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Sample records for heavy metal atoms

  1. Comparative study of heavy metals in dried and fluid milk in Peshawar by atomic absorption spectrophotometry.

    PubMed

    Lutfullah, Ghosia; Khan, Abid Ali; Amjad, Azra Yasmeen; Perveen, Sajida

    2014-01-01

    Various essential and toxic heavy metals (Ca, Mg, Cu, Zn, Fe, Mn, Pb, Cd, Cr, and Ni) contents in various types of dried (infant formula and powdered) and fluid (fresh and processed) cow milk were assessed by atomic absorption spectrophotometry. The milk samples were collected from local markets of different parts of Peshawar city, Pakistan. Heavy metal concentrations varied significantly depending upon the type of milk. The heavy metal concentrations in most of the samples were within normal and permissible ranges. It was observed that the samples contained considerable amounts of calcium, while magnesium levels were well above the required levels. The results also revealed that copper levels were slightly lower than the permissible limits. The concentration of zinc in dried milk samples was greater than the values for the liquid milk types. Infant milk formulae had higher iron levels as compared to other milk samples because of the added constituents. Significant differences were observed in the mean values of manganese and cadmium in different types of milk. The toxic metals were within the acceptable limits and did not show significant levels leading to toxicity.

  2. Comparative Study of Heavy Metals in Dried and Fluid Milk in Peshawar by Atomic Absorption Spectrophotometry

    PubMed Central

    Lutfullah, Ghosia; Khan, Abid Ali; Amjad, Azra Yasmeen; Perveen, Sajida

    2014-01-01

    Various essential and toxic heavy metals (Ca, Mg, Cu, Zn, Fe, Mn, Pb, Cd, Cr, and Ni) contents in various types of dried (infant formula and powdered) and fluid (fresh and processed) cow milk were assessed by atomic absorption spectrophotometry. The milk samples were collected from local markets of different parts of Peshawar city, Pakistan. Heavy metal concentrations varied significantly depending upon the type of milk. The heavy metal concentrations in most of the samples were within normal and permissible ranges. It was observed that the samples contained considerable amounts of calcium, while magnesium levels were well above the required levels. The results also revealed that copper levels were slightly lower than the permissible limits. The concentration of zinc in dried milk samples was greater than the values for the liquid milk types. Infant milk formulae had higher iron levels as compared to other milk samples because of the added constituents. Significant differences were observed in the mean values of manganese and cadmium in different types of milk. The toxic metals were within the acceptable limits and did not show significant levels leading to toxicity. PMID:24967439

  3. Preconcentration of heavy metals in urine and quantification by inductively coupled plasma atomic emission spectrometry.

    PubMed

    López-Artíguez, M; Cameán, A; Repetto, M

    1993-01-01

    This paper describes a method for the determination of heavy metals (Co, Ni, Cu, Cd, Pb) in urine by inductively coupled plasma atomic emission spectrometry (ICP-AES). The method proposed requires purification of the samples with activated charcoal under acidic conditions before preconcentration by complexation with ammonium pyrrolidinedithiocarbamate (APDC). The formed complexes are extracted with methyl isobutyl ketone (MIBK) and the resulting residue is finally digested under acid oxidant conditions. Because of its low detection limit (below 10 micrograms/L), this procedure can be applied conveniently for toxicological diagnostic purposes.

  4. Determination of effective atomic number and electron density of heavy metal oxide glasses

    NASA Astrophysics Data System (ADS)

    Ali, A. M.; El-Khayatt, A. M.; Akkurt, I.

    2016-03-01

    The effective atomic number (Zeff) and effective electron density (Neff) of eight heavy metal oxide (HMO) glasses have been determined using the Monte Carlo simulation code MCNP for the energy range of 10 keV-10 MeV. The interpolation method was employed to extract Zeff and Neff values from the simulation and that calculated with the help of XCOM program. Comparisons are also made with predictions from the Auto-Zeff software in the same energy region. Wherever possible, the simulated values of Zeff and Neff are compared with experimental data. In general, a very good agreement was noticed. It was found that the Zeff and Neff vary with photon energy and do not have extended intermediate regions where Compton scattering is truly dominating; only dips slightly above ∼1.5 MeV were recorded. Zeff and Neff are found to increase with PbO and Bi2O3 contents. It was found that the Zeff value rather than the Neff value is a better indicator for PbO and/or Bi2O3 contents.

  5. Heavy-atom derivatization.

    PubMed

    Garman, Elspeth; Murray, James W

    2003-11-01

    Most of the standard methods of solving macromolecular structures involve producing a protein crystal that is derivatized by an anomalous scatterer or heavy atom (MIR, SIRAS, MAD, SAD etc.). The theoretical methodology which underpins the extraction of phase information from such derivatives is widely available in the literature. In addition, there are comprehensive sources of information on the chemistry of heavy-atom compounds and the ligands with which they are known to interact, as well as the Heavy Atom Databank accessible on the World Wide Web. This contribution therefore aims to provide some information on the less well documented practical problems of firstly deciding on an overall strategy for derivatization and secondly performing the physical manipulations involved in producing heavy-atom derivatives from native protein crystals and then cryocooling them. Ways to optimize the chances of isomorphous unit cells are suggested. Methods of determining whether or not the heavy atom is bound are outlined, including the powerful technique of PIXE (particle-induced X-ray emission).

  6. Determination of heavy metal contents by atomic absorption spectroscopy (AAS) in some medicinal plants from Pakistani and Malaysian origin.

    PubMed

    Akram, Sobia; Najam, Rahila; Rizwani, Ghazala H; Abbas, Syed Atif

    2015-09-01

    This study depicts a profile of existence of heavy metals (Cu, Ni, Zn, Cd, Hg, Mn, Fe, Na, Ca, and Mg) in some important herbal plants like (H. Integrifolia, D. regia, R. communis, C. equisetifolia, N. oleander, T. populnea, M. elengi, H. schizopetalus, P. pterocarpum) from Pakistan and an antidiabetic Malaysian herbal drug product containing (Punica granatum L. (Mast) Hook, Momordica charantia L., Tamarindus indica L., Lawsonia inermis L.) using atomic absorption spectrophotometer. Heavy metals in these herbal plants and Malaysian product were in the range of 0.02-0.10 ppm of Cu, 0.00-0.02 ppm of Ni, 0.02-0.29 ppm of Zn, 0.00-0.04 ppm of Cd, 0.00-1.33 ppm of Hg, 0.00-0.54 ppm of Mn, 0.22-3.16 ppm of Fe, 0.00-9.17 ppm of Na, 3.27-15.63 ppm of Ca and 1.85-2.03 ppm of Mg. All the metals under study were within the prescribed limits except mercury. Out of 10 medicinal plants/product under study 07 were beyond the limit of mercury permissible limits. Purpose of this study is to determine heavy metals contents in selected herbal plants and Malaysian product, also to highlight the health concerns related to the presence of toxic levels of heavy metals.

  7. Heavy Metal.

    ERIC Educational Resources Information Center

    Shoemaker, W. Lee

    1998-01-01

    Discusses the advantages, both functional and economic, of using a standing-seam metal roof in both new roof installations and reroofing projects of educational facilities. Structural versus non-structural standing-seam roofs are described as are the types of insulation that can be added and roof finishes used. (GR)

  8. Heavy Metal.

    ERIC Educational Resources Information Center

    Shoemaker, W. Lee

    1998-01-01

    Discusses the advantages, both functional and economic, of using a standing-seam metal roof in both new roof installations and reroofing projects of educational facilities. Structural versus non-structural standing-seam roofs are described as are the types of insulation that can be added and roof finishes used. (GR)

  9. Simultaneous determination of trace heavy metals in ambient aerosols by inductively coupled plasma atomic emission spectrometry after pre-concentration with sodium diethyldithiocarbamate.

    PubMed

    Talebi, S M; Malekiha, M

    2008-07-01

    The simultaneous determination of heavy metals associated with airborne particulate matter in the atmosphere of the city Isfahan (Iran) was performed by inductively coupled plasma atomic emission spectrometry (ICP-AES) after pre-concentration with sodium diethyldithiocarbamate. The preconcentration procedure developed found instrumental to determine the trace heavy metals associated with ambient aerosols collected at a short sampling period or collected from rural areas where the concentrations of these metals are much less than those in urban areas. Several samples were analyzed by both flame atomic absorption spectrometry (FAAS) as a conventional method and the proposed method. The results obtained by the two methods were found in good agreement. The method was applied to the determination of atmospheric level of heavy metals in rural area and also for study of variation in levels of heavy metals in urban atmosphere during the days and nights.

  10. Ionic liquid-based extraction followed by graphite-furnace atomic absorption spectrometry for the determination of trace heavy metals in high-purity iron metal.

    PubMed

    Matsumiya, Hiroaki; Kato, Tatsuya; Hiraide, Masataka

    2014-02-01

    The analysis of high-purity materials for trace impurities is an important and challenging task. The present paper describes a facile and sensitive method for the determination of trace heavy metals in high-purity iron metal. Trace heavy metals in an iron sample solution were rapidly and selectively preconcentrated by the extraction into a tiny volume of an ionic liquid [1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide] for the determination by graphite-furnace atomic absorption spectrometry (GFAAS). A nitrogen-donating neutral ligand, 2,4,6-tris(2-pyridyl)-1,3,5-triazine (TPTZ), was found to be effective in the ionic liquid-based selective extraction, allowing the nearly complete (~99.8%) elimination of the iron matrix. The combination with the optimized GFAAS was successful. The detectability reached sub-μg g(-1) levels in iron metal. The novel use of TPTZ in ionic liquid-based extraction followed by GFAAS was successfully applied to the determination of traces of Co, Ni, Cu, Cd, and Pb in certified reference materials for high-purity iron metal.

  11. Determination of heavy metals in solid emission and immission samples using atomic absorption spectroscopy

    SciTech Connect

    Fara, M.; Novak, F.

    1995-12-01

    Both flame and electrothermal methods of atomic absorption spectroscopy (AAS) have been applied to the determination of Al, As, Be, Ca, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, TI, Se, V and Zn in emission and emission (deposition) samples decomposed in open PTFE test-tubes by individual fuming-off hydrofluoric, perchloroic and nitric acid. An alternative hydride technique was also used for As and Se determination and Hg was determined using a self-contained AAS analyzer. A graphite platform proved good to overcome non-spectral interferences in AAS-ETA. Methods developed were verified by reference materials (inc. NBS 1633a).

  12. Determination of heavy metals in bee honey with connected and not connected metal wires using inductively coupled plasma atomic emission spectrometry (ICP-AES).

    PubMed

    Özcan, Mehmet Musa; Al Juhaimi, Fahad Y

    2012-04-01

    Two honey samples are taken from two parts of the same honeycomb: one that contacts to the surface of the wire and the other taken from the surface that does not contact the wires. Heavy metal contents of these two samples were determined by inductively coupled plasma atomic emission spectrometry). The Mo, Cd, Cr, Fe, Mn, Ni and Zn contents of the honey in contact with wire is higher when compared to the other. Especially, Fe and Zn contents of honey in contact with wire is much higher than the non-contact one. These values are, respectively, 190.21 and 112.76 ppm. Besides, Ni content of honey in contact with wire is approximately 50% higher.

  13. Determination of some heavy metals by flame atomic absorption spectrometry before coprecipitation with neodymium hydroxide.

    PubMed

    Soylak, Mustafa; Kizil, Nebiye

    2011-01-01

    A procedure is described for the determination of trace amounts of Cd(II), Ni(II), Cu(II), Pb(II), Fe(III), Co(II), and Mn(II) that combines flame atomic absorption spectrometry with neodymium hydroxide coprecipitation. The influences of analytical parameters (amount of neodymium, pH of the model solutions, etc.) that affect quantitative recoveries of the analyte ions were investigated. The effects of concomitant ions were also examined. The detection limits for analytes were found in the range of 0.2-3.3 microg/L. The validation of the presented procedure was controlled by analysis of certified reference materials (National Institute of Standards and Technology 1570a spinach leaves and TMDA 54.4 fortified lake water). The applications of the procedure were performed by the analysis of water, food, and herbal plants from Turkey.

  14. Heavy Metal Stars

    NASA Astrophysics Data System (ADS)

    2001-08-01

    thereafter dies as a burnt-out, dim "white dwarf" . Stars with masses between 0.8 and 8 times that of the Sun are believed to evolve to AGB-stars and to end their lives in this particular way. At the same time, they produce beautiful nebulae like the "Dumbbell Nebula". Our Sun will also end its active life this way, probably some 7 billion years from now. Low-metallicity stars The detailed understanding of the "s-process" and, in particular, where it takes place inside an AGB-star, has been an area of active research for many years. Current state-of-the-art computer-based stellar models predict that the s-process should be particularly efficient in stars with a comparatively low content of metals ("metal-poor" or "low-metallicity" stars) . In such stars - which were born at an early epoch in our Galaxy and are therefore quite old - the "s-process" is expected to effectively produce atomic nuclei all the way up to the most heavy, stable ones, like Lead (atomic number 82 [2]) and Bismuth (atomic number 83) - since more neutrons are available per Iron-seed nucleus when there are fewer such nuclei (as compared to the solar composition). Once these elements have been produced, the addition of more s-process neutrons to those nuclei will only produce unstable elements that decay back to Lead. Hence, when the s-process is sufficiently efficient, atomic nuclei with atomic numbers around 82, that is, the Lead region, just continue to pile up. As a result, when compared to stars with "normal" abundances of the metals (like our Sun), those low-metallicity stars should thus exhibit a significant "over-abundance" of those very heavy elements with respect to Iron, in particular of Lead . Looking for Lead Direct observational support for this theoretical prediction would be the discovery of some low-metallicity stars with a high abundance of Lead. At the same time, the measured amounts of all the heavy elements and their relative abundances would provide very valuable information and

  15. Atom-efficient route for converting incineration ashes into heavy metal sorbents.

    PubMed

    Chiang, Yi Wai; Santos, Rafael M; Vanduyfhuys, Kenneth; Meesschaert, Boudewijn; Martens, Johan A

    2014-01-01

    Bottom ashes produced from municipal solid-waste incineration are suitable for sorbent synthesis because of their inherent composition, high alkalinity, metastable mineralogy, and residual heat. This work shows that bottom ashes can be atom-efficiently converted into valuable sorbents without the need for costly and hazardous chemicals. The ashes were hydrothermally treated in rotary autoclaves at autogenic pH conditions to promote the conversion of precursor mineral phases into zeolites and layered silicate hydrates. Two main mineral phases were formed: katoite and sodium aluminum phosphate silicate hydrate. These mineral alterations are accompanied by a tenfold increase in specific surface area and a twofold reduction in average particle size. Performance evaluation of the new sorbents for Cd(2+), Zn(2+), and Pb(2+) adsorption at pH5 indicates sorption capacities of 0.06, 0.08, and 0.22 mmol g(-1), respectively, which are similar to those of natural adsorbents and synthetic materials obtained from more demanding synthesis conditions.

  16. Metal Free Azide-Alkyne Click Reaction: Role of Substituents and Heavy Atom Tunneling.

    PubMed

    Karmakar, Sharmistha; Datta, Ayan

    2015-09-03

    Metal free click reactions provide an excellent noninvasive tool to modify and understand the processes in biological systems. Release of ring strain in cyclooctynes on reaction with azides on the formation of triazoles results in small activation energies for various intermolecular Huisgen reactions (1-9). Substitution of difluoro groups at the α, α' position of the cyclooctyne ring enhances the rates of cycloadditions by 10 and 20 times for methyl azide and benzyl azide respectively at room temperature. The computed rate enhancement on difluoro substitution using direct dynamical calculations using the canonical variational transition state theory (CVT/CAG) with small curvature tunneling (SCT) corrections are in excellent agreement with the experimental results. For the intramolecular click reaction (10) notwithstanding its much higher activation energy, quantum mechanical tunneling (QMT) enhances the rate of cycloaddition significantly and increases the N(14)/N(15) primary kinetic isotope effect at 298 K. QMT is shown to be rather efficient in 10 due to a thin barrier of ∼2.4 Å. The present study shows that tunneling effects can be significant for intramolecular click reactions.

  17. Metal atom oxidation laser

    DOEpatents

    Jensen, R.J.; Rice, W.W.; Beattie, W.H.

    1975-10-28

    A chemical laser which operates by formation of metal or carbon atoms and reaction of such atoms with a gaseous oxidizer in an optical resonant cavity is described. The lasing species are diatomic or polyatomic in nature and are readily produced by exchange or other abstraction reactions between the metal or carbon atoms and the oxidizer. The lasing molecules may be metal or carbon monohalides or monoxides. (auth)

  18. Metal atom oxidation laser

    DOEpatents

    Jensen, R.J.; Rice, W.W.; Beattie, W.H.

    1975-10-28

    A chemical laser which operates by formation of metal or carbon atoms and reaction of such atoms with a gaseous oxidizer in an optical resonant cavity is described. The lasing species are diatomic or polyatomic in nature and are readily produced by exchange or other abstraction reactions between the metal or carbon atoms and the oxidizer. The lasing molecules may be metal or carbon monohalides or monoxides.

  19. Metal atomization spray nozzle

    DOEpatents

    Huxford, Theodore J.

    1993-01-01

    A spray nozzle for a magnetohydrodynamic atomization apparatus has a feed passage for molten metal and a pair of spray electrodes mounted in the feed passage. The electrodes, diverging surfaces which define a nozzle throat and diverge at an acute angle from the throat. Current passes through molten metal when fed through the throat which creates the Lorentz force necessary to provide atomization of the molten metal.

  20. Metal atomization spray nozzle

    DOEpatents

    Huxford, T.J.

    1993-11-16

    A spray nozzle for a magnetohydrodynamic atomization apparatus has a feed passage for molten metal and a pair of spray electrodes mounted in the feed passage. The electrodes, diverging surfaces which define a nozzle throat and diverge at an acute angle from the throat. Current passes through molten metal when fed through the throat which creates the Lorentz force necessary to provide atomization of the molten metal. 6 figures.

  1. Spectrum, radial wave functions, and hyperfine splittings of the Rydberg states in heavy alkali-metal atoms

    NASA Astrophysics Data System (ADS)

    Sanayei, Ali; Schopohl, Nils

    2016-07-01

    We present numerically accurate calculations of the bound-state spectrum of the highly excited valence electron in the heavy alkali-metal atoms solving the radial Schrödinger eigenvalue problem with a modern spectral collocation method that applies also for a large principal quantum number n ≫1 . As an effective single-particle potential we favor the reputable potential of Marinescu et al. [Phys. Rev. A 49, 982 (1994)], 10.1103/PhysRevA.49.982. Recent quasiclassical calculations of the quantum defect of the valence electron agree for orbital angular momentum l =0 ,1 ,2 ,... overall remarkably well with the results of the numerical calculations, but for the Rydberg states of rubidium and also cesium with l =3 this agreement is less fair. The reason for this anomaly is that in rubidium and cesium the potential acquires for l =3 deep inside the ionic core a second classical region, thus invalidating a standard Wentzel-Kramers-Brillouin (WKB) calculation with two widely spaced turning points. Comparing then our numerical solutions of the radial Schrödinger eigenvalue problem with the uniform analytic WKB approximation of Langer constructed around the remote turning point rn,j ,l (" close=")n -δ0)">+ we observe everywhere a remarkable agreement, apart from a tiny region around the inner turning point rn,j ,l (-). For s states the centrifugal barrier is absent and no inner turning point exists: rn,j ,0 (-)=0 . With the help of an ansatz proposed by Fock we obtain for the s states a second uniform analytic approximation to the radial wave function complementary to the WKB approximation of Langer, which is exact for r →0+ . From the patching condition, that is, for l =0 the Langer and Fock solutions should agree in the intermediate region 0

  2. Heavy and Superheavy Atomic Nuclei

    NASA Astrophysics Data System (ADS)

    Sobiczewski, Adam

    2008-10-01

    The appearance and development of the concept of super-heavy atomic nuclei are described. The concept appeared during the studies of the limits of the nuclear chart and of the periodic table of the chemical elements. The article concentrates on theoretical studies of the properties of heaviest nuclei. Results of these studies are illustrated and discussed. Prospects for a nearest future of the research of heaviest nuclei are outlined.

  3. Heavy Metal Factory

    NASA Astrophysics Data System (ADS)

    Löbling, Lisa

    2017-07-01

    The metal enrichment in the cosmic circuit of matter is dominated by the yields of asymptotic giant branch (AGB) nucleosynthesis, that are blown back into the interstellar medium just before these stars die as white dwarfs. To establish constraints on AGB processes, spectral analyses of hot post-AGB stars are mandatory. These show that such stars are heavy metal factories due to the AGB s-process. The Virtual Observatory service TheoSSA offers access to synthetic stellar spectra calculated with our Tübingen non-local thermodynamic equilibrium model-atmosphere package that are suitable for the analysis of hot post-AGB stars.

  4. Biosorption of heavy metals

    SciTech Connect

    Volesky, B. |; Holan, Z.R.

    1995-05-01

    Only within the past decade has the potential of metal biosorption by biomass materials been well established. For economic reasons, of particular interest are abundant biomass types generated as a waste byproduct of large-scale industrial fermentations or certain metal-binding algae found in large quantities in the sea. These biomass types serve as a basis for newly developed metal biosorption processes foreseen particularly as a very competitive means for the detoxification of metal-bearing industrial effluents. The assessment of the metal-building capacity of some new biosorbents is discussed. Lead and cadmium, for instance, have been effectively removed from very dilute solutions by the dried biomass of some ubiquitous species of brown marine algae such as Ascophyllum and Sargassum, which accumulate more than 30% of biomass dry weight in the metal. Mycelia of the industrial steroid-transforming fungi Rhizopus and Absidia are excellent biosorbents for lead, cadmium, copper, zinc, and uranium and also bind other heavy metals up to 25% of the biomass dry weight. Biosorption isotherm curves, derived from equilibrium batch sorption experiments, are used in the evaluation of metal uptake by different biosorbents. Further studies are focusing on the assessment of biosorbent performance in dynamic continuous-flow sorption systems. In the course of this work, new methodologies are being developed that are aimed at mathematical modeling of biosorption systems and their effective optimization. 115 refs., 7 figs., 3 tabs.

  5. A rational approach to heavy-atom derivative screening

    SciTech Connect

    Joyce, M. Gordon; Radaev, Sergei; Sun, Peter D.

    2010-04-01

    In order to overcome the difficulties associated with the ‘classical’ heavy-atom derivatization procedure, an attempt has been made to develop a rational crystal-free heavy-atom-derivative screening method and a quick-soak derivatization procedure which allows heavy-atom compound identification. Despite the development in recent times of a range of techniques for phasing macromolecules, the conventional heavy-atom derivatization method still plays a significant role in protein structure determination. However, this method has become less popular in modern high-throughput oriented crystallography, mostly owing to its trial-and-error nature, which often results in lengthy empirical searches requiring large numbers of well diffracting crystals. In addition, the phasing power of heavy-atom derivatives is often compromised by lack of isomorphism or even loss of diffraction. In order to overcome the difficulties associated with the ‘classical’ heavy-atom derivatization procedure, an attempt has been made to develop a rational crystal-free heavy-atom derivative-screening method and a quick-soak derivatization procedure which allows heavy-atom compound identification. The method includes three basic steps: (i) the selection of likely reactive compounds for a given protein and specific crystallization conditions based on pre-defined heavy-atom compound reactivity profiles, (ii) screening of the chosen heavy-atom compounds for their ability to form protein adducts using mass spectrometry and (iii) derivatization of crystals with selected heavy-metal compounds using the quick-soak method to maximize diffraction quality and minimize non-isomorphism. Overall, this system streamlines the process of heavy-atom compound identification and minimizes the problem of non-isomorphism in phasing.

  6. A rational approach to heavy-atom derivative screening.

    PubMed

    Joyce, M Gordon; Radaev, Sergei; Sun, Peter D

    2010-04-01

    Despite the development in recent times of a range of techniques for phasing macromolecules, the conventional heavy-atom derivatization method still plays a significant role in protein structure determination. However, this method has become less popular in modern high-throughput oriented crystallography, mostly owing to its trial-and-error nature, which often results in lengthy empirical searches requiring large numbers of well diffracting crystals. In addition, the phasing power of heavy-atom derivatives is often compromised by lack of isomorphism or even loss of diffraction. In order to overcome the difficulties associated with the 'classical' heavy-atom derivatization procedure, an attempt has been made to develop a rational crystal-free heavy-atom derivative-screening method and a quick-soak derivatization procedure which allows heavy-atom compound identification. The method includes three basic steps: (i) the selection of likely reactive compounds for a given protein and specific crystallization conditions based on pre-defined heavy-atom compound reactivity profiles, (ii) screening of the chosen heavy-atom compounds for their ability to form protein adducts using mass spectrometry and (iii) derivatization of crystals with selected heavy-metal compounds using the quick-soak method to maximize diffraction quality and minimize non-isomorphism. Overall, this system streamlines the process of heavy-atom compound identification and minimizes the problem of non-isomorphism in phasing.

  7. Heavy metals in brick kiln located area using atomic absorption spectrophotometer: a case study from the city of Peshawar, Pakistan.

    PubMed

    Ishaq, M; Khan, Murad Ali; Jan, F Akbar; Ahmad, I

    2010-07-01

    Environmental pollution is one of the burning issues of the world. In developed countries, there are lot of awareness about the environment and the impact of various industries on their life and surroundings. A little has been done in this direction in developing countries. In Pakistan, a big problem is the rapid conglomeration of the brick kilns in the outskirts of nearly all the urban centers to cope with the rapid construction work in big cities. A huge amount of low-grade coal or rubber tires is used as fuel in a very non-scientific manner. The purpose of the present study was to look into the impact of the brick kilns on the different aspects of environmental pollution caused by these kilns. Concentration of metals Cu, Co, Zn, Pb, Cr, Ni, Cd, and Mn were measured on 36 soil samples collected from the area and the same number of plant samples in order to establish the distribution of heavy metals in the area and to determine the effect of this distribution on the surrounding atmosphere and the possible effects on human life.

  8. Disorders of heavy metals.

    PubMed

    Woimant, France; Trocello, Jean-Marc

    2014-01-01

    Heavy metals and trace elements play an important role in relation to the physiology and pathology of the nervous system. Neurologic diseases related to disorders of metabolism of copper and iron are reviewed. Copper disorders are divided into two classes: ATP7A- or ATP7B-related inherited copper transport disorders (Menkes disease, occipital horn syndrome, ATP7A-related distal motor neuropathy, and Wilson disease) and acquired diseases associated with copper deficiency or copper excess. Iron brain disorders are divided into genetic neurodegeneration with brain iron accumulation (NBIA, neuroferritinopathy, and aceruloplasminemia), genetic systemic iron accumulation with neurologic features (hemochromatosis), and acquired diseases associated with iron excess (superficial siderosis) or iron deficiency (restless leg syndrome). The main features of cadmium, lead, aluminum, mercury, and manganese toxicity are summarized.

  9. Separation and determination of heavy metals associated with low molecular weight chelators in xylem saps of Indian mustard (Brassica juncea) by size exclusion chromatography and atomic absorption spectrometry.

    PubMed

    Wei, Zhenggui G; Wong, Jonathan Woonchung C; Zhao, Haiyan Y; Zhang, Huijuan J; Li, Huixin X; Hu, Feng

    2007-08-01

    To elucidate the role of low molecular weight chelators in long-distance root-to-shoot transport of heavy metals in Indian mustard, an "off-line" size exclusion high-performance liquid chromatography-graphite furnace atomic absorption spectrometry was developed to investigate heavy metals associated with low molecular weight chelators in xylem saps of Indian mustard (Brassica juncea). The size exclusion chromatogram presented only the peaks with molecular weight for all xylem saps and directly indicated the long-distance transport of phytochelatins (PCs) of Indian mustard under Cd stress. In the absence of Cd stress, only organic acids and inorganic anions participated in the long-distance transport of Cd, but organic acids, inorganic anions, glutathione (GSH), and cysteine might relate to the long-distance transport of Cu or Zn. In the presence of Cd stress, PCs were induced, and Cd ions in xylem saps were associated with the induced PCs. As the Cd levels in nutrient solution increased, more Cd in xylem saps adopted the form of PC-Cd. Although PCs might participate in the long-distance transport of Cd under Cd stress, the majority of Cd was still transported by organic acids and inorganic anions in xylem vessels. Moreover, results indicated the existence of complexation competition for GSH and cysteine between Cd and Cu (or Zn) and complexation competition for Cd between PCs and GSH (or cysteine) in xylem vessels. Our work might be very useful for understanding the mechanism of long-distance transport of heavy metals in hyperaccumulator.

  10. Solid-phase chelate extractive preconcentration of heavy metal ions prior to their ultratrace determination by microsample injection system coupled flame atomic absorption spectrometry.

    PubMed

    Sarı, Serdar; Kartal, Aslıhan Arslan; Elçi, Aydan; Akdoğan, Abdullah; Höl, Aysen; Siyal, Ali Nawaz; Elçi, Latif

    2013-01-01

    Chromosorb-105 resin/1-(2-pyridylazo)-2-naphthol (PAN) system was developed for solid phase chelate extractive preconcentration of heavy metal ions. The metal ions on Chromosorb-105 resin column were eluted with 3.0 mL of 2.0 mol L-1 HNO3 and determined by microsample injection system coupled flame atomic spectrometry (MIS-FAAS) using 75.0 µL of sample solution for single element determination. The influence of pH, resin amount, reagent amount, flow rate and volume of eluent and sample solution was optimized. The quantitative recoveries (≥95%) of Fe(III), Zn(II), Cu(II) and Pb(II) ions were achieved at pH 9; resin amount, 700 mg; reagent amount, 6.0 µmol; flow rate of eluent and sample solution, 1.0 mL min-1 and 5.0 mL min-1, respectively. The limit of detection and limit of quantification of understudied analytes were found to be 0.17-1.74 µg L-1 and 0.40-2.98 µg L-1, respectively with preconcentration factor of 150-300. The proposed method was validated by analysis of waste water (BCR-715) as a certified reference material. The method was applied successfully for ultratrace determination of studied metal ions in tap water and hot spring water samples.

  11. [Microbial interactions with heavy metals].

    PubMed

    Cervantes, C; Espino-Saldaña, A E; Acevedo-Aguilar, F; León-Rodriguez, I L; Rivera-Cano, M E; Avila-Rodríguez, M; Wróbel-Kaczmarczyk, K; Wróbel-Zasada, K; Gutiérrez-Corona, J F; Rodríguez-Zavala, J S; Moreno-Sánchez, R

    2006-01-01

    Living organisms are exposed in nature to heavy metals, commonly present in their ionized species. These ions exert diverse toxic effects on microorganisms. Metal exposure both selects and maintains microbial variants able to tolerate their harmful effects. Varied and efficient metal resistance mechanisms have been identified in diverse species of bacteria, fungi and protists. The study of the interactions between microorganisms and metals may be helpful to understand the relations of toxic metals with higher organisms such as mammals and plants. Some microbial systems of metal tolerance have the potential to be used in biotechnological processes, such as the bioremediation of environmental metal pollution or the recovery of valuable metals. In this work we analyze several examples of the interactions of different types of microbes with heavy metals; these cases are related either with basic research or with possible practical applications.

  12. Heavy Metal Pumps in Plants

    SciTech Connect

    Harper, J.F.

    2000-10-01

    The long term goal of the funded research is to understand how heavy metals are taken up from the soil and translocated throughout the plant. The potential application of this research is to create plants with better heavy metal uptake systems and thereby improve the ability of these plants to help clean up toxic metals from soils. A rate limiting step is using plant for bioremediation is the normally poor capacity of plants to concentrate toxic metals. Our interest in metal ion transport systems includes those for essential mineral nutrients such as molybdenum, copper, iron, manganese, as well as toxic metals such as cerium, mercury, cesium, cadmium, arsenic and selenium. Understanding the pathways by which toxic metals accumulate in plants will enable the engineering of plants to exclude toxic metals and create healthier food sources, or to extract toxic metals from the soil as a strategy to clean up polluted lands and water.

  13. Determination of trace heavy metals in soil and sediments by atomic spectrometry following preconcentration with Schiff bases on Amberlite XAD-4.

    PubMed

    Kara, Derya; Fisher, Andrew; Hill, Steve J

    2009-06-15

    A matrix separation and analyte preconcentration system using Amberlite XAD copolymer resins functionalized by Schiff base reactions coupled with atomic spectrometry has been developed. Three different functionalized Amberlite XAD resins were synthesized using 4-phenylthiosemicarbazide, 2,3-dihydroxybenzaldehyde and 2-thiophenecarboxaldehyde as reagents. These resins could be used to preconcentrate transition and other trace heavy metal analytes from nitric acid digests of soil and sediment samples. Analyte retention was shown to work well at pH 6.0. After treatment of the digests with sodium fluoride and buffering to pH 6, samples that contain extremely large concentrations of iron were analysed for trace analytes without the excess iron overloading the capacity of the resin. The analytes Cd, Co, Cu, Ni and Pb were preconcentrated from acid extracts of certified soil/sediment samples and then eluted with 0.1M HNO(3) directly to the detection system. Flame atomic absorption spectrometry was used as a means of detection during the studies. The efficiency of the chelating resin and the accuracy of the proposed method were evaluated by the analysis of soil (SO-2) and sediment (LGC 6157 and MESS-3) certified reference materials.

  14. Heavy metals and coal combustion

    SciTech Connect

    Danihelka, P.; Ochodek, T.; Noskievic, P.; Seidlerova, J.

    1998-07-01

    Combustion of coal may be an important source of heavy metals pollution. The distribution of heavy metals during combustion process has been studied in six power plants, where fuel, bottom ash, fly ash and emissions have been analyzed and the relative concentrations of heavy metals have been estimated. For the most volatile metals (arsenic, antimony, lead, and zinc), the redistribution process involving condensation on surface is probable. Some metals like manganese or chromium are concentrated rather in coarse particles. In such cases, no clear conclusion can be made and probably several mechanisms are involved, including mineral form of metal. Typical results of low chlorine coal (0.01--0.03% Cl) exhibit increasing concentration of volatile metals in the magnitude of around one order when going from bottom ash to emissions. Different results have been found in similar operation conditions in the case of high content of chlorine in coal (0.3% of Cl in coal). In this case, the concentration of metals in emissions is significantly higher and also nickel, copper and manganese concentrations increase. It seems to be probable that chlorine in the coal increases the redistribution of metals by volatile chlorides formation. At three operation condition (nominal output, 70% and 40% respectively) emission factors of heavy metals have been estimated for 35 MW stoker-fired boiler. Ba, Pb, Sb and Zn increased their emission factors and Cr and Mn decreased when output was decreased. Heavy metals pollution caused by emissions from combustion of coal may be decreased by fine particles removal, other possibilities (metals extraction from the coal, changes of condition in the flame) are rather limited.

  15. Selective reduction of heavy metals

    SciTech Connect

    Bjorling, G.

    1984-12-11

    The present invention relates to selective reduction of heavy metals out of finey grained, substantially oxidic material by blowing the oxidic material into a furnace together with an amount of reducing agent required for obtaining desired selectivity while simultaneously heat energy is supplied by a gas heated in a plasma generator, the temperature being adjusted to such a level as to correspond to the oxygen potential at which the desired metals are transformed into a particular, isolatable phase as metal melt, metal vapor, speiss or matte and at which the remaining metals enter into a slag phase and can be isolated as slag melt.

  16. Heavy metals and coal combustion

    SciTech Connect

    Danihelka, P.; Ochodek, T.; Noskievic, P.; Seidlerova, J.

    1998-04-01

    Combustion of coal may be an important source of heavy metals pollution. The distribution of heavy metals during combustion process has been studied in six power plants, where fuel, bottom ash, fly ash and emissions have been analysed and the relative concentrations of heavy metals have been estimated. For the most volatile metals (arsenic, antimony, lead, and zinc), the redistribution process involving condensation on surface is probable. Some metals like manganese or chromium are concentrated rather in coarse particles. In such cases, no clear conclusion can be made and probably several mechanisms are involved, including mineral form of metal. Typical results of low chlorine coal (0.01-0.03% Cl) exhibit increasing concentration of volatile metals in the magnitude of around one order when going from bottom ash to emissions. Different results have been found in similar operation conditions in the case of high content of chlorine in coal (0.3 % of Cl in coal). In this case, the concentration of metals in emissions is significantly higher and also nickel, copper and manganese concentrations increase. It seems to be probable that chlorine in the coal increases the redistribution of metals by volatile chlorides formation.

  17. QED corrections for the valence electron in the heavy and superheavy metal atoms from the 11 and 12 groups

    NASA Astrophysics Data System (ADS)

    Goidenko, I. A.

    2009-10-01

    The first-order QED corrections for valence electron are investigated for the neutral Ag, Rg and their neighbours of the Mendeleev Periodic Table within the framework of the Dirac-Hartree-Fock method. The including of SE effects in such procedure was done first for superheavy atoms. The obtained results provide the limit of the accuracy for the modern relativistic theoretical calculations for the superheavy elements and open the discussion about the accuracy of the QED corrections in the superheavy elements themselves.

  18. Investigation of the transported heavy metal ions in xylem sap of cucumber plants by size exclusion chromatography and atomic absorption spectrometry.

    PubMed

    Mihucz, V G; Tatár, E; Kmethy, B; Záray, G; Cseh, E

    2000-07-15

    An 'off-line' high performance liquid chromatography-graphite furnace atomic absorption spectrometry (HPLC-GF-AAS) method using a size exclusion chromatography (SEC) column was developed to investigate heavy metal ions in xylem sap samples of cucumber plants grown in hydroponics containing iron as Fe(III)-ethylenediaminetetraacetate (Fe(III) EDTA), Fe(III) citrate or FeCl3 and exposed to lead, nickel or vanadium contamination. The SEC chromatogram of the samples contained the peak of nitrate ions (in significant concentration approximately 1400 microg/ml) and some small, unidentified compounds with molecular weight lower than 700 Da. The results indicate that Cu and Mn--which were added to the hydroponics as nutrient elements--determined in the collected fractions during the chromatographic runs are transported in the xylem vessels together with small inorganic ions like nitrate ions. In case of nickel other low-molecular weight compounds eluting earlier than the nitrate ions may take part in its transport toward the shoots. Lead could not be detected in the above mentioned fractions. Determination of vanadium in the fractions was not expected since it could not be detected in the sap samples.

  19. A rapid and rational approach to generating isomorphous heavy-atom phasing derivatives.

    PubMed

    Lu, Jinghua; Sun, Peter D

    2014-09-01

    In attempts to replace the conventional trial-and-error heavy-atom derivative search method with a rational approach, we previously defined heavy metal compound reactivity against peptide ligands. Here, we assembled a composite pH- and buffer-dependent peptide reactivity profile for each heavy metal compound to guide rational heavy-atom derivative search. When knowledge of the best-reacting heavy-atom compound is combined with mass spectrometry assisted derivatization, and with a quick-soak method to optimize phasing, it is likely that the traditional heavy-atom compounds could meet the demand of modern high-throughput X-ray crystallography. As an example, we applied this rational heavy-atom phasing approach to determine a previously unknown mouse serum amyloid A2 crystal structure.

  20. A rapid and rational approach to generating isomorphous heavy-atom phasing derivatives

    PubMed Central

    Lu, Jinghua; Sun, Peter D.

    2014-01-01

    In attempts to replace the conventional trial-and-error heavy-atom derivative search method with a rational approach, we previously defined heavy metal compound reactivity against peptide ligands. Here, we assembled a composite pH and buffer-dependent peptide reactivity profile for each heavy metal compound to guide rational heavy-atom derivative search. When knowledge of the best-reacting heavy-atom compound is combined with mass spectrometry-assisted derivatization, and with a quick-soak method to optimize phasing, it is likely that the traditional heavy-atom compounds could meet the demand of modern high-throughput X-ray crystallography. As an example, we applied this rational heavy-atom phasing approach to determine a previously unknown mouse serum amyloid A2 crystal structure. PMID:25040395

  1. Process for removing heavy metal compounds from heavy crude oil

    DOEpatents

    Cha, Chang Y.; Boysen, John E.; Branthaver, Jan F.

    1991-01-01

    A process is provided for removing heavy metal compounds from heavy crude oil by mixing the heavy crude oil with tar sand; preheating the mixture to a temperature of about 650.degree. F.; heating said mixture to up to 800.degree. F.; and separating tar sand from the light oils formed during said heating. The heavy metals removed from the heavy oils can be recovered from the spent sand for other uses.

  2. Heavy metals extraction by microemulsions.

    PubMed

    Dantas, T N Castro; Dantas Neto, A A; Moura, M C P A; Barros Neto, E L; Forte, K R; Leite, R H L

    2003-06-01

    The objective of this study is the heavy metal extraction by microemulsion, using regional vegetable oils as surfactants. Firstly, the main parameters, which have influence in the microemulsion region, such as: nature of cosurfactant, influence of cosurfactant (C)/surfactant (S) ratio and salinity were studied, with the objective of choosing the best extraction system. The extraction/reextraction process by microemulsion consists of two stages. In the first one, the heavy metal ion present in the aqueous phase is extracted by the microemulsion. In a second step, the reextraction process occurs: the microemulsion phase, rich in metal, is acidified and the metal is recovered in a new aqueous phase, with higher concentration. The used system had the following parameters: surfactant-saponified coconut oil; cosurfactant-n-butanol; oil phase-kerosene; C/S ratio=4; salinity-2% (NaCl); temperature of 27+/-1 degrees C; water phase-aqueous solution that varied according to the heavy metal in study (Cr, Cu, Fe, Mn, Ni and Pb). A methodology of experimental planning was used (Scheffé Net) to study the behavior of the extraction in a chosen domain. The extraction was accomplished in one step and yielded extraction percentage higher than 98% for all metals. In the reextraction HCl-8M was used as reextraction agent and the influence of the pH and time were verified. This work showed the great efficiency of the microemulsion, indicating that it is possible to extract selectively the heavy metals from the aqueous phase.

  3. Determination of some heavy metal levels in soft drinks on the Ghanaian market using atomic absorption spectrometry method.

    PubMed

    Ackah, Michael; Anim, Alfred Kwablah; Zakaria, Nafisatu; Osei, Juliet; Saah-Nyarko, Esther; Gyamfi, Eva Tabuaa; Tulasi, Delali; Enti-Brown, Sheriff; Hanson, John; Bentil, Nash Owusu

    2014-12-01

    Twenty-three soft drink samples (i.e., four pineapple-based fruit drinks, eight citrus-based fruit juices, one soya-based drink, three cola carbonated drinks, one apple-based fruit drink, and six cocktail fruit drinks) were randomly purchased from retail outlets in an urban market in Accra and analyzed for the concentrations of iron, cobalt, cadmium, zinc, lead, and copper using flame atomic absorption spectrometry. The mean concentration of iron and cadmium were 0.723 ± 0.448 mg/L and 0.032 ± 0.012 mg/L, respectively. The mean cobalt concentration was 0.071 ± 0.049 mg/L, while the mean Zn concentration in the samples was 0.060 ± 0.097 mg/L. The mean concentrations of Pb and Cu in the fruit juice samples were 0.178 ± 0.091 mg/L and 0.053 ± 0.063 mg/L respectively. About 78 % of the samples exceeded the United States Environmental Protection Agency (USEPA) maximum contaminant level of 0.3 mg/L prescribed for iron, whereas all the samples exceeded the USEPA maximum contaminant level of 0.005 mg/L prescribed for cadmium. About 91 % of the samples exceeded the EU maximum contaminant level prescribed for lead insoft drinks.

  4. Abatement of Marine Coatings Containing Heavy Metals

    DTIC Science & Technology

    1995-06-01

    in the abatement of heavy metal containing marine coatings. Funding for this...shipyards to be proactive in the area of heavy metal coating systems abatement as current regulations were not "user friendly" in shipboard applications.

  5. Sub-Angstrom Atomic-Resolution Imaging of Heavy Atoms to Light Atoms

    SciTech Connect

    O'Keefe, Michael A.; Shao-Horn, Yang

    2003-05-23

    Three decades ago John Cowley and his group at ASU achieved high-resolution electron microscope images showing the crystal unit cell contents at better than 4Angstrom resolution. Over the years, this achievement has inspired improvements in resolution that have enabled researchers to pinpoint the positions of heavy atom columns within the cell. More recently, this ability has been extended to light atoms as resolution has improved. Sub-Angstrom resolution has enabled researchers to image the columns of light atoms (carbon, oxygen and nitrogen) that are present in many complex structures. By using sub-Angstrom focal-series reconstruction of the specimen exit surface wave to image columns of cobalt, oxygen, and lithium atoms in a transition metal oxide structure commonly used as positive electrodes in lithium rechargeable batteries, we show that the range of detectable light atoms extends to lithium. HRTEM at sub-Angstrom resolution will provide the essential role of experimental verification for the emergent nanotech revolution. Our results foreshadow those to be expected from next-generation TEMs with Cs-corrected lenses and monochromated electron beams.

  6. Heavy Metals Resisting Gravity in White Dwarfs?

    NASA Astrophysics Data System (ADS)

    Rauch, T.; Gamrath, S.; Quinet, P.; Hoyer, D.; Werner, K.; Kruk, J. W.

    2017-03-01

    Spectral lines of heavy metals, identified in high-resolution ultraviolet spectra of the DO-type white dwarf RX J0503.9–2854 (RE 0503–289), allow precise abundance determinations of these species by means of advanced non-local thermodynamic equilibrium stellar-atmosphere models – provided that reliable atomic data is available. Such analyses of Zn (atomic number Z = 30), Ga (31), Ge (32), As (33), Mo (42), Kr (36), Zr (40), Xe (54), and Ba (56) have recently shown that, without exception, their abundances are unexpectedly strongly supersolar (up to about 5 dex). This is much higher than predicted by recent asymptotic giant branch nucleosynthesis calculations. Thus, the interplay of gravitational settling and radiative levitation may play an important role for their photospheric prominence.

  7. Absorption spectroscopy of heavy alkaline earth metals Ba and Sr in rare gas matrices—CCSD(T) calculations and atomic site occupancies

    NASA Astrophysics Data System (ADS)

    Davis, Barry M.; McCaffrey, John G.

    2016-01-01

    Isolation of the heavier alkaline earth metals Ba and Sr in the solid rare gases (RGs) Ar, Kr, and Xe is analysed with absorption spectroscopy and interpreted partly with the assistance of ab initio calculations of the diatomic M ṡ RG ground state interaction potentials. The y1P←a1S resonance transitions in the visible spectral region are used to compare the isolation conditions of these two metal atom systems and calcium. Complex absorption bands were recorded in all three metal atom systems even after extensive sample annealing. Coupled cluster calculations conducted on the ground states of the nine M ṡ RG diatomics (M = Ca, Sr, and Ba; RG = Ar, Kr, and Xe) at the coupled cluster single, double, and non-iterative triple level of theory revealed long bond lengths (>5 Å) and shallow bound regions (<130 cm-1). All of the M ṡ RG diatomics have bond lengths considerably longer than those of the rare gas dimers, with the consequence that isolation of these metal atoms in a single substitutional site of the solid rare gas is unlikely, with the possible exception of Ca/Xe. The luminescence of metal dimer bands has been recorded for Ba and Sr revealing very different behaviours. Resonance fluorescence with a lifetime of 15 ns is observed for the lowest energy transition of Sr2 while this transition is quenched in Ba2. This behaviour is consistent with the absence of vibrational structure on the dimer absorption band in Ba2 indicating lifetime broadening arising from efficient relaxation to low-lying molecular states. More extensive 2D excitation-emission data recorded for the complex site structures present on the absorption bands of the atomic Ba and Sr systems will be presented in future publications.

  8. Absorption spectroscopy of heavy alkaline earth metals Ba and Sr in rare gas matrices—CCSD(T) calculations and atomic site occupancies

    SciTech Connect

    Davis, Barry M.; McCaffrey, John G.

    2016-01-28

    Isolation of the heavier alkaline earth metals Ba and Sr in the solid rare gases (RGs) Ar, Kr, and Xe is analysed with absorption spectroscopy and interpreted partly with the assistance of ab initio calculations of the diatomic M ⋅ RG ground state interaction potentials. The y{sup 1}P←a{sup 1}S resonance transitions in the visible spectral region are used to compare the isolation conditions of these two metal atom systems and calcium. Complex absorption bands were recorded in all three metal atom systems even after extensive sample annealing. Coupled cluster calculations conducted on the ground states of the nine M ⋅ RG diatomics (M = Ca, Sr, and Ba; RG = Ar, Kr, and Xe) at the coupled cluster single, double, and non-iterative triple level of theory revealed long bond lengths (>5 Å) and shallow bound regions (<130 cm{sup −1}). All of the M ⋅ RG diatomics have bond lengths considerably longer than those of the rare gas dimers, with the consequence that isolation of these metal atoms in a single substitutional site of the solid rare gas is unlikely, with the possible exception of Ca/Xe. The luminescence of metal dimer bands has been recorded for Ba and Sr revealing very different behaviours. Resonance fluorescence with a lifetime of 15 ns is observed for the lowest energy transition of Sr{sub 2} while this transition is quenched in Ba{sub 2}. This behaviour is consistent with the absence of vibrational structure on the dimer absorption band in Ba{sub 2} indicating lifetime broadening arising from efficient relaxation to low-lying molecular states. More extensive 2D excitation-emission data recorded for the complex site structures present on the absorption bands of the atomic Ba and Sr systems will be presented in future publications.

  9. Absorption spectroscopy of heavy alkaline earth metals Ba and Sr in rare gas matrices--CCSD(T) calculations and atomic site occupancies.

    PubMed

    Davis, Barry M; McCaffrey, John G

    2016-01-28

    Isolation of the heavier alkaline earth metals Ba and Sr in the solid rare gases (RGs) Ar, Kr, and Xe is analysed with absorption spectroscopy and interpreted partly with the assistance of ab initio calculations of the diatomic M ⋅ RG ground state interaction potentials. The y(1)P ← a(1)S resonance transitions in the visible spectral region are used to compare the isolation conditions of these two metal atom systems and calcium. Complex absorption bands were recorded in all three metal atom systems even after extensive sample annealing. Coupled cluster calculations conducted on the ground states of the nine M ⋅ RG diatomics (M = Ca, Sr, and Ba; RG = Ar, Kr, and Xe) at the coupled cluster single, double, and non-iterative triple level of theory revealed long bond lengths (>5 Å) and shallow bound regions (<130 cm(-1)). All of the M ⋅ RG diatomics have bond lengths considerably longer than those of the rare gas dimers, with the consequence that isolation of these metal atoms in a single substitutional site of the solid rare gas is unlikely, with the possible exception of Ca/Xe. The luminescence of metal dimer bands has been recorded for Ba and Sr revealing very different behaviours. Resonance fluorescence with a lifetime of 15 ns is observed for the lowest energy transition of Sr2 while this transition is quenched in Ba2. This behaviour is consistent with the absence of vibrational structure on the dimer absorption band in Ba2 indicating lifetime broadening arising from efficient relaxation to low-lying molecular states. More extensive 2D excitation-emission data recorded for the complex site structures present on the absorption bands of the atomic Ba and Sr systems will be presented in future publications.

  10. Isolation and characterization of a heavy metal-resistant Burkholderia sp. from heavy metal-contaminated paddy field soil and its potential in promoting plant growth and heavy metal accumulation in metal-polluted soil.

    PubMed

    Jiang, Chun-yu; Sheng, Xia-fang; Qian, Meng; Wang, Qing-ya

    2008-05-01

    A heavy metal-resistant bacterial strain was isolated from heavy metal-contaminated soils and identified as Burkholderia sp. J62 based on the 16S rDNA gene sequence analysis. The heavy metal- and antibiotic resistance, heavy metal solubilization of the isolate were investigated. The isolate was also evaluated for promoting plant growth and Pb and Cd uptakes of the plants from heavy metal-contaminated soils in pot experiments. The isolate was found to exhibit different multiple heavy metal and antibiotic resistance characteristics. Atomic absorption spectrometer analysis showed increased bacterial solubilization of lead and cadmium in solution culture and in soils. The isolate produced indole acetic acid, siderophore and 1-aminocyclopropane-1-carboxylate deaminase. The isolate also solubilized inorganic phosphate. Inoculation with the isolate was found to significantly (p<0.05) increase the biomass of maize and tomato plants. Increase in tissue Pb and Cd contents varied from 38% to 192% and from 5% to 191% in inoculated plants growing in heavy metal-contaminated soils compared to the uninoculated control, respectively. These results show that heavy metal-solubilizing and plant growth promoting bacteria are important for plant growth and heavy metal uptake which may provide a new microbial enhanced-phytoremediation of metal-polluted soils.

  11. Magnetic ordering and anisotropy in heavy atom radicals.

    PubMed

    Winter, Stephen M; Hill, Stephen; Oakley, Richard T

    2015-03-25

    Recent developments in stable radical chemistry have afforded "heavy atom" radicals, neutral open-shell (S = 1/2) molecular species containing heavy p-block elements (S, Se), which display solid-state magnetic properties once considered exclusive to conventional metal-based magnets. These highly spin-delocalized radicals do not associate in the solid state and yet display extensive networks of close intermolecular interactions. Spin density on the heavy atoms allows for increased isotropic and spin-orbit mediated anisotropic exchange effects. Structural variations induced by chemical modification and physical pressure, coupled with ab-initio methods to estimate exchange energies, have facilitated the development of predictive structure/property relationships. These results, coupled with detailed theoretical analyses and magnetic resonance spectroscopic measurements, have provided insight into the magnetic structure of ferromagnetic and spin-canted antiferromagnetic ordered materials as well as an understanding of the importance of spin-orbit coupling contributions to magnetic hysteresis and anisotropy. Isotropic and anisotropic ferromagnetic exchange can also be enhanced indirectly by the incorporation of heavy atoms into nonspin-bearing sites, where they can contribute to multi-orbital spin-orbit coupling.

  12. Heavy metals in plants and phytoremediation.

    PubMed

    Cheng, Shuiping

    2003-01-01

    In some cases, soil, water and food are heavily polluted by heavy metals in China. To use plants to remediate heavy metal pollution would be an effective technique in pollution control. The accumulation of heavy metals in plants and the role of plants in removing pollutants should be understood in order to implement phytoremediation, which makes use of plants to extract, transfer and stabilize heavy metals from soil and water. The information has been compiled from Chinese publications stemming mostly from the last decade, to show the research results on heavy metals in plants and the role of plants in controlling heavy metal pollution, and to provide a general outlook of phytoremediation in China. Related references from scientific journals and university journals are searched and summarized in sections concerning the accumulation of heavy metals in plants, plants for heavy metal purification and phytoremediation techniques. Plants can take up heavy metals by their roots, or even via their stems and leaves, and accumulate them in their organs. Plants take up elements selectively. Accumulation and distribution of heavy metals in the plant depends on the plant species, element species, chemical and bioavailiability, redox, pH, cation exchange capacity, dissolved oxygen, temperature and secretion of roots. Plants are employed in the decontamination of heavy metals from polluted water and have demonstrated high performances in treating mineral tailing water and industrial effluents. The purification capacity of heavy metals by plants are affected by several factors, such as the concentration of the heavy metals, species of elements, plant species, exposure duration, temperature and pH. Phytoremediation, which makes use of vegetation to remove, detoxify, or stabilize persistent pollutants, is a green and environmentally-friendly tool for cleaning polluted soil and water. The advantage of high biomass productive and easy disposal makes plants most useful to remediate

  13. Industrial hygiene of selected heavy metals

    SciTech Connect

    Woodring, J.L.

    1993-08-01

    The industrial hygiene of heavy metals consists of recognition, evaluation, and control of exposures in the occupational environment. Several of these metals have been in use since ancient times. Reports of health effects and poisonings from overexposures also have a long history. This report discusses the industrial hygiene of the heavy metals, lead, cadmium, mercury, and manganese.

  14. The Heavy Metal Subculture and Suicide.

    ERIC Educational Resources Information Center

    Stack, Steven; And Others

    1994-01-01

    Assessed relationship between heavy metal music and suicide with data on heavy metal magazine subscriptions and youth suicide in 50 states. Found that, controlling for other predictors of suicide, greater strength of metal subculture, higher youth suicide rate, suggests that music perhaps nurtures suicidal tendencies already present in subculture.…

  15. The Heavy Metal Subculture and Suicide.

    ERIC Educational Resources Information Center

    Stack, Steven; And Others

    1994-01-01

    Assessed relationship between heavy metal music and suicide with data on heavy metal magazine subscriptions and youth suicide in 50 states. Found that, controlling for other predictors of suicide, greater strength of metal subculture, higher youth suicide rate, suggests that music perhaps nurtures suicidal tendencies already present in subculture.…

  16. Biomolecules for removal of heavy metal.

    PubMed

    Singh, Namita Ashish

    2017-02-23

    Heavy metals are natural constituents of the earth's crust, but some heavy metals like cadmium, lead, mercury, arsenic etc. are injurious to living organisms at higher concentration. Nowadays, anthropogenic activities have altered geochemical cycles and biochemical balance of heavy metals. Biomolecules are used nowadays for removal of heavy metals compared to other synthetic biosorbents due to their environmental friendly nature and cost effectiveness. The goal of this work is to review research work and patents related to adsorption through biomolecules like polysaccharides, polypeptides, lignin etc. and bio-sorption by biological material that are used for heavy metal removal. Biomolecules are cost effective and there have been significant progresses in the remediation of heavy metals but, still there are some problems that need to be rectified for its application at industrial processes.

  17. Heavy Metal - Exploring a magnetised metallic asteroid

    NASA Astrophysics Data System (ADS)

    Wahlund, Jan-Erik; Andrews, David; Futaana, Yoshifumi; Masters, Adam; Thomas, Nicolas; De Sanctis, Maria Cristina; Herique, Alain; Retherford, Kurt; Tortora, Paolo; Trigo-Rodriguez, Joseph; Ivchenko, Nickolay; Simon, Sven

    2017-04-01

    We propose a spacecraft mission (Heavy Metal) to orbit and explore (16) Psyche - the largest M-class metallic asteroid in the main belt. Recent estimates of the shape, 279×232×189 km and mass, 2.7×10(19) kg make it one of the largest and densest of asteroids, and together with the high surface radar reflectivity and the spectral data measured from Earth it is consistent with a bulk composition rich in iron-nickel. The M5 mission Heavy Metal will investigate if (16) Psyche is the exposed metallic core of a planetesimal, formed early enough to melt and differentiate. High-resolution mapping of the surface in optical, IR, UV and radar wavebands, along with the determination of the shape and gravity field will be used to address the formation and subsequent evolution of (16) Psyche, determining the origin of metallic asteroids. It is conceivable that a cataclysmic collision with a second body led to the ejection of all or part of the differentiated core of the parent body. Measurements at (16) Psyche therefore provide a possibility to directly examine an iron-rich planetary core, similar to that expected at the center of all the major planets including Earth. A short-lived dynamo producing a magnetic field early in the life of (16) Psyche could have led to a remnant field (of tens of micro Tesla) being preserved in the body today. (16) Psyche is embedded in the variable flow of the solar wind. Whereas planetary magnetospheres and induced magnetospheres are the result of intense dynamo fields and dense conductive ionospheres presenting obstacles to the solar wind, (16) Psyche may show an entirely new 'class' of interaction as a consequence of its lack of a significant atmosphere, the extremely high bulk electrical conductivity of the asteroid, and the possible presence of intense magnetic fields retained in iron-rich material. The small characteristic scale of (16) Psyche ( 200 km) firmly places any solar wind interaction in the "sub-MHD" scale, in which kinetic

  18. Heavy metals, islet function and diabetes development.

    PubMed

    Chen, Ya Wen; Yang, Ching Yao; Huang, Chun Fa; Hung, Dong Zong; Leung, Yuk Man; Liu, Shing Hwa

    2009-01-01

    It has long been believed that heavy metals possess many adverse health effects. Uncontrolled industrialization has released heavy metal pollution in the world. Heavy metal pollutants damage organ functions and disrupt physiological homeostasis. Diabetes mellitus is growing in prevalence worldwide. Several studies have indicated that the deficiency and efficiency of some essential trace metals may play a role in the islet function and development of diabetes mellitus. Some toxic metals have also been shown to be elevated in biological samples of diabetes mellitus patients. In the present work, we review the important roles of heavy metals in islet function and diabetes development in which the in vitro, in vivo or human evidences are associated with exposure to zinc, arsenic, cadmium, mercury and nickel. Through this work, we summarize the evidence which suggests that some heavy metals may play an important role in diabetes mellitus as environmental risk factors.

  19. A heavy-metal home

    NASA Image and Video Library

    2016-05-30

    This 10.5-billion-year-old globular cluster, NGC 6496, is home to heavy-metal stars of a celestial kind! The stars comprising this spectacular spherical cluster are enriched with much higher proportions of metals — elements heavier than hydrogen and helium, are in astronomy curiously known as metals — than stars found in similar clusters. A handful of these high-metallicity stars are also variable stars, meaning that their brightness fluctuates over time. NGC 6496 hosts a selection of long-period variables — giant pulsating stars whose brightness can take up to, and even over, a thousand days to change — and short-period eclipsing binaries, which dim when eclipsed by a stellar companion. The nature of the variability of these stars can reveal important information about their mass, radius, luminosity, temperature, composition, and evolution, providing astronomers with measurements that would be difficult or even impossible to obtain through other methods. NGC 6496 was discovered in 1826 by Scottish astronomer James Dunlop. The cluster resides at about 35 000 light-years away in the southern constellation of Scorpius (The Scorpion).

  20. Heavy metals in Antarctic organisms

    SciTech Connect

    Moreno, J.E.A. de; Moreno, V.J.; Gerpe, M.S.; Vodopivez, C.

    1997-02-01

    To evaluate levels of essential (zinc and copper) and non-essential (mercury and cadmium) heavy metals, 34 species of organisms from different areas close to the Antarctic Peninsula were analysed. These included algae, filter-feeders, omnivorous invertebrates and vertebrates. Mercury was not detected, while cadmium was found in the majority of organisms analysed (detection limit was 0.05 ppm for both metals). The highest cadmium concentration was observed in the starfish Odontaster validus. Anthozoans, sipunculids and nudibranchs showed maximum levels of zinc, while the highest copper level was found in the gastropod Trophon brevispira. Mercury and cadmium levels in fishes were below the detection limit. Concentrations of essential and non-essential metals in birds were highest in liver followed by muscle and eggs. Cadmium and mercury levels in muscle of southern elephant seals were above the detection limit, whereas in Antarctic fur seals they were below it. The objective of the study was to gather baseline information for metals in Antarctic Ocean biota that may be needed to detect, measure and monitor future environmental changes. 46 refs., 7 figs., 8 tabs.

  1. Effect of heavy atoms in bioluminescent reactions.

    PubMed

    Kirillova, Tamara N; Kudryasheva, Nadezhda S

    2007-03-01

    Bioluminescent reactions of luminous organisms are excellent models for studying the effects of heavy atoms on enzymatic processes. The effects of potassium halides with halide anions of different atomic weight were compared in bioluminescent reactions of the firefly (Luciola mingrelica), a marine coelenterate (Obelia longissima), and a marine bacterium (Photobacterium leiognathi). Two mechanisms of the effects of the halides were examined-the physicochemical effect of the external heavy atom, based on spin-orbit interactions in electron-excited structures, and the biochemical effect, i.e. interactions with the enzymes resulting in changes of enzymatic activity. The physicochemical effect was evaluated by using photoexcitation of model fluorescent compounds (flavin mononucleotide, firefly luciferin, and coelenteramide) of similar structure to the bioluminescence emitters. The bioluminescent and photoluminescent inhibition coefficients were calculated and compared for the luminous organisms to evaluate the relative contributions of the two mechanisms. The biochemical mechanism was found to be dominant. Hence, the bioluminescent reactions can be used as assays to monitor enzyme inhibition, in metabolic processes, by Br or I-containing compounds.

  2. Relativistic heavy-atom effects on heavy-atom nuclear shieldings.

    PubMed

    Lantto, Perttu; Romero, Rodolfo H; Gómez, Sergio S; Aucar, Gustavo A; Vaara, Juha

    2006-11-14

    The principal relativistic heavy-atom effects on the nuclear magnetic resonance (NMR) shielding tensor of the heavy atom itself (HAHA effects) are calculated using ab initio methods at the level of the Breit-Pauli Hamiltonian. This is the first systematic study of the main HAHA effects on nuclear shielding and chemical shift by perturbational relativistic approach. The dependence of the HAHA effects on the chemical environment of the heavy atom is investigated for the closed-shell X(2+), X(4+), XH(2), and XH(3) (-) (X=Si-Pb) as well as X(3+), XH(3), and XF(3) (X=P-Bi) systems. Fully relativistic Dirac-Hartree-Fock calculations are carried out for comparison. It is necessary in the Breit-Pauli approach to include the second-order magnetic-field-dependent spin-orbit (SO) shielding contribution as it is the larger SO term in XH(3) (-), XH(3), and XF(3), and is equally large in XH(2) as the conventional, third-order field-independent spin-orbit contribution. Considering the chemical shift, the third-order SO mechanism contributes two-thirds of the difference of approximately 1500 ppm between BiH(3) and BiF(3). The second-order SO mechanism and the numerically largest relativistic effect, which arises from the cross-term contribution of the Fermi contact hyperfine interaction and the relativistically modified spin-Zeeman interaction (FC/SZ-KE), are isotropic and practically independent of electron correlation effects as well as the chemical environment of the heavy atom. The third-order SO terms depend on these factors and contribute both to heavy-atom shielding anisotropy and NMR chemical shifts. While a qualitative picture of heavy-atom chemical shifts is already obtained at the nonrelativistic level of theory, reliable shifts may be expected after including the third-order SO contributions only, especially when calculations are carried out at correlated level. The FC/SZ-KE contribution to shielding is almost completely produced in the s orbitals of the heavy atom

  3. Relativistic heavy-atom effects on heavy-atom nuclear shieldings

    NASA Astrophysics Data System (ADS)

    Lantto, Perttu; Romero, Rodolfo H.; Gómez, Sergio S.; Aucar, Gustavo A.; Vaara, Juha

    2006-11-01

    The principal relativistic heavy-atom effects on the nuclear magnetic resonance (NMR) shielding tensor of the heavy atom itself (HAHA effects) are calculated using ab initio methods at the level of the Breit-Pauli Hamiltonian. This is the first systematic study of the main HAHA effects on nuclear shielding and chemical shift by perturbational relativistic approach. The dependence of the HAHA effects on the chemical environment of the heavy atom is investigated for the closed-shell X2+, X4+, XH2, and XH3- (X =Si-Pb) as well as X3+, XH3, and XF3 (X =P-Bi) systems. Fully relativistic Dirac-Hartree-Fock calculations are carried out for comparison. It is necessary in the Breit-Pauli approach to include the second-order magnetic-field-dependent spin-orbit (SO) shielding contribution as it is the larger SO term in XH3-, XH3, and XF3, and is equally large in XH2 as the conventional, third-order field-independent spin-orbit contribution. Considering the chemical shift, the third-order SO mechanism contributes two-thirds of the difference of ˜1500ppm between BiH3 and BiF3. The second-order SO mechanism and the numerically largest relativistic effect, which arises from the cross-term contribution of the Fermi contact hyperfine interaction and the relativistically modified spin-Zeeman interaction (FC/SZ-KE), are isotropic and practically independent of electron correlation effects as well as the chemical environment of the heavy atom. The third-order SO terms depend on these factors and contribute both to heavy-atom shielding anisotropy and NMR chemical shifts. While a qualitative picture of heavy-atom chemical shifts is already obtained at the nonrelativistic level of theory, reliable shifts may be expected after including the third-order SO contributions only, especially when calculations are carried out at correlated level. The FC/SZ-KE contribution to shielding is almost completely produced in the s orbitals of the heavy atom, with values diminishing with the principal

  4. Multivariate analysis of heavy metals concentrations in river estuary.

    PubMed

    Alkarkhi, Abbas F M; Ahmad, Anees; Ismail, Norli; Easa, Azhar Mat

    2008-08-01

    Multivariate statistical techniques such as multivariate analysis of variance (MANOVA) and discriminant analysis (DA) were applied for analyzing the data obtained from two rivers in the Penang State of Malaysia for the concentration of heavy metal ions (As, Cr, Cd, Zn, Cu, Pb, and Hg) using a flame atomic absorption spectrometry (F-AAS) for Cr, Cd, Zn, Cu, Pb, As and cold vapor atomic absorption spectrometry (CV-AAS) for Hg. The two locations of interest with 20 sampling points of each location were Kuala Juru (Juru River) and Bukit Tambun (Jejawi River). MANOVA showed a strong significant difference between the two rivers in terms of heavy metal concentrations in water samples. DA gave the best result to identify the relative contribution for all parameters in discriminating (distinguishing) the two rivers. It provided an important data reduction as it used four parameters (Zn, Pb, Cd and Cr) affording 100% correct assignations. Results indicated that the two rivers were different in terms of heavy metals concentrations in water, and the major difference was due to the contribution of Zn. A negative correlation was found between discriminate functions (DF) and Cr and As, whereas positive correlation was exhibited with other heavy metals. Therefore, DA allowed a reduction in the dimensionality of the data set, delineating a few indicator parameters responsible for large variations in heavy metal concentrations. Correlation matrix between the parameters exhibited a strong evidence of mutual dependence of these metals.

  5. Heavy metal uptake of Geosiphon pyriforme

    NASA Astrophysics Data System (ADS)

    Scheloske, Stefan; Maetz, Mischa; Schüßler, Arthur

    2001-07-01

    Geosiphon pyriforme represents the only known endosymbiosis between a fungus, belonging to the arbuscular mycorrhizal (AM) fungi, and cyanobacteria (blue-green algae). Therefore we use Geosiphon as a model system for the widespread AM symbiosis and try to answer some basic questions regarding heavy metal uptake or resistance of AM fungi. We present quantitative micro-PIXE measurements of a set of heavy metals (Cu, Cd, Tl, Pb) taken up by Geosiphon-cells. The uptake is studied as a function of the metal concentration in the nutrient solution and of the time Geosiphon spent in the heavy metal enriched medium. The measured heavy metal concentrations range from several ppm to some hundred ppm. Also the influence of the heavy metal uptake on the nutrition transfer of other elements will be discussed.

  6. Arbuscular mycorrhiza and heavy metal tolerance.

    PubMed

    Hildebrandt, Ulrich; Regvar, Marjana; Bothe, Hermann

    2007-01-01

    Arbuscular mycorrhizal fungi (AMF) have repeatedly been demonstrated to alleviate heavy metal stress of plants. The current manuscript summarizes results obtained to date on the colonization of plants by AMF in heavy metal soils, the depositions of heavy metals in plant and fungal structures and the potential to use AMF-plant combinations in phytoremediation, with emphasis on pennycresses (Thlaspi ssp.). The focus of this manuscript is to describe and discuss studies on the expression of genes in plants and fungi under heavy metal stress. The summary is followed by data on differential gene expression in extraradical mycelia (ERM) of in vitro cultured Glomus intraradices Sy167 supplemented with different heavy metals (Cd, Cu or Zn). The expression of several genes encoding proteins potentially involved in heavy metal tolerance varied in their response to different heavy metals. Such proteins included a Zn transporter, a metallothionein, a 90 kD heat shock protein and a glutathione S-transferase (all assignments of protein function are putative). Studies on the expression of the selected genes were also performed with roots of Medicago truncatula grown in either a natural, Zn-rich heavy metal "Breinigerberg" soil or in a non-polluted soil supplemented with 100 microM ZnSO(4). The transcript levels of the genes analyzed were enhanced up to eight fold in roots grown in the heavy metal-containing soils. The data obtained demonstrate the heavy metal-dependent expression of different AMF genes in the intra- and extraradical mycelium. The distinct induction of genes coding for proteins possibly involved in the alleviation of damage caused by reactive oxygen species (a 90 kD heat shock protein and a glutathione S-transferase) might indicate that heavy metal-derived oxidative stress is the primary concern of the fungal partner in the symbiosis.

  7. Hazards of heavy metal contamination.

    PubMed

    Järup, Lars

    2003-01-01

    The main threats to human health from heavy metals are associated with exposure to lead, cadmium, mercury and arsenic. These metals have been extensively studied and their effects on human health regularly reviewed by international bodies such as the WHO. Heavy metals have been used by humans for thousands of years. Although several adverse health effects of heavy metals have been known for a long time, exposure to heavy metals continues, and is even increasing in some parts of the world, in particular in less developed countries, though emissions have declined in most developed countries over the last 100 years. Cadmium compounds are currently mainly used in re-chargeable nickel-cadmium batteries. Cadmium emissions have increased dramatically during the 20th century, one reason being that cadmium-containing products are rarely re-cycled, but often dumped together with household waste. Cigarette smoking is a major source of cadmium exposure. In non-smokers, food is the most important source of cadmium exposure. Recent data indicate that adverse health effects of cadmium exposure may occur at lower exposure levels than previously anticipated, primarily in the form of kidney damage but possibly also bone effects and fractures. Many individuals in Europe already exceed these exposure levels and the margin is very narrow for large groups. Therefore, measures should be taken to reduce cadmium exposure in the general population in order to minimize the risk of adverse health effects. The general population is primarily exposed to mercury via food, fish being a major source of methyl mercury exposure, and dental amalgam. The general population does not face a significant health risk from methyl mercury, although certain groups with high fish consumption may attain blood levels associated with a low risk of neurological damage to adults. Since there is a risk to the fetus in particular, pregnant women should avoid a high intake of certain fish, such as shark, swordfish and

  8. Coal combustion and heavy metals pollution

    SciTech Connect

    Danihelka, P.; Ochodek, T.; Borovec, K.

    1996-12-31

    Combustion of coal may be an important source of heavy metals pollution. The major environmental risks of heavy metals are connected to their toxicity and mobility in the environment. In the flame, heavy metals are re-distributed with respect to their volatility. Enrichment of fine particles by volatile metals is the most important mechanism for most of the metals. Nevertheless, Hg is emitted mainly in gaseous form and some metals like Mn are concentrated rather in coarse particles. Heavy metals pollution caused by emissions from combustion of coal may be decreased by fine particles removal; other possibilities (metals extraction from the coal, changes of condition in the flame) are limited. Fly ashes from the most important Czech power plants were examined with respect to the heavy metals content. The easily leachable elements with high volatility in the flame (arsenic, zinc, lead) were recognized as the most important fly ash pollutants. The average concentrations of these metals in fly ash were: bituminous coal 46{+-}18 ppm As, 196{+-}93 ppm Zn, 126{+-}46 ppm Pb; brown coal 283{+-}260 ppm As, 60{+-}28 ppm Pb and 212{+-}116 ppm Zn. When ESP and cyclones are used in series, fly ashes from ESP have higher concentration of volatile heavy metals, mainly Pb, Zn and As. Presence of chlorine in fuel increases the volatility of metals.

  9. Heavy Metal Music and Adolescent Suicidal Risk.

    ERIC Educational Resources Information Center

    Lacourse, Eric; Claes, Michel; Villeneuve, Martine

    2001-01-01

    Studied differentiating characteristics of youth who prefer heavy metal music, worship music, and use music for vicarious release. Data for 275 secondary school students suggest that heavy metal music preference and worshipping is not related to suicidal risk when controlling for other suicide factors. Discusses findings in the context of…

  10. Heavy Metal, Religiosity, and Suicide Acceptability.

    ERIC Educational Resources Information Center

    Stack, Steven

    1998-01-01

    Reports on data taken from the General Social Survey that found a link between "heavy metal" rock fanship and suicide acceptability. Finds that relationship becomes nonsignificant once level of religiosity is controlled. Heavy metal fans are low in religiosity, which contributes to greater suicide acceptability. (Author/JDM)

  11. Heavy Metal Music and Adolescent Suicidal Risk.

    ERIC Educational Resources Information Center

    Lacourse, Eric; Claes, Michel; Villeneuve, Martine

    2001-01-01

    Studied differentiating characteristics of youth who prefer heavy metal music, worship music, and use music for vicarious release. Data for 275 secondary school students suggest that heavy metal music preference and worshipping is not related to suicidal risk when controlling for other suicide factors. Discusses findings in the context of…

  12. Heavy Metal, Religiosity, and Suicide Acceptability.

    ERIC Educational Resources Information Center

    Stack, Steven

    1998-01-01

    Reports on data taken from the General Social Survey that found a link between "heavy metal" rock fanship and suicide acceptability. Finds that relationship becomes nonsignificant once level of religiosity is controlled. Heavy metal fans are low in religiosity, which contributes to greater suicide acceptability. (Author/JDM)

  13. Effect of heavy metals on soil fungi

    NASA Astrophysics Data System (ADS)

    Sosak-Świderska, Bożena

    2010-05-01

    Fungi constitute a high proportion of the microbial biomass in soil.Being widespread in soil their large surface-to-volume ratio and high metabolic activity, fungi can contribute significantly to heavy metal dynamics in soil. At neutral pH heavy metals in soils tend to be immobilized to precipitation and/or absorption to cation exchange sites of clay minerals. In the acidic soils, metals are more mobile and enter food webs easier. Microbial production of acids and chelating agents can mobilize to toxic metals. Mobilization is often by uptake and intracellular accumulation of the heavy metlas, and in this way, the bioavailability of metals towards other organisms can be more reduced. Fungi were isolated from soils from Upper Silesia in Poland and belonged to widespread genera: Aspergillus, Cladosporium, Penicillium and Trichoderma. Fungi from different taxonomic groups differ greatly in their tolerance to heavy metals. This could be related to their wall structure and chemistry as well as biochemical and physiological characteristics of fungi. Localization of metals in fungal cells was studied using electron microscopy analysis. Metal biosorption in the cell wall can be complex as melanin granules. Fungal vacuoles have an important role in the regulation of the cytosolic concentration of metal ions, and may contribute to heavy metal tolerance.In polluted soils with heavy metals, fungal species composition can be changed and their physiological activity can be changed, too.

  14. Flame atomic absorption spectrometric determination of heavy metals in aqueous solution and surface water preceded by co-precipitation procedure with copper(II) 8-hydroxyquinoline

    NASA Astrophysics Data System (ADS)

    Ipeaiyeda, Ayodele Rotimi; Ayoade, Abisayo Ruth

    2017-07-01

    Co-precipitation procedure has widely been employed for preconcentration and separation of metal ions from the matrices of environmental samples. This is simply due to its simplicity, low consumption of separating solvent and short duration for analysis. Various organic ligands have been used for this purpose. However, there is dearth of information on the application of 8-hydroxyquinoline (8-HQ) as ligand and Cu(II) as carrier element. The use of Cu(II) is desirable because there is no contamination and background adsorption interference. Therefore, the objective of this study was to use 8-HQ in the presence of Cu(II) for coprecipitation of Cd(II), Co(II), Cr(III), Ni(II) and Pb(II) from standard solutions and surface water prior to their determinations by flame atomic absorption spectrometry (FAAS). The effects of pH, sample volume, amount of 8-HQ and Cu(II) and interfering ions on the recoveries of metal ions from standard solutions were monitored using FAAS. The water samples were treated with 8-HQ under the optimum experimental conditions and metal concentrations were determined by FAAS. The metal concentrations in water samples not treated with 8-HQ were also determined. The optimum recovery values for metal ions were higher than 85.0%. The concentrations (mg/L) of Co(II), Ni(II), Cr(III), and Pb(II) in water samples treated with 8-HQ were 0.014 ± 0.002, 0.03 ± 0.01, 0.04 ± 0.02 and 0.05 ± 0.02, respectively. These concentrations and those obtained without coprecipitation technique were significantly different. Coprecipitation procedure using 8-HQ as ligand and Cu(II) as carrier element enhanced the preconcentration and separation of metal ions from the matrix of water sample.

  15. Heavy Metals Toxicity and the Environment

    PubMed Central

    Tchounwou, Paul B; Yedjou, Clement G; Patlolla, Anita K; Sutton, Dwayne J

    2013-01-01

    Heavy metals are naturally occurring elements that have a high atomic weight and a density at least 5 times greater than that of water. Their multiple industrial, domestic, agricultural, medical and technological applications have led to their wide distribution in the environment; raising concerns over their potential effects on human health and the environment. Their toxicity depends on several factors including the dose, route of exposure, and chemical species, as well as the age, gender, genetics, and nutritional status of exposed individuals. Because of their high degree of toxicity, arsenic, cadmium, chromium, lead, and mercury rank among the priority metals that are of public health significance. These metallic elements are considered systemic toxicants that are known to induce multiple organ damage, even at lower levels of exposure. They are also classified as human carcinogens (known or probable) according to the U.S. Environmental Protection Agency, and the International Agency for Research on Cancer. This review provides an analysis of their environmental occurrence, production and use, potential for human exposure, and molecular mechanisms of toxicity, genotoxicity, and carcinogenicity. PMID:22945569

  16. Atomic oxygen effects on metals

    NASA Technical Reports Server (NTRS)

    Fromhold, Albert T.

    1987-01-01

    The effect of specimen geometry on the attack of metals by atomic oxygen is addressed. This is done by extending the coupled-currents approach in metal oxidation to spherical and cylindrical geometries. Kinetic laws are derived for the rates of oxidation of samples having these geometries. It is found that the burn-up time for spherical particles of a given diameter can be as much as a factor of 3 shorter than the time required to completely oxidize a planar sample of the same thickness.

  17. Atomic displacements in transition metals

    NASA Astrophysics Data System (ADS)

    Moghadam, Nassrin Y.

    Using the order-N locally-self-consistent multiple scattering (LSMS) method, we carry out first-principles studies of the displacement of atoms from their average sites in the vicinity of a vacancy and transition metal impurities in copper. Our approach is to relax the first nearest neighbor distance and to calculate total energy for a number of relaxed geometries. We then obtain the equilibrium configuration of the nuclei from minimization of the total energy.

  18. Heavy metals contamination of table salt consumed in iran.

    PubMed

    Cheraghali, Abdol Majid; Kobarfard, Farzad; Faeizy, Noroldin

    2010-01-01

    Lead, cadmium, mercury and arsenic are the most important heavy metals which may cause health risks following consumption of contaminated foods. Table salt is one the mostly used food additive with unique place in food consumption. Although purified table salt is expected to have lower level of contamination, some Iranians still prefer to use rock salt. Use of rock salt for food purposes has been banned by Iranian health authorities. In this study, heavy metal contamination of table salt consumed in Iran has been investigated. One hundred samples of rock and refined table salts were analyzed using atomic absorption spectrophotometeric methods for the presence of toxic heavy metals. The mean concentration of tested tracer metals including Cd, Pb, Hg and As was 0.024, 0.438, 0.021 and 0.094 μg/g, respectively. The concentrations of tested heavy metals were well below the maximum levels set by Codex. However, no statistically significant difference was found between contamination of rock salt and refined salt to heavy metals.

  19. Heavy atom isotope effects on enzymatic reactions

    NASA Astrophysics Data System (ADS)

    Paneth, Piotr

    1994-05-01

    The theory of isotope effects, which has proved to be extremely useful in providing geometrical details of transition states in a variety of chemical reactions, has recently found an application in studies of enzyme-catalyzed reactions. These reactions are multistep in nature with few steps being partially rate-limiting, thus interpretation of these isotope effects is more complex. The theoretical framework of heavy-atom isotope effects on enzymatic reactions is critically analyzed on the basis of recent results of: carbon kinetic isotope effects on carbonic anhydrase and catalytic antibodies; multiple carbon, deuterium isotope effects on reactions catalyzed by formate decarboxylase; oxygen isotope effects on binding processes in reactions catalyzed by pyruvate kinase; and equilibrium oxygen isotope effect on binding an inhibitor to lactate dehydrogenase. The advantages and disadvantages of reaction complexity in learning details of formal and molecular mechanisms are discussed in the examples of reactions catalyzed by phosphoenolpyruvate carboxylase, orotidine decarboxylase and glutamine synthetase.

  20. Heavy metals in canned tuna from Italian markets.

    PubMed

    Russo, R; Lo Voi, A; De Simone, A; Serpe, F P; Anastasio, A; Pepe, T; Cacace, D; Severino, L

    2013-02-01

    Fish is a good source of nutrients for humans but can pose a risk to human health because of the possible presence of some xenobiotics such as heavy metals and persistent organic contaminants. Constant monitoring is needed to minimize health risks and ensure product quality and consumer safety. The aim of the present study was to use atomic absorption spectrometry to determine the concentrations of some heavy metals (Hg, Pb, and Cd) in tuna packaged in different kinds of packages (cans or glass) in various countries (Italy and elsewhere). Concentrations of Cd and Hg were within the limits set by European Commission Regulation (EC) No 1881/2006 and in many samples were below the detection limit. Pb concentrations exceeded European limits in 9.8% of the analyzed samples. These results are reassuring in terms of food safety but highlighted the need to constantly monitor the concentrations of heavy metals in fish products that could endanger consumer health.

  1. Heavy metals intake by cultured mushrooms growing in model system.

    PubMed

    Ozcan, Mehmet Musa; Dursun, Nesim; Al Juhaimi, Fahad Y

    2013-10-01

    Micro element and heavy metal contents of mushrooms were determined by Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES). It was seen an increase in the heavy metal contents (except Cu and Zn) of the mushrooms until the second dose. A decrease was seen in heavy metal intake of the mushroom in the application of the third dose. The highest accumulation occurred from the upper soils treated with the second dose. Amounts of Cd, Cr, Cu, Pb and Zn, which were accumulated in the mushroom after the application of this dose, were detected as 5.7, 23.1, 75.7, 62.8 and 99.3 ppm, respectively.

  2. Investigation of (235)U, (226)Ra, (232)Th, (40)K, (137)Cs, and heavy metal concentrations in Anzali international wetland using high-resolution gamma-ray spectrometry and atomic absorption spectroscopy.

    PubMed

    Zare, Mohammad Reza; Kamali, Mahdi; Fallahi Kapourchali, Maryam; Bagheri, Hashem; Khoram Bagheri, Mahdi; Abedini, Ali; Pakzad, Hamid Reza

    2016-02-01

    Measurements of natural radioactivity levels and heavy metals in sediment and soil samples of the Anzali international wetland were carried out by two HPGe-gamma ray spectrometry and atomic absorption spectroscopy techniques. The concentrations of (235)U, (226)Ra, (232)Th, (40)K, and (137)Cs in sediment samples ranged between 1.05 ± 0.51-5.81 ± 0.61, 18.06 ± 0.63-33.36 ± .0.34, 17.57 ± 0.38-45.84 ± 6.23, 371.88 ± 6.36-652.28 ± 11.60, and 0.43 ± 0.06-63.35 ± 0.94 Bq/kg, while in the soil samples they vary between 2.36-5.97, 22.71-38.37, 29.27-42.89, 472.66-533, and 1.05-9.60 Bq/kg for (235)U, (226)Ra, (232)Th, (40)K, and (137)Cs, respectively. Present results are compared with the available literature data and also with the world average values. The radium equivalent activity was well below the defined limit of 370 Bq/kg. The external hazard indices were found to be less than 1, indicating a low dose. Heavy metal concentrations were found to decrease in order as Fe > Mn > Sr > Zn > Cu > Cr > Ni > Pb > Co > Cd. These measurements will serve as background reference levels for the Anzali wetland.

  3. Monitoring of trace amounts of heavy metals in different food and water samples by flame atomic absorption spectrophotometer after preconcentration by amine-functionalized graphene nanosheet.

    PubMed

    Behbahani, Mohammad; Tapeh, Nasim Akbari Ghareh; Mahyari, Mojtaba; Pourali, Ali Reza; Amin, Bahareh Golrokh; Shaabani, Ahmad

    2014-11-01

    We are introducing graphene oxide modified with amine groups as a new solid phase for extraction of heavy metal ions including cadmium(II), copper(II), nickel(II), zinc(II), and lead(II). Effects of pH value, flow rates, type, concentration, and volume of the eluent, breakthrough volume, and the effect of potentially interfering ions were studied. Under optimized conditions, the extraction efficiency is >97 %, the limit of detections are 0.03, 0.05, 0.2, 0.1, and 1 μg L(-1) for the ions of cadmium, copper, nickel, zinc, and lead, respectively, and the adsorption capacities for these ions are 178, 142, 110, 125, and 210 mg g(-1). The amino-functionalized graphene oxide was characterized by thermogravimetric analysis, transmission electron microscopy, scanning electron microscopy, and Fourier transform infrared spectrometry. The proposed method was successfully applied in the analysis of environmental water and food samples. Good spiked recoveries over the range of 95.8-100.0 % were obtained. This work not only proposes a useful method for sample preconcentration but also reveals the great potential of modified graphene as an excellent sorbent material in analytical processes.

  4. Heavy metal contamination from geothermal sources.

    PubMed

    Sabadell, J E; Axtmann, R C

    1975-12-01

    Liquid-dominated hydrothermal reservoirs, which contain saline fluids at high temperatures and pressures, have a significant potential for contamination of the environment by heavy metals. The design of the power conversion cycle in a liquid-dominated geothermal plant is a key factor in determining the impact of the installation. Reinjection of the fluid into the reservoir minimizes heavy metal effluents but is routinely practiced at few installations. Binary power cycles with reinjection would provide even cleaner systems but are not yet ready for commercial application. Vapor-dominated systems, which contain superheated steam, have less potential for contamination but are relatively uncommon. Field data on heavy metal effluents from geothermal plants are sparse and confounded by contributions from "natural" sources such as geysers and hot springs which often exist nearby. Insofar as geothermal power supplies are destined to multiply, much work is required on their environmental effects including those caused by heavy metals.

  5. Removal of heavy metals from waste streams

    SciTech Connect

    Spence, M.D.; Kozaruk, J.M.; Melvin, M.; Gardocki, S.M.

    1988-07-19

    A method for removing heavy metals from effluent water is described comprising performing sequentially the following steps: (a) adding from 7-333 ppm of an anionic surfactant to the effluent water to provide coagulatable heavy metal ion; (b) adjusting the effluent water pH to within the range of 8 to 10, (c) providing from 10-200 ppm of a cationic coagulant to coagulate the heavy metal ion, (d) providing from 0.3 to 5.0 ppm of a polymeric flocculant whereby a heavy metal containing floc is formed for removal from the effluent water, and, (e) then removing the floc from the effluent water, wherein the anionic surfactant is sodium lauryl ether sulfate. The cationic coagulant is selected from the group consisting of diallyl dimethylammonium chloride polymer, epichlorohydrin dimethylamine polymer, ethylene amine polymer, polyaluminum chloride, and alum; and the flocculant is an acrylamide/sodium acrylate copolymer having an RSV greater than 23.

  6. Heavy metal contamination from geothermal sources.

    PubMed Central

    Sabadell, J E; Axtmann, R C

    1975-01-01

    Liquid-dominated hydrothermal reservoirs, which contain saline fluids at high temperatures and pressures, have a significant potential for contamination of the environment by heavy metals. The design of the power conversion cycle in a liquid-dominated geothermal plant is a key factor in determining the impact of the installation. Reinjection of the fluid into the reservoir minimizes heavy metal effluents but is routinely practiced at few installations. Binary power cycles with reinjection would provide even cleaner systems but are not yet ready for commercial application. Vapor-dominated systems, which contain superheated steam, have less potential for contamination but are relatively uncommon. Field data on heavy metal effluents from geothermal plants are sparse and confounded by contributions from "natural" sources such as geysers and hot springs which often exist nearby. Insofar as geothermal power supplies are destined to multiply, much work is required on their environmental effects including those caused by heavy metals. PMID:1227849

  7. Heavy Metals in Seafood and Farm Produce from Uyo, Nigeria

    PubMed Central

    Orisakwe, Orish E.; Mbagwu, Herbert O. C.; Ajaezi, Godwin C.; Edet, Ukeme W.; Uwana, Patrick U.

    2015-01-01

    Objectives: This study aimed to obtain representative data on the levels of heavy metals in seafood and farm produce consumed by the general population in Uyo, Akwa Ibom State, Nigeria, a region known for the exploration and exploitation of crude oil. Methods: In May 2012, 25 food items, including common types of seafood, cereals, root crops and vegetables, were purchased in Uyo or collected from farmland in the region. Dried samples were ground, digested and centrifuged. Levels of heavy metals (lead, cadmium, nickel, cobalt and chromium) were analysed using an atomic absorption spectrophotometer. Average daily intake and target hazard quotients (THQ) were estimated. Results: Eight food items (millet, maize, periwinkle, crayfish, stock fish, sabina fish, bonga fish and pumpkin leaf) had THQ values over 1.0 for cadmium, indicating a potential health risk in their consumption. All other heavy metals had THQ values below 1.0, indicating insignificant health risks. The total THQ for the heavy metals ranged from 0.389 to 2.986. There were 14 items with total THQ values greater than 1.0, indicating potential health risks in their consumption. Conclusion: The regular consumption of certain types of farm produce and seafood available in Uyo, Akwa Ibom State, Nigeria, is likely adding to the body burden of heavy metals among those living in this region. PMID:26052462

  8. Enhanced Reverse Saturable Absorption and Optical Limiting in Heavy-Atom Substituted Phthalocyanines

    NASA Technical Reports Server (NTRS)

    Perry, J. W.; Mansour, K.; Marder, S. R.; Alvarez, D., Jr.; Perry, K. J.; Choong, I.

    1994-01-01

    The reverse saturable absorption and optical limiting response of metal phthalocyaninies can be enhanced by using the heavy-atom effect. Phthalocyanines containing heavy metal atoms, such as In, Sn, and Pb show nearly a factor of two enhancement in the ratio of effective excited-state to ground-state absorption cross sections compared to those containing lighter atoms, such as Al and Si. In an f/8 optical geometry, homogeneous solutions of heavy metal phthalocyanines, at 30% linear transmission, limit 8-ns, 532-nm laser pulses to less than or equal to 3 (micro)J (the energy for 50% probability of eye damage) for incident pulses up to 800 (micro)J.

  9. Enhanced Reverse Saturable Absorption and Optical Limiting in Heavy-Atom Substituted Phthalocyanines

    NASA Technical Reports Server (NTRS)

    Perry, J. W.; Mansour, K.; Marder, S. R.; Alvarez, D., Jr.; Perry, K. J.; Choong, I.

    1994-01-01

    The reverse saturable absorption and optical limiting response of metal phthalocyaninies can be enhanced by using the heavy-atom effect. Phthalocyanines containing heavy metal atoms, such as In, Sn, and Pb show nearly a factor of two enhancement in the ratio of effective excited-state to ground-state absorption cross sections compared to those containing lighter atoms, such as Al and Si. In an f/8 optical geometry, homogeneous solutions of heavy metal phthalocyanines, at 30% linear transmission, limit 8-ns, 532-nm laser pulses to less than or equal to 3 (micro)J (the energy for 50% probability of eye damage) for incident pulses up to 800 (micro)J.

  10. Heavy metals and living systems: An overview

    PubMed Central

    Singh, Reena; Gautam, Neetu; Mishra, Anurag; Gupta, Rajiv

    2011-01-01

    Heavy metals are natural constituents of the earth's crust, but indiscriminate human activities have drastically altered their geochemical cycles and biochemical balance. This results in accumulation of metals in plant parts having secondary metabolites, which is responsible for a particular pharmacological activity. Prolonged exposure to heavy metals such as cadmium, copper, lead, nickel, and zinc can cause deleterious health effects in humans. Molecular understanding of plant metal accumulation has numerous biotechnological implications also, the long term effects of which might not be yet known. PMID:21713085

  11. Heavy metal removal and recovery using microorganisms

    SciTech Connect

    Wilde, E.W. ); Benemann, J.R. , Pinole, CA )

    1991-02-01

    Microorganisms -- bacteria, fungi, and microalgae -- can accumulate relatively large amounts of toxic heavy metals and radionuclides from the environment. These organisms often exhibit specificity for particular metals. The metal content of microbial biomass can be a substantial fraction of total dry weight with concentration factors (metal in dry biomass to metal in solution) exceeding one million in some cases. Both living and inert (dead) microbial biomass can be used to reduce heavy metal concentrations in contaminated waters to very low levels -- parts per billion and even lower. In many respects (e.g. specificity, residual metal concentrations, accumulation factors, and economics) microbial bioremoval processes can be superior to conventional processes, such as ion exchange and caustic (lime or hydroxide) precipitation for heavy metals removal from waste and contaminated waters. Thus, bioremoval could be developed to contribute to the clean-up of wastes at the Savannah River Site (SRS) and other DOE facilities. However, the potential advantages of bioremoval processes must still be developed into practical operating systems. A detailed review of the literature suggests that appropriate bioremoval processes could be developed for the SRS. There is great variability from one biomass source to another in bioremoval capabilities. Bioremoval is affected by pH, other ions, temperature, and many other factors. The biological (living vs. dead) and physical (immobilized vs. dispersed) characteristics of the biomass also greatly affect metal binding. Even subtle differences in the microbial biomass, such as the conditions under which it was cultivated, can have major effects on heavy metal binding.

  12. Heavy Metals and the Petroleum Industr

    DTIC Science & Technology

    1993-05-01

    geosphere and hydrosphere. Table 2.2 lists the elemental composition of native soils from an oilfield . The average concentration of metals in both...monitored these sources of metals are generally restricted according to applicable regulations. In industrialized areas the magnitude of wastewater and...into local sewage systems . Another industrial source of heavy metals is atmospheric emissions. Metals enter the atmosphere as a vapor and as particulates

  13. Quantum Electrodynamics Effects in Heavy Ions and Atoms

    SciTech Connect

    Shabaev, V. M.; Andreev, O. V.; Bondarev, A. I.; Glazov, D. A.; Kozhedub, Y. S.; Maiorova, A. V.; Tupitsyn, I. I.; Plunien, G.; Volotka, A. V.

    2011-05-11

    Quantum electrodynamics theory of heavy ions and atoms is considered. The current status of calculations of the binding energies, the hyperfine splitting and g factor values in heavy few-electron ions is reviewed. The theoretical predictions are compared with available experimental data. A special attention is focused on tests of quantum electrodynamics in strong electromagnetic fields and on determination of the fundamental constants. Recent progress in calculations of the parity nonconservation effects with heavy atoms and ions is also reported.

  14. Heavy Metal Risk Management: Case Analysis

    PubMed Central

    Kim, Ji Ae; Lee, Seung Ha; Choi, Seung Hyun; Jung, Ki Kyung; Park, Mi Sun; Jeong, Ji Yoon; Hwang, Myung Sil; Yoon, Hae Jung; Choi, Dal Woong

    2012-01-01

    To prepare measures for practical policy utilization and the control of heavy metals, hazard control related institutions by country, present states of control by country, and present states of control by heavy metals were examined. Hazard control cases by heavy metals in various countries were compared and analyzed. In certain countries (e.g., the U.S., the U.K., and Japan), hazardous substances found in foods (e.g., arsenic, lead, cadmium, and mercury) are controlled. In addition, the Joint FAO/WHO Expert Committee on Food Additives (JECFA) recommends calculating the provisional tolerable weekly intake (PTWI) of individual heavy metals instead of the acceptable daily intake (ADI) to compare their pollution levels considering their toxicity accumulated in the human body. In Korea, exposure assessments have been conducted, and in other countries, hazardous substances are controlled by various governing bodies. As such, in Korea and other countries, diverse food heavy metal monitoring and human body exposure assessments are conducted, and reducing measures are prepared accordingly. To reduce the danger of hazardous substances, many countries provide leaflets and guidelines, develop hazardous heavy metal intake recommendations, and take necessary actions. Hazard control case analyses can assist in securing consumer safety by establishing systematic and reliable hazard control methods. PMID:24278603

  15. Simultaneous removal of nitrate and heavy metals by iron metal.

    PubMed

    Hao, Zhi-Wei; Xu, Xin-Hua; Jin, Jian; He, Ping; Liu, Yong; Wang, Da-Hui

    2005-05-01

    Great attention should be paid now to simultaneously removing common pollutants, especially inorganic pollutants such as nitrate and heavy metals, as individual removal has been investigated extensively. Removing common pollutants simultaneously by iron metal is a very effective alternative method. Near neutral pH, heavy metals, such as copper and nickel, can be removed rapidly by iron metal, while nitrate removal very much slower than that of copper and nickel, and copper can accelerate nitrate removal when both are removed simultaneously. Even a little amount of copper can enhance nitrate removal efficiently. Different mechanisms of these contaminants removal by iron metal were also discussed.

  16. Strong Exchange Anisotropy in Heavy Atom Radical Ferromagnets

    NASA Astrophysics Data System (ADS)

    Winter, Stephen

    2012-02-01

    The discovery twenty years ago of ferromagnetic ordering in ``light atom'' p-block (N, O based) radicals appeared to provide a major conceptual advance, suggesting the possibility of a new era in non-metal molecular magnetism. However, the weak through-space magnetic exchange interactions present in these early radical-based ferromagnets afforded very low Curie temperatures TC (< 2 K), and the localization of spin density on light atoms ensured low coercive fields Hc (< 100 Oe). In this context, the observation of ferromagnetic ordering in ``heavy atom'' (Se) radicals, with TC as high as 17 K and coercive fields Hc up to 1370 Oe (at 2 K), represents a significant improvement in properties. This presentation will provide a theoretical and experimental examination of the source of the large coercive fields reported for these ``heavy atom'' radical ferromagnets. High-field ferromagnetic resonance (FMR) measurements, interpreted in the context of the anisotropic exchange interactions between the radicals in the solid state, leads to the conclusion that spin-orbit effects are responsible for the large observed magnetic anisotropy. This conclusion is supported by detailed analysis of the symmetry and magnitude of the spin-orbit interactions. An interesting discussion is the extent to which these anisotropic exchange terms also contribute to the enhancement of TC. That is, in the field of organic magnetism, where low dimensional magnetic structures are commonly found, long range ordering may depend crucially on such anisotropy. [4pt] See JACS 130, 8414-8425 (2008), JACS 133, 8126-8129 (2011).

  17. ANALYSIS OF HEAVY METALS IN STORMWATER

    EPA Science Inventory

    Stormwater sampling for colloidal and dissolved metals and organic carbon has been initiated at six outfalls draining locally-designated, nonindustrial land uses in Monmouth County, NJ. Of the heavy metals, only Cu and Zn were found in all samples, mostly in dissolved form. Large...

  18. ANALYSIS OF HEAVY METALS IN STORMWATER

    EPA Science Inventory

    Stormwater sampling for colloidal and dissolved metals and organic carbon has been initiated at six outfalls draining locally-designated, nonindustrial land uses in Monmouth County, NJ. Of the heavy metals, only Cu and Zn were found in all samples, mostly in dissolved form. Large...

  19. Prediction of Heavy Metal Uptake by Marsh Plants Based on Chemical Extraction of Heavy Metals from Dredged Material.

    DTIC Science & Technology

    1978-02-01

    A field and laboratory study was conducted to establish the extent of heavy metal absorption and uptake by marsh plant species from dredged material...emphasizes the need for a method to predict heavy metal availability from dredged material to plants. DTPA extraction of heavy metals gave the best correlations with actual heavy metal concentrations in marsh plants.

  20. The heavy metal subculture and suicide.

    PubMed

    Stack, S; Gundlach, J; Reeves, J L

    1994-01-01

    The impact of the heavy metal music subculture on suicide has been the subject of much public debate but little scholarly research. The present paper assesses this relationship with data on heavy metal magazine subscriptions and youth suicide in the 50 states. We find that, controlling for other predictors of suicide, the greater the strength of the metal subculture, the higher the youth suicide rate. The music perhaps nurtures suicidal tendencies already present in the subculture. The model explains 51% of the variance in youth suicide.

  1. Heavy Metal Poisoning and Cardiovascular Disease

    PubMed Central

    Alissa, Eman M.; Ferns, Gordon A.

    2011-01-01

    Cardiovascular disease (CVD) is an increasing world health problem. Traditional risk factors fail to account for all deaths from CVD. It is mainly the environmental, dietary and lifestyle behavioral factors that are the control keys in the progress of this disease. The potential association between chronic heavy metal exposure, like arsenic, lead, cadmium, mercury, and CVD has been less well defined. The mechanism through which heavy metals act to increase cardiovascular risk factors may act still remains unknown, although impaired antioxidants metabolism and oxidative stress may play a role. However, the exact mechanism of CVD induced by heavy metals deserves further investigation either through animal experiments or through molecular and cellular studies. Furthermore, large-scale prospective studies with follow up on general populations using appropriate biomarkers and cardiovascular endpoints might be recommended to identify the factors that predispose to heavy metals toxicity in CVD. In this review, we will give a brief summary of heavy metals homeostasis, followed by a description of the available evidence for their link with CVD and the proposed mechanisms of action by which their toxic effects might be explained. Finally, suspected interactions between genetic, nutritional and environmental factors are discussed. PMID:21912545

  2. Recovering heavy rare earth metals from magnet scrap

    DOEpatents

    Ott, Ryan T.; McCallum, Ralph W.; Jones, Lawrence L.

    2017-08-08

    A method of treating rare earth metal-bearing permanent magnet scrap, waste or other material in a manner to recover the heavy rare earth metal content separately from the light rare earth metal content. The heavy rare earth metal content can be recovered either as a heavy rare earth metal-enriched iron based alloy or as a heavy rare earth metal based alloy.

  3. [Heavy metals in water of drinking fountains].

    PubMed

    Segura-Muñoz, Susana I; Trevilato, Tânia M; Takayanagui, Angela M; Hering, Sylvia E; Cupo, Palmira

    2003-03-01

    The purpose of this study was to analyze the levels of lead (Pb), cadmium (Cd), aluminum (Al), zinc (Zn), cooper (Cu) and chromium (Cr) in the water of drinking fountains distributed in the Campus of the University of São Paulo. Ribeirão Preto, Brazil. Thirty random samples were collected in different parts of the Campus that were analyzed by Atomic Absorption Spectrophotometry. According to WHO's Drinking Water Guidelines; lead, cadmium and zinc were found in concentrations higher than those recommended in 40%, 20% and 13% of the samples, respectively. The results were analyzed considering nutritional and toxicological aspects related to the presence of essential and toxic elements for the human being. Reviewing the regulatory limits established in ten countries of America, authors focus in the necessity to find a consensus in the establishment of the higher levels of heavy metals in potable water. The tolerable daily intake, have to be the basis to assure the prevention of diseases associated with a long-term ingestion of these elements through foods.

  4. Community Heavy Metal Exposure, San Francisco, California

    NASA Astrophysics Data System (ADS)

    Chavez, A.; Devine, M.; Ho, T.; Zapata, I.; Bissell, M.; Neiss, J.

    2008-12-01

    Heavy metals are natural elements that generally occur in minute concentrations in the earth's crust. While some of these elements, in small quantities, are vital to life, most are harmful in larger doses. Various industrial and agricultural processes can result in dangerously high concentrations of heavy metals in our environment. Consequently, humans can be exposed to unsafe levels of these elements via the air we breathe, the water and food we consume, and the many products we use. During a two week study we collected numerous samples of sediments, water, food, and household items from around the San Francisco Bay Area that represent industrial, agricultural, and urban/residential settings. We analyzed these samples for Mercury (Hg), Lead (Pb), and Arsenic (As). Our goal was to examine the extent of our exposure to heavy metals in our daily lives. We discovered that many of the common foods and materials in our lives have become contaminated with unhealthy concentrations of these metals. Of our food samples, many exceeded the EPA's Maximum Contaminant Levels (MCL) set for each metal. Meats (fish, chicken, and beef) had higher amounts of each metal than did non-meat items. Heavy metals were also prevalent in varying concentrations in the environment. While many of our samples exceeded the EPA's Sediment Screening Level (SSL) for As, only two other samples surpassed the SSL set for Pb, and zero of our samples exceeded the SSL for Hg. Because of the serious health effects that can result from over-exposure to heavy metals, the information obtained in this study should be used to influence our future dietary and recreational habits.

  5. Trends in speciation analysis of some heavy metals in serum of patients with chronic hepatitis C and chronic hepatitis B using differential pulse adsorptive stripping voltammetric measurement and atomic absorption spectrophotometry.

    PubMed

    Rashed, Mohamed Nageeb; Ahmed, Mahasen Mohamed; Al-Hossainy, Ahmed Farouk; Abd, Safaa Mahmoud

    2010-04-01

    The relationships between chronic liver diseases and trace heavy metal contents in blood are debatable and have not been understood clearly. The present study is undertaken to determine Co, Fe, and Ni concentrations in sera from viral hepatitis patients. In all eighty patients with chronic hepatitis (B, C) and 29 healthy individuals were chosen for this study. Donors were selected from different environmental areas, including Aswan, Kom Ombo, and Edfu as polluted areas, and Daraw as an unpolluted area. Co, Fe, and Ni concentrations in patient and healthy blood serum were measured by two different analytical techniques: differential pulse adsorptive stripping voltammetry (DPA(d)SV) and atomic absorption spectrophotometer (AAS). The results reveal that Fe is present in higher level in the blood serum of hepatitis patients than in the healthy control, whereas Co and Ni showed the opposite trend. Hepatitis patients from Edfu area exhibited higher Fe level in their serum than those from the other areas, while hepatitis patients and healthy control from Daraw area (free from pollution) exhibited the lowest metal values. Patients with hepatitis C show lower levels of Co, Ni, and Fe in their serum than those with hepatitis B. A comparative study was carried out between the results using DPA(d)SV and AAS techniques, which are in very good agreements. 2009 Elsevier GmbH. All rights reserved.

  6. A Plasmid Containing the Human Metallothionein II Gene Can Function as an Antibody-assisted Electrophoretic Biosensor for Heavy Metals

    DTIC Science & Technology

    2015-01-16

    function as an antibody-assisted electrophoretic biosensor for heavy metals 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER...Immunotoxicol, Early Online: 1–9 14. ABSTRACT Different forms of heavy metals affect biochemical systems in characteristic ways that cannot be detected...with typical metal analysis methods like atomic absorption spectrometry. Further, using living systems to analyze interaction of heavy metals with

  7. Statistical Analysis of the Heavy Neutral Atoms Measured by IBEX

    NASA Astrophysics Data System (ADS)

    Park, Jeewoo; Kucharek, Harald; Möbius, Eberhard; Galli, André; Livadiotis, George; Fuselier, Steve A.; McComas, David J.

    2015-10-01

    We investigate the directional distribution of heavy neutral atoms in the heliosphere by using heavy neutral maps generated with the IBEX-Lo instrument over three years from 2009 to 2011. The interstellar neutral (ISN) O&Ne gas flow was found in the first-year heavy neutral map at 601 keV and its flow direction and temperature were studied. However, due to the low counting statistics, researchers have not treated the full sky maps in detail. The main goal of this study is to evaluate the statistical significance of each pixel in the heavy neutral maps to get a better understanding of the directional distribution of heavy neutral atoms in the heliosphere. Here, we examine three statistical analysis methods: the signal-to-noise filter, the confidence limit method, and the cluster analysis method. These methods allow us to exclude background from areas where the heavy neutral signal is statistically significant. These methods also allow the consistent detection of heavy neutral atom structures. The main emission feature expands toward lower longitude and higher latitude from the observational peak of the ISN O&Ne gas flow. We call this emission the extended tail. It may be an imprint of the secondary oxygen atoms generated by charge exchange between ISN hydrogen atoms and oxygen ions in the outer heliosheath.

  8. STATISTICAL ANALYSIS OF THE HEAVY NEUTRAL ATOMS MEASURED BY IBEX

    SciTech Connect

    Park, Jeewoo; Kucharek, Harald; Möbius, Eberhard; Galli, André; Livadiotis, George; Fuselier, Steve A.; McComas, David J.

    2015-10-15

    We investigate the directional distribution of heavy neutral atoms in the heliosphere by using heavy neutral maps generated with the IBEX-Lo instrument over three years from 2009 to 2011. The interstellar neutral (ISN) O and Ne gas flow was found in the first-year heavy neutral map at 601 keV and its flow direction and temperature were studied. However, due to the low counting statistics, researchers have not treated the full sky maps in detail. The main goal of this study is to evaluate the statistical significance of each pixel in the heavy neutral maps to get a better understanding of the directional distribution of heavy neutral atoms in the heliosphere. Here, we examine three statistical analysis methods: the signal-to-noise filter, the confidence limit method, and the cluster analysis method. These methods allow us to exclude background from areas where the heavy neutral signal is statistically significant. These methods also allow the consistent detection of heavy neutral atom structures. The main emission feature expands toward lower longitude and higher latitude from the observational peak of the ISN O and Ne gas flow. We call this emission the extended tail. It may be an imprint of the secondary oxygen atoms generated by charge exchange between ISN hydrogen atoms and oxygen ions in the outer heliosheath.

  9. Transfer of heavy metals through terrestrial food webs: a review.

    PubMed

    Gall, Jillian E; Boyd, Robert S; Rajakaruna, Nishanta

    2015-04-01

    Heavy metals are released into the environment by both anthropogenic and natural sources. Highly reactive and often toxic at low concentrations, they may enter soils and groundwater, bioaccumulate in food webs, and adversely affect biota. Heavy metals also may remain in the environment for years, posing long-term risks to life well after point sources of heavy metal pollution have been removed. In this review, we compile studies of the community-level effects of heavy metal pollution, including heavy metal transfer from soils to plants, microbes, invertebrates, and to both small and large mammals (including humans). Many factors contribute to heavy metal accumulation in animals including behavior, physiology, and diet. Biotic effects of heavy metals are often quite different for essential and non-essential heavy metals, and vary depending on the specific metal involved. They also differ for adapted organisms, including metallophyte plants and heavy metal-tolerant insects, which occur in naturally high-metal habitats (such as serpentine soils) and have adaptations that allow them to tolerate exposure to relatively high concentrations of some heavy metals. Some metallophyte plants are hyperaccumulators of certain heavy metals and new technologies using them to clean metal-contaminated soil (phytoextraction) may offer economically attractive solutions to some metal pollution challenges. These new technologies provide incentive to catalog and protect the unique biodiversity of habitats that have naturally high levels of heavy metals.

  10. Toxic heavy metals in commercially important food fishes collected from Palk Bay, Southeastern India.

    PubMed

    Arulkumar, Abimannan; Paramasivam, Sadayan; Rajaram, Rajendran

    2017-06-15

    Toxic heavy metals are an important group of emerging chemical contaminants in seafood. Heavy metal concentrations in commercially important and most commonly eaten 10 fish species from Thondi fish landing, southeast coast of India, were determined by atomic absorption spectrometry. The concentrations of heavy metals significantly varied within and between the investigated fish species (P<0.05). The results of this study showed best significant correlations among the toxic heavy metals in the fish samples. It was revealed that Cd, Pb, Cu, and Zn metals were present in the fish samples at various levels. The residual levels of toxic heavy metals were less than the permissible levels specified for human consumption by the European Union, Food and Agriculture Organization and World Health Organization guidelines. Therefore, the fish species found in the Thondi fish landing and their fishery products can be considered safe for human consumption and can be exported worldwide. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Heavy metal, religiosity, and suicide acceptability.

    PubMed

    Stack, S

    1998-01-01

    There has been little work at the national level on the subject of musical subcultures and suicide acceptability. The present work explores the link between "heavy metal" rock fanship and suicide acceptability. Metal fanship is thought to elevate suicide acceptability through such means as exposure to a culture of personal and societal chaos marked by hopelessness, and through its associations with demographic risk factors such as gender, socioeconomic status, and education. Data are taken from the General Social Survey. A link between heavy metal fanship and suicide acceptability is found. However, this relationship becomes nonsignificant once level of religiosity is controlled. Metal fans are low in religiosity, which contributes, in turn, to greater suicide acceptability.

  12. Approaches for enhanced phytoextraction of heavy metals.

    PubMed

    Bhargava, Atul; Carmona, Francisco F; Bhargava, Meenakshi; Srivastava, Shilpi

    2012-08-30

    The contamination of the environment with toxic metals has become a worldwide problem. Metal toxicity affects crop yields, soil biomass and fertility. Soils polluted with heavy metals pose a serious health hazard to humans as well as plants and animals, and often requires soil remediation practices. Phytoextraction refers to the uptake of contaminants from soil or water by plant roots and their translocation to any harvestable plant part. Phytoextraction has the potential to remove contaminants and promote long-term cleanup of soil or wastewater. The success of phytoextraction as a potential environmental cleanup technology depends on factors like metal availability for uptake, as well as plants ability to absorb and accumulate metals in aerial parts. Efforts are ongoing to understand the genetics and biochemistry of metal uptake, transport and storage in hyperaccumulator plants so as to be able to develop transgenic plants with improved phytoremediation capability. Many plant species are being investigated to determine their usefulness for phytoextraction, especially high biomass crops. The present review aims to give an updated version of information available with respect to metal tolerance and accumulation mechanisms in plants, as well as on the environmental and genetic factors affecting heavy metal uptake. The genetic tools of classical breeding and genetic engineering have opened the door to creation of 'remediation' cultivars. An overview is presented on the possible strategies for developing novel genotypes with increased metal accumulation and tolerance to toxicity. Copyright © 2012 Elsevier Ltd. All rights reserved.

  13. Pyrolized biochar for heavy metal adsorption

    EPA Pesticide Factsheets

    Removal of copper and lead metal ions from water using pyrolized plant materials. Method can be used to develop a low cost point-of-use device for cleaning contaminated water. This dataset is associated with the following publication:DeMessie, B., E. Sahle-Demessie , and G. Sorial. Cleaning Water Contaminated With Heavy Metal Ions Using Pyrolyzed Banana Peel Adsorbents. Separation Science and Technology. Marcel Dekker Incorporated, New York, NY, USA, 50(16): 2448-2457, (2015).

  14. Heavy metal detoxification in eukaryotic microalgae.

    PubMed

    Perales-Vela, Hugo Virgilio; Peña-Castro, Julián Mario; Cañizares-Villanueva, Rosa Olivia

    2006-06-01

    Microalgae are aquatic organisms possessing molecular mechanisms that allow them to discriminate non-essential heavy metals from those essential ones for their growth. The different detoxification processes executed by algae are reviewed with special emphasis on those involving the peptides metallothioneins, mainly the post transcriptionally synthesized class III metallothioneins or phytochelatins. Also, the features that make microalgae suitable organisms technologies specially to treat water that is heavily polluted with metals is discussed.

  15. Heavy metal and abiotic stress inducible metallothionein isoforms from Prosopis juliflora (SW) D.C. show differences in binding to heavy metals in vitro.

    PubMed

    Usha, B; Venkataraman, Gayatri; Parida, Ajay

    2009-01-01

    Prosopis juliflora is a tree species that grows well in heavy metal laden industrial sites and accumulates heavy metals. To understand the possible contribution of metallothioneins (MTs) in heavy metal accumulation in P. juliflora, we isolated and compared the metal binding ability of three different types of MTs (PjMT1-3). Glutathione S-transferase fusions of PjMTs (GSTMT1-3) were purified from Escherichia coli cells grown in the presence of 0.3 mM cadmium, copper or zinc. Analysis of metal bound fusion proteins using atomic absorption spectrometry showed that PjMT1 bound higher levels of all three heavy metals as compared to PjMT2 and PjMT3. A comparative analysis of the genomic regions (including promoter for all three PjMTs) is also presented. All three PjMTs are induced by H(2)O(2) and ABA applications. PjMT1 and PjMT2 are induced by copper and zinc respectively while PjMT3 is induced by copper, zinc and cadmium. Variation in induction of PjMTs in response to metal exposure and their differential binding to metals suggests that each MT has a specific role in P. juliflora. Of the three MTs analyzed, PjMT1 shows maximum heavy metal sequestration and is thus a potential candidate for use in heavy metal phytoremediation.

  16. Determination of absolute configuration using heavy atom based co-crystallization method: Halogen atom effects

    NASA Astrophysics Data System (ADS)

    Wang, Jian-Rong; Fan, Xiaowu; Ding, Qiaoce; Mei, Xuefeng

    2016-09-01

    Heavy atom (chloride, bromide, and iodide) based co-crystals for determination of absolute configuration (AC) for chiral molecules were synthesized and evaluated. Co-crystals of cholestanol and L-ascorbic acid were analysed and the effects and potential benefits of varying the heavy atom are discussed. Changing the halogen atoms (chloride, bromide, or iodide) affects the co-crystal formation, X-ray absorption, and anomalous dispersion, and hence the ability to determine AC.

  17. Bacterial sorption of heavy metals.

    PubMed Central

    Mullen, M D; Wolf, D C; Ferris, F G; Beveridge, T J; Flemming, C A; Bailey, G W

    1989-01-01

    Four bacteria, Bacillus cereus, B. subtilis, Escherichia coli, and Pseudomonas aeruginosa, were examined for the ability to remove Ag+, Cd2+, Cu2+, and La3+ from solution by batch equilibration methods. Cd and Cu sorption over the concentration range 0.001 to 1 mM was described by Freundlich isotherms. At 1 mM concentrations of both Cd2+ and Cu2+, P. aeruginosa and B. cereus were the most and least efficient at metal removal, respectively. Freundlich K constants indicated that E. coli was most efficient at Cd2+ removal and B. subtilis removed the most Cu2+. Removal of Ag+ from solution by bacteria was very efficient; an average of 89% of the total Ag+ was removed from the 1 mM solution, while only 12, 29, and 27% of the total Cd2+, Cu2+, and La3+, respectively, were sorbed from 1 mM solutions. Electron microscopy indicated that La3+ accumulated at the cell surface as needlelike, crystalline precipitates. Silver precipitated as discrete colloidal aggregates at the cell surface and occasionally in the cytoplasm. Neither Cd2+ nor Cu2+ provided enough electron scattering to identify the location of sorption. The affinity series for bacterial removal of these metals decreased in the order Ag greater than La greater than Cu greater than Cd. The results indicate that bacterial cells are capable of binding large quantities of different metals. Adsorption equations may be useful for describing bacterium-metal interactions with metals such as Cd and Cu; however, this approach may not be adequate when precipitation of metals occurs. Images PMID:2515800

  18. Heavy Atom Effect on Photophysical Deactivation of Molecular Triplet States

    NASA Astrophysics Data System (ADS)

    Gastilovich, E. A.; Serov, S. A.; Korol'Kova, N. V.; Klimenko, V. G.

    2000-03-01

    The decrease in the spin-orbit (SO) interaction with increasing number of chlorine atoms in molecules of dibenzo- p-dioxine derivatives is found and explained. The heavy atom effect on components of the rate constant of phosphorescence k ph=k SO+k VSO related to SO and vibronic-spin-orbit (VSO) interactions is quantitatively estimated.

  19. Hydroponics reducing effluent's heavy metals discharge.

    PubMed

    Rababah, Abdellah; Al-Shuha, Ahmad

    2009-01-01

    This paper investigates the capacity of Nutrient Film Technique (NFT) to control effluent's heavy metals discharge. A commercial hydroponic system was adapted to irrigate lettuces with primary treated wastewater for studying the potential heavy metals removal. A second commercial hydroponic system was used to irrigate the same type of lettuces with nutrient solution and this system was used as a control. Results showed that lettuces grew well when irrigated with primary treated effluent in the commercial hydroponic system. The NFT-plant system heavy metals removal efficiency varied amongst the different elements, The system's removal efficiency for Cr was more than 92%, Ni more than 85%, in addition to more than 60% reduction of B, Pb, and Zn. Nonetheless, the NFT-plants system removal efficiencies for As, Cd and Cu were lower than 30%. Results show that lettuces accumulated heavy metals in leaves at concentrations higher than the maximum acceptable European and Australian levels. Therefore, non-edible plants such as flowers or pyrethrum are recommended as value added crops for the proposed NFT.

  20. Heavy Metals and Related Trace Elements.

    ERIC Educational Resources Information Center

    Leland, Harry V.; And Others

    1978-01-01

    Presents a literature review of heavy metals and related trace elements in the environment, covering publications of 1976-77. This review includes: (1) trace treatment in natural water and in sediments; and (2) bioaccumulation and toxicity of trace elements. A list of 466 references is presented. (HM)

  1. ANALYSIS OF HEAVY METALS IN STORMWATER

    EPA Science Inventory

    Sampling has been undertaken to determine the concentrations of heavy metals, both particle-associated and dissolved, in stormwater from several storm sewer outfalls in Monmouth County, NJ. This project is ongoing in concert with coordinated studies of pathogen and nutrient input...

  2. Heavy Metals and Related Trace Elements.

    ERIC Educational Resources Information Center

    Leland, Harry V.; And Others

    1978-01-01

    Presents a literature review of heavy metals and related trace elements in the environment, covering publications of 1976-77. This review includes: (1) trace treatment in natural water and in sediments; and (2) bioaccumulation and toxicity of trace elements. A list of 466 references is presented. (HM)

  3. ANALYSIS OF HEAVY METALS IN STORMWATER

    EPA Science Inventory

    Sampling has been undertaken to determine the concentrations of heavy metals, both particle-associated and dissolved, in stormwater from several storm sewer outfalls in Monmouth County, NJ. This project is ongoing in concert with coordinated studies of pathogen and nutrient input...

  4. Acinetobacter bioreporter assessing heavy metals toxicity.

    PubMed

    Abd-El-Haleem, Desouky; Zaki, Sahar; Abulhamd, Ashraf; Elbery, Hassan; Abu-Elreesh, Gadallah

    2006-01-01

    This work was conducted to employ a whole cell-based biosensor to monitor toxicity of heavy metals in water and wastewater. An isolate of industrial wastewater bacterium, Acinetobacter sp. DF4, was genetically modified with lux reporter gene to create a novel bioluminescent bacterial strain, designated as DF4/PUTK2. This bioreporter can investigate the toxicity through light inhibition due to cell death or metabolic burden and the specific stress effects of the tested soluble materials simultaneously. The use of Acinetobacter DF4/PUTK2 as a bioluminescent reporter for heavy metal toxicity testing and for the application of wastewater treatment influent toxicity screening is presented in this study. Among eight heavy metals tested, the bioluminescence of DF4/PUTK2 was most sensitive to Zn, Cd, Fe, Co, Cr followed by Cu in order of decreasing sensitivity. The same pattern of sensitivity was observed when several contaminated water and wastewater effluents were assayed. This work suggested that luxCDABE -marked Acinetobacter bacterium DF4/PUTK2 can be used to bioassay the ecotoxicity of wastewater and effluent samples contaminated with heavy metals. Using this assay, it is possible to pre-select the more toxic samples for further chemical analysis and to discard wastewater samples with low or no inhibition because they are not toxic to the environment.

  5. Heavy metals in the environment

    SciTech Connect

    Storm, G.L.; Fosmire, G.J.; Bellis, E.D.

    1994-05-01

    Concentration (Cd, Pb, Zn, and Cu) in soil and wildlife at the Palmerton zinc smelter site in eastern Pennsylvania were determined 6 yr after zinc smelting was terminated in 1980. Levels of the four metals were higher in litter (01 and 02 horizon) than in soil (A1 horizon), and the metals were at or near levels when the smelters were still in operation. Levels of metals in sod weft highest at sites close to the smelters and decreased as distances from the smelters increased. The relation of decreasing amounts of metals in body tissues with increasing distance from the smelters also held true for amphibians and mammals. An exception to this relation was higher level of Cu in red-lacked salamanders (Plethodon cinereus) captured {approx}17 km downwind than those captured {approx}12 km downwind. Levels of Zn, Pb, and Co in liver, kidney, and muscle tissue of white-footed mice (Peromyscus leucopus) were not different (P >0.05) among sites. Cadmium in kidneys in white-footed mice exceeded 10 mg&& which is reportedly considered an indication of environmental contamination. Levels of Cd in kidneys and liver of white-tailed deer (Odocoileus virginianus) at Palmerton were five times higher than those for white-tailed deer collected 180 km southwest of Palmerton in southcentral Pennsylvania. The abnormal amounts of metals in the tissues of terrestrial vertebrates, and the absence or low abundance of wildlife at Palmerton indicated that ecological processes within 5 km of the smelters were markedly influenced 6 yr after zinc smelting was discontinued. 41 refs., 5 figs., 4 tabs.

  6. Heavy metals and its chemical speciation in sewage sludge at different stages of processing.

    PubMed

    Tytła, Malwina; Widziewicz, Kamila; Zielewicz, Ewa

    2016-01-01

    The analysis of heavy metal concentrations and forms in sewage sludge constitutes an important issue in terms of both health and environmental hazards the metals pose. The total heavy metals concentration enables only the assessment of its contamination. Hence the knowledge of chemical forms is required to determine their environmental mobility and sludge final disposal. Heavy metals speciation was studied by using four-stage sequential extraction BCR (Community Bureau of Reference). This study was aimed at determining the total concentration of selected heavy metals (Zn, Cu, Ni, Pb, Cd, Cr and Hg) and their chemical forms (except for Hg) in sludge collected at different stages of its processing at two municipal Wastewater Treatment Plants in southern Poland. Metals contents in sludge samples were determined by using flame atomic absorption spectrometry (FAAS) and electrothermal atomic absorption spectrometry (ETAAS). This study shows that Zn and Cu appeared to be the most abundant in sludge, while Cd and Hg were in the lowest concentrations. The sewage sludge revealed the domination of immobile fractions over the mobile ones. The oxidizable and residual forms were dominant for all the heavy metals. There was also a significant difference in metals speciation between sludges of different origin which was probably due to differences in wastewater composition and processes occurring in biological stage of wastewater treatment. The results indicate a negligible capability of metals to migrate from sludge into the environment. Our research revealed a significant impact of thickening, stabilization and hygienization on the distribution of heavy metals in sludge and their mobility.

  7. How composting affects heavy metal content

    SciTech Connect

    Canarutto, S.; Petruzzelli, G.; Lubrano, L.; Guidi, G.V.

    1991-06-01

    This paper describes ways in which a properly conducted composting process can alter the chemical forms of heavy metals and consequently the quality of the compost. This process is of particular interest in the Italian policy of waste management due to the low level of organic matter in Italian agricultural soils. Results of the studies show that the proper process of compost maturation seems to increase the concentrations of humic acids with respect to those of fulvic acids. These variations in the quantity and quality of humic substances influence the speciation of heavy metals with a large part of the metals complexed and reaching the soil in a less mobile form. The distribution of copper, cadmium, zinc, nickel, lead and chromium among humic fractions is compared in two composting procedures.

  8. Heavy metal fates in laboratory bioretention systems.

    PubMed

    Sun, Xueli; Davis, Allen P

    2007-01-01

    Key to managing heavy metals in bioretention is to understand their fates in bioretention facilities. In this study, pot prototypes filled with bioretention media were built to simulate the conditions of natural growth of plants. Synthetic runoff with different heavy metal loadings (copper, cadmium, lead, and zinc) was periodically applied. Metal accumulations in tissues of grasses -Panicum virgatum, Kentucky-31, and Bromus ciliatus, were investigated after 230d of growth and multiple runoff treatment events. After 183d of periodic runoff application, the concentrations of Zn, Cu, Pb and Cd with low and high loadings had the same trends in the plant tissues, Zn>Cu>Pb>Cd, following the trend of the input metal concentrations. The fates of input metals were 88-97% captured in soil media, 2.0-11.6% not captured by bioretention media, and 0.5-3.3% accumulated in plants. Compared to the metals retained by the soil, the percentages of input metals taken up by plants were relatively low due to the low plant biomass produced in this study. Greater biomass density would be required for the vegetation to have a valuable impact in prolonging the lifetime of a bioretention cell.

  9. Minor heavy metal: A review on occupational and environmental intoxication

    PubMed Central

    Wiwanitkit, Viroj

    2008-01-01

    Heavy metal is widely used in industries and presents as a problematic environmental pollution. Some heavy metals, especially lead and mercury, are well described for their occupational and environmental intoxication whereas the other minor heavy metals are less concerned. In this article, the author will present the details of occupational and environmental minor heavy metal intoxication. This review focuses mainly on aluminum, tin, copper, manganese, chromium, cadmium and nickel. PMID:20040969

  10. Heavy metal removal from sediments by biosurfactants.

    PubMed

    Mulligan, C N; Yong, R N; Gibbs, B F

    2001-07-30

    Batch washing experiments were used to evaluate the feasibility of using biosurfactants for the removal of heavy metals from sediments. Surfactin from Bacillus subtilis, rhamnolipids from Pseudomonas aeruginosa and sophorolipid from Torulopsis bombicola were evaluated using a metal-contaminated sediment (110mg/kg copper and 3300mg/kg zinc). A single washing with 0.5% rhamnolipid removed 65% of the copper and 18% of the zinc, whereas 4% sophorolipid removed 25% of the copper and 60% of the zinc. Surfactin was less effective, removing 15% of the copper and 6% of the zinc. The technique of ultrafiltration and zeta potential measurements were used to determine the mechanism of metal removal by the surfactants. It was then postulated that metal removal by the biosurfactants occurs through sorption of the surfactant on to the soil surface and complexation with the metal, detachment of the metal from the soil into the soil solution and hence association with surfactant micelles. Sequential extraction procedures were used on the sediment to determine the speciation of the heavy metals before and after surfactant washing. The carbonate and oxide fractions accounted for over 90% of the zinc present in the sediments. The organic fraction constituted over 70% of the copper. Sequential extraction of the sediments after washing with the various surfactants indicated that the biosurfactants, rhamnolipid and surfactin could remove the organically-bound copper and that the sophorolipid could remove the carbonate and oxide-bound zinc. Therefore, heavy metal removal from sediments is feasible and further research will be conducted.

  11. Atomic Bond Deficiency Defects in Amorphous Metals

    NASA Astrophysics Data System (ADS)

    Zhu, Aiwu; Shiflet, Gary J.; Poon, S. Joseph

    2012-10-01

    Atomic bond deficiency (BD) is considered to be characteristic structural defects in amorphous metals. They are the necessary feature of local atomic configurations that facilitate various atomic transports under different driving forces. Compared with vacancies in crystalline solids, they are "small" in terms of their formation energies, volume costs, and elementary steps involved in atomic transport. This article reviews the authors' recent efforts made to analyze how various local configurations containing BD are related to amorphous metal's unique characteristics, such as glass transition, diffusion, shear flow, and structural relaxation.

  12. PREPARATION OF OXALATES OF METALS OF ATOMIC NUMBER GREATER THAN 88

    DOEpatents

    Duffield, R.B.

    1959-02-01

    A method is presented for the preparation of oxalates of metals of atomic number greater than 88. A solid peroxide of the heavy metal is contacted with an aqueous oxalic acid solution ai a temperature of about 50 C for a period of time sufficient to form the insoluble metal oxalate which is subsequentiy recovered as a pures crystalline compound.

  13. Arbuscular Mycorrhizal Fungi Can Benefit Heavy Metal Tolerance and Phytoremediation

    ERIC Educational Resources Information Center

    Forgy, David

    2012-01-01

    Sites contaminated by heavy metals, such as industrial waste sites, create unwelcoming environments for plant growth. Heavy metals can have a wide range of toxic effects such as replacing essential elements or disrupting enzyme function. While some heavy metals are essential to plant nutrition at low concentrations, high concentrations of any…

  14. Arbuscular Mycorrhizal Fungi Can Benefit Heavy Metal Tolerance and Phytoremediation

    ERIC Educational Resources Information Center

    Forgy, David

    2012-01-01

    Sites contaminated by heavy metals, such as industrial waste sites, create unwelcoming environments for plant growth. Heavy metals can have a wide range of toxic effects such as replacing essential elements or disrupting enzyme function. While some heavy metals are essential to plant nutrition at low concentrations, high concentrations of any…

  15. Bacterial sorption of heavy metals

    SciTech Connect

    Mullen, M.D.; Wolf, D.C.; Ferris, F.G.; Beveridge, T.J.; Flemming, C.A.

    1989-01-01

    Four bacteria, Bacillus cereus, B. subtilis, Escherichia coli, and Pseudomonas aeruginosa, were examined for the ability to remove Ag{sup +}, Cd{sup 2+}, Cu{sup 2+}, and La{sup 3+} from solution by batch equilibration methods. Cd and Cu sorption over the concentration range 0.001 to 1 mM was described by Freundlich isotherms. At 1 mM concentrations of both Cd{sup 2+} and Cu{sup 2+}, P. aeruginosa and B. cereus were the most and least efficient at metal removal, respectively. Freundlich K constants indicated that E. coli was most efficient at Cd{sup 2+} removal and B. subtilis removed the most Cu{sup 2+}. Removal of Ag{sup +} from solution by bacteria was very efficient; an average of 89% of the total Ag{sup +} was removed from the 1 mM solution, whereas only 12, 29, and 27% of the total Cd{sup 2+}, Cu{sup 2+}, and La{sup 3+}, respectively, were sorbed from 1 mM solutions. Electron microscopy indicated that La{sup 3+} accumulated at the cell surface as needlelike, crystalline precipitates. Silver precipitated as discrete colloidal aggregates at the cell surface and occasionally in the cytoplasma. The results indicate that bacterial cells are capable of binding large quantities of different metals.

  16. Customizable Biopolymers for Heavy Metal Remediation

    NASA Astrophysics Data System (ADS)

    Kostal, Jan; Prabhukumar, Giridhar; Lao, U. Loi; Chen, Alin; Matsumoto, Mark; Mulchandani, Ashok; Chen*, Wilfred

    2005-10-01

    Nanoscale materials have been gaining increasing interest in the area of environmental remediation because of their unique physical, chemical and biological properties. One emerging area of research has been the development of novel materials with increased affinity, capacity, and selectivity for heavy metals because conventional technologies are often inadequate to reduce concentrations in wastewater to acceptable regulatory standards. Genetic and protein engineering have emerged as the latest tools for the construction of nanoscale materials that can be controlled precisely at the molecular level. With the advent of recombinant DNA techniques, it is now possible to create `artificial' protein polymers with fundamentally new molecular organization. The most significant feature of these nanoscale biopolymers is that they are specifically pre-programmed within a synthetic gene template and can be controlled precisely in terms of sizes, compositions and functions at the molecular level. In this review, the use of specifically designed protein-based nano-biomaterials with both metal-binding and tunable properties for heavy metal removal is summarized. Several different strategies for the selective removal of heavy metals such as cadmium and mercury are highlighted.

  17. Remediation processes for heavy metals contaminated soils

    SciTech Connect

    Torma, G.A.; Torma, A.E.; Hsu, Pei-Cheng

    1996-12-31

    This paper provides information on selected technologies available for remediation of metal contaminated soils and industrial effluent solutions. Because some of the industrial sites are contaminated with organics (solvents, gasolines and oils), an effort has been made to introduce the most frequently used cost-effective cleanup methods, such as {open_quotes}bioventing{close_quotes} and {open_quotes}composting.{close_quotes} The microorganisms involved in these processes are capable of degrading organic soil contaminants to environmentally harmless compounds: water and carbon dioxide. Heavy metals and radionuclides contaminated mining and industrial sites can be remediated by using adapted heap and dump leaching technologies, which can be chemical in nature or bio-assisted. The importance of volume reduction by physical separation is discussed. A special attention is devoted to the remediation of soils by leaching (soil washing) to remove heavy metal contaminants, such as chromium, lead, nickel and cadmium. Furthermore, the applicability of biosorption technology in the remediation of heavy metals and radionuclides contaminated industrial waste waters and acidic mining effluent solutions was indicated. 60 refs., 9 figs.

  18. Heavy metals and the origin of life

    NASA Astrophysics Data System (ADS)

    Nriagu, J.

    2003-05-01

    The functional value of heavy metals in proto-cells was immense and involved critical roles in catalysis of molecular synthesis, translation, electrical neutrality and conduction, energy capture, cross-linking and precipitation (stabilizers of protective cell walls), and to a limited extent, osmotic pressure control. Metals must have modulated the evolutionary choices of the types of building blocks, such as ribose sugars as a constituent of RNA, or the the chirality and enantiopurity of many biomolecules. The formation of an enclosing membrane led to intracellular prokaryotic life (believed to have originated in an anaerobic environment) and much enhanced control over primary metabolism, the uptake and incorporation of heavy metals and the management of biomolecules (especially RNA, DNA and proteins) that were formed. Cells of the most primitive organisms (archaebacteria) reveal complex mechanisms designed specifically to deal with selective pressures from metal-containing environments including intra- and extra-cellular sequestration, exclusion by cell wall barrier, removal through active efflux pumps, enzymatic detoxification, and reduction in sensitivity of cellular targets to metal ions. Adaptation to metals using a variety of chromosomal, and transposon and plasmid-mediated systems began early in the evolution of life on Earth. Recent studies, however, show that the roles played by many heavy metals have changed over time. Divalent lead, for instance, has relinquished its unique catalytic role in the conversion of carbohydrates into ribose in the prebiotic world. The putative elements that dominated the primordial biochemistry were V, Mo, W, Co, Fe(II) and Ni; with the development of oxygenated atmosphere, these elements gave way to Zn, Cu and Fe(Ill) in their metabolic functions.

  19. Stabilize heavy metals in soils and sludges

    SciTech Connect

    1995-03-01

    To stabilize heavy metals in soils, sludges, ash from incinerators and power plants, and baghouse dusts, Solucorp Industries (Saddle Brook, N.J.) has developed the Molecular Bonding System (MBS). Using a patented mix of chemical additives, the MBS process bonds highly reactive metal ions to form non-leachable molecules, rendering the metals inert. The chemical reactions are said to be permanent, and for each application, the additive mix is specially formulated to meet site-specific conditions. Recently, the MBS process was accepted into the US Environmental Protection Agency`s Site Demonstration Program as an innovative technology for stabilizing heavy metals. Bench-scale and pilot tests have proven the effectiveness of the MBS process for a wide array of metals, including arsenic, cadmium, chromium, copper, lead, mercury, nickel, silver and zinc. The process is designed for wastes classified as D004 through D011, as well as K-listed wastes associated with metal-plating operations. It can treat waste in drums or in bulk, says the firm, but is not suitable for liquid streams.

  20. Determination of heavy metals in the ambient atmosphere.

    PubMed

    Suvarapu, Lakshmi Narayana; Baek, Sung-Ok

    2017-01-01

    Heavy metal determination in ambient air is an important task for environmental researchers because of their toxicity to human beings. Some heavy metals (hexavalent chromium (Cr), arsenic (As), cadmium (Cd) and nickel (Ni)) have been listed as carcinogens. Furthermore, heavy metals in the atmosphere can accumulate in various plants and animals and enter humans through the food chain. This article reviews the determination of heavy metals in the atmosphere in different areas of the world since 2006. The results showed that most researchers concentrated on toxic metals, such as Cr, Cd, Ni, As and lead. A few studies used plant materials as bio-monitors for the atmospheric levels of heavy metals. Some researchers found higher concentrations of heavy metals surrounding industrial areas compared with residential and/or commercial areas. Most studies reported the major sources of the particulate matter and heavy metals in the atmosphere to be industrial emissions, vehicular emissions and secondary aerosols.

  1. Determination of the Content of Heavy Metals in Pyrite Contaminated Soil and Plants.

    PubMed

    Antonijević, Milan M; Marić, Miroslava

    2008-09-24

    Determination of a pyrite contaminated soil texture, content of heavy metals in the soil and soil pH, was the aim in the investigation. Acidification of damaged soil was corrected by calcium carbonate. Mineral nutrients and organic matter (NPK, dung, earthworm cast, straw and coal dust) were added to damaged soil. Afterwards, the soil was used for oat production. Determination of total heavy metal contents (Cu, Pb, Zn, Fe) in soil was performed by atomic absorption spectrofotometry. Plant material (stems, seeds ) was analysed, too. Total concentration of the heavy metals in the plant material were greater than in crop obtained in unaffected soil.

  2. Determination of the Content of Heavy Metals in Pyrite Contaminated Soil and Plants

    PubMed Central

    Antonijević, Milan M.; Marić, Miroslava

    2008-01-01

    Determination of a pyrite contaminated soil texture, content of heavy metals in the soil and soil pH, was the aim in the investigation. Acidification of damaged soil was corrected by calcium carbonate. Mineral nutrients and organic matter (NPK, dung, earthworm cast, straw and coal dust) were added to damaged soil. Afterwards, the soil was used for oat production. Determination of total heavy metal contents (Cu, Pb, Zn, Fe) in soil was performed by atomic absorption spectrofotometry. Plant material (stems, seeds) was analysed, too. Total concentration of the heavy metals in the plant material were greater than in crop obtained in unaffected soil. PMID:27873845

  3. [Chemical hazards induced by heavy metals refining processes].

    PubMed

    Gaweda, Ewa

    2003-01-01

    Processes of refining heavy metals consist in removing impurities, which can be found in metals produced on industrial scale. People involved in heavy metals refining processes are primarily exposed to metals (Pb, Cd, Cu), metalloids (As, Se) and metal compounds. Exposure to dusts (from 2 to 50% SiO2) and sulfuric acid is an additional hazard. The air concentrations of harmful chemical agents at heavy metals refining stations in two Polish Plants are presented. Several tens of workers employed in the processes of copper, lead, nickel sulfate, zinc, cadmium and silver production were examined. Concentrations of Cd, Ni, Se, Cu, Pb, Ag, As and Sb were determined by atomic absorption spectrometry (AAS) with a graphite tube, whereas Fe, ZnO oxide (as Zn), MgO (as Mg) and CaO (as Ca) by AAS with air-acetylene flame, and sulfuric acid by method described in PN-91/Z-04056/02. Lead concentrations in the samples collected in both Plants were often high (significantly exceeding Polish MAC values at some workstations). Arsenic concentrations ranged from very low in all processes in one Plant to very high, exceeding Polish MAC values, at some workstations in the other. In general, air concentrations of other agents were not high (fraction of MAC). The occurrence of antimony and magnesium oxide was not determined. The risk created by metals and metalloids at the workstations in two Plants was diversified. There is no need to determine Sb and MgO in further studies. Lead should be determined at all workstations, other agents can be determined at workstations with concentrations exceeding the determinability of relevant methods.

  4. The UKB prescription and the heavy atom effects on the nuclear magnetic shielding of vicinal heavy atoms.

    PubMed

    Maldonado, Alejandro F; Aucar, Gustavo A

    2009-07-21

    Fully relativistic calculations of NMR magnetic shielding on XYH3 (X = C, Si, Ge and Sn; Y = Br, I), XHn (n = 1-4) molecular systems and noble gases performed with a fully relativistic polarization propagator formalism at the RPA level of approach are presented. The rate of convergence (size of basis set and time involved) for calculations with both kinetic balance prescriptions, RKB and UKB, were investigated. Calculations with UKB makes it feasible to obtain reliable results for two or more heavy-atom-containing molecules. For such XYH3 systems, the influence of heavy vicinal halogen atoms on sigma(X) is such that heavy atom effects on heavy atoms (vicinal plus their own effects or HAVHA + HAHA effects) amount to 30.50% for X = Sn and Y = I; being the HAHA effect of the order of 25%. So the vicinal effect alone is of the order of 5.5%. The vicinal heavy atom effect on light atoms (HALA effect) is of the order of 28% for X = C and Y = I. A similar behaviour, but of opposite sign, is observed for sigma(Y) for which sigmaR-NR (I; X = C) (HAHA effect) is around 27% and sigmaR-NR(I; X = Sn) (HAVHA + HAHA effects) is close to 21%. Its electronic origin is paramagnetic for halogen atoms but both dia- and paramagnetic for central atoms. The effect on two bond distant hydrogen atoms is such that the largest variation of sigma(H) within the same family of XYH3 molecules appears for X = Si and Y = I: around 20%. In this case sigma(H; X = Sn, Y = I) = 33.45 ppm and sigma(H; X = Sn, Y = H) = 27.82 ppm.

  5. An overview of heavy-atom derivatization of protein crystals

    PubMed Central

    Pike, Ashley C. W.; Garman, Elspeth F.; Krojer, Tobias; von Delft, Frank; Carpenter, Elisabeth P.

    2016-01-01

    Heavy-atom derivatization is one of the oldest techniques for obtaining phase information for protein crystals and, although it is no longer the first choice, it remains a useful technique for obtaining phases for unknown structures and for low-resolution data sets. It is also valuable for confirming the chain trace in low-resolution electron-density maps. This overview provides a summary of the technique and is aimed at first-time users of the method. It includes guidelines on when to use it, which heavy atoms are most likely to work, how to prepare heavy-atom solutions, how to derivatize crystals and how to determine whether a crystal is in fact a derivative. PMID:26960118

  6. An overview of heavy-atom derivatization of protein crystals.

    PubMed

    Pike, Ashley C W; Garman, Elspeth F; Krojer, Tobias; von Delft, Frank; Carpenter, Elisabeth P

    2016-03-01

    Heavy-atom derivatization is one of the oldest techniques for obtaining phase information for protein crystals and, although it is no longer the first choice, it remains a useful technique for obtaining phases for unknown structures and for low-resolution data sets. It is also valuable for confirming the chain trace in low-resolution electron-density maps. This overview provides a summary of the technique and is aimed at first-time users of the method. It includes guidelines on when to use it, which heavy atoms are most likely to work, how to prepare heavy-atom solutions, how to derivatize crystals and how to determine whether a crystal is in fact a derivative.

  7. The distribution of the heavy metal accumulation rate in the biomass of three Daphnia species

    SciTech Connect

    Gajula, V.K.; Hovorka, J.; Stuchlik, E.

    1995-12-31

    The difference in the accumulation rate of a mixture of heavy metals in aquatic organisms is of considerable interest because of its importance in the prediction of the effect of pollutants in aquatic systems. In this study the authors are making an effort to evaluate the accumulation patterns of pollutants in aquatic organisms by establishing a relation between the level of an accumulated mixture of heavy metals (Cd, Zn, Pb, As, Hg) in individuals of Daphnia magna, Daphnia pulicaria and Daphnia galeata and its dry weight with respect to the form of heavy metals in the aquatic environment. One age group of Daphnia species (10 day old) were exposed to 5 ppb, 10 ppb and 20 ppb of the mixture of heavy metals for 24 hours in three different experiments. In the first experiment the mixture of heavy metals was present exclusively in labelled algae (Scendesmus actus), in the second in an aquatic medium with non labelled algae, and in the third experiment the mixture of heavy metals was dissolved in the aquatic medium only without the addition of algae. The concentration of the heavy metal mixture in individuals of D.magna; D.pulicaria and D.galeata was determined using atomic absorption spectrometry. Results were statistically evaluated and the rate of accumulation and influence of various heavy metals in the biomass of three Daphnia species is discussed.

  8. Volatile (As and Hg) and non-volatile (Pb and Cd) toxic heavy metals analysis in rhizome of Zingiber officinale collected from different locations of North Western Himalayas by Atomic Absorption Spectroscopy.

    PubMed

    Gupta, S; Pandotra, P; Gupta, A P; Dhar, J K; Sharma, G; Ram, G; Husain, M K; Bedi, Y S

    2010-10-01

    Ginger is an important ingredient of spice and herbals. The monitoring of toxic heavy metals in the rhizome of ginger is important for protecting public health against the hazards of metal toxicity. The concentration of volatile and non-volatile metals (As, Hg, Pb and Cd), in the soil and rhizome of Zingiber officinale were analyzed using AAS. Soil analysis profile showed uniformity in the metal contents, in active root zone and subsoil, except mercury, which was present in higher quantity in one, out of the four sectors, of the field. The infield metal content in the soil in increasing order was, cadmium < arsenic < lead < mercury. In ginger rhizome the volatile toxic heavy metals arsenic (As) and mercury (Hg) varied from not detected to 0.13 μg/g and 0.01 to 0.42 μg/g, respectively. The non-volatile metals lead (Pb) and cadmium (Cd) ranged from 0.06 to 0.64 μg/g and 0.002 to 0.03 μg/g, respectively(.) The results illustrated the findings that soil is the major but not the only source of metal accumulation in the plants. In our study, the volatile metal content (As, Hg) was found more in rhizomes collected from Himachal Pradesh while the non-volatile metals were predominant in samples from Uttarakhand.

  9. Quantum Electrodynamics of Heavy Ions and Atoms

    SciTech Connect

    Shabaev, V. M.; Artemyev, A. N.; Glazov, D. A.; Tupitsyn, I. I.; Volotka, A. V.; Yerokhin, V. A.

    2006-11-07

    The present status of quantum electrodynamics (QED) theory of heavy few-electrons is reviewed. The theoretical results are compared with available experimental data. A special attention is focused on tests of QED at strong fields and on determination of the fundamental constants. A recent progress on calculations of the QED corrections to the parity nonconserving 6s-7s transition amplitude in neutral Cs is also discussed.

  10. Atomization of metal (Materials Preparation Center)

    SciTech Connect

    2010-01-01

    Atomization of metal requires high pressure gas and specialized chambers for cooling and collecting the powders without contamination. The critical step for morphological control is the impingement of the gas on the melt stream. The video is a color video of a liquid metal stream being atomized by high pressure gas. This material was cast at the Ames Laboratorys Materials Preparation Center http://www.mpc.ameslab.gov WARNING - AUDIO IS LOUD.

  11. Effect of heavy metals on bacterial transport

    NASA Astrophysics Data System (ADS)

    Zhang, H.; Olson, M. S.

    2010-12-01

    Adsorption of metals onto bacteria and soil takes place as stormwater runoff infiltrates into the subsurface. Changes in both bacterial surfaces and soil elemental content have been observed, and may alter the attachment of bacteria to soil surfaces. In this study, scanning electron microscopy (SEM) and Energy Dispersive X-ray Spectrometry (EDS) analyses were performed on soil samples equilibrated with synthetic stormwater amended with copper, lead and zinc. The results demonstrate the presence of copper and zinc on soil surfaces. To investigate bacterial attachment behavior, sets of batch sorption experiments were conducted on Escherichia Coli (E. coli) under different chemical conditions by varying solution compositions (nutrient solution vs synthetic stormwater). The adsorption data is best described using theoretical linear isotherms. The equilibrium coefficient (Kd) of E. coli is higher in synthetic stormwater than in nutrient solution without heavy metals. The adsorption of heavy metals onto bacterial surfaces significantly decreases their negative surface charge as determined via zeta potential measurements (-17.0±5.96mv for E. coli equilibrated with synthetic stormwater vs -21.6±5.45mv for E. coli equilibrated with nutrient solution), indicating that bacterial attachment may increase due to the attachment of metals onto bacterial surfaces and their subsequent change in surface charge. The attachment efficiency (α) of bacteria was also calculated and compared for both solution chemistries. Bacterial attachment efficiency (α) in synthetic stormwater is 0.997, which is twice as high as that in nutrient solution(α 0.465). The ratio of bacterial diameter : collector diameter suggests minimal soil straining during bacterial transport. Results suggest that the presence of metals in synthetic stormwater leads to an increase in bacterial attachment to soil surfaces. In terms of designing stormwater infiltration basins, the presence of heavy metals seems to

  12. Environmental impact of mercury and other heavy metals

    NASA Astrophysics Data System (ADS)

    Lindqvist, Oliver

    The environmental impact of heavy metals is reviewed. One significant source of emissions of heavy metals to air is waste incineration. Consumer batteries contributes significantly to this problem, as well as to heavy metal leakage to groundwater from landfill deposits. The situation in Sweden is used as an example to describe how the deposition from the atmosphere still is increasing the load of heavy metals, like mercury, cadmium and lead, in top soils and aquatic sediments. Critical factors and effect levels for Hg, Cd, Pb, Cu, Zn and As are discussed. Specific questions like mercury contents in present battery waste and heavy metal contents in new and future secondary batteries are addressed.

  13. Heavy metal transfer from atmosphere to plants

    NASA Astrophysics Data System (ADS)

    Asta, J.; Guillard, E.; Tissut, M.; Gaude, T.; Ravanel, P.

    2003-05-01

    Heavy metal contamination due to traffic was studied in the water basin of the Aiguebelette lake (Savoie, France) in the alpine chain. It is surrounded by mountains and crossed by a highway on a 6-km-distance. Contamination of lichens, mosses, barks and dead leaves litters were submitted to a comparative study. The quantities of six metals (Pb, Al, Cd, Zn, Mn, Ni) were estimated in each of these materials. Except for Al which was highly concentrated in Xanthoria parietina and to a lesser extent in mosses, all the matrices accumulated the metals in a relatively similar way. The hyperaccumulation factor varied from 2 to 258, depending on the sampling point on the studied metal and on the matrix. Bark represented a long-term accumulator and contained more lead than the other matrices. In the studied water basin, a specific atmospheric movement allowed to distribute the contaminants far away from the highway, especially on the west slope of the highest mountain.

  14. Multiple heavy metal removal using an entomopathogenic fungi Beauveria bassiana.

    PubMed

    Gola, Deepak; Dey, Priyadarshini; Bhattacharya, Arghya; Mishra, Abhishek; Malik, Anushree; Namburath, Maneesh; Ahammad, Shaikh Ziauddin

    2016-10-01

    Towards the development of a potential remediation technology for multiple heavy metals [Zn(II), Cu(II), Cd(II), Cr(VI) and Ni(II)] from contaminated water, present study examined the growth kinetics and heavy metal removal ability of Beauveria bassiana in individual and multi metals. The specific growth rate of B. bassiana varied from 0.025h(-1) to 0.039h(-1) in presence of individual/multi heavy metals. FTIR analysis indicated the involvement of different surface functional groups in biosorption of different metals, while cellular changes in fungus was reflected by various microscopic (SEM, AFM and TEM) analysis. TEM studies proved removal of heavy metals via sorption and accumulation processes, whereas AFM studies revealed increase in cell surface roughness in fungal cells exposed to heavy metals. Present study delivers first report on the mechanism of bioremediation of heavy metals when present individually as well as multi metal mixture by entomopathogenic fungi.

  15. Heavy metals in edible seaweeds commercialised for human consumption

    NASA Astrophysics Data System (ADS)

    Besada, Victoria; Andrade, José Manuel; Schultze, Fernando; González, Juan José

    2009-01-01

    Though seaweed consumption is growing steadily across Europe, relatively few studies have reported on the quantities of heavy metals they contain and/or their potential effects on the population's health. This study focuses on the first topic and analyses the concentrations of six typical heavy metals (Cd, Pb, Hg, Cu, Zn, total As and inorganic As) in 52 samples from 11 algae-based products commercialised in Spain for direct human consumption ( Gelidium spp.; Eisenia bicyclis; Himanthalia elongata; Hizikia fusiforme; Laminaria spp.; Ulva rigida; Chondrus crispus; Porphyra umbilicales and Undaria pinnatifida). Samples were ground, homogenised and quantified by atomic absorption spectrometry (Cu and Zn by flame AAS; Cd, Pb and total As by electrothermal AAS; total mercury by the cold vapour technique; and inorganic As by flame-hydride generation). Accuracy was assessed by participation in periodic QUASIMEME (Quality Assurance of Information in Marine Environmental Monitoring in Europe) and IAEA (International Atomic Energy Agency) intercalibration exercises. To detect any objective differences existing between the seaweeds' metal concentrations, univariate and multivariate studies (principal component analysis, cluster analysis and linear discriminant analysis) were performed. It is concluded that the Hizikia fusiforme samples contained the highest values of total and inorganic As and that most Cd concentrations exceeded the French Legislation. The two harvesting areas (Atlantic and Pacific oceans) were differentiated using both univariate studies (for Cu, total As, Hg and Zn) and a multivariate discriminant function (which includes Zn, Cu and Pb).

  16. Metallic adhesion in atomic-size junctions.

    PubMed

    Rubio-Bollinger, G; Joyez, P; Agraït, N

    2004-09-10

    We report high resolution simultaneous measurements of electrical conductance and force gradient between two sharp gold tips as their separation is varied from the tunneling distance to atomic-size contact. The use of atomically sharp tips minimizes van der Waals interaction, making it possible to identify the short-range metallic adhesion contribution to the total force.

  17. Earthworm contamination by PCBs and heavy metals

    SciTech Connect

    Diercxsens, P.; de Weck, D.; Borsinger, N.; Rosset, B.; Tarradellas, J.

    1985-01-01

    A comparison is made of soil and earthworm contamination by PCBs and heavy metals between a nature reserve and two sites conditioned by the addition of sewage sludge and compost. The tissues and gut content of the earthworms shows a higher PCB concentration than that of the surrounding soil and also a difference in the fingerprint of some single PCB compounds. Earthworms display a selective accumulation of cadmium and zinc in their tissues and gut content.

  18. Heavy metals in Ratnapura alluvial gem sediments, Sri Lanka

    NASA Astrophysics Data System (ADS)

    Vithanage, M. S.; Hettiarachchi, J. K.; Rajapaksha, A. U.; Wijesekara, H.; Hewawasam, T.

    2011-12-01

    The valuable gems in Sri Lanka are found from the sedimentary gem deposits in Ratnapura District, which are found as alluvial deposits some are about >50 m deep. Gem bearing gravel layer is taken out from the mine, washed by panning to recover the gem minerals in the heavy mineral fraction, is a common practice in the gem mining area. Gem bearing sediment layer is associated with different heavy minerals in which different trace metals as Co, Cr, Cu, Al, Zr, Pb and As also can be present. During panning, the sediment is washed away and the heavy metals attached to the sediments are released into the environment. Hence we studied the lability and bioavailability of arsenic and other heavy metals from the gem sediments. Sediment samples were collected from 15 small scale gem mines (3 soil layers- top, gem mineral layer and layer below gem bearing gravel layer), air dried and sieved to obtain <63μm fraction. Bioavailable, exchangeable and residual fractions were 0.01M CaCl2, 1M NaOAc, pH 8.2 and microwave digestion using HF, HNO3 and HClO4. Filtered samples were analyzed for As, Co, Zn, Mn, Cu, Ni, Pb and Fe using atomic absorption spectrophotometer (GBC 933AA). Total digestion results in different layers indicated that heavy metals show an increasing pattern with depth. About 4 gem bearing gravel layers were consist of high concentrations of Ni (>150 mg/kg), Cu (>150 mg/kg), Pb (>400 mg/kg), Zn (>600 mg/kg) and Co ions (>100 mg/kg). Arsenite in the gem sediments were low and recorded as <5mg/kg. Total arsenic analysis is under investigation. Highest concentrations for bioavailable and exchangeable (leach to water) metals were Fe>Co>Zn>Mn>Ni>Cu>Pb. Sediments from few gem pits showed considerably high concentrations of metals analyzed. In some places Fe, Ni, Cu, Zn reported high in bioavailable fractions 70, 25, 20, 10 mg/kg respectively. Mobilization of these metals may increase due to changes in the pH and the presence of other ions in the environment. High

  19. Quantification of Heavy Metals in Mining Affected Soil and Their Bioaccumulation in Native Plant Species.

    PubMed

    Nawab, Javed; Khan, Sardar; Shah, Mohammad Tahir; Khan, Kifayatullah; Huang, Qing; Ali, Roshan

    2015-01-01

    Several anthropogenic and natural sources are considered as the primary sources of toxic metals in the environment. The current study investigates the level of heavy metals contamination in the flora associated with serpentine soil along the Mafic and Ultramafic rocks northern-Pakistan. Soil and wild native plant species were collected from chromites mining affected areas and analyzed for heavy metals (Cr, Ni, Fe, Mn, Co, Cu and Zn) using atomic absorption spectrometer (AAS-PEA-700). The heavy metal concentrations were significantly (p < 0.01) higher in mine affected soil as compared to reference soil, however Cr and Ni exceeded maximum allowable limit (250 and 60 mg kg(-1), respectively) set by SEPA for soil. Inter-metal correlations between soil, roots and shoots showed that the sources of contamination of heavy metals were mainly associated with chromites mining. All the plant species accumulated significantly higher concentrations of heavy metals as compared to reference plant. The open dumping of mine wastes can create serious problems (food crops and drinking water contamination with heavy metals) for local community of the study area. The native wild plant species (Nepeta cataria, Impatiens bicolor royle, Tegetis minuta) growing on mining affected sites may be used for soil reclamation contaminated with heavy metals.

  20. Modeling heavy metal removal in wetlands

    SciTech Connect

    Lung, W.S.; Light, R.N.

    1994-12-31

    Although the use of wetland ecosystems to purify water has gained increased attention only recently, it has been recognized as a wastewater treatment technique for centuries. While considerable research has occurred to quantify the nutrient (nitrogen and phosphorus) removal mechanisms of wetlands, relatively few investigators have focused on the mechanisms of heavy metal removal and uptake by wetland sediments and plants. The quantification of the assimilative capacity of heavy metals by wetland ecosystems is a critical component in the design and use of wetlands for this purpose. A computer model has been developed to simulate the fate and transport of heavy metals introduced to a wetland ecosystem. Modeled water quality variables include phytoplankton biomass and productivity; macrophyte (Nulumbo lutea) biomass; total phosphorus in the water column; dissolved copper in the water column and sediments; particulate copper in the water column and sediments; and suspended solids. These variables directly affect the calculated rate of copper uptake by macrophytes, and the rate of copper recycling as a function of the decomposition of copper-laden biomass litter. The model was calibrated using total phosphorus and chlorophyll a data from the Old Woman Creek Wetland in Ohio. Verification of the model was achieved using data on the copper content of the macrophyte Nelumbo lutea.

  1. Removal of heavy metals using waste eggshell.

    PubMed

    Park, Heung Jai; Jeong, Seong Wook; Yang, Jae Kyu; Kim, Boo Gil; Lee, Seung Mok

    2007-01-01

    The removal capacity of toxic heavy metals by the reused eggshell was studied. As a pretreatment process for the preparation of reused material from waste eggshell, calcination was performed in the furnace at 800 degrees C for 2 h after crushing the dried waste eggshell. Calcination behavior, qualitative and quantitative elemental information, mineral type and surface characteristics before and after calcination of eggshell were examined by thermal gravimetric analysis (TGA), X-ray fluorescence (XRF), X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. After calcination, the major inorganic composition was identified as Ca (lime, 99.63%) and K, P and Sr were identified as minor components. When calcined eggshell was applied in the treatment of synthetic wastewater containing heavy metals, a complete removal of Cd as well as above 99% removal of Cr was observed after 10 min. Although the natural eggshell had some removal capacity of Cd and Cr, a complete removal was not accomplished even after 60 min due to quite slower removal rate. However, in contrast to Cd and Cr, an efficient removal of Pb was observed with the natural eggshell rather than the calcined eggshell. From the application of the calcined eggshell in the treatment of real electroplating wastewater, the calcined eggshell showed a promising removal capacity of heavy metal ions as well as had a good neutralization capacity in the treatment of strong acidic wastewater.

  2. Variations in Heavy Metals Across Urban Streams

    NASA Astrophysics Data System (ADS)

    Kaushal, S. S.; Belt, K. T.; Stack, W. P.; Pouyat, R. V.; Groffman, P. M.; F, S. E.

    2006-05-01

    Urbanization has led to increased concentrations of metals such as lead (Pb), zinc (Zn), and copper (Cu) in streams due to industrial sources, domestic activities, vehicle use, and runoff from roadways. These metals can be dangerous to aquatic organisms and humans at high concentrations. We investigated variations in concentrations of heavy metals in streams across Baltimore, Maryland and within the context of convergent increases in salinity and organic carbon (two important variables that are known to affect metal transport in surface waters) due to urbanization. Despite past reductions of lead in gasoline and paints, mean concentrations of lead in some Baltimore streams were still approximately 75 micrograms/L and exceeded the U.S. EPA recommended criteria by 50 times. Mean concentrations of zinc and copper across Baltimore streams were also elevated and ranged between 15 to 140 micrograms/L and 2 to 40 micrograms/L, and mean concentrations of these metals were considerably higher than national means reported by the National Storm Water Quality database (NSWQ), which spans 3,770 storm events across the U.S. There were substantial increases in concentrations of heavy metals in streams during storms with greater than 80 percent, 70 percent, and 20 percent of storm samples exceeding recommended U.S. EPA metals criteria for Cu, Pb, and Zn respectively. Relationships between metal concentrations and stream discharge followed different patterns than nitrate and total phosphorus, other regulated pollutants in the Chesapeake Bay watershed, suggesting differences in sources and transport mechanisms within watersheds. Environmental factors such as increasing salinity from deicer use (with chloride concentrations in streams now ranging up to 5 g/L) may contribute to elevated transport of metals through ion exchange and mobilization of metals in soils and sediments. Environmental factors such as increasing organic carbon in urban streams, with ranges of 2 - 16 times greater

  3. Heavy Atom Labeled Nucleotides for Measurement of Kinetic Isotope Effects

    PubMed Central

    Weissman, Benjamin P.; Li, Nan-Sheng; York, Darrin; Harris, Michael; Piccirilli, Joseph A.

    2015-01-01

    Experimental analysis of kinetic isotope effects represents an extremely powerful approach for gaining information about the transition state structure of complex reactions not available through other methodologies. Implementation of this approach to the study of nucleic acid chemistry requires the synthesis of nucleobases and nucleotides enriched for heavy isotopes at specific positions. In this review we highlight current approaches to the synthesis of nucleic acids site-specifically enriched for heavy oxygen and nitrogen and their application in heavy atom isotope effect studies. PMID:25828952

  4. Heavy atom labeled nucleotides for measurement of kinetic isotope effects.

    PubMed

    Weissman, Benjamin P; Li, Nan-Sheng; York, Darrin; Harris, Michael; Piccirilli, Joseph A

    2015-11-01

    Experimental analysis of kinetic isotope effects represents an extremely powerful approach for gaining information about the transition state structure of complex reactions not available through other methodologies. The implementation of this approach to the study of nucleic acid chemistry requires the synthesis of nucleobases and nucleotides enriched for heavy isotopes at specific positions. In this review, we highlight current approaches to the synthesis of nucleic acids enriched site specifically for heavy oxygen and nitrogen and their application in heavy atom isotope effect studies. This article is part of a special issue titled: Enzyme Transition States from Theory and Experiment. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. Data on heavy metal levels (Cd, Co, and Cu) in wheat grains cultured in Dashtestan County, Iran.

    PubMed

    Esmaili, Abdolhamid; Noroozi Karbasdehi, Vahid; Saeedi, Reza; Javad Mohammadi, Mohammad; Sobhani, Tayebeh; Dobaradaran, Sina

    2017-10-01

    Due to importance of wheat as the most popular food, in this data article, we determined the accumulation of heavy metal levels including Cd, Co, and Cu in wheat grains in Dashtestan county, Iran. The concentration levels of heavy metals in wheat grains cultured were determined by Flame Atomic Absorption Spectrometry (FAAS).

  6. Advanced atom chips with two metal layers.

    SciTech Connect

    Stevens, James E.; Blain, Matthew Glenn; Benito, Francisco M.; Biedermann, Grant

    2010-12-01

    A design concept, device layout, and monolithic microfabrication processing sequence have been developed for a dual-metal layer atom chip for next-generation positional control of ultracold ensembles of trapped atoms. Atom chips are intriguing systems for precision metrology and quantum information that use ultracold atoms on microfabricated chips. Using magnetic fields generated by current carrying wires, atoms are confined via the Zeeman effect and controllably positioned near optical resonators. Current state-of-the-art atom chips are single-layer or hybrid-integrated multilayer devices with limited flexibility and repeatability. An attractive feature of multi-level metallization is the ability to construct more complicated conductor patterns and thereby realize the complex magnetic potentials necessary for the more precise spatial and temporal control of atoms that is required. Here, we have designed a true, monolithically integrated, planarized, multi-metal-layer atom chip for demonstrating crossed-wire conductor patterns that trap and controllably transport atoms across the chip surface to targets of interest.

  7. Plant rhamnogalacturonan II complexation of heavy metal cations

    DOEpatents

    O'Neill, Malcolm A.; Pellerin, Patrice J. M.; Warrenfeltz, Dennis; Vidal, Stephane; Darvill, Alan G.; Albersheim, Peter

    1999-01-01

    The present invention provides rhamnogalacturonan-II (RG-II) and relates to its ability to complex specific multivalent heavy metal cations. In the presence of boric acid, RG-II monomers form dimers that are cross-linked by a borate ester. The yield of such borate ester cross-linked dimers of RG-II is enhanced in the presence of specific heavy metal cations. The present invention further relates to the utility of RG-II in assays for the detection of specific heavy metal contamination; as a reagent useful in the removal of specific heavy metal cations contaminating foods and liquids, for example, fish, wines, etc.; as a pharmaceutical composition useful as an antidote in specific heavy metal cation poisoning; as a treatment for the detoxification of specific heavy metal cations from blood and/or tissues; and in a method of remediation of waters and soils contaminated with specific heavy metal cations.

  8. Plant rhamnogalacturonan II complexation of heavy metal cations

    DOEpatents

    O`Neill, M.A.; Pellerin, P.J.M.; Warrenfeltz, D.; Vidal, S.; Darvill, A.G.; Albersheim, P.

    1999-03-02

    The present invention provides rhamnogalacturonan-II (RG-II) and relates to its ability to complex specific multivalent heavy metal cations. In the presence of boric acid, RG-II monomers form dimers that are cross-linked by a borate ester. The yield of such borate ester cross-linked dimers of RG-II is enhanced in the presence of specific heavy metal cations. The present invention further relates to the utility of RG-II in assays for the detection of specific heavy metal contamination; as a reagent useful in the removal of specific heavy metal cations contaminating foods and liquids, for example, fish, wines, etc.; as a pharmaceutical composition useful as an antidote in specific heavy metal cation poisoning; as a treatment for the detoxification of specific heavy metal cations from blood and/or tissues; and in a method of remediation of waters and soils contaminated with specific heavy metal cations. 15 figs.

  9. Atomic physics experiments with stored cooled heavy ion beams

    SciTech Connect

    Datz, S.

    1986-01-01

    The wide ranging interest in the development of heavy ion synchrotrons with electron beam cooling is evident from the number of projects presently under way. Although much of the initial motivation for these rings stemmed from nuclear and particle physics, a considerable amount of atomic physics experimentation is planned. This paper surveys some of the new opportunities in atomic physics which may be made available with storage ring systems. 25 refs., 3 tabs.

  10. Slurry preparation by high-pressure homogenization for the determination of heavy metals in zoological and botanical certified reference materials and animal feeds by electrothermal atomic absorption spectrometry.

    PubMed

    Tan, Y; Blais, J S; Marshall, W D

    1996-10-01

    High-pressure homogenization was evaluated for the preparation of slurries suitable for the determination by ETAAS of Cr, Cu, Fe, Mn, Ni and Se in soft organ tissues (liver and kidney), certified reference materials of biological and botanical origin and animal feeds. Frozen fresh organ tissue, (2 g) or certified reference material or dried, ground plant material (0.1 g) was blended, at high speed with 20 ml of ethanol-water (1 + 9 v/v) containing 0.25% m/m of tetramethylammonium hydroxide and the resulting mixture was subjected to homogenization at 38.9 MPa. After four passes through the homogenizer, the resulting solution was suitable for analysis by ETAAS. Capping the flat valve head of the homogenizer with a ruby disc appreciably reduced (but did not eliminate) metal contamination introduced by the processing. Homogenization of botanical reference materials or dried animal feeds resulted in preparations with variable amounts of residual fibres and particulate matter in the resulting suspensions. Nonetheless, all the Cu and Mn and virtually all of the Fe had been transferred to the supernatant fraction and remained with that fraction for at least 10 d. The addition of EDTA to the solvent modestly increased the mobilization of Fe from the matrix but also increased the contamination from the homogenizer. The slopes of the calibration curves generated by the method of standard additions were not significantly different from those of calibration curves generated with aqueous standards in a homogenized blank indicating that there was no significant matrix effect for any of the analytes in the nine reference materials, liver or kidney or the five animal feed samples and that aqueous standards could be used to calibrate the instrumental response.

  11. Heavy Metals in the Vegetables Collected from Production Sites

    PubMed Central

    Taghipour, Hassan; Mosaferi, Mohammad

    2013-01-01

    Background: Contamination of vegetable crops (as an important part of people's diet) with heavy metals is a health concern. Therefore, monitoring levels of heavy metals in vegetables can provide useful information for promoting food safety. The present study was carried out in north-west of Iran (Tabriz) on the content of heavy metals in vegetable crops. Methods: Samples of vegetables including kurrat (n=20) (Allium ampeloprasumssp. Persicum), onion (n=20) (Allium cepa) and tomato (n=18) (Lycopersiconesculentum var. esculentum), were collected from production sites in west of Tabriz and analyzed for presence of Cd, Cr, Cu, Ni, Pb and Zn by atomic absorption spectroscopy (AAS) after extraction by aqua regia method (drying, grounding and acid diges­tion). Results: Mean ± SD (mg/kg DW) concentrations of Cd, Cu, Cr, Ni and Zn were 0.32 ± 0.58, 28.86 ± 28.79, 1.75 ± 2.05, 6.37± 5.61 and 58.01 ± 27.45, respec­tively. Cr, Cu and Zn were present in all the samples and the highest concentra­tions were observed in kurrat (leek). Levels of Cd, Cr and Cu were higher than the acceptable limits. There was significant difference in levels of Cr (P<0.05) and Zn (P<0.001) among the studied vegetables. Positive correlation was observed be­tween Cd:Cu (R=0.659, P<0.001) Cr:Ni (R=0.326, P<0.05) and Cr:Zn (R=0.308, P<0.05).   Conclusion: Level of heavy metals in some of the analyzed vegetables, especially kurrat samples, was higher than the standard levels. Considering the possi­ble health outcomes due to the consumption of contaminated vegetables, it is re­quired to take proper actions for avoiding people's chronic exposure. PMID:24688968

  12. Material Removes Heavy Metal Ions From Water

    NASA Technical Reports Server (NTRS)

    Philipp, Warren H., Jr.; Street, Kenneth W.; Hill, Carol; Savino, Joseph M.

    1995-01-01

    New high capacity ion-exchange polymer material removes toxic metal cations from contaminated water. Offers several advantages. High sensitivities for such heavy metals as lead, cadmium, and copper and capable of reducing concentrations in aqueous solutions to parts-per-billion range. Removes cations even when calcium present. Material made into variety of forms, such as thin films, coatings, pellets, and fibers. As result, adapted to many applications to purify contaminated water, usually hard wherever found, whether in wastewater-treatment systems, lakes, ponds, industrial plants, or homes. Another important feature that adsorbed metals easily reclaimed by either destructive or nondestructive process. Other tests show ion-exchange polymer made inexpensively; easy to use; strong, flexible, not easily torn; and chemically stable in storage, in aqueous solutions, and in acidic or basic solution.

  13. Material Removes Heavy Metal Ions From Water

    NASA Technical Reports Server (NTRS)

    Philipp, Warren H., Jr.; Street, Kenneth W.; Hill, Carol; Savino, Joseph M.

    1995-01-01

    New high capacity ion-exchange polymer material removes toxic metal cations from contaminated water. Offers several advantages. High sensitivities for such heavy metals as lead, cadmium, and copper and capable of reducing concentrations in aqueous solutions to parts-per-billion range. Removes cations even when calcium present. Material made into variety of forms, such as thin films, coatings, pellets, and fibers. As result, adapted to many applications to purify contaminated water, usually hard wherever found, whether in wastewater-treatment systems, lakes, ponds, industrial plants, or homes. Another important feature that adsorbed metals easily reclaimed by either destructive or nondestructive process. Other tests show ion-exchange polymer made inexpensively; easy to use; strong, flexible, not easily torn; and chemically stable in storage, in aqueous solutions, and in acidic or basic solution.

  14. A ferritin from Dendrorhynchus zhejiangensis with heavy metals detoxification activity.

    PubMed

    Li, Chenghua; Li, Zhen; Li, Ye; Zhou, Jun; Zhang, Chundan; Su, Xiurong; Li, Taiwu

    2012-01-01

    Ferritin, an iron homeostasis protein, has important functions in transition and storage of toxic metal ions. In this study, the full-length cDNA of ferritin was isolated from Dendrorhynchus zhejiangensis by cDNA library and RACE approaches. The higher similarity and conserved motifs for ferritin were also identified in worm counterparts, indicating that it belonged to a new member of ferritin family. The temporal expression of worm ferritin in haemocytes was analyzed by RT-PCR, and revealed the ferritin could be induced by Cd(2+), Pb(2+) and Fe(2+). The heavy metal binding activity of recombinant ferritin was further elucidated by atomic force microscopy (AFM). It was observed that the ferritin protein could form a chain of beads with different size against three metals exposure, and the largest one with 35~40 nm in height was identified in the Cd(2+) challenge group. Our results indicated that worm ferritin was a promising candidate for heavy metals detoxification.

  15. Dislocation loop formation by swift heavy ion irradiation of metals

    NASA Astrophysics Data System (ADS)

    Khara, Galvin S.; Murphy, Samuel T.; Duffy, Dorothy M.

    2017-07-01

    A coupled two-temperature, molecular dynamics methodology is used to simulate the structural evolution of bcc metals (Fe and W) and fcc metals (Cu and Ni) following irradiation by swift heavy ions. Electronic temperature dependent electronic specific heat capacities and electron-phonon coupling strengths are used to capture the full effects of the variation in the electronic density of states. Tungsten is found to be significantly more resistant to damage than iron, due both to the higher melting temperature and the higher thermal conductivity. Very interesting defect structures, quite different from defects formed in cascades, are found to be created by swift heavy ion irradiation in the bcc metals. Isolated vacancies form a halo around elongated interstitial dislocation loops that are oriented along the ion path. Such configurations are formed by rapid recrystallization of the molten cylindrical region that is created by the energetic ion. Vacancies are created at the recrystallization front, resulting in excess atoms at the core which form interstitial dislocation loops on completion of crystallization. These unique defect structures could, potentially, be used to create metal films with superior mechanical properties and interesting nanostructures.

  16. A Ferritin from Dendrorhynchus zhejiangensis with Heavy Metals Detoxification Activity

    PubMed Central

    Li, Chenghua; Li, Zhen; Li, Ye; Zhou, Jun; Zhang, Chundan; Su, Xiurong; Li, Taiwu

    2012-01-01

    Ferritin, an iron homeostasis protein, has important functions in transition and storage of toxic metal ions. In this study, the full-length cDNA of ferritin was isolated from Dendrorhynchus zhejiangensis by cDNA library and RACE approaches. The higher similarity and conserved motifs for ferritin were also identified in worm counterparts, indicating that it belonged to a new member of ferritin family. The temporal expression of worm ferritin in haemocytes was analyzed by RT-PCR, and revealed the ferritin could be induced by Cd2+, Pb2+ and Fe2+. The heavy metal binding activity of recombinant ferritin was further elucidated by atomic force microscopy (AFM). It was observed that the ferritin protein could form a chain of beads with different size against three metals exposure, and the largest one with 35∼40 nm in height was identified in the Cd2+ challenge group. Our results indicated that worm ferritin was a promising candidate for heavy metals detoxification. PMID:23284696

  17. Magnetoresistance in paramagnetic heavy fermion metals.

    PubMed

    Parihari, D; Vidhyadhiraja, N S

    2009-10-07

    A theoretical study of magnetic field (h) effects on single-particle spectra and the transport quantities of heavy fermion metals in the paramagnetic phase is carried out. We have employed a non-perturbative local moment approach (LMA) to the asymmetric periodic Anderson model within the dynamical mean field framework. The lattice coherence scale ω(L), which is proportional within the LMA to the spin-flip energy scale, and has been shown in earlier studies to be the energy scale at which crossover to single-impurity physics occurs, increases monotonically with increasing magnetic field. The many body Kondo resonance in the density of states at the Fermi level splits into two, with the splitting being proportional to the field itself. For h≥0, we demonstrate adiabatic continuity from the strongly interacting case to a corresponding non-interacting limit, thus establishing Fermi liquid behaviour for heavy fermion metals in the presence of a magnetic field. In the Kondo lattice regime, the theoretically computed magnetoresistance is found to be negative in the entire temperature range. We argue that such a result could be understood at [Formula: see text] by field-induced suppression of spin-flip scattering and at [Formula: see text] through lattice coherence. The coherence peak in the heavy fermion resistivity diminishes and moves to higher temperatures with increasing field. Direct comparison of the theoretical results to the field dependent resistivity measurements in CeB(6) yields good agreement.

  18. Atomic Manipulation on Metal Surfaces

    NASA Astrophysics Data System (ADS)

    Ternes, Markus; Lutz, Christopher P.; Heinrich, Andreas J.

    Half a century ago, Nobel Laureate Richard Feynman asked in a now-famous lecture what would happen if we could precisely position individual atoms at will [R.P. Feynman, Eng. Sci. 23, 22 (1960)]. This dream became a reality some 30 years later when Eigler and Schweizer were the first to position individual Xe atoms at will with the probe tip of a low-temperature scanning tunneling microscope (STM) on a Ni surface [D.M. Eigler, E.K. Schweizer, Nature 344, 524 (1990)].

  19. Chitosan removes toxic heavy metal ions from cigarette mainstream smoke

    NASA Astrophysics Data System (ADS)

    Zhou, Wen; Xu, Ying; Wang, Dongfeng; Zhou, Shilu

    2013-09-01

    This study investigated the removal of heavy metal ions from cigarette mainstream smoke using chitosan. Chitosan of various deacetylation degrees and molecular weights were manually added to cigarette filters in different dosages. The mainstream smoke particulate matter was collected by a Cambridge filter pad, digested by a microwave digestor, and then analyzed for contents of heavy metal ions, including As(III/V), Pb(II), Cd(II), Cr(III/VI) and Ni(II), by graphite furnace atomic absorption spectrometry (GFAAS). The results showed that chitosan had a removal effect on Pb(II), Cd(II), Cr(III/VI) and Ni(II). Of these, the percent removal of Ni(II) was elevated with an increasing dosage of chitosan. Chitosan of a high deace tylation degree exhibited good binding performance toward Cd(II), Cr(III/VI) and Ni(II), though with poor efficiency for Pb(II). Except As(III/V), all the tested metal ions showed similar tendencies in the growing contents with an increasing chitosan molecular weight. Nonetheless, the percent removal of Cr(III/VI) peaked with a chitosan molecular weight of 200 kDa, followed by a dramatic decrease with an increasing chitosan molecular weight. Generally, chitosan had different removal effects on four out of five tested metal ions, and the percent removal of Cd(II), Pb(II), Cr(III/VI) and Ni(II) was approximately 55%, 45%, 50%, and 16%, respectively. In a word, chitosan used in cigarette filter can remove toxic heavy metal ions in the mainstream smoke, improve cigarette safety, and reduce the harm to smokers.

  20. Advances in Understanding How Heavy Metal Pollution Triggers Gastric Cancer

    PubMed Central

    Yuan, Wenzhen; Yang, Ning

    2016-01-01

    With the development of industrialization and urbanization, heavy metals contamination has become a major environmental problem. Numerous investigations have revealed an association between heavy metal exposure and the incidence and mortality of gastric cancer. The mechanisms of heavy metals (lead, cadmium, mercury, chromium, and arsenic) contamination leading to gastric cancer are concluded in this review. There are four main potential mechanisms: (1) Heavy metals disrupt the gastric mucosal barrier by decreasing mucosal thickness, mucus content, and basal acid output, thereby affecting the function of E-cadherin and inducing reactive oxygen species (ROS) damage. (2) Heavy metals directly or indirectly induce ROS generation and cause gastric mucosal and DNA lesions, which subsequently alter gene regulation, signal transduction, and cell growth, ultimately leading to carcinogenesis. Exposure to heavy metals also enhances gastric cancer cell invasion and metastasis. (3) Heavy metals inhibit DNA damage repair or cause inefficient lesion repair. (4) Heavy metals may induce other gene abnormalities. In addition, heavy metals can induce the expression of proinflammatory chemokine interleukin-8 (IL-8) and microRNAs, which promotes tumorigenesis. The present review is an effort to underline the human health problem caused by heavy metal with recent development in order to garner a broader perspective. PMID:27803929

  1. Advances in Understanding How Heavy Metal Pollution Triggers Gastric Cancer.

    PubMed

    Yuan, Wenzhen; Yang, Ning; Li, Xiangkai

    2016-01-01

    With the development of industrialization and urbanization, heavy metals contamination has become a major environmental problem. Numerous investigations have revealed an association between heavy metal exposure and the incidence and mortality of gastric cancer. The mechanisms of heavy metals (lead, cadmium, mercury, chromium, and arsenic) contamination leading to gastric cancer are concluded in this review. There are four main potential mechanisms: (1) Heavy metals disrupt the gastric mucosal barrier by decreasing mucosal thickness, mucus content, and basal acid output, thereby affecting the function of E-cadherin and inducing reactive oxygen species (ROS) damage. (2) Heavy metals directly or indirectly induce ROS generation and cause gastric mucosal and DNA lesions, which subsequently alter gene regulation, signal transduction, and cell growth, ultimately leading to carcinogenesis. Exposure to heavy metals also enhances gastric cancer cell invasion and metastasis. (3) Heavy metals inhibit DNA damage repair or cause inefficient lesion repair. (4) Heavy metals may induce other gene abnormalities. In addition, heavy metals can induce the expression of proinflammatory chemokine interleukin-8 (IL-8) and microRNAs, which promotes tumorigenesis. The present review is an effort to underline the human health problem caused by heavy metal with recent development in order to garner a broader perspective.

  2. Contamination of environment with heavy metals emitted from automotives

    SciTech Connect

    Falahi-Ardakani, A.

    1984-04-01

    Interest has arisen in heavy-metal contamination of the environment, mostly because of potential hazards to the health of animals and human (directly and/or indirectly). High levels of heavy metals in soil, plants, and the atmosphere are often related to industries, highways, chemical dumping, impure chemical fertilizers, and pesticides containing metals. An important source of heavy metals, especially lead, is from the combustion of leaded gasoline used for transportation. Other heavy metals associated with transportation include nickel, which is also added to gasoline and is contained in engine parts, zinc, and cadmium from tires, lubricating oils, and galvanized parts such as fuel tanks.

  3. Facultative hyperaccumulation of heavy metals and metalloids.

    PubMed

    Pollard, A Joseph; Reeves, Roger D; Baker, Alan J M

    2014-03-01

    Approximately 500 species of plants are known to hyperaccumulate heavy metals and metalloids. The majority are obligate metallophytes, species that are restricted to metalliferous soils. However, a smaller but increasing list of plants are "facultative hyperaccumulators" that hyperaccumulate heavy metals when occurring on metalliferous soils, yet also occur commonly on normal, non-metalliferous soils. This paper reviews the biology of facultative hyperaccumulators and the opportunities they provide for ecological and evolutionary research. The existence of facultative hyperaccumulator populations across a wide edaphic range allows intraspecific comparisons of tolerance and uptake physiology. This approach has been used to study zinc and cadmium hyperaccumulation by Noccaea (Thlaspi) caerulescens and Arabidopsis halleri, and it will be instructive to make similar comparisons on species that are distributed even more abundantly on normal soil. Over 90% of known hyperaccumulators occur on serpentine (ultramafic) soil and accumulate nickel, yet there have paradoxically been few experimental studies of facultative nickel hyperaccumulation. Several hypotheses suggested to explain the evolution of hyperaccumulation seem unlikely when most populations of a species occur on normal soil, where plants cannot hyperaccumulate due to low metal availability. In such species, it may be that hyperaccumulation is an ancestral phylogenetic trait or an anomalous manifestation of physiological mechanisms evolved on normal soils, and may or may not have direct adaptive benefits. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  4. Ion exchange extraction of heavy metals from wastewater sludges.

    PubMed

    Al-Enezi, G; Hamoda, M F; Fawzi, N

    2004-01-01

    Heavy metals are common contaminants of some industrial wastewater. They find their way to municipal wastewaters due to industrial discharges into the sewerage system or through household chemicals. The most common heavy metals found in wastewaters are lead, copper, nickel, cadmium, zinc, mercury, arsenic, and chromium. Such metals are toxic and pose serious threats to the environment and public health. In recent years, the ion exchange process has been increasingly used for the removal of heavy metals or the recovery of precious metals. It is a versatile separation process with the potential for broad applications in the water and wastewater treatment field. This article summarizes the results obtained from a laboratory study on the removal of heavy metals from municipal wastewater sludges obtained from Ardhiya plant in Kuwait. Data on heavy metal content of the wastewater and sludge samples collected from the plant are presented. The results obtained from laboratory experiments using a commercially available ion exchange resin to remove heavy metals from sludge were discussed. A technique was developed to solubilize such heavy metals from the sludge for subsequent treatment by the ion exchange process. The results showed high efficiency of extraction, almost 99.9%, of heavy metals in the concentration range bound in wastewater effluents and sludges. Selective removal of heavy metals from a contaminated wastewater/sludge combines the benefits of being economically prudent and providing the possibility of reuse/recycle of the treated wastewater effluents and sludges.

  5. Evaluation of the bioaccumulation of heavy metals in white shrimp (Litopenaeus vannamei) along the Persian Gulf coast.

    PubMed

    Dadar, Maryam; Peyghan, Rahim; Memari, Hamid Rajabi

    2014-09-01

    The concentrations of heavy metals in Persian Gulf are low, but petrochemical and refinery activities have caused an increase in heavy metal wastes, especially in coastal regions. The present study was done to determine the bioaccumulation of heavy metals in the muscle of white shrimp (Litopenaeus vannamei) using flame atomic absorption spectrophotometry. The experiment was conducted in four important coastal regions of the Persian Gulf: Bushehr, Deylam, Mahshahr, and Abadan. Amounts of seven heavy metals such as Copper (Cu), Iron (Fe), Lead (Pb), Zinc (Zn), Nickel (Ni), Cadmium (Cd), and Cobalt (Co), were measured as µg/g heavy metal in dry weight in the muscle of white shrimp from the afore-mentioned regions during 2011. This study revealed information that the primary risk for human health and the marine life chain was lead in the muscles of white shrimp in Mahshahr, where intense petrochemical and refinery activities are conducted. Concentrations of other heavy metals were lower than world standards.

  6. Assessment of heavy metals in Averrhoa bilimbi and A. carambola fruit samples at two developmental stages.

    PubMed

    Soumya, S L; Nair, Bindu R

    2016-05-01

    Though the fruits of Averrhoa bilimbi and A. carambola are economically and medicinally important, they remain underutilized. The present study reports heavy metal quantitation in the fruit samples of A. bilimbi and A. carambola (Oxalidaceae), collected at two stages of maturity. Heavy metals are known to interfere with the functioning of vital cellular components. Although toxic, some elements are considered essential for human health, in trace quantities. Heavy metals such as Cr, Mn, Co, Cu, Zn, As, Se, Pb, and Cd were analyzed by atomic absorption spectroscopy (AAS). The samples under investigation included, A. bilimbi unripe (BU) and ripe (BR), A. carambola sour unripe (CSU) and ripe (CSR), and A. carambola sweet unripe (CTU) and ripe (CTR). Heavy metal analysis showed that relatively higher level of heavy metals was present in BR samples compared to the rest of the samples. The highest amount of As and Se were recorded in BU samples while Mn content was highest in CSU samples and Co in CSR. Least amounts of Cr, Zn, Se, Cd, and Pb were noted in CTU while, Mn, Cu, and As were least in CTR. Thus, the sweet types of A. carambola (CTU, CTR) had comparatively lower heavy metal content. There appears to be no reason for concern since different fruit samples of Averrhoa studied presently showed the presence of various heavy metals in trace quantities.

  7. Visualizing plumes of heavy metals and radionuclides

    NASA Astrophysics Data System (ADS)

    Prigiobbe, V.; Liu, T.; Bryant, S. L.; Hesse, M. A.

    2015-12-01

    The understanding of the transport behaviors in porous media resides on the ability to reproduce fundamental phenomena in a lab setting. Experiments with quasi 2D tanks filled with beads are performed to study physical phenomena induced by chemical and fluid dynamic processes. When an alkaline solution containing heavy metals or radionuclides invades a low pH region, mixing due to longitudinal dispersion induces destabilization of the front forming a fast travelling pulse [1]. When the two fluids travel in parallel, instead, mixing induced by transverse dispersion creates a continuous leakage from the alkaline region into the acidic one forming a fast travelling plume [2] (Figure 1). Impact of these phenomena are on aquifers upon leaking of alkaline fluids, rich in heavy metals and radionuclides, from waste storage sites. Here, we report the results from a study where experiments with a quasi 2D tank are performed to analyze the effect of transverse mixing on strontium (Sr2+) transport. To visualize the leaking plume, a fluorescent dye (Fura-2) is added the acidic solution, which has been widely used in biomedical applications [3]. It is the aim of this work to optimize its application under the conditions relevant to this work. Spectrometric measurements of absorption and fluorescence show sensitivity of the dye to the presence of Sr2+ throughout a broad range of pH and Sr2+ concentration (Figure 2). In the absence of Sr2+, no significant absorption and fluorescence was measured, but as Sr2+ was added the relevant peaks increase significantly and sample dilution of tenfold was required to remain within the measuring threshold. These results show a strong sensitivity of the dye to the cation opening the opportunity to use Fura-2 as a tool to visualize heavy metals and radionuclides plumes. References[1] Prigiobbe et al. (2012) GRL 39, L18401. [2] Prigiobbe and Hesse (2015) in preparation. [3] Xu-Friedman and Regehr (2000) J. Neurosci. 20(12) 4414-4422.

  8. Heavy metal retention of different embankments

    NASA Astrophysics Data System (ADS)

    Werkenthin, Moritz; Kluge, Bjoern; Wessolek, Gerd

    2013-04-01

    The accumulation and retention of heavy metals in roadside soils has been studied for at least over forty years, but it is still subject of major interest. The continuously increasing road traffic induces high heavy metal loadings in runoff and seepage water. Elevated concentrations of heavy metals are a potential environmental risk. Especially in the long term development there is an increasing problem of soil contamination and groundwater pollution. A significant rate of road runoff infiltrates into the hard and soft shoulder. They are usually built during road construction and located directly along the road edge. According to valid german law, newly constructed hard shoulders have to provide a specific bearing capacity to enable trafficability in emergency cases. Therefore the applicable materials consist of defined gravel-soil mixtures, which can fulfill this requirement. To determine and compare the concentration of Pb, Cd, Zn, Cu, Ni, Cr in the road runoff and seepage water of different hard shoulder substrates, we installed 6 lysimeters along the edge of the german highway A115. Three lysimeters were filled with different materials wich are commonly used for road construction in Germany and compacted afterwards. Surface runoff is sampled, as is seepage water in two depths in the three lysimeters. Furthermore three lysimeters where installed and filled with plain gravel, to observe the distribution, quantity and quality of road runoff. Additionally soil column experiments were carried out with the same construction material. Both, the measured seepage water concentrations from field and column experiments of Pb, Cd, Zn, Cu, Ni, Cr do not yet exceed the trigger values of the German Federal Soil Protection and Contamination Ordinance (BBodSchV). No significant differences in heavy metal concentrations of the three artificial hard shoulder lysimeters were determined so far. First analytical results of the road runoff show concentrations of up to 12.9 µg/l Pb

  9. Performance of Raphidocelis subcapitata exposed to heavy metal mixtures.

    PubMed

    Expósito, Nora; Kumar, Vikas; Sierra, Jordi; Schuhmacher, Marta; Giménez Papiol, Gemma

    2017-12-01

    Microalgae growth inhibition assays are candidates for referent ecotoxicological assays, and are a fundamental part in the strategy to reduce the use of fish and other animal models in aquatic toxicology. In the present work, the performance of Raphidocelis subcapitata exposed to heavy metals following standardized growth inhibition assays has been assessed in three different scenarios: 1) dilutions of single heavy metals, 2) artificial mixture of heavy metals at similar levels than those found in natural rivers and, 3) natural samples containing known mixtures of contaminants (heavy metals). Chemical speciation of heavy metals has been estimated with Eh-pH diagram and Visual MINTEQ software; heavy metal and free heavy metal ion concentrations were used as input data, together with microalgae growth inhibition, for Dr. Fit software. The final goal was to assess the suitability of the ecotoxicological test based on the growth inhibition of microalgae cultures, and the mathematic models based on these results, for regulatory and decision-making purposes. The toxicity of a given heavy metal is not only determined by its chemical speciation; other chemical and biological interaction play an important role in the final toxicity. Raphidocelis subcapitata 48h-h-EC50 for tested heavy metals (especially Cu and Zn) were in agreement with previous studies, when ion metal bioavailability was assumed to be 100%. Nevertheless, the calculated growth inhibition was not in agreement with the obtained inhibition when exposed to the artificial mixture of heavy metals or the natural sample. Interactions between heavy metal ions and the compounds of the culture media and/or the natural sample determine heavy metal bioavailability, and eventually their toxicity. More research is needed for facing the challenge posed by pollutant mixtures as they are present in natural environments, and make microalgae-based assays suitable for pollution management and regulatory purposes. Copyright

  10. Atom Probe Tomography Characterization of a Gas Atomized Metallic Glass

    SciTech Connect

    Miller, Michael K; Venkataraman, Shankar; Eckert, Jurgen; Schultz, Ludwig; Sordelet, Daniel

    2006-01-01

    Summary form only given. A number of metallic glasses that exhibit a wide supercooled liquid region before crystallization and a high glass-forming ability have been discovered. These metallic glasses exhibit useful properties such as high strength and high stiffness and can be fabricated from the melt in a bulk form with a thickness of {approx} 10 mm. The high glass-forming ability facilitates the formation of metallic glass powders by conventional gas-atomization technique. Subsequent consolidation of the powders to any dimensions is possible due to the viscous flow of the material in the supercooled liquid region. Hence, the synthesis of bulk metallic glasses using gas atomization coupled with subsequent consolidation holds a promising future. Atom probe tomography, X-ray diffraction and differential scanning calorimetry (DSC) characterizations of gas atomized powder particles of a Cu{sub 47}Ti{sub 33}Zr{sub 11}Ni{sub 8}Si{sub 1} metallic glass have been performed. The needle-shaped specimens required for the local electrode atom probe were fabricated from individual 10-40 mum diameter particles with the use of a dual beam focused ion beam miller. The microstructure of the alloy was investigated from the as-atomized powder and annealing treatments up to the completion of the first and second exothermic events at 785 and 838 K. Atom probe tomography revealed that the microstructure consisted of an interconnected network structure of two amorphous phases after an annealing treatment of 360 min. at 623 K. A fine-scale multiphase microstructure of an irregularly shaped copper-enriched and titanium-, nickel- and silicon-depleted phase that was 10-20 nm in extent, a higher number density of smaller, {approx}10 nm diameter, and roughly spherical titanium-enriched and copper- and zirconium-depleted phase and a matrix phase was found after continuous heating in a DSC to 785 and 838 K. The scanning electron microscope also revealed 4 distinct coarser phases consistent

  11. [Comparison of heavy metal elements between natural and plantation forests in a subtropical Montane forest].

    PubMed

    Nie, Ming; Wan, Jia-Rong; Chen, Xiao-Feng; Wang, Li; Li, Bo; Chen, Jia-Kuan

    2011-11-01

    Heavy metals as one of major pollutants is harmful to the health of forest ecosystems. In the present paper, the concentrations of thirteen heavy metals (Fe, Al, Ti, Cr, Cu, Mn, V, Zn, Ni, Co, Pb, Se and Cd) were compared between natural and plantation forests in the Mt. Lushan by ICP-AES and atomic absorption spectroscopy. The results suggest that the soil of natural forest had higher concentrations of Fe, Al, Ti, Cu, Mn, V, Zn, Ni, Co, Pb, Se, and Cd than the plantation forest except for Cr. The soil of natural forest had a higher level of heavy metals than that of the plantation forest as a whole. This might be due to that the natural forest has longer age than the plantation forest, and fixed soil heavy metals take a longer period of time than the plantation forest.

  12. Heavy metal contamination and its indexing approach for groundwater of Goa mining region, India

    NASA Astrophysics Data System (ADS)

    Singh, Gurdeep; Kamal, Rakesh Kant

    2016-06-01

    The objective of the study is to reveal the seasonal variations in the groundwater quality with respect to heavy metal contamination. To get the extent of the heavy metals contamination, groundwater samples were collected from 45 different locations in and around Goa mining area during the monsoon and post-monsoon seasons. The concentration of heavy metals, such as lead, copper, manganese, zinc, cadmium, iron, and chromium, were determined using atomic absorption spectrophotometer. Most of the samples were found within limit except for Fe content during the monsoon season at two sampling locations which is above desirable limit, i.e., 300 µg/L as per Indian drinking water standard. The data generated were used to calculate the heavy metal pollution index (HPI) for groundwater. The mean values of HPI were 1.5 in the monsoon season and 2.1 in the post-monsoon season, and these values are well below the critical index limit of 100.

  13. Heavy metal contamination and its indexing approach for groundwater of Goa mining region, India

    NASA Astrophysics Data System (ADS)

    Singh, Gurdeep; Kamal, Rakesh Kant

    2017-06-01

    The objective of the study is to reveal the seasonal variations in the groundwater quality with respect to heavy metal contamination. To get the extent of the heavy metals contamination, groundwater samples were collected from 45 different locations in and around Goa mining area during the monsoon and post-monsoon seasons. The concentration of heavy metals, such as lead, copper, manganese, zinc, cadmium, iron, and chromium, were determined using atomic absorption spectrophotometer. Most of the samples were found within limit except for Fe content during the monsoon season at two sampling locations which is above desirable limit, i.e., 300 µg/L as per Indian drinking water standard. The data generated were used to calculate the heavy metal pollution index (HPI) for groundwater. The mean values of HPI were 1.5 in the monsoon season and 2.1 in the post-monsoon season, and these values are well below the critical index limit of 100.

  14. Heavy metal music and reckless behavior among adolescents.

    PubMed

    Arnett, J

    1991-12-01

    Adolescents who liked heavy metal music were compared to those who did not on a variety of outcome variables, particularly focusing on reckless behavior. Boys who liked heavy metal music reported a higher rate of a wide range of reckless behavior, including driving behavior, sexual behavior, and drug use. They were also less satisfied with their family relationships. Girls who liked heavy metal music were more reckless in the areas of shoplifting, vandalism, sexual behavior, and drug use, and reported lower self-esteem. Both boys and girls who liked heavy metal music were higher in sensation seeking and more self-assured with regard to sexuality and dating. In regression analyses, the relation between reckless behavior and liking heavy metal music was sustained for five out of twelve variables concerning reckless behavior, including three of four among girls, when sensation seeking and family relationships were entered into the equation before liking or not liking heavy metal music.

  15. Heavy metal pumps in plants. 1998 annual progress report

    SciTech Connect

    Harper, J.F.

    1998-06-01

    'The purpose of the proposed DOE research is to determine the function of AMA1, a novel heavy metal pump identified in a model plant system, Arabidopsis. Heavy metal pumps belong to a superfamily of P-type ATPases which include the plasma membrane Na/K-ATPase in animals and the plasma membrane H + ATPase in plants and fungi. Heavy metal pumps have been implicated in heavy metal resistance (e.g., cadmium) and regulation of essential micronutrients (e.g., copper). Although several heavy metal pumps have now been identified in plants, their isoform specific functions have not been investigated. The results suggest that AMA1 is a molydenum uptake pump. The authors are exploring the possibility to engineer the ion specificity of these pumps to take up other heavy metals from the soil. This report summarizes work after 2 years of a 3 year project.'

  16. [Bioremediation of heavy metal pollution by edible fungi: a review].

    PubMed

    Liu, Jian-Fei; Hu, Liu-Jie; Liao, Dun-Xiu; Su, Shi-Ming; Zhou, Zheng-Ke; Zhang, Sheng

    2011-02-01

    Bioremediation is the method of using organisms and their derivatives to absorb heavy metals from polluted environment, with the characteristics of low cost, broad sources, and no secondary pollution. Heavy metals enrichment by edible fungi is an important research focus of bioremediation, because it can decrease the eco-toxicity of heavy metals via the uptake by edible fungi, and thereby, take a definite role in heavy metal remediation. This paper reviewed the research progress on the enrichment of heavy metal copper, cadmium, lead, zinc, arsenic, and chromium by edible fungi and the possible enrichment mechanisms, and prospected the development and applications of heavy metal enrichment by edible fungi in the management of polluted environment.

  17. Hyperaccumulators, arbuscular mycorrhizal fungi and stress of heavy metals.

    PubMed

    Miransari, Mohammad

    2011-01-01

    Use of plants, with hyperaccumulating ability or in association with soil microbes including the symbiotic fungi, arbuscular mycorrhiza (AM), are among the most common biological methods of treating heavy metals in soil. Both hyperaccumulating plants and AM fungi have some unique abilities, which make them suitable to treat heavy metals. Hyperaccumulator plants have some genes, being expressed at the time of heavy metal pollution, and can accordingly localize high concentration of heavy metals to their tissues, without showing the toxicity symptoms. A key solution to the issue of heavy metal pollution may be the proper integration of hyperaccumulator plants and AM fungi. The interactions between the soil microbes and the host plant can also be important for the treatment of soils polluted with heavy metals.

  18. Atomic-Scale Imprinting into Amorphous Metals

    NASA Astrophysics Data System (ADS)

    Schwarz, Udo; Li, Rui; Simon, Georg; Kinser, Emely; Liu, Ze; Chen, Zheng; Zhou, Chao; Singer, Jonathan; Osuji, Chinedum; Schroers, Jan

    Nanoimprinting by thermoplastic forming (TPF) has attracted significant attention in recent years due to its promise of low-cost fabrication of nanostructured devices. Usually performed using polymers, amorphous metals have been identified as a material class that might be even better suited for nanoimprinting due to a combination of mechanical properties and processing ability. Commonly referred to as metallic glasses, their featureless atomic structure suggests that there may not be an intrinsic size limit to the material's ability to replicate a mold. To study this hypothesis, we demonstrate atomic-scale imprinting into amorphous metals by TPF under ambient conditions. Atomic step edges of a SrTiO3 (STO) single crystal used as mold were successfully imprinted into Pt-based bulk metallic glasses (BMGs) with high fidelity. Terraces on the BMG replicas possess atomic smoothness with sub-Angstrom roughness that is identical to the one measured on the STO mold. Systematic studies revealed that the quality of the replica depends on the loading rate during imprinting, that the same mold can be used multiple times without degradation of mold or replicas, and that the atomic-scale features on as-imprinted BMG surfaces has impressive long-term stability (months).

  19. Ultrahigh stability of atomically thin metallic glasses

    SciTech Connect

    Cao, C. R.; Huang, K. Q.; Zhao, N. J.; Sun, Y. T.; Bai, H. Y.; Gu, L. E-mail: dzheng@iphy.ac.cn Zheng, D. N. E-mail: dzheng@iphy.ac.cn Wang, W. H. E-mail: dzheng@iphy.ac.cn

    2014-07-07

    We report the fabrication and study of thermal stability of atomically thin ZrCu-based metallic glass films. The ultrathin films exhibit striking dynamic properties, ultrahigh thermal stability, and unique crystallization behavior with discrete crystalline nanoparticles sizes. The mechanisms for the remarkable high stability and crystallization behaviors are attributed to the dewetting process of the ultrathin film. We demonstrated a promising avenue for understanding some fundamental issues such as glassy structure, crystallization, deformation, and glass formation through atomic resolution imaging of the two dimensional like metallic glasses.

  20. Removal of dissolved heavy metals and radionuclides by microbial spores

    SciTech Connect

    Revis, N.W.; Hadden, C.T.; Edenborn, H.

    1997-11-01

    Microbial systems have been shown to remove specific heavy metals from contaminated aqueous waste to levels acceptable to EPA for environmental release. However, systems capable of removing a variety of heavy metals from aqueous waste to environmentally acceptable levels remain to be reported. The present studies were performed to determine the specificity of spores of the bacterium Bacillus megaterium for the adsorption of dissolved metals and radionuclides from aqueous waste. The spores effectively adsorbed eight heavy metals from a prepared metal mix and from a plating rinse waste to EPA acceptable levels for waste water. These results suggest that spores have multiple binding sites for the adsorption of heavy metals. Spores were also effective in adsorbing the radionuclides {sup 85}strontium and {sup 197}cesium. The presence of multiple sites in spores for the adsorption of heavy metals and radionuclides makes this biosorbent a good candidate for the treatment of aqueous wastes associated with the plating and nuclear industries. 17 refs., 4 tabs.

  1. Heavy metal atmospheric deposition and biomonitoring

    NASA Astrophysics Data System (ADS)

    Ayrault, S.; Clocchiatti, R.; Carrot, F.; Michel, A.; Gaudry, A.; Moskura, M.

    2003-05-01

    The atmospheric fluxes of heavy metals were measured continuously in the Paris area. The dry depositions were collected on quartz fiber filters, after comparison between clogging capacities and blank levels on commercial filters. Rain was collected in a polyethylene gauge. Two transplanted biomonitors, the epiphytic lichen Evernia prunastri, and the pleurocarpeous moss Scleropodium purum, were exposed simultaneously. These two common biomonitors have been used in previous passive biomonitoring campaigns [Galsomies 1999, Grasso 1999]. This work attempts to produce data on heavy metal exposure of this populated area near Paris, and to compare these two cryptogamic species behaviour. The results on bioaccumulation were compared to those given by a previous work in Italy [Bargagli, 2002] comparing the moss Hypnum cupressiforme and the lichen Parmelia caperata. In our study, the transplanted lichens were exposed in different conditions: to the rain or protected from rain, in vertical, horizontal or oblique position. Dry (filters) and wet (rain) depositions and biomonitors were analysed by Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) and Neutron Activation Analysis (NAA) for more than 30elements [Ayrault, 2001]. The individual particle composition (on filters and cryptogams) was determined by nuclear microprobe (PIXE) and electron microprobe. The lichens displayed different accumulation rates, depending on exposition conditions. In particular, the inclination influenced the bulk concentrations in the lichen. Relation was made between fluxes and concentration accumulated by the biomonitors. The enrichment factors were spectacular for some elements, e.g. lead.

  2. Heavy metals in the cell nucleus - role in pathogenesis.

    PubMed

    Sas-Nowosielska, Hanna; Pawlas, Natalia

    2015-01-01

    People are exposed to heavy metals both in an occupational and natural environment. The most pronounced effects of heavy metals result from their interaction with cellular genetic material packed in form of chromatin. Heavy metals influence chromatin, mimicking and substituting natural microelements in various processes taking place in the cell, or interacting chemically with nuclear components: nucleic acids, proteins and lipids. This paper is a review of current knowledge on the effects of heavy metals on chromatin, exerted at the level of various nuclear components.

  3. Adsorption of heavy metal in freeway by asphalt block

    NASA Astrophysics Data System (ADS)

    Zheng, Chaocheng

    2017-08-01

    Heavy metals are toxic, persistent, and carcinogenic in freeway. Various techniques are available for the removal of heavy metals from waste water among soils during freeway including ion-exchange, membrane filtration, electrolysis, coagulation, flotation, and adsorption. Among them, bio-sorption processes are widely used for heavy metal and other pollutant removal due to its sustainable, rapid and economic. In this paper, heavy metal removal facilitated by adsorption in plants during freeway was illustrated to provide concise information on exploring the adsorption efficiency.

  4. Bioremediation of Toxic Heavy Metals: A Patent Review.

    PubMed

    Verma, Neelam; Sharma, Rajni

    2017-01-01

    The global industrialization is fulfilling the demands of modern population at the cost of environmental exposure to various contaminants including heavy metals. These heavy metals affect water and soil quality. Moreover, these enter into the food chain and exhibit their lethal effects on the human health even when present at slightly higher concentration than required for normal metabolism. To the worst of their part, the heavy metals may become carcinogenic. Henceforth, the efficient removal of heavy metals is the demand of sustainable development. Remedy: Bioremediation is the 'green' imperative technique for the heavy metal removal without creating secondary metabolites in the ecosystem. The metabolic potential of several bacterial, algal, fungal as well as plant species has the efficiency to exterminate the heavy metals from the contaminated sites. Different strategies like bioaccumulation, biosorption, biotransformation, rhizofilteration, bioextraction and volatilization are employed for removal of heavy metals by the biological species. Bioremediation approach is presenting a splendid alternate for conventional expensive and inefficient methods for the heavy metal removal. The patents granted on the bioremediation of toxic heavy metals are summarized in the present manuscript which supported the applicability of bioremediation technique at commercial scale. However, the implementation of the present information and advanced research are mandatory to further explore the concealed potential of biological species to resume the originality of the environment. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  5. Determination of heavy metal toxicity of finished leather solid waste.

    PubMed

    Aslan, Ahmet

    2009-05-01

    This paper investigates the toxicity in leather products of heavy metals known to be detrimental to the ecosystem. Heavy metal concentrations in leather samples were identified with ICP-OES, and toxicity was determined using a MetPLATE bioassay. Chromium and aluminium were found to constitute 98% of the total concentration of heavy metals in finished leather tanned with chromium and aluminium salts, while in some vegetable-tanned leather, zirconium was the only heavy metal identified. The average inhibition values for chromium, aluminium and vegetable tanned leather were 98.08%, 97.04% and 62.36%, respectively.

  6. [Underlying mechanisms of the heavy metal tolerance of mycorrhizal fungi].

    PubMed

    Chen, Bao-Dong; Sun, Yu-Qing; Zhang, Xin; Wu, Song-Lin

    2015-03-01

    Mycorrhizal fungi are ubiquitous in natural ecosystems and can form symbiotic associations with the majority of terrestrial plants. They can be detected even in heavy metal-contaminated soils, while some fungal strains show strong heavy metal tolerance and could potentially be used in bioremediation of contaminated soils. We reviewed current research progresses in the underlying mechanisms of heavy metal tolerance of mycorrhizal fungi, with focuses on habitat selection, physiological adaptation and functional genes. Future research perspectives were proposed to promote the basic research and development of mycorrhizal technology for remediation of heavy metal-contaminated soils.

  7. Peltier effect in normal metal-insulator-heavy fermion metal junctions

    NASA Astrophysics Data System (ADS)

    Goltsev, A. V.; Rowe, D. M.; Kuznetsov, V. L.; Kuznetsova, L. A.; Min, Gao

    2003-04-01

    A theoretical study has been undertaken of the Peltier effect in normal metal-insulator-heavy fermion metal junctions. The results indicate that, at temperatures below the Kondo temperature, such junctions can be used as electronic microrefrigerators to cool the normal metal electrode and are several times more efficient in cooling than the normal metal-heavy fermion metal junctions.

  8. Heavy-atom Database System: a tool for the preparation of heavy-atom derivatives of protein crystals based on amino-acid sequence and crystallization conditions.

    PubMed

    Sugahara, Michihiro; Asada, Yukuhiko; Ayama, Haruhiko; Ukawa, Hisashi; Taka, Hideyuki; Kunishima, Naoki

    2005-09-01

    Heavy-atom Database System (HATODAS) is a WWW-based tool designed to assist the heavy-atom derivatization of proteins. The conventional procedure for the preparation of derivatives is usually a time-consuming 'trial-and-error' process. The present program provides a solution for this problem using a database of known heavy-atom derivatives. A database search suggests potential heavy-atom reagents for any target protein based on its amino-acid sequence and crystallization conditions. A mining of the database identified 93 preferred motifs for heavy-atom binding. The motifs are observed frequently at the actual heavy-atom-binding sites encountered in the process of structure determination.

  9. Atomic Transport in Metallic Glasses.

    DTIC Science & Technology

    1983-11-01

    creep, amorphous metals, canpositionally modulated films, structural relaxation, iso-configurational flow, bimolecular kinetics, Stokes-Einstein relation ...34 731471 60 rcoe F I iov s isasso Einstain relation from the viscosity. - S/N8CUN@4* 40 CLASSIPICATIOOW OF T04lS PAGEL(010 fON41 EW PREFACE This report...12- tion, B is related to the macroscopic interdiffusion coefficient, B, by r 2 K 13 I+ -.1 (2) where f; is the second derivative, with respect to

  10. Heavy metals in surface sediments of the Jialu River, China: their relations to environmental factors.

    PubMed

    Fu, Jie; Zhao, Changpo; Luo, Yupeng; Liu, Chunsheng; Kyzas, George Z; Luo, Yin; Zhao, Dongye; An, Shuqing; Zhu, Hailiang

    2014-04-15

    This work investigated heavy metal pollution in surface sediments of the Jialu River, China. Sediment samples were collected at 19 sites along the river in connection with field surveys and the total concentrations were determined using atomic fluorescence spectrometer and inductively coupled plasma optical emission spectrometer. Sediment samples with higher metal concentrations were collected from the upper reach of the river, while sediments in the middle and lower reaches had relatively lower metal concentrations. Multivariate techniques including Pearson correlation, hierarchical cluster and principal components analysis were used to evaluate the metal sources. The ecological risk associated with the heavy metals in sediments was rated as moderate based on the assessments using methods of consensus-based Sediment Quality Guidelines, Potential Ecological Risk Index and Geo-accumulation Index. The relations between heavy metals and various environmental factors (i.e., chemical properties of sediments, water quality indices and aquatic organism indices) were also studied. Nitrate nitrogen, total nitrogen, and total polycyclic aromatic hydrocarbons concentrations in sediments showed a co-release behavior with heavy metals. Ammonia nitrogen, total nitrogen, orthophosphate, total phosphate and permanganate index in water were found to be related to metal sedimentation. Heavy metals in sediments posed a potential impact on the benthos community.

  11. Heavy metal pumps in plants. 1997 annual progress report

    SciTech Connect

    Harper, J.F.

    1997-01-01

    'Plants have been proposed as a bioremediation tool to help remove toxic heavy metals from contaminated land and water. However, little is known about how plants take up heavy metals from the soil and transport them to different parts of the plant. An important long term goal is to understand how heavy metals, such as copper and cadmium, are transported across the plasma membrane of plant cells. The proposed research is focused on a putative heavy metal uptake pump, AXA2p [Arabidopsis X (unknown heavy metal) ATPase, isoform 2 protein], identified in a model plant, Arabidopsis. AXA belongs to a super-family of ion-translocating P-type ATPases and is the first heavy metal pump cloned from plants. AXA2 is most similar to a subfamily of pumps recently identified in bacteria, yeast and humans which appear to pump heavy metals such as copper and cadmium. Three specific aims are proposed: (1) Determine the ion specificity of the AXA2 pump, (2) Determine how pumping activity is regulated, and (3) Determine if an increased uptake of specific heavy metals can be achieved by engineering a transgenic plant with a hyper-active pump. The hypothesis being tested is that AXA2 encodes a high affinity uptake pump for copper, with lower affinity for metals such as cadmium, zinc and nickel. Fundamental research on heavy metal transporters may eventually permit transgenic plants to be engineered with specific heavy metal uptake systems useful for bioremediation. The long term goal of the proposed research is to understand how heavy metals, such as copper and cadmium, are taken up from the soil and translocated throughout the plant. The focus is on a putative heavy metal pump, AXA2p [Arabidopsis X (unknown heavy metal) ATPase, isoform 2 protein], identified in a model plant, Arabidopsis. AXA2 belongs to a large family of ion-translocating P-type ATPases. AXA2p is the first heavy metal pump cloned from plants and is most similar to a subfamily of heavy metal pumps recently identified in

  12. Modeling Emission of Heavy Energetic Neutral Atoms from the Heliosphere

    NASA Astrophysics Data System (ADS)

    Swaczyna, Paweł; Bzowski, Maciej

    2017-09-01

    Observations of energetic neutral atoms (ENAs) are a fruitful tool for remote diagnosis of the plasma in the heliosphere and its vicinity. So far, instruments detecting ENAs from the heliosphere were configured for observations of hydrogen atoms. Here, we estimate emissions of ENAs of the heavy chemical elements helium, oxygen, nitrogen, and neon. A large portion of the heliospheric ENAs is created in the inner heliosheath from neutralized interstellar pick-up ions (PUIs). We modeled this process and calculated full-sky intensities of ENAs for energies 0.2–130 keV/nuc. We found that the largest fluxes among considered species are expected for helium, smaller for oxygen and nitrogen, and smallest for neon. The obtained intensities are 50–106 times smaller than the hydrogen ENA intensities observed by IBEX. The detection of heavy ENAs will be possible if a future ENA detector is equipped with the capability to measure the masses of observed atoms. Because of different reaction cross-sections among the different species, observations of heavy ENAs can allow for a better understanding of global structure of the heliosphere as well as the transport and energization of PUIs in the heliosphere.

  13. [Concentration of heavy metals in pregnant women].

    PubMed

    Jacyszyn, K; Walas, J; Malinowski, A; Latkowski, T; Cwynar, L

    1982-01-01

    Copper, zinc, and lead concentrations were measured in two groups 72 pregnant women. Twenty-one of them, making up the control group, lived and worked in Wrocław. The other 51 women, the second group, had lived more than five years in Lubin-Polkowice and worked in the local non-ferrous metal plants. They were particularly endangered by their exposure to copper, zinc, and lead concentrations. Pregnancy was normal in all cases. Maternal blood, umbilical cord blood, placenta homogenate, and amniotic fluid were examined by techniques of atom-absorption spectrometry. The metals tested were conspicuously absorbed by placental tissue, but no danger to the pregnant women could be established.

  14. Determination of trace and heavy metals in some commonly used medicinal herbs in Ayurveda.

    PubMed

    Nema, Neelesh K; Maity, Niladri; Sarkar, Birendra K; Mukherjee, Pulok K

    2014-11-01

    Traditionally, the herbal drugs are well established for their therapeutic benefits. Depending upon their geographical sources sometimes the trace and heavy metals' content may differ, which may lead to severe toxicity. So, the toxicological and safety assessment of these herbal drugs are one of the major issues in recent days. Eight different plant species including Aloe vera, Centella asiatica, Calendula officinalis, Cucumis sativus, Camellia sinensis, Clitoria ternatea, Piper betel and Tagetes erecta were selected to determine their heavy and trace metals content and thereby to assure their safer therapeutic application. The trace and heavy metals were detected through atomic absorption spectrometry analysis. The selected medicinal plant materials were collected from the local cultivated regions of West Bengal, India, and were digested with nitric acid and hydrochloric acid as specified. Absorbance was measured through atomic absorption spectrometer (AA 303) and the concentration of different trace and heavy metals in the plant samples were calculated. The quantitative determinations were carried out using standard calibration curve obtained by the standard solutions of different metals. The contents of heavy metals were found to be within the prescribed limit. Other trace metals were found to be present in significant amount. Thus, on the basis of experimental outcome, it can be concluded that the plant materials collected from the specific region are safe and may not produce any harmful effect of metal toxicity during their therapeutic application. The investigated medicinal plants contain trace metals such as copper (Cu), chromium (Cr), manganese (Mn), iron (Fe) and nickel (Ni) as well as heavy metals such as arsenic (As), lead (Pb) and mercury (Hg), which were present within the permissible limit. © The Author(s) 2012.

  15. [Biological activity of selenorganic compounds at heavy metal salts intoxication].

    PubMed

    Rusetskaya, N Y; Borodulin, V B

    2015-01-01

    Possible mechanisms of the antitoxic action of organoselenium compounds in heavy metal poisoning have been considered. Heavy metal toxicity associated with intensification of free radical oxidation, suppression of the antioxidant system, damage to macromolecules, mitochondria and the genetic material can cause apoptotic cell death or the development of carcinogenesis. Organic selenium compounds are effective antioxidants during heavy metal poisoning; they exhibit higher bioavailability in mammals than inorganic ones and they are able to activate antioxidant defense, bind heavy metal ions and reactive oxygen species formed during metal-induced oxidative stress. One of promising organoselenium compounds is diacetophenonyl selenide (DAPS-25), which is characterized by antioxidant and antitoxic activity, under conditions including heavy metal intoxication.

  16. Magnesium oxide for improved heavy metals removal

    SciTech Connect

    Schiller, J.E.; Khalafalla, S.E.

    1984-01-01

    To improve technology for treating process water, US Bureau of Mines research has shown that magnesium oxide (MgO) has many advantages over lime or caustic soda for precipitating heavy metals. Sludge produced by MgO occupies only 0.2-0.3 times as much volume as the precipitate made using a soluble base. While a settled, lime-formed precipitate is easily resuspended, the MgO-metal hydroxide sludge becomes cemented together on standing. Settling of the metal hydroxides from a dilute suspension is more complete than precipitates formed with other bases. Virtually any metal that can be precipitated by raising the pH can be treated using MgO. A three-fold to four-fold stoichiometric excess of solid reagent is added. The mixture is reacted for five to 10 minutes. Polymer is added, and settling or filtration completes the process. Because of the greater cost of MgO compared with lime, large-scale practice of this technology will probably be limited to water containing 50 mg/L (3 gr per gal) or less of dissolved metals. For such dilute solutions, chemicals are not a large fraction of total treatment costs, so more desirable sludge properties might justify higher chemical expenses. While the MgO process is technically suitable for widespread application, the extent to which it is adopted will probably be determined by a trade-off between the greater cost of MgO compared with lime and the superior properties of the precipitates and their corresponding ultimate disposal costs.

  17. Emissions of heavy metals into river basins of Germany.

    PubMed

    Scherer, U; Fuchs, S; Behrendt, H; Hillenbrand, T

    2003-01-01

    The input of seven heavy metals (Cd, Cr, Cu, Hg, Ni, Pb and Zn) into the large river basins of Germany via various point and diffuse pathways were estimated for the period of 1985 through 2000. To quantify the emissions via point sources a nationwide survey on heavy metal data of municipal wastewater treatment plants and industrial direct discharges was carried out. The input via diffuse pathways was calculated using an adapted version of the model MONERIS. This model accounts for the significant transport processes, and it includes a Geographical Information System (GIS) that provides digital maps as well as extensive statistical information. For a comparison of the calculated heavy metal emission with the measured heavy metal load at monitoring stations the losses of heavy metals due to retention processes within the river systems have to be considered. Therefore heavy metal retention was calculated according to the retention functions given by Vink and Behrendt. For the large river basins a good correspondence could be found between estimated and measured heavy metal loads in rivers. The total emission into the North Sea decreased for each metal during the period of 1986 to 2000. The reduction varies between 87% for Hg and 41% for Ni mainly caused by the decline via point sources. Today's emissions of heavy metals into river basins of Germany are dominated by the input via diffuse pathways. The most important diffuse emission pathways are "paved urban areas" and "erosion".

  18. Heavy Metal Induced Antibiotic Resistance in Bacterium LSJC7.

    PubMed

    Chen, Songcan; Li, Xiaomin; Sun, Guoxin; Zhang, Yingjiao; Su, Jianqiang; Ye, Jun

    2015-09-29

    Co-contamination of antibiotics and heavy metals prevails in the environment, and may play an important role in disseminating bacterial antibiotic resistance, but the selective effects of heavy metals on bacterial antibiotic resistance is largely unclear. To investigate this, the effects of heavy metals on antibiotic resistance were studied in a genome-sequenced bacterium, LSJC7. The results showed that the presence of arsenate, copper, and zinc were implicated in fortifying the resistance of LSJC7 towards tetracycline. The concentrations of heavy metals required to induce antibiotic resistance, i.e., the minimum heavy metal concentrations (MHCs), were far below (up to 64-fold) the minimum inhibition concentrations (MIC) of LSJC7. This finding indicates that the relatively low heavy metal levels in polluted environments and in treated humans and animals might be sufficient to induce bacterial antibiotic resistance. In addition, heavy metal induced antibiotic resistance was also observed for a combination of arsenate and chloramphenicol in LSJC7, and copper/zinc and tetracycline in antibiotic susceptible strain Escherichia coli DH5α. Overall, this study implies that heavy metal induced antibiotic resistance might be ubiquitous among various microbial species and suggests that it might play a role in the emergence and spread of antibiotic resistance in metal and antibiotic co-contaminated environments.

  19. Heavy Metal Induced Antibiotic Resistance in Bacterium LSJC7

    PubMed Central

    Chen, Songcan; Li, Xiaomin; Sun, Guoxin; Zhang, Yingjiao; Su, Jianqiang; Ye, Jun

    2015-01-01

    Co-contamination of antibiotics and heavy metals prevails in the environment, and may play an important role in disseminating bacterial antibiotic resistance, but the selective effects of heavy metals on bacterial antibiotic resistance is largely unclear. To investigate this, the effects of heavy metals on antibiotic resistance were studied in a genome-sequenced bacterium, LSJC7. The results showed that the presence of arsenate, copper, and zinc were implicated in fortifying the resistance of LSJC7 towards tetracycline. The concentrations of heavy metals required to induce antibiotic resistance, i.e., the minimum heavy metal concentrations (MHCs), were far below (up to 64-fold) the minimum inhibition concentrations (MIC) of LSJC7. This finding indicates that the relatively low heavy metal levels in polluted environments and in treated humans and animals might be sufficient to induce bacterial antibiotic resistance. In addition, heavy metal induced antibiotic resistance was also observed for a combination of arsenate and chloramphenicol in LSJC7, and copper/zinc and tetracycline in antibiotic susceptible strain Escherichia coli DH5α. Overall, this study implies that heavy metal induced antibiotic resistance might be ubiquitous among various microbial species and suggests that it might play a role in the emergence and spread of antibiotic resistance in metal and antibiotic co-contaminated environments. PMID:26426011

  20. Toxic heavy metals: materials cycle optimization.

    PubMed Central

    Ayres, R U

    1992-01-01

    Long-term ecological sustainability is incompatible with an open materials cycle. The toxic heavy metals (arsenic, cadmium, chromium, copper, lead, mercury, silver, uranium/plutonium, zinc) exemplify the problem. These metals are being mobilized and dispersed into the environment by industrial activity at a rate far higher than by natural processes. Apart from losses to the environment resulting from mine wastes and primary processing, many of these metals are utilized in products that are inherently dissipative. Examples of such uses include fuels, lubricants, solvents, fire retardants, stabilizers, flocculants, pigments, biocides, and preservatives. To close the materials cycle, it will be necessary to accomplish two things. The first is to ban or otherwise discourage (e.g., by means of high severance taxes on virgin materials) dissipative uses of the above type. The second is to increase the efficiency of recycling of those materials that are not replaceable in principle. Here, also, economic instruments (such as returnable deposits) can be effective in some cases. A systems view of the problem is essential to assess the cost and effectiveness of alternative strategies. PMID:11607259

  1. Toxic Heavy Metals: Materials Cycle Optimization

    NASA Astrophysics Data System (ADS)

    Ayres, Robert U.

    1992-02-01

    Long-term ecological sustainability is incompatible with an open materials cycle. The toxic heavy metals (arsenic, cadmium, chromium, copper, lead, mercury, silver, uranium/plutonium, zinc) exemplify the problem. These metals are being mobilized and dispersed into the environment by industrial activity at a rate far higher than by natural processes. Apart from losses to the environment resulting from mine wastes and primary processing, many of these metals are utilized in products that are inherently dissipative. Examples of such uses include fuels, lubricants, solvents, fire retardants, stabilizers, flocculants, pigments, biocides, and preservatives. To close the materials cycle, it will be necessary to accomplish two things. The first is to ban or otherwise discourage (e.g., by means of high severance taxes on virgin materials) dissipative uses of the above type. The second is to increase the efficiency of recycling of those materials that are not replaceable in principle. Here, also, economic instruments (such as returnable deposits) can be effective in some cases. A systems view of the problem is essential to assess the cost and effectiveness of alternative strategies.

  2. Bioindication of atmospheric heavy metal deposition in the Southeastern US using the moss Thuidium delicatulum

    NASA Astrophysics Data System (ADS)

    Schilling, Jonathan S.; Lehman, Mary E.

    Ectohydric mosses are known accumulators of atmospheric heavy metals. Reliable bioindication of atmospheric heavy metals in the Southern Appalachians using moss has been limited by poor species distribution in moss used in analogous studies. In this study, Pb, Cu, Cr, and Ni concentrations were quantified in the tissue of fern moss Thuidium delicatulum in the central Blue Ridge of Virginia. The objectives of the study were to evaluate the suitability of fern moss for moss-monitoring studies in the Southern Appalachians, to compare local terrestrial metal concentrations, and to test the effects of several geographical and environmental variables on deposition. Fern moss was sampled over four mountains in Virginia following the standard protocol of the German moss-monitoring method. Sampling was standardized for monitoring in deciduous forests, and analysis was performed by graphite furnace-atomic absorption spectrophotometry. Overall concentrations of two metals were significantly different depending on the presence of Pinus spp. in the canopy. Positive and negative correlations of heavy metal concentrations with elevation were also observed, suggesting a need for comprehensive sampling at high and low elevations in mountainous areas. A role for similar moss-monitoring is suggested as a complement to current precipitation analysis techniques and as a compendium for landscape-scale metal monitoring projects. The applications of heavy metal bioindication with this particular species throughout the physiographic province of the Blue Ridge and the Appalachians in future heavy metal deposition studies are discussed.

  3. Influence of heavy metal stress on antioxidant status and DNA damage in Urtica dioica.

    PubMed

    Gjorgieva, Darinka; Kadifkova Panovska, Tatjana; Ruskovska, Tatjana; Bačeva, Katerina; Stafilov, Trajče

    2013-01-01

    Heavy metals have the potential to interact and induce several stress responses in the plants; thus, effects of heavy metal stress on DNA damages and total antioxidants level in Urtica dioica leaves and stems were investigated. The samples are sampled from areas with different metal exposition. Metal content was analyzed by Inductively Coupled Plasma-Atomic Emission Spectrometer (ICP-AES), for total antioxidants level assessment the Ferric-Reducing Antioxidant Power (FRAP) assay was used, and genomic DNA isolation from frozen plant samples was performed to obtain DNA fingerprints of investigated plant. It was found that heavy metal contents in stems generally changed synchronously with those in leaves of the plant, and extraneous metals led to imbalance of mineral nutrient elements. DNA damages were investigated by Random Amplified Polymorphic DNA (RAPD) technique, and the results demonstrated that the samples exposed to metals yielded a large number of new fragments (total 12) in comparison with the control sample. This study showed that DNA stability is highly affected by metal pollution which was identified by RAPD markers. Results suggested that heavy metal stress influences antioxidant status and also induces DNA damages in U. dioica which may help to understand the mechanisms of metals genotoxicity.

  4. Influence of Heavy Metal Stress on Antioxidant Status and DNA Damage in Urtica dioica

    PubMed Central

    Kadifkova Panovska, Tatjana; Bačeva, Katerina; Stafilov, Trajče

    2013-01-01

    Heavy metals have the potential to interact and induce several stress responses in the plants; thus, effects of heavy metal stress on DNA damages and total antioxidants level in Urtica dioica leaves and stems were investigated. The samples are sampled from areas with different metal exposition. Metal content was analyzed by Inductively Coupled Plasma-Atomic Emission Spectrometer (ICP-AES), for total antioxidants level assessment the Ferric-Reducing Antioxidant Power (FRAP) assay was used, and genomic DNA isolation from frozen plant samples was performed to obtain DNA fingerprints of investigated plant. It was found that heavy metal contents in stems generally changed synchronously with those in leaves of the plant, and extraneous metals led to imbalance of mineral nutrient elements. DNA damages were investigated by Random Amplified Polymorphic DNA (RAPD) technique, and the results demonstrated that the samples exposed to metals yielded a large number of new fragments (total 12) in comparison with the control sample. This study showed that DNA stability is highly affected by metal pollution which was identified by RAPD markers. Results suggested that heavy metal stress influences antioxidant status and also induces DNA damages in U. dioica which may help to understand the mechanisms of metals genotoxicity. PMID:23862140

  5. Ionization of Atoms by Slow Heavy Particles, Including Dark Matter

    NASA Astrophysics Data System (ADS)

    Roberts, B. M.; Flambaum, V. V.; Gribakin, G. F.

    2016-01-01

    Atoms and molecules can become ionized during the scattering of a slow, heavy particle off a bound electron. Such an interaction involving leptophilic weakly interacting massive particles (WIMPs) is a promising possible explanation for the anomalous 9 σ annual modulation in the DAMA dark matter direct detection experiment [R. Bernabei et al., Eur. Phys. J. C 73, 2648 (2013)]. We demonstrate the applicability of the Born approximation for such an interaction by showing its equivalence to the semiclassical adiabatic treatment of atomic ionization by slow-moving WIMPs. Conventional wisdom has it that the ionization probability for such a process should be exponentially small. We show, however, that due to nonanalytic, cusplike behavior of Coulomb functions close to the nucleus this suppression is removed, leading to an effective atomic structure enhancement. We also show that electron relativistic effects actually give the dominant contribution to such a process, enhancing the differential cross section by up to 1000 times.

  6. Hydroponic phytoremediation of heavy metals and radionuclides

    SciTech Connect

    Hartong, J.; Szpak, J.; Hamric, T.; Cutright, T.

    1998-07-01

    It is estimated that the Departments of Defense, Energy, and Agriculture will spend up to 300 billion federal dollars on environmental remediation during the next century. Current remediation processes can be expensive, non-aesthetic, and non-versatile. Therefore, the need exists for more innovative and cost effective solutions. Phytoremediation, the use of vegetation for the remediation of contaminated sediments, soils, and ground water, is an emerging technology for treating several categories of persistent, toxic contaminants. Although effective, phytoremediation is still in a developmental stage, and therefore is not a widely accepted technology by regulatory agencies and public groups. Research is currently being conducted to validate the processes effectiveness as well as increase regulatory and community acceptance. This research will focus on the ability of plants to treat an aquifer contaminated with heavy metals and radionuclides. Specifically, the effectiveness of hydroponically grown dwarf sunflowers and mustard seed will be investigated.

  7. Plant productivity and heavy metal contamination

    SciTech Connect

    Guidi, G.V.; Petruzzelli, G.; Vallini, G.; Pera, A.

    1990-06-01

    This article describes the potential for use of composts from green waste and from municipal solid wastes for agricultural use in Italy. The accumulation of heavy metals in compost-amended soils and crops was evaluated and the influence of these composts on plant productivity was studied. Green compost was obtained from vegetable organic residues; municipal solid waste derived compost was obtained from the aerobic biostabilization of a mixture of the organic biodegradable fraction of municipal solid waste and sewage sludge. The two composts had good chemical characteristics and their use caused no pollution to soil and plants. The overall fertilizing effect was higher for green compost even though green compost and municipal solid waste derived compost had similar contents of primary elements of fertility.

  8. Outer-core emission spectra of heavy alkali metals

    NASA Astrophysics Data System (ADS)

    Fink, R. L.; First, P. N.; Flynn, C. P.

    1988-09-01

    We report np5(n+1)s2-->np6(n+1)s emission spectra of K (n=3), Rb (n=4), and Cs (n=5), and compare emission-band characteristics through the series Na-Cs using earlier data for Na. The normalized band profiles of the different alkali metals are remarkably similar when scaled by the Fermi energy EF. However, the spin-orbit partner intensity ratios are far from the ideal value 2, reaching approximately 60 for Rb and above 65 for Cs, mainly owing to Coster-Kronig decays from higher levels. We confirm that the Mahan-Nozières-De Dominicis ``anomaly'' at EF is generally weaker in emission than in absorption. It decreases through the series to become undetectable for emission from Cs. A systematic increase of the core-hole-lifetime width occurs through the column of alkali metals from a reported estimate of 10 meV for Na to a value of 50 meV for Cs. A study of the Fermi-edge shape between 20 and 300 K reveals temperature-dependent phonon broadening in generally good agreement with theoretical predictions. Incomplete relaxation plays only a minor role in the edge processes of the heavy alkali metals. Additional Fermi-edge broadening and the shifted emission edges of surface atoms are observed for alkali-metal films 10-100 Å thick.

  9. Heavy Metal Music and Adolescent Suicidality: An Empirical Investigation.

    ERIC Educational Resources Information Center

    Scheel, Karen R.; Westefeld, John S.

    1999-01-01

    Investigates the relationship between preference for heavy metal music and vulnerability to suicide among high school students. Results indicate that preference for heavy metal music among adolescents may be sign of increased suicidal vulnerability, but also suggests that the source of the problem may lie more in personal and familial…

  10. Heavy Metal Music and Reckless Behavior among Adolescents.

    ERIC Educational Resources Information Center

    Arnett, Jeffrey

    1991-01-01

    Fifty-four male and 30 female adolescents who like heavy metal music were compared on various outcome variables to 56 male and 105 female peers who do not like it. Those who like heavy metal report a wider range of reckless behavior than those who do not like it. (SLD)

  11. Radiation-initiated removal of heavy metals from water

    SciTech Connect

    Al-Sheikhly, M.; Chaychian, M.; McLaughlin, W.L.

    1995-12-31

    This paper describes the technical viability of high-powered industrial radiation processes as high-volume and low-cost techniques suitable for the removal of the heavy metals and chelated heavy-metal compounds from water that has been contaminated by marine paints and other similar organometallic compounds.

  12. Heavy Metal Music and Adolescent Suicidality: An Empirical Investigation.

    ERIC Educational Resources Information Center

    Scheel, Karen R.; Westefeld, John S.

    1999-01-01

    Investigates the relationship between preference for heavy metal music and vulnerability to suicide among high school students. Results indicate that preference for heavy metal music among adolescents may be sign of increased suicidal vulnerability, but also suggests that the source of the problem may lie more in personal and familial…

  13. Heavy Metal Toxicity in Bioremediation: Microbial Cultures and Microscopy.

    DTIC Science & Technology

    1997-12-01

    This research employed a variety of microscopy and spread plating techniques to observe the effects of heavy metal treatments on a toluene-selected...of bacteria and offered new techniques for potential heavy metal toxicity measurements as well as differentiation methods.

  14. A Process for Making Bulk Heavy Metal Fluoride Glasses.

    DTIC Science & Technology

    This invention relates to the preparation of glasses, and, in particular, relates to the preparation of heavy metal fluoride glasses with...reproducible high optical qualities. Considerable effort has been expended to develop heavy metal fluoride glasses ( HMFG ) as a viable family of infrared

  15. Heavy Metal Music and Reckless Behavior among Adolescents.

    ERIC Educational Resources Information Center

    Arnett, Jeffrey

    1991-01-01

    Fifty-four male and 30 female adolescents who like heavy metal music were compared on various outcome variables to 56 male and 105 female peers who do not like it. Those who like heavy metal report a wider range of reckless behavior than those who do not like it. (SLD)

  16. Heavy metals alter the potency of medicinal plants.

    PubMed

    Nasim, Sekh Abdul; Dhir, Bhupinder

    2010-01-01

    There has been increased use of herbal drugs in recent years. Because of increasing demand and wider use, it is essential that the quality of plant-based drugs should be assured prior to use. When heavy metals contaminate the plants from which herbal drugs are derived, they affect both plant growth characteristics and production of secondary plant metabolites. Plants exposed to heavy metal stress show changes in production of secondary metabolites. High levels of heavy metal contamination in medicinal or other plants may suppress secondary metabolite production. Alternatively, the presence of heavy metals in medicinal plants may stimulate production of bioactive compounds in many plant species. Moreover, some research results suggest that heavy metals may play an important role in triggering plant genes to alter the titers or nature of secondary plant metabolites, although the exact mechanism by which this happens remains unclear. Oxidative stress induced by heavy metals triggers signaling pathways that affect production of specific plant metabolites. In particular, reactive oxygen species (ROS), generated during heavy metal stress, may cause lipid peroxidation that stimulates formation of highly active signaling compounds capable of triggering production of bioactive compounds (secondary metabolites) that enhances the medicinal value of the plant. As usual, further research is needed to clarify the mechanism by which heavy metals induce responses that result in enhanced secondary metabolite production.

  17. Heavy metals in soils of cocoa plantation (Theobroma cacao L.)

    USDA-ARS?s Scientific Manuscript database

    Cocoa has experienced significant growth in recent years in Peru and the presence of heavy metals in the soils of these plantations is a potential problem for the export of this product. Contents of heavy metals (Cd, Ni, Pb, Fe, Cu, Zn, Mn) in soils from 19 plantations that have been in production f...

  18. Species sensitivity analysis of heavy metals to freshwater organisms.

    PubMed

    Xin, Zheng; Wenchao, Zang; Zhenguang, Yan; Yiguo, Hong; Zhengtao, Liu; Xianliang, Yi; Xiaonan, Wang; Tingting, Liu; Liming, Zhou

    2015-10-01

    Acute toxicity data of six heavy metals [Cu, Hg, Cd, Cr(VI), Pb, Zn] to aquatic organisms were collected and screened. Species sensitivity distributions (SSD) curves of vertebrate and invertebrate were constructed by log-logistic model separately. The comprehensive comparisons of the sensitivities of different trophic species to six typical heavy metals were performed. The results indicated invertebrate taxa to each heavy metal exhibited higher sensitivity than vertebrates. However, with respect to the same taxa species, Cu had the most adverse effect on vertebrate, followed by Hg, Cd, Zn and Cr. When datasets from all species were included, Cu and Hg were still more toxic than the others. In particular, the toxicities of Pb to vertebrate and fish were complicated as the SSD curves of Pb intersected with those of other heavy metals, while the SSD curves of Pb constructed by total species no longer crossed with others. The hazardous concentrations for 5 % of the species (HC5) affected were derived to determine the concentration protecting 95 % of species. The HC5 values of the six heavy metals were in the descending order: Zn > Pb > Cr > Cd > Hg > Cu, indicating toxicities in opposite order. Moreover, potential affected fractions were calculated to assess the ecological risks of different heavy metals at certain concentrations of the selected heavy metals. Evaluations of sensitivities of the species at various trophic levels and toxicity analysis of heavy metals are necessary prior to derivation of water quality criteria and the further environmental protection.

  19. Studies on heavy metal contamination in Godavari river basin

    NASA Astrophysics Data System (ADS)

    Hussain, Jakir; Husain, Ikbal; Arif, Mohammed; Gupta, Nidhi

    2017-09-01

    Surface water samples from Godavari river basin was analyzed quantitatively for the concentration of eight heavy metals such as arsenic, cadmium, chromium, copper, iron, lead, nickel and zinc using atomic absorption spectrophotometer. The analyzed data revealed that iron and zinc metals were found to be the most abundant metals in the river Godavari and its tributaries. Iron (Fe) recorded the highest, while cadmium (Cd) had the least concentration. Arsenic, cadmium, chromium, iron and zinc metals are within the acceptable limit of BIS (Bureau of Indian Standards (BIS) 1050 (2012) Specification for drinking water, pp 1-5). The analysis of Godavari river and its tributary's water samples reveals that the water is contaminated at selected points which are not suitable for drinking. Nickel and Copper concentration is above acceptable limit and other metal concentration is within the acceptable limit. Comprehensive study of the results reveals that out of 18 water quality stations monitored, water samples collected at 7 water quality stations are found to be within the permissible limit for all purposes. While Rajegaon, Tekra, Nandgaon, P. G. Bridge, Bhatpalli, Kumhari, Pauni, Hivra, Ashti, Bamini, and Jagda stations were beyond the desirable limit due to presence of copper and nickel metals. The contents of copper metal ions were higher at some water quality stations on Wunna river (Nandgaon); Wardha river (Hivra) and Wainganga river (Kumhari, Pauni, Ashti) during Feb. 2012, while nickel concentration during Feb. 2012, June 2012, March 2013 and Aug. 2013 at some water quality stations on rivers Bagh, Indravati, Pranhita, Wunna, Penganga, Peddavagu, Wainganga and Wardha. It can be concluded that rapid population growth and industrialization have brought about resource degradation and a decline in environmental quality.

  20. Heavy metal retention of different roadside soils

    NASA Astrophysics Data System (ADS)

    Werkenthin, Moritz; Kluge, Björn; Wessolek, Gerd

    2014-05-01

    Emissions from major highways contain different kinds of contaminants such as heavy metals, polycyclic aromatic hydrocarbons and road salts which can occur in both particulate and dissolved form. Pollutants are transferred to the environment via aerial transport or the infiltration of road runoff and spray water. A significant rate of the road runoff infiltrates into the Embankment which is usually built during road construction and located next to the road edge. Especially in the long term development there is an increasing problem of soil contamination and groundwater pollution. According to valid German law, newly constructed hard shoulders have to provide a specific bear-ing capacity to enable trafficability in emergency cases. Therefore the applicable materials consist of accurately defined gravel-soil mixtures, which can fulfil this requirement. To determine and com-pare the total and dissolved concentrations of Pb, Cd, Zn, Cu, Ni, Cr in the road runoff and seep-age water of newly constructed embankments, we installed 6 Lysimeter along the edge of the German highway A115. Three lysimeter were filled with different materials which are recently used for embankment construction in Germany. Three further lysimeter where installed and filled with plain gravel, to observe the distribution, quantity and quality of road runoff. Fist results showed that heavy metal concentrations determined in the road runoff were compara-ble to literature values. The solute concentrations in the seepage water of the different embank-ment materials do not show considerable differences and exceed the trigger values of the German Federal Soil Protection & Contamination Ordinance (BBodSchV) only sporadically. Total concentra-tions of the seepage water are significantly higher than solute concentrations and clearly differ be-tween stable and non stable variant. In order to estimate the risk of groundwater pollution further monitoring of seepage water quality is necessary.

  1. Health risks associated with heavy metals in the drinking water of Swat, northern Pakistan.

    PubMed

    Lu, Yonglong; Khan, Hizbullah; Zakir, Shahida; Ihsanullah; Khan, Sardar; Khan, Akbar Ali; Wei, Luo; Wang, Tieyu

    2013-10-01

    The concentrations of heavy metals such as Cd, Cr, Cu, Mn, Ni, Pb and Zn were investigated in drinking water sources (surface and groundwater) collected from Swat valley, Khyber Pakhtunkhwa, Pakistan. The potential health risks of heavy metals to the local population and their possible source apportionment were also studied. Heavy metal concentrations were analysed using atomic absorption spectrometer and compared with permissible limits set by Pakistan Environmental Protection Agency and World Health Organization. The concentrations of Cd, Cr, Ni and Pb were higher than their respective permissible limits, while Cu, Mn and Zn concentrations were observed within their respective limits. Health risk indicators such as chronic daily intake (CDI) and health risk index (HRI) were calculated for adults and children separately. CDIs and HRIs of heavy metals were found in the order of Cr > Mn > Ni > Zn > Cd > Cu > Pb and Cd > Ni > Mn > Cr > Cu > Pb > Zn, respectively. HRIs of selected heavy metals in the drinking water were less than 1, indicating no health risk to the local people. Multivariate and univariate statistical analyses showed that geologic and anthropogenic activities were the possible sources of water contamination with heavy metals in the study area.

  2. Common plants as alternative analytical tools to monitor heavy metals in soil

    PubMed Central

    2012-01-01

    Background Herbaceous plants are common vegetal species generally exposed, for a limited period of time, to bioavailable environmental pollutants. Heavy metals contamination is the most common form of environmental pollution. Herbaceous plants have never been used as natural bioindicators of environmental pollution, in particular to monitor the amount of heavy metals in soil. In this study, we aimed at assessing the usefulness of using three herbaceous plants (Plantago major L., Taraxacum officinale L. and Urtica dioica L.) and one leguminous (Trifolium pratense L.) as alternative indicators to evaluate soil pollution by heavy metals. Results We employed Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP-AES) to assess the concentration of selected heavy metals (Cu, Zn, Mn, Pb, Cr and Pd) in soil and plants and we employed statistical analyses to describe the linear correlation between the accumulation of some heavy metals and selected vegetal species. We found that the leaves of Taraxacum officinale L. and Trifolium pratense L. can accumulate Cu in a linearly dependent manner with Urtica dioica L. representing the vegetal species accumulating the highest fraction of Pb. Conclusions In this study we demonstrated that common plants can be used as an alternative analytical tool for monitoring selected heavy metals in soil. PMID:22594441

  3. Heavy metal resistance in halophilic Bacteria and Archaea.

    PubMed

    Voica, Doriana Mădălina; Bartha, Laszlo; Banciu, Horia Leonard; Oren, Aharon

    2016-07-01

    Heavy metals are dense chemicals with dual biological role as micronutrients and intoxicants. A few hypersaline environmental systems are naturally enriched with heavy metals, while most metal-contaminated sites are a consequence of human activities. Numerous halotolerant and moderately halophilic Bacteria possess metal tolerance, whereas a few archaeal counterparts share similar features. The main mechanisms underlying heavy metal resistance in halophilic Bacteria and Archaea include extracellular metal sequestration by biopolymers, metal efflux mediated by specific transporters and enzymatic detoxification. Biotransformation of metals by halophiles has implications both for trace metal turnover in natural saline ecosystems and for development of novel bioremediation strategies. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  4. Fabrication of crystals from single metal atoms

    PubMed Central

    Barry, Nicolas P. E.; Pitto-Barry, Anaïs; Sanchez, Ana M.; Dove, Andrew P.; Procter, Richard J.; Soldevila-Barreda, Joan J.; Kirby, Nigel; Hands-Portman, Ian; Smith, Corinne J.; O’Reilly, Rachel K.; Beanland, Richard; Sadler, Peter J.

    2014-01-01

    Metal nanocrystals offer new concepts for the design of nanodevices with a range of potential applications. Currently the formation of metal nanocrystals cannot be controlled at the level of individual atoms. Here we describe a new general method for the fabrication of multi-heteroatom-doped graphitic matrices decorated with very small, ångström-sized, three-dimensional (3D)-metal crystals of defined size. We irradiate boron-rich precious-metal-encapsulated self-spreading polymer micelles with electrons and produce, in real time, a doped graphitic support on which individual osmium atoms hop and migrate to form 3D-nanocrystals, as small as 15 Å in diameter, within 1 h. Crystal growth can be observed, quantified and controlled in real time. We also synthesize the first examples of mixed ruthenium–osmium 3D-nanocrystals. This technology not only allows the production of ångström-sized homo- and hetero-crystals, but also provides new experimental insight into the dynamics of nanocrystals and pathways for their assembly from single atoms. PMID:24861089

  5. Fabrication of crystals from single metal atoms.

    PubMed

    Barry, Nicolas P E; Pitto-Barry, Anaïs; Sanchez, Ana M; Dove, Andrew P; Procter, Richard J; Soldevila-Barreda, Joan J; Kirby, Nigel; Hands-Portman, Ian; Smith, Corinne J; O'Reilly, Rachel K; Beanland, Richard; Sadler, Peter J

    2014-05-27

    Metal nanocrystals offer new concepts for the design of nanodevices with a range of potential applications. Currently the formation of metal nanocrystals cannot be controlled at the level of individual atoms. Here we describe a new general method for the fabrication of multi-heteroatom-doped graphitic matrices decorated with very small, ångström-sized, three-dimensional (3D)-metal crystals of defined size. We irradiate boron-rich precious-metal-encapsulated self-spreading polymer micelles with electrons and produce, in real time, a doped graphitic support on which individual osmium atoms hop and migrate to form 3D-nanocrystals, as small as 15 Å in diameter, within 1 h. Crystal growth can be observed, quantified and controlled in real time. We also synthesize the first examples of mixed ruthenium-osmium 3D-nanocrystals. This technology not only allows the production of ångström-sized homo- and hetero-crystals, but also provides new experimental insight into the dynamics of nanocrystals and pathways for their assembly from single atoms.

  6. Removal of heavy metal ions from wastewaters: a review.

    PubMed

    Fu, Fenglian; Wang, Qi

    2011-03-01

    Heavy metal pollution has become one of the most serious environmental problems today. The treatment of heavy metals is of special concern due to their recalcitrance and persistence in the environment. In recent years, various methods for heavy metal removal from wastewater have been extensively studied. This paper reviews the current methods that have been used to treat heavy metal wastewater and evaluates these techniques. These technologies include chemical precipitation, ion-exchange, adsorption, membrane filtration, coagulation-flocculation, flotation and electrochemical methods. About 185 published studies (1988-2010) are reviewed in this paper. It is evident from the literature survey articles that ion-exchange, adsorption and membrane filtration are the most frequently studied for the treatment of heavy metal wastewater.

  7. Dietary heavy metal uptake by the least shrew, Cryptotis parva

    SciTech Connect

    Brueske, C.C.; Barrett, G.W. )

    1991-12-01

    Heavy metals from sewage sludge have been reported to concentrate in producers, in primary consumers, and in detritivores. Little research, however, has focused on the uptake of heavy metals from sewage sludge by secondary consumers. The Family Soricidae represents an ideal mammalian taxonomic group to investigate rates of heavy metal transfer between primary and secondary consumers. The least shrew (Cryptotis parva) was used to evaluate the accumulation of heavy metals while maintained on a diet of earthworms collected from long-term sludge-treated old-field communities. This secondary consumer is distributed widely through the eastern United States and its natural diet includes earthworms which makes it a potentially good indicator of heavy metal transfer in areas treated with municipal sludge.

  8. Pollution evaluation of heavy metals in soil near smelting area by index of geoaccumulation (Igeo)

    NASA Astrophysics Data System (ADS)

    Huang, S. H.; Yang, Y.; Yuan, C. Y.; Li, Q.; Ouyang, K.; Wang, B.; Wang, Z. X.

    2017-01-01

    In order to investigate the heavy metal pollution conditions of soil of smelting area in Zijiang of Chenzhou, Hunan province, 42 samples were studied. The concentrations of heavy metals As, Pb, Cd, Zn and Cu in the soil were determined by using atomic absorption spectrometry(AAS) and atomic fluorescence spectrometry(AFS). Then the potential pollution risks of heavy metal in the soil were evaluated by method of geological acumination index (Igeo). The results indicated that the average concentrations of As, Pb, Cd, Zn and Cu were 187.79, 2074.52, 15.72, 2178.89, 39.69 mg/kg respectively. The geological evaluation of the cumulative index results showed that the contamination degree of 5 heavy metals follow the sequence of Cd> Zn >Pb > As >Cu. The results show that Cd reached extremely pollution degree, Zn reached strong pollution-extremely pollution levels, the pollution of Pb in the soil is classified as strong pollution degree, Cu and As of no pollution according to the results of Igeo based on the background value of heavy metals in the soil of Hunan Province.

  9. Reducing hazardous heavy metal ions using mangium bark waste.

    PubMed

    Khabibi, Jauhar; Syafii, Wasrin; Sari, Rita Kartika

    2016-08-01

    The objective of this study was to evaluate the characteristics of mangium bark and its biosorbent ability to reduce heavy metal ions in standard solutions and wastewater and to assess changes in bark characteristics after heavy metal absorption. The experiments were conducted to determine heavy metal absorption from solutions of heavy metals alone and in mixtures as well as from wastewater. The results show that mangium bark can absorb heavy metals. Absorption percentages and capacities from single heavy metal solutions showed that Cu(2+) > Ni(2+) > Pb(2+) > Hg(2+), while those from mixture solutions showed that Hg(2+) > Cu(2+) > Pb(2+) > Ni(2+). Wastewater from gold mining only contained Cu, with an absorption percentage and capacity of 42.87 % and 0.75 mg/g, respectively. The highest absorption percentage and capacity of 92.77 % and 5.18 mg/g, respectively, were found for Hg(2+) in a mixture solution and Cu(2+) in single-metal solution. The Cu(2+) absorption process in a single-metal solution changed the biosorbent characteristics of the mangium bark, yielding a decreased crystalline fraction; changed transmittance on hydroxyl, carboxyl, and carbonyl groups; and increased the presence of Cu. In conclusion, mangium bark biosorbent can reduce hazardous heavy metal ions in both standard solutions and wastewater.

  10. Bioindication of a surplus of heavy metals in terrestrial ecosystems.

    PubMed

    Ernst, W H; Verkleij, J A; Vooijs, R

    1983-09-01

    A survey of the methods of boindication of heavy metals in terrestrial ecosystems and their effectiveness for predicting the consequences of environmental stress on organisms is presented. Two main inputs of heavy metals for terrestrial ecosystems have been considered: airborne and soil-borne.Airborne metals can be monitored due to physical adsorption on plant surfaces or due to chemical exchange processes in cell walls. Active biomonitoring widely uses both aspects, however, without predictive values.Meaningful bioindication of soilborne heavy metals can only be achieved by passive monitoring. Due to the different functions of heavy metals in organisms-micronutrients and trace elements-the knowledge of natural background values is important, considering the qualitative aspects of metals in the soil. In exceptional situations morphological and anatomical changes of plant organs will facilitate bioindication; in every case chemical analysis of the concentration of heavy metals is an essential part of the monitoring program.A long-term exposure of organisms to heavy metals will influence the genetic structure of populations. Therefore measurement of heavy metal tolerance of plants has to be a standard procedure in monitoring programs.

  11. Characterisation of heavy metal discharge into the Ria of Huelva.

    PubMed

    Sainz, A; Grande, J A; de la Torre, M L

    2004-06-01

    The Ria of Huelva estuary, in SW Spain, is known to be one of the most heavy metal contaminated estuaries in the world. River contribution to the estuary of dissolved Cu, Zn, Mn, Cr, Ni, Cd, and As were analysed for the period 1988-2001. The obtained mean values show that this contribution, both because of the magnitude of total metals (895.1 kg/h), composition, toxicity (8.7 kg/h of As+Cd+Pb) and persistence, is an incomparable case in heavy metal contamination of estuaries. The amount and typology of heavy metal discharge to the Ria of Huelva are related to freshwater flow (and, consequently, to rainfall); as a result, two different types of heavy metal discharge can be distinguished in the estuary: during low water (50% of the days), with only 19.3 kg/h of heavy metals, and during high water or flood (17% of the days), where daily maximum discharge of 72,475 kg of heavy metals were recorded, from which 1481 kg were of As, 470 kg of Pb, and 170 kg of Cd. In the most frequent situation (77% of the days), the Odiel River discharges from 90% to 100% of the freshwater received by the estuary. Despite this, the high concentration of heavy metals in the Tinto River water causes this river to discharge into the Ria of Huelva 12.5% of fluvial total dissolved metal load received by the estuary.

  12. Heavy metal levels in goats from Notasulga, Alabama

    SciTech Connect

    Khan, A.T.; Diffay, B.C.; Forester, D.M.; Thompson, S.J.; Mielke, H.W.

    1994-12-31

    Goat meat farming is increasing in popularity in southeastern region of United States. In order to monitor environmental contamination of heavy metals in goat meat, samples of liver, kidney, and muscle were collected from 20 goats on a goat farm in Notasulga, Alabama. These samples were analyzed by Inductively Coupled Plasma Atomic Emission Spectroscopy. The copper concentration was significantly higher in livers than the concentration in kidneys and muscles. Lead, cadmium, and zinc levels did not show any significant differences between liver, kidney, and muscle samples. The concentrations of lead and copper in livers and cadmium in kidneys were significantly different in males when compared to females. However, in muscle, the concentrations of lead, cadmium, copper, and zinc showed no significant difference between male and female or between young and old goats. Further, the concentrations of lead in livers and cadmium in kidneys showed a significant difference between young and old goats.

  13. [Beijing common green tree leaves' accumulation capacity for heavy metals].

    PubMed

    Li, Shao-Ning; Kong, Ling-Wei; Lu, Shao-Wei; Chen, Bo; Gao, Chen; Shi, Yuan

    2014-05-01

    Seasonal variation of heavy metal contents in leaves and their relationships with soil heavy metal pollution levels were studied through measuring and analyzing the leaves of the common tree species in Beijing and soil heavy metal contents, to detect heavy metal accumulation ability of plant leaves. The results showed that: (1) the contents of Cu, Pb, Zn in plant leaves first decreased and then increased, again declined with changing the seasons (from spring to winter). Cr concentration showed the trend of first increase and then decrease from spring to winter, and the highest in the autumn; the accumulation capacities of Cu for Babylonica and Japonica were higher in the spring, summer and autumn, while Tabuliformis was in winter; the higher accumulation capacities for Cr, Pb were Japonica and Platycladus, and in winter were Platycladus and Bungeana; the higher accumulation capacities for Zn were Babylonica and Bungeana, while Platycladus in winter; (2) the pollution degree of four kinds of heavy metals (Cu, Cr, Pb, Zn) from downtown to suburbs showed that: Jingshan (C =2.48, C is contamination factor) > Olympic (C = 1.27) > Songshan (C = 1.20) > Shuiguan (C = 1. 18); (3) the heavy metals concentration of same plant leaves in the water of the Great Wall changed larger, but those in the other three areas showed that: Jingshan > Olympic > Songshan; the ability of same species leaf to absorb different sorts of heavy metals showed that: Zn >Cu >Pb >Cr; the difference between Zn content and Cr content was significant (P <0.01); (4) the relationship between heavy metal content in plant leaves and soil heavy metal pollution levels presented a quadratic polynomial relation; the significant correlation was found between other three heavy metal contents of plant samples and soil samples, but they were not the case for the Cu, and the correlation coefficients were above 0. 9.

  14. Content of heavy metals in the hair

    NASA Astrophysics Data System (ADS)

    Patrashkov, S. A.; Petukhov, V. L.; Korotkevich, O. S.; Petukhov, I. V.

    2003-05-01

    The aim of our investigation was to determine of HM content in the hair of people and animals. Two of the main essential elements-Zn and Cu and two of the supertoxical heavy metals- Pb and Cd were chosen. The investigations were conducted in Russian Federation and Belarus Republic in 2001-2002. About 500 hair samples of people, dogs, cats, cattle, horses, yaks, pigs, sheep goats and rabbits were studied by the stripping voltammetric analysis (SVA) method with TA- 2 analyzer to determine Zn, Cu, Pb and Cd concentrations. The hair samples were prepared according to the methods developed in Tomsk University (Russia) and improved by the authors. The essence of the methods is the multiconsecutive burning of hair samples to ashes and boiling them in concentrated acids to dissolve chemical combinations and transform their metals into ion forms. The zinc concentration was the highest in all hair samples (58.65 ... 195.15 mg/kg). The copper content was several times less (5.49 ... 22.63 mg/kg). Lead and cadmium were detected in relatively low amounts (0.32 ... 2.42 mg/kg and 0.04 ... 0.92 mg/kg respectively). The highest Pb and Cd levels were detected in cats and people hair.

  15. Remediation technologies for heavy metal contaminated groundwater.

    PubMed

    Hashim, M A; Mukhopadhyay, Soumyadeep; Sahu, Jaya Narayan; Sengupta, Bhaskar

    2011-10-01

    The contamination of groundwater by heavy metal, originating either from natural soil sources or from anthropogenic sources is a matter of utmost concern to the public health. Remediation of contaminated groundwater is of highest priority since billions of people all over the world use it for drinking purpose. In this paper, thirty five approaches for groundwater treatment have been reviewed and classified under three large categories viz chemical, biochemical/biological/biosorption and physico-chemical treatment processes. Comparison tables have been provided at the end of each process for a better understanding of each category. Selection of a suitable technology for contamination remediation at a particular site is one of the most challenging job due to extremely complex soil chemistry and aquifer characteristics and no thumb-rule can be suggested regarding this issue. In the past decade, iron based technologies, microbial remediation, biological sulphate reduction and various adsorbents played versatile and efficient remediation roles. Keeping the sustainability issues and environmental ethics in mind, the technologies encompassing natural chemistry, bioremediation and biosorption are recommended to be adopted in appropriate cases. In many places, two or more techniques can work synergistically for better results. Processes such as chelate extraction and chemical soil washings are advisable only for recovery of valuable metals in highly contaminated industrial sites depending on economical feasibility.

  16. Heavy metals in Tuskegee Lake crayfish

    SciTech Connect

    Khan, A.T.

    1995-12-31

    The crayfish, Onconectes virifis, is a bottom dweller and eats insect larvae, worms, crustaceans, small snails, fishes, and dead animal matter. They can be used to monitor the aquatic environment such as lakes, ponds and creeks. To monitor the environmental contamination of heavy metals (Hg, Pb, Cd, Cu, Co, Ni, and Zn) in Tuskegee Lake, Tuskegee, Alabama, adult crayfish were collected and analyzed for these metals. The Pb, Cd, Cu, Ni, and Zn concentrations were 3.91, 0.22, 8.06, 1.11, and 33.37 ppm in muscle and 28.98, 1.15, 9.86, 2.1 8, and 32.62 ppm in exoskeleton of crayfish, respectively. The concentrations of Pb and Cd were significantly higher in exoskeleton than those of muscle. However, the concentrations of Cu, Ni, and Zn did not show any significant difference between the muscle and the exoskeleton of the crayfish. The concentrations of Hg and Co were undetected in both the exoskeleton and muscle of the crayfish.

  17. Fate, transport, and interactions of heavy metals.

    PubMed Central

    Serrano, O R

    1995-01-01

    Mishandling of hazardous wastes, like their unauthorized disposal in abandoned dump yards or sites, in river beds, estuaries or in the sea, causes substantial damage to the environment and its resources and, given the persistence and toxicity of these pollutants, they can seriously damage human health and quality of life. The importance of controlling management, transport, and disposal of toxic and hazardous substances in the years to come will be a crucial issue in the design and implementation of public policies. This is especially true for residents of such areas as the border between the United States and Mexico, where historically hazardous wastes have been a public health and environmental problem. The aim of this Conference on the Fate, Transport, and Interactions of Metals, A Joint United States-Mexico Conference, co-sponsored by the National Institute of Environmental Health Sciences, Superfund Basic Research Program, the National University of Mexico, Program for the Environment and the Pan American Health Organization, and hosted by the University of Arizona Center for Toxicology, College of Pharmacy, is to begin a joint effort by the United States and Mexico to better understand the complex problems related to heavy metals as hazardous wastes. PMID:7621804

  18. Conservative heavy metal total discharge schemes.

    PubMed

    Yeh, Tzung-Yuh; Chen, Ho-Chi

    2017-08-23

    Currently, according to Taiwan's Water Pollution Control Act, the environmental control of waterbodies and water quality depends on the effluent standards and the standard of water quality in the rivers. The Act demands that each stationary pollution source comply with the effluent standard before being discharged into the rivers, and that the overall water quality in the river shall not exceed the declared standard of water quality. To improve the condition of the waterbodies and water quality of the rivers, the Environmental Protection Administration (EPA) in Taiwan has made stricter regulations concerning the discharge standard. Such regulations will help to reduce the weight of individual pollutants discharged; the discharged wastewater, however, will still gradually worsen the water quality of the rivers even after complying with the effluent standard since some of the pollutant dischargers may decrease the concentration of pollutants by diluting the water before discharging; thus, the total weight of metals discharged in the rivers will not be reduced, and the water quality in the areas where the pollutant sources are concentrated will not thereby be significantly improved. To protect the irrigation water and farmlands from being polluted by discharged heavy metals in industrial wastewater, the EPA started controlling the sources in accordance with the total quantity control (TQC) as defined in the Water Pollution Control Act, in the hope of perfecting the environmental protection of waterbodies and water quality, as well as ensuring clean water sources without any pollution for the rivers, land, and people.

  19. Functional expression of a bacterial heavy metal transporter in Arabidopsis enhances resistance to and decreases uptake of heavy metals.

    PubMed

    Lee, Joohyun; Bae, Hyunju; Jeong, Jeeyon; Lee, Jae-Yun; Yang, Young-Yell; Hwang, Inhwan; Martinoia, Enrico; Lee, Youngsook

    2003-10-01

    Large parts of agricultural soil are contaminated with lead (Pb) and cadmium (Cd). Although most environments are not heavily contaminated, the low levels observed nonetheless pose a high risk of heavy metal accumulation in the food chain. Therefore, approaches to develop plants with reduced heavy metal uptake are important. Recently, many transgenic plants with increased heavy metal resistance and uptake of heavy metals were developed for the purpose of phytoremediation. However, to reduce heavy metal in the food chain, plants that transfer less heavy metals to the shoot are required. We tested whether an Escherichia coli gene, ZntA, which encodes a Pb(II)/Cd(II)/Zn(II) pump, could be useful for developing plants with reduced heavy metal content. Yeast cells transformed with this gene had improved resistance to Pb(II) and Cd(II). In Arabidopsis plants transformed with ZntA, ZntA was localized at the plasma membrane and improved the resistance of the plants to Pb(II) and Cd(II). The shoots of the transgenic plants had decreased Pb and Cd content. Moreover, the transgenic protoplasts showed lower accumulation of Cd and faster release of preloaded Cd than wild-type protoplasts. These results show that a bacterial transporter gene, ZntA, can be functionally expressed in plant cells, and that that it may be useful for the development of crop plants that are safe from heavy metal contamination.

  20. Modeling of Heavy Metal Transformation in Soil Ecosystem

    NASA Astrophysics Data System (ADS)

    Kalinichenko, Kira; Nikovskaya, Galina N.

    2017-04-01

    The intensification of industrial activity leads to an increase in heavy metals pollution of soils. In our opinion, sludge from biological treatment of municipal waste water, stabilized under aerobic-anaerobic conditions (commonly known as biosolid), may be considered as concentrate of natural soil. In their chemical, physical and chemical and biological properties these systems are similar gel-like nanocomposites. These contain microorganisms, humic substances, clay, clusters of nanoparticles of heavy metal compounds, and so on involved into heteropolysaccharides matrix. It is known that microorganisms play an important role in the transformation of different nature substances in soil and its health maintenance. The regularities of transformation of heavy metal compounds in soil ecosystem were studied at the model of biosolid. At biosolid swelling its structure changing (gel-sol transition, weakening of coagulation contacts between metal containing nanoparticles, microbial cells and metabolites, loosening and even destroying of the nanocomposite structure) can occur [1, 2]. The promotion of the sludge heterotrophic microbial activities leads to solubilization of heavy metal compounds in the system. The microbiological process can be realized in alcaligeneous or acidogeneous regimes in dependence on the type of carbon source and followed by the synthesis of metabolites with the properties of flocculants and heavy metals extragents [3]. In this case the heavy metals solubilization (bioleaching) in the form of nanoparticles of hydroxycarbonate complexes or water soluble complexes with oxycarbonic acids is observed. Under the action of biosolid microorganisms the heavy metals-oxycarbonic acids complexes can be transformed (catabolised) into nano-sizing heavy metals- hydroxycarbonates complexes. These ecologically friendly complexes and microbial heteropolysaccharides are able to interact with soil colloids, stay in the top soil profile, and improve soil structure due

  1. Biomedical Implications of Heavy Metals Induced Imbalances in Redox Systems

    PubMed Central

    Singh, Shweta; Siddiqi, Nikhat J.

    2014-01-01

    Several workers have extensively worked out the metal induced toxicity and have reported the toxic and carcinogenic effects of metals in human and animals. It is well known that these metals play a crucial role in facilitating normal biological functions of cells as well. One of the major mechanisms associated with heavy metal toxicity has been attributed to generation of reactive oxygen and nitrogen species, which develops imbalance between the prooxidant elements and the antioxidants (reducing elements) in the body. In this process, a shift to the former is termed as oxidative stress. The oxidative stress mediated toxicity of heavy metals involves damage primarily to liver (hepatotoxicity), central nervous system (neurotoxicity), DNA (genotoxicity), and kidney (nephrotoxicity) in animals and humans. Heavy metals are reported to impact signaling cascade and associated factors leading to apoptosis. The present review illustrates an account of the current knowledge about the effects of heavy metals (mainly arsenic, lead, mercury, and cadmium) induced oxidative stress as well as the possible remedies of metal(s) toxicity through natural/synthetic antioxidants, which may render their effects by reducing the concentration of toxic metal(s). This paper primarily concerns the clinicopathological and biomedical implications of heavy metals induced oxidative stress and their toxicity management in mammals. PMID:25184144

  2. Biomedical implications of heavy metals induced imbalances in redox systems.

    PubMed

    Sharma, Bechan; Singh, Shweta; Siddiqi, Nikhat J

    2014-01-01

    Several workers have extensively worked out the metal induced toxicity and have reported the toxic and carcinogenic effects of metals in human and animals. It is well known that these metals play a crucial role in facilitating normal biological functions of cells as well. One of the major mechanisms associated with heavy metal toxicity has been attributed to generation of reactive oxygen and nitrogen species, which develops imbalance between the prooxidant elements and the antioxidants (reducing elements) in the body. In this process, a shift to the former is termed as oxidative stress. The oxidative stress mediated toxicity of heavy metals involves damage primarily to liver (hepatotoxicity), central nervous system (neurotoxicity), DNA (genotoxicity), and kidney (nephrotoxicity) in animals and humans. Heavy metals are reported to impact signaling cascade and associated factors leading to apoptosis. The present review illustrates an account of the current knowledge about the effects of heavy metals (mainly arsenic, lead, mercury, and cadmium) induced oxidative stress as well as the possible remedies of metal(s) toxicity through natural/synthetic antioxidants, which may render their effects by reducing the concentration of toxic metal(s). This paper primarily concerns the clinicopathological and biomedical implications of heavy metals induced oxidative stress and their toxicity management in mammals.

  3. Cell surface engineering of microorganisms towards adsorption of heavy metals.

    PubMed

    Li, Peng-Song; Tao, Hu-Chun

    2015-06-01

    Heavy metal contamination has become a worldwide environmental concern due to its toxicity, non-degradability and food-chain bioaccumulation. Conventional physical and chemical treatment methods for heavy metal removal have disadvantages such as cost-intensiveness, incomplete removal, secondary pollution and the lack of metal specificity. Microbial biomass-based biosorption is one of the approaches gaining increasing attention because it is effective, cheap, and environmental friendly and can work well at low concentrations. To enhance the adsorption properties of microbial cells to heavy metal ions, the cell surface display of various metal-binding proteins/peptides have been performed using a cell surface engineering approach. The surface engineering of Gram-negative bacteria, Gram-positive bacteria and yeast towards the adsorption of heavy metals are reviewed in this article. The problems and future perspectives of this technology are discussed.

  4. Bismuth film electrodes for heavy metals determination

    NASA Astrophysics Data System (ADS)

    Rehacek, Vlastimil; Hotovy, Ivan; Vojs, Marian; Mika, Fedor

    2007-05-01

    Bismuth film electrodes (BiFEs) have a potential to replace toxic mercury used most frequently for determination of heavy metals (Cd, Pb, Zn) by anodic stripping voltammetry. We prepared a graphite disc electrode (0.5 mm in diameter) from a pencil-lead rod and developed a nitrogen doped diamond-like carbon (NDLC) microelectrode array consisting of 50 625 microdiscs with 3 μm in diameter and interelectrode distances of 20 μm on a highly conductive silicon substrate as a support for BiFEs. The disc graphite BiFE was used for simultaneous determination of Pb(II), Cd(II) and Zn(II) by square wave voltammetry (SWV) in an aqueous solution. We found the optimum bismuth-to-metal concentration ratio in the solution to be 20. The dependence of the stripping responses on the concentration of target metals was linear in the range from 1×10 -8 to 1.2×10 -7 mol/L. Detection limits 2.4×10 -9 mol/L for Pb(II), 2.9×10 -9 mol/L for Cd(II) and 1.2×10 -8 mol/L for Zn(II) were estimated. A bismuth-plated NDLC microelectrode array was used for Pb(II) determination by differential pulse voltammetry (DPV) in an aqueous solution. We found that the stripping current for bismuth-plated NDLC array was linear in the concentration range of Pb(II) from 2×10 -8 to 1.2×10 -7 mol/L. The detection limit 2.2×10 -8 mol/L was estimated from a calibration plot.

  5. Heavy metal pollution of ambient air in Nagpur City.

    PubMed

    Chaudhari, Pramod R; Gupta, Rakhi; Gajghate, Daulat Ghilagi; Wate, Satish R

    2012-04-01

    Heavy metals released from different sources in urban environment get adsorbed on respirable particulate matter less than 10 μm in size (PM(10)) and are important from public health point of view causing morbidity and mortality. Therefore, the ambient air quality monitoring was carried out to study the temporal and special pattern in the distribution of PM(10) and associated heavy metal content in the atmosphere of Nagpur, Maharashtra State, India during 2001 as well as in 2006. PM(10) fraction was observed to exceed the stipulated standards in both years. It was also observed that minimum range of PM(10) was observed to be increased in 2006 indicating increase in human activity during nighttime also. Six heavy metals were analyzed and were observed to occur in the order Zn > Fe > Pb > Ni > Cd > Cr in 2006, similar to the trend in other metro cities in India. Lead and Nickel were observed to be within the stipulated standards. Poor correlation coefficient (R(2)) between lead and PM(10) indicated that automobile exhaust is not the source of metals to air pollution. Commercial and industrial activity as well as geological composition may be the potential sources of heavy metal pollution. Total load of heavy metals was found to be increased in 2006 with prominent increase in zinc, lead, and nickel in the environment. Public health impacts of heavy metals as well as certain preventive measures to mitigate the impact of heavy metals on public health are also summarized.

  6. Impact of heavy metals on the female reproductive system.

    PubMed

    Rzymski, Piotr; Tomczyk, Katarzyna; Rzymski, Pawel; Poniedziałek, Barbara; Opala, Tomasz; Wilczak, Maciej

    2015-01-01

    It has been recognized that environmental pollution can affect the quality of health of the human population. Heavy metals are among the group of highly emitted contaminants and their adverse effect of living organisms has been widely studied in recent decades. Lifestyle and quality of the ambient environment are among these factors which can mainly contribute to the heavy metals exposure in humans. A review of literature linking heavy metals and the female reproductive system and description of the possible associations with emission and exposure of heavy metals and impairments of female reproductive system according to current knowledge. The potential health disorders caused by chronic or acute heavy metals toxicity include immunodeficiency, osteoporosis, neurodegeneration and organ failures. Potential linkages of heavy metals concentration found in different human organs and blood with oestrogen-dependent diseases such as breast cancer, endometrial cancer, endometriosis and spontaneous abortions, as well as pre-term deliveries, stillbirths and hypotrophy, have also been reported. Environmental deterioration can lead to the elevated risk of human exposure to heavy metals, and consequently, health implications including disturbances in reproduction. It is therefore important to continue the investigations on metal-induced mechanisms of fertility impairment on the genetic, epigenetic and biochemical level.

  7. Growth and heavy metals accumulation potential of microalgae grown in sewage wastewater and petrochemical effluents.

    PubMed

    Ajayan, K V; Selvaraju, M; Thirugnanamoorthy, K

    2011-08-15

    Microalgae exhibit a number of heavy metal uptake process by different metabolism. In this study, the ability of microalgae for removal of heavy metal from wastewater was studied. Growth and biochemical contents of microalgae were determined by spectrophotometer. Heavy metal analysis of wastewater effluents were performed by atomic absorption spectrophotometer before and after treatment at laboratory scale. The growth of Scenedesmus bijuga and Oscillatoria quadripunctulata in sewage wastewater was higher than those grown in synthetic medium. Whereas, the growth of S. bijuga and O. quadripunctulata in sterilized petrochemical effluents was slightly lower than that grown in the standard synthetic medium. The chlorophyll, carotenoid and protein content of S. bijuga and O. quadripunctulata grown in sterilized sewage wastewater were higher than those grown in the standard medium. Similarly S. bijuga and O. quadripunctulata grown in sterilized petrochemical effluents showed lower contents of pigments and protein than those grown in sewage and synthetic medium. Heavy metals copper, cobalt, lead and zinc were removed by 37-50, 20.3-33.3, 34.6-100 and 32.1-100%, respectively from sewage wastewater and petrochemical effluent using Ocillatoria culture. The metal absorption by S. bijuga were (Cu, Co, Pb, Zn) 60-50, 29.6-66, 15.4-25 and 42.9-50%, respectively from sewage and petrochemical effluents. Both species showed high level of heavy metal removal efficiency and metal sorption efficiency of both microalgae depended on the type of biosorbent, the physiological status of the cells, availability of heavy metal, concentration of heavy metal and chemical composition of wastewater.

  8. Covalent bonding in heavy metal oxides

    NASA Astrophysics Data System (ADS)

    Bagus, Paul S.; Nelin, Connie J.; Hrovat, Dave A.; Ilton, Eugene S.

    2017-04-01

    Novel theoretical methods were used to quantify the magnitude and the energetic contributions of 4f/5f-O2p and 5d/6d-O2p interactions to covalent bonding in lanthanide and actinide oxides. Although many analyses have neglected the involvement of the frontier d orbitals, the present study shows that f and d covalencies are of comparable importance. Two trends are identified. As is expected, the covalent mixing is larger when the nominal oxidation state is higher. More subtly, the importance of the nf covalent mixing decreases sharply relative to (n + 1)d as the nf occupation increases. Atomic properties of the metal cations that drive these trends are identified.

  9. Optical methods for the detection of heavy metal ions

    NASA Astrophysics Data System (ADS)

    Uglov, A. N.; Bessmertnykh-Lemeune, A.; Guilard, R.; Averin, A. D.; Beletskaya, I. P.

    2014-03-01

    The review covers an important area of the modern chemistry, namely, the detection of heavy metal ions using optical molecular detectors. The role of this method in metal ion detection and the physicochemical grounds of operation of chemosensors are discussed, and examples of detection of most abundant heavy metal ions and synthetic approaches to molecular detectors are presented. The immobilization of molecular detectors on solid substrates for the design of analytical sensor devices is described. The bibliography includes 178 references.

  10. [Application of ICP-MS to determination of heavy metal content of heavy metals in two kinds of N fertilizer].

    PubMed

    Rui, Yu-kui; Shen, Jian-bo; Zhang, Fu-suo

    2008-10-01

    Environmental safety has been the focus worldwide, where involved are the pollutions of heavy metals, pesticides and persistent organic pollutants. Fertilizer has become one of the polluting sources of heavy metals, which are very deleterious to human health and environmental safety. Heavy metals are difficult to metabolize in human body and very harmful, so research on the pollution of heavy metals is considered increasingly important. The pollution sources of heavy metals include waste residue, waste water and exhaust gas from industry and automobile, and garbage from human life. The heavy metals in fertilizer can endanger the human body by the crop containing heavy metals. Two kinds of nitrogen fertilizer were analyzed in terms of the content of heavy metals by ICP-MS, and the results showed that the content of 10 kinds of heavy metals (Al, Ti, Cr, Ni, Cu, Zn, As, Cd, Hg and Pb) in (NH4)2SO4 was 1345.13, 35.12, 2539.27, 287.26, 674.05, 270.79, 42.54, 22.13, 27.20 and 123.87 ng x g(-1) respectively; and in CO(NH2)2 it is 71.59, 5.36, 1167.71, 188.60, 7.46, 64.45, 10.55, 0.00, 0.09 and 3.71 ng x g(-1) respectively. All the data showed that CO(NH2)2 contained much less heavy metals than (NH4)2SO4, so we should select CO(NH2)2 as the nitrogen fertilizer in agricultural production.

  11. Heavy metal displacement in chelate-irrigated soil during phytoremediation

    NASA Astrophysics Data System (ADS)

    Madrid, F.; Liphadzi, M. S.; Kirkham, M. B.

    2003-03-01

    Heavy metals in wastewater sewage sludge (biosolids), applied to land, contaminate soils. Phytoremediation, the use of plants to clean up toxic heavy metals, might remove them. Chelating agents are added to soil to solubilize the metals for enhanced phytoextraction. Yet no studies follow the displacement and leaching of heavy metals in soil with and without roots following solubilization with chelates. The objective of this work was to determine the mobility of heavy metals in biosolids applied to the surface of soil columns (76 cm long; 17 cm diam.) with or without plants (barley; Hordeum vulgare L.). Three weeks after barley was planted, all columns were irrigated with the disodium salt of the chelating agent, EDTA (ethylenediamine tetraacetic acid) (0.5 g/kg soil). Drainage water, soil, and plants were analyzed for heavy metals (Cd, Cu, Fe, Mn, Ni, Pb, Zn). Total concentrations of the heavy metals in all columns at the end of the experiment generally were lower in the top 30 cm of soil with EDTA than without EDTA. The chelate increased concentrations of heavy metals in shoots. With or without plants, the EDTA mobilized Cd, Fe, Mn, Ni, Pb, and Zn, which leached to drainage water. Drainage water from columns without EDTA had concentrations of these heavy metals below detection limits. Only Cu did not leach in the presence of EDTA. Even though roots retarded the movement of Cd, Fe, Mn, Ni, Pb, and Zn through the EDTA-treated soil from 1 d (Cd) to 5 d (Fe), the drainage water from columns with EDTA had concentrations of Cd, Fe, Mn, and Pb that exceeded drinking water standards by 1.3, 500, 620, and 8.6 times, respectively. Because the chelate rendered Cd, Fe, Mn, Ni, Pb, and Zn mobile, it is suggested that the theory for leaching of soluble salts, put forward by Nielsen and associates in 1965, could be applied to control movement of the heavy metals for maximum uptake during chelate-assisted phytoremediation.

  12. Studies Concerning the Accumulation of Minerals and Heavy Metals in Fruiting Bodies of Wild Mushrooms

    SciTech Connect

    Stihi, Claudia; Radulescu, Cristiana; Gheboianu, Anca; Bancuta, Iulian; Popescu, Ion V.; Busuioc, Gabriela

    2011-10-03

    The minerals and heavy metals play an important role in the metabolic processes, during the growth and development of mushrooms, when they are available in appreciable concentration. In this work the concentrations of Cr, Mn, Fe, Ni, Cu, Zn, Se, Cd and Pb were analyzed using the Flame Atomic Absorption spectrometry (FAAS) together with Energy Dispersive X-ray Fluorescence spectrometry (EDXRF) in 3 wild mushrooms species and their growing substrate, collected from various forestry fields in Dambovita County, Romania. The analyzed mushrooms were: Amanita phalloides, Amanita rubescens and Armillariella mellea. The accumulation coefficients were calculated to assess the mobility of minerals and heavy metals from substrate to mushrooms [1].

  13. Studies Concerning the Accumulation of Minerals and Heavy Metals in Fruiting Bodies of Wild Mushrooms

    NASA Astrophysics Data System (ADS)

    Stihi, Claudia; Gheboianu, Anca; Radulescu, Cristiana; Popescu, Ion V.; Busuioc, Gabriela; Bancuta, Iulian

    2011-10-01

    The minerals and heavy metals play an important role in the metabolic processes, during the growth and development of mushrooms, when they are available in appreciable concentration. In this work the concentrations of Cr, Mn, Fe, Ni, Cu, Zn, Se, Cd and Pb were analyzed using the Flame Atomic Absorption spectrometry (FAAS) together with Energy Dispersive X-ray Fluorescence spectrometry (EDXRF) in 3 wild mushrooms species and their growing substrate, collected from various forestry fields in Dambovita County, Romania. The analyzed mushrooms were: Amanita phalloides, Amanita rubescens and Armillariella mellea. The accumulation coefficients were calculated to assess the mobility of minerals and heavy metals from substrate to mushrooms [1].

  14. Inducibility of a molecular bioreporter system by heavy metals

    SciTech Connect

    Klimowski, L.; Rayms-Keller, A.; Olson, K.E.; Yang, R.S.H.; Tessari, J.; Carlson, J.; Beaty, B.

    1996-02-01

    The authors have developed a molecular bioreporter model for detecting an invertebrate response to heavy metals in streams. The bioreporter system, pMt2-luc, utilizes a Drosophila melanogaster metallothionein promoter to regulate luciferase expression in stably transformed mosquito cells.The LucC5 clone, which was isolated from pMt2-luc transformed, hygromycin-resistant C6/36 (Aedes albopictus) cells, demonstrated a 12-fold increase in luciferase-specific activity 48 h after exposure to 13 ppm copper (Cu). In addition to Cu, exposure of LucC5 cells to 19 ppm lead (Pb) or 3 ppm mercury (Hg) for 48 h induced luciferase expression threefold and fourfold, respectively. Exposures of up to 30 ppm arsenic (As), 8 ppm cadmium (Cd), 7 ppm chromium (Cr), or 5 ppm nickel (Ni) had no effect on luciferase induction. LucC5 cells exposed to metal mixtures of 13 ppm Cu and 19 ppm Pb yielded an additive response with a 14-fold increase in luciferase expression. When organic chemicals such as phenol (3 ppm) were mixed with 13 ppm Cu, 19 ppm Pb, or 3 ppm Hg a significant reduction in luciferase activity was noted. Additionally, atomic absorption spectroscopy suggested that two of the metals, Cu and Pb, show marked differences in accumulation within the LucC5 cell line.

  15. Heavy metal-induced glutathione accumulation and its role in heavy metal detoxification in Phanerochaete chrysosporium.

    PubMed

    Xu, Piao; Liu, Liang; Zeng, Guangming; Huang, Danlian; Lai, Cui; Zhao, Meihua; Huang, Chao; Li, Ningjie; Wei, Zhen; Wu, Haipeng; Zhang, Chen; Lai, Mingyong; He, Yibin

    2014-01-01

    Phanerochaete chrysosporium are known to be vital hyperaccumulation species for heavy metal removal with admirable intracellular bioaccumulation capacity. This study analyzes the heavy metal-induced glutathione (GSH) accumulation and the regulation at the intracellular heavy metal level in P. chrysosporium. P. chrysosporium accumulated high levels of GSH, accompanied with high intracellular concentrations of Pb and Cd. Pb bioaccumulation lead to a narrow range of fluctuation in GSH accumulation (0.72-0.84 μmol), while GSH plummeted under Cd exposure at the maximum value of 0.37 μmol. Good correlations between time-course GSH depletion and Cd bioaccumulation were determined (R (2) > 0.87), while no significant correlations have been found between GSH variation and Pb bioaccumulation (R (2) < 0.38). Significantly, concentration-dependent molar ratios of Pb/GSH ranging from 0.10 to 0.18 were observed, while molar ratios of Cd/GSH were at the scope of 1.53-3.32, confirming the dominant role of GSH in Cd chelation. The study also demonstrated that P. chrysosporium showed considerable hypertolerance to Pb ions, accompanied with demand-driven stimulation in GSH synthesis and unconspicuous generation of reactive oxygen stress. GSH plummeted dramatically response to Cd exposure, due to the strong affinity of GSH to Cd and the involvement of GSH in Cd detoxification mechanism mainly as Cd chelators. Investigations into GSH metabolism and its role in ameliorating metal toxicity can offer important information on the application of the microorganism for wastewater treatment.

  16. Leaching Properties of Naturally Occurring Heavy Metals from Soils

    NASA Astrophysics Data System (ADS)

    Zhang, M.; Hoshino, M.; Yoshikawa, M.; Hara, J.; Sugita, H.

    2014-12-01

    The major threats to human health from heavy metals are associated with exposure to arsenic, lead, cadmium, chromium, mercury, as well as some other elements. The effects of such heavy metals on human health have been extensively studied and reviewed by international organizations such as WHO. Due to their toxicity, heavy metal contaminations have been regulated by national environmental standards in many countries, and/or laws such as the Soil Contamination Countermeasures Act in Japan. Leaching of naturally occurring heavy metals from the soils, especially those around abandoned metal mines into surrounding water systems, either groundwater or surface water systems, is one of the major pathways of exposure. Therefore, understanding the leaching properties of toxic heavy metals from naturally polluted soils is of fundamentally importance for effectively managing abandoned metal mines, excavated rocks discharged from infrastructure constructions such as tunneling, and/or selecting a pertinent countermeasure against pollution when it is necessary. In this study, soil samples taken from the surroundings of abandoned metal mines in different regions in Japan were collected and analyzed. The samples contained multiple heavy metals such as lead, arsenic and chromium. Standard leaching test and sequential leaching test considering different forms of contaminants, such as trivalent and pentavalent arsenics, and trivalent and hexavalent chromiums, together with standard test for evaluating total concentration, X-ray Fluorescence Analysis (XRF), X-ray diffraction analysis (XRD) and Cation Exchange Capacity (CEC) tests were performed. In addition, sequential leaching tests were performed to evaluate long-term leaching properties of lead from representative samples. This presentation introduces the details of the above experimental study, discusses the relationships among leaching properties and chemical and mineral compositions, indicates the difficulties associated with

  17. A Drinking Water Sensor for Lead and Other Heavy Metals.

    PubMed

    Lin, Wen-Chi; Li, Zhongrui; Burns, Mark A

    2017-09-05

    Leakage of lead and other heavy metals into drinking water is a significant health risk and one that is not easily detected. We have developed simple sensors containing only platinum electrodes for the detection of heavy metal contamination in drinking water. The two-electrode sensor can identify the existence of a variety of heavy metals in drinking water, and the four-electrode sensor can distinguish lead from other heavy metals in solution. No false-positive response is generated when the sensors are placed in simulated and actual tap water contaminated by heavy metals. Lead detection on the four-electrode sensor is not affected by the presence of common ions in tap water. Experimental results suggest the sensors can be embedded in water service lines for long-time use until lead or other heavy metals are detected. With its low cost (∼$0.10/sensor) and the possibility of long-term operation, the sensors are ideal for heavy metal detection of drinking water.

  18. Microalgae - A promising tool for heavy metal remediation.

    PubMed

    Suresh Kumar, K; Dahms, Hans-Uwe; Won, Eun-Ji; Lee, Jae-Seong; Shin, Kyung-Hoon

    2015-03-01

    Biotechnology of microalgae has gained popularity due to the growing need for novel environmental technologies and the development of innovative mass-production. Inexpensive growth requirements (solar light and CO2), and, the advantage of being utilized simultaneously for multiple technologies (e.g. carbon mitigation, biofuel production, and bioremediation) make microalgae suitable candidates for several ecofriendly technologies. Microalgae have developed an extensive spectrum of mechanisms (extracellular and intracellular) to cope with heavy metal toxicity. Their wide-spread occurrence along with their ability to grow and concentrate heavy metals, ascertains their suitability in practical applications of waste-water bioremediation. Heavy metal uptake by microalgae is affirmed to be superior to the prevalent physicochemical processes employed in the removal of toxic heavy metals. In order to evaluate their potential and to fill in the loopholes, it is essential to carry out a critical assessment of the existing microalgal technologies, and realize the need for development of commercially viable technologies involving strategic multidisciplinary approaches. This review summarizes several areas of heavy metal remediation from a microalgal perspective and provides an overview of various practical avenues of this technology. It particularly details heavy metals and microalgae which have been extensively studied, and provides a schematic representation of the mechanisms of heavy metal remediation in microalgae.

  19. Toxicity of heavy metals and metal-containing nanoparticles on plants.

    PubMed

    Mustafa, Ghazala; Komatsu, Setsuko

    2016-08-01

    Plants are under the continual threat of changing climatic conditions that are associated with various types of abiotic stresses. In particular, heavy metal contamination is a major environmental concern that restricts plant growth. Plants absorb heavy metals along with essential elements from the soil and have evolved different strategies to cope with the accumulation of heavy metals. The use of proteomic techniques is an effective approach to investigate and identify the biological mechanisms and pathways affected by heavy metals and metal-containing nanoparticles. The present review focuses on recent advances and summarizes the results from proteomic studies aimed at understanding the response mechanisms of plants under heavy metal and metal-containing nanoparticle stress. Transport of heavy metal ions is regulated through the cell wall and plasma membrane and then sequestered in the vacuole. In addition, the role of different metal chelators involved in the detoxification and sequestration of heavy metals is critically reviewed, and changes in protein profiles of plants exposed to metal-containing nanoparticles are discussed in detail. Finally, strategies for gaining new insights into plant tolerance mechanisms to heavy metal and metal-containing nanoparticle stress are presented. This article is part of a Special Issue entitled: Plant Proteomics--a bridge between fundamental processes and crop production, edited by Dr. Hans-Peter Mock. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. Data on heavy metals and selected anions in the Persian popular herbal distillates.

    PubMed

    Keshtkar, Mozhgan; Dobaradaran, Sina; Soleimani, Farshid; Karbasdehi, Vahid Noroozi; Mohammadi, Mohammad Javad; Mirahmadi, Roghayeh; Ghasemi, Fatemeh Faraji

    2016-09-01

    In this data article, we determined the concentration levels of heavy metals including Pb, Co, Cd, Mn, Mg, Fe and Cu as well as selected anions including [Formula: see text] , [Formula: see text], [Formula: see text] and [Formula: see text] in the most used and popular herbal distillates in Iran. It is well known that heavy metals may pose a serious health hazard due to their bioaccumulation throughout the trophic chain ("Heavy metals (Cd, Cu, Ni and Pb) content in two fish species of Persian Gulf in Bushehr Port, Iran" (Dobaradaran et al., 2013) [1]; "Comparative investigation of heavy metal, trace, and macro element contents in commercially valuable fish species harvested off from the Persian Gulf" (Abadi et al., 2015) [2]) as well as some other environmental pollutions, "Assessment of sediment quality based on acid-volatile sulfide and simultaneously extracted metals in heavily industrialized area of Asaluyeh, Persian Gulf: concentrations, spatial distributions, and sediment bioavailability/toxicity" (Arfaeinia et al., 2016) [3]. The concentration levels of heavy metals and anions in herbal distillates samples were determined using flame atomic absorption spectrometry (FAAS, Varian AA240, Australia) and a spectrophotometer (M501 Single Beam Scanning UV/VIS, UK) respectively.

  1. Leachability of heavy metals from growth media containing source-separated municipal solid waste compost

    SciTech Connect

    Sawhney, B.L.; Bugbee, G.J.; Stilwell, D.E.

    1994-07-01

    The leaching of heavy metals in source-separated municipal solid waste (MSW) compost was determined by irrigation leaching of growth medium, admixed with varying amounts of compost, used for container grown plants. Perennial flowers (black-eyed Susan, Rudbeckia hirta L.) were grown in 2-L containers filled with the growth medium for a 10-wk period. Rainfall was supplemented with overhead irrigation to supply 2 cm of water per day. Leachates collected over each 2-wk period were analyzed for Cd, Cr, Cu, Ni, Pb, and Zn using atomic spectrometry. Concentrations of the heavy metals in the leachates increased with increasing proportions of MSW compost in the growth medium, but decreased with time of leaching. Leaching of the metals occurred at relatively high concentrations initially, followed by continued leaching at low concentrations. The initial leaching of heavy metals is attributed to their soluble or exchangeable forms and the subsequent slow leaching to the solid compounds. The concentrations of the heavy metals remained below the current drinking water standards in all treatments throughout the leaching period. The results thus suggest that contamination of groundwater with heavy metals from source-separated MSW compost applied as a soil amendment should be negligible, as the low concentrations in the leachates leaving the surface soil would be further attenuated by the subsoil. 29 refs., 6 figs., 1 tab.

  2. Bioaccumulation of heavy metals in Mbaa River and the impact on aquatic ecosystem.

    PubMed

    Ajima, M N O; Nnodi, P C; Ogo, O A; Adaka, G S; Osuigwe, D I; Njoku, D C

    2015-12-01

    The bioaccumulation and toxic effects of heavy metals have caused ecological damage to aquatic ecosystem. In this study, concentration of heavy metals including zinc, lead, cadmium, iron, and copper were determined in the sediment and water as well as in the muscle, gill, and intestine of two fish species (Pelmatochromis guentheri and Pelmatochromis pulcher) of Mbaa River in Southeastern Nigeria. Samples were collected at three different spots from the river, and the level of heavy metals specified above were determined by atomic absorption spectroscopy (AAS) after a modified wet digestion process. The results indicated that sediment had the highest concentration of the heavy metals investigated while water had the lowest concentration. Fish tissues showed appreciable bioaccumulation of these metals as evidenced by a higher concentration profile when compared with that of water. Furthermore, the concentration of these heavy metals in water and their bioconcentration factor in the fish were above the recommended limit by WHO and FEPA, indicating that Mbaa River along Inyishi may not be suitable for drinking nor the fish safe for human consumption. The study also reveals the use of fish as bioindicator of aquatic environment.

  3. Use of Complementary Cation And Anion Heavy Atom-Atom Salt Derivatives to Solve the Structure of Cytochrome P450 46a1

    SciTech Connect

    White, M.A.; Mast, N.; Bjorkhem, I.; Johnson, E.F.; Stout, C.D.; Pikuleva, I.A.

    2009-05-26

    Human cytochrome P450 46A1 (CYP46A1) is one of the key enzymes in cholesterol homeostasis in the brain. The crystallization and heavy-atom structure solution of an active truncated CYP46A1 in complex with the high-affinity substrate analogue cholesterol-3-sulfate (CH-3S) is reported. The 2.6 {angstrom} structure of CYP46A1-CH-3S was solved using both anion and cation heavy-atom salts. In addition to the native anomalous signal from the haem iron, an NaI anion halide salt derivative and a complementary CsCl alkali-metal cation salt derivative were used. The general implications of the use of halide and alkali-metal quick soaks are discussed. The importance of using isoionic strength buffers, the titration of heavy-atom salts into different ionic species and the role of concentration are considered. It was observed that cation/anion-binding sites will occasionally overlap, which could negatively impact upon mixed RbBr soaks used for multiple anomalous scatterer MAD (MMAD). The use of complementary cation and anion heavy-atom salt derivatives is a convenient and powerful tool for MIR(AS) structure solution.

  4. Improving crop tolerance to heavy metal stress by polyamine application.

    PubMed

    Soudek, Petr; Ursu, Marina; Petrová, Šárka; Vaněk, Tomáš

    2016-12-15

    Many areas have been heavily contaminated by heavy metals from industry and are not suitable for food production. The consumption of contaminated foods represents a health risk in humans, although some heavy metals are essential at low concentrations. Increasing the concentrations of essential elements in foods is one goal to improve nutrition. The aim of this study was to increase the accumulation of heavy metals in plant foods by the external application of putrescine. The levels of cadmium, zinc and iron were measured in different vegetables grown in hydroponic medium supplemented with heavy metals and compared with those grown in a reference medium. The estimated daily intake, based on the average daily consumption for various vegetable types, and the influence of polyamines on metal uptake were calculated. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Biosorption of heavy metals and uranium from dilute solutions

    SciTech Connect

    Schneider, I.A.H.; Misra, M.; Smith, R.W.

    1995-08-01

    Eichhornia crassipes approaches being a scourge in many parts of the world, choking waterways and hindering transport upon them. At the same time it is known to readily abstract heavy metal ions from water and, thus, aids in the removal of heavy metals found in such waters. This paper considers the possibility of using specific parts of the plant as an inexpensive adsorbent for the removal of heavy metals from contaminated chemical and mining industry waste waters. In particular the root of the plant was found to be an excellent accumulator of heavy metal ions including uranium from solution. It is also suggested that dried roots of the plant might be placed in simple bags and used in a very low cost metal ion removal system.

  6. Prospective of Microbial Exopolysaccharide for Heavy Metal Exclusion.

    PubMed

    Mohite, Bhavana V; Koli, Sunil H; Narkhede, Chandrakant P; Patil, Sucheta N; Patil, Satish V

    2017-09-09

    Metals as a resource are depleting, and on another side, it fetches serious environmental pollution causing a threat to human health and ecosystem. The heavy metal accumulation due to anthropogenic activities results in toxicological manifestation. The traditional methods of remediation are not cost effective, efficient, and ecofriendly which necessitate and motivate towards the safe, effective, and ecofriendly biological methods. The increasing presence of heavy metals in the microbial habitat compels the microbes to develop the ability to tolerate or resist the presence of heavy metals. Exopolysaccharide (EPS) production is one of the strategies of microbes to fight against metal stress. EPS is a microbial biopolymer which is generally produced under stress from harsh environment and nutrition conditions. EPSs are cell-associated or secreted outside the cell and comprised organic macromolecules such as polysaccharides, proteins, and phospholipids in addition to some non-polymeric molecules. EPSs work as competent biosorbents with an anionic reactant group that effectively sequesters cationic heavy metals by electrostatic interactions. The present paper summarizes the EPSs with its types, role, and biosynthesis and an endeavor to elucidate the interaction mechanism of EPSs with heavy metal with supportive and distinctive applications for heavy metal exclusion. The review concluded with the current challenges and future prospects to make the EPS an efficient biosorbent.

  7. Heavy metals in red crabs, Chaceon quinquedens, from the Gulf of Mexico.

    PubMed

    Perry, Harriet; Isphording, Wayne; Trigg, Christine; Riedel, Ralf

    2015-12-30

    The red crab, Chaceon quinquedens, is distributed in deep waters of the Gulf of Mexico (GOM) and is most abundant in an area associated with sediment deposition from the Mississippi River. Sediment geochemistry and biological and ecological traits of red crabs favor accumulation of contaminants. Red crabs, sediment, and bottom water samples were taken from three distinct geographic locations representing areas with differing exposure to contaminant laden effluents from the Mississippi River. Inductively coupled plasma spectrophotometry and atomic absorption spectrophotometry were employed to determine levels of heavy metals in red crab muscle tissue. Ion site partitioning was used to determine metal speciation in sediments. Red crabs showed evidence of heavy metal bioaccumulation in all sample areas with high variability in contaminant levels in individual crabs for some metals. Bioavailability of metals in sediment did not always result in accumulation in muscle tissue. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. Heavy metal music and adolescent suicidality: an empirical investigation.

    PubMed

    Scheel, K R; Westefeld, J S

    1999-01-01

    This study investigated the relationship between preference for heavy metal music and vulnerability to suicide among 121 high school students. Heavy metal fans had less strong reasons for living (especially male fans) and had more thoughts of suicide (especially female fans). For a large majority, listening to music (all types) had a positive effect on mood. Overall, the results indicate that preference for heavy metal music among adolescents may be a "red flag" for increased suicidal vulnerability, but also suggest that the source of the problem may lie more in personal and familial characteristics than in any direct effects of the music. Implications for intervention and for future research are discussed.

  9. Heavy metals influence on ascorbic acid level

    NASA Astrophysics Data System (ADS)

    Kamaldinov, E. V.; Patrashkov, S. A.; Batenyeva, E. V.; Korotkevich, O. S.

    2003-05-01

    It is well known that heavy metals (HM) are extremely dangerous pollutants influencing to metabolism in animals' organisms. The vitamin C is one of the most important metabolites taking part in many biochemical processes. We studied the influence of main essential HM-Zn and Cu as well as the based supertoxical elements - Cd and Pd on ascorbic acid level in serum. The studies were carried out in Tulinskoe farm of Novosibirsk region. The objects of investigations were piglets (2 month after weaning) and 6-month pigs of Early Ripe Meat breed. The levels of HM in bristle were found by stripping voltammetric analysis using the TA-2 analyzer. Vitamin C content was determined by I.P. Kondrakhin (1985) method using 2,2-dipyridyl. The significant negative correlations between Pb, Cd content and vitamin C (-0.46 ± 0.18, -0.47 ± 0.19) in 6-month pigs were determined. The tendencies of negative correlation between all HM levels in hair and ascorbic acid level in plasma of piglets were revealed. Thus, the obtained correlations let us to suppose that all studied HM influence on 1-gulono-gamma-lactone oxidase and other vitamin C metabolism enzymes activity.

  10. Heavy Metals Stimulate Human LINE-1 Retrotransposition

    PubMed Central

    Kale, Shubha P.; Moore, Lakisha; Deininger, Prescott L.; Roy-Engel, Astrid M.

    2005-01-01

    L1 and Alu elements are among the most active retroposons (mobile elements) in the human genome. Several human diseases, including certain forms of breast cancer and leukemia, are associated with L1 and Alu insertions in functionally important areas of the genome. We present data demonstrating that environmental pollutants, such as heavy metals, can stimulate L1 retrotransposition in a tissue culture system using two different types of assays. The response to these agents was equivalent when using a cell line with a stably integrated L1 vector (genomic) or a by introducing the L1 vector by transient transfection (episomal) of the cell. Reproducible results showed that mercury (HgS), cadmium (CdS), and nickel (NiO) increase the activity of L1 by an average of three (3) fold p<0.001. This observation is the first to link several carcinogenic agents with the increased retrotransposition activity of L1 as an alternate mechanism of generating genomic instability contributing to the process of carcinogenesis. Our results demonstrate that mobile element activation must be considered as one of the mechanisms when evaluating genomic damage/instability in response to environmental agents. PMID:16705797

  11. Adsorption behavior of heavy metals on biomaterials.

    PubMed

    Minamisawa, Mayumi; Minamisawa, Hiroaki; Yoshida, Shoichiro; Takai, Nobuharu

    2004-09-08

    We have investigated adsorption of Cd(II) and Pb(II) at pH 2-6.7 onto the biomaterials chitosan, coffee, green tea, tea, yuzu, aloe, and Japanese coarse tea, and onto the inorganic adsorbents, activated carbon and zeolite. High adsorptive capabilities were observed for all of the biomaterials at pH 4 and 6.7. In the adsorption of Cd(II), blend coffee, tea, green tea, and coarse tea have comparable loading capacities to activated carbon and zeolite. Although activated carbon, zeolite, and chitosan are utilized in a variety of fields such as wastewater treatment, chemical and metallurgical engineering, and analytical chemistry, these adsorbents are costly. On the other hand, processing of the test biomaterials was inexpensive, and all the biomaterials except for chitosan were able to adsorb large amounts of Pb(II) and Cd(II) ions after a convenient pretreatment of washing with water followed by drying. The high adsorption capability of the biomaterials prepared from plant materials is promising in the development of a novel, low-cost adsorbent. From these results, it is concluded that heavy metal removal using biomaterials would be an effective method for the economic treatment of wastewater. The proposed adsorption method was applied to the determination of amounts of Cd(II) and Pb(II) in water samples.

  12. Water-soluble species and heavy metal contamination of the petroleum refinary area, Jordan.

    PubMed

    Momani, Kamal A; Jaradat, Qasem M; Jbarah, Abed El-Aziz Q; Omari, Ayed A; Al-Momani, Idrees F

    2002-12-01

    The levels of lead, cadmium, copper, zinc, aluminum, chromium, and iron in street dust, soil, and plants in the Jordanian petroleum refinery were determined using flame and graphite-furnace atomic absorption spectrophotometry. Major cations (Li+, Na+, NH4+, K+, Mg2+, and Ca2+) and anions (F-, Cl-, NO3-, SO4(2-), and Br-) were also determined using suppression mode ion chromatography. Generally, higher levels of the heavy metals studied were found in street dust samples than in soil samples. On the other hand, except Cl-, and Li+ ions, other anions and cations showed higher concentrations in soil than in street dust samples. For plant samples, unwashed samples showed higher levels of heavy metals than their washed counterparts, indicating that dust fall is a source of heavy metal contamination.

  13. Genotoxicity assessment in aquatic environment impacted by the presence of heavy metals.

    PubMed

    Barbosa, J S; Cabral, T M; Ferreira, D N; Agnez-Lima, L F; de Medeiros, S R Batistuzzo

    2010-03-01

    The aim of this study was to access the genotoxic potential of Extremoz Lake waters in Northeastern Brazilian coast, using the Allium cepa system, piscine micronucleus test and comet assay. In addition, heavy metal levels were quantified by atomic absorption flame spectrometry. The results of the A. cepa system showed significant changes in the frequency of chromosome aberrations and in the mitotic index compared to negative control. No significant changes were observed in micronuclei frequency in the erythrocytes of Oreochromis niloticus. The comet assay showed a statistically significant alteration in the level of DNA breaks of O. niloticus. Chemical analysis detected an increase in heavy metal levels in different sampling periods. These results point out a state of deterioration of water quality at Extremoz Lake, caused by heavy metal contamination and genotoxic activity. It is recommended to establish a monitoring program for the presence of genotoxic agents in this water lake.

  14. β-Galactosidase-based colorimetric paper sensor for determination of heavy metals.

    PubMed

    Hossain, S M Zakir; Brennan, John D

    2011-11-15

    We demonstrate a novel approach for rapid, selective, and sensitive detection of heavy metals using a solid-phase bioactive lab-on-paper sensor that is inkjet printed with sol-gel entrapped reagents to allow colorimetric visualization of the enzymatic activity of β-galactosidase (B-GAL). The bioactive paper assay is able to detect a range of heavy metals, either alone or as mixtures, in as little as 10 min, with detection limits as follows: Hg(II) = 0.001 ppm; Ag(I) = 0.002 ppm, Cu(II) = 0.020 ppm; Cd(II) = 0.020 ppm; Pb(II) = 0.140 ppm; Cr(VI) = 0.150 ppm; Ni(II) = 0.230 ppm. The paper-based assay was immune to interferences from nontoxic metal ions such as Na(+) or K(+), could be used to detect heavy metals that were spiked into tap water or lake water, and provided quantitative data that was in agreement with values obtained by atomic absorption. With the incorporation of standard chromogenic metal sensing reagents into a multiplexed bioactive paper sensor, it was possible to identify specific metals in mixtures, albeit with much lower detection limits than were obtained with the enzymatic assay. The paper-based sensor should be valuable for rapid, on-site screening of trace levels of heavy metals in resource limited areas and developing countries.

  15. Heavy metals in livers and kidneys of goats in Alabama

    SciTech Connect

    Khan, A.T.; Diffay, B.C.; Datiri, B.C.

    1995-10-01

    The popularity of goat farming is increasing in the southeastern region of the United States. Baseline values of Hg, Pb, and Cd are not available in goat tissues in the United States. These values are needed when monitoring food for heavy metal contamination which may be associated with urbanization and industrialization. Due to human activities or anthropogenic sources of metals in the environment, high concentrations of these metals have been observed in herbage and animal tissues. It has also been reported that toxic heavy metals are concentrated mostly in kidneys and livers of animals. The risk of exposure of humans to heavy metals contained in edible organs of animals has received widespread concern. The objectives of this study were to (i) measure the levels of Hg,Pb, and Cd in livers and kidneys of goats; and (ii) determine whether accumulation of these metals is related to age and/or sex. 20 refs., 3 tabs.

  16. Selection of ectomycorrhizal willow genotype in phytoextraction of heavy metals.

    PubMed

    Hrynkiewicz, Katarzyna; Baum, Christel

    2013-01-01

    Willow clones are used for the phytoextraction of heavy metals from contaminated soils and are usually mycorrhizal. The receptiveness of willow clones for mycorrhizal inoculum varies specific to genotype; however, it is unknown if this might have a significant impact on their efficiency in phytoextraction of heavy metals. Therefore, a model system with mycorrhizal and non-mycorrhizal willows of two different genotypes--one with usually stronger natural mycorrhizal colonization (Salix dasyclados), and one with lower natural mycorrhizal colonization (S. viminalis)--was investigated for its efficiency of phytoextraction of heavy metals (Cd, Pb, Cu, Zn) from contaminated soil. Inoculation with the ectomycorrhizal fungus Amanita muscaria significantly decreased the biomass of leaves of both inoculated willow clones, and increased or had no effect on the biomass of trunks and roots of S. dasyclados and S. viminalis, respectively. The concentrations of heavy metals in the biomass of S. dasyclados were in general higher than in S. viminalis irrespective of inoculation with the ectomycorrhizal fungus. Inoculation with A. muscaria significantly decreased the concentration of Cu in the trunks of both Salix taxa, but did not affected the concentrations of other heavy metals in the biomass. In conclusion, stronger receptiveness of willow clones for mycorrhizal inoculum was correlated with an increased total extraction of heavy metals from contaminated soils. Therefore, this seems to be a suitable criterion for effective willow clone selection for phytoremediation. Increased biomass production with relatively constant metal concentrations seems to be a major advantage of mycorrhizal formation of willows in phytoremediation of contaminated soils.

  17. Estimation of heavy metal transformations in municipal solid waste.

    PubMed

    Flyhammar, P

    1997-05-30

    The behaviour of heavy metals bound to municipal solid waste (MSW) and exposed to 2 decades of anaerobic waste stabilization processes have been estimated. Heavy metal solid forms in a waste degradation residue have been compared with a reconstructed waste similar to that initially disposed of in 1973. The initial waste was composed of a mixture of shredded MSW (95% dry wt.) and anaerobic sewage sludge (5% dry wt.). A sequential chemical extraction method has been used to fractionate the heavy metals into five categories of available and reactive solid forms. The results imply that these forms can be ascribed to approximately 30% of the total content of the heavy metals in the degraded waste and the portion of heavy metals bound to oxidizable solid forms seems to be higher in the degraded than the fresh MSW. The bulk of the remaining heavy metals are assumed to be less available and bound into resistant lattice structures, such as metal and polymer items. A comparison between fractionation patterns of the waste in this study and of a few sediments collected from different environments imply similarities between the fresh MSW and an oxic sediment from one site and the sewage sludge and anoxic sediments from another site. Fractionation patterns of the degraded waste are found to be quite similar to those of the anoxic sediments, except for Pb, Ni and Cd which are more similar to fresh MSW.

  18. Contamination of Polish national parks with heavy metals.

    PubMed

    Staszewski, Tomasz; Łukasik, Włodzimierz; Kubiesa, Piotr

    2012-07-01

    The paper presents results of screening analysis of all Polish national parks (23) contamination with Cd, Cu, Pb and Zn on the basis of a three-level characteristic of heavy metal presence in Norway spruce stands: accumulation on the needle surface, concentration of heavy metals in spruce needles and concentration of bioavailable heavy metals in the soil. Based on the obtained results, the classification of forest ecosystem hazard in national parks with heavy metals was made using synthetic indicators. It was found out that Babiogórski, Magurski, Ojcowski and Gorczański National Parks, located in the southern part of the country, were the most polluted with heavy metals. It is probably due to a higher industrial activity in this part of Poland and the transboundary transport of air pollutants. A little lower level of pollution was observed in Kampinoski National Park located in the middle of the country. The concentration of heavy metals found in needles from national parks does not seem to be harmful for the health status of the trees. Statistically significant correlation between all parameters, which was found for cadmium--the most mobile of the analysed elements--shows that this metal can be proposed as a marker to reflect present effect of industrial emission on forests.

  19. Heavy Metals and Epigenetic Alterations in Brain Tumors

    PubMed Central

    Caffo, Maria; Caruso, Gerardo; Fata, Giuseppe La; Barresi, Valeria; Visalli, Maria; Venza, Mario; Venza, Isabella

    2014-01-01

    Heavy metals and their derivatives can cause various diseases. Numerous studies have evaluated the possible link between exposure to heavy metals and various cancers. Recent data show a correlation between heavy metals and aberration of genetic and epigenetic patterns. From a literature search we noticed few experimental and epidemiological studies that evaluate a possible correlation between heavy metals and brain tumors. Gliomas arise due to genetic and epigenetic alterations of glial cells. Changes in gene expression result in the alteration of the cellular division process. Epigenetic alterations in brain tumors include the hypermethylation of CpG group, hypomethylation of specific genes, aberrant activation of genes, and changes in the position of various histones. Heavy metals are capable of generating reactive oxygen assumes that key functions in various pathological mechanisms. Alteration of homeostasis of metals could cause the overproduction of reactive oxygen species and induce DNA damage, lipid peroxidation, and alteration of proteins. In this study we summarize the possible correlation between heavy metals, epigenetic alterations and brain tumors. We report, moreover, the review of relevant literature. PMID:25646073

  20. Heavy metals content of municipal wastewater and sludges in Kuwait.

    PubMed

    Al Enezi, G; Hamoda, M F; Fawzi, N

    2004-01-01

    Municipal wastewater may contain heavy metals, which are hazardous to the environment and humans. With stringent regulations concerning water reuse and sludge utilization in agriculture, there is a great need to determine levels of heavy metals in liquid wastes, sludges and agricultural crops. The state of Kuwait has programs to utilize waste sludge produced at wastewater treatment plants as soil conditioner and fertilizer for greenery and agricultural development projects and to reuse treated wastewater effluents in irrigation. The common metals found in Kuwait's raw wastewater and sludge are Cd, Cr, Cu, Hg, Ni, Pb, and Zn. The effects of accumulation of heavy metals in soil are long lasting and even permanent. In this study, the variations in the concentration levels of heavy metals were measured in wastewater and sludge produced at Ardiya municipal wastewater treatment plant in Kuwait. A relationship was observed between the concentrations of heavy metals in treated wastewater and sludge used for agriculture and the level of accumulated heavy metals found in residual tissues of some crops.

  1. Several methods to determine heavy metals in the human brain

    NASA Astrophysics Data System (ADS)

    Andrási, Erzsébet; Igaz, Sarolta; Szoboszlai, Norbert; Farkas, Éva; Ajtony, Zsolt

    1999-05-01

    The determination of naturally occurring heavy metals in various parts of the human brain is discussed. The patients had no diseases in their central nervous systems (five individuals, mean age 70 years). Twenty brain parts were selected from both hemispheres. The analysis was carried out by graphite furnace atomic absorption spectrometry, inductively coupled plasma atomic emission spectrometry and instrumental neutron activation analysis methods. Accuracy and precision of the applied techniques were tested by using standard reference materials. Two digestion methods were used to dissolve the brain samples for ICP-AES and GF-AAS. One was performed in a Parr-bomb and the second in a microwave oven. The present results show a non-homogeneous distribution of the essential elements (Cu, Fe, Mn, Zn) in normal human brain. Corresponding regions in both hemispheres showed an almost identical concentration of these elements. In the case of toxic elements (Pb, Cd) an average value in different brain regions can not be established because of the high variability of individual data. This study indicates that beside differences in Pb and Cd intake with foods or cigarette smoke inhalation, the main factors of the high inter-individual variability of these element concentrations in human brain parts may be a marked difference in individual elimination or accumulation capabilities.

  2. Assessment of arsenic and heavy metal contents in cockles (Anadara granosa) using multivariate statistical techniques.

    PubMed

    Abbas Alkarkhi, F M; Ismail, Norli; Easa, Azhar Mat

    2008-02-11

    Cockles (Anadara granosa) sample obtained from two rivers in the Penang State of Malaysia were analyzed for the content of arsenic (As) and heavy metals (Cr, Cd, Zn, Cu, Pb, and Hg) using a graphite flame atomic absorption spectrometer (GF-AAS) for Cr, Cd, Zn, Cu, Pb, As and cold vapor atomic absorption spectrometer (CV-AAS) for Hg. The two locations of interest with 20 sampling points of each location were Kuala Juru (Juru River) and Bukit Tambun (Jejawi River). Multivariate statistical techniques such as multivariate analysis of variance (MANOVA) and discriminant analysis (DA) were applied for analyzing the data. MANOVA showed a strong significant difference between the two rivers in term of As and heavy metals contents in cockles. DA gave the best result to identify the relative contribution for all parameters in discriminating (distinguishing) the two rivers. It provided an important data reduction as it used only two parameters (Zn and Cd) affording more than 72% correct assignations. Results indicated that the two rivers were different in terms of As and heavy metal contents in cockle, and the major difference was due to the contribution of Zn and Cd. A positive correlation was found between discriminate functions (DF) and Zn, Cd and Cr, whereas negative correlation was exhibited with other heavy metals. Therefore, DA allowed a reduction in the dimensionality of the data set, delineating a few indicator parameters responsible for large variations in heavy metals and arsenic content. Taking into account of these results, it can be suggested that a continuous monitoring of As and heavy metals in cockles be performed in these two rivers.

  3. Determination of toxic metals in some herbal drugs through atomic absorption spectroscopy.

    PubMed

    Hina, Bushra; Rizwani, Ghazala Hafeez; Naseem, Shahid

    2011-07-01

    This study presents a picture of occurrence of heavy metals (Pb, Cd, Cu, Cr, Co, Fe, Ni, Zn) in some selected valuable herbal drugs (G. glabra, O. bracteatum, V. odorata , F. vulgare, C. cyminum, C. sativum, and Z. officinalis) purchased from three different zones (southern, eastern, and western) of Karachi city using atomic absorption spectrophotometer. Heavy metal concentrations in these drugs were found in the range of: 3.26-30.46 for Pb, 1.6-4.91 for Cd, 0.65-120.21 for Cu, 83.74-433.76 for Zn, 1.61-186.75 for Cr, 0.48-76.97 for Ni, 5.54-77.97 for Co and 65.68-1652.89 µg/g for Fe. Percentage of heavy metals that were found beyond the permissible limits were: 71.4% for Pb, 28.51% for Cd, 14.2% for Cu, and 9.5 % for Cr. Significant difference was noticed for each heavy metal among herbal drugs as well as their zones of collection using two way ANOVA followed by least significant (LSD) test at p<0.05.Purpose of this research is to detect each type of heavy metal contaminant of herbal drugs by environmental pollution, as well as to highlight the health risks associated with the use of such herbal drugs that contain high levels of toxic heavy metals.

  4. Atomic Layer Deposition of Metal Sulfide Materials

    SciTech Connect

    Dasgupta, Neil P.; Meng, Xiangbo; Elam, Jeffrey W.; Martinson, Alex B. F.

    2015-02-17

    The field of nanoscience is delivering increasingly intricate yet elegant geometric structures incorporating an ever-expanding palette of materials. Atomic layer deposition (ALD) is a powerful driver of this field, providing exceptionally conformal coatings spanning the periodic table and atomic-scale precision independent of substrate geometry. This versatility is intrinsic to ALD and results from sequential and self-limiting surface reactions. This characteristic facilitates digital synthesis, in which the film grows linearly with the number of reaction cycles. While the majority of ALD processes identified to date produce metal oxides, novel applications in areas such as energy storage, catalysis, and nanophotonics are motivating interest in sulfide materials. Recent progress in ALD of sulfides has expanded the diversity of accessible materials as well as a more complete understanding of the unique chalcogenide surface chemistry.

  5. Heavy metals testing in active pharmaceutical ingredients: an alternate approach.

    PubMed

    Raghuram, P; Soma Raju, I V; Sriramulu, J

    2010-01-01

    The principle of the pharmacopoeial heavy metals test is detection and estimation of the metallic impurities colored by sulfide ion by comparison against lead standard. The test suffers from a loss of analytes upon ashing and from having varied responses for various metals. An inductively coupled plasma-optical emission spectroscopy (ICP-OES) for estimating 23 metals in active pharmaceutical ingredients is being proposed. The method covers the metals listed in USP, Ph. Eur and EMEA guidance on "Residues of Metal Catalysts or Metal Reagents".

  6. NMR microscopy of heavy metal absorption in calcium alginate beads

    SciTech Connect

    Nestle, N.; Kimmich, R.

    1996-01-01

    In recent years, heavy metal uptake by biopolymer gels, such as Cal-Alginate or chitosan, has been studied by various methods. This is of interest because such materials might be an alternative to synthetical ion-exchange resins in the treatment of industrial waste waters. Most of the work done in this field consisted of studies of equilibrium absorption of different heavy metal ions with dependence on various experimental parameters. In some publications, the kinetics of absorption were studied, too. However, no experiments on the spatial distribution of heavy metals during the absorption process are known to us. Using Cu as an example, it is demonstrated in this article that NMR microscopy is an appropriate tool for such studies. By the method presented here, it is possible to monitor the spatial distribution of heavy metal ions with a time resolution of about 5 min and a spatial resolution of 100 {mu}m or even better. 14 refs., 10 figs.

  7. DETERMINATION OF HEAVY METALS AND PESTICIDES IN GINSENG PRODUCTS

    EPA Science Inventory

    Medicinal plants may carry residuals of environmentally persistent pesticides or assimilate heavy metals in varying degrees. Several factors may influence contaminant accumulation, including species, level and duration of contaminant exposure, and topography. As part of a progra...

  8. Heavy metal exposure in patients suffering from electromagnetic hypersensitivity.

    PubMed

    Ghezel-Ahmadi, David; Engel, Alice; Weidemann, Jörg; Budnik, Lygia Therese; Baur, Xaver; Frick, Ulrich; Hauser, Simone; Dahmen, Norbert

    2010-01-15

    Risks from electromagnetic devices are of considerable concern. Electrohypersensitive (EHS) persons attribute a variety of rather unspecific symptoms to the exposure to electromagnetic fields. The pathophysiology of EHS is unknown and therapy remains a challenge. Heavy metal load has been discussed as a potential factor in the symptomatology of EHS patients. The main objective of the study was to test the hypothesis of a link between EHS and heavy metal exposure. We measured lead, mercury and cadmium concentrations in the blood of 132 patients (n=42 males and n=90 females) and 101 controls (n=34 males and n=67 females). Our results show that heavy metal load is of no concern in most cases of EHS but might play a role in exceptional cases. The data do not support the general advice to heavy metal detoxification in EHS. Copyright 2009 Elsevier B.V. All rights reserved.

  9. View of interior detail; in kitchen; builtiniron and heavy metal ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View of interior detail; in kitchen; built-in-iron and heavy metal clock. - Mare Island Naval Shipyard, Quarters P, Walnut Avenue, northwest corner of Walnut Avenue & Fifth Street, Vallejo, Solano County, CA

  10. DETERMINATION OF HEAVY METALS AND PESTICIDES IN GINSENG PRODUCTS

    EPA Science Inventory

    Medicinal plants may carry residuals of environmentally persistent pesticides or assimilate heavy metals in varying degrees. Several factors may influence contaminant accumulation, including species, level and duration of contaminant exposure, and topography. As part of a progra...

  11. Accumulation of heavy metals in oil-contaminated peat soils

    NASA Astrophysics Data System (ADS)

    Vodyanitskii, Yu. N.; Savichev, A. T.; Trofimov, S. Ya.; Shishkonakova, E. A.

    2012-10-01

    X-ray fluorescence and X-ray radiometry represent easy and simple methods to determine concentrations of heavy metals in the ash of peat soils contaminated with oil and can be applied for soil monitoring purposes. Oil spills on peat bogs produce two contamination zones differing in the composition of heavy metals. In the zone of primary contamination, the peat surface is covered by a bitumen crust with V, Ni, Sr, Ba, Ce, and La accumulating there. This zone adjoins the zone of secondary peat contamination, where heavy alkaline-earth metals (Sr, Ba) and lanthanides (Ce and La) are accumulated to a lesser extent. Biological preparations recommended for remediation of oil-contaminated peat soils should be tolerant to high concentrations of heavy metals, particularly, V, Ni, and Ba that are present in the oil contaminated soils in relatively high amounts.

  12. Detection of heavy metal by paper-based microfluidics.

    PubMed

    Lin, Yang; Gritsenko, Dmitry; Feng, Shaolong; Teh, Yi Chen; Lu, Xiaonan; Xu, Jie

    2016-09-15

    Heavy metal pollution has shown great threat to the environment and public health worldwide. Current methods for the detection of heavy metals require expensive instrumentation and laborious operation, which can only be accomplished in centralized laboratories. Various microfluidic paper-based analytical devices have been developed recently as simple, cheap and disposable alternatives to conventional ones for on-site detection of heavy metals. In this review, we first summarize current development of paper-based analytical devices and discuss the selection of paper substrates, methods of device fabrication, and relevant theories in these devices. We then compare and categorize recent reports on detection of heavy metals using paper-based microfluidic devices on the basis of various detection mechanisms, such as colorimetric, fluorescent, and electrochemical methods. To finalize, the future development and trend in this field are discussed.

  13. Combined toxicity of heavy metal mixtures in liver cells.

    PubMed

    Lin, Xialu; Gu, Yuanliang; Zhou, Qi; Mao, Guochuan; Zou, Baobo; Zhao, Jinshun

    2016-09-01

    With rapid industrialization, China is now facing great challenges in heavy metal contamination in the environment. Human exposure to heavy metals through air, water and food commonly involves a mixture consisting of multiple heavy metals. In this study, eight common heavy metals (Pb, Cd, Hg, Cu, Zn, Mn, Cr, Ni) that cause environmental contamination were selected to investigate the combined toxicity of different heavy metal mixtures in HL7702 cells. Toxicity (24 h LC50 ) of each individual metal on the cells ranked Hg > Cr = Cd > Cu > Zn > Ni > Mn > Pb; toxicity of the different mixtures ranked: M5 > M3PbHgCd > M5+Mn > M5+Cu > M2CdNi > M4A > M8-Mn > M8 > M5+Zn > M4B > M8-Cr > M8-Zn > M8-Cu > M8-Pb > M8-Cd > M8-Hg > M8-Ni > M3PbHgNi > M3CuZnMn. The cytotoxicity data of individual metals were successfully used to build the additive models of two- to eight-component metal mixtures. The comparison between additive model and combination model or partly additive model was useful to evaluate the combined effects in mixture. Synergistic, antagonistic or additive effects of the toxicity were observed in different mixtures. These results suggest that the combined effects should be considered in the risk assessment of heavy metal co-exposure, and more comprehensive investigations on the combined effects of different heavy metal mixtures are needed in the future. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  14. Molecular mechanisms of heavy metal hyperaccumulation and phytoremediation.

    PubMed

    Yang, Xiaoe; Feng, Ying; He, Zhenli; Stoffella, Peter J

    2005-01-01

    A relatively small group of hyperaccumulator plants is capable of sequestering heavy metals in their shoot tissues at high concentrations. In recent years, major scientific progress has been made in understanding the physiological mechanisms of metal uptake and transport in these plants. However, relatively little is known about the molecular bases of hyperaccumulation. In this paper, current progresses on understanding cellular/molecular mechanisms of metal tolerance/hyperaccumulation by plants are reviewed. The major processes involved in hyperaccumulation of trace metals from the soil to the shoots by hyperaccumulators include: (a) bioactivation of metals in the rhizosphere through root-microbe interaction; (b) enhanced uptake by metal transporters in the plasma membranes; (c) detoxification of metals by distributing to the apoplasts like binding to cell walls and chelation of metals in the cytoplasm with various ligands, such as phytochelatins, metallothioneins, metal-binding proteins; (d) sequestration of metals into the vacuole by tonoplast-located transporters. The growing application of molecular-genetic technologies led to the well understanding of mechanisms of heavy metal tolerance/accumulation in plants, and subsequently many transgenic plants with increased resistance and uptake of heavy metals were developed for the purpose of phytoremediation. Once the rate-limiting steps for uptake, translocation, and detoxification of metals in hyperaccumulating plants are identified, more informed construction of transgenic plants would result in improved applicability of the phytoremediation technology.

  15. Bioaccumulation of heavy metals in crop plants grown near Almeda Textile Factory, Adwa, Ethiopia.

    PubMed

    Gitet, Hintsa; Hilawie, Masho; Muuz, Mehari; Weldegebriel, Yirgaalem; Gebremichael, Dawit; Gebremedhin, Desta

    2016-09-01

    The contents of heavy metals cadmium (Cd), cobalt (Co), chromium (Cr), copper (Cu), manganese (Mn), nickel (Ni), lead (Pb), and zinc (Zn) present in water (wastewater and wetland), soils, and food crops collected from the vicinity of Almeda Textile Factory were quantified using Flame Atomic Absorption Spectrometer (FAAS) in order to assess the environmental impact of the textile factory. The contents of heavy metals determined in the wastewater were found below the recommended limit set by WHO and United States Environmental Protection Agency (US EPA) except for Cr, which was found slightly higher than WHO permissible limit. Besides, the contents of the heavy metals determined in soils were below the permissible level of FAO/WHO and Canada maximum allowable limits. Moreover, only the concentrations of Cd and Pb were found above the permissible level set by FAO/WHO in the crop plants studied. Generally, the mean concentrations of heavy metals in the plants were in the decreasing order of: Mn > Zn > Cu > Pb > Ni > Co > Cr > Cd. Nevertheless, higher bioconcentration factor (BCF) was found for Cd (0.108-1.156) followed by Zn (0.081-0.499). In conclusion, comparison of heavy metal concentrations with the permissible limits in all collected sample types i.e. water, soil, and crop plants did not show significant pollution from the factory.

  16. Heavy metal concentration in fish tissues inhabiting waters of "Busko Blato" reservoir (Bosnia and Herzegovina).

    PubMed

    Has-Schön, Elizabeta; Bogut, Ivan; Kralik, Gordana; Bogut, Stjepan; Horvatić, Janja; Cacić, Milan; Cacić, Ivan

    2008-09-01

    Heavy metals concentration (mercury, lead, cadmium, arsenic, copper, zinc and chromium) in tissues (muscles, liver, kidney and gonads) of Dalmatian barbelgudgeon, the nase, the souffie and brown trout, inhabiting waters of Busko Blato reservoir in Bosnia and Herzegovina, has been determined by atomic absorption spectrophotometry. The meat of the tested fish sorts does not contain elevated concentration of most analyzed heavy metals with exception of lead (higher than MAC in Italy, Germany and Denmark) and mercury (in muscles of brown trout higher than MAC in most countries). The lowest level of all heavy metals is always detected in gonads, with higher values in fry compared to milt for copper, zinc, chromium and arsenic. The highest copper concentration is observed in the liver from the souffie which is suggested as a suitable biomonitor for copper intoxication. In muscles of all fish sorts, lead was always present in much higher concentration than cadmium, while in kidneys of most fish sorts, lead and cadmium concentrations were similar. We showed that bioaccumulation of some heavy metals in the fish sorts analyzed is tissue and sex dependent. Also, we concluded that the small water exchange in reversible shallow reservoir does not induce elevated concentration of heavy metals in fish tissues inhabiting Busko Blato.

  17. Atomically Precise Metal Nanoclusters for Catalytic Application

    SciTech Connect

    Jin, Rongchao

    2016-11-18

    The central goal of this project is to explore the catalytic application of atomically precise gold nanoclusters. By solving the total structures of ligand-protected nanoclusters, we aim to correlate the catalytic properties of metal nanoclusters with their atomic/electronic structures. Such correlation unravel some fundamental aspects of nanocatalysis, such as the nature of particle size effect, origin of catalytic selectivity, particle-support interactions, the identification of catalytically active centers, etc. The well-defined nanocluster catalysts mediate the knowledge gap between single crystal model catalysts and real-world conventional nanocatalysts. These nanoclusters also hold great promise in catalyzing certain types of reactions with extraordinarily high selectivity. These aims are in line with the overall goals of the catalytic science and technology of DOE and advance the BES mission “to support fundamental research to understand, predict, and ultimately control matter and energy at the level of electrons, atoms, and molecules”. Our group has successfully prepared different sized, robust gold nanoclusters protected by thiolates, such as Au25(SR)18, Au28(SR)20, Au38(SR)24, Au99(SR)42, Au144(SR)60, etc. Some of these nanoclusters have been crystallographically characterized through X-ray crystallography. These ultrasmall nanoclusters (< 2 nm diameter) exhibit discrete electronic structures due to quantum size effect, as opposed to quasicontinuous band structure of conventional metal nanoparticles or bulk metals. The available atomic structures (metal core plus surface ligands) of nanoclusters serve as the basis for structure-property correlations. We have investigated the unique catalytic properties of nanoclusters (i.e. not observed in conventional nanogold catalysts) and revealed the structure-selectivity relationships. Highlights of our

  18. Assessment of carcinogenic heavy metal levels in Brazilian cigarettes.

    PubMed

    Viana, Gustavo Freitas de Sousa; Garcia, Karina S; Menezes-Filho, Jose Antonio

    2011-10-01

    Several studies have associated high cancer incidence with smoking habits. According to IARC, lead (Pb), cadmium (Cd), arsenic (As), nickel (Ni), and chromium (Cr) are carcinogenic to humans. These metals are present in cigarettes and their levels vary according to geographical region of tobacco cultivation, fertilizer treatment, plant variety etc. This study aims to assess these metal levels in cigarettes commercialized in Brazil. Three cigarettes of each 20 different brands were individually weighed, the tobacco filling removed, and homogenized. After desiccation, samples were subjected to microwave-assisted digestion. Analyses were performed by graphite furnace atomic absorption spectrometry. Mean levels for Pb, Cd, As, Ni, and Cr were, respectively, 0.27 ± 0.054, 0.65 ± 0.091, 0.09 ± 0.024, 1.26 ± 0.449, and 1.43 ± 0.630, in micrograms per gram of tobacco. No correlation was observed between Cd and any other metal analyzed. A mild correlation (r = 0.483, p < 0.05) was observed between Pb and Cr levels. Strong significant (p < 0.01) correlations were observed between Ni and Cr (r = 0.829), Ni and As (r = 0.799), Ni and Pb (r = 0.637), and between Cr and As (r = 0.621). Chromium and Ni levels were significantly higher in cigarettes from a multinational manufacturer. Our results show a high variability in heavy metal levels in cigarettes, representing an important exposure source of smokers and passive smokers to carcinogenic substances.

  19. Variation in dry grassland communities along a heavy metals gradient.

    PubMed

    Woch, Marcin W; Kapusta, Paweł; Stefanowicz, Anna M

    2016-01-01

    The aim of this study was to investigate the variation in plant communities growing on metal-enriched sites created by historical Zn–Pb mining. The study sites were 65 small heaps of waste rock covered by grassland vegetation and scattered mostly over agricultural land of southern Poland. The sites were described in terms of plant coverage, species richness and composition, and the composition of plant traits. They were classified using phytosociological methods and detrended correspondence analysis. Identified plant communities were compared for vegetation parameters and habitat properties (soil characteristics, distance from the forest) by analysis of variance. The variation in plant community parameters was explained by multiple regression, in which the predictors were properties of the habitat selected on the basis of factor analysis. Grasslands that developed at low and high concentrations of heavy metals in soil were similar to some extent: they were composed on average of 17–20 species (per 4 m(2)), and their total coverage exceeded 90%. The species composition changed substantially with increasing contamination with heavy metals; metal-sensitive species withdrew, while the metal-tolerant became more abundant. Other important predictors of community structure were: proximity to the forest (responsible for the encroachment of competitive forest species and ruderals), and the thickness of the surface soil (shallow soil favored the formation of the heavy metal grassland). The heavy metal grassland was closely related to the dry calcareous grasslands. The former was an earlier succession stage of the latter at low contamination with heavy metals.

  20. Industrial age anthropogenic inputs of heavy metals into the pedosphere.

    PubMed

    Han, Fengxiang X; Banin, Amos; Su, Yi; Monts, David L; Plodinec, M John; Kingery, William L; Triplett, Glover E

    2002-11-01

    Heavy metals have been increasingly released into our environment. We present here, for the first time, the global industrial age production of Cd, Cu, Cr, Hg, Ni, Pb, and Zn, and their potential accumulation and environmental effects in the pedosphere. World soils have been seriously polluted by Pb and Cd and slightly by Zn. The potential industrial age anthropogenic Pb, Hg, and Cd inputs in the pedosphere are 9.6, 6.1, and 5.2 times those in the lithosphere, respectively. The potential anthropogenic heavy metal inputs in the pedosphere increased tremendously after the 1950s, especially for Cr and Ni. In 2000, the cumulative industrial age anthropogenic global production of Cd, Cr, Cu, Hg, Ni, Pb, and Zn was 1.1, 105, 451, 0.64, 36, 235, and 354 million tonnes, respectively. The global industrial age metal burdens per capita (in 2000) were 0.18, 17.3, 74.2, 0.10, 5.9, 38.6, and 58.2 kg for Cd, Cr, Cu, Hg, Ni, Pb, and Zn, respectively. Acidification may increase the bioavailability and toxicity of heavy metals in the pedosphere. The improvement of industrial processing technology reducing the metal dispersion rate, the recycling of metal-containing outdated products, by-products and wastes, and the development of new substitute materials for heavy metals are possible strategies to minimize the effects of heavy metals on our environment.

  1. Heavy metal music and drug abuse in adolescents.

    PubMed

    King, P

    1988-04-01

    A large number of adolescents in a psychiatric population, particularly those who are chemically dependent, prefer to listen to heavy metal music. Young people who do not identify with traditional values may find simple but unconventional answers to complex problems in the lyrics of this type of music. While a clearcut relationship cannot be established between heavy metal music and destructive behavior, evidence shows that such music promotes and supports patterns of drug abuse, promiscuous sexual activity, and violence.

  2. Human health risk assessment of heavy metals in urban stormwater.

    PubMed

    Ma, Yukun; Egodawatta, Prasanna; McGree, James; Liu, An; Goonetilleke, Ashantha

    2016-07-01

    Toxic chemical pollutants such as heavy metals (HMs) are commonly present in urban stormwater. These pollutants can pose a significant risk to human health and hence a significant barrier for urban stormwater reuse. The primary aim of this study was to develop an approach for quantitatively assessing the risk to human health due to the presence of HMs in stormwater. This approach will lead to informed decision making in relation to risk management of urban stormwater reuse, enabling efficient implementation of appropriate treatment strategies. In this study, risks to human health from heavy metals were assessed as hazard index (HI) and quantified as a function of traffic and land use related parameters. Traffic and land use are the primary factors influencing heavy metal loads in the urban environment. The risks posed by heavy metals associated with total solids and fine solids (<150μm) were considered to represent the maximum and minimum risk levels, respectively. The study outcomes confirmed that Cr, Mn and Pb pose the highest risks, although these elements are generally present in low concentrations. The study also found that even though the presence of a single heavy metal does not pose a significant risk, the presence of multiple heavy metals could be detrimental to human health. These findings suggest that stormwater guidelines should consider the combined risk from multiple heavy metals rather than the threshold concentration of an individual species. Furthermore, it was found that risk to human health from heavy metals in stormwater is significantly influenced by traffic volume and the risk associated with stormwater from industrial areas is generally higher than that from commercial and residential areas.

  3. An optical dosimeter for monitoring heavy metal ions in water

    NASA Astrophysics Data System (ADS)

    Mignani, Anna G.; Regan, Fiona; Leamy, D.; Mencaglia, A. A.; Ciaccheri, L.

    2005-05-01

    This work presents an optochemical dosimeter for determining and discriminating nickel, copper, and cobalt ions in water that can be used as an early warning system for water pollution. An inexpensive fiber optic spectrophotometer monitors the sensor's spectral behavior under exposure to water solutions of heavy metal ions in the 1-10 mg/l concentration range. The Principal Component Analysis (PCA) method quantitatively determines the heavy metals and discriminates their type and combination.

  4. Distribution of heavy metals from flue gas in algal bioreactor

    NASA Astrophysics Data System (ADS)

    Napan, Katerine

    Flue gas from coal-fired power plants is a major source of CO2 to the atmosphere. Microalgae can use this enriched form of CO2 as carbon source and in turn the biomass can be used to produce food, feed, fertilizer and biofuels. However, along with CO2, coal-based flue gas will inevitably introduce heavy metals, which have a high affinity to bind algal cells, could be toxic to the organisms and if transferred to the products could limit their uses. This study seeks to address the distribution and impact of heavy metals present in flue gas on microalgae production systems. To comprehend its effects, algae Scenedesmus obliquus was grown in batch reactors in a multimetal system. Ten heavy metals (Cu, Co, Zn, Pb, As, Se, Cr, Hg, Ni and Cd) were selected and were evaluated at four concentrations (1X, 2X, 5X and 10X). Results show that most heavy metals accumulated mainly in biomass and were found in very low concentrations in media. Hg was shown to be lost from the culture, with low amounts present in the biomass. An upper limit for As uptake was observed, suggesting its likelihood to build-up in the system during medium recycle. The As limited bioaccumulation was overcome by addition of sulfur to the algal medium. Heavy metal at 2X, 5X and 10X inhibited both growth and lipid production, while at the reference concentration both biomass and lipids yields were increased. Heavy metal concentrations in the medium and biomass were time dependent, and at the end of the cultivation most heavy metals in the supernatant solution complied with the recommendations for irrigation water, while biomass was below limits for cattle and poultry feed, fertilizer, plastic and paper. This research shows that bioremediation of CO2 and heavy metals in combination with energy production can be integrated, which is an environmentally friendly form of biotechnology.

  5. Staining of Tissue Sections for Electron Microscopy with Heavy Metals

    PubMed Central

    Watson, Michael L.

    1958-01-01

    Heavy metals may be incorporated from solution into tissue sections for electron microscopy. The resulting increase in density of the tissue provides greatly enhanced contrast with minimal distortion. Relative densities of various structures are found to depend on the heavy metal ions present and on the conditions of staining. Certain hitherto unobserved details are revealed and some sort of specificity exists, although the factors involved are not yet understood. PMID:13563554

  6. Regional distribution pattern of groundwater heavy metals resulting from agricultural activities

    NASA Astrophysics Data System (ADS)

    Nouri, J.; Mahvi, A. H.; Jahed, G. R.; Babaei, A. A.

    2008-09-01

    Contaminations of groundwater by heavy metals due to agricultural activities are growing recently. The objective of this study was to evaluate and map regional patterns of heavy metals (Cd, Zn and Cu) in groundwater on a plain with high agricultural activities. The study was conducted to investigate the concentration of heavy metals and distribution in groundwater in regions of Shush Danial and Andimeshk aquifers in the southern part of Iran. Presently, groundwater is the only appropriate and widely used source of drinking water for rural and urban communities in this region. The region covers an area of 1,100 km2 between the Dez and Karkhe rivers, which lead to the Persian Gulf. For this study, the region was divided into four sub-regions A, B, C and D. Additionally, 168 groundwater samples were collected from 42 water wells during the earlier months of 2004. The flame atomic absorption spectrometry (AAS-Flame) was used to measure the concentration of heavy metals in water samples and the Surfer software was used for determination of the contour map of metal distribution. The results demonstrated that in all of the samples, Cd and Zn concentrations were below the EPA MCLG and EPA secondary standard, respectively. However, the Cu contents of 4.8 % of all samples were higher than EPA MCL. It is also indicated that the concentrations of metals were more pronounced at the southern part of the studied region than at the others. The analysis of fertilizers applied for agricultural activities at this region also indicated that a great majority of the above-mentioned heavy metals were discharged into the environment. Absence of confining layers, proximity to land surface, excess agricultural activities in the southern part and groundwater flow direction that is generally from the north to the southern parts in this area make the southern region of the Shush plain especially vulnerable to pollution by heavy metals than by other contaminants.

  7. Carbon nanotube-clamped metal atomic chain

    PubMed Central

    Tang, Dai-Ming; Yin, Li-Chang; Li, Feng; Liu, Chang; Yu, Wan-Jing; Hou, Peng-Xiang; Wu, Bo; Lee, Young-Hee; Ma, Xiu-Liang; Cheng, Hui-Ming

    2010-01-01

    Metal atomic chain (MAC) is an ultimate one-dimensional structure with unique physical properties, such as quantized conductance, colossal magnetic anisotropy, and quantized magnetoresistance. Therefore, MACs show great potential as possible components of nanoscale electronic and spintronic devices. However, MACs are usually suspended between two macroscale metallic electrodes; hence obvious technical barriers exist in the interconnection and integration of MACs. Here we report a carbon nanotube (CNT)-clamped MAC, where CNTs play the roles of both nanoconnector and electrodes. This nanostructure is prepared by in situ machining a metal-filled CNT, including peeling off carbon shells by spatially and elementally selective electron beam irradiation and further elongating the exposed metal nanorod. The microstructure and formation process of this CNT-clamped MAC are explored by both transmission electron microscopy observations and theoretical simulations. First-principles calculations indicate that strong covalent bonds are formed between the CNT and MAC. The electrical transport property of the CNT-clamped MAC was experimentally measured, and quantized conductance was observed. PMID:20427743

  8. Aquifer vulnerability assessment to heavy metals using ordinal logistic regression.

    PubMed

    Twarakavi, Navin K C; Kaluarachchi, Jagath J

    2005-01-01

    A methodology using ordinal logistic regression is proposed to predict the probability of occurrence of heavy metals in ground water. The predicted probabilities are defined with reference to the background concentration and the maximum contaminant level. The model is able to predict the occurrence due to different influencing variables such as the land use, soil hydrologic group (SHG), and surface elevation. The methodology was applied to the Sumas-Blaine Aquifer located in Washington State to predict the occurrence of five heavy metals. The influencing variables considered were (1) SHG; (2) land use; (3) elevation; (4) clay content; (5) hydraulic conductivity; and (6) well depth. The predicted probabilities were in agreement with the observed probabilities under existing conditions. The results showed that aquifer vulnerability to each heavy metal was related to different sets of influencing variables. However, all heavy metals had a strong influence from land use and SHG. The model results also provided good insight into the influence of various hydrogeochemical factors and land uses on the presence of each heavy metal. A simple economic analysis was proposed and demonstrated to evaluate the cost effects of changing the land use on heavy metal occurrence.

  9. Heavy metal ions are potent inhibitors of protein folding

    SciTech Connect

    Sharma, Sandeep K.; Goloubinoff, Pierre; Christen, Philipp

    2008-07-25

    Environmental and occupational exposure to heavy metals such as cadmium, mercury and lead results in severe health hazards including prenatal and developmental defects. The deleterious effects of heavy metal ions have hitherto been attributed to their interactions with specific, particularly susceptible native proteins. Here, we report an as yet undescribed mode of heavy metal toxicity. Cd{sup 2+}, Hg{sup 2+} and Pb{sup 2+} proved to inhibit very efficiently the spontaneous refolding of chemically denatured proteins by forming high-affinity multidentate complexes with thiol and other functional groups (IC{sub 50} in the nanomolar range). With similar efficacy, the heavy metal ions inhibited the chaperone-assisted refolding of chemically denatured and heat-denatured proteins. Thus, the toxic effects of heavy metal ions may result as well from their interaction with the more readily accessible functional groups of proteins in nascent and other non-native form. The toxic scope of heavy metals seems to be substantially larger than assumed so far.

  10. Comparison of Eleven Heavy Metals in Moringa Oleifera Lam. Products

    PubMed Central

    Limmatvapirat, C.; Limmatvapirat, S.; Charoenteeraboon, J.; Wessapan, C.; Kumsum, A.; Jenwithayaamornwech, S.; Luangthuwapranit, P.

    2015-01-01

    Eleven heavy metals in various products of Moringa oleifera were analyzed to determine eleven heavy metals (Al, As, Cd, Cr, Cu, Fe, Pb, Mn, Hg, Ni, and Zn) using Inductively Coupled Plasma-Mass Spectrometry. The products of M. oleifera were purchased in Nakhon Pathom, Thailand. All products were digested with nitric acid solution before determining the concentrations of heavy metals. The recoveries of all heavy metals were found to be in the range of 99.89-103.05%. Several criteria such as linearity, limits of detection, limits of quantification, specificity, precision under repeatability conditions and intermediate precision reproducibility were evaluated. Results indicate that this method could be used in the laboratory for determination of eleven heavy metals in M. oleifera products with acceptable analytical performance. The results of analysis showed that the highest concentrations of As, Cr, Hg, and Mn were found in tea leaves while the highest concentrations of Al, Cd, Cu, Fe, Ni, Pb, and Zn were found in leaf capsules. Continuous monitoring of heavy metals in M. oleifera products is crucial for consumer health. PMID:26664066

  11. Separation of metal ions in nitrate solution by ultrasonic atomization

    NASA Astrophysics Data System (ADS)

    Sato, Masanori; Ikeno, Masayuki; Fujii, Toshitaka

    2004-11-01

    In the ultrasonic atomization of metal nitrate solutions, the molar ratio of metal ions is changed between solution and mist. Small molar metal ions tend to be transferred to mist by ultrasonic wave acceleration, while large molar ions tend to remain in solution. As a result, metal ions can be separated by ultrasonic atomization. We show experimental data and propose a conceptual mechanism for the ultrasonic separation of metal ions.

  12. Separation of metal ions in nitrate solution by ultrasonic atomization.

    PubMed

    Sato, Masanori; Ikeno, Masayuki; Fujii, Toshitaka

    2004-11-15

    In the ultrasonic atomization of metal nitrate solutions, the molar ratio of metal ions is changed between solution and mist. Small molar metal ions tend to be transferred to mist by ultrasonic wave acceleration, while large molar ions tend to remain in solution. As a result, metal ions can be separated by ultrasonic atomization. We show experimental data and propose a conceptual mechanism for the ultrasonic separation of metal ions.

  13. Heavy metals in five Sabellidae species (Annelida, Polychaeta): ecological implications.

    PubMed

    Giangrande, Adriana; Licciano, Margherita; Del Pasqua, Michela; Fanizzi, Francesco Paolo; Migoni, Danilo; Stabili, Loredana

    2017-02-01

    The present work analyzed three hard-bottom and two soft-bottom species of sabellid polychaetes to determine the content of several heavy metals in their branchial crown and body. The highest concentrations of heavy metals were recorded in the hard-bottom species Branchiomma bairdi, a recent Mediterranean introduction. Differences in the metal concentrations were most notable in the high trace metal levels of the branchial crown for all the studied species. Statistical analysis showed that the Mediterranean hard-bottom species were similar each other in their heavy metal content in the body as well as in the branchial crown and appeared separated from all the other species. Arsenic and vanadium hyperaccumulation in the branchial crowns of the considered sabellid species probably acts as a deterrent for predation. The observed differences among the examined species were discussed not only at the light of habitat colonization but also in terms of the phylogeny.

  14. Heavy metal content in various types of candies and their daily dietary intake by children.

    PubMed

    Devi, Parmila; Bajala, Vandana; Garg, V K; Mor, Suman; Ravindra, Khaiwal

    2016-02-01

    Children are vulnerable to heavy metal contamination through consumption of candies and chocolates. Considering this representative samples (69) of candies and chocolates based on cocoa, milk and sugar were analyzed for selected heavy metals by means of flame atomic absorption spectrometry. The average concentration of Zn, Pb, Ni, and Cd was found to be 2.52 ± 2.49, 2.0 ± 1.20, 0.84 ± 1.35, and 0.17 ± 0.22 μg/g respectively. Results indicate that cocoa-based candies have higher metal content than milk- or sugar-based candies. The daily dietary intake of metals for children eating candies and chocolates was also calculated, and results indicated highest intake of Pb and Zn followed by Ni, Cd, and Cu. Comparison of the current study results with other studies around the globe shows that the heavy metal content in candies and chocolates is lower in India than reported elsewhere. However, to reduce the further dietary exposure of heavy metals through candies and chocolates, their content should be monitored regularly and particularly for Pb as children are highly susceptible to its toxicity.

  15. Using Moss to Assess Airborne Heavy Metal Pollution in Taizhou, China.

    PubMed

    Zhou, Xiaoli; Chen, Qin; Liu, Chang; Fang, Yanming

    2017-04-17

    Bryophytes act as bioindicators and bioaccumulators of metal deposition in the environment. To understand the atmospheric deposition of heavy metals (cadmium (Cd), chromium (Cr), copper (Cu), mercury (Hg), nickel (Ni), lead (Pb), and zinc (Zn)) in Taizhou, East China, samples of moss (Haplocladium microphyllum) were collected from 60 sites selected by a systematic sampling method during the summer of 2012, and the concentrations of these heavy metals were determined by inductively coupled plasma atomic emission spectroscopy (ICP-AES). The results suggested that the concentrations of these metals varied moderately among different sites, indicating a similar contamination level for each element throughout the monitoring region. The mean values under investigation were higher than those from neighboring cities, such as Wuxi, Xuzhou, and Nanjing, and much higher than those in Europe based on a 2010 survey. Significant (p < 0.01) correlations were identified among some of the heavy metals, suggesting that these originated from identical sources. There was no statistically significant correlation between Hg and all the other elements. Spatial distribution maps of the elements over the sampled territory were created using Arc-GIS 9.0. The potential ecological risk index indicated that the air was heavily polluted by Cd and Hg, and that there was a considerable potential ecological risk from all the heavy metals studied.

  16. Effect of ultrasonic treatment on heavy metal decontamination in milk.

    PubMed

    Porova, Nataliya; Botvinnikova, Valentina; Krasulya, Olga; Cherepanov, Pavel; Potoroko, Irina

    2014-11-01

    Ultrasound has been found useful in increasing the efficiency and consumer safety in food processing. Removal of heavy metal (lead, mercury, and arsenic) contamination in milk is extremely important in regions of poor ecological environment - urban areas with heavy motor traffic or well established metallurgical/cement industry. In this communication, we report on the preliminary studies on the application of low frequency (20kHz) ultrasound for heavy metal decontamination of milk without affecting its physical, chemical, and microbiological properties. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. Electrokinetic treatment of an agricultural soil contaminated with heavy metals.

    PubMed

    Figueroa, Arylein; Cameselle, Claudio; Gouveia, Susana; Hansen, Henrik K

    2016-07-28

    The high organic matter content in agricultural soils tends to complex and retain contaminants such as heavy metals. Electrokinetic remediation was tested in an agricultural soil contaminated with Co(+2), Zn(+2), Cd(+2), Cu(+2), Cr(VI), Pb(+2) and Hg(+2). The unenhanced electrokinetic treatment was not able to remove heavy metals from the soil due to the formation of precipitates in the alkaline environment in the soil section close to the cathode. Moreover, the interaction between metals and organic matter probably limited metal transportation under the effect of the electric field. Citric acid and ethylenediaminetetraacetic acid (EDTA) were used in the catholyte as complexing agents in order to enhance the extractability and removal of heavy metals from soil. These complexing agents formed negatively charged complexes that migrated towards the anode. The acid front electrogenerated at the anode favored the dissolution of heavy metals that were transported towards the cathode. The combined effect of the soil pH and the complexing agents resulted in the accumulation of heavy metals in the center of the soil specimen.

  18. Phytoremediation of heavy metals--concepts and applications.

    PubMed

    Ali, Hazrat; Khan, Ezzat; Sajad, Muhammad Anwar

    2013-05-01

    The mobilization of heavy metals by man through extraction from ores and processing for different applications has led to the release of these elements into the environment. Since heavy metals are nonbiodegradable, they accumulate in the environment and subsequently contaminate the food chain. This contamination poses a risk to environmental and human health. Some heavy metals are carcinogenic, mutagenic, teratogenic and endocrine disruptors while others cause neurological and behavioral changes especially in children. Thus remediation of heavy metal pollution deserves due attention. Different physical and chemical methods used for this purpose suffer from serious limitations like high cost, intensive labor, alteration of soil properties and disturbance of soil native microflora. In contrast, phytoremediation is a better solution to the problem. Phytoremediation is the use of plants and associated soil microbes to reduce the concentrations or toxic effects of contaminants in the environments. It is a relatively recent technology and is perceived as cost-effective, efficient, novel, eco-friendly, and solar-driven technology with good public acceptance. Phytoremediation is an area of active current research. New efficient metal hyperaccumulators are being explored for applications in phytoremediation and phytomining. Molecular tools are being used to better understand the mechanisms of metal uptake, translocation, sequestration and tolerance in plants. This review article comprehensively discusses the background, concepts and future trends in phytoremediation of heavy metals. Copyright © 2013 Elsevier Ltd. All rights reserved.

  19. Heavy metal music meets complexity and sustainability science.

    PubMed

    Angeler, David G

    2016-01-01

    This paper builds a bridge between heavy metal music, complexity theory and sustainability science to show the potential of the (auditory) arts to inform different aspects of complex systems of people and nature. The links are described along different dimensions. This first dimension focuses on the scientific aspect of heavy metal. It uses complex adaptive systems theory to show that the rapid diversification and evolution of heavy metal into multiple subgenres leads to a self-organizing and resilient socio-musicological system. The second dimension builds on the recent use of heavy metal as a critical thinking model and educational tool, emphasizing the artistic component of heavy metal and its potential to increase people's awareness of environmental sustainability challenges. The relationships between metal, complexity theory and sustainability are first discussed independently to specifically show mechanistic links and the reciprocal potential to inform one domain (science) by the other (metal) within these dimensions. The paper concludes by highlighting that these dimensions entrain each other within a broader social-cultural-environmental system that cannot be explained simply by the sum of independent, individual dimensions. Such a unified view embraces the inherent complexity with which systems of people and nature interact. These lines of exploration suggest that the arts and the sciences form a logical partnership. Such a partnership might help in endeavors to envision, understand and cope with the broad ramifications of sustainability challenges in times of rapid social, cultural, and environmental change.

  20. Heavy metals in urban soils of East St. Louis, IL, Part I: Total concentration of heavy metals in soils.

    PubMed

    Kaminski, M D; Landsberger, S

    2000-09-01

    The city of East St. Louis, IL, has a history of abundant industrial activities including smelters of ferrous and non-ferrous metals, a coal-fired power plant, companies that produce organic and inorganic chemicals, and petroleum refineries. A protocol for soil analysis was developed to produce sufficient information on the extent of heavy metal contamination in East St. Louis soils. Soil cores representing every borough of East St. Louis were analyzed for heavy metals--As, Cd, Cu, Cr, Hg, Ni, Pb, Sb, Sn, and Zn. The topsoil contained heavy metal concentrations as high as 12.5 ppm Cd, 14,400 ppm Cu, ppm quantities of Hg, 1860 ppm Pb, 40 ppm Sb, 1130 ppm Sn, and 10,360 ppm Zn. Concentrations of Sb, Cu, and Cd were well correlated with Zn concentrations, suggesting a similar primary industrial source. In a sandy loam soil from a vacated rail depot near the bank of the Mississippi River, the metals were evenly distributed down to a 38-cm depth. The clay soils within a half-mile downwind of the Zn smelter and Cu products company contained elevated Cd (81 ppm), Cu (340 ppm), Pb (700 ppm), and Zn (6000 ppm) and displayed a systematic drop in concentration of these metals with depth. This study demonstrates the often high concentration of heavy metals heterogeneously distributed in the soil and provides baseline data for continuing studies of heavy metal soil leachability.

  1. Body burdens of heavy metals in Lake Michigan wetland turtles.

    PubMed

    Smith, Dayna L; Cooper, Matthew J; Kosiara, Jessica M; Lamberti, Gary A

    2016-02-01

    Tissue heavy metal concentrations in painted (Chrysemys picta) and snapping (Chelydra serpentina) turtles from Lake Michigan coastal wetlands were analyzed to determine (1) whether turtles accumulated heavy metals, (2) if tissue metal concentrations were related to environmental metal concentrations, and (3) the potential for non-lethal sampling techniques to be used for monitoring heavy metal body burdens in freshwater turtles. Muscle, liver, shell, and claw samples were collected from painted and snapping turtles and analyzed for cadmium, chromium, copper, iron, lead, magnesium, manganese, and zinc. Turtle tissues had measurable quantities of all eight metals analyzed. Statistically significant correlations between tissue metal concentrations and sediment metal concentrations were found for a subset of metals. Metals were generally found in higher concentrations in the larger snapping turtles than in painted turtles. In addition, non-lethal samples of shell and claw were found to be possible alternatives to lethal liver and muscle samples for some metals. Human consumption of snapping turtles presents potential health risks if turtles are harvested from contaminated areas. Overall, our results suggest that turtles could be a valuable component of contaminant monitoring programs for wetland ecosystems.

  2. Atomic nuclei decay modes by spontaneous emission of heavy ions

    NASA Astrophysics Data System (ADS)

    Poenaru, D. N.; Ivaşcu, M.; Sndulescu, A.; Greiner, Walter

    1985-08-01

    The great majority of the known nuclides with Z>40, including the so-called stable nuclides, are metastable with respect to several modes of spontaneous superasymmetric splitting. A model extended from the fission theory of alpha decay allows one to estimate the lifetimes and the branching ratios relative to the alpha decay for these natural radioactivities. From a huge amount of systematic calculations it is concluded that the process should proceed with maximum intensity in the trans-lead nuclei, where the minimum lifetime is obtained from parent-emitted heavy ion combinations leading to a magic (208Pb) or almost magic daughter nucleus. More than 140 nuclides with atomic number smaller than 25 are possible candidates to be emitted from heavy nuclei, with half-lives in the range of 1010-1030 s: 5He, 8-10Be, 11,12B, 12-16C, 13-17N, 15-22O, 18-23F, 20-26Ne, 23-28Na, 23-30Mg, 27-32Al, 28-36Si, 31-39P, 32-42S, 35-45Cl, 37-47Ar, 40-49 K, 42-51. . .Ca, 44-53 Sc, 46-53Ti, 48-54V, and 49-55 Cr. The shell structure and the pairing effects are clearly manifested in these new decay modes.

  3. Biomonitoring heavy metal contaminations by moss visible parameters.

    PubMed

    Chen, Yang-Er; Cui, Jun-Mei; Yang, Jin-Chuan; Zhang, Zhong-Wei; Yuan, Ming; Song, Chun; Yang, Hui; Liu, Han-Mei; Wang, Chang-Quan; Zhang, Huai-Yu; Zeng, Xian-Yin; Yuan, Shu

    2015-10-15

    Traditional sampling for heavy metal monitoring is a time-consuming and inconvenient method, which also does not indicate contaminants non-invasively and instantaneously. Moss is sensitive to heavy metals and is therefore considered a pollution indicator. However, it is unknown what kind physiological parameters can indicate metal contaminations quickly and non-invasively. Here, we systematically examined the effects of six heavy metals on physiological parameters and photosynthetic activities of two moss species grown in aquatic media or moist soil surface. We suggest that a phenotype with anthocyanin accumulation pattern and chlorosis pattern and two chlorophyll fluorescence parameters with their images can roughly reflect metal species groups, concentrations and differences between the two moss species. In other words, metal contaminations could be roughly estimated visually using the naked eye. Enzymatic and non-enzymatic anti-oxidative abilities and photosynthetic protein contents of Eurhynchium eustegium were higher than those of Taxiphyllum taxirameum, indicating their differential metal tolerance. Neither anti-oxidative abilities nor photosynthetic proteins were found to be ideal indicators. This study provides new ideas to monitor heavy metals rapidly and non-invasively in water or on wetland and moist soil surface.

  4. Nitrification and Heavy Metal Removal in the Activated Sludge Treatment Process.

    DTIC Science & Technology

    1976-08-01

    parameters to heavy metal removal in the activated sludge waste treatment process. The heavy metals studied were chromium and silver. Analyses...performed on the influent, mixed liquor, return sludge, and effluent included heavy metal concentration, pH, dissolved oxygen, temperature, suspended solids...related to heavy metal removal. Nitrification is only indirectly related. A theory for the mechanisms contributing to heavy metal removal is developed.

  5. Physiological sensitivity of freshwater macroinvertebrates to heavy metals.

    PubMed

    Malaj, Egina; Grote, Matthias; Schäfer, Ralf B; Brack, Werner; von der Ohe, Peter Carsten

    2012-08-01

    Macroinvertebrate species traits, such as physiological sensitivity, have successfully been introduced in trait-based bioassessment approaches and are important predictors of species sensitivity in the field. The authors ranked macroinvertebrate species according to their physiological sensitivity to heavy metals using toxicity data from acute laboratory assays. Rankings for each of the heavy metals, Cd, Cu, Cr, Ni, Pb, Zn, and Hg, were standardized based on all available species data. Rankings for different heavy metals on the species level showed no significant difference between compounds and were reasonably well correlated pairwise (0.50heavy metal ranking was developed, which assigns a single physiological sensitivity value (S(metal) ) to macroinvertebrate taxa. Considering the high variation, especially for higher taxonomic levels, that is, in the order level, it is recommended to use S values of the genus or species level for meaningful analyses. In terms of taxonomic ranking, crustaceans were overall the most sensitive taxonomic group, whereas insects were generally the most tolerant group. Species in the order of Cladocera were three orders of magnitude more sensitive than insects of the order of Trichoptera. By contrast, mollusks covered a wide range of sensitivities, with bivalves being on average one order of magnitude more sensitive than gastropods. The authors concluded that physiological sensitivity represents a promising trait for trait-based risk assessment that together with other demographic and recolonization traits may help to identify the effects of heavy metal pollution in aquatic ecosystems.

  6. Magnetic process for removing heavy metals from water employing magnetites

    DOEpatents

    Prenger, F. Coyne; Hill, Dallas D.; Padilla, Dennis D.; Wingo, Robert M.; Worl, Laura A.; Johnson, Michael D.

    2003-07-22

    A process for removing heavy metals from water is provided. The process includes the steps of introducing magnetite to a quantity of water containing heavy metal. The magnetite is mixed with the water such that at least a portion of, and preferably the majority of, the heavy metal in the water is bound to the magnetite. Once this occurs the magnetite and absorbed metal is removed from the water by application of a magnetic field. In most applications the process is achieved by flowing the water through a solid magnetized matrix, such as steel wool, such that the magnetite magnetically binds to the solid matrix. The magnetized matrix preferably has remnant magnetism, but may also be subject to an externally applied magnetic field. Once the magnetite and associated heavy metal is bound to the matrix, it can be removed and disposed of, such as by reverse water or air and water flow through the matrix. The magnetite may be formed in-situ by the addition of the necessary quantities of Fe(II) and Fe(III) ions, or pre-formed magnetite may be added, or a combination of seed and in-situ formation may be used. The invention also relates to an apparatus for performing the removal of heavy metals from water using the process outlined above.

  7. Magnetic process for removing heavy metals from water employing magnetites

    DOEpatents

    Prenger, F. Coyne; Hill, Dallas D.

    2006-12-26

    A process for removing heavy metals from water is provided. The process includes the steps of introducing magnetite to a quantity of water containing heavy metal. The magnetite is mixed with the water such that at least a portion of, and preferably the majority of, the heavy metal in the water is bound to the magnetite. Once this occurs the magnetite and absorbed metal is removed from the water by application of a magnetic field. In most applications the process is achieved by flowing the water through a solid magnetized matrix, such as steel wool, such that the magnetite magnetically binds to the solid matrix. The magnetized matrix preferably has remnant magnetism, but may also be subject to an externally applied magnetic field. Once the magnetite and associated heavy metal is bound to the matrix, it can be removed and disposed of, such as by reverse water or air and water flow through the matrix. The magnetite may be formed in-situ by the addition of the necessary quantities of Fe(II) and Fe(III) ions, or pre-formed magnetite may be added, or a combination of seed and in-situ formation may be used. The invention also relates to an apparatus for performing the removal of heavy metals from water using the process outlined above.

  8. Phytochemicals Mediated Remediation of Neurotoxicity Induced by Heavy Metals.

    PubMed

    Gupta, Vivek Kumar; Singh, Shweta; Agrawal, Anju; Siddiqi, Nikhat Jamal; Sharma, Bechan

    2015-01-01

    Almost all the environmental components including both the abiotic and biotic factors have been consistently threatened by excessive contamination of heavy metals continuously released from various sources. Different heavy metals have been reported to generate adverse effects in many ways. Heavy metals induced neurotoxicity and impairment in signalling cascade leading to cell death (apoptosis) has been indicated by several workers. On one hand, these metals are required by the cellular systems to regulate various biological functions of normal cells, while on the other their biomagnification in the cellular systems produces adverse effects. The mechanism by which the heavy metals induce neurotoxicity follows free radicals production pathway(s) specially the generation of reactive oxygen species and reactive nitrogen species. These free radicals produced in excess have been shown to create an imbalance between the oxidative and antioxidative systems leading to emergence of oxidative stress, which may cause necrosis, DNA damage, and many neurodegenerative disorders. This mini review summarizes the current knowledge available on the protective role of varied natural products isolated from different herbs/plants in imparting protection against heavy metals (cadmium, lead, arsenic, and mercury) mediated neurotoxicity.

  9. Phytochemicals Mediated Remediation of Neurotoxicity Induced by Heavy Metals

    PubMed Central

    Gupta, Vivek Kumar; Singh, Shweta; Agrawal, Anju; Siddiqi, Nikhat Jamal; Sharma, Bechan

    2015-01-01

    Almost all the environmental components including both the abiotic and biotic factors have been consistently threatened by excessive contamination of heavy metals continuously released from various sources. Different heavy metals have been reported to generate adverse effects in many ways. Heavy metals induced neurotoxicity and impairment in signalling cascade leading to cell death (apoptosis) has been indicated by several workers. On one hand, these metals are required by the cellular systems to regulate various biological functions of normal cells, while on the other their biomagnification in the cellular systems produces adverse effects. The mechanism by which the heavy metals induce neurotoxicity follows free radicals production pathway(s) specially the generation of reactive oxygen species and reactive nitrogen species. These free radicals produced in excess have been shown to create an imbalance between the oxidative and antioxidative systems leading to emergence of oxidative stress, which may cause necrosis, DNA damage, and many neurodegenerative disorders. This mini review summarizes the current knowledge available on the protective role of varied natural products isolated from different herbs/plants in imparting protection against heavy metals (cadmium, lead, arsenic, and mercury) mediated neurotoxicity. PMID:26618004

  10. Ecotoxicology of heavy metals: Liquid-phase extraction by nanosorbents

    NASA Astrophysics Data System (ADS)

    Burakov, A.; Romantsova, I.; Babkin, A.; Neskoromnaya, E.; Kucherova, A.; Kashevich, Z.

    2015-11-01

    The paper considers the problem of extreme toxicity heavy metal compounds dissolved in wastewater and liquid emissions of industrial enterprises to living organisms and environment as a whole. The possibility of increasing extraction efficiency of heavy metal ions by sorption materials was demonstrated. The porous space of the latter was modified by carbon nanotubes (CNTs) during process of the chemical vapour deposition (CVD) of carbon on metal oxide catalysts. The increasing of the sorption capacity (10-30%) and the sorption rate of nanomodified activated carbons in comparison with standard materials in the example of absorption of Co2+ and Ni2+ ions from aqueous solutions was proven.

  11. Water hyacinth as indicator of heavy metal pollution the tropics

    SciTech Connect

    Gonzalez, H.; Otero, M. ); Lodenius, M. )

    1989-12-01

    The water hyacinth (Eichhornia crassipes) is a common aquatic plant in many tropical countries. Its ability absorb nutrients and other elements from the water has made it possible to use it for water purification purposes. Eichhornia, especially stems and leaves, have been successfully used as indicators of heavy metal pollution in tropical countries. The uptake of heavy metals in this plant is stronger in the roots than in the floating shoots. Metallothionein-like compounds have been found from roots of this species after cadmium exposure. The purpose of this investigation was to study the possibilities of using roots of water hyacinth as a biological indicator of metal pollution in tropical aquatic ecosystems.

  12. Heavy metal toxicity to bacteria - are the existing growth media accurate enough to determine heavy metal toxicity?

    PubMed

    Rathnayake, I V N; Megharaj, Mallavarapu; Krishnamurti, G S R; Bolan, Nanthi S; Naidu, Ravi

    2013-01-01

    A new minimal medium was formulated considering the limitations of the existing media for testing heavy metal sensitivity to bacteria. Toxicity of cadmium and copper to three bacteria was investigated in the new medium and compared with three other media commonly used to study the effect of the toxic metals. Based on speciation data arrived at using ion-selective electrodes, the available free-metal concentration in solution was highest in the MES-buffered medium. This finding was strongly supported by the estimated EC(50) values for the metals tested based on the toxicity bioassays. The free-ionic cadmium and copper concentrations in the medium provide more accurate determination of metal concentrations that affects the bacteria, than with most of other existing media. This will avoid doubts on other media and misleading conclusions relevant to the toxicity of heavy metals to bacteria and provides a better option for the study of metal-bacteria interactions.

  13. Heavy metals effects on forage crops yields and estimation of elements accumulation in plants as affected by soil.

    PubMed

    Grytsyuk, N; Arapis, G; Perepelyatnikova, L; Ivanova, T; Vynograds'ka, V

    2006-02-01

    Heavy metals (Cu, Cd, Pb, Zn) effect on the productivity of forage crops (clover and perennial cereal grasses) and their accumulation in plants, depending on the concentration of these elements in a soil, has been studied in micro-field experiments on three types of soil. The principle objective was to determine regularities of heavy metals migration in a soil-plant system aiming the estimation of permissible levels of heavy metals content in soils with the following elaboration of methods, which regulate the toxicants transfer to plants. Methods of field experiments, agrochemical and atomic absorption analysis were used. Results were statistically treated by Statistica 6.0, S-Plus 6. Experimental results have shown that the intensity of heavy metals accumulation in plants depends on the type of the soil, the species of plants, the physicochemical properties of heavy metals and their content in the soil. Logarithmic interdependency of heavy metals concentration in soils and their accumulation in plants is suggested. However, the strong correlation between the different heavy metals concentrations in the various soils and the yield of crops was not observed. Toxicants accumulation in crops decreased in time.

  14. Violets of the section Melanium, their colonization by arbuscular mycorrhizal fungi and their occurrence on heavy metal heaps.

    PubMed

    Słomka, A; Kuta, E; Szarek-Łukaszewska, G; Godzik, B; Kapusta, P; Tylko, G; Bothe, H

    2011-07-15

    Violets of the sections Melanium were examined for their colonization by arbuscular mycorrhizal fungi (AMF). Heartsease (Viola tricolor) from several heavy metal soils was AMF-positive at many sites but not at extreme biomes. The zinc violets Viola lutea ssp. westfalica (blue zinc violet) and ssp. calaminaria (yellow zinc violet) were always AMF-positive on heavy metal soils as their natural habitats. As shown for the blue form, zinc violets germinate independently of AMF and can be grown in non-polluted garden soils. Thus the zinc violets are obligatorily neither mycotrophs nor metalophytes. The alpine V. lutea, likely ancestor of the zinc violets, was at best poorly colonized by AMF. As determined by atomic absorption spectrometry, the contents of Zn and Pb were lower in AMF colonized plants than in the heavy metal soils from where the samples had been taken. AMF might prevent the uptake of toxic levels of heavy metals into the plant organs. Dithizone staining indicated a differential deposition of heavy metals in tissues of heartsease. Leaf hairs were particularly rich in heavy metals, indicating that part of the excess of heavy metals is sequestered into these cells.

  15. Heavy metal capture and accumulation in bioretention media.

    PubMed

    Li, Houng; Davis, Allen P

    2008-07-15

    Heavy metal capture and accumulation in bioretention media were investigated through the use of a one-dimensional filtration equation for particulate metals, advection/dispersion/adsorption transport equations for dissolved metals, and sequential extractions. Predicted spatial profiles and partitioning patterns of captured metals were compared to data derived from a bioretention cell in the District of Columbia. Zinc, lead, and copper profiles showed a high surface accumulation, significantly decreasing with the media depth. Surface street particle-enriched areas had the highest heavy metal levels, demonstrating a close relationship between capture of metals and runoff particles. Sequential extractions suggested that most captured metals were of anthropogenic origin. Soluble-exchangeable bound metals from the sequential extraction correlated well with predicted aqueous dissolved metals; the more strongly associated metal fractions correlated with modeled runoff and media particulate metals. A simple risk evaluation indicated thatlead isthe limiting metal in bioretention accumulation. On the basis of information collected in this study, a shallow bioretention cell design is suggested for systems with a focus on metal capture.

  16. A plasmid containing the human metallothionein II gene can function as an antibody-assisted electrophoretic biosensor for heavy metals.

    PubMed

    Wooten, Dennis C; Starr, Clarise R; Lyon, Wanda J

    2016-01-01

    Different forms of heavy metals affect biochemical systems in characteristic ways that cannot be detected with typical metal analysis methods like atomic absorption spectrometry. Further, using living systems to analyze interaction of heavy metals with biochemical systems can be laborious and unreliable. To generate a reliable easy-to-use biologically-based biosensor system, the entire human metallothionein-II (MT-II) gene was incorporated into a plasmid (pUC57-MT) easily replicated in Escherichia coli. In this system, a commercial polyclonal antibody raised against human metal-responsive transcription factor-1 protein (MTF-1 protein) could modify the electrophoretic migration patterns (i.e. cause specific decreases in agarose gel electrophoretic mobility) of the plasmid in the presence or absence of heavy metals other than zinc (Zn). In the study here, heavy metals, MTF-1 protein, and polyclonal anti-MTF-1 antibody were used to assess pUC57-MT plasmid antibody-assisted electrophoretic mobility. Anti-MTF-1 antibody bound both MTF-1 protein and pUC57-MT plasmid in a non-competitive fashion such that it could be used to differentiate specific heavy metal binding. The results showed that antibody-inhibited plasmid migration was heavy metal level-dependent. Zinc caused a unique mobility shift pattern opposite to that of other metals tested, i.e. Zn blocked the antibody ability to inhibit plasmid migration, despite a greatly increased affinity for DNA by the antibody when Zn was present. The Zn effect was reversed/modified by adding MTF-1 protein. Additionally, antibody inhibition of plasmid mobility was resistant to heat pre-treatment and trypsinization, indicating absence of residual DNA extraction-resistant bacterial DNA binding proteins. DNA binding by anti-DNA antibodies may be commonly enhanced by xenobiotic heavy metals and elevated levels of Zn, thus making them potentially effective tools for assessment of heavy metal bioavailability in aqueous solutions and

  17. Molecular Indicators of Soil Humification and Interaction with Heavy Metals

    SciTech Connect

    Fan, Teresa W.-M.; Higashi, Richard M.; Cassel, Teresa; Green, Peter; Lane, Andrew N.

    2003-03-26

    For stabilization of heavy metals at contaminated sites, interaction of soil organic matter (SOM) with heavy metal ions is critically important for long-term sustainability, a factor that is poorly understood at the molecular level. Using 13C- and 15N-labeled soil humates (HS), we investigated the turnover of five organic amendments (celluose, wheat straw, pine shavings, chitin and bone meal) in relation to heavy metal ion leaching in soil column experiments. The labeled molecular substructures in HS were examined by multinuclear 2-D NMR and pyrolysis GC-MS while the element profile in the leachates was analyzed by ICP-MS. Preliminary analysis revealed that peptidic and polysaccharidic structures were highly enriched, which suggests their microbial origin. Cd(II) leaching was significantly attenuated with humification of lignocellulosic materials. Correlation of 13C and 15N turnovers of HS substructures to metal leaching is underway.

  18. Spatial distribution of heavy metals in surface soil, plant and mushroom beside high-frequency road

    NASA Astrophysics Data System (ADS)

    Krbić, Biljana Å.; Milovac, Snežana; Stošić, Dušan; Zorić, Miroslav; Matavulj, Milan

    2010-05-01

    One of the undesirable aspects of urbanization process is the introduction of potentially harmful pollutants into environment. Urban soils are often contaminated by metals deriving from industry, transportation and other human activities. In this study, concentration of heavy metals were investigated in roadside surface soil, linden tree bark (Tilia sp.), mushroom Schizophyllum commune and dust samples collected at different distances (0.2 - 200 m) from main high-frequency road. The samples were microwave digested in accordance to US EPA 3051 method and analyzed by flame (Cd, Cu, Co, Fe, Ni, Mn, Pb and Zn), graphite furnace (Cr) and cold vapor (Hg) atomic absorption spectrometry. The results of the analysis were used to determine major sources and distribution of heavy metals pollution. The obtained results showed significant decrease of traffic-related metals (Fe, Zn, Pb, Ni, Cu and Cd) in soil samples with increasing distance from road edge. In order to assess possible pollution, heavy metal contents in soil were compared with the National legislation and Netherlands soil quality standards. Also, elevated concentrations of traffic-related metals, especially Pb and Cr in analyzed tree bark, mushroom and dust samples, indicate the obvious roadside contamination whose primary contributors appear to be vehicular local traffic. In addition, Index of Bioaccumulation (IBA) was calculated in order to estimate plant and mushroom ability of heavy metals accumulation. Assessment of statistical differences among samples was performed by one-way analysis of variance (ANOVA) and Tukey honestly significant difference (HSD) test. Moreover, Principal Component Analysis (PCA) was performed on the heavy metals content allowed a meaningful classification of the samples according to the main sources of pollution.

  19. Increased Tolerance to Heavy Metals Exhibited by Swarming Bacteria

    NASA Astrophysics Data System (ADS)

    Anyan, M.; Shrout, J. D.

    2014-12-01

    Pseudomonas aeruginosa is a ubiquitous, Gram-negative bacterium that utilizes several different modes of motility to colonize surfaces, including swarming, which is the coordinated movement of cells over surfaces in groups. Swarming facilitates surface colonization and biofilm development for P. aeruginosa, and it is known that swarming behavior is influenced by changes in nutrient composition and surface moisture. To understand the fate and cycling of heavy metals in the environment, it is important to understand the interaction and toxicity of these metals upon bacteria. While previous studies have shown surface-attached bacterial biofilms to be highly resistant to heavy metal toxicity, little is known about the influence of heavy metals upon surface motile bacteria and developing biofilms. Using a combination of laboratory assays we examined differences in bacterial behavior in response to two metals, Cd and Ni. We find that surface swarming bacteria are able to grow on 4x and 2.5x more Cd and Ni, respectively, than planktonic cells (i.e., test tube cultures). P. aeruginosa was able to swarm in the presence ≤0.051mM Ni and ≤0.045mM Cd. To investigate the bioavailability of metals to bacteria growing under our examined conditions, we separated cell and supernatant fractions of P. aeruginosa cultures, and used ICP-MS techniques to measure Cd and Ni sorption. A greater percentage of Cd than Ni was sorbed by both cells and supernatant (which contains rhamnolipid, a surfactant known to sorb some metals and improve swarming). While we show that cell products such as rhamnolipid bind heavy metals (as expected) and should limit metal bioavailability, our results suggest at least one additional mechanism (as yet undetermined) that promotes cell survival during swarming in the presence of these heavy metals.

  20. Heavy metals concentration relationship with Perna viridis physical properties in Mengkabong Lagoon, Sabah, Malaysia.

    PubMed

    Abdullah, Noraini; Tair, Rohana; Abdullah, Mohd Harun

    2014-01-01

    Perna viridis (P. viridis) has been identified as a good biological indicator in identifying environmental pollution, especially when there are various types of Heavy Metals Accumulations (HMA) inside its tissue. Based on the potential of P. viridis to accumulate heavy metals and the data on its physical properties, this study proffers to determine the relationships between both properties. The similarities of the physical properties are used to mathematical model their relationships, which included the size (length, width, height) and weight (wet and dry) of P. viridis, whilst the heavy metals are focused on concentrations of Pb, Cu, Cr, Cd and Zn. The concentrations of metal elements are detected by using Flame Atomic Adsorption Spectrometry. Results show that the mean concentration of Pb, Cu, Cr, Cd, Zn, length, width, height, wet weight and dry weight are: 1.12 +/- 1.00, 2.36 +/- 1.65, 2.12 +/- 2.74, 0.44 +/- 0.41 and 16.52 +/- 10.64 mg kg(-1) (dry weight), 105.08 +/- 14.35, 41.64 +/- 4.64, 28.75 +/- 3.92 mm, 14.56 +/- 3.30 and 2.37 +/- 0.86 g, respectively. It is also found out that the relationships between the Heavy Metals Concentrations (HMA) and the physical properties can be represented using Multiple Linear Regressions (MLR) models, relating that the HMA of Zinc has affected significantly the physical growth properties of P. viridis.

  1. Self-excitation of Rydberg atoms at a metal surface

    NASA Astrophysics Data System (ADS)

    Bordo, V. G.

    2017-08-01

    The novel effect of self-excitation of an atomic beam propagating above a metal surface is predicted and a theory is developed. Its underlying mechanism is positive feedback provided by the reflective surface for the atomic polarization. Under certain conditions the atomic beam flying in the near field of the metal surface acts as an active device that supports sustained atomic dipole oscillations, which generate, in their turn, an electromagnetic field. This phenomenon does not exploit stimulated emission and therefore does not require population inversion in atoms. An experiment with Rydberg atoms in which this effect should be most pronounced is proposed and the necessary estimates are given.

  2. Atomic layer deposition of metal sulfide materials.

    PubMed

    Dasgupta, Neil P; Meng, Xiangbo; Elam, Jeffrey W; Martinson, Alex B F

    2015-02-17

    CONSPECTUS: The field of nanoscience is delivering increasingly intricate yet elegant geometric structures incorporating an ever-expanding palette of materials. Atomic layer deposition (ALD) is a powerful driver of this field, providing exceptionally conformal coatings spanning the periodic table and atomic-scale precision independent of substrate geometry. This versatility is intrinsic to ALD and results from sequential and self-limiting surface reactions. This characteristic facilitates digital synthesis, in which the film grows linearly with the number of reaction cycles. While the majority of ALD processes identified to date produce metal oxides, novel applications in areas such as energy storage, catalysis, and nanophotonics are motivating interest in sulfide materials. Recent progress in ALD of sulfides has expanded the diversity of accessible materials as well as a more complete understanding of the unique chalcogenide surface chemistry. ALD of sulfide materials typically uses metalorganic precursors and hydrogen sulfide (H2S). As in oxide ALD, the precursor chemistry is critical to controlling both the film growth and properties including roughness, crystallinity, and impurity levels. By modification of the precursor sequence, multicomponent sulfides have been deposited, although challenges remain because of the higher propensity for cation exchange reactions, greater diffusion rates, and unintentional annealing of this more labile class of materials. A deeper understanding of these surface chemical reactions has been achieved through a combination of in situ studies and quantum-chemical calculations. As this understanding matures, so does our ability to deterministically tailor film properties to new applications and more sophisticated devices. This Account highlights the attributes of ALD chemistry that are unique to metal sulfides and surveys recent applications of these materials in photovoltaics, energy storage, and photonics. Within each application

  3. Atomic layer deposition of metal sulfide materials

    DOE PAGES

    Dasgupta, Neil P.; Meng, Xiangbo; Elam, Jeffrey W.; ...

    2015-01-12

    The field of nanoscience is delivering increasingly intricate yet elegant geometric structures incorporating an ever-expanding palette of materials. Atomic layer deposition (ALD) is a powerful driver of this field, providing exceptionally conformal coatings spanning the periodic table and atomic-scale precision independent of substrate geometry. This versatility is intrinsic to ALD and results from sequential and self-limiting surface reactions. This characteristic facilitates digital synthesis, in which the film grows linearly with the number of reaction cycles. While the majority of ALD processes identified to date produce metal oxides, novel applications in areas such as energy storage, catalysis, and nanophotonics are motivatingmore » interest in sulfide materials. Recent progress in ALD of sulfides has expanded the diversity of accessible materials as well as a more complete understanding of the unique chalcogenide surface chemistry. ALD of sulfide materials typically uses metalorganic precursors and hydrogen sulfide (H2S). As in oxide ALD, the precursor chemistry is critical to controlling both the film growth and properties including roughness, crystallinity, and impurity levels. By modification of the precursor sequence, multicomponent sulfides have been deposited, although challenges remain because of the higher propensity for cation exchange reactions, greater diffusion rates, and unintentional annealing of this more labile class of materials. A deeper understanding of these surface chemical reactions has been achieved through a combination of in situ studies and quantum-chemical calculations. As this understanding matures, so does our ability to deterministically tailor film properties to new applications and more sophisticated devices. This Account highlights the attributes of ALD chemistry that are unique to metal sulfides and surveys recent applications of these materials in photovoltaics, energy storage, and photonics. Within each application space

  4. Characterisation and distribution of heavy metals at Masaya volcano, Nicaragua

    NASA Astrophysics Data System (ADS)

    Hinrichs, M.; Rymer, H.; Gillman, M.; Blake, S.

    2011-12-01

    Activity at Masaya volcano, Nicaragua, is characterised by periodic cycles of intense gas emission that last years to decades. The volcano entered its current phase of degassing in 1993, which resulted in a low-level persistent gas plume. As a result of this continuous emission, the substantial deposition of heavy metals onto the surrounding soils (andosols) is thought to be occurring (Delfosse et al., 2003). The deposition of these heavy metal plume components, and their incorporation into soil, is of key interest because once discharged to the environment they accumulate throughout the food chain and may pose a serious ecological threat (Alloway, 1995). Although many studies have focused on the impacts of volcanic gases on the environment, few have addressed the fate of the metals released by persistent gas plumes. This study therefore investigates the patterns of heavy metal transport, deposition and distribution at Masaya in order to provide additional information on the processes that govern the behaviour of volcanic heavy metals. A number of agricultural and non-agricultural soils at two horizons (A: 0-10 cm and B: 20-30 cm) were collected and their trace metal content analysed. Twenty sites were sampled from the active vent to ~5 km downwind, as well as two control sites upwind of the volcano. Preliminary data suggest that a rapid deposition of metals occurs close to the source, with metal concentrations in the soil generally decreasing with distance away from the active vent. Cr and As clearly follow this trend, with maximum concentrations of 20.71 and 7.61 mg/kg respectively occurring closest to the vent. Concentration peaks for Mn, Co, Ni, Cu, and Zn (959.30, 21.57, 13.44, 152.85, and 72.73 mg/kg respectively) occur slightly further away from the vent, implying that these metals are transported further. The concentration of Cr, Co, Al, Ni and Mn was found to increase from soil horizon A to B, whereas the abundance of Zn decreases with depth. Heavy metal

  5. Levels of Heavy Metals in Popular Cigarette Brands and Exposure to These Metals via Smoking

    PubMed Central

    Ashraf, Muhammad Waqar

    2012-01-01

    The levels of selected heavy metals in popular cigarette brands sold and/or produced in Saudi Arabia were determined by graphite furnace-atomic absorption spectrometry (GFAAS). Average concentrations of Cadmium and Lead in different cigarette brands were 1.81 and 2.46 μg g−1 (dry weight), respectively. The results obtained in this study estimate the average quantity of Cd inhaled from smoking one packet of 20 cigarettes to be in the range of 0.22–0.78 μg. Results suggest that the quantity of Pb inhaled of smoking one packet of 20 cigarettes is estimated to be 0.97–2.64 μg. The concentrations of Cd and Pb in cigarettes were significantly different between cigarette brands tested. The results of the present study were compared with those of other regional and international studies. PMID:22489199

  6. Heavy metals contamination in water and three species of most consumed fish sampled from Caspian Sea, 2011.

    PubMed

    Saeedi Saravi, S S; Shokrzadeh, M

    2013-12-01

    The present study is an attempt to evaluate the heavy metal contamination in the marine environment of the Caspian Sea of Iran. The concentrations of zinc, chromium, cadmium, and lead were measured in water and dorsal muscle of fish sampled from 10 selected stations along Gorgan coast using atomic absorption spectrophotometry during summer of 2011. The average concentrations of lead in water and fish samples (115.29 ± 14.78 and 113.23 ± 27.01 μg/L) were significantly higher than that of cadmium and chromium (P < 0.05). The highest heavy metals content was observed in Cyprinus carpio samples. The heavy metals concentrations in the samples were within the acceptable recommended standards. But, elevating levels of heavy metals in water and fish made a serious concern about ecosystem and food chain contamination. It is recommended that protective authorities should carry out a continual assessment on the levels of pollutants in the sea.

  7. Heavy metals in the volcanic environment and thyroid cancer.

    PubMed

    Vigneri, R; Malandrino, P; Gianì, F; Russo, M; Vigneri, P

    2017-12-05

    In the last two decades thyroid cancer incidence has increased worldwide more than any other cancer. Overdiagnosis of subclinical microcarcinomas has certainly contributed to this increase but many evidences indicate that a true increase, possibly due to environmental factors, has also occurred. Thyroid cancer incidence is markedly increased in volcanic areas. Thus, the volcanic environment is a good model to investigate the possible factors favoring thyroid cancer. In the volcanic area of Mt. Etna in Sicily, as well as in other volcanic areas, a non-anthropogenic pollution with heavy metals has been documented, a consequence of gas, ash and lava emission. Soil, water and atmosphere contamination, via the food chain, biocontaminate the residents as documented by high levels in the urines and the scalp hair compared to individuals living in adjacent non-volcanic areas. Trace amounts of metals are essential nutrients but, at higher concentrations, can be toxic for living cells. Metals can behave both as endocrine disruptors, perturbing the hormonal system, and as carcinogens, promoting malignant transformation. Similarly to other carcinogens, the transforming effect of heavy metals is higher in developing organisms as the fetus (contaminated via the mother) and individuals in early childhood. In the last decades environment metal pollution has greatly increased in industrialized countries. Although still within the "normal" limits for each single metal the hormesis effect (heavy metal activity at very low concentration because of biphasic, non linear cell response) and the possible potentiation effect resulting from the mixture of different metals acting synergistically can explain cell damage at very low concentrations. The effect of metals on the human thyroid is poorly studied: for some heavy metals no data are available. The scarce studies that have been performed mainly focus on metal effect as thyroid endocrine disruptors. The metal concentration in tissues has

  8. Heavy Metals in ToxCast: Relevance to Food Safety (SOT)

    EPA Science Inventory

    Human exposure to heavy metals occurs through food contamination due to industrial processes, vehicle emissions and farming methods. Specific toxicity endpoints have been associated with metal exposures, e.g. lead and neurotoxicity; however, numerous varieties of heavy metals hav...

  9. Heavy metals in composts of separated municipal wastes

    SciTech Connect

    Liao, W.P.; Huang, W.C.; Fan, W.H.; Hsu, C.C.

    1997-12-31

    This study is to examine the influence of the metal components on the contents of heavy metals in composts of Municipal Solid Wastes (MSW). Fresh MSW used in composting was obtained from the city landfill of Taichung in Taiwan. Compost 1 was from as-collected MSW; Compost 2 was from degradable fraction in MSW; Compost 3 was from MSW without metal. The results show that the total concentration of zinc is the highest among the five heavy metals examined. Paper wastes are main sources of lead and copper with average concentrations of 18.53 mg/kg and 26.92 mg/kg of compost on dry weight. The contents of nickel and cadmium are relatively low. The total concentrations of the five heavy metals in composts increase by typical ratios between 1.72 and 2.58 for Composts 2 and 3, but 3.16 to 4.69 for Compost 1. The increase of concentration around a ratio of 2.0 is due to the loss of degraded organic matter. For the ratios above 2.0, fractions of some heavy metals have corroded from the surfaces of metal components into the Compost 1 in the early phase of acidic fermentation.

  10. Heavy metal bioaccumulation and toxicity with special reference to microalgae

    NASA Astrophysics Data System (ADS)

    Arunakumara, K. K. I. U.; Zhang, Xuecheng

    2008-02-01

    The bioaccumulation and toxicity of heavy metals were reviewed with special reference to microalgae, the key component of the food web in aquatic ecosystems. Heavy metals enter algal cells either by means of active transport or by endocytosis through chelating proteins and affect various physiological and biochemical processes of the algae. The toxicity primarily results from their binding to the sulphydryl groups in proteins or disrupting protein structure or displacing essential elements. Metals can break the oxidative balance of the algae, inducing antioxidant enzymes, such as superoxide dismutase (SOD), glutathione peroxidase (GPX) and ascorbate peroxidase (APX). The amount of oxidized proteins and lipids in the algal cells thus indicates the severity of the stress. Algal tolerance to heavy metal is highly dependent upon the defense response against the probable oxidative damages. Production of binding factors and proteins, exclusion of metals from cells by ion-selective transporters and excretion or compartmentalization have been suggested with regard to reducing heavy metal toxicity. However, a comprehensive description on the mechanisms underlining metal toxicity of microalgae and gaining tolerance is yet to be elaborated.

  11. [Concentrations and safety evaluation of heavy metals in aquatic products of Yancheng, Jiangsu Province].

    PubMed

    Liu, Yang; Fu, Qiang; Gao, Jun; Xu, Wang-Gu; Yin, Bo; Cao, Ya-Qiao; Qin, Wei-Hua

    2013-10-01

    Current status and intake risk of heavy metal pollution in aquatic products were studied in Yancheng, Jiangsu Province. Twenty-two kinds of aquatic products were sampled in May 2012, and the concentrations of Cd, Cu, Zn, Pb and Cr in muscles were measured using atomic absorption spectroscopy. Single factor pollution index (Pg) and metal pollution index (MPI) were used to evaluate the degree of pollution, and provisional tolerable weekly intake (PTWI) and carcinogenic risks were used to assess the edible safety and health risk, respectively. We found all the aquatic products were contaminated, and the pollutions by Cd, Pb and Cr were more serious, with the exceeding rates of 31.8% , 31.8% and 40.9% , respectively. Pi indices indicated the contents of Cd, Pb and Cr exceeded the allowable criteria of " Light Pollution", while Cd and Pb in freshwater fish, Pb and Cr in shellfish, and Cr in cephalopoda reached the criteria of " Heavy Pollution". The MPI results showed that heavy metal pollution in shellfish was the most severe, followed by crustacean, freshwater fish, and cephalopoda, while it was slight in marine fish. At present, the edible safety of heavy metals in aquatic products was acceptable in Yancheng, but the Cr intake of shellfish and cephalopoda was approaching PTWI and that of a minority of marine fishes even exceeded the PTWI value. The model estimation for health risk indicated that the health risk value of heavy metal ingestion was still below the maximal acceptable level (5.0 x 10(-5) a-1), recommended by International Commission on Radiation Protection (ICRP) , but the values of Cr for shellfish and cephalopoda were approaching the criterion. In summary, heavy metal pollution in aquatic products in Yancheng is rather severe, especially for Cr pollution, and more attention should be paid to the pollution status, edible safety and health risk.

  12. Source of atmospheric heavy metals in winter in Foshan, China.

    PubMed

    Tan, Ji-Hua; Duan, Jing-Chun; Ma, Yong-Liang; Yang, Fu-Mo; Cheng, Yuan; He, Ke-Bin; Yu, Yong-Chang; Wang, Jie-Wen

    2014-09-15

    Foshan is a ceramics manufacturing center in the world and the most polluted city in the Pearl River Delta (PRD) in southern China measured by the levels of atmospheric heavy metals. PM2.5 samples were collected in Foshan in winter 2008. Among the 22 elements and ions analyzed, 7 heavy metals (Zn, V, Mn, Cu, As, Cd and Pb) were studied in depth for their levels, spatiotemporal variations and sources. The ambient concentrations of the heavy metals were much higher than the reported average concentrations in China. The levels of Pb (675.7 ± 378.5 ng/m(3)), As (76.6 ± 49.1 ng/m(3)) and Cd (42.6 ± 45.2 ng/m(3)) exceeded the reference values of NAAQS (GB3095-2012) and the health guidelines of the World Health Organization. Generally, the levels of atmospheric heavy metals showed spatial distribution as: downtown site (CC, Chancheng District)>urban sites (NH and SD, Nanhai and Shunde Districts)>rural site (SS, Shanshui District). Two sources of heavy metals, the ceramic and aluminum industries, were identified during the sampling period. The large number of ceramic manufactures was responsible for the high levels of atmospheric Zn, Pb and As in Chancheng District. Transport from an aluminum industry park under light north-west winds contributed high levels of Cd to the SS site (Shanshui District). The average concentration of Cd under north-west wind was 220 ng/m(3), 20.5 times higher than those under other wind directions. The high daily maximum enrichment factors (EFs) of Cd, Pb, Zn, As and Cu at all four sites indicated extremely high contamination by local emissions. Back trajectory analysis showed that the heavy metals were also closely associated with the pathway of air mass. A positive matrix factorization (PMF) method was applied to determine the source apportionment of these heavy metals. Five factors (industry including the ceramic industry and coal combustion, vehicle emissions, dust, transportation and sea salt) were identified and industry was the most

  13. Perspectives in endocrine toxicity of heavy metals--a review.

    PubMed

    Rana, S V S

    2014-07-01

    An attempt has been made to review the endocrine/hormonal implications of a few environmentally significant metals, viz, lead, mercury, cadmium, copper, arsenic and nickel, in man and animals. Special emphasis has been given to the adrenals, thyroid, testis, ovary and pancreas. Toxic metals can cause structural and functional changes in the adrenal glands. Their effects on steroidogenesis have been reviewed. It has been reported that thyroid hormone kinetics are affected by a number of metallic compounds. Occupational exposure to a few of these metals can cause testicular injury and sex hormone disturbances. Protective effects of a few antioxidants on their reproductive toxicity have also been discussed. Information gathered on female reproductive toxicity of heavy metals shows that exposure to these metals can lead to disturbances in reproductive performance in exposed subjects. Certain metals can cause injury to the endocrine pancreas. Exposure to them can cause diabetes mellitus and disturb insulin homeostasis. The need to develop molecular markers of endocrine toxicity of heavy metals has been suggested. Overall information described in this review is expected to be helpful in planning future studies on endocrine toxicity of heavy metals.

  14. Implications of soil pollution with heavy metals for public health

    NASA Astrophysics Data System (ADS)

    Juozulynas, Algirdas; Jurgelėnas, Antanas; Butkienė, Birutė; Greičiūtė, Kristina; Savičiūtė, Rasa

    2008-01-01

    Soil of military grounds is often polluted with heavy metals. Their concentrations may be dosens of times higher in polluted regions. The affected soils are permeable, so the pollutions can get into water and spread to the environment. Into human and animal organisms they can get with food and water. Heavy metals are very dangerous for people's health, and we must know their accumulation places, intensity of scatter and integral risk for health. The purpose of this work was to establish links between zones polluted with heavy metals and morbidity caused by pollution with heavy metals. The morbidity caused by heavy metals (Pb, Cu, Zn, Ca and other) in the polluted regions is 1.4-1.5 times higher for adults and teenagers and 1.5-3.9 times higher for children aged under 14 years than the mean morbidity of the same diseases in Lithuania. Hypothetically, it is possible to prognosticate that this problem will grow in future because the ratio of the newly registered and the existing cases of morbidity for children aged under 14 years is 1.3-1.5 times higher than for adults.

  15. [Immobilization impact of different fixatives on heavy metals contaminated soil].

    PubMed

    Wu, Lie-shan; Zeng, Dong-mei; Mo, Xiao-rong; Lu, Hong-hong; Su, Cui-cui; Kong, De-chao

    2015-01-01

    Four kinds of amendments including humus, ammonium sulfate, lime, superphosphate and their complex combination were added to rapid immobilize the heavy metals in contaminated soils. The best material was chosen according to the heavy metals' immobilization efficiency and the Capacity Values of the fixative in stabilizing soil heavy metals. The redistributions of heavy metals were determined by the European Communities Bureau of Referent(BCR) fraction distribution experiment before and after treatment. The results were as follows: (1) In the single material treatment, lime worked best with the dosage of 2% compared to the control group. In the compound amendment treatments, 2% humus combined with 2% lime worked best, and the immobilization efficiency of Pb, Cu, Cd, Zn reached 98.49%, 99.40%, 95.86%, 99.21%, respectively. (2) The order of Capacity Values was lime > humus + lime > ammonium sulfate + lime > superphosphate > ammonium sulfate + superphosphate > humus + superphosphate > humus > superphosphate. (3) BCR sequential extraction procedure results indicated that 2% humus combined with 2% lime treatment were very effective in immobilizing heavy metals, better than 2% lime treatment alone. Besides, Cd was activated firstly by 2% humus treatment then it could be easily changed into the organic fraction and residual fraction after the subsequent addition of 2% lime.

  16. Heavy metal contamination in the Western Indian Ocean (a review)

    NASA Astrophysics Data System (ADS)

    Mamboya, F. A.; Pratap, H. B.; Björk, M.

    2003-05-01

    Western Indian Ocean Coast has many potential marine ecosystems such as mangrove, seagrass meadows, macroalgae, and coral reefs. It is largely unspoiled environment however, tourism and population growth in coastal urban centres, industrialization, are presenting a risk of pollutants input to the marine environment of the Western Indian Ocean. Mining, shipping and agricultural activities also input contaminants into the marine environment via runoff, vessel operations and accidental spillage. Heavy metals are among the pollutants that are expected to increase in the marine environment of the Western Indian Ocean. The increase in heavy metal pollution can pose a serious health problem to marine organism and human through food chain. This paper reviews studies on heavy metal contamination in the Western Indian Ocean. It covers heavy metal studies in the sediments, biota, particulates and seawater collected in different sites. In comparison to other regions, only few studies have been conducted in the Western Indian Ocean and are localized in some certain areas. Most of these studies were conducted in Kenyan and Tanzanian coasts while few of them were conducted in Mauritius, Somalia and Reunion. No standard or common method has been reported for the analysis or monitoring of heavy metals in the Western Indian Ocean.

  17. Effect of heavy metals on germination of seeds.

    PubMed

    Sethy, Sunil Kumar; Ghosh, Shyamasree

    2013-07-01

    With the expansion of the world population, the environmental pollution and toxicity by chemicals raises concern. Rapid industrialization and urbanization processes has led to the incorporation of pollutants such as pesticides, petroleum products, acids and heavy metals in the natural resources like soil, water and air thus degrading not only the quality of the environment, but also affecting both plants and animals. Heavy metals including lead, nickel, cadmium, copper, cobalt, chromium and mercury are important environmental pollutants that cause toxic effects to plants; thus, lessening productivity and posing dangerous threats to the agro-ecosystems. They act as stress to plants and affect the plant physiology. In this review, we have summarized the effects of heavy metals on seeds of different plants affecting the germination process. Although reports exist on mechanisms by which the heavy metals act as stress and how plants have learnt to overcome, the future scope of this review remains in excavating the signaling mechanisms in germinating seeds in response to heavy metal stress.

  18. New trends in removing heavy metals from wastewater.

    PubMed

    Zhao, Meihua; Xu, Ying; Zhang, Chaosheng; Rong, Hongwei; Zeng, Guangming

    2016-08-01

    With the development of researches, the treatments of wastewater have reached a certain level. Whereas, heavy metals in wastewater cause special concern in recent times due to their recalcitrance and persistence in the environment. Therefore, it is important to get rid of the heavy metals in wastewater. The previous studies have provided many alternative processes in removing heavy metals from wastewater. This paper reviews the recent developments and various methods for the removal of heavy metals from wastewater. It also evaluates the advantages and limitations in application of these techniques. A particular focus is given to innovative removal processes including adsorption on abiological adsorbents, biosorption, and photocatalysis. Because these processes have leaded the new trends and attracted more and more researches in removing heavy metals from wastewater due to their high efficency, pluripotency and availability in a copious amount. In general, the applicability, characteristic of wastewater, cost-effectiveness, and plant simplicity are the key factors in selecting the most suitable method for the contaminated wastewater.

  19. Heavy metal content of combustible municipal solid waste in Denmark.

    PubMed

    Riber, Christian; Fredriksen, Gry S; Christensen, Thomas H

    2005-04-01

    Data on the heavy metal composition of outlets from Danish incinerators was used to estimate the concentration of Zn, Cu, Pb, Cr, Ni, Cd, As and Hg in combustible waste (wet as received) at 14 Danish incinerators, representing about 80% of the waste incinerated in Denmark. Zn (1020 mg kg(-1)), Cu (620 mg kg(-1)) and Pb (370 mg kg(-1)) showed the highest concentration, whereas Hg (0.6 mg kg(-1)) showed the lowest concentration. The variation among the incinerators was in most cases within a factor of two to three, except for Cr that in two cases showed unexplained high concentrations. The fact that the data represent many incinerators and, in several cases, observations from a period of 4 to 5 years provides a good statistical basis for evaluating the content of heavy metals in combustible Danish waste. Such data may be used for identifying incinerators receiving waste with high concentrations of heavy metals suggesting the introduction of source control, or, if repeated in time, the data must also be used for monitoring the impacts of national regulation controlling heavy metals. It is recommended that future investigations consider the use of sample digestion methods that ensure complete digestion in order to use the data for determining the total heavy metal content of waste.

  20. Effect of heavy metals on germination of seeds

    PubMed Central

    Sethy, Sunil Kumar; Ghosh, Shyamasree

    2013-01-01

    With the expansion of the world population, the environmental pollution and toxicity by chemicals raises concern. Rapid industrialization and urbanization processes has led to the incorporation of pollutants such as pesticides, petroleum products, acids and heavy metals in the natural resources like soil, water and air thus degrading not only the quality of the environment, but also affecting both plants and animals. Heavy metals including lead, nickel, cadmium, copper, cobalt, chromium and mercury are important environmental pollutants that cause toxic effects to plants; thus, lessening productivity and posing dangerous threats to the agro-ecosystems. They act as stress to plants and affect the plant physiology. In this review, we have summarized the effects of heavy metals on seeds of different plants affecting the germination process. Although reports exist on mechanisms by which the heavy metals act as stress and how plants have learnt to overcome, the future scope of this review remains in excavating the signaling mechanisms in germinating seeds in response to heavy metal stress. PMID:24082715

  1. Towards a rational approach for heavy-atom derivative screening in protein crystallography

    SciTech Connect

    Agniswamy, Johnson; Joyce, M. Gordon; Hammer, Carl H.; Sun, Peter D.

    2008-04-01

    Heavy-atom derivatization is routinely used in protein structure determination and is thus of critical importance in structural biology. In order to replace the current trial-and-error heavy-atom derivative screening with a knowledge-based rational derivative-selection method, the reactivity of more than 40 heavy-atom compounds over a wide range of buffer and pH values was systematically examined using peptides which contained a single reactive amino-acid residue. Heavy-atom derivatization is routinely used in protein structure determination and is thus of critical importance in structural biology. In order to replace the current trial-and-error heavy-atom derivative screening with a knowledge-based rational derivative-selection method, the reactivity of more than 40 heavy-atom compounds over a wide range of buffer and pH values was systematically examined using peptides which contained a single reactive amino-acid residue. Met-, Cys- and His-containing peptides were derivatized against Hg, Au and Pt compounds, while Tyr-, Glu-, Asp-, Asn- and Gln-containing peptides were assessed against Pb compounds. A total of 1668 reactive conditions were examined using mass spectrometry and were compiled into heavy-atom reactivity tables. The results showed that heavy-atom derivatization reactions are highly linked to buffer and pH, with the most accommodating buffer being MES at pH 6. A group of 21 compounds were identified as most successful irrespective of ligand or buffer/pH conditions. To assess the applicability of the peptide heavy-atom reactivity to proteins, lysozyme crystals were derivatized with a list of peptide-reactive compounds that included both known and new compounds for lysozyme derivatization. The results showed highly consistent heavy-atom reactivities between the peptides and lysozyme.

  2. Sequential extraction of heavy metals during composting of sewage sludge.

    PubMed

    Amir, Soumia; Hafidi, Mohamed; Merlina, Georges; Revel, Jean-Claude

    2005-05-01

    The major limitation of soil application of sewage sludge compost is the total heavy metal contents and their bioavailability to the soil-plant system. This study was conducted to determine the heavy metal speciation and the influence of changing the physico-chemical properties of the medium in the course of composting on the concentrations, bioavailability or chemical forms of Cu, Zn, Pb and Ni in sewage sludge. Principal physical and chemical properties and FTIR spectroscopical characterization of sludge compost during treatment show the stability and maturity of end product. The total metal contents in the final compost were much lower than the limit values of composts to be used as good soil fertilizer. Furthermore, it was observed by using a sequential extraction procedure in sludge compost at different steps of treatment, that a large proportion of the heavy metals were associated to the residual fraction (70-80%) and more resistant fractions to extraction X-NaOH, X-EDTA, X-HNO3 (12-29%). Less than 2% of metals bound to bioavailable fractions X-(KNO3+H2O). Heavy metal distribution and bioavailability show some changes during composting depending on the metal itself and the physico-chemical properties of the medium. Bioavailable fractions of all elements tend to decrease except Ni-H2O. Zn and mainly Cu present more affinity to organic and carbonate fractions. In contrast, Pb is usually preferentially bound to sulfide forms X-HNO3. Nickel shows a significant decrease of organic form. Significant degrees of correlation were found between heavy metal fractions and changes of some selected variables (e.g. pH, ash, organic matter, humic substance) during the course of composting. Mobile fractions of metals are poorly predictable from the total content. The R2 value was significantly increased by the inclusion of other variables such as the amount of organic matter (OM) and pH.

  3. Magnetoresistance of heavy and light metal/ferromagnet bilayers

    SciTech Connect

    Avci, Can Onur; Garello, Kevin; Mendil, Johannes; Ghosh, Abhijit; Blasakis, Nicolas; Gabureac, Mihai; Trassin, Morgan; Fiebig, Manfred; Gambardella, Pietro

    2015-11-09

    We studied the magnetoresistance of normal metal (NM)/ferromagnet (FM) bilayers in the linear and nonlinear (current-dependent) regimes and compared it with the amplitude of the spin-orbit torques and thermally induced electric fields. Our experiments reveal that the magnetoresistance of the heavy NM/Co bilayers (NM = Ta, W, and Pt) is phenomenologically similar to the spin Hall magnetoresistance (SMR) of YIG/Pt, but has a much larger anisotropy of the order of 0.5%, which increases with the atomic number of the NM. This SMR-like behavior is absent in light NM/Co bilayers (NM = Ti and Cu), which present the standard anisotropic magnetoresistance expected from polycrystalline FM layers. In the Ta, W, and Pt/Co bilayers, we find an additional magnetoresistance directly proportional to the current and to the transverse component of the magnetization. This so-called unidirectional SMR, of the order of 0.005%, is largest in W and correlates with the amplitude of the antidamping spin-orbit torque. The unidirectional SMR is below the accuracy of our measurements in YIG/Pt.

  4. Cocoa shells for heavy metal removal from acidic solutions.

    PubMed

    Meunier, N; Laroulandie, J; Blais, J F; Tyagi, R D

    2003-12-01

    The development of economic and efficient processes for the removal of heavy metals present in acidic effluents from industrial sources or decontamination technologies has become a priority. The purpose of this work was to study the efficiency with which cocoa shells remove heavy metals from acidic solutions (pH 2) and to investigate how the composition of these solutions influences heavy metal uptake efficiency. Adsorption tests were conducted in agitated flasks with single-metal solutions (0.25 mM Al, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn), multi-metal solution (comprised of 0.25 mM of each of the cations above) and an effluent obtained from chemical leaching of metal-contaminated soil, in the presence of different cocoa shell concentrations (5-40 g/l). Results from the single-metal solution assays indicated that the fixation capacity of heavy metals by cocoa shells followed a specific order: Pb>Cr>Cd=Cu=Fe>Zn=Co>Mn=Ni=Al. Cocoa shells are particularly efficient in the removal of lead from very acidic solutions (q(max)=6.2 mg Pb/g, pH(i)=2.0 and T=22 degrees C). The presence of other metals and cations in solution did not seem to affect the recovery of lead. It was also observed that the maximum metal uptake was reached in less than 2 h. This research has also demonstrated that the removal of metals caused a decline in solution proton concentration (pH increase) and release of calcium, magnesium, potassium and sodium from the cocoa shells.

  5. Assessment of Heavy Metal Contamination in Vegetables Grown Using Paper Mill Wastewater in Wonji Gefersa, Ethiopia.

    PubMed

    Eliku, Temesgen; Leta, Seyoum

    2016-11-01

    Heavy metals are among the major contaminants of vegetables. A study was conducted at Wonji Gefersa farms where paper wastewater is used for cultivation of vegetable crops. Four vegetable samples, namely Swiss chard, carrot, tomato, green pepper, as well as paper wastewater were examined for heavy metal [Lead (Pb), Zinc (Zn), Cadmium (Cd), Iron (Fe), Copper (Cu), Chromium (Cr) and Cobalt (Co)] contamination using atomic absorption spectroscopy. The levels of Pb, Cd and Cr in paper wastewater were all above the safe limit for FAO standards for wastewater quality for irrigation. The concentration of Pb in Swiss chard and Green peeper was exceeded the permissible limits. The study reveals that Pb metal contamination in the study area which poses health risk with time unless an urgent step is taken by relevant agencies to address this issue.

  6. Trees as bioindicator of heavy metal pollution in three European cities.

    PubMed

    Sawidis, T; Breuste, J; Mitrovic, M; Pavlovic, P; Tsigaridas, K

    2011-12-01

    Concentrations of four heavy metals were determined in tree leaves and bark collected from polluted and non-polluted areas of three European cities (Salzburg, Belgrade and Thessaloniki) for a comparative study. Platanus orientalis L. and Pinus nigra Arn., widespread in urban northern and southern Europe, were tested for their suitability for air quality biomonitoring. Leaves and barks were collected uniformly of an initial quantity of about 30 g of each sample. Analysis was accomplished by electrothermal atomic absorption spectrometry after total digestion. Site-dependent variations were found with the highest concentration level measured in Belgrade, followed by Thessaloniki and Salzburg. A higher accumulation of heavy metals was found in bark compared to leaves. Pine tree bark, accumulating higher concentrations of trace metals compared to plane tree bark, shows a higher efficiency as bioindicator for urban pollution. Both indicator species are suitable for comparative studies on bioindication of urban air pollution.

  7. Heavy Metal Exposure Influences Double Strand Break DNA Repair Outcomes.

    PubMed

    Morales, Maria E; Derbes, Rebecca S; Ade, Catherine M; Ortego, Jonathan C; Stark, Jeremy; Deininger, Prescott L; Roy-Engel, Astrid M

    2016-01-01

    Heavy metals such as cadmium, arsenic and nickel are classified as carcinogens. Although the precise mechanism of carcinogenesis is undefined, heavy metal exposure can contribute to genetic damage by inducing double strand breaks (DSBs) as well as inhibiting critical proteins from different DNA repair pathways. Here we take advantage of two previously published culture assay systems developed to address mechanistic aspects of DNA repair to evaluate the effects of heavy metal exposures on competing DNA repair outcomes. Our results demonstrate that exposure to heavy metals significantly alters how cells repair double strand breaks. The effects observed are both specific to the particular metal and dose dependent. Low doses of NiCl2 favored resolution of DSBs through homologous recombination (HR) and single strand annealing (SSA), which were inhibited by higher NiCl2 doses. In contrast, cells exposed to arsenic trioxide preferentially repaired using the "error prone" non-homologous end joining (alt-NHEJ) while inhibiting repair by HR. In addition, we determined that low doses of nickel and cadmium contributed to an increase in mutagenic recombination-mediated by Alu elements, the most numerous family of repetitive elements in humans. Sequence verification confirmed that the majority of the genetic deletions were the result of Alu-mediated non-allelic recombination events that predominantly arose from repair by SSA. All heavy metals showed a shift in the outcomes of alt-NHEJ repair with a significant increase of non-templated sequence insertions at the DSB repair site. Our data suggest that exposure to heavy metals will alter the choice of DNA repair pathway changing the genetic outcome of DSBs repair.

  8. Cold collisions of heavy 2Σ molecules with alkali-metal atoms in a magnetic field: Ab initio analysis and prospects for sympathetic cooling of SrOH (+2Σ) by Li (2S)

    NASA Astrophysics Data System (ADS)

    Morita, Masato; Kłos, Jacek; Buchachenko, Alexei A.; Tscherbul, Timur V.

    2017-06-01

    We use accurate ab initio and quantum scattering calculations to explore the prospects for sympathetic cooling of the heavy molecular radical SrOH (2Σ+) by ultracold Li atoms in a magnetic trap. Our ab initio calculations show that the chemical reaction between spin-polarized Li and SrOH, which occurs on the triplet Li-SrOH potential energy surface (PES), is strongly endothermic and hence energetically forbidden at ultralow temperatures. The chemical reaction Li (2S) +SrOH (2Σ+) →Sr (1S) +LiOH (1Σ+) occurs barrierlessly on the singlet PES and is exothermic by 2505 cm-1. A two-dimensional PES for the triplet electronic state of Li-SrOH is calculated ab initio using the partially spin-restricted coupled cluster method with single, double, and perturbative triple excitations and a large correlation-consistent basis set. The highly anisotropic PES has a deep global minimum in the skewed Li-HOSr geometry with De=4932 cm-1 and saddle points in collinear configurations. Our quantum scattering calculations predict low spin-relaxation rates in fully spin-polarized Li + SrOH collisions with the ratios of elastic to inelastic collision rates well in excess of 100 over a wide range of magnetic fields (1-1000 G) and collision energies (10-5 to 0.1 K), suggesting favorable prospects for sympathetic cooling of SrOH molecules with spin-polarized Li atoms in a magnetic trap. We find that spin relaxation in Li + SrOH collisions occurs via a direct mechanism mediated by the magnetic dipole-dipole interaction between the electron spins of Li and SrOH, and that the indirect (spin-rotation) mechanism is strongly suppressed. The upper limit to the Li + SrOH reaction rate coefficient calculated for the singlet PES using adiabatic capture theory is found to decrease from 4 ×10-10cm3 /s to a limiting value of 3.5 ×10-10cm3 /s with decreasing temperature from 0.1 K to 1 μ K .

  9. Investigations of Atomic Transport Induced by Heavy Ion Irradiation

    NASA Astrophysics Data System (ADS)

    Banwell, Thomas Clyde

    The mechanisms of atomic transport induced by ion irradiation generally fall into the categories of anisotropic or isotropic processes. Typical examples of these are recoil implantation and cascade mixing, respectively. We have measured the interaction of these processes in the mixing of Ti/SiO(,2)/Si, Cr/SiO(,2)/Si and Ni/SiO(,2)/Si multi-layers irradiated with Xe at fluences of 0.01 - 10 x 10('15)cm('-2). The fluence dependence of net metal transport into the underlying layers was measured with different thicknesses of SiO(,2) and different sample temperatures during irradiation (-196 to 500C). There is a linear dependence at low fluences. At high fluences, a square-root behavior predominates. For thin SiO(,2) layers (<20nm), the cross -over point depends on the SiO(,2) thickness. These results are readily interpreted in terms of competition between the flux of injected atoms and diffusion of the accumulating metal. The detailed analysis allows us to speculate on the role of chemical reaction kinetics in controlling the outcome of intra-cascade processes. There is no significant correlation between the reactivity of the metal with SiO(,2) and the amount of mixing observed when the irradiations are performed at 25C or below. The contribution from primary recoils is quite pronounced since the gross mixing is small. A significant correlation exists between the mixing and the energy deposited through elastic collisions F(,D ). Several models are examined in an attempt to describe the transport process in Ni/SiO(,2). It is likely that injection of Ni by secondary recoil implantation is primarily responsible for getting Ni into the SiO(,2). Secondary recoil injection is thought to scale with F(,D). Trends in the mixing rates indicate that the dominant mechanism for Ti and Cr could be the same as for Ni. The processes of atomic transport and phase formation clearly fail to be separable at higher temperatures. A positive correlation with chemical reactivity emerges at

  10. Certain antioxidant enzymes of Allium cepa as biomarkers for the detection of toxic heavy metals in wastewater.

    PubMed

    Fatima, Riffat A; Ahmad, Masood

    2005-06-15

    The utility of antioxidant enzymes, viz glutathione-S-transferase (GST), glutathione reductase (GR), superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), glutathione peroxidase (GPX), monodehydroascorbate reductase (MDHAR) and dehydroascorbate reductase (DHAR), as biomarkers of heavy metal pollution in water was investigated using the Allium cepa (onion) system. These antioxidant enzymes were assayed in onion bulbs exposed to certain heavy metals taken separately, the test metals taken in combination as well as the industrial wastewater especially found to contain these metals. GST exhibited significantly enhanced activity upon treatment with individual heavy metals. However, GR, SOD and CAT did not show such a pronounced increase in activities. At higher heavy metal concentrations, GR, SOD and CAT showed a steep decline while GST activity still showed a rise. Moreover, APX, GPX and MDHAR also exhibited remarkable induction with increase in the concentration of individual heavy metals. However, there was no significant change in DHAR activity with respect to the controls. Metabolites like ascorbate (ASC) and glutathione (GSH) exhibited significant decline with increase in the concentration of individual heavy metals while the level of H(2)O(2) continued to display the rise up to a heavy metal concentration of 100 microM, after which it showed a gradual decline. A. cepa bulbs treated with wastewater sample showed enzyme activity profiles similar to that shown with heavy metals, thereby suggesting the presence of heavy metals in the test wastewater. Atomic absorption spectrophotometry also detected large amounts of Cd, Cr, Cu, Hg, Pb and Zn in the test water sample. The metal mixture, containing the amounts of heavy metals equivalent to those found in the wastewater, resulted in steep declines in GR, SOD and CAT activities in A. cepa while GST showed a rise. However, when this metal mixture was diluted to 2000-fold, GR, SOD and CAT also showed

  11. Heavy Metal Contaminated Soil Treatment: Conceptual Development

    DTIC Science & Technology

    1987-02-01

    circuit without trans- ferring hear from a metallic resistance element. Contaminated soils may be accepted directly with little or (to pretreatment ...with metals has been demon-- strated. No pretreatment for organics destruction would be required. The system can also readily handle liquid wastes and...applications as a pretreatment /recovery step. J 38 0458Bi 3.7.3 Long term stability/performance. The process would remove metals from the soil. Therefore, if

  12. The environmental impact of gold mines: pollution by heavy metals

    NASA Astrophysics Data System (ADS)

    Abdul-Wahab, Sabah Ahmed; Marikar, Fouzul Ameer

    2012-06-01

    The gold mining plant of Oman was studied to assess the contribution of gold mining on the degree of heavy metals into different environmental media. Samples were collected from the gold mining plant area in tailings, stream waters, soils and crop plants. The collected samples were analyzed for 13 heavy metals including vanadium (V), chromium (Cr), manganese (Mn), nickel (Ni), copper (Cu), cadmium (Cd), cobalt (Co), lead (Pb), zinc (Zn), aluminium (Al), strontium (Sr), iron (Fe) and barium (Ba). The water in the acid evaporation pond showed a high concentration of Fe as well as residual quantities of Zn, V, and Al, whereas water from the citizens well showed concentrations of Al above those of Omani and WHO standards. The desert plant species growing closed to the gold pit indicated high concentrations of heavy metals (Mn, Al, Ni, Fe, Cr, and V), while the similar plant species used as a control indicated lesser concentrations of all heavy metals. The surface water (blue) indicated very high concentrations of copper and significant concentrations of Mn, Ni, Al, Fe, Zn, lead, Co and Cd. The results revealed that some of the toxic metals absorbed by plants indicated significant metal immobilization.

  13. The environmental impact of gold mines: pollution by heavy metals

    NASA Astrophysics Data System (ADS)

    Abdul-Wahab, Sabah; Marikar, Fouzul

    2012-06-01

    The gold mining plant of Oman was studied to assess the contribution of gold mining on the degree of heavy metals into different environmental media. Samples were collected from the gold mining plant area in tailings, stream waters, soils and crop plants. The collected samples were analyzed for 13 heavy metals including vanadium (V), chromium (Cr), manganese (Mn), nickel (Ni), copper (Cu), cadmium (Cd), cobalt (Co), lead (Pb), zinc (Zn), aluminium (Al), strontium (Sr), iron (Fe) and barium (Ba). The water in the acid evaporation pond showed a high concentration of Fe as well as residual quantities of Zn, V, and Al, whereas water from the citizens well showed concentrations of Al above those of Omani and WHO standards. The desert plant species growing closed to the gold pit indicated high concentrations of heavy metals (Mn, Al, Ni, Fe, Cr, and V), while the similar plant species used as a control indicated lesser concentrations of all heavy metals. The surface water (blue) indicated very high concentrations of copper and significant concentrations of Mn, Ni, Al, Fe, Zn, lead, Co and Cd. The results revealed that some of the toxic metals absorbed by plants indicated significant metal immobilization.

  14. Beneficial effect of sesame oil on heavy metal toxicity.

    PubMed

    Chandrasekaran, Victor Raj Mohan; Hsu, Dur-Zong; Liu, Ming-Yie

    2014-02-01

    Heavy metals become toxic when they are not metabolized by the body and accumulate in the soft tissue. Chelation therapy is mainly for the management of heavy metal-induced toxicity; however, it usually causes adverse effects or completely blocks the vital function of the particular metal chelated. Much attention has been paid to the development of chelating agents from natural sources to counteract lead- and iron-induced hepatic and renal damage. Sesame oil (a natural edible oil) and sesamol (an active antioxidant) are potently beneficial for treating lead- and iron-induced hepatic and renal toxicity and have no adverse effects. Sesame oil and sesamol significantly inhibit iron-induced lipid peroxidation by inhibiting the xanthine oxidase, nitric oxide, superoxide anion, and hydroxyl radical generation. In addition, sesame oil is a potent inhibitor of proinflammatory mediators, and it attenuates lead-induced hepatic damage by inhibiting nitric oxide, tumor necrosis factor-α, and interleukin-1β levels. Because metal chelating therapy is associated with adverse effects, treating heavy metal toxicity in addition with sesame oil and sesamol may be better alternatives. This review deals with the possible use and beneficial effects of sesame oil and sesamol during heavy metal toxicity treatment.

  15. Agro-improving method of phytoextracting heavy metal contaminated soil.

    PubMed

    Wei, Shuhe; Teixeira da Silva, Jaime A; Zhou, Qixing

    2008-02-11

    Phytoextraction of heavy metal contaminated soils is a promising remediation technology. Till now, more than several hundreds of hyperaccumulators or non-hyperaccumulators which can be used to clean polluted soils with heavy metals have been reported. However, phytoextraction is still not extensively applied. Thus, some measurements should be taken to improve phytoremediation. This paper introduced the basic mechanisms of phytoextration, its main restrictive factors, its relationship with agricultural technology and some agricultural improvement methods. We suggested that unavailable heavy metal activation, crop breeding, seed-coating and felicitous utilization of fertilizer and water, as well as the use of two-phase planting may be important and indispensable paths for phytoextraction to be widely applied at a commercial level in the future.

  16. Dustfall Heavy Metal Pollution During Winter in North China.

    PubMed

    Xiong, Qiu-lin; Zhao, Wen-ji; Guo, Xiao-yu; Shu, Tong-tong; Chen, Fan-tao; Zheng, Xiao-xia; Gong, Zhao-ning

    2015-10-01

    In order to study heavy metal pollution in dustfall during Winter in North China, forty-four dustfall samples were collected in North China Region from November 2013 to March 2014. Then forty trace elements content were measured for each sample by inductively coupled plasma-mass spectrometry. Finally, the contamination characteristics of the main heavy metals were studied through a multi-method analysis, including variability analysis, Pearson correlation analysis and principal component analysis. Results showed that the relative contents of cadmium (Cd), zinc (Zn), copper (Cu), bismuth (Bi), lead (Pb) exceeded the standards stipulated in Chinese soil elements background values by amazing 4.9 times. In this study, conclusions were drawn that dustfall heavy metal pollution in the region was mainly caused by transport pollution, metallurgy industrial pollution, coal pollution and steel industrial pollution.

  17. Baker's yeast assay procedure for testing heavy metal toxicity

    SciTech Connect

    Bitton, G.; Koopman, B.; Wang, H.D.

    1984-01-01

    Baker's yeast (Saccharomyces cerevisiae) is microorganism which is commercially available and sold as packaged dry pellets in any food store at low cost. Studies have been undertaken on the effects of organic xenobiotics as well as heavy metals on yeast metabolism. This type of study has been generally useful in examining the mechanism(s) of chemical toxicity. However, a rapid and quantitative toxicity test using S. cerevisiae as the test organism has not been developed. The purpose of this study was to develop a toxicity assay for heavy metals, using commercial dry yeast as the test microorganism. This rapid and simple procedure is based on the reduction of 2-(p-iodophenyl)-3-(p-nitrophenyl)-5-phenyltetrazolium chloride (INT) to INT-formazan by the yeast electron transport system. The scoring of active cells following exposure to heavy metals was undertaken according to the MINT (malachite green-INT) method developed by Bitton and Koopman.

  18. Interactions between plant hormones and heavy metals responses

    PubMed Central

    Bücker-Neto, Lauro; Paiva, Ana Luiza Sobral; Machado, Ronei Dorneles; Arenhart, Rafael Augusto; Margis-Pinheiro, Marcia

    2017-01-01

    Abstract Heavy metals are natural non-biodegradable constituents of the Earth's crust that accumulate and persist indefinitely in the ecosystem as a result of human activities. Since the industrial revolution, the concentration of cadmium, arsenic, lead, mercury and zinc, amongst others, have increasingly contaminated soil and water resources, leading to significant yield losses in plants. These issues have become an important concern of scientific interest. Understanding the molecular and physiological responses of plants to heavy metal stress is critical in order to maximize their productivity. Recent research has extended our view of how plant hormones can regulate and integrate growth responses to various environmental cues in order to sustain life. In the present review we discuss current knowledge about the role of the plant growth hormones abscisic acid, auxin, brassinosteroid and ethylene in signaling pathways, defense mechanisms and alleviation of heavy metal toxicity. PMID:28399194

  19. Effect of Heavy Metals in Plants of the Genus Brassica

    PubMed Central

    Mourato, Miguel P.; Moreira, Inês N.; Leitão, Inês; Pinto, Filipa R.; Sales, Joana R.; Louro Martins, Luisa

    2015-01-01

    Several species from the Brassica genus are very important agricultural crops in different parts of the world and are also known to be heavy metal accumulators. There have been a large number of studies regarding the tolerance, uptake and defense mechanism in several of these species, notably Brassica juncea and B. napus, against the stress induced by heavy metals. Numerous studies have also been published about the capacity of these species to be used for phytoremediation purposes but with mixed results. This review will focus on the latest developments in the study of the uptake capacity, oxidative damage and biochemical and physiological tolerance and defense mechanisms to heavy metal toxicity on six economically important species: B. juncea, B. napus, B. oleracea, B. carinata, B. rapa and B. nigra. PMID:26247945

  20. Separation Characteristics of Heavy Metal Compounds by Hot Gas Cleaning System

    SciTech Connect

    Sakano, T.; Kanaoka, C.; Furuuchi, M.; Yang, K-S.; Hata, M.

    2002-09-20

    The purpose of this research is the basic study for the development of separation technology of heavy metal compounds from hot flue gas. While the hot flue gas containing heavy metals from a melting furnace of industrial waste passes through the high temperature dust collector which can be varied the operating temperature. The heavy metals can be separated due to different boiling point of each heavy metal. On the basis of this concept, the concentration of heavy metals in the flue gas were sampled and measured at inlet, outlet of the ceramic filter housing in the actual industrial waste processing system. Speciation of heavy metals in collected ashes was clarified by separating heavy metals according to compounds using their elution characteristics. Moreover, equilibrium analysis was performed to determine the effect of temperature, flue gases conditions on heavy metals speciation, and it was compared with experimental data. From these results, we discussed about separation performance of heavy metal compounds by hot gas cleaning.

  1. Total concentrations and chemical speciation of heavy metals in liquefaction residues of sewage sludge.

    PubMed

    Yuan, Xingzhong; Huang, Huajun; Zeng, Guangming; Li, Hui; Wang, Jingyu; Zhou, Chunfei; Zhu, Huina; Pei, Xiaokai; Liu, Zhifeng; Liu, Zhantao

    2011-03-01

    The risk (including bioavailability and eco-toxicity) of heavy metals (Pb, Zn, Cu, Cd, Cr and Ni) in liquefaction residues (LR) of sewage sludge (SS) was estimated, according to both the speciation of heavy metals and the local environmental characteristics. The amount of organic matters in LR was lower than that in SS, resulting in a smaller calorific value, while the total content of heavy metals in LR nearly doubled. High residual rates of heavy metals (about 80%) indicated that the heavy metals in SS were concentrated into LR after liquefaction. The comparisons of sequential extraction results between SS and LR showed that after liquefaction, the mobile and easily available heavy metal fractions (acid soluble/exchangeable and reducible fractions) were mainly transformed into the relatively stable heavy metal fractions (oxidizable and residual fractions). The bioavailability and eco-toxicity of heavy metals in LR were relieved, though the total concentrations of heavy metals increased.

  2. Heavy metal pollution in coastal areas of South China: a review.

    PubMed

    Wang, Shuai-Long; Xu, Xiang-Rong; Sun, Yu-Xin; Liu, Jin-Ling; Li, Hua-Bin

    2013-11-15

    Coastal areas of South China face great challenges due to heavy metal contamination caused by rapid urbanization and industrialization. In this paper, more than 90 articles on levels, distributions, and sources of heavy metals in sediments and organisms were collected to review the status of heavy metal pollution along coastal regions of South China. The results show that heavy metal levels were closely associated with local economic development. Hong Kong and the Pearl River Estuary were severely contaminated by heavy metals. However, concentrations of heavy metals in sediments from Hong Kong have continually decreased since the early 1990 s. High levels of heavy metals were found in biota from Lingdingyang in Guangdong province. Mollusks had higher concentrations of heavy metals than other species. Human health risk assessments suggested that levels of heavy metals in some seafood from coastal areas of South China exceeded the safety limit.

  3. Characterization of a heavy metal translocating P-type ATPase gene from an environmental heavy metal resistance Enterobacter sp. isolate.

    PubMed

    Chien, Chih-Ching; Huang, Chia-Hsuan; Lin, Yi-Wei

    2013-03-01

    Heavy metals are common contaminants found in polluted areas. We have identified a heavy metal translocating P-type ATPase gene (hmtp) via fosmid library and in vitro transposon mutagenesis from an Enterobacter sp. isolate. This gene is believed to participate in the bacterium's heavy metal resistance traits. The complete gene was identified, cloned, and expressed in a suitable Escherichia coli host cell. E. coli W3110, RW3110 (zntA::Km), GG48 (ΔzitB::Cm zntA::Km), and GG51 (ΔzitB::Cm) were used to study the possible effects of this gene for heavy metal (cadmium and zinc in particular) resistance. Among the E. coli strains tested, RW3110 and GG48 showed more sensitivity to cadmium and zinc compared to the wild-type E. coli W3110 and strain GG51. Therefore, strains RW3110 and GG48 were chosen for the reference hosts for further evaluation of the gene's effect. The results showed that expression of this heavy metal translocating P-type ATPase gene could increase the ability for zinc and cadmium resistance in the tested microorganisms.

  4. Contamination, toxicity and speciation of heavy metals in an industrialized urban river: Implications for the dispersal of heavy metals.

    PubMed

    Wu, Qihang; Zhou, Haichao; Tam, Nora F Y; Tian, Yu; Tan, Yang; Zhou, Song; Li, Qing; Chen, Yongheng; Leung, Jonathan Y S

    2016-03-15

    Urban rivers are often utilized by the local residents as water source, but they can be polluted by heavy metals due to industrialization. Here, the concentrations, toxicity, speciation and vertical profiles of heavy metals in sediment were examined to evaluate their impact, dispersal and temporal variation in Dongbao River. Results showed that the sediment in the industrialized areas was seriously contaminated with Cr, Cu and Ni which posed acute toxicity. Heavy metals, except Cr and Pb, were mainly associated with non-residual fractions, indicating their high mobility and bioavailability. The non-industrialized areas were also seriously contaminated, suggesting the dispersal of heavy metals along the river. The surface sediment could be more contaminated than the deep sediment, indicating the recent pollution events. Overall, when the point sources are not properly regulated, intense industrialization can cause both serious contamination and dispersal of heavy metals, which have far-reaching consequences in public health and environment. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Heavy metals accumulation affects bone microarchitecture in osteoporotic patients.

    PubMed

    Scimeca, Manuel; Feola, Maurizio; Romano, Lorenzo; Rao, Cecilia; Gasbarra, Elena; Bonanno, Elena; Brandi, Maria Luisa; Tarantino, Umberto

    2017-04-01

    Bone metabolism is affected by mechanical, genetic, and environmental factors and plays a major role in osteoporosis. Nevertheless, the influence of environmental pollution on the occurrence of osteoporosis is still unclear and controversial. In this context, heavy metals are the most important pollutants capable to affect bone mass. The aim of this study was to investigate whether heavy metals accumulation in bone tissues could be related to the altered bone metabolism and architecture of osteoporotic patients. To this end, we analyzed 25 bone head biopsies osteoporotic patients and 25 bone head biopsies of osteoarthritic patients. Moreover we enrolled 15 patients underwent hip arthroplasty for high-energy hip fracture or osteonecrosis of the femoral head as a control group. Bone head biopsies were studied by BioQuant-osteo software, scanning electron microscopy and Energy Dispersive X-ray microanalysis. We found a prevalence of lead, cadmium and chromium accumulation in osteoporotic patients. Noteworthy, high levels of sclerostin, detected by immunohistochemistry, correlate with the accumulation of heavy metal found in the bone of osteoporotic patients, suggesting a molecular link between heavy metal accumulation and bone metabolism impairment. In conclusion, the presence of heavy metals into bone shed new light on the comprehension of the pathogenesis of osteoporosis since these elements could play a non redundant role in the development of osteoporosis at cellular/molecular and epigenetic level. Nevertheless, in vivo and in vitro studies need to better elucidate the molecular mechanism in which heavy metals can participate to osteoporosis. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 1333-1342, 2017. © 2016 Wiley Periodicals, Inc.

  6. Assessment of Heavy Metal Pollution in Topsoil around Beijing Metropolis.

    PubMed

    Sun, Ranhao; Chen, Liding

    2016-01-01

    The topsoil around Beijing metropolis, China, is experiencing impacts of rapid urbanization, intensive farming, and extensive industrial emissions. We analyzed the concentrations of Cu, Ni, Pb, Zn, Cd, and Cr from 87 topsoil samples in the pre-rainy season and 115 samples in the post-rainy season. These samples were attributed to nine land use types: forest, grass, shrub, orchard, wheat, cotton, spring maize, summer maize, and mixed farmland. The pollution index (PI) of heavy metals was calculated from the measured and background concentrations. The ecological risk index (RI) was assessed based on the PI values and toxic-response parameters. The results showed that the mean PI values of Pb, Cr, and Cd were > 1 while those of Cu, Ni, and Zn were < 1. All the samples had low ecological risk for Cu, Ni, Pb, Zn, and Cr while only 15.35% of samples had low ecological risk for Cd. Atmospheric transport rather than land use factors best explained the seasonal variations in heavy metal concentrations and the impact of atmospheric transport on heavy metal concentrations varied according to the heavy metal types. The concentrations of Cu, Cd, and Cr decreased from the pre- to post-rainy season, while those of Ni, Pb, and Zn increased during this period. Future research should be focused on the underlying atmospheric processes that lead to these spatial and seasonal variations in heavy metals. The policymaking on environmental management should pay close attention to potential ecological risks of Cd as well as identifying the transport pathways of different heavy metals.

  7. Assessment of Heavy Metal Pollution in Topsoil around Beijing Metropolis

    PubMed Central

    Sun, Ranhao; Chen, Liding

    2016-01-01

    The topsoil around Beijing metropolis, China, is experiencing impacts of rapid urbanization, intensive farming, and extensive industrial emissions. We analyzed the concentrations of Cu, Ni, Pb, Zn, Cd, and Cr from 87 topsoil samples in the pre-rainy season and 115 samples in the post-rainy season. These samples were attributed to nine land use types: forest, grass, shrub, orchard, wheat, cotton, spring maize, summer maize, and mixed farmland. The pollution index (PI) of heavy metals was calculated from the measured and background concentrations. The ecological risk index (RI) was assessed based on the PI values and toxic-response parameters. The results showed that the mean PI values of Pb, Cr, and Cd were > 1 while those of Cu, Ni, and Zn were < 1. All the samples had low ecological risk for Cu, Ni, Pb, Zn, and Cr while only 15.35% of samples had low ecological risk for Cd. Atmospheric transport rather than land use factors best explained the seasonal variations in heavy metal concentrations and the impact of atmospheric transport on heavy metal concentrations varied according to the heavy metal types. The concentrations of Cu, Cd, and Cr decreased from the pre- to post-rainy season, while those of Ni, Pb, and Zn increased during this period. Future research should be focused on the underlying atmospheric processes that lead to these spatial and seasonal variations in heavy metals. The policymaking on environmental management should pay close attention to potential ecological risks of Cd as well as identifying the transport pathways of different heavy metals. PMID:27159454

  8. Heavy metal concentrations in marine green, brown, and red seaweeds from coastal waters of Yemen, the Gulf of Aden

    NASA Astrophysics Data System (ADS)

    Al-Shwafi, Nabil A.; Rushdi, Ahmed I.

    2008-08-01

    The purpose of this study was to investigate the concentration levels of heavy metals in different species of the main three marine algal divisions from the Gulf of Aden coastal waters, Yemen. The divisions included Chlorophyta—green plants ( Halimeda tuna, Rhizoclonium kochiamum, Caldophora koiei, Enteromorpha compressa, and Caulerpa racemosa species), Phaeophyta—brown seaweeds ( Padina boryana, Turbinaria elatensis, Sargassum binderi, Cystoseira myrica, and Sargassum boveanum species), and Rhodophyta—red seaweeds ( Hypnea cornuta, Champia parvula, Galaxaura marginate, Laurencia paniculata, Gracilaria foliifere, and species). The heavy metals, which included cadmium (Cd), cobalt (Co), copper (Cu), chromium (Cr), Iron (Fe), manganese (Mn), nickel (Ni), lead (Pb), zinc (Zn), and vanadium (V) were measured by Atomic Absorption Spectrophotometer (AAs). The concentrations of heavy metals in all algal species are in the order of Fe >> Cu > Mn > Cr > Zn > Ni > Pb > Cd > V > Co. The results also showed that the uptake of heavy metals by different marine algal divisions was in the order of Chlorophyta > Phaeophyta > Rhodophyta. These heavy metals were several order of magnitude higher than the concentrations of the same metals in seawater. This indicates that marine alga progressively uptake heavy metals from seawater.

  9. Heavy metal bioaccumulation in mangrove ecosystem at the coral triangle ecoregion, Southeast Sulawesi, Indonesia.

    PubMed

    Analuddin, Kangkuso; Sharma, Sahadev; Jamili; Septiana, Andi; Sahidin, Idin; Rianse, Usman; Nadaoka, Kazuo

    2017-08-07

    This study aimed to determine the role of mangroves as a biofilter of heavy metals. The concentrations of heavy metals, namely copper, mercury, cadmium, zinc, and lead, in the mangroves Rhizophora apiculata, Ceriops tagal, Bruguiera gymnorrhiza, Lumnitzera racemosa, Xylocarpus granatum, Sonneratia alba, and Bruguiera parviflora at RAWN Park were determined using a Flame atomic absorption spectrophotometer. High concentrations of Cu (83.85μgg(-1)) and Hg (0.52μgg(-1)) were found in the tissues of L. racemosa, while high concentrations of Cd (10.81μgg(-1)), Zn (70.41μgg(-1)), and Pb (1.36μgg(-1)) were found in the tissues of B. gymnorrhiza, B. parviflora and C. tagal, respectively. The translocation and bioaccumulation factors of heavy metals by mangroves showed a variety of trends, which indicated the different partitioning and uptake capability of heavy metals in the tissues of various mangrove species. Thus, maintaining high diversity of mangroves is crucial to ensure the health and productivity of coastal zones. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Effects of rare earth elements on the distribution of mineral elements and heavy metals in horseradish.

    PubMed

    Wang, Lihong; Huang, Xiaohua; Zhou, Qing

    2008-09-01

    In order to investigate the effects of rare earth elements (REEs) on horseradish, the distribution of the mineral elements and heavy metals in different organs of horseradish have been studied by using inductively coupled plasma-atomic emission spectrometry (ICP-AES). Meanwhile, three variable major parameters, namely the concentration of REEs, the type of REEs, and the growth stage of plant were chosen. The results indicated that the test REEs, Ce(III) and Tb(III), could be accumulated in leaves, stems and roots of horseradish. In addition, we found that the content of mineral elements was increased in horseradish treated with 20mgl(-1) of Ce(III), but not those with the 20mgl(-1) of Tb(III). Moreover, the content of mineral elements in horseradish was decreased with the increasing concentration of REEs (100, 300mgl(-1)). Furthermore, we found that there were the opposite effects on the content of the heavy metals in horseradish treated with REEs. Finally, we found that the effect of REEs on the accumulation of REEs, and the content of mineral elements or heavy metals of horseradish during vigorous growth stage, no matter positive or negative, was more obvious than that of the other growth stages. These results demonstrated that the distribution behaviors of mineral elements and heavy metals in horseradish can be affected by the type and concentration of REEs, and the growth period of plant.

  11. Removal of heavy metals from tannery effluents of Ambur industrial area, Tamilnadu by Arthrospira (Spirulina) platensis.

    PubMed

    Balaji, S; Kalaivani, T; Rajasekaran, C; Shalini, M; Vinodhini, S; Priyadharshini, S Sunitha; Vidya, A G

    2015-06-01

    The present study was carried out with the tannery effluent contaminated with heavy metals collected from Ambur industrial area to determine the phycoremediation potential of Arthrospira (Spirulina) platensis. Two different concentrations (50 and 100 %) of heavy metals containing tannery effluent treated with A. platensis were analysed for growth, absorption spectra, biochemical properties and antioxidant enzyme activity levels. The effluent treatments revealed dose-dependent decrease in the levels of A. platensis growth (65.37 % for 50 % effluent and 49.32 % for 100 % effluent), chlorophyll content (97.43 % for 50 % effluent and 71.05 % for 100 % effluent) and total protein content (82.63 % for 50 % effluent and 62.10 % for 100 % effluent) that leads to the reduction of total solids, total dissolved solids and total suspended solids. A. platensis with lower effluent concentration was effective than at higher concentration. Treatment with the effluent also resulted in increased activity levels of antioxidant enzymes, such as superoxide dismutase (14.58 units/g fresh weight for 50 % and 24.57 units/g fresh weight for 100 %) and catalase (0.963 units/g fresh weight for 50 % and 1.263 units/g fresh weight for 100 %). Furthermore, heavy metal content was determined using atomic absorption spectrometry. These results indicated that A. platensis has the ability to combat heavy metal stress by the induction of antioxidant enzymes demonstrating its potential usefulness in phycoremediation of tannery effluent.

  12. Screening heavy metals levels in hair of sanitation workers by X-ray fluorescence analysis.

    PubMed

    Md Khudzari, Jauharah; Wagiran, Husin; Hossain, I; Ibrahim, Noorddin

    2013-01-01

    This work presents a study of human hair as a bio-indicator for detection of heavy metals as part of environmental health surveillance programs project to develop a subject of interest in the biomedical and environmental sciences. A total of 34 hair samples were analyzed that consisting of 29 samples from sanitation workers and five samples from students. The hair samples were prepared and treated in accordance to the International Atomic Energy Agency (IAEA) recommendations. The concentrations of heavy metals were analyzed using the energy dispersive X-ray fluorescence (EDXRF) technique by X-50 Mobile X-ray Fluorescence (XRF) at Oceanography Institute, Universiti Malaysia Terengganu. The performance of EDXRF analyzer was tested by Standard Reference Material (SRM 2711) Montana Soil which was in good agreement with certified value within 14% deviations except for Hg. While seven heavy metals: Mn, Fe, Ni, Cu, Zn, Se, and Sb were detected in both groups, three additional elements, i.e. As, Hg and Pb, were detected only in sanitation workers group. For sanitation workers group, the mean concentration of six elements, Mn, Fe, Cu, Zn, Se, and Sb, shows elevated concentration as compared to the control samples concentration. Results from both groups were compared and discussed in relation to their respective heavy metals concentrations.

  13. [Genotoxic effects in a human population exposed to heavy metals in the region of La Mojana, Colombia, 2013].

    PubMed

    Calao, Clelia Rosa; Marrugo, José Luis

    2015-08-01

    Mining is an economically important activity in Colombia which generates large quantities of residues containing potentially toxic elements such as heavy metals. These contaminate ecosystems and place human health at risk. La Mojana lies within one of the most biodiversity-rich zones on Earth and has been subjected to processes of contamination closely related to gold mining activities in the surrounding areas. To evaluate genotoxicity in the population of La Mojana region exposed to heavy metals. Genotoxic effects and their relationship with concentrations of heavy metals (mercury, cadmium and lead) in blood were evaluated among an exposed population and a control group. The exposed group comprised inhabitants of the municipalities of Guaranda, Sucre, Majagual and San Marcos; inhabitants of the municipality of Montería were chosen as a control group. DNA damage was determined using the alkaline comet assay. Concentrations of mercury were determined by cold vapor atomic absorption spectrometry, and those of cadmium and lead by graphite furnace atomic absorption spectrometry. Concentrations of the heavy metals exceeded the limits permitted by the World Health Organization. Genotoxic effects were found in the exposed population, possibly associated with the presence of these metals in blood. Significant associations (p<0.05) were found between mercury and cadmium levels and damage to DNA. These results suggest that the genetic damage recorded among inhabitants of the region of La Mojana, Colombia, may be associated with the presence of heavy metals in the blood.

  14. Heavy Metals in the Environment-Historical Trends

    NASA Astrophysics Data System (ADS)

    Callender, E.

    2003-12-01

    These six metals, commonly classified as heavy metals, are a subset of a larger group of trace elements that occur in low concentration in the Earth's crust. These heavy metals were mined extensively for use in the twentieth century Industrial Society. Nriagu (1988a) estimated that between 0.5 (Cd) and 310 (Cu) million metric tons of these metals were mined and ultimately deposited in the biosphere. In many instances, the inputs of these metals from anthropogenic sources exceed the contributions from natural sources (weathering, volcanic eruptions, forest fires) by several times ( Adriano, 1986). In this chapter, heavy metals (elements having densities greater than 5) and trace elements (elements present in the lithosphere in concentrations less than 0.1%) are considered synonymous.It has been observed in the past that the rate of emission of these trace metals into the atmosphere is low due to their low volatility. However, with the advent of large-scale metal mining and smelting as well as fossil-fuel combustion in the twentieth century, the emission rate of these metals has increased dramatically. As most of these emissions are released into the atmosphere where the mammals live and breathe, we see a great increase in the occurrence of health problems such as lead (Pb) poisoning, cadmium (Cd) Itai-itai disease, chromium (Cr), and nickel (Ni) carcinogenesis.In this chapter, the author has attempted to present a synopsis of the importance of these metals in the hydrocycle, their natural and anthropogenic emissions into the environment, their prevalent geochemical form incorporated into lacustrine sediments, and their time-trend distributions in watersheds that have been impacted by urbanization, mining and smelting, and other anthropogenic activities. These time trends are reconstructed from major-minor-trace-element distributions in age-dated sediment cores, mainly from reservoirs where the mass sedimentation rates (MSRs) are orders of magnitude greater than

  15. New experiments on few-electron very heavy atoms

    SciTech Connect

    Gould, H.

    1985-07-01

    New experiments, to test quantum electrodynamics (QED) in strong Coulomb fields and to study atomic collisions at ultrarelativistic energies, are proposed. A 0.1% measurement of the 2/sup 2/P/sub 1/2/-2/sup 2/S/sub 1/2/ splitting in lithium like uranium (Z=92) and the 2/sup 3/P/sub 0/ - 2/sup 3/S/sub 1/ splitting in heliumlike uranium is proposed as a sub 1% test of the Lamb shift in a strong Coulomb field. Measurements of the hyperfine splitting of hydrogenlike thallium (Z=81) and the g/sub j/ factor of the ground state of hydrogenlike uranium are propsed as a test of the QED contribution to the magnetic moment of an electron bound in a strong Coulomb field. Measurements of capture cross sections for ultra relativistic very heavy nuclei are proposed to look for the capture of electrons from pair production. 40 refs., 7 figs., 2 tabs.

  16. Oil palm biomass as an adsorbent for heavy metals.

    PubMed

    Vakili, Mohammadtaghi; Rafatullah, Mohd; Ibrahim, Mahamad Hakimi; Abdullah, Ahmad Zuhairi; Salamatinia, Babak; Gholami, Zahra

    2014-01-01

    Many industries discharge untreated wastewater into the environment. Heavy metals from many industrial processes end up as hazardous pollutants of wastewaters.Heavy metal pollution has increased in recent decades and there is a growing concern for the public health risk they may pose. To remove heavy metal ions from polluted waste streams, adsorption processes are among the most common and effective treatment methods. The adsorbents that are used to remove heavy metal ions from aqueous media have both advantages and disadvantages. Cost and effectiveness are two of the most prominent criteria for choosing adsorbents. Because cost is so important, great effort has been extended to study and find effective lower cost adsorbents.One class of adsorbents that is gaining considerable attention is agricultural wastes. Among many alternatives, palm oil biomasses have shown promise as effective adsorbents for removing heavy metals from wastewater. The palm oil industry has rapidly expanded in recent years, and a large amount of palm oil biomass is available. This biomass is a low-cost agricultural waste that exhibits, either in its raw form or after being processed, the potential for eliminating heavy metal ions from wastewater. In this article, we provide background information on oil palm biomass and describe studies that indicate its potential as an alternative adsorbent for removing heavy metal ions from wastewater. From having reviewed the cogent literature on this topic we are encouraged that low-cost oil-palm-related adsorbents have already demonstrated outstanding removal capabilities for various pollutants.Because cost is so important to those who choose to clean waste streams by using adsorbents, the use of cheap sources of unconventional adsorbents is increasingly being investigated. An adsorbent is considered to be inexpensive when it is readily available, is environmentally friendly, is cost-effective and be effectively used in economical processes. The

  17. [Heavy metal poisoning and renal injury in children].

    PubMed

    Rong, Li-Ping; Xu, Yuan-Yuan; Jiang, Xiao-Yun

    2014-04-01

    Along with global environmental pollution resulting from economic development, heavy metal poisoning in children has become an increasingly serious health problem in the world. It can lead to renal injury, which tends to be misdiagnosed due to the lack of obvious or specific early clinical manifestations in children. Early prevention, diagnosis and intervention are valuable for the recovery of renal function and children's good health and growth. This paper reviews the mechanism of renal injury caused by heavy metal poisoning in children, as well as the clinical manifestations, diagnosis, and prevention and treatment of renal injury caused by lead, mercury, cadmium, and chromium.

  18. Brassinosteroids and Response of Plants to Heavy Metals Action

    PubMed Central

    Rajewska, Iwona; Talarek, Marta; Bajguz, Andrzej

    2016-01-01

    Brassinosteroids (BRs) are a widespread group of plant hormones. These phytohormones play a crucial role in the regulation of growth and development of various plant species, and they demonstrate high biological activity. BRs are considered to demonstrate protective activity in the plants exposed to various stresses. Due to rapid industrialization and urbanization, heavy metals have become one of the most important plant stressors. In plants, accumulation of heavy metals beyond the critical levels leads to oxidative stress. However, BRs may inhibit the degradation of lipids, resulted from the overproduction of reactive oxygen species under stress conditions, and increase the activity of antioxidants. They also have the ability to promote phytochelatins synthesis. PMID:27242833

  19. Heavy metals in natural waters: applied monitoring and impact assessment

    SciTech Connect

    Moore, J.W.; Ramamoorthy, S.

    1984-01-01

    An attempt has been made to review a large amount of environmental data on eight common heavy metals. The chemistry, uptake and toxicity of arsenic, cadmium, chromium, copper, lead, mercury, nickel, and zinc are presented. With this information, it is possible to assess their impact in aquatic systems. A review is also provided on the status and likely value of current methods used in monitoring and impact assessment. Information is included on environmental chemistry, the pollution-ecology of algae, invertebrates and fish, and on aquatic toxicology, genetic toxicology, and the pathology of fishes and invertebrates in relation to heavy metals.

  20. [Hyperspectral remote sensing in monitoring the vegetation heavy metal pollution].

    PubMed

    Li, Na; Lü, Jian-sheng; Altemann, W

    2010-09-01

    Mine exploitation aggravates the environment pollution. The large amount of heavy metal element in the drainage of slag from the mine pollutes the soil seriously, doing harm to the vegetation growing and human health. The investigation of mining environment pollution is urgent, in which remote sensing, as a new technique, helps a lot. In the present paper, copper mine in Dexing was selected as the study area and China sumac as the study plant. Samples and spectral data in field were gathered and analyzed in lab. The regression model from spectral characteristics for heavy metal content was built, and the feasibility of hyperspectral remote sensing in environment pollution monitoring was testified.

  1. Susceptibility of halobacteria to heavy metals

    SciTech Connect

    Nieto, J.J.; Ventosa, A.; Ruiz-Berraquero, F.

    1987-05-01

    Sixty-eight halobacteria, including both culture collection strains and fresh isolates from widely differing geographical areas, were tested for susceptibility to arsenate, cadmium, chromium, cobalt, copper, lead, mercury, nickel, silver, and zinc ions by an agar dilution technique. The culture collection strains showed different susceptibilities, clustering into five groups. Halobacterium mediterranei and Halobacterium volcanii were the most metal tolerant, whereas Haloarcula californiae and Haloarcula sinaiiensis had the highest susceptibilities of the culture collection strains. Different patterns of metal susceptibility were found for all the halobacteria tested, and there was a uniform susceptibility to mercury and silver. All strains tested were multiply metal tolerant.

  2. Risk assessment of mineral and heavy metal content of selected tea products from the Ghanaian market.

    PubMed

    Nkansah, Marian Asantewah; Opoku, Francis; Ackumey, Abiathar Abraham

    2016-06-01

    Food consumption is the most likely route of human exposure to metals. Tea (Camellia sinensis L.) is among the most widely consumed non-alcoholic beverages. Concentrations of heavy metals and minerals in tea from 15 different brands in Kumasi, Ghana were measured to assess the health risk associated with their consumption. The mineral and metal contents (Fe, Cu, Zn, Pb, As, Cd) were analyzed using atomic absorption spectrophotometer (Z-8100 polarized Zeeman). The results revealed that the mean concentrations were in the order: Ca > Fe > As > Cd > Zn > Pb. The average contents of Ca, Fe, Zn, Pb, Cd, and As in the samples were 94.08, 6.15, 0.20, 0.16, 0.36, and 1.66 mg/kg, respectively. All the minerals and heavy metals were below the maximum permissible limits stipulated by the World Health Organization (WHO) and US Pharmacopeia (USP). Metal-to-metal correlation indicated strong correlations between As/Zn, Cd/Zn, Cd/As, and Pb/As pairs. Factor analysis demonstrated a clear separation between minerals, grouped on one side, and heavy metals, clustered on another side. Both the target hazard quotient (THQ) and hazard index (HI) levels in green tea were far below 1, suggesting that consumption of green tea should pose no potential risk to human health. However, carcinogenic risk levels for arsenic were high; R > 10(-6). The results showed that residents in Kumasi consume tea could be at risk from exposure to these heavy metals and minerals.

  3. Heavy Metal Bioavailability and Bioaccessibility in Soil

    NASA Astrophysics Data System (ADS)

    Dean, John Richard

    This chapter considers the use of a variety of approaches to assess either the bioavailability or the bioaccessibility of metals in soil. The bioavailability of metals from soils is considered with respect to a series of single-extraction methods, including the use of ethylenediaminetetraacetic acid (EDTA), acetic acid, diethylenetriaminepentaacetic acid (DTPA), ammonium nitrate, calcium chloride and sodium nitrate. Then, a procedure for the recovery of metals using a three-stage sequential extraction protocol is described. Two alternate approaches for assessing the environmental health risk to humans by undertaking in vitro gastrointestinal extraction (also known as the physiologically based extraction test, PBET) are considered. Finally, two acid digestion protocols that allow the pseudo-total metal content of samples to be assessed are provided.

  4. Normal concentrations of heavy metals in autistic spectrum disorders.

    PubMed

    Albizzati, A; Morè, L; Di Candia, D; Saccani, M; Lenti, C

    2012-02-01

    Autism is a neurological-psychiatric disease. In the last 20 years we witnessed a strong increase of autism diagnoses. To explain this increase, some scientists put forward the hypothesis that heavy metal intoxication may be one of the causes of autism. The origin of such an intoxication was hypothesised to be vaccines containing thimerosal as antimicrobic preservative. This preservative is mainly made up of mercury. The aim of our research was to investigate the correlation between autism and high biological concentrations of heavy metals. Seventeen autistic patients, between 6 and 16 years old (average: 11.52 DS: 3.20) (15 males and 2 females), were investigated, as well as 20 non autistic subjects from neuropsychiatric service between 6 and 16 years (average: 10.41 DS: 3.20) (15 males and 2 females). In both groups blood, urine and hair samples were analysed trough means of a semiquantitative analysis of heavy metal dosing. The metals analysed were Lead, mercury, cadmium and aluminium, since their build-up may give both neurological and psychiatric symptoms. The comparison of the mean values of the concentrations between the groups, performed with ANOVA test, has shown no statistically relevant differences. There wasn't correlation between autism and heavy metal concentration.

  5. Heavy metal characterization of circulating fluidized bed derived biomass ash.

    PubMed

    Li, Lianming; Yu, Chunjiang; Bai, Jisong; Wang, Qinhui; Luo, Zhongyang

    2012-09-30

    Although the direct combustion of biomass for energy that applies circulating fluidized bed (CFB) technology is steadily expanding worldwide, only few studies have conducted an environmental assessment of biomass ash thus far. Therefore, this study aims to integrate information on the environmental effects of biomass ash. We investigated the concentration of heavy metal in biomass ash samples (bottom ash, cyclone ash, and filter ash) derived from a CFB boiler that combusted agricultural and forest residues at a biomass power plant (2×12 MW) in China. Ash samples were gathered for the digestion and leaching test. The heavy metal content in the solution and the leachate was studied via an inductively coupled plasma-mass spectrometer and a Malvern Mastersizer 2000 mercury analyzer. Measurements for the chemical composition, particle size distribution, and the surface morphology were carried out. Most of the metals in cyclone ash particles were enriched, whereas Ti and Hg were enriched in filter ash. Residence time contributed most to heavy metal enrichment. Under HJ/T 300 conditions, the heavy metals showed serious leaching characteristics. Under EN 12457-2 conditions, leaching behavior was hardly detected.

  6. Coal burning leaves toxic heavy metal legacy in the Arctic

    SciTech Connect

    McConnell, J.R.; Edwards, R.

    2008-08-26

    Toxic heavy metals emitted by industrial activities in the midlatitudes are transported through the atmosphere and deposited in the polar regions; bioconcentration and biomagnification in the food chain mean that even low levels of atmospheric deposition may threaten human health and Arctic ecosystems. Little is known about sources and long-term trends of most heavy metals before approximate to 1980, when modern measurements began, although heavy-metal pollution in the Arctic was widespread during recent decades. Lacking detailed, long-term measurements until now, ecologists, health researchers, and policy makers generally have assumed that contamination was highest during the 1960s and 1970s peak of industrial activity in North America and Europe. We present continuous 1772-2003 monthly and annually averaged deposition records for highly toxic thallium, cadmium, and lead from a Greenland ice core showing that atmospheric deposition was much higher than expected in the early 20th century, with tenfold increases from preindustrial levels by the early 1900s that were two to five times higher than during recent decades. Tracer measurements indicate that coal burning in North America and Europe was the likely source of these metals in the Arctic after 1860. Although these results show that heavy-metal pollution in the North Atlantic sector of the Arctic is substantially lower today than a century ago, contamination of other sectors may be increasing because of the rapid coal-driven growth of Asian economies.

  7. Coal burning leaves toxic heavy metal legacy in the Arctic.

    PubMed

    McConnell, Joseph R; Edwards, Ross

    2008-08-26

    Toxic heavy metals emitted by industrial activities in the midlatitudes are transported through the atmosphere and deposited in the polar regions; bioconcentration and biomagnification in the food chain mean that even low levels of atmospheric deposition may threaten human health and Arctic ecosystems. Little is known about sources and long-term trends of most heavy metals before approximately 1980, when modern measurements began, although heavy-metal pollution in the Arctic was widespread during recent decades. Lacking detailed, long-term measurements until now, ecologists, health researchers, and policy makers generally have assumed that contamination was highest during the 1960s and 1970s peak of industrial activity in North America and Europe. We present continuous 1772-2003 monthly and annually averaged deposition records for highly toxic thallium, cadmium, and lead from a Greenland ice core showing that atmospheric deposition was much higher than expected in the early 20th century, with tenfold increases from preindustrial levels by the early 1900s that were two to five times higher than during recent decades. Tracer measurements indicate that coal burning in North America and Europe was the likely source of these metals in the Arctic after 1860. Although these results show that heavy-metal pollution in the North Atlantic sector of the Arctic is substantially lower today than a century ago, contamination of other sectors may be increasing because of the rapid coal-driven growth of Asian economies.

  8. Transformation of heavy metal speciation during sludge drying: mechanistic insights.

    PubMed

    Weng, Huan-Xin; Ma, Xue-Wen; Fu, Feng-Xia; Zhang, Jin-Jun; Liu, Zan; Tian, Li-Xun; Liu, Chongxuan

    2014-01-30

    Speciation can fundamentally affect on the stability and toxicity of heavy metals in sludge from wastewater treatment plants. This research investigated the speciation of heavy metals in sludge from both municipal and industrial sources, and metal speciation change as a result of drying process to reduce sludge volume. The changes in sludge properties including sludge moisture content, temperature, density, and electrical conductivity were also monitored to provide insights into the mechanisms causing the change in heavy metal speciation. The results show that the drying process generally stabilized Cr, Cu, Cd, and Pb in sludge by transforming acid-soluble, reducible, and oxidizable species into structurally stable forms. Such transformation and stabilization occurred regardless of the sludge source and type, and were primarily caused by the changes in sludge properties associated with decomposition of organic matter and sulfide. The results enhanced our understanding of the geochemical behavior of heavy metals in municipal sludge, and are useful for designing a treatment system for environment-friendly disposal of sludge.

  9. Transformation of heavy metal speciation during sludge drying: mechanistic insights

    SciTech Connect

    Weng, Huanxin; Ma, Xue-Wen; Fu, Feng-Xia; Zhang, Jin-Jun; Liu, Zan; Tian, Li-Xun; Liu, Chongxuan

    2014-01-30

    Speciation can fundamentally affect on the stability and toxicity of heavy metals in sludge from wastewater treatment plants. This research investigated the speciation of heavy metals in sludge from both municipal and industrial sources, and metal speciation change as a result of drying process to reduce sludge volume. The changes in sludge properties including sludge moisture content, temperature, density, and electrical conductivity were also monitored to provide insights into the mechanisms causing the change in heavy metal speciation. The results show that the drying process generally stabilized the Cr, Cu, Cd and Pb in sludge by transforming acid-soluble, reducible and oxidizable species into structurally stable forms. Such transformation and stabilization occurred regardless of the sludge source and type, and were primarily caused by the changes in sludge properties associated with decomposition of organic matter and sulfide. The results enhanced our understanding of the geochemical behavior of heavy metals in municipal sludge, and are useful for designing a treatment system for environment-friendly disposal of sludge.

  10. Rhizobacteria of Populus euphratica Promoting Plant Growth Against Heavy Metals.

    PubMed

    Zhu, Donglin; Ouyang, Liming; Xu, Zhaohui; Zhang, Lili

    2015-01-01

    The heavy metal-resistant bacteria from rhizospheric soils of wild Populus euphratica forest growing in arid and saline area of northwestern China were investigated by cultivation-dependent methods. After screening on medium sparked with zinc, copper, nickel and lead, 146 bacteria strains with different morphology were isolated and most of them were found to be resistant to at least two kinds of heavy metals. Significant increase in fresh weight and leaf surface area of Arabidopsis thaliana seedlings under metal stress were noticed after inoculated with strains especially those having multiple-resistance to heavy metals such as Phyllobacterium sp. strain C65. Investigation on relationship between auxin production and exogenous zinc concentration revealed that Phyllobacterium sp. strain C65 produced auxin, and production decreased as the concentration of zinc in medium increased. For wheat seedlings treated with zinc of 2 mM, zinc contents in roots of inoculated plants decreased by 27% (P < 0.05) compared to the uninoculated control. Meanwhile, zinc accumulation in the above-ground tissues increased by 22% (P < 0.05). The translocation of zinc from root to above-ground tissues induced by Phyllobacterium sp. strain C65 helped host plants extract zinc from contaminated environments more efficiently thus alleviated the growth inhibition caused by heavy metals.

  11. Phytoremediation of heavy metal contaminated soil by Jatropha curcas.

    PubMed

    Chang, Fang-Chih; Ko, Chun-Han; Tsai, Ming-Jer; Wang, Ya-Nang; Chung, Chin-Yi

    2014-12-01

    This study employed Jatropha curcas (bioenergy crop plant) to assist in the removal of heavy metals from contaminated field soils. Analyses were conducted on the concentrations of the individual metals in the soil and in the plants, and their differences over the growth periods of the plants were determined. The calculation of plant biomass after 2 years yielded the total amount of each metal that was removed from the soil. In terms of the absorption of heavy metal contaminants by the roots and their transfer to aerial plant parts, Cd, Ni, and Zn exhibited the greatest ease of absorption, whereas Cu, Cr, and Pb interacted strongly with the root cells and remained in the roots of the plants. J. curcas showed the best absorption capability for Cd, Cr, Ni, and Zn. This study pioneered the concept of combining both bioremediation and afforestation by J. curcas, demonstrated at a field scale.

  12. Rheumatic disease, heavy-metal pigments, and the Great Masters.

    PubMed

    Pedersen, L M; Permin, H

    1988-06-04

    The painters Rubens, Renoir, and Dufy suffered from rheumatoid arthritis and Klee from scleroderma. Analysis of the areas of various colours in randomly selected paintings by these four artists and by eight "controls" (contemporary painters without rheumatic disease) suggests that Rubens, Renoir, Dufy, and Klee used significantly more bright and clear colours based on toxic heavy metals and fewer earth colours containing harmless iron and carbon compounds. These four painters may have been heavily exposed to mercury sulphide, cadmium sulphide, arsenic sulphide, lead, antimony, tin, cobalt, manganese, and chromium, the metals of the bright and clear colours, and exposure to these metals may be of importance in the development of inflammatory rheumatic diseases. Artists today are not so exposed, but heavy metal contamination in food and drinking water exists and experience from the occupational exposure of old masters is still relevant.

  13. Characterization of disposable optical sensors for heavy metal determination.

    PubMed

    Vuković, Jadranka; Avidad, María Ariza; Capitán-Vallvey, Luis Fermín

    2012-05-30

    This paper presents the development, characterization and quality control of analytical methods based on the use of disposable optical sensors for determination of heavy metals. Chromogenic reagents such as 1-(2-pyridylazo)-2-naphthol, (2-pyridylazo)resorcinol, Zincon, Ferrozine, and Chromazurol S were used to develop optical sensors of heavy metal ions found as contaminants in pharmaceutical substances and products, such as Zn(II), Cu(II), Ni(II), Fe(II), and Fe(III). The chromogenic reagents were immobilized in polymeric membranes by spin-coating from cocktails containing all reagents needed. The methods were prevalidated using a comprehensive quality control strategy based on a system of mathematical/statistical testing and diagnosis of each prevalidation step. This system involved characterization of analytical groups; checking of two limiting groups; testing of data homogeneity; recognition of outliers; and determination of analytical functions, limiting values, precision and accuracy. The prevalidation strategy demonstrated the reliability of the proposed method and pointed out some limitations. Combining the optical sensors with multicomponent linear regression allowed simultaneous determination of multiple metals in synthetic mixtures with different compositions. Good agreement between experimental and theoretical amounts of heavy metals in the mixtures was obtained for the majority of sensors and metals. Even better agreement was obtained between the experimental and theoretical total amounts of metals in the mixtures. The proposed analytical methods were successfully applied to the determination of zinc in pharmaceutical preparations of insulin and the determination of metal mixtures in a commercial nasal spray of isotonic seawater. The reliable and sensitive individual optical sensors developed in this study may be useful for designing a multimembrane optical tongue that with appropriate further optimization can be used for screening heavy metals in

  14. Heavy metal contamination of drinking water in Kamrup district, Assam, India.

    PubMed

    Chakrabarty, Sutapa; Sarma, Hari Prasad

    2011-08-01

    This study was undertaken to assess the heavy metal concentration of the drinking water with respect to zinc, copper, cadmium, manganese, lead and arsenic in Kamrup district of Assam, India. Ground water samples were collected from tube wells, deep tube wells and ring wells covering all the major hydrogeological environs. Heavy metals in groundwater are estimated by using Atomic Absorption Spectrometer, Perkin Elmer Analyst 200. Data were assessed statistically to find the distribution pattern and other related information for each metal. The study revealed that a good number of the drinking water sources were contaminated with cadmium, manganese and lead. Arsenic concentrations although did not exceeded WHO limits but was found to be slightly elevated. Copper and zinc concentrations were found to be within the prescribed WHO limits. An attempt has also been made to ascertain the possible source of origin of the metals. Positive and significant correlation existing between manganese with zinc and copper indicates towards their similar source of origin and mobility. In view of the present study and the level of heavy metal contamination, it could be suggested to test the potability of the water sources before using it for drinking purpose.

  15. Pollution Problem in River Kabul: Accumulation Estimates of Heavy Metals in Native Fish Species

    PubMed Central

    Ahmad, Habib; Yousafzai, Ali Muhammad; Siraj, Muhammad; Ahmad, Rashid; Ahmad, Israr; Nadeem, Muhammad Shahid; Ahmad, Waqar; Akbar, Nazia; Muhammad, Khushi

    2015-01-01

    The contamination of aquatic systems with heavy metals is affecting the fish population and hence results in a decline of productivity rate. River Kabul is a transcountry river originating at Paghman province in Afghanistan and inters in Khyber Pakhtunkhwa province of Pakistan and it is the major source of irrigation and more than 54 fish species have been reported in the river. Present study aimed at the estimation of heavy metals load in the fish living in River Kabul. Heavy metals including chromium, nickel, copper, zinc, cadmium, and lead were determined through atomic absorption spectrophotometer after tissue digestion by adopting standard procedures. Concentrations of these metals were recorded in muscles and liver of five native fish species, namely, Wallago attu, Aorichthys seenghala, Cyprinus carpio, Labeo dyocheilus, and Ompok bimaculatus. The concentrations of chromium, nickel, copper, zinc, and lead were higher in both of the tissues, whereas the concentration of cadmium was comparatively low. However, the concentration of metals was exceeding the RDA (Recommended Dietary Allowance of USA) limits. Hence, continuous fish consumption may create health problems for the consumers. The results of the present study are alarming and suggest implementing environmental laws and initiation of a biomonitoring program of the river. PMID:26339622

  16. Pollution Problem in River Kabul: Accumulation Estimates of Heavy Metals in Native Fish Species.

    PubMed

    Ahmad, Habib; Yousafzai, Ali Muhammad; Siraj, Muhammad; Ahmad, Rashid; Ahmad, Israr; Nadeem, Muhammad Shahid; Ahmad, Waqar; Akbar, Nazia; Muhammad, Khushi

    2015-01-01

    The contamination of aquatic systems with heavy metals is affecting the fish population and hence results in a decline of productivity rate. River Kabul is a transcountry river originating at Paghman province in Afghanistan and inters in Khyber Pakhtunkhwa province of Pakistan and it is the major source of irrigation and more than 54 fish species have been reported in the river. Present study aimed at the estimation of heavy metals load in the fish living in River Kabul. Heavy metals including chromium, nickel, copper, zinc, cadmium, and lead were determined through atomic absorption spectrophotometer after tissue digestion by adopting standard procedures. Concentrations of these metals were recorded in muscles and liver of five native fish species, namely, Wallago attu, Aorichthys seenghala, Cyprinus carpio, Labeo dyocheilus, and Ompok bimaculatus. The concentrations of chromium, nickel, copper, zinc, and lead were higher in both of the tissues, whereas the concentration of cadmium was comparatively low. However, the concentration of metals was exceeding the RDA (Recommended Dietary Allowance of USA) limits. Hence, continuous fish consumption may create health problems for the consumers. The results of the present study are alarming and suggest implementing environmental laws and initiation of a biomonitoring program of the river.

  17. Effect of heavy metals on the stabilization of mercury(II) by DTCR in desulfurization solutions.

    PubMed

    Hou, Jiaai; Lu, Rongjie; Sun, Mingyang; Baig, Shams Ali; Tang, Tingmei; Cheng, Lihua; Xu, Xinhua

    2012-05-30

    Several heavy metals, including Cu(2+), Ni(2+), Pb(2+), and Zn(2+), were investigated in simulated desulfurization solutions to evaluate their interferences with Hg(2+) during the reaction with dithiocarbamate type chelating resin (DTCR). Appropriate DTCR dosage and the effect of pH were also explored with respect to restoration of high Hg(2+) precipitation efficiency and reduction of mercury concentrations. The experimental results suggested that increasing heavy metal concentration inhibited Hg(2+) precipitation efficiency to a considerable extent and the inhibition order of the four heavy metals was Cu(2+)>Ni(2+)>Pb(2+)>Zn(2+). However, the coordination ability was closely related to the configuration and the orbital hybridization of each metal. In the cases of Cu(2+) and Pb(2+), increased DTCR dosage was beneficial to Hg(2+) precipitation, which could lay the foundation of practical applications of DTCR dosage for industrial wastewater treatment. The enhanced Hg(2+) precipitation performance seen for increasing pH might have come from the deprotonation of sulfur atoms on the DTCR functional groups and the formation of metal hydroxides (M(OH)(2), M=Cu, Pb, Hg).

  18. Biosorption of heavy metals by Fucus spiralis.

    PubMed

    Romera, E; González, F; Ballester, A; Blázquez, M L; Muñoz, J A

    2008-07-01

    The sorption uptake of cadmium, nickel, zinc, copper and lead by marine brown alga Fucus spiralis was investigated in bimetallic, trimetallic and multimetallic solutions. The experimental data fitted very well to Langmuir model. In bimetallic systems, the affinity of biomass for lead and copper increased and the sorption uptake of these metals was not affected by increasing concentrations of cadmium, nickel or zinc. However, in solutions with both metals there was a significant mutual decrease of their sorption levels at high concentrations of the other metal. The sorption uptake of cadmium, nickel and copper was investigated in trimetallic aqueous systems. Based on the kinetic parameter b, the affinity of F. spiralis for copper was considerably higher than for cadmium or nickel: bCd=6.39, bNi=1.82 and bCu=17.89. In all tests, the maximum sorption uptake remained practically constant around 1 mmol/g, indicating that the number of active sites on the biomass was limited. Tests with four and five metals showed that copper was preferentially adsorbed. The differences between the experimental sorption data and those given by the chemical speciation program PHREEQCI were negligible. In general, the software used provided satisfactory estimated data for each metal and hence can be a useful tool to predict or simulate the real process.

  19. Analysis of heavy metals concentration in water and sediment in the Hara biosphere reserve, southern Iran.

    PubMed

    Nowrouzi, Mohsen; Mansouri, Borhan; Nabizadeh, Sahar; Pourkhabbaz, Alireza

    2014-02-01

    This study determined the concentration of heavy metals (Al, Cr, Cu, and Zn) in water and sediments at nine sites in the Hara biosphere reserve of southern Iran during the summer and winter 2010. Determination of Al, Cr, Cu, and Zn in water was carried out by graphite furnace atomic absorption spectrometer (Shimadzu, AA 610s) and in sediment by flame atomic absorption spectrometer (Perkin Elmer, AA3030). Results showed that the heavy metal concentrations in the water samples decreased in the sequence of Zn > Al > Cu > Cr, while in sediment samples were Cr > Zn > Cu > Al. Data analysis indicated that with the exception of Al, there was a Pearson's correlation coefficient between pH and Cu, Zn, and Cr at α = 0.01, 0.05, and 0.001 in sediment (in winter), respectively. There were also significant differences between heavy metals of Cr, Cu, and Zn during the two seasons (p < 0.001) in the water and sediment.

  20. Effects of metal-contaminated soils on the accumulation of heavy metals in gotu kola (Centella asiatica) and the potential health risks: a study in Peninsular Malaysia.

    PubMed

    Ong, Ghim Hock; Wong, Ling Shing; Tan, Ai Li; Yap, Chee Kong

    2016-01-01

    Centella asiatica is a commonly used medicinal plant in Malaysia. As heavy metal accumulation in medicinal plants which are highly consumed by human is a serious issue, thus the assessment of heavy metals in C. asiatica is important for the safety of consumers. In this study, the heavy metal accumulation in C. asiatica and the potential health risks were investigated. Samples of C. asiatica and surface soils were collected from nine different sites around Peninsular Malaysia. The concentration of six heavy metals namely Cd, Cu, Ni, Fe, Pb and Zn were determined by air-acetylene flame atomic absorption spectrophotometer (AAS). The degree of anthropogenic influence was assessed by calculating the enrichment factor (EF) and index of geoaccumulation (Igeo). The heavy metal uptake into the plant was estimated through the calculation of translocation factor (TF), bioconcentration factor (BCF) and correlation study. Estimated daily intakes (EDI) and target hazard quotients (THQ) were used to determine the potential health risk of consuming C. asiatica. The results showed that the overall surface soil was polluted by Cd, Cu and Pb, while the uptake of Zn and Ni by the plants was high. The value of EDI and THQ showed that the potential of Pb toxicity in C. asiatica was high as well. As heavy metal accumulation was confirmed in C. asiatica, daily consumption of the plant derived from polluted sites in Malaysia was not recommended.

  1. Chelate-Assisted Heavy Metal Movement Through the Root Zone

    NASA Astrophysics Data System (ADS)

    Kirkham, M.; Madrid, F.; Liphadzi, M. S.

    2001-12-01

    Chelating agents are added to soil as a means to mobilize heavy metals for plant uptake during phytoremediation. Yet almost no studies follow the displacement of heavy metals through the vadose zone following solubilization with chelating agents. The objective of this work was to determine the movement of heavy metals through the soil profile and their absorption by barley (Hordeum vulgare L.) in a soil amended with biosolids and in the presence of a chelating agent (EDTA). Twelve columns 75 cm in height and 17 in diameter were packed with a Haynie very fine sandy loam (coarse-silty, mixed, calcareous, mesic Mollic Udifluvents) and watered with liquid biosolids applied at the surface at a rate of 120 kg N/ha. Three weeks after plants germinated, soil was irrigated with a solution of the disodium salt of EDTA added at a rate of 0.5 g/kg soil. Four treatments were imposed: columns with no plants and no EDTA; columns with no plants plus EDTA; columns with plants and no EDTA; and columns with plants and EDTA. Columns were watered intensively for 35 days until two pore volumes of water had been added, and the leachates were collected daily. With or without plants, columns with EDTA had lower total concentrations of Cu, Zn, Cd, Ni, and Pb in the surface 20 cm than columns without EDTA. Concentrations of the heavy metals in this layer were not afffected by the presence of roots. Iron in leachate was followed as an indicator metal for movement to groundwater. No iron appeared in the leachate without EDTA, either in the columns with plants or without plants. The peak concentration of iron in the leachate occurred three days earlier in the columns without plants and EDTA compared to the columns with plants and EDTA. The results indicated the importance of vegetation on retarding heavy metal leaching to groundwater during chelate-facilitated phytoremediation.

  2. Removal of heavy metal from industrial effluents using Baker's yeast

    NASA Astrophysics Data System (ADS)

    Ferdous, Anika; Maisha, Nuzhat; Sultana, Nayer; Ahmed, Shoeb

    2016-07-01

    Bioremediation of wastewater containing heavy metals is one of the major challenges in environmental biotechnology. Heavy metals are not degraded and as a result they remain in the ecosystem, and pose serious health hazards as it comes in contact with human due to anthropogenic activities. Biological treatment with various microorganisms has been practiced widely in recent past, however, accessing and maintaining the microorganisms have always been a challenge. Microorganisms like Baker's yeast can be very promising biosorbents as they offer high surface to volume ratio, large availability, rapid kinetics of adsorption and desorption and low cost. The main aim of this study is to evaluate the applicability of the biosorption process using baker's yeast. Here we present an experimental investigation of biosorption of Chromium (Cr) from water using commercial Baker's Yeast. It was envisaged that yeast, dead or alive, would adsorb heavy metals, however, operating parameters could play vital roles in determining the removal efficiency. Parameters, such as incubation time, pH, amount of biosorbent and heavy metal concentration were varied to investigate the impacts of those parameters on removal efficiency. Rate of removal was found to be inversely proportional to the initial Cr (+6) concentrations but the removal rate per unit biomass was a weakly dependent on initial Cr(+6) concentrations. Biosorption process was found to be more efficient at lower pH and it exhibited lower removal with the increase in solution pH. The optimum incubation time was found to be between 6-8 hours and optimum pH for the metal ion solution was 2. The effluents produced in leather industries are the major source of chromium pollution in Bangladesh and this study has presented a very cost effective yet efficient heavy metal removal approach that can be adopted for such kind of wastewater.

  3. The potential for heavy metal decontamination

    SciTech Connect

    Baker, A.J.M.; McGrath, S.P.; Sidoli, C.M.D.; Reeves, R.D.

    1996-12-31

    Preliminary trials to assess the ability of plant species to extract metals are presented. A range of zinc and nickel hyperaccumulator plants from the Brassicaceae family, collected from diverse populations in Europe, were grown on plots along with nonaccumulating crop plants from the same family. Extraction efficiencies and the number of croppings required to reduce the total zinc in the soil to a concentration of 300 mg/kg are tabulated. Zinc accumulation remained high over a wide range of soil metal concentration. However, the concentration of nickel in the hyperaccumulators increased in accordance with increasing total nickel concentrations in the soil. Calculations suggest that there is an excellent potential for using hyperaccumulator species to remove metals from the rhizosphere where remediation can be considered over a period of years and multiple cropping is a viable option.

  4. Adsorption of heavy metals by road deposited solids.

    PubMed

    Gunawardana, Chandima; Goonetilleke, Ashantha; Egodawatta, Prasanna

    2013-01-01

    The research study discussed in the paper investigated the adsorption/desorption behaviour of heavy metals commonly deposited on urban road surfaces, namely, Zn, Cu, Cr and Pb, for different particle size ranges of solids. The study outcomes, based on field studies and batch experiments, confirmed that road deposited solids particles contain a significantly high amount of vacant charge sites with the potential to adsorb additional heavy metals. Kinetic studies and adsorption experiments indicated that Cr is the most preferred metal element to associate with solids due to the relatively high electronegativity and high charge density of trivalent cation (Cr(3+)). However, the relatively low availability of Cr in the urban road environment could influence this behaviour. Comparing total adsorbed metals present in solids particles, it was found that Zn has the highest capacity for adsorption to solids. Desorption experiments confirmed that a low concentration of Cu, Cr and Pb in solids was present in water-soluble and exchangeable form, whilst a significant fraction of adsorbed Zn has a high likelihood of being released back into solution. Among heavy metals, Zn is considered to be the most commonly available metal among road surface pollutants.

  5. Use of cestodes as indicator of heavy-metal pollution.

    PubMed

    Yen Nhi, Tran Thi; Mohd Shazili, Noor Azhar; Shaharom-Harrison, Faizah

    2013-01-01

    Thirty snakehead fish, Channa micropeltes (Cuvier, 1831) were collected at Lake Kenyir, Malaysia. Muscle, liver, intestine and kidney tissues were removed from each fish and the intestine was opened to reveal cestodes. In order to assess the concentration of heavy metal in the environment, samples of water in the surface layer and sediment were also collected. Tissues were digested and the concentrations of manganese (Mn), zinc (Zn), copper (Cu), cadmium (Cd) and lead (Pb) were analysed by using inductively-coupled plasma mass-spectrometry (ICP-MS) equipment. The results demonstrated that the cestode Senga parva (Fernando and Furtado, 1964) from fish hosts accumulated some heavy metals to a greater extent than the water and some fish tissues, but less than the sediment. In three (Pb, Zn and Mn) of the five elements measured, cestodes accumulated the highest metal concentrations, and in remaining two (Cu and Cd), the second highest metal accumulation was recorded in the cestodes when compared to host tissues. Therefore, the present study indicated that Senga parva accumulated metals and might have potential as a bioindicator of heavy-metal pollution.

  6. Heavy metal removal from water/wastewater by nanosized metal oxides: a review.

    PubMed

    Hua, Ming; Zhang, Shujuan; Pan, Bingcai; Zhang, Weiming; Lv, Lu; Zhang, Quanxing

    2012-04-15

    Nanosized metal oxides (NMOs), including nanosized ferric oxides, manganese oxides, aluminum oxides, titanium oxides, magnesium oxides and cerium oxides, provide high surface area and specific affinity for heavy metal adsorption from aqueous systems. To date, it has become a hot topic to develop new technologies to synthesize NMOs, to evaluate their removal of heavy metals under varying experimental conditions, to reveal the underlying mechanism responsible for metal removal based on modern analytical techniques (XAS, ATR-FT-IR, NMR, etc.) or mathematical models, and to develop metal oxide-based materials of better applicability for practical use (such as granular oxides or composite materials). The present review mainly focuses on NMOs' preparation, their physicochemical properties, adsorption characteristics and mechanism, as well as their application in heavy metal removal. In addition, porous host supported NMOs are particularly concerned because of their great advantages for practical application as compared to the original NMOs. Also, some magnetic NMOs were included due to their unique separation performance.

  7. Natural Jordanian zeolite: removal of heavy metal ions from water samples using column and batch methods.

    PubMed

    Baker, Hutaf M; Massadeh, Adnan M; Younes, Hammad A

    2009-10-01

    The adsorption behavior of natural Jordanian zeolites with respect to Cd(2 + ), Cu(2 + ), Pb(2 + ), and Zn(2 + ) was studied in order to consider its application to purity metal finishing drinking and waste water samples under different conditions such as zeolite particle size, ionic strength and initial metal ion concentration. In the present work, a new method was developed to remove the heavy metal by using a glass column as the one that used in column chromatography and to make a comparative between the batch experiment and column experiment by using natural Jordanian zeolite as adsorbent and some heavy metals as adsorbate. The column method was used using different metal ions concentrations ranged from 5 to 20 mg/L with average particle size of zeolite ranged between 90 and 350 mum, and ionic strength ranged from 0.01 to 0.05. Atomic absorption spectrometry was used for analysis of these heavy metal ions, the results obtained in this study indicated that zeolitic tuff is an efficient ion exchanger for removing heavy metals, in particular the fine particle sizes of zeolite at pH 6, whereas, no clear effect of low ionic strength values is noticed on the removal process. Equilibrium modeling of the removal showed that the adsorption of Cd(2 + ), Cu(2 + ), Pb(2 + ), and Zn(2 + ) were fitted to Langmuir, Freundlich and Dubinin-Kaganer-Radushkevich (DKR). The sorption energy E determined in the DKR equation (9.129, 10.000, 10.541, and 11.180 kJ/mol for Zn(2 + ), Cu(2 + ), Cd(2 + ) and Pb(2 + ) respectively) which revealed the nature of the ion-exchange mechanism.

  8. Study of heavy metals transport by runoff and sediments from an abandoned mine: Alagoa, Portugal

    NASA Astrophysics Data System (ADS)

    Gerardo, R.; de Lima, J. L. M. P.; de Lima, M. I. P.

    2009-04-01

    Over time, several studies have been designed to understand heavy metals fate and its impact on the environment and on human health. However, only a few studies have focused on the transport of heavy metals in mining areas through the various hydrological processes such as runoff, infiltration, and subsurface flow. In particular, heavy rainfall events have a great impact on the dispersion of metals existing in the soil. This problem is often more serious in abandoned and inactive mining sites causing environmental problems. In Portugal, there are 175 identified abandoned mines that continuously threaten the environment through acid drainage waters that pollute the soil as well as surface and groundwater. An example is the abandoned mine of Alagoa, located near the village of Penacova (Centre of Portugal); in this site mining activities ceased about 30 years ago. The area is characterized by very steep slopes that are confining with a small stream; the mining excavation by-products were deposited on these slopes. We have selected this mine as a case study, aiming at understanding the transport mechanisms and dispersion of heavy metals and at contributing to the definition of the most appropriate mitigation measures for this area that is contaminated by heavy metals from the mine tailings. So far a total of 30 soil samples from 3 contaminated zones were collected and analysed for pH, texture and heavy metal content, using atomic absorption spectroscopy. Results indicate that the contents of Zn and Pb in the soil samples are in the range from 95-460 mg/kg and 67-239 mg/kg, respectively, which exceed the critical limit-values defined by the Portuguese legislation. These metals are dispersed downslope and downstream from the mine tailings by storm water. The next step of this work is to investigate the transport of heavy metals by runoff, by mobilization of sediments and by subsurface flow. Three spatial scales tests will be conducted: on the mine tailings, on the slope

  9. HEAVY METAL CONTAMINATION IN THE TAIMYR PENINSULA, SIBERIAN ARCTIC

    EPA Science Inventory

    The Taimyr Peninsula is directly north of the world's largest heavy metal smelting complex (Norilsk, Russia). Despite this proximity, there has been little research to examine the extent of contamination of the Taimyr Peninsula, primarily because of the remoteness of this area. W...

  10. HEAVY METAL CONTENT OF AYURVEDIC HERBAL MEDICINE PRODUCTS

    EPA Science Inventory

    Case reports of individuals taking Ayurvedic herbal medicine products (HMPs) suggest that they may contain lead, mercury, and/or arsenic. We analyzed the heavy metal content of Ayurvedic HMPs manufactured in India and Pakistan, available in South Asian grocery stores in the Bost...

  11. Phenol degradation and heavy metal tolerance of Antarctic yeasts.

    PubMed

    Fernández, Pablo Marcelo; Martorell, María Martha; Blaser, Mariana G; Ruberto, Lucas Adolfo Mauro; de Figueroa, Lucía Inés Castellanos; Mac Cormack, Walter Patricio

    2017-03-07

    In cold environments, biodegradation of organic pollutants and heavy metal bio-conversion requires the activity of cold-adapted or cold-tolerant microorganisms. In this work, the ability to utilize phenol, methanol and n-hexadecane as C source, the tolerance to different heavy metals and growth from 5 to 30 °C were evaluated in cold-adapted yeasts isolated from Antarctica. Fifty-nine percent of the yeasts were classified as psychrotolerant as they could grow in all the range of temperature tested, while the other 41% were classified as psychrophilic as they only grew below 25 °C. In the assimilation tests, 32, 78, and 13% of the yeasts could utilize phenol, n-hexadecane, and methanol as C source, respectively, but only 6% could assimilate the three C sources evaluated. In relation to heavy metals ions, 55, 68, and 80% were tolerant to 1 mM of Cr(VI), Cd(II), and Cu(II), respectively. Approximately a half of the isolates tolerated all of them. Most of the selected yeasts belong to genera previously reported as common for Antarctic soils, but several other genera were also isolated, which contribute to the knowledge of this cold environment mycodiversity. The tolerance to heavy metals of the phenol-degrading cold-adapted yeasts illustrated that the strains could be valuable as inoculant for cold wastewater treatment in extremely cold environments.

  12. Heavy metal resistant strains are widespread along Streptomyces phylogeny.

    PubMed

    Alvarez, Analía; Catalano, Santiago A; Amoroso, María Julia

    2013-03-01

    The genus Streptomyces comprises a group of bacteria species with high economic importance. Several of these species are employed at industrial scale for the production of useful compounds. Other characteristic found in different strains within this genus is their capability to tolerate high level of substances toxic for humans, heavy metals among them. Although several studies have been conducted in different species of the genus in order to disentangle the mechanisms associated to heavy metal resistance, little is known about how they have evolved along Streptomyces phylogeny. In this study we built the largest Streptomyces phylogeny generated up to date comprising six genes, 113 species of Streptomyces and 27 outgroups. The parsimony-based phylogenetic analysis indicated that (i) Streptomyces is monophyletic and (ii) it appears as sister clade of a group formed by Kitasatospora and Streptacidiphilus species, both genera also monophyletic. Streptomyces strains resistant to heavy metals are not confined to a single lineage but widespread along Streptomyces phylogeny. Our result in combination with genomic, physiological and biochemical data suggest that the resistance to heavy metals originated several times and by different mechanisms in Streptomyces history.

  13. Impact of heavy metals and PCBs on marine picoplankton.

    PubMed

    Caroppo, Carmela; Stabili, Loredana; Aresta, Michele; Corinaldesi, Cinzia; Danovaro, Roberto

    2006-12-01

    Synergistic/antagonistic effects of multiple contaminants in marine environments are almost completely unexplored. In the present study, we investigated the effects of heavy metals (Zn and Pb) and PCBs on picoplankton abundance, biomass, cell size distribution, and bacterial C production. Natural picoplankton assemblages were exposed to heavy metals (Zn or Pb), organic contaminants (PCBs, Aroclor 1260), and to a mixture of different contaminants. The results of the present study indicate that Zn addition stimulated heterotrophic growth, whereas Pb has a negative impact on heterotrophic picoplankton, particularly significant in the first 24 h. Heavy metals had no effects on the autotrophic component. The addition of Aroclor 1260 had a significant impact on abundance, biomass, and cell size of autotrophic and heterotrophic picoplankton, and reduced significantly bacterial secondary production. Three weeks after PCB treatment, heterotrophic bacteria displayed a clear resilience, both in terms of abundance and biomass, reaching values comparable to those of the controls, but not in terms of bacterial C production. Our results indicate that picoplankton can be sensitive indicators of impact determined by heavy metals and PCBs in coastal marine systems.

  14. Heavy metals pollution in the environment of Kathmandu

    NASA Astrophysics Data System (ADS)

    Shrestha, H. D.

    2003-05-01

    Nepal situated on the lap of mighty Himalayas is now threatened by heavy metals pollution in her atmosphere, land and river system. The indigenious technology of Nepal heavily depends on the use of mercury in gold plating technique. The mercury vapours are released to the atmosphere, when gold-amalgam smeared untesils and idols are strongly heated. Absence of control mechanism to collect mercury vapours has not only polluted atmosphere but it has also caused health hazard to the workers working in the poorly ventilated workshop. The craftsmen and articians have been victim of mercury poisoining. Another heavy metal that has caused atmospheric pollution in Nepal is lead. The lead containing gasoline used in greater amount in vehicles has released more and more lead in the from of exhaust gas into the atmosphere. The atmospheric pollution has been more acute in Nepal due to the use of lead gasoline in used vehicles. Likewise the river system of the urban areas of Nepal is polluted by heavy metals like cadmium, lead salt, ferrous salt, etc. The effulents of battery industries, leather factories, dye factories are directly dumped into the river system of urban areas. This has killed many aquatic animals of rivers. Thus Nepal is facing the problem of heavy metals pollution in her environnent.

  15. Optimization of heavy metals total emission, case study: Bor (Serbia)

    NASA Astrophysics Data System (ADS)

    Ilić, Ivana; Bogdanović, Dejan; Živković, Dragana; Milošević, Novica; Todorović, Boban

    2011-07-01

    The town of Bor (Serbia) is one of the most polluted towns in southeastern Europe. The copper smelter which is situated in the centre of the town is the main pollutant, mostly because of its old technology, which leads to environmental pollution caused by higher concentrations of SO 2 and PM 10. These facts show that the word is about a very polluted region in Europe which, apart from harming human health in the region itself, poses a particular danger for wider area of southeastern Europe. Optimization of heavy metal's total emission was undertaken because years of long contamination of the soil with heavy metals of anthropogenic origin created a danger that those heavy metals may enter the food chains of animals and people, which can lead to disastrous consequences. This work represents the usage of Geographic Information System (GIS) for establishing a multifactor assessment model to quantitatively divide polluted zones and for selecting control sites in a linear programming model, combined with PROMETHEE/GAIA method, Screen View modeling system, and linear programming model. The results show that emissions at some control sites need to be cut for about 40%. In order to control the background of heavy metal pollution in Bor, the ecological environment must be improved.

  16. Semax prevents learning and memory inhibition by heavy metals.

    PubMed

    Inozemtsev, A N; Bokieva, S B; Karpukhina, O V; Gumargalieva, K Z; Kamensky, A A; Myasoedov, N F

    2016-05-01

    Separate and joint effect of Semax, ascorbic acid, lead diacetate, and ammonium molybdate on avoidance conditioning in rats was studied. It was established that the heavy metal salts inhibited the avoidance response, and the peptide counteracted this inhibition as strongly as ascorbic acid or to a comparable degree. These findings confirm the antioxidant properties of Semax.

  17. Fate of heavy metals and agrochemicals in biochar amended soils

    USDA-ARS?s Scientific Manuscript database

    Heavy metals and agrochemicals are the key targets for biochar-induced mitigation of runoff/groundwater contamination. Inorganic and organic contaminants interact differently with biochars as well as soil components. Mechanistic understandings are needed on sorption, desorption, and competitive sor...

  18. Using biopolymers to remove heavy metals from soil and water

    SciTech Connect

    Krishnamurthy, S.; Frederick, R.M.

    1993-11-19

    Chemical remediation of soil may involve the use of harsh chemicals that generate waste streams, which may adversely affect the soil's integrity and ability to support vegetation. This article reviews the potential use of benign reagents, such as biopolymers, to extract heavy metals. The biopolymers discussed are chitin and chitosan, modified starch, cellulose, and polymer-containing algae. (Copyright (c) Remediation 1994.)

  19. Adolescents and Heavy Metal Music: From the Mouths of Metalheads.

    ERIC Educational Resources Information Center

    Arnett, Jeffrey

    1991-01-01

    Attitudes and characteristics of adolescents who like heavy metal music (HMM) were explored in a study of 52 adolescents (largely White males) who liked HMM and 123 who did not in suburban Atlanta (Georgia). HMM is discussed as a reflection of, rather than a cause of, adolescent alienation. (SLD)

  20. MICROBIAL SEQUESTRATION OF LEAD AND OTHER HEAVY METALS

    EPA Science Inventory

    Human activity resulting in heavy metal contamination is a worldwide concern. Lead is a potent neurotoxin that can cause heart problems, kidney damage, and mental retardation. Mercury causes toxicity based on its form and route of exposure. Effects range from allergic reactions t...

  1. TREATMENT OF HEAVY METALS USING AN ORGANIC SULFATE REDUCING PRB

    EPA Science Inventory

    A mpilot-scale permeable reactive wall consisting of a leaf-rich compost-pea gravel mixture was installed at a site in the Vancouver area, Canada to evaluate its potential use for treatment of a large dissolved heavy metal plume. The compost based permeable reactive wall promote...

  2. Heavy metal contamination in the Delhi segment of Yamuna basin.

    PubMed

    Sehgal, Meena; Garg, Ankur; Suresh, R; Dagar, Priya

    2012-01-01

    Concentration of heavy metals (Cd, Ni, Zn, Fe, Cu, Mn, Pb, Cr, Hg and As) in the waters of River Yamuna and in the soil of agricultural fields along its course in Delhi are reported from 13 sites, spread through the Delhi stretch of Yamuna, starting from the Wazirabad barrage till the Okhla barrage. Varying concentration of heavy metals was found. Peaks were observed in samples collected downstream of Wazirabad and Okhla barrage, indicating the anthropogenic nature of the contamination. The Wazirabad section of the river receives wastewater from Najafgarh and its supplementary drains, whereas the Shahdara drain releases its pollution load upstream of the Okhla barrage. Average heavy metal concentration at different locations in the river water varied in the order of Fe>Cr>Mn>Zn>Pb>Cu>Ni>Hg>As>Cd. The river basin soil shows higher level of contamination with lesser variation than the water samples among sampling locations, thereby suggesting deposition over long periods of time through the processes of adsorption and absorption. The average heavy metal concentration at different locations in soil varied in the order of Fe>Mn>Zn>Cr>Pb>Ni>Hg>Cu>As>Cd.

  3. HEAVY METAL CONTAMINATION IN THE TAIMYR PENINSULA, SIBERIAN ARCTIC

    EPA Science Inventory

    The Taimyr Peninsula is directly north of the world's largest heavy metal smelting complex (Norilsk, Russia). Despite this proximity, there has been little research to examine the extent of contamination of the Taimyr Peninsula, primarily because of the remoteness of this area. W...

  4. TREATMENT OF HEAVY METALS USING AN ORGANIC SULFATE REDUCING PRB

    EPA Science Inventory

    A mpilot-scale permeable reactive wall consisting of a leaf-rich compost-pea gravel mixture was installed at a site in the Vancouver area, Canada to evaluate its potential use for treatment of a large dissolved heavy metal plume. The compost based permeable reactive wall promote...

  5. Screening Capsicum chinense fruits for heavy metals bioaccumulation

    USDA-ARS?s Scientific Manuscript database

    Elevated concentrations of heavy metals in edible plants could expose consumers to excessive levels of potentially hazardous chemicals. Sixty-three accessions (genotypes) of Capsicum chinense Jacq, collected from 8 countries of origin, were grown in a silty-loam soil under field conditions. At matur...

  6. Adolescents and Heavy Metal Music: From the Mouths of Metalheads.

    ERIC Educational Resources Information Center

    Arnett, Jeffrey

    1991-01-01

    Attitudes and characteristics of adolescents who like heavy metal music (HMM) were explored in a study of 52 adolescents (largely White males) who liked HMM and 123 who did not in suburban Atlanta (Georgia). HMM is discussed as a reflection of, rather than a cause of, adolescent alienation. (SLD)

  7. Antibiogram and heavy metal tolerance of bullfrog bacteria in Malaysia

    PubMed Central

    Tee, L.W.; Najiah, M.

    2011-01-01

    Bacterial isolates from 30 farmed bullfrogs (Lithobates catesbeianus) weighing 500-600 g at Johore, Malaysia with external clinical signs of ulcer, red leg and torticollis were tested for their antibiograms and heavy metal tolerance patterns. A total of 17 bacterial species with 77 strains were successfully isolated and assigned to 21 antibiotics and 4 types of heavy metal (Hg2+, Cr6+, Cd2+, Cu2+). Results revealed that bacteria were resistant against lincomycin (92%), oleandomycin (72.7%) and furazolidone (71.4%) while being susceptible to chloramphenicol and florfenicol at 97.4%. The multiple antibiotic resistance (MAR) index for C. freundii, E. coli and M. morganii was high with the value up to 0.71. Bacterial strains were found to exhibit 100 % resistance to chromium and mercury. High correlation of resistance against both antibiotics and heavy metals was found (71.4 to 100%) between bullfrog bacteria isolates, except bacteria that were resistant to kanamycin showed only 25% resistance against Cu2+. Based on the results in this study, bacterial pathogens of bullfrog culture in Johore, Malaysia, were highly resistant to both antibiotics and heavy metals. PMID:26623279

  8. MICROBIAL SEQUESTRATION OF LEAD AND OTHER HEAVY METALS

    EPA Science Inventory

    Human activity resulting in heavy metal contamination is a worldwide concern. Lead is a potent neurotoxin that can cause heart problems, kidney damage, and mental retardation. Mercury causes toxicity based on its form and route of exposure. Effects range from allergic reactions t...

  9. Organochlorines, heavy metals, and the biology of North American accipiters

    USGS Publications Warehouse

    Snyder, N.F.R.; Snyder, H.A.; Lincer, J.L.; Reynolds, R.T.

    1973-01-01

    Analyses of eggs of three species of North American accipitrine hawks for organochlorines and heavy metals indicate that contamination with DDE may be the primary cause of recent population declines of two of the species, Cooper's hawk and sharp-shinned hawk.

  10. [Biological toxicity of heavy metals to Caenorhabditis elegans].

    PubMed

    Huang, Yue-e; Zhang, Nan; Jiang, Yu-xin; Guo, Wei; Li, Chao-pin

    2015-06-01

    To evaluate the biological toxicity of heavy metals by using Caenorhabditis elegans. The C. elegans at L4 stage were exposed to CdCl, CrCl3, As2O3, PbCh2, HgCl2 with low concentrations and M9 buffer (the control group) for 72 h, respectively, and the effects of heavy metals with different concentrations on the survival time and reproduction of C. elegans were evaluated. After exposure to 2.5, 10 µmol/L HgCl2 and PbCl2, 10 µmol/L CdCl2, and 50 µmol/L CrCl3 for 72 h, respectively, the life spans and survival curves of the C. elegans were different from those in the control group, the differences were statistically significant (all P < 0.05). After exposure to CdCl2, CrCl3, As2O3, PbCl2 and HgCl2 with the con- centrations of 2.5, 50, 100 µmol/L for 72 h, respectively, the generational time and brood size of C. elegans were all different from those in the control group (all P < 0.01). Among the 5 heavy metals at low concentrations, the reproduction toxicity of Hg was bigger than Pb, Cd, Cr, and the toxicity of As was the weakest. Heavy metal exposure can affect the life span and reproductive toxicity of C. elegans.

  11. HEAVY METAL CONTENT OF AYURVEDIC HERBAL MEDICINE PRODUCTS

    EPA Science Inventory

    Case reports of individuals taking Ayurvedic herbal medicine products (HMPs) suggest that they may contain lead, mercury, and/or arsenic. We analyzed the heavy metal content of Ayurvedic HMPs manufactured in India and Pakistan, available in South Asian grocery stores in the Bost...

  12. High level leaching of heavy metals from colorful ceramic foodwares: a potential risk to human.

    PubMed

    Aderemi, Taiwo Adedoyin; Adenuga, Adeniyi Abiodun; Oyekunle, John Adekunle Oyedele; Ogunfowokan, Aderemi Okunola

    2017-07-01

    Ceramic foodwares are among the products used by people on daily basis without being cautious of exposures to heavy metals through possible leaching from the glaze ceramics. This study investigated the levels of heavy metals found in some commonly used ceramic foodwares in Nigeria with the aim of determining levels of human exposures through the use of the ceramics. To achieve this, acid digestion was carried out for the total metal concentrations and leaching tests were done using 4% acetic acid as a leaching agent. Metal concentrations were quantified using flame atomic absorption spectrometry (FAAS) and particle-induced X-ray emission spectrometry (PIXES) analysis. All the ceramic foodwares studied were found to contain varied amounts of heavy metals in their glazes, with concentrations in the range of 26.45-2071.46, 5.20-547.00, 1.24-2681.02, 2590.00-8848.40, 6.42-654.66, 112.69-649.95, 63.38-2518.51, and 3786.51-8249.44 μg g(-1) for Pb, Cd, Zn, As, Cu, Cr, Mn, and Fe, respectively. Concentrations of the metals leached from the ceramics were in the range of 0.11-0.97, 0.01-0.28, 0.00-4.19, 1.93-15.00, 0.01-0.41, 0.09-0.60, 0.01-2.14, and 0.01-11.53 mgL(-1) for Pb, Cd, Zn, As, Cu, Cr, Mn, and Fe, respectively. Comparing the ratio of the metals leached from the ceramic wares with those of the metal oxides in the ceramics, it was noticeable that not all the metals detected in the ceramic samples were domiciled in the glaze but in the clay materials used for the ceramics.

  13. Heavy Metal Tolerance in Stenotrophomonas maltophilia

    PubMed Central

    Pages, Delphine; Rose, Jerome; Conrod, Sandrine; Cuine, Stephane; Carrier, Patrick; Heulin, Thierry; Achouak, Wafa

    2008-01-01

    Stenotrophomonas maltophilia is an aerobic, non-fermentative Gram-negative bacterium widespread in the environment. S. maltophilia Sm777 exhibits innate resistance to multiple antimicrobial agents. Furthermore, this bacterium tolerates high levels (0.1 to 50 mM) of various toxic metals, such as Cd, Pb, Co, Zn, Hg, Ag, selenite, tellurite and uranyl. S. maltophilia Sm777 was able to grow in the presence of 50 mM selenite and 25 mM tellurite and to reduce them to elemental selenium (Se0) and tellurium (Te0) respectively. Transmission electron microscopy and energy dispersive X-ray analysis showed cytoplasmic nanometer-sized electron-dense Se0 granules and Te0 crystals. Moreover, this bacterium can withstand up to 2 mM CdCl2 and accumulate this metal up to 4% of its biomass. The analysis of soluble thiols in response to ten different metals showed eightfold increase of the intracellular pool of cysteine only in response to cadmium. Measurements by Cd K-edge EXAFS spectroscopy indicated the formation of Cd-S clusters in strain Sm777. Cysteine is likely to be involved in Cd tolerance and in CdS-clusters formation. Our data suggest that besides high tolerance to antibiotics by efflux mechanisms, S. maltophilia Sm777 has developed at least two different mechanisms to overcome metal toxicity, reduction of oxyanions to non-toxic elemental ions and detoxification of Cd into CdS. PMID:18253487

  14. Heavy metal pollutants and chemical ecology: exploring new frontiers.

    PubMed

    Boyd, Robert S

    2010-01-01

    Heavy metals are an important class of pollutants with both lethal and sublethal effects on organisms. The latter are receiving increased attention, as these may have harmful ecological outcomes. For example, recent explorations of heavy metals in freshwater habitats reveal that they can modify chemical communication between individuals, resulting in "info-disruption" that can impact ecological relationships within and between species. Info-disruption can affect animal behavior and social structure, which in turn can modify both intraspecies and interspecies interactions. In terrestrial habitats, info-disruption by metals is not well studied, but recent demonstrations of chemical signaling between plants via both roots and volatile organic molecules provide potential opportunities for info-disruption. Metals in terrestrial habitats also can form elemental plant defenses, in which they can defend a plant against natural enemies. For example, hyperaccumulation of metals by terrestrial plants has been shown to provide defensive benefits, although in almost all known cases the metals are not anthropogenic pollutants but are naturally present in soils inhabited by these plants. Info-disruption among microbes is another arena in which metal pollutants may have ecological effects, as recent discoveries regarding quorum sensing in bacteria provide an avenue for metals to affect interactions among bacteria or between bacteria and other organisms. Metal pollutants also may influence immune responses of organisms, and thus affect pathogen/host relationships. Immunomodulation (modification of immune system function) has been tied to some metal pollutants, although specific metals may boost or reduce immune system function depending on dose. Finally, the study of metal pollutants is complicated by their frequent occurrence as mixtures, either with other metals or with organic pollutants. Most studies of metal pollutants focus on single metals and therefore oversimplify complex

  15. Heavy metals fractionation in Ganga River sediments, India.

    PubMed

    Purushothaman, P; Chakrapani, G J

    2007-09-01

    The Ganga River is the largest river in India which, originates in the Himalayas and along with the Brahmaputra River, another Himalayan river, transports enormous amounts of sediments from the Indian sub-continent to the Bay of Bengal. Because of the important role of river sediments in the biogeochemical cycling of elements, the Ganga river sediments, collected from its origin to the down stretches, were studied in the present context, to assess the heavy metals associated with different chemical fractions of sediments. The fractionation of metals were studied in the sediments using SM&T protocol for the extraction of heavy metals and geo-accumulation index (GAI) (Muller, Schwermetalle in den sedimenten des rheins - Veranderungen seit. Umschau, 79, 778-783, 1979) and Metal Enrichment Factor (MEF) in different fractions were calculated. As with many river systems, residual fractions constitute more than 60% of total metals, except Zn, Cu and Cr. However, the reducible and organic and sulfide components also act as major sinks for metals in the down stretches of the river, which is supported by the high GAI and MEF values. The GAI values range between 4 and 5 and MEF exceed more than 20 for almost all the locations in the downstream locations indicating to the addition of metals through urban and industrial effluents, as compared to the low metals concentrations with less GAI and MEF in the pristine river sediments from the rivers in Himalayas.

  16. Bonds Between Metal Atoms: A New Mode of Transition Metal Chemistry.

    ERIC Educational Resources Information Center

    Cotton, F. Albert; Chisholm, Malcolm H.

    1982-01-01

    Discusses polynuclear metal clusters (containing two or more metal atoms bonded to one another as well as to nonmetallic elements), including their formation and applications. Studies of bonds between metal atoms reveal superconductors, organic-reaction catalysts, and photosensitive complexes that may play a role in solar energy. (JN)

  17. Bonds Between Metal Atoms: A New Mode of Transition Metal Chemistry.

    ERIC Educational Resources Information Center

    Cotton, F. Albert; Chisholm, Malcolm H.

    1982-01-01

    Discusses polynuclear metal clusters (containing two or more metal atoms bonded to one another as well as to nonmetallic elements), including their formation and applications. Studies of bonds between metal atoms reveal superconductors, organic-reaction catalysts, and photosensitive complexes that may play a role in solar energy. (JN)

  18. Bioethanol production from recovered napier grass with heavy metals.

    PubMed

    Ko, Chun-Han; Yu, Fan-Chun; Chang, Fang-Chih; Yang, Bing-Yuan; Chen, Wen-Hua; Hwang, Wen-Song; Tu, Ta-Chih

    2017-05-11

    Using plants to absorb and accumulate heavy metals from polluted soil, followed by the recycling of explants containing heavy metals, can help achieve the goal of reverting contaminated soil to low heavy-metal content soil. However, the re-use of recovered explants can also be problematic. Meanwhile, bioethanol has become a popular energy source. In this study, napier grass was used for the remediation of soil contaminated with heavy metals (artificially contaminated soil). The influence of bioethanol production from napier grass after phytoremediation was also investigated. The concentration of Zn, Cd, and Cr in the contaminated soil was 1000, 100, and 250 mg/kg, respectively. After napier grass phytoremediation, the concentration (dry biomass) of Zn, Cd, and Cr in the explants was 2701.97 ± 173.49, 6.1 ± 2.3, and 74.24 ± 1.42 mg/kg, respectively. Biomass production in the unpolluted soil was 861.13 ± 4.23 g. The biomass production ratio in high Zn-polluted soil was only 3.89%, while it was 4.68% for Cd and 21.4% for Cr. The biomass obtained after napier grass phytoremediation was pretreated using the steam explosion conditions of 180 °C, for 10 min, with 1.5% H2SO2, followed by enzymatic hydrolysis. The efficiency of enzymatic hydrolysis for Zn-polluted biomass was 90% of the unpolluted biomass, while it was 77% for Cd, and approximately the same for Cr. The fermentation efficiency of the heavy-metal-containing biomass was higher than the control biomass. The fermentation ethanol concentration obtained was 8.69-12.68, 13.03-15.50, and 18.48-19.31 g/L in Zn, Cd, and Cr environments, respectively. Results show that the heavy metals had a positive effect on bacteria fermentation. However, the fermentation efficiency was lower for biomass with severe heavy metal pollution. Thus, the utilization of napier grass phytoremediation for bioethanol production has a positive effect on the sustainability of environmental resources. Copyright © 2017

  19. Influence of voltage input to heavy metal removal from electroplating wastewater using electrocoagulation process

    NASA Astrophysics Data System (ADS)

    Wulan, D. R.; Cahyaningsih, S.; Djaenudin

    2017-03-01

    In medium capacity, electroplating industry usually treats wastewater until 5 m3 per day. Heavy metal content becomes concern that should be reduced. Previous studies performed electrocoagulation method on laboratory scale, either batch or continuous. This study was aimed to compare the influence of voltage input variation into heavy metal removal in electroplating wastewater treatment using electrocoagulation process on laboratory-scale in order to determine the optimum condition for scaling up the reactor into pilot-scale. The laboratory study was performed in 1.5 L glass reactor in batch system using wastewater from electroplating industry, the voltage input varied at 20, 30 and 40 volt. The electrode consisted of aluminium 32 cm2 as sacrifice anode and copper 32 cm2 as cathode. During 120 min electrocoagulation process, the pH value was measured using pH meter, whereas the heavy metal of chromium, copper, iron, and zinc concentration were analysed using Atomic Absorption Spectrophotometer (AAS). Result showed that removal of heavy metals from wastewater increased due to the increasing of voltage input. Different initial concentration of heavy metals on wastewater, resulted the different detention time. At pilot-scale reactor with 30 V voltage input, chromium, iron, and zinc reached removal efficiency until 89-98%, when copper reached 79% efficiency. At 40V, removal efficiencies increased on same detention time, i.e. chromium, iron, and zinc reached 89-99%, whereas copper reached 85%. These removal efficiencies have complied the government standard except for copper that had higher initial concentration in wastewater. Kinetic rate also calculated in this study as the basic factor for scaling up the process.

  20. Baseline values for heavy metals in agricultural soils in an European Mediterranean region.

    PubMed

    Micó, Carolina; Peris, Mónica; Recatalá, Luis; Sánchez, Juan

    2007-05-25

    Baseline values for heavy metals were proposed in Alicante (Spain), a representative agricultural area of the European Mediterranean region, as a basis to identify and assess soil contamination processes at regional level. Fifty-four agricultural plots were sampled and heavy metals concentrations were analysed for nine elements (Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, and Zn) by atomic absorption spectrometry (AAS) after acid digestion with HNO(3) and HCl in a microwave oven. Heavy metal concentrations obtained in the study area were similar to concentrations analysed by other authors within the European Mediterranean region. However, some agricultural plots with a high heavy metal content were identified by statistical treatment (boxplots) as outliers and, therefore, were not considered for establishing baseline values. Baseline values in Alicante were proposed by taking into account the statistical approach extensively used elsewhere, which refers to the increase in the mean plus twice the standard deviation. The baseline values were: 0.7 mg/kg for Cd, 11 mg/kg for Co, 36 mg/kg for Cr, 28 mg/kg for Cu, 19,822 mg/kg for Fe, 402 mg/kg for Mn, 31 mg/kg for Ni, 28 mg/kg for Pb and 83 mg/kg for Zn. The experience gained in this work further suggests that baseline values for heavy metals should be proposed in other areas. This is necessary to facilitate the identification of soil contamination processes over the whole European Mediterranean region as a basis to undertaking appropriate action to protect soil resource quality.

  1. Heavy metal bioaccumulation in two passerines with differing migration strategies.

    PubMed

    Cooper, Zoë; Bringolf, Robert; Cooper, Robert; Loftis, Kathy; Bryan, Albert L; Martin, James A

    2017-03-11

    Various anthropogenic activities have resulted in concentration of heavy metals and contamination of surrounding environments. Historically, heavy metal contamination at the Savannah River Site (SRS) in South Carolina has resulted from accidental releases of stored waste generated from nuclear weapon production in the early 1950s. Songbirds inhabiting and using resources from these areas have the potential to bioaccumulate metals but there is limited information on metal concentration levels in areas suspected of contamination as well as uncontaminated sites. Nonlethal tissues samples from avian blood and feathers provide a reliable approach for determining the bioavailability of these pollutants (As, Cd, Cr, Cu, Hg, Ni, Pb, Se, and Zn). The objectives of this study were to survey terrestrial heavy metal contamination at the SRS on potentially bioavailable contaminated (PBC) sites through blood and feather samples from resident Northern Cardinals (Cardinalis cardinalis) and migratory Great Crested Flycatchers (Myiarchus crinitus) and quantify sex-specific concentrations within species. Samples were collected in April to June of 2016. Cardinals had lower blood concentrations of Hg (β=-0.17, 85% CL=-0.26, -0.09) and Se (β=-0.33, 85% CL=-0.50, -0.16) than flycatchers. Cr feather concentrations were less in cardinals (β=-1.46, 85% CL=-2.44, -0.49) and all feathers of both species from reference locations had significantly less Zn (β=-67.92, 85% CL=-128.71, -7.14). Results indicate flycatchers were exposed to differing heavy metal levels during feather formation on their wintering grounds as compared to their recent exposure (through bloods samples) on their breeding grounds. Sex of individuals did not have a significant impact on bioaccumulation in either species. Overall, metal concentration levels in both species indicate minimal risk for acute toxicity; however, there is limited research on wild passerine populations with similar concentration levels. Therefore

  2. Analysis of mosses and topsoils for detecting sources of heavy metal pollution: multivariate and enrichment factor analysis.

    PubMed

    Dragović, S; Mihailović, N

    2009-10-01

    In order to assess the contribution of emission sources to the pollution of areas remote from industrial facilities, a combined approach of enrichment factor analysis and multivariate statistics was used for detecting the origin of heavy metal pollution in the Zlatibor ecosystem, in Serbia. Samples of moss (Pleurozium schreberi, Hylocomium splendens, Scleropodium purum, Hypnum cupressiforme and Thuidum delicatulum) and of topsoil (0-5 cm) were collected in 2005. The concentrations of seven heavy metals (Cd, Cr, Cu, Mn, Ni, Pb and Zn) were determined in moss and soil samples by atomic absorption spectrometry. The results obtained by enrichment factor analysis and two multivariate statistical methods, principal component analysis and cluster analysis, enabled discrimination of the lithologic and anthropogenic sources of heavy metals in the mosses. Enrichment factors, calculated to evaluate the contribution to the metal content in moss from anthropogenic sources, revealed pollution of the investigated area by Cd and Pb, originating from long-range transport and fossil fuel burning.

  3. [Occupational exposure to carcinogenic metals and metalloids in refining of heavy metals].

    PubMed

    Gaweda, Ewa

    2005-01-01

    The article presents the results of measurements of carcinogenic metals (cadmium, nickel) and metalloids (arsenic) concentrations in the workplace air in processes of heavy metals refining. The tests were conducted in two large Polish plants (copper smelter--Plant I, non-ferrous metals smelter--Plant II) at a few dozen workstations in copper, zinc, cadmium, lead, silver refining, sulphate Ni(I), and selenium production. The tested elements were determined by atomic absorption spectrometry with graphite tube (AAS-GT). Air samples were taken according to the principles of personal dosimetry. The presence of arsenic in the workplace air was found in both plants. In Plant I, exposure to arsenic was diversified--from very low in copper electro-refining processes, to higher than the Polish MAC value in copper, and higher than 0.5 Polish MAC value in silver refining processes. In Plant II, the amounts of arsenic determined in the air were smaller, however, the average values of occupational exposure factor were frequently higher than Polish MAC value of 0.1. Exposure to cadmium occurs only in Plant II. The highest exposure was found at workstations in the lead and cadmium refining processes. But even in these processes, occupational exposure factors Cw did not exceed the Polish MAC value for cadmium. The presence of nickel was found only at workstations with NiSO4 production, however, its concentrations were very low (fractions of the Polish MAC value). The results of the tests show that routine measurements of arsenic concentrations should be recommended at all workstations in the production processes of metals with a high degree of purity.

  4. Electronic Tongue-FIA system for the Monitoring of Heavy Metal Biosorption Processes

    NASA Astrophysics Data System (ADS)

    Wilson, D.; Florido, A.; Valderrama, C.; de Labastida, M. Fernández; Alegret, S.; del Valle, M.

    2011-09-01

    An automated flow injection potentiometric (FIP) system with electronic tongue detection (ET) was used for the monitoring of biosorption processes of heavy metals on waste biomaterial. Grape stalk wastes were used as biosorbent to remove Cu2+ ions in a fixed-bed column setup. For the monitoring, the used ET employed a sensor array formed by Cu2+ and Ca2+ selective electrodes and two generic heavy-metal electrodes. The subsequent cross-response obtained was processed by a multilayer artificial neural network (ANN) model in order to resolve the concentrations of the monitored species. The coupling of the electronic tongue with the automation features of the flow-injection system (ET-FIP) allowed us to accurately characterize the biosorption process, through obtaining its breakthrough curves. In parallel, fractions of the extract solution were analyzed by atomic absorption spectroscopy in order to validate the results obtained with the reported methodology.

  5. Means for obtaining a metal ion beam from a heavy-ion cyclotron source

    DOEpatents

    Hudson, E.D.; Mallory, M.L.

    1975-08-01

    A description is given of a modification to a cyclotron ion source used in producing a high intensity metal ion beam. A small amount of an inert support gas maintains the usual plasma arc, except that it is necessary for the support gas to have a heavy mass, e.g., xenon or krypton as opposed to neon. A plate, fabricated from the metal (or anything that can be sputtered) to be ionized, is mounted on the back wall of the ion source arc chamber and is bombarded by returning energetic low-charged gas ions that fail to cross the initial accelerating gap between the ion source and the accelerating electrode. Some of the atoms that are dislodged from the plate by the returning gas ions become ionized and are extracted as a useful beam of heavy ions. (auth)

  6. [Determination and analysis of heavy metals content in Panax notoginseng of different origination].

    PubMed

    Zhao, Jing; Liu, Yong; Zhang, Ai-Hua; Wang, Ying-Li; Hao, Qing-Xiu; Guo, Lan-Ping; Huang, Lu-Qi; Liu, Da-Hui

    2014-10-01

    Six heavy metals, including As, Cu, Hg, Cd, Pb and Cr in Panax notoginseng were determined by inductively coupled plasma atomic emission spectrometry (ICP-AES) combined with wet digestion method. The samples of P. notoginseng were collected in 12 different regions, including Yunnan and Guangxi Province. Green Standards of Foreign Trading Medicinal Plants & Preparations was used as the standard to evaluate the pollution status of As, Cu, Hg, Cd, Pb and Cr in P. notoginseng. The results showed that content of As and Cd exceeded the limit of the standard and the percentage was 32.4% and 29.7%, respectively, while Cu, Hg and Pb were all bellow the limit. The SPSS 16.0 software was used to analyze the data. The occurrence of contained heavy metals has been discussed.

  7. Anaerobes into heavy metal: Dissimilatory metal reduction in anoxic environments

    USGS Publications Warehouse

    Lovley, D.R.

    1993-01-01

    Within the last decade, a novel form of microbial metabolism of major environmental significance has been elucidated. In this process, known as dissimilatory metal reduction, specialized microorganisms, living in anoxic aquatic sediments and ground water, oxidize organic compounds to carbon dioxide with metals serving as the oxidant. Recent studies have demonstrated that this metabolism explains a number of important geochemical phenomena in ancient and modern sedimentary environments, affecting not only the cycling of metals but also the fate of organic matter. Furthermore, this metabolism may have practical application in remediation of environments contaminated with toxic metals and/or organics.

  8. Heavy metal contamination of soil and water in the vicinity of an abandoned e-waste recycling site: implications for dissemination of heavy metals.

    PubMed

    Wu, Qihang; Leung, Jonathan Y S; Geng, Xinhua; Chen, Shejun; Huang, Xuexia; Li, Haiyan; Huang, Zhuying; Zhu, Libin; Chen, Jiahao; Lu, Yayin

    2015-02-15

    Illegal e-waste recycling activity has caused heavy metal pollution in many developing countries, including China. In recent years, the Chinese government has strengthened enforcement to impede such activity; however, the heavy metals remaining in the abandoned e-waste recycling site can still pose ecological risk. The present study aimed to investigate the concentrations of heavy metals in soil and water in the vicinity of an abandoned e-waste recycling site in Longtang, South China. Results showed that the surface soil of the former burning and acid-leaching sites was still heavily contaminated with Cd (>0.39 mg kg(-1)) and Cu (>1981 mg kg(-1)), which exceeded their respective guideline levels. The concentration of heavy metals generally decreased with depth in both burning site and paddy field, which is related to the elevated pH and reduced TOM along the depth gradient. The pond water was seriously acidified and contaminated with heavy metals, while the well water was slightly contaminated since heavy metals were mostly retained in the surface soil. The use of pond water for irrigation resulted in considerable heavy metal contamination in the paddy soil. Compared with previous studies, the reduced heavy metal concentrations in the surface soil imply that heavy metals were transported to the other areas, such as pond. Therefore, immediate remediation of the contaminated soil and water is necessary to prevent dissemination of heavy metals and potential ecological disaster. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. Utilizing heavy metal-laden water hyacinth biomass in vermicomposting.

    PubMed

    Tereshchenko, Natalya N; Akimova, Elena E; Pisarchuk, Anna D; Yunusova, Tatyana V; Minaeva, Oksana M

    2015-05-01

    We studied the efficiency of water treatment by water hyacinth (Eichhornia crassipes) from heavy metals (Zn, Cd, Pb, Cu), as well as a possibility of using water hyacinth biomass obtained during treatment for vermicomposting by Eisenia fetida and the vermicompost quality in a model experiment. The results showed that the concentration of heavy metals in the trials with water hyacinth decreased within 35 days. We introduced water hyacinth biomass to the organic substrate for vermicomposting, which promoted a significant weight gain of earthworms and growth in their number, as well as a 1.5- to 3-fold increase in coprolite production. In the trial with 40 % of Eichhornia biomass in the mixture, we observed a 26-fold increase in the number and a 16-fold weight gain of big mature individuals with clitellum; an increase in the number of small individuals 40 times and in the number of cocoons 140 times, as compared to the initial substrate. The utilization of water hyacinth biomass containing heavy metals in the mixture led to a 10-fold increase in the number of adult individuals and cocoons, which was higher than in control. We found out that adding 10 % of Eichhornia biomass to the initial mixture affected slightly the number of microorganisms and their species diversity in the vermicompost. Adding Eichhornia biomass with heavy metals reduced the total number of microorganisms and sharply diminished their species diversity. In all trials, adding water hyacinth in the mixture for vermicomposting had a positive impact on wheat biometric parameters in a 14-day laboratory experiment, even in the trial with heavy metals.

  10. Metal powder production by gas atomization

    NASA Technical Reports Server (NTRS)

    Ting, E. Y.; Grant, N. J.

    1986-01-01

    The confined liquid, gas-atomization process was investigated. Results from a two-dimensional water model showed the importance of atomization pressure, as well as delivery tube and atomizer design. The atomization process at the tip of the delivery tube was photographed. Results from the atomization of a modified 7075 aluminum alloy yielded up to 60 wt pct. powders that were finer than 45 microns in diameter. Two different atomizer designs were evaluated. The amount of fine powders produced was correlated to a calculated gas-power term. An optimal gas-power value existed for maximized fine powder production. Atomization at gas-power greater than or less than this optimal value produced coarser powders.

  11. Fractal atomic-level percolation in metallic glasses.

    PubMed

    Chen, David Z; Shi, Crystal Y; An, Qi; Zeng, Qiaoshi; Mao, Wendy L; Goddard, William A; Greer, Julia R

    2015-09-18

    Metallic glasses are metallic alloys that exhibit exotic material properties. They may have fractal structures at the atomic level, but a physical mechanism for their organization without ordering has not been identified. We demonstrated a crossover between fractal short-range (<2 atomic diameters) and homogeneous long-range structures using in situ x-ray diffraction, tomography, and molecular dynamics simulations. A specific class of fractal, the percolation cluster, explains the structural details for several metallic-glass compositions. We postulate that atoms percolate in the liquid phase and that the percolating cluster becomes rigid at the glass transition temperature.

  12. Disposable cuvette test for enzymatic determination of heavy metals

    NASA Astrophysics Data System (ADS)

    Wolfbeis, Otto S.; Preininger, Claudia

    1995-10-01

    We report on an optical cuvette test for total heavy metals based on the inhibition of the enzyme urease by metals ions including silver(I), mercury(II), copper(II), nickel(II), cobalt(II), and cadmium(II). The enzymatic action is monitored using an optical ammonia transducer deposited on the wall of a disposable cuvette. This results in a rapid and inexpensive single-shot device for heavy metal sensing. A solution of urease and buffer is placed in the cuvette with the ammonium sensor membrane fixed on one of its walls. Enzymatic action starts after addition of a defined quantity of urea. This is indicated by the increase in the absorption of the ammonia sensor membrane whose color changes from yellow to blue. The slop of the increase in signal is the information for the un-inhibited reaction. After several minutes,the sample (containing the heavy metal) is added to the cuvette. Heavy metal ions inhibit the enzyme (by binding to the sulfhydryl groups) and cause a decrease in the slope. The ratio of slopes of un-inhibited and inhibited reactions is a direct parameter for detecting and calculating total heavy metals. The optimum pH was a trade-off between optimum enzyme activity (pH 7 at 25 degree(s)C) and the relative signal change of the ammonia-sensor (highest at pH 8). pH 7.5 was found to be optimal. The system was calibrated at optimized activities of urease (1.5 (mu) ) and an optimized urea concentration (0.5 mmol). Heavy metals inhibit in the following order: Ag(I) > Hg(II) > Cu(II) >> Ni(II) > Co(II) > Cd(II) > Fe(III) > Pb(II), Zn(II). The following concentrations that cause 50% inhibition were found: Ag(I) (0.1 ppm), Hg(II) (0.5 ppm), Cu(II) (0.5 ppm), Ni(II) (7 ppm), Co(II) (30 ppm), Cd(II) (95 ppm), Fe(III) (50 ppm), Zn(II) (85 ppm) and Pb(II) (210 ppm). We also studied the inhibitory effect of combinations of metal ions, the influence of ionic strength, and the effect of incubation time.

  13. PROCESS FOR SEPARATION OF HEAVY METALS

    DOEpatents

    Duffield, R.B.

    1958-04-29

    A method is described for separating plutonium from aqueous acidic solutions of neutron-irradiated uranium and the impurities associated therewith. The separation is effected by adding, to the solution containing hexavalent uranium and plutonium, acetate ions and the ions of an alkali metal and those of a divalent metal and thus forming a complex plutonium acetate salt which is carried by the corresponding complex of uranium, such as sodium magnesium uranyl acetate. The plutonium may be separated from the precipitated salt by taking the same back into solution, reducing the plutonium to a lower valent state on reprecipitating the sodium magnesium uranyl salt, removing the latter, and then carrying the plutonium from ihe solution by means of lanthanum fluoride.

  14. Thermodynamics of binding interactions between extracellular polymeric substances and heavy metals by isothermal titration microcalorimetry.

    PubMed

    Yan, Peng; Xia, Jia-Shuai; Chen, You-Peng; Liu, Zhi-Ping; Guo, Jin-Song; Shen, Yu; Zhang, Cheng-Cheng; Wang, Jing

    2017-05-01

    Extracellular polymeric substances (EPS) play a crucial role in heavy metal bio-adsorption using activated sludge, but the interaction mechanism between heavy metals and EPS remains unclear. Isothermal titration calorimetry was employed to illuminate the mechanism in this study. The results indicate that binding between heavy metals and EPS is spontaneous and driven mainly by enthalpy change. Extracellular proteins in EPS are major participants in the binding process. Environmental conditions have significant impact on the adsorption performance. Divalent and trivalent cations severely impeded the binding of heavy metal ions to EPS. Electrostatic interaction mainly attributed to competition between divalent cations and heavy metal ions; trivalent cations directly competed with heavy metal ions for EPS binding sites. Trivalent cations were more competitive than divalent cations for heavy metal ion binding because they formed complexing bonds. This study facilitates a better understanding about the interaction between heavy metals and EPS in wastewater treatment. Copyright © 2017 Elsevier Ltd. All rights reserved.