贵州省原煤中微量元素的组成特征

研究了贵州省各主要煤田中主要采煤层的Ａｓ,Ｂ,Ｂａ,Ｂｅ,Ｃｄ,Ｃｏ,Ｃｒ,Ｃ,Ｈｇ,Ｌｉ,Ｎｉ,Ｐｂ,Ｓｂ,Ｓｅ,Ｓｒ,Ｔｌ,Ｖ,Ｚｎ等微量元素的组成特征,贵州省原煤中微量元素的含量总体上的世界范围内的一致,但Ｓｂ,Ａｓ,Ｈｇ等有害元素则明显富集,由于煤炭成因上的特殊性,其微量元素的组成除受煤植物的影响外,后期在煤作用对其有决定性的影响。     

Geochemistry of the barkinite liptobiolith (Late Permian) from the Jinshan Mine,Anhui Province,China

This paper discusses the geochemistry and mineralogy of the barkinite liptobiolith of the Late Permian age from the Jinshan Mine, Guangde County, Anhui Province, China. Samples were examined using inductively coupled plasma-mass spectroscopy, X-ray fluorescence, cold-vapor atomic absorption spectrometry, ion-selective electrode, sequential chemical extraction, scanning electron microscopy equipped with energy-dispersive X-ray, and optical microscopy. The coal is a medium-ash and high-sulfur resource. Minerals in the coal are composed of kaolinite, pyrite, calcite, and quartz. Pyrite and calcite are derived from seawater during peat accumulation. Quartz in the coal is of authigenic origin. Part of the kaolinite is from a land-source region, and part occurs as cell-fillings and is of authigenic origin. The results also indicate that the barkinite liptobiolith contains some toxic elements in high concentrations. Elements including Li, Be, Si, Sc, Ti, V, Cr, Fe, Ga, Se, Y, Zr, Mo, the rare earth elements (REEs), W, Hg, Tl, Pb, Th, and U in the coals are enriched in the barkinite liptobiolith. Results of sequential chemical extraction showed that Li, Sc, Ti, Cr, Y, Zr, REEs, and Th in the coal mainly occur as silicates, while Be and W are related to organic matter. Pyrite is the dominant source of S, Mo, Hg, Tl, and Pb. Gallium only occurs in silicate, and U and V occur both in organic and silicate associations.     

Characterization of Santa Catarina (Brazil) coal with respect to human health and environmental concerns

The current paper presents the concentration, distribution, and modes of occurrence of trace elements of 13 coals from south Brazil. The samples were collected in the state of Santa Catarina. Chemical analyses and the high ash yields indicate that all studied coals are rich in mineral matter, with SiO₂ and Al₂O₃ dominating as determined by inductively coupled plasma-atomic emission spectrometry (ICP-AES). Quartz is the main mineral species and is associated with minor levels of feldspars, kaolinite, hematite, and iron-rich carbonates. The contents of trace elements, including As, Pb, Cd, Ni, Cr, Mn, Be, V, U, Zn, Li, Cu, Tl, and Ni, in coals were determined. A comparison of ranges and means of elemental concentrations in Santa Catarina, Brazil, and world coals shows that the ranges of most elements in Santa Catarina coal are very close to the usual worldwide concentration ranges in coal.     

Coal utilization in China: environmental impacts and human health

Coal is one of the major energy resources in China, accounting for approximately 70 % of primary energy consumption. Many environmental problems and human health risks arise during coal exploitation, utilization, and waste disposal, especially in the remote mountainous areas of western China (e.g., eastern Yunnan, western Guizhou and Hubei, and southern Shaanxi). In this paper, we report a thorough review of the environmental and human health impacts related to coal utilization in China. The abundance of the toxic trace elements such as F, As, Se, and Hg in Chinese coals is summarized. The environmental problems (i.e., water, soil, and air pollution) that are related to coal utilization are outlined. The provenance, distributions, typical symptoms, sources, and possible pathways of endemic fluorosis, arsenism, and selenosis due to improper coal usage (briquettes mixed with high-F clay, mineralized As-rich coal, and Se-rich stone coal) are discussed in detail. In 2010, 14.8, 1.9 million, and 16,000 Chinese people suffered from dental fluorosis, skeletal fluorosis, and arsenism, respectively. Finally, several suggestions are proposed for the prevention and treatment for endemic problems caused by coal utilization.     

Lead distribution in Permo-Carboniferous coal from the North China Plate,China

The content and distribution of the lead in coal, gangue and the sulfur ball and the pyritic gangue of the Permo-Carboniferous in the North China Plate have been systematically studied (nearly 300 samples) in this paper. The Permo-Carboniferous coals in the North China Plate account for nearly 44.45 of total Chinese coal resources, and most of the steam coals in China come from the Permo-Carboniferous coals in the North China Plate. The result shows that lead content in the coal varied from 1.45 to 63.60 mg kg^–1, averaging 23.95 mg kg^–1; the lead content of the sulfur ball and the pyritic gangue in the coal seam ranges from 70.26–1060 mg kg^–1, with an average of 271.28 mg kg^–1; the lead content of the gangue is from 29.5 to 77.81 mg kg^–1, averaging at 40.77 mg kg^–1. The lead in the coal seam is mainly concentrated in the pyrite, such as sulfur ball, pyritic gangue or pyrite, and is the least concentrated in the organic of coal. The content of the lead has a direct ratio with the ash and the pyretic sulfur. Coal washing can reduce the content of the pyretic sulfur and the lead.     

Lead in Chinese coals: distribution,modes of occurrence,and environmental effects

Lead (Pb) has gained much attention since the 1970s because of its potential and cumulative toxicity. As one of the most hazardous elements in coals, Pb can be released into the environment during coal mining, processing, and utilization. This study presents a synthesis on the abundance, distribution, modes of occurrence, and environmental impacts of Pb in Chinese coals. Using the expected coal reserves as the weighting factor and based on the previously published Pb content in 4,304 coal samples (including results obtained in our laboratory) from main coalfields or coal mines in China, the weighted mean Pb content in Chinese coals is 13.0 μg/g, which is higher than that of the American coals (11 μg/g) and average world coals (7.8 μg/g). With respect to regional distribution of Pb in Chinese coals, Pb content can be arbitrarily divided into three groups (<20, 20–40, >40 μg/g). Following this classification, coals from Tibet have the highest average Pb content (128.94 μg/g). The abundance of Pb in coals varies with coal-forming periods and coal ranks, with the late Triassic and higher rank coals having the highest Pb content, which could be ascribed to regional geochemical differences and later geological evolution as well as magma hydrothermal activities. The enrichment of Pb in coals is influenced by several geological factors, including coal-forming plants, source rocks, hydrothermal fluid, and depositional environment. Pb, dominantly associates with sulfide minerals, especially galena in coals. During coal combustion or pyrolysis, Pb is partly emitted into the atmosphere and partly partitioned to solid residues. Accumulation of Pb from coal utilization in human body could lead to a range of health problems and increase the risk of cancer.     

贵州省煤中挥发性和半挥发性微量元素分布规律的初步研究

研究了贵州省四大煤田不同层位、不同煤种中Hg,As,Se,Pb,Cd,Tl,Zn,Sb等挥发性和半挥发性微量元素的分布规律。贵州省原煤中Hg,As,Se,Pb,Cd,Sb等元素的含量高于地壳克拉克值;Tl,Zn等的含量低于地壳克拉克值;另外,除了Pb,Zn外,贵州省原煤中Hg,As,Se,Cd的含量远远高于东北和内蒙古东部地区。微量元素聚类分析结果表明,Hg,As,Sb可能主要分布于煤的黄铁矿中;Zn和Se可能主要赋存于闪锌矿中;Cd可能部分存在于硫化物中,部分存在于硅酸盐矿物相中;Pb可能主要存在于硅酸盐矿物相中;而Tl在煤中的赋存形式较复杂。     

Dissolved Ions of Trace and Major Elements and in Suspended Sediments in the Nile, Egypt

Dissolved ions and suspended participates from twelve water samples from Sohag (different localities) and Aswan (behind and below the High Dam) areas were collected along the River Nile, upper Egypt, which is at present affected seriously by pressure of population, intense industrial and agricultural activities, and atmospheric fallout. Eighteen trace and nine major ions in solution and fourteen metals in suspension were analyzed to establish whether elements are of anthropogenic or natural origin. Results of this study show that the Nile water was contaminated with high concentrations of dissolved lead, and with copper, nickel and mercury to a lesser extent, suggesting that these contaminants are generated from anthropogenic activities. the other dissolved ions in the Nile are of natural origin because their metal concentrations fall within the range of the normal background and average world dissolved values for inland waters. Results show that the usual constituents of suspended particulates in the Nile seem to be some metals (Cu and Zn) adsorbed on iron and manganese oxide/hydroxide. the results also reveal that most trace and major metal particulates increase from south to north due to activities associated with the dense population living along the Nile banks. No significant differences were observed between the chemical composition of trace and major elements taken on the east and west river Nile banks.     

Arsenic content and distribution pattern in Chinese coals

About 500 samples of coal, pyritic coal balls, pyritic gangue and coal seam gangue were collected from different coal basins and geologic periods of coal formation to determine the arsenic (As) content and distribution pattern in China. The Permian-Carboniferous and Jurassic coals in the North China Plate and Northwest China account for nearly 85% of total Chinese coal reserves and data showed that As content ranged from 0.1 to 94?mg?kg^?1, with the majority between 1 and 14.9?mg?kg^?1. The As content of some Late Permian coals in Southwest Guizhou Province and stone coal in the South Qinling Mountain area were exceedingly high (30–534?mg?kg^?1), but the majority of coal in the Southwest Guizhou Province contained low to medium amounts. Only the coals, which are situated in or near igneous rocks and are not considered a part of Chinese coal reserves, possessed unusually high As content (>30?mg?kg^?1). Arsenic was also concentrated in pyritic coal balls and the pyritic gangue of the coal seam with values ranging from 21.5 to 142.46?mg?kg^?1 and an average of 69?mg?kg^?1 in Shaanxi and 78?mg?kg^?1 in Shandong. Arsenic contents in coal gangue in the Northwest and North China Plate is about 0.2–15?mg?kg^?1, a little lower than coals in the same seam. Washing gangue (waste from coal washing) generally contained more As than coal, because the washed gangue has more pyrite than the natural gangue (black shale). Washing coal reduced the content of the pyritic sulfur, heavy metals and As. Based on amounts of coal used with different As content in Chinese coal reserves, the average As content of Chinese coals is about 4.5?mg?kg^?1.     

煤燃烧过程中5种微量元素的迁移和富集

通过一维炉燃烧模拟实验,研究了褐煤、肥煤、无烟煤及其燃烧产物中As,Cr,Pb,Cd,Hg的含量和分布;计算了在不同燃烧条件下的飞灰和底灰对煤的元素含量比和富集因子,以及飞灰对底灰的元素含量比和富集因子;详细探讨了3种煤在不同燃烧过程中5种元素的迁移和富集行为．结果表明,5种元素在各燃烧产物中都有一定含量的分布,只是各元素在不同燃烧过程中所呈现的集散规律不同,说明煤燃烧过程中微量元素的迁移和富集行为不仅与煤中微量元素的含量和赋存状态有直接关系,还受煤燃烧方式、炉温、气氛条件等人为因素的影响．     

Seasonal variation and partition of trace metals (Fe, Zn, Cu, Mn, Cr, Cd and Pb) in surface sediments: relationship with physico-chemical variables of water from the Calabar River, South Eastern Nigeria

The seasonal variation and partition of trace metals (Fe, Cu, Zn, Mn, Cd, Cr and Pb) in the surface sediments of the Calabar River are reported. Chemical partition of the metals in the sediments reveals that 2–30% of the total metal load was contributed by the non-detrital (acid-soluble) fraction, while fine-grained host minerals/compounds are the main carriers of the detrital (acid-insoluble) fraction (70–98%). Using multivariate statistical analysis, the seasonal fluctuations in the distribution of some of the metals show significant influence by physio-chemical changes (dissolved oxygen, pH, salinity and conductivity) in the water column. Fe–Mn oxide grain coatings and sulphide materials have been identified as scavengers of some of the non-detrital and detrital trace metals in the sediments. On the basis of index of geoaccumulation (I-geo) and comparison with previous studies, the Calabar River surface sediments have been classified as unpolluted.     

Research review trends of food analysis in Latvia: major and trace element content

The current paper involves overview of several studies concerning quantitative major and trace element analysis of different food samples, such as products of plant origin, e.g., locally grown vegetables (carrots, onions, potatoes) and products of animal origin derived with or without processing (cottage cheese, eggs, honey). Food samples were collected over the territory of Latvia in the time period 2009–2012. Sample pre-treatment was chosen according to the product specifics but mostly wet mineralization with concentrated nitric acid was applied. Analysis of major elements (e.g., Ca, Fe, K, Mg, Na) and trace elements (e.g., As, Cd, Co, Cr, Cu, Ni, Pb, Se, Zn) was performed by appropriate quantitative analytical technique: atomic absorption spectrometry, inductively coupled plasma mass spectrometry or total reflection X-ray fluorescence spectrometry. Not only the influence of environmental factors (e.g., geographical or seasonal impact) was detected in element dissemination in food, also botanical origin (if applicable) and applied agricultural praxis, product processing and storage specifics were found to be important. Possible food contamination by potentially toxic elements can be associated mostly with the consequences of anthropogenic activities. The studies revealed the significance of food research in the context of environmental science.     

Leaching of trace and major elements from coal ash dumps

Coal ash samples taken from an active, currently filled cassette as well as samples taken from passive cassettes of the power plant in Obrenovac (Yugoslavia) were subjected to sequential leaching, comprising of extraction with distilled water, 1 M KC1 and 0.1 M HC1. Concentrations of trace and major elements found in extracts revealed that lead and cadmium are not present in significant concentrations, while other elements show different behavior: practically all absorbed trace elements and most of the major elements are partially leached during transport, while later, on the dump, only a slow release of most of the examined ion‐exchangeable elements occurs.     

Natural and anthropogenic metal inputs to soils in urban Uppsala, Sweden

Urban soils are complex systems due to human activities that disturb the natural development of the soil horizons and add hazardous elements. Remediation projects are common in urban areas and guideline values are set to represent a desired level of elements. However, the natural content of trace elements may not always equal the desired levels. In this study, an attempt is made to distinguish between metals that are present in the soil due to natural origins and to anthropogenic origins. Seventy-five soil samples of the 0–5, 5–10 and 10–20 cm layers were collected from 25 sites in urban areas of Uppsala City and analysed for aluminium (Al), arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), iron (Fe), mercury (Hg), manganese (Mn), nickel (Ni), lead (Pb), tungsten (W) and zinc (Zn) using aqua regia for digestion. In order to highlight elements of geological origin, the results were compared to a similar study carried out in Gothenburg City, which has about three times as many inhabitants as Uppsala and has a more industrial history. A cluster analysis was also performed to distinguish between elements of natural and anthropogenic origin. Contents of As, Al, Fe, Cr, Ni, Mn and W in Uppsala were concluded to be of mainly geological origin, while contents of Cd, Cu, Zn, Pb and Hg seemed to have been impacted upon by mainly urban activities.     

Evaluation of acidity in late Permian outcrop coals and its association with endemic fluorosis in the border area of Yunnan,Guizhou, and Sichuan in China

The junction area of Yunnan, Guizhou, and Sichuan provinces is the heaviest coal-burning endemic fluorosis zones in China. To better understand the pathogenicity of endemic fluorosis in this area, 87 coal samples from the late Permian outcrop or semi-outcrop coal seams were collected in eight counties of the junction area of Yunnan, Guizhou, and Sichuan provinces. The total fluorine and sulfate content, etc. in the coal was determined using combustion-hydrolysis/fluoride-ion-selective electrode method and ion chromatography, respectively. The results show that the total fluorine concentrations in the samples ranged from 44 to 382 µg g^?1, with an average of 127 µg g^?1. The average pH of the coals is 5.03 (1.86–8.62), and the sulfate content varied from 249 to 64,706 µg g^?1 (average 7127 µg g^?1). In addition, the coals were medium- and high-sulfur coals, with sulfur mass fraction ranging from 0.08 to 13.41%. By heating the outcrop coals, HF release from the coal was verified quantitatively without exception, while simulated combustion directly confirmed the release of sulfuric acid (H₂SO₄). The acid in coal may be in the form of acidic sulfate (\({\text{HSO}}_{4}^{ - }\)/H₂SO₄) because of a positive relationship between pH and \(p\left( {{\text{SO}}_{4}^{2 - } } \right)\) in the acidic coal. The possible reaction mechanism would be that a chemical reaction between the acid (H₂SO₄ or \({\text{HSO}}_{4}^{ - }\)) and fluorine in the coal occurred, thereby producing hydrogen fluoride (HF), which would be the chemical form of fluorine released from coal under relatively mild conditions. The unique chemical and physical property of HF may bring new insight into the pathogenic mechanism of coal-burning endemic fluorosis. The phenomenon of coal-burning fluorosis is not limited to the study area, but is common in southwest China and elsewhere. Further investigation is needed to determine whether other endemic fluorosis areas are affected by this phenomenon.     

The sorption of selenite from aqueous solutions by pyrite

Selenium (Se) is an essential trace nutrient for mammals; however, the range between deficit and toxic levels is narrow. In this study, the potential sorption of selenite onto pyrite particles from an aqueous solution was investigated. An intraparticle diffusion model was used to describe kinetic data of sorption, yielding diffusivity values of 5 × 10^?7 cm²/s. The Langmuir isotherm equation could be used to describe the experimental data. The fitting results indicated that b and {Se(IV)}_max have values of 0.37 L/mg and 3.49 mg/g, respectively. The sorption of selenite onto the surface of pyrite particles was dependent on a pH range of 2–12, and the quantity of sorption onto pyrite was negatively correlated with pH; that is, the amount of sorption onto pyrite increased with a decrease in pH. In addition, organic matter did not exert a significant effect on removal of selenite. With a reaction time greater than 1 week, sorption of selenite onto pyrite particles was found to partially reduce the amount of elemental Se.     

Distribution and mode of occurrence of selenium in US coals

Selenium excess and deficiency have been established as the cause of various health problems in man and animals. Combustion of fossil fuels, especially coal, may be a major source of the anthropogenic introduction of selenium in the environment. Coal is enriched in selenium relative to selenium's concentration in most other rocks and relative to selenium in the Earth's crust.Data from almost 9,000 coal samples have been used to determine the concentration and distribution of selenium in US coals. The geometric mean concentration of selenium in US coal is 1.7 ppm. The highest mean selenium value (geometric mean 4.7 ppm) is in the Texas Region. Atlantic Coast (Virginia and North Carolina) and Alaska coals have the lowest geometric means (0.2 and 0.42 ppm, respectively). All western coal regions have mean selenium concentrations of less than 2.0 ppm. In contrast, all coal basins east of the Rocky Mountains (except for several small basins in Rhode Island, Virginia, and North Carolina) have mean selenium values of 1.9 or greater.Generally, variations in selenium concentration do not correlate with variations in ash yield, pyritic sulphur, or organic sulphur concentrations. This may be the result of multiple sources of selenium; however, in some non-marine basins with restricted sources of selenium, selenium has positive correlations with other coal quality parameters.Selenium occurs in several forms in coal but appears to be chiefly associated with the organic fraction, probably substituting for organic sulphur. Other important forms of selenium in coal are selenium-bearing pyrite, selenium-bearing galena, and lead selenide (clausthalite). Water-soluble and ion-exchangeable selenium also have been reported.     

Groundwater vulnerability to selenium in semi-arid environments: Amman Zarqa Basin,Jordan

An evaluation of ~250 samples of groundwater in the Amman Zarqa Basin for selenium along with other major and trace elements showed that concentrations of Se ranged between 0.09 and 742 μg/L, with an average value of about 24 μg/L. Selenium concentrations exceeded the recommended threshold for drinking water of the World Health Organization (WHO; 10 μ/L of Se) in 114 samples, with greater than 50 μg/L (quantity equivalent to the Jordanian standard of the allowed concentration of the element in water) of Se in nine cases. The average concentrations of Se in the lower, middle, and upper aquifers of the basin were 3.41, 32.99, and 9.19 μg/L, respectively. Based on the correlation with geologic formations and the statistical analysis of major/minor constituents and Piper tri-linear diagrams, we suggest that carbonate/phosphate dissolution, oxidation–reduction processes, and fertilizers/irrigation return flow are, together, the primary factors affecting the chemistry of the groundwater. Factor analysis helped to define the relative role of limestone-dolomitic dissolution in the aquifers (calcium, magnesium, and bicarbonate), agricultural activities (sulfate, nitrates, phosphorus, and potassium), oxidation–reduction factor (Eh, Fe, Mn, Cu, Zn, and Se), and anthropogenic (industrial) factor (EC, Fe, Cr, Co, Zn, and As). The high variability in Se concentrations might be related to the possibility of a multi-source origin of Se in the area.     

Geochemical and mineralogical characteristics of elephant geophagic soils in Udawalawe National Park,Sri Lanka

Geophagy or deliberate ingestion of soils was observed among Asian elephants (Elephas maximus) in the Udawalwe National Park, Sri Lanka, for several years. The geochemical and mineralogical composition of the clayey soil layers which are purposefully selected and eaten by elephants in the park were studied, in order to identify the possible reasons for elephant geophagy. The concentrations of major and trace elements were determined by means of X-ray fluorescence spectrometry in 21 soil samples from eight geophagic sites and six soil samples collected from four non-geophagic sites. The mineralogical composition of selected soil samples was investigated using X-ray diffractometry (XRD). These geochemical analyses revealed that geophagic soils in the study areas are deeply weathered and that most of the elements are leached from the soil layers under extreme weathering conditions. The XRD data showed that the soils of the area consisted mainly quartz, feldspar, and the clay minerals kaolinite, Fe-rich illite, and smectite. Although no significant geochemical differences were identified between geophagic and non-geophagic soils, a clear difference was observed in their clay mineralogical content. Soils eaten by elephants are richer in kaolinite and illite than non-geophagic soils, which contain a higher amount of smectite. It is suggested that elephants in Udawalawe National Park ingest soils mainly not to supplement the mineral contents of their forage but to detoxify unpalatable compounds in their diet.     

Concentration profiles of various toxic and non‐toxic elements in sized coal fly ashes from coals of the León basin

The concentration levels of major (Al, Ca, Fe, K, Mg, Mn, Na, Si, Ti) and some trace (Be, Se, Tl) elements were determined by atomic absorption spectrometry for the coal fly ashes emitted in the combustion of anthracite and soft coals. Total contents and concentration profiles were established for all elements studied as a function of the mean particle size. The content of those elements volatilized during coal combustion (Se, Tl) decreases with increasing particle size, while the unvolatilized elements show small changes in their concentration profiles. The content of aluminium shows a minimum level at a mean particle size of about 25 μm.