scholarly journals Pollution Characteristics of Sb, As, Hg, Pb, Cd, and Zn in Soils from Different Zones of Xikuangshan Antimony Mine

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Saijun Zhou ◽  
Andrew Hursthouse ◽  
Tengshu Chen
Keyword(s):  
Risk Index ◽  
Hydride Generation ◽  
Morphological Characteristics ◽  
Soil Samples ◽  
Mining Waste ◽  
Waste Rock ◽  
Residual Fraction ◽  
Chemical Extraction ◽  
Underground Tunnel ◽  
Sequential Chemical Extraction

Major sources of pollution during the antimony (Sb) mining and processing are mining waste rock, smelting waste, tailings dam, and underground tunnel wastewater. The aim of the present study was to assess magnitude of pollution from Sb mine by taking four types of samples: soil in the mining waste rock zone, soil in the smelting zone, soil in tailings zone, and soil in underground tunnel wastewater zone. Sixty soil samples from the four zones were taken for experimental work, and the contents and morphological characteristics of the six potentially toxic elements (PTEs) such as Sb, As, Hg, Pb, Cd, and Zn in the soil samples were measured by using a hydride generation atomic fluorescence spectrometer (AFS-9700). The results show that the soil of the mine area is seriously polluted. The average contents of Sb, As, Hg, Pb, Cd, and Zn in the soil reach 1267.20 mg·kg−1, 94.44 mg·kg−1, 1.46 mg·kg−1, 184.19 mg·kg−1, 8.54 mg·kg−1, and 1054.11 mg·kg−1, respectively. There exists good correlation between the PTEs in the soil, with Sb strongly positively correlated with As, Hg, Pb, and Zn. The intensity of pollution is highest in the antimony-smelting zone, where the potential ecological risk index is over 15,000, followed by the tailings zone and mining waste rock zone, with the underground tunnel wastewater zone being the lowest. Using sequential chemical extraction, the elements are associated with the residual fraction, followed by organic-sulfide fraction, and smaller portions in the Fe-Mn oxide, carbonate, and exchangeable fractions. There are great differences in the speciation content of different elements in different sampling zones. The study implicates that Sb-smelting zone is the potential source of PTEs and maximum metals are associated with residual phase, out of which significant portion is associated with mobile fraction or phase.

scholarly journals Development of a Tellurium Speciation Study Using IC-ICP-MS on Soil Samples Taken from an Area Associated with the Storage, Processing, and Recovery of Electrowaste

Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2651
Author(s):  
Magdalena Jabłońska-Czapla ◽  
Katarzyna Grygoyć
Keyword(s):  
Inductively Coupled Plasma ◽  
Total Concentration ◽  
Soil Samples ◽  
Chemical Extraction ◽  
Soil Extraction ◽  
Inductively Coupled ◽  
Sequential Chemical Extraction ◽  
Icp Ms ◽  
Speciation Study ◽  
Plasma Mass Spectrometry

The optimization and validation of a methodology for determining and extracting inorganic ionic Te(VI) and Te(IV) forms in easily-leached fractions of soil by Ion Chromatography-Inductively Coupled Plasma-Mass Spectrometry (IC-ICP-MS) were studied. In this paper, the total concentration of Te, pH, and red-ox potential were determined. Ions were successfully separated in 4 min on a Hamilton PRPX100 column with 0.002 mg/kg and 0.004 mg/kg limits of detection for Te(VI) and Te(IV), respectively. Soil samples were collected from areas subjected to the influence of an electrowaste processing and sorting plant. Sequential chemical extraction of soils showed that tellurium was bound mainly with sulphides, organic matter, and silicates. Optimization of soil extraction allowed 20% average extraction efficiency to be obtained, using 100 mM citric acid as the extractant. In the tested soil samples, both tellurium species were present. In most cases, the soils contained a reduced Te form, or the concentrations of both species were similar.

scholarly journals Impact of Mining Dump on the Accumulation and Mobility of Metals in the Bytomka River Sediments

2014 ◽  
Vol 40 (2) ◽  
pp. 3-19 ◽  
Author(s):  
Magdalena Jabłońska-Czapla ◽  
Sebastian Szopa ◽  
Czesława Rosik-Dulewska
Keyword(s):  
Heavy Metals ◽  
Ion Exchange ◽  
Bottom Sediments ◽  
River Sediments ◽  
Extraction Procedure ◽  
Residual Fraction ◽  
Chemical Extraction ◽  
Coal Waste ◽  
Waste Dump ◽  
Sequential Chemical Extraction

Abstract The research aim was to determine the long-term impact of the mine waste stored at the coal waste dump Hałda Ruda on the content of heavy metals in the bottom sediments of the Bytomka River. It is a watercourse flowing along this coal waste dump and has been under its influence for over fifty years. The research also attempted to determine the seasonality of changes (2 years) and mobility of selected elements. The article presents total contents of Cr, Mn, Ni, Cu, Zn, As, Cd and Pb in the bottom sediments collected from the Bytomka River. It also focuses on the distribution of these elements in particular geochemical fractions determined with the Tessier's sequential chemical extraction procedure. Total element contents were determined with an EDPXRF (Energy Dispersive X-ray Fluorescence) technique. The extractants of particular Tessier's fractions were determined quantitatively with an ICP-MS (Inductively Coupled Plasma Mass Spectrometry) spectrometer. The research results show that the stored waste significantly influences the contents of heavy metals in the Bytomka River bottom sediments. The lowest concentration of heavy metals was observed at the B1 spot (above the dump), while the highest one was measured at the B3 spot (below the dump). Sequential chemical extraction of the bottom sediments indicates that the Zn content in the ion-exchange and carbonate fractions diminished within a year. Nevertheless, Zn bound to Fe and Mn oxides acted in the opposite way. Mn, Zn and Pb are the most dangerous elements from the viewpoint of environmental hazards, as their total concentrations were high. Moreover, their high contents were observed in the most mobile (ion-exchange and carbonate) fractions. Extremely toxic Cd was bound to the oxide fraction to the largest extent. Cu was mainly bound to the organic fraction while environmentally hazardous Cr was bound to the residual fraction.

scholarly journals Arsenic in Soils Affected by Mining: Microscopic Studies vs. Sequential Chemical Extraction

2020 ◽  
Vol 17 (22) ◽  
pp. 8426
Author(s):  
Jessica Álvarez-Quintana ◽  
Rodrigo Álvarez ◽  
Almudena Ordóñez
Keyword(s):  
Electron Microscopy ◽  
Residual Fraction ◽  
Chemical Extraction ◽  
Sequential Chemical Extraction ◽  
Transmission Electron ◽  
Microscopic Studies ◽  
Sequential Extraction Method ◽  
As Adsorption ◽  
Microscopic Techniques

Soil samples from three inactive mines, corresponding to different Arsenic-bearing mineralization types, were collected and studied. The aim was to determine the influence of mine wastes mineralogy/geochemistry and texture in As mobility and to compare results from sequential chemical extraction and microscopic techniques (optical and electron) at a grain scale. Arsenic in soils is found mainly associated to the residual fraction, indicating that mechanical As dispersion is mainly responsible for As soil pollution. The use of objective microscopic techniques (i.e., Scanning Electron Microscopy-Energy Dispersive Spectroscopy -SEM-EDS-, High Resolution Transmission Electron Microscopy -HR-TEM) has pointed out that the selected sequential extraction method overestimates the role of Mn amorphous oxy-hydroxides and organic matter in As retention while underestimating the mechanism of As adsorption onto clay particle surfaces.

scholarly journals Mobility and distribution of barium and strontium in profiles of podzolic soils

2013 ◽  
Vol 64 (1) ◽  
pp. 2-7 ◽  
Author(s):  
Agnieszka Jeske
Keyword(s):  
Manganese Oxides ◽  
Extraction Procedure ◽  
Residual Fraction ◽  
Chemical Extraction ◽  
Geochemical Background ◽  
Podzolic Soils ◽  
Sequential Chemical Extraction ◽  
Wide Range ◽  
Low Levels ◽  
Fraction Bound

Abstract The study was aimed at determining the content, distribution and mobility of barium and strontium in various forest podzol soils. Samples with a wide range of chemical and physical properties were collected from typical uncontaminated soils of south-western Poland. The total metal content in the analyzed soils was considered as the geochemical background thanks to the natural features of the study site. Sequential chemical extraction procedure were used to provide information on the mobility and bioavailability of the studied metals in the soil. Fractions of Ba and Sr were determined using the five-step procedure of Tessier et al. (1979). The results show that heavy metals were generally represented by the exchangeable fraction (F1 . barium) and the residual fraction (F5 . strontium) with the average values at 53 and 69%, respectively. The mobility of barium in all soil profiles was very high, ranging within 52.54% and indicating a generally high availability and mobility. Relatively very low levels of the trace elements were found in the fraction bound to organic matter (F4: 3.8%). Very low levels of strontium were found also in the fraction bound to carbonates (F2: 2.3%). Humic-eluvial, illuvial and sideric horizons were enriched in the fractions of barium and strontium bound to iron and manganese oxides (F3).

scholarly journals Mercury Speciation in Various Coals Based on Sequential Chemical Extraction and Thermal Analysis Methods

Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2361
Author(s):  
Yinjiao Su ◽  
Xuan Liu ◽  
Yang Teng ◽  
Kai Zhang
Keyword(s):  
Thermal Stability ◽  
Coal Combustion ◽  
Decomposition Methods ◽  
Chemical Extraction ◽  
Anthropogenic Source ◽  
Coal Rank ◽  
Coal Pyrolysis ◽  
Mercury Emissions ◽  
Sequential Chemical Extraction ◽  
Removal Technology

Coal combustion is an anthropogenic source of mercury (Hg) emissions to the atmosphere. The strong toxicity and bioaccumulation potential have prompted attention to the control of mercury emissions. Pyrolysis has been regarded as an efficient Hg removal technology before coal combustion and other utilization processes. In this work, the Hg speciation in coal and its thermal stability were investigated by combined sequential chemical extraction and temperature programmed decomposition methods; the effect of coal rank on Hg speciation distribution and Hg release characteristics were clarified based on the weight loss of coal; the amount of Hg released; and the emission of sulfur-containing gases during coal pyrolysis. Five species of mercury were determined in this study: exchangeable Hg (F1), carbonate + sulfate + oxide bound Hg (F2), silicate + aluminosilicate bound Hg (F3), sulfide bound Hg (F4), and residual Hg (F5), which are quite distinct in different rank coals. Generally, Hg enriched in carbonates, sulfates, and oxides might migrate to sulfides with the transformation of minerals during the coalification process. The order of thermal stability of different Hg speciation in coal is F1 < F5 < F2 < F4 < F3. Meanwhile, the release of Hg is accompanied with sulfur gases during coal pyrolysis, which is heavily dependent on the coal rank.

scholarly journals A Preliminary Study on Dependence of Mercury Distribution on the Degree of Coalification in Ningwu Coalfield, Shanxi, China

Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3119
Author(s):  
Yinjiao Su ◽  
Xuan Liu ◽  
Yang Teng ◽  
Kai Zhang
Keyword(s):  
Linear Correlation ◽  
Bituminous Coal ◽  
Rank Correlation ◽  
Correlation Coefficients ◽  
Chemical Extraction ◽  
Mercury Distribution ◽  
Sequential Chemical Extraction ◽  
Average Proportion ◽  
Total Proportion ◽  
The Relationship

Mercury (Hg) is a toxic trace element emitted from coal conversion and utilization. Samples with different coal ranks and gangue from Ningwu Coalfield are selected and investigated in this study. For understanding dependence of mercury distribution characteristics on coalification degree, Pearson regression analysis coupled with Spearman rank correlation is employed to explore the relationship between mercury and sulfur, mercury and ash in coal, and sequential chemical extraction method is adopted to recognize the Hg speciation in the samples of coal and gangue. The measured results show that Hg is positively related to total sulfur content in coal and the affinity of Hg to different sulfur forms varies with the coalification degree. Organic sulfur has the biggest impact on Hg in peat, which becomes weak with increasing the coalification degree from lignite to bituminous coal. Sulfate sulfur is only related to Hg in peat or lignite as little content in coal. However, the Pearson linear correlation coefficients of Hg and pyritic sulfur are relatively high with 0.479 for lignite, 0.709 for sub-bituminous coal and 0.887 for bituminous coal. Hg is also related to ash content in coal, whose Pearson linear correlation coefficients are 0.504, 0.774 and 0.827 respectively, in lignite, sub-bituminous coal and bituminous coal. Furthermore, Hg distribution is directly depended on own speciation in coal. The total proportion of F2 + F3 + F4 is increased from 41.5% in peat to 87.4% in bituminous coal, but the average proportion of F5 is decreased from 56.8% in peat to 12.4% in bituminous coal. The above findings imply that both Hg and sulfur enrich in coal largely due to the migration from organic state to inorganic state with the increase of coalification degree in Ningwu Coalfield.

scholarly journals OBSERVATIONS IMPLICATING AN EXTRACELLULAR ENZYMIC MECHANISM OF CONTROL OF BONE MORPHOGENESIS

1974 ◽  
Vol 22 (2) ◽  
pp. 88-103 ◽  
Author(s):  
MARSHALL R. URIST ◽  
HISASHI IWATA ◽  
STUART D. BOYD ◽  
PETER L. CECCOTTI ◽  
MARLYS OKADA ◽  
...  
Keyword(s):  
Chemical Reactions ◽  
Phosphate Buffer ◽  
Bone Matrix ◽  
Chemical Extraction ◽  
Ammonium Bromide ◽  
Property A ◽  
Noncollagenous Proteins ◽  
Buffer Solutions ◽  
Sequential Chemical Extraction ◽  
Chloroform Methanol

Data on physicochemical conditions leading to loss of the bone morphogenetic property of bone matrix in neutral buffer solutions support the concept of an enzymic control mechanism better than a chemical blocking reaction or denaturation. The loss is associated with release of 35S-labeled constituents and not prevented by ε-amino caproic acid, an inhibitor of cathepsins. The loss is also associated with release of 35S-cysteine-labeled protein; about 60% of the yield is sustained by the addition of only 3 mmoles/liter of iodoacetic acid. A latent period of about 12 hr, decreased by extraction of bone matrix with CaCl2, is characterized by release of protein polysaccharide and other noncollagenous proteins. Release of sialic acid from the bone matrix by neuraminidase at pH 7.4 has no effect upon bone yield. At 2°C, Tris-HCl buffer or ethylenediaminetetraacetic acid extracts noncollagenous proteins without loss of bone yield; at 37°C, pH 7.4, these solutions also activate endogenous enzymes and reduce bone yield. The component of bone matrix responsible for reduction in bone yield is separable from bone matrix by extraction with phosphate buffer, by catheptic digestion of bone matrix in acidic buffer solutions, by sequential chemical extraction of noncollagenous proteins with cold slightly acidic salt solutions or by extraction-denaturation with chloroform-methanol. Detergents neither extinguish nor denature the morphogenetic property but some solubilize or extract degradative enzymes; hexodecyl trimethyl ammonium bromide, at pH 5.0, is positively charged and extracts hydrophobic proteins, including part of the bone morphogenetic property. A special selection of sulfhydryl chemical inhibitors remarkably different from the selection inhibiting known enzymes preserves the bone morphogenetic property of bone matrix; p-chloromercuribenzoate preservation is reversible by chemical reactions with cysteine. Reduction in bone yield in phosphate buffer is not attributable to a chemical block because chloroform-methanol extraction of the agent does not restore bone yield and is not attributable to denaturation because bone yield sustained by p-chloromercuribenzoate is lost by chemical reactions with cysteine. An hypothetical insoluble bone morphogenetic protein (BMP) firmly bound to collagen is degraded by a soluble neutral proteinase (BMPase). Digestion of the hypothetical BMP occurs without loss of the 640-A electron micrographic image of bone collagen, resembles tryptic digestion and is more selective as well as physiologic in action.

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