Concentrations Of Selected Trace Elements Research Articles

Selected trace element concentrations in run-of-mine coal, discard, and coal product, and environmental implications

The concentrations of selected trace elements (As, Cd, Hg, and Pb in run-of-mine (ROM) coal, discard, and coal product were investigated to assess the efficiency of beneficiation in reducing trace element concentrations and ascertain any implications regarding environmental compliance to regulatory frameworks. Samples were collected from a colliery in Mpumalanga Province twice a month for a period of 24 months. The samples were ashed to approximately 0.21 mm, then digested in a mixture of 70% HNO3 and 40% HF and analysed using inductively coupled plasma-mass spectrometry (ICP-MS). Except for Pb, the mean concentration of all elements decreased from the ROM stage to the coal product stage. The order in which trace elements occurred from the highest to lowest throughout the production chain was Pb>As>Hg>Cd. With the exception of Cd, the mean trace element concentrations in the discard were above the total concentration threshold (TCT) set for landfill disposal. The As, Hg, and Cd concentrations in the product were well below the thresholds for all land uses. However, Pb concentrations in the product coal were above legal limits, which is of concern with regard to environmental compliance and the performance and marketability of the product.

Tephrostratigraphy and Magma Evolution Based on Combined Zircon Trace Element and U-Pb Age Data: Fingerprinting Miocene Silicic Pyroclastic Rocks in the Pannonian Basin

We present a novel approach to use zircon as a correlation tool as well as a monitor for magma reservoir processes in silicic volcanic systems. Fingerprinting eruption products based on trace element content and U-Pb dates of zircon offers a promising, previously underestimated tephra correlation perspective, particularly in cases where the main minerals and glass are altered. Using LA-ICP-MS analyses, a rapid and cost-effective method, this study presents U-Pb dates and trace element concentration data of more than 950 zircon crystals from scattered occurrences of early to mid-Miocene silicic ignimbrites in the northern Pannonian Basin, eastern-central Europe. This magmatic phase produced >4000 km3of erupted material, which provide unique stratigraphic marker horizons in central and southern Europe. The newly determined zircon U-Pb eruption ages for the distal pyroclastic deposits are between 17.5 and 14.3 Ma, comparable with the previously published ages of the main eruptive events. Multivariate discriminant analysis of selected trace element concentrations in zircon proved to be useful to distinguish the main volcanic units and to correlate the previously ambiguously categorized pyroclastic deposits with them. Using the zircon trace element content together with published glass data from crystal-poor ignimbrites, we determined the zircon/melt partition coefficients. The obtained values of the distinct eruption units are very similar and comparable to published data for silicic volcanic systems. This suggests that zircon/melt partition coefficients in calc-alkaline dacitic to rhyolitic systems are not significantly influenced by the melt composition at >70 wt% SiO2at near solidus temperature. The partition coefficients and zircon trace element data were used to calculate the equilibrium melt composition, which characterizes the eruption products even where glass is thoroughly altered or missing. Hence, our results provide important proxies for tephrostratigraphy in addition to yielding insights into the complex processes of silicic magma reservoirs.

Environmental risk of trace elements in mangrove ecosystems: An assessment of natural vs oil and urban inputs

The petrochemical industry and urban activities are widely recognized worldwide as a source of pollution to mangrove environments. They can supply pollutants such as trace elements that can modify the ecosystem structure and associated services, as well as human populations. Through geochemical data, multivariate statistical analysis and pollution indices such as the enrichment factor (EF), geo-accumulation index (Igeo), adverse effect index (AEI) and the pollution load index (PLI), we evaluated the factors that control trace element distribution, punctual sources and determined the pollution level of sediments and their potential biological impact in the mangrove ecosystem of Isla del Carmen, Mexico. The factor and cluster analysis highlighted that the distribution of trace elements is influenced by the mineralogy, texture as well as urban derived sources. The pollution indices showed values in the punctual sources from the urban area of EF > 10, Igeo > 3, AEI > 3, PLI > 1 by Cu, Zn and Pb. Finally, the results revealed that mangroves from Isla del Carmen has a major influence from urban activities and natural sources rather than oil industry and also indicate a degraded environment as a result of anthropogenic activities that could have knock-on effect for human health if polluted marine organisms derived from the urban mangroves are consumed. Capsule abstractSurface sediments show the influence of point sources on selected trace element concentrations correlated with human activities within the mangroves of Isla del Carmen, Mexico.

Historical trace element accumulation in marine sediments from the Tamaulipas shelf, Gulf of Mexico: An assessment of natural vs anthropogenic inputs

The Gulf of Mexico is considered one of the world's major marine ecosystems, supporting important fisheries and habitats such as barrier islands, mangrove forests, seagrass beds, coral reefs etc. It also hosts a range of complex offshore petroleum exploration, extraction, and refining industries, which may have chronic or acute impacts on ecosystem functioning. Previous work on the marine effects of this activity is geographically incomplete, and has tended to focus on direct hydrocarbon impacts, while impacts from other related contaminants (e.g. heavy metals, salt-rich drilling muds) which may be discharged from oil facilities have not been widely assessed. Here, we examine historical trace element accumulation in marine sediments collected from four sites in the Tamaulipas shelf, Gulf of Mexico, in the area of the Arenque oil field. Dated sediment cores were used to examine the sources, and historical and contemporary inputs, of trace metals (including those typically present in oil industry discharges) and their potential biological impact in the Tamaulipas aquatic environment over the last 100years. CaO (i.e. biogenic component) normalized data showed increasing V, Cr, Zn, Cu, Pb, Zr and Ba towards the sediment surface in three of the four cores, with Ba and V (based on an adverse effect index) possibly associated with adverse effects on organisms. Dated Ba/CaO profiles show an increase of 30–137% after opening of oil installations in the study area, and can be broadly correlated with increasing oil industry activities across the wider Gulf of Mexico. Data do not record however a clear enhancement of Ba concentration in sediment cores collected near to oil platforms over more distal cores, indicating that any Ba released from drilling platforms is incorporated quickly into the sediments around the drilling sites, and once this element has been deposited its rate of resuspension and mobility is low. Capsule abstractSediment core data from the Tamaulipas shelf show the influence of oil industry activities on selected trace element concentrations, with Ba/CaO broadly correlating with increasing oil industry activities across the wider Gulf of Mexico.

Selected Trace Element Concentrations in Peat Used for Cosmetic Production – A Case Study from Southern Poland

Abstract The aim of the study was to assess the concentration of selected trace elements in organic soils used as a source to obtain a unique peat extract for cosmetics production. Peat material for laboratory analysis were collected from fen peatland located in the Prosna River Valley (Borek village). Studied peatland is managed by “Torf Corporation” company as a source of material to obtain peat extract for cosmetics production. In the collected soil samples (four soil profiles) Zn, Cu and Pb concentrations were determined by using atomic absorption spectrometer SpectraAA 220 (Varian), after acid digestion. Obtained results showed that the highest concentrations of selected trace elements were recorded in the surface horizons of organic soils. This fact might be the results of Prosna river flooding or air deposition. Howevere, according to the new Polish regulations (Ordinance of the Minister for Environment 01.09.2016 - the way of conducting contamination assessment of the earth surface), the content of trace elements in the examined soils was greatly belowe the permissible limit for areas from group IV (mine lands). Thus, described soils are proper to obtain peat extract used as a component in cosmetic production.

Selected trace element concentrations in ambient air and in horse chestnut leaves in Belgrade

In this study, airborne particulates (PM10) and leaves of horse chestnut were collected at selected urban sites in Belgrade, Serbia, in years 2006, 2009 and 2012. All samples were analysed for trace element concentrations of As, Cd, Cr, Ni and Pb. It has been shown that, during the study period, the differences among PM10 mass trace element concentrations were not considerable, and that the measured mass and trace elements concentrations were below the Serbian and EU legislation limits. Highest values of trace element concentrations in leaves were observed in year 2012, with the exception of Pb. Lead concentration had a decreasing trend during the whole studied period, in both PM10 and tree leaves. Since leaded gasoline was banned in 2011, a possible reason could be an increasing number of vehicles using unleaded kind along the previous years. Although trace elements in horse chestnut leaves were accumulated only during summer season, horse chestnut leaves showed good response to changes in trace element atmospheric concentrations. However, seasonal variability was evident in trace element source apportionment due to the lack of stationary heating system influence. The Principal Component Analysis showed that during the studied period, one of the major sources of the measured elements was fossil fuel combustion.

GEM-QUALITY DIAMONDS: SOURCE DISCRIMINATION

Conflict diamonds, those that are traded by rebel groups to fund wars against legitimate governments, have been a problem of grave concern in the international diamond industry since before 2000. Although procedural efforts such as the Kimberley Process Certification Scheme exist, fingerprinting of diamonds - i.e., the scientific discrimination of diamonds by source - has been suggested as a potential solution to halt the flow of conflict diamonds. Combined physical (morphological) and chemical studies on ten parcels of gem-quality diamonds from African alluvial and kimberlitic sources are presented here. Nitrogen contents and aggregation states were determined from Fourier Transform Infrared Spectroscopy; Laser Ablation Inductively Coupled Plasma Mass Spectrometry was utilized for selected trace element concentrations. It is evident that only a few elements are consistently enriched in significant quantities, and that it is possible that the elements that were not detected in the parcels may form more of a significant discriminatory tool. Although subtle differences between parcels (and areas of origin) are evident, the intrinsic heterogeneous nature of diamonds, particularly those that are gem-quality, creates difficulties with scientific fingerprinting as a mechanism to discriminate diamonds.

Heavy metal contents in Veronica species and soil from mountain areas in Serbia

This paper describes the relationships between concentrations of selected trace elements in soil and their bioaccumulation in aerial parts of three Veronica species (Plantaginaceae). Plant and soil samples were collected from three mountainous areas in Serbia, prepared by microwave acid-assisted digestion and analyzed by flame and flameless atomic absorption spectrometry. Total concentrations of Cu, Zn, Mn, Fe and Cr in the soil varied from 12.38 to 47.77, 62.78 to 138.00, 517.58 to 1675.78, 13574.22 to 35920.00 and 36.18 to 115.15 mg/kg, while those in the plants ranged from 6.04 to 12.8, 27.66 to 58.01, 25.38 to 89.25, 35.53 to 563.26 and 0.44 to 18.96 mg/kg, respectively. There were no significant differences in heavy metal concentrations between tested Veronica species from the same location, indicating that their heavy metal uptake pattern was not species specific. In the case of Mn, despite its wide variation in soil, concentrations in plant samples were uniform, which suggests potential ability of tested species to control Mn uptake or translocation to upper plant parts. Additionally, the lowest concentrations of Cu were obtained in plant samples collected from soil with the highest Fe concentrations, pointing out that Cu availability to plants might be reduced due to high Fe content in soil solution.

Timing of normal faulting along the Indus Suture in Pakistan Himalaya and a case of major 231Pa/235U initial disequilibrium in zircon

We report age data by TIMS U–Pb, LA-ICP-MS and 39Ar–40Ar techniques for main magmatic events in the Lower Swat region of Pakistan, in order to constrain the tectonic evolution of the northwestern Himalaya. The pre-Himalayan history of the Indian continent is documented by single-zircon U–Pb results from the peraluminous Choga granite gneiss, which yielded a 468±5 Ma lower concordia intercept interpreted to approximate the time of magmatic emplacement. The presence of a well-defined 870±7 Ma inherited component (upper intercept) suggests a plutonic or volcanic protolith residing at unexposed levels of the Indian crust. Zircon data for the Swat granite gneiss from the northern part of the Loe Sar dome give an emplacement age of 267+6/−3 Ma, which is at variance with earlier correlations favoring an early Paleozoic origin. Subsequent to metamorphic overprint by the Himalayan orogeny, the Swat granite was intruded by late kinematic alkali-granite dykes. Single zircons from one of these dykes show reproducible 206Pb/238U data giving a precise mean age of 29.26±0.12 Ma, whereas the 207Pb/235U ages scatter between 34 and 81 Ma, pointing to huge and variable enrichment in 207Pb. The unsupported 207Pb can be explained by incorporation of 231Pa, an intermediate long-lived daughter nuclide in the 235U decay chain, in excess of the secular equilibrium ratio. LA-ICP-MS measurements confirm the presence of unsupported 207Pb, but do not show any correlation between the latter and other selected trace element concentrations in these zircons. A concordant Ar–Ar muscovite age of 28.4±1.1 Ma obtained for the same dyke postdates regional mica ‘cooling’ ages and indicates a lack of younger regional events capable of resetting the K–Ar system in muscovite. Because the dyke is pre- to synkinematic relative to normal faulting and related north-vergent folds, its emplacement age provides a maximum age for this event or reflects already ongoing local extension. A lower limit of 15 Ma has previously been established by apatite fission track analysis. The 29–15 Ma age bracket for normal faulting is coeval with extension along the South Tibetan Detachment System (STDS) on the north side of the High Himalaya. This suggests that the Indus Suture in Pakistan has acted as a western continuation of the STDS and that related faulting was roughly contemporaneous over most of the Himalaya.

Roadside particulate and trace element concentrations at four London sites

Measurements of black smoke (BS), total suspended particulates (TSP) and selected trace element concentrations were made at two locations (four sites) in London, UK. One location was in Ealing, West London, the other was in Wood Green, North London. At each location, a residential and commercial roadside site was identified and monitored. The black smoke measurements were taken over 24-hour periods via a British standard 8-port smoke sampler situated inside a mobile laboratory. The TSP measurements were taken during peak traffic periods and 24-hour periods using glass fibre filters and high volume sampling pumps. At one site (the residential site at Wood Green), the TSP samples were analysed for 17 elements Pb, Zn, Br, Mg, Al, V, Fe, Sb, Mo, Co, Ni, Cu, Mn, Cr, Ba, Sn and Pt. After gravimetric analysis, the trace elements were extracted from the filter papers and analysed using inductively coupled plasma-source mass spectrometry. Two methods of extracting the trace elements were investigated, and the most efficient technique, the "nitric-perchloric", was used. Quantitative determinations of BS were made for a total of 98 and 115 days at the Ealing and Wood Green locations respectively during 1991/92. The average concentrations determined at the residential locations were 18.3 (Ealing) and 20.5 (Wood Green) µg/m³, respectively, and for the commercial sites the corresponding values were 30.6 and 69.5 µg/m³. The daily TSP values at the four sites are also reported and compared with measurements taken during the morning and afternoon rush hours. The particulate values reported here are discussed and compared with previously reported measurements in the UK. A total of 55 filter papers from the residential site at Wood Green were extracted for trace element analysis and the results are reported. Sufficient samples were collected to allow the data to be divided into morning, afternoon and 24-hour time periods, allowing comparison of the trends with the TSP data. The total and individual contributions of the trace elements to the particulate mass have been calculated and the most abundant trace elements (Zn, Pb, Br, Fe, Al, Mg) identified.

Soluble Trace Elements and Total Mercury in Arctic Alaskan Snow

Ultraclean field and laboratory procedures were used to examine trace element concentrations in northern Alaskan snow. Sixteen soluble trace elements and total mercury were determined in snow core samples representing the annual snowfall deposited during the 1993-94 season at two sites in the Prudhoe Bay oil field and nine sites in the Arctic National Wildlife Refuge (Arctic NWR). Results indicate there were two distinct point sources for trace elements in the Prudhoe Bay oil field- a source associated with oil and gas production and a source associated with municipal solid-waste incineration. Soluble trace element concentrations measured in snow from the Arctic NWR resembled concentrations of trace elements measured elsewhere in the Arctic using clean sample-collection and processing techniques and were consistent with deposition resulting from widespread arctic atmospheric contamination. With the exception of elements associated with sea salts, there were no orographic or east-west trends observed in the Arctic NWR data, nor were there any detectable influences from the Prudhoe Bay oil field, probably because of the predominant easterly and northeasterly winds on the North Slope of Alaska. However, regression analysis on latitude suggested significant south-to-north increases in selected trace element concentrations, many of which appear unrelated to the sea salt contribution.

Trace element study of high‐ and low‐refractive index Muong Nong‐type tektites from Indochina

Abstract— Previous work indicates that Muong Nong‐type tektites from Indochina with low refractive indices and high silica contents contain relict mineral grains while those with high refractive indices and low silica contents do not. Instrumental Neutron Activation Analysis (INAA) was used to determine selected trace element concentrations for four Muong Nong‐type tektites with high refractive indices and no relict mineral inclusions and one with low refractive index and relict inclusions, to determine if there are any systematic differences in trace element compositions between the two groups. The data also were compared with published trace element data for sixteen Muong Nong‐type tektites which have low refractive indices and, therefore, should contain relict inclusions. Except for Ta which had lower concentrations in the high refractive index group, there is no consistent difference in trace element compositions between the two groups. We interpret these results to indicate a single, slightly heterogeneous source for the Muong Nong‐type tektites, rather than different source regions.