WorldWideScience

Sample records for modelling trace metal

  1. Resolving and modelling trace metal partitioning in a freshwater sediment

    International Nuclear Information System (INIS)

    Devallois, V.; Boyer, P.; Coulomb, B.; Boudenne, J. L.

    2009-01-01

    Elevated concentrations of trace metals in sediments pose toxicological risks to biota and may impair water quality. the sediment-water interface is the site where gradients in physical, chemical and biological properties are the greatest. Both chemical and microbiological transformation processes are responsible for cycling elements between water and sediments. (Author)

  2. Geochemistry of trace metals in a fresh water sediment: Field results and diagenetic modeling

    International Nuclear Information System (INIS)

    Canavan, R.W.; Cappellen, P. van; Zwolsman, J.J.G.; Berg, G.A. van den; Slomp, C.P.

    2007-01-01

    Concentrations of Fe, Mn, Cd, Co, Ni, Pb, and Zn were determined in pore water and sediment of a coastal fresh water lake (Haringvliet Lake, The Netherlands). Elevated sediment trace metal concentrations reflect anthropogenic inputs from the Rhine and Meuse Rivers. Pore water and sediment analyses, together with thermodynamic calculations, indicate a shift in trace metal speciation from oxide-bound to sulfide-bound over the upper 20 cm of the sediment. Concentrations of reducible Fe and Mn decline with increasing depth, but do not reach zero values at 20 cm depth. The reducible phases are relatively more important for the binding of Co, Ni, and Zn than for Pb and Cd. Pore waters exhibit supersaturation with respect to Zn, Pb, Co, and Cd monosulfides, while significant fractions of Ni and Co are bound to pyrite. A multi-component, diagenetic model developed for organic matter degradation was expanded to include Zn and Ni dynamics. Pore water transport of trace metals is primarily diffusive, with a lesser contribution of bioirrigation. Reactions affecting trace metal mobility near the sediment-water interface, especially sulfide oxidation and sorption to newly formed oxides, strongly influence the modeled estimates of the diffusive effluxes to the overlying water. Model results imply less efficient sediment retention of Ni than Zn. Sensitivity analyses show that increased bioturbation and sulfate availability, which are expected upon restoration of estuarine conditions in the lake, should increase the sulfide bound fractions of Zn and Ni in the sediments

  3. Trace metals of an acid mine drainage stream using a chemical model (WATEQ) and sediment analysis

    International Nuclear Information System (INIS)

    West, K.A.; Wilson, T.P.

    1992-01-01

    The high metal contents common to the discharge of acid-mine drainage (AMD) from mines and mine spoils is an environmental concern to both government and industry. This paper reports the results of investigation of the behavior of metals in an AMD system at a former surface coal mine in Tuscarawas County, Oh. AMD discharges from seeps travels, in respective order through a laminar flow stream; a Typha-dominated wetland; a turbulent flow stream; and a sediment retention pond. Dissolved metals (Fe, Mn, Zn, Cr, Cd, Cu, and Al) major and minor components, and other parameters (pH, dissolved oxygen and Eh) were measured in the AMD water at each sample location. A chemical mineral equilibrium model (WATEQ) was used to predict the minerals which should precipitate at each site. Results suggest that the seeps are supersaturated and should be precipitating hematite, goethite and magnetite (iron oxides), and siderite (iron carbonate), whereas water of the other downstream sites were at or below equilibrium conditions for these minerals. The hydrogeochemistry of the AMD was further studied using sequential chemical attacks on the precipitate sediment surface coatings, in order to determine metal concentrations in the exchangeable, carbonate, Fe-Mn oxyhydroxide, and oxidizable fractions. The carbonate and exchangeable fractions of the precipitate are dominated by Ca and Fe, as well as Mg in the carbonate fraction. The Fe-Mn oxyhydroxide fraction contained Fe, Al, Mn, Mg, and trace metals, and also contained the greatest concentration of total elements in the system. The Fe-Mn oxyhydroxide is therefore, the major sink for metals of this AMD system. The decrease in the concentration of metals in the sediment precipitates in the downstream locations, is consistent with WATEQ and water analysis results

  4. Modelling the atmospheric transport of trace metals from Europe to the North Sea and the Baltic Sea

    Energy Technology Data Exchange (ETDEWEB)

    Petersen, G; Weber, H; Grassl, H [GKSS-Forschungszentrum Geesthacht G.m.b.H., Geesthacht-Tesperhude (Germany, F.R.). Inst. fuer Physik

    1989-01-01

    Within the framework of a research contract with the German Federal Environmental Agency the long range transport of trace metals over Europe and the deposition of trace metals into the North Sea and the Baltic Sea are estimated using the EMEP- (European Monitoring and Evaluation Programme) trajectory model. The methodology for the model calculations is explained. Preliminary results for the total deposition of lead into the North Sea and the Baltic Sea show, that the calculated values are lower than previous estimates based on extrapolations from measurements at coastal sites and ship measurements in the southern Baltic Sea, respectively. (orig.).

  5. Trace Metal Bioremediation: Assessment of Model Components from Laboratory and Field Studies to Identify Critical Variables

    International Nuclear Information System (INIS)

    Peter Jaffe; Herschel Rabitz

    2003-01-01

    The objective of this project was to gain an insight into the modeling support needed for the understanding, design, and operation of trace metal/radionuclide bioremediation. To achieve this objective, a workshop was convened to discuss the elements such a model should contain. A ''protomodel'' was developed, based on the recommendations of the workshop, and was used to perform sensitivity analysis as well as some preliminary simulations in support for bioremediation test experiments at UMTRA sites. To simulate the numerous biogeochemical processes that will occur during the bioremediation of uranium contaminated aquifers, a time-dependent one-dimensional reactive transport model has been developed. The model consists of a set of coupled, steady state mass balance equations, accounting for advection, diffusion, dispersion, and a kinetic formulation of the transformations affecting an organic substrate, electron acceptors, corresponding reduced species, and uranium. This set of equations is solved numerically, using a finite element scheme. The redox conditions of the domain are characterized by estimating the pE, based on the concentrations of the dominant terminal electron acceptor and its corresponding reduced specie. This pE and the concentrations of relevant species are passed to a modified version of MINTEQA2, which calculates the speciation and solubilities of the species of interest. Kinetics of abiotic reactions are described as being proportional to the difference between the actual and equilibrium concentration. A global uncertainty assessment, determined by Random Sampling High Dimensional Model Representation (RS-HDMR), was performed to attain a phenomenological understanding of the origins of output variability and to suggest input parameter refinements as well as to provide guidance for field experiments to improve the quality of the model predictions. Results indicated that for the usually high nitrate contents found ate many DOE sites, overall

  6. Trace metal speciation: Finally, correctly addressing trace metal issues

    International Nuclear Information System (INIS)

    Donard, O.F.X.

    2001-01-01

    The history of the development of trace metal speciation was discussed and the reasons behind the relatively slow widespread acceptance of its importance were presented. Partially, this was due to the lack of availability of commercial instrumentation and partly to the drive towards improving sensitivity in analytical chemistry which had focused attention on total concentration determinations. The sophistication and control of analytical instrumentation is now such that the spotlight must be turned onto the chemical species of an element present in a sample since this is what governs its behaviour in the biosphere. Indeed, several companies are currently considering the introduction of instrumentation specifically designed for metal species determination

  7. Trace Metals Bioaccumulation Potentials of Three Indigenous ...

    African Journals Online (AJOL)

    User

    grasses as bioaccumulators of trace metals from polluted soils. Seeds of ... transfer factor (TF) showed that Zn was the most bioaccumulated trace metals by all the grasses followed by. Pb, Mn ... was used to de-contaminate copper (Cu) and.

  8. Interpretation of complexometric titration data: An intercomparison of methods for estimating models of trace metal complexation by natural organic ligands

    NARCIS (Netherlands)

    Pižeta, I.; Sander, S.G.; Hudson, R.J.M.; Omanovic, D.; Baars, O.; Barbeau, K.A.; Buck, K.N.; Bundy, R.M.; Carrasco, G.; Croot, P.L.; Garnier, C.; Gerringa, L.J.A.; Gledhill, M.; Hirose, K.; Kondo, Y.; Laglera, L.M.; Nuester, J.; Rijkenberg, M.J.A.; Takeda, S.; Twining, B.S.; Wells, M.

    2015-01-01

    With the common goal of more accurately and consistently quantifying ambient concentrations of free metal ions and natural organic ligands in aquatic ecosystems, researchers from 15 laboratories that routinely analyze trace metal speciation participated in an intercomparison of statistical methods

  9. Evaluation of trace metals bioavailability in Japanese river waters using DGT and a chemical equilibrium model.

    Science.gov (United States)

    Han, Shuping; Naito, Wataru; Hanai, Yoshimichi; Masunaga, Shigeki

    2013-09-15

    To develop efficient and effective methods of assessing and managing the risk posed by metals to aquatic life, it is important to determine the effects of water chemistry on the bioavailability of metals in surface water. In this study, we employed the diffusive gradients in thin-films (DGT) to determine the bioavailability of metals (Ni, Cu, Zn, and Pb) in Japanese water systems. The DGT results were compared with a chemical equilibrium model (WHAM 7.0) calculation to examine its robustness and utility to predict dynamic metal speciation. The DGT measurements showed that biologically available fractions of metals in the rivers impacted by mine drainage and metal industries were relatively high compared with those in urban rivers. Comparison between the DGT results and the model calculation indicated good agreement for Zn. The model calculation concentrations for Ni and Cu were higher than the DGT concentrations at most sites. As for Pb, the model calculation depended on whether the precipitated iron(III) hydroxide or precipitated aluminum(III) hydroxide was assumed to have an active surface. Our results suggest that the use of WHAM 7.0 combined with the DGT method can predict bioavailable concentrations of most metals (except for Pb) with reasonable accuracy. Copyright © 2013. Published by Elsevier Ltd.

  10. Modeling approaches of competitive sorption and transport of trace metals and metalloids in soils: a review.

    Science.gov (United States)

    Selim, H M; Zhang, Hua

    2013-01-01

    Competition among various heavy metal species for available adsorption sites on soil matrix surfaces can enhance the mobility of contaminants in the soil environment. Accurate predictions of the fate and behavior of heavy metals in soils and geologic media requires the understanding of the underlying competitive-sorption and transport processes. In this review, we present equilibrium and kinetic models for competitive heavy metal sorption and transport in soils. Several examples are summarized to illustrate the impact of competing ions on the reactivities and mobility of heavy metals in the soil-water environment. We demonstrate that equilibrium Freundlich approaches can be extended to account for competitive sorption of cations and anions with the incorporation of competition coefficients associated with each reaction. Furthermore, retention models of the multiple-reaction type including the two-site nonlinear equilibrium-kinetic models and the concurrent- and consecutive-multireaction models were modified to describe commonly observed time-dependent behaviors of heavy metals in soils. We also show that equilibrium Langmuir and kinetic second-order models can be extended to simulate the competitive sorption and transport in soils, although the use of such models is limited due to their simplifying assumptions. A major drawback of the empirically based Freundlich and Langmuir approaches is that their associated parameters are specific for each soil. Alternatively, geochemical models that are based on ion-exchange and surface-complexation concepts are capable of quantifying the competitive behavior of several chemical species under a wide range of environmental conditions. Such geochemical models, however, are incapable of describing the time-dependent sorption behavior of heavy metal ions in competitive systems. Further research is needed to develop a general-purpose model based on physical and chemical mechanisms governing competitive sorption in soils. Copyright

  11. Evaluation of dust and trace metal estimates from the Community Multiscale Air Quality (CMAQ model version 5.0

    Directory of Open Access Journals (Sweden)

    K. W. Appel

    2013-07-01

    Full Text Available The Community Multiscale Air Quality (CMAQ model is a state-of-the-science air quality model that simulates the emission, transformation, transport, and fate of the many different air pollutant species that comprise particulate matter (PM, including dust (or soil. The CMAQ model version 5.0 (CMAQv5.0 has several enhancements over the previous version of the model for estimating the emission and transport of dust, including the ability to track the specific elemental constituents of dust and have the model-derived concentrations of those elements participate in chemistry. The latest version of the model also includes a parameterization to estimate emissions of dust due to wind action. The CMAQv5.0 modeling system was used to simulate the entire year 2006 for the continental United States, and the model estimates were evaluated against daily surface-based measurements from several air quality networks. The CMAQ modeling system overall did well replicating the observed soil concentrations in the western United States (mean bias generally around ±0.5 μg m−3; however, the model consistently overestimated the observed soil concentrations in the eastern United States (mean bias generally between 0.5–1.5 μg m−3, regardless of season. The performance of the individual trace metals was highly dependent on the network, species, and season, with relatively small biases for Fe, Al, Si, and Ti throughout the year at the Interagency Monitoring of Protected Visual Environments (IMPROVE sites, while Ca, K, and Mn were overestimated and Mg underestimated. For the urban Chemical Speciation Network (CSN sites, Fe, Mg, and Mn, while overestimated, had comparatively better performance throughout the year than the other trace metals, which were consistently overestimated, including very large overestimations of Al (380%, Ti (370% and Si (470% in the fall. An underestimation of nighttime mixing in the urban areas appears to contribute to the overestimation of

  12. Biodynamic modelling and the prediction of accumulated trace metal concentrations in the polychaete Arenicola marina

    International Nuclear Information System (INIS)

    Casado-Martinez, M. Carmen; Smith, Brian D.; DelValls, T. Angel; Luoma, Samuel N.; Rainbow, Philip S.

    2009-01-01

    The use of biodynamic models to understand metal uptake directly from sediments by deposit-feeding organisms still represents a special challenge. In this study, accumulated concentrations of Cd, Zn and Ag predicted by biodynamic modelling in the lugworm Arenicola marina have been compared to measured concentrations in field populations in several UK estuaries. The biodynamic model predicted accumulated field Cd concentrations remarkably accurately, and predicted bioaccumulated Ag concentrations were in the range of those measured in lugworms collected from the field. For Zn the model showed less but still good comparability, accurately predicting Zn bioaccumulation in A. marina at high sediment concentrations but underestimating accumulated Zn in the worms from sites with low and intermediate levels of Zn sediment contamination. Therefore, it appears that the physiological parameters experimentally derived for A. marina are applicable to the conditions encountered in these environments and that the assumptions made in the model are plausible. - Biodynamic modelling predicts accumulated field concentrations of Ag, Cd and Zn in the deposit-feeding polychaete Arenicola marina.

  13. Heavy metals and related trace elements

    International Nuclear Information System (INIS)

    Leland, H.V.; Luoma, S.N.; Wilkes, D.J.

    1977-01-01

    A review is given of heavy metals and related trace elements in the aquatic environment. Other reviews and bibliographies are cited, dealing with the metabolism and transport of metal ions and with the toxic effects of stable and radioactive trace metals on aquatic organisms. The sources of trace elements in natural waters are discussed. It is suggested that atmospheric inputs of several trace metals comprise sizable fractions of total inputs to the Great Lakes and continental shelf waters. Information on stack emissions of trace elements from a coal-fired steam plant was used to estimate the likely range of air concentrations and inputs to a forested watershed in Tennessee. Some basic concepts of cycling of elements through aquatic communities were examined, such as the Pb, Mn and Zn concentrations in sediment and estuarine plants and animals colonizing dredge-spoil disposal areas. The use of plants as biological indicators of trace element contamination was outlined, as well as bioaccumulation in aquatic fauna. The effects of environmental factors on the kinetics of element exchange were noted, for example the influx rates of Cs 137 in tubificid worms, and Co 60 and Zn 65 in shrimp were shown to be temperature dependent. The toxicity of heavy metals on aquatic fauna was discussed, such as the histopathological lesions in the kidney and liver of fishes caused by heavy metals, and the effects of Hg and Cu on the olfactory response of rainbow trout

  14. Response of dissolved trace metals to land use/land cover and their source apportionment using a receptor model in a subtropic river, China.

    Science.gov (United States)

    Li, Siyue; Zhang, Quanfa

    2011-06-15

    Water samples were collected for determination of dissolved trace metals in 56 sampling sites throughout the upper Han River, China. Multivariate statistical analyses including correlation analysis, stepwise multiple linear regression models, and principal component and factor analysis (PCA/FA) were employed to examine the land use influences on trace metals, and a receptor model of factor analysis-multiple linear regression (FA-MLR) was used for source identification/apportionment of anthropogenic heavy metals in the surface water of the River. Our results revealed that land use was an important factor in water metals in the snow melt flow period and land use in the riparian zone was not a better predictor of metals than land use away from the river. Urbanization in a watershed and vegetation along river networks could better explain metals, and agriculture, regardless of its relative location, however slightly explained metal variables in the upper Han River. FA-MLR analysis identified five source types of metals, and mining, fossil fuel combustion, and vehicle exhaust were the dominant pollutions in the surface waters. The results demonstrated great impacts of human activities on metal concentrations in the subtropical river of China. Copyright © 2011 Elsevier B.V. All rights reserved.

  15. Immunoglobulin classes, metal binding proteins, and trace metals in ...

    African Journals Online (AJOL)

    , IgA and IgM), metal binding proteins (Transferrin, Caeruloplasmin, Alpha-2- Macroglobulin and Haptoglobin) and nutritionally essential trace metals/heavy metals (Zn, Fe, Se, Cu, Mg, Cd and Pb) in Nigerian cassava processors using single ...

  16. studies on trace metal concentration pseudotolithus elongatus from ...

    African Journals Online (AJOL)

    DJFLEX

    KEY WORDS: Trace metals, Lead Pollution, Pseudotolithus elongatus, Mbo coastal waters, ..... Analysis of soil heavy metal pollution and ... Pekey, H., Karakas, D., and Bakog'lu, M., 2004. Source apportionment of trace metals in the surface.

  17. Plasma trace metals during total parenteral alimentation.

    Science.gov (United States)

    Solomons, N W; Layden, T J; Rosenberg, I H; Vo-Khactu, K; Sandstead, H H

    1976-06-01

    The plasma concentrations of the trace metals zinc and copper were studied prospectively in 13 patients with gastrointestinal diseases treated with parenteral alimentation (TPA) for periods of from 8 days to 7 1/2 weeks. Plasma copper levels fell rapidly and consistently in all patients, with an overall rate of - 11 mug per 100 ml per week. Zinc concentrations declined in 10 of 13 patients at a more gradual rate. Analysis of the standard parenteral alimentation fluids revealed zinc content equivalent to 50% of the daily requirement and a negligible content of copper. From combined analysis of plasma zinc, hair zinc, and taste acuity, there is evidence that increased utilization or redistribution within the body may effect plasma concentrations in some patients. Neither an increase in urinary excretion nor a primary decrease in plasma binding proteins appeared to be a major factor in lowering plasma trace metal concentrations. These findings indicate that a marked decrease in plasma copper is regular and a decline in plasma zinc is common during TPA using fluids unsupplemented with trace metals. Supplementation of parenteral alimentation fluids with the trace metals zinc and copper is recommended.

  18. Atmospheric trace metal concentrations in Suspended Particulate ...

    African Journals Online (AJOL)

    The air particulate samples were collected from the kitchens, living rooms and outdoor environment of five households in the community. The quantification of the trace metals was done using Atomic Absorption spectrometry method, employing HNO based wet digestion. High baseline concentration of SPMwere obtained ...

  19. Urban environmental geochemistry of trace metals

    International Nuclear Information System (INIS)

    Wong, Coby S.C.; Li Xiangdong; Thornton, Iain

    2006-01-01

    As the world's urban population continues to grow, it becomes increasingly imperative to understand the dynamic interactions between human activities and the urban environment. The development of urban environmental geochemistry has yielded a significant volume of scientific information about geochemical phenomena found uniquely in the urban environment, such as the distribution, dispersion, and geochemical characteristics of some toxic and potentially toxic trace metals. The aim of this paper is to provide an overview of the development of urban environmental geochemistry as a field of scientific study and highlight major transitions during the course of its development from its establishment to the major scientific interests in the field today. An extensive literature review is also conducted of trace metal contamination of the urban terrestrial environment, in particular of urban soils, in which the uniqueness of the urban environment and its influences on trace metal contamination are elaborated. Potential areas of future development in urban environmental geochemistry are identified and discussed. - Urban environmental geochemistry as a scientific discipline provides valuable information on trace metal contamination of the urban environment and its associated health effects

  20. Trace Metals Bioaccumulation Potentials of Three Indigenous ...

    African Journals Online (AJOL)

    The rapid increase in the number of industries may have increased the levels of trace metals in the soil. Phytoremediation of these polluted soils using indigenous grasses is now considered an alternative method in remediating these polluted soils. The present study investigated and compared the ability of three ...

  1. Biodynamic modelling of the bioaccumulation of trace metals (Ag, As and Zn) by an infaunal estuarine invertebrate, the clam Scrobicularia plana

    International Nuclear Information System (INIS)

    Kalman, J.; Smith, B.D.; Bury, N.R.; Rainbow, P.S.

    2014-01-01

    Highlights: • Biodynamic modelling is used to predict accumulation of Ag, As and Zn in S. plana. • Dissolved and sediment-associated metals contribute to total metal bioaccumulation. • Relative importance varies with water and sediment concentrations and geochemistries. - Abstract: Biodynamic modelling was used to investigate the uptake and accumulation of three trace metals (Ag, As, Zn) by the deposit feeding estuarine bivalve mollusc Scrobicularia plana. Radioactive labelling techniques were used to quantify the rates of trace metal uptake (and subsequent elimination) from water and sediment diet. The uptake rate constant from solution (±SE) was greatest for Ag (3.954 ± 0.375 l g −1 d −1 ) followed by As (0.807 ± 0.129 l g −1 d −1 ) and Zn (0.103 ± 0.016 l g −1 d −1 ). Assimilation efficiencies from ingested sediment were 40.2 ± 1.3% (Ag), 31.7 ± 1.0% (Zn) and 25.3 ± 0.9% (As). Efflux rate constants after exposure to metals in the solution or sediment fell in the range of 0.014–0.060 d −1 . By incorporating these physiological parameters into biodynamic models, our results showed that dissolved metal is the predominant source of accumulated Ag, As and Zn in S. plana, accounting for 66–99%, 50–97% and 52–98% of total accumulation of Ag, As and Zn, respectively, under different field exposure conditions. In general, model-predicted steady state concentrations of Ag, As and Zn matched well with those observed in clams collected in SW England estuaries. Our findings highlight the potential of biodynamic modelling to predict Ag, As and Zn accumulation in S. plana, taking into account specific dissolved and sediment concentrations of the metals at a particular field site, together with local water and sediment geochemistries

  2. Trace Metals Concentration Assessment in Urban Particulate Matter ...

    African Journals Online (AJOL)

    ADOWIE PERE

    Principal component analysis revealed that major sources of trace metals in ambient air ... contributed by earth crust and windblown soil .... Source Apportionment: To probe the origin of trace .... atmospheric accumulation of heavy metals and.

  3. Photometric determination of traces of metals

    International Nuclear Information System (INIS)

    Onishi, H.

    1986-01-01

    The first three editions of this widely used classic were published under the title Colorimetric Determination of Traces of Metals, with E.B. Sandell as author. Part I (General Aspects) of the fourth edition was co-authored by E.B. Sandell and H. Onishi and published in 1978. After Sandell's death in 1984, Onishi assumed the monumental task of revising Part II. This book (Part IIA) consists of 21 chapters in which the photometric determinations of the individual metals, aluminium to lithium (including the lanthanoids), are described. Each chapter is divided into three sections: Separations, Methods of Determination, and Applications. The sections on Separations are of general interest and include methods based on precipitation, ion-exchange, chromatography, and liquid-liquid extraction. Molecular absorption and fluorescence techniques are described in the sections on determinations, and the emphasis is on the use of well-established reagents. Several reagents that have been recently introduced for the determination of trace levels of metals are also critically reviewed at the end of each section on methods of determination. Important applications of these methods to the determination of trace metals in complex organic and inorganic materials are described in detail at the end of each chapter

  4. Geochemical modeling of reactions and partitioning of trace metals and radionuclides during titration of contaminated acidic sediments.

    Science.gov (United States)

    Zhang, Fan; Luo, Wensui; Parker, Jack C; Spalding, Brian P; Brooks, Scott C; Watson, David B; Jardine, Philip M; Gu, Baohua

    2008-11-01

    Many geochemical reactions that control aqueous metal concentrations are directly affected by solution pH. However, changes in solution pH are strongly buffered by various aqueous phase and solid phase precipitation/dissolution and adsorption/desorption reactions. The ability to predict acid-base behavior of the soil-solution system is thus critical to predict metal transport under variable pH conditions. This studywas undertaken to develop a practical generic geochemical modeling approach to predict aqueous and solid phase concentrations of metals and anions during conditions of acid or base additions. The method of Spalding and Spalding was utilized to model soil buffer capacity and pH-dependent cation exchange capacity by treating aquifer solids as a polyprotic acid. To simulate the dynamic and pH-dependent anion exchange capacity, the aquifer solids were simultaneously treated as a polyprotic base controlled by mineral precipitation/ dissolution reactions. An equilibrium reaction model that describes aqueous complexation, precipitation, sorption and soil buffering with pH-dependent ion exchange was developed using HydroGeoChem v5.0 (HGC5). Comparison of model results with experimental titration data of pH, Al, Ca, Mg, Sr, Mn, Ni, Co, and SO4(2-) for contaminated sediments indicated close agreement suggesting that the model could potentially be used to predictthe acid-base behavior of the sediment-solution system under variable pH conditions.

  5. Trace metal fronts in European shelf waters

    International Nuclear Information System (INIS)

    Kremling, K.

    1983-01-01

    The Hebrides shelf edge area is characterized by strong horizontal salinity gradients (fronts) which mark the boundary between Scottish coastal and oceanic waters. The results presented here, obtained in summer 1981 on a transect between the open north Atlantic and the German Bight, confirm that the hydrographical front is accompanied by dramatic increases in inorganic nutrients (phosphate, silicate) and dissolved trace elements such as Cd, Cu, Mn, and 226 Ra. These data (together with measurements from North Sea regions) suggest that the trace metals are mobilized from partly reduced (organic-rich) sediments and vertically mixed into the surface waters. The regional variations evident from the transect are interpreted as being the result of the hydrography prevailing in waters around the British Isles. (author)

  6. Biodynamic modelling of the bioaccumulation of trace metals (Ag, As and Zn) by an infaunal estuarine invertebrate, the clam Scrobicularia plana

    Energy Technology Data Exchange (ETDEWEB)

    Kalman, J., E-mail: judit.kalman@uca.es [Department of Life Sciences, The Natural History Museum, Cromwell Road, London SW7 5BD (United Kingdom); Smith, B.D. [Department of Life Sciences, The Natural History Museum, Cromwell Road, London SW7 5BD (United Kingdom); Bury, N.R. [Division of Diabetes and Nutritional Science, King' s College London, Franklin-Wilkins Building, 150 Stamford Street, London SE1 9NH (United Kingdom); Rainbow, P.S. [Department of Life Sciences, The Natural History Museum, Cromwell Road, London SW7 5BD (United Kingdom)

    2014-09-15

    Highlights: • Biodynamic modelling is used to predict accumulation of Ag, As and Zn in S. plana. • Dissolved and sediment-associated metals contribute to total metal bioaccumulation. • Relative importance varies with water and sediment concentrations and geochemistries. - Abstract: Biodynamic modelling was used to investigate the uptake and accumulation of three trace metals (Ag, As, Zn) by the deposit feeding estuarine bivalve mollusc Scrobicularia plana. Radioactive labelling techniques were used to quantify the rates of trace metal uptake (and subsequent elimination) from water and sediment diet. The uptake rate constant from solution (±SE) was greatest for Ag (3.954 ± 0.375 l g{sup −1} d{sup −1}) followed by As (0.807 ± 0.129 l g{sup −1} d{sup −1}) and Zn (0.103 ± 0.016 l g{sup −1} d{sup −1}). Assimilation efficiencies from ingested sediment were 40.2 ± 1.3% (Ag), 31.7 ± 1.0% (Zn) and 25.3 ± 0.9% (As). Efflux rate constants after exposure to metals in the solution or sediment fell in the range of 0.014–0.060 d{sup −1}. By incorporating these physiological parameters into biodynamic models, our results showed that dissolved metal is the predominant source of accumulated Ag, As and Zn in S. plana, accounting for 66–99%, 50–97% and 52–98% of total accumulation of Ag, As and Zn, respectively, under different field exposure conditions. In general, model-predicted steady state concentrations of Ag, As and Zn matched well with those observed in clams collected in SW England estuaries. Our findings highlight the potential of biodynamic modelling to predict Ag, As and Zn accumulation in S. plana, taking into account specific dissolved and sediment concentrations of the metals at a particular field site, together with local water and sediment geochemistries.

  7. Trace metal assay of uranium silicide fuel

    International Nuclear Information System (INIS)

    Kulkarni, M.J.; Argekar, A.A.; Thulasidas, S.K.; Dhawale, B.A.; Rajeswari, B.; Adya, V.C.; Purohit, P.J.; Neelam, G.; Bangia, T.R.; Page, A.G.; Sastry, M.D.; Iyer, R.H.

    1994-01-01

    A comprehensive trace metal assay of uranium silicide, a fuel for nuclear research reactors that employs low-enrichment uranium, is carried out by atomic spectrometry. Of the list of specification elements, 21 metallic elements are determined by a direct current (dc) arc carrier distillation technique; the rare earths yttrium and zirconium are chemically separated from the major matrix followed by a dc arc/inductively coupled argon plasma (ICP) excitation technique in atomic emission spectrometry (AES); silver is determined by electrothermal atomization-atomic absorption spectrometry (ETA-AAS) without prior chemical separation of the major matrix. Gamma radioactive tracers are used to check the recovery of rare earths during the chemical separation procedure. The detection limits for trace metallics vary in the 0.1- to 40-ppm range. The precision of the determinations as evaluated from the analysis of the synthetic sample with intermediate range analyte concentration is better than 25% relative standard deviation (RSD) for most of the elements employing dc arc-AES, while that for silver determination by ETS-AAS is 10% RSD. The precision of the determinations for four crucially important rare earths by ICP-AES is better than 3% RSD

  8. Limitation of productivity by trace metals in the sea

    International Nuclear Information System (INIS)

    Morel, F.M.M.; Price, N.M.; Hudson, R.J.M.

    1991-01-01

    Some trace metals such as Fe, Ni, Cu, and Zn are essential for the growth of phytoplankton. The concentrations of these essential trace elements in seawater are so low as to limit their availability to aquatic microbiota. Trace element uptake is ultimately limited by kinetics of reaction with transport ligands or by diffusion to the cell. From what the authors know of the characteristics of the uptake systems of phytoplankton and their trace metal requirements they can estimate that Fe and Zn may at some times in some place limit phytoplankton productivity, which is in accord with available field data on trace metal enrichments

  9. Trace metal contamination of Beaufort's Dyke, North Channel, Irish Sea: A legacy of ordnance disposal

    International Nuclear Information System (INIS)

    Callaway, Alexander; Quinn, Rory; Brown, Craig J.; Service, Matthew; Benetti, Sara

    2011-01-01

    Highlights: → Our samples are the first trace metal concentrations taken from the valley of Beaufort's Dyke. → There is no clear trend between concentrations of trace metals in Dyke and NMMP sediments. → Particle transport simulations show dispersal of trace metals from Beaufort's Dyke is possible. → Disposed ordnance may also contribute to contamination of surrounding areas. → These methods could help predict areas at risk of future trace metal contamination as a result of ordnance disposal. - Abstract: Beaufort's Dyke is a disused ordnance disposal ground within the North Channel of the Irish Sea. Over 1 million tonnes of ordnance were disposed of in the dyke over a 40 year period representing a substantial volume of trace metal pollutants introduced to the seabed. Utilising particle transport modelling software we simulated the potential transport of metal particles from Beaufort's Dyke over a 3 month period. This demonstrated that Beaufort's Dyke has the potential to act as a source for trace metal contamination to areas beyond the submarine valley. Trace metal analysis of sediments from the Dyke and surrounding National Marine Monitoring Programme areas demonstrate that the Dyke is not the most contaminated site in the region. Particle transport modelling enables the transport pathways of trace metal contaminants to be predicted. Implementation of the technique in other munitions disposal grounds will provide valuable information for the selection of monitoring stations.

  10. Particulate trace metals in Cochin backwaters: Distribution of seasonal indices

    Digital Repository Service at National Institute of Oceanography (India)

    Sankaranarayanan, V.N.; Jayalakshmy, K.V.; Joseph, T.

    that surface distribution pattern of the trace metal concentration of cobalt, nickel and iron was almost similar at the four stations thereby stressing the fact that seasonal fluctuations contributed a major part in the surface distribution of these metals...

  11. TXRF analysis of trace metals in thin silicon nitride films

    International Nuclear Information System (INIS)

    Vereecke, G.; Arnauts, S.; Verstraeten, K.; Schaekers, M.; Heyrts, M.M.

    2000-01-01

    As critical dimensions of integrated circuits continue to decrease, high dielectric constant materials such as silicon nitride are being considered to replace silicon dioxide in capacitors and transistors. The achievement of low levels of metal contamination in these layers is critical for high performance and reliability. Existing methods of quantitative analysis of trace metals in silicon nitride require high amounts of sample (from about 0.1 to 1 g, compared to a mass of 0.2 mg for a 2 nm thick film on a 8'' silicon wafer), and involve digestion steps not applicable to films on wafers or non-standard techniques such as neutron activation analysis. A novel approach has recently been developed to analyze trace metals in thin films with analytical techniques currently used in the semiconductor industry. Sample preparation consists of three steps: (1) decomposition of the silicon nitride matrix by moist HF condensed at the wafer surface to form ammonium fluosilicate. (2) vaporization of the fluosilicate by a short heat treatment at 300 o C. (3) collection of contaminants by scanning the wafer surface with a solution droplet (VPD-DSC procedure). The determination of trace metals is performed by drying the droplet on the wafer and by analyzing the residue by TXRF, as it offers the advantages of multi-elemental analysis with no dilution of the sample. The lower limits of detection for metals in 2 nm thick films on 8'' silicon wafers range from about 10 to 200 ng/g. The present study will focus on the matrix effects and the possible loss of analyte associated with the evaporation of the fluosilicate salt, in relation with the accuracy and the reproducibility of the method. The benefits of using an internal standard will be assessed. Results will be presented from both model samples (ammonium fluoride contaminated with metallic salts) and real samples (silicon nitride films from a production tool). (author)

  12. Trace metals analysis in molybdenite mineral sample

    International Nuclear Information System (INIS)

    Tamrakar, Praveen Kumar; Pitre, K.S.

    2000-01-01

    DC polarography and other related techniques, viz., DPP and DPASV have been successfully used for the simultaneous determination of trace metals in molybdenite mineral sample. The polarograms and voltammograms of sample solution have been recorded in 0.1 M (NH 4 ) 2 tartrate supporting electrolyte at two different pH values i.e., 2.7±0.1 and 9.0±0.1. The results indicate the presence of Cu 2+ , Mo 6+ , Cd 2+ , Ni 2+ , In 3+ , Fe 3+ and W 6+ metal ions in the sample. For the determination of tungsten(VI), 11 M HCl has been used as supporting electrolyte. Tungsten(VI) produces a well defined wave/peak with E 1/2 /Ep=-0.42V/-0.48V vs SCE in 11 M HCl. The quantitative analysis by the method of standard addition shows the mineral sample to have the following composition, Cu 2+ ( 14.83), Mo 6+ (253.70), Cd 2+ (41.36), Ni 2+ (16.08), In 3+ (3.06), Fe 3+ (83.00)and W 6+ (4.14 )mg/g of the sample. Statistical treatment of the observed voltammetric data reveals high accuracy and good precision of determination. The observed voltammetric results are comparable with those obtained using AAS method. (author)

  13. Levels and occupational health risk assessment of trace metals in ...

    African Journals Online (AJOL)

    The levels of trace metals (Pb, Cu, Ni and Cd) were determined in soils from a major automobile repair workshop located in Uyo, Akwa Ibom State, Nigeria. This was carried out to evaluate the potential occupational risk to operators working in and around the site. The mean of trace metal levels were: lead (14.52 mg/kg); ...

  14. Trace metal mobilization in an experimental carbon sequestration scenario

    Energy Technology Data Exchange (ETDEWEB)

    Marcon, Virginia [University of Wyoming, Geology and Geophysics, Laramie, WY. 82070 (United States); Kaszuba, John [University of Wyoming, Geology and Geophysics, Laramie, WY. 82070 (United States); Univeristy of Wyoming, School of Energy Resources, Larmaie, WY. 82070 (United States)

    2013-07-01

    Mobilizing trace metals with injection of supercritical CO{sub 2} into deep saline aquifers is a concern for geologic carbon sequestration. Hydrothermal experiments investigate the release of harmful metals from two zones of a sequestration injection reservoir: at the cap-rock-reservoir boundary and deeper within the reservoir, away from the cap-rock. In both systems, Cd, Cr, Cu, Pb, and Zn behave in a similar manner, increasing in concentration with injection, but subsequently decreasing in concentration over time. SEM images and geochemical models indicate initial dissolution of minerals and precipitation of Ca-Mg-Fe carbonates, metal sulfides (i.e. Fe, As, Ag, and Co sulfides), and anhydrite in both systems. The results suggest that Ba, Cu, and Zn will not be contaminants of concern, but Pb, Fe, and As may require careful attention. (authors)

  15. Analysis of trace metals in various brands of cigarettes

    International Nuclear Information System (INIS)

    Iqbal, M.

    1996-01-01

    The present work deals with the analysis of trace metals in various brands of cigarettes belonging to four different countries. In the present research seven trace elements have been determined spectrophotometrically by the use of suitable analytical reagent of the respective metal ions. The metals which has been analysed quantitatively in forty one brand of cigarettes are aluminium, copper, chromium, nickel, iron titanium and zinc. The concentration per cigarette of these metals are in tolerable range. The concentration of above mentioned metal ions is highest in Pakistani cigarettes tobacco while the concentration of nickel is highest in American cigarettes. (author) 221 refs

  16. Bioaccessibility of selected trace metals in urban PM{sub 2.5} and PM{sub 10} samples: a model study

    Energy Technology Data Exchange (ETDEWEB)

    Falta, Thomas; Koellensperger, Gunda; Hann, Stephan [University of Natural Resources and Applied Life Sciences, Division of Analytical Chemistry, Vienna (Austria); Limbeck, Andreas [Vienna University of Technology, Institute of Chemical Technologies and Analytics, Vienna (Austria)

    2008-02-15

    Bioaccessibility of trace metals originating from urban particulate matter was assessed in a worst case scenario to evaluate the uptake and thus the hazardous potential of these metals via gastric juice. Sampling was performed over a period of about two months at the Getreidemarkt in downtown Vienna. Concentrations of the assayed trace metals (Ti, Cr, Mn, Co, Ni, Cu, Zn, Mo, Ag, Cd, Sn, Sb, Tl and Pb) were determined in PM{sub 2.5} and PM{sub 10} samples by ICP-MS. The metal concentrations in sampled air were in the low picogram to high nanogram per cubic metre range. The concentrations in PM{sub 2.5} samples were generally lower than those in PM{sub 10} samples. The average daily intake of these metals by inhalation for a healthy adult was estimated to be in the range of <1 ng (Tl) to >1,000 ng (Zn). To estimate the accessibility of the inhaled and subsequently ingested metals (i.e. after lung clearance had taken place) in the size range from 2.5- to 10-{mu}m aerodynamic equivalent diameter, a batch-extraction with synthetic gastric juice was performed. The data were used to calculate the bioaccessibility of the investigated trace metals. Extractable fractions ranged from 2.10% (Ti in PM{sub 2.5}) to 91.0% (Cd in PM{sub 2.5}), thus yielding bioaccessible fractions (PM{sub 2.5-10}) from 0.16 ng (Ag) to 178 ng (Cu). (orig.)

  17. Trace Metal Concentrations in Commercially Important Fishes from ...

    African Journals Online (AJOL)

    komla

    Some trace metals such as zinc and copper are important in small quantities for ...... Cameroon: Institut de recherches meddicales et d'etudes des plantes edicinales, ... Determination of Total Cadmium, Zinc, Lead, Copper in Selected Marine ...

  18. Trace metal concentrations in tropical mangrove sediments, NE Brazil.

    Science.gov (United States)

    Miola, Brígida; Morais, Jáder Onofre de; Pinheiro, Lidriana de Souza

    2016-01-15

    Sediment cores were taken from the mangroves of the Coreaú River estuary off the northeast coast of Brazil. They were analyzed for grain size, CaCO3, organic matter, and trace metal (Cd, Pb, Zn, Cu, Al, and Fe) contents. Mud texture was the predominant texture. Levels of trace metals in surface sediments indicated strong influence of anthropogenic processes, and diagenetic processes controlled the trace metal enrichment of core sediments of this estuary. The positive relationships between trace metals and Al and Fe indicate that Cu, Zn, Pb, and Cd concentrations are associated mainly with Al and Fe oxy-hydroxides and have natural sources. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Trace Metals And Organic Matter Diagenesis At The Oman Margin

    Digital Repository Service at National Institute of Oceanography (India)

    Alagarsamy, R.

    Trace Metals (e.g. Mn and Fe) play an important role as secondary oxidants in the degradation of sedimentary OM under sub-oxic conditions. Hence the remineralisation of organic constituents of sediments in the marine environment may significantly...

  20. Hyperaccumulators of metal and metalloid trace elements: facts and fiction.

    NARCIS (Netherlands)

    van der Ent, A.; Baker, A.J.M.; Reeves, R.D.; Pollard, A.J.; Schat, H.

    2012-01-01

    Background: Plants that accumulate metal and metalloid trace elements to extraordinarily high concentrations in their living biomass have inspired much research worldwide during the last decades. Hyperaccumulators have been recorded and experimentally confirmed for elements such as nickel, zinc,

  1. Trace metal emissions from the Estonian oil shale fired power

    DEFF Research Database (Denmark)

    Aunela-Tapola, Leena A.; Frandsen, Flemming; Häsänen, Erkki K.

    1998-01-01

    Emission levels of selected trace metals from the Estonian oil shale fired power plant were studied. The plant is the largest single power plant in Estonia with an electricity production capacity of 1170 MWe (1995). Trace metals were sampled from the flue gases by a manual method incorporating...... in the flue gases of the studied oil shale plant contribute, however, to clearly higher total trace metal emission levels compared to modern coal fired power plants. Although the old electrostatic precipitators in the plant have been partly replaced by state-of-the-art electrostatic precipitators...... a two-fraction particle sampling and subsequent absorption of the gaseous fraction. The analyses were principally performed with ICP-MS techniques. The trace metal contents of Estonian oil shale were found to be in the same order of magnitude as of coal on average. The high total particle concentrations...

  2. Bibliography on cycling of trace metals in freshwater ecosystems

    International Nuclear Information System (INIS)

    LaRiviere, M.G.; Scott, A.J.; Woodfield, W.G.; Cushing, C.E.

    1978-07-01

    This bibliography is a listing of pertinent literature directly addressing the cycling of trace metals in freshwater ecosystems. Data on cycling, including the influences of environmental mediators, are included. 151 references

  3. Trace Metal Requirements and Interactions in Symbiodinium kawagutii

    Directory of Open Access Journals (Sweden)

    Irene B. Rodriguez

    2018-02-01

    Full Text Available Photosynthetic organisms need trace metals for various biological processes and different groups of microalgae have distinctive obligate necessities due to their respective biochemical requirements and ecological niches. We have previously shown that the dinoflagellate Symbiodinium kawagutii requires high concentrations of bioavailable Fe to achieve optimum growth. Here, we further explored the trace metal requirements of S. kawagutii with intensive focus on the effect of individual metal and its interaction with other divalent metals. We found that low Zn availability significantly decreases growth rates and results in elevated intracellular Mn, Co, Ni, and Fe quotas in the dinoflagellate. The results highlight the complex interaction among trace metals in S. kawagutii and suggest either metal replacement strategy to counter low Zn availability or enhanced uptake of other metals by non-specific divalent metal transporters. In this work, we also examined the Fe requirement of S. kawagutii using continuous cultures. We validated that 500 pM of Fe′ was sufficient to support maximum cell density during steady state growth period either at 26 or 28°C. This study shows that growth of S. kawagutii was limited by metal availability in the following order, Fe > Zn > Mn > Cu > Ni > Co. The fundamental information obtained for the free-living Symbiodinium shall provide insights into how trace metal availability, either from ambient seawater or hosts, affects growth and proliferation of symbiotic dinoflagellates and the interaction between symbiont and their hosts.

  4. Adsorption of trace metals to plastic resin pellets in the marine environment

    International Nuclear Information System (INIS)

    Holmes, Luke A.; Turner, Andrew; Thompson, Richard C.

    2012-01-01

    Plastic production pellets collected from beaches of south west England contain variable concentrations of trace metals (Cr, Co, Ni, Cu, Zn, Cd and Pb) that, in some cases, exceed concentrations reported for local estuarine sediments. The rates and mechanisms by which metals associate with virgin and beached polyethylene pellets were studied by adding a cocktail of 5 μg L −1 of trace metals to 10 g L −1 pellet suspensions in filtered seawater. Kinetic profiles were modelled using a pseudo-first-order equation and yielded response times of less than about 100 h and equilibrium partition coefficients of up to about 225 ml g −1 that were consistently higher for beached pellets than virgin pellets. Adsorption isotherms conformed to both the Langmuir and Freundlich equations and adsorption capacities were greater for beached pellets than for virgin pellets. Results suggest that plastics may represent an important vehicle for the transport of metals in the marine environment. - Highlights: ► Beached plastic production pellets contain considerable concentrations of trace metals. ► In laboratory experiments trace metals are shown to adsorb to both virgin and beached pellets. ► Metal adsorption is greater on aged pellets. ► Pellets may represent an important vehicle for metal transport in the marine environment. - Trace metals accumulate on plastic resin pellets in the marine environment through adsorption to the polymer and to chemical and biological attritions thereon.

  5. Mobilization of Trace Metals in an Experimental Carbon Sequestration Scenario

    Science.gov (United States)

    Marcon, V.; Kaszuba, J. P.

    2012-12-01

    Mobilizing trace metals with injection of supercritical CO2 into deep saline aquifers is a concern for geologic carbon sequestration. The potential for leakage from these systems requires an understanding of how injection reservoirs interact with the overlying potable aquifers. Hydrothermal experiments were performed to evaluate metal mobilization and mechanisms of release in a carbonate storage reservoir and at the caprock-reservoir boundary. Experiments react synthetic Desert Creek limestone and/or Gothic Shale, formations in the Paradox Basin, Utah, with brine that is close to equilibrium with these rocks. A reaction temperature of 1600C accelerates the reaction kinetics without changing in-situ water-rock reactions. The experiments were allowed to reach steady state before injecting CO2. Changes in major and trace element water chemistry, dissolved carbon and sulfide, and pH were tracked throughout the experiments. CO2 injection decreases the pH by 1 to 2 units; concomitant mineral dissolution produces elevated Ba, Cu, Fe, Pb, and Zn concentrations in the brine. Concentrations subsequently decrease to approximately steady state values after 120-330 hours, likely due to mineral precipitation as seen in SEM images and predicted by geochemical modeling. In experiments that emulate the caprock-reservoir boundary, final Fe (0.7ppb), an element of secondary concern for the EPA, and Pb (0.05ppb) concentrations exceed EPA limits, whereas Ba (0.140ppb), Cu (48ppb), and Zn (433ppb) values remain below EPA limits. In experiments that simulate deeper reservoir conditions, away from the caprock boundary, final Fe (3.5ppb) and Pb (0.017ppb) values indicate less mobilization than seen at the caprock-reservoir boundary, but values still exceed EPA limits. Barium concentrations always remain below the EPA limit of 2ppb, but are more readily mobilized in experiments replicating deeper reservoir conditions. In both systems, transition elements Cd, Cr, Cu, Pb and Zn behave in a

  6. Trace metal physiology in normal and pathological tissues

    International Nuclear Information System (INIS)

    Hamer, C.J.A. van den; Nooijen, J.L.

    1979-01-01

    Many of the ionic tumour seeking radiopharmaceuticals consist of a metal ion combined with an anion. The choice of metal depends on the existence of radionuclides with suitable radiological properties, and on their availability. Because several of the metal complexes used in nuclear medicine are of rather recent interest, information about their metabolism is scarce. Although nuclear medicine is limited to those metals which radiochemists can produce, we can manipulate the chemical form in which the metals are introduced into the organism to some extent. The relation between chemical form and biological pathway, e.g., the extent of accumulation in certain tissues, is subject of study related to trace metal physiology. It is the purpose of this paper to try and bridge the gap between nuclear medicine and trace metal physiology by showing the progress made by the latter in the study of the metabolism of copper and zinc. Few trace metals have been studied as thoroughly as these, although iron could have been chosen just as well. This presentation is limited to a study of the fate of a metal derivative after its intravenous injection. Where possible the results obtained are related to the behaviour of metals presently of interest to nuclear medicine. (Auth.)

  7. Experimental determination and modelling of trace metal-humate interactions: a pragmatic approach for applications in groundwater

    International Nuclear Information System (INIS)

    Glaus, M.A.; Hummel, W.; Loon, L.R. van

    1997-12-01

    Complexation of radionuclides by humic substances and the concomitant remobilisation of sorbed radionuclides is a source of uncertainty in performance assessment of radioactive waste repositories. Despite more than 30 years of world-wide intensive research in this field, only very few datasets are available which are relevant for performance assessment. The reason for this unusual situation is found in the poor understanding of chemical structures of humic substances, which is a label for a most complex, heterogeneous mixture of organic molecules. Because of the ignorance of the 'real' structures of the complexes formed between radionuclides and humic substances, no binding model was developed up to now, which is firmly based on thermodynamics and which would allow extrapolations outside the chemical parameter space at which it has been calibrated. It is therefore the main purpose of the present work to develop means for performance assessment to conservatively bound the effect of humic substances on radionuclide speciation in solution at relevant chemical conditions. (author) 70 figs., tabs., refs

  8. Experimental determination and modelling of trace metal-humate interactions: a pragmatic approach for applications in groundwater

    Energy Technology Data Exchange (ETDEWEB)

    Glaus, M A; Hummel, W; Loon, L.R. van [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1997-12-01

    Complexation of radionuclides by humic substances and the concomitant remobilisation of sorbed radionuclides is a source of uncertainty in performance assessment of radioactive waste repositories. Despite more than 30 years of world-wide intensive research in this field, only very few datasets are available which are relevant for performance assessment. The reason for this unusual situation is found in the poor understanding of chemical structures of humic substances, which is a label for a most complex, heterogeneous mixture of organic molecules. Because of the ignorance of the `real` structures of the complexes formed between radionuclides and humic substances, no binding model was developed up to now, which is firmly based on thermodynamics and which would allow extrapolations outside the chemical parameter space at which it has been calibrated. It is therefore the main purpose of the present work to develop means for performance assessment to conservatively bound the effect of humic substances on radionuclide speciation in solution at relevant chemical conditions. (author) 70 figs., tabs., refs.

  9. Trace Metals in Mussels from the N.W. Mediterranean

    International Nuclear Information System (INIS)

    Fowler, S.W.; Oregioni, B.

    1976-01-01

    A coastal survey in the northwestern Mediterranean region was initiated to measure existing levels of selected trace metals in mussels. For most metals the highest values were found in samples from port cities and areas in the vicinity of river discharge. Marked seasonal variation for many metals was evident; an overall increase in metal concentration in mussels from most stations during March 1974 was attributed to high precipitation and attendant run-off rather than to local pollution. Data comparison indicates that average metal levels in northwestern Mediterranean mussels do not differ markedly from those measured in similar species from different localities throughout the world. (author)

  10. Mapping human health risks from exposure to trace metal contamination of drinking water sources in Pakistan

    International Nuclear Information System (INIS)

    Bhowmik, Avit Kumar; Alamdar, Ambreen; Katsoyiannis, Ioannis; Shen, Heqing; Ali, Nadeem; Ali, Syeda Maria; Bokhari, Habib; Schäfer, Ralf B.; Eqani, Syed Ali Musstjab Akber Shah

    2015-01-01

    The consumption of contaminated drinking water is one of the major causes of mortality and many severe diseases in developing countries. The principal drinking water sources in Pakistan, i.e. ground and surface water, are subject to geogenic and anthropogenic trace metal contamination. However, water quality monitoring activities have been limited to a few administrative areas and a nationwide human health risk assessment from trace metal exposure is lacking. Using geographically weighted regression (GWR) and eight relevant spatial predictors, we calculated nationwide human health risk maps by predicting the concentration of 10 trace metals in the drinking water sources of Pakistan and comparing them to guideline values. GWR incorporated local variations of trace metal concentrations into prediction models and hence mitigated effects of large distances between sampled districts due to data scarcity. Predicted concentrations mostly exhibited high accuracy and low uncertainty, and were in good agreement with observed concentrations. Concentrations for Central Pakistan were predicted with higher accuracy than for the North and South. A maximum 150–200 fold exceedance of guideline values was observed for predicted cadmium concentrations in ground water and arsenic concentrations in surface water. In more than 53% (4 and 100% for the lower and upper boundaries of 95% confidence interval (CI)) of the total area of Pakistan, the drinking water was predicted to be at risk of contamination from arsenic, chromium, iron, nickel and lead. The area with elevated risks is inhabited by more than 74 million (8 and 172 million for the lower and upper boundaries of 95% CI) people. Although these predictions require further validation by field monitoring, the results can inform disease mitigation and water resources management regarding potential hot spots. - Highlights: • Predictions of trace metal concentration use geographically weighted regression • Human health risk

  11. Mapping human health risks from exposure to trace metal contamination of drinking water sources in Pakistan

    Energy Technology Data Exchange (ETDEWEB)

    Bhowmik, Avit Kumar [Institute for Environmental Sciences, University of Koblenz-Landau, Fortstrasse 7, D-76829 Landau in der Pfalz (Germany); Alamdar, Ambreen [Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021 (China); Katsoyiannis, Ioannis [Aristotle University of Thessaloniki, Department of Chemistry, Division of Chemical Technology, Box 116, Thessaloniki 54124 (Greece); Shen, Heqing [Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021 (China); Ali, Nadeem [Department of Environmental Sciences, FBAS, International Islamic University, Islamabad (Pakistan); Ali, Syeda Maria [Center of Excellence in Environmental Studies, King Abdulaziz University, Jeddah (Saudi Arabia); Bokhari, Habib [Public Health and Environment Division, Department of Biosciences, COMSATS Institute of Information Technology, Islamabad (Pakistan); Schäfer, Ralf B. [Institute for Environmental Sciences, University of Koblenz-Landau, Fortstrasse 7, D-76829 Landau in der Pfalz (Germany); Eqani, Syed Ali Musstjab Akber Shah, E-mail: ali_ebl2@yahoo.com [Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021 (China); Public Health and Environment Division, Department of Biosciences, COMSATS Institute of Information Technology, Islamabad (Pakistan)

    2015-12-15

    The consumption of contaminated drinking water is one of the major causes of mortality and many severe diseases in developing countries. The principal drinking water sources in Pakistan, i.e. ground and surface water, are subject to geogenic and anthropogenic trace metal contamination. However, water quality monitoring activities have been limited to a few administrative areas and a nationwide human health risk assessment from trace metal exposure is lacking. Using geographically weighted regression (GWR) and eight relevant spatial predictors, we calculated nationwide human health risk maps by predicting the concentration of 10 trace metals in the drinking water sources of Pakistan and comparing them to guideline values. GWR incorporated local variations of trace metal concentrations into prediction models and hence mitigated effects of large distances between sampled districts due to data scarcity. Predicted concentrations mostly exhibited high accuracy and low uncertainty, and were in good agreement with observed concentrations. Concentrations for Central Pakistan were predicted with higher accuracy than for the North and South. A maximum 150–200 fold exceedance of guideline values was observed for predicted cadmium concentrations in ground water and arsenic concentrations in surface water. In more than 53% (4 and 100% for the lower and upper boundaries of 95% confidence interval (CI)) of the total area of Pakistan, the drinking water was predicted to be at risk of contamination from arsenic, chromium, iron, nickel and lead. The area with elevated risks is inhabited by more than 74 million (8 and 172 million for the lower and upper boundaries of 95% CI) people. Although these predictions require further validation by field monitoring, the results can inform disease mitigation and water resources management regarding potential hot spots. - Highlights: • Predictions of trace metal concentration use geographically weighted regression • Human health risk

  12. Influence of Protozoan Grazing on the Marine Geochemistry of Particle Reactive Trace Metals

    National Research Council Canada - National Science Library

    Barbeau, Katherine

    1998-01-01

    .... Principle findings included mobilization of extracellular as well as intracellular trace metals by protists, apparent generation of metal-organic complexes, and decoupling of metal and carbon cycling...

  13. Trace metals in urban road dust

    International Nuclear Information System (INIS)

    Randazzo, Loredana Antonella; Dongarra, Gaetano; Manno, Emanuela; Varrica, Daniela

    2006-01-01

    Heavy metals associated with urban road dust is a matter for concern as they may have serious effects on biological systems. The bioavailability and potential toxicity of metals bound to urban dust is related to the specific chemical form of the element. In the present article are reported the determinations and chemical speciation of As, Ba, Cr, Cu, Mo, Ni, Pb and Zn in six samples of road dust collected within the urban centre and the outskirts of Palermo [it

  14. Measurement of trace metals in vitiligo by atomic absorption spectroscopy

    International Nuclear Information System (INIS)

    Abdel-Hamid, Abdel-Aziz M.; Amin, N.E.; Mohy El-Din, Safaa M.

    1985-01-01

    Zn, Cu, Fe, Pb, Mn, Co, Ag, Ca, and Mg were estimated in hair, fingernails and epidermis of vitiligo patients by atomic absorption spectroscopy. There has been a significant reduction in the concentration of trace metals in the studied sites. It seems that any speculation on the role of trace elements in vitiligo would have to take into account the structural defect which underlies the absence of melanin

  15. Trace metal removal from aqueous solution

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, R. (ed.)

    1986-01-01

    The Industrial Division of the Royal Society of Chemistry organized the symposium, held at the University of Warwick, that gave rise to the 12 typescript papers in this softbound volume. Both biological and chemical methods of recovering or removing metals from water are discussed, and two papers are concerned solely with analysis. Not indexed.

  16. Removal of trace metal contaminants from potable water by electrocoagulation

    OpenAIRE

    Heffron, Joe; Marhefke, Matt; Mayer, Brooke K.

    2016-01-01

    This study investigated the effects of four operational and environmental variables on the removal of trace metal contaminants from drinking water by electrocoagulation (EC). Removal efficiencies for five metals (arsenic, cadmium, chromium, lead and nickel) were compared under varying combinations of electrode material, post-treatment, water composition and pH. Iron electrodes out-performed aluminum electrodes in removing chromium and arsenic. At pH 6.5, aluminum electrodes were slightly more...

  17. Nanomolar Trace Metal Analysis of Copper at Gold Microband Arrays

    Science.gov (United States)

    Wahl, A.; Dawson, K.; Sassiat, N.; Quinn, A. J.; O'Riordan, A.

    2011-08-01

    This paper describes the fabrication and electrochemical characterization of gold microband electrode arrays designated as a highly sensitive sensor for trace metal detection of copper in drinking water samples. Gold microband electrodes have been routinely fabricated by standard photolithographic methods. Electrochemical characterization were conducted in 0.1 M H2SO4 and found to display characteristic gold oxide formation and reduction peaks. The advantages of gold microband electrodes as trace metal sensors over currently used methods have been investigated by employing under potential deposition anodic stripping voltammetry (UPD-ASV) in Cu2+ nanomolar concentrations. Linear correlations were observed for increasing Cu2+ concentrations from which the concentration of an unknown sample of drinking water was estimated. The results obtained for the estimation of the unknown trace copper concentration in drinking was in good agreement with expected values.

  18. Nanomolar Trace Metal Analysis of Copper at Gold Microband Arrays

    International Nuclear Information System (INIS)

    Wahl, A; Dawson, K; Sassiat, N; Quinn, A J; O'Riordan, A

    2011-01-01

    This paper describes the fabrication and electrochemical characterization of gold microband electrode arrays designated as a highly sensitive sensor for trace metal detection of copper in drinking water samples. Gold microband electrodes have been routinely fabricated by standard photolithographic methods. Electrochemical characterization were conducted in 0.1 M H 2 SO 4 and found to display characteristic gold oxide formation and reduction peaks. The advantages of gold microband electrodes as trace metal sensors over currently used methods have been investigated by employing under potential deposition anodic stripping voltammetry (UPD-ASV) in Cu 2+ nanomolar concentrations. Linear correlations were observed for increasing Cu 2+ concentrations from which the concentration of an unknown sample of drinking water was estimated. The results obtained for the estimation of the unknown trace copper concentration in drinking was in good agreement with expected values.

  19. Fate of alkali and trace metals in biomass gasification

    International Nuclear Information System (INIS)

    Salo, K.; Mojtahedi, W.

    1998-01-01

    The fate of alkali metals (Na, K) and eleven toxic trace elements (Hg, Cd, Be, Se, Sb, As, Pb, Zn, Cr, Co, Ni) in biomass gasification have been extensively investigated in Finland in the past ten years. The former due to the gas turbine requirements and the latter to comply with environmental regulations. In this paper the results of several experimental studies to measure Na and K in the vapor phase after the gas cooler of a simplified (air-blown) Integrated Gasification Combined-Cycle (IGCC) system are reported. Also, trace element emissions from an IGCC plant using alfalfa as the feedstock are discussed and the concentration of a few toxic trace metals in the vapor phase in the gasifier product gas are reported. (author)

  20. Trace Metals and Mineral Composition of Harmattan Dust Haze in ...

    African Journals Online (AJOL)

    ADOWIE PERE

    2018-01-29

    Jan 29, 2018 ... ABSTRACT: Trace metals and mineralogical composition of harmattan dust haze was carried out on samples collected at Ilorin (80 32'N, ... Sahara desert which transports the dust by wind. Junge (1979) reported that on the .... Schwela et al 2002, it was observed that road transport emission sources ...

  1. Concentration of Trace Metals in Boreholes in the Ankobra Basin ...

    African Journals Online (AJOL)

    Fiifi Baidoo

    Most of the boreholes with high trace metal concentrations were located in and around the Bawdie-Bogoso-Prestea area. Introduction. Ankobra basin is one of the main mining areas in Ghana. The major minerals mined in this area include gold, manganese, bauxite and diamond. Gold mining in this basin dates about 500 ...

  2. Trace Metal Levels in Raw and Heat Processed Nigerian Staple ...

    African Journals Online (AJOL)

    The levels of some trace metals (Fe, Zn, Cu, Ni, Cd) were quantitatively determined in raw and heat processed staple food cultivars (yam, cassava, cocoyam and maize) from oil producing areas of part of the Niger Delta and compared with a non-oil producing area of Ebonyi State as control. The survey was conducted to ...

  3. Determination of Sugar and Some Trace Metals Content in Selected ...

    African Journals Online (AJOL)

    Ten brands of commercial fruit juices were analyzed for pH, specific gravity, total solids, reducing sugar and total sugar trace metals contents. The pH was determined using a Hanna pH meter. Sugar content was determined using the Lane and Eynon method. Sodium and potassium were determined by flame photometry ...

  4. Coagulation / flocculation process in the removal of trace metals ...

    African Journals Online (AJOL)

    Attempts were made in this study to examine the effectiveness of polymer addition to coagulation process during treatment of a beverage industrial wastewater to remove some of its trace metals content such as lead, cadmium, total iron, total chromium, nickel and zinc. Experiments were conducted using the standard Jar ...

  5. An appraisal of physicochemical parameters and some trace metals ...

    African Journals Online (AJOL)

    Industrial effluent samples collected from the disposal point of five different companies in Trans-Amadi industrial area of Port Harcourt were analyzed to investigate effect on the environment. The analyzed effluent samples showed results of the physicochemical parameters and trace metals in the ranges : (pH 3.60 - 6.90), ...

  6. 12 Trace Metals Distribution in Fish Tissues, Bottom Sediments and ...

    African Journals Online (AJOL)

    `123456789jkl''''#

    Abstract. Water samples, bottom sediments, Tilapia, and Cat Fish from Okumeshi River in Delta state of Nigeria were analysed ... Keywords: Trace metals, Fish Tissues, Water, Bottom sediments, Okumeshi River. Introduction ..... Grey Mangroove Avicemmia marina (Forsk). ... sewage treatment plant oulet pipe extension on.

  7. Trace Metal Contamination in Water from Abandoned Mining and ...

    African Journals Online (AJOL)

    Fiifi Baidoo

    copper and lead sulpho-salts (Dzigbordi-Adjimah, 1988). ... The resulting solution was analysed for trace metals at the Institute of Mining and Mineral ..... found in the samples (Tables 3 and 4) may be due to the mineral-water interactions and.

  8. Trace metals and vitamin levels in Nigerian patients with sensory ...

    African Journals Online (AJOL)

    The significance of the higher levels of magnesium in the patients is unclear and needs further investigation. Further studies with larger sample sizes are needed to confirm this observation. Keywords: ataxia, trace metals, vitamins, Nigerians Nigerian Journal of Health and Biomedical Sciences Vol. 4(2) 2005: 156–160 ...

  9. Trace metals transfer during vine cultivation and winemaking processes

    Czech Academy of Sciences Publication Activity Database

    Vystavna, Yuliya; Zaichenko, L.; Klimenko, N.; Rätsep, R.

    2017-01-01

    Roč. 97, č. 13 (2017), s. 4520-4525 ISSN 0022-5142 Institutional support: RVO:60077344 Keywords : white wine * Chardonnay * Vitis * Ukraine * vineyard * trace metals Subject RIV: DJ - Water Pollution ; Quality OBOR OECD: Environmental sciences (social aspects to be 5.7) Impact factor: 2.463, year: 2016

  10. enrichment factor of atmospheric trace metal using zirconium

    African Journals Online (AJOL)

    user

    Twelve (12) elements (Cl, K, Ca, Ti, V, Fe, Ni, Cu, Zn, Ba, Sr, and Zr ) were detected in total suspended particulate matter (TSP) ..... Ni and V didn't show spatial variation (p>0.05). For K, ..... K.A. Wet deposition of trace metals to a remote.

  11. Diagnostic value of lipids, total antioxidants, and trace metals in ...

    African Journals Online (AJOL)

    Materials and Methods: Anthropometric characteristics, total prostate specific antigen (tPSA), serum lipids (total cholesterol, LDL cholesterol, HDL cholesterol, and triglycerides), Vit. E, total antioxidant status (TAS), and trace metals (Se, Cu, Fe, Zn, and Mn) were determined in 40 patients with histopathological diagnosis of ...

  12. Serum Lipids and Lipoproteins Levels and Selected Trace Metals In ...

    African Journals Online (AJOL)

    This study aim to determine the serum levels of trace metals and correlate same with serum levels of lipoproteins (an established marker of HBP) in newly diagnosed hypertensives (NDH) A total of 50 NDH subjects (24 males and 26 females) attending Ladoke Akintola University of Technology Teaching Hospital, Osogbo ...

  13. Spectrochemical determination of impurities and noble metal traces in carnallite

    International Nuclear Information System (INIS)

    Goldbart, Z.; Carmi, U.; Harrel, A.

    1978-02-01

    A spectrochemical method was developed for the determination of impurities and noble metal traces in carnallite by DC arc excitation. The investigated sample is brought to a standard form of potassium-magnesium sulphate mixed with graphite. Detection limits of 1-10 ppm were determined for 27 elements; the dynamical detection range is 1-400 ppm

  14. Bioavailability of metals-trace in sediments: a review

    International Nuclear Information System (INIS)

    Rodrigues, Rafaela E. de A.V.; Souza, Vivianne Lucia Bormann; Lima, Vanessa Lemos de; Hazin, Clovis Abrahao

    2014-01-01

    The chemical association of metals in sediments provides an indication of its release by physical, chemical and biological processes, with toxic effects under certain environmental conditions. Knowing about their chemical bonds in sediments, can recognize specific sources of pollution, and speciation of trace metals is important for bioavailability and toxicity to animals and plants. The accumulation of these particles in the sediment occur by the following mechanisms: a) adsorption to the finest particles; b) precipitating of the element in the form of compounds; c) co-precipitating of the element with iron and manganese oxides; d) complexation with organic matter; e) incorporation into the crystal lattice of minerals. Currently, five phases are considered when studying the bioavailability of trace elements in sediments: a) the exchangeable phase, MgCl 2 (causes saltiness change); b) leachable phase, (acetic acid causes pH change); c) reducible phase (hydroxylamine hydrochloride causes release of the bound metals linked to Fe and Mn oxides); d) oxidized phase, the peroxide hydrogen (cause the degradation of organic matter); e) the residual pseudo-phase, the aqua regia (cause release of metals associated to minerals). The first three phases are considered the most bioavailable. In the last two fractions, the metals are linked to sediment constituents and not bioavailable. The organic phase is relatively stable and the metal present therein are removed under oxidative conditions. Metals present in the pseudo-phase residual measure the degree of environmental pollution, since great amount of metals at this stage indicates a lower degree of pollution

  15. Particle Tracing Modeling with SHIELDS

    Science.gov (United States)

    Woodroffe, J. R.; Brito, T. V.; Jordanova, V. K.

    2017-12-01

    The near-Earth inner magnetosphere, where most of the nation's civilian and military space assets operate, is an extremely hazardous region of the space environment which poses major risks to our space infrastructure. Failure of satellite subsystems or even total failure of a spacecraft can arise for a variety of reasons, some of which are related to the space environment: space weather events like single-event-upsets and deep dielectric charging caused by high energy particles, or surface charging caused by low to medium energy particles; other space hazards are collisions with natural or man-made space debris, or intentional hostile acts. A recently funded project through the Los Alamos National Laboratory (LANL) Directed Research and Development (LDRD) program aims at developing a new capability to understand, model, and predict Space Hazards Induced near Earth by Large Dynamic Storms, the SHIELDS framework. The project goals are to understand the dynamics of the surface charging environment (SCE), the hot (keV) electrons on both macro- and microscale. These challenging problems are addressed using a team of world-class experts and state-of-the-art physics-based models and computational facilities. We present first results of a coupled BATS-R-US/RAM-SCB/Particle Tracing Model to evaluate particle fluxes in the inner magnetosphere. We demonstrate that this setup is capable of capturing the earthward particle acceleration process resulting from dipolarization events in the tail region of the magnetosphere.

  16. Trace metal levels in sediments of Pearl Harbor (Hawaii)

    International Nuclear Information System (INIS)

    Ashwood, T.L.; Olsen, C.R.; Larsen, I.L.; Tamura, T.

    1986-09-01

    This study was conducted to measure the distribution of lead and other trace metals in the sediments of Pearl Harbon (Hawaii) to determine whether paint chips from vessels of the US Navy's Inactive Fleet have affected the environmental quality of Middle Loch. Sediment cores (ranging from 0.5 to 3.0 m long) were collected from Middle Loch near the Naval Inactive Ships Maintenance Facility and in an area of West Loch that is relatively isolated and unaffected by naval operations. Concentrations of copper, lead, and zinc averaged 180 μg/g, 49 μg/g, and 272 μg/g, respectively, in recent Middle Loch sediments. These concentrations are significantly higher than those in either historical Middle Loch sediments or recent West Loch sediments. However, except for lead, the concentrations in recent Middle Loch sediments are similar to those of older Middle Loch sediments, which indicates that the increase in trace metal contamination began before the onset of Inactive Fleet operations (about 1946). Increased trace metal levels in recent Middle Loch sediments might be expected to result from two potential sources: (1) sewage discharges and (2) paint from inactive vessels. Since paint contains elevated levels of lead and zinc but little copper, the elevated copper levels in Middle Loch sediments tend to implicate sewage as the source of trace metal contamination. Moreover, the lead:zinc ratio of recent Middle Loch sediments (0.18:1) is a factor of 10 lower than that measured in paint (2.1:1), and the Middle Loch lead:zinc ratio is not significantly greater than that measured in recent West Loch sediments (0.21:1). Hence, we suggest that sewage rather than paint is the major source of trace metal contamination of Middle Loch. This is consistent with the findings of a previous study by US navy personnel

  17. Bioaccumulation of trace metals in the Antarctic amphipod Paramoera walkeri (Stebbing, 1906): comparison of two-compartment and hyperbolic toxicokinetic models

    International Nuclear Information System (INIS)

    Clason, B.; Duquesne, S.; Liess, M.; Schulz, R.; Zauke, G.-P.

    2003-01-01

    Bioaccumulation of Cd, Pb, Cu and Zn in the Antarctic gammaridean amphipod Paramoera walkeri (Stebbing, 1906) was investigated at Casey station (Australian Antarctic Territory). The main goals were to provide information on accumulation strategies of the organisms tested and to verify toxicokinetic models as a predictive tool. The organisms accumulated metals upon exposure and it was possible to estimate significant model parameters of two-compartment and hyperbolic models. These models were successfully verified in a second toxicokinetic study. However, the application of hyperbolic models appears to be more promising as a predictive tool for metals in amphipods compared to compartment models, which have failed to adequately predict metal accumulation in experiments with increasing external exposures in previous studies. The following kinetic bioconcentration factors (BCFs) for the theoretical equilibrium were determined: 150-630 (Cd), 1600-7000 (Pb), 1700-3800 (Cu) and 670-2400 (Zn). We find decreasing BCFs with increasing external metal dosing but similar results for treatments with and without natural UV radiation and for the combined effect of different exposure regimes (single versus multiple metal exposure) and/or the amphipod collective involved (Beall versus Denison Island). A tentative estimation showed the following sequence of sensitivity of P. walkeri to an increase of soluble metal exposure: 0.2-3.0 μg Cd l -1 , 0.12-0.25 μg Pb l -1 , 0.9-3.0 μg Cu l -1 and 9-26 μg Zn l -1 . Thus, the amphipod investigated proved to be more sensitive as biomonitor compared to gammarids from German coastal waters (with the exception of Cd) and to copepods from the Weddell Sea inferred from literature data

  18. Pathways of trace metal uptake in the lugworm Arenicola marina

    International Nuclear Information System (INIS)

    Casado-Martinez, M.C.; Smith, B.D.; Valls, T.A. del; Rainbow, P.S.

    2009-01-01

    Radiotracer techniques were used to determine the rates of trace metal (Ag, Cd and Zn) uptake and elimination (33 psu, 10 deg. C) from water and sediment by the deposit-feeding polychaete Arenicola marina, proposed as a test species for estuarine-marine sediments in whole-sediment toxicity tests. Metal uptake rates from solution increase with increasing dissolved metal concentrations, with uptake rate constants (± SE) (l g -1 d -1 ) of 1.21 ± 0.11 (Ag), 0.026 ± 0.002 (Zn) and 0.012 ± 0.001 (Cd). Assimilation efficiencies from ingested sediments were measured using a pulse-chase radiotracer feeding technique in two different lugworm populations, one from a commercial supplier (Blyth, Northumberland, UK) and the other a field-collected population from the outer Thames estuary (UK). Assimilation efficiencies ranged from 2 to 20% for Zn, 1 to 6% for Cd and 1 to 9% for Ag for the Northumberland worms, and from 3 to 22% for Zn, 6 to 70% for Cd and 2 to 15% for Ag in the case of the Thames population. Elimination of accumulated metals followed a two-compartment model, with similar efflux rate constants for Zn and Ag and lower rates of elimination of Cd from the slow pool. Efflux rate constants (± SE) of Zn and Ag accumulated from the dissolved phase were 0.037 ± 0.002 and 0.033 ± 0.006 d -1 whereas Cd was eliminated with an efflux rate constant one order of magnitude lower (0.003 ± 0.002 d -1 ). When metals were accumulated from ingested sediments, the efflux rate constants for the slow-exchanging compartment were of the same order of magnitude for the three metals, and of the same order of magnitude as those derived after the dissolved exposure for Zn and Ag (0.042 ± 0.004 and 0.056 ± 0.012 d -1 for Zn and 0.044 ± 0.012 and 0.069 ± 0.016 d -1 for Ag for the Northumberland and Thames populations, respectively). Cd accumulated from ingested sediments was eliminated with a rate constant not different from the fast-exchanging compartment after the water

  19. Trace metal contents in barbeque (BBQ) charcoal products

    Energy Technology Data Exchange (ETDEWEB)

    Kabir, Ehsanul [Department of Environment and Energy, Sejong University, 98 Goon Ja Dong, Seoul 143-747 (Korea, Republic of); Kim, Ki-Hyun, E-mail: khkim@sejong.ac.kr [Department of Environment and Energy, Sejong University, 98 Goon Ja Dong, Seoul 143-747 (Korea, Republic of); Yoon, H.O. [Korea Basic Science Institute, Seoul Center, Seoul 136-701 (Korea, Republic of)

    2011-01-30

    In this study, the concentrations of trace elements contained in solid barbeque (BBQ) charcoal products have been investigated. Eleven brands of charcoal products were analyzed, consisting of both Korean (3 types) and imported products (eight types from three countries) commonly available in the Korean market places. The concentrations of trace metals in solid charcoal varied widely across metal types and between samples with the overall range of 5 {mu}g kg{sup -1} (As) to 118 mg kg{sup -1} (Zn). The patterns of metal distribution between different products appeared to be affected by the properties of raw materials and/or the processes involved in their production. Although concentrations of certain trace metals were significantly high in certain charcoal samples, their emission concentrations were below legislative guidelines (e.g., the permissible exposure limit (PEL) set by the Occupational Safety and Health Administration (OSHA)). In light of the potential harm of grilling activities, proper regulation should be considered to control the use of BBQ charcoal from a toxicological viewpoint to help reduce the potential health risks associated with its use.

  20. Trace metal contents in barbeque (BBQ) charcoal products

    International Nuclear Information System (INIS)

    Kabir, Ehsanul; Kim, Ki-Hyun; Yoon, H.O.

    2011-01-01

    In this study, the concentrations of trace elements contained in solid barbeque (BBQ) charcoal products have been investigated. Eleven brands of charcoal products were analyzed, consisting of both Korean (3 types) and imported products (eight types from three countries) commonly available in the Korean market places. The concentrations of trace metals in solid charcoal varied widely across metal types and between samples with the overall range of 5 μg kg -1 (As) to 118 mg kg -1 (Zn). The patterns of metal distribution between different products appeared to be affected by the properties of raw materials and/or the processes involved in their production. Although concentrations of certain trace metals were significantly high in certain charcoal samples, their emission concentrations were below legislative guidelines (e.g., the permissible exposure limit (PEL) set by the Occupational Safety and Health Administration (OSHA)). In light of the potential harm of grilling activities, proper regulation should be considered to control the use of BBQ charcoal from a toxicological viewpoint to help reduce the potential health risks associated with its use.

  1. Removal of trace metal contaminants from potable water by electrocoagulation

    Science.gov (United States)

    Heffron, Joe; Marhefke, Matt; Mayer, Brooke K.

    2016-06-01

    This study investigated the effects of four operational and environmental variables on the removal of trace metal contaminants from drinking water by electrocoagulation (EC). Removal efficiencies for five metals (arsenic, cadmium, chromium, lead and nickel) were compared under varying combinations of electrode material, post-treatment, water composition and pH. Iron electrodes out-performed aluminum electrodes in removing chromium and arsenic. At pH 6.5, aluminum electrodes were slightly more effective at removing nickel and cadmium, while at pH 8.5, iron electrodes were more effective for these metals. Regardless of electrode, cadmium and nickel removal efficiencies were higher at pH 8.5 than at pH 6.5. Post-EC treatment using membrane filtration (0.45 μm) enhanced contaminant removal for all metals but nickel. With the exception of lead, all metals exhibited poorer removal efficiencies as the ionic strength of the background electrolyte increased, particularly in the very high-solids synthetic groundwaters. Residual aluminum concentrations were lowest at pH 6.5, while iron residuals were lowest in low ionic strength waters. Both aluminum and iron residuals required post-treatment filtration to meet drinking water standards. EC with post-treatment filtration appears to effectively remove trace metal contaminants to potable water standards, but both reactor and source water parameters critically impact removal efficiency.

  2. The Effect of Metal Concentration on the Parameters Derived from Complexometric Titrations of Trace Elements in Seawater—A Model Study

    NARCIS (Netherlands)

    Gledhill, M.; Gerringa, L.J.A.

    2017-01-01

    In this study we examine the impact of dissolved metal concentrations on the parametersthat are commonly determined from complexometric titrations in seawater. We use thenon-ideal competitive adsorption (NICA) model within the framework of the chemicalspeciation program visual MINTEQ with iron as a

  3. Trace metal uptake by tropical vegetables grown on soil amended with urban sewage sludge

    International Nuclear Information System (INIS)

    Nabulo, G.; Black, C.R.; Young, S.D.

    2011-01-01

    Trace metal uptake was measured for tropical and temperate leafy vegetables grown on soil from an urban sewage disposal farm in the UK. Twenty-four leafy vegetables from East Africa and the UK were assessed and the five vegetable types that showed the greatest Cd concentrations were grown on eight soils differing in the severity of contamination, pH and other physico-chemical properties. The range of Cd concentrations in the edible shoots was greater for tropical vegetables than for temperate types. Metal uptake was modelled as a function of (i) total soil metal concentration, (ii) CaCl 2 -soluble metal, (iii) soil solution concentration and (iv) the activity of metal ions in soil pore water. Tropical vegetables were not satisfactorily modelled as a single generic 'green vegetable', suggesting that more sophisticated approaches to risk assessment may be required to assess hazard from peri-urban agriculture in developing countries. - Research highlights: → Cadmium uptake by tropical green vegetables varies greatly between types. → Modelling metal uptake works best for Ni, Cd and Zn but is poor for Cu, Ba and Pb. → Modelling with dilute CaCl 2 extraction is as good as metal ion activity in pore water. - Trace metal uptake by tropical leaf vegetables can be predicted from dilute CaCl 2 extraction of soil but model parameters are genotype-specific.

  4. Trace metal uptake by tropical vegetables grown on soil amended with urban sewage sludge

    Energy Technology Data Exchange (ETDEWEB)

    Nabulo, G.; Black, C.R. [School of Biosciences, University of Nottingham, University Park, Nottingham, NG7 2RD (United Kingdom); Young, S.D., E-mail: scott.young@nottingham.ac.u [School of Biosciences, University of Nottingham, University Park, Nottingham, NG7 2RD (United Kingdom)

    2011-02-15

    Trace metal uptake was measured for tropical and temperate leafy vegetables grown on soil from an urban sewage disposal farm in the UK. Twenty-four leafy vegetables from East Africa and the UK were assessed and the five vegetable types that showed the greatest Cd concentrations were grown on eight soils differing in the severity of contamination, pH and other physico-chemical properties. The range of Cd concentrations in the edible shoots was greater for tropical vegetables than for temperate types. Metal uptake was modelled as a function of (i) total soil metal concentration, (ii) CaCl{sub 2}-soluble metal, (iii) soil solution concentration and (iv) the activity of metal ions in soil pore water. Tropical vegetables were not satisfactorily modelled as a single generic 'green vegetable', suggesting that more sophisticated approaches to risk assessment may be required to assess hazard from peri-urban agriculture in developing countries. - Research highlights: Cadmium uptake by tropical green vegetables varies greatly between types. Modelling metal uptake works best for Ni, Cd and Zn but is poor for Cu, Ba and Pb. Modelling with dilute CaCl{sub 2} extraction is as good as metal ion activity in pore water. - Trace metal uptake by tropical leaf vegetables can be predicted from dilute CaCl{sub 2} extraction of soil but model parameters are genotype-specific.

  5. Use and abuse of trace metal concentrations in plant tissue for biomonitoring and phytoextraction

    NARCIS (Netherlands)

    Mertens, Jan; Luyssaert, Sebastiaan; Verheyen, Kris

    2005-01-01

    Some plant species accumulate trace metals from the soil in their aboveground biomass. Therefore, some scientists have concluded that these species are suitable for biomonitoring trace metal concentrations in the soil or for removing excessive trace metals from the soil by means of phytoextraction.

  6. Modeling of contact tracing in social networks

    Science.gov (United States)

    Tsimring, Lev S.; Huerta, Ramón

    2003-07-01

    Spreading of certain infections in complex networks is effectively suppressed by using intelligent strategies for epidemic control. One such standard epidemiological strategy consists in tracing contacts of infected individuals. In this paper, we use a recently introduced generalization of the standard susceptible-infectious-removed stochastic model for epidemics in sparse random networks which incorporates an additional (traced) state. We describe a deterministic mean-field description which yields quantitative agreement with stochastic simulations on random graphs. We also discuss the role of contact tracing in epidemics control in small-world and scale-free networks. Effectiveness of contact tracing grows as the rewiring probability is reduced.

  7. Trace metal pollution in Umtata River | Fatoki | Water SA

    African Journals Online (AJOL)

    Dissolved trace metals, i.e Fe, Mn, Al, Cu, Zn, Pb and Cd were determined in the Umtata River. High levels of Al, Cd, Pb, Zn and. Cu were observed, which may affect the “health” of the aquatic ecosystem. The high levels of Al, Cd and Pb may also affect the health of the rural community that uses the river water directly for ...

  8. Trace Metals in Urban Stormwater Runoff and their Management

    Science.gov (United States)

    Li, T.; Hall, K.; Li, L. Y.; Schreier, H.

    2009-04-01

    In past decades, due to the rapid urbanization, land development has replaced forests, fields and meadows with impervious surfaces such as roofs, parking lots and roads, significantly affecting watershed quality and having an impact on aquatic systems. In this study, non-point source pollution from a diesel bus loop was assessed for the extent of trace metal contamination of Cu, Mn, Fe, and Zn in the storm water runoff. The study was carried out at the University of British Columbia (UBC) in the Greater Vancouver Regional District (GVRD) of British Columbia, Canada. Fifteen storm events were monitored at 3 sites from the diesel bus loop to determine spatial and temporal variations of dissolved and total metal concentrations in the storm water runoff. The dissolved metal concentrations were compared with the provincial government discharge criteria and the bus loop storm water quality was also compared with previous studies conducted across the GVRD urban area. To prevent storm water with hazardous levels of contaminants from being discharged into the urban drainage system, a storm water catch basin filter was installed and evaluated for its efficiency of contaminants removal. The perlite filter media adsorption capacities for the trace metals, oil and grease were studied for better maintenance of the catch basin filter. Dissolved copper exceeded the discharge criteria limit in 2 out of 15 cases, whereas dissolved zinc exceeded the criteria in 4 out of 15 cases, and dissolved manganese was below the criteria in all of the events sampled. Dissolved Cu and Zn accounted for 36 and 45% of the total concentration, whereas Mn and Fe only accounted for 20 and 4% of their total concentration, respectively. Since they are more mobile and have higher bioaccumulation potentials, Zn and Cu are considered to be more hazardous to the aquatic environment than Fe and Mn. With high imperviousness (100%) and intensive traffic at the UBC diesel bus loop, trace metal concentrations

  9. Trace metals in heavy crude oils and tar sand bitumens

    Energy Technology Data Exchange (ETDEWEB)

    Reynolds, J.G.

    1990-11-28

    Fe, Ni, and V are considered trace impurities in heavy crude oils and tar sand bitumens. In order to understand the importance of these metals, we have examined several properties: (1) bulk metals levels, (2) distribution in separated fractions, (3) size behavior in feeds and during processing, (4) speciation as a function of size, and (5) correlations with rheological properties. Some of the results of these studies show: (1) V and Ni have roughly bimodal size distributions, (2) groupings were seen based on location, size distribution, and Ni/V ratio of the sample, (3) Fe profiles are distinctively different, having a unimodal distribution with a maximum at relatively large molecular size, (4) Fe concentrations in the tar sand bitumens suggest possible fines solubilization in some cases, (5) SARA separated fractions show possible correlations of metals with asphaltene properties suggesting secondary and tertiary structure interactions, and (6) ICP-MS examination for soluble ultra-trace metal impurities show the possibility of unexpected elements such as U, Th, Mo, and others at concentrations in the ppB to ppM range. 39 refs., 13 figs., 5 tabs.

  10. Urban farming as a possible source of trace metals in human diets

    Directory of Open Access Journals (Sweden)

    Joshua O. Olowoyo

    2016-02-01

    Full Text Available Rapid industrialisation and urbanisation have greatly increased the concentrations of trace metals as pollutants in the urban environment. These pollutants (trace metals are more likely to have an adverse effect on peri-urban agriculture which is now becoming a permanent feature of the landscape of many urban cities in the world. This review reports on the concentrations of trace metals in crops, including leafy vegetables harvested from different urban areas, thus highlighting the presence of trace metals in leafy vegetables. Various pathways of uptake of trace metals by leafy vegetables, such as the foliar and roots, and possible health risks associated with urban faming are discussed and various morphological and physiological impacts of trace metals in leafy vegetables are described. Defensive mechanisms and positive aspects of trace metals in plants are also highlighted.

  11. Study of trace metals in evaporites of Sergipe, Brazil

    International Nuclear Information System (INIS)

    Andrade, L.L.

    1982-01-01

    Heavy metals and others which form strong complexes must be present in the brine feed of electrolytic cells only at very low levels. Their occurrence in quantities above the established levels has a deleterious effect on the membranes of the cells and will produce interference on voltage, current efficiency and other factors. The waste resulting from decantation of the brine causes serious environmental problems. Thirty brine samples from different sites, provided by Petrobras Mineracao S.A. (Brazil) were studied. The sample preparation method and the analytical results obtained from semiquantitative determination of trace metals by optical emission spectrography are described. The toxicity of certain metals, their effects on the environment and on electrolytic cell membranes are also discussed. (Author) [pt

  12. Radionuclides and trace metals in eastern Mediterranean Sea algae

    International Nuclear Information System (INIS)

    Al-Masri, M.S.; Mamish, S.; Budier, Y.

    2003-01-01

    Three types of sea alga distributed along the Syrian coast have been collected and analyzed for radioactivity and trace elements. Results have shown that 137 Cs concentrations in all the analyzed sample were relatively low (less than 1.2 Bq kg -1 dry weight) while the levels of naturally occurring radionuclides, such as 210 Po and 210 Pb, were found to be high in most samples; the highest observed value (27.43 Bq kg -1 dry weight) for 210 Po being in the red Jania longifurca alga. In addition, most brown alga species were also found to accumulate 210 Po, which indicates their selectivity to this isotope. On the other hand, brown alga (Cystoseira and Sargassum Vulgare) have shown a clear selectivity for some trace metals such as Cr, As, Cu and Co, this selectivity may encourage their use as biomonitor for pollution by trace metals. Moreover, the red alga species were found to contain the highest levels of Mg while the brown alga species were found to concentrate Fe, Mn, Na and K and nonmetals such as Cl, I and Br

  13. The Effect of Metal Concentration on the Parameters Derived from Complexometric Titrations of Trace Elements in Seawater—A Model Study

    Directory of Open Access Journals (Sweden)

    Martha Gledhill

    2017-08-01

    Full Text Available In this study we examine the impact of dissolved metal concentrations on the parameters that are commonly determined from complexometric titrations in seawater. We use the non-ideal competitive adsorption (NICA model within the framework of the chemical speciation program visual MINTEQ with iron as a model metal. We demonstrate that dissolved iron concentrations effect the determined parameters for a heterogeneous binding site distribution with a fixed concentration of dissolved organic carbon. The commonly used terms “ligand concentration” and “binding constant” are therefore dependent on metal concentration, so we adopt the terminology suggested by Town and Filella (2000 and use the terms ligand quotient and stability quotient here. The systematic increase in the ligand quotient with dissolved iron concentration likely contributes toward the trend of increasing ligand quotient with dissolved iron concentration observed in field studies, and makes it hard to assign an objective meaning to the parameter. We suggest that calculation of the side reaction coefficient, a parameter that describes the probability that any added metal will be complexed, could be less prone to bias and misinterpretation than calculation of conditional stability and ligand quotients. We explore the impact of experimental design on side reaction coefficients by applying different detection windows, and multiwindow and reverse titration approaches. We identify the method that results in the best estimates of side reaction coefficients over a range of iron concentrations between 0.1 and 1.5 nmol L−1. We find that single window titrations can only reliably estimate side reaction coefficients over a limited range of iron concentrations. Multiwindow titrations provided estimates of side reaction coefficients within the 99% confidence interval of the values calculated directly from the NICA model at all iron concentrations examined here. We recommend that future

  14. Facilitation of trace metal uptake in cells by inulin coating of metallic nanoparticles

    Science.gov (United States)

    Santillán-Urquiza, Esmeralda; Arteaga-Cardona, Fernando; Torres-Duarte, Cristina; Cole, Bryan; Wu, Bing; Méndez-Rojas, Miguel A.; Cherr, Gary N.

    2017-09-01

    Trace elements such as zinc and iron are essential for the proper function of biochemical processes, and their uptake and bioavailability are dependent on their chemical form. Supplementation of trace metals through nanostructured materials is a new field, but its application raises concerns regarding their toxicity. Here, we compared the intracellular zinc uptake of different sources of zinc: zinc sulfate, and ZnO and core-shell α-Fe2O3@ZnO nanoparticles, coated or uncoated with inulin, an edible and biocompatible polysaccharide. Using mussel haemocytes, a well-known model system to assess nanomaterial toxicity, we simultaneously assessed zinc accumulation and multiple cellular response endpoints. We found that intracellular zinc uptake was strongly enhanced by inulin coating, in comparison to the uncoated nanoparticles, while no significant effects on cell death, cell viability, mitochondrial membrane integrity, production of reactive oxygen species or lysosome abundance were observed at concentrations up to 20 ppm. Since no significant increments in toxicity were observed, the coated nanomaterials may be useful to increase in vivo zinc uptake for nutritional applications.

  15. Contamination from an affluent of Furnas reservoir by trace metals

    Directory of Open Access Journals (Sweden)

    PP Cavalcanti

    Full Text Available This study aims to determine concentrations and characterize trace metals distribution in an affluent of Furnas reservoir, Alfenas-MG. Water and sediment samples were taken monthly, 2010/10-2011/07 in five sites of Córrego do Pântano for subsequent determination of Pb, Cd and Zn levels by chemical analysis. The stream studied is in disagreement with Brazilian legislation for Class II water bodies (CONAMA 357. The highlights are the unsuitable concentrations of Pb for human consumption, according to Ministry of Health 2914 decree, providing risk for population.

  16. Radionuclides and trace metals in surface air. Appendix C

    International Nuclear Information System (INIS)

    Feely, H.W.; Toonkel, L.E.; Larsen, R.J.

    1981-01-01

    Since January 1963, the Environmental Measurements Laboratory (EML), formerly the Health and Safety Laboratory (HASL), has been conducting the Surface Air Sampling Program. This study is a direct outgrowth of a program initiated by the US Naval Research Laboratory (NRL) in 1957 and continued through 1962. The primary objective of this program is to study the spatial and temporal distribution of specific natural and man-made radioisotopes, and of trace metals in the surface air. Other special studies of surface air contamination have been performed during the course of the program

  17. Source apportionment of trace metals in river sediments: A comparison of three methods

    International Nuclear Information System (INIS)

    Chen, Haiyang; Teng, Yanguo; Li, Jiao; Wu, Jin; Wang, Jinsheng

    2016-01-01

    Increasing trace metal pollution in river sediment poses a significant threat to watershed ecosystem health. Identifying potential sources of sediment metals and apportioning their contributions are of key importance for proposing prevention and control strategies of river pollution. In this study, three advanced multivariate receptor models, factor analysis with nonnegative constraints (FA-NNC), positive matrix factorization (PMF), and multivariate curve resolution weighted-alternating least-squares (MCR-WALS), were comparatively employed for source apportionment of trace metals in river sediments and applied to the Le'an River, a main tributary of Poyang Lake which is the largest freshwater lake in China. The pollution assessment with contamination factor and geoaccumulation index suggested that the river sediments in Le'an River were contaminated severely by trace metals due to human activities. With the three apportionment tools, similar source profiles of trace metals in sediments were extracted. Especially, the MCR-WALS and PMF models produced essentially the same results. Comparatively speaking, the weighted schemes might give better solutions than the unweighted FA-NNC because the uncertainty information of environmental data was considered by PMF and MCR-WALS. Anthropogenic sources were apportioned as the most important pollution sources influencing the sediment metals in Le'an River with contributions of about 90%. Among them, copper tailings occupied the largest contribution (38.4–42.2%), followed by mining wastewater (29.0–33.5%), and agricultural activities (18.2–18.7%). To protect the ecosystem of Le'an River and Poyang Lake, special attention should be paid to the discharges of mining wastewater and the leachates of copper tailing ponds in that region. - Highlights: • Three advanced receptor models were comparatively employed for source apportionment. • The MCR-WALS and PMF models produce essentially same source profiles. • Copper

  18. Occurrence of Trace and Toxic metals in River Narmada

    Directory of Open Access Journals (Sweden)

    Mohammed Arif

    2014-12-01

    Full Text Available Deteriorating water quality has become a serious problem in developing countries. Almost 70% of Indian’s surface water resources have become contaminated due to the discharge of untreated sewage and industrial effluents. The results reveals that out of nine water quality stations monitored, water samples collected at 5 water quality stations (Amarkantak, Dindori, Manot, Barmanghat and Handia are found to be within the permissible limit for all purposes in respect to trace & toxic metals. While Sandia, Hoshangabad, Mandleshwar and Garudeshwar stations were beyond the permissible limit due to presence of chromium, copper and iron metals. The major source of pollution to the Narmada river is the anthropogenic municipal solid waste and sewage from nearby towns/habitations, agricultural runoff and native soil erosion. The quality of the Narmada River is degraded due to the municipal and industrial discharges from the catchment.

  19. Interactive influences of bioactive trace metals on biological production in oceanic waters

    International Nuclear Information System (INIS)

    Bruland, K.W.; Donat, J.R.; Hutchins, D.A.

    1991-01-01

    The authors present an overview of the oceanic chemistries of the bioactive trace metals, Mn, Fe, Co, Ni, Cu, and Zn; the authors combine field data with results from laboratory phytoplankton culture-trace metal studies and speculate on the potential influences of these trace metals on oceanic plankton production and species composition. Most field studies have focused on the effects of single metals. However, they propose that synergistic and antagonistic interactions between multiple trace metals could be very important in the oceans. Trace metal antagonisms that may prove particularly important are those between Cu and the potential biolimiting metals Fe, Mn, and Zn. These antagonistic interactions could have the greatest influence on biological productivity in areas of the open ocean isolated from terrestrial inputs, such as the remote high nutrient regions of the Pacific and Antarctic Oceans. The emerging picture of trace metal-biota interactions in these oceanic areas is one in which biology strongly influences distribution and chemical speciation of all these bioactive trace metals. It also seems likely that many of these bioactive trace metals and their speciation may influence levels of primary productivity, species composition, and trophic structure. Future investigations should give more complete consideration to the interactive effects of biologically important trace metals

  20. Transfer and mobility of trace metallic elements in the sedimentary column of continental hydro-systems

    International Nuclear Information System (INIS)

    Devallois, V.

    2009-02-01

    In freshwater systems, trace metal pollutants are transferred into water and sedimentary columns under dissolved forms and/or fixed onto solid particles. Accumulated in the sedimentary areas, these latter ones can constitute important stocks of materials and associated pollutants and may impair water quality when environmental changes lead to increase their mobility. The mobility of the stocks of pollutants is mainly depending on the erosion, on the interstitial diffusion of the mobile phases (dissolved and colloidal) and on the bioturbation. In this context, this study involves the analysis of the mobility by interstitial diffusion. This topic consists in studying trace metal fractionation between their mobile (dissolved and colloidal) and non mobile (fixed onto the particles) forms. This point is governed by sorption/desorption processes at the particle surfaces. These processes are regulated by physico-chemical parameters (pH, redox potential, ionic strength...) and are influenced by biogeochemical reactions resulting from the oxidation of the organic matter by the microbial activity. These reactions generate vertical profiles of nutrients and metal concentrations along the sedimentary column. To understand these processes, this work is based on a mixed approach that combines in situ, analysis and modelling. In situ experimental part consists in sampling natural sediments cores collected at 4 different sites (1 site in Durance and 3 sites on the Rhone). These samples are analyzed according to an analytical protocol that provides the vertical distribution of physicochemical parameters (pH, redox potential, size distribution, porosity), nutrients and solid - liquid forms of trace metals (cobalt, copper, nickel, lead, zinc). The analysis and interpretation of these experimental results are based on a model that was developed during this study and that includes: 1) model of interstitial diffusion (Boudreau, 1997), 2) biogeochemical model (Wang and Van Cappellen

  1. Reactive solute transport in streams: A surface complexation approach for trace metal sorption

    Science.gov (United States)

    Runkel, Robert L.; Kimball, Briant A.; McKnight, Diane M.; Bencala, Kenneth E.

    1999-01-01

    A model for trace metals that considers in-stream transport, metal oxide precipitation-dissolution, and pH-dependent sorption is presented. Linkage between a surface complexation submodel and the stream transport equations provides a framework for modeling sorption onto static and/or dynamic surfaces. A static surface (e.g., an iron- oxide-coated streambed) is defined as a surface with a temporally constant solid concentration. Limited contact between solutes in the water column and the static surface is considered using a pseudokinetic approach. A dynamic surface (e.g., freshly precipitated metal oxides) has a temporally variable solid concentration and is in equilibrium with the water column. Transport and deposition of solute mass sorbed to the dynamic surface is represented in the stream transport equations that include precipitate settling. The model is applied to a pH-modification experiment in an acid mine drainage stream. Dissolved copper concentrations were depressed for a 3 hour period in response to the experimentally elevated pH. After passage of the pH front, copper was desorbed, and dissolved concentrations returned to ambient levels. Copper sorption is modeled by considering sorption to aged hydrous ferric oxide (HFO) on the streambed (static surface) and freshly precipitated HFO in the water column (dynamic surface). Comparison of parameter estimates with reported values suggests that naturally formed iron oxides may be more effective in removing trace metals than synthetic oxides used in laboratory studies. The model's ability to simulate pH, metal oxide precipitation-dissolution, and pH-dependent sorption provides a means of evaluating the complex interactions between trace metal chemistry and hydrologic transport at the field scale.

  2. Estimation of trace metal contents in locally-baked breads

    International Nuclear Information System (INIS)

    Khalid, N.; Rehman, S.

    2013-01-01

    In order to establish base line levels, estimation of some essential trace metals (Cu, Fe, Mn and Zn) has been conducted in four brands of fifteen locally baked breads of Rawalpindi /Islamabad area employing Atomic Absorption Spectrophotometry (AAS). The samples were digested in a mixture of nitric acid and perchloric acid and the analysis was done with air-acetylene flame. The reliability of the procedure employed was verify by analyzing Standard Reference Material, i.e., wheat flour (NBS-SRM-1567) for its Cu, Fe, Mn and Zn contents which were in good agreement with the certified values. The results revealed that brown breads contained higher amount of Fe 177.3 micro g g/sup -1/and Zn 19.27 micro g g/sup -1/while levels of Cu 21.90 micro g g/-sup 1/was found higher in the samples of plain bread. The determined metal concentrations in the bread samples were compared with the reported values for other countries. The effect of kneading/baking/slicing processes on the concentration levels of these metals was also studied. The daily intake of these metals through this source was calculated and compared with the recommended dietary allowance. (author)

  3. Authoring Model-Tracing Cognitive Tutors

    Science.gov (United States)

    Blessing, Stephen B.; Gilbert, Stephen B.; Ourada, Stephen; Ritter, Steven

    2009-01-01

    Intelligent Tutoring Systems (ITSs) that employ a model-tracing methodology have consistently shown their effectiveness. However, what evidently makes these tutors effective, the cognitive model embedded within them, has traditionally been difficult to create, requiring great expertise and time, both of which come at a cost. Furthermore, an…

  4. Speciation and Distribution of Trace Metals and Organic Matter in Marine Lake as In Situ Laboratory

    Science.gov (United States)

    Mlakar, M.; Fiket, Ž.; Cuculić, V.; Cukrov, N.; Geček, S.

    2016-02-01

    Marine lakes are unique, isolated marine systems, also recognized as in situ "laboratories" in which geochemical processes on a different scale compared to the open sea, can be observed. Impact of organic matter cycling on distribution of trace metals in the marine lake Mir, located on Dugi Otok Island, in the central part of the eastern Adriatic Sea, was investigated. Intense spatial and seasonal variations of physico-chemical parameters and organic matter concentrations in the water column of the Lake are governed predominantly by natural processes. Enhanced oxygen consumption in the Lake during summer season, high organic carbon concentrations and low redox potential result in occasional occurrence of anoxic conditions in the bottom layers. Speciation modelling showed that dissolved trace metals Cu, Pb and Zn, are mostly bound to organic matter, while Cd, Co and Ni are present predominantly as free ions and inorganic complexes. Trace metals removal from the water column and their retention in the sediment was found to depend on the nature of the relationship between specific metal and high proportion of organic matter (up to 9%) and inorganic phases, Fe-oxyhydroxydes or biogenic calcite. Surrounding karstic background, with occasional occurrences of red soil characterize deposited sediments as coarse grained and carbonate rich, whose elemental composition is affected by bathymetry of the basin and overall biological production.

  5. Changes in trace metals in Thalassia testudinum after hurricane impacts.

    Science.gov (United States)

    Whelan, T; Van Tussenbroek, B I; Santos, M G Barba

    2011-12-01

    Major hurricanes Emily and Wilma hit the Mexican Caribbean in 2005. Changes in trace metals in the seagrass Thalassia testudinum prior to (May 2004, 2005) and following passage of these hurricanes (May, June 2006) were determined at four locations along a ≈ 130 km long stretch of coast. Before the hurricanes, essential metals were likely limiting and concentrations of potentially toxic Pb were high in a contaminated lagoon (27.5 μg g(-1)) and near submarine springs (6.10 μg g(-1)); the likely sources were inland sewage disposal or excessive boat traffic. After the hurricanes, Pb decreased to 2.0 μg g(-1) in the contaminated lagoon probably through flushing. At the northern sites, essential Fe increased >2-fold (from 26.8 to 68.3 μg g(-1) on average), possibly from remobilization of anoxic sediments or upwelling of deep seawater during Wilma. Thus, hurricanes can be beneficial to seagrass beds in flushing toxic metals and replenishing essential elements. Copyright © 2011 Elsevier Ltd. All rights reserved.

  6. Simplicial models of trace spaces

    DEFF Research Database (Denmark)

    Raussen, Martin

    2010-01-01

    variation of the end points. The original motivation stems from certain models for concurrent computation. So far, homotopy types of spaces of d-paths and their topological invariants have only been determined in cases that were elementary to overlook. In this paper, we develop a systematic approach...

  7. Accumulation of trace metals in coastal marine organisms

    International Nuclear Information System (INIS)

    Weers, A.W. van; Raaphorst, J.G. van

    1980-01-01

    ECN at Petten carries out a survey on the occurrence of trace metals in coastal marine organisms. The survey is aimed to provide an estimate of concentration factors in local marine organisms for neutron activation products released as low-level liquid radioactive waste into the North Sea. The organisms studied are red and brown seaweed, edible mussels ans shrimp. A summary of the results of analyses of iron, cobalt, zinc, silver and antimony in these organisms is presented. Concentration factors derived from mean stable-element concentrations range from about 50 for Sb in red seaweed and shrimp to about 10 4 for Fe in red seaweed and mussels. The largest variation is shown for zinc in seaweed, which variation is seasonal and most pronounced in brown seaweed. A discussion of the data is presented in relation to data from other West-European coastal areas and to data used for the radiological assessment of deep sea disposal of radioactive waste

  8. Modified electrode voltammetric sensors for trace metals in environmental samples

    Directory of Open Access Journals (Sweden)

    Brett Christopher M.A.

    2000-01-01

    Full Text Available Nafion-modified mercury thin film electrodes have been investigated for the analysis of trace metals in environmental samples of waters and effluent by batch injection analysis with square wave anodic stripping voltammetry. The method, involving injection over the detector electrode of untreated samples of volume of the order of 50 microlitres has fast response, blocking and fouling of the electrode is minimum as shown by studies with surface-active components. Comparison is made between glassy carbon substrate electrodes and carbon fibre microelectrode array substrates, the latter leading to a small sensitivity enhancement. Application to analysis of river water and industrial effluent for labile zinc, cadmium, lead and copper ions is demonstrated in collected samples and after acid digestion.

  9. Relation between tobacco trace metals and soil type in Lebanon

    International Nuclear Information System (INIS)

    SLIM, K.; Saad, Z.; Kazpard, V.; El Samarani, A; Nabhan, Ph.

    2006-01-01

    The aim of study was to determine the concentration of nutrients in soil and tobacco samples from different agricultural regions. We studied the influence of soil type on tobacco quality and the transfer and accumulation of trace metals in tobacco leaves. The results showed that human activities in the Nabatiyeh region had a none pronounced effect on one agricultural plot than on its neighbor. The transfer factor of elements between soil and tobacco plants showed that major constituents are leached and absorbed from the soil, whereas some trace elements are finely absorbed from the alkaline soil. Statistical analysis of the micro nutrients in soil and plants confirmed the existence of two principal factors that control the distribution of elements in different compartments. Four tobacco plots in different regions were also studied as a functions of their pedologic and geologic characteristics. The major elements varied in all regions, but were always ordered Ca > Mg > Na > K. The highest transfer factor for nutrients was found in young soil layers. In the Akkar region, clay nutrients form complexes with micronutrients. Thereby reducing their absorption by tobacco plants. (author)

  10. Simplicial models for trace spaces

    DEFF Research Database (Denmark)

    Raussen, Martin

    Directed Algebraic Topology studies topological spaces in which certain directed paths (d-paths) - in general irreversible - are singled out. The main interest concerns the spaces of directed paths between given end points - and how those vary under variation of the end points. The original...... motivation stems from certain models for concurrent computation. So far, spaces of d-paths and their topological invariants have only been determined in cases that were elementary to overlook. In this paper, we develop a systematic approach describing spaces of directed paths - up to homotopy equivalence...

  11. Standard Model Effective Potential from Trace Anomalies

    Directory of Open Access Journals (Sweden)

    Renata Jora

    2018-01-01

    Full Text Available By analogy with the low energy QCD effective linear sigma model, we construct a standard model effective potential based entirely on the requirement that the tree level and quantum level trace anomalies must be satisfied. We discuss a particular realization of this potential in connection with the Higgs boson mass and Higgs boson effective couplings to two photons and two gluons. We find that this kind of potential may describe well the known phenomenology of the Higgs boson.

  12. Levels of trace metals in water and sediment from Tyume River and ...

    African Journals Online (AJOL)

    Levels of trace metals (Cd, Pb, Co, Zn Cu and Ni) were determined in water and sediment ... mg/l) and Pb (0.021 ± 0.004 to 0.035 ± 0.001 mg/l) were found in the river water, ... Key words: trace metals, water, sediment, farmland, Tyume River

  13. Mapping human health risks from exposure to trace metal contamination of drinking water sources in Pakistan.

    Science.gov (United States)

    Bhowmik, Avit Kumar; Alamdar, Ambreen; Katsoyiannis, Ioannis; Shen, Heqing; Ali, Nadeem; Ali, Syeda Maria; Bokhari, Habib; Schäfer, Ralf B; Eqani, Syed Ali Musstjab Akber Shah

    2015-12-15

    The consumption of contaminated drinking water is one of the major causes of mortality and many severe diseases in developing countries. The principal drinking water sources in Pakistan, i.e. ground and surface water, are subject to geogenic and anthropogenic trace metal contamination. However, water quality monitoring activities have been limited to a few administrative areas and a nationwide human health risk assessment from trace metal exposure is lacking. Using geographically weighted regression (GWR) and eight relevant spatial predictors, we calculated nationwide human health risk maps by predicting the concentration of 10 trace metals in the drinking water sources of Pakistan and comparing them to guideline values. GWR incorporated local variations of trace metal concentrations into prediction models and hence mitigated effects of large distances between sampled districts due to data scarcity. Predicted concentrations mostly exhibited high accuracy and low uncertainty, and were in good agreement with observed concentrations. Concentrations for Central Pakistan were predicted with higher accuracy than for the North and South. A maximum 150-200 fold exceedance of guideline values was observed for predicted cadmium concentrations in ground water and arsenic concentrations in surface water. In more than 53% (4 and 100% for the lower and upper boundaries of 95% confidence interval (CI)) of the total area of Pakistan, the drinking water was predicted to be at risk of contamination from arsenic, chromium, iron, nickel and lead. The area with elevated risks is inhabited by more than 74 million (8 and 172 million for the lower and upper boundaries of 95% CI) people. Although these predictions require further validation by field monitoring, the results can inform disease mitigation and water resources management regarding potential hot spots. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. Holographic models and the QCD trace anomaly

    International Nuclear Information System (INIS)

    Goity, Jose L.; Trinchero, Roberto C.

    2012-01-01

    Five dimensional dilaton models are considered as possible holographic duals of the pure gauge QCD vacuum. In the framework of these models, the QCD trace anomaly equation is considered. Each quantity appearing in that equation is computed by holographic means. Two exact solutions for different dilaton potentials corresponding to perturbative and non-perturbative β-functions are studied. It is shown that in the perturbative case, where the β-function is the QCD one at leading order, the resulting space is not asymptotically AdS. In the non-perturbative case, the model considered presents confinement of static quarks and leads to a non-vanishing gluon condensate, although it does not correspond to an asymptotically free theory. In both cases analyses based on the trace anomaly and on Wilson loops are carried out.

  15. Interactions of trace metals with hydrogels and filter membranes used in DET and DGT techniques.

    Science.gov (United States)

    Garmo, Oyvind A; Davison, William; Zhang, Hao

    2008-08-01

    Equilibrium partitioning of trace metals between bulk solution and hydrogels/filter was studied. Under some conditions, trace metal concentrations were higher in the hydrogels or filter membranes compared to bulk solution (enrichment). In synthetic soft water, enrichment of cationic trace metals in polyacrylamide hydrogels decreased with increasing trace metal concentration. Enrichment was little affected by Ca and Mg in the concentration range typically encountered in natural freshwaters, indicating high affinity but low capacity binding of trace metals to solid structure in polyacrylamide gels. The apparent binding strength decreased in the sequence: Cu > Pb > Ni approximately to Cd approximately to Co and a low concentration of cationic Cu eliminated enrichment of weakly binding trace metal cations. The polyacrylamide gels also had an affinity for fulvic acid and/or its trace metal complexes. Enrichment of cationic Cd in agarose gel and hydrophilic polyethersulfone filter was independent of concentration (10 nM to 5 microM) but decreased with increasing Ca/ Mg concentration and ionic strength, suggesting that it is mainly due to electrostatic interactions. However, Cu and Pb were enriched even after equilibration in seawater, indicating that these metals additionally bind to sites within the agarose gel and filter. Compared to the polyacrylamide gels, agarose gel had a lower affinity for metal-fulvic complexes. Potential biases in measurements made with the diffusive equilibration in thin-films (DET) technique, identified by this work, are discussed.

  16. Potential release of in vivo trace metals from metallic medical implants in the human body: from ions to nanoparticles--a systematic analytical review.

    Science.gov (United States)

    Matusiewicz, Henryk

    2014-06-01

    Metal ion release from metallic materials, e.g. metallic alloys and pure metals, implanted into the human body in dental and orthopedic surgery is becoming a major cause for concern. This review briefly provides an overview of both metallic alloys and pure metals used in implant materials in dental and orthopedic surgery. Additionally, a short section is dedicated to important biomaterials and their corrosive behavior in both real solutions and various types of media that model human biological fluids and tissues. The present review gives an overview of analytical methods, techniques and different approaches applied to the measurement of in vivo trace metals released into body fluids and tissues from patients carrying metal-on-metal prostheses and metal dental implants. Reference levels of ion concentrations in body fluids and tissues that have been determined by a host of studies are compiled, reviewed and presented in this paper. Finally, a collection of published clinical data on in vivo released trace metals from metallic medical implants is included. Copyright © 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  17. Advanced Gasification Mercury/Trace Metal Control with Monolith Traps

    Energy Technology Data Exchange (ETDEWEB)

    Musich, Mark; Swanson, Michael; Dunham, Grant; Stanislowski, Joshua

    2010-10-05

    Two Corning monoliths and a non-carbon-based material have been identified as potential additives for mercury capture in syngas at temperatures above 400°F and pressure of 600 psig. A new Corning monolith formulation, GR-F1-2189, described as an active sample appeared to be the best monolith tested to date. The Corning SR Liquid monolith concept continues to be a strong candidate for mercury capture. Both monolith types allowed mercury reduction to below 5-μg/m{sup 3} (~5 ppb), a current U.S. Department of Energy (DOE) goal for trace metal control. Preparation methods for formulating the SR Liquid monolith impacted the ability of the monolith to capture mercury. The Energy & Environmental Research Center (EERC)-prepared Noncarbon Sorbents 1 and 2 appeared to offer potential for sustained and significant reduction of mercury concentration in the simulated fuel gas. The Noncarbon Sorbent 1 allowed sustained mercury reduction to below 5-μg/m{sup 3} (~5 ppb). The non-carbon-based sorbent appeared to offer the potential for regeneration, that is, desorption of mercury by temperature swing (using nitrogen and steam at temperatures above where adsorption takes place). A Corning cordierite monolith treated with a Group IB metal offered limited potential as a mercury sorbent. However, a Corning carbon-based monolith containing prereduced metallic species similar to those found on the noncarbon sorbents did not exhibit significant or sustained mercury reduction. EERC sorbents prepared with Group IB and IIB selenide appeared to have some promise for mercury capture. Unfortunately, these sorbents also released Se, as was evidenced by the measurement of H2Se in the effluent gas. All sorbents tested with arsine or hydrogen selenide, including Corning monoliths and the Group IB and IIB metal-based materials, showed an ability to capture arsine or hydrogen selenide at 400°F and 600 psig. Based on current testing, the noncarbon metal-based sorbents appear to be the most

  18. ADVANCED GASIFICATION MERCURY/TRACE METAL CONTROL WITH MONOLITH TRAPS

    Energy Technology Data Exchange (ETDEWEB)

    Mark A. Musich; Michael L. Swanson; Grant E. Dunham; Joshua J. Stanislowski

    2010-07-31

    Two Corning monoliths and a non-carbon-based material have been identified as potential additives for mercury capture in syngas at temperatures above 400°F and pressure of 600 psig. A new Corning monolith formulation, GR-F1-2189, described as an active sample appeared to be the best monolith tested to date. The Corning SR Liquid monolith concept continues to be a strong candidate for mercury capture. Both monolith types allowed mercury reduction to below 5-μg/m3 (~5 ppb), a current U.S. Department of Energy (DOE) goal for trace metal control. Preparation methods for formulating the SR Liquid monolith impacted the ability of the monolith to capture mercury. The Energy & Environmental Research Center (EERC)-prepared Noncarbon Sorbents 1 and 2 appeared to offer potential for sustained and significant reduction of mercury concentration in the simulated fuel gas. The Noncarbon Sorbent 1 allowed sustained mercury reduction to below 5-μg/m3 (~5 ppb). The non-carbon-based sorbent appeared to offer the potential for regeneration, that is, desorption of mercury by temperature swing (using nitrogen and steam at temperatures above where adsorption takes place). A Corning cordierite monolith treated with a Group IB metal offered limited potential as a mercury sorbent. However, a Corning carbon-based monolith containing prereduced metallic species similar to those found on the noncarbon sorbents did not exhibit significant or sustained mercury reduction. EERC sorbents prepared with Group IB and IIB selenide appeared to have some promise for mercury capture. Unfortunately, these sorbents also released Se, as was evidenced by the measurement of H2Se in the effluent gas. All sorbents tested with arsine or hydrogen selenide, including Corning monoliths and the Group IB and IIB metal-based materials, showed an ability to capture arsine or hydrogen selenide at 400°F and 600 psig. Based on current testing, the noncarbon metal-based sorbents appear to be the most effective arsine

  19. Release kinetics and mechanisms of trace heavy metals from cement based material; Cinetiques et mecanismes de relargage des metaux lourds presents en traces dans les matrices cimentaires

    Energy Technology Data Exchange (ETDEWEB)

    Moudilou, E.

    2002-12-15

    Chemical species contained in a solid matrix may be transferred to the environment through water leaching. Previous studies of trace metals released from building materials (particularly cement-based ones) highlight an important analytical difficulty. The aim of this study is to determine the kinetics and the mechanisms involved in the release of trace heavy metals (Cr, Cu, Ni, Pb, V and Zn) from industrial cement pastes (usually ranging from 20 to 300 ppm). The development of a dynamic leaching system, named CTG-LEACHCRETE, (used at pH=5, 20 C) which permits the evaluation of the kinetics of trace heavy metals is presented in the first part. Also, innovative solid analysis techniques (ICP-MS-Laser Ablation, local and Grazing Incidence X-rays Diffraction (GIXD) technique) were used to characterise the cement-degraded layers formed during leaching experiments. These techniques enable to monitor the mineralogical evolution and the distribution of trace metals in these areas. The confrontation of these two approaches, kinetic and solid analysis, coupled with a thorough investigation of previously developed models, lead to proposals concerning the mechanisms of release of the trace heavy metals studied. In all the cement pastes studied (CPA-CEM I, CPJ-CEM II/A and CLC-CEM V/A), chromium is trapped in ettringite by substitution SO{sub 4}{sup 2-}(U)CrO{sub 4}{sup 2-} and its release is then controlled by the dissolution of this hydrate. The behaviour of copper, nickel and zinc in degraded areas and in leachates, are correlated to the silicon of the hydrated calcium silicate (CSH), which imply that they are localised there. Lead, was never detected in the leachates. But it is also correlated to the silicon in the degraded layers. (author)

  20. Effect of Ocean Acidification on Organic and Inorganic Speciation of Trace Metals.

    Science.gov (United States)

    Stockdale, Anthony; Tipping, Edward; Lofts, Stephen; Mortimer, Robert J G

    2016-02-16

    Rising concentrations of atmospheric carbon dioxide are causing acidification of the oceans. This results in changes to the concentrations of key chemical species such as hydroxide, carbonate and bicarbonate ions. These changes will affect the distribution of different forms of trace metals. Using IPCC data for pCO2 and pH under four future emissions scenarios (to the year 2100) we use a chemical speciation model to predict changes in the distribution of organic and inorganic forms of trace metals. Under a scenario where emissions peak after the year 2100, predicted free ion Al, Fe, Cu, and Pb concentrations increase by factors of up to approximately 21, 2.4, 1.5, and 2.0 respectively. Concentrations of organically complexed metal typically have a lower sensitivity to ocean acidification induced changes. Concentrations of organically complexed Mn, Cu, Zn, and Cd fall by up to 10%, while those of organically complexed Fe, Co, and Ni rise by up to 14%. Although modest, these changes may have significance for the biological availability of metals given the close adaptation of marine microorganisms to their environment.

  1. Bioaccumulation of Trace Metals in Bloody Cockle (Anadara senilis) from Ghana: Biokinetics and Human Bioaccessibility Studies

    International Nuclear Information System (INIS)

    Kuranchie-Mensah, Harriet

    2016-07-01

    A series of experimental studies has been carried out to study the kinetic of accumulation and human exposure to trace metals using the bloody cockle (Anadara senilis) as a model organism. This species is of ecological and economic importance in Ghana and other parts of Western Africa where they are commonly found. Trace metals mainly Mn, Co, Zn, Ag and Cd were studied using both laboratory mesocosm and field investigations. The laboratory experiments were carried out through the use of radiotracers: "5"4Mn, "5"7Co, "6"5Zn, "1"1"0"mAg and "1"0"9Cd, to study the kinetics of metal accumulation in the cockle through 2 different exposure pathways. The variability of metal bioaccumulation in the bloody cockle as a function of environmental and physiological conditions was also investigated. Metal subcellular fractionation, tissue distribution and simulating human digestion through the use of in vitro methodology were incorporated to understand the processes governing metal accumulation and human health risk assessment from the consumption of contaminated shellfish. Following a 2-hour single feeding and a 28-day depuration period, metals ingested with food (Isochrysis galbana or Skeletonema costatum) were moderate to highly assimilated in the cockle (11 to 72%), although, the degree of assimilation was dependant on the type of phytoplankton strain, the studied metals and the size of the cockle. Retention of assimilated metals was metal dependant being described as weak for Ag (T_b_1_/_2 of 2 to 6 days), moderate for Mn, Co and Zn (T_b_1_/_2 of 13 to 47 days) and strong for Cd (T_b_1_/_2 ≥ 97 days). Over a 28-day dissolved exposure period, bioconcentration kinetics of metals in two size classes of bloody cockles studied under different exposure conditions (high and low salinity) generally were best described by a saturation model assuming an apparent steady state concentration. The results showed strong variability on the kinetics of metal uptake among different size

  2. Predicting trace metal solubility and fractionation in Urban soils from isotopic exchangeability

    International Nuclear Information System (INIS)

    Mao, L.C.; Young, S.D.; Tye, A.M.; Bailey, E.H.

    2017-01-01

    Metal-salt amended soils (MA, n = 23), and historically-contaminated urban soils from two English cities (Urban, n = 50), were investigated to assess the effects of soil properties and contaminant source on metal lability and solubility. A stable isotope dilution method, with and without a resin purification step, was used to measure the lability of Cd, Cu, Ni, Pb and Zn. For all five metals in MA soils, lability (%E-values) could be reasonably well predicted from soil pH value with a simple logistic equation. However, there was evidence of continuing time-dependent fixation of Cd and Zn in the MA soils, following more than a decade of storage under air-dried conditions, mainly in high pH soils. All five metals in MA soils remained much more labile than in Urban soils, strongly indicating an effect of contaminant source on metal lability in the latter. Metal solubility was predicted for both sets of soil by the geochemical speciation model WHAM-VII, using E-value as an input variable. For soils with low metal solution concentrations, over-estimation of Cd, Ni and Zn solubility was associated with binding to the Fe oxide fraction while accurate prediction of Cu solubility was dependent on humic acid content. Lead solubility was most poorly described, especially in the Urban soils. Generally, slightly poorer estimation of metal solubility was observed in Urban soils, possibly due to a greater incidence of high pH values. The use of isotopically exchangeable metal to predict solubility is appropriate both for historically contaminated soils and where amendment with soluble forms of metal is used, as in toxicological trials. However, the major limitation to predicting solubility may lie with the accuracy of model input variables such as humic acid and Fe oxide contents where there is often a reliance on relatively crude analytical estimations of these variables. Trace metal reactivity in urban soils depends on both soil properties and the original source material

  3. Trace metal excretion in patients with homozygous hypercholesterolaemia.

    Science.gov (United States)

    Jackson, G E; Blewet, R; Rodgers, A L; Wood, L; Jacobs, P

    1999-07-01

    In patients with familial hypercholesterolaemia regular therapeutic apheresis is acknowledged to have long-term benefit. A previously unrecognised complication of such intervention is the development of anaemia that reflects a sub-optimal dietary iron intake coupled with accelerated loss of this trace metal in the fluid discarded after each procedure. Additional contributions result from enhanced urinary excretion as a result of chelation to citrate used as an anticoagulant and frequent blood sampling. The underlying pathophysiologic process appears to be reduced deformability. We now document similar and significant losses of zinc, copper and chromium in these circumstances. In the case of the latter three elements, no associated clinical syndromes have thus far been identified, probably because deficiency states are less well-recognised than that due to iron loss and, additionally, because critical reductions are avoided by their replenishment during a normal food intake. These studies are, nevertheless, relevant since they are the basis for recommending prophylactic supplementation during this form of management.

  4. Distribution and Potential Toxicity of Trace Metals in the Surface Sediments of Sundarban Mangrove Ecosystem, Bangladesh

    Science.gov (United States)

    Kumar, A.; Ramanathan, A.; Mathukumalli, B. K. P.; Datta, D. K.

    2014-12-01

    The distribution, enrichment and ecotoxocity potential of Bangladesh part of Sundarban mangrove was investigated for eight trace metals (As, Cd, Cr, Cu, Fe, Mn, Pb and Zn) using sediment quality assessment indices. The average concentration of trace metals in the sediments exceeded the crustal abundance suggesting sources other than natural in origin. Additionally, the trace metals profile may be a reflection of socio-economic development in the vicinity of Sundarban which further attributes trace metals abundance to the anthropogenic inputs. Geoaccumulation index suggests moderately polluted sediment quality w.r.t. Ni and As and background concentrations for Al, Fe, Mn, Cu, Zn, Pb, Co, As and Cd. Contamination factor analysis suggested low contamination by Zn, Cr, Co and Cd, moderate by Fe, Mn, Cu and Pb while Ni and As show considerable and high contamination, respectively. Enrichment factors for Ni, Pb and As suggests high contamination from either biota or anthropogenic inputs besides natural enrichment. As per the three sediment quality guidelines, Fe, Mn, Cu, Ni, Co and As would be more of a concern with respect to ecotoxicological risk in the Sundarban mangroves. The correlation between various physiochemical variables and trace metals suggested significant role of fine grained particles (clay) in trace metal distribution whereas owing to low organic carbon content in the region the organic complexation may not be playing significant role in trace metal distribution in the Sundarban mangroves.

  5. Fraction-specific controls on the trace element distribution in iron formations : Implications for trace metal stable isotope proxies

    NARCIS (Netherlands)

    Oonk, Paul B.H.; Tsikos, Harilaos; Mason, Paul R.D.; Henkel, Susann; Staubwasser, Michael; Fryer, Lindi; Poulton, Simon W.; Williams, Helen M.

    2017-01-01

    Iron formations (IFs) are important geochemical repositories that provide constraints on atmospheric and ocean chemistry, prior to and during the onset of the Great Oxidation Event. Trace metal abundances and their Mo-Cr-U isotopic ratios have been widely used for investigating ocean redox processes

  6. Trace metals partitioning among different sedimentary mineral phases and the deposit-feeding polychaete Armandia brevis

    International Nuclear Information System (INIS)

    Díaz-de-Alba, Margarita; Huerta-Diaz, Miguel Angel; Delgadillo-Hinojosa, Francisco; Hare, Landis; Galindo-Riaño, M. Dolores; Siqueiros-Valencia, Arturo

    2016-01-01

    Trace metals (Cd, Co, Cu, Fe, Mn, Ni, Pb, Zn) were determined in two operationally defined fractions (HCl and pyrite) in sediments from Ensenada and El Sauzal harbors (Mexico). The HCl fraction had significantly higher metal concentrations relative to the pyrite fraction in both harbors, underlining the weak tendency of most trace metals to associate with pyrite. Exceptionally, Cu was highly pyritized, with degrees of trace metal pyritization (DTMP) > 80% in both harbors. Dissolved Fe flux measurements combined with solid phase Fe sulfide data indicated that 98 mt of Fe are precipitated as iron sulfides every year in Ensenada Harbor. These Fe sulfides (and associated trace metals) will remain preserved in the sediments, unless they are perturbed by dredging or sediment resuspension. Calculations indicate that dredging activities could export to the open ocean 0.20 ± 0.13 to (0.30 ± 0.56) × 10"3 mt of Cd and Cu, respectively, creating a potential threat to marine benthic organisms. Degrees of pyritization (DOP) values in Ensenada and El Sauzal harbors were relatively low (< 25%) while degrees of sulfidization (DOS) were high (~ 50%) because of the contribution of acid volatile sulfide. DOP values correlated with DTMP values (p ≤ 0.001), indicating that metals are gradually incorporated into pyrite as this mineral is formed. Significant correlations were also found between DTMP values and − log(K_s_p_(_M_e_S_)/K_s_p_(_p_y_r_)) for both harbors, indicating that incorporation of trace metals into the pyrite phase is a function of the solubility product of the corresponding metal sulfide. The order in which elements were pyritized in both harbors was Zn ≈ Mn < Fe < Cd ≈ Pb < Ni ≈ Co < < Cu. Lastly, a strong correlation (r"2 = 0.87, p < 0.01) was found between average reactive trace metal concentrations and metal concentrations measured in Armandia brevis (a deposit-feeding Opheliid polychaete), suggesting that these labile sedimentary metals are

  7. Trace metals partitioning among different sedimentary mineral phases and the deposit-feeding polychaete Armandia brevis

    Energy Technology Data Exchange (ETDEWEB)

    Díaz-de-Alba, Margarita [Department of Analytical Chemistry, Institute of Biomolecules (INBIO), Faculty of Sciences, CEI-MAR, University of Cadiz, Campus Rio S. Pedro, E-11510, Puerto Real, Cadiz (Spain); Huerta-Diaz, Miguel Angel, E-mail: huertam@uabc.edu.mx [Instituto de Investigaciones Oceanológicas, Universidad Autónoma de Baja California, Campus Ensenada, Km. 103 Carr. Tijuana-Ensenada, Ensenada 22800, Baja California (Mexico); Delgadillo-Hinojosa, Francisco [Instituto de Investigaciones Oceanológicas, Universidad Autónoma de Baja California, Campus Ensenada, Km. 103 Carr. Tijuana-Ensenada, Ensenada 22800, Baja California (Mexico); Hare, Landis [Centre Eau Terre Environnement, 490, rue de la Couronne, Québec, Québec G1K 9A9 (Canada); Galindo-Riaño, M. Dolores [Department of Analytical Chemistry, Institute of Biomolecules (INBIO), Faculty of Sciences, CEI-MAR, University of Cadiz, Campus Rio S. Pedro, E-11510, Puerto Real, Cadiz (Spain); Siqueiros-Valencia, Arturo [Instituto de Investigaciones Oceanológicas, Universidad Autónoma de Baja California, Campus Ensenada, Km. 103 Carr. Tijuana-Ensenada, Ensenada 22800, Baja California (Mexico)

    2016-02-01

    Trace metals (Cd, Co, Cu, Fe, Mn, Ni, Pb, Zn) were determined in two operationally defined fractions (HCl and pyrite) in sediments from Ensenada and El Sauzal harbors (Mexico). The HCl fraction had significantly higher metal concentrations relative to the pyrite fraction in both harbors, underlining the weak tendency of most trace metals to associate with pyrite. Exceptionally, Cu was highly pyritized, with degrees of trace metal pyritization (DTMP) > 80% in both harbors. Dissolved Fe flux measurements combined with solid phase Fe sulfide data indicated that 98 mt of Fe are precipitated as iron sulfides every year in Ensenada Harbor. These Fe sulfides (and associated trace metals) will remain preserved in the sediments, unless they are perturbed by dredging or sediment resuspension. Calculations indicate that dredging activities could export to the open ocean 0.20 ± 0.13 to (0.30 ± 0.56) × 10{sup 3} mt of Cd and Cu, respectively, creating a potential threat to marine benthic organisms. Degrees of pyritization (DOP) values in Ensenada and El Sauzal harbors were relatively low (< 25%) while degrees of sulfidization (DOS) were high (~ 50%) because of the contribution of acid volatile sulfide. DOP values correlated with DTMP values (p ≤ 0.001), indicating that metals are gradually incorporated into pyrite as this mineral is formed. Significant correlations were also found between DTMP values and − log(K{sub sp(MeS)}/K{sub sp(pyr)}) for both harbors, indicating that incorporation of trace metals into the pyrite phase is a function of the solubility product of the corresponding metal sulfide. The order in which elements were pyritized in both harbors was Zn ≈ Mn < Fe < Cd ≈ Pb < Ni ≈ Co < < Cu. Lastly, a strong correlation (r{sup 2} = 0.87, p < 0.01) was found between average reactive trace metal concentrations and metal concentrations measured in Armandia brevis (a deposit-feeding Opheliid polychaete), suggesting that these labile sedimentary metals are

  8. Temporal variability in trace metal solubility in a paddy soil not reflected in uptake by rice (Oryza sativa L.)

    NARCIS (Netherlands)

    Pan, Yunyu; Koopmans, Gerwin F.; Bonten, Luc T.C.; Song, Jing; Luo, Yongming; Temminghoff, Erwin J.M.; Comans, Rob N.J.

    2016-01-01

    Alternating flooding and drainage conditions have a strong influence on redox chemistry and the solubility of trace metals in paddy soils. However, current knowledge of how the effects of water management on trace metal solubility are linked to trace metal uptake by rice plants over time is still

  9. Quantification and localization of trace metals in natural plankton using a synchrotron x-ray fluorescence microprobe

    International Nuclear Information System (INIS)

    Twining, B. S.; Baines, S. B.; Fisher, N. S.; Jacobsen, C.; Maser, J.; State Univ. of New York at Stony Brook

    2003-01-01

    The accumulation of trace metals by planktonic protists influences the growth of primary producers, metal biogeochemical cycling, and metal bioaccumulation in aquatic food chains. Despite their importance, unequivocal measurements of trace element concentrations in individual plankton cells have not been possible to date. We have used the 2-ID-E side-branch hard x-ray microprobe at the Advanced Photon Source to measure trace elements in individual marine plankton cells. This microprobe employs zoneplate optics to produce the sub-micron spatial resolution and low background fluorescence required to produce trace element maps of planktonic protist cells ranging in size from 3 to >50 (micro)m. We have developed preservation, rinsing, and mounting protocols that remove most of the salt from our marine samples, thus simplifying the identification of unknown cells and reducing high Cl-related background fluorescence. We have also developed spectral modeling techniques that account for the frequent overlap of adjacent fluorescence peaks and non-uniform detector response. Finally, we have used parallel soft x-ray transmission and epifluorescence microscopy images to estimate C normalized trace element concentrations, identify functional cell types (e.g., photosynthetic vs. non-photosynthetic), and correlate cell structures with spatial patterns in trace element fluorescence

  10. Quantification and localization of trace metals in natural plancton using a synchrotron x-ray fluorescence microprobe.

    Energy Technology Data Exchange (ETDEWEB)

    Twining, B. S.; Baines, S. B.; Fisher, N. S.; Jacobsen, C.; Maser, J.; State Univ. of New York at Stony Brook

    2003-03-01

    The accumulation of trace metals by planktonic protists influences the growth of primary producers, metal biogeochemical cycling, and metal bioaccumulation in aquatic food chains. Despite their importance, unequivocal measurements of trace element concentrations in individual plankton cells have not been possible to date. We have used the 2-ID-E side-branch hard x-ray microprobe at the Advanced Photon Source to measure trace elements in individual marine plankton cells. This microprobe employs zoneplate optics to produce the sub-micron spatial resolution and low background fluorescence required to produce trace element maps of planktonic protist cells ranging in size from 3 to >50 {micro}m. We have developed preservation, rinsing, and mounting protocols that remove most of the salt from our marine samples, thus simplifying the identification of unknown cells and reducing high Cl-related background fluorescence. We have also developed spectral modeling techniques that account for the frequent overlap of adjacent fluorescence peaks and non-uniform detector response. Finally, we have used parallel soft x-ray transmission and epifluorescence microscopy images to estimate C normalized trace element concentrations, identify functional cell types (e.g., photosynthetic vs. non-photosynthetic), and correlate cell structures with spatial patterns in trace element fluorescence.

  11. Study of heavy trace metals in some medicinal-herbal plants of Pakistan

    International Nuclear Information System (INIS)

    Khattak, M.I.

    2011-01-01

    The paper presents heavy trace metals analysis in some widely used medicinal- herbal plants of Pakistan by using Inductively Coupled Plasma. Because these commonly used medicinal- herbal plants from Pakistan are being specifically utilized for the treatment of various diseases, so samples of medicinal-herbal plants were collected from open market and from the fields. Collected samples were digested and analyzed for their nutritional trace metals (Pb, Cd, Fe, Zn, Ni, Cu and Mn) composition and then the results obtained were compared to international and national standards as required by World Health Organizations. The deficiency or excess of the samples for essential trace metals are reported. (author)

  12. Contribution of trace metals in structuring in situ macroinvertebrate community composition along a salinity gradient

    NARCIS (Netherlands)

    Peeters, E.T.H.M.; Gardeniers, J.J.P.; Koelmans, A.A.

    2000-01-01

    Macroinvertebrates were studied along a salinity gradient in the North Sea Canal, The Netherlands, to quantify the effect of trace metals (cadmium, copper, lead, zinc) on community composition. In addition, two methods for assessing metal bioavailability (normalizing metal concentrations on organic

  13. On nutrients and trace metals: Effects from Enhanced Weathering

    Science.gov (United States)

    Amann, T.; Hartmann, J.

    2015-12-01

    The application of rock flour on suitable land ("Enhanced Weathering") is one proposed strategy to reduce the increase of atmospheric CO2 concentrations. At the same time it is an old and established method to add fertiliser and influence soil properties. Investigations of this method focused on the impact on the carbonate system, as well as on engineering aspects of a large-scale application, but potential side effects were never discussed quantitatively. We analysed about 120,000 geochemically characterised volcanic rock samples from the literature. Applying basic statistics, theoretical release rates of nutrients and potential contaminants by Enhanced Weathering were evaluated for typical rock types. Applied rock material can contain significant amounts of essential or beneficial nutrients (potassium, phosphorus, micronutrients). Their release can partly cover the demand of major crops like wheat, rice or corn, thereby increasing crop yield on degraded soils. However, the concentrations of considered elements are variable within a specific rock type, depending on the geological setting. High heavy metal concentrations are found in (ultra-) basic rocks, the class with the highest CO2 drawdown potential. More acidic rocks contain less or no critical amounts, but sequester less CO2. Findings show that the rock selection determines the capability to supply significant amounts of nutrients, which could partly substitute industrial mineral fertiliser usage. At the same time, the release of harmful trace element has to be considered. Through careful selection of regionally available rocks, benefits could be maximised and drawbacks reduced. The deployment of Enhanced Weathering to sequester CO2 and to ameliorate soils necessitates an ecosystem management, considering the release and fate of weathered elements in plants, soils and water. Cropland with degraded soils would benefit while having a net negative CO2 effect, while other carbon dioxide removal strategies, like

  14. Interpretation of aerosol trace metal particle size distributions

    International Nuclear Information System (INIS)

    Johansson, T.B.; Van Grieken, R.E.; Winchester, J.W.

    1974-01-01

    Proton-induced X-ray emission (PIXE) analysis is capable of rapid routine determination of 10--15 elements present in amounts greater than or equal to 1 ng simultaneously in aerosol size fractions as collected by single orifice impactors over short periods of time. This enables detailed study of complex relationships between elements detected. Since absolute elemental concentrations may be strongly influenced by meteorological and topographical conditions, it is useful to normalize to a reference element. Comparison between the ratios of concentrations with aerosol and corresponding values for anticipated sources may lead to the identification of important sources for the elements. Further geochemical insights may be found through linear correlation coefficients, regression analysis, and cluster analysis. By calculating correlations for elemental pairs, an indication of the degree of covariance between the elements is obtained. Preliminary results indicate that correlations may be particle size dependent. A high degree of covariance may be caused either by a common source or may only reflect the conservative nature of the aerosol. In a regression analysis, by plotting elemental pairs and estimating the regression coefficients, we may be able to conclude if there is more than one source operating for a given element in a certain size range. Analysis of clustering of several elements, previously investigated for aerosol filter samples, can be applied to the analysis of aerosol size fractions. Careful statistical treatment of elemental concentrations as a function of aerosol particle size may thus yield significant information on the generation, transport and deposition of trace metals in the atmosphere

  15. Marine lake as in situ laboratory for studies of organic matter influence on speciation and distribution of trace metals

    Science.gov (United States)

    Mlakar, Marina; Fiket, Željka; Geček, Sunčana; Cukrov, Neven; Cuculić, Vlado

    2015-07-01

    Karst marine lakes are unique marine systems, also recognized as in situ "laboratories" in which geochemical processes on a different scale compared to the open sea, can be observed. In this study, organic matter cycle and its impact on distribution of trace metals in the marine lake Mir, located on Dugi Otok Island, in the central part of the eastern Adriatic Sea, was investigated for the first time. Studied marine lake is small, isolated, shallow basin, with limited communication with the open sea. Intense spatial and seasonal variations of organic matter, dissolved and particulate (DOC, POC), and dissolved trace metals concentrations in the water column of the Lake are governed predominantly by natural processes. Enhanced oxygen consumption in the Lake during summer season, high DOC and POC concentrations and low redox potential result in occasional occurrence of anoxic conditions in the bottom layers with appearance of sulfur species. Speciation modeling showed that dissolved trace metals Cu, Pb and Zn, are mostly bound to organic matter, while Cd, Co and Ni are present predominantly as free ions and inorganic complexes. Trace metals removal from the water column and their retention in the sediment was found to depend on the nature of the relationship between specific metal and organic or inorganic phases, sulfides, Fe-oxyhydroxydes or biogenic calcite. The above is reflected in the composition of the sediments, which are, in addition to influence of karstic background and bathymetry of the basin, significantly affected by accumulation of detritus at the bottom of the Lake.

  16. Reduced-Order Model for the Geochemical Impacts of Carbon Dioxide, Brine and Trace Metal Leakage into an Unconfined, Oxidizing Carbonate Aquifer, Version 2.1

    Energy Technology Data Exchange (ETDEWEB)

    Bacon, Diana H.

    2013-03-31

    The National Risk Assessment Partnership (NRAP) consists of 5 U.S DOE national laboratories collaborating to develop a framework for predicting the risks associated with carbon sequestration. The approach taken by NRAP is to divide the system into components, including injection target reservoirs, wellbores, natural pathways including faults and fractures, groundwater and the atmosphere. Next, develop a detailed, physics and chemistry-based model of each component. Using the results of the detailed models, develop efficient, simplified models, termed reduced order models (ROM) for each component. Finally, integrate the component ROMs into a system model that calculates risk profiles for the site. This report details the development of the Groundwater Geochemistry ROM for the Edwards Aquifer at PNNL. The Groundwater Geochemistry ROM for the Edwards Aquifer uses a Wellbore Leakage ROM developed at LANL as input. The detailed model, using the STOMP simulator, covers a 5x8 km area of the Edwards Aquifer near San Antonio, Texas. The model includes heterogeneous hydraulic properties, and equilibrium, kinetic and sorption reactions between groundwater, leaked CO2 gas, brine, and the aquifer carbonate and clay minerals. Latin Hypercube sampling was used to generate 1024 samples of input parameters. For each of these input samples, the STOMP simulator was used to predict the flux of CO2 to the atmosphere, and the volume, length and width of the aquifer where pH was less than the MCL standard, and TDS, arsenic, cadmium and lead exceeded MCL standards. In order to decouple the Wellbore Leakage ROM from the Groundwater Geochemistry ROM, the response surface was transformed to replace Wellbore Leakage ROM input parameters with instantaneous and cumulative CO2 and brine leakage rates. The most sensitive parameters proved to be the CO2 and brine leakage rates from the well, with equilibrium coefficients for calcite and dolomite, as well as the number of illite and kaolinite

  17. Process modeling for Humanities: tracing and analyzing scientific processes

    OpenAIRE

    Hug , Charlotte; Salinesi , Camille; Deneckere , Rebecca; Lamasse , Stéphane

    2011-01-01

    International audience; This paper concerns epistemology and the understanding of research processes in Humanities, such as Archaeology. We believe that to properly understand research processes, it is essential to trace them. The collected traces depend on the process model established, which has to be as accurate as possible to exhaustively record the traces. In this paper, we briefly explain why the existing process models for Humanities are not sufficient to represent traces. We then pres...

  18. Terrestrial sedimentary pyrites as a potential source of trace metal release to groundwater – A case study from the Emsland, Germany

    International Nuclear Information System (INIS)

    Houben, Georg J.; Sitnikova, Maria A.; Post, Vincent E.A.

    2017-01-01

    Pyrite is a common minor constituent of terrestrial freshwater sediments and a sink for trace elements. Different amounts and morphological types (framboids and euhedral crystals) of sedimentary pyrites were found in the heavy mineral fraction of cores obtained from several drillholes located in the Emsland region, NW Germany. Their trace element contents were investigated to assess their potential for groundwater contamination after oxidation, e.g. induced by dewatering or autotrophic denitrification. Nickel, arsenic and cadmium were found in significant concentrations in pyrite. Geochemical modeling showed that elevated trace metal concentrations in groundwater, potentially exceeding drinking water standards, should preferentially occur in a less than 1 m thick zone situated around the depth of the redoxcline, where nitrate is reduced by pyrite. This was confirmed by depth-specific groundwater sampling in the Emsland and by previously published studies. The absolute concentration of released trace metals depends on their content in the pyrite but also strongly on the nitrate load of groundwater. - Highlights: • Pyrite from heavy mineral fraction of aquifer sediment analyzed for trace metal content. • Pyrites contain significant concentration of trace metals, such as nickel, arsenic, cadmium. • Trace elements are released by autotrophic denitrification. • Reactive transport model predicts small zone of trace element accumulation. • Release of trace elements strongly dependent on nitrate content of groundwater.

  19. Variation in levels and removal efficiency of heavy and trace metals ...

    African Journals Online (AJOL)

    CPUT

    trace metals from wastewater treatment plant effluents in Cape Town and .... Geographical locations and design .... The new. Bellville plant uses University of Cape Town design (UCT) ...... batteries, paints, fungicides, textiles, cosmetics, pulp,.

  20. Guidelines for the determination of selected trace metals in aerosols and in wet precipitation

    International Nuclear Information System (INIS)

    1988-01-01

    This publication describes sampling and analytical procedures suitable for the collection and analysis of representative samples of atmospheric aerosols and wet precipitation for selected trace metals. 11 refs, 2 tabs

  1. Statistical significance of biomonitoring of marine algae for trace metal levels in a coral environment

    Digital Repository Service at National Institute of Oceanography (India)

    Gopinath, A.; Muraleedharan, N.S.; Chandramohanakumar, N.; Jayalakshmy, K.V.

    towards essential elements, and the concentration of Fe seemed to be the highest in all the species, irrespective of their classification. The trace metal content reported in this study was much lower than the limit prescribed by Food and Agricultural...

  2. TRACE ELEMENT CHEMISTRY IN RESIDUAL-TREATED SOIL: KEY CONCEPTS AND METAL BIOAVAILABILITY

    Science.gov (United States)

    Trace element solubility and availability in land-applied residuals is governed by fundamental chemical reactions between metal constituents, soil, and residual components. Iron, aluminum, and manganese oxides; organic matter; and phosphates, carbonates, and sulfides are importan...

  3. Trace Metal and Ancillary Data in Puget Sound, 1980 - 1986 (NODC Accession 9100153)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — In first of three data reports on the trace metal and ancillary data in Puget Sound and its watershed (Paulson et al., 1991a), all water column, sediment, and...

  4. Impact of trace metal concentrations on coccolithophore growth and morphology: laboratory simulations of Cretaceous stress

    Science.gov (United States)

    Faucher, Giulia; Hoffmann, Linn; Bach, Lennart T.; Bottini, Cinzia; Erba, Elisabetta; Riebesell, Ulf

    2017-07-01

    The Cretaceous ocean witnessed intervals of profound perturbations such as volcanic input of large amounts of CO2, anoxia, eutrophication and introduction of biologically relevant metals. Some of these extreme events were characterized by size reduction and/or morphological changes of a few calcareous nannofossil species. The correspondence between intervals of high trace metal concentrations and coccolith dwarfism suggests a negative effect of these elements on nannoplankton biocalcification processes in past oceans. In order to test this hypothesis, we explored the potential effect of a mixture of trace metals on growth and morphology of four living coccolithophore species, namely Emiliania huxleyi, Gephyrocapsa oceanica, Pleurochrysis carterae and Coccolithus pelagicus. The phylogenetic history of coccolithophores shows that the selected living species are linked to Mesozoic species showing dwarfism under excess metal concentrations. The trace metals tested were chosen to simulate the environmental stress identified in the geological record and upon known trace metal interactions with living coccolithophore algae.Our laboratory experiments demonstrated that elevated trace metal concentrations, similarly to the fossil record, affect coccolithophore algae size and/or weight. Smaller coccoliths were detected in E. huxleyi and C. pelagicus, while coccoliths of G. oceanica showed a decrease in size only at the highest trace metal concentrations. P. carterae coccolith size was unresponsive to changing trace metal concentrations. These differences among species allow discriminating the most- (P. carterae), intermediate- (E. huxleyi and G. oceanica) and least-tolerant (C. pelagicus) taxa. The fossil record and the experimental results converge on a selective response of coccolithophores to metal availability.These species-specific differences must be considered before morphological features of coccoliths are used to reconstruct paleo-chemical conditions.

  5. Impact of trace metal concentrations on coccolithophore growth and morphology: laboratory simulations of Cretaceous stress

    Directory of Open Access Journals (Sweden)

    G. Faucher

    2017-07-01

    Full Text Available The Cretaceous ocean witnessed intervals of profound perturbations such as volcanic input of large amounts of CO2, anoxia, eutrophication and introduction of biologically relevant metals. Some of these extreme events were characterized by size reduction and/or morphological changes of a few calcareous nannofossil species. The correspondence between intervals of high trace metal concentrations and coccolith dwarfism suggests a negative effect of these elements on nannoplankton biocalcification processes in past oceans. In order to test this hypothesis, we explored the potential effect of a mixture of trace metals on growth and morphology of four living coccolithophore species, namely Emiliania huxleyi, Gephyrocapsa oceanica, Pleurochrysis carterae and Coccolithus pelagicus. The phylogenetic history of coccolithophores shows that the selected living species are linked to Mesozoic species showing dwarfism under excess metal concentrations. The trace metals tested were chosen to simulate the environmental stress identified in the geological record and upon known trace metal interactions with living coccolithophore algae.Our laboratory experiments demonstrated that elevated trace metal concentrations, similarly to the fossil record, affect coccolithophore algae size and/or weight. Smaller coccoliths were detected in E. huxleyi and C. pelagicus, while coccoliths of G. oceanica showed a decrease in size only at the highest trace metal concentrations. P. carterae coccolith size was unresponsive to changing trace metal concentrations. These differences among species allow discriminating the most- (P. carterae, intermediate- (E. huxleyi and G. oceanica and least-tolerant (C. pelagicus taxa. The fossil record and the experimental results converge on a selective response of coccolithophores to metal availability.These species-specific differences must be considered before morphological features of coccoliths are used to reconstruct paleo-chemical conditions.

  6. Effects of trace metal concentrations on the growth of the coral endosymbiont Symbiodinium kawagutii

    Directory of Open Access Journals (Sweden)

    Irene Barra Rodriguez

    2016-02-01

    Full Text Available Symbiodinium is an indispensable endosymbiont in corals and the most important primary producer in coral reef ecosystems. During the past decades, coral bleaching attributed to the disruption of the symbiosis has frequently occurred resulting in reduction of coral reef coverage globally. Growth and proliferation of corals require some specific trace metals that are essential components of pertinent biochemical processes, such as in photosynthetic systems and electron transport chains. In addition, trace metals are vital in the survival of corals against oxidative stress because these metals serve as enzymatic cofactors in antioxidative defense mechanisms. The basic knowledge about trace metal requirement of Symbiodinium is lacking. Here we show that the requirement of S. kawagutii for antioxidant-associated trace metals exhibits the following order: Fe >> Cu/Zn/Mn >> Ni. In growth media with Cu, Zn, Mn and varying Fe concentrations, we observed that Cu, Zn and Mn cellular quotas were inversely related to Fe concentrations. In the absence of Cu, Zn and Mn, growth rates increased with increasing inorganic Fe concentrations up to 1250 pM, indicating the relatively high Fe requirement for Symbiodinium growth and potential functional complementarity of these metals. These results demonstrate the relative importance of trace metals to sustain Symbiodinium growth and a potential metal interreplacement strategy in Symbiodinium to ensure survival of coral reefs in an oligotrophic and stressful environment.

  7. Vertical and horizontal fluxes of selected radionuclides and trace metals off the coast of southern California

    International Nuclear Information System (INIS)

    Huh, C.-A.

    1990-01-01

    The overall objective of our research, within the structure of the CaBS program, is to understand the transport pathways and mass balances of some metabolically-active and inactive chemical species in the Santa Monica/San Pedro (SM/SP) Basin. Our focus is to examine selected trace metals and radionuclides in seawater, sediment trap material, and bottom sediments. Knowledge of the inventories, fluxes, and routes of these nuclides and metals in or among these reservoirs should lead to a cogent model for these elements in SM/SP Basin, which in turn should shed light on the fate and effects of energy-related by-products in a coastal region impacted by intense human activities. 4 figs., 3 tabs

  8. Facilitation drives the positive effects of plant richness on trace metal removal in a biodiversity experiment.

    Directory of Open Access Journals (Sweden)

    Jiang Wang

    Full Text Available BACKGROUND: Phytoextraction is an environmentally acceptable and inexpensive technique for mine tailing rehabilitation that uses metallophyte plants. These plants reduce the soil trace metal contents to environmentally acceptable levels by accumulating trace metals. Recently, whether more trace metals can be removed by species-rich communities of these plants received great attention, as species richness has been reported having positive effects on ecosystem functions. However, how the species richness affects trace metals removal of plant communities of mine tailing is rarely known. METHODOLOGY/PRINCIPAL FINDINGS: We examined the effects of species richness on soil trace metal removal in both natural and experimental plant communities. The root lengths and stem heights of each plant species were measured in order to calculate the functional diversity indices. Our results showed that trace metal (Cu, Cd, Pb and Zn concentrations in mine tailing soil declined as species richness increased in both the natural and experimental plant communities. Species richness, rather than functional diversity, positively affected the mineralomass of the experimental plant communities. The intensity of plant-plant facilitation increased with the species richness of experimental communities. Due to the incremental role of plant-plant facilitation, most of the species had higher biomasses, higher trace metal concentrations in their plant tissues and lower malondialdehyde concentrations in their leaves. Consequently, the positive effects of species richness on mineralomass were mostly attributable to facilitation among plants. CONCLUSIONS/SIGNIFICANCE: Our results provide clear evidence that, due to plant-plant facilitation, species richness positively affects the removal of trace metals from mine tailing soil through phytoextraction and provides further information on diversity conservation and environmental remediation in a mine tailing environment.

  9. Modified interstitial water squeezer for trace metal analysis

    Digital Repository Service at National Institute of Oceanography (India)

    Nath, B.N.; Rajaraman, V.S.; Mudholkar, A.V.

    Hydraulic squeezer of Manheim, used in the extraction of pore water of sediments, has been modified by providing teflon inner lining and increasing the volume of squeezer. The modified version facilitates collection of pore water sample, for trace...

  10. Metallic glasses: structural models

    International Nuclear Information System (INIS)

    Nassif, E.

    1984-01-01

    The aim of this work is to give a summary of the attempts made up to the present in order to discribe by structural models the atomic arrangement in metallic glasses, showing also why the structure factors and atomic distribution functions cannot be always experimentally determined with a reasonable accuracy. (M.W.O.) [pt

  11. The Little Penguin (Eudyptula minor) as an indicator of coastal trace metal pollution

    International Nuclear Information System (INIS)

    Finger, Annett; Lavers, Jennifer L.; Dann, Peter; Nugegoda, Dayanthi; Orbell, John D.; Robertson, Bruce; Scarpaci, Carol

    2015-01-01

    Monitoring trace metal and metalloid concentrations in marine animals is important for their conservation and could also reliably reflect pollution levels in their marine ecosystems. Concentrations vary across tissue types, with implications for reliable monitoring. We sampled blood and moulted feathers of the Little Penguin (Eudyptula minor) from three distinct colonies, which are subject to varying levels of anthropogenic impact. Non-essential trace metal and metalloid concentrations in Little Penguins were clearly linked to the level of industrialisation adjacent to the respective foraging zones. This trend was more distinct in blood than in moulted feathers, although we found a clear correlation between blood and feathers for mercury, lead and iron. This study represents the first reported examination of trace metals and metalloids in the blood of any penguin species and demonstrates that this high trophic feeder is an effective bioindicator of coastal pollution. - Highlights: • Trace metals measured in blood and feathers. • Arsenic, Mercury and Lead significantly higher at urban colony. • Correlations found between trace metals in feathers and blood. • Little Penguins are suitable bioindicators for coastal metal pollution. - This study confirms the suitability of the Little Penguin as a bioindicator of coastal metal pollution in coastal areas using non-destructive sampling methods

  12. Distributions of traces of metals on sorption from solutions of vanadium(V)

    International Nuclear Information System (INIS)

    Evseeva, N.K.; Turnaov, A.N.; Telegin, G.F.; Kremenskaya, I.N.

    1983-01-01

    A study is made of the distributions of traces of metals between aqueous solutions of vanadium(V) and a solid reagent made by introducing di-2-ethylhexylphosphoric acid into an inert matrix: a nonionic macroporous copolymer of polystyrene with divinyl benzene (wofatit Y 29). As regards degree of extraction, the trace components fall in the series zinc > cadmium > manganese > copper > cobalt, which resemble the extractability series. The vanadium content of the solution and the concentrations of the trace components have virtually no effect on the sorption. The process is effective in concentrating trace components from solutions containing vanadium(V)

  13. The importance of biomass net uptake for a trace metal budget in a forest stand in north-eastern France

    International Nuclear Information System (INIS)

    Gandois, L.; Nicolas, M.; VanderHeijden, G.; Probst, A.

    2010-01-01

    The trace metal (TM: Cd, Cu, Ni, Pb and Zn) budget (stocks and annual fluxes) was evaluated in a forest stand (silver fir, Abies alba Miller) in north-eastern France. Trace metal concentrations were measured in different tree compartments in order to assess TM partitioning and dynamics in the trees. Inputs included bulk deposition, estimated dry deposition and weathering. Outputs were leaching and biomass exportation. Atmospheric deposition was the main input flux. The estimated dry deposition accounted for about 40% of the total trace metal deposition. The relative importance of leaching (estimated by a lumped parameter water balance model, BILJOU) and net biomass uptake (harvesting) for ecosystem exportation depended on the element. Trace metal distribution between tree compartments (stem wood and bark, branches and needles) indicated that Pb was mainly stored in the stem, whereas Zn and Ni, and to a lesser extent Cd and Cu, were translocated to aerial parts of the trees and cycled in the ecosystem. For Zn and Ni, leaching was the main output flux (> 95% of the total output) and the plot budget (input-output) was negative, whereas for Pb the biomass net exportation represented 60% of the outputs and the budget was balanced. Cadmium and Cu had intermediate behaviours, with 18% and 30% of the total output relative to biomass exportation, respectively, and the budgets were negative. The net uptake by biomass was particularly important for Pb budgets, less so for Cd and Cu and not very important for Zn and Ni in such forest stands.

  14. Trace metal pyritization variability in response to mangrove soil aerobic and anaerobic oxidation processes.

    Science.gov (United States)

    Machado, W; Borrelli, N L; Ferreira, T O; Marques, A G B; Osterrieth, M; Guizan, C

    2014-02-15

    The degree of iron pyritization (DOP) and degree of trace metal pyritization (DTMP) were evaluated in mangrove soil profiles from an estuarine area located in Rio de Janeiro (SE Brazil). The soil pH was negatively correlated with redox potential (Eh) and positively correlated with DOP and DTMP of some elements (Mn, Cu and Pb), suggesting that pyrite oxidation generated acidity and can affect the importance of pyrite as a trace metal-binding phase, mainly in response to spatial variability in tidal flooding. Besides these aerobic oxidation effects, results from a sequential extraction analyses of reactive phases evidenced that Mn oxidized phase consumption in reaction with pyrite can be also important to determine the pyritization of trace elements. Cumulative effects of these aerobic and anaerobic oxidation processes were evidenced as factors affecting the capacity of mangrove soils to act as a sink for trace metals through pyritization processes. Copyright © 2013 Elsevier Ltd. All rights reserved.

  15. Spatial distribution of trace metals in water resources impacted by PGM activities

    CSIR Research Space (South Africa)

    Walters, Chavon R

    2012-05-01

    Full Text Available the aquatic environment from natural and anthropogenic sources (such as industrial effluents and mining wastes). Trace metals can accumulate in fish (which are often at the top of the aquatic food chain) either through water or the food chain (1), and metals...

  16. Use and abuse of trace metal concentrations in plant tissue for biomonitoring and phytoextraction

    International Nuclear Information System (INIS)

    Mertens, Jan; Luyssaert, Sebastiaan; Verheyen, Kris

    2005-01-01

    Some plant species accumulate trace metals from the soil in their aboveground biomass. Therefore, some scientists have concluded that these species are suitable for biomonitoring trace metal concentrations in the soil or for removing excessive trace metals from the soil by means of phytoextraction. A significant correlation between the chemical composition of foliage and soil is not a sufficient condition for using the chemical composition of foliage as a biomonitor for the quality of the soil. The chemical composition of foliage can, however, provide additional information to the traditional soil samples. The phytoextraction potential of a plant species cannot solely be evaluated on the basis of the trace metal concentrations in the plant and soil tissue. Data on the depth of the rooting zone, the density of the soil and the harvestable biomass should also be taken into account. Although plant tissue analysis is a useful tool in a wide range of studies and applications, trace metal concentrations in plant tissue cannot be viewed in isolation. Instead it should be analysed and interpreted in relation to other information such as soil concentrations, rooted zone, biomass production, etc. - Plants that accumulate soil metals in their aboveground biomass are often incorrectly considered to be suitable for monitoring soil pollution or for phytoextraction purposes

  17. Temporal variability in trace metal solubility in a paddy soil not reflected in uptake by rice (Oryza sativa L.).

    Science.gov (United States)

    Pan, Yunyu; Koopmans, Gerwin F; Bonten, Luc T C; Song, Jing; Luo, Yongming; Temminghoff, Erwin J M; Comans, Rob N J

    2016-12-01

    Alternating flooding and drainage conditions have a strong influence on redox chemistry and the solubility of trace metals in paddy soils. However, current knowledge of how the effects of water management on trace metal solubility are linked to trace metal uptake by rice plants over time is still limited. Here, a field-contaminated paddy soil was subjected to two flooding and drainage cycles in a pot experiment with two rice plant cultivars, exhibiting either high or low Cd accumulation characteristics. Flooding led to a strong vertical gradient in the redox potential (Eh). The pH and Mn, Fe, and dissolved organic carbon concentrations increased with decreasing Eh and vice versa. During flooding, trace metal solubility decreased markedly, probably due to sulfide mineral precipitation. Despite its low solubility, the Cd content in rice grains exceeded the food quality standards for both cultivars. Trace metal contents in different rice plant tissues (roots, stem, and leaves) increased at a constant rate during the first flooding and drainage cycle but decreased after reaching a maximum during the second cycle. As such, the high temporal variability in trace metal solubility was not reflected in trace metal uptake by rice plants over time. This might be due to the presence of aerobic conditions and a consequent higher trace metal solubility near the root surface, even during flooding. Trace metal solubility in the rhizosphere should be considered when linking water management to trace metal uptake by rice over time.

  18. Octanol-solubility of dissolved and particulate trace metals in contaminated rivers: implications for metal reactivity and availability

    Energy Technology Data Exchange (ETDEWEB)

    Turner, Andrew [School of Earth, Ocean and Environmental Sciences, University of Plymouth, Drake Circus, Plymouth PL4 8AA (United Kingdom)]. E-mail: aturner@plymouth.ac.uk; Mawji, Edward [School of Earth, Ocean and Environmental Sciences, University of Plymouth, Drake Circus, Plymouth PL4 8AA (United Kingdom)

    2005-05-01

    The lipid-like, amphiphilic solvent, n-octanol, has been used to determine a hydrophobic fraction of dissolved and particulate trace metals (Al, Cd, Co, Cu, Mn, Ni, Pb, Zn) in contaminated rivers. In a sample from the River Clyde, southwest Scotland, octanol-solubility was detected for all dissolved metals except Co, with conditional octanol-water partition coefficients, D{sub ow}, ranging from about 0.2 (Al and Cu) to 1.25 (Pb). In a sample taken from the River Mersey, northwest England, octanol-solubility was detected for dissolved Al and Pb, but only after sample aliquots had been spiked with individual ionic metal standards and equilibrated. Spiking of the River Clyde sample revealed competition among different metals for hydrophobic ligands. Metal displacement from hydrophobic complexes was generally most significant following the addition of ionic Al or Pb, although the addition of either of these metals had little effect on the octanol-solubility of the other. In both river water samples hydrophobic metals were detected on the suspended particles retained by filtration following their extraction in n-octanol. In general, particulate Cu and Zn (up to 40%) were most available, and Al, Co and Pb most resistant (<1%) to octanol extraction. Distribution coefficients defining the concentration ratio of octanol-soluble particle-bound metal to octanol-soluble dissolved metal were in the range 10{sup 3.3}-10{sup 5.3} ml g{sup -1}. The presence of hydrophobic dissolved and particulate metal species has implications for our understanding of the biogeochemical behaviour of metals in aquatic environments. Specifically, such species are predicted to exhibit characteristics of non-polar organic contaminants, including the potential to penetrate the lipid bilayer. Current strategies for assessing the bioavailability and toxicity of dissolved and particulate trace metals in natural waters may, therefore, require revision. - New approaches are presented for fractionating

  19. Leveraging First Response Time into the Knowledge Tracing Model

    Science.gov (United States)

    Wang, Yutao; Heffernan, Neil T.

    2012-01-01

    The field of educational data mining has been using the Knowledge Tracing model, which only look at the correctness of student first response, for tracking student knowledge. Recently, lots of other features are studied to extend the Knowledge Tracing model to better model student knowledge. The goal of this paper is to analyze whether or not the…

  20. TraceLink: A model of amnesia and consolidation.

    NARCIS (Netherlands)

    Meeter, M.; Murre, J.M.J.

    2005-01-01

    A connectionist model is presented, the TraceLink model, that implements an autonomous "off-line" consolidation process. The model consists of three subsystems: (1) a trace system (neocortex), (2) a link system (hippocampus and adjacent regions), and (3) a modulatory system (basal forebrain and

  1. Trace metals concentration assessment in urban particulate matter ...

    African Journals Online (AJOL)

    This study was conducted to investigate the distribution and correlation of selected trace elements (Ca, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, and Zn) in Yenagoa, Bayelsa State and its environs. Air particulate matter was collected gravimetrically at five stations (using a high volume portable SKC air check MTXSidekickair sampler ...

  2. Trace metal characterization and speciation in geothermal effluent by multiple scanning anodic stripping voltammetry and atomic absorption analysis

    Energy Technology Data Exchange (ETDEWEB)

    Kowalski, B.R.

    1979-05-25

    Recent studies have shown geothermal power plants to have a significant environmental impact on the ground water of the area. The heavy metals arsenic and mercury are special problems, as both are concentrated by flora and fauna exposed to the effluent waters. Because the toxicity of these and other metallic pollutants present in geothermal effluent depends on the chemical form, or speciation, of the particular metal, any serious study of the environmental impact of a geothermal development should include studies of trace metal speciation, in addition to trace metal concentration. This proposal details a method for determining metal speciation in dilute waters. The method is based on ion-exchange and backed by atomic absorption spectrometry and multiple scanning anodic stripping voltammetry. Special laboratory studies will be performed on mercury, arsenic and selenium speciation in synthetic geothermal water. The method will be applied to three known geothermal areas in Washington and Oregon, with emphasis on the speciation of mercury, arsenic and selenium in these waters. The computer controlled electrochemical instrumentation was built and tested. Using this instrumentation, a new experimental procedure was developed to determine the chemical form (speciation) of metal ions in very dilute solutions (ng/ml). This method was tested on model systems including Pb, Cd, and As with C1/sup -/, CO/sub 3//sup 2 -/ and glycine ligands. Finally, the speciation of lead in a geothermal water was examined and the PbC1/sup +/ complex was observed and quantified.

  3. Evaluation of Heavy and Trace Metals in Fingernails of Young ...

    African Journals Online (AJOL)

    WAHAB

    These elements have been produced by alteration and distribution via wind blow. The result indicates that soil or road dust plays an important role in the concentration buildup of the road side dust near automobile workshops. Table 2: Concentration of heavy metals in the soil samples in the automobile workshop. Metals.

  4. Assessment of trace metal contamination of soils around Oluyole ...

    African Journals Online (AJOL)

    This study was carried out to determine the level of metals contamination of the soils around Oluyole industrial estate in Ibadan. Oluyole industrial estate has heavy concentration of manufacturing industries that generate a lot of waste products capable of introducing metals into the environment. Consequently, twenty-one ...

  5. Tracing heavy metals in 'swine manure - maggot - chicken' production chain.

    Science.gov (United States)

    Wang, Wanqiang; Zhang, Wenjuan; Wang, Xiaoping; Lei, Chaoliang; Tang, Rui; Zhang, Feng; Yang, Qizhi; Zhu, Fen

    2017-08-21

    With the development of large-scale livestock farming, manure pollution has drawn much attention. Conversion by insects is a rapid and cost-effective new method for manure management. Swine manure conversion with maggots (Musca domestica larvae) has developed, and the harvested maggots are often used as animal feed. However, the flow of heavy metals from manure to downstream processes cannot be ignored, and therefore, heavy metal content was measured in untreated raw manure, maggot-treated manure, harvested maggots and maggot-eating chickens (chest muscle and liver) to evaluate potential heavy metal risks. The levels of zinc, copper, chromium, selenium, cadmium and lead had significant differences between untreated raw manure and maggot-treated manure. The concentrations of all detected heavy metals, except for cadmium and selenium, in maggots met the limits established by the feed or feed additive standards of many countries. The bioaccumulation factor (BAF) of heavy metals decreased with the increase of the maggot instar, indicating that heavy metals were discharged from the bodies of maggots with the growth of maggots. Also, the contents of overall heavy metals in chickens fed harvested maggots met the standards for food. In conclusion, regarding heavy metals, it is eco-safe to use maggots in manure management.

  6. Assessment of trace metals contamination of soils around some ...

    African Journals Online (AJOL)

    This study was carried out to determine the level of soil contamination by metals around some automobile mechanic workshops in Oyo town in order to assess their possible adverse health implications on man and his environment. Concentrations of metals above certain levels have been shown to impair man's health.

  7. Past 140-year environmental record in the northern South China Sea: Evidence from coral skeletal trace metal variations

    International Nuclear Information System (INIS)

    Song, Yinxian; Yu, Kefu; Zhao, Jianxin; Feng, Yuexing; Shi, Qi; Zhang, Huiling; Ayoko, Godwin A.; Frost, Ray L.

    2014-01-01

    About 140-year changes in the trace metals in Porites coral samples from two locations in the northern South China Sea were investigated. Results of PCA analyses suggest that near the coast, terrestrial input impacted behavior of trace metals by 28.4%, impact of Sea Surface Temperature (SST) was 19.0%, contribution of war and infrastructure were 14.4% and 15.6% respectively. But for a location in the open sea, contribution of War and SST reached 33.2% and 16.5%, while activities of infrastructure and guano exploration reached 13.2% and 14.7%. While the spatiotemporal change model of Cu, Cd and Pb in seawater of the north area of South China Sea during 1986–1997 were reconstructed. It was found that in the sea area Cu and Cd contaminations were distributed near the coast while areas around Sanya, Hainan had high Pb levels because of the well-developed tourism related activities. -- Highlights: • Geochemical behaviors of trace elements in corals from South China Sea were investigated. • Terrestrial input, SST, war and infrastructure explain about 77.4% of elements behaviors in coral. • Changes of trace elements in coral of Xisha Islands were mainly impacted by local activities. • Spatial change of elements in seawater by was evaluated in 1986–1997 using distribution coefficient K D of coral. -- 140-year changes in the trace metals in corals from South China Sea were investigated. The spatiotemporal change model of the metals in seawater was reconstructed using coral record

  8. Composition of Trace Metals in Dust Samples Collected from Selected High Schools in Pretoria, South Africa

    Directory of Open Access Journals (Sweden)

    J. O. Olowoyo

    2016-01-01

    Full Text Available Potential health risks associated with trace metal pollution have necessitated the importance of monitoring their levels in the environment. The present study investigated the concentrations and compositions of trace metals in dust samples collected from classrooms and playing ground from the selected high schools In Pretoria. Schools were selected from Pretoria based on factors such as proximity to high traffic ways, industrial areas, and residential areas. Thirty-two dust samples were collected from inside and outside the classrooms, where learners often stay during recess period. The dust samples were analysed for trace metal concentrations using Inductively Coupled Plasma-Mass Spectrometry (ICP-MS. The composition of the elements showed that the concentrations of Zn were more than all other elements except from one of the schools. There were significant differences in the concentrations of trace metals from the schools (p<0.05. Regular cleaning, proximity to busy road, and well maintained gardens seem to have positive effects on the concentrations of trace metals recorded from the classrooms dust. The result further revealed a positive correlation for elements such as Pb, Cu, Zn, Mn, and Sb, indicating that the dust might have a common source.

  9. N-myc oncogene amplification is correlated to trace metal concentrations in neuroblastoma cultured cells

    International Nuclear Information System (INIS)

    Gouget, B.; Sergeant, C.; Benard, J.; Llabador, Y.; Simonoff, M.

    2000-01-01

    N-myc oncogene amplification is a powerful predictor of aggressive behavior of neuroblastoma (NB), the most common solid tumor of the early childhood. Since N-myc overexpression - subsequent to amplification - determines a phenotype of invasiveness and metastatic spreading, it is assumed that N-myc amplified neuroblasts synthesize zinc metalloenzymes leading to tumor invasion and formation of metastases. In order to test a possible relation between N-myc oncogene amplification and trace metal contents in human NB cells, Fe, Cu and Zn concentrations have been measured by nuclear microprobe analysis in three human neuroblastoma cell lines with various degrees of N-myc amplification. Elemental determinations show uniform distribution of trace metals within the cells, but variations of intracellular trace metal concentrations with respect to the degree of N-myc amplification are highly dependent on the nature of the element. Zinc concentration is higher in both N-myc amplified cell lines (IMR-32 and IGR-N-91) than in the non-amplified cells (SK-N-SH). In contrast, intracellular iron content is particularly low in N-myc amplified cell lines. Moreover, copper concentrations showed an increase with the degree of N-myc amplification. These results indicate that a relationship exists between intracellular trace metals and N-myc oncogene amplification. They further suggest that trace metals very probably play a determinant role in mechanisms of the neuroblastoma invasiveness

  10. Trophic transfer of trace metals: Subcellular compartmentalization in a polychaete and assimilation by a decapod crustacean

    Science.gov (United States)

    Rainbow, P.S.; Poirier, L.; Smith, B.D.; Brix, K.V.; Luoma, S.N.

    2006-01-01

    The chemical form of accumulated trace metal in prey is important in controlling the bioavailataility of dietary metal to a predator. This study investigated the trophic transfer of radiolabelled Ag, Cd and Zn from the polychaete worm Nereis diversicolor to the decapod crustacean Palaemonetes varians. We used 2 populations of worms with different proportions of accumulated metals in different subcellular fractions as prey, and loaded the worms with radiolabelled metals either from sediment or from solution. Accumulated radiolabelled metals were fractionated into 5 components : metal-rich granules (MRG), cellular debris, organelles, metallothionein-like proteins (MTLP), and other (heat-sensitive) proteins (HSP). Assimilation efficiencies (AE) of the metals by P. varians were measured from the 4 categories of prey (i.e. 2 populations, radiolabelled from sediment or solution). There were significant differences for each metal between the AEs from the different prey categories, confirming that origin of prey and route of uptake of accumulated trace metal will cause intraspecific differences in subsequent metal assimilation. Correlations were sought between AEs and selected fractions or combinations of fractions of metals in the prey-MRG, Trophically Available Metal (TAM = MTLP + HSP + organelles) and total protein (MTLP + HSP). TAM explained 28% of the variance in AEs for Ag, but no consistent relationships emerged between AEs and TAM or total protein when the metals were considered separately. AEs did, however, show significant positive regressions with both TAM and total protein when the 3 metals were considered together, explaining only about 21 % of the variance in each case. A significant negative relationship was observed between MRG and AE for all metals combined. The predator (P. varians) can assimilate dietary metal from a range of the fractions binding metals in the prey (N. diversicolor), with different assimilation efficiencies summated across these

  11. Octanol-solubility of dissolved and particulate trace metals in contaminated rivers: implications for metal reactivity and availability

    International Nuclear Information System (INIS)

    Turner, Andrew; Mawji, Edward

    2005-01-01

    The lipid-like, amphiphilic solvent, n-octanol, has been used to determine a hydrophobic fraction of dissolved and particulate trace metals (Al, Cd, Co, Cu, Mn, Ni, Pb, Zn) in contaminated rivers. In a sample from the River Clyde, southwest Scotland, octanol-solubility was detected for all dissolved metals except Co, with conditional octanol-water partition coefficients, D ow , ranging from about 0.2 (Al and Cu) to 1.25 (Pb). In a sample taken from the River Mersey, northwest England, octanol-solubility was detected for dissolved Al and Pb, but only after sample aliquots had been spiked with individual ionic metal standards and equilibrated. Spiking of the River Clyde sample revealed competition among different metals for hydrophobic ligands. Metal displacement from hydrophobic complexes was generally most significant following the addition of ionic Al or Pb, although the addition of either of these metals had little effect on the octanol-solubility of the other. In both river water samples hydrophobic metals were detected on the suspended particles retained by filtration following their extraction in n-octanol. In general, particulate Cu and Zn (up to 40%) were most available, and Al, Co and Pb most resistant ( 3.3 -10 5.3 ml g -1 . The presence of hydrophobic dissolved and particulate metal species has implications for our understanding of the biogeochemical behaviour of metals in aquatic environments. Specifically, such species are predicted to exhibit characteristics of non-polar organic contaminants, including the potential to penetrate the lipid bilayer. Current strategies for assessing the bioavailability and toxicity of dissolved and particulate trace metals in natural waters may, therefore, require revision. - New approaches are presented for fractionating trace metals in natural waters

  12. DETERMINATION OF TRACE HEAVY METALS IN SOME TEXTILE ...

    African Journals Online (AJOL)

    a

    the environmental and industrial samples including textile products [1-5]. Textile is one of the ... Toxic and allergic metals including cadmium, copper, nickel, zinc, and chemicals like formaldehyde and chlorinated hydrocarbons can exist in ...

  13. 49 Trace Metals' Contamination of Stream Water and Irrigated Crop ...

    African Journals Online (AJOL)

    ABUBAKAR AHMED

    human consumption as they pose serious health risks due to contamination with the metals. For environmental ... mining activities, industrial and domestic effluents, urban ... drinking and bathing water, irrigation, food, fuel and energy.

  14. Levels and occupational health risk assessment of trace metals in ...

    African Journals Online (AJOL)

    JohnDOCTOR;OFFIONG, edu

    2015-04-01

    Apr 1, 2015 ... Edu Inam*, John B. Edet, and Nnanake-Abasi O. Offiong. Department of ... as they are difficult to metabolize (Pezzarossa et al.,. 2011). ... Metals from this source get leached into ..... Besnard E, Chenu C, Robert M (2001).

  15. Coagulation / flocculation process in the removal of trace metals ...

    African Journals Online (AJOL)

    DR. MIKE HORSFALL

    elements such as Cu, Zn, Ni and Cr, as well as ... solids, (2) separation of suspended solids by chemical ... Total Metal Concentration Of The Wastewater: The .... Copper adsorption by esterifies and unesterified fractions of sphagnum peat ...

  16. Trace metals in pelagic organisms from the Mediterranean Sea

    International Nuclear Information System (INIS)

    Fowler, S.W.; Oregioni, B.; LaRosa, J.

    1976-01-01

    As a result of current interest in heavy metal pollution in the marine environment much information is accruing on the present levels of metals in certain marine species. By far the majority of the studies have involved elemental analysis of coastal organisms which are relatively easy to collect. However, due to inherent problems in sampling, far less information exists on element concentration in pelagic organisms, species which are important in terms of total marine biomass, their position in the food web, and their ability to concentrate and transport relatively large amounts of metals in various ways. Microplankton and larger zooplanktonic and nektonic species were sampled over a wide geographical range throughout the Mediterranean as well as along selected transects to assess possible gradients in metal concentrations in plankton communities

  17. assessment of trace metals contamination of soils around some ...

    African Journals Online (AJOL)

    ABSTRACT. This study was carried out to determine the level of soil contamination by metals around some automobile mechanic .... and this was done all through the sample preparation. ... shaking was done by a mechanical sieve shaker and.

  18. A dual-trace model for visual sensory memory.

    Science.gov (United States)

    Cappiello, Marcus; Zhang, Weiwei

    2016-11-01

    Visual sensory memory refers to a transient memory lingering briefly after the stimulus offset. Although previous literature suggests that visual sensory memory is supported by a fine-grained trace for continuous representation and a coarse-grained trace of categorical information, simultaneous separation and assessment of these traces can be difficult without a quantitative model. The present study used a continuous estimation procedure to test a novel mathematical model of the dual-trace hypothesis of visual sensory memory according to which visual sensory memory could be modeled as a mixture of 2 von Mises (2VM) distributions differing in standard deviation. When visual sensory memory and working memory (WM) for colors were distinguished using different experimental manipulations in the first 3 experiments, the 2VM model outperformed Zhang and Luck (2008) standard mixture model (SM) representing a mixture of a single memory trace and random guesses, even though SM outperformed 2VM for WM. Experiment 4 generalized 2VM's advantages of fitting visual sensory memory data over SM from color to orientation. Furthermore, a single trace model and 4 other alternative models were ruled out, suggesting the necessity and sufficiency of dual traces for visual sensory memory. Together these results support the dual-trace model of visual sensory memory and provide a preliminary inquiry into the nature of information loss from visual sensory memory to WM. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  19. Trace metal uptake by garden herbs and vegetables.

    Science.gov (United States)

    Shariatpanahi, M; Anderson, A C; Mather, F

    1986-12-01

    In many regions of Iran, crops are irrigated with municipal and industrial wastewater that contain a variety of metals. The purpose of this study was to simulate the level of metals that may be presented to plants over a growing season in a controlled laboratory setting. Cadmium, lead, arsenic, chromium, mercury, nickel, copper, zinc, and selenium were applied to plants at the high rate of 200 g metal/ha/wk. The following plants were examined for metal accumulation and effects on yield: garden cress (Lipidium sativum), leek (Allium porrum L.), basil (Ocimum basilicum L.), mint (Mentha arvensis L.), onion (Allium capa L.), radish (Raphanus sativus L.), and tarragon (Artemisia draculus L.). All plants showed significant uptake of all metals when compared to control (p=0.05), and growth was significantly reduced (p=0.05). Cadmium and chromium levels of 85±7.4 and 47.6±8.9 μg/g); selenium levels were highest in tarragon (16.5±5.8 μg/g). Zinc levels were similar (p=0.05) in all species tested, as were mercury and lead. The remaining metals (nickel and copper) showed significant differences in uptake, depending on plant species.

  20. Distribution of particulate trace metals in the western Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    Satyanarayana, D.; Murty, P.V.S.P.; Sarma, V.V.

    continuous increase from surface to bottom in the case ofFe, Ni, which appeared to be related to a combination offactors suchas authigenicprecipita tion/scavenging, rcsuspension of bottom rich sediments, and diffusion followed by precipitation at sedimcnt... ), most of these studies do not provide information onthe interaction of trace elements with particulate matter. The present study deals with the distribution of particulate trace metals (Fe, Mn, Co, Ni, Cu, Pb, Zn and Cd) and their possible interactions...

  1. The Determination of Uranium and Trace Metal Impurities in Yellow Cake Sample by Chemical Method

    International Nuclear Information System (INIS)

    Busamongkol, Arporn; Rodthongkom, Chouvana

    1999-01-01

    The purity of uranium cake is very critical in nuclear-grade uranium (UO 2 ) and uranium hexafluoride (UF 6 ) production. The major element in yellow cake is uranium and trace metal impurities. The objective of this study is to determine uranium and 25 trace metal impurities; Aluminum, Barium, Bismuth, Calcium, Cadmium, Cobalt, Chromium, Copper, Iron, Potassium, Iithium, Magnesium, Manganese, Molybdenum, Sodium, Niobium, Nickel, Lead, Antimony, Tin, Strontium, Titanium, Vanadium, Zinc and Zirconium, Uranium is determined by Potassium dichromate titration, after solvent extraction with Cupferon in Chloroform, Trace metal impurities are determined by solvent extraction with Tributyl Phosphate in Carbon-tetrachloride ( for first 23 elements) and N-Benzoyl-N-Phenylhydroxylamine in Chloroform ( for last 2 elements), then analyzed by Atomic Absorption Spectrophotometer (AAS) compared with Inductively Couple Plasma Spectrophotometers (ICP). The accuracy and precision are studied with standard uranium octaoxide

  2. The Little Penguin (Eudyptula minor) as an indicator of coastal trace metal pollution.

    Science.gov (United States)

    Finger, Annett; Lavers, Jennifer L; Dann, Peter; Nugegoda, Dayanthi; Orbell, John D; Robertson, Bruce; Scarpaci, Carol

    2015-10-01

    Monitoring trace metal and metalloid concentrations in marine animals is important for their conservation and could also reliably reflect pollution levels in their marine ecosystems. Concentrations vary across tissue types, with implications for reliable monitoring. We sampled blood and moulted feathers of the Little Penguin (Eudyptula minor) from three distinct colonies, which are subject to varying levels of anthropogenic impact. Non-essential trace metal and metalloid concentrations in Little Penguins were clearly linked to the level of industrialisation adjacent to the respective foraging zones. This trend was more distinct in blood than in moulted feathers, although we found a clear correlation between blood and feathers for mercury, lead and iron. This study represents the first reported examination of trace metals and metalloids in the blood of any penguin species and demonstrates that this high trophic feeder is an effective bioindicator of coastal pollution. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Transport of trace metals in the Magela Creek system, Northern Territory. II. Trace metal concentrations in the Magela Creek billabongs at the end of the 1978 dry season

    International Nuclear Information System (INIS)

    Davies, S.H.R.; Hart, B.T.

    1981-12-01

    Billabongs downstream of the Ranger uranium mining operation have been identified as potential deposition areas for released trace metals. Samples were taken at the end of the dry season and analysed for total and filterable concentrations of Fe, Mn, Cd, Cu and Zn. There was an increase in the concentrations of total Fe, Zn, Cd and Cu in the backflow and flood plain billabongs compared with the concentrations recorded during the wet season. The increase was most noticeable for iron

  4. Dry deposition fluxes and deposition velocities of trace metals in the Tokyo metropolitan area measured with a water surface sampler.

    Science.gov (United States)

    Sakata, Masahiro; Marumoto, Kohji

    2004-04-01

    Dry deposition fluxes and deposition velocities (=deposition flux/atmospheric concentration) for trace metals including Hg, Cd, Cu, Mn, Pb, and Zn in the Tokyo metropolitan area were measured using an improved water surface sampler. Mercury is deposited on the water surface in both gaseous (reactive gaseous mercury, RGM) and particulate (particulate mercury, Hg(p)) forms. The results based on 1 yr observations found that dry deposition plays a significant if not dominant role in trace metal deposition in this urban area, contributing fluxes ranging from 0.46 (Cd) to 3.0 (Zn) times those of concurrent wet deposition fluxes. The deposition velocities were found to be dependent on the deposition of coarse particles larger than approximately 5 microm in diameter on the basis of model calculations. Our analysis suggests that the 84.13% diameter is a more appropriate index for each deposited metal than the 50% diameter in the assumed undersize log-normal distribution, because larger particles are responsible for the flux. The deposition velocities for trace metals other than mercury increased exponentially with an increase in their 84.13% diameters. Using this regression equation, the deposition velocities for Hg(p) were estimated from its 84.13% diameter. The deposition fluxes for Hg(p) calculated from the estimated velocities tended to be close to the mercury fluxes measured with the water surface sampler during the study periods except during summer.

  5. Homogeneous and Heterogeneous Reaction and Transformation of Hg and Trace Metals in Combustion Systems

    Energy Technology Data Exchange (ETDEWEB)

    J. Helble; Clara Smith; David Miller

    2009-08-31

    The overall goal of this project was to produce a working dynamic model to predict the transformation and partitioning of trace metals resulting from combustion of a broad range of fuels. The information provided from this model will be instrumental in efforts to identify fuels and conditions that can be varied to reduce metal emissions. Through the course of this project, it was determined that mercury (Hg) and arsenic (As) would be the focus of the experimental investigation. Experiments were therefore conducted to examine homogeneous and heterogeneous mercury oxidation pathways, and to assess potential interactions between arsenic and calcium. As described in this report, results indicated that the role of SO{sub 2} on Hg oxidation was complex and depended upon overall gas phase chemistry, that iron oxide (hematite) particles contributed directly to heterogeneous Hg oxidation, and that As-Ca interactions occurred through both gas-solid and within-char reaction pathways. Modeling based on this study indicated that, depending upon coal type and fly ash particle size, vaporization-condensation, vaporization-surface reaction, and As-CaO in-char reaction all play a role in arsenic transformations under combustion conditions.

  6. Comparative analysis of trace metal accumulation in forest ecosystems

    International Nuclear Information System (INIS)

    Turner, R.R.; Lindberg, S.E.; Coe, J.M.

    1985-01-01

    Wet- and dry-deposition inputs and streamflow outputs of Cd, Mn, Pb, and Zn were measured at four forested watersheds in the southeastern United States. Atmospheric inputs to each site were similar, varying by a factor of 1.1 to 2.2. Dry deposition dominated input of Mn, while wet deposition was the major process for the other metals (54 to 85% of total). Except for Mn, the metals were strongly retained by each system: only 2% of the Pb, 8 to 29% of the Cd, and 8 to 34% of the Zn inputs were transported in annual streamflow. Metal export is related to stream pH, dissolved organic carbon, and bedrock geology at each site

  7. Trace metal content in aspirin and women's cosmetics via proton induced x-ray emission (PIXE)

    International Nuclear Information System (INIS)

    Hichwa, B.P.; Pun, D.D.; Wang, D.

    1981-01-01

    A multielemental analysis to determine the trace metal content of generic and name-brand aspirins and name-brand lipsticks was done via proton induced x-ray (PIXE) measurements. The Hope College PIXE system is described as well as the target preparation methods. The trace metal content of twelve brands of aspirin and aspirin substitutes and fourteen brands of lipstick are reported. Detection limits for most elements are in the range of 100 parts per billion (ppb) to 10 parts per million

  8. Altitudinal patterns and controls of trace metal distribution in soils of a remote high mountain, Southwest China.

    Science.gov (United States)

    Li, Rui; Bing, Haijian; Wu, Yanhong; Zhou, Jun; Xiang, Zhongxiang

    2018-02-01

    The aim of this study is to reveal the effects of regional human activity on trace metal accumulation in remote alpine ecosystems under long-distance atmospheric transport. Trace metals (Cd, Pb, and Zn) in soils of the Mt. Luoji, Southwest China, were investigated along a large altitudinal gradient [2200-3850 m above sea level (a.s.l.)] to elaborate the key factors controlling their distribution by Pb isotopic composition and statistical models. The concentrations of Cd, Pb, and Zn in the surface soils (O and A horizons) were relatively low at the altitudes of 3500-3700 m a.s.l. The enrichment factors of trace metals in the surface soils increased with altitude. After normalization for soil organic matter, the concentrations of Cd still increased with altitude, whereas those of Pb and Zn did not show a clear altitudinal trend. The effects of vegetation and cold trapping (CTE) (pollutant enrichment by decreasing temperature with increasing altitude) mainly determined the distribution of Cd and Pb in the O horizon, whereas CTE and bedrock weathering (BW) controlled that of Zn. In the A horizon, the distribution of Cd and Pb depended on the vegetation regulation, whereas that of Zn was mainly related to BW. Human activity, including ores mining and fossil fuels combustion, increased the trace metal deposition in the surface soils. The anthropogenic percentage of Cd, Pb, and Zn quantified 92.4, 67.8, and 42.9% in the O horizon, and 74.5, 33.9, and 24.9% in the A horizon, respectively. The anthropogenic metals deposited at the high altitudes of Mt. Luoji reflected the impact of long-range atmospheric transport on this remote alpine ecosystem from southern and southwestern regions.

  9. Estuaries as Filters: The Role of Tidal Marshes in Trace Metal Removal

    Science.gov (United States)

    Teuchies, Johannes; Vandenbruwaene, Wouter; Carpentier, Roos; Bervoets, Lieven; Temmerman, Stijn; Wang, Chen; Maris, Tom; Cox, Tom J. S.; Van Braeckel, Alexander; Meire, Patrick

    2013-01-01

    Flux calculations demonstrate that many estuaries are natural filters for trace metals. Yet, the underlying processes are poorly investigated. In the present study, it was hypothesized that intertidal marshes contribute significantly to the contaminant filter function of estuaries. Trace metal concentrations and sediment characteristics were measured along a transect from the subtidal, over an intertidal flat and marsh to a restored marsh with controlled reduced tide. Metal concentrations in the intertidal and restored marsh were found to be a factor two to five higher than values in the subtidal and intertidal flat sediments. High metal concentrations and high accretion rates indicate a high metal accumulation capacity of the intertidal marshes. Overbank sedimentation in the tidal marshes of the entire estuary was calculated to remove 25% to 50% of the riverine metal influx, even though marshes comprise less than 8% of the total surface of the estuary. In addition, the large-scale implementation of planned tidal marsh restoration projects was estimated to almost double the trace metal storage capacity of the present natural tidal marshes in the estuary. PMID:23950927

  10. Estuaries as filters: the role of tidal marshes in trace metal removal.

    Directory of Open Access Journals (Sweden)

    Johannes Teuchies

    Full Text Available Flux calculations demonstrate that many estuaries are natural filters for trace metals. Yet, the underlying processes are poorly investigated. In the present study, it was hypothesized that intertidal marshes contribute significantly to the contaminant filter function of estuaries. Trace metal concentrations and sediment characteristics were measured along a transect from the subtidal, over an intertidal flat and marsh to a restored marsh with controlled reduced tide. Metal concentrations in the intertidal and restored marsh were found to be a factor two to five higher than values in the subtidal and intertidal flat sediments. High metal concentrations and high accretion rates indicate a high metal accumulation capacity of the intertidal marshes. Overbank sedimentation in the tidal marshes of the entire estuary was calculated to remove 25% to 50% of the riverine metal influx, even though marshes comprise less than 8% of the total surface of the estuary. In addition, the large-scale implementation of planned tidal marsh restoration projects was estimated to almost double the trace metal storage capacity of the present natural tidal marshes in the estuary.

  11. Laser Direct Metal Deposition of 2024 Al Alloy: Trace Geometry Prediction via Machine Learning.

    Science.gov (United States)

    Caiazzo, Fabrizia; Caggiano, Alessandra

    2018-03-19

    Laser direct metal deposition is an advanced additive manufacturing technology suitably applicable in maintenance, repair, and overhaul of high-cost products, allowing for minimal distortion of the workpiece, reduced heat affected zones, and superior surface quality. Special interest is growing for the repair and coating of 2024 aluminum alloy parts, extensively utilized for a wide range of applications in the automotive, military, and aerospace sectors due to its excellent plasticity, corrosion resistance, electric conductivity, and strength-to-weight ratio. A critical issue in the laser direct metal deposition process is related to the geometrical parameters of the cross-section of the deposited metal trace that should be controlled to meet the part specifications. In this research, a machine learning approach based on artificial neural networks is developed to find the correlation between the laser metal deposition process parameters and the output geometrical parameters of the deposited metal trace produced by laser direct metal deposition on 5-mm-thick 2024 aluminum alloy plates. The results show that the neural network-based machine learning paradigm is able to accurately estimate the appropriate process parameters required to obtain a specified geometry for the deposited metal trace.

  12. Laser Direct Metal Deposition of 2024 Al Alloy: Trace Geometry Prediction via Machine Learning

    Directory of Open Access Journals (Sweden)

    Fabrizia Caiazzo

    2018-03-01

    Full Text Available Laser direct metal deposition is an advanced additive manufacturing technology suitably applicable in maintenance, repair, and overhaul of high-cost products, allowing for minimal distortion of the workpiece, reduced heat affected zones, and superior surface quality. Special interest is growing for the repair and coating of 2024 aluminum alloy parts, extensively utilized for a wide range of applications in the automotive, military, and aerospace sectors due to its excellent plasticity, corrosion resistance, electric conductivity, and strength-to-weight ratio. A critical issue in the laser direct metal deposition process is related to the geometrical parameters of the cross-section of the deposited metal trace that should be controlled to meet the part specifications. In this research, a machine learning approach based on artificial neural networks is developed to find the correlation between the laser metal deposition process parameters and the output geometrical parameters of the deposited metal trace produced by laser direct metal deposition on 5-mm-thick 2024 aluminum alloy plates. The results show that the neural network-based machine learning paradigm is able to accurately estimate the appropriate process parameters required to obtain a specified geometry for the deposited metal trace.

  13. Trace metals in water and sediments from Ologe Lagoon, southwestern Nigeria

    International Nuclear Information System (INIS)

    Yusuf, K.A.; Osibanjo, O.

    2006-01-01

    The concentrations of trace metals in water and sediment samples from Ologe lagoon located in southwestern Nigeria were investigated. The lagoon is a source of water for domestic, transportation and fishing activities. The water quality characteristics for a period of two years (January, 1997 - November, 1998), and the speciation of metals in the lagoon sediments were evaluated. The lagoon water quality characteristics, with respect to heavy metal contamination, were compared with global averages for freshwater and international water quality standards for drinking water. All elements except iron, were well within the safety limits. Sequential extraction techniques were used to establish the association of the total concentrations of Zn, Cu, Pb, Cd and Mn in the sediment samples with their contents as exchangeable, carbonates, Fe/Mn oxides, and organic and residual fractions. The concentrations of trace metals in the whole sediments were generally below the world-wide background levels. When compared to a number of sediment quality guidelines, the concentrations of trace metals were found to be below the level considered to have the potential to cause biological effects. Pb and Cd were extracted from the residual fraction at values greater than 50%. The metals that were most easily extractable in the samples analyzed were Mn and Zn, which posed the highest risk to water contamination. The low level of industrialization in the study area has kept the lagoon relatively free from heavy metal contamination. (author)

  14. Spatial Gradients in Trace Metal Concentrations in the Surface Microlayer of the Mediterranean Sea

    Directory of Open Access Journals (Sweden)

    Antonio eTovar-Sanchez

    2014-12-01

    Full Text Available The relationship between dust deposition and surface water metal concentrations is poorly understood. Dissolution, solubility, and partitioning reactions of trace metals from dust particles are governed by complex chemical, biological, and physical processes occurring in the surface ocean. Despite that, the role of the sea surface microlayer (SML, a thin, but fundamental component modulating the air-sea exchange of materials has not been properly evaluated. Our study revealed that the SML of the Mediterranean Sea is enriched with bioactive trace metals (i.e., Cd, Co, Cu and Fe, ranging from 8 (for Cd to 1000 (for Fe times higher than the dissolved metal pool in the underlying water column. The highest enrichments were spatially correlated with the atmospheric deposition of mineral particles. Our mass balance results suggest that the SML in the Mediterranean Sea contains about 2 tonnes of Fe. However, we did not detect any trends between the concentrations of metals in SML with the subsurface water concentrations and biomass distributions. These findings suggest that future studies are needed to quantify the rate of metal exchange between the SML and the bioavailable pool and that the SML should be considered to better understand the effect of atmospheric inputs on the biogeochemistry of trace metals in the ocean.

  15. Study of particle size and trace metal distribution in atmospheric aerosols of islamabad

    International Nuclear Information System (INIS)

    Shah, M.H.; Shaheen, N.

    2009-01-01

    Atmospheric aerosol samples were collected on glass fibre filters using high volume air samplers Half of each aerosol sample was solubilized in nitric acid/hydrochloric acid based wet digestion method and the concentration of trace metals was determined through flame atomic absorption spectrophotometer. Among the eight trace metals analyzed, mean concentration recorded for Zn (844 ng/m3), Fe (642 ng/m3) and Pb (253 ng/m3), was found to be higher than mean levels of Mn, Cr and Co. The size distribution of the collected particulate samples was carried out on mastersizer, which revealed PM/sub 100-10/ as the major fraction (55 %) followed by PM/sub 2.5-10/ (28 %). The correlation study evidenced a strong tendency of trace metals to be associated with fine particulate fractions. The atmospheric trace metal levels showed that the mean metal concentrations in the atmosphere of Islamabad are far higher than background and European urban sites mainly due to the anthropogenic emissions. (author)

  16. Molecular Speciation of Trace Metal Organic Complexes in the Pacific Ocean

    Science.gov (United States)

    Repeta, D.; Boiteau, R. M.; Bundy, R. M.; Babcock-Adams, L.

    2017-12-01

    Microbial production across approximately one third of the surface ocean is limited by extraordinarily low (picomolar) concentrations of dissolved iron, essentially all of which is complexed to strong organic ligands of unknown composition. Other biologically important trace metals (cobalt, copper, zinc, nickel) are also complexed to strong organic ligands, which again have not been extensively characterized. Nevertheless, organic ligands exert a strong influence on metal bioavailability and toxicity. For example, amendment experiments using commercially available siderophores, organic compounds synthesized by microbes to facilitate iron uptake, show these ligands can both facilitate or impede iron uptake depending on the siderophore composition and available uptake pathways. Over the past few years we have developed analytical techniques using high pressure liquid chromatography interfaced with inductively coupled plasma and electrospray ionization mass spectrometry to identify and quantify trace metal organic complexes in laboratory cultures of marine microbes and in seawater. We found siderophores to be widely distributed in the ocean, particularly in regions characterized by low iron concentrations. We also find chemically distinct complexes of copper, zinc, colbalt and nickel that we have yet to fully characterize. We will discuss some of our recent work on trace metal organic speciation in seawater and laboratory cultures, and outline future efforts to better understand the microbial cycling of trace metal organic complexes in the sea.

  17. Metals pollution tracing in the sewerage network using the diffusive gradients in thin films technique.

    Science.gov (United States)

    Thomas, P

    2009-01-01

    Diffusive Gradients in Thin-films (DGT) is a quantitative, passive monitoring technique that can be used to measure concentrations of trace species in situ in solutions. Its potential for tracing metals pollution in the sewer system has been investigated by placing the DGT devices into sewage pumping stations and into manholes, to measure the concentration of certain metals in the catchment of a sewage treatment works with a known metals problem. In addition the methodology and procedure of using the DGT technique in sewers was investigated. Parameters such as temperature and pH were measured to ensure they were within the limits required by the DGT devices, and the optimum deployment time was examined. It was found that although the results given by the DGT technique could not be considered to be fully quantitative, they could be used to identify locations that were showing an excess concentration of metals, and hence trace pollution back to its source. The DGT technique is 'user friendly' and requires no complicated equipment for deployment or collection, and minimal training for use. It is thought that this is the first time that the DGT technique has been used in situ in sewers for metals pollution tracing.

  18. Reconstructing Early Industrial Contributions to Legacy Trace Metal Contamination in Southwestern Pennsylvania

    Science.gov (United States)

    Rossi, R.; Bain, D.; Hillman, A. L.; Pompeani, D. P.; Abbott, M. B.

    2015-12-01

    The remobilization of legacy contamination stored in floodplain sediments remains a threat to ecosystem and human health, particularly with potential changes in global precipitation patterns and flooding regimes. Vehicular and industrial emissions are often the dominant, recognized source of anthropogenic trace metal loadings to ecosystems today. However, loadings from early industrial activities are poorly characterized and potential sources of trace metal inputs. While potential trace metal contamination from these activities is recognized (e.g., the historical use of lead arsenate as a pesticide), the magnitude and distribution of legacy contamination is often unknown. This presentation reconstructs a lake sediment record of trace metal inputs from an oxbow lake in Southwestern Pennsylvania. Sediment cores were analyzed for major and trace metal chemistry, carbon to nitrogen ratios, bulk density, and magnetic susceptibility. Sediment trace metal chemistry in this approximately 250 year record (180 cm) record changes in land use and industry both in the 19th century and the 20th century. Of particular interest is early 19th century loadings of arsenic and calcium to the lake, likely attributable to pesticides and lime used in tanning processes near the lake. After this period of tanning dominated inputs, sediment barium concentrations rise, likely reflecting the onset of coal mining operations and resulting discharge of acid mine drainage to surface waters. In the 20th century portion of our record (70 -20 cm), patterns in sediment zinc, cadmium, and lead concentrations are dominated by the opening and closing of the nearby Donora Zinc Works and the American Steel & Wire Works, infamous facilities in the history of air quality regulation. The most recent sediment chemistry records periods include the enactment of air pollution legislation (~ 35 cm), and the phase out of tetraethyl leaded gasoline (~30 cm). Our study documents the impact of early industry in the

  19. Hydrobiological constraints of trace metals in surface water, coastal ...

    African Journals Online (AJOL)

    SERVER

    2007-10-18

    Oct 18, 2007 ... of Calabar River are presented in Tables 1, 2 and 3. Table 4, 5 and 6 present the correlation matrices for sediment, surface water and N. lotus samples respec- tively, showing values of Pearson's correlation coefficient. (p<0.05, n=4) for pairs of heavy metals at the four locations. The concentrations of As, Cd, ...

  20. LEVELS OF MAJOR AND TRACE METALS IN THE LEAVES AND ...

    African Journals Online (AJOL)

    B. S. Chandravanshi

    to meet some of their primary health care needs. In Africa, up to ... of children with high fever resulting from malaria is the use of herbal medicines at home [3]. Many of the .... Blending device (Moulex, France) and ceramic pestle and mortar were used for grinding and ..... minimize the risk of these two heavy metal toxicity.

  1. Trace metal levels in the sediments of the Cochin backwaters

    Digital Repository Service at National Institute of Oceanography (India)

    Venugopal, P.; Devi, K.S.; Remani, K.N.; Unnithan, R.V.

    Levels of Cu, Mn, Co, Ni and Zn at four stations in the northern arm of the Cochin backwaters, Kerala, India, which runs through an industrial belt is reported. All metals showed some degree of variation over the area studied. Co showed the lowest...

  2. concentration levels of major and trace metals in onion

    African Journals Online (AJOL)

    Preferred Customer

    like stews, soups, tomato sauces, cooked vegetables and meat by slicing, chopping, ... including metal concentrations in soils, soil pH, cation exchange capacity, ... determination was done by flame atomic absorption spectrophotometer (FAAS) (Buck ...... Margen, S. Onions, The Wellness Encyclopedia of Food and Nutrition, ...

  3. Octanol-solubility of dissolved and particulate trace metals in contaminated rivers: implications for metal reactivity and availability.

    Science.gov (United States)

    Turner, Andrew; Mawji, Edward

    2005-05-01

    The lipid-like, amphiphilic solvent, n-octanol, has been used to determine a hydrophobic fraction of dissolved and particulate trace metals (Al, Cd, Co, Cu, Mn, Ni, Pb, Zn) in contaminated rivers. In a sample from the River Clyde, southwest Scotland, octanol-solubility was detected for all dissolved metals except Co, with conditional octanol-water partition coefficients, D(ow), ranging from about 0.2 (Al and Cu) to 1.25 (Pb). In a sample taken from the River Mersey, northwest England, octanol-solubility was detected for dissolved Al and Pb, but only after sample aliquots had been spiked with individual ionic metal standards and equilibrated. Spiking of the River Clyde sample revealed competition among different metals for hydrophobic ligands. Metal displacement from hydrophobic complexes was generally most significant following the addition of ionic Al or Pb, although the addition of either of these metals had little effect on the octanol-solubility of the other. In both river water samples hydrophobic metals were detected on the suspended particles retained by filtration following their extraction in n-octanol. In general, particulate Cu and Zn (up to 40%) were most available, and Al, Co and Pb most resistant (octanol extraction. Distribution coefficients defining the concentration ratio of octanol-soluble particle-bound metal to octanol-soluble dissolved metal were in the range 10(3.3)-10(5.3)mlg(-1). The presence of hydrophobic dissolved and particulate metal species has implications for our understanding of the biogeochemical behaviour of metals in aquatic environments. Specifically, such species are predicted to exhibit characteristics of non-polar organic contaminants, including the potential to penetrate the lipid bilayer. Current strategies for assessing the bioavailability and toxicity of dissolved and particulate trace metals in natural waters may, therefore, require revision.

  4. Rapid and gradual modes of aerosol trace metal dissolution in seawater

    Directory of Open Access Journals (Sweden)

    Katherine Rose Marie Mackey

    2015-01-01

    Full Text Available Atmospheric deposition is a major source of trace metals in marine surface waters and supplies vital micronutrients to phytoplankton, yet measured aerosol trace metal solubility values are operationally defined and there are relatively few multi-element studies on aerosol-metal solubility in seawater. Here we measure the solubility of aluminum (Al, cadmium (Cd, cobalt (Co, copper (Cu, iron (Fe, manganese (Mn, nickel (Ni, lead (Pb, and zinc (Zn from natural aerosol samples in seawater over a 7 day period to (1 evaluate the role of extraction time in trace metal dissolution behavior and (2 explore how the individual dissolution patterns could influence biota. Dissolution behavior occurs over a continuum ranging from rapid dissolution, in which the majority of soluble metal dissolved immediately upon seawater exposure (Cd and Co in our samples, to gradual dissolution, where metals dissolved slowly over time (Zn, Mn, Cu, and Al in our samples. Additionally, dissolution affected by interactions with particles was observed in which a decline in soluble metal concentration over time occurred (Fe and Pb in our samples. Natural variability in aerosol chemistry between samples can cause metals to display different dissolution kinetics in different samples, and this was particularly evident for Ni, for which samples showed a broad range of dissolution rates. The elemental molar ratio of metals in the bulk aerosols was 23,189Fe: 22,651Al: 445Mn: 348Zn: 71Cu: 48Ni: 23Pb: 9Co: 1Cd, whereas the seawater soluble molar ratio after 7 days of leaching was 11Fe: 620Al: 205Mn: 240Zn: 20Cu: 14Ni: 9Pb: 2Co: 1Cd. The different kinetics and ratios of aerosol metal dissolution have implications for phytoplankton nutrition, and highlight the need for unified extraction protocols that simulate aerosol metal dissolution in the surface ocean.

  5. Mobility of nutrients and trace metals during weathering in the late Archean

    Science.gov (United States)

    Hao, Jihua; Sverjensky, Dimitri A.; Hazen, Robert M.

    2017-08-01

    The evolution of the geosphere and biosphere depends on the availability of bio-essential nutrients and trace metals. Consequently, the chemical and isotopic variability of trace elements in the sedimentary record have been widely used to infer the existence of early life and fluctuations in the near-surface environment on the early Earth, particularly fluctuations in the redox state of the atmosphere. In this study, we applied late Archean weathering models (Hao et al., 2017), developed to estimate the behavior of major elements and the composition of late Archean world average river water, to explore the behavior of nutrient and trace metals and their potential for riverine transport. We focused on P, Mn, Cr, and Cu during the weathering of olivine basalt. In our standard late Archean weathering model (pCO2,g = 10-1.5 bars, pH2,g = 10-5.0 bars), crustal apatite was totally dissolved by the acidic rainwater during weathering. Our model quantitatively links the pCO2,g of the atmosphere to phosphate levels transported by rivers. The development of late Archean river water (pH = 6.4) resulted in riverine phosphate of at least 1.7 μmolar, much higher than at the present-day. At the end of the early Proterozoic snowball Earth event when pCO2,g could be 0.01-0.10 bars, river water may have transported up to 70 μmolar phosphate, depending on the availability of apatite, thereby stimulating high levels of oxygenic photosynthesis in the marine environment. Crustal levels of Mn in olivine dissolved completely during weathering, except at large extents of weathering where Mn was stored as a component of a secondary carbonate mineral. The corresponding Mn content of river water, about 1.2 μmolar, is higher than in modern river water. Whiffs of 10-5 mole O2 gas or HNO3 kg-1 H2O resulted in the formation of pyrolusite (MnO2) and abundant hematite and simultaneous dramatic decreases in the concentration of Mn(II) in the river water. Chromite dissolution resulted in negligible

  6. Study of the migration of toxic metals in steelmaking waste using radioactive tracing

    International Nuclear Information System (INIS)

    Andre, C.; Jauzein, M.; Charentus, T.; Margrita, R.; Dechelette, O.

    1991-01-01

    The danger presented by toxic metals contained in steelmaking wastes put into slag piles may be neutralized by suitably chosen alternation of these wastes when they are deposited. Presentation of a study method using radioactive tracing of the migration of toxic metal (cadmium, zinc, chromium) in steelmaking wastes (slag, blast furnace sludge). This non destructive method was used in columns in the laboratory, but may be used in on-site slag piles [fr

  7. Biorefine: Recovery of nutrients and metallic trace elements from different wastes by chemical and biochemical processes

    OpenAIRE

    Tarayre, Cédric; Fischer, Christophe; De Clercq, Lies; Michels, Evi; Meers, Erik; Buysse, Jeroen; Delvigne, Frank; Thonart, Philippe

    2014-01-01

    At present, most waste processing operations are not oriented towards the valorization of valuable reusable components such as nitrogen, phosphorus, potassium and even Metallic Trace Elements (MTEs). Currently, sewage sludge, for example is usually used as a fertilizer in agriculture, in energy production or in the field of construction. Ashes originating from sludge incineration contain heavy metals and minerals in large quantities. Manure is mainly used in agriculture, although considerable...

  8. Trace metal contamination in mangrove sediments, Guanabara Bay, Rio de Janeiro, Brazil

    OpenAIRE

    Farias,Cassia O.; Hamacher,Claudia; Wagener,Angela de Luca R.; Campos,Reinaldo C. de; Godoy,José M.

    2007-01-01

    The Guanabara Bay in Rio de Janeiro has undergone profound alterations of its natural environmental conditions. Metal concentration increase in sediments has been reported to be among these alterations. Trace-metal contamination and availability were studied in sediments of 3 mangrove areas of the bay. Cd, Zn, Pb, Ni, Cu and Al concentrations were determined in segments of sediment cores, after treatment with 1 mol L-1 HCl and with concentrated HNO3. Fe and Mn were determined in the leach wit...

  9. Atmospherically deposited trace metals from bulk mineral concentrate port operations.

    Science.gov (United States)

    Taylor, Mark Patrick

    2015-05-15

    Although metal exposures in the environment have declined over the last two decades, certain activities and locations still present a risk of harm to human health. This study examines environmental dust metal and metalloid hazards (arsenic, cadmium, lead and nickel) associated with bulk mineral transport, loading and unloading port operations in public locations and children's playgrounds in the inner city of Townsville, northern Queensland. The mean increase in lead on post-play hand wipes (965 μg/m(2)/day) across all sites was more than 10-times the mean pre-play loadings (95 μg/m(2)/day). Maximum loading values after a 10-minute play period were 3012 μg/m(2), more than seven times the goal of 400 μg/m(2) used by the Government of Western Australia (2011). Maximum daily nickel post-play hand loadings (404 μg/m(2)) were more than 26 times above the German Federal Immission Control Act 2002 annual benchmark of 15 μg/m(2)/day. Repeat sampling over the 5-day study period showed that hands and surfaces were re-contaminated daily from the deposition of metal-rich atmospheric dusts. Lead isotopic composition analysis of dust wipes ((208)Pb/(207)Pb and (206)Pb/(207)Pb) showed that surface dust lead was similar to Mount Isa type ores, which are exported through the Port of Townsville. While dust metal contaminant loadings are lower than other mining and smelting towns in Australia, they exceeded national and international benchmarks for environmental quality. The lessons from this study are clear - even where operations are considered acceptable by managing authorities, targeted assessment and monitoring can be used to evaluate whether current management practices are truly best practice. Reassessment can identify opportunities for improvement and maximum environmental and human health protection. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. Determination of some trace metals in elsaraf dam (GEDAREF)

    International Nuclear Information System (INIS)

    Yagoob, T. I.

    2001-07-01

    In this study the part of the plant analyzed was the root, while by the soil we mean the soil which is in direct contact with the plant root. This analysis was carried to find the relation between the concentrations of the free ions in water, the mobile ions in the soil in contact with the root of the plant and the ions uptake by the plant as well as the movement of these ions between different reservoirs. The nutrient elements, (Fe, Mn, Zn, Cu, Co) showed higher concentrations than toxic elements (Cr, Ni, Cd). Because of its natural abundance, iron has the highest concentration (54900/56600, 33580/36800), manganese has shown the second highest concentration, followed by nickel and zinc. Copper, cobalt and chromium have shown relatively similar concentrations, while cadmium has shown the lowest concentration. In general, almost for all elements the soils have shown higher concentration followed by the plant and then water. Cyperus rotandus has shown high affinity towards most of the metal ions, while the rest of plants have shown almost similar affinity. Because of the generally low concentration of metal ions in water, preconcentration was used using 8-hydroxyquinoline (oxine) and ammonium pyrolidine dithiocarbamate APDC to extract (pre concentrate) the metal ions at the optimum parameters before measurement in AAS.(Author)

  11. New method for mass spectrometric trace analysis of metals in biology and medicine

    International Nuclear Information System (INIS)

    Schulten, H.R.; Bahr, U.; Palavinskas, R.

    1984-01-01

    A first survey on the basic aspects and applications of a novel method for trace analyses of metals is given. The advantages of this methodology for analyses of trace metals which was developed by our group are: small sample amount, high sensitivity and selectivity, simple sample preparation for the measurement (no ashing) and reliability and precision of the results. The time consumption for one complete quantitative analysis lies below 30 min. The concentration of monoisotopic metals, as for example aluminium, cesium, manganese etc. is determined using a calibration curve. Using stable isotope dilution analysis quantification of metals with at least two stable isotopes further improved the precision of the results. If this technique is utilized, on one hand contamination of the environment by radioactive substances is avoided, on the other even the smallest changes in concentrations of trace metals are detected unambigeously. The accuracy of the resulting quantitative data has been confirmed test measurements with other analytical methods such as atomic absorption spectroscopy and thermal ionization mass spectrometry. Although there is no doubt that the greatest analytical capacity of field desorption mass spectrometry is in the field of high-molecular weight natural products, it has been possible in the last years to modify the method for qualitative and quantitative investigations of more than 60 metals. (orig./EF) [de

  12. Sandhopper solar orientation as a behavioural biomarker of trace metals contamination

    International Nuclear Information System (INIS)

    Ungherese, Giuseppe; Ugolini, Alberto

    2009-01-01

    Although many studies have focused on trace metals accumulation, investigations of talitrid amphipods as biomarkers are rare. This study explores the possibility of using the solar orientation capacity of Talitrus saltator as a behavioural marker of exposure to two essential (Cu and Zn) and two non-essential (Cd and Hg) metals. LC 50 analyses performed before the solar orientation tests showed that the 72 h LC 50 for Hg was 0.02 ppm while the 96 h LC 50 values for Cu, Cd and Zn were 13.28 ppm, 27.66 ppm, and 62.74 ppm, respectively. The presence of metals in seawater affects the solar orientation capacity of T. saltator in a concentration-dependent manner and according to the toxicity ranking of the metals (Hg > Cu > Cd > Zn). Therefore, the solar orientation capacity of T. saltator seems to be a promising behavioural marker for exposure to trace metals. - Solar orientation capacity is a promising behavioural marker for exposure to trace metals in sandhoppers

  13. Assessment of concentrations of trace and toxic heavy metals in soil ...

    African Journals Online (AJOL)

    This study reports on determination of concentrations of trace and toxic heavy metals in soil and vegetables grown near of Manyoni uranium deposit. Soil and vegetable samples were collected from five sites namely Mitoo Mbuga, farming area, Miyomboni, Tambukareli and near water pump. The concentrations of heavy ...

  14. Metals in environmental media: A study of trace and platinum group ...

    African Journals Online (AJOL)

    A detailed study has been conducted to determine the contamination of Thohoyandou roadside soils, vegetation, sewage and river waters by Zn, Cu, Cr, Pb, Cd, Fe, Pt and Pd. The study further investigated the correlation between these trace metals in roadside soils and vegetation in order to infer the potential impacts of ...

  15. Microbial and trace metal content of well water in three rural ...

    African Journals Online (AJOL)

    Microbial and trace metal content of well water in three rural communities in Bauchi State, Nigeria*. E Ikeh, PN Durfee, RH Glew, R Amato, FJ Frost, DJ Vanderjagt. Abstract. No Abstract. Nigerian Journal of Health and Biomedical Sciences Vol. 5 (2) 2006: 66-70. Full Text: EMAIL FULL TEXT EMAIL FULL TEXT

  16. Seasonal comparison of trace metal residues in white-footed mice and soil from colliery stripmines

    International Nuclear Information System (INIS)

    Hausbeck, J.S.; Husby, M.P.; McBee, K.

    1994-01-01

    Mine tailings of abandoned coal stripmines in Oklahoma and other regions of the US have been shown to contain slightly elevated levels of copper (Cu) and zinc (Zn). Metalliferous stripmine spoil has been found to contain much higher levels of Cu and Zn than colliery stripmines, and many other trace metals including cadmium (Cd) and lead (Pb) among others. Although levels of trace metal contamination were lower for coal stripmines, research has shown small mammals exposed to low levels of trace metals may bioaccumulate trace metals. This study intended to determine the levels of Cd, Cu, Pb, and Zn in liver, kidney, and bone tissues of white-footed mice (Peromyscus leucopus) and examine the variance of these levels among sites and seasons. Preliminary results of soil analysis have indicated that mice collected from stripmine sites were exposed to slightly elevated levels of Zn and Cd in stripmine spoil collected from Okmulgee Co., OK. Kidney and liver tissues from mice collected at stripmine sites within this county have shown significantly greater levels of Cd and Zn than tissues collected from reference mice. Significant seasonal variation in renal and hepatic Zn concentrations was observed and possibly was related to a change in diet or reproductive activity

  17. Monsoon control on trace metal fluxes in the deep Arabian Sea

    Indian Academy of Sciences (India)

    Monsoon control on trace metal fluxes in the deep Arabian Sea ... at marine boundaries and surface ocean processes: Forcings and feedbacks Volume 115 ... Annual Al fluxes at shallow and deep trap depths were 0.47 and 0.46 gm−2 in the ...

  18. Petroleum hydrocarbons and trace metals in Visakhapatnam harbour and Kakinada Bay, east coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Sarma, V.V.; VaraPrasad, S.J.D.; Gupta, G.V.M.; Sudhakar, U.

    High concentrations of PHC were observed in the inner channels (viz. South lighter canal, Northern arm, North Western arm and Western arm) of Visakhapatnam Harbour, Andhra Pradesh, India. The estimation of trace metals (Cu, Zn, Pb, Cd, Co, Ni and Cr...

  19. Minor and trace metals levels in human milk in north western cities of Libya

    International Nuclear Information System (INIS)

    Mahabbis, M. T.; Elkubat, M. S.; Kut, H. M.

    2009-01-01

    Levels of twelve minor and trace metals were determined by using (AAS, ES and ICP/MS) in breast milk obtained from 60 women living in north western cities of Libya. Samples were collected at one week up to two years after delivery. Women with age>21 years old to an age of <43 years old were investigated. (Author)

  20. Trace metal dynamics in zooplankton from the Bay of Bengal during summer monsoon

    Digital Repository Service at National Institute of Oceanography (India)

    Rejomon, G.; DineshKumar, P.K.; Nair, M.; Muraleedharan, K.R.

    Trace metal (Fe, Co, Ni, Cu, Zn, Cd, and Pb) concentrations in zooplankton from the mixed layer were investigated at 8 coastal and 20 offshore stations in the western Bay of Bengal during the summer monsoon of 2003. The ecotoxicological importance...

  1. Biogeochemical Cycling of Nutrients and Trace Metals in the Sediment of Haringvliet Lake: Response to Salinization

    NARCIS (Netherlands)

    Canavan, R.W.

    2006-01-01

    This thesis examines sediment redox processes associated with organic matter degradation and their impact on the cycling of nutrients (N, P) and trace metals (Cd, Co, Ni, Pb, Zn). Our study site, Haringvliet Lake, is located in the Rhine-Meuse River Delta in the southwest of The Netherlands. This

  2. Evaluation of toxic trace metals Cd and Pb in Arabian Sea waters

    Digital Repository Service at National Institute of Oceanography (India)

    Sanzgiri, S.; Mesquita, A.; Kureishy, T.W.; SenGupta, R.

    An attempt has been made to present a picture of the distribution of toxic trace elements Cd and Pb in the Northern Arabian Sea by applying an improved analytical technique for the detection of dissolved forms of the metals at nanogram levels...

  3. Trace metal concentrations in zooplankton from the eastern Arabian Sea and western Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    Rejomon, G.; Balachandran, K.K.; Nair, M.; Joseph, T.; DineshKumar, P.K.; Achuthankutty, C.T.; Nair, K.K.C.; Pillai, N.G.K.

    Trace metal contents in zooplankton samples were estimated as a part of the Marine Research-Living Resource program at 24 stations in the Bay of Bengal (November, 2002) and 29 stations in the Arabian Sea (September-October, 2003) during the Cruises...

  4. Dissolved and particulate trace metals in the western Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    Rajendran, A.; De; Reddy, C.V.G.

    Concentrations of Cu, Zn, Mn, Fe, Co, Ni and Pb, both in soluble and particulate forms were studied in the upper 200 m depth. Correlation between the trace metal concentration and the primary productivity was also investigated. Zn, Ni and Co were...

  5. Activation analysis of trace metals in several kinds of tissues of even-toed ungulates

    International Nuclear Information System (INIS)

    Fukushima, M.; Tamate, H.; Sato, S.; Terui, S.; Mitsugashira, T.

    1999-01-01

    The normal concentration levels of trace metals in several kinds of tissues of even-toed ungulates have been determined by instrumental neutron activation analysis, photon activation analysis, and flame atomic absorption spectrometry. In the present work the concentrations of 13 elements (Ag, Br, Ca, Co, Cu, Fe, Mg, Mn, Mo, Na, Rb, Se, and Zn) were analyzed. (author)

  6. Trace metal enrichments in core sediments in Muthupet mangroves, SE coast of India: Application of acid leachable technique

    International Nuclear Information System (INIS)

    Janaki-Raman, D.; Jonathan, M.P.; Srinivasalu, S.; Armstrong-Altrin, J.S.; Mohan, S.P.; Ram-Mohan, V.

    2007-01-01

    Core sediments from Mullipallam Creek of Muthupet mangroves on the southeast coast of India were analyzed for texture, CaCO 3 , organic carbon, sulfur and acid leachable trace metals (Fe, Mn, Cr, Cu, Ni, Co, Pb, Zn and Cd). Textural analysis reveals a predominance of mud while CaCO 3 indicates dissolution in the upper half of the core, and reprecipitation of carbonates in reduction zones. Trace metals are diagenetically modified and anthropogenic processes control Pb and, to some extent, Ni, Zn and Fe. A distinct event is identified at 90 cm suggesting a change in deposition. Strong relationship of trace metals with Fe indicates that they are associated with Fe-oxyhydroxides. The role of carbonates in absorbing trace metals is evident from their positive relationship with trace metals. Comparison of acid leachable trace metals indicates increase in concentrations in the study area and the sediments act as a sink for trace metals contributed from multiple sources. - Natural and anthropogenic trace metals afeecting mangrove sediments

  7. Determination of the side-reaction coefficient of desferrioxamine B in trace-metal-free seawater

    Directory of Open Access Journals (Sweden)

    Johan Schijf

    2016-07-01

    Full Text Available Electrochemical techniques like adsorptive cathodic stripping voltammetry with competitive ligand equilibration (ACSV-CLE can determine total concentrations of marine organic ligands and their conditional binding constants for specific metals, but cannot identify them. Individual organic ligands, isolated from microbial cultures or biosynthesized through genomics, can be structurally characterized via NMR and tandem MS analysis, but this is tedious and time-consuming. A complementary approach is to compare known properties of natural ligands, particularly their conditional binding constants, with those of model organic ligands, measured under suitable conditions. Such comparisons cannot be meaningfully interpreted unless the side-reaction coefficient (SRC of the model ligand in seawater is thoroughly evaluated.We conducted series of potentiometric titrations, in non-coordinating medium at seawater ionic strength (0.7 M NaClO4 over a range of metal:ligand molar ratios, to study complexation of the siderophore desferrioxamine B (DFOB with Mg and Ca, for which it has the highest affinity among the major seasalt cations. From similar titrations of acetohydroxamic acid in the absence and presence of methanesulfonate (mesylate, it was determined that Mg and Ca binding to this common DFOB counter-ion is not strong enough to interfere with the DFOB titrations. Stability constants were measured for all DFOB complexes with Mg and Ca including, for the first time, the bidentate complexes. No evidence was found for Mg and Ca coordination with the DFOB terminal amine. From the improved DFOB speciation, we calculated five SRCs for each of the five (deprotonated forms of DFOB in trace-metal-free seawater, yet we also present a more convenient definition of a single SRC that allows adjustment of all DFOB stability constants to seawater conditions, no matter which of these forms is selected as the 'component' (reference species. An example of Cd speciation in

  8. A Geographic Information System (GIS) analysis for trace metal assessment of sediments in the Gulf of Paria, Trinidad

    International Nuclear Information System (INIS)

    Ragbirsingh, Y.; Norville, W.

    2005-01-01

    The Gulf of Paria is a semi-enclosed shallow basin with increasing coastal development activities along Trinidad's west coast. Sediments present a host for trace metal pollutants from overlying waters, therefore determination of their content is critical in evaluating and detecting sources of marine pollution. This paper presents a Geographic Information System (GIS) analysis of geochemical assessment for trace metals in coastal sediments of the Gulf of Paria. This GIS approach facilitates interpretation of the spatial relationships among key environmental processes. The GIS development involves the integration of spatial and attribute data pertaining to bathymetry, current systems, topography, rivers, land use/land cover and coastal sediments. It employs spatial interpolation and retrieval operations to analyze the total trace metal concentrations of aluminum, copper and lead in the sediments and the clay-enriched sediments, to determine whether they are related to sediment type or are affected by the discharge from anthropogenic sources. Spatial distribution modeling of element concentrations are produced to indicate contamination plumes from possible anthropogenic sources such as rivers entering the Gulf of Paria, and to reveal potential hot spots and dispersion patterns. A direct spatial correlation between clay-enriched sediments and high concentrations of aluminum and lead is detected, however regions of high concentrations of copper and lead indicate a relationship to anthropogenic sources. The effectiveness of GIS for visualization, spatial query and overlay of geochemical analysis is demonstrated [es

  9. The importance of biomass net uptake for a trace metal budget in a forest stand in north-eastern France.

    Science.gov (United States)

    Gandois, L; Nicolas, M; VanderHeijden, G; Probst, A

    2010-11-01

    The trace metal (TM: Cd, Cu, Ni, Pb and Zn) budget (stocks and annual fluxes) was evaluated in a forest stand (silver fir, Abies alba Miller) in north-eastern France. Trace metal concentrations were measured in different tree compartments in order to assess TM partitioning and dynamics in the trees. Inputs included bulk deposition, estimated dry deposition and weathering. Outputs were leaching and biomass exportation. Atmospheric deposition was the main input flux. The estimated dry deposition accounted for about 40% of the total trace metal deposition. The relative importance of leaching (estimated by a lumped parameter water balance model, BILJOU) and net biomass uptake (harvesting) for ecosystem exportation depended on the element. Trace metal distribution between tree compartments (stem wood and bark, branches and needles) indicated that Pb was mainly stored in the stem, whereas Zn and Ni, and to a lesser extent Cd and Cu, were translocated to aerial parts of the trees and cycled in the ecosystem. For Zn and Ni, leaching was the main output flux (>95% of the total output) and the plot budget (input-output) was negative, whereas for Pb the biomass net exportation represented 60% of the outputs and the budget was balanced. Cadmium and Cu had intermediate behaviours, with 18% and 30% of the total output relative to biomass exportation, respectively, and the budgets were negative. The net uptake by biomass was particularly important for Pb budgets, less so for Cd and Cu and not very important for Zn and Ni in such forest stands. Copyright © 2010 Elsevier B.V. All rights reserved.

  10. Trace moisture emissions from heated metal surfaces in hydrogen service

    International Nuclear Information System (INIS)

    Funke, Hans H.; Yao Jianlong; Raynor, Mark W.

    2004-01-01

    The formation of trace moisture by exposure of dry heated surfaces of 316 L stainless-steel, Restek Silcosteel registered , and nickel 1/8 in. outer diameter line segments to purified Ar and H 2 was studied using atmospheric pressure ionization mass spectrometry at flow rates of 2 slpm. Prior to H 2 exposure, adsorbed moisture was removed by heating incrementally to 500 deg. C in an argon matrix, where the Restek Silcosteel registered material released a maximum of 50 ppb moisture at 300 deg. C and moisture spikes from the Ni and stainless-steel surfaces reached several 100 ppb. Upon exposure to H 2 , persistent low ppb moisture emissions due to the reduction of surface oxide species were observed at temperatures as low as 100 deg. C. Spikes at 300-500 deg. C ranged from ∼100 ppb for the stainless-steel lines to 400 ppb for the Restek Silcosteel registered material. The observed moisture emissions have to be considered as a potential contamination source for high-purity processes utilizing H 2 purge at elevated temperatures

  11. Trace metals in coastal sediments of Costa Rica

    International Nuclear Information System (INIS)

    Garcia Cespedes, J.; Acuna Gonzalez, J.; Vargas Zamora, J.A.

    2004-01-01

    Marine sediment samples from four coastal ecosystems in Costa Rica were taken between the years 2000-2002 and their iron, lead, copper and zinc concentrations were determined by the atomic absorption technique with flame or graphite furnace. In the Pacific coast, Culebra Bay (Papagayo Gulf), Gulf of Nicoya, and Golfito Bay (Dulce Gulf), were selected as representative sites, and Moin Bay, at the Caribbean coast. Mean metal concentrations for all ecosystems followed the same pattern: Fe> Zn> Cu> Pb. No temporal pattern was found for any metal. Iron and copper mean concentrations were higher in Golfito Bay (5.8% and 87 μg / g, respectively) and lower in Moin Bay (3.4% and 52 μg / g, respectively). Zinc mean concentration was also higher in Golfito Bay (96 μg / g), but lower in Culebra Bay (66 μg / g). Lead mean concentration was higher in Moin Bay (6.4 μg / g) and lower in Culebra Bay (3.0 μg / g). Lead highest concentrations occurred in the Caribbean and in Golfito Bay, and for the rest of the elements the maximum values were found in Golfito Bay. On the basis of data obtained in this work, Culebra Bay was considered a relatively unpolluted location; Golfito Bay was more contaminated, and Moin Bay and the Gulf of Nicoya showed an intermediate condition. (Author) [es

  12. Biogeochemical and hydrological controls on fate and distribution of trace metals in oiled Gulf salt marshes

    Science.gov (United States)

    Keevan, J.; Natter, M.; Lee, M.; Keimowitz, A.; Okeke, B.; Savrda, C.; Saunders, J.

    2011-12-01

    On April 20, 2010, the drilling rig Deepwater Horizon exploded in the Gulf of Mexico, resulting in the release of approximately 5 million barrels of crude oil into the environment. Oil and its associated trace metals have been demonstrated to have a detrimental effect on coastal wetland ecosystems. Wetlands are particularly susceptible to oil contamination because they are composed largely of fine-grained sediments, which have a high capacity to adsorb organic matter and metals. The biogeochemical cycling of trace metals can be strongly influenced by microbial activity, specifically those of sulfate- and iron-reducing bacteria. Microbial activity may be enhanced by an increase in amounts of organic matter such as oil. This research incorporates an assessment of levels of trace metals and associated biogeochemical changes from ten coastal marshes in Alabama, Mississippi, and Louisiana. These sampling sites range in their pollution levels from pristine to highly contaminated. A total digestion analysis of wetland sediments shows higher concentrations of certain trace metals (e.g., Ni, Cu, Pb, Zn, Sr, Co, V, Ba, Hg, As) in heavily-oiled areas compared to less-affected and pristine sites. Due to chemical complexation among organic compounds and metals, crude oils often contain elevated levels (up to hundreds of mg/kg) of trace metals At the heavily-oiled Louisiana sites (e.g., Bay Jimmy, Bayou Dulac, Bay Batiste), elevated levels of metals and total organic carbon have been found in sediments down to depths of 30 cm. Clearly the contamination is not limited to shallow sediments and oil, along with various associated metals, may be invading into deeper (pre-industrial) portions of the marsh sediments. Pore-waters extracted from contaminated sediments are characterized by very high levels of reduced sulfur (up to 80 mg/kg), in contrast to fairly low ferrous iron concentrations (<0.02 mg/kg). The influx of oil into the wetlands might provide the initial substrate and

  13. Determination of metallic traces in kidneys, livers, lungs and spleens of rats with metallic implants after a long implantation time.

    Science.gov (United States)

    Rubio, Juan Carlos; Garcia-Alonso, Maria Cristina; Alonso, Concepcion; Alobera, Miguel Angel; Clemente, Celia; Munuera, Luis; Escudero, Maria Lorenza

    2008-01-01

    Metallic transfer from implants does not stop at surrounding tissues, and metallic elements may be transferred by proteins to become lodged in organs far from the implant. This work presents an in vivo study of metallic implant corrosion to measure metallic element accumulation in organs located far from the implant, such as kidneys, livers, lungs and spleens. The studied metallic implant materials were CoCr alloy, Ti, and the experimental alloy MA956 coated with alpha-alumina. The implants were inserted in the hind legs of Wistar rats. Analysis for Co, Cr, Ti and Al metallic traces was performed after a long exposure time of 12 months by Inductively Coupled Plasma (ICP) with Mass Spectrometry (MS). According to the results, the highest Cr and Ti concentrations were detected in spleens. Co is mainly found in kidneys, since this element is eliminated via urine. Cr and Ti traces increased significantly in rat organs after the long implantation time. The organs of rats implanted with the alpha-alumina coated experimental MA956 did not present any variation in Al content after 12 months, which means there was no degradation of the alumina layer surface.

  14. Comparison of trace metals in intake and discharge waters of power plants using clean techniques

    International Nuclear Information System (INIS)

    Salvito, D.T.; Allen, H.E.

    1995-01-01

    In order to determine the impact to receiving waters of trace metals potentially discharged from a once-through, non-contact cooling water system from a power plant, a study was conducted utilizing clean sampling and analytical techniques for a series of metals. Once-through, non-contact cooling water at power plants is frequently discharged back to the fresh or saline waterbody utilized for its intake water. This water is used to cool plant condensers. Intake and discharge data were collected and evaluated using paired t-tests. Study results indicate that there is no measurable contribution of metals from non-contact cooling water from this power plant

  15. Chemical speciation of trace metals in the industrial sludge of Dhaka City, Bangladesh.

    Science.gov (United States)

    Islam, Md Saiful; Al-Mamun, Md Habibullah; Feng, Ye; Tokumura, Masahiro; Masunaga, Shigeki

    2017-07-01

    The objective of this study was to assess total concentration and chemical fractionation of trace metals in the industrial wastewater and sludge collected from seven different types of industries in Dhaka City, Bangladesh. The sludge from industries is either dumped on landfills or reused as secondary resources in order to preserve natural resources. Metals were analyzed using inductively coupled plasma mass spectrometry (ICP-MS). The ranges of Cr, Ni, Cu, As, Cd, and Pb in the sludges were 1.4-9,470, 4.8-994, 12.8-444, 2.2-224, 1.9-46.0 and 1.3-87.0 mg/kg, respectively. As a whole, the average concentrations of trace metals in samples were in the decreasing order of Cr > Ni > Cu > As > Pb > Cd. The results of the Community Bureau of Reference (BCR) sequential extraction showed that the studied metals were predominantly associated with the residual fraction followed by the oxidizable fraction. The study revealed that the mobile fractions of trace metals are poorly predictable from the total content, and bioavailability of all fractions of elements tends to decrease.

  16. Sorbent control of trace metals in sewage sludge combustion and incineration

    Science.gov (United States)

    Naruse, I.; Yao, H.; Mkilaha, I. S. N.

    2003-05-01

    Coal and wastes combustion have become an important issue not only in terms of energy generation but also environmental conservation. The need for alternative fuels and wastes management has made the two energy sources of importance. However, the utilization of the two is faced with problems of impurity trace metals in the fuel. These metals usually speciate during combustion or incineration leading to generation of fumes and subsequently particles. This paper reports on the study aimed at understanding the speciation of trace metals and their emission from combustion systems as particulates. Experiments carried out using a down-flow furnace and theoretical study carried out using lead, chromium and cadmium as basic metals had shown that their speciation and subsequent emission is controlled by both chemical composition and physical properties of the fuel. The physical and chemical and physical properties of the fuel and their respective compounds and the operating conditions of the incineration and combustion system control the enrichment of the particles with trace metals.

  17. Mass spectrometric methods for trace analysis of metals

    International Nuclear Information System (INIS)

    Bahr, U.; Schulten, H.R.

    1981-01-01

    A brief outline is given of the principles of mass spectrometry (MS) and the fundamentals of qualitative and quantitative mass spectrometric analysis emphasizing recent developments and results. Classical methods of the analysis of solids, i.e. spark-source MS and thermal ionization MS, as well as recent methods of metal analysis are described. Focal points in this survey of recently developed techniques include secondary ion MS, laser probe MS, plasma ion source MS, gas discharge MS and field desorption MS. Here, a more detailed description is given and the merits of these emerging methods are discussed more explicitly. In particular, the results of the field desorption techniques in elemental analyses are reviewed and critically evaluated

  18. Bioindication of atmospheric trace metals - With special references to megacities

    International Nuclear Information System (INIS)

    Markert, Bernd; Wuenschmann, Simone; Fraenzle, Stefan; Graciana Figueiredo, Ana Maria; Ribeiro, Andreza P.; Wang Meie

    2011-01-01

    After considering the particular problems of atmospheric pollution in megacities, i.e. agglomerations larger than 5 mio. inhabitants, with urbanization of World's population going on steadily, possibilities of active biomonitoring by means of green plants are discussed. Based on specific definitions of active and passive bioindication the chances of monitoring heavy metals in Sao Paulo megacity were demonstrated (first results published before). This is to show that there is need for increased use of bioindication to tackle the particular problems of megacities concerning environmental 'health', the data to be processed according to the Multi-Markered-Bioindication-Concept (MMBC). Comparison to other work shows this approach to be reasonable. - Highlights: → Chemical Pollution. → Bioindication. → Multi-Markered-Bioindication-Concept (MMBC). → Mega cities. - Bioindication is a relevant technique for observing the atmospheric deposition of chemical elements of the environment in megacities.

  19. Determination of fluorine trace amounts in metallic uranium

    Energy Technology Data Exchange (ETDEWEB)

    Kukisheva, T N; Bolshakova, A S; Yefimova, N S

    1976-05-01

    A simple and rapid method was proposed for the determination of fluorine in metallic uranium without the removal of the latter. The method is based on the weakening of the color intensity of a complex of zirconium with xylenol orange in the presence of fluorine in a 1 N solution with respect to hydrochloric acid. For preparation for photometry, the solution to be analyzed is neutralized with ammonia to a pH of approximately 3. It is suggested that a complex of sulfosalicylic acid with uranium (VI) be used as the indicator in neutralization. The required acidity in the solution subjected to photometry is provided by the addition of a 5 N hydrochloric acid solution of zirconium. The coefficient of variation V/sub 15/ (at a fluorine content 3x10/sup -3/%) is 10%. In 7 h, 15-20 determinations can be performed.

  20. Source Evaluation and Trace Metal Contamination in Benthic Sediments from Equatorial Ecosystems Using Multivariate Statistical Techniques.

    Directory of Open Access Journals (Sweden)

    Nsikak U Benson

    Full Text Available Trace metals (Cd, Cr, Cu, Ni and Pb concentrations in benthic sediments were analyzed through multi-step fractionation scheme to assess the levels and sources of contamination in estuarine, riverine and freshwater ecosystems in Niger Delta (Nigeria. The degree of contamination was assessed using the individual contamination factors (ICF and global contamination factor (GCF. Multivariate statistical approaches including principal component analysis (PCA, cluster analysis and correlation test were employed to evaluate the interrelationships and associated sources of contamination. The spatial distribution of metal concentrations followed the pattern Pb>Cu>Cr>Cd>Ni. Ecological risk index by ICF showed significant potential mobility and bioavailability for Cu, Cu and Ni. The ICF contamination trend in the benthic sediments at all studied sites was Cu>Cr>Ni>Cd>Pb. The principal component and agglomerative clustering analyses indicate that trace metals contamination in the ecosystems was influenced by multiple pollution sources.

  1. Trace metals behaviour during salt and fresh water mixing in the Venice Lagoon

    International Nuclear Information System (INIS)

    Ghermandi, G.; Campolieti, D.; Cecchi, R.; Costa, F.; Zaggia, L.; Zonta, R.

    1993-01-01

    Preliminary results of an investigation on trace metals behaviour in the estuarine system of the Dese River (Venice Lagoon) are described. Hydrodynamical and water chemical-physical measurements and PIXE concentrations analysis on size-fractionated samples emphasize the complexity of the processes occurring in the area of salt and fresh water mixing. Suspended load variations in the bottom layer of the water column, which may be mostly ascribed to resuspension, regulate the trace metal concentrations and seem to play a fundamental role in the transport of pollutants in shallow water areas of the estuary. The behaviour of dissolved metals is masked by the presence of suspended matter, but some relationships with chemical-physical variables are distinguishable, furnishing information on the processes affecting their concentration in the system. (orig.)

  2. Are acid volatile sulfides (AVS) important trace metals sinks in semi-arid mangroves?

    Science.gov (United States)

    Queiroz, Hermano Melo; Nóbrega, Gabriel Nuto; Otero, Xose L; Ferreira, Tiago Osório

    2018-01-01

    Acid-volatile sulfides (AVS) formation and its role on trace metals bioavailability were studied in semi-arid mangroves. The semi-arid climatic conditions at the studied sites, marked by low rainfall and high evapotranspiration rates, clearly limited the AVS formation (AVS contents varied from 0.10 to 2.34μmolg -1 ) by favoring oxic conditions (Eh>+350mV). The AVS contents were strongly correlated with reactive iron and organic carbon (r=0.84; r=0.83 respectively), evidencing their dominant role for AVS formation under semi-arid conditions. On the other hand, the recorded ΣSEM/AVS values remained >1 evidencing a little control of AVS over the bioavailability of trace metals and, thus, its minor role as a sink for toxic metals. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Trace metals in corals--hind casting environmental chemical changes in the tropical Atlantic waters

    Science.gov (United States)

    Holmes, C. W.; Koenig, A.; Ridley, W. I.; Wilson, S. A.

    2002-12-01

    As corals grow, they secrete a calcareous skeleton with the aid of photosynthetic activity of endosymbiotic dinoflagellates (zooxanthellae). The rate of this secretion varies inter-annually. Entrapped with the carbonate are trace substances that record the chemistry of the surrounding ocean. Detailing changes in chemistry requires careful and very tedious high-resolution sampling. The advent of laser ablation inductive couple plasma/mass spectroscopy (LA-ICP/MS) circumvents this sampling problem. This method also permits a continuous scan of the entire coral skeleton. Another problem has been the lack of a carbonate standard which appears to be resolved with the creation of an artificial carbonate standard (USGS MAC-1). This standard is presently undergoing rigorous analysis, but preliminary results are very positive. The LA-ICP/MS data of three Atlantic corals reveals an intriguing distribution of trace metals and boron that may be related to climatic driven chemical changes during the last hundred years. The distribution of the trace metals appears to have an association with three climate signals: 1. the strength of the North Atlantic Oscillation (NAO), 2. the local effects of El Nino in the Florida region and 3. change in oceanic chemistry, possibly due to rising CO2. Aluminum and titanium levels vary with the strength of the NAO. The highest concentrations occur at the time of strong positive NOA when there is large amount of sediment transported off the deserts of North Africa. This relationship is particularly strong in the coral from the Cape Verde Islands. Along the eastern seaboard of the Atlantic, the relationship is not as pronounced but still observable. Nutrients and anthropogenic trace metals, such as zinc, lead, and mercury appear to correlate with local conditions and show a weak correspondence to the El Nino as it affects south Florida. Boron variation is directly related to the high-density bands of the corals. The long-term record of boron

  4. Variations in time and space of trace metal aerosol concentrations in urban areas and their surroundings

    Science.gov (United States)

    Moreno, T.; Querol, X.; Alastuey, A.; Reche, C.; Cusack, M.; Amato, F.; Pandolfi, M.; Pey, J.; Richard, A.; Prévôt, A. S. H.; Furger, M.; Gibbons, W.

    2011-09-01

    Using an unprecedentedly large geochemical database, we compare temporal and spatial variations in inhalable trace metal background concentrations in a major city (Barcelona, Spain) and at a nearby mountainous site (Montseny) affected by the urban plume. Both sites are contaminated by technogenic metals, with V, Pb, Cu, Zn, Mn, Sn, Bi, Sb and Cd all showing upper continental crust (UCC) normalised values >1 in broadly increasing order. The highest metal concentrations usually occur during winter at Barcelona and summer in Montseny. This seasonal difference was especially marked at the remote mountain site in several elements such as Ti and Rare Earth Elements, which recorded campaign maxima, exceeding PM10 concentrations seen in Barcelona. The most common metals were Zn, Ti, Cu, Mn, Pb and V. Both V and Ni show highest concentrations in summer, and preferentially fractionate into the finest PM sizes (PM1/PM10 > 0.5) especially in Barcelona, this being attributed to regionally dispersed contamination from fuel oil combustion point sources. Within the city, hourly metal concentrations are controlled either by traffic (rush hour double peak for Cu, Sb, Sn, Ba) or industrial plumes (morning peak of Ni, Mn, Cr generated outside the city overnight), whereas at Montseny metal concentrations rise during the morning to a single, prolonged afternoon peak as contaminated air transported by the sea breeze moves into the mountains. Our exceptional database, which includes hourly measurements of chemical concentrations, demonstrates in more detail than previous studies the spatial and temporal variability of urban pollution by trace metals in a given city. Technogenic metalliferous aerosols are commonly fine in size and therefore potentially bioavailable, emphasising the case for basing urban background PM characterisation not only on physical parameters such as mass but also on sample chemistry and with special emphasis on trace metal content.

  5. Trace metals in Antarctica related to climate change and increasing human impact.

    Science.gov (United States)

    Bargagli, R

    2000-01-01

    Metals are natural constituents of the abiotic and biotic components of all ecosystems, and under natural conditions they are cycled within and between the geochemical spheres--the atmosphere, lithosphere, hydrosphere, and biosphere--at quite steady fluxes. In the second half of the twentieth century, the huge increase in energy and mineral consumption determined anthropogenic emissions of several metals exceeding those from natural sources, e.g., volcanoes and windborne soil particles. In the Northern Hemisphere, the biogeochemical cycles of Pb, Cd, Zn, Cu, and other metals were significantly altered, even in Arctic regions. On the contrary, available data on trace metal concentrations in abiotic matrices from continental Antarctica, summarized in this review, suggest that the biogeochemical cycle of Pb is probably the only one that has been significantly altered by anthropogenic emissions in Antarctica and elsewhere in the Southern Hemisphere, especially in the period 1950-1975. Environmental contamination by other metals from anthropogenic sources in Antarctica itself can generally only be detected in snow samples taken within a range of a few kilometers or several hundred meters from scientific stations. Local metal pollution from human activities in Antarctica may compromise studies aimed at assessing the biogeochemical cycle of trace elements and the effects of global climate change. Thus, this review focuses on concentrations of metals in atmospheric particulate, snow, surface soils, and freshwater from the Antarctic continent and surface sediments and seawater from the Southern Ocean, which can plausibly be regarded as global background values of trace elements. These baselines are also necessary in view of the construction of new stations, the expansion of existing facilities to support research, and the growth of tourism and fisheries. Despite difficulties in making comparisons with data from other remote areas of the world, concentrations of trace metals

  6. Trace metal anomalies in bleached Porites coral at Meiji Reef, tropical South China Sea

    Science.gov (United States)

    Li, Shu; Yu, Kefu; Zhao, Jianxin; Feng, Yuexing; Chen, Tianran

    2017-01-01

    Coral bleaching has generally been recognized as the main reason for tropical coral reef degradation, but there are few long-term records of coral bleaching events. In this study, trace metals including chromium (Cr), copper (Cu), molybdenum (Mo), manganese (Mn), lead (Pb), tin (Sn), titanium (Ti), vanadium (V), and yttrium (Y), were analyzed in two Porites corals collected from Meiji Reef in the tropical South China Sea (SCS) to assess differences in trace metal concentrations in bleached compared with unbleached coral growth bands. Ti, V, Cr, and Mo generally showed irregular fluctuations in both corals. Bleached layers contained high concentrations of Mn, Cu, Sn, and Pb. Unbleached layers showed moderately high concentrations of Mn and Cu only. The different distribution of trace metals in Porites may be attributable to different selectivity on the basis of vital utility or toxicity. Ti, V, Cr, and Mo are discriminated against by both coral polyps and zooxanthellae, but Mn, Cu, Sn, and Pb are accumulated by zooxanthellae and only Mn and Cu are accumulated by polyps as essential elements. The marked increase in Cu, Mn, Pb, and Sn are associated with bleaching processes, including mucus secretion, tissue retraction, and zooxanthellae expulsion and occlusion. Variation in these trace elements within the coral skeleton can be used as potential tracers of short-lived bleaching events.

  7. Radioactive contaminants in the subsurface: the influence of complexing ligands on trace metal speciation

    International Nuclear Information System (INIS)

    Hummel, W. . Author

    2006-01-01

    Equilibrium thermodynamics is one of the pillars which support safety analyzes of repositories for radioactive waste. The research summarized in this review deals with approaches to resolve the problems related to thermodynamic equilibrium constants and solubility of solid phases in the field of radioactive waste management. The results have been obtained at the Paul Scherrer Institut between 1995 and 2005 and comprise the scientific basis of the author's habilitation thesis in the field of nuclear environmental chemistry. The topics are grouped according to three different levels of problem solving strategies: critical and comprehensive reviews of the available literature, which are necessary in order to establish a reliable chemical thermodynamic database that fulfils the requirements for rigorous modeling of the behavior of the actinides and fission products in the environment. In many case studies involving inorganic and simple organic ligands a serious lack of reliable thermodynamic data is encountered. There, a new modeling approach to estimate the effects of these missing data was applied. This so called 'backdoor approach' begins with the question, 'What total concentration of a ligand is necessary to significantly influence the speciation, and hence the solubility, of a given trace metal?' In the field of natural organics, mainly humic and fulvic acids, we face an ill-defined problem concerning the molecular structure of the ligands. There, a pragmatic approach for performance assessment purposes was applied, the 'conservative roof' approach, which does not aim to accurately model all experimental data, but allows estimates of maximum effects on metal complexation by humic substances to be calculated. (author)

  8. Trace metal contaminants in sediments and soils: comparison between ICP and XRF quantitative determination

    Directory of Open Access Journals (Sweden)

    Congiu A.

    2013-04-01

    Full Text Available A mineralization method HCl-free for heavy metals analysis in sediments and soils by DRC-ICP-MS was developed. The procedure, which uses concentrated nitric, hydrofluoric acid and hydrogen peroxide, was applied for the analysis of arsenic, cadmium, chromium, nickel and vanadium. The same samples were then analyzed, as pressed pellets, by wavelength dispersive X ray fluorescence (WD-XRF using the dedicated PANalytical Pro Trace solution for the determination of trace elements. Comparison of ICP and XRF data showed good agreement for the elements under investigation, unless for chromium in soils, which recovery was not complete.

  9. Migration of trace heavy metals at the sea water/sediment interface

    International Nuclear Information System (INIS)

    Terada, Kikuo; Tomiyama, Chisato

    1984-01-01

    Migration behavior of some trace heavy metals such as Co(II), Cu(II), Mn(II) and Zn(II) at the sea water/sediment interface was investigated by tank experiments. The sea water which was doped with these metal ions (ppb to ppm levels) allowed to contact with the raw-, ignited- and autoclaved-marine sediments and the change of the concentration of each metal was traced at definite time intervals. At the end of the experiments, a core sample of the sediment was taken and analyzed for each metal in every 1 mm thick segment. On the other hand, the surface sediment was submitted to partial extraction with various kinds of reagents to estimate the chemical species of the metals captured in the sediment. While every metal ion was quickly adsorbed on surface of the raw sediment, a concentration gradient from surface to bottom of the water phase occurred in the ignited sediment system. The migration of manganese to the sediment phase was assumed to be concerned with bacterial activity in the sediment. Copper and zinc seemed to be adsorbed very quickly onto some fine sediment particles by the formation of organometallic complexes with some organic materials existing in the sediments. Cobalt migrated relatively fast downward within the sediment phase after its deposition. (author)

  10. Trace metal contents of selected seeds and vegetables from oil producing areas of Nigeria.

    Science.gov (United States)

    Wegwu, Matthew O; Omeodu, Stephen I

    2010-07-01

    The concentrations of accumulated trace metals in selected seeds and vegetables collected in the oil producing Rivers State of Nigeria were investigated. The values were compared with those of seeds and vegetables cultivated in Owerri, a less industrialized area in Nigeria. The lead (Pb) and cadmium (Cd) contents of the seeds obtained from Rivers State ranged between 0.10 and 0.23 microg/g dry weight, while those of the seeds cultivated in Owerri fell below the detection limit of 0.01 microg/g dry weight. The highest manganese (Mn) level (902 microg/g dry weight) was found in Irvingia garbonesis seeds cultivated in Rivers State. Similarly, the highest nickel (Ni) value (199 microg/g dry weight) was also obtained in I. garbonesis, however, in the seeds sampled in Owerri. The highest copper (Cu), zinc (Zn), and iron (Fe) levels (16.8, 5.27, and 26.2 microg/g dry weight, resp.) were detected in seeds collected in Rivers State. With the exception of Talinum triangulae, Ocinum gratissimum, and Piper guineese, with Pb levels of 0.09, 0.10, and 0.11 microg/g dry weight, respectively, the Pb and Cd levels in the vegetables grown in Owerri fell below the detection limit of 0.01 microg/g dry weight. The trace metal with the highest levels in all the vegetables studied was Mn, followed by Fe. The highest concentrations of Ni and Cu occurred in vegetables collected from Rivers State, while the highest level of Zn was observed in Piper guineese collected in Owerri, with a value of 21.4 microg/g dry weight. Although the trace metal concentrations of the seeds and vegetables collected in Rivers State tended to be higher than those of the seeds and vegetables grown in Owerri, the average levels of trace metals obtained in this study fell far below the WHO specifications for metals in foods.

  11. Trace metal geochemistry in mangrove sediments and their transfer to mangrove plants (New Caledonia)

    International Nuclear Information System (INIS)

    Marchand, C.; Fernandez, J.-M.; Moreton, B.

    2016-01-01

    Because of their physico-chemical inherent properties, mangrove sediments may act as a sink for pollutants coming from catchments. The main objective of this study was to assess the distribution of some trace metals in the tissues of various mangrove plants developing downstream highly weathered ferralsols, taking into account metals partitioning in the sediment. In New Caledonia, mangroves act as a buffer between open-cast mines and the world's largest lagoon. As a result of the erosion of lateritic soils, Ni and Fe concentrations in the sediment were substantially higher than the world average. Whatever the mangrove stand and despite low bioaccumulation and translocations factors, Fe and Ni were also the most abundant metals in the different plant tissues. This low bioaccumulation may be explained by: i) the low availability of metals, which were mainly present in the form of oxides or sulfur minerals, and ii) the root systems acting as barriers towards the transfer of metals to the plant. Conversely, Cu and Zn metals had a greater mobility in the plant, and were characterized by high bioconcentration and translocation factors compared to the other metals. Cu and Zn were also more mobile in the sediment as a result of their association with organic matter. Whatever the metal, a strong decrease of trace metal stock was observed from the landside to the seaside of the mangrove, probably as a result of the increased reactivity of the sediment due to OM enrichment. This reactivity lead to higher dissolution of bearing phases, and thus to the export of dissolved trace metals trough the tidal action. Cu and Zn were the less concerned by the phenomenon probably as a result of higher plant uptake and their restitution to the sediment with litter fall in stands where tidal flushing is limited. - Highlights: • Unusual high concentrations of Fe and Ni were measured in mangrove tissues. • Bioconcentration and translocation factors of Fe, Ni, Co and Mn were low. • Low

  12. Trace metal geochemistry in mangrove sediments and their transfer to mangrove plants (New Caledonia)

    Energy Technology Data Exchange (ETDEWEB)

    Marchand, C., E-mail: cyril.marchand@ird.fr [Institut de Recherche pour le Développement (IRD), UR 206/UMR 7590 IMPMC, 98848 Nouméa, New Caledonia (France); Fernandez, J.-M.; Moreton, B. [AEL/LEA, 7 rue Loriot de Rouvray, 98800 Nouméa, New Caledonia (France)

    2016-08-15

    Because of their physico-chemical inherent properties, mangrove sediments may act as a sink for pollutants coming from catchments. The main objective of this study was to assess the distribution of some trace metals in the tissues of various mangrove plants developing downstream highly weathered ferralsols, taking into account metals partitioning in the sediment. In New Caledonia, mangroves act as a buffer between open-cast mines and the world's largest lagoon. As a result of the erosion of lateritic soils, Ni and Fe concentrations in the sediment were substantially higher than the world average. Whatever the mangrove stand and despite low bioaccumulation and translocations factors, Fe and Ni were also the most abundant metals in the different plant tissues. This low bioaccumulation may be explained by: i) the low availability of metals, which were mainly present in the form of oxides or sulfur minerals, and ii) the root systems acting as barriers towards the transfer of metals to the plant. Conversely, Cu and Zn metals had a greater mobility in the plant, and were characterized by high bioconcentration and translocation factors compared to the other metals. Cu and Zn were also more mobile in the sediment as a result of their association with organic matter. Whatever the metal, a strong decrease of trace metal stock was observed from the landside to the seaside of the mangrove, probably as a result of the increased reactivity of the sediment due to OM enrichment. This reactivity lead to higher dissolution of bearing phases, and thus to the export of dissolved trace metals trough the tidal action. Cu and Zn were the less concerned by the phenomenon probably as a result of higher plant uptake and their restitution to the sediment with litter fall in stands where tidal flushing is limited. - Highlights: • Unusual high concentrations of Fe and Ni were measured in mangrove tissues. • Bioconcentration and translocation factors of Fe, Ni, Co and Mn were low.

  13. Microscopic evaluation of trace metals in cloud droplets in an acid precipitation region.

    Science.gov (United States)

    Li, Weijun; Wang, Yan; Collett, Jeffrey L; Chen, Jianmin; Zhang, Xiaoye; Wang, Zifa; Wang, Wenxing

    2013-05-07

    Mass concentrations of soluble trace metals and size, number, and mixing properties of nanometal particles in clouds determine their toxicity to ecosystems. Cloud water was found to be acidic, with a pH of 3.52, at Mt. Lu (elevation 1,165 m) in an acid precipitation region in South China. A combination of Inductively Coupled Plasma Mass Spectrometry (ICPMS) and Transmission Electron Microscopy (TEM) for the first time demonstrates that the soluble metal concentrations and solid metal particle number are surprisingly high in acid clouds at Mt. Lu, where daily concentrations of SO2, NO2, and PM10 are 18 μg m(-3), 7 μg m(-3), and 22 μg m(-3). The soluble metals in cloudwater with the highest concentrations were zinc (Zn, 200 μg L(-1)), iron (Fe, 88 μg L(-1)), and lead (Pb, 77 μg L(-1)). TEM reveals that 76% of cloud residues include metal particles that range from 50 nm to 1 μm diameter with a median diameter of 250 nm. Four major metal-associated particle types are Pb-rich (35%), fly ash (27%), Fe-rich (23%), and Zn-rich (15%). Elemental mapping shows that minor soluble metals are distributed within sulfates of cloud residues. Emissions of fine metal particles from large, nonferrous industries and coal-fired power plants with tall stacks were transported upward to this high elevation. Our results suggest that the abundant trace metals in clouds aggravate the impacts of acid clouds or associated precipitation on the ecosystem and human health.

  14. Assessment of acid leachable trace metals in sediment cores from River Uppanar, Cuddalore, Southeast coast of India

    International Nuclear Information System (INIS)

    Ayyamperumal, T.; Jonathan, M.P.; Srinivasalu, S.; Armstrong-Altrin, J.S.; Ram-Mohan, V.

    2006-01-01

    An acid leachable technique is employed in core samples (C1, C2 and C3) to develop a baseline data on the sediment quality for trace metals of River Uppanar, Cuddalore, southeast coast of India. Acid leachable metals (Fe, Mn, Cr, Cu, Ni, Co, Pb, Zn and Cd) indicate peak values at the sulphidic phase and enrichment of metals in the surface layers are due to the anthropogenic activities. Association of trace metals with Fe, Mn indicates their adsorption onto Fe-Mn oxyhydroxides and their correlation with S indicate that they are precipitated as metal sulphides. Factor analysis identified three possible types of geochemical associations and the supremacy of trace metals along with Fe, Mn, S and mud supports their geochemical associations. Factor analysis also signifies that anthropogenic activities have affected both the estuarine and fresh water regions of River Uppanar. - Both natural and anthropogenic factors are affecting metals in sediments

  15. Recovery of Trace and Heavy Metals from Coal Combustion Residues for Reuse and Safe Disposal: A Review

    Science.gov (United States)

    Kumar, Ashvani; Samadder, Sukha Ranjan; Elumalai, Suresh Pandian

    2016-09-01

    The safe disposal of coal combustion residues (CCRs) will remain a major public issue as long as coal is used as a fuel for energy production. Both dry and wet disposal methods of CCRs create serious environmental problems. The dry disposal method creates air pollution initially, and the wet disposal method creates water pollution as a result of the presence of trace and heavy metals. These leached heavy metals from fly ash may become more hazardous when they form toxic compounds such as arsenic sulfite (As2S3) and lead nitrate (N2O6Pb). The available studies on trace and heavy metals present in CCRs cannot ensure environmentally safe utilization. In this work, a novel approach has been offered for the retrieval of trace and heavy metals from CCRs. If the proposed method becomes successful, then the recovered trace and heavy metals may become a resource and environmentally safe use of CCRs may be possible.

  16. Mobility and fluxes of major, minor and trace metals during basalt weathering and groundwater transport at Mt. Etna volcano (Sicily)

    Energy Technology Data Exchange (ETDEWEB)

    Aiuppa, A.; Allard, P.; D' Alessandro, W.; Michel, A.; Parello, F.; Treuil, M.; Valenza, M.

    2000-06-01

    The concentrations and fluxes of major, minor and trace metals were determined in 53 samples of groundwaters from around Mt. Etna, in order to evaluate the conditions and extent of alkali basalt weathering by waters enriched in magma-derived CO{sub 2} and the contribution of aqueous transport to the overall metal discharge of the volcano. The authors show that gaseous input of magmatic volatile metals into the Etnean aquifer is small or negligible, being limited by cooling of the rising fluids. Basalt leaching by weakly acidic, CO{sub 2}-charged water is the overwhelming source of metals and appears to be more extensive in two sectors of the S-SW (Paterno) and E (Zafferana) volcano flanks, where out flowing groundwaters are the richest in metals and bicarbonate of magmatic origin. Thermodynamic modeling of the results allows evaluation of the relative mobility and chemical speciation of various elements during their partitioning between solid and liquid phases through the weathering process. At Mt. Etna, poorly mobile elements (Al, Th, Fe) are preferentially retained in the solid residue of weathering, while alkalis, alkaline earth and oxo-anion-forming elements (As, Se, Sb, Mo) are more mobile and released to the aqueous system. Transition metals display an intermediate behavior and are strongly dependent on either the redox conditions (Mn, Cr, V) or solid surface-related processes (V, Zn, Cu).

  17. First assessment of trace metal concentration in mangrove crab eggs and other tissues, SE Brazil.

    Science.gov (United States)

    de Almeida, Eduardo Vianna; Kütter, Vinicius Tavares; Marques, Eduardo Duarte; da Silva-Filho, Emmanoel Vieira

    2016-07-01

    The mangrove crab Ucides cordatus is widespread in the Brazilian coast, which has an important role in nutrient cycling. This species reproduces in summer and females carry eggs about a month, when they maintain contact with water and sediments. It remains unclear if trace metals can be absorbed or adsorbed by the eggs during development. The present study aims to investigate, for the first time, trace metal concentrations in ovigerous female tissues and eggs of U. cordatus in two areas with different metal pollution levels in the Southeastern Brazil. Samples were collected in two different mangroves, Guanabara Bay (GB) highly polluted environment and Paraíba do Sul River (PSR). In both populations, we observed significant increase of V, Cr, and Mn concentrations along eggs maturation. The higher metals averages were found in PSR population. This trend was reported since the 1990s and lower concentrations in GB marine organisms were attributed to reducing conditions, high organic load, and the presence of sulfide ions. These conditions restrict the bioavailability of metals in the bay, with exception of Mn. No significant differences were observed in gills and muscles. In both populations of the present study, V, Zn, As, and Pb were higher in eggs of initial stage, whereas Mn, Ni, Cu, and Cd were higher in hepatopancreas. Beside this, V, Cr, Mn, As, and Pb showed an increase concerning egg development. Thus, V, As, and Pb in eggs come from two sources previous discussed: females and environment. Zinc came mainly from females due to essential function. Those new information should be considered as one of the mechanisms of trace metal transfer to the trophic chain, between benthonic and pelagic environment.

  18. Feedback interactions between trace metal nutrients and phytoplankton in the ocean

    Directory of Open Access Journals (Sweden)

    William eSunda

    2012-06-01

    Full Text Available In addition to control by major nutrient elements (nitrogen, phosphorus, and silicon the productivity and species composition of marine phytoplankton communities are affected by a number of trace metal nutrients (iron, zinc, cobalt, manganese, copper, and cadmium. Of these, iron exerts the greatest limiting influence on carbon fixation rates and has the greatest effect on algal species diversity. It also plays an important role in limiting di-nitrogen (N2 fixation rates, and thus exerts an important influence on ocean inventories of biologically available fixed nitrogen. Because of these effects, iron is thought to play a key role in controlling the biological cycles of carbon and nitrogen in the ocean, including the biological transfer of carbon to the deep sea, the so-called biological CO2 pump, which helps regulate atmospheric CO2 levels and CO2-linked global warming. Other trace metal nutrients (zinc, cobalt, copper, and manganese have a lesser effect on productivity; but may exert an important influence on the species composition of algal communities because of large differences in metal requirements among algal species. The interactions between trace metals and ocean plankton are reciprocal: not only do the metals affect the plankton, but the plankton regulate the distributions, chemical speciation, and cycling of these metals through cellular uptake and regeneration processes, downward flux of biogenic particles, cellular release of organic chelators, and mediation of redox reactions. This two way interaction has influenced not only the biology and chemistry of the modern ocean, but has had a profound influence on biogeochemistry of the ocean and earth system as a whole, and on the evolution marine and terrestrial biology over geologic history.

  19. Trace and low concentration co2 removal methods and apparatus utilizing metal organic frameworks

    KAUST Repository

    Eddaoudi, Mohamed

    2016-03-10

    In general, this disclosure describes techniques for removing trace and low concentration CO2 from fluids using SIFSIX-n-M MOFs, wherein n is at least two and M is a metal. In some embodiments, the metal is zinc or copper. Embodiments include devices comprising SIFSIX-n-M MOFs for removing CO2 from fluids. In particular, embodiments relate to devices and methods utilizing SIFSIX-n-M MOFs for removing CO2 from fluids, wherein CO2 concentration is trace. Methods utilizing SIFSIX-n-M MOFs for removing CO2 from fluids can occur in confined spaces. SIFSIX-n-M MOFs can comprise bidentate organic ligands. In a specific embodiment, SIFSIX-n-M MOFs comprise pyrazine or dipryidilacetylene ligands.

  20. LA-ICP-MS Study of Trace Elements in the Chanuskij Metal

    Science.gov (United States)

    Petaev, Michail I.

    2005-01-01

    This progress report covers work done during the second year of the 3-year proposal. During this year we resolved many issues relevant to the analytical technique developed by us for measuring trace elements in meteoritic metals. This technique was used to measure concentrations of Fe, Ni, Co, Cr, Cu, Ga, Ge, As, Mo, Ru, Rh, Pd, Sb, W, Re, Os, Ir, Pt, and Au in eight large (120 - 160 microns) metal grains from both "igneous" and "metamorphic" lithologies of the Chanuskij silicate inclusions. The first application of OUT technique to metal grains from thin sections showed some limitations. Small thickness of metal grains in the thin section limited the signal to 3-4 time-slices instead of 10- 1 1 ones in polished sections of iron meteorites studied before.

  1. Distribution of uranium and some selected trace metals in human scalp hair from Balkans.

    Science.gov (United States)

    Zunic, Z S; Tokonami, S; Mishra, S; Arae, H; Kritsananuwat, R; Sahoo, S K

    2012-11-01

    The possible consequences of the use of depleted uranium (DU) used in Balkan conflicts in 1995 and 1999 for the people and the environment of this reason need attention. The heavy metal content in human hair may serve as a good indicator of dietary, environmental and occupational exposures to the metal compounds. The present work summarises the distribution of uranium and some selected trace metals such as Mn, Ni, Cu, Zn, Sr, Cd and Cs in the scalp hair of inhabitants from Balkans exposed to DU directly and indirectly, i.e. Han Pijesak, Bratoselce and Gornja Stubla areas. Except U and Cs, all other metals were compared with the worldwide reported values of occupationally unexposed persons. Uranium concentrations show a wide variation ranging from 0.9 ± 0.05 to 449 ± 12 µg kg(-1). Although hair samples were collected from Balkan conflict zones, uranium isotopic measurement ((235)U/(238)U) shows a natural origin rather than DU.

  2. Comparison of trace metal bioavailabilities in European coastal waters using mussels from Mytilus edulis complex as biomonitors

    NARCIS (Netherlands)

    Przytarska, J.E.; Sokołowski, A.; Wołowicz, M.; Hummel, H.; Jansen, J.M.

    2010-01-01

    Mussels from Mytilus edulis complex were used as biomonitors of the trace metals Fe, Mn, Pb, Zn, and Cu at 17 sampling sites to assess the relative bioavailability of metals in coastal waters around the European continent. Because accumulated metal concentrations in a given area can differ

  3. Tracing the cosmic metal evolution in the low-redshift intergalactic medium

    Energy Technology Data Exchange (ETDEWEB)

    Michael Shull, J. [Also at Institute of Astronomy, University of Cambridge, Cambridge CB3 OHA, UK. (United Kingdom); Danforth, Charles W.; Tilton, Evan M., E-mail: michael.shull@colorado.edu, E-mail: danforth@colorado.edu, E-mail: evan.tilton@colorado.edu [CASA, Department of Astrophysical and Planetary Sciences, University of Colorado, Boulder, CO 80309 (United States)

    2014-11-20

    Using the Cosmic Origins Spectrograph aboard the Hubble Space Telescope, we measured the abundances of six ions (C III, C IV, Si III, Si IV, N V, and O VI) in the low-redshift (z ≤ 0.4) intergalactic medium (IGM). Both C IV and Si IV have increased in abundance by a factor of ∼10 from z ≈ 5.5 to the present. We derive ion mass densities, ρ{sub ion} ≡ Ω{sub ion}ρ{sub cr}, with Ω{sub ion} expressed relative to the closure density. Our models of mass-abundance ratios, (Si III/Si IV) =0.67{sub −0.19}{sup +0.35}, (C III/C IV) =0.70{sub −0.20}{sup +0.43}, and (Ω{sub C} {sub III}+Ω{sub C} {sub IV})/(Ω{sub Si} {sub III}+Ω{sub Si} {sub IV})=4.9{sub −1.1}{sup +2.2}, are consistent with the photoionization parameter log U = –1.5 ± 0.4, hydrogen photoionization rate Γ{sub H} = (8 ± 2) × 10{sup –14} s{sup –1} at z < 0.4, and specific intensity I {sub 0} = (3 ± 1) × 10{sup –23} erg cm{sup –2} s{sup –1} Hz{sup –1} sr{sup –1} at the Lyman limit. Consistent ionization corrections for C and Si are scaled to an ionizing photon flux Φ{sub 0} = 10{sup 4} cm{sup –2} s{sup –1}, baryon overdensity Δ {sub b} ≈ 200 ± 50, and ''alpha-enhancement'' (Si/C enhanced to three times its solar ratio). We compare these metal abundances to the expected IGM enrichment and abundances in higher photoionized states of carbon (C V) and silicon (Si V, Si VI, and Si VII). Our ionization modeling infers IGM metal densities of (5.4 ± 0.5) × 10{sup 5} M {sub ☉} Mpc{sup –3} in the photoionized Lyα forest traced by the C and Si ions and (9.1 ± 0.6) × 10{sup 5} M {sub ☉} Mpc{sup –3} in hotter gas traced by O VI. Combining both phases, the heavy elements in the IGM have mass density ρ {sub Z} = (1.5 ± 0.8) × 10{sup 6} M {sub ☉} Mpc{sup –3} or Ω {sub Z} ≈ 10{sup –5}. This represents 10% ± 5% of the metals produced by (6 ± 2) × 10{sup 8} M {sub ☉} Mpc{sup –3} of integrated star formation with yield y{sub m} = 0

  4. Integrated luminometer for the determination of trace metals in seawater using fluorescence, phosphorescence and chemiluminescence detection

    OpenAIRE

    Worsfold, P. J.; Achterberg, E. P.; Bowie, A. R.; Cannizzaro, V.; Charles, S.; Costa, J. M.; Dubois, F.; Pereiro, R.; San Vicente, B.; Sanz-Medel, A.; Vandeloise, R.; Donckt, E. Vander; Wollast, P.; Yunus, S.

    2002-01-01

    The paper describes an integrated luminometer able to perform fluorescence (FL), room temperature phosphorescence (RTP) and chemiluminescence (CL) measurements on seawater samples. The technical details of the instrumentation are presented together with flow injection (FI) manifolds for the determination of cadmium and zinc (by FL), lead (RTP) and cobalt (CL). The analytical figures of merit are given for each mainfold and results are presented for the determination of the four trace metals i...

  5. Levels of trace metals in water and sediment from Tyume River and ...

    African Journals Online (AJOL)

    Higher levels of Cd (0.038 ± 0.004 to 0.044 ± 0.003 mg/l) and Pb (0.021 ± 0.004 to 0.035 ± 0.001 mg/l) were found in the river water, which may be detrimental to the “health” of the aquatic ecosystem and the rural communities that utilise the river water for ... Key words: trace metals, water, sediment, farmland, Tyume River

  6. Trace metal concentrations in marine organisms from the Eastern Aegean, Turkey

    International Nuclear Information System (INIS)

    Kucuksezgin, F.

    1999-01-01

    Monitoring of mercury, cadmium and lead levels in striped mullet (Mullus barbatus) was conducted in the Eastern Aegean over 3 year period and in some other species during 1996 in the framework of a National Marine Measurement Program and MED-POL II Project for the Aegean Sea. Of all the research on the concentrations of trace metals in the Aegean environment only a little has been carried out in that part of the Eastern Aegean

  7. Determination of trace metals in Cladophora glomerata: C. glomerata as a potential biological monitor

    Energy Technology Data Exchange (ETDEWEB)

    Keeny, W.L.; Breck, W.G.; Vanloon, G.W.; Page, J.A.

    1976-01-01

    A differential pulse anodic stripping voltammetry method has been developed for the determination of Zn, Cd, Pb and Cu in Cladophora glomerata. The method has been applied to samples taken in August from a remote island in Lake Ontario (Main Duck) and a shore site near Kingston, Ontario (Deadman Bay). It is postulated that C. glomerata can act as a biological monitor, concentrating the trace metals present in the aqueous environment with a reasonably constant CF for each element.

  8. The interaction of trace heavy metal with lipid monolayer in the sea surface microlayer.

    Science.gov (United States)

    Li, Siyang; Du, Lin; Tsona, Narcisse T; Wang, Wenxing

    2018-04-01

    Lipid molecules and trace heavy metals are enriched in sea surface microlayer and can be transferred into the sea spray aerosol. To better understand their impact on marine aerosol generation and evolution, we investigated the interaction of trace heavy metals including Fe 3+ , Pb 2+ , Zn 2+ , Cu 2+ , Ni 2+ , Cr 3+ , Cd 2+ , and Co 2+ , with dipalmitoylphosphatidylcholine (DPPC) monolayers at the air-water interface. Phase behavior of the DPPC monolayer on heavy metal solutions was probed with surface pressure-area (π-A) isotherms. The conformation order and orientation of DPPC alkyl chains were characterized by infrared reflection-absorption spectroscopy (IRRAS). The π-A isotherms show that Zn 2+ and Fe 3+ strongly interact with DPPC molecules, and induce condensation of the monolayers in a concentration-dependent manner. IRRAS spectra show that the formation of cation-DPPC complex gives rise to conformational changes and immobilization of the headgroups. The current results suggest that the enrichment of Zn 2+ in sea spray aerosols is due to strong binding to the DPPC film. The interaction of Fe 3+ with DPPC monolayers can significantly influence their surface organizations through the formation of lipid-coated particles. These results suggest that the sea surface microlayer is capable of accumulating much higher amounts of these metals than the subsurface water. The organic and metal pollutants may transfer into the atmosphere by this interaction. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. The trace metals accumulation in marine organisms of the southeastern Adriatic coast, Montenegro

    Directory of Open Access Journals (Sweden)

    Joksimovic Danijela

    2012-01-01

    Full Text Available The concentration and accumulation of trace metals (Co, Ni, As, Cd, Pb and Hg were measured in sea water, sediments and marine organisms in the coastline of the Montenegro. The obtained results of trace metals in seagrass and mussels were compared with those found in the water column and sediment. Sampling was performed in the fall of 2005 at five locations in the Montenegrin coastline, Sveta Stasija, Herceg Novi, Zanjice, Budva and Bar, which present different levels and sources of human impact. The heavy metals analyses in seawater, sediment, P. oceanica and M. galloprovincialis identified the harbor of Bar as the most Hg-contaminated site, Zanjice as the most As contaminated and Sveta Stasija as the most Pb-contaminated areas of the Montenegrin coastal area. This study showed that P. oceanica may have a greater bioaccumulation capacity than M. galloprovincialis for the considered metals, except for As and Hg, and both organisms may reflect contamination in the water column and in the sediment. For the first time, seagrass P. oceanica and M. galloprovincialis were employed as metal bioindicators for the southeastern Adriatic. The results of this study could serve as a baseline in the future for the assessment of anthropogenic effects in this marine ecosystem.

  10. Heavy metal pollution and Pb isotopic tracing in the intertidal surface sediments of Quanzhou Bay, southeast coast of China

    International Nuclear Information System (INIS)

    Yu, Ruilian; Zhang, Weifang; Hu, Gongren; Lin, Chengqi; Yang, Qiuli

    2016-01-01

    Concentrations of 16 heavy metals and Pb isotopic ratios in the intertidal surface sediments of Quanzhou Bay were determined to study the pollution level of heavy metals and the sources of Pb. The results showed that most concentrations of Cd, Sn, Mn, Cu, Zn, Cr, Pb, Hg, Ni, Co, Cs, Fe and V were higher than the background values, while most concentrations of Ti, Sb and Sr were lower than the background values. The mean concentrations of Cu, Zn, Pb, Cr and Cd exceeded the first-grade criteria of Chinese marine sediment quality. The geo-accumulation indexes revealed that the sediments had been polluted by some heavy metals. The results of Pb isotopic tracing indicated that the total Pb in the sediments were mainly from parent material, industrial emission and vehicle exhaust with the mean contributions of 38.2%, 51.3% and 10.5%, respectively, calculated by a three-end-member model of Pb isotopic ratios. - Highlights: •Level of 16 heavy metals in intertidal surface sediments of Quanzhou Bay was studied. •The sediments had been polluted by some heavy metals including Pb. •Pb isotopic compositions in the sediments and the potential sources were determined. •A three-end member model was applied to estimate the contributions of Pb sources. •Industrial emission was the major anthropogenic Pb contributor in the sediments.

  11. Concentration of trace metals in boreholes in the Ankobra Basin, Ghana

    International Nuclear Information System (INIS)

    Kortasi, B. K.

    2006-01-01

    Analysis of trace metals in ground water from the Ankobra basin revealed high levels of iron, manganese and aluminium. Approximately 40% of boreholes had total iron concentration exceeding 1000 μ 1 -1 (maximum WHO permissible limit). Aluminium concentration varied from 0.1 μ to 2510 μ 1 -1 with a median value of 10.0 μ 1 -1 . Approximately 20% of the boreholes had aluminium concentration exceeding the WHO maximum acceptable limit (200 μ 1 -1 ) for drinking water. Manganese concentration was in the range 6-2510 μ 1 -1 with a median of 356 μ 1 -1 . Roughly 25% of the boreholes had manganese concentrations higher that 500 μ 1 -1 , which is the WHO maximum acceptable limit for drinking water. The concentrations of mercury was higher than 1.0 μ 1 -1 (WHO maximum acceptable limit) in 60% of the boreholes during the rainy season but below detection limit in the dry season, suggesting anthropogenic origin for mercury in the groundwater. Other trace metals that occurred, but in insignificant concentration in the boreholes, include lead, arsenic, nickel and selenium. Most of the boreholes with high trace metal concentrations were located in and around the Bawdie-Bogoso-Prestea area. (au)

  12. Highly sensitive colour change system within slight differences in metal ion concentrations based on homo-binuclear complex formation equilibrium for visual threshold detection of trace metal ions

    International Nuclear Information System (INIS)

    Mizuguchi, Hitoshi; Atsumi, Hiroshi; Hashimoto, Keigo; Shimada, Yasuhiro; Kudo, Yuki; Endo, Masatoshi; Yokota, Fumihiko; Shida, Junichi; Yotsuyanagi, Takao

    2004-01-01

    A new technique of expressing slight differences in metal ion concentrations by clear difference in colour was established for visual threshold detection of trace metal ions. The proposed method is based on rapid change of the mole fraction of the homo-binuclear complex (M 2 L) about a ligand in a narrow range of the total metal ion concentration (M T ) in a small excess, in case the second metal ion is bound to the reagent molecule which can bind two metal ions. Theoretical simulations showed that the highly sensitive colour change within slight differences in metal ion concentrations would be realized under the following conditions: (i) both of the stepwise formation constants of complex species are sufficiently large; (ii) the stepwise formation constant of the 1:1 complex (ML) is larger than that of M 2 L; and (iii) the absorption spectrum of M 2 L is far apart from the other species in the visible region. Furthermore, the boundary of the colour region in M T would be readily controlled by the total ligand concentration (L T ). Based on this theory, the proposed model was verified with the 3,3'-bis[bis(carboxymethyl)amino]methyl derivatives of sulphonephthalein dyes such as xylenol orange (XO), methylthymol blue (MTB), and methylxylenol blue (MXB), which can bind two metal ions at both ends of a π-electron conjugated system. The above-mentioned model was proved with the iron(III)-XO system at pH 2. In addition, MTB and MXB were suitable reagents for the visual threshold detection of trivalent metal ions such as iron(III), aluminium(III), gallium(III) and indium(III) ion in slightly acidic media. The proposed method has been applied successfully as a screening test for aluminium(III) ion in river water sampled at the downstream area of an old mine

  13. Phytotoxicity of trace metals in spiked and field-contaminated soils: Linking soil-extractable metals with toxicity.

    Science.gov (United States)

    Hamels, Fanny; Malevé, Jasmina; Sonnet, Philippe; Kleja, Dan Berggren; Smolders, Erik

    2014-11-01

    Soil tests have been widely developed to predict trace metal uptake by plants. The prediction of metal toxicity, however, has rarely been tested. The present study was set up to compare 8 established soil tests for diagnosing phytotoxicity in contaminated soils. Nine soils contaminated with Zn or Cu by metal mining, smelting, or processing were collected. Uncontaminated reference soils with similar soil properties were sampled, and series of increasing contamination were created by mixing each with the corresponding soil. In addition, each reference soil was spiked with either ZnCl2 or CuCl2 at several concentrations. Total metal toxicity to barley seedling growth in the field-contaminated soils was up to 30 times lower than that in corresponding spiked soils. Total metal (aqua regia-soluble) toxicity thresholds of 50% effective concentrations (EC50) varied by factors up to 260 (Zn) or 6 (Cu) among soils. For Zn, variations in EC50 thresholds decreased as aqua regia > 0.43 M HNO3  > 0.05 M ethylenediamine tetraacetic acid (EDTA) > 1 M NH4 NO3  > cobaltihexamine > diffusive gradients in thin films (DGT) > 0.001 M CaCl2 , suggesting that the last extraction is the most robust phytotoxicity index for Zn. The EDTA extraction was the most robust for Cu-contaminated soils. The isotopically exchangeable fraction of the total soil metal in the field-contaminated soils markedly explained the lower toxicity compared with spiked soils. The isotope exchange method can be used to translate soil metal limits derived from soils spiked with metal salts to site-specific soil metal limits. © 2014 SETAC.

  14. Accumulation of trace metals by aquatic macrophytes and their possible use in phytoremediation techniques

    Directory of Open Access Journals (Sweden)

    Michaela Hillermannová

    2008-01-01

    Full Text Available The aim of the performed research was to obtain knowledge on the ability of aquatic plants naturally growing at a site to absorb trace metals contained in bottom sediments and surface water. Furthermore, we compared differences in the accumulation of trace metals by the individual groups of aquatic plants (submerged and emergent and assessed a possible use of the individual plant species in phytoremediation techniques. Representative samples of water, sediments and aquatic macrophytes were taken from three anthropogenically loaded streams in six monitoring cycles in several collection profiles differing in the distance from a source of contamination. The samples were analysed for the total content of selected trace metals (As, Cd, Pb, Al, Hg, Zn, Fe, Mn, Cr, Ni and Cu. For comparison, one profile at an unloaded site was sampled as well. The obtained results were subjected to multivariate statistical analysis of data. Increased contents of Fe, Al, Mn, Cr and Zn were detected in sediments and plant biomass at loaded sites, namely 2–3× higher than at the comparing site. The contents of metals in surface water samples were altogether below the detection limit of the analytical method. When evaluating the individual plant species, we can state that the lowest contents of metals were detected in shore species (reed canary grass Phalaroides arundinacea, wood club-rush Scirpus silvaticus and red dock Rumex aquaticus; plant species growing in the very water current (water star-wort Callitriche sp. and flote-grass Glyceria fluitans exhibited mean contents of metals. In species forming mats (Fontinalis antipyretica and Cladophora sp., these contents were several times higher as compared to the previous species. The results of the performed research show that one of important factors, which influence the accumulation of trace metals in plants, is their ecological group (emergent – submerged affiliation and the species classification within this group

  15. ARTEAM - Advanced ray tracing with earth atmospheric models

    NARCIS (Netherlands)

    Kunz, G.J.; Moerman, M.M.; Eijk, A.M.J. van

    2002-01-01

    The Advanced Ray Tracing with Earth Atmospheric Models (ARTEAM) aims at a description of the electro-optical propagation environment in the marine atmospheric surface layer. For given meteorological conditions, the model evaluates height- and range-resolved transmission losses, refraction and

  16. Health Risk Assessment of Trace Metals in Various Environmental Media, Crops and Human Hair from a Mining Affected Area

    Directory of Open Access Journals (Sweden)

    Wushuang Xie

    2017-12-01

    Full Text Available Long term exposure to trace metals in various media is of great concern for people living in known pollution sources, such as mining and industrial activities. Health risk assessment and human hair analysis can provide important information for local environmental management. Information on distribution characteristics of trace metals in soil, water, sediment, air, local crops, and human hair from a typical mining area in southern China was collected. Results show there exists severely trace metal contamination in soil, sediment, and air. Arsenic and Pb contents in the local children’s hair are higher than the upper reference values, and the accumulation of residents’ hair trace metals shows great correlation with the ingestion and inhalation pathways. Arsenic contributes 52.27% and 58.51% to the total non-cancer risk of adults and children, respectively. The cancer risk of Cd in adults and children are 4.66 and 3.22 times higher than the safe level, respectively. Ingestion exposure pathway of trace metals largely contributes to the total non-cancer and cancer effect. The metals As, Cd, and Pb are major risk sources and pollutants that should be given priority for management, and ingestion pathway exposure to trace metals through soil and crops should be controlled.

  17. Effects of incubation on solubility and mobility of trace metals in two contaminated soils

    International Nuclear Information System (INIS)

    Ma, Lena Q.; Dong Yan

    2004-01-01

    Much research has focused on changes in solubility and mobility of trace metals in soils under incubation. In this experiment, changes in solubility and mobility of trace metals (Pb, Cu and As) and Fe in two contaminated soils from Tampa, Florida and Montreal, Canada were examined. Soils of 30 g were packed in columns and were incubated for 3-80 days under water-flooding incubation. Following incubation, metal concentrations in pore water (water soluble) and in 0.01 M CaCl 2 leachates (exchangeable+water soluble) were determined. While both soils were contaminated with Pb (1600-2500 mg kg -1 ), Tampa soil was also contaminated with As (230 mg kg -1 ). Contrast to the low pH (3.8) of Tampa soil, Montreal soil had an alkaline pH of 7.7 and high Ca of 1.6%. Concentrations of Fe(II) increased with incubation time in the Tampa soil mainly due to reductive Fe dissolution, but decreased in the Montreal soil possibly due to formation of FeCO 3 . The inverse relationship between concentrations of Pb and Fe(II) in pore water coupled with the fact that Fe(II) concentrations were much greater than those of Pb in pore water may suggest the importance of Fe(II) in controlling Pb solubility in soils. However, changes in concentrations of Fe(II), Pb, Cu and As in pore water with incubation time were similar to those in leachate, i.e. water soluble metals were positively related to exchangeable metals in the two contaminated soils. This research suggests the importance of Fe in controlling metal solubility and mobility in soils under water-flooded incubation. - Iron is important in controlling metal solubility and mobility in flooded soils

  18. Contamination and Health Risks from Heavy Metals (Cd and Pb and Trace Elements (Cu and Zn in Dairy Products

    Directory of Open Access Journals (Sweden)

    Hamid Reza Ghafari

    2017-08-01

    Conclusion: Considering the serious contamination of some brands of butter and cheese by Cu and Pb, a control of heavy metals and trace elements levels during the whole production processing of dairy products must be applied.

  19. Distribution, provenance and early diagenesis of major and trace metals in sediment cores from the Mandovi estuary, western India

    Digital Repository Service at National Institute of Oceanography (India)

    Prajith, A.; Rao, V.P.; Chakraborty, P.

    Major elements and trace metals were analyzed in four sediment cores recovered along a transect in the Mandovi estuary for their distribution, provenance and early diagenesis. The sediments were clayey silts in cores from the upper/lower estuary...

  20. Distribution and seasonal variation of trace metals in surface sediments of the Mandovi estuary, west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Alagarsamy, R.

    The concentration and distribution of selected trace metals in surface sediments of the Mandovi estuary were studied to determine the extent of anthropogenic inputs from mining activities and to estimate the effects of monsoon on geochemical...

  1. PENGEMBANGAN MODEL TRACKING DAN TRACING DALAM DISTRIBUSI KOMODITI PERTANIAN

    Directory of Open Access Journals (Sweden)

    Yandra Rahadian Perdana

    2011-06-01

    Full Text Available Kegagalan distribusi komoditi pertanian dapat berdampak pada penurunan dan kehilangan nilai baik secara kualitas dan kuantitas karena suatu perubahan dimensi waktu-jarak atau suhu serta sarana pengangkutan dalam setiap mata rantai aktivitas distribusi. Model tracking dan tracing system dapat menjadi strategi untuk menjamin keberhasilan distribusi komoditi pertanian secara tepat baik kuantitas maupun kualitas. Model tracking dan tracing komoditi pertanian adalah sebuah sistem proaktif yang real time yang dilengkapi dengan komponen pendukung proses distribusi dengan data yang akurat, terpercaya, berguna, dan cepat dengan memberikan informasi posisi barang atau sarana moda transportasinya.

  2. A Multi-Scale Study on the Role of Trace Metals on Physiological and Pathological Mineralization

    Science.gov (United States)

    Rammelkamp, Derek

    The work in this thesis provides mulit-scale contributions towards understanding the effects of trace metals on the pathological mineralization process relating to both the development of healthy bone tissue, the diseased state of osteoporosis, and microcalcifications which develop in breast cancers. A protein level study was performed on ECM protein fibronectin, which plays a role in cell adhesion. The protein studies showed zinc interactions with fibronectin and its fragment, anastellin, to influence protein structure. Zinc is also shown to decrease cell migration in vitro, which may be influenced by changes in fibronectin ECM structure. The effects of osteoporosis on micronutrient composition in vivo were examined using the technique of x-ray fluorescence (XRF) in an ovariectomized rat model. Compared to healthy bone, subtle difference are observed in zinc and iron in osteoporotic rat bones, showing micronutrients may play an important role in healthy bone regulation. Effects of micronutrient zinc was used to inhibit microcalcification formation in breast cancers. Microcalcifications have been linked malignancy of breast cancers, but the process of microcalcification formation has yet to be well understood. In this work, exogenous zinc is used to inhibit microcalcification formation, and metastatic potential in both a 2D and 3D spheroid environment. A novel in vitro self-assembled three dimensional multi-cellular tumor spheroid (MCTS) model for the study of breast cancer microcalcifications was developed for this experiment. A MCTS model for studying breast cancer microcalcifications has potential to be used in drug discovery, or for basic research applications studying mechanisms of microcalcification formation, which are still not fully understood. Taken together this study uses a multi-scale approach to gain a better understanding of micronutrients involved in pathological mineralization.

  3. Levels of some Trace Metals in Macroalgae from the Red Sea in Egypt

    International Nuclear Information System (INIS)

    Aboul-Naga, Wafiqa Mohamed

    2005-01-01

    The concentrations of iron (Fe), Zinc (Zn), manganese (Mn), Copper (Cu), chromium (Cr), nickel (Ni), and cobalt (Co) in ten macroalgae species from the Red Sea coastal water varied widely and also the trend of abundance of each metal also differed from one group to another. Concentration factors varied among species for iron (Fe) copper (Cu) manganese (Mn), but with iron (Fe) showing generally high concentration factors. Highly significant (P<0.05) relationships were found between manganese (Mn) and Nickel (Ni), and, Zinc (Zn) and copper (Cu). Moreover, moderate correlations were observed between manganese (Mn) and iron (Fe) and chromium (Cr), indicating that manganese (Mn) is the most accumulated metal in the macro algae of the Red Sea. In spite of the level of trace metals in the macro algae of the Red Sea. In spite of the level of trace metals in the macro algae, dominance is moderate relative to other sea areas subjected to intensive pollution. That is, the results indicated a nonpolluted environment. (author)

  4. Transfer and mobility of trace metallic elements in the sedimentary column of continental hydro-systems; Transferts et mobilite des elements traces metalliques dans la colonne sedimentaire des hydrosystemes continentaux

    Energy Technology Data Exchange (ETDEWEB)

    Devallois, V.

    2009-02-15

    In freshwater systems, trace metal pollutants are transferred into water and sedimentary columns under dissolved forms and/or fixed onto solid particles. Accumulated in the sedimentary areas, these latter ones can constitute important stocks of materials and associated pollutants and may impair water quality when environmental changes lead to increase their mobility. The mobility of the stocks of pollutants is mainly depending on the erosion, on the interstitial diffusion of the mobile phases (dissolved and colloidal) and on the bioturbation. In this context, this study involves the analysis of the mobility by interstitial diffusion. This topic consists in studying trace metal fractionation between their mobile (dissolved and colloidal) and non mobile (fixed onto the particles) forms. This point is governed by sorption/desorption processes at the particle surfaces. These processes are regulated by physico-chemical parameters (pH, redox potential, ionic strength...) and are influenced by biogeochemical reactions resulting from the oxidation of the organic matter by the microbial activity. These reactions generate vertical profiles of nutrients and metal concentrations along the sedimentary column. To understand these processes, this work is based on a mixed approach that combines in situ, analysis and modelling. In situ experimental part consists in sampling natural sediments cores collected at 4 different sites (1 site in Durance and 3 sites on the Rhone). These samples are analyzed according to an analytical protocol that provides the vertical distribution of physicochemical parameters (pH, redox potential, size distribution, porosity), nutrients and solid - liquid forms of trace metals (cobalt, copper, nickel, lead, zinc). The analysis and interpretation of these experimental results are based on a model that was developed during this study and that includes: 1) model of interstitial diffusion (Boudreau, 1997), 2) biogeochemical model (Wang and Van Cappellen

  5. Factors controlling the solubility of trace metals in atmospheric aerosols over the Eastern Mediterranean

    Science.gov (United States)

    Nikolaou, Panagiota; Mihalopoulos, Nikolaos; Kanakidou, Maria

    2015-04-01

    Atmospheric input of aerosols is recognized, as an important source of nutrients, for the oceans. The chemical interactions between aerosols and varying composition of air masses lead to different coating of their surfaces with sulfate, nitrate and organic compounds, increasing their solubility and their role as a carrier of nutrients and pollutants in ecosystems. Recent works have highlighted that atmospheric inputs of nutrients and trace metals can considerably influence the marine ecosystem functioning at semi-enclosed or enclosed water bodies such as the eastern Mediterranean. The current work aims to determine the sources and the factors controlling the variability of nutrients in the eastern Mediterranean. Special focus has been given on trace elements solubility, considered either as key nutrients for phytoplankton growth such as iron (Fe), phosphorus (P) or inhibitors such as copper (Cu). This has been accomplished by analyzing size segregated aerosol samples collected at the background site of Finokalia in Crete for an entire year. Phosphorus concentrations indicate important increases in air masses influenced both by anthropogenic activities in the northeast European countries and by dust outbreaks. The last is confirmed by the correlation observed between total P and dust concentrations and by the air mass backward trajectories computed by running the NOAA Hysplit Model (Hybrid Single - Particle Langrangian Integrated Trajectory (http://www.arl.noaa.gov/ready/hysplit4.html). Overall 73% of total P has been found to be associated with anthropogenic sources. The solubility of P and Fe has been found to be closely related to the acidity (pH) and dust amount in aerosols. The aerosol pH was predicted using thermodynamic modeling (ISORROPIA-II), meteorological observations (RH, T), and gas/particle observations. More specifically P and Fe solubility appears to be inversely related to the crustal elements levels, while it increases in acidic environment. The

  6. Epiphytic lichen Flavoparmelia caperata as a sentinel for trace metal pollution

    Directory of Open Access Journals (Sweden)

    Mitrović Tatjana

    2012-01-01

    Full Text Available Widely spread lichen specie Flavoparmelia caperata is used in a biomonitoring study for atmospheric trace metal pollution in natural ecosystems in Southeastern Serbia. The concentration and distribution pattern of 21 metals in lichens were determined by inductively coupled plasma atomic emission spectrometry. The difference observed between metal deposition in peripheral and central parts of lichen thalli reflected air quality changes in the last and previous years. These findings were confirmed with principal component analysis. Our study demonstrated the accumulation of Ba, K, Mg, Na, Tl and Zn in peripheral parts of thalli, while As, B, Cd, Cr, Cu, Fe, Ga, In, Li, Ni, Pb and Se were concentrated in central parts of thalli.

  7. Monitoring of Trace Metal Pollution in Meenachil River at Kottayam, Kerala (India

    Directory of Open Access Journals (Sweden)

    Indu. V. Nair

    2011-01-01

    Full Text Available The water quality of the Meenachil river at Kottayam has been studied with reference to toxic trace metals during pre and post monsoon seasons for 10 stations during May 2009-September 2009. The metals analyzed include Zinc, Manganese, Iron, Lead, Copper and Cadmium. Among the metals studied, iron, lead and cadmium showed higher concentrations above the permissible limit for drinking water prescribed by Bureau of Indian Standards. Iron and lead showed higher concentration during post monsoon and the cadmium content was high during pre-monsoon. It was observed that the main causes of deterioration in water quality might be due to the discharge of domestic wastes, municipal wastes, terrestrial runoff from seepage sites, agricultural sites and also due to geological weathering process.

  8. Geochemical distribution of trace metals and organochlorine contaminants of a lake ontario shoreline marsh

    Energy Technology Data Exchange (ETDEWEB)

    Glooschenko, W A; Capocianco, J; Coburn, J; Glooschenko, V

    1981-02-01

    Rattray Marsh, an 8 ha marsh on the Lake Ontario shoreline at Mississauga, Ontario, is an important local habitat for waterfowl and shorebirds during spring and fall migration. A study was conducted to determine the distribution of nutrients (carbon, nitrogen, and phosphorus) and potential trace metal and organochlorine pollutants in the marsh as evidenced by the sedimentary concentrations of these compounds. Generally, copper, zinc, lead, and mercury were higher in concentration in local soils than in Lake Ontario sediments. Metals and organic carbon levels did not correlate, and the metals appeared to be associated with silts and clays. Organochlorine contaminants include p,p1-DDE, p,p1-DDD, p,p1-DDT, alpha-chlordane, PCB, mirex, and HCB.

  9. Changes in Trace Metal Species and Other Components of the Rhizosphere During Growth of Radish

    DEFF Research Database (Denmark)

    Hamon, R. E.; Lorenz, S. E.; Holm, Peter Engelund

    1995-01-01

    Changes in the properties of soil solution in the rhizosphere of developing radish plants were investigated. Variations in these properties were expected to affect the distribution and speciation of metals in the soil and soil solution. Applications of essential nutrients were linked to plant...... transpiration rates and prevented excess addition of nutrient ions, so that subtle changes in soil solution composition would not be obscured. Soil solution pH, the concentration of dissolved organic carbon (DOC) and the concentrations of major and trace elements in solution were found to vary over time. Strict...... existing in the uncomplexed state. Changes in the concentrations of uncomplexed Cd and Zn with time gave the best correlations with changes in plant uptake of these metals over time, supporting the hypothesis that plants mainly absorb the free metal ion from soil solution....

  10. Respiratory trace deposition models. Final report

    International Nuclear Information System (INIS)

    Yeh, H.C.

    1980-03-01

    Respiratory tract characteristics of four mammalian species (human, dog, rat and Syrian hamster) were studied, using replica lung casts. An in situ casting techniques was developed for making the casts. Based on an idealized branch model, over 38,000 records of airway segment diameters, lengths, branching angles and gravity angles were obtained from measurements of two humans, two Beagle dogs, two rats and one Syrian hamster. From examination of the trimmed casts and morphometric data, it appeared that the structure of the human airway is closer to a dichotomous structure, whereas for dog, rat and hamster, it is monopodial. Flow velocity in the trachea and major bronchi in living Beagle dogs was measured using an implanted, subminiaturized, heated film anemometer. A physical model was developed to simulate the regional deposition characteristics proposed by the Task Group on Lung Dynamics of the ICRP. Various simulation modules for the nasopharyngeal (NP), tracheobronchial (TB) and pulmonary (P) compartments were designed and tested. Three types of monodisperse aerosols were developed for animal inhalation studies. Fifty Syrian hamsters and 50 rats were exposed to five different sizes of monodisperse fused aluminosilicate particles labeled with 169 Yb. Anatomical lung models were developed for four species (human, Beagle dog, rat and Syrian hamster) that were based on detailed morphometric measurements of replica lung casts. Emphasis was placed on developing a lobar typical-path lung model and on developing a modeling technique which could be applied to various mammalian species. A set of particle deposition equations for deposition caused by inertial impaction, sedimentation, and diffusion were developed. Theoretical models of particle deposition were developed based on these equations and on the anatomical lung models

  11. Assessment of trace metal levels in size-resolved particulate matter in the area of Leipzig

    Science.gov (United States)

    Fomba, Khanneh Wadinga; van Pinxteren, Dominik; Müller, Konrad; Spindler, Gerald; Herrmann, Hartmut

    2018-03-01

    Size-resolved trace metal concentrations at four sites in Leipzig (Germany) and its surrounding were assessed between the winter of 2013 and the summer of 2015. The measurements were performed in parallel at; traffic dominated (Leipzig - Mitte, LMI), traffic and residential dominated (Eisenbahnstrasse, EIB), urban background (TROPOS, TRO) and regional background (Melpitz, MEL) sites. In total, 19 trace metals, i.e. K, Ca, Ti, Mn, Fe, Cu, Zn, As, Se, Ba, V, Pb, Ni, Cr, Sr, Sn, Sb, Co and Rb were analysed using total reflection x-ray fluorescence (TXRF). The major metals were Fe, K and Ca with concentrations ranging between; 31-440 ng/m3, 42-153 ng/m3 and 24-322 ng/m3, respectively, while the trace metals with the lowest concentrations were Co, Rb and Se with concentrations of; tire wear (Cu, Sb, Ba, Fe, Zn, Pb), biomass burning (K, Rb), oil and coal combustion (V, Zn, As, Pb). Crustal matter contributed 5-12% in winter and 8-19% in summer of the PM10 mass. Using Cu and Zn as markers for brake and tire wear, respectively, the estimated brake and tire wear contributions to the PM10 mass were 0.1-0.8% and 1.7-2.9%, respectively. The higher contributions were observed at the traffic sites while the lower contributions were observed at the regional background site. In total, non-exhaust emissions could account for about 10-22% of the PM10 mass in the summer and about 7-15% of the PM10 mass in the winter.

  12. Spatial distribution and potential sources of trace metals in insoluble particles of snow from Urumqi, China.

    Science.gov (United States)

    Li, Xiaolan; Jiang, Fengqing; Wang, Shaoping; Turdi, Muyesser; Zhang, Zhaoyong

    2015-01-01

    The purpose of this work is to characterize trace elements in snow in urban-suburb gradient over Urumqi city, China. The spatial distribution patterns of 11 trace metals in insoluble particulate matters of snow were revealed by using 102 snow samples collected in and around urban areas of Urumqi, a city suffering from severe wintertime air pollution in China. Similar spatial distribution for Mn, Cu, Zn, Ni, and Pb was found and their two significant high-value areas located in the west and east, respectively, and a high-value area in the south, which were correlated with factory emissions, traffic activities, and construction fugitive dust. The high-value areas of Cr, Ni, and V occurred in the northeast corner and along main traffic paths, which were linked to oil refinery and vehicular emissions. High value of Be presented in the west of the city. The high-value area of Co in the northeast could be related to local soil. Cd and U displayed relatively even spatial patterns in the urban area. In view of distance from the urban center, e.g., from the first circular belt to the fourth circular belt, except Be, V, Cd, and U, the contents of other metals generally decreased from the first circular belt to the forth circular belt, implying the effect of human activity clearly. Additionally, prevailing northwesterly winds and occasionally southeasterly winds in winter were associated with decreased, generally, concentrations of trace metal in snow from the urban center to the southern suburb along a northwest and southeast transect. The information on concentrations and spatial distributions of these metals in insoluble particles of snow in winter will be valuable for further environmental protection and planning.

  13. Statistical analysis of trace metals in the plasma of cancer patients versus controls

    International Nuclear Information System (INIS)

    Pasha, Qaisara; Malik, Salman A.; Shah, Munir H.

    2008-01-01

    The plasma of cancer patients (n = 112) and controls (n = 118) were analysed for selected trace metals (Al, Ca, Cd, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Mo, Na, Ni, Pb, Sb, Sr and Zn) by flame atomic absorption spectroscopy. In the plasma of cancer patients, mean concentrations of macronutrients/essential metals, Na, K, Ca, Mg, Fe and Zn were 3971, 178, 44.1, 7.59, 4.38 and 3.90 ppm, respectively, while the mean metal levels in the plasma of controls were 3844, 151, 74.2, 18.0, 6.60 and 2.50 ppm, respectively. Average concentrations of Cd, Cr, Cu, Mn, Mo, Ni, Pb, Sb, Sr and Zn were noted to be significantly higher in the plasma of cancer patients compared with controls. Very strong mutual correlations (r > 0.70) in the plasma of cancer patients were observed between Fe-Mn, Ca-Mn, Ca-Ni, Ca-Co, Cd-Pb, Co-Ni, Mn-Ni, Mn-Zn, Cr-Li, Ca-Zn and Fe-Ni, whereas, Ca-Mn, Ca-Mg, Fe-Zn, Ca-Zn, Mg-Mn, Mg-Zn, Cd-Sb, Cd-Co, Cd-Zn, Co-Sb and Sb-Zn exhibited strong relationships (r > 0.50) in the plasma of controls, all were significant at p < 0.01. Principal component analysis (PCA) of the data extracted five PCs, both for cancer patients and controls, but with considerably different loadings. The average metals levels in male and female donors of the two groups were also evaluated and in addition, the general role of trace metals in the carcinogenesis was discussed. The study indicated appreciably different pattern of metal distribution and mutual relationships in the plasma of cancer patients in comparison with controls

  14. Statistical analysis of trace metals in the plasma of cancer patients versus controls

    Energy Technology Data Exchange (ETDEWEB)

    Pasha, Qaisara; Malik, Salman A. [Department of Biochemistry, Quaid-i-Azam University, Islamabad 45320 (Pakistan); Shah, Munir H. [Department of Chemistry, Quaid-i-Azam University, Islamabad 45320 (Pakistan)], E-mail: munir_qau@yahoo.com

    2008-05-30

    The plasma of cancer patients (n = 112) and controls (n = 118) were analysed for selected trace metals (Al, Ca, Cd, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Mo, Na, Ni, Pb, Sb, Sr and Zn) by flame atomic absorption spectroscopy. In the plasma of cancer patients, mean concentrations of macronutrients/essential metals, Na, K, Ca, Mg, Fe and Zn were 3971, 178, 44.1, 7.59, 4.38 and 3.90 ppm, respectively, while the mean metal levels in the plasma of controls were 3844, 151, 74.2, 18.0, 6.60 and 2.50 ppm, respectively. Average concentrations of Cd, Cr, Cu, Mn, Mo, Ni, Pb, Sb, Sr and Zn were noted to be significantly higher in the plasma of cancer patients compared with controls. Very strong mutual correlations (r > 0.70) in the plasma of cancer patients were observed between Fe-Mn, Ca-Mn, Ca-Ni, Ca-Co, Cd-Pb, Co-Ni, Mn-Ni, Mn-Zn, Cr-Li, Ca-Zn and Fe-Ni, whereas, Ca-Mn, Ca-Mg, Fe-Zn, Ca-Zn, Mg-Mn, Mg-Zn, Cd-Sb, Cd-Co, Cd-Zn, Co-Sb and Sb-Zn exhibited strong relationships (r > 0.50) in the plasma of controls, all were significant at p < 0.01. Principal component analysis (PCA) of the data extracted five PCs, both for cancer patients and controls, but with considerably different loadings. The average metals levels in male and female donors of the two groups were also evaluated and in addition, the general role of trace metals in the carcinogenesis was discussed. The study indicated appreciably different pattern of metal distribution and mutual relationships in the plasma of cancer patients in comparison with controls.

  15. HAIR HEAVY METAL AND ESSENTIAL TRACE ELEMENT CONCENTRATION IN CHILDREN WITH AUTISM SPECTRUM DISORDER.

    Science.gov (United States)

    Tabatadze, T; Zhorzholiani, L; Kherkheulidze, M; Kandelaki, E; Ivanashvili, T

    2015-11-01

    Our study aims evaluation of level of essential trace elements and heavy metals in the hair samples of children with autistic spectrum disorder (ASD) and identification of changes that are associated with autistic spectrum disorders. Case-control study was conducted at Child Development Center of Iashvili Children's Central Hospital (LD).We studied 60 children aged from 4 to 5 years old. The concentrations of 28 elements among (Ca,Zn, K, Fe, Cu, Se, Mn, Cr, S, Br, Cl, Co, Ag, V, Ni, Rb, Mo, Sr, Ti, Ba, Pb, As, Hg, Cd, Sb, Zr, Sn, Bi) them trace elements and toxic metals) were determined in scalp hair samples of children (n=30) with autistic spectrum disorder (ASD) and from control group of healthy children (n=30) with matched sex and age. Micro-elemental status was detected in the hair, with roentgen-fluorescence spectrometer method (Method MBИ 081/12-4502-000, Apparatus ALVAX- CIP, USA - UKRAIN) .To achieve the similarity of study and control groups, pre and postnatal as well as family and social history were assessed and similar groups were selected. Children with genetic problems, malnourished children, children from families with social problems were excluded from the study. The diagnosis of ASD were performed by pediatrician and psychologist (using M-CHAT and ADOS) according to DSM IV (Diagnostic and Statistical Manual of Mental Disorders from the American Psychiatric association) criteria. The study was statistically analyzed using computer program SPSS 19. Deficiencies of essential trace microelements revealed in both group, but there was significant difference between control and studied groups. The most deficient element was zinc (92% in target and 20% in control), then - manganese (55% and 8%) and selenium (38% and 4%). In case of cooper study revealed excess concentration of this element only in target group in 50% of cases. The contaminations to heavy metals were detected in case of lead (78% and 16), mercury (43% and 10%) and cadmium (38% and 8%). The

  16. Effective removal of hazardous trace metals from recovery boiler fly ashes.

    Science.gov (United States)

    Kinnarinen, Teemu; Golmaei, Mohammad; Jernström, Eeva; Häkkinen, Antti

    2018-02-15

    The objective of this study is to introduce a treatment sequence enabling straightforward and effective recovery of hazardous trace elements from recovery boiler fly ash (RBFA) by a novel method, and to demonstrate the subsequent removal of Cl and K with the existing crystallization technology. The treatment sequence comprises two stages: dissolution of most other RBFA components than the hazardous trace elements in water in Step 1 of the treatment, and crystallization of the process chemicals in Step 2. Solid-liquid separation has an important role in the treatment, due to the need to separate first the small solid residue containing the trace elements, and to separate the valuable crystals, containing Na and S, from the liquid rich in Cl and K. According to the results, nearly complete recovery of cadmium, lead and zinc can be reached even without pH adjustment. Some other metals, such as Mg and Mn, are removed together with the hazardous metals. Regarding the removal of Cl and K from the process, in this non-optimized case the removal efficiency was satisfactory: 60-70% for K when 80% of sodium was recovered, and close to 70% for Cl when 80% of sulfate was recovered. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Possibilities of assessing trace metal pollution using Betula pendula Roth. leaf and bark - experience in Serbia

    Directory of Open Access Journals (Sweden)

    Pavlović Dragana

    2017-01-01

    Full Text Available In this study, both seasonal and spatial variations in trace metal uptake, as well as concentration of photosynthetic pigments in Silver birch (Betula pendula Roth. trees in five urban parks in Pančevo, Smederevo, Obrenovac and Belgrade (Serbia affected by different anthropogenic activities were studied. The characteristics of soil were assessed in terms of texture, pH and trace element content. Concentrations of boron, strontium and zinc in both leaves and bark showed an increasing temporal trend, however, copper showed an opposite seasonal trend. A higher accumulation of trace elements was noticed in leaves compared to bark. The obtained results for photosynthetic pigments showed low sensitivity of birch to B, Cu, Sr and Zn contamination, indicating that birch tolerates pollution and climate stress by increasing the amount of pigments. Analysis of the effects on soil chemistry of trace element accumulation in plant tissues proved that soil chemistry poorly explains the variability of elements in bark (27.6 % compared to leaves (82.99 %. Discriminant analysis showed that Belgrade and Smederevo are clearly separated from the other three sites. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. 173018

  18. Adsorption and Detection of Hazardous Trace Gases by Metal-Organic Frameworks.

    Science.gov (United States)

    Woellner, Michelle; Hausdorf, Steffen; Klein, Nicole; Mueller, Philipp; Smith, Martin W; Kaskel, Stefan

    2018-06-19

    The quest for advanced designer adsorbents for air filtration and monitoring hazardous trace gases has recently been more and more driven by the need to ensure clean air in indoor, outdoor, and industrial environments. How to increase safety with regard to personal protection in the event of hazardous gas exposure is a critical question for an ever-growing population spending most of their lifetime indoors, but is also crucial for the chemical industry in order to protect future generations of employees from potential hazards. Metal-organic frameworks (MOFs) are already quite advanced and promising in terms of capacity and specific affinity to overcome limitations of current adsorbent materials for trace and toxic gas adsorption. Due to their advantageous features (e.g., high specific surface area, catalytic activity, tailorable pore sizes, structural diversity, and range of chemical and physical properties), MOFs offer a high potential as adsorbents for air filtration and monitoring of hazardous trace gases. Three advanced topics are considered here, in applying MOFs for selective adsorption: (i) toxic gas adsorption toward filtration for respiratory protection as well as indoor and cabin air, (ii) enrichment of hazardous gases using MOFs, and (iii) MOFs as sensors for toxic trace gases and explosives. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Enrichment of trace metals in water utilizing the coagulation of soybean protein

    International Nuclear Information System (INIS)

    Musha, Soichiro; Takahashi, Yoshihisa.

    1975-01-01

    An enrichment of trace metals in water with a coagulated soybean protein and the complex-forming character of heavy metal ions with the soybean protein were investigated by means of emission spectrography. Fixed amounts of soybean milk (collector) and delta-gluconic lactone (coagulant) were added to a sample solution containing various metal ions, and then the mixture was heated to boiling in order to coagulate the protein. The coagulum (soybean curd) separated from the suspension with a centrifuge was burned to ashes with a low temperature plasma asher. Then metals enriched in the soybean curd were determined by means of emission spectrography. The pH of the solution was adjusted to 4.4--5.0 by adding suitable amounts of delta-gluconic lactone for the complete coagulation of the soybean protein. The proposed method can be applied to the collection and enrichment of various metal ions such as gold, silver, mercury, platinum, cadmium, beryllium, palladium, antimony, gallium, indium, cerium, lanthanum, thorium, yttrium, zirconium, etc. Those metals are not detectable in the original soybean. (auth.)

  20. Donnan membrane speciation of Al, Fe, trace metals and REEs in coastal lowland acid sulfate soil-impacted drainage waters.

    Science.gov (United States)

    Jones, Adele M; Xue, Youjia; Kinsela, Andrew S; Wilcken, Klaus M; Collins, Richard N

    2016-03-15

    Donnan dialysis has been applied to forty filtered drainage waters collected from five coastal lowland acid sulfate soil (CLASS) catchments across north-eastern NSW, Australia. Despite having average pH values70%) as negatively-charged complexes. In contrast, the speciation of the divalent trace metals Co, Mn, Ni and Zn was dominated by positively-charged complexes and was strongly correlated with the alkaline earth metals Ca and Mg. Thermodynamic equilibrium speciation calculations indicated that natural organic matter (NOM) complexes dominated Fe(III) speciation in agreement with that obtained by Donnan dialysis. In the case of Fe(II), however, the free cation was predicted to dominate under thermodynamic equilibrium, whilst our results indicated that Fe(II) was mainly present as neutral or negatively-charged complexes (most likely with sulfate). For all other divalent metals thermodynamic equilibrium speciation calculations agreed well with the Donnan dialysis results. The proportion of Al and REEs predicted to be negatively-charged was also grossly underestimated, relative to the experimental results, highlighting possible inaccuracies in the stability constants developed for these trivalent Me(SO4)2(-) and/or Me-NOM complexes and difficulties in modeling complex environmental samples. These results will help improve metal mobility and toxicity models developed for CLASS-affected environments, and also demonstrate that Australian CLASS environments can discharge REEs at concentrations an order of magnitude greater than previously reported. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. Microscopic study of gum-metal alloys: A role of trace oxygen for dislocation-free deformation

    International Nuclear Information System (INIS)

    Nagasako, Naoyuki; Asahi, Ryoji; Isheim, Dieter; Seidman, David N.; Kuramoto, Shigeru; Furuta, Tadahiko

    2016-01-01

    A class of Ti–Nb–Ta–Zr–O alloys called gum metal are known to display high strength, low Young's modulus and high elastic deformability up to 2.5%, simultaneously, and considered to deform by a dislocation-free deformation mechanism. A trace of oxygen (∼1%) in gum metal is indispensable to realize such significant properties; however, the detailed mechanism and the role of the oxygen has not been understood. To investigate an effect of trace oxygen included in gum metal, first-principles calculations for gum-metal approximants including zirconium and oxygen are performed. Calculated results clearly indicate that oxygen site with less neighboring Nb atom is energetically favorable, and that Zr–O bonding has an important role to stabilize the bcc structure of gum metal. The three-dimensional atom-probe tomography (3-D APT) measurements for gum metal were also performed to identify compositional inhomogeneity attributed to the trace elements. From the 3-D APT measurements, Zr ions bonding with oxygen ions are observed, which indicates existence of Zr–O nano-clusters in gum metal. Consequently, it is found that (a) coexistence of Zr atom and oxygen atom improves elastical stability of gum metal, (b) inhomogeneous distribution of the compositions induced by the trace elements causes anisotropical change of shear moduli, and (c) Zr–O nano-clusters existing in gum metal are expected to be obstacles to suppress movemen of dislocations.

  2. Numerical modeling of flow boiling instabilities using TRACE

    International Nuclear Information System (INIS)

    Kommer, Eric M.

    2015-01-01

    Highlights: • TRACE was used to realistically model boiling instabilities in single and parallel channel configurations. • Model parameters were chosen to exactly mimic other author’s work in order to provide for direct comparison of results. • Flow stability maps generated by the model show unstable flow at operating points similar to other authors. • The method of adjudicating when a flow is “unstable” is critical in this type of numerical study. - Abstract: Dynamic flow instabilities in two-phase systems are a vitally important area of study due to their effects on a great number of industrial applications, including heat exchangers in nuclear power plants. Several next generation nuclear reactor designs incorporate once through steam generators which will exhibit boiling flow instabilities if not properly designed or when operated outside design limits. A number of numerical thermal hydraulic codes attempt to model instabilities for initial design and for use in accident analysis. TRACE, the Nuclear Regulatory Commission’s newest thermal hydraulic code is used in this study to investigate flow instabilities in both single and dual parallel channel configurations. The model parameters are selected as to replicate other investigators’ experimental and numerical work in order to provide easy comparison. Particular attention is paid to the similarities between analysis using TRACE Version 5.0 and RELAP5/MOD3.3. Comparison of results is accomplished via flow stability maps non-dimensionalized via the phase change and subcooling numbers. Results of this study show that TRACE does indeed model two phase flow instabilities, with the transient response closely mimicking that seen in experimental studies. When compared to flow stability maps generated using RELAP, TRACE shows similar results with differences likely due to the somewhat qualitative criteria used by various authors to determine when the flow is truly unstable

  3. A survey of Trace Metals Determination in Hospital Waste Incinerator in Lucknow City, India

    Directory of Open Access Journals (Sweden)

    Ranjan Kumar

    2004-08-01

    Full Text Available Information on the elemental content of incinerator burning of human organ, animal and medical waste is scanty in India Nineteen trace elements were analyzed in the incinerator ash from four major hospitals, one municipal waste incinerator and two R & D laboratories engaged in animal experiment in Lucknow city. Concentrations of Zinc and Lead were found to be very high in comparison to other metals due to burning of plastic products. The source of Ca, P and K are mainly bone, teeth and other animal organs. A wide variation in trace concentration of several toxic elements have been seen due to variation in initial waste composition, design of the incinerator and operating conditions.

  4. Liquid membrane extraction techniques for trace metal analysis and speciation in environmental and biological matrices

    Energy Technology Data Exchange (ETDEWEB)

    Ndungu, Kuria

    1999-04-01

    In this thesis, liquid-membrane-based methods for the analysis of trace metal species in samples of environmental and biological origin were developed. By incorporating extracting reagents in the membrane liquid, trace metal ions were selectively separated from humic-rich natural waters and urine samples, prior to their determination using various instrumental techniques. The extractions were performed in closed flow systems thus allowing easy automation of both the sample clean-up and enrichment. An acidic organophosphorus reagent (DEHPA) and a basic tetraalkylammonium reagent (Aliquat-336) were used as extractants in the membrane liquid to selectively extract and enrich cationic and anionic metal species respectively. A speciation method for chromium species was developed that allowed the determination of cationic Cr(III) species and anionic CR(VI) species in natural water samples without the need of a chromatographic separation step prior to their detection. SLM was also coupled on-line to potentiometric stripping analysis providing a fast and sensitive method for analysis of Pb in urine samples. A microporous membrane liquid-liquid extraction (MMLLE) method was developed for the determination of organotin compounds in natural waters that reduced the number of manual steps involved in the LLE of organotin compounds prior to their CC separation. Clean extracts obtained after running unfiltered humic-rich river water samples through the MMLLE flow system allowed selective determination of all the organotin compounds in a single run using GC-MS in the selected ion monitoring mode (SIM) 171 refs, 9 figs, 4 tabs

  5. Central Tibetan Plateau atmospheric trace metals contamination: a 500-year record from the Puruogangri ice core

    Science.gov (United States)

    Beaudon, E.; Gabrielli, P.; Sierra Hernandez, R.; Wegner, A.; Thompson, L. G.

    2017-12-01

    Since the 1980s, Asia has experienced enormous industrial development from rapid population growth, industrialization and consequent large-scale environmental changes. The inherent generated atmospheric pollution currently contributes to half of all Earth's anthropogenic trace metals emissions. Asian trace metal aerosols, when deposited on glaciers of the surrounding mountains of the Tibetan Plateau (TP), leave a characteristic chemical fingerprint. Interpreting trace element (TE) records from glaciers implies a thorough comprehension of their provenance and temporal variability. It is then essential to discriminate the TEs' natural background components from their anthropogenic components. Here we present 500-year TE records from the Puruogangri ice core (Tibet, China) that provide a highly resolved account of the impact of past atmospheric influences, environmental processes and human activities on the central TP. A decreasing aeolian dust input to the ice cap allowed the detection of an atmospheric pollution signal. The anthropogenic pollution contribution emerges in the record since the early 1900s and increases substantially after 1935. The metallurgy (Zn, Pb and steel smelting) emission products from the former Soviet Union and especially from central Asia likely enhanced the anthropogenic deposition to the Puruogangri ice cap between 1935 and 1980, suggesting that the westerlies served as a conveyor of atmospheric pollution to central Tibet. The impact of this industrial pollution cumulated with that of the hemispheric coal and gasoline combustion which are respectively traced by Sb and Pb enrichment in the ice. The Chinese steel production accompanying the Great Leap Forward (1958-1961) and the Chinese Cultural Revolution (1966-1976) is proposed as a secondary but proximal source of Pb pollution affecting the ice cap between 1958 and 1976. The most recent decade (1980-1992) of the enrichment time series suggests that Puruogangri ice cap recorded the early

  6. Trace metal associations in the water column of South San Francisco Bay, California

    Science.gov (United States)

    Kuwabara, J.S.; Chang, Cecily C.Y.; Cloern, J.E.; Fries, T.L.; Davis, J.A.; Luoma, S.N.

    1989-01-01

    Spatial distributions of copper (Cu), zinc (Zn) and cadmium (Cd) were followed along a longitudinal gradient of dissolved organic carbon (DOC) in South San Francisco Bay (herein referred to as the South Bay). Dissolved Cu, Zn and Cd concentrations ranged from 24 to 66 nM, from 20 to 107 nM and from 1??2 to 4??7 nM, respectively, in samples collected on five dates beginning with the spring phytoplankton bloom and continuing through summer,1985. Dissolved Cu and Zn concentrations varied indirectly with salinity and directly with DOC concentration which ranged from 2??1 to 4??1 mg l-1. Available thermodynamic data strongly support the hypothesis that Cu speciation may be dominated by association with dissolved organic matter. Analogous control of Zn speciation by organic complexation was, however, not indicated in our computations. Computed free ion activity estimates for Cu, Zn and Cd were of the order of 10-10, 10-8 and 10-10 M, respectively. The availability of these metals may be among the factors regulating the growth of certain phytoplankton species within this region of the estuary. In contrast to dissolved Cu, dissolved Cd was directly related to the concentration of suspended particulate matter, suggesting a source of dissolved Cd coincident with elevated particle concentrations in the South Bay (e.g. runoff and solute desorption). Consistent with work in other estuaries, partitioning of all three trace metals onto suspended particulates was negatively correlated with salinity and positively correlated with increases in particulate organic carbon associated with the phytoplankton bloom. These results for the South Bay indicate that sorption processes influence dissolved concentrations of these trace metals, the degree of this influence varies among metals, and processes controlling metal distribution in this estuary appear to be more element-specific than spatially- or temporally-specific. ?? 1989.

  7. Macro and micro plastics sorb and desorb metals and act as a point source of trace metals to coastal ecosystems.

    Science.gov (United States)

    Munier, B; Bendell, L I

    2018-01-01

    Nine urban intertidal regions in Burrard Inlet, Vancouver, British Columbia, Canada, were sampled for plastic debris. Debris included macro and micro plastics and originated from a wide diversity of uses ranging from personal hygiene to solar cells. Debris was characterized for its polymer through standard physiochemical characteristics, then subject to a weak acid extraction to remove the metals, zinc, copper, cadmium and lead from the polymer. Recently manufactured low density polyethylene (LDPE), nylon, polyethylene terephthalate (PET), polypropylene (PP), polystyrene (PS) and polyvinyl chloride (PVC) were subject to the same extraction. Data was statistically analyzed by appropriate parametric and non-parametric tests when needed with significance set at P Plastic debris will affect metals within coastal ecosystems by; 1) providing a sorption site (copper and lead), notably for PVC 2) desorption from the plastic i.e., the "inherent" load (cadmium and zinc) and 3) serving as a point source of acute trace metal exposure to coastal ecosystems. All three mechanisms will put coastal ecosystems at risk to the toxic effects of these metals.

  8. Development Status of TRACE model for PGSFR Safety Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Andong; Choi, Yong Won; Kim, Jihun; Bae, Moohoon [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

    2014-05-15

    For the preparation of the review of licensing application for PGSFR, TRACE model for the PGSFR is being developed considering the sodium related properties and model in the code. For the use of licensing purpose, it is identified and need to be improved that model uncertainty in the code and conservative conditions for accident analysis is needs to be defined and validated. And current simulations are applicable only to assembly-averaged assessment. So it is also need to be defined for pin-wise assessment within hot assembly. On the basis on the developed model, PGSFR design change will be applied and improved for independent audit calculation for incoming licensing review. Prototype Generation IV Sodium cooled Fast Reactor (PGSFR) of 150MWe is under developing targeting licensing application by 2017. KINS is preparing review of its licensing application, especially the audit calculation tool for transient and accident analysis is being prepared for review. Since 2012, TRACE code applicability study has been doing for the Sodium-cooled Fast Reactor. At first, Sodium properties and the related heat transfer model in the code were reviewed. Demonstration Sodium cooled Fast Reactor (DSFR-600) were model and representing DBAs were assessed until the PGSFR design is fixed. EBR-II Shutdown Heat Removal Test (SHRT) experiment is also being analyzed in terms of IAEA Cooperated Research Program. In this paper, PGSFR TRACE code modeling status and considerations for SFR DBA assessment is introduced.

  9. Past 140-year environmental record in the northern South China Sea: evidence from coral skeletal trace metal variations.

    Science.gov (United States)

    Song, Yinxian; Yu, Kefu; Zhao, Jianxin; Feng, Yuexing; Shi, Qi; Zhang, Huiling; Ayoko, Godwin A; Frost, Ray L

    2014-02-01

    About 140-year changes in the trace metals in Porites coral samples from two locations in the northern South China Sea were investigated. Results of PCA analyses suggest that near the coast, terrestrial input impacted behavior of trace metals by 28.4%, impact of Sea Surface Temperature (SST) was 19.0%, contribution of war and infrastructure were 14.4% and 15.6% respectively. But for a location in the open sea, contribution of War and SST reached 33.2% and 16.5%, while activities of infrastructure and guano exploration reached 13.2% and 14.7%. While the spatiotemporal change model of Cu, Cd and Pb in seawater of the north area of South China Sea during 1986-1997 were reconstructed. It was found that in the sea area Cu and Cd contaminations were distributed near the coast while areas around Sanya, Hainan had high Pb levels because of the well-developed tourism related activities. Copyright © 2013 Elsevier Ltd. All rights reserved.

  10. The effects of trace metal exposure on agonistic encounters in juvenile rainbow trout, Oncorhynchus mykiss

    International Nuclear Information System (INIS)

    Sloman, K.A.; Baker, D.W.; Ho, C.G.; McDonald, D.G.; Wood, C.M.

    2003-01-01

    The effects of five trace metals, copper, cadmium, nickel, zinc and lead (presented as soluble salts) on the ability of juvenile rainbow trout to form social relationships were investigated. Comparable concentrations of the five metals in relation to their acute 96 h LC50s (concentration at which population mortality=50% at 96 h) were used (i.e. 15% of the 96 h LC50) and water quality parameters (hardness=120 mg l -1 as CaCO 3 , pH 8; DOC=3 mg l -1 ) were kept constant throughout. In the first experiment, trout exposed to sublethal concentrations of cadmium for 24 h displayed significantly lower numbers of aggressive attacks during pair-wise agonistic encounters than fish paired in the copper, nickel, zinc, lead and control water. In a second experiment, fish were exposed to the same concentration of metal for 24 h, and then returned to normal water for 24 h. When these metal pre-exposed fish were paired with non-exposed fish only cadmium pre-exposure had a significant effect on social interaction. All of the cadmium pre-exposed fish became subordinate when paired with non-exposed fish, whereas the probability of a fish pre-exposed to copper, nickel, zinc or lead becoming subordinate did not significantly differ from random. Therefore, at around 15% of the 96 h LC50, different metals exert different effects on the social behaviour of fish, suggesting potential implications for social structure and population stability

  11. Trace Metal Content of Sediments Close to Mine Sites in the Andean Region

    Directory of Open Access Journals (Sweden)

    Cristina Yacoub

    2012-01-01

    Full Text Available This study is a preliminary examination of heavy metal pollution in sediments close to two mine sites in the upper part of the Jequetepeque River Basin, Peru. Sediment concentrations of Al, As, Cd, Cu, Cr, Fe, Hg, Ni, Pb, Sb, Sn, and Zn were analyzed. A comparative study of the trace metal content of sediments shows that the highest concentrations are found at the closest points to the mine sites in both cases. The sediment quality analysis was performed using the threshold effect level of the Canadian guidelines (TEL. The sediment samples analyzed show that potential ecological risk is caused frequently at both sites by As, Cd, Cu, Hg, Pb, and Zn. The long-term influence of sediment metals in the environment is also assessed by sequential extraction scheme analysis (SES. The availability of metals in sediments is assessed, and it is considered a significant threat to the environment for As, Cd, and Sb close to one mine site and Cr and Hg close to the other mine site. Statistical analysis of sediment samples provides a characterization of both subbasins, showing low concentrations of a specific set of metals and identifies the main characteristics of the different pollution sources. A tentative relationship between pollution sources and possible ecological risk is established.

  12. Macrobenthic community in the Douro estuary: relations with trace metals and natural sediment characteristics

    International Nuclear Information System (INIS)

    Mucha, A.P.; Vasconcelos, M.T.S.D.; Bordalo, A.A.

    2003-01-01

    This study used a novel approach to detect a clear signature of metal contamination and biological impacts in an estuary. - The relationship between macrobenthic community structure and natural characteristics of sediment and trace metal contamination were studied in the lower Douro estuary (Portugal, NW, Iberian Peninsula), using an innovative threefold approach (SQG, Sediment Quality Guidelines), metal normalization to Fe, and macrobenthic community structure. This study allowed detection of a clear signature of anthropogenic contamination, in terms of Zn, Cu, Pb, and Cr in the north bank of the estuary, which experiences high urban pressure. Using the SQG approach, metal concentrations above ERM (effects range--median) were observed only at one sampling station, but several stations had levels above ERL (effects range-low). The macrobenthic community had a low diversity, with only 19 species found in the entire estuarine area, dominated by opportunistic species. The granulometric distribution of the sediments (estimated from the combination of organic matter, Fe and Al) seemed to be the major structuring factor for the communities, establishing the natural macrobenthic distribution pattern. The metals (Zn, Cu, Pb, and Cr) seemed to act as a disturbing factor over the natural distribution, with deleterious consequences for the macrobenthic communities

  13. Concentrations and solubility of selected trace metals in leaf and bagged black teas commercialized in Poland

    Directory of Open Access Journals (Sweden)

    L. Polechońska

    2015-09-01

    Full Text Available The objective of this study was to determine the concentrations of heavy metals in bagged and leaf black teas of the same brand and evaluate the percentage transfer of metals to tea infusion to assess the consumer exposure. Ten leaf black teas and 10 bagged black teas of the same brand available in Poland were analyzed for Zn, Mn, Cd, Pb, Ni, Co, Cr, Al, and Fe concentrations both in dry material and their infusion. The bagged teas contained higher amounts of Pb, Mn, Fe, Ni, Al, and Cr compared with leaf teas of the same brand, whereas the infusions of bagged tea contained higher levels of Mn, Ni, Al, and Cr compared with leaf tea infusions. Generally, the most abundant trace metals in both types of tea were Al and Mn. There was a wide variation in percentage transfer of elements from the dry tea materials to the infusions. The solubility of Ni and Mn was the highest, whereas Fe was insoluble and only a small portion of this metal content may leach into infusion. With respect to the acceptable daily intake of metals, the infusions of both bagged and leaf teas analyzed were found to be safe for human consumption.

  14. Latest approaches on green chemistry preconcentration methods for trace metal determination in seawater--a review.

    Science.gov (United States)

    La Colla, Noelia Soledad; Domini, Claudia Elizabeth; Marcovecchio, Jorge Eduardo; Botté, Sandra Elizabeth

    2015-03-15

    Evaluation of trace metal levels in seawater samples is undertaken regularly by research groups all over the world, leading to a growing demand for techniques involving fewer toxic reagents, less time-consuming protocols and lower limits of detection. This review focuses on providing a brief but concise description of the latest methodologies developed to this end, outlining the advantages and disadvantages of the various protocols, chelating and dispersive agents and instruments used. Conclusions are drawn on the basis of the articles reviewed, highlighting improvements introduced in order to enhance the performance of the protocols. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. Exploiting flow Injection and sequential injection schemes for trace metal determinations by electrothermal atomic absorption spectrometry

    DEFF Research Database (Denmark)

    Hansen, Elo Harald

    Determination of low or trace-level amounts of metals by electrothermal atomic absorption spectrometry (ETAAS) often requires the use of suitable preconcentration and/or separation procedures in order to attain the necessary sensitivity and selectivity. Such schemes are advantageously executed...... by superior performance and versatility. In fact, two approaches are conceivable: The analyte-loaded ion-exchange beads might either be transported directly into the graphite tube where they are pyrolized and the measurand is atomized and quantified; or the loaded beads can be eluted and the eluate forwarded...

  16. Neutron activation analysis of trace metals in the livers of Japanese sika deer (cervus Nippon)

    International Nuclear Information System (INIS)

    Fukushima, Michiko; Tamate, Hidetoshi; Sasaki, Yoshiro; Mitsugasira, Satoaki; Masumoto, Kazuyoshi.

    1997-01-01

    Neutron activation analysis facilities at the JMTR reactor was used to determine the levels of trace metals in the livers of nine Japanese sika deer. The samples were cut into pieces, pulverized in liquid nitrogen, freeze-dried, and finally fractionated through a stainless steel sieve of 200 mesh. Then the samples were irradiated for 6 or 24 hours by a neutron flux of 1.0x10 14 n·cm -2 ·sec -1 . In the present work, we analysed the concentrations of six elements (Ag, Co, Fe, Rb, Se, and Zn) in the livers of nine deer. (author)

  17. Determination of the free ion concentration of trace metals in soil solution using a soil column Donnan membrane technique

    NARCIS (Netherlands)

    Weng, L.; Temminghoff, E.J.M.; Riemsdijk, van W.H.

    2001-01-01

    Accurate measurement of the free metal ion is difficult, especially for trace metals present in very small concentrations (less than micromolar) in natural systems. The recently developed Donnan membrane technique can measure the concentrations in solution in the presence of inorganic and organic

  18. Ray Tracing modelling of reflector for vertical bifacial panel

    DEFF Research Database (Denmark)

    Jakobsen, Michael Linde; Thorsteinsson, Sune; Poulsen, Peter Behrensdorff

    2016-01-01

    Bifacial solar panels have recently become a new attractive building block for PV systems. In this work we propose a reflector system for a vertical bifacial panel, and use ray tracing modelling to model the performance. Particularly, we investigate the impact of the reflector volume being filled...... with a refractive medium, and shows the refractive medium improves the reflector performance since it directs almost all the light incident on the incoming plane into the PV panel....

  19. Investigating Planetesimal Evolution by Experiments with Fe-Ni Metallic Melts: Light Element Composition Effects on Trace Element Partitioning Behavior

    Science.gov (United States)

    Chabot, N. L.

    2017-12-01

    As planetesimals were heated up in the early Solar System, the formation of Fe-Ni metallic melts was a common occurrence. During planetesimal differentiation, the denser Fe-Ni metallic melts separated from the less dense silicate components, though some meteorites suggest that their parent bodies only experienced partial differentiation. If the Fe-Ni metallic melts did form a central metallic core, the core eventually crystallized to a solid, some of which we sample as iron meteorites. In all of these planetesimal evolution processes, the composition of the Fe-Ni metallic melt influenced the process and the resulting trace element chemical signatures. In particular, the metallic melt's "light element" composition, those elements present in the metallic melt in a significant concentration but with lower atomic masses than Fe, can strongly affect trace element partitioning. Experimental studies have provided critical data to determine the effects of light elements in Fe-Ni metallic melts on trace element partitioning behavior. Here I focus on combining numerous experimental results to identify trace elements that provide unique insight into constraining the light element composition of early Solar System Fe-Ni metallic melts. Experimental studies have been conducted at 1 atm in a variety of Fe-Ni systems to investigate the effects of light elements on trace element partitioning behavior. A frequent experimental examination of the effects of light elements in metallic systems involves producing run products with coexisting solid metal and liquid metal phases. Such solid-metal-liquid-metal experiments have been conducted in the Fe-Ni binary system as well as Fe-Ni systems with S, P, and C. Experiments with O-bearing or Si-bearing Fe-Ni metallic melts do not lend themselves to experiments with coexisting solid metal and liquid metal phases, due to the phase diagrams of these elements, but experiments with two immiscible Fe-Ni metallic melts have provided insight into

  20. A trace-based model for multiparty contracts

    DEFF Research Database (Denmark)

    Hvitved, Tom; Klaedtke, Felix; Zălinescu, Eugen

    2012-01-01

    In this article we present a model for multiparty contracts in which contract conformance is defned abstractly as a property on traces. A key feature of our model is blame assignment, which means that for a given contract, every breach is attributed to a set of parties. We show that blame...... assignment is compositional by de¿ning contract conjunction and contract disjunction. Moreover, to specify real-world contracts, we introduce the contract speci¿cation language CSL with an operational semantics. We show that each CSL contract has a counterpart in our trace-based model and from...... the operational semantics we derive a run-time monitor. CSL overcomes limitations of previously proposed formalisms for specifying contracts by supporting: (history sensitive and conditional) commitments, parametrised contract templates, relative and absolute temporal constraints, potentially in¿nite contracts...

  1. Fingerprinting Marcellus Shale waste products from Pb isotope and trace metal perspectives

    International Nuclear Information System (INIS)

    Johnson, Jason D.; Graney, Joseph R.

    2015-01-01

    Highlights: • Dry drilled, uncontaminated cuttings from Marcellus Shale and surrounding units. • Unoxidized and oxidized samples leached short and long term with H 2 O or dilute HCl. • Pb isotope ratios have distinctly different values from Marcellus Shale samples. • Mo and other trace metals can be used as Marcellus Shale environmental tracers. • Marcellus Shale leachate concentrations can exceed EPA contaminant screening levels. - Abstract: Drill cuttings generated during unconventional natural gas extraction from the Marcellus Shale, Appalachian Basin, U.S.A., generally contain a very large component of organic-rich black shale because of extensive lateral drilling into this target unit. In this study, element concentrations and Pb isotope ratios obtained from leached drill cuttings spanning 600 m of stratigraphic section were used to assess the potential for short and long term environmental impacts from Marcellus Shale waste materials, in comparison with material from surrounding formations. Leachates of the units above, below and within the Marcellus Shale yielded Cl/Br ratios of 100–150, similar to produced water values. Leachates from oxidized and unoxidized drill cuttings from the Marcellus Shale contain distinct suites of elevated trace metal concentrations, including Cd, Cu, Mo, Ni, Sb, U, V and Zn. The most elevated Mo, Ni, Sb, U, and V concentrations are found in leachates from the lower portion of the Marcellus Shale, the section typically exploited for natural gas production. In addition, lower 207 Pb/ 206 Pb ratios within the lower Marcellus Shale (0.661–0.733) provide a distinctive fingerprint from formations above (0.822–0.846) and below (0.796–0.810), reflecting 206 Pb produced as a result of in situ 238 U decay within this organic rich black shale. Trace metal concentrations from the Marcellus Shale leachates are similar to total metal concentrations from other black shales. These metal concentrations can exceed screening

  2. Trace Metals in Vegetables and Cereals- A Case Study of Indian Market-2016

    Directory of Open Access Journals (Sweden)

    Abaidya Nath Singh

    2017-03-01

    Full Text Available Background & Aims of the Study: Vegetables and Cereals are considered vital for properly-balanced diet given that they deliver vitamins, minerals, nutritional fiber, and phytochemicals. This study aimed to assess the concentration of As, Cu, Cd, Pb, Cr and Hg in common vegetables and cereals in urban open markets in Varanasi district, India Materials & Methods: Total 260 edible portions of vegetable samples of 13 species were collected in March to October, 2016 from predefined market sites. These samples classified into roots, stems, leafy vegetables, fruits, and legumes. These samples (unwashed, acetic acid washed and boiled were assessed using atomic absorption spectrophotometer. The statistical evaluations were carried out using the IBM SPSS 21. Results: The results obtained reveal that unwashed vegetables and cereals as compared to washed and boiled samples contain higher trace metal concentration. The order of heavy metal concentration was observed in Cu>Pb>Cd>As in vegetable and cereals samples. Hg and Cr were not detected in any samples. The mean value of Cu, Cd and Pb in unwashed and washed vegetables and cereals were lower than PFA standard except As, whereas in boiled vegetables and cereals are lower than PFA standard but the mean value of Cd and Pb were many folds higher than the EU standard at all the market site samples. Leafy vegetables were found to contain the highest metals values especially Spinacia oleracea followed by roots vegetable like Brassica rapa, at all the studied sites. The market sites MS3 located in the vicinity of industrial zone and in proximity to national highway showed elevated levels of trace metals concentration in the vegetables and cereals as compared to other market sites. Conclusions: The results showed that, the As, Cu, Cd and Pb concentration were reduced to about 12.5%, 5.87%, 11.36% and 10.42% of the initial concentrations by 2% acetic acid washing and to 25%, 21.87%, 20.45% and 16.67% of the initial

  3. Humic substances in natural waters and their complexation with trace metals and radionuclides: a review

    International Nuclear Information System (INIS)

    Boggs, S. Jr.; Livermore, D.; Seitz, M.G.

    1985-07-01

    Dissolved humic substances (humic and fulvic acids) occur in surface waters and groundwaters in concentrations ranging from less than 1 mg(C)/L to more than 100 mg(C)/L. Humic substances are strong complexing agents for many trace metals in the environment and are also capable of forming stable soluble complexes or chelates with radionuclides. Concentrations of humic materials as low as 1 mg(C)/L can produce a detectable increase in the mobility of some actinide elements by forming soluble complexes that inhibit sorption of the radionuclides onto rock materials. The stability of trace metal- or radionuclide-organic complexes is commonly measured by an empirically determined conditional stability constant (K'), which is based on the ratio of complexed metal (radionuclide) in solution to the product concentration of uncomplexed metal and humic complexant. Larger values of stability constants indicate greater complex stability. The stability of radionuclide-organic complexes is affected both by concentration variables and envionmental factors. In general, complexing is favored by increased of radionuclide, increased pH, and decreased ionic strength. Actinide elements are generally most soluble in their higher oxidation states. Radionuclides can also form stable, insoluble complexes with humic materials that tend to reduce radionuclide mobility. These insoluble complexes may be radionuclide-humate colloids that subsequently precipitate from solution, or complexes of radionuclides and humic substances that sorb to clay minerals or other soil particulates strongly enough to immobilize the radionuclides. Colloid formation appears to be favored by increased radionuclide concentration and lowered pH; however, the conditions that favor formation of insoluble complexes that sorb to particulates are still poorly understood. 129 refs., 25 figs., 19 tabs

  4. Monitoring hydrocarbons and trace metals in Beaufort Sea sediments and organisms. Final report

    International Nuclear Information System (INIS)

    Boehm, P.; LeBlanc, L.; Trefry, J.; Marajh-Whittemore, P.; Brown, J.

    1990-01-01

    As part of the Minerals Management Service's environmental studies of oil and gas exploration and production activities in the Alaskan Beaufort Sea, a study was conducted in 1989 to monitor the marine environment for inputs of chemicals related to drilling and exploration. The 1989 Beaufort Sea Monitoring Program (BSMP) was designed to monitor sediments and selected benthic organisms for trace metals and hydrocarbons so as to infer any changes that might have resulted from drilling and production activities. A series of 49 stations were sampled during the program. The study area extended from Cape Halkett on the western end of Harrison Bay to Griffin Point, east of Barter Island. The sampling design combined an area-wide approach in which stations were treated as replicates of 8 specific geographic regions, with an activity-specific approach, which focused on the potential establishment of metal or hydrocarbon concentration gradients with distance from the Endicott Production Field in Prudhoe Bay. The analytical program focused on the analysis of the fine-fraction of the sediment for a series of trace metals and elements and the analysis of a suite of saturated and aromatic hydrocarbons in the bulk sediment. The total organic carbon (TOB) content and the grain size distribution in the sediments were determined as well. Benthic bivalve molluscs, representative of several feeding types were collected from those stations for which data previously existed from the 1984-1986 BSMP, and were analyzed for metals and saturated and aromatic hydrocarbons. The benthic amphipods were collected, pooled by station or region, and analyzed as well

  5. Sediments of the Lagoa Olho D'Agua: geochronology and accumulation of trace metals

    International Nuclear Information System (INIS)

    Honorato, Eliane Valentim

    2002-01-01

    An assessment of the environmental impact of anthropic activities in the Lagoa Olho D'Agua, located in Jaboatao dos Guararapes County, Brazil, was carried out by assessing the vertical distribution of some trace metals (Cd, Cr, Fe, Hg, Ni, U, Zn and Zr) in dated sediment samples. Sediment cores were collected from thirteen locations at the northern, central and southern sections of the lagoon. The metal content in the samples was determined by Instrumental Neutron Activation Analysis (INAA). Its organic carbon content was also determined and used to characterize the environment as, either oxic or anoxic environments can bias the trace element content of sediment samples. The influence of the hydrodynamic characteristics in the sedimentation process was also studied. The results obtained for the geochronology of sediments showed a pronounced increase in sedimentation rates in the period of 1970 - 1980 and 1980 - 1990 in the sampling stations ST-09, ST-10, ST-11, ST-12 e ST-13 (ca.480% in the 80's to 90's ) compared to ca. 90% increase observed in other sampling stations. This increase can be associated to the demographic growth of ca. 500% that occurred in Jaboatao dos Guararapes County in the 80's to 90's predominantly along the shoreline. The geochemistry analyses of sediment samples, on the other hand, showed that the severe degradation process the occurred in the lagoon in the last 30 years was caused by the release of pollutants from industrial facilities as well as by the discharge of untreated domestic sewage. These domestic sewage favorable the increase of the concentration of organic material in the lagoon, accentuating the adsorption process of the metals on the sediments, mainly Fe and Zr in the suspense particles. The accentuated increase observed in both Fe and Zr concentrations is compatible with period of built industries basic steel works foundries and painting, indicating the anthropogenic origin these metals. (author)

  6. Donnan membrane speciation of Al, Fe, trace metals and REEs in coastal lowland acid sulfate soil-impacted drainage waters

    Energy Technology Data Exchange (ETDEWEB)

    Jones, Adele M.; Xue, Youjia [School of Civil and Environmental Engineering, University of New South Wales, Sydney, NSW 2052 (Australia); Kinsela, Andrew S. [School of Civil and Environmental Engineering, University of New South Wales, Sydney, NSW 2052 (Australia); Institute for Environmental Research (IER), Australian Nuclear Science and Technology Organisation (ANSTO), Lucas Heights, NSW 2234 (Australia); Wilcken, Klaus M. [Institute for Environmental Research (IER), Australian Nuclear Science and Technology Organisation (ANSTO), Lucas Heights, NSW 2234 (Australia); Collins, Richard N., E-mail: richard.collins@unsw.edu.au [School of Civil and Environmental Engineering, University of New South Wales, Sydney, NSW 2052 (Australia)

    2016-03-15

    Donnan dialysis has been applied to forty filtered drainage waters collected from five coastal lowland acid sulfate soil (CLASS) catchments across north-eastern NSW, Australia. Despite having average pH values < 3.9, 78 and 58% of Al and total Fe, respectively, were present as neutral or negatively-charged species. Complementary isotope dilution experiments with {sup 55}Fe and {sup 26}Al demonstrated that only soluble (i.e. no colloidal) species were present. Trivalent rare earth elements (REEs) were also mainly present (> 70%) as negatively-charged complexes. In contrast, the speciation of the divalent trace metals Co, Mn, Ni and Zn was dominated by positively-charged complexes and was strongly correlated with the alkaline earth metals Ca and Mg. Thermodynamic equilibrium speciation calculations indicated that natural organic matter (NOM) complexes dominated Fe(III) speciation in agreement with that obtained by Donnan dialysis. In the case of Fe(II), however, the free cation was predicted to dominate under thermodynamic equilibrium, whilst our results indicated that Fe(II) was mainly present as neutral or negatively-charged complexes (most likely with sulfate). For all other divalent metals thermodynamic equilibrium speciation calculations agreed well with the Donnan dialysis results. The proportion of Al and REEs predicted to be negatively-charged was also grossly underestimated, relative to the experimental results, highlighting possible inaccuracies in the stability constants developed for these trivalent Me(SO{sub 4}){sub 2}{sup −} and/or Me–NOM complexes and difficulties in modeling complex environmental samples. These results will help improve metal mobility and toxicity models developed for CLASS-affected environments, and also demonstrate that Australian CLASS environments can discharge REEs at concentrations an order of magnitude greater than previously reported. - Highlights: • CLASS discharge large amounts of metals and their speciation is poorly

  7. The Effect of Organism Size on the Content of Certain Trace Metals in Marine Zooplancton

    International Nuclear Information System (INIS)

    Fowler, S.W.

    1976-01-01

    Individual species of euphausiids and pelagic shrimp, collected at the same time and place, were sorted into different size groups and analyzed for several biologically important trace metals by atomic absorption spectrophotometry and neutron activation. Other specimens from these samples were dissected into gross anatomical parts and analyzed in the same way. Molts collected from zooplankters maintained live in the laboratory were also analyzed for metals. Results for the different size-group experiments showed that in general the concentrations of zinc, iron, and manganese were inversely correlated with dry body weight. Depending upon the crustacean species, metal concentrations in smaller individuals ranged from 1.2 to 4.1 times greater than those in larger individuals of the same species. Copper concentration on the other hand, tended to be a direct function of dry weight. Concentrations of zinc, iron, and manganese were generally higher in molts and dissected exoskeletons than in muscle tissue, however, the opposite was true for copper. The amount of material shed by euphausiids in molting ranged from 4.7 to 10.9% of dry body weight with smaller animals tending to lose a greater percentage of body weight than the larger specimens. These molts, in which ash accounted for about 40-50% of the dry weight, contained 15-20, 19-45, 28-40, and 15% of the total body zinc, iron, cobalt and manganese, respectively. Only 5% of the total body copper content was associated with the molt. In addition, molts from smaller crustaceans had higher concentrations of zinc and iron than those from larger species. With the exception of copper, it appears that a relatively large fraction of the animal's metal content is associated with the older inert chitin, indicating that much of the trace metal measured in small planktonic crustaceans is merely sorbed to the surface and is not physiologically necessary. In an ecological sense, the rapid molting frequency of these Crustacea

  8. Determination of trace amounts of metals in saline water by energy-dispersive XRF (with the Na-DDTC preconcentration)

    International Nuclear Information System (INIS)

    Holynska, B.; Bisiniek, K.

    1975-01-01

    A simple method for the determination of trace concentrations of metals in saline water is described. The analytical procedure involves the separation of metal ions of Cu(2), Zn(2), Hg(2) and Fe(3) by precipitation with diethyldithiocarbamate (DDTC). The radioisotope X-ray fluorescence method using Si/Li detector has been applied for the determination of metal ions closed in the DDTC deposition. (author)

  9. Radioactive contaminants in the subsurface: the influence of complexing ligands on trace metal speciation

    International Nuclear Information System (INIS)

    Hummel, W.

    2007-01-01

    in Swiss radioactive waste disposal projects. Within the scope of this TDB project I reviewed extensively thermodynamic data for Th, Pd, Al, and solubility and metal complexation of silicates, the review considering not only U, Np, Pu, Am, Tc, Ni, Se and Zr, but also the major constituents of ground and surface waters, i.e. H, Na, K, Mg and Ca. The decision to evaluate the organic ligands oxalate, citrate, ethylenediaminetetraacetate (edta) and α-isosaccharinate (isa) was based on two aspects, namely the importance of the ligands in radioactive waste problems, and the availability of experimental data. (ii) In many case studies involving inorganic and simple organic ligands a serious lack of reliable thermodynamic data is encountered. There, a new modeling approach to estimate the effects of these missing data was applied. This so called 'backdoor approach' begins with the question: 'What total concentration of a ligand is necessary to significantly influence the speciation, and hence the solubility, of a given trace metal?' Radioactive waste contains substantial amounts of ion-exchange resins from decontamination procedures. Degradation of these organic waste forms by radiolysis in a repository is a source of concern in radioactive waste management. Radiolytic degradation experiments with strong acidic ion exchange resins resulted in the formation of the complexing ligands oxalate and ligand X, whose structure could not be identified. In the case of anion exchange resins, ammonia and methylamines were detected. I assessed the influence of these ligands on radionuclide speciation in groundwater and cement pore water of a repository using the 'backdoor approach'. Prussian Blue, Fe III 4 [Fe II (CN) 6 ] 3 , and structurally related transition metal compounds like Ni 2 [Fe(CN) 6 ] are used as cesium ion exchangers in decontamination procedures of liquid radioactive waste. The used ion exchangers are conditioned as cementitious waste form for interim storage and finally

  10. Trace metal determinations by total-reflection x-ray fluorescence analysis in the open Atlantic Ocean

    International Nuclear Information System (INIS)

    Schmidt, D.; Gerwinski, W.; Radke, I.

    1993-01-01

    The Intergovernmental Oceanographic Commission (IOC), as a major component of its programme ''Global Investigation of Pollution in the Marine Environment'' (GIPME), maintains a long-standing project on ''Open Ocean Baseline Studies of Trace Contaminants''. Initially, the Atlantic Ocean and trace metals were selected. Four deep-water stations in the Cape Basin, Angola Basin, Cape Verde Abyssal Plain and Seine Abyssal Plain were regularly sampled for at least 36 depths. Additional samples were taken between stations. Samples were distributed to participants and a similar number of additional laboratories. As a central part of our own contribution to the project, we determined the trace heavy metals manganese, nickel, copper, zinc and lead and the lighter selenium by total-reflection X-ray fluorescence analysis. For the TXRF, the pre-enrichment of the trace metals and the separation from the salt matrix were performed by complexation with sodium dibenzyldithiocarbamate and reverse-phase chromatography. Generally, very low levels of trace elements were found in filtered and unfiltered water samples from these remote areas of the open Atlantic Ocean. Typical examples of the distributions of trace metal concentrations on depth profiles from the four deep-water stations as well as intercomparisons between the stations are presented. (author)

  11. Over one hundred years of trace metal fluxes in the sediments of the Pearl River Estuary, South China

    International Nuclear Information System (INIS)

    Ip, C.C.M.; Li, X.D.; Zhang, G.; Farmer, J.G.; Wai, O.W.H.; Li, Y.S.

    2004-01-01

    The rapid economic development in the Pearl River Delta (PRD) region in South China in the last three decades has had a significant impact on the local environment. Estuarine sediment is a major sink for contaminants and nutrients in the surrounding ecosystem. The accumulation of trace metals in sediments may cause serious environmental problems in the aquatic system. Thirty sediment cores were collected in the Pearl River Estuary (PRE) in 2000 for a study on trace metal pollution in this region. Heavy metal concentrations and Pb isotopic compositions in the four 210 Pb-dated sediment cores were determined to assess the fluxes in metal deposits over the last one hundred years. The concentrations of Cu, Pb and Zn in the surface sediment layers were generally elevated when compared with the sub-surface layers. There has been a significant increase in inputs of Cu, Pb and Zn in the PRE since the 1970s. The results also showed that different sampling locations in the estuary received slightly different types of inputs. Pb isotopic composition data indicated that the increased Pb in the recent sediments was of anthropogenic origin. The results of trace metal influxes showed that about 30% of total Pb and 15% of total Zn in the sediments in the 1990s were from anthropogenic sources. The combination of trace metal analysis, Pb isotopic composition and 210 Pb dating in an estuary can provide vital information on the long-term accumulation of metals in sediments

  12. Potential human health risk assessment of trace metals via the consumption of marine fish in Persian Gulf

    International Nuclear Information System (INIS)

    Naji, Abolfazl; Khan, Farhan R.; Hashemi, Seyed Hassan

    2016-01-01

    This study was carried out to evaluate the concentration of trace metals (Cd, Cu, Ni, Pb and Zn) in the muscle of four fish species from the Persian Gulf. Trace metals were analyzed using atomic absorption spectroscopy and consumption rates advisory for minimizing chronic systemic effects in children and adults were estimated. The metals concentrations in analyzed fish samples were lower than legal limits. Cadmium target hazard quotient values suggested that the threshold to avoid the potential risk for children health is an exposure level lower than 3 meals per week. Hazard index values based on four metals (not including Pb) for the child age class were higher than those of the adult age class, suggesting that children may suffer from a higher health risk. This study provides information about the consumption limits of certain metals, in particular Cd, necessary for minimizing potential health risks resulting from human consumption. - Highlights: • Trace metals in wild marine fish from the Persian Gulf were investigated. • Metal concentrations descended in the following order: Zn > Cu > Pb ≈ Ni > Cd > . • The Cd and Pb may be potential risk to human. • No obvious health risk from the intake of trace elements through fish consumption.

  13. Spatial variability and temporal changes in the trace metal content of soils: implications for mine restoration plan.

    Science.gov (United States)

    Chandra, Rachna; Prusty, B Anjan Kumar; Azeez, P A

    2014-06-01

    Trace metals in soils may be inherited from the parent materials or added to the system due to anthropogenic activities. In proposed mining areas, trace metals become an integral part of the soil system. Usually, researchers undertake experiments on plant species selection (for the restoration plan) only after the termination of mining activities, i.e. without any pre-mining information about the soil-plant interactions. Though not shown in studies, it is clear that several recovery plans remain unsuccessful while carrying out restoration experiments. Therefore, we hypothesize that to restore the area effectively, it is imperative to consider the pre-mining scenario of metal levels in parent material as well as the vegetation ecology of the region. With these specifics, we examined the concentrations of trace metals in parent soils at three proposed bauxite locations in the Eastern Ghats, India, and compared them at a spatio-temporal scale. Vegetation quantification and other basic soil parameters accounted for establishing the connection between soil and plants. The study recorded significant spatial heterogeneity in trace metal concentrations and the role of vegetation on metal availability. Oxidation reduction potential (ORP), pH and cation exchange capacity (CEC) directly influenced metal content, and Cu and Ni were lithogenic in origin. It implies that for effective restoration plant species varies for each geological location.

  14. Determination of trace metals and analysis of arsenic species in tropical marine fishes from Spratly islands.

    Science.gov (United States)

    Li, Jingxi; Sun, Chengjun; Zheng, Li; Jiang, Fenghua; Wang, Shuai; Zhuang, Zhixia; Wang, Xiaoru

    2017-09-15

    Trace metal contents in 38 species of tropical marine fishes harvested from the Spratly islands of China were determined by microwave digestion and inductively coupled plasma mass spectrometry analysis. Arsenic species were determined by high-performance liquid chromatography and inductively coupled plasma mass spectrometry analysis. The average levels of Al, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Mo, Cd, Pb, and U in the fish samples were 1.683, 0.350, 0.367, 2.954, 36.615, 0.087, 0.319, 1.566, 21.946, 20.845, 2.526, 3.583, 0.225, 0.140, and 0.061mg·kg -1 , respectively; Fe, Zn, and As were found at high concentrations. The trace metals exhibited significant positive correlation between each other, with r value of 0.610-0.852. Further analysis indicated that AsB (8.560-31.020mg·kg -1 ) was the dominant arsenic species in the fish samples and accounted for 31.48% to 47.24% of the total arsenic. As(III) and As(V) were detected at low concentrations, indicating minimal arsenic toxicity. Copyright © 2017. Published by Elsevier Ltd.

  15. Trace elements and heavy metals in hair of stage III breast cancer patients.

    Science.gov (United States)

    Benderli Cihan, Yasemin; Sözen, Selim; Oztürk Yıldırım, Sema

    2011-12-01

    This prospective study was designed to compare the hair levels of 36 elements in 52 patients with stage III breast cancer to those of an equal number of healthy individuals. Principal component and cluster analysis were used for source of identification and apportionment of heavy metals and trace elements in these two groups. A higher average level of iron was found in samples from patients while controls had higher levels of calcium. Both patients and controls had elevated levels of tin, magnesium, zinc, and sodium. Almost all element values in cancer patients showed higher dispersion and asymmetry than in healthy controls. Between the two groups, there were statistically significant differences in the concentrations of silver, arsenic, gold, boron, barium, beryllium, calcium, cadmium, cerium, cobalt, cesium, gadolinium, manganese, nickel, lead, antimony, scandium, selenium, and zinc (p heavy metals and trace elements in the hair of breast cancer patients in comparison to healthy controls. These results could be of significance in the diagnosis of breast cancer.

  16. Determination of trace metals in coastal seawater around Okinawa and its multielement profiling analysis

    International Nuclear Information System (INIS)

    Itoh, Akihide; Ishigaki, Teruyuki; Arakaki, Teruo; Yamada, Ayako; Yamaguchi, Mami; Kabe, Noriko

    2009-01-01

    In the present study, trace metals in coastal surface seawater around Okinawa were determined by inductively coupled plasma mass spectrometry (ICP-MS) with chelating disk preconcentration. As a result, the concentrations of V, Mn, Co, Ni, Cu, Zn, Mo, Cd, Pb, and U were obtained in the range from 10 μgL -1 to 0.001 μgL -1 for 6 samples. In addition, multielement profiling analyses were carried out using analytical values obtained in order to elucidate the features of trace metals in each coastal sea area. For coastal surface seawater near an urban area, the analytical values for Zn, Cu, Mn, and Pb were higher by more than 10-fold the literature values for open-surface seawater, and those of Cd were also relatively high. Such a trend concerning the multi-element profile was almost similar to the literature values for coastal seawater of the main island of Japan. On the other hand, the analytical values of most elements for coastal surface seawater near a suburb area were in the range from 0.5 to 5 fold, compared to the literature values for open surface seawater. From multielement profiling analyses for nutrient type elements in marine chemistry, it was suggested that the concentrations of Zn and Cd in a coral sea area normalized to literature values for open surface-seawater were higher than those of Ni and Cu. (author)

  17. Levels of essential and potentially toxic trace metals in Antarctic macro algae

    International Nuclear Information System (INIS)

    Farias, Silvia; Arisnabarreta, Sebastian Perez; Vodopivez, Cristian; Smichowski, Patricia

    2002-01-01

    Eleven species of Antarctic algae were examined for their accumulation ability in the uptake of different metals and metalloids from the Antarctic aquatic environment. Macro algae were collected during the 2000 austral summer season at Jubany Station (Argentinean base) around Potter Cove, King George Island. The elements quantified were: As, Cd, Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb, Se, Sr, V, and Zn. An optimized microwave-assisted digestion procedure was used to digest the samples and the elements were determined by inductively coupled plasma optical emission spectrometry. A wide range of metal retention capacity among the different species was observed. The highest levels of trace elements were found in Monostroma hariotii and Phaeurus antarcticus, with concentrations up to 3095 μg g -1 for Fe. On the basis of the levels of trace elements observed in Monostroma hariotii and its wide distribution in the Antarctic Peninsula, this organism accomplishes a number of prerequisites to be considered as an adequate biomonitor for future studies

  18. Temporal and spatial trends for trace metals in streams and rivers across Sweden (1996–2009

    Directory of Open Access Journals (Sweden)

    J. Fölster

    2011-07-01

    Full Text Available Long term data series (1996 through 2009 for trace metals were analyzed from a large number of streams and rivers across Sweden varying in tributary watershed size from 0.05 to 48 193 km2. The final data set included 139 stream sites with data for arsenic (As, cobalt (Co, copper (Cu, chromium (Cr, nickel (Ni, lead (Pb, zinc (Zn, and vanadium (V. Between 7 % and 46 % of the sites analyzed showed significant trends according to the seasonal Kendall test. However, in contrast to previous studies and depositional patterns, a substantial portion of the trends were positive, especially for V (100 %, As (95 %, and Pb (68 %. Other metals (Zn and Cr generally decreased, were mixed (Ni and Zn, or had very few trends (Co over the study period. Trends by region were also analyzed and some showed significant variation between the north and south of Sweden. Regional trends for both Cu and Pb were positive (60 % and 93 %, respectively in the southern region but strongly negative (93 % and 75 %, respectively in the northern region. Kendall's τ coefficients were used to determine dependence between metals and potential in-stream drivers including total organic carbon (TOC, iron (Fe, pH, and sulphate (SO42−. TOC and Fe correlated positively and strongly with As, V, Pb, and Co while pH and SO42− generally correlated weakly, or not at all with the metals studied.

  19. Metals and trace elements in feathers: A geochemical approach to avoid misinterpretation of analytical responses.

    Science.gov (United States)

    Borghesi, Fabrizio; Migani, Francesca; Andreotti, Alessandro; Baccetti, Nicola; Bianchi, Nicola; Birke, Manfred; Dinelli, Enrico

    2016-02-15

    Assessing trace metal pollution using feathers has long attracted the attention of ecotoxicologists as a cost-effective and non-invasive biomonitoring method. In order to interpret the concentrations in feathers considering the external contamination due to lithic residue particles, we adopted a novel geochemical approach. We analysed 58 element concentrations in feathers of wild Eurasian Greater Flamingo Phoenicopterus roseus fledglings, from 4 colonies in Western Europe (Spain, France, Sardinia, and North-eastern Italy) and one group of adults from zoo. In addition, 53 elements were assessed in soil collected close to the nesting islets. This enabled to compare a wide selection of metals among the colonies, highlighting environmental anomalies and tackling possible causes of misinterpretation of feather results. Most trace elements in feathers (Al, Ce, Co, Cs, Fe, Ga, Li, Mn, Nb, Pb, Rb, Ti, V, Zr, and REEs) were of external origin. Some elements could be constitutive (Cu, Zn) or significantly bioaccumulated (Hg, Se) in flamingos. For As, Cr, and to a lesser extent Pb, it seems that bioaccumulation potentially could be revealed by highly exposed birds, provided feathers are well cleaned. This comprehensive study provides a new dataset and confirms that Hg has been accumulated in feathers in all sites to some extent, with particular concern for the Sardinian colony, which should be studied further including Cr. The Spanish colony appears critical for As pollution and should be urgently investigated in depth. Feathers collected from North-eastern Italy were the hardest to clean, but our methods allowed biological interpretation of Cr and Pb. Our study highlights the importance of external contamination when analysing trace elements in feathers and advances methodological recommendations in order to reduce the presence of residual particles carrying elements of external origin. Geochemical data, when available, can represent a valuable tool for a correct

  20. Trace metals content (contaminants) as initial indicator in the quality of heat treated palm oil whole extract

    Energy Technology Data Exchange (ETDEWEB)

    Mohd Fauzi, Noor Akhmazillah bt [Chemical and Bioprocess Department, Faculty of Civil and Environmental Engineering, Universiti Tun Hussein Onn Malaysia, 86400 Parit Raja, Batu Pahat, Johor (Malaysia); Sarmidi, Mohd Roji [Chemical Engineering Pilot Plant, Faculty of Chemical and Natural Resources Engineering, Universiti Teknologi Malaysia, 81310 Skudai, Johor (Malaysia)

    2011-07-01

    An investigation was carried out on the effect of different sterilization time on the trace metals concentration of palm oil whole extract. Palm fruits were collected, cleaned and sterilized for 0, 20, 40 and 60 minutes. The kernels were then stripped from the sterilized fruits to get the pulp and later the pulp was pressed using small scale expeller. The resulting puree was centrifuge at 4000 rpm for 20 minutes. The palm oil whole extract were then collected and trace metals analysis was conducted using Inductively Couple Plasma-Mass Spectrometry (ICP-MS). The result showed that the highest yield was obtained at 40 minutes of sterilization with 19.9 {+-} 0.21 % (w/w). There was no significant different (p < 0.5) in total trace metals content between the degrees of the heat treatment. Na+ was found as the highest trace metals content in the extract with mean concentration ranging from 1.05 {+-} 0.03 ppm to 2.36 {+-} 0.01 ppm. 40 minutes of heating time was predicted to have good oil quality due to higher content in trace metals that inhibit the lipase enzyme activity.

  1. Trace metals bioaccumulation potentials of three indigenous grasses grown on polluted soils collected around mining areas in Pretoria, South Africa

    International Nuclear Information System (INIS)

    Lion, G. N.; Olowoyo, J. O.; Modise, T. A.

    2016-01-01

    The rapid increase in the number of industries may have increased the levels of trace metals in the soil. Phyto remediation of these polluted soils using indigenous grasses is now considered an alternative method in re mediating these polluted soils. The present study investigated and compared the ability of three indigenous grasses as bioaccumulators of trace metals from polluted soils. Seeds of these grasses were introduced into pots containing polluted soil samples after the addition of organic manure. The seeds of the grasses were allowed to germinate and grow to maturity before harvesting. The harvested grasses were later separated into shoots and roots and the trace metal contents were determined using ICP –MS. From all the grasses, the concentrations of trace metals in the roots were more than those recorded in the shoot with a significant difference (P Themeda trianda > Cynodon dactylon. The study concluded that the three grasses used were all able to bioaccumulate trace metals in a similar proportion from the polluted soils. However, since livestock feed on these grasses, they should not be allowed to feed on the grasses used in this study especially when harvested from a polluted soil due to their bioaccumulative potentials. (au)

  2. Short-term acute hypercapnia affects cellular responses to trace metals in the hard clams Mercenaria mercenaria

    International Nuclear Information System (INIS)

    Ivanina, Anna V.; Beniash, Elia; Etzkorn, Markus; Meyers, Tiffany B.; Ringwood, Amy H.; Sokolova, Inna M.

    2013-01-01

    Highlights: •P CO 2 alters accumulation of Cd and Cu in clam cells. •Accumulation of Cd induces release of free Zn 2+ . •Accumulation of Cu induces an increase in free Cu 2+ and Fe 2+ . •Metal-induced oxidative stress is alleviated at high P CO 2 . •Toxicity of Cu in likely enhanced while that of Cd alleviated by high P CO 2 . -- Abstract: Estuarine and coastal habitats experience large fluctuations of environmental factors such as temperature, salinity, partial pressure of CO 2 (P CO 2 ) and pH; they also serve as the natural sinks for trace metals. Benthic filter-feeding organisms such as bivalves are exposed to the elevated concentrations of metals in estuarine water and sediments that can strongly affect their physiology. The effects of metals on estuarine organisms may be exacerbated by other environmental factors. Thus, a decrease in pH caused by high P CO 2 (hypercapnia) can modulate the effects of trace metals by affecting metal bioavailability, accumulation or binding. To better understand the cellular mechanisms of interactions between P CO 2 and trace metals in marine bivalves, we exposed isolated mantle cells of the hard clams (Mercenaria mercenaria) to different levels of P CO 2 (0.05, 1.52 and 3.01 kPa) and two major trace metal pollutants – cadmium (Cd) and copper (Cu). Elevated P CO 2 resulted in a decrease in intracellular pH (pH i ) of the isolated mantle cells from 7.8 to 7.4. Elevated P CO 2 significantly but differently affected the trace metal accumulation by the cells. Cd uptake was suppressed at elevated P CO 2 levels while Cu accumulation has greatly accelerated under hypercapnic conditions. Interestingly, at higher extracellular Cd levels, labile intracellular Cd 2+ concentration remained the same, while intracellular levels of free Zn 2+ increased suggesting that Cd 2+ substitutes bound Zn 2+ in these cells. In contrast, Cu exposure did not affect intracellular Zn 2+ but led to a profound increase in the intracellular levels

  3. Reference-data modelling for tracking and tracing

    NARCIS (Netherlands)

    Dorp, van C.A.

    2004-01-01

    Subject headings: supply chain, tracking and tracing, reference-data modelling

  4. Content and distribution of trace metals in pristine permafrost environments of Northeastern Siberia, Russia

    Science.gov (United States)

    Antcibor, I.; Eschenbach, A.; Kutzbach, L.; Bolshiyanov, D.; Pfeiffer, E.-M.

    2012-04-01

    Arctic regions are one of the most sensitive areas with respect to climatic changes and human impacts. Research is required to discover how the function of permafrost soils as a buffering system for metal pollutants could change in response to the predicted changes. The goal of this work is to determine the background levels of trace metals in the pristine arctic ecosystems of the Lena River Delta in Northeastern Siberia and to evaluate the possible effect of human impacts on this arctic region. The Lena River Delta represents areas with different dominating geomorphologic processes that can generally be divided between accumulation and erosion sites. Frequent changes of the river water level create different periods of sedimentation and result in the formation of stratified soils and sediment layers which are dominated either by mineral substrates with allochthonous organic matter or pure autochthonous peat. The deposited sediments that have formed the delta islands are mostly composed of sand fractions; therefore the buffering effects of clay materials can be neglected. Samoylov Island is representative of the south-central and eastern modern delta surfaces of the Lena River Delta and is selected as a pilot study site. We determined total element contents of Fe, Mn, Zn, Cd, Ni, Cu, As, Pb, Co and Hg in soil horizons from different polygonal elevated rims, polygonal depressed centers and the middle floodplain. High gravimetric concentrations (related to dry mass of soil material) of Mn and Fe are found within all soil profiles and vary from 0.14 to 1.39 g kg-1 and from 10.7 to 41.2 g kg-1, respectively. While the trace element concentrations do not exceed typical crustal abundances, the maximum values of most of the metals are observed within the soil profile situated at the middle floodplain. This finding suggests that apart from the parent material the second potential source of trace metals is due to allochthonous substance input during annual flooding of the

  5. Macronutrients and trace metals in soil and food crops of Isfahan Province, Iran.

    Science.gov (United States)

    Keshavarzi, Behnam; Moore, Farid; Ansari, Maryam; Rastegari Mehr, Meisam; Kaabi, Helena; Kermani, Maryam

    2015-01-01

    The distribution of 10 macronutrients and trace metals in the arable soils of Isfahan Province, their phytoavailability, and associated health risks were investigated; 134 plant and 114 soil samples (from 114 crop fields) were collected and analyzed at harvesting time. Calculation of the soil pollution index (SPI) revealed that arable soil polluted by metals was more severe in the north and southwest of the study area. The results of cluster analysis indicated that Pb, Zn, and Cu share a similar origin from industries and traffic. The concentrations of macronutrients and trace metals in the sampled crops were found in the order of K > Ca > S > Mg > P and Fe > Mn > Zn > Cu > Pb, respectively, whereas calculation of the bioconcentration factor (BCF) indicated that the accumulation of the investigated elements in crops was generally in the order of S ≈ K > P > Mg > Ca and Zn > Cu > Mn > Pb > Fe, respectively. Thus, various parameters including crop species and the physical, chemical, and biological properties of soil also affected the bioavailability of the elements besides the total element contents in soil. Daily intake (DI) values of elements were lower than the recommended daily intake (RDI) levels in rice grains except for Fe and Mn, but for wheat grains, all elements displayed DI values higher than the RDI. Moreover, based on the hazard index (HI) values, inhabitants are experiencing a significant potential health risk solely due to the consumption of wheat and rice grains (particularly wheat grains). Mn health quotient (HQ) also indicated a high risk of Mn absorption for crop consumer inhabitants.

  6. Short-term acute hypercapnia affects cellular responses to trace metals in the hard clams Mercenaria mercenaria.

    Science.gov (United States)

    Ivanina, Anna V; Beniash, Elia; Etzkorn, Markus; Meyers, Tiffany B; Ringwood, Amy H; Sokolova, Inna M

    2013-09-15

    Estuarine and coastal habitats experience large fluctuations of environmental factors such as temperature, salinity, partial pressure of CO2 ( [Formula: see text] ) and pH; they also serve as the natural sinks for trace metals. Benthic filter-feeding organisms such as bivalves are exposed to the elevated concentrations of metals in estuarine water and sediments that can strongly affect their physiology. The effects of metals on estuarine organisms may be exacerbated by other environmental factors. Thus, a decrease in pH caused by high [Formula: see text] (hypercapnia) can modulate the effects of trace metals by affecting metal bioavailability, accumulation or binding. To better understand the cellular mechanisms of interactions between [Formula: see text] and trace metals in marine bivalves, we exposed isolated mantle cells of the hard clams (Mercenaria mercenaria) to different levels of [Formula: see text] (0.05, 1.52 and 3.01 kPa) and two major trace metal pollutants - cadmium (Cd) and copper (Cu). Elevated [Formula: see text] resulted in a decrease in intracellular pH (pHi) of the isolated mantle cells from 7.8 to 7.4. Elevated [Formula: see text] significantly but differently affected the trace metal accumulation by the cells. Cd uptake was suppressed at elevated [Formula: see text] levels while Cu accumulation has greatly accelerated under hypercapnic conditions. Interestingly, at higher extracellular Cd levels, labile intracellular Cd(2+) concentration remained the same, while intracellular levels of free Zn(2+) increased suggesting that Cd(2+) substitutes bound Zn(2+) in these cells. In contrast, Cu exposure did not affect intracellular Zn(2+) but led to a profound increase in the intracellular levels of labile Cu(2+) and Fe(2+). An increase in the extracellular concentrations of Cd and Cu led to the elevated production of reactive oxygen species under the normocapnic conditions (0.05 kPa [Formula: see text] ); surprisingly, this effect was mitigated in

  7. Potential human health risk assessment of trace metals via the consumption of marine fish in Persian Gulf

    DEFF Research Database (Denmark)

    Naji, Abolfazl; Khan, Farhan; Hashemi, Seyed Hassan

    2016-01-01

    This study was carried out to evaluate the concentration of trace metals (Cd, Cu, Ni, Pb and Zn) in the muscle of four fish species from the Persian Gulf. Trace metals were analyzed using atomic absorption spectroscopy and consumption rates advisory for minimizing chronic systemic effects in chil...... health risks resulting from human consumption....... in children and adults were estimated. The metals concentrations in analyzed fish samples were lower than legal limits. Cadmium target hazard quotient values suggested that the threshold to avoid the potential risk for children health is an exposure level lower than 3 meals per week. Hazard index values based...... on four metals (not including Pb) for the child age class were higher than those of the adult age class, suggesting that children may suffer from a higher health risk. This study provides information about the consumption limits of certain metals, in particular Cd, necessary for minimizing potential...

  8. Trace metal distribution in sediments of the Pearl River Estuary and the surrounding coastal area, South China

    International Nuclear Information System (INIS)

    Ip, Carman C.M.; Li Xiangdong; Zhang Gan; Wai, Onyx W.H.; Li, Y.-S.

    2007-01-01

    Surface sediments and sediment cores collected at the Pearl River Estuary (PRE) and its surrounding coastal area were analysed for total metal concentrations, chemical partitioning, and Pb isotopic compositions. The distribution of Cu, Cr, Pb, and Zn demonstrated a typical diffusion pattern from the land to the direction of the sea. Two hotspots of trace metal contamination were located at the mixed zone between freshwater and marine waters. The enrichment of metals in the sediments could be attributed to the deposition of the dissolved and particulate trace metals in the water column at the estuarine area. The similar Pb isotopic signatures of the sediments at the PRE and its surrounding coastal area offered strong evidence that the PRE was a major source of trace metals to the adjacent coastal area. Slightly lower 206 Pb/ 207 Pb ratios in the coastal sediments may indicate other inputs of Pb in addition to the PRE sources, including the inputs from Hong Kong and other parts of the region. - The distribution of trace metals in sediments reflected contaminant sources, physical and chemical deposition processes

  9. Trace metals in vegetables and fruits cultivated around the surroundings of Tummalapalle uranium mining site, Andhra Pradesh, India

    Directory of Open Access Journals (Sweden)

    Allabaksh Murad Basha

    2014-01-01

    Full Text Available Vegetables (Tomato – Solanum lycopersicum, green chilli – Capsicum annum and bitter gourd – Momordica charantia and fruits (Banana – Musa acuminata colla, papaya – Carica papaya and mosambi – Citrus limetta from the cultivated areas around the Tummalapalle uranium mining site were analyzed for trace metals (Al, Cr, Mn, Fe, Ni, Cu, Zn, Pb, Be, V, Co, Cd and U using inductively coupled plasma-mass spectrometer (ICP-MS. As per the estimated data, the concentrations of trace metals in vegetables and fruits are found in the range of 47.5–7.8 mg/kg for Al, 9.7–1.0 mg/kg for Cr, 3.8–1.0 mg/kg for Mn, 75.5–13.9 mg/kg for Fe, 1.4–0.2 mg/kg for Ni, 2.3–0.8 mg/kg for Cu, 9.2–3.1 mg/kg for Zn, 0.2–1.4 mg/kg for Pb, 19.2–1.9 μg/kg for Be, 96.1–15.8 μg/kg for V, 48.2–12.9 μg/kg for Co, 46.5–2.3 μg/kg for Cd and 16.4–2.7 μg/kg for U. The trace metals observed are compared to the literature reported values. Trace elemental data were subjected to statistical analysis to examine the interrelationship between the investigated trace elements and possible source identification of the trace metal contamination in vegetable and fruits. Daily intake of trace metals through ingestion of vegetables and fruits are also calculated.

  10. Chemical speciation and human health risk of trace metals in urban street dusts from a metropolitan city, Nanjing, SE China

    Energy Technology Data Exchange (ETDEWEB)

    Li, Huiming; Qian, Xin, E-mail: xqian@nju.edu.cn; Hu, Wei; Wang, Yulei; Gao, Hailong

    2013-07-01

    The modified BCR (the European Community Bureau of Reference) sequential extraction procedure was applied for partitioning and evaluating the mobility, availability and persistence of trace metals (Al, Cd, Co, Cr, Cu, Ni, Pb, Sr, V and Zn) in urban street dusts collected from different areas of Nanjing, China. The mobility sequence based on the sum of the BCR sequential extraction stages was: Sr (91.65%) > Pb (79.16%) > Zn (74.26%) > Cu (68.53%) > Co (45.98%) > Al (40.01%) ≈ V (38.45%) ≈ Ni (37.88%) > Cr (29.35%) > Cd (22.68%). Almost every trace metal had its highest total concentrations in the industrial area, except for Sr which had its highest concentration in the commercial area. Contamination factors (Cf), risk assessment code (RAC) and enrichment factor (Ef) were then calculated to further assess the environmental risk and provide a preliminary estimate of the main sources of trace metals in street dusts. Non-carcinogenic effects and carcinogenic effects due to exposure to urban street dusts were assessed for both children and adults. For non-carcinogenic effects, ingestion was the main route of exposure to street dusts for these metals, followed by dermal contact and inhalation. Hazard index values for all studied metals were lower than the safe level of 1, and Pb exhibited the highest risk value (0.125) in the case of children. The carcinogenic risk for Cd, Co, Cr and Ni were all below the acceptable level (< 10{sup −6}). - Highlights: • This study assesses a comprehensive environmental risk of urban trace metal pollution. • This study evaluates human health risk combined with the speciation of trace metals. • This study points the critical contaminated metals that need to be paid special attention. • This study supplies useful information and reference on the application of BCR SPE method.

  11. Monitoring of trace metals and pharmaceuticals as anthropogenic and socio-economic indicators of urban and industrial impact on surface waters

    Science.gov (United States)

    Vystavna, Yuliya

    2014-05-01

    The research focuses on the monitoring of trace metals and pharmaceuticals as potential anthropogenic indicators of industrial and urban influences on surface water in poorly gauged transboundary Ukraine/Russia region. This study includes analysis of tracers use for the indication of water pollution events, including controlled and emerging discharges, and discussion of the detection method of these chemicals. The following criteria were proposed for the evaluation of indicators: specificity (physical chemical properties), variability (spatial and temporal) and practicality (capacity of the sampling and analytical techniques). The combination of grab and passive water sampling (i.e. DGT and POCIS) procedure was applied for the determination of dissolved and labile trace metals (Ag, Cd, Cr, Cu, Ni, Pb and Zn) and pharmaceuticals (carbamazepine, diazepam, paracetamol, caffeine, diclofenac and ketoprofen). Samples were analysed using ICP - MS (trace metals) and LC-MS/MS ESI +/- (pharmaceuticals). Our results demonstrate the distinctive spatial and temporal patterns of trace elements distribution along an urban watercourse. Accordingly, two general groups of trace metals have been discriminated: 'stable' (Cd and Cr) and 'time-varying' (Cu, Zn, Ni and Pb). The relationship Cd >> Cu > Ag > Cr ≥ Zn was proposed as an anthropogenic signature of the industrial and urban activities pressuring the environment from point sources (municipal wastewaters) and the group Pb - Ni was discussed as a relevant fingerprint of the economic activity (industry and transport) mainly from non-point sources (run-off, atmospheric depositions, etc.). Pharmaceuticals with contrasting hydro-chemical properties of molecules (water solubility, bioaccumulation, persistence during wastewater treatment processes) were discriminated on conservative, labile and with combined properties in order to provide information on wastewater treatment plant efficiency, punctual events (e.g. accidents on sewage

  12. A constrained rasch model of trace redintegration in serial recall.

    Science.gov (United States)

    Roodenrys, Steven; Miller, Leonie M

    2008-04-01

    The notion that verbal short-term memory tasks, such as serial recall, make use of information in long-term as well as in short-term memory is instantiated in many models of these tasks. Such models incorporate a process in which degraded traces retrieved from a short-term store are reconstructed, or redintegrated (Schweickert, 1993), through the use of information in long-term memory. This article presents a conceptual and mathematical model of this process based on a class of item-response theory models. It is demonstrated that this model provides a better fit to three sets of data than does the multinomial processing tree model of redintegration (Schweickert, 1993) and that a number of conceptual accounts of serial recall can be related to the parameters of the model.

  13. Selected Trace Metals and Organic Compounds and Bioavailability of Selected Organic Compounds in Soils, Hackberry Flat, Tillman County, Oklahoma, 1994-95

    National Research Council Canada - National Science Library

    Becker, Mark F

    1997-01-01

    .... S. Geological Survey, in cooperation with Wildlife Conservation and the Oklahoma Geological Survey, examined the soils of Hackberry Flat to determine trace metal concentrations, presence of selected...

  14. Trophic relationships in an Arctic food web and implications for trace metal transfer

    Energy Technology Data Exchange (ETDEWEB)

    Dehn, Larissa-A. [Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, Alaska, 99775-7000 (United States)]. E-mail: ftld@uaf.edu; Follmann, Erich H. [Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, Alaska, 99775-7000 (United States); Thomas, Dana L. [Department of Mathematical Sciences, University of Alaska Fairbanks, Fairbanks, Alaska, 99775-6660 (United States); Sheffield, Gay G. [Alaska Department of Fish and Game, Fairbanks, Division of Wildlife Conservation, Fairbanks, Alaska, 99701-1599 (United States); Rosa, Cheryl [Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, Alaska, 99775-7000 (United States); Duffy, Lawrence K. [Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, Alaska, 99775-7000 (United States); O' Hara, Todd M. [Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, Alaska, 99775-7000 (United States)

    2006-06-01

    dynamic and actively regulated trace metals.

  15. Trophic relationships in an Arctic food web and implications for trace metal transfer

    International Nuclear Information System (INIS)

    Dehn, Larissa-A.; Follmann, Erich H.; Thomas, Dana L.; Sheffield, Gay G.; Rosa, Cheryl; Duffy, Lawrence K.; O'Hara, Todd M.

    2006-01-01

    Tissues of subsistence-harvested Arctic mammals were analyzed for silver (Ag), cadmium (Cd), and total mercury (THg). Muscle (or total body homogenates of potential fish and invertebrate prey) was analyzed for stable carbon (δ 13 C) and nitrogen (δ 15 N) isotopes to establish trophic interactions within the Arctic food chain. Food web magnification factors (FWMFs) and biomagnification factors for selected predator-prey scenarios (BMFs) were calculated to describe pathways of heavy metals in the Alaskan Arctic. FWMFs in this study indicate that magnification of selected heavy metals in the Arctic food web is not significant. Biomagnification of Cd occurs mainly in kidneys; calculated BMFs are higher for hepatic THg than renal THg for all predator-prey scenarios with the exception of polar bears (Ursus maritimus). In bears, the accumulation of renal THg is approximately 6 times higher than in liver. Magnification of hepatic Ag is minimal for all selected predator-prey scenarios. Though polar bears occupy a higher trophic level than belugas (Delphinapterus leucas), based on δ 15 N, the metal concentrations are either not statistically different between the two species or lower for bears. Similarly, concentrations of renal and hepatic Cd are significantly lower or not statistically different in polar bears compared to ringed (Phoca hispida) and bearded seals (Erignathus barbatus), their primary prey. THg, on the other hand, increased significantly from seal to polar bear tissues. Mean δ 15 N was lowest in muscle of Arctic fox (Alopex lagopus) and foxes also show the lowest levels of Hg, Cd and Ag in liver and kidney compared to the other species analyzed. These values are in good agreement with a diet dominated by terrestrial prey. Metal deposition in animal tissues is strongly dependent on biological factors such as diet, age, sex, body condition and health, and caution should be taken when interpreting magnification of dynamic and actively regulated trace metals

  16. Trace metal mobilization from oil sands froth treatment thickened tailings exhibiting acid rock drainage.

    Science.gov (United States)

    Kuznetsova, Alsu; Kuznetsov, Petr; Foght, Julia M; Siddique, Tariq

    2016-11-15

    Froth treatment thickened tailings (TT) are a waste product of bitumen extraction from surface-mined oil sands ores. When incubated in a laboratory under simulated moist oxic environmental conditions for ~450d, two different types of TT (TT1 and TT2) exhibited the potential to generate acid rock drainage (ARD) by producing acid leachate after 250 and 50d, respectively. We report here the release of toxic metals from TT via ARD, which could pose an environmental threat if oil sands TT deposits are not properly managed. Trace metal concentrations in leachate samples collected periodically revealed that Mn and Sr were released immediately even before the onset of ARD. Spikes in Co and Ni concentrations were observed both pre-ARD and during active ARD, particularly in TT1. For most elements measured (Fe, Cr, V, As, Cu, Pb, Zn, Cd, and Se), leaching was associated with ARD production. Though equivalent acidification (pH2) was achieved in leachate from both TT types, greater metal release was observed from TT2 where concentrations reached 10,000ppb for Ni, 5000ppb for Co, 3000ppb for As, 2000ppb for V, and 1000ppb for Cr. Generally, metal concentrations decreased in leachate with time during ARD and became negligible by the end of incubation (~450d) despite appreciable metals remaining in the leached TT. These results suggest that using TT for land reclamation purposes or surface deposition for volume reduction may unfavorably impact the environment, and warrants application of appropriate strategies for management of pyrite-enriched oil sands tailings streams. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Macro and micro plastics sorb and desorb metals and act as a point source of trace metals to coastal ecosystems.

    Directory of Open Access Journals (Sweden)

    B Munier

    . Plastic debris will affect metals within coastal ecosystems by; 1 providing a sorption site (copper and lead, notably for PVC 2 desorption from the plastic i.e., the "inherent" load (cadmium and zinc and 3 serving as a point source of acute trace metal exposure to coastal ecosystems. All three mechanisms will put coastal ecosystems at risk to the toxic effects of these metals.

  18. Surface distribution of dissolved trace metals in the oligotrophic ocean and their influence on phytoplankton biomass and productivity

    KAUST Repository

    Pinedo-González, Paulina

    2015-10-25

    The distribution of bioactive trace metals has the potential to enhance or limit primary productivity and carbon export in some regions of the world ocean. To study these connections, the concentrations of Cd, Co, Cu, Fe, Mo, Ni, and V were determined for 110 surface water samples collected during the Malaspina 2010 Circumnavigation Expedition (MCE). Total dissolved Cd, Co, Cu, Fe, Mo, Ni, and V concentrations averaged 19.0 ± 5.4 pM, 21.4 ± 12 pM, 0.91 ± 0.4 nM, 0.66 ± 0.3 nM, 88.8 ± 12 nM, 1.72 ± 0.4 nM, and 23.4 ± 4.4 nM, respectively, with the lowest values detected in the Central Pacific and increased values at the extremes of all transects near coastal zones. Trace metal concentrations measured in surface waters of the Atlantic Ocean during the MCE were compared to previously published data for the same region. The comparison revealed little temporal changes in the distribution of Cd, Co, Cu, Fe, and Ni over the last 30 years. We utilized a multivariable linear regression model to describe potential relationships between primary productivity and the hydrological, biological, trace nutrient and macronutrient data collected during the MCE. Our statistical analysis shows that primary productivity in the Indian Ocean is best described by chlorophyll a, NO3, Ni, temperature, SiO4, and Cd. In the Atlantic Ocean, primary productivity is correlated with chlorophyll a, NO3, PO4, mixed layer depth, Co, Fe, Cd, Cu, V, and Mo. The variables salinity, temperature, SiO4, NO3, PO4, Fe, Cd, and V were found to best predict primary productivity in the Pacific Ocean. These results suggest that some of the lesser studied trace elements (e.g., Ni, V, Mo, and Cd) may play a more important role in regulating oceanic primary productivity than previously thought and point to the need for future experiments to verify their potential biological functions.

  19. Surface distribution of dissolved trace metals in the oligotrophic ocean and their influence on phytoplankton biomass and productivity

    KAUST Repository

    Pinedo-Gonzá lez, Paulina; West, A. Joshua; Tovar-Sá nchez, Antonio; Duarte, Carlos M.; Marañ ó n, Emilio; Cermeñ o, Pedro; Gonzá lez, Natalia; Sobrino, Cristina; Huete-Ortega, Marí a; Ferná ndez, Ana; Ló pez-Sandoval, Daffne C.; Vidal, Montserrat; Blasco, Dolors; Estrada, Marta; Sañ udo-Wilhelmy, Sergio A.

    2015-01-01

    The distribution of bioactive trace metals has the potential to enhance or limit primary productivity and carbon export in some regions of the world ocean. To study these connections, the concentrations of Cd, Co, Cu, Fe, Mo, Ni, and V were determined for 110 surface water samples collected during the Malaspina 2010 Circumnavigation Expedition (MCE). Total dissolved Cd, Co, Cu, Fe, Mo, Ni, and V concentrations averaged 19.0 ± 5.4 pM, 21.4 ± 12 pM, 0.91 ± 0.4 nM, 0.66 ± 0.3 nM, 88.8 ± 12 nM, 1.72 ± 0.4 nM, and 23.4 ± 4.4 nM, respectively, with the lowest values detected in the Central Pacific and increased values at the extremes of all transects near coastal zones. Trace metal concentrations measured in surface waters of the Atlantic Ocean during the MCE were compared to previously published data for the same region. The comparison revealed little temporal changes in the distribution of Cd, Co, Cu, Fe, and Ni over the last 30 years. We utilized a multivariable linear regression model to describe potential relationships between primary productivity and the hydrological, biological, trace nutrient and macronutrient data collected during the MCE. Our statistical analysis shows that primary productivity in the Indian Ocean is best described by chlorophyll a, NO3, Ni, temperature, SiO4, and Cd. In the Atlantic Ocean, primary productivity is correlated with chlorophyll a, NO3, PO4, mixed layer depth, Co, Fe, Cd, Cu, V, and Mo. The variables salinity, temperature, SiO4, NO3, PO4, Fe, Cd, and V were found to best predict primary productivity in the Pacific Ocean. These results suggest that some of the lesser studied trace elements (e.g., Ni, V, Mo, and Cd) may play a more important role in regulating oceanic primary productivity than previously thought and point to the need for future experiments to verify their potential biological functions.

  20. Simulation of trace metals and PAH atmospheric pollution over Greater Paris: Concentrations and deposition on urban surfaces

    Science.gov (United States)

    Thouron, L.; Seigneur, C.; Kim, Y.; Legorgeu, C.; Roustan, Y.; Bruge, B.

    2017-10-01

    Urban areas can be subject not only to poor air quality, but also to contamination of other environmental media by air pollutants. Here, we address the potential transfer of selected air pollutants (two metals and three PAH) to urban surfaces. To that end, we simulate meteorology and air pollution from Europe to a Paris suburban neighborhood, using a four-level one-way nesting approach. The meteorological and air quality simulations use urban canopy sub-models in order to better represent the effect of the urban morphology on the air flow, atmospheric dispersion, and deposition of air pollutants to urban surfaces. This modeling approach allows us to distinguish air pollutant deposition among various urban surfaces (roofs, roads, and walls). Meteorological model performance is satisfactory, showing improved results compared to earlier simulations, although precipitation amounts are underestimated. Concentration simulation results are also satisfactory for both metals, with a fractional bias Paris region. The model simulation results suggest that both wet and dry deposition processes need to be considered when estimating the transfer of air pollutants to other environmental media. Dry deposition fluxes to various urban surfaces are mostly uniform for PAH, which are entirely present in fine particles. However, there is significantly less wall deposition compared to deposition to roofs and roads for trace metals, due to their coarse fraction. Meteorology, particle size distribution, and urban morphology are all important factors affecting air pollutant deposition. Future work should focus on the collection of data suitable to evaluate the performance of atmospheric models for both wet and dry deposition with fine spatial resolution.

  1. Quantitative Modelling of Trace Elements in Hard Coal.

    Science.gov (United States)

    Smoliński, Adam; Howaniec, Natalia

    2016-01-01

    The significance of coal in the world economy remains unquestionable for decades. It is also expected to be the dominant fossil fuel in the foreseeable future. The increased awareness of sustainable development reflected in the relevant regulations implies, however, the need for the development and implementation of clean coal technologies on the one hand, and adequate analytical tools on the other. The paper presents the application of the quantitative Partial Least Squares method in modeling the concentrations of trace elements (As, Ba, Cd, Co, Cr, Cu, Mn, Ni, Pb, Rb, Sr, V and Zn) in hard coal based on the physical and chemical parameters of coal, and coal ash components. The study was focused on trace elements potentially hazardous to the environment when emitted from coal processing systems. The studied data included 24 parameters determined for 132 coal samples provided by 17 coal mines of the Upper Silesian Coal Basin, Poland. Since the data set contained outliers, the construction of robust Partial Least Squares models for contaminated data set and the correct identification of outlying objects based on the robust scales were required. These enabled the development of the correct Partial Least Squares models, characterized by good fit and prediction abilities. The root mean square error was below 10% for all except for one the final Partial Least Squares models constructed, and the prediction error (root mean square error of cross-validation) exceeded 10% only for three models constructed. The study is of both cognitive and applicative importance. It presents the unique application of the chemometric methods of data exploration in modeling the content of trace elements in coal. In this way it contributes to the development of useful tools of coal quality assessment.

  2. Foundations for Survivable System Development: Service Traces, Intrusion Traces, and Evaluation Models

    National Research Council Canada - National Science Library

    Linger, Richard

    2001-01-01

    .... On the system side, survivability specifications can be defined by essential-service traces that map essential-service workflows, derived from user requirements, into system component dependencies...

  3. Portable detection of trace metals in airborne particulates and sediments via μPADs and smartphone.

    Science.gov (United States)

    Jia, Yuan; Dong, Hui; Zheng, Jianping; Sun, Hao

    2017-11-01

    Particulate matter (PM), a key indicator of air pollution by natural and anthropogenic activities, contributes to a wide spectrum of diseases that lead to a shortening of life expectancy. It has been recognized that trace metals in airborne PM are highly toxic and can be correlated with lesion in respiratory, gastrointestinal, immunological, and hematological systems. Traditional methods for trace metal assay require sophisticated instrumentations and highly trained operators in centralized laboratories. In this work, by integrating the technologies of microfluidic paper-based analytical devices, additive manufacturing, smartphone, and colorimetric sensing, we developed the first smartphone based paper microfluidic platform for portable, disposable, and quantitative measurements of cobalt (Co), copper (Cu), and iron (Fe) in ambient air and street sediments. On a single A4-sized paper, 48 devices were fabricated in under 30 s with a total cost of ∼$1.9. On each device, 12 reaction units were patterned and used for colorimetric tests. Particulate samples from urban ambient air and street sediments were collected, processed, and analyzed. Signals of the on-chip complexation product were recorded using a smartphone camera and processed by a self-developed app on an iOS system. For precisely controlling the object distance, chip position, and luminance, a hand-held 3D cellphone housing was designed and printed. The detection limits of Co, Cu, and Fe were determined to be 8.2, 45.8, and 186.0 ng, while the linear dynamic ranges were calculated to be 8.2-81.6, 45.8-4.58 × 10 2 , and 1.86 × 10 2 -1.86 × 10 3  ng, representing a practically relevant device performance with a significant reduction in the detection cost and time consumption. Trace metals in ambient air and sediments of two cities in China have been quantified portably, thus demonstrating the utility of our system in improving strategies for air pollution control in low-resource settings.

  4. Selected trace metal levels in common vegetables grown in NWFP, Pakistan

    International Nuclear Information System (INIS)

    Masud, K.; Jaffar, M.

    1998-01-01

    Seventeen vegetables procured from local markets of Peshawar and its suburbs were analyzed using wet digestion atomic absorption method for Fe, Pb, As, Hg, Cd, Cr, and Ni. The families investigated were: Cucurbitaceae, Solanaceae, Cruciferae, Liliaceae, Araceae, Leguminosae, Malvaceae, Umbelliferae and Zingiberaceae. The heavy metal data are reported at 99%(- + 2S) confidence level for triplicate measurements on sub samples of a given sample with an overall reproducibility of 2% compared with standard material samples. Comparison of averages through t-test indicates that each vegetable group is distinctly different from the other in terms of metal content. Maximum iron was present in garlic, at 4.585 mu g/g, dry weight (edible part-stem) of the Liliacease family. Arsenic was found to be below detection limit in all the vegetable groups. Lead levels were quite low, maximum concentration (0.0200 mu g/g, dry weight) was found in karaila (edible part-fruit). Mercury levels were relatively higher, with maximum concentration (2.590 mu g/g, dry weight) in gem (edible part-stem). The levels of nickel were moderately higher, being maximum (2.375 mu g/g dry weight) in karaila. The overall content of trace metals appeared to be within laid down internationally for safe human consumption, with only a few exceptions. (author)

  5. Linking Environmental Magnetism to Geochemical Studies and Management of Trace Metals. Examples from Fluvial, Estuarine and Marine Systems

    Directory of Open Access Journals (Sweden)

    Michael Scoullos

    2014-07-01

    Full Text Available Among the diverse research fields and wide range of studies encompassed by environmental magnetism, the present work elaborates on critical aspects of the geochemistry of trace metals that emerged through years of original research in a variety of environmental compartments. This review aims at sharing the insights gained on (a tracing metal pollution sources; and (b identifying processes and transport pathways from sources to depositional environments. Case studies on the Elefsis Gulf (Greece and the Gulf of Lions (France demonstrate the potential of combined magnetic measurements and chemical analysis to trace pollution signals resulting from land-based sources and atmospheric deposition. Case studies on estuarine environments, namely the Louros, Acheloos, and Asopos Estuaries (Greece, address modes of trace metal behavior under the influence of different hydrological regimes and elucidate in situ processes within the transitional estuarine zone, that define their ultimate fate. As sources, transport pathways, and processes of trace metals are fundamental in environmental management assessments, the involvement of magnetic measurements in the policy cycle could facilitate the development and implementation of appropriate regulatory measures for the integrated management of river basins, coastal, and marine areas.

  6. Investigation of exposure rates and radionuclide and trace metal distributions along the Hanford Reach of the Columbia River

    International Nuclear Information System (INIS)

    Cooper, A.T.; Woodruff, R.K.

    1993-09-01

    Studies have been conducted to investigate exposure rates, and radionuclide and trace metal distributions along the Columbia River where it borders the Hanford Site. The last major field study was conducted in 1979. With recently renewed interest in various land use and resource protection alternatives, it is important to have data that represent current conditions. Radionuclides and trace metals were surveyed in Columbia River shoreline soils along the Hanford Site (Hanford Reach). The work was conducted as part of the Surface Environmental Surveillance Project, Pacific Northwest Laboratory. The survey consisted of taking exposure rate measurements and soil samples primarily at locations known or expected to have elevated exposure rates

  7. Application of neutron activation analysis to the development of a monitoring system for trace metals in coastal waters

    International Nuclear Information System (INIS)

    Karbe, L.; Schnier, C.

    1976-03-01

    In view of the development of monitoring systems for trace metals in coastal waters, a research program has been started for a better understanding of interrelationships between input of trace metals, water chemistry, suspended matter, sediment and organisms. For multielement determinations neutron activation analysis has been chosen. Since environmental studies require the analysis of a large number of samples, the efficiency of the method is improved by automation of the acquisition and analysis of the γ-spectra from the Ge(Li) detectors. An automatic sample changer with counting device is described. First applications of the method in environmental research are presented. (orig.) [de

  8. Risks of using membrane filtration for trace metal analysis and assessing the dissolved metal fraction of aqueous media - A study on zinc, copper and nickel

    International Nuclear Information System (INIS)

    Hedberg, Yolanda; Herting, Gunilla; Wallinder, Inger Odnevall

    2011-01-01

    Membrane filtration is commonly performed for solid-liquid separation of aqueous solutions prior to trace metal analysis and when assessing 'dissolved' metal fractions. Potential artifacts induced by filtration such as contamination and/or adsorption of metals within the membrane have been investigated for different membrane materials, metals, applied pressures and pre-cleaning steps. Measurements have been conducted on aqueous solutions including well-defined metal standards, ultrapure water, and on runoff water from corroded samples. Filtration using both non-cleaned and pre-cleaned filters revealed contamination and adsorption effects, in particular pronounced for zinc, evident for copper but non-significant for nickel. The results clearly show these artifacts to be non-systematic both for non-cleaned and pre-cleaned membranes. The applied pressure was of minor importance. Measurements of the labile fraction by means of stripping voltammetry clearly elucidate that membrane filtration followed by total metal analysis cannot accurately assess the labile or the dissolved metal fraction. - Highlights: → Membrane filtration for trace metal analysis can introduce significant artifacts. → The dissolved metal fraction cannot be assessed by membrane filtration. → Non-specified filtration procedures are inadequate for scientific studies. → Artifacts caused by membrane filtration need to be addressed by regulators. - Membrane filtration cannot be used to assess the dissolved metal fraction of aqueous media and needs to be defined in detail in standard tests.

  9. Soil microbial communities as suitable bioindicators of trace metal pollution in agricultural volcanic soils

    Science.gov (United States)

    Parelho, Carolina; dos Santos Rodrigues, Armindo; do Carmo Barreto, Maria; Gonçalo Ferreira, Nuno; Garcia, Patrícia

    2015-04-01

    Summary: The biological, chemical and physical properties of soil confer unique characteristics that enhance or influence its overall biodiversity. The adaptive character of soil microbial communities (SMCs) to metal pollution allows discriminating soil health, since changes in microbial populations and activities may function as excellent indicators of soil pollutants. Volcanic soils are unique naturally fertile resources, extensively used for agricultural purposes and with particular physicochemical properties that may result in accumulation of toxic substances, such as trace metals (TM). In our previous works, we identified priority TM affecting agricultural Andosols under different agricultural land uses. Within this particular context, the objectives of this study were to (i) assess the effect of soil TM pollution in different agricultural systems (conventional, traditional and organic) on the following soil properties: microbial biomass carbon, basal soil respiration, metabolic quotient, enzymatic activities (β-glucosidase, acid phosphatase and dehydrogenase) and RNA to DNA ratio; and (ii) evaluate the impact of TM in the soil ecosystem using the integrated biomarker response (IBR) based on a set of biochemical responses of SMCs. This multi-biomarker approach will support the development of the "Trace Metal Footprint" for different agricultural land uses in volcanic soils. Methods: The study was conducted in S. Miguel Island (Azores, Portugal). Microbial biomass carbon was measured by chloroform-fumigation-incubation-assay (Vance et al., 1987). Basal respiration was determined by the Jenkinson & Powlson (1976) technique. Metabolic quotient was calculated as the ratio of basal respiration to microbial biomass C (Sparkling & West, 1988). The enzymatic activities of β-glucosidase and acid phosphatase were determined by the Dick et al. (1996) method and dehydrogenase activity by the Rossel et al. (1997) method. The RNA and DNA were co-extracted from the same

  10. Preparation of an estuarine sediment quality control material for the determination of trace metals

    Directory of Open Access Journals (Sweden)

    Hatje Vanessa

    2006-01-01

    Full Text Available Quality Control Materials (QCM have being used routinely in daily laboratory work as a tool to fill the gap between need and availability of Certified Reference Materials (CRM. The QCM are a low-cost alternative to CRMs, and they are in high demand, especially, for the implementation of quality control systems in laboratories of several areas. This paper describes the preparation of a QCM for the determination of trace metals in estuarine sediments and the results of an interlaboratory exercise. Homogeneity and stability studies were performed and analysis of variance was carried out with the results. No statistical significant differences were observed in the concentrations of Co, Cr, Cu, Mn, Pb and Zn between- or within bottle results. Neither the storage nor temperature affected the results. Therefore, the QCM produced is considered homogeneous and stable and can be used for statistical control charts, evaluation of reproducibility and interlaboratory exercises.

  11. Trace metal concentrations in mussels in the outfall zones of thermal and nuclear power plants

    International Nuclear Information System (INIS)

    Krishna Kumar, P.T.; Sekimoto, Hiroshi

    2008-01-01

    Many trace elements (TE) like Mn, Fe, Cu, and Zn, occur naturally in marine environments and these TE accomplish decisive functions in humans to maintain good health. Living organisms like Mytilus galloprovincialis are a rich source of TE and are grown extensively near the industrial water outfalls. Some of these TE tend to be pollutants when their elevated levels produce deleterious effects on the ecological system. As chemical analysis for TE toxicity are expensive, organisms like Mytilus galloprovincialis can be used as monitors of environmental contamination. Most studies reported so far are directed towards the effect of a single environmental factor on marine bivalves. However in the areas receiving mixed effluents from various point and non-point sources, the studies on combined effect of two or more stresses would be a more practical approach. In this paper, We investigate the heavy metal concentrations of mercury, cadmium, lead, zinc, cooper, nickel, manganese, and chromium in Mytilus galloprovincialis to provide information on the pollution of water bodies by thermal and nuclear power plants for the choice of sites from where edible mussels can be harvested. We also propose a chemometric approach developed by us using information theory to mitigate trace element toxicity in the edible part of Mytilus galloprovincialis harvested in these sites. (author)

  12. Alkaline phosphatase activity in the subtropical ocean: insights from nutrient, dust and trace metal addition experiments

    Directory of Open Access Journals (Sweden)

    Claire eMahaffey

    2014-12-01

    Full Text Available Phosphorus is an essential nutrient for all life on earth. In the ocean, the most bioavailable form of phosphorus is inorganic phosphate, but in the extensive subtropical gyres, phosphate concentrations can be chronically low and limit primary productivity and nitrogen fixation. In these regions, organisms produce hydrolytic enzymes, such as alkaline phosphatase (AP, that enable them to utilize the more replete dissolved organic phosphorus (DOP pool to meet their cellular phosphorus demands. In this study, we synthesized data from 14 published studies and present our own findings from two research cruises (D326 and D361 in the eastern subtropical Atlantic to explore the relationship between AP activity (APA and nutrients, Saharan dust and trace metals. We found that below a threshold phosphate concentration of ~ 30 nM, APA increased with an inverse hyperbolic relationship with phosphate concentration. Meanwhile, DOP concentrations decreased with enhanced APA, indicating utilization of the DOP pool. We found APA rates were significantly higher in the subtropical Atlantic compared to the subtropical Pacific Ocean, even over the same low phosphate concentration range (0 to 50 nM. While the phosphate concentration may have a first order control on the APA rates, we speculate that other factors influence this basin scale contrast. Using bioassay experiments, we show that the addition of Saharan dust and zinc significantly increased the rate of APA. To our knowledge, our results are the first direct field-based evidence that APA is limited by zinc in the subtropical ocean. Further work is required to explore the relationship between trace metals such as iron and zinc, which are co-factors of phosphohydrolytic enzymes, specifically PhoX and PhoA, respectively, and APA in the ocean.

  13. Pollution characteristics and source identification of trace metals in riparian soils of Miyun Reservoir, China.

    Science.gov (United States)

    Han, Lanfang; Gao, Bo; Lu, Jin; Zhou, Yang; Xu, Dongyu; Gao, Li; Sun, Ke

    2017-10-01

    The South-to-North Water Diversion Project, one of China's largest water diversion projects, has aroused widespread concerns about its potential ecological impacts, especially the potential release of trace metals from shoreline soils into Miyun Reservoir (MYR). Here, riparian soil samples from three elevations and four types of land use were collected. Soil particle size distributions, contents and chemical fractionations of trace metals and lead (Pb) isotopic compositions were analyzed. Results showed that soil texture was basically similar in four types of land use, being mainly composed of sand, with minor portions of clay and silt, while recreational land contained more abundant chromium (Cr), copper (Cu), zinc (Zn) and cadmium (Cd), suggesting a possible anthropogenic source for this soil pollution. The potential ecological risk assessment revealed considerable contamination of recreational land, with Cd being the predominant contaminant. Chemical fractionations showed that Cu, arsenic (As), Pb and Cd had potential release risks. Additionally, the 206 Pb/ 207 Pb and 208 Pb/ 207 Pb values of soils were similar to those of coal combustion. By combining principal component analysis (PCA) with Pb isotopic results, coal combustion was identified as the major anthropogenic source of Zn, Cr, Cu, Cd and Pb. Moreover, isotope ratios of Pb fell in the scope of aerosols, indicating that atmospheric deposition may be the primary input pathway of anthropogenic Zn, Cr, Cu, Cd and Pb. Therefore, controlling coal combustion should be a priority to reduce effectively the introduction of additional Zn, Cu, Cd, and Pb to the area in the future. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. Sediment trace metal profiles in lakes of Killarney Park, Canada from regional to continental influence

    International Nuclear Information System (INIS)

    Belzile, Nelson; Chen Yuwei; Gunn, John M.; Dixit, Sushil S.

    2004-01-01

    The lakes in Killarney Provincial Park (KPP) located 40-60 km southwest of Sudbury, Ontario are beginning to recover after decades of being severely affected by acidification and atmospheric pollutants. Detailed profiles of acid-recoverable trace elements (As. Cd, Cu, Co. Fe, Mn, Ni, Pb and Zn) were obtained after aqua regia digestion and ICP-OES analysis of sediment cores taken from six Park lakes. Results permitted the identification of two types of profiles. The first type applies to elements such as Fe, Mn, As and Co for which historical deposition and recent recovery are strongly masked by diagenetic remobilization. The second type of profile applies to elements such as Cd, Cu, Ni, Pb and Zn on which the history of industrialisation in North America and mining activities in Sudbury can be superimposed. Based on sediment data of trace elements less affected by diagenetic remobilization (Cd, Cu, Ni, Pb, Zn), chemical recovery indices can be estimated from depth profiles. Indices of maximum (C p ) and surface (C s ) contamination were calculated by dividing the concentration of a given metal by the pre-industrial level. The ratio of the two indices provided a simple estimation of the chemical recovery of lakes that does not consider the influence of the watershed or the lake pH. Profiles of metals in sediment of KPP complement the water quality monitoring data and tend to indicate that this area is in transition from dominant influence of regional pollution sources to becoming controlled by continental atmospheric deposition. - Lakes in Killarney Park are in transition from being impacted by regional pollution to being controlled by continental atmospheric deposition

  15. Investigation and evaluation of airborne pollution in the framework of PARCOM (North Sea) and HELCOM (Baltic Sea) - subproject: Measurements of trace metals

    International Nuclear Information System (INIS)

    Schneider, B.

    1993-01-01

    On the basis of measurements of the deposition and concentrations of atmospheric trace metals the annual input of some selected elements (Pb, Zn, Cd, Ni, V) into the North Sea and the Baltic Sea was estimated. For the Baltic Sea, deposition measurements with a buoy system in the Kiel Bight and data from the EGAP(HELCOM)-monitoring network were used. Data from the measurement stations were extrapolated to related sub-basins according to the deposition fields obtained from model calculations (EMEP). For the North Sea, a mean atmospheric trace metal distribution was determined from numerous measurements at a coastal site and over the central North Sea and the annual input was calculated by multiplication with corresponding deposition velocities and scavenging ratios. A comparison of the deposition data based on measurements with those from model calculations show good agreement in the case of Pb in the Baltic Sea as well as in the North Sea. However, for Zn and Cd large discrepancies are observed. Additionally, deposition processes were studied. Scavenging ratios were determined and dry deposition velocities were estimated by the use of a new method for high time resolution measurements of atmospheric trace metal concentrations (impactor/TXRF). (orig.). 9 figs., 14 tabs [de

  16. Assessment of trace metals using lichen transplant from automobile mechanic workshop in Ile-Ife metropolis, Nigeria.

    Science.gov (United States)

    Odiwe, Anthony I; Adesanwo, Adeyemi T J; Olowoyo, Joshua O; Raimi, Idris O

    2014-04-01

    The level of air pollution around the automobile mechanic workshops has been generally overlooked. This study, examined the level of trace metals in automobile mechanic workshops and the suitability of using transplanted lichen thalli of Lepraria incana for measuring air pollution in such areas. Samples of the lichen thalli were transplanted into seven different sites and were attached to the bark of trees at each site. The samples were harvested from the sites after 3-month exposure. Concentrations of Pb, Cu, Cd, Fe, Zn, and S content were determined using an atomic absorption spectrophotometer. Results showed that there was a significant difference in the trace metals concentrations across the sites (p trend in the concentration of these heavy metals suggests that activities in these workshops might become a major source of certain heavy metals in the environment and if the pollution activities persist, it might become worrisome over time.

  17. Evaluating fugacity models for trace components in landfill gas

    Energy Technology Data Exchange (ETDEWEB)

    Shafi, Sophie [Integrated Waste Management Centre, Sustainable Systems Department, Building 61, School of Industrial and Manufacturing Science, Cranfield University, Cranfield, Bedfordshire MK43 0AL (United Kingdom); Sweetman, Andrew [Department of Environmental Science, Lancaster University, Lancaster LA1 4YQ (United Kingdom); Hough, Rupert L. [Integrated Waste Management Centre, Sustainable Systems Department, Building 61, School of Industrial and Manufacturing Science, Cranfield University, Cranfield, Bedfordshire MK43 0AL (United Kingdom); Smith, Richard [Integrated Waste Management Centre, Sustainable Systems Department, Building 61, School of Industrial and Manufacturing Science, Cranfield University, Cranfield, Bedfordshire MK43 0AL (United Kingdom); Rosevear, Alan [Science Group - Waste and Remediation, Environment Agency, Reading RG1 8DQ (United Kingdom); Pollard, Simon J.T. [Integrated Waste Management Centre, Sustainable Systems Department, Building 61, School of Industrial and Manufacturing Science, Cranfield University, Cranfield, Bedfordshire MK43 0AL (United Kingdom)]. E-mail: s.pollard@cranfield.ac.uk

    2006-12-15

    A fugacity approach was evaluated to reconcile loadings of vinyl chloride (chloroethene), benzene, 1,3-butadiene and trichloroethylene in waste with concentrations observed in landfill gas monitoring studies. An evaluative environment derived from fictitious but realistic properties such as volume, composition, and temperature, constructed with data from the Brogborough landfill (UK) test cells was used to test a fugacity approach to generating the source term for use in landfill gas risk assessment models (e.g. GasSim). SOILVE, a dynamic Level II model adapted here for landfills, showed greatest utility for benzene and 1,3-butadiene, modelled under anaerobic conditions over a 10 year simulation. Modelled concentrations of these components (95 300 {mu}g m{sup -3}; 43 {mu}g m{sup -3}) fell within measured ranges observed in gas from landfills (24 300-180 000 {mu}g m{sup -3}; 20-70 {mu}g m{sup -3}). This study highlights the need (i) for representative and time-referenced biotransformation data; (ii) to evaluate the partitioning characteristics of organic matter within waste systems and (iii) for a better understanding of the role that gas extraction rate (flux) plays in producing trace component concentrations in landfill gas. - Fugacity for trace component in landfill gas.

  18. Tracing the value of data for flood loss modelling

    Directory of Open Access Journals (Sweden)

    Schröter Kai

    2016-01-01

    Full Text Available Flood loss modelling is associated with considerable uncertainty. If prediction uncertainty of flood loss models is large, the reliability of model outcomes is questionable, and thus challenges the practical usefulness. A key problem in flood loss estimation is the transfer of models to geographical regions and to flood events that may differ from the ones used for model development. Variations in local characteristics and continuous system changes require regional adjustments and continuous updating with current evidence. However, acquiring data on damage influencing factors is usually very costly. Therefore, it is of relevance to assess the value of additional data in terms of model performance improvement. We use empirical flood loss data on direct damage to residential buildings available from computer aided telephone interviews that were compiled after major floods in Germany. This unique data base allows us to trace the changes in predictive model performance by incrementally extending the data base used to derive flood loss models. Two models are considered: a uni-variable stage damage function and RF-FLEMO, a multi-variable probabilistic model approach using Random Forests. Additional data are useful to improve model predictive performance and increase model reliability, however the gains also seem to depend on the model approach.

  19. Studies of trace metals in fish, sediment and water from kpong reservior

    International Nuclear Information System (INIS)

    Yikpo, Wisdom Kwasi

    2014-06-01

    Water of good quality is indispensable to human survival on earth. The provision of potable water to both the rural and the urban populations is necessary to prevent health hazards. The aim of this research was to assess water quality with respect to physicochemical parameters and trace metals levels in the water, the sediment and the fish species from the Kpong Reservoir on the Lower Volta River. The water, the sediment and the fish samples were collected monthly for six (6) months from November 2011 to February 2012 (dry season) and from May to July 2012 ( wet season). The water, the sediment and the fish samples were analyzed for Hg, Se, Fe, Mn and Pb using Atomic Absorption spectroscopy (AAS). Mercury was determined using a cold vapour technique with the AAS equipped with a hydride generator. Selenium was also determined by hydride generation. A mixture of nitric acid (HNO3 65%), hydrochloric acid ( HCl 35%) and hydrogen peroxide (H2O2 30%) was used for complete oxidation of the organic sample in a fume chamber. The samples were loaded on a Milestone microwave Labstation ETHOS 900, INSTR:MLS -1200 MEGA. The results of this study showed that there were significant differences in concentrations of the physicochemical parameters between the two seasons. Domestic, municipal and Agricultural waste might have contributed to the release of higher contaminants into the sediment in both seasons. Coefficients of variation for the physicochemical parameters were below 50%, while iron and lead in addition to phosphate and sulphate were more than 50%. The mean concentration of trace metals in the water were 0.008 mg/L for Hg, 0.0035 mg/L for Se, 0.255 mg/L for Fe, 0.087 mg/L for Mn and 0.135 mg/L for Pb. Levels of all trace metals were below the WHO guideline values, except Pb which exceeded at 0.05 mg/L. Levels of nutrients were also below the WHO guideline value except phosphate which recorded a standard deviation of ±0.02 for the WHO guideline value of 0.3 mg/ L. The

  20. Trace/Heavy Metal Impact on Agricultural Soils from Commonly used Fertilizers of Bangladesh

    International Nuclear Information System (INIS)

    Islam, A.; Jolly, Y. N.

    2005-01-01

    On investigation of seven commonly used fertilizers of Bangladesh for evaluation of their trace/heavy metal impact on the agricultural soils it was observed that TSP, SSP and Cow-dung were more potential in supplying a broad range of these elements including toxin ones such as, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Br, Rb, Sr, Y, Pb, Cd. In phosphate fertilizers, the concentrations of Cr, Mn, Co, Ni, Cu, Zn, Cd and Pb ranged from 106-129, 21.1-124, 12.2-16.1, 8.6-27.1, 8.2-12.5, 93.5-245, 8.4-12.1 mgkg -1 respectively. In cow-dung the respective contents of the same elements except Cd were 8.1, 820, 11.1, 6.1, 12.4, 72.2, 12.1 mg kg -1 . Zinc sulphate was also found to be a potential fertilizer capable of supplying Mn, Co, Ni, Cu, Zn, Cd, Pb, containing 182, 311, 63, 10.5, 300, 27.5, 28.1 mg kg -1 respectively. MP and Gypsum has shown to be of less potential in adding trace/heavy elements in soils. MP contained Mn, Fe, Br, Sr and its Mn concentration was 13.2 mg kg -1 . The elements, Fe, Cu, Zn, Sr were measured in Gypsum where Cu and Fe concentrations were 15.3 and 13.2 mg kg -1 respectively. Urea was found to contain Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Br and Sr at low levels in comparison with other fertilizers. The trace/heavy metals load from chemical fertilizers per hectare of agricultural land per year was also calculated. The Maximum input of V, Cr, Mn, Fe, Ni, Cu, Zn, Cd and Pb were 14.8, 23.2, 22.3, 646, 2.9, 4.9, 3.9, 2816, 2.2 and 4.5 g respectively.(author)

  1. Distribution of trace metals at Hopewell Furnace National Historic Site, Berks and Chester Counties, Pennsylvania

    Science.gov (United States)

    Sloto, Ronald A.; Reif, Andrew G.

    2011-01-01

    Hopewell Furnace, located approximately 50 miles northwest of Philadelphia, was a cold-blast, charcoal iron furnace that operated for 113 years (1771 to 1883). The purpose of this study by the U.S. Geological Survey, in cooperation with the National Park Service, was to determine the distribution of trace metals released to the environment from an historical iron smelter at Hopewell Furnace National Historic Site (NHS). Hopewell Furnace used iron ore from local mines that contained abundant magnetite and accessory sulfide minerals enriched in arsenic, cobalt, copper, and other metals. Ore, slag, cast iron furnace products, soil, groundwater, stream base flow, streambed sediment, and benthic macroinvertebrates were sampled for this study. Soil samples analyzed in the laboratory had concentrations of trace metals low enough to meet Pennsylvania Department of Environmental Protection standards for non-residential use. Groundwater samples from the supply well met U.S. Environmental Protection Agency drinking-water regulations. Concentrations of metals in surface-water base flow at the five stream sampling sites were below continuous concentration criteria for protection of aquatic organisms. Concentrations of metals in sediment at the five stream sites were below probable effects level guidelines for protection of aquatic organisms except for copper at site HF-3. Arsenic, copper, lead, zinc, and possibly cobalt were incorporated into the cast iron produced by Hopewell Furnace. Manganese was concentrated in slag along with iron, nickel, and zinc. The soil near the furnace has elevated concentrations of chromium, copper, iron, lead, and zinc compared to background soil concentrations. Concentrations of toxic elements were not present at concentrations of concern in water, soil, or stream sediments, despite being elevated in ore, slag, and cast iron furnace products. The base-flow surface-water samples indicated good overall quality. The five sampled sites generally had

  2. A coordination chemistry approach for modeling trace element adsorption

    International Nuclear Information System (INIS)

    Bourg, A.C.M.

    1986-01-01

    The traditional distribution coefficient, Kd, is highly dependent on the water chemistry and the surface properties of the geological system being studied and is therefore quite inappropriate for use in predictive models. Adsorption, one of the many processes included in Kd values, is described here using a coordination chemistry approach. The concept of adsorption of cationic trace elements by solid hydrous oxides can be applied to natural solids. The adsorption process is thus understood in terms of a classical complexation leading to the formation of surface (heterogeneous) ligands. Applications of this concept to some freshwater, estuarine and marine environments are discussed. (author)

  3. Aerosol trace metals, particle morphology and total gaseous mercury in the atmosphere of Oxford, UK

    Science.gov (United States)

    Witt, M. L. I.; Meheran, N.; Mather, T. A.; de Hoog, J. C. M.; Pyle, D. M.

    2010-04-01

    An investigation of atmospheric trace metals was conducted in Oxford, UK, a small city ˜60 miles northwest of London, in 2007 and 2008. Concentrations of Sr, Mo, Cd, Pb, V, Cr, Mn, Fe, Co, Ni, Cu and Zn in aerosol were measured in bulk and size segregated samples. In addition, total gaseous mercury (TGM) concentrations were monitored semi-continuously by cold vapour-atomic fluorescence spectroscopy. Metal concentrations in Oxford were intermediate between previously reported levels of UK rural and urban areas for most metals studied and levels of Cd, Ni and Pb were within European guidelines. Metal concentrations appeared to be influenced by higher traffic volume on a timescale of hours. The influence of traffic on the aerosols was also suggested by the observation of carbonaceous particles via scanning electron microscopy (SEM). Air mass back trajectories suggest air masses arriving in Oxford from London and mainland Europe contained the highest metal concentrations. Aerosol samples collected over Bonfire Weekend, a period of intense firework use and lighting of bonfires in the UK, showed metal concentrations 6-46 times higher than at other times. Strontium, a tracer of firework release, was present at higher concentrations and showed a change in its size distribution from the coarse to fine mode over Bonfire Weekend. The presence of an abundance of spherical Sr particles was also confirmed in SEM images. The average TGM concentration in Oxford was 3.17 ng m -3 (st. dev. 1.59) with values recorded between 1.32 and 23.2 ng m -3. This is a higher average value than reported from nearby rural locations, although during periods when air was arriving from the west, similar concentrations to these rural areas were seen in Oxford. Comparison to meteorological data suggests that TGM in Oxford's air is highest when wind is arriving from the east/southeast. This may be due to emissions from London/mainland Europe with a possible contribution from emissions from a local

  4. Anthropogenic impact on diffuse trace metal accumulation in river sediments from agricultural reclamation areas with geochemical and isotopic approaches

    Energy Technology Data Exchange (ETDEWEB)

    Jiao, Wei; Ouyang, Wei, E-mail: wei@itc.nl; Hao, Fanghua; Lin, Chunye

    2015-12-01

    A better understanding of anthropogenic impact can help assess the diffuse trace metal accumulation in the agricultural environment. In this study, both river sediments and background soils were collected from a case study area in Northeast China and analyzed for total concentrations of six trace metals, four major elements and three lead isotopes. Results showed that Pb, Cd, Cu, Zn, Cr and Ni have accumulated in the river sediments after about 40 years of agricultural development, with average concentrations 1.23–1.71 times higher than local soil background values. Among them Ni, Cr and Cu were of special concern and they may pose adverse biological effects. By calculating enrichment factor (EF), it was found that the trace metal accumulation was still mainly ascribed to natural weathering processes, but anthropogenic contribution could represent up to 40.09% of total sediment content. For Pb, geochemical and isotopic approaches gave very similar anthropogenic contributions. Principal component analysis (PCA) further suggested that the anthropogenic Pb, Cu, Cr and Ni inputs were mostly related to the regional atmospheric deposition of industrial emissions and gasoline combustion, which had a strong affinity for iron oxides in the sediments. Concerning Cd, however, it mainly originated from local fertilizer applications and was controlled by sediment carbonates. - Graphical abstract: The trace metal accumulation was mainly ascribed to natural weathering processes, but anthropogenic contribution could represent up to 40.09% of total sediment content. Anthropogenic Pb, Cu, Cr and Ni mostly came from atmospheric deposition, while fertilizer application was the main anthropogenic source of Cd. - Highlights: • Trace metals have accumulated in the Naolihe sediments. • Natural weathering was still a major contributor to metal accumulation. • Anthropogenic Pb, Cu, Cr and Ni mostly came from atmospheric deposition. • Local fertilizer application was the main

  5. Trace metals, melanin-based pigmentation and their interaction influence immune parameters in feral pigeons (Columba livia).

    Science.gov (United States)

    Chatelain, M; Gasparini, J; Frantz, A

    2016-04-01

    Understanding the effects of trace metals emitted by anthropogenic activities on wildlife is of great concern in urban ecology; yet, information on how they affect individuals, populations, communities and ecosystems remains scarce. In particular, trace metals may impact survival by altering the immune system response to parasites. Plumage melanin is assumed to influence the effects of trace metals on immunity owing to its ability to bind metal ions in feathers and its synthesis being coded by a pleiotropic gene. We thus hypothesized that trace metal exposure would interact with plumage colouration in shaping immune response. We experimentally investigated the interactive effect between exposure to an environmentally relevant range of zinc and/or lead and melanin-based plumage colouration on components of the immune system in feral pigeons (Columba livia). We found that zinc increased anti-keyhole limpet hemocyanin (KLH) IgY primary response maintenance, buffered the negative effect of lead on anti-KLH IgY secondary response maintenance and tended to increase T-cell mediated phytohaemagglutinin (PHA) skin response. Lead decreased the peak of the anti-KLH IgY secondary response. In addition, pheomelanic pigeons exhibited a higher secondary anti-KLH IgY response than did eumelanic ones. Finally, T-cell mediated PHA skin response decreased with increasing plumage eumelanin level of birds exposed to lead. Neither treatments nor plumage colouration correlated with endoparasite intensity. Overall, our study points out the effects of trace metals on some parameters of birds' immunity, independently from other confounding urbanization factors, and underlines the need to investigate their impacts on other life history traits and their consequences in the ecology and evolution of host-parasite interactions.

  6. Total petroleum hydrocarbons and trace metals in tropical estuary of Todos os Santos Bay, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Celino, Joil Jose; Oliveira, Olivia Maria Cordeiro de; Queiroz, Antonio Fernando de Souza [Universidade Federal da Bahia (UFBA), Salvador, BA (Brazil); Trigueis, Jorge Alberto [Universidade Estadual do Norte Fluminense (UENF), Campos dos Goytacazes, RJ (Brazil); Garcia, Karina Santos [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil)

    2008-07-01

    As part of the environmental assessment within Todos os Santos Bay, State of Bahia - Brazil, in summer of 2005, superficial water and sediments samples of the mangrove were collected at five locations to determine the spatial distribution of anthropogenic pollutants in the Dom Joao estuary at the Sao Francisco do Conde Region. Sandy sediments with low organic matter content dominate the studied area. Trace metal levels indicated that sediments were moderately polluted with Cu (overall mean: 21.48 +/- 4.76 {mu}g.g-1 dry sediment), but not with Pb (15 +/- 8), Zn (38 +/- 10), Cr (15 +/- 7), Ni (13 +/- 6) and Cd (0.4 +/- 0.2). Depending on location, total petroleum hydrocarbons ranged from 1.6 to 10.6 {mu}g.g-1. To discriminate pattern differences and similarities among samples, principal component analysis (PCA) was performed using a correlation matrix. PCA revealed the latent relationships among all the stations investigated and confirmed our analytical results. Principal components analysis confirmed two regions according to their environmental quality. The results pointed out that almost all the area presented some substances that can cause adverse biological effects, especially in the outermost region where some metals are above TEL level. (author)

  7. Tracing low-temperature aqueous metal migration in mineralized watersheds with Cu isotope fractionation

    International Nuclear Information System (INIS)

    Mathur, R.; Munk, L.A.; Townley, B.; Gou, K.Y.; Gómez Miguélez, N.; Titley, S.; Chen, G.G.; Song, S.; Reich, M.; Tornos, F.; Ruiz, J.

    2014-01-01

    Highlights: • Cu isotope fractionation of ores and waters identifies copper sulfide weathering. • Redox reactions cause isotopic shift measured in areas of sulfide weathering. • Consistent isotope signature in different deposit, climate, or concentration. - Abstract: Copper isotope signatures in waters emanating from mineralized watersheds provide evidence for the source aqueous copper in solution. Low-temperature aqueous oxidation of Cu sulfide minerals produces significant copper isotopic fractionation between solutions and residues. Abiotic experimental data of fractionation (defined as Δ liquid–solid ‰ = δ 65 Cu liquid − δ 65 Cu solid ) are on the order of 1–3‰ and are unique for copper rich-sulfide minerals. Data presented here from ores and waters within defined boundaries of porphyry copper, massive sulfide, skarn, and epithermal ore deposits mimic abiotic experiments. Thus, the oxidation of sulfide minerals appears to cause the signatures in the waters although significant biological, temperature, and pH variations exist in the fluids. Regardless of the deposit type, water type, concentration of Cu in solution, or location, the data provide a means to trace sources of metals in solutions. This relationship allows for tracking sources and degree of metal migration in low temperature aqueous systems and has direct application to exploration geology and environmental geochemistry

  8. Studies on chelation properties of ampicillin with trace metal ions and comparison with penicillin complexes

    International Nuclear Information System (INIS)

    Rehmani, F.S.; Hameed, W.

    2003-01-01

    The penicillin is highly effective antibiotic with extremely wide margin of safety. Ampicillin e is the penicillin group of antibiotic in which side chain is phenyl group i.e. D-amino benzyl penicillin. The side chain determines many of anti bacterial and pharmacological characteristics. They inhibit the protein synthesis in bacterial cell wall. The chelating properties of the antibiotic may be used in the metal transport across the membrane. The present investigations are helpful in drug metabolism and their effects on minerals contents of the body. The complex formation between Ampicillin and penicillin with trace metal ions such as Fe(III), Cr(III), Al(III), Mn(II), Ni(II), Co(II), Ca(II), Mg(II), Cu(III) and Zn(II) were studied by potentiometric titrations and spectrophotometric methods. Stoichiometry of these complexes were studied by mole ratio method. It was found that the Fe(III) and Cu(II) ions form most stable complexes near physiological pH and the mole ratio was 1:1. (author)

  9. Trace metal chemistry and silicification of microorganisms in geothermal sinter, Taupo Volcanic Zone, New Zealand

    Energy Technology Data Exchange (ETDEWEB)

    McKenzie, E.J.; Brown, K.L.; Campbell, K.A. [University of Auckland (New Zealand). Dept. of Geology; Cady, S.L. [Portland State University, Portland, OR (United States). Dept. of Geology

    2001-08-01

    As part of a pilot study investigating the role of microorganisms in the immobilisation ol As, Sb, B, Tl and Ug, the inorganic geochemistry of seven different active sinter deposits and their contact fluids were characterised. A comprehensive series of sequential extractions for a suite of trace elements was carried out on siliceous sinter and a mixed silica-carbonate sinter. The extractions showed whether metals were loosely exchangeable or bound to carbonate, oxide, organic or crystalline fractions. Hyperthermophilic microbial communities associated with sinters deposited from high temperature (92-94{sup o}C) fluids at a variety of geothermal sources were investigated using SEM. The rapidity and style of silicification of the hyperthermophiles can be correlated with the dissolved silica content of the fluid. Although high concentrations of Hg and TI were found associated with the organic fraction of the sinters, there was no evidence to suggest that any of the heavy metals were associated preferentially with the hyperthermophiles at the high temperature (92-94{sup o}C) ends of the terrestrial thermal spring ecosystems studied. (author)

  10. TRACE METAL CONTENT (Cu, Zn, Mn AND Fe) IN URTICA DIOICA L. AND PLANTAGO MAJOR L.

    Science.gov (United States)

    Krolak, Elzbieta; Raczuk, Jolanta; Borkowska, Lidia

    2016-11-01

    The aim of the study was to compare the contents of Cu, Zn, Mn and Fe in the washed and unwashed leaves and roots of two plant species: Urica dioica L. and Plantago major L., used in herbal medicine. These two herb species occur in the same environmental habitats, yet their morphological structure is different. The soil and plant samples for analyses were collected from an uncontaminated area in Eastern Poland. In each habitat location, the samples were taken from sandy soils with slightly acidic and neutral pH values. The obtained results showed that U. dioica and P. major accumulated similar amounts of trace metals, such as: Cu, Zn and Fe, in leaves, despite the differences in the morphological structure of their overground parts. The content of Mn in leaves U. dioica was about twice as much as in P. major. Also, no differences in the metal content were observed between washed and unwashed leaves of both species. However, in the same habitat conditions, a significantly higher content of Cu, Zn and Mn was found in the roots of P. major than U. dioica. The content of Fe in the roots was similar in both species. P. major and U. dioica may be a valuable source of microelements, if they are obtained from unpolluted habitats.

  11. Made-to-order metal-organic frameworks for trace carbon dioxide removal and air capture

    KAUST Repository

    Shekhah, Osama

    2014-06-25

    Direct air capture is regarded as a plausible alternate approach that, if economically practical, can mitigate the increasing carbon dioxide emissions associated with two of the main carbon polluting sources, namely stationary power plants and transportation. Here we show that metal-organic framework crystal chemistry permits the construction of an isostructural metal-organic framework (SIFSIX-3-Cu) based on pyrazine/copper(II) two-dimensional periodic 4 4 square grids pillared by silicon hexafluoride anions and thus allows further contraction of the pore system to 3.5 versus 3.84 for the parent zinc(II) derivative. This enhances the adsorption energetics and subsequently displays carbon dioxide uptake and selectivity at very low partial pressures relevant to air capture and trace carbon dioxide removal. The resultant SIFSIX-3-Cu exhibits uniformly distributed adsorption energetics and offers enhanced carbon dioxide physical adsorption properties, uptake and selectivity in highly diluted gas streams, a performance, to the best of our knowledge, unachievable with other classes of porous materials. 2014 Macmillan Publishers Limited.

  12. The development and assessment of TRACE/PARCS model for Lungmen ABWR

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Hao-Tzu, E-mail: htlin@iner.gov.tw [Institute of Nuclear Energy Research, Atomic Energy Council, R.O.C., 1000, Wenhua Road, Jiaan Village, Longtan Township, Taoyuan County, 32546, Taiwan, ROC (China); Wang, Jong-Rong, E-mail: jrwang@iner.gov.tw [Institute of Nuclear Energy Research, Atomic Energy Council, R.O.C., 1000, Wenhua Road, Jiaan Village, Longtan Township, Taoyuan County, 32546, Taiwan, ROC (China); Chen, Hsiung-Chih, E-mail: km8385@gmail.com [Institute of Nuclear Engineering and Science, National Tsing Hua University, No. 101, Section 2, Kuang Fu Road, HsinChu 30013, Taiwan, ROC (China); Shih, Chunkuan, E-mail: ckshih@ess.nthu.edu.tw [Institute of Nuclear Engineering and Science, National Tsing Hua University, No. 101, Section 2, Kuang Fu Road, HsinChu 30013, Taiwan, ROC (China)

    2014-07-01

    Highlights: • The development of a TRACE/PARCS model of Lungmen (ABWR). • Thermal-hydraulics model of TRACE is coupling with 3-D neutronics model of PARCS. • The 3-D geometry vessel component of TRACE is used in this study. • The parameters responses of Lungmen TRACE/PARCS model are consistent with FSAR data. - Abstract: This study consists of two steps. The first step is the development of a TRACE (TRAC/RELAP Advanced Computational Engine)/PARCS (Purdue Advanced Reactor Core Simulator) model of Lungmen nuclear power plant (NPP) which includes the vessel, reactor internal pumps (RIPs), main steam lines, and important control systems (such as the feedwater control system, steam bypass and pressure control system, and recirculation flow control system), etc. Key parameters were identified to refine the TRACE/PARCS model further in the frame of a steady state analysis. The second step is the performance of Lungmen NPP TRACE/PARCS model transient analyses. The transient data of Final Safety Analysis Report (FSAR) chapter 15th were used to compare with the results of Lungmen NPP TRACE/PARCS model. The trends of TRACE/PARCS analysis results were consistent with the FSAR data. It indicated that there was a respectable accuracy in the Lungmen NPP TRACE/PARCS model and it also depicted that the Lungmen NPP TRACE/PARCS model was satisfying for the purpose of Lungmen NPP safety analyses.

  13. Impact of simulated acid rain on trace metals and aluminum leaching in latosol from Guangdong Province, China

    Science.gov (United States)

    Jia-En Zhang; Jiayu Yu; Ying Ouyang; Huaqin. Xu

    2014-01-01

    Acid rain is one of the most serious ecological and environmental problems worldwide. This study investigated the impacts of simulated acid rain (SAR) upon leaching of trace metals and aluminum (Al) from a soil. Soil pot leaching experiments were performed to investigate the impacts of SAR at five different pH levels (or treatments) over a 34-day period upon the...

  14. Trace elements and heavy metals in the Grand Bay National Estuarine Reserve in the northern Gulf of Mexico

    Science.gov (United States)

    The Grand Bay National Estuarine Research Reserve has the highest biotic diversity of habitats and offer a reserve of food resources and commercially significant species. Rapid human civilization has led to accumulation of heavy metals and trace elements in estuaries. The Grand Bay National Estuarin...

  15. Arsenic and trace metals in river water and sediments from the southeast portion of the Iron Quadrangle, Brazil.

    Science.gov (United States)

    Varejão, Eduardo V V; Bellato, Carlos R; Fontes, Maurício P F; Mello, Jaime W V

    2011-01-01

    The Iron Quadrangle has been one of the most important gold production regions in Brazil since the end of the seventeenth century. There, arsenic occurs in close association with sulfide-rich auriferous rocks. The most abundant sulfide minerals are pyrite and arsenopyrite, yet trace metal sulfides occur in subordinate phases as well. Historical mining activities have been responsible for the release of As and trace metals to both aquatic and terrestrial environments close to mining sites in the region. Therefore, this study was aimed to evaluate the distribution and mobility of As, Cd, Co, Cr, Cu, Ni, Pb, and Zn in streams in the southeast portion of the Iron Quadrangle between the municipalities of Ouro Preto and Mariana, the oldest Brazilian Au mining province. Total concentrations of some trace metals and arsenic in water were determined. The four-stage sequential extraction procedure proposed by the commission of the European Communities Bureau of Reference (BCR) was used to investigate the distribution of these elements in stream sediments. Arsenic concentration in water was > 10 μg L⁻¹ (maximum limit permitted by Brazilian environmental regulations for water destined for human consumption) at all sampling sites, varying between 36.7 and 68.3 μg L⁻¹. Sequential extraction in sediments showed high concentrations of As and trace metals associated with easily mobilized fractions.

  16. Temporal and spatial variability of trace metals in suspended matter of the Mandovi estuary, central west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Shynu, R.; Rao, V.P.; Kessarkar, P.M.; Rao, T.G.

    of the estuary. SPM is consistently low at all stations during the post-monsoon. Trace metals (Cu, Ni, Zn, Cr, and Pb) show strong inter-relationships. They correlate well with Fe and Mn only during the monsoon. The concentrations of Cr, Cu, and Pb are high...

  17. Effects of nutrient trace metal speciation on algal growth in the presence of the chelator [S,S]-EDDS

    NARCIS (Netherlands)

    Schowanek, D.; McAvoy, D.; Versteeg, D.; Hanstveit, A.

    1996-01-01

    This study tests the hypothesis that the apparent toxicity of strong chelators in standard algal growth inhibition tests (e.g. method OECD 201, EC C.3., ISO 8692) is related to essential trace metal bioavailability. This hypothesis was investigated for the chelator [S,S]-ethylene diamine disuccinate

  18. Bromate and trace metal levels in bread loaves from outlets within Ile-Ife Metropolis, Southwestern Nigeria

    Directory of Open Access Journals (Sweden)

    J.A.O. Oyekunle

    2014-01-01

    Full Text Available Bread loaves randomly sampled from nine outlets and bakeries within Ile-Ife were analysed to determine their safety levels for human consumption with respect to bromate and trace metal contents. Bromate determination was carried out via spectrophotometric method while trace metals in the digested bread samples were profiled using Flame Atomic Absorption Spectrophotometer. Bromate levels in the analyzed bread samples ranged from 2.051 ± 0.011 μg/g to 66.224 ± 0.014 μg/g while the trace metal levels were of the order: 0.03–0.10 μg/g Co = 0.03–0.10 μg/g Pb < 0.23–0.46 μg/g Cu < 2.23–6.63 μg/g Zn < 25.83–75.53 μg/g Mn. This study revealed that many bread bakers around Ile-Ife had not fully complied with the bromate-free rule stipulated by NAFDAC contrary to the “bromate free” inscribed on the labels of the bread. The bread samples contained both essential and toxic trace metals to levels that could threaten the health of consumers over prolonged regular consumption.

  19. Assessment and source identification of trace metals in the soils of greenhouse vegetable production in eastern China.

    Science.gov (United States)

    Yang, Lanqin; Huang, Biao; Hu, Wenyou; Chen, Yong; Mao, Mingcui

    2013-11-01

    Worldwide concern about the occurrence of trace metals in greenhouse vegetable production soils (GVPS) is growing. In this study, a total of 385 surface GVPS samples were collected in Shouguang and four vegetable production bases in Nanjing, Eastern China, for the determination of As and Hg using atomic fluorescence spectrometry and Pb, Cu, Cd, and Zn using inductively coupled plasma-mass spectrometry. Geo-accumulation indices and factor analysis were used to investigate the accumulation and sources of the trace metals in soils in Eastern China. The results revealed that greenhouse production practices increased accumulation of the trace metals, particularly Cd, Zn, and Cu in soils and their accumulation became significant with increasing years of cultivation. Accumulation of Cd and Zn was also found in soils from organic greenhouses. The GVPS was generally less polluted or moderately polluted by As, Cu, Zn, and Pb but heavily polluted by Cd and Hg in some locations. Overall, accumulation of Cd, Zn, and Cu in GVPS was primarily associated with anthropogenic activities, particularly, application of manure. The high level of Hg found in some sites was related to historical heavy application of Hg containing pesticides. However, further identification of Hg sources is needed. To reduce accumulation of the trace metals in GVPS, organic fertilizer application should be suggested through development and implementation of reasonable and sustainable strategies. © 2013 Elsevier Inc. All rights reserved.

  20. THE FATE OF TRACE METALS IN A ROTARY KILN INCINERATOR WITH A VENTURI/PACKED COLUMN SCRUBBER - VOLUME II: APPENDICES

    Science.gov (United States)

    A 5-week series of pilot-scale incineration tests, employing a synthetic waste feed, was performed at the U.S. Environmental Protection Agency's Incineration Research Facility to evaluate the fate of trace metals fed to a rotary kiln incinerator equipped with a venturi scrubber/p...

  1. Metal and trace element sediment assessment from Guarapiranga reservoir, Alto Tiete Basin, Sao Paulo, SP, Brazil

    International Nuclear Information System (INIS)

    Guimaraes, Guilherme Moura

    2011-01-01

    The Guarapiranga Reservoir, located in Sao Paulo metropolitan region, Brazil, is responsible for supplying about 20% of the entire population's water needs of this region or approximately 3.7 million people. However, this system has shown significant degradation in water quality, due to untreated domestic sewage and industrial effluents. In this study sediment samples were collected at five points along the reservoir and total concentration of some major (Fe, K and Na), trace (As, Ba, Br, Co, Cr, Cs, Hf, Hg, Rb, Sb, Sc, Ta, Tb, Th, U, V and Zn) and rare earth (Ce, Eu, La, Lu, Nd, Sm, Tb and Yb) elements were determined by instrumental neutron activation analysis (INAA). By inductively coupled plasma optical emission spectrometry (ICP OES) the concentrations of Al, Ba, Be, Ca, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Na, Ni, Pb, Ti, V e Zn were determined after digestion procedure following US EPA 3051 methodology. The concentrations of metals Cd and Pb were determined by graphite furnace atomic absorption spectrometry (GFAAS) and total Hg by cold vapor atomic absorption spectrometry (CVAAS). Methodology validation according to precision and accuracy was performed by reference materials analyses for the three different analytical techniques used. Multielemental results obtained by INAA were compared to NASC (North American Shale Composite), Upper Continental Crust (UCC) and soil from Guarapiranga park values. The Enrichment Factor (EF) and Geo accumulation Index (Igeo) were also evaluated for these data. Metal concentration results by ICP OES and AAS in the samples were compared to the TEL and PEL oriented values established by the Canadian Council of Ministers of the Environment and also adopted by CETESB (Environmental Protection Agency of the Sao Paulo State). The results were also compared to regional reference values (VRR) of limnic sediments from the Alto Tiete Basin. From these data an assessment of metal and trace element accumulated in the sediments from the

  2. Definition of new trace-metal proxies for the controls on organic matter enrichment in marine sediments based on Mn, Co, Mo and Cd concentrations

    NARCIS (Netherlands)

    Sweere, T.; Van den Boorn, S.; Dickson, A.J.; Reichart, G.-J.

    2016-01-01

    Trace metal enrichments in sedimentary deposits are of prime interest because they are governed by processes that also control the production and preservation of organic matter. Consequently, trace metals have been used in reconstructions of the (palaeo)depositional environment of organic-rich

  3. A STUDY OF LEAKAGE OF TRACE METALS FROM CORROSION OF THE MUNICIPAL DRINKING WATER DISTRIBUTION SYSTEM

    Directory of Open Access Journals (Sweden)

    M.R SHA MANSOURI

    2003-09-01

    Full Text Available Introduction: A high portion of lead and copper concentration in municipal drinking water is related to the metallic structure of the distribution system and facets. The corrosive water in pipes and facets cause dissolution of the metals such as Pb, Cu, Cd, Zn, Fe and Mn into the water. Due to the lack of research work in this area, a study of the trace metals were performed in the drinking water distribution system in Zarin Shahr and Mobareke of Isfahan province. Methods: Based on the united states Environmental protection Agency (USEPA for the cities over than 50,000 population such as Zarin Shahr and Mobareke, 30 water samples from home facets with the minimum 6 hours retention time of water in pipes, were collected. Lead and cadmium concentration were determined using flameless Atomic Absorption. Cupper, Zinc, Iron and Manganese were determined using Atomic Absorption. Results: The average concentration of Pb, Cd, Zn, Fe and Mn in water distribution system fo Zarin Shahr were 5.7, 0.1, 80, 3042, 23065 and in Mobareke were 7.83, 0.8,210,3100, 253, 17µg respectively. The cocentration of Pb, Cd and Zn were zero at the beginning of the water samples from the municipal drinking water distribution system for both cities. Conclusion: The study showed that the corrosion by products (such as Pb, Cd and Zn was the results of dissolution of the galvanized pipes and brass facets. Lead concentration in over that 10 percent of the water samples in zarin shahr exceeded the drinking water standard level, which emphasize the evaluation and control of corrosion in drinking water distribution systems.

  4. Lead and other trace metals in preeclampsia: A case-control study in Tehran, Iran

    International Nuclear Information System (INIS)

    Vigeh, Mohsen; Yokoyama, Kazuhito; Ramezanzadeh, Fateme; Dahaghin, Mojgan; Sakai, Tadashi; Morita, Yoko; Kitamura, Fumihiko; Sato, Hajime; Kobayashi, Yasuki

    2006-01-01

    To assess the effects of environmental exposures to trace metals on the incidence of preeclampsia, concentrations of lead (Pb), antimony (Sb), manganese (Mn), mercury, cadmium, cobalt and zinc in umbilical cord blood (UCB) and mother whole blood (MWB) were measured in 396 postpartum women without occupational exposure to metals in Tehran, Iran, using inductively coupled plasma mass spectrometry. Mother's ages ranged from 15 to 49 (mean 27) years. Preeclampsia was diagnosed in 31 subjects (7.8%). Levels of Pb, Sb and Mn in UCB were significantly higher in preeclampsia cases [mean+/-SD of 4.30+/-2.49μg/dl, 4.16+/-2.73 and 46.87+/-15.03μg/l, respectively] than in controls [3.52+/-2.09μg/dl, 3.17+/-2.68 and 40.32+/-15.19μg/l, respectively] (P<0.05). The logistic regression analysis revealed that one unit increase in the common logarithms of UCB concentration of Pb, Sb or Mn led to increase in the risk of preeclampsia several-fold; unit risks (95% CI) were 12.96 (1.57-107.03), 6.11 (1.11-33.53) and 34.2 (1.81-648.04) for Pb, Sb and Mn, respectively (P<0.05). These findings suggest that environmental exposure to Pb, Sb and Mn may increase the risk of preeclampsia in women without occupational exposure; levels of metals in UCB to be sensitive indicators of female reproductive toxicity as compared with those in mother MWB. Further studies are necessary to confirm these findings, especially on Sb and Mn

  5. Trace metal analysis in sea grasses from Mexican Caribbean Coast by particle induced X-ray emission (PIXE)

    International Nuclear Information System (INIS)

    Solis, C.; Issac O, K.; Martinez, A.; Lavoisier, E.; Martinez, M. A.

    2008-01-01

    The growing urban and tourist activity in the Mexican Caribbean coasts has resulted in an increase of chemical substances, metals in particular, discharged to the coastal waters. In order to reach an adequate management and conservation of these marine ecosystems it is necessary to perform an inventory of the actual conditions that reflect the vulnerability and the level of damage. Sea-grasses are considered good biological indicators of heavy metal contamination in marine systems. The goal of this preliminary work is to evaluate the concentrations of trace metals such as Cr, Mn, Fe, Co, Cu, Zn, and Pb in Thalassia testudinum, a very common sea-grass in the Mexican Caribbean Sea. Samples were collected from several locations in the coasts of the Yucatan Peninsula: Holbox, Blanquizal and Punta Allen, areas virtually uninfluenced by anthropogenic activities. Trace elements in different part plants were determined by particle induced X-ray emission (PIXE). This is a very suitable technique since it offers a fast, accurate and multi-element analysis. Also, the analysis by PIXE can be performed directly on powdered leaves without a laborious sample preparation. The trace metal concentration determined in sea-grasses growing in Caribbean generally fall in the range of the lowest valuables reported for sea grasses from the Gulf of Mexico. The results indicate that the studied areas do not present contamination by heavy metals. (Author)

  6. A pilot test of methods for determination of trace metals bound to colloids in surface waters

    Energy Technology Data Exchange (ETDEWEB)

    Nilsson, Kersti (Geosigma AB (Sweden))

    2011-01-15

    Two methods have been tested for the determination of trace metals associated with colloid species in surface waters, using test water from Eckarfjaerden (PFM000070) in Forsmark; 1) fractionation (ultra filtration) using special membrane filters with cut-offs of 1 kD and 5 kD and 2) filtration using a system of standard membrane filters with varying pore sizes connected in series. Both methods were somewhat modified compared to previous methods for colloid determination in groundwater within the site investigations at Forsmark and Laxemar (PLU). The results show that, in general, the largest amounts of metals associated with a colloid phase were recovered in the fraction between 1kD and 5 kD which indicates that the metal ions are associated with low molecular weight organic acids. Similar amounts were recovered on the filters in the filtration experiment. A minor part of the colloidal phase metals was recovered in the fraction larger than 5 kD i.e. metal ions associated with larger organic acids or colloidal size clay minerals. The metals present preferably as colloids in the fractionation experiment were: iron, thorium, cerium, uranium, neodymium, titanium, zirconium and yttrium. The filtering experiment showed larger parts of titanium and aluminum in the colloid phase than the fractionation experiment while the iron and cerium portions were equal and the uranium, yttrium and neodymium portions were lower. The results from the fractionation test showed that the dissolved parts were large for barium, manganese, strontium and rubidium. In the filtration test, uranium, yttrium and rubidium, were also present mainly as dissolved ions. The detection limit for filter analysis of thorium was high, and the part of thorium present as colloids was determined to <50%. Issues and methodological problems: - Severe contamination caused interpretation difficulties for several metal ions, especially chromium, nickel and zinc. - Both methods are time consuming and difficult to

  7. Determination of metal traces in lubricating oils by Aas and Icp-SFMS after microwave digestion

    International Nuclear Information System (INIS)

    Perez B, M. A.; Acosta L, C. E.; Hernandez M, H.; Romero G, E. T.; Lara A, N.; Kuri C, A.

    2016-09-01

    The analysis of lubricating oils allows to monitor the operating conditions of the machines and equipment, their pollution levels, degradation and finally their wear and useful life, as well as to establish a preventive lubrication program as a technical diagnostic maintenance tool. The useful life of oil is the period of functional time has in the machine until the antioxidants are consumed, producing large changes in the physical (density and viscosity) and chemical properties of the base oil, resulting in a wear of the components that make up the machine. The present work includes a theoretical as well as analytical basis for determining the content of metallic elements (Ag, Al, Cu, Fe, Mg, Sn and Zn) at trace level in used lubricating oils. A simple and rapid method of analysis is proposed, consisting mainly of the pretreatment of the sample by acidic digestion with a microwave oven. Subsequently an open digestion in a heating plate is carried out to dryness and recovered with concentrated HNO 3 . For the quantitative analysis two analytical techniques were used: flame atomic absorption spectroscopy (Aas) and magnetic sector mass spectrometry with inductively coupled plasma source (Icp-SFMS). In both cases, the proposed method offers a good linearity and sensitivity for each of the trace elements under study. The accuracy of the method expressed as relative standard deviation ranges from 1.4 to 2.3%. In relation to the accuracy measurement, an oil was also analyzed as a certified reference material (Conostan 500 mg/L), with the concentration of certified Mg, obtaining satisfactory results. (Author)

  8. Biomonitoring of trace metal bioavailabilities to the barnacle Amphibalanus amphitrite along the Iranian coast of the Persian Gulf.

    Science.gov (United States)

    Nasrolahi, A; Smith, B D; Ehsanpour, M; Afkhami, M; Rainbow, P S

    2014-10-01

    The fouling barnacle Amphibalanus amphitrite is a cosmopolitan biomonitor of trace metal bioavailabilities, with an international comparative data set of body metal concentrations. Bioavailabilities of As, Cd, Cr, Cu, Fe, Mn, Pb, V and Zn to A. amphitrite were investigated at 19 sites along the Iranian coast of the understudied Persian Gulf. Commercial and fishing ports showed extremely high Cu bioavailabilities, associated with high Zn bioavailabilities, possibly from antifouling paints and procedures. V availability was raised at one port, perhaps associated with fuel leakage. Cd bioavailabilities were raised at sites near the Strait of Hormuz, perhaps affected by adjacent upwelling off Oman. The As data allow a reinterpretation of the typical range of accumulated As concentrations in A. amphitrite. The Persian Gulf data add a new region to the A. amphitrite database, confirming its importance in assessing the ecotoxicologically significant trace metal contamination of coastal waters across the world. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. Trace metal incorporation in otoliths of a territorial coral reef fish (Abudefduf saxatilis as an environmental monitoring tool

    Directory of Open Access Journals (Sweden)

    Herrera-Reveles A. T.

    2013-04-01

    Full Text Available Trace metal levels in the otolith external layer of newly Abudefduf saxatilis (Pomacentridae recruits, a common fish of the Caribbean coral reef, were examined as an indicator of recently occupied habitat from the most important coral reefs of the east of Venezuela (Mochima National Park and La Tortuga Island. These otoliths were analyzed trough an Energy-dispersive X-ray spectroscopy (EDS fixed to scanning electron microscopy (SEM. The five trace metals analyzed (Cd, Cu, Hg, Pb and Zn were found at external layer of most evaluated otoliths at all localities, in which %weight of Pb/Ca and Hg/Ca showed the highest values. These results show the bioavailability of evaluated metals at Mochima National Park and La Tortuga Island, and their significant spatial variations on otoliths make evidence of different concentration of Cd, Hg and Pb in water and/or sediments of these locations.

  10. Determination of several trace metals in biological materials by PIXE analysis after solvent extraction and polystyrene-film collection

    International Nuclear Information System (INIS)

    Iwata, Yoshihiro; Korenaga, Tatsumi; Suzuki, Nobuo

    1991-01-01

    Traces of vanadium, manganese, iron, cobalt, nickel, copper, and zinc were quantitatively extracted with diethyldithiocarbamate (DDTC) in benzene from a digested solution of biological materials and the metal-DDTC complexes were collected into a small amount of polystyrene foam produced by lyophilization of the benzene extract after addition of polystyrene. The polystyrene foam was dissolved in benzene and spread on Mylar film. After drying, a polystyrene film containing metal-DDTC complexes was produced on Mylar film, and then the polystyrene film was peeled from the Mylar film. This film was subjected to PIXE analysis. This method was applied to NBS SRM 1572 citrus leaves and a marine macroalgal sample, and 6 trace metals were simultaneously and accurately determined. (author)

  11. Calcium EDTA toxicity: renal excretion of endogenous trace metals and the effect of repletion on collagen degradation in the rat.

    Science.gov (United States)

    Braide, V B

    1984-01-01

    Studies on total hydroxyproline concentrations in urine of rats infused with toxic doses of CaEDTA at 6 mmol/kg per 24 hr for 48 hr or injected i.p. with the chelate at 4.8 mmol/kg/day for 10 days, indicate a two- to six-fold increase in urine excretion of the imino acid. This is due to increased degradation of collagen induced by CaEDTA. CaEDTA infusion was also shown to enhance urine excretion of some trace metals (Zn, Mn, Cu and Fe). Rats infused with CaEDTA for 36 hr showed a gradual fall in concentration of hydroxyproline in the urine, following cessation of chelate infusion. The decline in hydroxyproline concentrations was faster in rats receiving trace metal (Zn, Co, Mn or Ni) treatment during the post-CaEDTA infusion period; suggesting that the metals may affect collage, making the protein less susceptible to degradation in the body.

  12. Preservation of NOM-metal complexes in a modern hyperalkaline stalagmite: Implications for speleothem trace element geochemistry

    Science.gov (United States)

    Hartland, Adam; Fairchild, Ian J.; Müller, Wolfgang; Dominguez-Villar, David

    2014-03-01

    We report the first quantitative study of the capture of colloidal natural organic matter (NOM) and NOM-complexed trace metals (V, Co, Cu, Ni) in speleothems. This study combines published NOM-metal dripwater speciation measurements with high-resolution laser ablation ICPMS (LA-ICPMS) and sub-annual stable isotope ratio (δ18O and δ13C), fluorescence and total organic carbon (TOC) analyses of a fast-growing hyperalkaline stalagmite (pH ˜11) from Poole’s Cavern, Derbyshire UK, which formed between 1997 and 2008 AD. We suggest that the findings reported here elucidate trace element variations arising from colloidal transport and calcite precipitation rate changes observed in multiple, natural speleothems deposited at ca. pH 7-8. We find that NOM-metal(aq) complexes on the boundary between colloidal and dissolved (˜1 nm diameter) show an annual cyclicity which is inversely correlated with the alkaline earth metals and is explained by calcite precipitation rate changes (as recorded by kinetically-fractionated stable isotopes). This relates to the strength of the NOM-metal complexation reaction, resulting in very strongly bound metals (Co in this system) essentially recording NOM co-precipitation (ternary complexation). More specifically, empirical partition coefficient (Kd) values between surface-reactive metals (V, Co, Cu, Ni) [expressed as ratio of trace element to Ca ratios in calcite and in solution] arise from variations in the ‘free’ fraction of total metal in aqueous solution (fm). Hence, differences in the preservation of each metal in calcite can be explained quantitatively by their complexation behaviour with aqueous NOM. Differences between inorganic Kd values and field measurements for metal partitioning into calcite occur where [free metal] ≪ [total metal] due to complexation reactions between metals and organic ligands (and potentially inorganic colloids). It follows that where fm ≈ 0, apparent inorganic Kd app values are also ≈0, but the

  13. Concentrations of trace elements in human tissues and relation of ratios of mutual metals to the human health

    International Nuclear Information System (INIS)

    Ling-wei, X.; Shao-xian, L.; Xiao-juan, Z.

    1989-01-01

    According to the experimental results, the concentrations and concentrations in order, of trace elements in human tissues among Changsha's People in China are reported. The authors particularly present that the ratios of mutual metals (M/N) in normal physiological tissues and fluids are very important factors which indicate the metabolic situations of trace elements in the body and as the indices which evaluate the situation of human health. (M and N mean the concentrations of different trace elements in the tissues or fluids, respectively.) Up to now, it is still an interesting field to study the functions of trace elements for the human health. There are previously some reports about the concentrations of trace elements in normal physiological tissues/ or organs and fluids of human body. These provide very valuable data for biological medicine. In the study presented atomic absorption method was adopted in order to determine the concentrations of Zn, Cu, Mn, Ni, Pb and Cd in human tissues (liver, spleen, kidney, bone, lung, pancreas, heart and artery and muscle) at autopsy. The authors suggest that trace elements, are contained in the body in an aproportional way, in normal physiological tissues and fluids, and the ratios may directly indicate metabolic situation of trace elements in the body which further reveal the mystery of trace elements for human health. Therefore, the ratios M/N as an indicator of health is more proper than that only using concentrations of trace elements. Schroeder (1973) reported that incidence of heart disease is related to the imbalance of ration Zn/Cd and Zn/Cu rather than the concentrations of Zn, Cd, Cu, and the intellectual development also depends on the proper proportion among copper, cadmium, lead, zinc in the body

  14. Energetic model of metal hardening

    Directory of Open Access Journals (Sweden)

    Ignatova O.N.

    2011-01-01

    Full Text Available Based on Bailey hypothesis on the link between strain hardening and elastic lattice defect energy this paper suggests a shear strength energetic model that takes into consideration plastic strain intensity and rate as well as softening related to temperature annealing and dislocation annihilation. Metal strain hardening was demonstrated to be determined only by elastic strain energy related to the energy of accumulated defects. It is anticipated that accumulation of the elastic energy of defects is governed by plastic work. The suggested model has a reasonable agreement with the available experimental data for copper up to P = 70 GPa , for aluminum up to P = 10 GPa and for tantalum up to P = 20 GPa.

  15. Trace metals in fugitive dust from unsurfaced roads in the Viburnum Trend resource mining District of Missouri--implementation of a direct-suspension sampling methodology.

    Science.gov (United States)

    Witt, Emitt C; Wronkiewicz, David J; Pavlowsky, Robert T; Shi, Honglan

    2013-09-01

    Fugitive dust from 18 unsurfaced roadways in Missouri were sampled using a novel cyclonic fugitive dust collector that was designed to obtain suspended bulk samples for analysis. The samples were analyzed for trace metals, Fe and Al, particle sizes, and mineralogy to characterize the similarities and differences between roadways. Thirteen roads were located in the Viburnum Trend (VT) mining district, where there has been a history of contaminant metal loading of local soils; while the remaining five roads were located southwest of the VT district in a similar rural setting, but without any mining or industrial process that might contribute to trace metal enrichment. Comparison of these two groups shows that trace metal concentration is higher for dusts collected in the VT district. Lead is the dominant trace metal found in VT district dusts representing on average 79% of the total trace metal concentration, and was found moderately to strongly enriched relative to unsurfaced roads in the non-VT area. Fugitive road dust concentrations calculated for the VT area substantially exceed the 2008 Federal ambient air standard of 0.15μgm(-3) for Pb. The pattern of trace metal contamination in fugitive dust from VT district roads is similar to trace metal concentrations patterns observed for soils measured more than 40years ago indicating that Pb contamination in the region is persistent as a long-term soil contaminant. Published by Elsevier Ltd.

  16. Comparing trace metal bioaccumulation characteristics of three freshwater decapods of the genus Macrobrachium

    Energy Technology Data Exchange (ETDEWEB)

    Cresswell, Tom, E-mail: tom.cresswell@ansto.gov.au [Centre for Environmental Contaminants Research, CSIRO Land and Water, New Illawarra Rd, Lucas Heights, 2234, NSW (Australia); School of Applied Sciences, RMIT University, Plenty Road, Bundoora 3083, VIC (Australia); Smith, Ross E.W. [Hydrobiology, Lang Parade, Auchenflower 4066, QLD (Australia); Nugegoda, Dayanthi [School of Applied Sciences, RMIT University, Plenty Road, Bundoora 3083, VIC (Australia); Simpson, Stuart L. [Centre for Environmental Contaminants Research, CSIRO Land and Water, New Illawarra Rd, Lucas Heights, 2234, NSW (Australia)

    2014-07-01

    Highlights: • Exposed three species of prawns of same genus to solid- and dissolved-phase metals. • Cd bioaccumulated from dissolved phase was significantly different between species. • All three species retained >95% of bioaccumulated Cd during the depuration phase. • Bioaccumulation of As, Pb and Zn from solid phase was different between species. • Results highlight variability among species, even under controlled conditions. - Abstract: Potential sources and kinetics of metal bioaccumulation by the three Macrobrachium prawn species M. australiense, M. rosenbergii and M. latidactylus were assessed in laboratory experiments. The prawns were exposed to two scenarios: cadmium in water only; and exposure to metal-rich mine tailings in the same water. The cadmium accumulation from the dissolved exposure during 7 days, followed by depuration in cadmium-free water for 7 days, was compared with predictions from a biokinetic model that had previously been developed for M. australiense. M. australiense and M. latidactylus accumulated significant tissue cadmium during the exposure phase, albeit with different uptake rates. All three species retained >95% of the bioaccumulated cadmium during the depuration phase, indicating very slow efflux rates. Following exposure to tailings, there were significant (p < 0.05) differences in tissue arsenic, cadmium, lead and zinc concentrations among species. Cadmium and zinc concentrations were increased relative to controls for all three species but were not different between treatments (direct/indirect contact with tailings), suggesting these metals were primarily accumulated via the dissolved phase. All species bioaccumulated significantly greater arsenic and lead when in direct contact with mine tailings, demonstrating the importance of an ingestion pathway for these metals. Copper was not bioaccumulated above control concentrations for any species. The differences between the metal accumulation of the three prawns indicated

  17. New technique for the determination of trace noble metal content in geological and process materials

    Energy Technology Data Exchange (ETDEWEB)

    Mitkin, V.N. E-mail: mit@che.nsk.su; Zayakina, S.B.; Anoshin, G.N

    2003-02-03

    A new two-step sample preparation technique is proposed for the instrumental determination of trace quantities of noble metals (NM) in refractory geological and process materials. The decomposition procedure is based on the oxidizing fluorination of samples with subsequent sulfatization (OFS) of the sample melt or cake. Fluorination of samples is accomplished using a mixture of KHF{sub 2}+KBrF{sub 4} or KHF{sub 2}+BrF{sub 3} depending on the ratio of sample mass to oxidizing mixture. Both cakes and melts can result using this procedure. Sulfatization of resulting fluorides is completed using concentrated sulfuric acid heated to 550 deg. C. Validation studies using certified geostandard reference materials (GSO VP-2, ZH-3, Matte RTP, HO-1, SARM-7) have shown that the proposed method is fast, convenient and most often produces non-hygroscopic homogeneous residues suitable for analysis by atomic absorption spectrometry (AAS) and atomic emission spectrometry (AES). Results obtained for NM concentrations in reference materials agreed with certified concentration ranges and results obtained using other methods of analysis. The OFS procedure combined with direct current plasma d.c. plasma AES achieved the following limits of detection (LOD) for the noble metals: Ag, Au, Pd, 1-2x10{sup -6}; Pt, 5x10{sup -6}; and Ru, Rh, Ir, Os, 1-3x10{sup -7} wt.%. Using graphite furnace AAS (GFAAS) combined extraction pre-concentration the following LODs for NMs were achieved: Pt, Ru, 1x10{sup -6}; Pd, Rh, 1x10{sup -7}; and Au, Ag, 1-2x10{sup -8} wt.%. The relative standard deviation for NM determinations (S{sub r}) was dependent on NM concentration and sample type, but commonly was in the range of 3-15% for d.c. plasma AES and 5-30% for GFAAS.

  18. Correlation study of trace metals in malignant and normal breast tissues by AAS technique

    International Nuclear Information System (INIS)

    Rahman, S.

    2012-01-01

    The study reports the application of atomic absorption spectrophotometry (AAS) for quantification of Fe, Cu and Zn in forty one formalin-fixed biopsy breast carcinoma tissue and adjoining fifteen normal tissue samples. These tissues samples were of category two breast carcinoma patients and of normal subjects. The qualitative comparison between the elements levels measured in the two types of specimens suggests significant elevation of these metals in the histopathological samples of carcinoma tissue. The samples were collected from women aged 19-51 years. Most of the patients belong to urban areas of Pakistan and middle to high socioeconomic status with the exception of few. Findings of study depicts that these elements have an important role in the initiation and development of carcinoma as consistent pattern of elevation for Fe, Cu and Zn was observed. The results showed the excessive accumulation of Fe (166.9 mg/L) in tissue samples of breast carcinoma patients (p < 0.01) than that in normal tissues samples (23.5 mg/L). In order to validate our method of analysis certified reference material Muscle Tissue Lyophilised (IAEA) MA-M-2/TM was analyzed for Fe, Cu and Zn. Determined concentrations were in good agreement with certified levels. The concentration distribution of trace elements Cu, Zn and Fe measured in the malignant tissues were found to be higher when compared to benign tissues, indicating the involvement of these metals in the breast malignancy. Results also indicate that excess iron may play a role in breast carcinogenesis. (Orig./A.B.)

  19. A new atomization cell for trace metal determinations by tungsten coil atomic spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Donati, G.L., E-mail: georgedonati@yahoo.com.br [Department of Chemistry, Wake Forest University, Winston-Salem, NC 27109 (United States); Wildman, R.B.; Jones, B.T. [Department of Chemistry, Wake Forest University, Winston-Salem, NC 27109 (United States)

    2011-02-28

    A new metallic atomization cell is used for trace metal determinations by tungsten coil atomic absorption spectrometry and tungsten coil atomic emission spectrometry. Different protecting gas mixtures are evaluated to improve atomic emission signals. Ar, N{sub 2}, CO{sub 2} and He are used as solvents, and H{sub 2} and C{sub 2}H{sub 2} as solutes. A H{sub 2}/Ar mixture provided the best results. Parameters such as protecting gas flow rate and atomization current are also optimized. The optimal conditions are used to determine the figures of merit for both methods and the results are compared with values found in the literature. The new cell provides a better control of the radiation reaching the detector and a small, more isothermal environment around the atomizer. A more concentrated atomic cloud and a smaller background signal result in lower limits of detection using both methods. Cu (324.7 nm), Cd (228.8 nm) and Sn (286.3 nm) determined by tungsten coil atomic absorption spectrometry presented limits of detection as low as 0.6, 0.1, and 2.2 {mu}g L{sup -1}, respectively. For Cr (425.4 nm), Eu (459.4 nm) and Sr (460.7 nm) determined by tungsten coil atomic emission spectrometry, limits of detection of 4.5, 2.5, and 0.1 {mu}g L{sup -1} were calculated. The method is used to determine Cu, Cd, Cr and Sr in a water standard reference material. Results for Cu, Cd and Cr presented no significant difference from reported values in a 95% confidence level. For Sr, a 113% recovery was obtained.

  20. Estuarine modification of dissolved and particulate trace metals in major rivers of East-Hainan, China

    Science.gov (United States)

    Fu, Jun; Tang, Xiao-Liang; Zhang, Jing; Balzer, Wolfgang

    2013-04-01

    Wenchang/Wenjiao river estuary significant trace metal contamination was observed.

  1. A new method for automatic discontinuity traces sampling on rock mass 3D model

    Science.gov (United States)

    Umili, G.; Ferrero, A.; Einstein, H. H.

    2013-02-01

    A new automatic method for discontinuity traces mapping and sampling on a rock mass digital model is described in this work. The implemented procedure allows one to automatically identify discontinuity traces on a Digital Surface Model: traces are detected directly as surface breaklines, by means of maximum and minimum principal curvature values of the vertices that constitute the model surface. Color influence and user errors, that usually characterize the trace mapping on images, are eliminated. Also trace sampling procedures based on circular windows and circular scanlines have been implemented: they are used to infer trace data and to calculate values of mean trace length, expected discontinuity diameter and intensity of rock discontinuities. The method is tested on a case study: results obtained applying the automatic procedure on the DSM of a rock face are compared to those obtained performing a manual sampling on the orthophotograph of the same rock face.

  2. Accumulation of Trace Metals in Anadara granosa and Anadara inaequivalvis from Pattani Bay and the Setiu Wetlands.

    Science.gov (United States)

    Pradit, Siriporn; Shazili, Noor Azhar Mohamed; Towatana, Prawit; Saengmanee, Wuttipong

    2016-04-01

    This study was undertaken to assess the levels of trace metals (As, Cd, Cu, Pb, and Zn) in two common species of cockles (Anadara granosa and Anadara inaequivalvis) from two coastal areas in Thailand (Pattani Bay) and Malaysia (the Setiu Wetlands). A total of 350 cockles were collected in February and September 2014. Trace metals were determined by Inductively Coupled Plasma Mass Spectrometry. We observed that cockles in both areas had a higher accumulation of metals in September. Notably, the biota-sediment accumulation (BSAF) of Cd was highest in both areas. A strong positive correlation of Cd with the length of the cockles at Pattani Bay (r(2) = 0.597) and the Setiu Wetlands (r(2) = 0.675) was noted. It was suggested that As could be a limiting element (BSAF Malaysia Food Regulations, mean values of As, Cd, Cu, Pb, and Zn were within acceptable limits, but the maximum values of Cd and Pb exceeded the limits for both areas. Regular monitoring of trace metals in cockles from both areas is suggested for more definitive contamination determination.

  3. The changes in trace metal contamination over the last decade in surface sediments of the Pearl River Estuary, South China.

    Science.gov (United States)

    Chen, Baowei; Liang, Ximei; Xu, Weihai; Huang, Xiaoping; Li, Xiangdong

    2012-11-15

    Surface sediments can provide useful information on the recent pollution status of an estuary. One recent field survey was carried out in the Pearl River Estuary (PRE), South China in 2011. The comparisons with previous surveys demonstrated that the concentrations of Ni and Pb in the PRE declined over the last decade, but the concentration of Cu increased in the same time frame. The significant decreases in the concentrations of Ni and Pb were probably due to a reduction of anthropogenic inputs, such as industrial wastewater, into the PRE environment, and the ban imposed on leaded gasoline. Statistical analyses have consistently demonstrated that the process of the sedimentation of fine particles was the dominant factor in controlling the transport and distribution of trace metals in the PRE. The riverine trace metals generally displayed a pattern of diffusion from the northwest to the southeast in the estuary. However, the riparian industrial activities at the east bank of the inner PRE caused significant metal contamination in sediments. In general, effective pollution control measures in the PRD region have decreased the levels of some trace metals in the entire PRE over the last decade with the exception of Cu. Copyright © 2012 Elsevier B.V. All rights reserved.

  4. Differential Effects of Low-Molecular-Weight Organic Acids on the Mobilization of Soil-Borne Arsenic and Trace Metals.

    Science.gov (United States)

    Nworie, Obinna Elijah; Qin, Junhao; Lin, Chuxia

    2017-08-21

    A batch experiment was conducted to examine the effects of six low-molecular-weight organic acids on the mobilization of arsenic and trace metals from a range of contaminated soils. The results showed that the organic acids behaved differently when reacting with soil-borne As and trace metals. Oxalic acid and acetic acid had the strongest and weakest capacity to mobilize the investigated elements, respectively. The solubilisation of iron oxides by the organic acids appears to play a critical role in mobilizing other trace metals and As. Apart from acidification and complexation, reductive dissolution played a dominant role in the dissolution of iron oxides in the presence of oxalic acid, while acidification tended to be more important for dissolving iron oxides in the presence of other organic acids. The unique capacity of oxalic acid to solubilize iron oxides tended to affect the mobilization of other elements in different ways. For Cu, Mn, and Zn, acidification-driven mobilization was likely to be dominant while complexation might play a major role in Pb mobilization. The formation of soluble Fe and Pb oxalate complexes could effectively prevent arsenate or arsenite from combining with these metals to form solid phases of Fe or Pb arsenate or arsenite.

  5. Geochemistry of Dissolved Trace Metals in the Waters of Bahia Magdalena, Baja California Sur, Pacific Coast, Mexico

    Science.gov (United States)

    Suresh Babu, S.

    2016-12-01

    Forty two samples were acquired from the surface and bottom water profiles along 5 transects spread over Bahia Magdalena lagoon, Baja California Sur to assess the behavior of trace metals in a high influenced upwelling region on the Pacific coast. To elaborate the fate of metals, also the physico-chemical parameters (pH, temperature, salinity, conductivity, dissolved oxygen). Determination of the concentrations of trace metals (Fe, Mn, Cr, Cu, Co, Pb, Ni, Zn, Cd As, Hg) were measured using Atomic absorption spectrometry. The results demonstrated high values of As, Ni and Co which is attributed to the local geology and phosphate deposits. Low values of Fe and Mn are attested to the oxic conditions of the lagoon which are responsible for the oxidation of Fe and Mn. The region witnesses raised temperatures (28.92ºC) and salinities of 35.2 PSU for its arid climatic conditions and high rates of evaporation. In general, the region presented minor quantities of dissolved trace metals due to dispersion and high intense interaction with the open sea. The results were also compared with other studies to understand the enrichment pattern in this side of the pacific coast which experiences various geothermal activities and upwelling phenomenon.

  6. Santos estuarine sediments, Brazil - metal and trace element assessment by neutron activation analysis

    International Nuclear Information System (INIS)

    Amorim, Eduardo P.; Favaro, Deborah I.T.; Berbel, Glaucia; Braga, Elisabete S.

    2009-01-01

    The Santos estuary system is an intricate pattern of tidal channels and small rivers originating from the adjacent Pre-Cambrian slopes. These two major estuaries share a common area in the upper portion of the region which interacts with each other. The largest harbor in Latin America is located at the eastern outlet of the Santos estuary. This intricate and sensitive ecosystem is highly susceptible to human impact from industrial activities, urban sewage and polluted solid wastes disposal. Due to its high vulnerability CETESB (Environmental Control Agency of the Sao Paulo State) sporadically monitors the contamination levels of water, sediment and marine organisms in this region. The present study reports results concerning the distribution of some major, trace and rare earth elements in the Santos estuarine marine sediments. Thirty two bottom sediment samples (SS0601 to SS0616 (summer) and SW0601 to SW0616 (winter) were collected in this estuary, including regions of Sao Vicente, Santos, Cubatao and Vicente de Carvalho, by a vanVeen sampler in the summer and winter of 2006. Multielemental analysis was carried out by instrumental neutron activation analysis (INAA). The concentration values obtained for As and metals Cr and Zn in the sediment samples were compared to Canadian Council of Minister of the Environment (CCME) oriented values (TEL and PEL values) and are adopted by CETESB. (author)

  7. Santos estuarine sediments, Brazil - metal and trace element assessment by neutron activation analysis

    Energy Technology Data Exchange (ETDEWEB)

    Amorim, Eduardo P.; Favaro, Deborah I.T., E-mail: ducamorim@yahoo.com.b, E-mail: defavaro@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP) Sao Paulo, SP (Brazil); Berbel, Glaucia; Braga, Elisabete S., E-mail: edsbraga@usp.b [Universidade de Sao Paulo (USP), SP (Brazil). Inst. Oceanografico. Lab. de Nutrientes, Micronutrientes e Tracos nos Oceanos (LABNUT)

    2009-07-01

    The Santos estuary system is an intricate pattern of tidal channels and small rivers originating from the adjacent Pre-Cambrian slopes. These two major estuaries share a common area in the upper portion of the region which interacts with each other. The largest harbor in Latin America is located at the eastern outlet of the Santos estuary. This intricate and sensitive ecosystem is highly susceptible to human impact from industrial activities, urban sewage and polluted solid wastes disposal. Due to its high vulnerability CETESB (Environmental Control Agency of the Sao Paulo State) sporadically monitors the contamination levels of water, sediment and marine organisms in this region. The present study reports results concerning the distribution of some major, trace and rare earth elements in the Santos estuarine marine sediments. Thirty two bottom sediment samples (SS0601 to SS0616 (summer) and SW0601 to SW0616 (winter) were collected in this estuary, including regions of Sao Vicente, Santos, Cubatao and Vicente de Carvalho, by a vanVeen sampler in the summer and winter of 2006. Multielemental analysis was carried out by instrumental neutron activation analysis (INAA). The concentration values obtained for As and metals Cr and Zn in the sediment samples were compared to Canadian Council of Minister of the Environment (CCME) oriented values (TEL and PEL values) and are adopted by CETESB. (author)

  8. Analysis of trace metals in sodium by flameless atomic absorption spectrophotometry

    International Nuclear Information System (INIS)

    Mahalingam, T.R.; Geetha, R.; Thiruvengadasamy, A.; Mathews, C.K.

    1981-01-01

    The estimation of trace metallic impurities in sodium is normally carried out by distilling off the sodium in vacuuum and analysing the residue by atomic absorption spectrophotometry (AAS). This paper describes the direct determination of the following impurities (viz.) Fe, Co, Ni, Cr, Mn, Ca, and Cu in sodium without going through the distillation step. Here sodium is simply dissolved and the solution is subjected to analysis by AAS using flameless atomisation in a graphite furnace. The method of standard additions is employed. Preliminary experiments were carried out to study the matrix effect of sodium on the atomic absorption of cobalt. It has been found that if pyrolysis is done at 1250 0 C for 20 seconds prior to atomisation, the bulk of the sodium nitrate matrix could be successfully removed. The use of the optimum pyrolysis temperatures for the various elements listed above and the matrix interference on the absorbances of these analytes are discussed in this paper. The precision and accuracy of our analytical procedure is also presented. (orig.)

  9. Investigation of Water Safety in Non-treated Drinking Water with Trace Toxic Metals.

    Science.gov (United States)

    Ly, Suw Young; Kim, Dae Hong; Lee, Ga Eun

    2013-09-01

    The trace toxic metal copper was assayed using mercury immobilized on a carbon nanotube electrode (MCW), with a graphite counter and a reference electrode. In this study, a macro-scale convection motor was interfaced with a MCW three-electrode system, in which a handmade MCW was optimized using cyclic- and square-wave stripping voltammetry. An analytical electrolyte for tap water was used instead of an expensive acid or base ionic solution. Under these conditions, optimum parameters were 0.09 V amplitude, 40 Hz frequency, 0.01 V incremental potential, and a 60-s accumulation time. A diagnostic working curve was obtained from 50.0 to 350 μg/L. At a constant Cu(II) concentration of 10.0 μg/L, the statistical relative standard deviation was 1.78% (RSD, n = 15), the analytical accumulation time was only 60 s, and the analytical detection limit approached 4.6 μg/L (signal/noise = 3). The results were applied to nontreated drinking water. The content of the analyzed copper using 9.0 and 4.0 μg/L standards were 8.68 μg/L and 3.96 μg/L; statistical values R(2) = 0.9987 and R(2) = 0.9534, respectively. This method is applicable to biological diagnostics or food surveys.

  10. Determination of trace elements and heavy metals in sediment using x-ray fluorescence

    International Nuclear Information System (INIS)

    Sidahmed, Muataz Ahmed Ibrahem

    2014-01-01

    In this study, 30 sediment samples were taken randomly from the area of Suba south of Khartoum state. Trace elements and heavy metal were determined in sediments samples using x-ray fluoresce spectroscopy (X RF). K, Ca, Ti, Mn, Fe, Cu, Zn, Pb, Rb, Sr, and Zr were determined by X RF. Standard Reference Material (SRM) from international Atomic Energy Agency (IAEA-Soil-7) has been used to achieve accuracy of X RF method. Measured values were found in agreements with certified values. The average elemental concentrations of K, Ca, Ti, Mn, Fe, Cu, Zn, Pb, Rb, Sr, and Zr were 5882.7, 20703.3, 6264.3, 460.97, 26713.3, 7.7, 43.4, 18.6, 28.6, 144.8, and 173.06, respectively. Correlation between elements was performed also cluster analysis was used to check the similarly between the samples result. The result of study were compared with previous studies and the concentrations of some elements found to be similar.(Author)

  11. Linear extension rates and fluctuations of trace metals in Porites sp. from around Peninsular Malaysia

    Science.gov (United States)

    Amir, Liyana; Mohamed, Che Abd Rahim

    2018-04-01

    Coral cores were collected from P. Payar, Port Dickson, P. Redang and P. Tioman. The length of cores represented data spanning from year 2009 - 2015. Satellite sea surface temperatures from year 2009 - 2015 were obtained from the Reynolds and Smith dataset. Sr/Ca concentrations were measured from the coral powder taken at 1mm intervals along the vertical growth axis. Sea Surface Temperature (SST) was significantly higher during year 2010 in all four locations and linear extension was observed to have declined in year 2010 compared to year 2009 in cores from both sites. This decline coincides with the higher SST observed in year 2010 as a result of the El Niño event. Correlation analysis showed that Sr/Ca ratios in cores from all sites have a significant inverse relationship with SST. Analysis of the trace metals such as Pb, Ba, Cr and Cu produced results that were within the reported range in coral skeleton. Concentrations were significantly higher in Port Dickson and the lowest in P. Redang. These findings could be due to differences in terrestrial input at respective reef sites.

  12. Comparison of trace metals in South Carolina floodplain and marsh sediments

    International Nuclear Information System (INIS)

    Gardner, L.R.; Chen, H.S.; Settlemyre, J.L.

    1978-01-01

    A comparative study of trace metals (copper, zinc, lead, and molybdenum) in sediment cores from a pristine marsh near North Inlet, S.C., a polluted marsh near Charleston Harbor, S.C., and South Carolina river floodplains indicates that the Charleston Harbor marsh samples have significantly higher concentrations of copper, zinc, and lead than either North Inlet samples or river floodplain samples. It is not clear, however, whether this result can be attributed to industrial contamination because the peak concentrations of copper and zinc in cores from the Charleston Harbor marsh occur at depths between 10 and 60 cm rather than at or near the sediment surface, as is the case for well-documented occurrences of contaminated marine sediments. Also, both marsh areas show similar linear relationships for copper vs. zinc, which suggest that both areas received the same relative inputs of copper and zinc from similar or identical sources and that the differences in concentrations between the two areas are due to differences in the rates of accumulation. Natural mechanisms are suggested to explain the higher content of copper and zinc in Charleston Harbor vs. North Inlet marsh sediments and the variable depth of peak copper and zinc concentrations

  13. Emission rates of sulfur dioxide, trace gases and metals from Mount Erebus, Antartica

    Energy Technology Data Exchange (ETDEWEB)

    Kyle, P.R.; Meeker, K. (New Mexico Institute of Mining and Technology, Socorro (USA)); Finnegan, D. (Los Alamos National Lab., NM (USA))

    1990-11-01

    SO{sub 2} emission rates have been measured annually since 1983 at Mount Erebus, Antarctica by correlation spectrometer (COSPEC V). Following a 4 month period of sustained strombolian activity in late 1984, SO{sub 2} emissions declined from 230 Mg/day in 1983 to 25 Mg/day and then slowly increased from 16 Mg/day in 1985 to 51 Mg/day in 1987. Nine sets of filter packs containing partcle and {sup 7}LiOH treated filters were collected in the plume in 1986 and analyzed by neutron activation. Using the COSPEC data and measured element/S ratios on the filters, emission rates have been determined for trace gases and metals. The authors infer HCl and HF emissions in 1983 to be about 1200 and 500 Mg/day, respectively. Mt Erebus has therefore been an important source of halogens to the Anarctic atmosphere and could be responsible for excess Cl found in Central Antarctica snow.

  14. Autonomous water sampling for long-term monitoring of trace metals in remote environments.

    Science.gov (United States)

    Kim, Hyojin; Bishop, James K B; Wood, Todd J; Fung, Inez Y

    2012-10-16

    A remotely controlled autonomous method for long-term high-frequency sampling of environmental waters in remote locations is described. The method which preserves sample integrity of dissolved trace metals and major ions for month-long periods employs a gravitational filtration system (GFS) that separates dissolved and particulate phases as samples are collected. The key elements of GFS are (1) a modified "air-outlet" filter holder to maximize filtration rate and thus minimize filtration artifacts; and (2) the direct delivery of filtrate to dedicated bottle sets for specific analytes. Depth and screen filter types were evaluated with depth filters showing best performance. GFS performance is validated using ground, stream, and estuary waters. Over 30 days of storage, samples with GFS treatment had average recoveries of 95 ± 19% and 105 ± 7% of Fe and Mn, respectively; without GFS treatment, average recoveries were only 16% and 18%. Dissolved major cations K, Mg, and Na were stable independent of collection methodology, whereas Ca in some groundwater samples decreased up to 42% without GFS due to CaCO(3) precipitation. In-field performance of GFS equipped autosamplers is demonstrated using ground and streamwater samples collected at the Angelo Coast Range Reserve, California from October 3 to November 4 2011.

  15. Geochemical and hydrodynamic controls on arsenic and trace metal cycling in a seasonally stratified US sub-tropical reservoir

    International Nuclear Information System (INIS)

    Brandenberger, Jill M.; Louchouarn, Patrick; Herbert, Bruce; Tissot, Philippe

    2004-01-01

    The phase distribution of trace metals and oxyanions was investigated within a South Texas watershed hosting a high density of surface uranium mine pits and tailings. The objectives of the study were to evaluate the potential impact of these old uranium mining sites on the watershed with particular emphasis on spatial and temporal changes in water quality of a reservoir that serves as the major source of freshwater to a population of ∼ 350,000 people in the region. A livestock pond, bordered by uranium mine tailings, was used as a model case-study site to evaluate the cycling of uranium mine-derived oxyanions under changing redox conditions. Although the pond showed seasonal thermal and chemical stratification, geochemical cycling of metals was limited to Co and Pb, which seemed to be mostly associated with redox cycling of Mn mineral phases, and U, which suggested reductive precipitation in the ponds hypolimnion. Uranium levels, however, were too low to support strong inputs from th e tailings into the water column of the pond. The strong relations observed between particulate Cr, Cs, V and Fe suggest that these metals are associated with a stable particulate phase (probably allochthonous aluminosilicates) enriched in unreactive iron. This observation is supported by a parallel relationship in sediments collected across a broad range of sediment depositional processed (and histories) in the basin. Arsenic, though selectively enriched in the ponds water column, remained stable and mostly in solution throughout the depth of the profile and showed no sign of geochemical cycling or interaction with Fe-rich particles. We found no evidence of anthropogenic impacts of U mines beyond the purely local scale. Arsenic does decrease in concentration downstream of uranium mining sites but its presence within the Nueces drainage basin is related to interactions between surface and ground waters with uranium-rich geological formations rather than long-scale transport of

  16. Accumulation of heavy metals and trace elements in fluvial sediments received effluents from traditional and semiconductor industries.

    Science.gov (United States)

    Hsu, Liang-Ching; Huang, Ching-Yi; Chuang, Yen-Hsun; Chen, Ho-Wen; Chan, Ya-Ting; Teah, Heng Yi; Chen, Tsan-Yao; Chang, Chiung-Fen; Liu, Yu-Ting; Tzou, Yu-Min

    2016-09-29

    Metal accumulation in sediments threatens adjacent ecosystems due to the potential of metal mobilization and the subsequent uptake into food webs. Here, contents of heavy metals (Cd, Cr, Cu, Ni, Pb, and Zn) and trace elements (Ga, In, Mo, and Se) were determined for river waters and bed sediments that received sewage discharged from traditional and semiconductor industries. We used principal component analysis (PCA) to determine the metal distribution in relation to environmental factors such as pH, EC, and organic matter (OM) contents in the river basin. While water PCA categorized discharged metals into three groups that implied potential origins of contamination, sediment PCA only indicated a correlation between metal accumulation and OM contents. Such discrepancy in metal distribution between river water and bed sediment highlighted the significance of physical-chemical properties of sediment, especially OM, in metal retention. Moreover, we used Se XANES as an example to test the species transformation during metal transportation from effluent outlets to bed sediments and found a portion of Se inventory shifted from less soluble elemental Se to the high soluble and toxic selenite and selenate. The consideration of environmental factors is required to develop pollution managements and assess environmental risks for bed sediments.

  17. Trace metal in surface water and groundwater and its transfer in a Yellow River alluvial fan: Evidence from isotopes and hydrochemistry

    Energy Technology Data Exchange (ETDEWEB)

    Li, Jing; Li, Fadong, E-mail: lifadong@igsnrr.ac.cn; Liu, Qiang; Zhang, Yan

    2014-02-01

    Metals are ubiquitous in the environment. The aim of sustainable management of the agro-ecosystem includes ensuring that water continues to fulfill its function in agricultural production, cycling of elements, and as a habitat of numerous organisms. There is no doubt that the influence of large-scale irrigation projects has impacted the regional surface–groundwater interactions in the North China Plain (NCP). Given these concerns, the aim of this study is to evaluate the pollution, identify the sources of trace metals, analyze the influence of surface–groundwater interactions on trace metal distribution, and to propose urgent management strategies for trace metals in the agriculture area in China. Trace metals, hydrochemical indicators (EC, pH, concentrations of Na{sup +}, K{sup +}, Mg{sup 2+}, Ca{sup 2+}, Cl{sup −}, SO{sub 4}{sup 2−}, and HCO{sub 3}{sup −}) and stable isotopic composition (δ{sup 18}O and δ{sup 2}H) were determined for surface water (SW) and groundwater (GW) samples. Trace metals were detected in all samples. Concentrations of Fe, Se, B, Mn, and Zn in SW exceeded drinking water standards by 14.8%, 29.6%, 25.9%, 11.1%, and 14.8% higher, respectively, and by 3.8%, 23.1%, 11.5%, 11.5%, and 7.7% in GW. The pollution of trace metals in surface water was more serious than that in groundwater, and was also higher than in common irrigation areas in NCP. Trace metals were found to have a combined origin of geogenic and agriculture and industrial activities. Their distribution varied greatly and exhibited a certain relationship with the water flow direction, with the exception of a number of singular sites. Hydrochemical and environmental isotopic evidence indicates surface–groundwater interactions influence the spatial distribution of trace metal in the study area. Facing the ongoing serious pollution, management practices for source control, improved control technologies, and the construction of a monitoring net to warn of increased risk are

  18. TRACE/PARCS modelling of rips trip transients for Lungmen ABWR

    Energy Technology Data Exchange (ETDEWEB)

    Chang, C. Y. [Inst. of Nuclear Engineering and Science, National Tsing-Hua Univ., No.101, Kuang-Fu Road, Hsinchu 30013, Taiwan (China); Lin, H. T.; Wang, J. R. [Inst. of Nuclear Energy Research, No. 1000, Wenhua Rd., Longtan Township, Taoyuan County 32546, Taiwan (China); Shih, C. [Inst. of Nuclear Engineering and Science, Dept. of Engineering and System Science, National Tsing-Hua Univ., No.101, Kuang-Fu Road, Hsinchu 30013, Taiwan (China)

    2012-07-01

    The objectives of this study are to examine the performances of the steady-state results calculated by the Lungmen TRACE/PARCS model compared to SIMULATE-3 code, as well as to use the analytical results of the final safety analysis report (FSAR) to benchmark the Lungmen TRACE/PARCS model. In this study, three power generation methods in TRACE were utilized to analyze the three reactor internal pumps (RIPs) trip transient for the purpose of validating the TRACE/PARCS model. In general, the comparisons show that the transient responses of key system parameters agree well with the FSAR results, including core power, core inlet flow, reactivity, etc. Further studies will be performed in the future using Lungmen TRACE/PARCS model. After the commercial operation of Lungmen nuclear power plant, TRACE/PARCS model will be verified. (authors)

  19. Trace metal concentrations in Posidonia oceanica of North Corsica (northwestern Mediterranean Sea: use as a biological monitor?

    Directory of Open Access Journals (Sweden)

    Gosselin Marc

    2006-09-01

    Full Text Available Abstract Background Within semi-closed areas like the Mediterranean Sea, anthropic wastes tend to concentrate in the environment. Metals, in particular, are known to persist in the environment and can affect human health due to accumulation in the food chain. The seagrass Posidonia oceanica, widely found in Mediterranean coastal waters, has been chosen as a "sentinel" to quantify the distribution of such pollutants within the marine environment. Using a technique similar to dendrochronology in trees, it can act as an indicator of pollutant levels over a timeframe of several months to years. In the present study, we measured and compared the levels of eight trace metals (Cr, Ni, Cu, Zn, As, Se, Cd, and Pb in sheaths dated by lepidochronology and in leaves of shoots sampled from P. oceanica meadows collected from six offshore sites in northern Corsica between 1988 and 2004; in the aim to determine 1 the spatial and 2 temporal variations of these metals in these areas and 3 to compared these two types of tissues. Results We found low trace metal concentrations with no increase over the last decade, confirming the potential use of Corsican seagrass beds as reference sites for the Mediterranean Sea. Temporal trends of trace metal concentrations in sheaths were not significant for Cr, Ni, Cu, As or Se, but Zn, Cd, and Pb levels decreased, probably due to the reduced anthropic use of these metals. Similar temporal trends between Cu levels in leaves (living tissue and in sheaths (dead tissue demonstrated that lepidochronology linked with Cu monitoring is effective for surveying the temporal variability of this metal. Conclusion Leaves of P. oceanica can give an indication of the metal concentration in the environment over a short time period (months with good accuracy. On the contrary, sheaths, which gave an indication of changes over long time periods (decades, seem to be less sensitive to variations in the metal concentration in the environment

  20. Main considerations for modelling a station blackout scenario with trace

    International Nuclear Information System (INIS)

    Querol, Andrea; Turégano, Jara; Lorduy, María; Gallardo, Sergio; Verdú, Gumersindo

    2017-01-01

    In the nuclear safety field, the thermal hydraulic phenomena that take place during an accident in a nuclear power plant is of special importance. One of the most studied accidents is the Station BlackOut (SBO). The aim of the present work is the analysis of the PKL integral test facility nodalization using the thermal-hydraulic code TRACE5 to reproduce a SBO accidental scenario. The PKL facility reproduces the main components of the primary and secondary systems of its reference nuclear power plant (Philippsburg II). The results obtained with different nodalization have been compared: 3D vessel vs 1D vessel, Steam Generator (SG) modelling using PIPE or TEE components and pressurizer modelling with PIPE or PRIZER components. Both vessel nodalization (1D vessel and 3D vessel) reproduce the physical phenomena of the experiment. However, there are significant discrepancies between them. The appropriate modelling of the SG is also relevant in the results. Regarding the other nodalization (PIPE or TEE components for SG and PIPE or PRIZER components for pressurizer), do not produce relevant differences in the results. (author)

  1. Main considerations for modelling a station blackout scenario with trace

    Energy Technology Data Exchange (ETDEWEB)

    Querol, Andrea; Turégano, Jara; Lorduy, María; Gallardo, Sergio; Verdú, Gumersindo, E-mail: anquevi@upv.es, E-mail: jaturna@upv.es, E-mail: maloral@upv.es, E-mail: sergalbe@iqn.upv.es, E-mail: gverdu@iqn.upv.es [Instituto Universitario de Seguridad Industrial, Radiofísica y Medioambiental (ISIRYM), Universitat Politècnica de València (Spain)

    2017-07-01

    In the nuclear safety field, the thermal hydraulic phenomena that take place during an accident in a nuclear power plant is of special importance. One of the most studied accidents is the Station BlackOut (SBO). The aim of the present work is the analysis of the PKL integral test facility nodalization using the thermal-hydraulic code TRACE5 to reproduce a SBO accidental scenario. The PKL facility reproduces the main components of the primary and secondary systems of its reference nuclear power plant (Philippsburg II). The results obtained with different nodalization have been compared: 3D vessel vs 1D vessel, Steam Generator (SG) modelling using PIPE or TEE components and pressurizer modelling with PIPE or PRIZER components. Both vessel nodalization (1D vessel and 3D vessel) reproduce the physical phenomena of the experiment. However, there are significant discrepancies between them. The appropriate modelling of the SG is also relevant in the results. Regarding the other nodalization (PIPE or TEE components for SG and PIPE or PRIZER components for pressurizer), do not produce relevant differences in the results. (author)

  2. Modified batch anaerobic digestion assay for testing efficiencies of trace metal additives to enhance methane production of energy crops.

    Science.gov (United States)

    Brulé, Mathieu; Bolduan, Rainer; Seidelt, Stephan; Schlagermann, Pascal; Bott, Armin

    2013-01-01

    Batch biochemical methane potential (BMP) assays to evaluate the methane yield of biogas substrates such as energy crops are usually carried out with undiluted inoculum. A BMP assay was performed on two energy crops (green cuttings and grass silage). Anaerobic digestion was performed both with and without supplementation of three commercial additives containing trace metals in liquid, solid or adsorbed form (on clay particles). In order to reveal positive effects of trace metal supplementation on the methane yield, besides undiluted inoculum, 3-fold and 10-fold dilutions of the inoculum were applied for substrate digestion. Diluted inoculum variants were supplemented with both mineral nutrients and pH-buffering substances to prevent a collapse of the digestion process. As expected, commercial additives had no effect on the digestion process performed with undiluted inoculum, while significant increases of methane production through trace element supplementation could be observed on the diluted variants. The effect of inoculum dilution may be twofold: (1) decrease in trace metal supplementation from the inoculum and (2) reduction in the initial number of bacterial cells. Bacteria require higher growth rates for substrate degradation and hence have higher trace element consumption. According to common knowledge of the biogas process, periods with volatile fatty acids accumulation and decreased pH may have occurred in the course ofanaerobic digestion. These effects may have led to inhibition, not only ofmethanogenes and acetogenes involved in the final phases of methane production, but also offibre-degrading bacterial strains involved in polymer hydrolysis. Further research is required to confirm this hypothesis.

  3. Trace Metals and Lead Isotopes in modern Sediments Near Rio de Janeiro, Brazil

    Science.gov (United States)

    Boyle, E. A.; Lazzari, L.; Wagener, A. L.; Carreira, R.; Godoy, J. M.; Noble, A.; Carrasco, G. G.; Moos, S. B.

    2014-12-01

    This work focuses on the export of trace metals and combustion residues from land to ocean and on the Southeast continental margin of Brazil and its historical variability using stable lead isotopes. Two sediment cores were collected, one in highly impacted Guanabara Bay and the other on the Southeast continental shelf. Continental shelf samples were analyzed for trace element concentrations [Mn (117±50 ppm), Ni (6.5±2.3 ppm), Zn (5.0±1.5), (233±46 ppm), ], Pb (5.4±2.4 ppm), as well as Cu, Ag, Cd, Sr, Ba, Tl, U and Pb isotope ratios & Pb-210. Most of the elements show higher concentrations on the upper part of the core compared to the bottom. Downcore changes of the concentrations of these elements were similar. The sediments of adjacent rivers and bays around the upper section of the southeast continental shelf of Brazil are considered highly enriched with Pb, Zn, Cu and Cr such as Guanabara Bay, Sepetiba Bay and Paraíba do Sul River compared with the natural concentrations and other regions in the world. A [Pb] maximum is seen between samples from 24 to 43 cm (~8 ppm). Utilization of tetraethyl lead (TEL) gasoline in Brazil was phased out beginning in 1983 and was largely completed by 1988. Continental shelf Pb-206/Pb-207 varies between 1.174 near the core top to 1.190 at 100 cm, with a sharp difference between samples at 6 and 8 cm. Higher core top Pb, Zn, and Ni corroborate the recent anthropogenic influence on the southeast continental shelf of Brazil. For Guanabara Bay sediment samples [Pb] varies between 90 ppm near the top to 1 ppm at the bottom. Pb-206/Pb-207 varies between 1.161 near the core top to 1.165 near the bottom. Using triple isotope plots we can discern different sources of lead to the region and how these vary with time.

  4. Contemporary and historical trace metal loadings to the sediments of four lakes of the Lake Washington drainage. Completion report

    International Nuclear Information System (INIS)

    Spyridakis, D.E.; Barnes, R.S.

    1978-01-01

    Contemporary and historical loadings of lead, zinc, and copper to the profundal sediments of Lakes Washington, Sammamish, Chester Morse, and Findley were determined using chemical analysis and 210 Pb dating of sediment cores. Elemental sedimentation rates, a cross product of the sedimentation rate, and sediment concentration of a given element, were corrected for natural background concentrations and rates, and extrapolated across established sediment accumulating areas to give a conservative estimate of the pollutional trace metal loadings to each lake. The resulting chronological loadings appeared consistent with the known cultural history of the individual watersheds. Substantial alterations in sedimentation rates were noted in all lakes where deforestation, road building, suburbanization or urbanization had occurred in the lake's watershed. The quantities, elemental ratios and pollutional histories of copper, lead and zinc in the lake sediments indicate that aeolian inputs are the dominant source of trace metal pollution to the lake sediments at the present time

  5. Determination of trace metals in sea waters of the albanian coast by energy-dispersive x-ray fluorescence

    International Nuclear Information System (INIS)

    Civici, N.

    1994-01-01

    Preconcentration of trace transition and heavy metal ions by precipitation with APDC has been combined with energy-dispersive X-ray fluorescence for environmental sea water analysis. The preconcentration procedure implies adding of 500 μg Mo ion and 10 ml of 1 % water solution of APDC to a 500 ml water sample at pH 4, filtering off on a Millipore filter and analyzing after drying. Realistic detection limits are at 1 μg * l -1 level and precision varies between 10 - 25% at about 5 μg * l -1 level, depending on the element. Eleven sea water samples, covering Albanian Adriatic and Ionian coast, are analyzed for trace metal ions. (author) 8 refs.; 2 figs.; 5 tabs

  6. Model predictions of metal speciation in freshwaters compared to measurements by in situ techniques.

    NARCIS (Netherlands)

    Unsworth, Emily R; Warnken, Kent W; Zhang, Hao; Davison, William; Black, Frank; Buffle, Jacques; Cao, Jun; Cleven, Rob; Galceran, Josep; Gunkel, Peggy; Kalis, Erwin; Kistler, David; Leeuwen, Herman P van; Martin, Michel; Noël, Stéphane; Nur, Yusuf; Odzak, Niksa; Puy, Jaume; Riemsdijk, Willem van; Sigg, Laura; Temminghoff, Erwin; Tercier-Waeber, Mary-Lou; Toepperwien, Stefanie; Town, Raewyn M; Weng, Liping; Xue, Hanbin

    2006-01-01

    Measurements of trace metal species in situ in a softwater river, a hardwater lake, and a hardwater stream were compared to the equilibrium distribution of species calculated using two models, WHAM 6, incorporating humic ion binding model VI and visual MINTEQ incorporating NICA-Donnan. Diffusive

  7. A new method for automated discontinuity trace mapping on rock mass 3D surface model

    Science.gov (United States)

    Li, Xiaojun; Chen, Jianqin; Zhu, Hehua

    2016-04-01

    This paper presents an automated discontinuity trace mapping method on a 3D surface model of rock mass. Feature points of discontinuity traces are first detected using the Normal Tensor Voting Theory, which is robust to noisy point cloud data. Discontinuity traces are then extracted from feature points in four steps: (1) trace feature point grouping, (2) trace segment growth, (3) trace segment connection, and (4) redundant trace segment removal. A sensitivity analysis is conducted to identify optimal values for the parameters used in the proposed method. The optimal triangular mesh element size is between 5 cm and 6 cm; the angle threshold in the trace segment growth step is between 70° and 90°; the angle threshold in the trace segment connection step is between 50° and 70°, and the distance threshold should be at least 15 times the mean triangular mesh element size. The method is applied to the excavation face trace mapping of a drill-and-blast tunnel. The results show that the proposed discontinuity trace mapping method is fast and effective and could be used as a supplement to traditional direct measurement of discontinuity traces.

  8. Leach tests on grouts made with actual and trace metal-spiked synthetic phosphate/sulfate waste

    International Nuclear Information System (INIS)

    Serne, R.J.; Martin, W.J.; LeGore, V.L.; Lindenmeier, C.W.; McLaurine, S.B.; Martin, P.F.C.; Lokken, R.O.

    1989-10-01

    Pacific Northwest Laboratory conducted experiments to produce empirical leach rate data for phosphate-sulfate waste (PSW) grout. Effective diffusivities were measured for various radionuclides ( 90 Sr, 99 Tc, 14 C, 129 I, 137 Cs, 60 Co, 54 Mn, and U), stable major components (NO 3 - , SO 4 2- , H 3 BO 3 , K and Na) and the trace constituents Ag, As, Cd, Hg, Pb, and Se. Two types of leach tests were used on samples of actual PSW grout and synthetic PSW grout: the American Nuclear Society (ANS) 16.1 intermittent replacement leach test and a static leach test. Grout produced from both synthetic and real PSW showed low leach rates for the trace metal constituents and most of the waste radionuclides. Many of the spiked trace metals and radionuclides were not detected in any leachates. None of the effluents contained measurable quantities of 137 Cs, 60 Co, 54 Mn, 109 Cd, 51 Cr, 210 Pb, 203 Hg, or As. For those trace species with detectable leach rates, 125 I appeared to have the greatest leach rate, followed by 99 Tc, 75 Se, and finally U, 14 C, and 110m Ag. Leach rates for nitrate are between those for I and Tc, but there is much scatter in the nitrate data because of the very low nitrate inventory. 32 refs., 6 figs., 15 tabs

  9. Trace metal distribution and mobility in drill cuttings and produced waters from Marcellus Shale gas extraction: Uranium, arsenic, barium

    International Nuclear Information System (INIS)

    Phan, Thai T.; Capo, Rosemary C.; Stewart, Brian W.; Graney, Joseph R.; Johnson, Jason D.; Sharma, Shikha; Toro, Jaime

    2015-01-01

    Highlights: • Distributions of U, As, and Ba in Marcellus Shale were determined. • As is primarily associated with sulfide minerals, Ba with exchange sites. • Most U is in the silicate minerals, but up to 20% is partitioned into carbonate. • Low [U] and [As] in produced water are consistent with reducing downhole conditions. • Proper waste management should account for potential mobilization of U and As. - Abstract: Development of unconventional shale gas wells can generate significant quantities of drilling waste, including trace metal-rich black shale from the lateral portion of the drillhole. We carried out sequential extractions on 15 samples of dry-drilled cuttings and core material from the gas-producing Middle Devonian Marcellus Shale and surrounding units to identify the host phases and evaluate the mobility of selected trace elements during cuttings disposal. Maximum whole rock concentrations of uranium (U), arsenic (As), and barium (Ba) were 47, 90, and 3333 mg kg −1 , respectively. Sequential chemical extractions suggest that although silicate minerals are the primary host for U, as much as 20% can be present in carbonate minerals. Up to 74% of the Ba in shale was extracted from exchangeable sites in the shale, while As is primarily associated with organic matter and sulfide minerals that could be mobilized by oxidation. For comparison, U and As concentrations were also measured in 43 produced water samples returned from Marcellus Shale gas wells. Low U concentrations in produced water (<0.084–3.26 μg L −1 ) are consistent with low-oxygen conditions in the wellbore, in which U would be in its reduced, immobile form. Arsenic was below detection in all produced water samples, which is also consistent with reducing conditions in the wellbore minimizing oxidation of As-bearing sulfide minerals. Geochemical modeling to determine mobility under surface storage and disposal conditions indicates that oxidation and/or dissolution of U

  10. Quantification of trace metals in infant formula premixes using laser-induced breakdown spectroscopy

    Science.gov (United States)

    Cama-Moncunill, Raquel; Casado-Gavalda, Maria P.; Cama-Moncunill, Xavier; Markiewicz-Keszycka, Maria; Dixit, Yash; Cullen, Patrick J.; Sullivan, Carl

    2017-09-01

    Infant formula is a human milk substitute generally based upon fortified cow milk components. In order to mimic the composition of breast milk, trace elements such as copper, iron and zinc are usually added in a single operation using a premix. The correct addition of premixes must be verified to ensure that the target levels in infant formulae are achieved. In this study, a laser-induced breakdown spectroscopy (LIBS) system was assessed as a fast validation tool for trace element premixes. LIBS is a promising emission spectroscopic technique for elemental analysis, which offers real-time analyses, little to no sample preparation and ease of use. LIBS was employed for copper and iron determinations of premix samples ranging approximately from 0 to 120 mg/kg Cu/1640 mg/kg Fe. LIBS spectra are affected by several parameters, hindering subsequent quantitative analyses. This work aimed at testing three matrix-matched calibration approaches (simple-linear regression, multi-linear regression and partial least squares regression (PLS)) as means for precision and accuracy enhancement of LIBS quantitative analysis. All calibration models were first developed using a training set and then validated with an independent test set. PLS yielded the best results. For instance, the PLS model for copper provided a coefficient of determination (R2) of 0.995 and a root mean square error of prediction (RMSEP) of 14 mg/kg. Furthermore, LIBS was employed to penetrate through the samples by repetitively measuring the same spot. Consequently, LIBS spectra can be obtained as a function of sample layers. This information was used to explore whether measuring deeper into the sample could reduce possible surface-contaminant effects and provide better quantifications.

  11. Assessment of trace metals pollution in estuarine sediments using SEM-AVS and ERM-ERL predictions.

    Science.gov (United States)

    Garcia, Carlos Alexandre Borges; Passos, Elisangela de Andrade; Alves, José do Patrocínio Hora

    2011-10-01

    This paper presents the distributions of the investigation of trace metals geochemistry in surface sediments of the Sergipe river estuary, northeast Brazil. Analyses were carried out by Flame or electrothermal atomic absorption spectrometry (FAAS or ETAAS). Principal component analysis was applied to results to identify any groupings among the different sampling sites. In order to determine the extent of contamination, taking into account natural variability within the region, metal concentrations were normalized relative to aluminium. Cr, Cu, Ni and Zn contamination was observed in sediments from the area receiving highest inputs of domestic wastes, while cadmium contamination occurred in sediments from the region affected by highest inflows of industrial effluents. Possible toxicity related to these metals was examined using the relationship simultaneously extracted metals/acid volatile sulfide and by comparing sediment chemical data with sediment quality guidelines ERL-ERM values. Results obtained using the two methods were in agreement and indicated that adverse effects on aquatic biota should rarely occur.

  12. Post-depositional redistribution of trace metals in reservoir sediments of a mining/smelting-impacted watershed (the Lot River, SW France)

    International Nuclear Information System (INIS)

    Audry, Stephane; Grosbois, Cecile; Bril, Hubert; Schaefer, Joerg; Kierczak, Jakub; Blanc, Gerard

    2010-01-01

    Mining/smelting wastes and reservoir sediment cores from the Lot River watershed were studied using mineralogical (XRD, SEM-EDS, EMPA) and geochemical (redox dynamics, selective extractions) approaches to characterize the main carrier phases of trace metals. These two approaches permitted determining the role of post-depositional redistribution processes in sediments and their effects on the fate and mobility of trace metals. The mining/smelting wastes showed heterogeneous mineral compositions with highly variable contents of trace metals. The main trace metal-bearing phases include spinels affected by secondary processes, silicates and sulfates. The results indicate a clear change in the chemical partitioning of trace metals between the reservoir sediments upstream and downstream of the mining/smelting activities, with the downstream sediments showing a 2-fold to 5-fold greater contribution of the oxidizable fraction. This increase was ascribed to stronger post-depositional redistribution of trace metals related to intense early diagenetic processes, including dissolution of trace metal-bearing phases and precipitation of authigenic sulfide phases through organic matter (OM) mineralization. This redistribution is due to high inputs (derived from mining/smelting waste weathering) at the water-sediment interface of (i) dissolved SO 4 promoting more efficient OM mineralization, and (ii) highly reactive trace metal-bearing particles. As a result, the main trace metal-bearing phases in the downstream sediments are represented by Zn- and Fe-sulfides, with minor occurrence of detrital zincian spinels, sulfates and Fe-oxyhydroxides. Sequestration of trace metals in sulfides at depth in reservoir sediments does not represent long term sequestration owing to possible resuspension of anoxic sediments by natural (floods) and/or anthropogenic (dredging, dam flush) events that might promote trace metal mobilization through sulfide oxidation. It is estimated that, during a major

  13. Trophic transfer of trace metals from the polychaete worm Nereis diversicolor to the polychaete N. virens and the decapod crustacean Palaemonetes varians

    Science.gov (United States)

    Rainbow, P.S.; Poirier, L.; Smith, B.D.; Brix, K.V.; Luoma, S.N.

    2006-01-01

    Diet is an important exposure route for the uptake of trace metals by aquatic invertebrates, with trace metal trophic transfer depending on 2 stages - assimilation and subsequent accumulation by the predator. This study investigated the trophic transfer of trace metals from the sediment-dwelling polychaete worm Nereis diversicolor from metal-rich estuarine sediments in southwestern UK to 2 predators - another polychaete N. virens (Cu, Zn, Pb, Cd, Fe) and the decapod crustacean Palaemonetes varians (Cu, Zn, Pb, Cd, Fe, Ag, As, Mn). N. virens showed net accumulation of Cu, Zn, Pb and Cd from the prey; accumulation increased with increasing prey concentration, but a coefficient of trophic transfer decreased with increasing prey concentration, probably because a higher proportion of accumulated metal in the prey is bound in less trophically available (insoluble) detoxified forms. The trace metal accumulation patterns of P. varians apparently restricted significant net accumulation of metals from the diet of N. diversicolor to just Cd. There was significant mortality of the decapods fed on the diets of metal-rich worms. Metal-rich invertebrates that have accumulated metals from the rich historical store in the sediments of particular SW England estuaries can potentially pass these metals along food chains, with accumulation and total food chain transfer depending on the metal assimilation efficiencies and accumulation patterns of the animal at each trophic level. This trophic transfer may be significant enough to have ecotoxicological effects. ?? Inter-Research 2006.

  14. Biomonitoring of trace metal elements by lichens of the Western Pyrenees.Study of elemental and isotopic signature of mercury

    OpenAIRE

    Queipo Abad, Silvia

    2012-01-01

    The lichens, organisms originated by symbiotic relationship between an algae and a fungus, have shown good properties as biomonitors of pollution from Trace Metal Elements. They can be used as indicators of local and long-range atmospheric pollution. The assessment of deposition of atmospheric pollutants results difficult to know their long term impact. This happens specially when the study is focalized in remote areas. In this project it has been developed the elemental and isotopic analy...

  15. Trace metal concentration in Great Tit (Parus major) and Greenfinch (Carduelis sinica) at the Western Mountains of Beijing, China

    International Nuclear Information System (INIS)

    Deng Haili; Zhang Zhengwang; Chang Chongyan; Wang Yong

    2007-01-01

    We examined the concentrations of 11 trace metals in tissues from 10 body parts of Great Tits and Greenfinches collected at Badachu Park in the Western Mountains of Beijing, China to assess the metal accumulation level, distribution among body parts, and species and gender related variations. The highest concentrations of Hg, Ni, Zn, and Mn were found in the feather; Pb and Co in the bone; Cd, Cr, and Se in the kidney, and Cu in the liver and heart. Metal concentrations had substantial interspecific variation with Great Tits showing higher levels of Hg, Cr, Ni, and Mn than Greenfinches in tissues of most body parts. Gender related variations were body part and species specific. Meta-analyses using data from this study and other studies suggested that metal concentrations of Great Tits at our study site were relatively low and below the toxic levels. - Trace metal concentrations of Great Tits and Greenfinches from Beijing, China, varied by body part, gender, and species, and were below toxic levels

  16. Geochemistry, water dynamics and metals: Major, trace elements, Pb and Sr isotope constraints on their origins and movements in a small anthropized catchment over a flood

    International Nuclear Information System (INIS)

    Luck, J.M.; Othman, D.B.

    1997-01-01

    Major, trace elements and Sr-Pb isotope data on the dissolved and particulate phases are reported for water samples taken regularly over the September flood of a Mediterranean river (S France). This river drains runoff from a small, carbonate, karstified watershed with Miocene and Jurassic lithologies, and characterized by agricultural, urban and road network activities. The objective is to combine all the data into a dynamic model for constraining the origin(s) and movements of waters and of their loads. Furthermore, for metals, it becomes then feasible to know their fate and bioavailability downstream

  17. Bioavailability of metals-trace in sediments: a review; Biodisponibilidade de metais-traco em sedimentos: uma revisao

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues, Rafaela E. de A.V.; Souza, Vivianne Lucia Bormann; Lima, Vanessa Lemos de; Hazin, Clovis Abrahao, E-mail: rafaelarodriguesss@hotmail.com, E-mail: vlsouza@cnen.gov.br, E-mail: lemos.nessa@yahoo.com.br, E-mail: chazin@cnen.gov.br [Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, PE (Brazil)

    2014-07-01

    The chemical association of metals in sediments provides an indication of its release by physical, chemical and biological processes, with toxic effects under certain environmental conditions. Knowing about their chemical bonds in sediments, can recognize specific sources of pollution, and speciation of trace metals is important for bioavailability and toxicity to animals and plants. The accumulation of these particles in the sediment occur by the following mechanisms: a) adsorption to the finest particles; b) precipitating of the element in the form of compounds; c) co-precipitating of the element with iron and manganese oxides; d) complexation with organic matter; e) incorporation into the crystal lattice of minerals. Currently, five phases are considered when studying the bioavailability of trace elements in sediments: a) the exchangeable phase, MgCl{sub 2} (causes saltiness change); b) leachable phase, (acetic acid causes pH change); c) reducible phase (hydroxylamine hydrochloride causes release of the bound metals linked to Fe and Mn oxides); d) oxidized phase, the peroxide hydrogen (cause the degradation of organic matter); e) the residual pseudo-phase, the aqua regia (cause release of metals associated to minerals). The first three phases are considered the most bioavailable. In the last two fractions, the metals are linked to sediment constituents and not bioavailable. The organic phase is relatively stable and the metal present therein are removed under oxidative conditions. Metals present in the pseudo-phase residual measure the degree of environmental pollution, since great amount of metals at this stage indicates a lower degree of pollution.

  18. Potential of kenaf (Hibiscus cannabinus L.) and corn (Zea mays L.) for phytoremediation of dredging sludge contaminated by trace metals.

    Science.gov (United States)

    Arbaoui, Sarra; Evlard, Aricia; Mhamdi, Mohamed El Wafi; Campanella, Bruno; Paul, Roger; Bettaieb, Taoufik

    2013-07-01

    The potential of kenaf (Hibiscus cannabinus L.) and corn (Zea mays L.) for accumulation of cadmium and zinc was investigated. Plants have been grown in lysimetres containing dredging sludge, a substratum naturally rich in trace metals. Biomass production was determined. Sludge and water percolating from lysimeters were analyzed by atomic absorption spectrometry. No visible symptoms of toxicity were observed during the three- month culture. Kenaf and corn tolerate trace metals content in sludge. Results showed that Zn and Cd were found in corn and kenaf shoots at different levels, 2.49 mg/kg of Cd and 82.5 mg/kg of Zn in kenaf shoots and 2.1 mg/kg of Cd and 10.19 mg/kg in corn shoots. Quantities of extracted trace metals showed that decontamination of Zn and Cd polluted substrates is possible by corn and kenaf crops. Tolerance and bioaccumulation factors indicated that both species could be used in phytoremediation.

  19. Heavy metal and trace elements in riparian vegetation and macrophytes associated with lacustrine systems in Northern Patagonia Andean Range.

    Science.gov (United States)

    Juárez, Andrea; Arribére, María A; Arcagni, Marina; Williams, Natalia; Rizzo, Andrea; Ribeiro Guevara, Sergio

    2016-09-01

    Vegetation associated with lacustrine systems in Northern Patagonia was studied for heavy metal and trace element contents, regarding their elemental contribution to these aquatic ecosystems. The research focused on native species and exotic vascular plant Salix spp. potential for absorbing heavy metals and trace elements. The native species studied were riparian Amomyrtus luma, Austrocedrus chilensis, Chusquea culeou, Desfontainia fulgens, Escallonia rubra, Gaultheria mucronata, Lomatia hirsuta, Luma apiculata, Maytenus boaria, Myrceugenia exsucca, Nothofagus antarctica, Nothofagus dombeyi, Schinus patagonicus, and Weinmannia trichosperma, and macrophytes Hydrocotyle chamaemorus, Isöetes chubutiana, Galium sp., Myriophyllum quitense, Nitella sp. (algae), Potamogeton linguatus, Ranunculus sp., and Schoenoplectus californicus. Fresh leaves were analyzed as well as leaves decomposing within the aquatic bodies, collected from lakes Futalaufquen and Rivadavia (Los Alerces National Park), and lakes Moreno and Nahuel Huapi (Nahuel Huapi National Park). The elements studied were heavy metals Ag, As, Cd, Hg, and U, major elements Ca, K, and Fe, and trace elements Ba, Br, Co, Cr, Cs, Hf, Na, Rb, Se, Sr, and Zn. Geochemical tracers La and Sm were also determined to evaluate contamination of the biological tissues by geological particulate (sediment, soil, dust) and to implement concentration corrections.

  20. Health Risk Assessment for Trace Metals, Polycyclic Aromatic Hydrocarbons and Trihalomethanes in Drinking Water of Cankiri, Turkey

    Directory of Open Access Journals (Sweden)

    Emrah Caylak

    2012-01-01

    Full Text Available Lifetime exposure to trace metals, pesticides, polycyclic aromatic hydrocarbons (PAHs, trihalomethanes (THMs, and the other chemicals in drinking water through ingestion, and dermal contact may pose risks to human health. In this study, drinking water samples were collected from 50 sampling sites from Cankiri and its towns during 2010. The concentrations of all pollutants were analyzed, and then compared with permissible limits set by Turkish and WHO. For health risk assessment of trace metals, chronic daily intakes (CDIs via ingestion and dermal contact, hazard quotient (HQ, and hazard index (HI were calculated by using statistical formulas. For ingestion pathway, the maximum HQ values of As-non cancer in central Cankiri and Kursunlu town were higher than one. Considering dermal adsorption pathway, the mean and maximum HQ values were below one. HI values of As-non cancer in central Cankiri and Kursunlu town were also higher than one. Each trace metal (As-non cancer, B, Cd, Cr, Pb, and Sb of the mean HI values were slightly below unity. Risks of As, PAHs, THMs, and benzene on human health were then evaluated using carcinogenic risk (CR. It is indicated that CRs of As and THMs were also found >10−5 in drinking water of Cankiri might exert potential carcinogenic risk for people. These assessments would point out required drinking water treatment strategy to ensure safety of consumers.

  1. Impact of Phosphate, Potassium, Yeast Extract, and Trace Metals on Chitosan and Metabolite Production by Mucor indicus.

    Science.gov (United States)

    Safaei, Zahra; Karimi, Keikhosro; Zamani, Akram

    2016-08-30

    In this study the effects of phosphate, potassium, yeast extract, and trace metals on the growth of Mucor indicus and chitosan, chitin, and metabolite production by the fungus were investigated. Maximum yield of chitosan (0.32 g/g cell wall) was obtained in a phosphate-free medium. Reversely, cell growth and ethanol formation by the fungus were positively affected in the presence of phosphate. In a phosphate-free medium, the highest chitosan content (0.42 g/g cell wall) and cell growth (0.66 g/g sugar) were obtained at 2.5 g/L of KOH. Potassium concentration had no significant effect on ethanol and glycerol yields. The presence of trace metals significantly increased the chitosan yield at an optimal phosphate and potassium concentration (0.50 g/g cell wall). By contrast, production of ethanol by the fungus was negatively affected (0.33 g/g sugars). A remarkable increase in chitin and decrease in chitosan were observed in the absence of yeast extract and concentrations lower than 2 g/L. The maximum chitosan yield of 51% cell wall was obtained at 5 g/L of yeast extract when the medium contained no phosphate, 2.5 g/L KOH, and 1 mL/L trace metal solution.

  2. Microparticles and human health: particulate materials, trace metals elements and black carbon in aerosols collected at Andravoahangy-Antananarivo, Madagascar

    International Nuclear Information System (INIS)

    Rasoazanany, E. O.; Andriamahenina, N. N.; Harinoely, M.; Ravoson, H. N.; Randriamanivo, L. V.; Raoelina Andriambololona; Ramaherison, H.

    2013-01-01

    The present work is to determine the concentrations of microparticles having diameter inferior to 10 μm (PM 10 ), the metal trace elements and the black carbon in the aerosols sampled in Andravoahangy-Antananarivo, Madagascar in 2008. The air sampler GENT is used to collect aerosol samples. The total reflection X-ray fluorescence spectrometer is used for qualitative and quantitative analysis of simultaneous way all metallic trace elements contained in the aerosols. The M43D reflectometer permits to measure the reflectances in order to determine the black carbon concentrations. The results show that the average concentrations of the particulate matters PM 2,5-10 are higher than those of PM 2,5 . The average concentrations of PM 10 in the aerosols are exceeding the World Health Organisation (WHO) and European Union guidelines, set at 50 μg.m -3 and those of PM 2,5 are higher than the 2005 WHO (25 μg.m-3) and the United States Environment Protection Agency (35 μg.m -3 ) guidelines. Consequently, air quality in Andravoahangy does not respect these daily guidelines. The identified metallic trace elements in the aerosols are Ti, Cr, Mn, Fe, Ni, Cu, Zn and Pb. The average concentrations of these elements are also higher in the coarse particles than in the fine particles. The concentrations of black carbon are higher in the fine particles. The maximum value is 9.12 μg.m -3 . [fr

  3. MIRAGE: Model description and evaluation of aerosols and trace gases

    Science.gov (United States)

    Easter, Richard C.; Ghan, Steven J.; Zhang, Yang; Saylor, Rick D.; Chapman, Elaine G.; Laulainen, Nels S.; Abdul-Razzak, Hayder; Leung, L. Ruby; Bian, Xindi; Zaveri, Rahul A.

    2004-10-01

    The Model for Integrated Research on Atmospheric Global Exchanges (MIRAGE) modeling system, designed to study the impacts of anthropogenic aerosols on the global environment, is described. MIRAGE consists of a chemical transport model coupled online with a global climate model. The chemical transport model simulates trace gases, aerosol number, and aerosol chemical component mass (sulfate, methane sulfonic acid (MSA), organic matter, black carbon (BC), sea salt, and mineral dust) for four aerosol modes (Aitken, accumulation, coarse sea salt, and coarse mineral dust) using the modal aerosol dynamics approach. Cloud-phase and interstitial aerosol are predicted separately. The climate model, based on Community Climate Model, Version 2 (CCM2), has physically based treatments of aerosol direct and indirect forcing. Stratiform cloud water and droplet number are simulated using a bulk microphysics parameterization that includes aerosol activation. Aerosol and trace gas species simulated by MIRAGE are presented and evaluated using surface and aircraft measurements. Surface-level SO2 in North American and European source regions is higher than observed. SO2 above the boundary layer is in better agreement with observations, and surface-level SO2 at marine locations is somewhat lower than observed. Comparison with other models suggests insufficient SO2 dry deposition; increasing the deposition velocity improves simulated SO2. Surface-level sulfate in North American and European source regions is in good agreement with observations, although the seasonal cycle in Europe is stronger than observed. Surface-level sulfate at high-latitude and marine locations, and sulfate above the boundary layer, are higher than observed. This is attributed primarily to insufficient wet removal; increasing the wet removal improves simulated sulfate at remote locations and aloft. Because of the high sulfate bias, radiative forcing estimates for anthropogenic sulfur given in 2001 by S. J. Ghan and

  4. Assessment of trace metal air pollution in Paris using slurry-TXRF analysis on cemetery mosses.

    Science.gov (United States)

    Natali, Marco; Zanella, Augusto; Rankovic, Aleksandar; Banas, Damien; Cantaluppi, Chiara; Abbadie, Luc; Lata, Jean -Christophe

    2016-12-01

    Mosses are useful, ubiquitous accumulation biomonitors and as such can be used for biomonitoring surveys. However, the biomonitoring of atmospheric pollution can be compromised in urban contexts if the targeted biomonitors are regularly disturbed, irregularly distributed, or are difficult to access. Here, we test the hypothesis that cemeteries are appropriate moss sampling sites for the evaluation of air pollution in urban areas. We sampled mosses growing on gravestones in 21 urban and peri-urban cemeteries in the Paris metropolitan area. We focused on Grimmia pulvinata (Hedwig) Smith, a species abundantly found in all studied cemeteries and very common in Europe. The concentration of Al, As, Br, Ca, Ce, Cl, Cr, Cu, Fe, K, Mn, Ni, V, P, Pb, Rb, S, Sr, Ti, and Zn was determined by a total reflection X-ray fluorescence technique coupled with a slurry sampling method (slurry-TXRF). This method avoids a digestion step, reduces the risk of sample contamination, and works even at low sample quantities. Elemental markers of road traffic indicated that the highest polluted cemeteries were located near the highly frequented Parisian ring road and under the influence of prevailing winds. The sites with the lowest pollution were found not only in the peri-urban cemeteries, adjoining forest or farming landscapes, but also in the large and relatively wooded cemeteries located in the center of Paris. Our results suggest that (1) slurry-TXRF might be successfully used with moss material, (2) G. pulvinata might be a good biomonitor of trace metals air pollution in urban context, and (3) cemetery moss sampling could be a useful complement for monitoring urban areas. Graphical abstract We tested the hypothesis that cemeteries are appropriate moss sampling sites for the evaluation of air pollution in urban areas. We sampled 110 moss cushions (Grimmia pulvinata) growing on gravestones in 21 urban and peri-urban cemeteries in the Paris metropolitan area. The concentration of 20

  5. Bioaccessible trace metals in lip cosmetics and their health risks to female consumers.

    Science.gov (United States)

    Gao, Peng; Lei, Tingting; Jia, Liming; Yury, Badmatsybenov; Zhang, Zhaohan; Du, Yingqiu; Feng, Yujie; Xing, Baoshan

    2018-07-01

    Females can be exposed to toxic elements in lip cosmetics following ingestion. The bioaccessibility of Cr, Mn, Co, Ni, Cu, Cd, Sb and Pb in lip cosmetics (n = 32) were assessed via the dilute HCl extraction method, In Vitro Gastrointestinal protocol (IVG) and the United States Pharmacopeia Methodology (USPM), and then health risks were characterized. The total concentrations of trace metals (TMs) in lip cosmetics were in the range of 15.55-111.97 mg/kg (Mean: 60.99 mg/kg). Cu, Pb and Cr were the three major TMs and accounting for >75% of the total concentrations. Except Sb and Pb in 4/32 and 4/32 samples were higher than the US FDA (Food and Drug Administration of the United States) limits, the other TMs were lower than that limits. Only bioaccessible Pb in all samples significantly exceeded the FDA limit 0.1 mg/kg in candy. Using IVG or USPM might be preferable for evaluating the TMs exposure over HCl since they better represent gastrointestinal physiology. The estimated average daily intake (ADI) of bioaccessible ∑TMs through lip cosmetics ingestion of career women and female college students were under safety level. The long-term exposure of bioaccessible TMs by lip cosmetics using would inevitably cause non-carcinogenic health risk. This is the first report on the in vitro tests used for evaluating bioaccessible TMs in lip cosmetics. Copyright © 2018. Published by Elsevier Ltd.

  6. Seasonal effect on trace metal elements behaviour in a reservoir of northern Thailand.

    Science.gov (United States)

    Grellier, S; Janeau, J L; Thothong, W; Boonsaner, A; Bonnet, M P; Lagane, C; Seyler, P

    2013-07-01

    Trace metal elements (TME) can be real threats for living organisms. However, few studies dealt with TME in reservoirs in rural areas where farming practises could induce negative effects. Mae Thang reservoir (northern Thailand) has been studied for 3 years to understand the seasonal behaviour of dissolved TME: Fe, Mn, Cd, Al, Pb, V, Cr, Co, Ni, Cu, Zn, Mo, U and As and associated physicochemical parameters. In situ measurements of these parameters were done during the dry and the wet seasons as well as water samples along the water column for further analyses and TME determination by inductively coupled plasma-mass spectrometry (ICP-MS). In the dry season, the water column was characterized by a strong stratification and anoxic conditions in the hypolimnion. High rain and water input from the watershed during the wet season induced mixing of the water. All TME, except Ni, Co and Cr were less concentrated in the wet season indicating a dilution effect by water input. There was thus no important dissolved pollution coming from the watershed. The anoxic conditions in the dry season enhanced the reduction of Fe and Mn and the desorption processes. Depth, and thus oxic-anoxic conditions were the main drivers of TME in the dry season, while in the wet season, dissolution processes from parent rocks of watershed were favoured. The average concentrations of TME in the reservoir were in the limit of the international and Thai standards. Only localized values in the bottom of the reservoir for Fe and Mn were higher than the limits.

  7. Urbanization, Trace Metal Pollution, and Malaria Prevalence in the House Sparrow

    Science.gov (United States)

    Bichet, Coraline; Scheifler, Renaud; Cœurdassier, Michaël; Julliard, Romain; Sorci, Gabriele; Loiseau, Claire

    2013-01-01

    Anthropogenic pollution poses a threat for the environment and wildlife. Trace metals (TMs) are known to have negative effects on haematological status, oxidative balance, and reproductive success in birds. These pollutants particularly increase in concentration in industrialized, urbanized and intensive agricultural areas. Pollutants can also interfere with the normal functioning of the immune system and, as such, alter the dynamics of host-parasite interactions. Nevertheless, the impact of pollution on infectious diseases has been largely neglected in natural populations of vertebrates. Here, we used a large spatial scale monitoring of 16 house sparrow (Passer domesticus) populations to identify environmental variables likely to explain variation in TMs (lead, cadmium, zinc) concentrations in the feathers. In five of these populations, we also studied the potential link between TMs, prevalence of infection with one species of avian malaria, Plasmodium relictum, and body condition. Our results show that lead concentration is associated with heavily urbanized habitats and that areas with large woodland coverage have higher cadmium and zinc feather concentrations. Our results suggest that lead concentration in the feathers positively correlates with P. relictum prevalence, and that a complex relationship links TM concentrations, infection status, and body condition. This is one of the first studies showing that environmental pollutants are associated with prevalence of an infectious disease in wildlife. The mechanisms underlying this effect are still unknown even though it is tempting to suggest that lead could interfere with the normal functioning of the immune system, as shown in other species. We suggest that more effort should be devoted to elucidate the link between pollution and the dynamics of infectious diseases. PMID:23342022

  8. Kinetics of trace metal removal from tidal water by mangrove sediments under different redox conditions

    International Nuclear Information System (INIS)

    Suzuki, K.N.; Machado, E.C.; Machado, W.; Bellido, A.V.B.; Bellido, L.F.; Osso, J.A.; Lopes, R.T.

    2014-01-01

    The extent in which redox conditions can affect the removal kinetics of 58 Co and 65 Zn from tidal water by mangrove sediments was evaluated in microcosm experiments, simulating a tidal flooding period of 6 h. The average half-removal time (t 1/2 ) of 58 Co from overlaying water was slightly higher (7.3 h) under an N 2 -purged water column than under an aerated water column (5.4 h). A lower difference was found for 65 Zn (1.9 h vs. 1.5 h, respectively). Average removals of 58 Co activities from water were 54.6% (N 2 treatment) and 43.5% (aeration treatment), whereas these values were 88.0% and 92.7% for 65 Zn, respectively. Very contrasting sorption kinetics of different radiotracers occurred, while more oxidising conditions favoured only a slightly higher removal. Average 58 Co and 65 Zn inventories within sediments were 30.4% and 18.8% higher in the aeration treatment, respectively. A stronger particle-reactive behaviour was found for 65 Zn that was less redox-sensitive and more efficiently removed by sediments than 58 Co. - Highlights: ► Radiotracer experiments evidenced the role of mangrove sediments in trapping trace metals. ► Very contrasting removal kinetics from tidal water were observed for 65 Zn and 58 Co. ► Nearly 40%–50% of 58 Co activities and nearly 90% of 65 Zn activities in overlying water were removed. ► 65 Zn showed a stronger particle-reactive behaviour than observed for 58 Co. ► 58 Co was more sensitive to redox conditions in tidal water than observed for 65 Zn

  9. Metal-Organic Frameworks for Resonant-Gravimetric Detection of Trace-Level Xylene Molecules.

    Science.gov (United States)

    Xu, Tao; Xu, Pengcheng; Zheng, Dan; Yu, Haitao; Li, Xinxin

    2016-12-20

    As one of typical VOCs, xylene is seriously harmful to human health. Nowadays, however, there is really lack of portable sensing method to directly detect environmental xylene that has chemical inertness. Especially when the concentration of xylene is lower than the human olfactory threshold of 470 ppb, people are indeed hard to be aware of and avoid this harmful vapor. Herein the metal-organic framework (MOF) of HKUST-1 is first explored for sensing to the nonpolar molecule of p-xylene. And the sensing mechanism is identified that is via host-guest interaction of MOF with xylene molecule. By loading MOFs on mass-gravimetric resonant-cantilevers, sensing experiments for four MOFs of MOF-5, HKUST-1, ZIF-8, and MOF-177 approve that HKUST-1 has the highest sensitivity to p-xylene. The resonant-gravimetric sensing experiments with our HKUST-1 based sensors have demonstrated that trace-level p-xylene of 400 ppb can be detected that is lower than the human olfactory threshold of 470 ppb. We analyze that the specificity of HKUST-1 to xylene comes from Cu 2+ -induced moderate Lewis acidity and the "like dissolves like" interaction of the benzene ring. In situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) is used to elucidate the adsorbing/sensing mechanism of HKUST-1 to p-xylene, where p-xylene adsorbing induced blue-shift phenomenon is observed that confirms the sensing mechanism. Our study also indicates that the sensor shows good selectivity to various kinds of common interfering gases. And the long-term repeatability and stability of the sensing material are also approved for the usage/storage period of two months. This research approves that the MOF materials exhibit potential usages for high performance chemical sensors applications.

  10. Trace Metals and Metalloids in Forest Soils and Exotic Earthworms in Northern New England, USA

    Science.gov (United States)

    Richardson, J.B.; Görres, J.H.; Jackson, B.P.; Friedland, A.J.

    2015-01-01

    Trace metals and metalloids (TMM) in forest soils and invasive earthworms were studied at 9 uncontaminated sites in northern New England, USA. Essential (Cu, Mo, Ni, Zn, Se) and toxic (As, Cd, Pb, Hg and U) TMM concentrations (mg kg-1) and pools (mg m-2) were quantified for organic horizons (forest floor), mineral soils and earthworm tissues. Essential TMM tissue concentrations were greatest for mineral soil-feeding earthworm Octolasion cyaneum. Toxic TMM tissue concentrations were highest for organic horizon-feeding earthworms Dendobaena octaedra, Aporrectodea rosea and Amynthas agrestis. Most earthworm species had attained tissue concentrations of Pb, Hg and Se potentially hazardous to predators. Bioaccumulation factors were Cd > Se > Hg > Zn > Pb > U > 1.0 > Cu > As > Mo > Ni. Only Cd, Se Hg and Zn were considered strongly bioaccumulated by earthworms because their average bioaccumulation factors were significantly greater than 1.0. Differences in bioaccumulation did not appear to be caused by soil concentrations as earthworm TMM tissue concentrations were poorly correlated with TMM soil concentrations. Instead, TMM bioaccumulation appears to be species and site dependent. The invasive Amynthas agrestis had the greatest tissue TMM pools, due to its large body mass and high abundance at our stands. We observed that TMM tissue pools in earthworms were comparable or exceeded organic horizon TMM pools; earthworm tissue pools of Cd were up 12 times greater than in the organic horizon. Thus, exotic earthworms may represent an unaccounted portion and flux of TMM in forests of the northeastern US. Our results highlight the importance of earthworms in TMM cycling in northern forests and warrant more research into their impact across the region. PMID:25883392

  11. Geochemical and hydrodynamic controls on arsenic and trace metal cycling in a seasonally stratified US sub-tropical reservoir

    International Nuclear Information System (INIS)

    Brandenberger, J.; Louchouarn, P.; Herbert, B.; Tissot, P.

    2004-01-01

    The phase distribution of trace metals and oxyanions, including U and As, in 2 surface water bodies was investigated within a South Texas watershed hosting a high density of surface U mine pits and tailings. The objectives of the study were to evaluate the environmental legacy of U mining, with particular emphasis on the spatial and temporal variability of water quality in Lake Corpus Christi, a downstream reservoir that serves as the major water resource to a population of ∼350,000 people in the region. Lyssy Pond, a livestock pond bordered by U mine tailings, was used as a model case-study site to evaluate the cycling of U mine-derived oxyanions under changing redox conditions. Although the pond showed seasonal thermal and chemical stratification, geochemical cycling of metals was limited to Co and Pb, which was correlated with redox cycling of Mn mineral phases, and U, which suggested reductive precipitation in the pond's hypolimnion. Uranium levels, however, were too low to support strong inputs from the tailings into the water column of the pond. The strong relationships observed between particulate Cr, Cs, V, and Fe suggest that these metals are associated with a stable particulate phase (probably allochthonous alumino-silicates) enriched in unreactive Fe. This observation is supported by a parallel relationship in sediments collected across a broad range of sediment depositional processes (and histories) in the basin. Arsenic, though selectively enriched in the pond's water column, was dominated by dissolved species throughout the depth of the profile and showed no sign of geochemical cycling or interaction with Fe-rich particles. Arsenic (and other oxyanions) in the water columns of Lake Corpus Christi and Lyssy pond were not affected by the abundant presence of Fe-rich particles but instead behaved conservatively. No evidence was found of anthropogenic impacts of U mines beyond the purely local scale. Arsenic's presence within the Nueces drainage basin

  12. Impact of long-term organic residue recycling in agriculture on soil solution composition and trace metal leaching in soils.

    Science.gov (United States)

    Cambier, Philippe; Pot, Valérie; Mercier, Vincent; Michaud, Aurélia; Benoit, Pierre; Revallier, Agathe; Houot, Sabine

    2014-11-15

    Recycling composted organic residues in agriculture can reduce the need of mineral fertilizers and improve the physicochemical and biological properties of cultivated soils. However, some trace elements may accumulate in soils following repeated applications and impact other compartments of the agrosystems. This study aims at evaluating the long-term impact of such practices on the composition of soil leaching water, especially on trace metal concentrations. The field experiment QualiAgro started in 1998 on typical loess Luvisol of the Paris Basin, with a maize-wheat crop succession and five modalities: spreading of three different urban waste composts, farmyard manure (FYM), and no organic amendment (CTR). Inputs of trace metals have been close to regulatory limits, but supplies of organic matter and nitrogen overpassed common practices. Soil solutions were collected from wick lysimeters at 45 and 100 cm in one plot for each modality, during two drainage periods after the last spreading. Despite wide temporal variations, a significant effect of treatments on major solutes appears at 45 cm: DOC, Ca, K, Mg, Na, nitrate, sulphate and chloride concentrations were higher in most amended plots compared to CTR. Cu concentrations were also significantly higher in leachates of amended plots compared to CTR, whereas no clear effect emerged for Zn. The influence of amendments on solute concentrations appeared weaker at 1 m than at 45 cm, but still significant and positive for major anions and DOC. Average concentrations of Cu and Zn at 1m depth lied in the ranges [2.5; 3.8] and [2.5; 10.5 μg/L], respectively, with values slightly higher for plots amended with sewage sludge compost or FYM than for CTR. However, leaching of both metals was less than 1% of their respective inputs through organic amendments. For Cd, most values were <0.05 μg/L. So, metals added through spreading of compost or manure during 14 years may have increased metal concentrations in leachates of

  13. Radioactive metals disposal and recycling impact modelling

    International Nuclear Information System (INIS)

    Kemp, N.W.; Lunn, R.J.; Belton, V.; Kockar, I.

    2014-01-01

    Screening life cycle assessment models developed to investigate hypothetical disposal and recycling options for the Windscale Advanced Gas-cooled Reactor heat exchangers were used to generate more complex models addressing the main UK radioactive metals inventory. Both studies show there are significant environmental advantages in the metals recycling promoted by the current low level waste disposal policies, strategies and plans. Financial benefits from current metals treatment options are supported and offer even greater benefits when applied to the UK radioactive metals inventory as a whole. (authors)

  14. Historical economic and environmental policies influencing trace metal inputs in Montevideo Bay, Río de la Plata

    International Nuclear Information System (INIS)

    Bueno, C.; Brugnoli, E.; Figueira, R.C.L.; Muniz, P.; Ferreira, P.A.L.

    2016-01-01

    Montevideo Bay is located in the middle zone of the Rio de la Plata, and since the foundation of the city, several key economic and environmental policies affected the industry, and thus, metal inputs into this ecosystem. The aim of this study is to evaluate the sedimentary geochemical record of Montevideo Bay, in order to determine the historical inputs of anthropogenic metals to the system. In addition, environmental and economic policies of the country were taken into account to infer the relationship between them and the historic metal input. Concentrations of aluminum, chromium, copper, lead, scandium and zinc were analyzed and the EF and SPI indices were calculated. The analysis showed that since Montevideo foundation, metal concentrations increased in accordance with industry development, and the indices as well as the metal concentration represent a reliable footprint of the history of different economic and environmental policies influencing historical industrial activities. - Highlights: • Trace metal record of a sediment core of Montevideo Bay/harbor was studied. • The historic inputs of metals in the area were inferred. • System degradation evolved from anthropogenic impacts. • A relationship between pollution and environmental/economic policies was discussed.

  15. How healthy is urban horticulture in high traffic areas? Trace metal concentrations in vegetable crops from plantings within inner city neighbourhoods in Berlin, Germany.

    Science.gov (United States)

    Säumel, Ina; Kotsyuk, Iryna; Hölscher, Marie; Lenkereit, Claudia; Weber, Frauke; Kowarik, Ingo

    2012-06-01

    Food production by urban dwellers is of growing importance in developing and developed countries. Urban horticulture is associated with health risks as crops in urban settings are generally exposed to higher levels of pollutants than those in rural areas. We determined the concentration of trace metals in the biomass of different horticultural crops grown in the inner city of Berlin, Germany, and analysed how the local setting shaped the concentration patterns. We revealed significant differences in trace metal concentrations depending on local traffic, crop species, planting style and building structures, but not on vegetable type. Higher overall traffic burden increased trace metal content in the biomass. The presence of buildings and large masses of vegetation as barriers between crops and roads reduced trace metal content in the biomass. Based on this we discuss consequences for urban horticulture, risk assessment, and planting and monitoring guidelines for cultivation and consumption of crops. Copyright © 2012 Elsevier Ltd. All rights reserved.

  16. Radionuclides, Trace Metals, and Organic Compounds in Shells of Native Freshwater Mussels Along the Hanford Reach of the Columbia River: 6000 Years Before Present to Current Times

    Energy Technology Data Exchange (ETDEWEB)

    B. L. Tiller; T. E. Marceau

    2006-01-25

    This report documents concentrations of radionuclides, trace metals, and semivolatile organic compounds measured in shell samples of the western pearl shell mussel collected along the Hanford Reach of the Columbia River.

  17. Data on Occurrence of Selected Trace Metals, Organochlorines, and Semivolatile Organic Compounds in Edible Fish Tissues From Lake Worth, Fort Worth, Texas 1999

    National Research Council Canada - National Science Library

    Moring, J. B

    2002-01-01

    .... Air Force and in collaboration with the Texas Department of Health, collected samples of edible fish tissues from Lake Worth for analysis of selected trace metals, organochlorines, and semivolatile...

  18. Accumulation and partitioning of seven trace metals in mangroves and sediment cores from three estuarine wetlands of Hainan Island, China

    International Nuclear Information System (INIS)

    Qiu Yaowen; Yu Kefu; Zhang Gan; Wang Wenxiong

    2011-01-01

    Trace metals in mangrove tissues (leaf, branch, root and fruit) of nine species and sediments of ten cores collected in 2008 from Dongzhai Harbor, Sanya Bay and Yalong Bay, Hainan Island, were analyzed. The average concentrations of Cu, Pb, Zn, Cd, Cr, Hg and As in surface sediments were 14.8, 24.1, 57.9, 0.17, 29.6, 0.08 and 9.7 μg g -1 , whereas those in mangrove tissues were 2.8, 1.4, 8.7, 0.03, 1.1, 0.03, and 0.2 μg g -1 , respectively. Compared to those from other typical mangrove wetlands of the world, the metal levels in Hainan were at low- to median-levels, which is consistent with the fact that Hainan Island is still in low exploitation and its mangroves suffer little impact from human activities. Metal concentrations among different tissues of mangroves were different. In general, Zn and Cu were enriched in fruit, Hg was enriched in leaf, Pb, Cd and Cr were enriched in branch, and As was enriched in root. The cycle of trace metals in mangrove species were estimated. The biota-sediment accumulation factors (BSAFs) followed the sequence of Hg (0.43) > Cu (0.27) > Cd (0.22) > Zn (0.17) > Pb (0.07) > Cr (0.06) > As (0.02).

  19. Accumulation and partitioning of seven trace metals in mangroves and sediment cores from three estuarine wetlands of Hainan Island, China

    Energy Technology Data Exchange (ETDEWEB)

    Qiu Yaowen, E-mail: yqiu@scsio.ac.cn [State Key Laboratory of Tropic Marine Environment, South China Sea Institute of Oceanology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou 510301 (China); Yu Kefu [State Key Laboratory of Tropic Marine Environment, South China Sea Institute of Oceanology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou 510301 (China); Zhang Gan [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Wang Wenxiong [Section of Marine Ecology and Biotechnology, Division of Life Science, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong (Hong Kong)

    2011-06-15

    Trace metals in mangrove tissues (leaf, branch, root and fruit) of nine species and sediments of ten cores collected in 2008 from Dongzhai Harbor, Sanya Bay and Yalong Bay, Hainan Island, were analyzed. The average concentrations of Cu, Pb, Zn, Cd, Cr, Hg and As in surface sediments were 14.8, 24.1, 57.9, 0.17, 29.6, 0.08 and 9.7 {mu}g g{sup -1}, whereas those in mangrove tissues were 2.8, 1.4, 8.7, 0.03, 1.1, 0.03, and 0.2 {mu}g g{sup -1}, respectively. Compared to those from other typical mangrove wetlands of the world, the metal levels in Hainan were at low- to median-levels, which is consistent with the fact that Hainan Island is still in low exploitation and its mangroves suffer little impact from human activities. Metal concentrations among different tissues of mangroves were different. In general, Zn and Cu were enriched in fruit, Hg was enriched in leaf, Pb, Cd and Cr were enriched in branch, and As was enriched in root. The cycle of trace metals in mangrove species were estimated. The biota-sediment accumulation factors (BSAFs) followed the sequence of Hg (0.43) > Cu (0.27) > Cd (0.22) > Zn (0.17) > Pb (0.07) > Cr (0.06) > As (0.02).

  20. Trace metal depositional patterns from an open pit mining activity as revealed by archived avian gizzard contents.

    Science.gov (United States)

    Bendell, L I

    2011-02-15

    Archived samples of blue grouse (Dendragapus obscurus) gizzard contents, inclusive of grit, collected yearly between 1959 and 1970 were analyzed for cadmium, lead, zinc, and copper content. Approximately halfway through the 12-year sampling period, an open-pit copper mine began activities, then ceased operations 2 years later. Thus the archived samples provided a unique opportunity to determine if avian gizzard contents, inclusive of grit, could reveal patterns in the anthropogenic deposition of trace metals associated with mining activities. Gizzard concentrations of cadmium and copper strongly coincided with the onset of opening and the closing of the pit mining activity. Gizzard zinc and lead demonstrated significant among year variation; however, maximum concentrations did not correlate to mining activity. The archived gizzard contents did provide a useful tool for documenting trends in metal depositional patterns related to an anthropogenic activity. Further, blue grouse ingesting grit particles during the time of active mining activity would have been exposed to toxicologically significant levels of cadmium. Gizzard lead concentrations were also of toxicological significance but not related to mining activity. This type of "pulse" toxic metal exposure as a consequence of open-pit mining activity would not necessarily have been revealed through a "snap-shot" of soil, plant or avian tissue trace metal analysis post-mining activity. Copyright © 2010 Elsevier B.V. All rights reserved.

  1. Tape seagrass (Enhalus acoroides) as a bioindicator of trace metal contamination in Merambong shoal, Johor Strait, Malaysia.

    Science.gov (United States)

    Sidi, Nordiani; Aris, Ahmad Zaharin; Mohamat Yusuff, Ferdaus; Looi, Ley Juen; Mokhtar, Nor Farhanna

    2018-01-01

    Revealing the potential of seagrass as a bioindicator for metal pollution is important for assessing marine ecosystem health. Trace metal ( 111 Cd, 63 Cu, 60 Ni, 208 Pb, 66 Zn) concentrations in the various parts (root, rhizome, and blade) of tape seagrass (Enhalus acoroides) collected from Merambong shoal of Sungai Pulai estuary, Johor Strait, Malaysia were acid-extracted using a microwave digester and analysed via inductively coupled plasma-mass spectrometry (ICP-MS). The ranges of trace metal concentrations (in μgg -1 dry weight) were as follows: Cd (0.05-0.81), Cu (1.62-27.85), Ni (1.89-9.35), Pb (0.69-4.16), and Zn (3.44-35.98). The translocation factor revealed that E. acoroides is a hyperaccumulator plant, as its blades can accumulate high concentrations of Cd, Cu, Ni, and Zn, but not Pb. The plant limits Pb mobility to minimize Pb's toxic impact. Thus, E. acoroides is a potential bioindicator of metal pollution by Cd, Cu, Ni, and Zn in estuarine environments. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Trace metal depositional patterns from an open pit mining activity as revealed by archived avian gizzard contents

    Energy Technology Data Exchange (ETDEWEB)

    Bendell, L.I., E-mail: bendell@sfu.ca

    2011-02-15

    Archived samples of blue grouse (Dendragapus obscurus) gizzard contents, inclusive of grit, collected yearly between 1959 and 1970 were analyzed for cadmium, lead, zinc, and copper content. Approximately halfway through the 12-year sampling period, an open-pit copper mine began activities, then ceased operations 2 years later. Thus the archived samples provided a unique opportunity to determine if avian gizzard contents, inclusive of grit, could reveal patterns in the anthropogenic deposition of trace metals associated with mining activities. Gizzard concentrations of cadmium and copper strongly coincided with the onset of opening and the closing of the pit mining activity. Gizzard zinc and lead demonstrated significant among year variation; however, maximum concentrations did not correlate to mining activity. The archived gizzard contents did provide a useful tool for documenting trends in metal depositional patterns related to an anthropogenic activity. Further, blue grouse ingesting grit particles during the time of active mining activity would have been exposed to toxicologically significant levels of cadmium. Gizzard lead concentrations were also of toxicological significance but not related to mining activity. This type of 'pulse' toxic metal exposure as a consequence of open-pit mining activity would not necessarily have been revealed through a 'snap-shot' of soil, plant or avian tissue trace metal analysis post-mining activity. - Research Highlights: {yields} Archived gizzard samples reveals mining history. {yields} Grit ingestion exposes grouse to cadmium and lead. {yields} Grit selection includes particles enriched in cadmium. {yields} Cadmium enriched particles are of toxicological significance.

  3. Trace metals accumulation in soil irrigated with polluted water and assessment of human health risk from vegetable consumption in Bangladesh.

    Science.gov (United States)

    Islam, Md Atikul; Romić, Davor; Akber, Md Ali; Romić, Marija

    2018-02-01

    Trace metals accumulation in soil irrigated with polluted water and human health risk from vegetable consumption was assessed based on the data available in the literature on metals pollution of water, soil, sediment and vegetables from the cites of Bangladesh. The quantitative data on metal concentrations, their contamination levels and their pollution sources have not been systematically gathered and studied so far. The data on metal concentrations, sources, contamination levels, sample collection and analytical tools used were collected, compared and discussed. The USEPA-recommended method for health risk assessment was used to estimate human risk from vegetable consumption. Concentrations of metals in water were highly variable, and the mean concentrations of Cd, Cr, Cu and As in water were found to be higher than the FAO irrigation water quality standard. In most cases, mean concentrations of metals in soil were higher than the Bangladesh background value. Based on geoaccumulation index (I geo ) values, soils of Dhaka city are considered as highly contaminated. The I geo shows Cd, As, Cu, Ni, Pb and Cr contamination of agricultural soils and sediments of the cities all over the Bangladesh. Polluted water irrigation and agrochemicals are identified as dominant sources of metals in agricultural soils. Vegetable contamination by metals poses both non-carcinogenic and carcinogenic risks to the public. Based on the results of the pollution and health risk assessments, Cd, As, Cr, Cu, Pb and Ni are identified as the priority control metals and the Dhaka city is recommended as the priority control city. This study provides quantitative evidence demonstrating the critical need for strengthened wastewater discharge regulations in order to protect residents from heavy metal discharges into the environment.

  4. Bioaccumulation of thallium and other trace metals in Biscutella laevigata nearby a decommissioned zinc-lead mine (Northeastern Italian Alps).

    Science.gov (United States)

    Pavoni, Elena; Petranich, Elisa; Adami, Gianpiero; Baracchini, Elena; Crosera, Matteo; Emili, Andrea; Lenaz, Davide; Higueras, Pablo; Covelli, Stefano

    2017-01-15

    The mineral body exploited in Salafossa (Eastern Dolomites) was one of the largest lead/zinc-containing mineral deposits in Europe. Both metals were mainly present as sulphides (sphalerite, ZnS and galena, PbS). Mining activity started around 1550, but it was only around 1960 that the richest veins of the minerals were discovered. The mine closed in 1985, and concentrations of several trace metals, such as thallium (Tl), iron (Fe), manganese (Mn), lead (Pb) and zinc (Zn), were detected in the soils and plant samples (Biscutella laevigata L.) that were collected from eighteen sites selected outside the mine. B. laevigata is a pseudometallophyta species, and it often grows near mining areas where the soil's metal concentrations are significantly higher than those of soil with a natural geochemical background. The total metal concentrations in the plant tissue (roots and leaves of Biscutella laevigata) and in the soil samples - both bulk-soil and the B. laevigata root system (rhizo-soil) - were determined through Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES). The metal extractability and leachability of the soil samples were estimated using soil extractions with DTPA (Diethylenetriaminepentaacetic acid). In addition, metal mobility caused by rainwater runoff was estimated by using a leaching test with a dilute solution of H 2 SO 4 and HNO 3 . The results showed that metals were present in a chemical form available for uptake by the plants' roots. In fact, high concentrations of the metals were also found in the plant tissue (roots and leaves) of B. laevigata, and these concentrations were higher than those whose soils present natural geochemical background levels in the corresponding rhizo-soil. Thus, B. laevigata has shown a marked ability to bioaccumulate trace metals, especially Tl and, to a lesser extent, Zn, Pb, Fe and Mn, and it ca