves of heart-shaped linden (69.9 %) and hanging birch (53.4%). Among the species that actively accumulate Zn &#8212; black poplar (32.5 %), in the leaves of other plants, the zinc content is 2.2 &#8212; 16.8% of the total pollutants. The highest content of strontium was found in samples of meadow clover (19.1 %), in the leaves of other plants the proportion of metal was significantly lower (1.8&#8212;11.4%). Analysis of the accumulation of metals in the leaves of the studied plants revealed a positive correlation between the content of Fe and Sr (r = 0.71).&#160;

Download Full-text