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Sample records for heavy metals behavior

  1. 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)

  2. Adsorption behavior of heavy metals on biomaterials.

    PubMed

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

    2004-09-01

    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.

  3. Synthesis and heavy metal immobilization behaviors of slag based geopolymer.

    PubMed

    Yunsheng, Zhang; Wei, Sun; Qianli, Chen; Lin, Chen

    2007-05-01

    In this paper, two aspects of studies are carried out: (1) synthesis of geopolymer by using slag and metakaolin; (2) immobilization behaviors of slag based geopolymer in a presence of Pb and Cu ions. As for the synthesis of slag based geopolymer, four different slag content (10%, 30%, 50%, 70%) and three types of curing regimes (standard curing, steam curing and autoclave curing) are investigated to obtain the optimum synthesis condition based on the compressive and flexural strength. The testing results showed that geopolymer mortar containing 50% slag that is synthesized at steam curing (80 degrees C for 8h), exhibits higher mechanical strengths. The compressive and flexural strengths of slag based geopolymer mortar are 75.2 MPa and 10.1 MPa, respectively. Additionally, Infrared (IR), X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques are used to characterize the microstructure of the slag based geopolymer paste. IR spectra show that the absorptive band at 1086 cm(-1) shifts to lower wave number around 1007 cm(-1), and some six-coordinated Als transforms into four-coordination during the synthesis of slag based geopolymer paste. The resulting slag based geopolymeric products are X-ray amorphous materials. SEM observation shows that it is possible to have geopolymeric gel and calcium silicate hydrate (C-S-H) gel forming simultaneously within slag based geopolymer paste. As for immobilization of heavy metals, the leaching tests are employed to investigate the immobilization behaviors of the slag based geopolymer mortar synthesized under the above optimum condition. The leaching tests show that slag based geopolymer mortar can effectively immobilize Cu and Pb heavy metal ions, and the immobilization efficiency reach 98.5% greater when heavy metals are incorporated in the slag geopolymeric matrix in the range of 0.1-0.3%. The Pb exhibits better immobilization efficiency than the Cu in the case of large dosages of heavy metals.

  4. Heavy Metals Behavior During Thermal Plasma Vitrification Of Incineration Residues

    NASA Astrophysics Data System (ADS)

    Cerqueira, Nuno; Vandensteendam, Colette; Baronnet, Jean Marie

    2006-01-01

    Incineration of wastes, widely and increasingly used nowadays, produces residues, mainly bottom ash and filter fly ash. Fly ash is especially problematic because of its high content in heavy metals easily drawn out. Thermal processes, based mainly on electrical arc processes, are used to melt the residues at high temperature and convert them into a relatively inert glass. Consequently, to improve the process and get a glass satisfying regulation, control of heavy metals (lead, zinc, cadmium and chromium…) volatility during plasma fly ash melting and vitrification is needed and basic data concerning vaporization of these metals are required. According to the volatility of these compounds observed during vitrification of fly ash, a predictive model has been used to simulate the elimination of Pb, Zn and S from the melt as a function of time and temperature for a system including chlorides, oxides and sulfates. The objective of this work was the experimental study of heavy metals volatility using optical emission spectroscopy. A twin torch plasma system, mounted above a cold crucible with Ar (or Ar + O2) as plasma gas, has been used. The crucible was filled with synthetic glass in which known amounts of metallic salts were added to obtain the same chemical composition as used in the model. From spectral lines intensities of Ar, the plasma temperature profiles along the observation direction has been first established, before using ratios of spectral lines of Ar and metallic (Pb, Zn) or Cl vapors to reach the evolution of the elements concentrations above the melt. Off-gases have been analyzed by mass spectrometry. The influence of the atmosphere (Ar or Ar + O2) above the crucible has been studied and differences in elements behaviors have been pointed out. The results of the spectroscopic measurements have been compared to the ones issued of modeling, in order to validate our model of vaporization.

  5. Transient behavior of heavy metals in soils during electrokinetic remediation.

    PubMed

    Al-Hamdan, Ashraf Z; Reddy, Krishna R

    2008-03-01

    This paper presents a systematic bench-scale laboratory study performed to assess the transient behavior of chromium, nickel, and cadmium in different soils during electrokinetic remediation. A series of laboratory electrokinetic experiments was conducted using two different clayey soils, kaolin and glacial till. For each type of soil, four electrokinetic experiments with 1, 2, 4, and 10 d of treatment time were performed. In all tests, the contaminants were Cr(VI), Ni(II), and Cd(II) combined in the soil. A geochemical assessment was performed using the geochemical model MINEQL(+) to determine the partitioning of the heavy metals in soils as precipitated, adsorbed, and aqueous forms. Results showed that in kaolin, the extent of Ni(II) and Cd(II) migration towards the cathode increased as the treatment time increased. Unlike kaolin, in glacial till treatment time had no effect on nickel and cadmium migration because of its high buffering capacity. In both kaolin and glacial till, the extent of Cr(VI) migration towards the anode increased as the treatment time increased. However, Cr(VI) migration was higher in glacial till as compared to kaolin because of the high pH conditions that existed in glacial till. In all tests, some Cr(VI) was reduced to Cr(III), and the Cr(VI) reduction rate to Cr(III) as well as the Cr(III) migration were significantly affected by the treatment time. Overall, this study showed that the electroosmotic flow as well as the direction and extent of contaminant migration and removal depend on the polarity of the contaminant, the type of soil, and the treatment duration. PMID:18155269

  6. Thermal behaviors and heavy metal vaporization of phosphatized tannery sludge in incineration process.

    PubMed

    Tang, Ping; Zhao, Youcai; Xia, Fengyi

    2008-01-01

    The high concentration of heavy metal (Cu, Cr, Zn, Pb) in tannery sludge causes severe heavy metal emissions in the process of incineration. In the present investigation, the tannery sludge was treated with 85% phosphoric acid before the incineration process in the tube furnace to control the heavy metal emissions. The thermal behavior and heavy metal vaporization of pre-treated tannery sludge were investigated, and X-ray diffraction (XRD) and scanning electron microscopy (SEM) analysis were also implemented to elucidate the chemical mechanisms responsible for the thermal behavior and weakening of heavy metal vaporization of pre-treated tannery sludge. The results obtained show that the differences in thermal behaviors between untreated and pre-treated tannery sludge are caused by the reaction of phosphoric acid and calcium carbonate. The vaporization percentage of heavy metal decreased efficiently with the increasing volumes of H3PO4, which indicated the important thermal stability of the water-insoluble metallic phosphates (Ca18Cu3(PO4)14, Ca9Cr(PO4)7, Ca19Zn2(PO4)14, PbMgP2O7) formed during tannery sludge phosphatation.

  7. The migration and transformation behaviors of heavy metals during the hydrothermal treatment of sewage sludge.

    PubMed

    Huang, Hua-Jun; Yuan, Xing-Zhong

    2016-01-01

    Various hydrothermal treatment methods, including hydrothermal carbonization, liquefaction and sub/super-critical water gasification, have been applied to the disposal of sewage sludge for producing bio-materials or bio-fuels. It has become a research hotspot whether the heavy metals contained in sewage sludge can be well treated/stabilized after the hydrothermal treatments. This review firstly summarized the methods of assessing heavy metals' contamination level/risk and then discussed the migration and transformation behaviors of heavy metals from the following aspects: the effect of reaction temperature, the effect of additives (catalysts and other biomass), the effect of the type of solvent and the effect of reaction time. This review can provide an important reference for the further study of the migration and transformation behaviors of heavy metals during the hydrothermal treatment of sewage sludge. PMID:26577578

  8. Study on the behavior of heavy metals during thermal treatment of municipal solid waste (MSW) components.

    PubMed

    Yu, Jie; Sun, Lushi; Wang, Ben; Qiao, Yu; Xiang, Jun; Hu, Song; Yao, Hong

    2016-01-01

    Laboratory experiments were conducted to investigate the volatilization behavior of heavy metals during pyrolysis and combustion of municipal solid waste (MSW) components at different heating rates and temperatures. The waste fractions comprised waste paper (Paper), disposable chopstick (DC), garbage bag (GB), PVC plastic (PVC), and waste tire (Tire). Generally, the release trend of heavy metals from all MSW fractions in rapid-heating combustion was superior to that in low-heating combustion. Due to the different characteristics of MSW fractions, the behavior of heavy metals varied. Cd exhibited higher volatility than the rest of heavy metals. For Paper, DC, and PVC, the vaporization of Cd can reach as high as 75% at 500 °C in the rapid-heating combustion due to violent combustion, whereas a gradual increase was observed for Tire and GB. Zn and Pb showed a moderate volatilization in rapid-heating combustion, but their volatilities were depressed in slow-heating combustion. During thermal treatment, the additives such as kaolin and calcium can react or adsorb Pb and Zn forming stable metal compounds, thus decreasing their volatilities. The formation of stable compounds can be strengthened in slow-heating combustion. The volatility of Cu was comparatively low in both high and slow-heating combustion partially due to the existence of Al, Si, or Fe in residuals. Generally, in the reducing atmosphere, the volatility of Cd, Pb, and Zn was accelerated for Paper, DC, GB, and Tire due to the formation of elemental metal vapor. TG analysis also showed the reduction of metal oxides by chars forming elemental metal vapor. Cu2S was the dominant Cu species in reducing atmosphere below 900 °C, which was responsible for the low volatility of Cu. The addition of PVC in wastes may enhance the release of heavy metals, while GB and Tire may play an opposite effect. In controlling heavy metal emission, aluminosilicate- and calcium-based sorbents can be co-treated with fuels. Moreover

  9. Study on the behavior of heavy metals during thermal treatment of municipal solid waste (MSW) components.

    PubMed

    Yu, Jie; Sun, Lushi; Wang, Ben; Qiao, Yu; Xiang, Jun; Hu, Song; Yao, Hong

    2016-01-01

    Laboratory experiments were conducted to investigate the volatilization behavior of heavy metals during pyrolysis and combustion of municipal solid waste (MSW) components at different heating rates and temperatures. The waste fractions comprised waste paper (Paper), disposable chopstick (DC), garbage bag (GB), PVC plastic (PVC), and waste tire (Tire). Generally, the release trend of heavy metals from all MSW fractions in rapid-heating combustion was superior to that in low-heating combustion. Due to the different characteristics of MSW fractions, the behavior of heavy metals varied. Cd exhibited higher volatility than the rest of heavy metals. For Paper, DC, and PVC, the vaporization of Cd can reach as high as 75% at 500 °C in the rapid-heating combustion due to violent combustion, whereas a gradual increase was observed for Tire and GB. Zn and Pb showed a moderate volatilization in rapid-heating combustion, but their volatilities were depressed in slow-heating combustion. During thermal treatment, the additives such as kaolin and calcium can react or adsorb Pb and Zn forming stable metal compounds, thus decreasing their volatilities. The formation of stable compounds can be strengthened in slow-heating combustion. The volatility of Cu was comparatively low in both high and slow-heating combustion partially due to the existence of Al, Si, or Fe in residuals. Generally, in the reducing atmosphere, the volatility of Cd, Pb, and Zn was accelerated for Paper, DC, GB, and Tire due to the formation of elemental metal vapor. TG analysis also showed the reduction of metal oxides by chars forming elemental metal vapor. Cu2S was the dominant Cu species in reducing atmosphere below 900 °C, which was responsible for the low volatility of Cu. The addition of PVC in wastes may enhance the release of heavy metals, while GB and Tire may play an opposite effect. In controlling heavy metal emission, aluminosilicate- and calcium-based sorbents can be co-treated with fuels. Moreover

  10. Antipredatory behavior as an index of heavy-metal pollution? A test using snails and caddisflies.

    PubMed

    Lefcort, H; Ammann, E; Eiger, S M

    2000-04-01

    The loss of behaviors that organisms use to avoid predation may serve as a sensitive indicator of pollution. We tested the hypothesis that a correlation exists in the field between heavy metal levels and antipredator behaviors. We examined the antipredator behavior of aquatic caddisfly larvae and snails at sites in the Coeur d'Alene basin of Northern Idaho which varied in their levels of heavy metals. We tested the antipredator response of Physella columbiana snails at 10 polluted lakes downstream from the Bunker Hill Environmental Protection Agency (EPA) Superfund cleanup site. We then compared their behavior to snails at 14 reference lakes. We placed the snails in a plastic testing apparatus, exposed them to an extract of crushed snail, and then monitored their movements to a normally preferred shaded area. We also tested the behavior of caddisfly larvae from 36 sites from a total of 6 streams/rivers adjacent to the Superfund site. Sites were located upstream and downstream of abandoned mines. We located active larvae of four genera, simulated predation by grasping the animals between thumb and forefinger (the larvae respond to being grasped by withdrawing into their case), lifted them from the water for 3 s, and then placed them in an adjacent, slower section of the stream. We then recorded how long it took each larvae to partially emerge from its case and attempt to move away. Unlike reference site snails, snails from heavy metal-polluted environments failed to exhibit antipredator behaviors in response to crushed conspecifics. These results are consistent with previous laboratory studies. We found no effect of heavy metals on the antipredatory behavior of caddisfly larvae.

  11. [Dynamic leaching behavior of heavy metals in eco-cement mortar block].

    PubMed

    Li, Cheng; Liu, Jian-Guo; Zhang, Jun-Li; Yue, Dong-Bei; Nie, Yong-Feng; Wang, Chang-Hai

    2008-03-01

    A dynamic leaching test with the renewal of acidic leaching medium was designed to study the leaching behavior of the seven heavy metals (As, Cd, Cr, Cu, Ni, Pb, Zn) in three solidified eco-cement mortar samples with different particle size (fine granule, coarse granule, block) under a long-term leaching condition. It was demonstrated that all the heavy metals were detected in the leachate except Cd. The leaching ratio of Cr was the highest when compared with other metals in the same sample, and the leaching ratio of every metal showed an identical tendency: fine granule> coarse granule > block. The on-going leaching part of the relationship curve of accumulative leaching point (Pt) and t1/2 of each metal presented a fairly good linearity, which indicated that the leaching process was under the control of diffusion mechanism by the Fick Law. To each metal, the effective diffusion coefficient (Deff) showed a tendency of fine granule < coarse granule < block, which was opposite to the tendency of leaching ratio. It could be concluded that the solidified eco-cement mortar with a bigger size would have a lower leaching ratio and a shorter period to finish the leaching test. To all the metals, the Deff was very low, with the magnitude around 10(-10) cm2/s, which meant the leaching process would take a relatively long time.

  12. Influence of chlorine, sulfur and phosphorus on the volatilization behavior of heavy metals during sewage sludge thermal treatment.

    PubMed

    Luan, Jingde; Li, Rundong; Zhang, Zhihui; Li, Yanlong; Zhao, Yun

    2013-10-01

    Chlorine, sulfur and phosphorus were selected as element donators to investigate their effect on the volatilization behavior of heavy metals in sludge sewage incineration. Principal component analysis indicated that the promotive effect on the volatilization of heavy metals was followed by chlorine, sulfur and phosphorus. This result was proved to be correct by total release of heavy metals in sewage sludge incineration using different element donators. The release of heavy metals was very chlorine dependent, especially cadmium (Cd), lead (Pb) and nickel (Ni). When chlorine content was in the range of 0.1-0.5wt%, the increase of the volatilization rate was 44.9% for Cd, 6.8% for Pb and 4.6% for Ni, respectively. Although sulfur contributed to the promotion of the volatilization of heavy metals, excess oxygen impaired the promotive effect of sulfur on the release of heavy metals from the condensed phase. For phosphorus, solidifying heavy metals was dominant. Energy analysis showed that metal chlorides and sulfides were prone to volatilize or to be decomposed at elevated temperature compared with sulfates and phosphates owing to low binding energy in absolute value (VLFA). It was the difference of binding energy that led to the different volatilization behavior of metal compounds in a high temperature, oxygen-enriched atmosphere.

  13. Heavy metals alter the survival, growth, metamorphosis, and antipredatory behavior of Columbia spotted frog (Rana luteiventris) tadpoles.

    PubMed

    Lefcort, H; Meguire, R A; Wilson, L H; Ettinger, W F

    1998-10-01

    Amphibian populations appear to be declining around the world. Although there is no single cause, one factor may be pollution from heavy metals. As a result of mining in the Silver Valley of Idaho, heavy metals have been released into habitats containing many species of sensitive organisms, including spotted frogs (Rana luteiventris). While the gross extent of pollution has been well documented, the more subtle behavioral effects of heavy metals such as lead, zinc, and cadmium are less well studied. We tested the effects of heavy metals on the short-term survival (LC50) of spotted frog tadpoles. Compared to single metals, metals presented together were toxic at lower doses. We also raised the tadpoles in outdoor mini-ecosystems containing either a single heavy metal or soil from an EPA Superfund site in the Silver Valley known to be composed of numerous heavy metals. Exposure to Silver Valley soil resulted in delayed metamorphosis. We tested the ability of metal-exposed tadpoles to detect and respond to chemical cues emanating from predacious rainbow trout. We found that high levels of Silver Valley soil, medium levels of zinc, and medium and high levels of lead resulted in a decreased fright response. Low levels of cadmium, zinc, and lead did not cause a significant effect, but low levels of soil did result in a decreased fright response. Heavy metals may alter interactions between tadpoles and their predators. PMID:9732476

  14. 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)

  15. Fractionation behavior of heavy metals in soil during bioleaching with Acidithiobacillus thiooxidans.

    PubMed

    Naresh Kumar, R; Nagendran, R

    2009-09-30

    The effects of bioleaching on the fractionation of soil heavy metals were investigated in this study. Bioleaching of heavy metals from contaminated soil was carried out in shake flask experiments. Acidophilic sulfur oxidizing bacteria Acidithiobacillus thiooxidans isolated from soil was used for bioleaching. Bioleaching resulted in removal of heavy metals at higher levels. Variations in the binding forms of heavy metals before, during and after bioleaching were evaluated. It was noticed that bioleaching affected the binding forms of all the heavy metals present in the soil. The major contaminant chromium bound mainly to the fractions of soil which are not very reactive (organic and residual fractions) also showed good removal efficiency. Bioleaching influenced the fractionation of metals in soil after treatment and most of the remnant heavy metals were bound either to residual fraction or to other not easily mobile fractions of soil. The results of this study indicated that the bioleaching process can be useful for efficient removal of heavy metals from soil. Further, the soil with remnant metals can be disposed off safely.

  16. Behavior and Distribution of Heavy Metals Including Rare Earth Elements, Thorium, and Uranium in Sludge from Industry Water Treatment Plant and Recovery Method of Metals by Biosurfactants Application

    PubMed Central

    Gao, Lidi; Kano, Naoki; Sato, Yuichi; Li, Chong; Zhang, Shuang; Imaizumi, Hiroshi

    2012-01-01

    In order to investigate the behavior, distribution, and characteristics of heavy metals including rare earth elements (REEs), thorium (Th), and uranium (U) in sludge, the total and fractional concentrations of these elements in sludge collected from an industry water treatment plant were determined and compared with those in natural soil. In addition, the removal/recovery process of heavy metals (Pb, Cr, and Ni) from the polluted sludge was studied with biosurfactant (saponin and sophorolipid) elution by batch and column experiments to evaluate the efficiency of biosurfactant for the removal of heavy metals. Consequently, the following matters have been largely clarified. (1) Heavy metallic elements in sludge have generally larger concentrations and exist as more unstable fraction than those in natural soil. (2) Nonionic saponin including carboxyl group is more efficient than sophorolipid for the removal of heavy metals in polluted sludge. Saponin has selectivity for the mobilization of heavy metals and mainly reacts with heavy metals in F3 (the fraction bound to carbonates) and F5 (the fraction bound to Fe-Mn oxides). (3) The recovery efficiency of heavy metals (Pb, Ni, and Cr) reached about 90–100% using a precipitation method with alkaline solution. PMID:22693485

  17. Behavior and distribution of heavy metals including rare Earth elements, thorium, and uranium in sludge from industry water treatment plant and recovery method of metals by biosurfactants application.

    PubMed

    Gao, Lidi; Kano, Naoki; Sato, Yuichi; Li, Chong; Zhang, Shuang; Imaizumi, Hiroshi

    2012-01-01

    In order to investigate the behavior, distribution, and characteristics of heavy metals including rare earth elements (REEs), thorium (Th), and uranium (U) in sludge, the total and fractional concentrations of these elements in sludge collected from an industry water treatment plant were determined and compared with those in natural soil. In addition, the removal/recovery process of heavy metals (Pb, Cr, and Ni) from the polluted sludge was studied with biosurfactant (saponin and sophorolipid) elution by batch and column experiments to evaluate the efficiency of biosurfactant for the removal of heavy metals. Consequently, the following matters have been largely clarified. (1) Heavy metallic elements in sludge have generally larger concentrations and exist as more unstable fraction than those in natural soil. (2) Nonionic saponin including carboxyl group is more efficient than sophorolipid for the removal of heavy metals in polluted sludge. Saponin has selectivity for the mobilization of heavy metals and mainly reacts with heavy metals in F3 (the fraction bound to carbonates) and F5 (the fraction bound to Fe-Mn oxides). (3) The recovery efficiency of heavy metals (Pb, Ni, and Cr) reached about 90-100% using a precipitation method with alkaline solution.

  18. Mutagenicity of heavy metals

    SciTech Connect

    Wong, P.K.

    1988-04-01

    Certain heavy metals are required, as trace elements for normal cellular functions. However, heavy metals are toxic to cells once their levels exceed their low physiological values. The toxicity of heavy metals on microorganisms, and on animals has been well-documented. These interactions may induce the alteration of the primary as well as secondary structures of the DNA and result in mutation(s). The present communication reports the results in determining the mutagenicity and carcinogenicity of ten heavy metals commonly found in polluted areas by using the Salmonella/mammalian-microsome mutagenicity test.

  19. MINTEQ modeling for evaluating the leaching behavior of heavy metals in MSWI fly ash.

    PubMed

    Zhang, Yan; Jiang, Jianguo; Chen, Maozhe

    2008-01-01

    At present, all kinds of municipal solid waste incineration (MSWI) fly ash stabilization technology has been reported and successfully applied in many countries. However, leaching procedures are very different that the technologies lack uniform standard, and it is even impossible to predict the long-term stabilization. Geochemical model can explain the environmental stabilization based on chemical phase and thermodynamic crystal structure, and it is also able to guide the development of environment-friendly stabilization technology and choosing of chemical agents. Both experiment analysis and geochemical modeling were used to study the correlation between leaching behavior of MSWI fly ash and variation of pH. Dissolution/precipitation mechanism was applied in the simulation. The result indicated that the pH-dependent leaching behavior predicted by Visual MINTEQ is well in agreement with the result of pH-dependent test. pH value of leachate can significantly change the leaching behavior of MSWI fly ash. The leaching behavior of heavy metals for Pb and Cd is controlled by dissolution/precipitation mechanism, whereas for Zn and Ni, it is effected by surface adsorption reaction over a special extent of pH value. PMID:19202882

  20. Exploiting differential electrochemical stripping behaviors of Fe3O4 nanocrystals toward heavy metal ions by crystal cutting.

    PubMed

    Yao, Xian-Zhi; Guo, Zheng; Yuan, Qing-Hong; Liu, Zhong-Gang; Liu, Jin-Huai; Huang, Xing-Jiu

    2014-08-13

    This study attempts to understand the intrinsic impact of different morphologies of nanocrystals on their electrochemical stripping behaviors toward heavy metal ions. Two differently shaped Fe3O4 nanocrystals, i.e., (100)-bound cubic and (111)-bound octahedral, have been synthesized for the experiments. Electrochemical results indicate that Fe3O4 nanocrystals with different shapes show different stripping behaviors toward heavy metal ions. Octahedral Fe3O4 nanocrystals show better electrochemical sensing performances toward the investigated heavy metal ions such as Zn(II), Cd(II), Pb(II), Cu(II), and Hg(II), in comparison with cubic ones. Specifically, Pb(II) is found to have the best stripping performance on both the (100) and (111) facets. To clarify these phenomena, adsorption abilities of as-prepared Fe3O4 nanocrystals have been investigated toward heavy metal ions. Most importantly, combined with theoretical calculations, their different electrochemical stripping behaviors in view of facet effects have been further studied and enclosed at the level of molecular/atom. Finally, as a trial to find a disposable platform completely free from noble metals, the potential application of the Fe3O4 nanocrystals for electrochemical detection of As(III) in drinking water is demonstrated.

  1. Heavy Metal and Hip-Hop Style Preferences and Externalizing Problem Behavior: A Two-Wave Longitudinal Study

    ERIC Educational Resources Information Center

    Selfhout, Maarten H. W.; Delsing, Marc J. M. H.; ter Bogt, Tom F. M.; Meeus, Wim H. J.

    2008-01-01

    This study examines (a) the stability of Dutch adolescents' preferences for heavy metal and hip-hop youth culture styles, (b) longitudinal associations between their preferences and externalizing problem behavior, and (c) the moderating role of gender in these associations. Questionnaire data were gathered from 931 adolescents between the ages of…

  2. Mutagenicity of heavy metals

    SciTech Connect

    Wong, P.K. )

    1988-05-01

    Certain heavy metals are required, as trace elements for normal cellular functions. However, heavy metals are toxic to cells once their levels exceed their low physiological values. The toxicity of heavy metals on microorganisms, on plants and on animals has been well-documented. These interactions may induce the alteration of the primary as well as secondary structures of the DNA and result in mutation(s). Though the rec assay with Bacillus subtilis and the reversion assay with Escherichia coli were used to assess the mutagenicity of some heavy metals, the present communication reports the results in determining the mutagenicity and carcinogenicity of ten heavy metals commonly found in polluted areas by using the Salmonella/mammalian-microsome mutagenicity test.

  3. The behavior of heavy metals in tidal flat sediments during fresh water leaching.

    PubMed

    Li, QuSheng; Liu, YaNan; Du, YeFeng; Cui, ZhiHong; Shi, Lei; Wang, LiLi; Li, HongJie

    2011-02-01

    Many of the coastal tidal flats in China that were polluted with heavy metals are now being reclaimed for arable land. The safety of these soils for agriculture is of great concern. The present study investigated the sediment chemical properties, concentrations, and speciation of heavy metals at different levels of desalination during a controlled leaching experiment. After leaching with fresh water, the average reductions in the heavy metal species examined in 0-65 cm depth sediment were 32.1% for Pb, 26.2% for Cd, 14.0% for Zn, 13.8% for Cu, and 11.0% for Cr, while the Ni concentration in sediment did not change significantly. The amounts of Cd, Pb, Cr, Cu, and Zn bound to the reducible fraction, the amounts of Cd, Pb, and Zn bound to the exchangeable fraction, the amounts of Pb, Cr, Cu, and Zn associated with the carbonate fraction, and the Cu associated with the oxidizable fraction all decreased significantly. Complexation with salt anions, ion exchange between the cations and the metal ions, removal of SO4(2-), dissolution of carbonate, and the redox potential variations all contributed to the decreases in Pb, Cd, Zn, Cu, and Cr. These results suggest that leaching with fresh water can also remove a fraction of the heavy metal contamination when it diminishes sediment salinity. PMID:21131022

  4. The behavior of heavy metals in tidal flat sediments during fresh water leaching.

    PubMed

    Li, QuSheng; Liu, YaNan; Du, YeFeng; Cui, ZhiHong; Shi, Lei; Wang, LiLi; Li, HongJie

    2011-02-01

    Many of the coastal tidal flats in China that were polluted with heavy metals are now being reclaimed for arable land. The safety of these soils for agriculture is of great concern. The present study investigated the sediment chemical properties, concentrations, and speciation of heavy metals at different levels of desalination during a controlled leaching experiment. After leaching with fresh water, the average reductions in the heavy metal species examined in 0-65 cm depth sediment were 32.1% for Pb, 26.2% for Cd, 14.0% for Zn, 13.8% for Cu, and 11.0% for Cr, while the Ni concentration in sediment did not change significantly. The amounts of Cd, Pb, Cr, Cu, and Zn bound to the reducible fraction, the amounts of Cd, Pb, and Zn bound to the exchangeable fraction, the amounts of Pb, Cr, Cu, and Zn associated with the carbonate fraction, and the Cu associated with the oxidizable fraction all decreased significantly. Complexation with salt anions, ion exchange between the cations and the metal ions, removal of SO4(2-), dissolution of carbonate, and the redox potential variations all contributed to the decreases in Pb, Cd, Zn, Cu, and Cr. These results suggest that leaching with fresh water can also remove a fraction of the heavy metal contamination when it diminishes sediment salinity.

  5. The Effects of Gravity on the Crystallization Behavior of Heavy Metal Fluoride Glasses

    NASA Technical Reports Server (NTRS)

    Tucker, Dennis S.; Smith, Guy A.

    2004-01-01

    Heavy metal fluoride glasses are used in such applications as fiber lasers and laser amplifiers. ZrF4-BaF2-LaF3-AlF3-NaF (ZBLAN) is one of the more commonly used heavy metal fluoride glasses. ZBLAN is an infrared transmitter and has a theoretical attenuation coefficient of 0.002 db/km. However, due to impurities and small crystallites this attenuation coefficient has not been achieved to date. ZBLAN is a fragile glass which can lead to rapid crystallization, if the glass is not cooled rapidly to below the glass transition temperature or if the glass is reheated near the crystallization temperature for any period of time. Studies carried on at Marshall Space Flight Center and the University of Alabama in Huntsville since 1993 have shown that heating ZBLAN glass at the crystallization temperature in reduced gravity results in a suppression of crystallization when compared to ZBLAN processed in unit gravity. These studies utilized NASA's KC-135 aircraft and the Conquest sounding rocket. In the first series of experiments, short lengths of ZBLAN fiber were heated to the crystallization temperature in reduced gravity on board the KC- 135 and the Conquest sounding rocket and compared with fibers heated in unit gravity. The fibers processed in reduced gravity showed no evidence of crystallization when studied with x-ray diffraction and scanning electron microscopy. However, the fibers processed in unit gravity were completely crystallized. Subsequent experiments included heating small pieces of ZBLAN glass at the crystallization temperature while viewing with a video camera to follow the crystallization phenomenon. In this experiment crystallization was observed in reduced gravity, however, it was suppressed when compared to heating in unit gravity. In the most recent experiment on board the KC-135, rapid thermal analysis of ZBLAN was performed. A mechanism to explain the observations has been proposed. This mechanism is based on shear thinning whereby, the glass

  6. Geochemical behavior of heavy metals in differents environments in Rodrigo de Freitas lagoon - RJ/Brazil.

    PubMed

    Fonseca, Estefan M; Baptista Neto, José A; Fernandez, Marcos A; McAlister, John; Smith, Bernard

    2011-06-01

    The accelerated urbanisation without a planning, brought several environmental problems to Rio de Janeiro coastal zone, especially in areas such as Rodrigo de Freitas lagoon, which receives a great amount of untreated sewage every day. To assess the nature, potentially sources and extent of heavy metal pollution in the lagoon, sediments from the surrounding streets, from the entrance of the main canal that drains to the lagoon and from the bottom of the lagoon were collected and analysed by a modified selective extraction procedure in order to study the geochemical partitioning and bioavailability of Zn, Cu, Cr, Ni and Pb in these three compartments. The present study verified an increase in the Cu, Pb and Zn concentrations in the north of the Rodrigo de Freitas lagoon. Despite the different levels of oxidation between the sediments accumulated in the streets and in the bottom of the lagoon, the geochemical partitioning of the heavy metals did not show any pattern of variation for the metals, except for the element Cu. No concentrations were found in the soluble phase of samples collected in the surfacial sediments of the lagoon, suggesting no bioavailability of heavy metals. PMID:21670872

  7. Competitive Adsorption and Oxidation Behavior of Heavy Metals on nZVI Coated with TEOS.

    PubMed

    Eglal, Mahmoud M; Ramamurthy, Amruthur S

    2015-11-01

    Zero valent iron nanoparticle (nanofer ZVI) is a powerful substance due to its coating with tetraethyl orthosilicate (TEOS). Tetraethyl orthosilicate imparts higher reactivity and decreases particle agglomeration. The competitive removal and displacement of multi-metals are influenced by time, pH, and initial concentration, the presence and properties of competing metals ion in the solution. For both the isotherm and kinetic studies performed for multi-metal removal experiments, compared to Pb II and Cd II, Cu II experienced a higher removal rate during the initial 5 minutes. After 120 minutes, all metals achieved removal efficiency in the range of 95 to 99%. The results of single and competitive kinetic tests for all three metals during the initial 5 minutes indicated that the presence of other metals generally reduce removal efficiency of metals. Both kinetic test and electron dispersive spectroscope (EDS) studies found that Cu II gets removed faster than the other metals. Pseudo-second order behavior was noted for the multi-metal removal systems.

  8. Sorption behavior of heavy metals on poorly crystalline manganese oxides: roles of water conditions and light.

    PubMed

    Kim, Eun-Ju; Kim, Jungwon; Choi, Sung-Chan; Chang, Yoon-Seok

    2014-05-01

    The objective of this study was to determine the effects of solution properties and light on the metal uptake and release in a nanosized, poorly crystalline manganese oxide (δ-MnO2) system. The results from synthetic water matrices revealed that the aggregation state was strongly affected by ionic strength, Ca(2+), and humic acid, and the particle aggregation subsequently changed the ability of δ-MnO2 to adsorb and sequester heavy metal ions (Cu(ii)). The extent of Cu(ii) uptake onto δ-MnO2 exhibited a negative correlation with the attachment efficiency value, which suggested that a lower sorption capacity could be achieved under aggregation-inducing conditions. Upon exposure to light, the adsorbed Cu(ii) was released from the δ-MnO2 surface via photoinduced dissolution of MnO2. The concentration of Cu(ii) desorbed was substantially higher when the humic acid was present together with Ca(2+). The present investigation enables us to better understand the adsorption-desorption processes of heavy metals occurring at the MnO2-solution interface in response to common environmental stimuli.

  9. Leaching Behavior of Heavy Metals from Cement Pastes Using a Modified Toxicity Characteristic Leaching Procedure (TCLP).

    PubMed

    Huang, Minrui; Feng, Huajun; Shen, Dongsheng; Li, Na; Chen, Yingqiang; Shentu, Jiali

    2016-03-01

    As the standard toxicity characteristic leaching procedure (TCLP) can not exhaust the acid neutralizing capacity of the cement rotary kiln co-processing solid wastes products which is particularly important for the assessment of the leaching concentrations of heavy metals. A modified TCLP was proposed. The extent of leaching of heavy metals is low using the TCLP and the leaching performance of the different metals can not be differentiated. Using the modified TCLP, however, Zn leaching was negligible during the first 180 h and then sharply increased (2.86 ± 0.18 to 3.54 ± 0.26 mg/L) as the acidity increased (pH < 6.0). Thus, Zn leaching is enhanced using the modified TCLP. While Pb leached readily during the first 126 h and then leachate concentrations decreased to below the analytical detection limit. To conclude, this modified TCLP is a more suitable method for these cement rotary kiln co-processing products. PMID:26781629

  10. Leaching behavior and solubility -- Controlling solid phases of heavy metals in municipal solid waste incinerator ash

    SciTech Connect

    Johnson, C.A.; Ziegler, F.; Kersten, M.; Moor, H.C.

    1996-12-31

    This paper highlights the uses and limitations of thermodynamic calculations in the planning of leach tests in the laboratory or for research in the field. Heavy metal solubility has been studied in leachate from Landfill Lostorf, AG, Switzerland. Also, the influence of pH on the solubility of Cu, Pb, Cd and Zn has been determined in the laboratory. The results have been compared with the maximum allowable heavy metal concentrations in equilibrium with the appropriate (hydr)oxides and carbonates. Copper is supersaturated with respect to Cu(OH){sub 2} in both laboratory and field studies. Complexation with organic ligands is a probable explanation for this observation. Both Zn and Pb are undersaturated with respect to pure (hydr)oxides and carbonates, though agreement between calculations and measurements are close enough, that PbCO{sub 3} could be controlling the solubility in the laboratory experiments. The markedly lower concentrations of Pb in the field in comparison with the laboratory data could be explained by the affinity for Pb to bind to solids and the higher solid:solution ratio in field conditions. The solubility of Cd could be controlled by the formation of CdCO{sub 3}. The relatively high concentrations of Mo in the landfill leachate could be limited by the precipitation of CaMoO{sub 4}.

  11. A long-term static immersion experiment on the leaching behavior of heavy metals from waste printed circuit boards.

    PubMed

    Zhao, Guo-Hua; Luo, Xing-Zhang; Chen, Gui; Zhao, Yong-Jun

    2014-08-01

    Printed circuit boards (PCBs) are the main components of electrical and electronic equipment (EEE). Waste PCBs contain several kinds of heavy metals, including Cu, Pb and Zn. We characterize the leaching of heavy metals (Cu, Pb, Zn and Ni) from waste PCBs in a pH range of 3.0 to 5.6 using a novel approach based on batch pH-static leaching experiments in this work. The results indicate that the leaching behavior of Cu, Pb, Zn and Ni is strongly dependent on pH. Leaching behavior also varies with different pH values and leaching times. The maximum concentrations of Cu, Pb, Zn and Ni in leachate from waste PCBs were 335.00, 17.57, 2.40 and 2.33 mg L(-1), respectively. The highest Pb, Ni, and Cu concentrations leached significantly exceeded the European Union waste-acceptance limit values with respect to inert waste landfills. The leaching of metals follows the shrinking core model with surface reaction control.

  12. 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.

  13. Plants absorb heavy metals

    SciTech Connect

    Parry, J.

    1995-02-01

    Decontamination of heavy metals-polluted soils remains one of the most intractable problems of cleanup technology. Currently available techniques include extraction of the metals by physical and chemical means, such as acid leaching and electroosmosis, or immobilization by vitrification. There are presently no techniques for cleanup which are low cost and retain soil fertility after metals removal. But a solution to the problem could be on the horizon. A small but growing number of plants native to metalliferous soils are known to be capable of accumulating extremely high concentrations of metals in their aboveground portions. These hyperaccumulators, as they are called, contain up to 1,000 times larger metal concentrations in their aboveground parts than normal species. Their distribution is global, including many different families of flowering plants of varying growth forms, from herbaceous plants to trees. Hyperaccumulators absorb metals they do not need for their own nutrition. The metals are accumulated in the leaf and stem vacuoles, and to a lesser extent in the roots.

  14. Preparation of porous nano-calcium titanate microspheres and its adsorption behavior for heavy metal ion in water.

    PubMed

    Zhang, Dong; Zhang, Chun-li; Zhou, Pin

    2011-02-28

    Using D311 resin as a template, porous nano-calcium titanate microspheres (PCTOM) were prepared by a citric acid complex sol-gel method and characterized by X-ray diffraction (XRD), SEM and FTIR. The method's adsorption capabilities for heavy metal ions such as lead, cadmium and zinc were studied and adsorption and elution conditions were investigated. Moreover, taking the cadmium ion as an example, the thermodynamics and kinetics of the adsorption were studied. The results show that the microspheres were porous and were made of perovskite nano-calcium titanate. The lead, cadmium and zinc ions studied could be quantitatively retained at a pH value range of 5-8. The adsorption capacities of PCTOM for lead, cadmium and zinc were found to be 141.8 mg g(-1), 18.0 mg g(-1) and 24.4 mg g(-1) respectively. The adsorption behavior followed a Langmuir adsorption isotherm and a pseudo-second-order kinetic model, where adsorption was an endothermic and spontaneous physical process. The adsorbed metal ions could be completely eluted using 2 mol L(-1) HNO(3) with preconcentration factors over 100 for all studied heavy metal ions. The method has also been applied to the preconcentration and FAAS determination of trace lead, cadmium and zinc ion in water samples with satisfactory results.

  15. Resorcarene-based receptor: versatile behavior in its interaction with heavy and soft metal cations.

    PubMed

    Danil de Namor, Angela F; Chaaban, Jinane K; Piro, Oscar E; Castellano, Eduardo E

    2006-02-01

    Standard solution Gibbs energies, DeltasG degrees, of the resorcarene-based receptor 5,11,17,23-ethylthiomethylated calix[4]resorcarene, (characterized by 1H NMR and X-ray diffraction studies) in its monomeric state (established through partition experiments) in various solvents are for the first time reported in the area of resorcarene chemistry. Transfer Gibbs energies of from hexane (reference solvent) to other medium are calculated. Agreement between DeltatG degrees (referred to the pure solvents) and standard partition Gibbs energies, DeltapG degrees (solvent mutually saturated) is found. Cation-ligand interactions were investigated through 1H NMR (CD3CN and CD3OD) and conductometric titrations in acetonitrile and methanol. 1H NMR data revealed the sites of interaction of with the metal cation. The composition of the metal-ion complexes (Ag+ and Pb2+ in acetonitrile and Ag+ and Cu2+ in methanol) was established through conductometric titrations. Thus, complexes of 1:1 stoichiometry were formed between and Ag+ and Pb2+ in acetonitrile and Cu2+ in methanol. However, in moving from acetonitrile to methanol, the composition of the silver complex was altered. Thus, two metal cations are hosted by a unit of the ligand. As far as Cu2+ and in acetonitrile is concerned, conductance data suggest that metalates are formed in which up to four units of Cu2+ are taken up per unit of resorcarene. The contrasting behavior of with Cu2+ in acetonitrile relative to methanol is discussed. As far as mercury (II) is concerned, the unusual jump in conductance observed in the titration of Hg2+ with in acetonitrile and methanol after the formation of a multicharged complex (undefined composition) is attributed to the presence of highly charged smaller units (higher mobility) resulting from the departure of pendant arms from the resorcarene backbone. Isolation of these species followed by X-ray diffraction studies corroborated this statement. The thermodynamic characterization of metal

  16. Resorcarene-based receptor: versatile behavior in its interaction with heavy and soft metal cations.

    PubMed

    Danil de Namor, Angela F; Chaaban, Jinane K; Piro, Oscar E; Castellano, Eduardo E

    2006-02-01

    Standard solution Gibbs energies, DeltasG degrees, of the resorcarene-based receptor 5,11,17,23-ethylthiomethylated calix[4]resorcarene, (characterized by 1H NMR and X-ray diffraction studies) in its monomeric state (established through partition experiments) in various solvents are for the first time reported in the area of resorcarene chemistry. Transfer Gibbs energies of from hexane (reference solvent) to other medium are calculated. Agreement between DeltatG degrees (referred to the pure solvents) and standard partition Gibbs energies, DeltapG degrees (solvent mutually saturated) is found. Cation-ligand interactions were investigated through 1H NMR (CD3CN and CD3OD) and conductometric titrations in acetonitrile and methanol. 1H NMR data revealed the sites of interaction of with the metal cation. The composition of the metal-ion complexes (Ag+ and Pb2+ in acetonitrile and Ag+ and Cu2+ in methanol) was established through conductometric titrations. Thus, complexes of 1:1 stoichiometry were formed between and Ag+ and Pb2+ in acetonitrile and Cu2+ in methanol. However, in moving from acetonitrile to methanol, the composition of the silver complex was altered. Thus, two metal cations are hosted by a unit of the ligand. As far as Cu2+ and in acetonitrile is concerned, conductance data suggest that metalates are formed in which up to four units of Cu2+ are taken up per unit of resorcarene. The contrasting behavior of with Cu2+ in acetonitrile relative to methanol is discussed. As far as mercury (II) is concerned, the unusual jump in conductance observed in the titration of Hg2+ with in acetonitrile and methanol after the formation of a multicharged complex (undefined composition) is attributed to the presence of highly charged smaller units (higher mobility) resulting from the departure of pendant arms from the resorcarene backbone. Isolation of these species followed by X-ray diffraction studies corroborated this statement. The thermodynamic characterization of metal

  17. Heavy Metals Exposure and Hygienic Behaviors of Workers in Sanitary Landfill Areas in Southern Thailand

    PubMed Central

    Decharat, Somsiri

    2016-01-01

    Objectives. The main objective of this study was to assess the cadmium and lead exposure levels in subject workers that work in sanitary landfill areas in southern Thailand. The study evaluated the blood cadmium and lead levels in terms of their possible role in worker contamination and transfer of cadmium and lead to the body. Materials and Methods. A cross-sectional study was conducted with 114 subjects. Whole blood samples were collected to determine cadmium and lead levels by graphite furnaces atomic absorption spectrometer chromium analyzer. Results and Discussion. The mean blood cadmium levels and blood lead levels of subjects workers were 2.95 ± 0.58 μg/L (range 1.58–7.03 μg/L) and 8.58 ± 2.58 μg/dL (range 1.98–11.12 μg/dL), respectively. Gender, income, smoked cigarettes, work position, duration of work, personal protective equipment (PPE), and personal hygiene were significantly associated with blood cadmium level and blood lead levels (p < 0.001 and p < 0.001). A multiple regression model was constructed. Significant predictors of blood cadmium levels and blood lead levels included smoked cigarettes, hours worked per day, days worked per week, duration of work (years), work position, use of PPE (mask and gloves), and personal hygiene behavior (ate snacks or drank water at work and washed hands before lunch). Conclusion. The elevated body burden of toxic metals in the solid waste exposure of subject workers is an indication of occupational metal toxicity associated with personal hygiene practices. PMID:27313961

  18. Heavy Metals Exposure and Hygienic Behaviors of Workers in Sanitary Landfill Areas in Southern Thailand.

    PubMed

    Decharat, Somsiri

    2016-01-01

    Objectives. The main objective of this study was to assess the cadmium and lead exposure levels in subject workers that work in sanitary landfill areas in southern Thailand. The study evaluated the blood cadmium and lead levels in terms of their possible role in worker contamination and transfer of cadmium and lead to the body. Materials and Methods. A cross-sectional study was conducted with 114 subjects. Whole blood samples were collected to determine cadmium and lead levels by graphite furnaces atomic absorption spectrometer chromium analyzer. Results and Discussion. The mean blood cadmium levels and blood lead levels of subjects workers were 2.95 ± 0.58 μg/L (range 1.58-7.03 μg/L) and 8.58 ± 2.58 μg/dL (range 1.98-11.12 μg/dL), respectively. Gender, income, smoked cigarettes, work position, duration of work, personal protective equipment (PPE), and personal hygiene were significantly associated with blood cadmium level and blood lead levels (p < 0.001 and p < 0.001). A multiple regression model was constructed. Significant predictors of blood cadmium levels and blood lead levels included smoked cigarettes, hours worked per day, days worked per week, duration of work (years), work position, use of PPE (mask and gloves), and personal hygiene behavior (ate snacks or drank water at work and washed hands before lunch). Conclusion. The elevated body burden of toxic metals in the solid waste exposure of subject workers is an indication of occupational metal toxicity associated with personal hygiene practices. PMID:27313961

  19. 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.

  20. Scaling behavior of the thermopower of the archetypal heavy-fermion metal YbRh2Si2

    NASA Astrophysics Data System (ADS)

    Shaginyan, V. R.; Msezane, A. Z.; Japaridze, G. S.; Popov, K. G.; Clark, J. W.; Khodel, V. A.

    2016-04-01

    We reveal and explain the scaling behavior of the thermopower S/T exhibited by the archetypal heavy-fermion (HF) metal YbRh2Si2 under the application of magnetic field B at temperature T. We show that the same scaling is demonstrated by different HF compounds such as ß-YbAlB4 and the strongly correlated layered cobalt oxide [BiBa0.66K0.36O2]CoO2. Using YbRh2Si2 as an example, we demonstrate that the scaling behavior of S/T is violated at the antiferromagnetic phase transition, while both the residual resistivity ρ 0 and the density of states, N, experience jumps at the phase transition, causing the thermopower to make two jumps and change its sign. Our elucidation is based on flattening of the single-particle spectrum that profoundly affects ρ 0 and N. To depict the main features of the S/T behavior, we construct a T-B schematic phase diagram of YbRh2Si2. Our calculated S/T for the HF compounds are in good agreement with experimental facts and support our observations.

  1. 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.

  2. [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.

  3. Heavy Metal in Children's Tooth Enamel: Related to Autism and Disruptive Behaviors?

    ERIC Educational Resources Information Center

    Abdullah, Maryam M.; Ly, Agnes R.; Goldberg, Wendy A.; Clarke-Stewart, K. Alison; Dudgeon, John V.; Mull, Christopher G.; Chan, Tony J.; Kent, Erin E.; Mason, Andrew Z.; Ericson, Jonathon E.

    2012-01-01

    To examine possible links between neurotoxicant exposure and neuropsychological disorders and child behavior, relative concentrations of lead, mercury, and manganese were examined in prenatal and postnatal enamel regions of deciduous teeth from children with Autism Spectrum Disorders (ASDs), high levels of disruptive behavior (HDB), and typically…

  4. 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

  5. Changes in speciation and leaching behaviors of heavy metals in dredged sediment solidified/stabilized with various materials.

    PubMed

    Bao, Jianping; Wang, Liang; Xiao, Man

    2016-05-01

    Solidification/stabilization (S/S) of sediments is frequently used to treat contaminants in dredged sediments. In this study, sediment collected from the Pearl River Delta (China) was solidified/stabilized with three different kinds of functional materials: cement, lime and bentonite. Lime primarily acted via induced increases in pH, while cements stabilization occurred through their silicate-based systems and the main function of bentonite was adsorption. The speciation and leaching behaviors of specific heavy metals before and after S/S were analyzed and the results showed that the residual speciation of Cd, Cr, Ni, Pb and Zn increased in all treatments except for Cu, as the exchangeable speciation, carbonate-bound speciation and Fe-Mn-oxide-bound speciation of Cu (all of which could be stabilized) were less than 2 % of the total amount. Pb leaching only decreased when pH increased, while the mobility of Cr and Ni only decreased in response to the silicate-based systems. The leached portion of the Fe-Mn-oxide-bound speciation followed the order Zn > Cu > Ni/Cd > Pb > Cr. The leached portion of organic-matter-bound species was less than 4 % for Cd, Cr, Ni and Pb, but 35.1 % and 20.6 % for Cu and Zn, respectively.

  6. Leaching behavior of heavy metals and transformation of their speciation in polluted soil receiving simulated acid rain.

    PubMed

    Zheng, Shun-an; Zheng, Xiangqun; Chen, Chun

    2012-01-01

    Heavy metals that leach from contaminated soils under acid rain are of increasing concern. In this study, simulated acid rain (SAR) was pumped through columns of artificially contaminated purple soil. Column leaching tests and sequential extraction were conducted for the heavy metals Cu, Pb, Cd, and Zn to determine the extent of their leaching as well as to examine the transformation of their speciation in the artificially contaminated soil columns. Results showed that the maximum leachate concentrations of Cu, Pb, Cd, and Zn were less than those specified in the Chinese Quality Standards for Groundwater (Grade IV), thereby suggesting that the heavy metals that leached from the polluted purple soil receiving acid rain may not pose as risks to water quality. Most of the Pb and Cd leachate concentrations were below their detection limits. By contrast, higher Cu and Zn leachate concentrations were found because they were released by the soil in larger amounts as compared with those of Pb and Cd. The differences in the Cu and Zn leachate concentrations between the controls (SAR at pH 5.6) and the treatments (SAR at pH 3.0 and 4.5) were significant. Similar trends were observed in the total leached amounts of Cu and Zn. The proportions of Cu, Pb, Cd, and Zn in the EXC and OX fractions were generally increased after the leaching experiment at three pH levels, whereas those of the RES, OM, and CAR fractions were slightly decreased. Acid rain favors the leaching of heavy metals from the contaminated purple soil and makes the heavy metal fractions become more labile. Moreover, a pH decrease from 5.6 to 3.0 significantly enhanced such effects.

  7. Leaching behavior of heavy metals and transformation of their speciation in polluted soil receiving simulated acid rain.

    PubMed

    Zheng, Shun-an; Zheng, Xiangqun; Chen, Chun

    2012-01-01

    Heavy metals that leach from contaminated soils under acid rain are of increasing concern. In this study, simulated acid rain (SAR) was pumped through columns of artificially contaminated purple soil. Column leaching tests and sequential extraction were conducted for the heavy metals Cu, Pb, Cd, and Zn to determine the extent of their leaching as well as to examine the transformation of their speciation in the artificially contaminated soil columns. Results showed that the maximum leachate concentrations of Cu, Pb, Cd, and Zn were less than those specified in the Chinese Quality Standards for Groundwater (Grade IV), thereby suggesting that the heavy metals that leached from the polluted purple soil receiving acid rain may not pose as risks to water quality. Most of the Pb and Cd leachate concentrations were below their detection limits. By contrast, higher Cu and Zn leachate concentrations were found because they were released by the soil in larger amounts as compared with those of Pb and Cd. The differences in the Cu and Zn leachate concentrations between the controls (SAR at pH 5.6) and the treatments (SAR at pH 3.0 and 4.5) were significant. Similar trends were observed in the total leached amounts of Cu and Zn. The proportions of Cu, Pb, Cd, and Zn in the EXC and OX fractions were generally increased after the leaching experiment at three pH levels, whereas those of the RES, OM, and CAR fractions were slightly decreased. Acid rain favors the leaching of heavy metals from the contaminated purple soil and makes the heavy metal fractions become more labile. Moreover, a pH decrease from 5.6 to 3.0 significantly enhanced such effects. PMID:23185399

  8. Leaching Behavior of Heavy Metals and Transformation of Their Speciation in Polluted Soil Receiving Simulated Acid Rain

    PubMed Central

    Zheng, Shun-an; Zheng, Xiangqun; Chen, Chun

    2012-01-01

    Heavy metals that leach from contaminated soils under acid rain are of increasing concern. In this study, simulated acid rain (SAR) was pumped through columns of artificially contaminated purple soil. Column leaching tests and sequential extraction were conducted for the heavy metals Cu, Pb, Cd, and Zn to determine the extent of their leaching as well as to examine the transformation of their speciation in the artificially contaminated soil columns. Results showed that the maximum leachate concentrations of Cu, Pb, Cd, and Zn were less than those specified in the Chinese Quality Standards for Groundwater (Grade IV), thereby suggesting that the heavy metals that leached from the polluted purple soil receiving acid rain may not pose as risks to water quality. Most of the Pb and Cd leachate concentrations were below their detection limits. By contrast, higher Cu and Zn leachate concentrations were found because they were released by the soil in larger amounts as compared with those of Pb and Cd. The differences in the Cu and Zn leachate concentrations between the controls (SAR at pH 5.6) and the treatments (SAR at pH 3.0 and 4.5) were significant. Similar trends were observed in the total leached amounts of Cu and Zn. The proportions of Cu, Pb, Cd, and Zn in the EXC and OX fractions were generally increased after the leaching experiment at three pH levels, whereas those of the RES, OM, and CAR fractions were slightly decreased. Acid rain favors the leaching of heavy metals from the contaminated purple soil and makes the heavy metal fractions become more labile. Moreover, a pH decrease from 5.6 to 3.0 significantly enhanced such effects. PMID:23185399

  9. 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

  10. Heavy metal behavior and dissolved organic matter (DOM) characterization of vermicomposted pig manure amended with rice straw.

    PubMed

    Zhu, Weiqin; Yao, Wu; Zhang, Zhi; Wu, Yang

    2014-11-01

    Vermicomposting is an eco-friendly method for disposing of livestock and poultry manure. In addition, dissolved organic matter (DOM) can serve as a carrier that enhances the migration and transformation of heavy metals. Here, pig manure amended with rice straw was vermicomposted with Eisenia fetida. The DOM content, molecular weight distribution, and spectroscopic properties of the amended pig manure were measured before and after vermicomposting. The Cu and Zn concentrations in the earthworms increased from 8.24 and 17.63 to 40.75 and 362.78 mg/kg separately after vermicomposting, and the earthworms also increased the heavy metal availability in the vermicompost. Relative to the DOM properties of conventional compost, the DOM molecular weight decreased and varied widely following vermicomposting, and the C/N ratio of the DOM in the vermicompost treatments decreased from 10.37 to 8.60. The Fourier transform far-infrared (FTIR) and fluorescence spectra of the DOM indicated that the amounts of oxygen-containing structures increased while the ratio of humic acid to fulvic acid decreased following vermicomposting. Accordingly, the earthworms augmented the heavy metal mitigation risk in the pig manure. This augment potentially resulted from the decreased humic acid-to-fulvic acid (HA/FA) ratio from DOM structural changes. PMID:24958537

  11. 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.

  12. Sorption behavior of heavy metal species by soakaway sediment receiving urban road runoff from residential and heavily trafficked areas.

    PubMed

    Murakami, Michio; Fujita, Makoto; Furumai, Hiroaki; Kasuga, Ikuro; Kurisu, Futoshi

    2009-05-30

    Groundwater contamination by heavy metals from infiltration facilities receiving road runoff is of potential concern. In this study, sorption tests were conducted to evaluate the influence of the water quality of road runoff, especially dissolved organic matter (DOM), on the sorption of heavy metal species by soakaway sediment. Sequential batch tests were conducted to assess metal sorption by the soakaway sediment receiving road runoff from residential and heavily trafficked areas. Ni was adsorbed by the sediment, indicating that soakaway sediments function to prevent groundwater contamination by Ni. In contrast, Zn was released from the soakaway sediment in sorption tests using heavily trafficked road dust leachates. Ni, Cu, Zn, and dissolved organic carbon concentrations were higher in soakaway sediment leachates obtained by sorption tests using heavily trafficked road dust leachates than those using residential road dust leachates, suggesting traffic activities contaminate these pollutants. A large portion of Zn, released from the soakaway sediment, existed as stable complexes. DOM in road runoff possibly enhances the release of Zn from the sediments within infiltration facilities and might cause groundwater contamination.

  13. Heavy metals bioremediation of soil.

    PubMed

    Diels, L; De Smet, M; Hooyberghs, L; Corbisier, P

    1999-09-01

    Historical emissions of old nonferrous factories lead to large geographical areas of metals-contaminated sites. At least 50 sites in Europe are contaminated with metals like Zn, Cd, Cu, and Pb. Several methods, based on granular differentiation, were developed to reduce the metals content. However, the obtained cleaned soil is just sand. Methods based on chemical leaching or extraction or on electrochemistry do release a soil without any salts and with an increased bioavailability of the remaining metals content. In this review a method is presented for the treatment of sandy soil contaminated with heavy metals. The system is based on the metal solubilization on biocyrstallization capacity of Alcaligenes eutrophus CH34. The bacterium can solubilize the metals (or increase their bioavailability) via the production of siderophores and adsorb the metals in their biomass on metal-induced outer membrane proteins and by bioprecipitation. After the addition of CH34 to a soil slurry, the metals move toward the biomass. As the bacterium tends to float quite easily, the biomass is separated from the water via a flocculation process. The Cd concentration in sandy soils could be reduced from 21 mg Cd/kg to 3.3 mg Cd/kg. At the same time, Zn was reduced from 1070 mg Zn/kg to 172 mg Zn/kg. The lead concentration went down from 459 mg Pb/kg to 74 mg Pb/kg. With the aid of biosensors, a complete decrease in bioavailability of the metals was measured.

  14. Biochar soil amendment: Impact of soil types on heavy metal sorption-desorption behaviors and repeated nutrient leaching

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Depending on soil types, properties of chars especially pH and leachable organic/inorganic components can have varying impacts when used as a soil amendment. We have investigated sorption-desorption behaviors of metal contaminant of concern in shooting ranges and urban soils (Cu), nutrient supply (...

  15. A novel on chip test method to characterize the creep behavior of metallic layers under heavy ion irradiation

    NASA Astrophysics Data System (ADS)

    Lapouge, P.; Onimus, F.; Vayrette, R.; Raskin, J.-P.; Pardoen, T.; Bréchet, Y.

    2016-08-01

    An on chip test method has been developed to characterize the irradiation creep behavior of thin freestanding films under uniaxial tension. The method is based on the use of a long beam involving large internal stress protected from the irradiation flux that imposes a spring like deformation to a specimen beam. These elementary freestanding structures fabricated using a combination of deposition, lithography and release steps are multiplied with different dimensions in order to test different levels of stress and of initial plastic deformation. The method has been validated on 200 and 500 nm thick copper films under heavy copper ions irradiation. The irradiation creep rate is shown to be at least one order of magnitude larger than in the absence of irradiation.

  16. Anomalous small angle x-ray scattering studies of heavy metal ion solvation behavior in clay minerals

    SciTech Connect

    Carrado, K.A.; Thiyagarajan, P.; Winans, R.E.; Song, Kang

    1997-09-01

    The authors have exploited anomalous small angle x-ray scattering (ASAXS) to monitor the solvation behavior of Cu(II), Er(III) and Yb(III) ions within the interlayers of the natural aluminosilicate clay mineral montmorillonite. The ASAXS technique can reveal the distribution of specific metallic species within a heterogeneous and disordered matrix. The variations of signal intensity as a function of absorption energy were monitored for all of the metal-clays as a function of hydration. Two different hydration levels were probed: as prepared at ambient conditions, or so-called {open_quotes}dry{close_quotes} powders, and {open_quotes}wet{close_quotes} pastes. ASAXS intensities should increase with absorption energy if the metal ion is associated with the interlayer solvent (water in this case), and decrease if the metal ion is associated with the solid matrix. The results show that: (1) Cu(II) is solvated within the interlayers of the wet sample, as expected, and (2) Er(III) and Yb(III) decrease in ASAXS intensity with increased hydration. This latter result was not expected and there is speculation that these ions have associated as hydrolyzed products with the clay surface. The basic principles underlying SAXS and ASAXS will also be presented in this paper.

  17. 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

  18. 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.…

  19. 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.

  20. Hematologic effects of heavy metal poisoning.

    PubMed

    Ringenberg, Q S; Doll, D C; Patterson, W P; Perry, M C; Yarbro, J W

    1988-09-01

    Heavy metal poisoning can cause a variety of hematologic disorders. Exposure to heavy metals is ubiquitous in the industrial environment and must be considered in the differential diagnosis of many types of anemia. The heavy metals most commonly associated with hematologic toxicity are arsenic and its derivative arsine, copper, gold, lead, and zinc. A few distinctive clinical features characterize the hematologic manifestations of many occult heavy metal poisonings. These features have a limited differential diagnosis. A knowledge of these clinical features can assist the astute clinician in making the correct diagnosis.

  1. 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.

  2. 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

  3. Bioremoval of heavy metals by bacterial biomass.

    PubMed

    Aryal, Mahendra; Liakopoulou-Kyriakides, Maria

    2015-01-01

    Heavy metals are among the most common pollutants found in the environment. Health problems due to the heavy metal pollution become a major concern throughout the world, and therefore, various treatment technologies such as reverse osmosis, ion exchange, solvent extraction, chemical precipitation, and adsorption are adopted to reduce or eliminate their concentration in the environment. Biosorption is a cost-effective and environmental friendly technique, and it can be used for detoxification of heavy metals in industrial effluents as an alternative treatment technology. Biosorption characteristics of various bacterial species are reviewed here with respect to the results reported so far. The role of physical, chemical, and biological modification of bacterial cells for heavy metal removal is presented. The paper evaluates the different kinetic, equilibrium, and thermodynamic models used in bacterial sorption of heavy metals. Biomass characterization and sorption mechanisms as well as elution of metal ions and regeneration of biomass are also discussed. PMID:25471624

  4. The comparison of the migration and transformation behavior of heavy metals during pyrolysis and liquefaction of municipal sewage sludge, paper mill sludge, and slaughterhouse sludge.

    PubMed

    Shao, Jianguang; Yuan, Xingzhong; Leng, Lijian; Huang, Huajun; Jiang, Longbo; Wang, Hou; Chen, Xiaohong; Zeng, Guangming

    2015-12-01

    Municipal sewage sludge, paper mill sludge, and slaughterhouse sludge were pyrolyzed and liquefied for the production of bio-char. The migration and transformation behavior of Cu, Cr, and Zn during pyrolysis and liquefaction of these sludges were studied. Pyrolysis and liquefaction promoted mobile fraction (F1 and F2) to stable fraction (F3 and F4). The results showed that pyrolysis and liquefaction largely affected the redistribution of Cu and Zn in raw materials. The environmental risk assessment results indicated that the environmental risk levels of Cu and Zn were significantly reduced in bio-char, and risk level of Cr was slightly decreased after pyrolysis or liquefaction. Both pyrolysis and liquefaction were promising detoxification technologies for the three sludges in terms of the mitigation of heavy metals toxicity. It was suggested that dewatered sludge could be reduced toxicity/risk before utilization by pyrolysis or liquefaction technology, especially for Cu and Zn in slaughterhouse sludge. PMID:26360600

  5. The comparison of the migration and transformation behavior of heavy metals during pyrolysis and liquefaction of municipal sewage sludge, paper mill sludge, and slaughterhouse sludge.

    PubMed

    Shao, Jianguang; Yuan, Xingzhong; Leng, Lijian; Huang, Huajun; Jiang, Longbo; Wang, Hou; Chen, Xiaohong; Zeng, Guangming

    2015-12-01

    Municipal sewage sludge, paper mill sludge, and slaughterhouse sludge were pyrolyzed and liquefied for the production of bio-char. The migration and transformation behavior of Cu, Cr, and Zn during pyrolysis and liquefaction of these sludges were studied. Pyrolysis and liquefaction promoted mobile fraction (F1 and F2) to stable fraction (F3 and F4). The results showed that pyrolysis and liquefaction largely affected the redistribution of Cu and Zn in raw materials. The environmental risk assessment results indicated that the environmental risk levels of Cu and Zn were significantly reduced in bio-char, and risk level of Cr was slightly decreased after pyrolysis or liquefaction. Both pyrolysis and liquefaction were promising detoxification technologies for the three sludges in terms of the mitigation of heavy metals toxicity. It was suggested that dewatered sludge could be reduced toxicity/risk before utilization by pyrolysis or liquefaction technology, especially for Cu and Zn in slaughterhouse sludge.

  6. 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…

  7. 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)

  8. 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.

  9. 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.

  10. Stabilization of heavy metals in sludge ceramsite.

    PubMed

    Xu, G R; Zou, J L; Li, G B

    2010-05-01

    This paper attempts to investigate the stabilization behaviours of heavy metals in ceramsite made from wastewater treatment sludge (WWTS) and drinking-water treatment sludge (DWTS). Leaching tests were conducted to find out the effects of sintering temperature, (Fe(2)O(3) + CaO + MgO)/(SiO(2) + Al(2)O(3)) (defined as F/SA ratios), pH, and oxidative condition. Results show that sintering exhibits good binding capacity for Cd, Cr, Cu, and Pb in ceramsite and leaching contents of heavy metals will not change above 1000 degrees C. The main crystalline phases in ceramsite sintered at 1000 degrees C are kyanite, quartz, Na-Ca feldspars, sillimanite, and enstatite. The main compounds of heavy metals are crocoite, chrome oxide, cadmium silicate, and copper oxide. Leaching contents of Cd, Cu, and Pb increase as the F/SA ratios increase. Heavy metals in ceramsite with variation of F/SA ratios are also in same steady forms, which prove that stronger chemical bonds are formed between these heavy metals and the components. Leaching contents of heavy metals decrease as pH increases and increase as H(2)O(2) concentration increases. The results indicate that when subjected to rigorous leaching conditions, the crystalline structures still exhibit good chemical binding capacity for heavy metals. In conclusion, it is environmentally safe to use ceramsite in civil and construction fields. PMID:20219229

  11. Topological basis for understanding the behavior of the heavy-fermion metal β -YbAlB4 under application of magnetic field and pressure

    NASA Astrophysics Data System (ADS)

    Shaginyan, V. R.; Msezane, A. Z.; Popov, K. G.; Clark, J. W.; Khodel, V. A.; Zverev, M. V.

    2016-05-01

    Informative recent measurements on the heavy-fermion metal β -YbAlB4 performed with applied magnetic field and pressure as control parameters are analyzed with the goal of establishing a sound theoretical explanation for the inferred scaling laws and non-Fermi-liquid (NFL) behavior, which demonstrate some unexpected features. Most notably, the robustness of the NFL behavior of the thermodynamic properties and of the anomalous T3 /2 temperature dependence of the electrical resistivity under applied pressure P in zero magnetic field is at variance with the fragility of the NFL phase under application of a field B . We show that a consistent topological basis for this combination of observations, as well as the empirical scaling laws, may be found within fermion-condensation theory in the emergence and destruction of a flat band, and explains that the paramagnetic NFL phase takes place without magnetic criticality, not from quantum critical fluctuations. Schematic T -B and T -P phase diagrams are presented to illuminate this scenario.

  12. Aging effect on the leaching behavior of heavy metals (Cu, Zn, and Cd) in red paddy soil.

    PubMed

    Huang, Bin; Li, Zhongwu; Huang, Jinquan; Chen, Guiqiu; Nie, Xiaodong; Ma, Wenming; Yao, Hongbo; Zhen, Jiamei; Zeng, Guangming

    2015-08-01

    Aging effect can influence the fractions distribution and mobility of metals after they are added into soil. In this study, incubation and soil column experiments under simulated acid rain condition were conducted to evaluate aging effect on the leaching characteristic of Cu, Zn, and Cd in artificial polluted red paddy soil. Our results showed that aging effect reduced metal contents in exchangeable and HoAc soluble fractions. Power function was the most excellent to describe the variation of exchangeable fraction, while pseudo first- and second-order functions were more successful to describe the leaching characteristic of metals from soil columns. The leaching amount of the metals from the polluted soil only accounted for a small part of their total content in soil, and the leachability of Cu was the weakest. Both the exchangeable and HoAc soluble fraction were available as indicators to evaluate the leachability of metals in red paddy soil. The shorter time the soil was contaminated, the more amounts of metals released from the soil. The reduction of exchangeable fraction caused by aging effect was the main reason for the decrease of metal mobility in soil. PMID:25821039

  13. Aging effect on the leaching behavior of heavy metals (Cu, Zn, and Cd) in red paddy soil.

    PubMed

    Huang, Bin; Li, Zhongwu; Huang, Jinquan; Chen, Guiqiu; Nie, Xiaodong; Ma, Wenming; Yao, Hongbo; Zhen, Jiamei; Zeng, Guangming

    2015-08-01

    Aging effect can influence the fractions distribution and mobility of metals after they are added into soil. In this study, incubation and soil column experiments under simulated acid rain condition were conducted to evaluate aging effect on the leaching characteristic of Cu, Zn, and Cd in artificial polluted red paddy soil. Our results showed that aging effect reduced metal contents in exchangeable and HoAc soluble fractions. Power function was the most excellent to describe the variation of exchangeable fraction, while pseudo first- and second-order functions were more successful to describe the leaching characteristic of metals from soil columns. The leaching amount of the metals from the polluted soil only accounted for a small part of their total content in soil, and the leachability of Cu was the weakest. Both the exchangeable and HoAc soluble fraction were available as indicators to evaluate the leachability of metals in red paddy soil. The shorter time the soil was contaminated, the more amounts of metals released from the soil. The reduction of exchangeable fraction caused by aging effect was the main reason for the decrease of metal mobility in soil.

  14. Sorption of toxic heavy metals to soil.

    PubMed

    Alumaa, Priit; Kirso, Uuve; Petersell, Valter; Steinnes, Eiliv

    2002-02-01

    The surface soil is a major recipient of pollutants, including heavy metals, through atmospheric deposition, agricultural practices, and waste disposal. In the present work the sorption capacity of different types of soils to toxic heavy metals, i.e. chromium, copper, cadmium and lead has been studied. Experimental adsorption data for metals to the soil obtained by the batch method were fitted by linear isotherm. The various soils showed a very different behaviour in sorption of heavy metals. The distribution coefficient Kd, which is an indication of the adsorbing capacity of the substrate, varies within a wide range, from 57 to 53,000 l kg-1. Desorption of metals from the solid phase was found to be small, indicating that the soil matrix is affecting the metal mobility by modifying the bonding of pollutants to the soil system consequently affecting the potential for soil remediation processes.

  15. 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. PMID:23466085

  16. Heavy metals in traditional Indian remedies.

    PubMed

    Ernst, E

    2002-02-01

    The growing popularity of traditional Indian remedies necessitates a critical evaluation of risks associated with their use. This systematic review aims at summarising all available data relating to the heavy metal content in such remedies. Computerised literature searches were carried out to identify all articles with original data on this subject. Fifteen case reports and six case series were found. Their collective results suggest that heavy metals, particularly lead, have been a regular constituent of traditional Indian remedies. This has repeatedly caused serious harm to patients taking such remedies. The incidence of heavy metal contamination is not known, but one study shows that 64% of samples collected in India contained significant amounts of lead (64% mercury, 41% arsenic and 9% cadmium). These findings should alert us to the possibility of heavy metal content in traditional Indian remedies and motivate us to consider means of protecting consumers from such risks.

  17. 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.

  18. 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. PMID:1227849

  19. 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

  20. 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

  1. 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.

  2. 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...

  3. Phytochelatins: peptides involved in heavy metal detoxification.

    PubMed

    Pal, Rama; Rai, J P N

    2010-03-01

    Phytochelatins (PCs) are enzymatically synthesized peptides known to involve in heavy metal detoxification and accumulation, which have been measured in plants grown at high heavy metal concentrations, but few studies have examined the response of plants even at lower environmentally relevant metal concentrations. Recently, genes encoding the enzyme PC synthase have been identified in plants and other species enabling molecular biological studies to untangle the mechanisms underlying PC synthesis and its regulation. The present paper embodies review on recent advances in structure of PCs, their biosynthetic regulation, roles in heavy metal detoxification and/or accumulation, and PC synthase gene expression for better understanding of mechanism involved and to improve phytoremediation efficiency of plants for wider application.

  4. Geochemical behavior of heavy metals in a Zn-Pb-Cu mining area in the State of Mexico (central Mexico).

    PubMed

    Lizárraga-Mendiola, L; González-Sandoval, M R; Durán-Domínguez, M C; Márquez-Herrera, C

    2009-08-01

    The geochemical behavior of zinc, lead and copper from sulfidic tailings in a mine site with potential to generate acidic drainage (pyrite (55%) and sphalerite (2%)) is reported in this paper. The mining area is divided in two zones, considering the topographic location of sampling points with respect to the tailings pile: (a) outer zone, out of the probable influence of acid mine drainage (AMD) pollution, and (b) inner zone, probably influenced by AMD pollution. Maximum total ions concentrations (mg/L) measured in superficial waters found were, in the outer zone: As (0.2), Cd (0.9), Fe (19), Mn (39), Pb (5.02), SO4(2-) (4650), Zn (107.67), and in the inner zone are As (0.1), Cd (0.2), Fe (88), Mn (13), Pb (6), SO4(2-) (4,880), Zn (46). The presence of these ions that exceeding the permissible maximum limits for human consume, could be associated to tailings mineralogy and acid leachates generated in tailings pile.

  5. Effects of sediment geochemical properties on heavy metal bioavailability.

    PubMed

    Zhang, Chang; Yu, Zhi-gang; Zeng, Guang-ming; Jiang, Min; Yang, Zhong-zhu; Cui, Fang; Zhu, Meng-ying; Shen, Liu-qing; Hu, Liang

    2014-12-01

    As the largest container and resource of metals, sediment has a special role in the fate of metals. Factors influencing bioavailability of heavy metals in sediment have never been comprehensively considered and the sediment properties still fail to understand and even controversial. In this review, the mechanisms of sediment properties such as acid-volatile sulfides (AVS), organic matter, texture (clay, silt or sand) and geology, organism behaviors as well as those influencing the bioavailability of metals were analyzed. Under anoxic condition, AVS mainly reduce the solubility and toxicity of metals, while organic matters, Fe-Mn oxides, clay or silt can stabilize heavy metals in elevated oxidative-reductive potential (ORP). Other factors including the variation of pH, redox potential, aging as well as nutrition and the behavior of benthic organism in sediment also largely alter metals mobility and distribution. These factors are often inter-related, and various toxicity assessment methods used to evaluate the bioavailability of trace metals have been also discussed. Additionally, we expect that some novel synthetic materials like polysulfides, nano-materials, provide the substantial amendments for metals pollution in sediment.

  6. Antiquenching effect of modifying cations on samarium clustering: Physical, structural and luminescent behavior of heavy metal borate glass systems

    NASA Astrophysics Data System (ADS)

    Kaur, Simranpreet; Kaur, Parvinder; Pal Singh, Gurinder; Kumar, Sunil; Singh, D. P.

    2015-09-01

    In this paper an attempt has been made to correlate the structural modifications and luminescence efficiencies by changing the environment of the glass network by modifying oxides. Sm3+ doped lead borate (SPB) and lead cadmium alumino borate (SCPB) glasses have been fabricated by melt quench technique at high temperature. The glass samples are characterized by XRD, FTIR, optical absorptions, fluorescence and density measurements. The effect of Sm3+ ion and glass host interaction on the emission spectra has been discussed in the view of the ionicity and covalency of hosts. The ratio of the intensities of electric to magnetic dipole emissions are calculated by varying both the concentration of the Sm3+ ion and the composition of the glass matrix. The XRD profile of all the glasses confirms their amorphous nature and FTIR spectrum shows the presence of BO3 and BO4 groups. These glasses have shown strong absorption bands in the visible (VIS and NIR) region and emit strong orange red wavelengths when excited by ultraviolet light. The concentration quenching has been noticed and ascribed to energy transfer through cross-relaxation between Sm3+ ions. Shifting of UV absorption edge towards longer wavelength with addition of Sm2O3 concentration has been observed. Incorporation of Al2O3 and CdO in 2nd glass system is responsible for strong effect on luminescence of the present glass system. Based on these results, an attempt has been made to throw some light on the relationship between the structural modifications and luminescence efficiencies in two different glass hosts as a laser active medium in the visible region. Moreover the optical basicity values were theoretically determined along with covalent behavior of two glass systems.

  7. 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.

  8. Extractable heavy metals in Atlantic coast soils

    SciTech Connect

    MacLean, K.S.; Langille, W.M.

    1980-01-01

    The analysis of soils, using 0.1 N HCl as an extractant for the heavy metals, Cd, Cr, Ni and Pb on fine textured North Shore and coarse textured Annapolis Valley soils was completed. Results show ranges of 0.012 to 0.469 ppM Cd, 0.102 to 2.90 ppM Cr, 0.16 to 29.25 ppM Ni, and 0.12 to 244.8 ppM Pb. Correlation studies indicate that the heavy metal content of fine textured soils is less influenced by changes in clay content and organic matter than are coarse textured soils. Generally the surface layers (0 to 15 cms) are higher in extractable heavy metal content than the lower layers (15 to 30 cms).

  9. Factors involved in heavy metal poisoning.

    PubMed

    Clarkson, T W

    1977-04-01

    The heavy metals include at least 40 elements but cadmium, lead, and mercury have been most extensively studied. The biological properties of heavy metals are discussed in terms of three important characteristics: the ability to form, irreversibly, complexes and chelates with organic ligands; the properties to form organic-metallic bonds; and the potential to undergo oxidation-reduction reactions. The formation of complexes and chelates within the body is shown to influence greatly the dynamics of transport, distribution, and excretion of several important metal cations. The excretion of uranium is influenced by acid-base balance in the body because uranium forms complexes with bicarbonate anions that are filtered by the kidneys. The biliary excretion of methylmercury depends on the formation of small molecular weight complexes with sulfur-containing amiono acids and the peptides in the liver. The degree of enterohepatic recirculation of a variety of heavy metals appears to depend on the chemical nature of the bilary complexes. The oxidation of elemental to divalent ionic mercury is the crurial step in the retention and tissue deposition of inhaled mercury vapor. That the oxidation process is, at least in part, catalyzed by the enzyme, catalase, explains the effects of ethanol, aminotriazole and the state of acatalasemia on the metabolism of inhaled vapor in man and animals. The formation of covalent bonds between metal cations and the carbon atom usually greatly modifies the biological properties of the metal. Methylarsenic and methylmercury compounds both differ from the inorganic forms in accumulation in animals.

  10. 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. PMID:22542973

  11. 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.

  12. 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. PMID:16405948

  13. 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.

  14. 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

  15. 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.

  16. 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...

  17. 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)

  18. 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.

  19. 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

  20. Heavy metal tolerance in metal hyperaccumulator plant, Salvinia natans.

    PubMed

    Dhir, B; Srivastava, S

    2013-06-01

    Metal tolerance capacity of Salvinia natans, a metal hyperaccumulator, was evaluated. Plants were exposed to 10, 30 and 50 mg L⁻¹ of Zn, Cd, Co, Cr, Fe, Cu, Pb, and Ni. Plant biomass, photosynthetic efficiency, quantum yield, photochemical quenching, electron transport rate and elemental (%C, H and N) constitution remained unaffected in Salvinia exposed to 30 mg L⁻¹ of heavy metals, except for Cu and Zn exposed plants, where significant reductions were noted in some of the measured parameters. However, a significant decline was noted in most of the measured parameters in plants exposed to 50 mg L⁻¹ of metal concentration. Results suggest that Salvinia has fairly high levels of tolerance to all the metals tested, but the level of tolerance varied from metal to metal. PMID:23553503

  1. 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…

  2. [Effects of heavy metals pollution on paddy soil aggregates composition and heavy metals distribution].

    PubMed

    Zhang, Liang-Yun; Li, Lian-Qing; Pan, Gen-Xing; Cui, Li-Qiang; Li, Hong-Lei; Wu, Xiao-Yan; Shao, Jie-Qi

    2009-11-01

    Topsoil samples were collected from a polluted and an adjacent non-polluted paddy field in the Taihu Lake region of China. Different particle size fractions of soil aggregates were separated by low-energy dispersion procedure, and their mass composition and Pb, Cd, Hg, and As concentrations were determined. Under heavy metals pollution, the mass composition of sand-sized fractions reduced, while that of clay-sized fractions increased. The concentrations of test metals in different particle size fractions differed, with the highest in < 0.002 mm fraction, followed by in 2-0.2 mm fraction. In 0.02-0.002 mm and 0.2-0.02 mm fractions, all the test metals were relatively deficient, with an enrichment index of 0.56-0.96. The present study showed that the aggregation of fine particles could be depressed by heavy metals pollution, which in turn, led to a relative increase in the mass composition of fine particles and the associated allocation of heavy metals in weakly aggregated silt particles, and further, increased the risks of heavy metals translocation from polluted farmland into water and atmosphere. Further studies should be made on the impacts of heavy metals pollution on soil biophysical and biochemical processes and related mechanisms.

  3. Heavy metal removal from wastewater using zero-valent iron nanoparticles.

    PubMed

    Chen, S Y; Chen, W H; Shih, C J

    2008-01-01

    Because of having a high reduction potential, the zero-valent iron (ZVI) is often applied for the remediation of wastewater or groundwater with heavy metals. The purpose of this study was aimed to investigate the reaction behavior of heavy metals with ZVI nanoparticles in the wastewater. The affecting factors, such as initial pH, dosage of nanoscale ZVI and initial concentration of heavy metal, on the removal efficiency of heavy metals by ZVI in the wastewater were examined by the batch experiments in this study. It was found that the removal of heavy metals was affected by initial pH. The rate and efficiency of metal removal increased with decreasing initial pH. Greater than 90% of the heavy metals were removed when the initial pH was controlled at 2. In addition, the rate and efficiency of metal removal increased as the dosage of nanoscale ZVI increased. The removal efficiency of heavy metal was higher than 80% when 2.0 g/L of ZVI was added in the wastewater. On the other hand, the slow rate and low efficiency of metal removal from the wastewater treated by nanoscale ZVI was found in the wastewater with high concentration of heavy metal.

  4. 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.

  5. 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.

  6. Heavy metals in common foodstuff: Quantitative analysis

    SciTech Connect

    Tsoumbaris, P.; Tsoukali-Papadopoulou, H. )

    1994-07-01

    The presence of heavy metals in human body always draws scientific concern as these are considered responsible for affecting health, especially in these days where the release of toxic wastes in the environment has been increased. Some metals are essential for life, others have unknown biologic function, either favourable or toxic and some others have the potential to produce disease. Those causing toxicity are the ones which accumulate in the body through food chain, water and air. The purpose of this study is the determination of Pb, Cd, Ni, Mn, Zn in different foodstuff consumed by inhabitants of the city of Thessaloniki, northern Greece, according to their dietary habits.

  7. 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.

  8. 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.

  9. 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. PMID:27387415

  10. 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.

  11. 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

  12. 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.

  13. 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.

  14. Quantum critical behavior in heavy electron materials

    PubMed Central

    Yang, Yi-feng; Pines, David

    2014-01-01

    Quantum critical behavior in heavy electron materials is typically brought about by changes in pressure or magnetic field. In this paper, we develop a simple unified model for the combined influence of pressure and magnetic field on the effectiveness of the hybridization that plays a central role in the two-fluid description of heavy electron emergence. We show that it leads to quantum critical and delocalization lines that accord well with those measured for CeCoIn5, yields a quantitative explanation of the field and pressure-induced changes in antiferromagnetic ordering and quantum critical behavior measured for YbRh2Si2, and provides a valuable framework for describing the role of magnetic fields in bringing about quantum critical behavior in other heavy electron materials. PMID:24912172

  15. 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.

  16. Heavy metals in common foodstuff: Daily intake

    SciTech Connect

    Tsoumbaris, P.; Tsoukali-Papadopoulou, H. )

    1994-07-01

    Lately, toxic effects of some heavy metals (Pb, Cd) as well as desirable ones of some others (Ni, Mn, Zn) have been a field of thorough investigation. The main way of human body fortification in metals is through foodchain depending on the kind and quantity of the consumed food, according to dietary habits. The purpose of this study is the calculation of metals daily intake through common foodstuff of Greek inhabitants. The calculation is based on results from quantitative analysis of Pb, Cd, Ni, Mn, and Zn in common foodstuff from the market of the city of Thessaloniki. The daily food consumption data is derived from three sources: (a) answers to a questionnaire distributed to families of the city of Thessaloniki, (b) nutrition data provided by the Agricultural Bank of Greece and (c) nutrition data according to international bibliography.

  17. Heavy metals in soils from Tirana (Albania).

    PubMed

    Gjoka, Fran; Felix-Henningsen, Peter; Wegener, Hans-R; Salillari, Ilir; Beqiraj, Ajran

    2011-01-01

    This study was aimed to establish background and reference values of total heavy metals in soils from a representative area of Albania (Tirana). Thirty-eight soil samples collected from genetic horizons of major soil types of Tirana were analyzed for important physicochemical properties by standard methods and for total contents of Cd, Cr, Ni, Pb, Zn, and Cu by atomic absorption spectrometer, after extraction with aqua regia. The results showed that the total contents of Cd, Cr, Ni, Pb, Zn, and Cu in surface horizons varied widely with respective mean values of 0.3 (± 0.6), 174.2 (± 63.7), 305.9 (± 133.0), 19.7 (± 12.4), 95.5 (± 26.3), and 42.7 (± 6.8) mg/kg. The highest metal contents were found in two soils developed in limestone. The depth distribution of metals showed a tendency for accumulation of Cd and Pb in the surface horizons of three soils, suggesting that these metals partially come from anthropogenic inputs. Correlation analysis indicated that the metal contents of soils were controlled by soil properties, including pH, CaCO₃, clay, organic matter, cation exchange capacity, and Fe oxides. The background values (given as the 90th percentile) were much higher than those reported in the literature, showing that the levels of respective metals were naturally higher. The total metal contents of some soils were above background levels, suggesting metal pollution. The reference values for all the analyzed metals were quite consistent with those of the Dutch system. The proposed background and reference values can be used to evaluate the soil pollution with these elements.

  18. Road traffic emission factors for heavy metals

    NASA Astrophysics Data System (ADS)

    Johansson, Christer; Norman, Michael; Burman, Lars

    Quantifying the emissions and concentrations of heavy metals in urban air is a prerequisite for assessing their health effects. In this paper a combination of measurements and modelling is used to assess the contribution from road traffic emissions. Concentrations of particulate heavy metals in air were measured simultaneously during 1 year at a densely trafficked street and at an urban background site in Stockholm, Sweden. Annual mean concentrations of cadmium were 50 times lower than the EU directive and for nickel and arsenic concentrations were 10 and six times lower, respectively. More than a factor of two higher concentrations was in general observed at the street in comparison to roof levels indicating the strong influence from local road traffic emissions. The only compound with a significantly decreasing trend in the urban background was Pb with 9.1 ng m -3 in 1995/96 compared to 3.4 ng m -3 2003/04. This is likely due to decreased emissions from wear of brake linings and reduced emissions due to oil and coal combustion in central Europe. Total road traffic emission factors for heavy metals were estimated using parallel measurements of NOx concentrations and knowledge of NOx emission factors. In general, the emission factors for the street were higher than reported in road tunnel measurements. This could partly be due to different driving conditions, since especially for metals which are mainly emitted from brake wear, more stop and go driving in the street compared to in road tunnels is likely to increase emissions. Total emissions were compared with exhaust emissions, obtained from the COPERT model and brake wear emissions based on an earlier study in Stockholm. For Cu, Ni and Zn the sum of brake wear and exhaust emissions agreed very well with estimated total emission factors in this study. More than 90% of the road traffic emissions of Cu were due to brake wear. For Ni more than 80% is estimated to be due to exhaust emissions and for Zn around 40% of

  19. 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

  20. 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.

  1. 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.

  2. Diel behavior of iron and other heavy metals in a mountain stream with acidic to neutral pH: Fisher Creek, Montana, USA

    NASA Astrophysics Data System (ADS)

    Gammons, Christopher H.; Nimick, David A.; Parker, Stephen R.; Cleasby, Thomas E.; McCleskey, R. Blaine

    2005-05-01

    Three simultaneous 24-h samplings at three sites over a downstream pH gradient were conducted to examine diel fluctuations in heavy metal concentrations in Fisher Creek, a small mountain stream draining abandoned mine lands in Montana. Average pH values at the upstream (F1), middle (F2), and downstream (F3) monitoring stations were 3.31, 5.46, and 6.80, respectively. The downstream increase in pH resulted in precipitation of hydrous ferric oxide (HFO) and hydrous aluminum oxide (HAO) on the streambed. At F1 and F2, Fe showed strong diel cycles in dissolved concentration and Fe(II)/Fe(III) ratio; these cycles were attributed to daytime photoreduction of Fe(III) to Fe(II), reoxidation of Fe(II) to Fe(III), and temperature-dependent hydrolysis and precipitation of HFO. At the near-neutral downstream station, no evidence of Fe(III) photoreduction was observed, and suspended particles of HFO dominated the total Fe load. HFO precipitation rates between F2 and F3 were highest in the afternoon, due in part to reoxidation of a midday pulse of Fe 2+ formed by photoreduction in the upper, acidic portions of the stream. Dissolved concentrations of Fe(II) and Cu decreased tenfold and 2.4-fold, respectively, during the day at F3. These changes were attributed to sorption onto fresh HFO surfaces. Results of surface complexation modeling showed good agreement between observed and predicted Cu concentrations at F3, but only when adsorption enthalpies were added to the thermodynamic database to take into account diel temperature variations. The field and modeling results illustrate that the degree to which trace metals adsorb onto actively forming HFO is strongly temperature dependent. This study is an example of how diel Fe cycles caused by redox and hydrolysis reactions can induce a diel cycle in a trace metal of toxicological importance in downstream waters.

  3. Diel behavior of iron and other heavy metals in a mountain stream with acidic to neutral pH: Fisher Creek, Montana, USA

    USGS Publications Warehouse

    Gammons, C.H.; Nimick, D.A.; Parker, S.R.; Cleasby, T.E.; McCleskey, R.B.

    2005-01-01

    Three simultaneous 24-h samplings at three sites over a downstream pH gradient were conducted to examine diel fluctuations in heavy metal concentrations in Fisher Creek, a small mountain stream draining abandoned mine lands in Montana. Average pH values at the upstream (F1), middle (F2), and downstream (F3) monitoring stations were 3.31, 5.46, and 6.80, respectively. The downstream increase in pH resulted in precipitation of hydrous ferric oxide (HFO) and hydrous aluminum oxide (HAO) on the streambed. At F1 and F2, Fe showed strong diel cycles in dissolved concentration and Fe(II)/Fe(III) ratio; these cycles were attributed to daytime photoreduction of Fe(III) to Fe(II), reoxidation of Fe(II) to Fe(III), and temperature-dependent hydrolysis and precipitation of HFO. At the near-neutral downstream station, no evidence of Fe(III) photoreduction was observed, and suspended particles of HFO dominated the total Fe load. HFO precipitation rates between F2 and F3 were highest in the afternoon, due in part to reoxidation of a midday pulse of Fe2+ formed by photoreduction in the upper, acidic portions of the stream. Dissolved concentrations of Fe(II) and Cu decreased tenfold and 2.4-fold, respectively, during the day at F3. These changes were attributed to sorption onto fresh HFO surfaces. Results of surface complexation modeling showed good agreement between observed and predicted Cu concentrations at F3, but only when adsorption enthalpies were added to the thermodynamic database to take into account diel temperature variations. The field and modeling results illustrate that the degree to which trace metals adsorb onto actively forming HFO is strongly temperature dependent. This study is an example of how diel Fe cycles caused by redox and hydrolysis reactions can induce a diel cycle in a trace metal of toxicological importance in downstream waters. Copyright ?? 2005 Elsevier Ltd.

  4. 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

  5. [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.

  6. [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. PMID:21608273

  7. Drug- and heavy metal--induced hyperpigmentation.

    PubMed

    Granstein, R D; Sober, A J

    1981-07-01

    Several categories of chemical and pharmacologic agents can cause alterations in cutaneous pigmentation, although the mechanisms differ and in several instances may be unknown. Fixed drug eruptions appear to have alteration of the basement membrane zone with incontinence of epidermal pigment as the mechanism of hyperpigmentation. Heavy metals produce increased pigmentation in part from deposition of metal particles and in part from an increase in epidermal melanin production. The antimalarials may bind to melanin. The phenothiazines and minocycline produce pigmentation from deposition of the drug. The mechanism, site, and nature of the pigment occurring with antineoplastic agents is not well understood, but the location is most likely predominantly epidermal. Clofazimine (Lamprene) alteration in pigmentation appears to result from deposition of the drug in subcutaneous fat.

  8. 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.

  9. 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. PMID:19165404

  10. 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.

  11. 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.

  12. [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.

  13. Challenges and opportunities in the phytoremediation of heavy metals contaminated soils: A review.

    PubMed

    Mahar, Amanullah; Wang, Ping; Ali, Amjad; Awasthi, Mukesh Kumar; Lahori, Altaf Hussain; Wang, Quan; Li, Ronghua; Zhang, Zengqiang

    2016-04-01

    Mining operations, industrial production and domestic and agricultural use of metal and metal containing compound have resulted in the release of toxic metals into the environment. Metal pollution has serious implications for the human health and the environment. Few heavy metals are toxic and lethal in trace concentrations and can be teratogenic, mutagenic, endocrine disruptors while others can cause behavioral and neurological disorders among infants and children. Therefore, remediation of heavy metals contaminated soil could be the only effective option to reduce the negative effects on ecosystem health. Thus, keeping in view the above facts, an attempt has been made in this article to review the current status, challenges and opportunities in the phytoremediation for remediating heavy metals from contaminated soils. The prime focus is given to phytoextraction and phytostabilization as the most promising and alternative methods for soil reclamation. PMID:26741880

  14. Challenges and opportunities in the phytoremediation of heavy metals contaminated soils: A review.

    PubMed

    Mahar, Amanullah; Wang, Ping; Ali, Amjad; Awasthi, Mukesh Kumar; Lahori, Altaf Hussain; Wang, Quan; Li, Ronghua; Zhang, Zengqiang

    2016-04-01

    Mining operations, industrial production and domestic and agricultural use of metal and metal containing compound have resulted in the release of toxic metals into the environment. Metal pollution has serious implications for the human health and the environment. Few heavy metals are toxic and lethal in trace concentrations and can be teratogenic, mutagenic, endocrine disruptors while others can cause behavioral and neurological disorders among infants and children. Therefore, remediation of heavy metals contaminated soil could be the only effective option to reduce the negative effects on ecosystem health. Thus, keeping in view the above facts, an attempt has been made in this article to review the current status, challenges and opportunities in the phytoremediation for remediating heavy metals from contaminated soils. The prime focus is given to phytoextraction and phytostabilization as the most promising and alternative methods for soil reclamation.

  15. Comparative characterization of sewage sludge compost and soil: Heavy metal leaching characteristics.

    PubMed

    Fang, Wen; Wei, Yonghong; Liu, Jianguo

    2016-06-01

    The leaching and accumulation of heavy metals are major concerns following the land application of sewage sludge compost (SSC). We comparatively characterized SSC, the reference soil, and the SSC amended soil to investigate their similarities and differences regarding heavy metal leaching behavior and then to evaluate the effect of SSC land application on the leaching behavior of soil. Results showed that organic matter, including both of particulate organic matter (POM) and dissolved organic matter (DOM), were critical factors influencing heavy metal leaching from both of SSC and the soil. When SSC was applied to soil at the application rate of 48t/ha, the increase of DOM content slightly enhanced heavy metal leaching from the amended soil over the applicable pH domain (6behavior of heavy metals. The geochemical speciation modeling revealed that heavy metal speciation in the solid phase were similar between the reference soil and the amended soil. PMID:26897569

  16. Comparative characterization of sewage sludge compost and soil: Heavy metal leaching characteristics.

    PubMed

    Fang, Wen; Wei, Yonghong; Liu, Jianguo

    2016-06-01

    The leaching and accumulation of heavy metals are major concerns following the land application of sewage sludge compost (SSC). We comparatively characterized SSC, the reference soil, and the SSC amended soil to investigate their similarities and differences regarding heavy metal leaching behavior and then to evaluate the effect of SSC land application on the leaching behavior of soil. Results showed that organic matter, including both of particulate organic matter (POM) and dissolved organic matter (DOM), were critical factors influencing heavy metal leaching from both of SSC and the soil. When SSC was applied to soil at the application rate of 48t/ha, the increase of DOM content slightly enhanced heavy metal leaching from the amended soil over the applicable pH domain (6behavior of heavy metals. The geochemical speciation modeling revealed that heavy metal speciation in the solid phase were similar between the reference soil and the amended soil.

  17. [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.

  18. 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

  19. Heavy Metal Induced Antibiotic Resistance in Bacterium LSJC7.

    PubMed

    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. 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.

  1. 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

  2. Toxic heavy metals: Materials cycle optimization

    SciTech Connect

    Ayers, R.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.

  3. 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

  4. 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.

  5. 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.

  6. Water-soluble organophosphorus reagents for mineralization of heavy metals.

    SciTech Connect

    Nash, K. L.

    1999-02-26

    In this report, we have described the principal stages of a two-step process for the in-situ stabilization of actinide ions in the environment. The combination of cation exchange and mineralization appears likely to provide a long-term solution to environments contaminated with heavy metals. Relying on a naturally occurring sequestering agent has obvious potential advantages from a regulatory standpoint. There are additional aspects of this technology requiring further elucidation, including the demonstration of the effect of these treatment protocols on the geohydrology of soil columns, further examination of the influence of humates and other colloidal species on cation uptake, and microbiological studies of phytate hydrolysis. We have learned during the course of this investigation that phytic acid is potentially available in large quantities. In the US alone, phytic acid is produced at an annual rate of several hundred thousand metric tons as a byproduct of fermentation processes (11). This material presently is not isolated for use. Instead, most of the insoluble phyate (as phytin) is being recycled along with the other solid fermentation residues for animal feed. This material is in fact considered undesirable in animal feed. The details of possible separation processes for phytate from these residues would have to be worked out before this untapped resource would be available for application to heavy metal sequestration. The results described emphasize the behavior of actinide and trivalent lanthanide metal ions, as these species are of primary interest to the Department of Energy for the cleanup of the former nuclear weapons production complex. While the specific demonstration includes this limited selection of metal ions, the technique should be readily applicable to any class of metal ions that form insoluble phosphate compounds under appropriate conditions. Further, though this demonstration has been conducted in the pH 5-8 range, it is conceivable that

  7. 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.

  8. Successful treatment of potentially fatal heavy metal poisonings.

    PubMed

    Wang, Ernest E; Mahajan, Niraj; Wills, Brandon; Leikin, Jerrold

    2007-04-01

    Pure inorganic heavy metal ingestions for suicidal intent are a rare occurrence. Most case reports on this subject focus on the serious neurological, hepatic, or renal side effects. We describe two cases of significant heavy metal poisonings (arsenic trioxide and mercuric chloride) that were successfully managed with aggressive decontamination and combined chelation therapy. Both chemicals were obtained in pure powder form through the Internet.

  9. 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.

  10. 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…

  11. 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.

  12. 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.

  13. 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. PMID:27179811

  14. 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.

  15. 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.

  16. 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

  17. 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.

  18. Fate and effects of heavy metals on the Arkansas river

    SciTech Connect

    Clements, W.H.

    1991-12-15

    The project examined fate and effects of heavy metals on biological communities in the upper Arkansas River Basin. The principal objectives of the research were: (1) to measure the impact of heavy metals (Cd, Cu, and Zn) on benthic invertebrate communities in the Arkansas River; (2) to delineate zones of high impact, moderate impact, and recovery based on the distribution and abundance of these organisms; (3) to examine seasonal variation in effects of metals on benthic communities; (4) to examine the potential transfer of heavy metals from benthic invertebrates to brown trout, Salmo trutta.

  19. 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.

  20. 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

  1. Current levels of heavy metal pollution in Africa.

    PubMed

    Yabe, John; Ishizuka, Mayuni; Umemura, Takashi

    2010-10-01

    Studies of environmental pollution in Africa indicate that toxic metal pollution has reached unprecedented levels over the past decade. Human exposure to toxic metals has become a major health risk on the continent and is the subject of increasing attention from national and international environmentalists. This paper reviews data from the past decade on environmental pollution in Africa and highlights countries where most heavy metal pollutions have been reported. Characteristics of heavy metal pollution in North, West, East and Southern regions of Africa have been described, as have major sources of pollution in the different regions. This review summarizes the sites where most of the heavy metal pollution has been reported in Africa and, where applicable, presents reported levels of pollution in different environmental compartments in the context of internationally acceptable limits. Contaminations in fish and food animals as well as impacts of heavy metal pollution on humans are also described.

  2. 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.

  3. 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. PMID:24561322

  4. 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.

  5. 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. PMID:26856647

  6. 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.

  7. 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.

  8. 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. PMID:26940747

  9. 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.

  10. 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

  11. Accumulation of heavy metals in selected medicinal plants.

    PubMed

    Sarma, Hemen; Deka, Suresh; Deka, Hemen; Saikia, Rashmi Rekha

    2011-01-01

    In this review, we evaluate the reports published between 1993 and 2011 that address the heavy metal accumulation in 88 medicinal plant species. We compare the safe limits for heavy metals set by governmental agencies vs. the levels at which such metals actually exist in selected medicinal plants. We also evaluate the uses and effectiveness of medicinal plants in health care, and assess the hazards of medicinal plant uses, in view of the growing worldwide use of medicinal plants. From our extensive review of the literature, we discovered that a maximum permissible level (MPL) of Pb is exceeded in 21 plant medicine species, Cd in 44 species, and Hg in 10 species. Vetiveria zizanioides a potential candidate species for the treatment of cardiovascular diseases absorb a wide range of heavy metals from metal-contaminated soils. We believe that this species is the single most impressive example of a potentially hazardous medicinal plant. Based on our review, we endorse the hypothesis that heavy metal accumulation by medicinal plants is mainly caused by extraction of soluble metals from contaminated soil, sediments and air. One continuing problem in protecting consumers of plant-based medicines is that permissible levels of all heavy metals in herbal medicine have not yet been standardized by regulating governmental entities. Moreover, there are few limit tests that exist for heavy metal content of medicinal plants, or permissible limits for essential dietary minerals, in most medicinal plants. The dearth of such limits hamstrings development of medicinal plant research and delays the release of either new or improved versions of medicinal plants or their components. In the present review, we emphasize that medicinal plants are often subjected to heavy metal contamination and that the levels at which these heavy metals sometimes occur exceeds permissible levels for some species. Therefore, collecting medicinal plants from areas that are, or may be, contaminated should be

  12. 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.

  13. [Evaluation of pulmonary toxicity of heavy metal compounds].

    PubMed

    Hirano, S

    1996-02-01

    The present report describes toxicological approaches to evaluate inflammatory potency of heavy metal compounds deposited in the lung. Although inhalation exposure is a well-accepted method to study effects of pulmonary toxicants, it requires expensive facilities and many man-hours to complete experiments. Intratracheal (i.t.) instillation, an alternative and simple method to expose animals to toxicants via airways, has been proved to be useful to investigate the pulmonary clearance of heavy metals. However, acute inhalation exposure caused more severe inflammatory lung injury than i. t. instillation when the same amount of nickel sulfate was administered in the rat. Among several biochemical inflammatory indices such as some enzyme activities and the protein concentration in bronchoalveolar lavage (BAL) fluid, only lactate dehydrogenase (LDH) activity increased linearly with a wide range of doses of heavy metals. The increase in polymorphonuclear leukocytes (PMN) in BAL fluid, a cytological index of inflammatory responses of the lung, is believed to reflect pulmonary toxicity of heavy metals. However, more extensive study is required to elucidate the mechanism of transpulmonary PMN infiltration upon heavy metal insult. In addition to the linearity between LDH activity in BAL fluid and doses of heavy metals, the increase in this cytosolic enzyme activity is associated with cell lysis in the bronchoalveolar milieu and appears to be the best index to evaluate pulmonary inflammatory potency of heavy metals.

  14. 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. PMID:25528489

  15. Surface discharge of heavy metals from low farmland.

    PubMed

    Hamada, K; Yoshinaga, I; Hitomi, T; Miura, A; Shiratani, E; Takaki, K

    2007-01-01

    Runoff heavy metals from farmland were examined using the field data for the summer of 2005. The observation farmland is located on lowland where the irrigation water was contaminated with the drained water from the upstream farmlands. The area of the farmland is 11.2 ha, of which 6.0 ha and 4.5 ha have been used for rice paddy fields and soybean cultivation, respectively. During the observation, heavy metal concentrations at the downstream end were usually found to be higher than those in the irrigation water. That is, the heavy metal concentrations increased due to the passage of the water through the farmland. This increase in the heavy metal concentrations is not equal to the discharge of the heavy metal because the evaporation on the surface of the paddy field and the absorption by plants makes the surface water volume small. The discharged load from the farmland generally indicates the gross surface load from the farmland. When the effects of circulation irrigation on the heavy metal concentrations are estimated, the discharged load from the farmland should be calculated as the net surface load. When the runoff heavy metals from the circulation irrigation farmland are estimated, it is important to consider the inflowing heavy metals with irrigation water. All the heavy metal types observed in this study were discharged from the farmland. The net surface loads of Cr, Fe, Cd, and Pb were 371 microg m(-2) day(-1), 14.9 mg m(-2) day(-1), 0.26 microg m(-2) day(-1), and 3.3 microm( -2) day(-1), respectively. PMID:17711004

  16. Immunotoxicology in wood mice along a heavy metal pollution gradient.

    PubMed

    Tersago, Katrien; De Coen, Wim; Scheirs, Jan; Vermeulen, Katrien; Blust, Ronny; Van Bockstaele, Dirk; Verhagen, Ron

    2004-12-01

    We carried out an immunotoxicological field study of wood mice in three populations along a heavy metal pollution gradient. Heavy metal concentrations in liver tissue indicated that exposure to silver, arsenic, cadmium, cobalt and lead decreased with increasing distance from a non-ferrous smelter. Host resistance to the endoparasite Heligmosomoides polygyrus decreased with increasing exposure, while the abundance of tick larvae and the nematode Syphacia stroma was unrelated to heavy metal exposure. Spleen mass was increased at the intermediate and the most polluted sites and was positively correlated with the number of H. polygyrus and tick larvae. Proportion of early apoptotic leukocytes increased towards the smelter and was positively related to cadmium exposure. Red and white blood cell counts and lysozyme activity showed no relationship with metal exposure. All together, our observations suggest negative effects of heavy metal exposure on the immune function of wood mice under field conditions.

  17. 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. PMID:27451175

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

    SciTech Connect

    Reynolds, J.G.

    1990-11-28

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

  19. Variegate porphyria and heavy metal poisoning from ingestion of "moonshine".

    PubMed

    Hughes, G S; Davis, L

    1983-08-01

    A patient with cavitary tuberculosis, hepatic cirrhosis, bullous skin lesions over sun-exposed surfaces, disorientation, and a chronic, as well as recent, history of illicit alcohol consumption was found to have acute variegate porphyria by characteristic fecal and urinary porphyrin studies. Elevated levels of lead and arsenic were found in serum and urine without evidence of heavy metal storage in hair and liver. We suspect that the variegate porphyria was precipitated by the ingestion of heavy metals contained in illicit alcohol. In a patient with disorientation, bullous skin lesions, and a history of illicit alcohol ingestion, one must consider heavy metal intoxication and secondary porphyrin abnormalities.

  20. 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.

  1. 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.

  2. 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

  3. Heavy metal removal from MSS fly ash by thermal and chlorination treatments

    PubMed Central

    Liu, Jingyong; Chen, Jiacong; Huang, Limao

    2015-01-01

    The thermal behavior of heavy metals in the co-incineration of municipal solid waste-sludge incinerator fly ash (MSS fly ash) was studied using a laboratory-scale tube furnace. The results indicate that without the addition of chlorinating agents, temperature was an important parameter and had significantly influenced on heavy metal removal, whereas the residence time had a weak effect. Between 900 and 1000 °C for 60 to 300 min, heavy metals reacted with chloride-inherent in the fly ash, and approximately 80 to 89% of Pb, 48% to 56% of Cd, 27% to 36% of Zn and 6% to 24% of Cu were removed. After the adding chlorinating agents, the evaporation rate of the heavy metals improved dramatically, where the evaporation rates of Cu and Zn were larger than that of Pb and Cd. As the amount of added chlorinating agents increased, the removal rate of heavy metals increased. However, the effect of the type of chlorinating agent on the chlorination of heavy metals differed considerably, where NaCl had the weakest effect on the removal rate of Cu, Cd and Zn. In terms of resource recovery and decontamination, MgCl2 and CaCl2 are the best choices due to their efficient removal of Zn. PMID:26602592

  4. Heavy metal removal from MSS fly ash by thermal and chlorination treatments

    NASA Astrophysics Data System (ADS)

    Liu, Jingyong; Chen, Jiacong; Huang, Limao

    2015-11-01

    The thermal behavior of heavy metals in the co-incineration of municipal solid waste-sludge incinerator fly ash (MSS fly ash) was studied using a laboratory-scale tube furnace. The results indicate that without the addition of chlorinating agents, temperature was an important parameter and had significantly influenced on heavy metal removal, whereas the residence time had a weak effect. Between 900 and 1000 °C for 60 to 300 min, heavy metals reacted with chloride-inherent in the fly ash, and approximately 80 to 89% of Pb, 48% to 56% of Cd, 27% to 36% of Zn and 6% to 24% of Cu were removed. After the adding chlorinating agents, the evaporation rate of the heavy metals improved dramatically, where the evaporation rates of Cu and Zn were larger than that of Pb and Cd. As the amount of added chlorinating agents increased, the removal rate of heavy metals increased. However, the effect of the type of chlorinating agent on the chlorination of heavy metals differed considerably, where NaCl had the weakest effect on the removal rate of Cu, Cd and Zn. In terms of resource recovery and decontamination, MgCl2 and CaCl2 are the best choices due to their efficient removal of Zn.

  5. Heavy metal removal from MSS fly ash by thermal and chlorination treatments.

    PubMed

    Liu, Jingyong; Chen, Jiacong; Huang, Limao

    2015-11-25

    The thermal behavior of heavy metals in the co-incineration of municipal solid waste-sludge incinerator fly ash (MSS fly ash) was studied using a laboratory-scale tube furnace. The results indicate that without the addition of chlorinating agents, temperature was an important parameter and had significantly influenced on heavy metal removal, whereas the residence time had a weak effect. Between 900 and 1000 °C for 60 to 300 min, heavy metals reacted with chloride-inherent in the fly ash, and approximately 80 to 89% of Pb, 48% to 56% of Cd, 27% to 36% of Zn and 6% to 24% of Cu were removed. After the adding chlorinating agents, the evaporation rate of the heavy metals improved dramatically, where the evaporation rates of Cu and Zn were larger than that of Pb and Cd. As the amount of added chlorinating agents increased, the removal rate of heavy metals increased. However, the effect of the type of chlorinating agent on the chlorination of heavy metals differed considerably, where NaCl had the weakest effect on the removal rate of Cu, Cd and Zn. In terms of resource recovery and decontamination, MgCl2 and CaCl2 are the best choices due to their efficient removal of Zn.

  6. Assessment of dissolved heavy metal in the Yangtze River estuary and its adjacent sea, China.

    PubMed

    An, Qiang; Wu, Yanqing; Wang, Jinhui; Li, Zhien

    2010-05-01

    The purpose of this paper is to determine the concentrations of dissolved heavy metals namely mercury (Hg), lead (Pb), cadmium (Cd), and copper (Cu) and to investigate the relationships between nutrients (nitrate-nitrogen and phosphate) and dissolved heavy metals. For this purpose, the concentrations of dissolved heavy metals were measured through 51 voyages form 1984 to 2006 in the Yangtze river estuary and its adjacent sea. Results analysis showed that dissolved heavy metals were not the main pollutants in the Yangtze river estuary, and the main source of heavy metal contamination was industrial wastewater from terrestrial pollution during the past 20 years. Heavy metal values showed significant abundance in the south branch of the Yangtze River estuary and Hangzhou Bay. In addition, Pb showed negative correlation with nutrients, while the positive correlations between Hg, Cd, and nutrients were shown. The obtained molar ratios, DeltaCd/DeltaN = 1.68 x 10(-5) and DeltaCd/DeltaP = 1.66 x 10(-4), are close to those in plankton, showing the biogeochemical behavior and process of dissolved cadmium.

  7. Heavy metal removal from MSS fly ash by thermal and chlorination treatments.

    PubMed

    Liu, Jingyong; Chen, Jiacong; Huang, Limao

    2015-01-01

    The thermal behavior of heavy metals in the co-incineration of municipal solid waste-sludge incinerator fly ash (MSS fly ash) was studied using a laboratory-scale tube furnace. The results indicate that without the addition of chlorinating agents, temperature was an important parameter and had significantly influenced on heavy metal removal, whereas the residence time had a weak effect. Between 900 and 1000 °C for 60 to 300 min, heavy metals reacted with chloride-inherent in the fly ash, and approximately 80 to 89% of Pb, 48% to 56% of Cd, 27% to 36% of Zn and 6% to 24% of Cu were removed. After the adding chlorinating agents, the evaporation rate of the heavy metals improved dramatically, where the evaporation rates of Cu and Zn were larger than that of Pb and Cd. As the amount of added chlorinating agents increased, the removal rate of heavy metals increased. However, the effect of the type of chlorinating agent on the chlorination of heavy metals differed considerably, where NaCl had the weakest effect on the removal rate of Cu, Cd and Zn. In terms of resource recovery and decontamination, MgCl2 and CaCl2 are the best choices due to their efficient removal of Zn. PMID:26602592

  8. Does Diffusion Sequester Heavy Metals in Old Contamination Soils?

    NASA Astrophysics Data System (ADS)

    Ma, J.; Jennings, A. A.

    2002-12-01

    Old soil contamination refers to soil contamination that has aged over a long period of time. For example, at some brownfields, the soil heavy metal contamination can be one hundred or more years old. When contamination is young, the heavy metals are bound relatively weakly to the soil. However, the speciation and/or mechanisms of association evolve with aging into much more stable forms. It also appears that the metals migrate deeper into the bulk soil matrix where they are less available to participate in surface-related phenomena. Previous research showed elevated heavy metal extraction result after the soil was pulverized, with all other experiment conditions remaining unchanged. This indicates the presence of sequestered heavy metal contamination within the large soil particles (aggregate). The mechanisms of sequestering are uncertain, but diffusion appears to be a major factor. There are two possible pathways of diffusion that can account for heavy metal sequestering: solid-state diffusion through the bulk aggregate or liquid-phase diffusion through micro-pores within the aggregate structure. The second diffusion mechanism can be coupled with sorption (or other surface-related phenomena) on the pore walls. The remediation of sequestered heavy metals is also impacted by diffusion. Grinding a soil significantly reduces its average particle size. This exposes more of its internal bulk volume to extraction and results in much shorter diffusion pathway for the sequestered heavy metals to be released. Evidence has illustrated that this both improves remediation efficiency and provides a method by which the degree of sequestering can be quantified. This paper will present the results of ongoing research that is developing methods to identify the mechanisms of, quantify the magnitude of and determine the relative importance of (i.e. risk analysis) heavy metals sequestered in old contamination soils.

  9. 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.

  10. 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

  11. 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.

  12. Heavy-metal complexation by de novo peptide design.

    PubMed

    Farrer, Brian T; Pecoraro, Vincent L

    2002-11-01

    From poisoning caused by lead-based paint on domestic buildings to groundwater contamination by naturally occurring arsenic deposits in India, heavy-metal toxicity is a global health problem. Contaminated ground water and acute cases of heavy-metal poisoning are treated with chelators to remove the heavy metals from the contaminated site or person. This review discusses the effort to generate heavy-metal chelators through peptide de novo design. De novo design entails the design of a primary sequence that will precisely fold into a predetermined secondary and tertiary protein structure. The first-generation peptide chelator used to initiate this investigation is the three-stranded coild coil containing Cys. Cys provides a potential trigonal binding site with soft thiolate ligands, which has been proposed to provide specific interactions with heavy metals. This hypothesis derives from the observation that similar sites on natural proteins show selectivity for heavy metals over other essential metals, such as Zn or Mg. A description of two systems, the TRI series and the IZ-AC peptide, is given, highlighting the interaction of these peptides with Hg, Cd, As and Pb. Arguments are also presented for the potential use of three-helix bundles as a second-generation design.

  13. Collective Motion of Humans in Mosh and Circle Pits at Heavy Metal Concerts

    NASA Astrophysics Data System (ADS)

    Silverberg, Jesse L.; Bierbaum, Matthew; Sethna, James P.; Cohen, Itai

    2013-05-01

    Human collective behavior can vary from calm to panicked depending on social context. Using videos publicly available online, we study the highly energized collective motion of attendees at heavy metal concerts. We find these extreme social gatherings generate similarly extreme behaviors: a disordered gaslike state called a mosh pit and an ordered vortexlike state called a circle pit. Both phenomena are reproduced in flocking simulations demonstrating that human collective behavior is consistent with the predictions of simplified models.

  14. Modeling of the distribution of heavy metals and trace elements in argan forest soil and parts of argan tree.

    PubMed

    Mohammed, Faez A E; Bchitou, Rahma; Boulmane, Mohamed; Bouhaouss, Ahmed; Guillaume, Dominique

    2013-01-01

    The transfer of heavy metals and trace elements from argan forest soil into the wood, leaves, almonds, and argan oil was studied. Analyzed metals were: chromium, cadmium, copper, zinc, lead, calcium, phosphorus, potassium, and magnesium. Correlations linking different behaviors of the studied heavy metals and trace elements observed by multidimensional analysis were attributed to partial-spatial variations. Whereas the RV-coefficient of wood, leaf, almond and oil groups was high, the soil group correlated poorly with the other groups.

  15. Validation of laboratory versus field avoidance behavior of schooling fathead minnows to heavy metal blends relative to acute toxicity during long term exposure

    SciTech Connect

    Hartwell, S.I.

    1985-01-01

    Avoidance and toxicity of four metals (relative proportions: 1.00 copper, 0.54 chromium, 1.85 arsenic, 0.38 selenium) were determined for schools of fathead minnows (Pimephalese promelas) in laboratory chamber, artificial stream and natural stream settings during continuous exposure to the metal blend. Laboratory avoidance responses were determined seasonally in a steep-gradient, laminar-flow chamber. Unexposed fish avoided 29 ug/L total metals. Fish exposed to 49 ug/L total metals for 3 months failed to avoid concentrations up to 245 ug/L total metals. Activity was not affected by long term exposure. Artificial stream avoidance responses were determined seasonally during 7 months of field laboratory holding in New River water for unexposed (control) fish and exposed (98 ug/L total metals) fish. In-stream avoidance responses were determined in the summer for unexposed (control) and exposed (98 ug/L total metals) fish in a second order tributary to the New River. Hardness, turbidity and physical setting are implicated as possible causative factors for differences between control fish responses tested in different seasons and locations. Laboratory exposed fish had a 96-hr LC50 1.25x higher than laboratory control fish. Control fish avoided metals levels at 0.4% of their 96-hr LC50. Field exposed fish had a 96-hr LC50 value 1.41x higher than field controls. Field control fish avoided metals levels between 0.7 and 2.5% of their 96-hr LC50 depending upon test location and season. There was no difference between the 96-hr LC50s of laboratory vs field control fish or between laboratory vs field exposed fish.

  16. 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

  17. HEAVY METAL CONCENTRATION OF SOIL IN THE REGIONAL CITY PLAYGROUNDS

    NASA Astrophysics Data System (ADS)

    Nakagawa, Kei; Tsuzuki, Megumi; Asakura, Hiroshi

    It seems important to examine heavy metal concentration in playgrounds, to evaluate potential risk for heavy metal ingestion by children. In this study, heavy metal concentrations of soil samples in 40 playgrounds in K-city were investigated by the voltammetric method. To visualize heavy metal concentration distribution in playgrounds, free GIS software MANDARA was used. According to the comparison between the 1 N HCl dissolved concentration and the PTWI (Provisional Tolerable Weekly Intake), playgrounds in K-city may not have intake risk of lead. Even if the possibility of the risk was very low, there are differences of the intensities. As for the specific playground where concentration is high, investigating continuously may be desirable hereafter.

  18. 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.

  19. 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.

  20. 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...

  1. 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. PMID:27131999

  2. 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.

  3. 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.

  4. 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.

  5. Disposal of heavy metal waste sludges in ceramic products

    SciTech Connect

    Wolfe, T.D.

    1990-06-01

    The report gives the results of a laboratory investigation of the feasibility of incorporating heavy metal waste sludges into ceramic products. Samples were fabricated by combining heavy metal waste sludges with bricks, roof tile, or vitrified clay pipe. The samples were then tested, using standard leaching tests. Test methods and results are presented and large scale process details are given. Detailed cost data were given for using waste and not using waste in the process to enable a comparison.

  6. 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.

  7. 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.

  8. 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. PMID:27046140

  9. Removal and recovery of heavy metals from incinerator ash residues

    SciTech Connect

    Forrester, K.E.

    1997-12-01

    This paper presents results of a novel and state-of-the-art patent-pending processes developed jointly by Forrester Environmental Services Inc. (FESI) and Brookhaven National Laboratories (BNL) for the extraction and recovery of lead (Pb), Cadmium (Cd), Copper (Cu), Zinc (Zn) and other heavy metals from heavy metal bearing wastes including but not limited to solid waste incinerator bottom ash, flyash and combined ash. The heavy metal extraction and recovery processes were found to be capable of high percentage of heavy metals extraction and recovery at a relatively low cost under bench scale and full-scale refuse incinerator facility conditions. This paper presents empirical data from bench scale studies only, as the full-scale data is currently under review. The ash product remaining after extraction passed all TCLP regulatory limits and retained only minimal Pb, Cd, Cu, and Zn content and other water insoluble heavy metal compounds. Results of heavy metals recovery and low cost from ongoing field applications of this technology are consistent with the bench scale data presented within this paper.

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

    PubMed

    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. 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

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

    PubMed

    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.

  13. Individual and competitive removal of heavy metals using capacitive deionization.

    PubMed

    Huang, Zhe; Lu, Lu; Cai, Zhenxiao; Ren, Zhiyong Jason

    2016-01-25

    This study presents the viability and preference of capacitive deionization (CDI) for removing different heavy metal ions in various conditions. The removal performance and mechanisms of three ions, cadmium (Cd(2+)), lead (Pb(2+)) and chromium (Cr(3+)) were investigated individually and as a mixture under different applied voltages and ion concentrations. It was found that CDI could effectively remove these metals, and the performance was positively correlated with the applied voltage. When 1.2 V was applied into solution containing 0.5mM individual ions, the Cd(2+), Pb(2+), and Cr(3+) removal was 32%, 43%, and 52%, respectively, and the electrosorption played a bigger role in Cd(2+) removal than for the other two ions. Interestingly, while the removal of Pb(2+) and Cr(3+) remained at a similar level of 46% in the mixture of three ions, the Cd(2+) removal significantly decreased to 14%. Similar patterns were observed when 0.05 mM was used to simulate natural contaminated water condition, but the removal efficiencies were much higher, with the removal of Pb(2+), Cr(3+), and Cd(2+) increased to 81%, 78%, and 42%, respectively. The low valence charge and lack of physical sorption of Cd(2+) were believed to be the reason for the removal behavior, and advanced microscopic analysis showed clear deposits of metal ions on the cathode surface after operation.

  14. Soil reclamation by municipal sewage compost: Heavy metals migration study.

    PubMed

    Kowalkowski, Tomasz; Buszewski, Bogusław

    2009-04-01

    This paper describes sorption and transport phenomena of selected heavy metals (e.g., Pb, Zn, Ni and Cu) in the superficial layer of soil and sewage sludge compost. The main aim of the study was the investigation of possibility of heavy metals contamination in soil profile reclaimed by sewage sludge compost. The column leaching test as well as the sequential Tessier extraction procedure were applied to investigate the mitigation of heavy metals. The results revealed that distribution of metals in specific Tessier fractions was the major factor influencing their transport in the investigated soils profiles. Moreover, sorption capacity of the soil sample studied was substantially greater to prevent transportation of metals into the lower horizons and groundwater.

  15. Heavy metal chelation in neurotoxic exposures.

    PubMed

    Jang, David H; Hoffman, Robert S

    2011-08-01

    Metals such as iron and copper are critical to living organisms, whereas other metals such as lead and arsenic have no known biologic role. Any metals in large amounts may cause toxicity. Many metals cause pervasive systemic effects involving the nervous system, which can be subtle in some cases. Although challenging, the diagnosis and treatment of metal poisoning can be made based on history, physical examination, and the proper use of metal testing. This article focuses on the use, and misuse, of chelation in the diagnosis and management of metal intoxication. PMID:21803213

  16. 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.

  17. Removal of Trichloroethylene and Heavy Metals by Zerovalent Iron Nanoparticles

    NASA Astrophysics Data System (ADS)

    Boparai, H. K.; O'Carroll, D. M.

    2009-05-01

    Heavy metals combined with chlorinated solvents are one class of mixed waste found at various hazardous waste sites in North America. Nano zerovalent iron (nZVI), an emerging technology, is being successfully used for treating chlorinated solvents and heavy metals independently, however comparatively little research has investigated the remediation of the wastes when they are present in the same mixture. The remediation of trichloroethylene (TCE)/heavy metal waste mixtures via nZVI has been investigated in the present study. Results suggest that some metals are reduced by nZVI to their zerovalent state and thus precipitate on nZVI particles. This improves the contaminant removal performance of nZVI by forming bimetallic iron nanoparticles. Other metals are directly precipitated or adsorbed on the nZVI particles in their original oxidation state and are rendered immobile. In some cases the presence of the heavy metals in the waste mixture enhanced the dechlorination of TCE while in other cases it did not. This study suggests that nano zerovalent iron particles can be effectively used for the remediation of mixed contamination of heavy metals and chlorinated solvents. Results have been supported by a variety of techniques including X-ray photoelectron spectroscopy (XPS) analysis.

  18. 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. PMID:27127923

  19. 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.

  20. The Relationship between Heavy Metal and Rap Music and Adolescent Turmoil: Real or Artifact?

    ERIC Educational Resources Information Center

    Took, Kevin J.; Weiss, David S.

    1994-01-01

    Investigated association between 87 adolescents' music preferences and psychosocial turmoil. Adolescents who preferred heavy metal and rap music had higher incidence of below-average school grades, school behavior problems, sexual activity, drug and alcohol use, and arrests. When gender was controlled, only below-average school grades and history…

  1. Aquatic snails from mining sites have evolved to detect and avoid heavy metals.

    PubMed

    Lefcort, H; Abbott, D P; Cleary, D A; Howell, E; Keller, N C; Smith, M M

    2004-05-01

    Toxicants in polluted environments are often patchily distributed. Hence, rather than being passive absorbers of pollution, some organisms have evolved the ability to detect and avoid toxicants. We studied the avoidance behavior of Physella columbiana, an aquatic pulmonate snail, in a pond that has been polluted with heavy metals for more than 120 years. Populations of this snail are rare at reference sites and are only robust at heavy-metal-polluted sites. We hypothesized that the snails are able to persist because they have evolved the ability to minimize their exposure to metals by actively avoiding metals in their environment. Using a Y-maze flow tank, we tested the avoidance behavior of snails to heavy-metal-polluted sediments and single-metal solutions of cadmium, zinc, or lead. We also tested the avoidance behaviors of the snails' laboratory-reared offspring raised in nonpolluted conditions. In addition, we tested the avoidance behavior of a small population of snails from a reference pond. Although all the snails we tested were able to detect low concentrations of heavy metals, we found that snails from the polluted site were the most sensitive, that their offspring were somewhat less sensitive, and that snails from the reference site were the least sensitive. This suggests that the ability of polluted-site snails to avoid heavy metals is both genetic and environmental. The concentrations of metals avoided by the snails from the polluted site were below the levels found at hot spots within their natal pond. The snails may be able to persist at this site because they decrease their exposure by moving to less-polluted sections of the pond. One application of our findings is the use of aquatic snails and our Y-maze design as an inexpensive pollution detector. Environmental pollutants such as lead, zinc, and arsenic are a problem throughout the world. People in underdeveloped countries often lack sophisticated pollution detection devices. We have developed a

  2. 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. PMID:26832725

  3. 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.

  4. [Carbonization of heavy metal Cu implanted sewage sludge and stability of heavy metal in the resulting char].

    PubMed

    Dou, Xiao-Min; Chen, De-Zhen; Dai, Xiao-Hu

    2014-11-01

    In this research, a new method for sewage sludge (SS) disposal was introduced, by which heavy metals were implanted into sewage sludge before pyrolysis. Cu was adopted as the representative of heavy metals to test this process and was implanted in the form of CuCl2. Effects of Cu implanting concentration and reaction temperature on the residual ratio and immobilization of heavy metals in pyrolysis char were studied. Meanwhile, two leaching methods were employed with the purpose to determine the maximum capacity of heavy metal immobilization in the char. The primary research results showed that when the Cu implanting concentration was 0.5% (mass fraction), more than 90% of Cu remained in the char after carbonization, and the leachability of heavy metals in the char was related to pyrolysis temperature. Cu leaching from the char increased with increasing pyrolysis temperature. There was also a limitation for Cu implanting concentration in the sewage sludge, which was determined by the destination of the pyrolyzed char. If it went to sanitary landfill, the limitation would be 0.5%. The primary results showed that sewage sludge could be kneaded with other wastes containing heavy metals before pyrolysis to achieve co-processing. PMID:25639117

  5. 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.

  6. 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. PMID:25919648

  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. 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.

  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. 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.

  13. Competitive adsorption of heavy metals onto sesame straw biochar in aqueous solutions.

    PubMed

    Park, Jong-Hwan; Ok, Yong Sik; Kim, Seong-Heon; Cho, Ju-Sik; Heo, Jong-Soo; Delaune, Ronald D; Seo, Dong-Cheol

    2016-01-01

    Objective of this research was to evaluate adsorption of heavy metals in mono and multimetal forms onto sesame straw biochar (SSB). Competitive sorption of metals by SSB has never been reported previously. The maximum adsorption capacities (mgg(-1)) of metals by SSB were in the order of Pb (102)≫Cd (86)≫Cr (65)>Cu (55)≫Zn (34) in the monometal adsorption isotherm and Pb (88)≫Cu (40)≫Cr (21)>Zn (7)⩾Cd (5) in the multimetal adsorption isotherm. Based on data obtained from the distribution coefficients, Freundlich and Langmuir adsorption models, and three-dimensional simulation, multimetal adsorption behaviors differed from monometal adsorption due to competition. Especially, during multimetal adsorption, Cd was easily exchanged and substituted by other metals. Further competitive adsorption studies are necessary in order to accurately estimate the heavy metal adsorption capacity of biochar in natural environments.

  14. Transport and deposition of heavy metals in the Ross Sea Region, Antarctica

    NASA Astrophysics Data System (ADS)

    Tuohy, Andrea; Bertler, Nancy; Neff, Peter; Edwards, Ross; Emanuelsson, Daniel; Beers, Thomas; Mayewski, Paul

    2015-10-01

    Emissions and long-range transport of toxic metals and metalloids pose a global threat to ecosystems and human health. Global industrialization occurring from the late nineteenth century releases large quantities of pollutants into the Earth's atmosphere. Despite international efforts to mitigate emissions, accumulation of metals is still observed in the most remote regions of the planet. New baseline studies are needed to determine (i) natural background concentration of pollutants, (ii) contributions of anthropogenic emissions, and (iii) potential remobilization of previously deposited metals. Constructing such records requires distinguishing source strength from transport efficiency to the recording site and accounting for local depositional effects. Here we investigate the sensitivity and representation of Southern Hemisphere atmospheric concentrations of heavy metals (Fe, Al, Mn, Pb, Tl, and As) in the Roosevelt Island Climate Evolution (RICE) ice core, a new coastal Antarctic ice core site. Concentration variability with precipitation is explored in daily surface snow samples collected over 70 days, while seasonal deposition is investigated through snow pit sampling. We find that snow sample concentrations increase with particular snow precipitation types (rime and fog) and enhanced meridional atmospheric transport to the site. Snow pit heavy metals peak in summer and also show variable intraannual peaks. Seasonal airmass modeling based on ERA Interim reanalysis data indicates a synoptic shift during the spring and summer months. We conclude that modern heavy metal concentrations are influenced by transport efficiency and scavenging behavior; and thus, time series records from RICE have the potential to provide representative data of regional changes in heavy metals.

  15. Biogeochemistry of heavy metals in contaminated excessively moistened soils (Analytical review)

    NASA Astrophysics Data System (ADS)

    Vodyanitskii, Yu. N.; Plekhanova, I. O.

    2014-03-01

    The biogeochemical behavior of heavy metals in contaminated excessively moistened soils depends on the development of reducing conditions (either moderate or strong). Upon the moderate biogenic reduction, Cr as the metal with variable valence forms low-soluble compounds, which decreases its availability to plants and prevents its penetration into surface- and groundwater. Creation of artificial barriers for Cr fixation on contaminated sites is based on the stimulation of natural metal-reducing bacteria. Arsenic, being a metalloid with a variable valence, is mobilized upon the moderate biogenic reduction. The mobility of siderophilic heavy metals with a constant valence grows under the moderate reducing conditions at the expense of dissolution of iron (hydr)oxides as carriers of these metals. Zinc, which can enter the newly formed goethite lattice, is an exception. Strong reduction processes in organic excessively moist and flooded soils (usually enriched in S) lead to the formation of low-soluble sulfides of heavy elements with both variable (As) and constant (Cu, Ni, Zn, and Pb) valence. On changing aquatic regime in overmoistened soils and their drying, sulfides of heavy metals are oxidized, and previously fixed metals are mobilized.

  16. Behavior of metal ions in bioelectrochemical systems: A review

    NASA Astrophysics Data System (ADS)

    Lu, Zhihao; Chang, Dingming; Ma, Jingxing; Huang, Guangtuan; Cai, Lankun; Zhang, Lehua

    2015-02-01

    Bioelectrochemical systems (BESs) have been focused on by many researchers to treat wastewater and recover energy or valuable chemicals from wastes. In BESs, metal ions play an important role in the conductivity of solution, reactors' internal resistance, power generation, chemical production and activity of microorganisms. Additionally, the metal ions are also involved in anodic or cathodic reaction processes directly or indirectly in BESs. This paper reviews the behavior of metal ions in BESs, including (1) increase of the conductivity of electrolyte and decrease of internal resistance, (2) transfer for desalination, (3) enhancement or inhibition of the biocatalysis in anode, (4) improvement of cathodic performance by metal ions through electron acceptance or catalysis in cathodic process and (5) behavior of metal ions on membranes. Moreover, the perspectives of BESs removing heavy metal ions in wastewater or solid waste are discussed to realize recovery, reduction and detoxification simultaneously.

  17. 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

  18. 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.

  19. 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

  20. 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. PMID:24898714

  1. 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.

  2. 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.

  3. [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. PMID:25898680

  4. [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.

  5. 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

  6. 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.

  7. Thermal treatment of harzardous waste for heavy metal recovery.

    PubMed

    Hoffmann, Gaston; Schirmer, Matthias; Bilitewski, Bernd; Kaszás Savos, Melania

    2007-07-16

    In this study, a new method for recovering heavy metals from hazardous waste is introduced. The process is characterized by a separation of heavy metals and residues during the thermal treatment under a sub-stoichiometric atmosphere in a rotary kiln. After leaving the rotary kiln the separated heavy metals are precipitated in a hot gas ceramic filter. Using this technology, hazardous materials, both liquids and pasty hazardous waste containing heavy metals, can be treated and a product with a quasi-raw material condition can be formed. In contrast to current methods,the harmful substances should not be immobilized and disposed. In fact, a saleable product highly concentrated with heavy metals should be formed. During preliminary investigations with a solution containing sodium chromate tetrahydrate, the process was tested in a pilot plant. Here,the separation of chromium could be demonstrated with leaching tests and characterization of the filter dust. Analysis concerning the disposability of the residues had not been carried out because only the process and the characteristic of the filter dust were in the centre of attention.

  8. 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. PMID:27318819

  9. Geochemical reconnaissance of heavy metals in kaolin after electrokinetic remediation.

    PubMed

    Al-Hamdan, Ashraf Z; Reddy, Krishna R

    2006-01-01

    The development or implementation of electrokinetic soil remediation technique requires a good knowledge of how the contaminants are retained within the soil-water system. This paper investigates the speciation and extent of migration of the heavy metals, Cr(VI), Cr(III), Ni(II), and Cd(II), during electrokinetic soil remediation. A geochemical assessment of how the contaminants are held within the kaolin soil under induced electric potential is made by using the equilibrium model MINEQL+. The study is performed for three different contaminant cases: the Cr(VI) existing alone in the soil, the Cr(VI) combined with Ni(II) and Cd(II) in the soil, and the Cr(VI) combined with Ni(II) and Cd(II) in the soil in the presence of a reducing agent (sulfide). The adsorption of the studied metals by kaolin was implemented as an electrostatic behavior. FITEQL 4.0 model was used to determine the equilibrium constants of the electrostatic adsorption model of kaolin for the studied metals by optimizing the experimental titration and adsorption data of kaolin. This study showed that the initial speciation of the contaminants in the soil prior to the electrokinetic treatment depends on the type and amounts of contaminants present as well as on the presence of the co-contaminants or any reducing agent. Moreover, the extent of migration of the contaminants is strongly dependent on their initial speciation prior electrokinetic treatment. This study also showed that adsorption and precipitation are the significant hindering mechanisms for the removal of heavy metals from kaolin soil during electrokinetic treatment. The adsorption and precipitation forms of Cr(III), Ni(II), and Cd(II) increased near the cathode and decreased near the anode, whereas the adsorption form of Cr(VI) increased near the anode as well as in the middle region. However, the precipitation form of Cr(III), Ni(II), and Cd(II) as Cr2O3 or Cr(OH)3, Ni(OH)2, and Cd(OH)2, respectively, dominates over their adsorption form

  10. 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.

  11. Heavy Metal Exposure Influences Double Strand Break DNA Repair Outcomes

    PubMed Central

    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. PMID:26966913

  12. Sublethal Toxicity Endpoints of Heavy Metals to the Nematode Caenorhabditis elegans

    PubMed Central

    Wu, Yue; Wang, Qiang; Li, Huixin

    2016-01-01

    Caenorhabditis elegans, a free-living nematode, is commonly used as a model organism in ecotoxicological studies. The current literatures have provided useful insight into the relative sensitivity of several endpoints, but few direct comparisons of multiple endpoints under a common set of experimental conditions. The objective of this study was to determine appropriate sublethal endpoints to develop an ecotoxicity screening and monitoring system. C. elegans was applied to explore the sublethal toxicity of four heavy metals (copper, zinc, cadmium and chromium). Two physiological endpoints (growth and reproduction), three behavioral endpoints (head thrash frequency, body bend frequency and feeding) and two enzymatic endpoints (acetylcholine esterase [AChE] and superoxide dismutase [SOD]) were selected for the assessment of heavy metal toxicity. The squared correlation coefficients (R2) between the responses observed and fitted by Logit function were higher than 0.90 and the RMSE were lower than 0.10, indicating a good significance statistically. There was no significant difference among the half effect concentration (EC50) endpoints in physiological and behavioral effects of the four heavy metals, indicating similar sensitivity of physiological and behavioral effects. AChE enzyme was more sensitive to copper, zinc, and cadmium than to other physiological and behavioral effects, and SOD enzyme was most sensitive to chromium. The EC50 of copper, zinc, and cadmium, to the AChE enzyme in the nematodes were 0.68 mg/L, 2.76 mg/L, and 0.92 mg/L respectively and the EC50 of chromium to the SOD enzyme in the nematode was 1.58 mg/L. The results of this study showed that there was a good concentration-response relationship between all four heavy metals and the sublethal toxicity effects to C. elegans. Considering these sublethal endpoints in terms of simplicity, accuracy, repeatability and costs of the experiments, feeding is the relatively ideal sublethal toxicity endpoint of

  13. Sublethal Toxicity Endpoints of Heavy Metals to the Nematode Caenorhabditis elegans.

    PubMed

    Jiang, Ying; Chen, Jiandong; Wu, Yue; Wang, Qiang; Li, Huixin

    2016-01-01

    Caenorhabditis elegans, a free-living nematode, is commonly used as a model organism in ecotoxicological studies. The current literatures have provided useful insight into the relative sensitivity of several endpoints, but few direct comparisons of multiple endpoints under a common set of experimental conditions. The objective of this study was to determine appropriate sublethal endpoints to develop an ecotoxicity screening and monitoring system. C. elegans was applied to explore the sublethal toxicity of four heavy metals (copper, zinc, cadmium and chromium). Two physiological endpoints (growth and reproduction), three behavioral endpoints (head thrash frequency, body bend frequency and feeding) and two enzymatic endpoints (acetylcholine esterase [AChE] and superoxide dismutase [SOD]) were selected for the assessment of heavy metal toxicity. The squared correlation coefficients (R2) between the responses observed and fitted by Logit function were higher than 0.90 and the RMSE were lower than 0.10, indicating a good significance statistically. There was no significant difference among the half effect concentration (EC50) endpoints in physiological and behavioral effects of the four heavy metals, indicating similar sensitivity of physiological and behavioral effects. AChE enzyme was more sensitive to copper, zinc, and cadmium than to other physiological and behavioral effects, and SOD enzyme was most sensitive to chromium. The EC50 of copper, zinc, and cadmium, to the AChE enzyme in the nematodes were 0.68 mg/L, 2.76 mg/L, and 0.92 mg/L respectively and the EC50 of chromium to the SOD enzyme in the nematode was 1.58 mg/L. The results of this study showed that there was a good concentration-response relationship between all four heavy metals and the sublethal toxicity effects to C. elegans. Considering these sublethal endpoints in terms of simplicity, accuracy, repeatability and costs of the experiments, feeding is the relatively ideal sublethal toxicity endpoint of

  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. PMID:23744838

  15. 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.

  16. Effect of Heavy Metals in Plants of the Genus Brassica.

    PubMed

    Mourato, Miguel P; Moreira, Inês N; Leitão, Inês; Pinto, Filipa R; Sales, Joana R; Martins, Luisa Louro

    2015-08-04

    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.

  17. Effect of Heavy Metals in Plants of the Genus Brassica.

    PubMed

    Mourato, Miguel P; Moreira, Inês N; Leitão, Inês; Pinto, Filipa R; Sales, Joana R; Martins, Luisa Louro

    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

  18. 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

  19. 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.

  20. Bacterial community structure and function along a heavy metal gradient

    SciTech Connect

    Dean-Ross, D. ); Mills, A.L. )

    1989-08-01

    The response to the planktonic, sediment, and epilithic bacterial communities to increasing concentrations of heavy metals was determined in a polluted river. None of the communities demonstrated a pollution-related effect on bacterial numbers (viable and total), heterotrophic activity, resistance to Pb or Cu, or species diversity as determined by either the Shannon-Wiener diversity index or rarefaction. The lack of correlation between concentrations of heavy metals and resistance in the sediment bacterial community was investigated and found to be due at least in part to the high pH of the river water and the resultant reduction in heavy metal toxicity. The three different communities demonstrated characteristic profiles based on the relative abundances of bacterial strains grouped according to functional similarities.

  1. 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.

  2. Impact of humic/fulvic acid on the removal of heavy metals from aqueous solutions using nanomaterials: a review.

    PubMed

    Tang, Wang-Wang; Zeng, Guang-Ming; Gong, Ji-Lai; Liang, Jie; Xu, Piao; Zhang, Chang; Huang, Bin-Bin

    2014-01-15

    Nowadays nanomaterials have been widely used to remove heavy metals from water/wastewater due to their large surface area and high reactivity. Humic acid (HA) and fulvic acid (FA) exist ubiquitously in aquatic environments and have a variety of functional groups which allow them to complex with metal ions and interact with nanomaterials. These interactions can not only alter the environmental behavior of nanomaterials, but also influence the removal and transportation of heavy metals by nanomaterials. Thus, the interactions and the underlying mechanisms involved warrant specific investigations. This review outlined the effects of HA/FA on the removal of heavy metals from aqueous solutions by various nanomaterials, mainly including carbon-based nanomaterials, iron-based nanomaterials and photocatalytic nanomaterials. Moreover, mechanisms involved in the interactions were discussed and potential environmental implications of HA/FA to nanomaterials and heavy metals were evaluated.

  3. 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. PMID:27159454

  4. 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

  5. Accumulation of heavy metals using Sorghum sp.

    PubMed

    Soudek, Petr; Petrová, Šarka; Vaňková, Radomíra; Song, Jing; Vaněk, Tomaš

    2014-06-01

    The essential requirement for the effective phytoremediation is selection of a plant species which should be metal tolerant, with high biomass production and known agronomic techniques. The above mentioned criteria are met by crop plant sorghum (Sorghum bicolor). The response of hydroponically grown S. bicolor plants to cadmium and zinc stress was followed. The impact of metal application on physiological parameters, including changes in chlorophylls contents and antioxidative enzymes activities, was followed during the stress progression. Cadmium and zinc were accumulated primarily in the roots of sorghum plants. However, elevation of metal concentrations in the media promoted their transfer to the shoots. Toxic effects of metals applied at lower concentrations were less serious in the shoots in comparison with their influence to the roots. When applied at higher concentrations, transfer of the metals into the leaves increased, causing growth reduction and leading to Chl loss and metal-induced chlorosis. Moreover, higher metal levels in the roots overcame the quenching capacity of peroxidase and glutathione transferase, which was associated with reduction of their activities. Fortification of antioxidant system by addition of glutathione significantly increased the accumulation of cadmium in the roots as well as in the shoots at the highest cadmium concentration applied.

  6. 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

  7. 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

  8. 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

  9. Brassinosteroids and Response of Plants to Heavy Metals Action.

    PubMed

    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

  10. [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.

  11. 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

  12. LIBS fiber optic sensor for subsurface heavy metals detection

    NASA Astrophysics Data System (ADS)

    Saggese, Steven J.; Greenwell, Roger A.

    1996-12-01

    Laser induced breakdown spectroscopy (LIBS) is being used to detect heavy metal concentrations in soils. The overall goal of this effort is to develop a field deployable system that will conduct heavy metal subsurface mapping of the vadose zone using a cone penetrometer deployed fiber optic sensor. This paper presents results on the LIBS analysis of different spiked soil samples with the same chemical matrix, NIST soil samples with variable matrices, a comparison of the performance of the LIBS system with free space delivery of the laser beam versus the performance using an optical fiber probe, and the effect of several system parameters on performance.

  13. Brassinosteroids and Response of Plants to Heavy Metals Action.

    PubMed

    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.

  14. Heavy metal concentrations along the Louisiana coastal zone

    SciTech Connect

    Pardue, J.H.; DeLaune, R.D.; Smith, C.J.; Patrick, W.H. Jr.

    1988-01-01

    Cores were taken from seven locations in southern Louisiana and analyzed for concentrations of heavy metals. Sedimentation rates for the locations were determined using the /sup 137/Cs dating technique. Correlations of metals with depth were calculated using absolute, aluminum normalized, and iron normalized concentrations. Correlations indicated recent increases at several sites (Lake Palourde, Manchac Pass, and Wax Lake Outlet) for several metals (Pb, Cd, Cr, Ni, Zn) when profiles were normalized to aluminum. Metal profiles from rapidly-accreting areas (Atchafalaya and Four league Bay) did not show historical increases comparable to areas accreting less rapidly (e.g., Wax Lake Outlet, Manchac Pass, and Lake Palourde).

  15. Can heavy metal pollution defend seed germination against heat stress? Effect of heavy metals (Cu(2+), Cd(2+) and Hg(2+)) on maize seed germination under high temperature.

    PubMed

    Deng, Benliang; Yang, Kejun; Zhang, Yifei; Li, Zuotong

    2016-09-01

    Heavy metal pollution, as well as greenhouse effect, has become a serious threat today. Both heavy metal and heat stresses can arrest seed germination. What response can be expected for seed germination under both stress conditions? Here, the effects of heavy metals (Cu(2+), Cd(2+) and Hg(2+)) on maize seed germination were investigated at 20 °C and 40 °C. Compared with 20 °C, heat stress induced thermodormancy. However, this thermodormancy could be significantly alleviated by the addition of a low concentration of heavy metals. Heavy metals, as well as heat stress induced H2O2 accumulation in germinating seeds. Interestingly, this low concentration of heavy metal that promoted seed germination could be partly blocked by DMTU (a specific ROS scavenger), irrespective of temperature. Accordingly, H2O2 addition reinforced this promoting effect on seed germination, which was induced by a low concentration of heavy metal. Furthermore, we found that the NADPH oxidase derived ROS was required for seed germination promoted by the heavy metals. Subsequently, treatment of seeds with fluridone (a specific inhibitor of ABA) or ABA significantly alleviated or aggravated thermodormancy, respectively. However, this alleviation or aggravation could be partly attenuated by a low concentration of heavy metals. In addition, germination that was inhibited by high concentrations of heavy metals was also partly reversed by fluridone. The obtained results support the idea that heavy metal-mediated ROS and hormone interaction can finally affect the thermodormancy release or not. PMID:27239687

  16. Can heavy metal pollution defend seed germination against heat stress? Effect of heavy metals (Cu(2+), Cd(2+) and Hg(2+)) on maize seed germination under high temperature.

    PubMed

    Deng, Benliang; Yang, Kejun; Zhang, Yifei; Li, Zuotong

    2016-09-01

    Heavy metal pollution, as well as greenhouse effect, has become a serious threat today. Both heavy metal and heat stresses can arrest seed germination. What response can be expected for seed germination under both stress conditions? Here, the effects of heavy metals (Cu(2+), Cd(2+) and Hg(2+)) on maize seed germination were investigated at 20 °C and 40 °C. Compared with 20 °C, heat stress induced thermodormancy. However, this thermodormancy could be significantly alleviated by the addition of a low concentration of heavy metals. Heavy metals, as well as heat stress induced H2O2 accumulation in germinating seeds. Interestingly, this low concentration of heavy metal that promoted seed germination could be partly blocked by DMTU (a specific ROS scavenger), irrespective of temperature. Accordingly, H2O2 addition reinforced this promoting effect on seed germination, which was induced by a low concentration of heavy metal. Furthermore, we found that the NADPH oxidase derived ROS was required for seed germination promoted by the heavy metals. Subsequently, treatment of seeds with fluridone (a specific inhibitor of ABA) or ABA significantly alleviated or aggravated thermodormancy, respectively. However, this alleviation or aggravation could be partly attenuated by a low concentration of heavy metals. In addition, germination that was inhibited by high concentrations of heavy metals was also partly reversed by fluridone. The obtained results support the idea that heavy metal-mediated ROS and hormone interaction can finally affect the thermodormancy release or not.

  17. 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.

  18. Flow analysis of heavy metals in a pilot-scale incinerator for residues from waste electrical and electronic equipment dismantling.

    PubMed

    Long, Yu-Yang; Feng, Yi-Jian; Cai, Si-Shi; Ding, Wei-Xu; Shen, Dong-Sheng

    2013-10-15

    The large amount of residues generated from dismantling waste electrical and electronic equipment (WEEE) results in a considerable environmental burden. We used material flow analysis to investigate heavy metal behavior in an incineration plant in China used exclusively to incinerate residues from WEEE dismantling. The heavy metals tested were enriched in the bottom and fly ashes after incineration. However, the contents of heavy metals in the bottom ash, fly ash and exhaust gas do not have a significant correlation with that of the input waste. The evaporation and recondensation behavior of heavy metals caused their contents to differ with air pollution control equipment because of the temperature difference during gas venting. Among the heavy metals tested, Cd had the strongest tendency to transfer during incineration (TCd=69.5%) because it had the lowest melting point, followed by Cu, Ni, Pb and Zn. The exchangeable and residual fractions of heavy metals increased substantially in the incineration products compared with that of the input residues. Although the mass of residues from WEEE dismantling can be reduced by 70% by incineration, the safe disposal of the metal-enriched bottom and fly ashes is still required. PMID:23973476

  19. Coal burning leaves toxic heavy metal legacy in the Arctic

    PubMed Central

    McConnell, Joseph R.; Edwards, Ross

    2008-01-01

    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 ≈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. PMID:18711138

  20. 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.

  1. Scale factors to quantify and predict the field scale variability of heavy metal sorption in soil

    NASA Astrophysics Data System (ADS)

    Xiao, Han; Boettcher, Juergen; Utermann, Jens

    2013-04-01

    Many studies report the close relationship between heavy metal sorption in soil and physicochemical soil properties. Since 1980s pedotransfer functions (PTF) were developed to predict the heavy metal sorption in soil, based on the Freundlich sorption isotherm with parameters K and n, and physicochemical soil properties. An important application of PTFs is to predict sorption behavior at larger scales (e.g. soil units) from easily measurable soil properties, but PTFs were also applied to predict the spatial variability of sorption at the field scale. A new method to quantify the spatial variability of heavy metal sorption in soils at the field scale is the calculation of scale factors (SF). This method reduces the broad spread of the sorption isotherms into an average relation, but saves the variation through the scale factors. For physicochemical soil properties scale factors can also be calculated. Scale factors from sorption isotherms and physicochemical soil properties are correlated. SF of isotherms are indirectly related to the Freundlich parameters K and n, but PTF directly and solely predict K. That is the reason, why SF in contrast to PTF were found in an earlier study with an acidic sandy soil under forest to increase the accuracy of model predictions. The two prediction methods, SF and PTF, were both evaluated for an agricultural field on a more or less homogeneous Luvisol developed in loess near Hannover, Germany. Samples were taken from the A and B horizon (each 50 samples) along a 250 m transect. Sorption isotherms for heavy metals (Cd, Cu, Pb and Zn) and soil properties as pH, CEC, organic carbon content, texture were measured, and scale factors were calculated. In our contribution we will present results on (1) the accuracy of PTF and SF to predict the field average sorption behavior of the soil, (2) a comparative numerical simulation of field scale heavy metal transport with spatially variable sorption behavior in unsaturated soil described by both

  2. 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.

  3. 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

  4. 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.

  5. 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.

  6. 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.

  7. Flow through luminescence for heavy metal analysis in seawater

    NASA Astrophysics Data System (ADS)

    San Vicente De la Riva, Blanca; Costa Fernandez, Jose M.; Pereiro Garcia, Rosario; Sanz-Medel, Alfredo

    1999-12-01

    The toxicity of heavy metals is well documented today and legislation for their control in seawater continuously becomes more and more restrictive. In order to control and ensure the marine environment quality it is demanded an effort to develop new analytical tools, which allow the analysis of trace levels of heavy metals in seawater. The measurement of luminescence (phosphorescence and fluorescence) gives rise to high sensitive, selective and innovative approaches which could be used to develop new trace metal sensing methods. In this way, we have observed that the metal-chelates formed between different sulphonic-hydroxyquinolines with heavy metals, such as lead, or the metal-chelates between mercury and purines exhibit strong room temperature phosphorescence and fluorescence, respectively. Based on the formation of such quelates, two luminescence methods are investigated for sensing of lead and mercury in seawater. Optimum experimental conditions and the analytical performance characteristics of the methods are discussed. Relative standard deviations in the order of 4% are typical at 100 ng mL-1 of Pb(II) and Hg (II). The detection limits are 0.1 and 1.4 ng mL-1 for lead and mercury, respectively. Possible interferences present in seawater, including sea water cations and anions are evaluated in detail. Finally, the methods are applied to the determination de mercury and lead in seawater samples.

  8. 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

  9. Phytoremediation of heavy metals from soils.

    PubMed

    McIntyre, Terry

    2003-01-01

    Phytoremediation offers owners and managers of metal-contaminated sites an innovative and cost-effective option to address recalcitrant environmental contaminants. The use of plants or plant products to restore or stabilize contaminated sites, collectively known as phytoremediation, takes advantage of the natural abilities of plants to take up, accumulate, store, or degrade organic and inorganic substances. Although not a new concept, phytoremediation is currently being re-examined as an environmentally friendly, cost-effective means of reducing metal contaminated soil and other substrates throughout North America and Europe. Processes include using plants that tolerate and accumulate metals at high levels (phytoextraction) and using plants that can grow under conditions that are toxic to other plants while preventing, for example, soil erosion (phytostabilization). Governments worldwide are establishing research and demonstration programs to use this potential. Environment Canada has developed a database (PHYTOREM) of 775 plants with capabilities to accumulate or hyperaccumulate one or several of 19 key metallic elements. This chapter addresses key research, potential benefits and limitations, and the potential future needs for phytoremediation. Issues related to intellectual property law, commercialization and public acceptance are touched on.

  10. 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. PMID:23247041

  11. 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.

  12. 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. PMID:21505769

  13. 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...

  14. 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...

  15. 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...

  16. Fate of heavy metals and agrochemicals in biochar amended soils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  17. 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...

  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. [Different leaching procedures for heavy metal toxicity of waste PCBs].

    PubMed

    Zhao, Guo-Hua; Huang, Zhuo-Hui; Zheng, Zheng; Luo, Xing-Zhang

    2009-05-15

    The purpose of this paper is to evaluate the hazardous of heavy metals of waste printed circuit boards (PCBs) by using four kinds of methods (GB 5086.1-1997, GB 5086.2-1997 from China and 1311 (TCLP), 1312 (SPLP) from USA), and the four kinds of methods are compared to choose a better way to identify toxicity characteristics of waste PCBs. The results show that the leaching concentrations of heavy metals (Cu, Pb, Ni, Mn, Zn and Fe) in the leachate after TCLP are much higher than that after the other three kinds of methods, the concentration of Pb is over the standards, so the waste PCBs may be the hazardous solid waste, the TCLP could be the appropriate way to assess the heavy metals hazardous characteristics of waste PCBs. The leaching concentrations by the leaching methods used in China are relatively lower, which could be disadvantageous to control the hazardous wastes. The initial pH and particle size of waste PCBs have great effect on the leachability of heavy metals from waste PCBs.

  20. 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.

  1. 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)

  2. 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.

  3. Assessing phytotoxicity of heavy metals in remediated soil.

    PubMed

    Branzini, A; Zubillaga, M S

    2010-01-01

    Copper (Cu), zinc (Zn) and chromium (Cr) are pollutants that usually are accumulated in soils. Their toxicity can be decreased by applying amendments. We proposed to evaluate changes in Cu, Zn, and Cr availability, due to the application of amendments, through chemical analysis and phytotoxicity tests. The phytotoxicity test was carried out using species belonging to Sesbania genus; plant parameters were measured 48, 72, 96, and 168 hours after the start of incubation. The treatments included enriched soil, in addition to biosolid compost and triple superphosphate. Cu and Zn amounts were higher in treatments without amendments, indicating immobilization on the part of these. The amounts of Cr tended to decrease with amendments application. The amendments increased pH values and decreased EC; however, this had no impact on the results. No relationship was found among pH, EC, and plant parameters. Different behaviors were observed. S. virgata showed germination seed delay. In addition, while in S. virgata the IG increased during the assay, in S. punicea it diminished. The application of compost, fertilizer or both combined could be of interest for contaminated soils remediation. The use of chemical analysis and phytotoxicity tests allowed to estimate heavy metal availability and the effect on both Sesbania species. PMID:20734911

  4. Assessing phytotoxicity of heavy metals in remediated soil.

    PubMed

    Branzini, A; Zubillaga, M S

    2010-01-01

    Copper (Cu), zinc (Zn) and chromium (Cr) are pollutants that usually are accumulated in soils. Their toxicity can be decreased by applying amendments. We proposed to evaluate changes in Cu, Zn, and Cr availability, due to the application of amendments, through chemical analysis and phytotoxicity tests. The phytotoxicity test was carried out using species belonging to Sesbania genus; plant parameters were measured 48, 72, 96, and 168 hours after the start of incubation. The treatments included enriched soil, in addition to biosolid compost and triple superphosphate. Cu and Zn amounts were higher in treatments without amendments, indicating immobilization on the part of these. The amounts of Cr tended to decrease with amendments application. The amendments increased pH values and decreased EC; however, this had no impact on the results. No relationship was found among pH, EC, and plant parameters. Different behaviors were observed. S. virgata showed germination seed delay. In addition, while in S. virgata the IG increased during the assay, in S. punicea it diminished. The application of compost, fertilizer or both combined could be of interest for contaminated soils remediation. The use of chemical analysis and phytotoxicity tests allowed to estimate heavy metal availability and the effect on both Sesbania species.

  5. 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.

  6. 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. PMID:17295113

  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. 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. PMID:25501861

  9. 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.

  10. 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.

  11. 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.

  12. Lake sediments as indicators of heavy-metal pollution.

    PubMed

    Förstner, U

    1976-10-01

    Heavy metals are one of the most toxic forms of environmental pollutants, constituting a threat both to aquatic life and the quality of drinking water. By analyzing lake sediments, it is possible to determine the provenance, distribution, extent, and also the possible hazards of metal contamination. Sedimentary cores, in particular, provide the means for evaluating the different influences from natural and civilizational sources; they represent a historical record of the metal accumulations which have taken place during the past decades as a result of population growth and industrial development. PMID:790198

  13. Simultaneous heavy metal removal mechanism by dead macrophytes.

    PubMed

    Miretzky, Patricia; Saralegui, Andrea; Fernández Cirelli, Alicia

    2006-01-01

    The use of dead, dried aquatic plants, for water removal of metals derived from industrial activities as a simple biosorbent material has been increasing in the last years. The mechanism of simultaneous metal removal (Cd2+, Ni2+, Cu2+, Zn2+ and Pb2+) by 3 macrophytes biomass (Spirodela intermedia, Lemna minor and Pistia stratiotes) was investigated. L. minor biomass presented the highest mean removal percentage and P. stratiotes the lowest for all metals tested. Pb2+ and Cd2+ were more efficiently removed by the three of them. The simultaneous metal sorption data were analysed according to Langmuir and Freundlich isotherms. Data fitted the Langmuir model only for Ni and Cd, but Freundlich isotherm for all metals tested, as it was expected. The K(F) values showed that Pb was the metal more efficiently removed from water solution. The adsorption process for the three species studied followed first order kinetics. The mechanism involved in biosorption resulted ion exchange between monovalent metals as counter ions present in the macrophytes biomass and heavy metal ions and protons taken up from water. No significant differences were observed in the metal exchange amounts while using multi-metal or individual metal solutions.

  14. CONSTRUCTED WETLANDS FOR TREATMENT OF HEAVY METALS IN URBAN STORMWATER RUNOFF: CHEMICAL SPECIATION OF WETLAND SEDIMENTS

    EPA Science Inventory

    Heavy metals in urban stormwater runoff are primarily removed by sedimentation in stormwater best management practices (BMPs) such as constructed wetlands. Heavy metals accumulated in wetland sediments may be potentially toxic to benthic invertebrates and aquatic microorganisms, ...

  15. A sensitive rapid on-site immunoassay for heavy metal contamination

    SciTech Connect

    Blake, R.; Blake, D.; Flowers, G.

    1996-05-02

    This project concerns the development of immunoassays for heavy metals that will permit the rapid on-site analysis of specific heavy metals, including lead and chromium in water and soil samples. 2 refs.

  16. [Influence of epiphysectomy on biochemical changes caused by heavy metal salts].

    PubMed

    El'bek'ian, K S

    2006-01-01

    10-days exposure of rats to studied combination of heavy metal salts caused intoxication manifesting through considerable biochemical changes. Epiphysis removal promotes toxic influence of heavy metal salts. PMID:17089520

  17. Plasma polymer-functionalized silica particles for heavy metals removal.

    PubMed

    Akhavan, Behnam; Jarvis, Karyn; Majewski, Peter

    2015-02-25

    Highly negatively charged particles were fabricated via an innovative plasma-assisted approach for the removal of heavy metal ions. Thiophene plasma polymerization was used to deposit sulfur-rich films onto silica particles followed by the introduction of oxidized sulfur functionalities, such as sulfonate and sulfonic acid, via water-plasma treatments. Surface chemistry analyses were conducted by X-ray photoelectron spectroscopy and time-of-flight secondary ion mass spectroscopy. Electrokinetic measurements quantified the zeta potentials and isoelectric points (IEPs) of modified particles and indicated significant decreases of zeta potentials and IEPs upon plasma modification of particles. Plasma polymerized thiophene-coated particles treated with water plasma for 10 min exhibited an IEP of less than 3.5. The effectiveness of developed surfaces in the adsorption of heavy metal ions was demonstrated through copper (Cu) and zinc (Zn) removal experiments. The removal of metal ions was examined through changing initial pH of solution, removal time, and mass of particles. Increasing the water plasma treatment time to 20 min significantly increased the metal removal efficiency (MRE) of modified particles, whereas further increasing the plasma treatment time reduced the MRE due to the influence of an ablation mechanism. The developed particulate surfaces were capable of removing more than 96.7% of both Cu and Zn ions in 1 h. The combination of plasma polymerization and oxidative plasma treatment is an effective method for the fabrication of new adsorbents for the removal of heavy metals.

  18. Bismuth nanoparticles integration into heavy metal electrochemical stripping sensor.

    PubMed

    Cadevall, Miquel; Ros, Josep; Merkoçi, Arben

    2015-08-01

    Between their many applications bismuth nanoparticles (BiNPs) are showing interest as pre-concentrators in heavy metals detection while being applied as working electrode modifiers used in electrochemical stripping analysis. From the different reported methods to synthesize BiNPs we are focused on the typical polyol method, largely used in these types of metallic and semi-metallic nanoparticles. This study presents the strategy for an easy control of the shape and size of BiNPs including nanocubes, nanosferes and triangular nanostructures. To improve the BiNP size and shape, different reducing agents (ethylene glycol or sodium hypophosphite) and stabilizers (polyvinyl pyrrolidone, PVP, in different amounts) have been studied. The efficiency of BiNPs for heavy metals analysis in terms of detection sensitivity while being used as modifiers of screen-printed carbon electrodes including the applicability of the developed device in real sea water samples is shown. A parallel study between the obtained nanoparticles and their performance in heavy metal sensing has been described in this communication.

  19. Two-stage anaerobic digestion enables heavy metal removal.

    PubMed

    Selling, Robert; Håkansson, Torbjörn; Björnsson, Lovisa

    2008-01-01

    To fully exploit the environmental benefits of the biogas process, the digestate should be recycled as biofertiliser to agriculture. This practice can however be jeopardized by the presence of unwanted compounds such as heavy metals in the digestate. By using two-stage digestion, where the first stage includes hydrolysis/acidification and liquefaction of the substrate, heavy metals can be transferred to the leachate. From the leachate, metals can then be removed by adsorption. In this study, up to 70% of the Ni, 40% of the Zn and 25% of the Cd present in maize was removed when the leachate from hydrolysis was circulated over a macroporous polyacrylamide column for 6 days. For Cu and Pb, the mobilization in the hydrolytic stage was lower which resulted in a low removal. A more efficient two-stage process with improved substrate hydrolysis would give lower pH and/or longer periods with low pH in the hydrolytic stage. This is likely to increase metal mobilisation, and would open up for an excellent opportunity of heavy metal removal. PMID:18359995

  20. Bismuth nanoparticles integration into heavy metal electrochemical stripping sensor.

    PubMed

    Cadevall, Miquel; Ros, Josep; Merkoçi, Arben

    2015-08-01

    Between their many applications bismuth nanoparticles (BiNPs) are showing interest as pre-concentrators in heavy metals detection while being applied as working electrode modifiers used in electrochemical stripping analysis. From the different reported methods to synthesize BiNPs we are focused on the typical polyol method, largely used in these types of metallic and semi-metallic nanoparticles. This study presents the strategy for an easy control of the shape and size of BiNPs including nanocubes, nanosferes and triangular nanostructures. To improve the BiNP size and shape, different reducing agents (ethylene glycol or sodium hypophosphite) and stabilizers (polyvinyl pyrrolidone, PVP, in different amounts) have been studied. The efficiency of BiNPs for heavy metals analysis in terms of detection sensitivity while being used as modifiers of screen-printed carbon electrodes including the applicability of the developed device in real sea water samples is shown. A parallel study between the obtained nanoparticles and their performance in heavy metal sensing has been described in this communication. PMID:25994368

  1. Plasma polymer-functionalized silica particles for heavy metals removal.

    PubMed

    Akhavan, Behnam; Jarvis, Karyn; Majewski, Peter

    2015-02-25

    Highly negatively charged particles were fabricated via an innovative plasma-assisted approach for the removal of heavy metal ions. Thiophene plasma polymerization was used to deposit sulfur-rich films onto silica particles followed by the introduction of oxidized sulfur functionalities, such as sulfonate and sulfonic acid, via water-plasma treatments. Surface chemistry analyses were conducted by X-ray photoelectron spectroscopy and time-of-flight secondary ion mass spectroscopy. Electrokinetic measurements quantified the zeta potentials and isoelectric points (IEPs) of modified particles and indicated significant decreases of zeta potentials and IEPs upon plasma modification of particles. Plasma polymerized thiophene-coated particles treated with water plasma for 10 min exhibited an IEP of less than 3.5. The effectiveness of developed surfaces in the adsorption of heavy metal ions was demonstrated through copper (Cu) and zinc (Zn) removal experiments. The removal of metal ions was examined through changing initial pH of solution, removal time, and mass of particles. Increasing the water plasma treatment time to 20 min significantly increased the metal removal efficiency (MRE) of modified particles, whereas further increasing the plasma treatment time reduced the MRE due to the influence of an ablation mechanism. The developed particulate surfaces were capable of removing more than 96.7% of both Cu and Zn ions in 1 h. The combination of plasma polymerization and oxidative plasma treatment is an effective method for the fabrication of new adsorbents for the removal of heavy metals. PMID:25603034

  2. Noninvasive Evaluation of Heavy Metal Uptake and Storage in Micoralgae Using a Fluorescence Resonance Energy Transfer-Based Heavy Metal Biosensor1[C][W][OPEN

    PubMed Central

    Rajamani, Sathish; Torres, Moacir; Falcao, Vanessa; Ewalt Gray, Jaime; Coury, Daniel A.; Colepicolo, Pio; Sayre, Richard

    2014-01-01

    We have developed a fluorescence resonance energy transfer (FRET)-based heavy metal biosensor for the quantification of bioavailable free heavy metals in the cytoplasm of the microalga Chlamydomonas reinhardtii. The biosensor is composed of an end-to-end fusion of cyan fluorescent protein (CFP), chicken metallothionein II (MT-II), and yellow fluorescent protein (YFP). In vitro measurements of YFP/CFP fluorescence emission ratios indicated that the addition of metals to the purified biosensor enhanced FRET between CFP and YFP, consistent with heavy metal-induced folding of MT-II. A maximum YFP/CFP FRET ratio of 2.8 was observed in the presence of saturating concentrations of heavy metals. The sensitivity of the biosensor was greatest for Hg2+ followed by Cd2+ ≈ Pb2+ > Zn2+ > Cu2+. The heavy metal biosensor was unresponsive to metals that do not bind to MT-II (Na+ and Mg2+). When expressed in C. reinhardtii, we observed a differential metal-dependent response to saturating external concentrations (1.6 mm) of heavy metals (Pb2+ > Cd2+) that was unlike that observed for the isolated biosensor (in vitro). Significantly, analysis of metal uptake kinetics indicated that equilibration of the cytoplasm with externally applied heavy metals occurred within seconds. Our results also indicated that algae have substantial buffering capacity for free heavy metals in their cytosol, even at high external metal concentrations. PMID:24368336

  3. Noninvasive evaluation of heavy metal uptake and storage in micoralgae using a fluorescence resonance energy transfer-based heavy metal biosensor.

    PubMed

    Rajamani, Sathish; Torres, Moacir; Falcao, Vanessa; Ewalt Gray, Jaime; Coury, Daniel A; Colepicolo, Pio; Sayre, Richard

    2014-02-01

    We have developed a fluorescence resonance energy transfer (FRET)-based heavy metal biosensor for the quantification of bioavailable free heavy metals in the cytoplasm of the microalga Chlamydomonas reinhardtii. The biosensor is composed of an end-to-end fusion of cyan fluorescent protein (CFP), chicken metallothionein II (MT-II), and yellow fluorescent protein (YFP). In vitro measurements of YFP/CFP fluorescence emission ratios indicated that the addition of metals to the purified biosensor enhanced FRET between CFP and YFP, consistent with heavy metal-induced folding of MT-II. A maximum YFP/CFP FRET ratio of 2.8 was observed in the presence of saturating concentrations of heavy metals. The sensitivity of the biosensor was greatest for Hg2+ followed by Cd2+≈Pb2+>Zn2+>Cu2+. The heavy metal biosensor was unresponsive to metals that do not bind to MT-II (Na+ and Mg2+). When expressed in C. reinhardtii, we observed a differential metal-dependent response to saturating external concentrations (1.6 mm) of heavy metals (Pb2+>Cd2+) that was unlike that observed for the isolated biosensor (in vitro). Significantly, analysis of metal uptake kinetics indicated that equilibration of the cytoplasm with externally applied heavy metals occurred within seconds. Our results also indicated that algae have substantial buffering capacity for free heavy metals in their cytosol, even at high external metal concentrations.

  4. Immobilization of heavy metals by Pseudomonas putida CZ1/goethite composites from solution.

    PubMed

    Chen, XinCai; Chen, LiTao; Shi, JiYan; Wu, WeiXiang; Chen, YingXu

    2008-02-15

    Bacterial-mineral composites are important in the retention of heavy metals due to their large sorption capacity under a wide range of environmental conditions. This study provides the first quantitative comparison of the metal-binding capacities of P. putida CZ1-goethite composite to its individual components. When the same amount (on a dry weight basis) of living and nonliving cells of P. putida CZ1, goethite or their composites was separately exposed to solutions of 0.5 mM Cu(II) and Zn(II) in 0.01 M KNO(3), the living cells removed the largest quantity of heavy metals. The results of calculated metal retention values indicated that the adsorption of goethite to bacteria has not mask or neutralize chemically reactive adsorption sites normally available to metal ions. Moreover, the nonliving cells-goethite composite retained approximately 82% more Zn than that predicted by their individual behavior. The preferential association of Zn with P. putida CZ1 was observed by TEM and EDS analyses of a mixture consisting of the bacteria and goethite. Desorption of Cu and Zn with 1.0M CH(3)COOK solution from P. putida CZ1 and goethite indicated the differences in the functional groups able to bind heavy metals. PMID:17869490

  5. Removal of heavy metals by hybrid electrocoagulation and microfiltration processes.

    PubMed

    Keerthi; Vinduja, V; Balasubramanian, N

    2013-01-01

    This study is based on the investigation of the performance of electrocoagulation (EC), followed by the microfiltration process for heavy metal removal in synthetic model waste water containing Zn2+, Ni2+ and Cd2+ ions. Effects of initial concentration, current density and pH on metal removal were analysed to optimize the EC process. The optimized EC process was then integrated with dead-end microfiltration (MF) and was found that the hybrid process was capable of 99% removal of heavy metals. The cake layer formed over the membrane by the hybrid process was analysed through scanning electron microscope-energy-dispersive X-ray spectroscopy. The particle size analysis of the sludge formed during EC was done to investigate the fouling caused during the process.

  6. Biosynthetic regulation of phytochelatins, heavy metal-binding peptides.

    PubMed

    Hirata, Kazumasa; Tsuji, Naoki; Miyamoto, Kazuhisa

    2005-12-01

    Phytochelatins (PCs) are heavy metal-binding peptides that play important roles in the detoxification of toxic heavy metals and the regulation of intracellular concentrations of essential metals in eukaryotes, including higher plants, fungi, and microalgae. Recently, PC synthase genes in higher plants and fission yeast have been identified and characterized, enabling molecular biological studies to unravel the mechanisms underlying PC synthesis. Moreover, recent routine database searches have unexpectedly identified genes that are similar to plant PC synthase genes in the genomes of worms and some prokaryotes. In this review, we introduce these recent advances in our understanding of the molecular mechanisms for PC biosynthesis and functions in order to supply basic information about the unique and attractive peptides applicable to various fields.

  7. Intelligent potentiostat for identification of heavy metals in situ

    NASA Astrophysics Data System (ADS)

    Christidis, K.; Gow, K.; Robertson, P.; Pollard, P.

    2006-01-01

    This article presents a low-cost portable electrochemical instrument capable of on-site identification of heavy metals. The instrument acquires metal-specific voltage and current signals by the application of differential pulse anodic stripping voltammetry. This technique enhances the analytical current and rejects the background current, resulting in a higher signal-to-noise ratio for a better detection limit. The identification of heavy metals is based on an intelligent machine-based method using a multilayer perceptron neural network consisting of three layers of neurons. The neural network is implemented using a 16 bit microcontroller. The system is developed for use in the field in order to avoid expensive and time-consuming procedures and can be used in a variety of situations to help environmental assessment and control.

  8. Deformation Behavior of Nanoporous Metals

    SciTech Connect

    Biener, J; Hodge, A M; Hamza, A V

    2007-11-28

    Nanoporous open-cell foams are a rapidly growing class of high-porosity materials (porosity {ge} 70%). The research in this field is driven by the desire to create functional materials with unique physical, chemical and mechanical properties where the material properties emerge from both morphology and the material itself. An example is the development of nanoporous metallic materials for photonic and plasmonic applications which has recently attracted much interest. The general strategy is to take advantage of various size effects to introduce novel properties. These size effects arise from confinement of the material by pores and ligaments, and can range from electromagnetic resonances to length scale effects in plasticity. In this chapter we will focus on the mechanical properties of low density nanoporous metals and how these properties are affected by length scale effects and bonding characteristics. A thorough understanding of the mechanical behavior will open the door to further improve and fine-tune the mechanical properties of these sometimes very delicate materials, and thus will be crucial for integrating nanoporous metals into products. Cellular solids with pore sizes above 1 micron have been the subject of intense research for many years, and various scaling relations describing the mechanical properties have been developed.[4] In general, it has been found that the most important parameter in controlling their mechanical properties is the relative density, that is, the density of the foam divided by that of solid from which the foam is made. Other factors include the mechanical properties of the solid material and the foam morphology such as ligament shape and connectivity. The characteristic internal length scale of the structure as determined by pores and ligaments, on the other hand, usually has only little effect on the mechanical properties. This changes at the submicron length scale where the surface-to-volume ratio becomes large and the effect

  9. Toxicity, mechanism and health effects of some heavy metals

    PubMed Central

    Jaishankar, Monisha; Tseten, Tenzin; Anbalagan, Naresh; Beeregowda, Krishnamurthy N.

    2014-01-01

    Heavy metal toxicity has proven to be a major threat and there are several health risks associated with it. The toxic effects of these metals, even though they do not have any biological role, remain present in some or the other form harmful for the human body and its proper functioning. They sometimes act as a pseudo element of the body while at certain times they may even interfere with metabolic processes. Few metals, such as aluminium, can be removed through elimination activities, while some metals get accumulated in the body and food chain, exhibiting a chronic nature. Various public health measures have been undertaken to control, prevent and treat metal toxicity occurring at various levels, such as occupational exposure, accidents and environmental factors. Metal toxicity depends upon the absorbed dose, the route of exposure and duration of exposure, i.e. acute or chronic. This can lead to various disorders and can also result in excessive damage due to oxidative stress induced by free radical formation. This review gives details about some heavy metals and their toxicity mechanisms, along with their health effects. PMID:26109881

  10. Phytoremediation potential of Lemna minor L. for heavy metals.

    PubMed

    Bokhari, Syeda Huma; Ahmad, Iftikhar; Mahmood-Ul-Hassan, Muhammad; Mohammad, Ashiq

    2016-01-01

    Phytoremediation potential of L. minor for cadmium (Cd), copper (Cu), lead (Pb), and nickel (Ni) from two different types of effluent in raw form was evaluated in a glass house experiment using hydroponic studies for a period of 31 days. Heavy metals concentration in water and plant sample was analyzed at 3, 10, 17, 24, and 31 day. Removal efficiency, metal uptake and bio-concentration factor were also calculated. Effluents were initially analyzed for physical, chemical and microbiological parameters and results indicated that municipal effluent (ME) was highly contaminated in terms of nutrient and organic load than sewage mixed industrial effluent (SMIE). Results confirmed the accumulation of heavy metals within plant and subsequent decrease in the effluents. Removal efficiency was greater than 80% for all metals and maximum removal was observed for nickel (99%) from SMIE. Accumulation and uptake of lead in dry biomass was significantly higher than other metals. Bio-concentration factors were less than 1000 and maximum BCFs were found for copper (558) and lead (523.1) indicated that plant is a moderate accumulator of both metals. Overall, L. minor showed better performance from SMIE and was more effective in extracting lead than other metals.

  11. Heavy Metal Stress and Some Mechanisms of Plant Defense Response

    PubMed Central

    Emamverdian, Abolghassem; Ding, Yulong; Mokhberdoran, Farzad; Xie, Yinfeng

    2015-01-01

    Unprecedented bioaccumulation and biomagnification of heavy metals (HMs) in the environment have become a dilemma for all living organisms including plants. HMs at toxic levels have the capability to interact with several vital cellular biomolecules such as nuclear proteins and DNA, leading to excessive augmentation of reactive oxygen species (ROS). This would inflict serious morphological, metabolic, and physiological anomalies in plants ranging from chlorosis of shoot to lipid peroxidation and protein degradation. In response, plants are equipped with a repertoire of mechanisms to counteract heavy metal (HM) toxicity. The key elements of these are chelating metals by forming phytochelatins (PCs) or metallothioneins (MTs) metal complex at the intra- and intercellular level, which is followed by the removal of HM ions from sensitive sites or vacuolar sequestration of ligand-metal complex. Nonenzymatically synthesized compounds such as proline (Pro) are able to strengthen metal-detoxification capacity of intracellular antioxidant enzymes. Another important additive component of plant defense system is symbiotic association with arbuscular mycorrhizal (AM) fungi. AM can effectively immobilize HMs and reduce their uptake by host plants via binding metal ions to hyphal cell wall and excreting several extracellular biomolecules. Additionally, AM fungi can enhance activities of antioxidant defense machinery of plants. PMID:25688377

  12. Heavy metal stress and some mechanisms of plant defense response.

    PubMed

    Emamverdian, Abolghassem; Ding, Yulong; Mokhberdoran, Farzad; Xie, Yinfeng

    2015-01-01

    Unprecedented bioaccumulation and biomagnification of heavy metals (HMs) in the environment have become a dilemma for all living organisms including plants. HMs at toxic levels have the capability to interact with several vital cellular biomolecules such as nuclear proteins and DNA, leading to excessive augmentation of reactive oxygen species (ROS). This would inflict serious morphological, metabolic, and physiological anomalies in plants ranging from chlorosis of shoot to lipid peroxidation and protein degradation. In response, plants are equipped with a repertoire of mechanisms to counteract heavy metal (HM) toxicity. The key elements of these are chelating metals by forming phytochelatins (PCs) or metallothioneins (MTs) metal complex at the intra- and intercellular level, which is followed by the removal of HM ions from sensitive sites or vacuolar sequestration of ligand-metal complex. Nonenzymatically synthesized compounds such as proline (Pro) are able to strengthen metal-detoxification capacity of intracellular antioxidant enzymes. Another important additive component of plant defense system is symbiotic association with arbuscular mycorrhizal (AM) fungi. AM can effectively immobilize HMs and reduce their uptake by host plants via binding metal ions to hyphal cell wall and excreting several extracellular biomolecules. Additionally, AM fungi can enhance activities of antioxidant defense machinery of plants. PMID:25688377

  13. Phytoremediation potential of Lemna minor L. for heavy metals.

    PubMed

    Bokhari, Syeda Huma; Ahmad, Iftikhar; Mahmood-Ul-Hassan, Muhammad; Mohammad, Ashiq

    2016-01-01

    Phytoremediation potential of L. minor for cadmium (Cd), copper (Cu), lead (Pb), and nickel (Ni) from two different types of effluent in raw form was evaluated in a glass house experiment using hydroponic studies for a period of 31 days. Heavy metals concentration in water and plant sample was analyzed at 3, 10, 17, 24, and 31 day. Removal efficiency, metal uptake and bio-concentration factor were also calculated. Effluents were initially analyzed for physical, chemical and microbiological parameters and results indicated that municipal effluent (ME) was highly contaminated in terms of nutrient and organic load than sewage mixed industrial effluent (SMIE). Results confirmed the accumulation of heavy metals within plant and subsequent decrease in the effluents. Removal efficiency was greater than 80% for all metals and maximum removal was observed for nickel (99%) from SMIE. Accumulation and uptake of lead in dry biomass was significantly higher than other metals. Bio-concentration factors were less than 1000 and maximum BCFs were found for copper (558) and lead (523.1) indicated that plant is a moderate accumulator of both metals. Overall, L. minor showed better performance from SMIE and was more effective in extracting lead than other metals. PMID:26114480

  14. Modification of porous starch for the adsorption of heavy metal ions from aqueous solution.

    PubMed

    Ma, Xiaofei; Liu, Xueyuan; Anderson, Debbie P; Chang, Peter R

    2015-08-15

    Porous starch xanthate (PSX) and porous starch citrate (PSC) were prepared in anticipation of the attached xanthate and carboxylate groups respectively forming chelation and electrostatic interactions with heavy metal ions in the subsequent adsorption process. The lead(II) ion was selected as the model metal and its adsorption by PSX and PSC was characterized. The adsorption capacity was highly dependent on the carbon disulfide/starch and citric acid/starch mole ratios used during preparation. The adsorption behaviors of lead(II) ion on PSXs and PSCs fit both the pseudo-second-order kinetic model and the Langmuir isotherm model. The maximum adsorption capacity from the Langmuir isotherm equation reached 109.1 and 57.6 mg/g for PSX and PSC when preparation conditions were optimized, and the adsorption times were just 20 and 60 min, respectively. PSX and PSC may be used as effective adsorbents for removal of heavy metals from contaminated liquid. PMID:25794731

  15. Modification of porous starch for the adsorption of heavy metal ions from aqueous solution.

    PubMed

    Ma, Xiaofei; Liu, Xueyuan; Anderson, Debbie P; Chang, Peter R

    2015-08-15

    Porous starch xanthate (PSX) and porous starch citrate (PSC) were prepared in anticipation of the attached xanthate and carboxylate groups respectively forming chelation and electrostatic interactions with heavy metal ions in the subsequent adsorption process. The lead(II) ion was selected as the model metal and its adsorption by PSX and PSC was characterized. The adsorption capacity was highly dependent on the carbon disulfide/starch and citric acid/starch mole ratios used during preparation. The adsorption behaviors of lead(II) ion on PSXs and PSCs fit both the pseudo-second-order kinetic model and the Langmuir isotherm model. The maximum adsorption capacity from the Langmuir isotherm equation reached 109.1 and 57.6 mg/g for PSX and PSC when preparation conditions were optimized, and the adsorption times were just 20 and 60 min, respectively. PSX and PSC may be used as effective adsorbents for removal of heavy metals from contaminated liquid.

  16. Enhanced mobilization of arsenic and heavy metals from mine tailings by humic acid.

    PubMed

    Wang, Suiling; Mulligan, Catherine N

    2009-01-01

    Arsenic and heavy metal mobilization from mine tailings is an issue of concern as it might pose potential groundwater or ecological risks. Increasing attention recently has been focused on the effects of natural organic matter on the mobility behavior of the toxicants in the environment. Column experiments were carried out in this research study to evaluate the feasibility of using humic acid (HA) to mobilize arsenic and heavy metals (i.e., Cu, Pb and Zn) from an oxidized Pb-Zn mine tailings sample collected from Bathurst, New Brunswick, Canada. Capillary electrophoresis analyses indicated that arsenate [As(V)] was the only extractable arsenic species in the mine tailings and the addition of HA at pH 11 did not incur the oxidation-reduction or methylation reactions of arsenic. A 0.1% HA solution with an initial pH adjusted to 11 was selected as the flushing solution, while distilled water (initial pH adjusted to 11) was used as the control to account for the mobilization of arsenic and the heavy metals by physical mixing and the effect of pH. It was found that the HA could significantly enhance the mobilization of arsenic and heavy metals simultaneously from the mine tailings. After a 70-pore-volume-flushing, the mobilization of arsenic, copper, lead and zinc reached 97, 35, 838 and 224 mg kg(-1), respectively. The mobilization of arsenic and the heavy metals was found to be positively correlated with the mobilization of Fe in the presence of the HA. Moreover, the mobilization of arsenic was also correlated well with that of the heavy metals. The mobilization of co-existing metals to some extent might enhance arsenic mobilization in the presence of the HA by helping incorporate it into soluble aqueous organic complexes through metal-bridging mechanisms. Use of HA in arsenic and heavy metal remediation may be developed as an environmentally benign and possible effective remedial option to reduce and avoid further contamination.

  17. Heavy metal speciation and toxicity characteristics of tannery sludge

    NASA Astrophysics Data System (ADS)

    Juel, Md. Ariful Islam; Chowdhury, Zia Uddin Md.; Ahmed, Tanvir

    2016-07-01

    Heavy metals present in tannery sludge can get mobilized in the environment in various forms and can be a cause for concern for the natural ecosystem and human health. The speciation of metals in sludge provides valuable information regarding their toxicity in the environment and determines their suitability for land application or disposal in landfills. Concentrations of seven heavy metals (Cr, Pb, Cd, Ni, Zn, As and Cu) in tannery sludge were determined to evaluate their toxicity levels. Metal contents ranged over the following intervals: As: 1.52-2.07 mg/kg; Pb: 57.5-67 mg/kg; Cr: 15339-26501 mg/kg; Cu: 261.3-579.5 mg/kg; Zn: 210.2-329.1 mg/kg and Ni: 137.5-141.3 mg/kg (dry weight basis). The concentrations of all heavy metals in the sludge samples were lower compared to EPA guidelines except chromium which was found to be several orders of magnitude higher than the guideline value. Toxicity Characteristics Leaching Procedure (TCLP) test indicated that the leaching potential of chromium was higher compared to the other heavy metals and exceeded the EPA land disposal restriction limits. To quantitatively assess the environmental burden of the chromium associated with tannery sludge, the IMPACT 2002+ methodology was adopted under the SimaPro software environment. Considering the USEPA limit for chromium as the baseline scenario, it was found that chromium in the tannery sludge had 6.41 times higher impact than the baseline in the categories of aquatic ecotoxicity, terrestrial ecotoxicity and non-carcinogens. Chromium has the highest contribution to toxicity in the category of aquatic ecotoxicity while copper is the major contributor to the category of terrestrial ecotoxicity in the tannery sludge.

  18. Bacteria immobilisation on hydroxyapatite surface for heavy metals removal.

    PubMed

    Piccirillo, C; Pereira, S I A; Marques, A P G C; Pullar, R C; Tobaldi, D M; Pintado, M E; Castro, P M L

    2013-05-30

    Selected bacterial strains were immobilised on the surface of hydroxyapatite (Ca10(PO4)6(OH)2 - HAp) of natural origin (fish bones). The capacity of the material, alone and in combination with the bacterial strains to act as heavy metal removers from aqueous streams was assessed. Pseudomonas fluorescens (S3X), Microbacterium oxydans (EC29) and Cupriavidus sp. (1C2) were chosen based on their resistance to heavy metals and capacity of adsorbing the metals. These systems were tested using solutions of Zn(II), Cd(II) and in solutions containing both metals. A synergistic effect between the strains and HAp, which is effective in removing the target heavy metals on its own, was observed, as the combination of HAp with the bacterial strains led to higher adsorption capacity for both elements. For the solutions containing only one metal the synergistic effect was greater for higher metal concentrations; 1C2 and EC29 were the most effective strains for Zn(II) and Cd(II) respectively, while S3X was less effective. Overall, an almost four-fold increase was observed for the maximum adsorption capacity for Zn(II) when 1C2 was employed - 0.433 mmol/g in comparison of 0.121 mmol/g for the unmodified HAp. For Cd(II), on the other hand, an almost three-fold increase was registered with EC29 bacterial strain - 0.090 vs 0.036 mmol/g for the unmodified HAp. When the solutions containing both metals were tested, the effect was more marked for lower concentrations. PMID:23524400

  19. 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.

  20. Concentration of heavy metals in ash produced from Lithuanian forests

    NASA Astrophysics Data System (ADS)

    Baltrenaite, Edita; Pereira, Paulo; Butkus, Donatas; Úbeda, Xavier

    2010-05-01

    Wood ash contains important amounts of heavy metals. This quantity depends on burned specie, temperature of exposition and heat duration time. Due the high mineralization imposed by the temperatures, ash is used as lime product in agriculture and forests. Also, after a forest fire large quantities of ash are produced and distributed in soil surface. This mineralized organic matter can induce important environmental problems, including soil toxicity provoked by heavy metals leachates from ash. There is an extensive literature about heavy metals contents on ash in different species. However, it recently highlighted that the same species placed in different environments can respond diversely to same temperatures. This question is of major importance because temperature effects on severity can be a function of the plant communities instead of specie characteristics. These findings add a higher degree of complexity in the understanding of temperature effects on ash composition and consequent availability of heavy metals. The aim of this study is to compare the ash chemical heavy metal composition, Cobalt (Co), Chromium (Cr), Cooper (Cu), Silver (Ag), Lead (Pb), Nickel (Ni), Manganese (Mn) and Zinc (Zn), from Pinus sylvestris and Betula pendula, collected in key and representative areas of Lithuanian forests, located in southern, coastal and central part. Samples were collected from alive trees, taken to laboratory and air dried. Subsequently were crushed and submitted to muffle furnace at temperature of 550°C during two hours. The ash samples were digested and in a HNO3-HCl solution and then analysed with AAS. Comparisons between species and sites were performed with a Non-parametric one-way ANOVA‘s on rank transformed data followed by Tukey‘s HSD, significant at a p<0.05. Results showed significant difference between Co and Ag concentrations between Pinus sylvestris and Betula pendula. Also, significantly different concentrations of Pb, Cu, Ni and Mn were

  1. Heavy metal enrichment characteristics in ash of municipal solid waste combustion in CO2/O2 atmosphere.

    PubMed

    Tang, YuTing; Ma, XiaoQian; Yu, QuanHeng; Zhang, Can; Lai, Zhiyi; Zhang, Xiaoshen

    2015-09-01

    This paper investigated the behavior of six heavy metals (Cd, Pb, Cu, Cr, Ni and Zn) in the bottom ashes of recycled polyvinyl chloride pellets (PVC), wood sawdust (WS) and paper mixture (PM), representing the common components of municipal solid waste (MSW), obtained during combustion in CO2/O2 atmosphere in a lab-scale electrically heated tube furnace. Replacement of N2 by CO2 did not obviously change the shape of relative enrichment factor (RE) curves and subsequent order of heavy metals, but increased enrichment of these heavy metals in bottom ashes of WS, PM and PVC. The increment of O2 concentration in CO2/O2 atmosphere further increased RE values. It was only when the temperature was higher than or equal to 700°C that the increment of the combustion temperature reduced the RE values of heavy metals. The effect of temperature on heavy metals evaporation was the most pronounced for the medium volatile metal Pb, and the least for the low volatiles Cr and Ni. The effect of temperature was more pronounced for PVC ash than for WS and PM ashes. This paper contributes to the control of heavy metals during MSW incineration and management of MSW oxy-fuel residues. PMID:26130169

  2. [Accumulation of heavy metals in the sediments of Shenzhen Bay, south China].

    PubMed

    Huang, Xiaoping; Li, Xiangdong; Yue, Weizhong; Huang, Liangmin; Li, Yoksheung

    2003-07-01

    Heavy metals concentrations in marine sediment cores of Shenzhen Bay were measured, and the profile distribution characteristic of heavy metals was discussed. Combined with the 210 Pb dating results, the contamination history of heavy metals was studied in high resolution records, and the metal accumulation processes were also analyzed. The results indicated that the concentrations of heavy metals was relatively low compared with other area in the world, but the elements of Pb, Cu and Zn were obviously contaminated by anthropogenic impact. The rapid economical development of Shenzhen in the last 20 years and Hong Kong in 1960-1970s contributed much on accumulation of heavy metals in the sediments.

  3. Stabilization of heavy metals in MSWI fly ash using silica fume

    SciTech Connect

    Li, Xinying; Chen, Quanyuan; Zhou, Yasu; Tyrer, Mark; Yu, Yang

    2014-12-15

    Highlights: • The stabilization of heavy metals in MSWI fly ash was investigated. • The addition of silica fume effectively reduced the leaching of Pb and Cd. • The relation of solid phase transformation and leaching behavior of heavy metals was discussed. - Abstract: The objective of this work was to investigate the feasibility and effectiveness of silica fume on stabilizing heavy metals in municipal solid waste incineration (MSWI) fly ash. In addition to compressive strength measurements, hydrated pastes were characterized by X-ray diffraction (XRD), thermal-analyses (DTA/TG), and MAS NMR ({sup 27}Al and {sup 29}Si) techniques. It was found that silica fume additions could effectively reduce the leaching of toxic heavy metals. At the addition of 20% silica fume, leaching concentrations for Cu, Pb and Zn of the hydrated paste cured for 7 days decreased from 0.32 mg/L to 0.05 mg/L, 40.99 mg/L to 4.40 mg/L, and 6.96 mg/L to 0.21 mg/L compared with the MSWI fly ash. After curing for 135 days, Cd and Pb in the leachates were not detected, while Cu and Zn concentrations decreased to 0.02 mg/L and 0.03 mg/L. The speciation of Pb and Cd by the modified version of the European Community Bureau of Reference (BCR) extractions showed that these metals converted into more stable state in hydrated pastes of MSWI fly ash in the presence of silica fume. Although exchangeable and weak-acid soluble fractions of Cu and Zn increased with hydration time, silica fume addition of 10% can satisfy the requirement of detoxification for heavy metals investigated in terms of the identification standard of hazardous waste of China.

  4. Beneficial role of bacterial endophytes in heavy metal phytoremediation.

    PubMed

    Ma, Ying; Rajkumar, Mani; Zhang, Chang; Freitas, Helena

    2016-06-01

    Phytoremediation is an emerging technology that uses plants and their associated microbes to clean up pollutants from the soil, water and air. In recent years, phytoremediation assisted by bacterial endophytes has been highly recommended for cleaning up of metal polluted soils since endophytic bacteria can alleviate metal toxicity in plant through their own metal resistance system and facilitate plant growth under metal stress. Endophytic bacteria improve plant growth in metal polluted soils in two different ways: 1) directly by producing plant growth beneficial substances including solubilization/transformation of mineral nutrients (phosphate, nitrogen and potassium), production of phytohormones, siderophores and specific enzymes; and 2) indirectly through controlling plant pathogens or by inducing a systemic resistance of plants against pathogens. Besides, they also alter metal accumulation capacity in plants by excreting metal immobilizing extracellular polymeric substances, as well as metal mobilizing organic acids and biosurfactants. The present work aims to review the progress of recent research on the isolation, identification and diversity of metal resistant endophytic bacteria and illustrate various mechanisms responsible for plant growth promotion and heavy metal detoxification/phytoaccumulation/translocation in plants.

  5. Environmental health implications of heavy metal pollution from car tires.

    PubMed

    Horner, J M

    1996-01-01

    This paper reviews the potential for environmental pollution by heavy metals from the disposal of used car tires and describes laboratory work and field research exploring the magnitude of the problem. The metals considered here are cadmium, lead, and zinc; their respective mean concentrations for ten makes of tires used in the United Kingdom ranged from 0-3.0, 8.1-22.3, and 2524-6012 ppm. The metals were extracted from tires by simulated acid-rain solutions (pH 2.5); zinc concentrations of the leachate ranged from 169-463 ppm, but cadmium and lead concentrations were negligible. A significant increase in surface soil concentrations of all three metals was measured with increasing proximity to a tire dump in West London. The respective mean concentrations of cadmium, lead, and zinc in soil at the base of the dump were 22, 1160, and 1235 ppm, indicating contamination by each metal.

  6. Ecological risk and pollution history of heavy metals in Nansha mangrove, South China.

    PubMed

    Wu, Qihang; Tam, Nora F Y; Leung, Jonathan Y S; Zhou, Xizhen; Fu, Jie; Yao, Bo; Huang, Xuexia; Xia, Lihua

    2014-06-01

    Owing to the Industrial Revolution in the late 1970s, heavy metal pollution has been regarded as a serious threat to mangrove ecosystems in the region of the Pearl River Estuary, potentially affecting human health. The present study attempted to characterize the ecological risk of heavy metals (Cd, Cr, Cu, Mn, Ni, Pb and Zn) in Nansha mangrove, South China, by estimating their concentrations in the surface sediment. In addition, the pollution history of heavy metals was examined by determining the concentrations of heavy metals along the depth gradient. The phytoremediation potential of heavy metals by the dominant plants in Nansha mangrove, namely Sonneratia apetala and Cyperus malaccensis, was also studied. Results found that the surface sediment was severely contaminated with heavy metals, probably due to the discharge of industrial sewage into the Pearl River Estuary. Spatial variation of heavy metals was generally unobvious. The ecological risk of heavy metals was very high, largely due to Cd contamination. All heavy metals, except Mn, decreased with depth, indicating that heavy metal pollution has been deteriorating since 1979. Worse still, the dominant plants in Nansha mangrove had limited capability to remove the heavy metals from sediment. Therefore, we propose that immediate actions, such as regulation of discharge standards of industrial sewage, should be taken by the authorities concerned to mitigate the ecological risk posed by heavy metals. PMID:24675443

  7. Botanical plants could rid soil of heavy metals

    SciTech Connect

    Brennan, M.

    1993-04-20

    A new technology that is now emerging holds promise of revolutionizing the remediation of soils contaminated with heavy metals. Called phytoremediation, it would use green plants to remove the metals. Plants take up the metals in their roots and translocate them to their shoots, which are harvested, burned in a kiln, and the metals recovered and recycled. The challenge is finding or engineering plants that can absorb, translocate, and tolerate heavy metals while producing enough foliage to make the process efficient. All plants take up small amounts of metals, he notes. What he looks for are weird plants that can accumulate them. Such plants exist, he says, giving credence to the feasibility of phytoremediation. Naturally occurring plants with spectacular metal uptake have been found growing on ore outcroppings, he explains. Cunningham scouts waste repositories and mining and industrial sites for metal-accumulating plant species. So far, he has identified two common weeds - hemp dogbane and ragweed - as candidates for remediating lead-contaminated soils. Both plants accumulate lead, he says, but their abilities vary across soils because lead exists in several forms in soil, and not all of its forms are easily absorbed. He finds that lowering the pH and the phosphate and sulfate content of the soil enhances uptake of the metal. The downside is these changes can impair the plant's nutritional environment. So, the chemistry of the soil must be carefully manipulated to boost metal uptake without losing plant biomass, he emphasizes. Cunningham's scheme is being field-tested at Chambers Works, a Due Pont facility in New Jersey. If ragweed proves to be the species of choice for remediating weapons sites and other lead-contaminated sites, he says allergy sufferers needn't worry. Only mutants of the weed that don't pollinate will be grown.

  8. Heavy metals in garden soils along roads in Szeged, Hungary

    NASA Astrophysics Data System (ADS)

    Szolnoki, Zsuzsanna; Farsang, Andrea

    2010-05-01

    The soils of the urban environment, owing to the various anthropogenic activities, can be contaminated by heavy metals. The traffic is well-known for more decades to be main source of heavy metals mostly in cities. The accumulation of these elements can have different effects, either directly endangering the natural soil functions, or indirectly endangering the biosphere by bio-accumulation and inclusion in the food chain. The hobby gardens and the vegetable gardens directly along roads can be potential risky for people since unknown amount of heavy metals can be accumulated into organization of local residents due to consumption of vegetables and fruits grown in their own garden. The aim of this study was to determine the heavy metal content of garden soils directly along roads with heavy traffic in order to assess possible risk for human health. The total content and the mobile content of Cd, Co, Cr, Cu, Ni, Pb and Zn have been determined in samples from garden soils along 5 busy roads of Szeged, South Hungary. Enrichment factor has been calculated with the help of control soil samples far from roads. The soil properties basically influencing on metal mobility have also been examined. Finally, the human health risk of these garden soils has been modelled by determination of health risk quotient (HRQ). As a result of our investigations, it can be claimed that mostly Cu, Zn and to a lesser degree the Ni, Cr and Pb accumulated in garden soils along roads depending on the traffic density. In general, the topsoils (0-10 cm) had higher amount of these metals rather than the subsoils (40-50 cm). Ni of these metals has approached; Cu has exceeded limit value while Pb is under it. Cd is very high in both soils along roads and control ones far from roads. Garden soils along the roads have such basic soil parameters (pH, mechanical soil type, humus content) that prove fairly high metal-binding capacity for these soils. Total risk of usage of these gardens (ingestion of soil

  9. 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

  10. Heavy metals in aquatic macrophytes drifting in a large river

    USGS Publications Warehouse

    Manny, Bruce A.; Nichols, Susan J.; Schloesser, Donald W.

    1991-01-01

    Macrophytes drifting throughout the water column in the Detroit River were collected monthly from May to October 1985 to estimate the quantities of heavy metals being transported to Lake Erie by the plants. Most macrophytes (80–92% by weight) drifted at the water surface. Live submersed macrophytes made up the bulk of each sample. The most widely distributed submersed macrophyte in the river, American wildcelery (Vallisneria americana), occurred most frequently in the drift. A total of 151 tonnes (ash-free dry weight) of macrophytes drifted out of the Detroit River from May to October. The drift was greatest (37 tonnes) in May. Concentrations of heavy metals were significantly higher in macrophytes drifting in the river than in those growing elsewhere in unpolluted waters. Annually, a maximum of 2796 kg (eight heavy metals combined) were transported into Lake Erie by drifting macrophytes. The enrichment of all metals was remarkably high (range: 4000 × to 161000 ×) in macrophytes, relative to their concentration in water of the Detroit River. Detroit River macrophytes are thus a source of contaminated food for animals in the river and in Lake Erie.

  11. Diazotrophs-assisted phytoremediation of heavy metals: a novel approach.

    PubMed

    Ullah, Abid; Mushtaq, Hafsa; Ali, Hazrat; Munis, Muhammad Farooq Hussain; Javed, Muhammad Tariq; Chaudhary, Hassan Javed

    2015-02-01

    Heavy metals, which have severe toxic effects on plants, animals, and human health, are serious pollutants of the modern world. Remediation of heavy metal pollution is utmost necessary. Among different approaches used for such remediation, phytoremediation is an emerging technology. Research is in progress to enhance the efficiency of this plant-based technology. In this regard, the role of rhizospheric and symbiotic microorganisms is important. It was assessed by enumeration of data from the current studies that efficiency of phytoremediation can be enhanced by assisting with diazotrophs. These bacteria are very beneficial because they bring metals to more bioavailable form by the processes of methylation, chelation, leaching, and redox reactions and the production of siderophores. Diazotrophs also posses growth-promoting traits including nitrogen fixation, phosphorous solubilization, phytohormones synthesis, siderophore production, and synthesis of ACC-deaminase which may facilitate plant growth and increase plant biomass, in turn facilitating phytoremediation technology. Thus, the aim of this review is to highlight the potential of diazotrophs in assisting phytoremediation of heavy metals in contaminated soils. The novel current assessment of literature suggests the winning combination of diazotroph with phytoremediation technology.

  12. Interaction of heavy metals and pyrene on their fates in soil and tall fescue (Festuca arundinacea).

    PubMed

    Lu, Mang; Zhang, Zhong-Zhi; Wang, Jing-Xiu; Zhang, Min; Xu, Yu-Xin; Wu, Xue-Jiao

    2014-01-21

    90-Day growth chamber experiments were performed to investigate the interactive effect of pyrene and heavy metals (Cu, Cd, and Pb) on the growth of tall fescue and its uptake, accumulation, and dissipation of heavy metals and pyrene. Results show that plant growth and phytomass production were impacted by the interaction of heavy metals and pyrene. They were significantly decreased with heavy metal additions (100-2000 mg/kg), but they were only slightly declined with pyrene spiked up to 100 mg/kg. The addition of a moderate dosage of pyrene (100 mg/kg) lessened heavy metal toxicity to plants, resulting in enhanced plant growth and increased metal accumulation in plant tissues, thus improving heavy metal removal by plants. In contrast, heavy metals always reduced both plant growth and pyrene dissipation in soils. The chemical forms of Cu, Cd, and Pb in plant organs varied with metal species and pyrene addition. The dissipation and mineralization of pyrene tended to decline in both planted soil and unplanted soils with the presence of heavy metals, whereas they were enhanced with planting. The results demonstrate the complex interactive effects of organic pollutants and heavy metals on phytoremediation in soils. It can be concluded that, to a certain extent, tall fescue may be useful for phytoremediation of pyrene-heavy metal-contaminated sites. Further work is needed to enhance methods for phytoremediation of heavy metal-organics co-contaminated soil.

  13. Plants accumulating heavy metals in the Danube River wetlands

    PubMed Central

    2013-01-01

    Background We present herein our results regarding the accumulation of four heavy metals (copper, cadmium, lead, and zinc) in four aquatic species plants (Ceratophyllum demersum, Potamogeton pectinatus, Potamogeton lucens, Potamogeton perfoliatus) collected from the Danube River, South-Western part of Romania and their possible use as indicators of aquatic ecosystems pollution with heavy metals. Methods Elements concentration from the vegetal material was determined through Inductively Coupled Plasma – Mass Spectrometry. Results The species were chosen based on their previous use as bioindicators in aquatic ecosystems and due to the fact they are one of the most frequent aquatic plant species of the Danube River ecosystems within the Iron Gates Natural Park. Highest amounts are recorded for Ceratophyllum demersum (3.52 μg/g for Cd; 22.71 μg/g for Cu; 20.06 μg/g for Pb; 104.23 μg/g for Zn). Among the Potamogeton species, the highest amounts of heavy metals are recorded in Potamogeton perfoliatus (1.88 μg/g for Cd; 13.14 μg/g for Cu; 13.32 μg/g for Pb; 57.96 μg/g for Zn). The sequence for the bioconcentration factors (BCFs) calculated in order to describe the accumulation of the four metals is Cd >> Zn > Pb > Cu. Increase of the zinc concentration determines an increase of the cadmium concentration (Spearman rho=0.40, p=0.02). Conclusions Despite the low ambiental levels of heavy metals, the four aquatic plants have the ability to accumulate significant amounts, which make them useful as biological indicators. BCF value for Ceratophyllum demersum indicated this species as a cadmium hyperaccumulator. PMID:24359799

  14. Fish consumption, fish atopy and related heavy metals in childhood eczema.

    PubMed

    Hon, Kam Lun; Lui, Heike; Wang, Shuxin Susan; Lam, Hugh Simon; Leung, Ting Fan

    2012-09-01

    Due to increasing worldwide water pollution, fish might be a source of excessive zinc, mercury, arsenic or manganese intake. The aim of this study was to evaluate if fish atopy/sensitization and fish consumption behavior are associated with eczema severity and blood levels of the 4 heavy metals.One-hundred and nineteen patients with eczema and 43 patients with miscellaneous non-eczema skin diseases were studied. There were no differences in average weekly fish consumption and blood levels of the 4 heavy metals between eczema and non-eczema groups. Blood levels of these metals were generally within the upper limits of local reference ranges in all these patients. In eczema patients, freshwater fish consumption behavior in days-per-week was correlated with blood arsenic and mercury levels (rho=0.17, p<0.01 for both metals), but not with zinc or manganese. Levels of arsenic and mercury were also correlated with days of seawater fish consumption per week (arsenic: 0.38, mercury: 0.24, p <0.05).Fish sensitization was present in 25% of patients with eczema. Nevertheless, there was no difference in terms of fish consumption behavior, eczema severity, quality of life, and heavy metal levels between eczema patients with or without fish sensitization. We conclude that without exceeding local normal reference ranges, blood arsenic and mercury levels correlated with fish consumption behavior. There is no evidence to suggest that fish sensitization is associated with more severe eczema (bad for eczema), or that patients have milder eczema with more days of fish consumption (good for eczema).

  15. Leachability of Arsenic and Heavy Metals from Mine Tailings of Abandoned Metal Mines

    PubMed Central

    Lim, Mihee; Han, Gi-Chun; Ahn, Ji-Whan; You, Kwang-Suk; Kim, Hyung-Seok

    2009-01-01

    Mine tailings from an abandoned metal mine in Korea contained high concentrations of arsenic (As) and heavy metals [e.g., As: 67,336, Fe: 137,180, Cu: 764, Pb: 3,572, and Zn: 12,420 (mg/kg)]. US EPA method 6010 was an effective method for analyzing total arsenic and heavy metals concentrations. Arsenic in the mine tailings showed a high residual fraction of 89% by a sequential extraction. In Toxicity Characteristic Leaching Procedure (TCLP) and Korean Standard Leaching Test (KSLT), leaching concentrations of arsenic and heavy metals were very low [e.g., As (mg/L): 0.4 for TCLP and 0.2 for KSLT; cf. As criteria (mg/L): 5.0 for TCLP and 1.5 for KSLT]. PMID:20049231

  16. Heavy Metals Contamination in Coastal Sediments of Karachi, Pakistan

    NASA Astrophysics Data System (ADS)

    Siddique, A.; Mumtaz, M.; Zaigham, N. A.; Mallick, K. A.; Saied, S.; Khwaja, H. A.

    2008-12-01

    Toxic compounds such as heavy metals exert chronic and lethal effects in animals, plants, and human health. With the rapid industrialization, urbanization, and economic development in Karachi, heavy metals are continuing to be introduced to estuarine and coastal environment through rivers, runoff and land-based point sources. Pollution in the Karachi coastal region (167 km long) is mainly attributed to Lyari and Malir Rivers flowing through the city of Karachi. Both rivers are served by various channels of domestic and industrial wastes carrying more than 300 million gallons per day untreated effluent of 6000 industries and ultimately drain into the beaches of Arabian Sea. Concentrations of selected heavy metals (Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, and Zn) in surface sediments from eighty-eight sites in Karachi coastal region were studied in order to understand metal contamination due to industrialization, urbanization, and economic development in Karachi. Sediment samples were collected in 2005 and 2006. We have found that heavy metal concentrations in surface sediments varied from 0.006 to 24.3 ug/g for Cd, 5.1 to 95 ug/g for Co, 2.9 to 571 ug/g for Cr, 6.9 to 272 ug/g for Cu, 0.55 to 6.5% for Fe, 1.2 to 318 ug/g for Mn, 7.5 to 75 ug/g for Ni, 6.3 to 121 ug/g for Pb, and 3.3 to 389 ug/g for Zn. Enrichment factors (EFs) were calculated to assess whether the concentrations observed represent background or contaminated levels. The highest levels of metals were found to be at the confluence of the Lyari and Malir River streams at the Arabian Sea, indicating the impact of the effluents of the highly urbanized and industrialized city of Karachi. Furthermore, this study assessed heavy metal toxicity risk with the application of Sediment Quality Guideline (SQG) indices (effect range low/effect range median values, ERL/ERM). Results indicated that the potential toxicity of marine environment can cause adverse biological effects to the biota directly and the human health

  17. Heavy liquid metals: Research programs at PSI

    SciTech Connect

    Takeda, Y.

    1996-06-01

    The author describes work at PSI on thermohydraulics, thermal shock, and material tests for mechnical properties. In the presentation, the focus is on two main programs. (1) SINQ LBE target: The phase II study program for SINQ is planned. A new LBE loop is being constructed. The study has the following three objectives: (a) Pump study - design work on an electromagnetic pump to be integrated into the target. (b) Heat pipe performance test - the use of heat pipes as an additional component of the target cooling system is being considered, and it may be a way to futher decouple the liquid metal and water coolant loops. (c) Mixed convection experiment - in order to find an optimal configuration of the additional flow guide for window cooling, mixed convection around the window is to be studied. The experiment will be started using water and then with LBE. (2) ESS Mercury target: For ESS target study, the following experimental studies are planned, some of which are exampled by trial experiments. (a) Flow around the window: Flow mapping around the hemi-cylindrical window will be made for optimising the flow channels and structures, (b) Geometry optimisation for minimizing a recirculation zone behind the edge of the flow separator, (c) Flow induced vibration and buckling problem for a optimised structure of the flow separator and (d) Gas-liquid two-phase flow will be studied by starting to establish the new experimental method of measuring various kinds of two-phase flow characteristics.

  18. Biochar Mechanisms of Heavy Metal Sorption and Potential Utility

    NASA Astrophysics Data System (ADS)

    Ippolito, J.

    2015-12-01

    Mining-affected lands are a global issue; in the USA alone there are an estimated 500,000 abandoned mines encompassing hundreds of thousands of hectares. Many of these sites generate acidic mine drainage that causes release of heavy metals, and subsequently degradation in environmental quality. Because of its potential liming characteristics, biochar may play a pivotal role as a soil amendment in future mine land reclamation. However, to date, most studies have focused on the use of biochar to sorb metals from solution. Previous studies suggest that metals are complexed by biochar surface function groups (leading to ion exchange, complexation), coordination with Pi electrons (C=C) of carbon, and precipitation of inorganic mineral phases. Several recent studies have focused on the use of biochar for amending mine land soils, showing that biochar can indeed reduce heavy metal lability, yet the mechanism(s) behind labile metal reduction have yet to be established. In a proof-of-concept study, we added lodgepole pine, tamarisk, and switchgrass biochar (0, 5, 10, 15% by weight; 500 oC) to four different western US mine land soils affected by various heavy metals (Cd, Cu, Mn, Pb, Zn). Extraction with 0.01M CaCl2 showed that increasing biochar application rate significantly decreased 'bioaccessible' metals in almost all instances. A concomitant increase in solution pH was observed, suggesting that metals may be rendered bio-inaccessible through precipitation as carbonate or (hydr)oxide phases, or sorbed onto mineral surfaces. However, this was only supposition and required further research. Thus, following the 0.01M CaCl2 extraction, biochar-soil mixtures were air-dried and metals were further extracted using the four-step BCR sequential removal procedure. Results from selective extraction suggest that, as compared to the controls, most metals in the biochar-amended mine land soils were associated with exchange sites, carbonate, and oxide phases. Biochar may play a

  19. [Heavy metal problems in the agricultural utilization of sewage sludge].

    PubMed

    Leschber, R

    1983-09-01

    Introductory comments on the problems linked with sewage sludge disposal and utilization are given and it is demonstrated that agricultural use of sludge must definitely be given preference over other disposal methods for reasons related to waste utilization and ecology. The legal development which led from the promulgation of the Waste Disposal Act via its recent revision to the Sewage Sludge Decree according to para 15 of this Act, is illustrated. Subsequently the objectives of the decree, which in particular also attempts to solve the problems associated with heavy metals in agricultural sludge utilization, as well as the technical contents of the draft are dealt with. Reference is made to the Sewage Sludge Decree promulgated by the Swiss Bundesrat and to a corresponding draft of guidelines prepared by the Commission of the EEC and the measures which must be adopted to solve the heavy metal problem in the future are then mentioned.

  20. [The biochemical carcinogenesis of selected heavy metals in bladder cancer].

    PubMed

    Rorbach-Dolata, Anna; Marchewka, Zofia; Piwowar, Agnieszka

    2015-01-01

    Bladder cancer takes the second place in the classification of morbidity of urinary system cancers. Many chemical factors take part in cancerogenesis. It is suggested that exposure to heavy metals such as arsenic, chromium, nickel and cadmium as well as its metabolites may trigger the bladder cancer through inducing excessive reactive oxygen species production and oxidative stress formation which are responsible for DNA damage. In patients with bladder cancer is observed the disorder of processes regulated by p-53, including apoptosis. There are many patients with bladder cancer with confirmed absence of retinoblastoma protein, which is responsible of holding on the process of coming up the cells with mutation into synthesis, where the replication process undergoes. It is mentioned that excessive expression of proto-oncogenes may also cause the bladder cancer. The article concerns biochemical effects of exposure to chosen heavy metals and their potential role in bladder cancer progression. PMID:26689010

  1. Situ formation of apatite for sequestering radionuclides and heavy metals

    DOEpatents

    Moore, Robert C.

    2003-07-15

    Methods for in situ formation in soil of a permeable reactive barrier or zone comprising a phosphate precipitate, such as apatite or hydroxyapatite, which is capable of selectively trapping and removing radionuclides and heavy metal contaminants from the soil, while allowing water or other compounds to pass through. A preparation of a phosphate reagent and a chelated calcium reagent is mixed aboveground and injected into the soil. Subsequently, the chelated calcium reagent biodegrades and slowly releases free calcium. The free calcium reacts with the phosphate reagent to form a phosphate precipitate. Under the proper chemical conditions, apatite or hydroxyapatite can form. Radionuclide and heavy metal contaminants, including lead, strontium, lanthanides, and uranium are then selectively sequestered by sorbing them onto the phosphate precipitate. A reducing agent can be added for reduction and selective sequestration of technetium or selenium contaminants.

  2. Heavy metal sorption in the lichen cationactive layer.

    PubMed

    Andrzej, Kłos; Małgorzata, Rajfur; Maria, Wacławek; Witold, Wacławek

    2007-09-01

    Results of copper ion sorption in lichens owing to the ion exchange between the surroundings (aqueous solution) and the lichen cationactive layer have been presented. It indicates that the course of sorption of these ions, similarly as in the case of cations of other heavy metals, depends on the concentration and type of cations naturally found in lichen surroundings: H+, Na+, K+, Mg2+ and Ca2+. A determination method of heavy metal concentration in lichen surroundings has been proposed. It consists in exposure of transplanted lichens in the presence of salts that provide precisely determined, artificial salinity of precipitation with which the lichens are in contact. The studies were conducted on Hypogymnia physodes lichens.

  3. Decomposition of heavy metal contaminated nettles (Urtica dioica L.) in soils subjected to heavy metal pollution by river sediments.

    PubMed

    Khan, Khalid Saifullah; Joergensen, Rainer Georg

    2006-11-01

    Two incubation experiments were conducted to evaluate differences in the microbial use of non-contaminated and heavy metal contaminated nettle (Urtica dioica L.) shoot residues in three soils subjected to heavy metal pollution (Zn, Pb, Cu, and Cd) by river sediments. The microbial use of shoot residues was monitored by changes in microbial biomass C, biomass N, biomass P, ergosterol, N mineralisation, CO(2) production and O(2) consumption rates. Microbial biomass C, N, and P were estimated by fumigation extraction. In the non-amended soils, the mean microbial biomass C to soil organic C ratio decreased from 2.3% in the low metal soil to 1.1% in the high metal soils. In the 42-d incubation experiment, the addition of 2% nettle residues resulted in markedly increased contents of microbial biomass P (+240%), biomass C (+270%), biomass N (+310%), and ergosterol (+360%). The relative increase in the four microbial properties was similar for the three soils and did not show any clear heavy metal effect. The contents of microbial biomass C, N and P and ergosterol contents declined approximately by 30% during the incubation as in the non-amended soils. The ratios microbial biomass C to N, microbial biomass C to P, and ergosterol to microbial biomass C remained constant at 5.2, 26, and 0.5%, respectively. In the 6-d incubation experiment, the respiratory quotient CO(2)/O(2) increased from 0.74 in the low metal soil to 1.58 in the high metal soil in the non-amended soils. In the treatments amended with 4% nettle residues, the respiratory quotient was constant at 1.13, without any effects of the three soils or the two nettle treatments. Contaminated nettle residues led generally to significantly lower N mineralisation, CO(2) production and O(2) consumption rates than non-contaminated nettle residues. However, the absolute differences were small. PMID:16677685

  4. Heavy metal transport in the hindon river basin, India.

    PubMed

    Jain, C K; Sharma, M K

    2006-01-01

    Total mass transfers of heavy metal in dissolved and particulate form has been determined in the downstream section of river Hindon, an important tributary of river Yamuna (India). The contribution of different point sources to the river Hindon has also been assessed. The river Kali has the largest contribution to the river Hindon. The highest metal loads were related to the highest flow of the river and thereby increased both by surface runoff and sediment resuspension. The contribution of monsoon months to the total transported load was also calculated and it was observed that monsoon months contributes more than 40% of total loading annually for all the metals. The metal fluxes from the river Hindon were compared with other rivers of Indian sub-continent. PMID:16404544

  5. Heavy metal transport in the hindon river basin, India.

    PubMed

    Jain, C K; Sharma, M K

    2006-01-01

    Total mass transfers of heavy metal in dissolved and particulate form has been determined in the downstream section of river Hindon, an important tributary of river Yamuna (India). The contribution of different point sources to the river Hindon has also been assessed. The river Kali has the largest contribution to the river Hindon. The highest metal loads were related to the highest flow of the river and thereby increased both by surface runoff and sediment resuspension. The contribution of monsoon months to the total transported load was also calculated and it was observed that monsoon months contributes more than 40% of total loading annually for all the metals. The metal fluxes from the river Hindon were compared with other rivers of Indian sub-continent.

  6. Surfactant biocatalyst for remediation of recalcitrant organics and heavy metals

    DOEpatents

    Brigmon, Robin L.; Story, Sandra; Altman, Denis J.; Berry, Christopher J.

    2011-05-03

    Novel strains of isolated and purified bacteria have been identified which have the ability to degrade petroleum hydrocarbons including a variety of PAHs. Several isolates also exhibit the ability to produce a biosurfactant. The combination of the biosurfactant-producing ability along with the ability to degrade PAHs enhances the efficiency with which PAHs may be degraded. Additionally, the biosurfactant also provides an additional ability to bind heavy metal ions for removal from a soil or aquatic environment.

  7. Surfactant biocatalyst for remediation of recalcitrant organics and heavy metals

    DOEpatents

    Brigmon, Robin L.; Story, Sandra; Altman; Denis J.; Berry, Christopher J.

    2011-03-29

    Novel strains of isolated and purified bacteria have been identified which have the ability to degrade petroleum hydrocarbons including a variety of PAHs. Several isolates also exhibit the ability to produce a biosurfactant. The combination of the biosurfactant-producing ability along with the ability to degrade PAHs enhances the efficiency with which PAHs may be degraded. Additionally, the biosurfactant also provides an additional ability to bind heavy metal ions for removal from a soil or aquatic environment.

  8. Surfactant biocatalyst for remediation of recalcitrant organics and heavy metals

    DOEpatents

    Brigmon, Robin L.; Story, Sandra; Altman, Denis J.; Berry, Christopher J.

    2011-03-15

    Novel strains of isolated and purified bacteria have been identified which have the ability to degrade petroleum hydrocarbons including a variety of PAHs. Several isolates also exhibit the ability to produce a biosurfactant. The combination of the biosurfactant-producing ability along with the ability to degrade PAHs enhances the efficiency with which PAHs may be degraded. Additionally, the biosurfactant also provides an additional ability to bind heavy metal ions for removal from a soil or aquatic environment.

  9. Surfactant biocatalyst for remediation of recalcitrant organics and heavy metals

    DOEpatents

    Brigmon, Robin L.; Story, Sandra; Altman, Denis; Berry, Christopher J.

    2009-01-06

    Novel strains of isolated and purified bacteria have been identified which have the ability to degrade petroleum hydrocarbons including a variety of PAHs. Several isolates also exhibit the ability to produce a biosurfactant. The combination of the biosurfactant-producing ability along with the ability to degrade PAHs enhances the efficiency with which PAHs may be degraded. Additionally, the biosurfactant also provides an additional ability to bind heavy metal ions for removal from a soil or aquatic environment.

  10. Chemical changes in heavy metals in the leachates from Technosols.

    PubMed

    Yao, F X; Macías, F; Virgel, S; Blanco, F; Jiang, X; Camps Arbestain, M

    2009-09-01

    A 2 month long column study was conducted to evaluate the mobility of heavy metals eluting from Technosols constituted from sewage sludges (aerobic or anaerobic) (as controls) or a mixture of different types of sewage sludges with green foundry sand (FS) or/and Linz-Donowitz slag (LD). The organic and inorganic wastes were mixed at a ratio of 56:44 (w/w). The mixtures and the controls were moistened to field capacity before adding them to the polypropylene columns (4.5 cm wide and 14 cm long). During the 8-week experimental period, the columns were watered, twice a week, with 100 mL of deionised water. The concentrations of heavy metals (Cu, Zn, Ni, Pb, Cd, and Cr) in the leachates were determined periodically. The concentrations of all the heavy metals were generally higher in the leachates from the Technosols containing anaerobic sewage sludge as a component. The concentration of Cu was strongly dependent on pH and was significantly higher (P<0.05) in the most alkaline leachates (pH>10) than in the other leachates. More Zn was mobilized in the most acidic leachates (pH<6) than in other leachates. The concentration of Ni in 80% of the leachates exceeded the EU drinking water limit for Ni (0.02 mgL(-1)). The concentrations of Pb were lower in the Technosols containing FS. The concentrations of Cd in the leachates from Technosols containing the conditioners were relatively high, while concentrations of Cr were higher in the controls. As far as the potential toxicity of heavy metals is concerned, the combination of aerobic sludge, inorganic conditioners able to buffer the pH to around neutrality, and reactive aluminosilicates, can be regarded as suitable choice for formulating Technosols from wastes. PMID:19580987

  11. Heavy metals in source-separated compost and digestates.

    PubMed

    Kupper, Thomas; Bürge, Diane; Bachmann, Hans Jörg; Güsewell, Sabine; Mayer, Jochen

    2014-05-01

    The production of compost and digestate from source-separated organic residues is well established in Europe. However, these products may be a source of pollutants when applied to soils. In order to assess this issue, composts, solid and liquid digestates from Switzerland were analyzed for heavy metals (Cd, Co, Cr, Cu, Ni, Pb and Zn) addressing factors which may influence the concentration levels: the treatment process, the composition, origin, particle size and impurity content of input materials, the season of input materials collection or the degree of organic matter degradation. Composts (n=81) showed mean contents being at 60% or less of the legal threshold values. Solid digestates (n=20) had 20-50% lower values for Cd, Co, Pb and Zn but similar values for Cr, Cu and Ni. Liquid digestates (n=5) exhibited mean concentrations which were approximately twice the values measured in compost for most elements. Statistical analyses did not reveal clear relationships between influencing factors and heavy metal contents. This suggests that the contamination was rather driven by factors not addressed in the present study. According to mass balance calculations related to Switzerland, the annual loads to agricultural soils resulting from the application of compost and digestates ranged between 2% (Cd) and 22% (Pb) of total heavy metal loads. At regional scale, composts and digestates are therefore minor sources of pollution compared to manure (Co, Cu, Ni, Zn), mineral fertilizer (Cd, Cr) and aerial deposition (Pb). However, for individual fields, fertilization with compost or digestates results in higher heavy metal loads than application of equivalent nutrient inputs through manure or mineral fertilizer. PMID:24613591

  12. 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

  13. Heavy Metal Bioabsorption Capacity of Intestinal Helminths in Urban Rats

    PubMed Central

    TEIMOORI, Salma; SABOUR YARAGHI, Aliakbar; MAKKI, Mahsa Sadat; SHAHBAZI, Farideh; NAZMARA, Shahrokh; ROKNI, Mohhamad Bagher; MESDAGHINIA, Alireza; SALAHI MOGHADDAM, Abdoreza; HOSSEINI, Mostafa; RAKHSHANPOUR, Arash; MOWLAVI, Gholamreza

    2014-01-01

    Abstract Background The aim of the present study was to evaluate the capability of helminths to absorb heavy metals in comparison with that of the host tissues. Methods We compared the concentration of cadmium (Cd) and chromium (Cr) in urban rats and in their harboring helminthes —Moniliformis moniliformis, Hymenolepis diminuta and larval stage of Taenia taenaeiformis (Cysticercus fasciolaris). The heavy metal absorption was evaluated in 1g wet weight of parasites and tissues digested in nitric acid, using Inductivity Coupled Plasma (ICP_OES). Results A higher concentration of heavy metals was revealed in the helminths than in the host tissues. Bioconcentration factor (BF= C in parasite/C in tissue) for both Cd and Cr absorption was more than 10-fold higher in M. moniliformis than in the three compared host tissues. The BF of Cd in M. moniliformis compared to the liver, kidney and muscle of the host was 9.16, 14.14 and 17.09, respectively. BF in Cr in the same parasite and the same host tissues ranged from 10.67, 7.06 and 4.6. High level of absorption in H. diminuta was significantly likewise; the individual BF of Cd and Cr in H. diminuta compared to the liver, kidney and muscle of the hosts was 4.95, 5.94 and 4.67 vs. 2.67, 11.56 and 5.59. The mean concentration of Cd and Cr in C. fasciolaris was also significantly higher than that in the rat livers (P<0.007 and P<0.004, respectively). Conclusion This study claims that parasites of terrestrial animals exposed to heavy metals can be more accurate indicators than the host tissues as new environmental monitoring agents. PMID:25988090

  14. Effects of Gravity on Processing Heavy Metal Fluoride Fibers

    NASA Technical Reports Server (NTRS)

    Tucker, Dennis S.; Workman, Gary L.; Smith, Guy A.

    1997-01-01

    The effects of gravity on the crystal nucleation of heavy metal fluoride fibers have been studied in preliminary experiments utilizing NASA's KC-135 reduced gravity aircraft and a microgravity sounding rocket flight. Commercially produced fibers were heated to the crystallization temperature in normal and reduced gravity. The fibers processed in normal gravity showed complete crystallization while the fibers processed in reduced gravity did not show signs of crystallization.

  15. Heavy metals and pain in the dysfunctional patient

    PubMed Central

    Di Paolo, Carlo; Serritella, Emanuela; Panti, Fabrizio; Falisi, Giovanni; Manna, Fedele

    2014-01-01

    Summary Aims The aim of this research is to verify the quality and quantity of heavy metals (HM) of dental origin in TMD patients. Methods A population of 100 subject was studied and divided in two homogeneous groups: Study Group (SG) and Control Group (CG). Organism heavy metals were tested by a spot sampling method in which the first urine of the day, through Inductively Coupled Plasma-Mass Spectrometry (ICP-MS), were analyzed. The results obtained were compared with reference values (RV) of Italian people. Descriptive statistical analysis and student’s t-test has been applied (statistical significance for p > 0.05). Results The SG presented the absolute highest levels of HM compared to the CG (p=0.787). As regards the relation between pain and HM, the subjects that refer “severe/very severe” values of pain present the highest levels of HM in urines. Conclusions The obtained results seem to highlight a possible direct proportionality between the level of pain the increase of the concentration of heavy metals in all the examined groups and subgroups. PMID:25002917

  16. Smart responsive microcapsules capable of recognizing heavy metal ions.

    PubMed

    Pi, Shuo-Wei; Ju, Xiao-Jie; Wu, Han-Guang; Xie, Rui; Chu, Liang-Yin

    2010-09-15

    Smart responsive microcapsules capable of recognizing heavy metal ions are successfully prepared with oil-in-water-in-oil double emulsions as templates for polymerization in this study. The microcapsules are featured with thin poly(N-isopropylacrylamide-co-benzo-18-crown-6-acrylamide) (P(NIPAM-co-BCAm)) membranes, and they can selectively recognize special heavy metal ions such as barium(II) or lead(II) ions very well due to the "host-guest" complexation between the BCAm receptors and barium(II) or lead(II) ions. The stable BCAm/Ba(2+) or BCAm/Pb(2+) complexes in the P(NIPAM-co-BCAm) membrane cause a positive shift of the volume phase transition temperature of the crosslinked P(NIPAM-co-BCAm) hydrogel to a higher temperature, and the repulsion among the charged BCAm/Ba(2+) or BCAm/Pb(2+) complexes and the osmotic pressure within the P(NIPAM-co-BCAm) membranes result in the swelling of microcapsules. Induced by recognizing barium(II) or lead(II) ions, the prepared microcapsules with P(NIPAM-co-BCAm) membranes exhibit isothermal and significant swelling not only in outer and inner diameters but also in the membrane thickness. The proposed microcapsules in this study are highly attractive for developing smart sensors and/or carriers for detection and/or elimination of heavy metal ions.

  17. Heavy-metal pollution and arseniasis in Hetao region, China.

    PubMed

    Zhang, Hui

    2004-05-01

    In the Hetao region in northern China drinking water has become toxic due to the presence of arsenic (As) and other heavy metals in soil and water. The 7 counties in this region cover approx. 6100 km2, and in all 180,000 people are suffering from the toxic effects of contaminated drinking water. However, very few studies have been carried out in the region on the possible source of this arsenic. This paper is based on studies of the distribution of heavy metals in soil and groundwater. Results show that the average content of As is 0.483 microg g(-1) in groundwater and 13.74 microg g(-1) in soil. These levels are higher than the drinking water standard of 0.05 microg g(-1) recommended by the World Health Organization in 1984, and for the local background level in soil (5.20 microg g(-1)). This heavy-metal content in water and soil decreases gradually with increasing distance from the contaminated area, which fronts the Yin Mountains. The ratios of the Pb and Sr isotope contents in water are closely related to the ratios found in the water of the regions' mining area, and the ratios in soil correspond to the content of As in groundwater and soil in the area where pathological changes have been detected. Results suggest that the contaminants originate in the ore deposit zone fronting Yin mountains in the upper reaches of the Hetao Region.

  18. Earliest evidence of pollution by heavy metals in archaeological sites.

    PubMed

    Monge, Guadalupe; Jimenez-Espejo, Francisco J; García-Alix, Antonio; Martínez-Ruiz, Francisca; Mattielli, Nadine; Finlayson, Clive; Ohkouchi, Naohiko; Sánchez, Miguel Cortés; de Castro, Jose María Bermúdez; Blasco, Ruth; Rosell, Jordi; Carrión, José; Rodríguez-Vidal, Joaquín; Finlayson, Geraldine

    2015-09-21

    Homo species were exposed to a new biogeochemical environment when they began to occupy caves. Here we report the first evidence of palaeopollution through geochemical analyses of heavy metals in four renowned archaeological caves of the Iberian Peninsula spanning the last million years of human evolution. Heavy metal contents reached high values due to natural (guano deposition) and anthropogenic factors (e.g. combustion) in restricted cave environments. The earliest anthropogenic pollution evidence is related to Neanderthal hearths from Gorham's Cave (Gibraltar), being one of the first milestones in the so-called "Anthropocene". According to its heavy metal concentration, these sediments meet the present-day standards of "contaminated soil". Together with the former, the Gibraltar Vanguard Cave, shows Zn and Cu pollution ubiquitous across highly anthropic levels pointing to these elements as potential proxies for human activities. Pb concentrations in Magdalenian and Bronze age levels at El Pirulejo site can be similarly interpreted. Despite these high pollution levels, the contaminated soils might not have posed a major threat to Homo populations. Altogether, the data presented here indicate a long-term exposure of Homo to these elements, via fires, fumes and their ashes, which could have played certain role in environmental-pollution tolerance, a hitherto neglected influence.

  19. Potentiometric stripping analysis of selected heavy metals in biological materials.

    PubMed

    Sattar, A; Ahmad, N; Khan, L A

    1993-01-01

    Different biological materials such as edible oils, refined and unrefined cane and beet sugar and tea (black and green) leaves were assayed for the heavy metals cadmium, copper, lead and zinc. The results revealed significant differences in heavy metal contents within each class of the biological materials (P < 0.05). Cadmium was not detectable in sugar samples. Among the oils, highest amounts of copper (0.263 microgram/g) and lead (0.154 microgram/g) were in corn oil and zinc in olive oil (3.01 micrograms/g) whereas cadmium exhibited a narrow range (0.023-0.033 microgram/g). The samples of beet-sugar generally contained higher levels of the heavy metals than cane-sugar. Black and green tea leaves contained 0.411-0.908 microgram Cd/g, 6.500-9.220 micrograms Cu/g, 2.200-5.238 micrograms Pb/g, and 14.500-25.180 micrograms Zn/g. PMID:8361526

  20. Heavy Metal Contamination in the Taimyr Peninsula, Siberian Arctic

    SciTech Connect

    Allen-Gil, Susan M.; Ford, Jesse; Lasorsa, Brenda K.; Monetti, Matthew; Vlasova, Tamara; Landers, Dixon H.

    2003-01-01

    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. We analyzed heavy metal concentrations in lichen (Cetraria cucullata), moss (Hylocomium splendens), soils, lake sediment, freshwater fish (Salvelinus alpinus, Lota lota, and Coregonus spp.) and collared lemming (Dicrostonyx torquatus) from 13 sites between 30 and 300 km from Norilsk. Element concentrations were low in both C. cucullata and H. splendens, although concentrations of Al, Fe, Cu, Ni, and Pb were significantly higher than those in Arctic Alaska, probably due to natural differences in the geochemical environments. Inorganic surface soils had significantly higher concentrations of Cd, Zn, Pb, and Mg than inorganic soils at depth, although a lake sediment core from the eastern Taimyr Peninsula indicated no recent enrichment by atmospherically transported elements. Tissue concentrations of heavy metals in fish and lemming were not elevated relative to other Arctic sites. Our results show that the impact of the Norilsk smelting complex is primarily localized rather than regional, and does not extend northward beyond 100 km.

  1. Heavy metal concentrations in Louisiana waterways, sediments, and biota

    SciTech Connect

    Bundy, K.J.; Berzins, D.

    1994-12-31

    In this investigation polarographic methods (along with GFAAS and ICP) have been used to study the distribution of lead and chromium in Bayou Trepagnier and Devil`s Swamp. Both laboratory and field research have been conducted. Separation and extraction methodology appropriate for analysis of the contaminants at these sites have been developed. Particular attention has been paid to extraction methods for chromium which do not lead to valence state conversion. The availability of such techniques is essential to take full advantage of polarography, a method capable of performing speciation analysis. The results indicate that there is a very inhomogeneous distribution of heavy metals in these environments. In Devil`s Swamp, for example, separation and analysis of aqueous and variously sized particulate moieties in the water and sediment compartments were conducted to determine the partition of lead between them. The results showed that the average lead content was 14.7 ppb and 19.8 ppm, respectively, in these compartments. Apparently bull frogs in Devil`s Swamp can bioaccumulate lead (compared to the measured water level), since the muscle concentration was found to be about 0.6 ppm. This phenomenon is being investigated in a Xenopus frog laboratory model of heavy metal uptake. The basic methodology validated in this study should be fairly generally applicable to assays of other heavy metals.

  2. Superhydrogels of nanotubes capable of capturing heavy-metal ions.

    PubMed

    Song, Shasha; Wang, Haiqiao; Song, Aixin; Hao, Jingcheng

    2014-01-01

    Self-assembly regulated by hydrogen bonds was successfully achieved in the system of lithocholic acid (LCA) mixed with three organic amines, ethanolamine (EA), diethanolamine (DEA), and triethanolamine (TEA), in aqueous solutions. The mixtures of DEA/LCA exhibit supergelation capability and the hydrogels consist of plenty of network nanotubes with uniform diameters of about 60 nm determined by cryogenic TEM. Interestingly, the sample with the same concentration in a system of EA and LCA is a birefringent solution, in which spherical vesicles and can be transformed into nanotubes as the amount of LCA increases. The formation of hydrogels could be driven by the delicate balance of diverse noncovalent interactions, including electrostatic interactions, hydrophobic interactions, steric effects, van der Waals forces, and mainly hydrogen bonds. The mechanism of self-assembly from spherical bilayer vesicles into nanotubes was proposed. The dried hydrogels with nanotubes were explored to exhibit the excellent capability for capturing heavy-metal ions, for example, Cu(2+), Co(2+), Ni(2+), Pb(2+), and Hg(2+). The superhydrogels of nanotubes from the self-assembly of low-molecular-weight gelators mainly regulated by hydrogen bonds used for the removal of heavy-metal ions is simple, green, and high efficiency, and provide a strategic approach to removing heavy-metal ions from industrial sewage.

  3. Earliest evidence of pollution by heavy metals in archaeological sites.

    PubMed

    Monge, Guadalupe; Jimenez-Espejo, Francisco J; García-Alix, Antonio; Martínez-Ruiz, Francisca; Mattielli, Nadine; Finlayson, Clive; Ohkouchi, Naohiko; Sánchez, Miguel Cortés; de Castro, Jose María Bermúdez; Blasco, Ruth; Rosell, Jordi; Carrión, José; Rodríguez-Vidal, Joaquín; Finlayson, Geraldine

    2015-01-01

    Homo species were exposed to a new biogeochemical environment when they began to occupy caves. Here we report the first evidence of palaeopollution through geochemical analyses of heavy metals in four renowned archaeological caves of the Iberian Peninsula spanning the last million years of human evolution. Heavy metal contents reached high values due to natural (guano deposition) and anthropogenic factors (e.g. combustion) in restricted cave environments. The earliest anthropogenic pollution evidence is related to Neanderthal hearths from Gorham's Cave (Gibraltar), being one of the first milestones in the so-called "Anthropocene". According to its heavy metal concentration, these sediments meet the present-day standards of "contaminated soil". Together with the former, the Gibraltar Vanguard Cave, shows Zn and Cu pollution ubiquitous across highly anthropic levels pointing to these elements as potential proxies for human activities. Pb concentrations in Magdalenian and Bronze age levels at El Pirulejo site can be similarly interpreted. Despite these high pollution levels, the contaminated soils might not have posed a major threat to Homo populations. Altogether, the data presented here indicate a long-term exposure of Homo to these elements, via fires, fumes and their ashes, which could have played certain role in environmental-pollution tolerance, a hitherto neglected influence. PMID:26388184

  4. Earliest evidence of pollution by heavy metals in archaeological sites

    NASA Astrophysics Data System (ADS)

    Monge, Guadalupe; Jimenez-Espejo, Francisco J.; García-Alix, Antonio; Martínez-Ruiz, Francisca; Mattielli, Nadine; Finlayson, Clive; Ohkouchi, Naohiko; Sánchez, Miguel Cortés; de Castro, Jose María Bermúdez; Blasco, Ruth; Rosell, Jordi; Carrión, José; Rodríguez-Vidal, Joaquín; Finlayson, Geraldine

    2015-09-01

    Homo species were exposed to a new biogeochemical environment when they began to occupy caves. Here we report the first evidence of palaeopollution through geochemical analyses of heavy metals in four renowned archaeological caves of the Iberian Peninsula spanning the last million years of human evolution. Heavy metal contents reached high values due to natural (guano deposition) and anthropogenic factors (e.g. combustion) in restricted cave environments. The earliest anthropogenic pollution evidence is related to Neanderthal hearths from Gorham's Cave (Gibraltar), being one of the first milestones in the so-called “Anthropocene”. According to its heavy metal concentration, these sediments meet the present-day standards of “contaminated soil”. Together with the former, the Gibraltar Vanguard Cave, shows Zn and Cu pollution ubiquitous across highly anthropic levels pointing to these elements as potential proxies for human activities. Pb concentrations in Magdalenian and Bronze age levels at El Pirulejo site can be similarly interpreted. Despite these high pollution levels, the contaminated soils might not have posed a major threat to Homo populations. Altogether, the data presented here indicate a long-term exposure of Homo to these elements, via fires, fumes and their ashes, which could have played certain role in environmental-pollution tolerance, a hitherto neglected influence.

  5. Earliest evidence of pollution by heavy metals in archaeological sites

    PubMed Central

    Monge, Guadalupe; Jimenez-Espejo, Francisco J.; García-Alix, Antonio; Martínez-Ruiz, Francisca; Mattielli, Nadine; Finlayson, Clive; Ohkouchi, Naohiko; Sánchez, Miguel Cortés; de Castro, Jose María Bermúdez; Blasco, Ruth; Rosell, Jordi; Carrión, José; Rodríguez-Vidal, Joaquín; Finlayson, Geraldine

    2015-01-01

    Homo species were exposed to a new biogeochemical environment when they began to occupy caves. Here we report the first evidence of palaeopollution through geochemical analyses of heavy metals in four renowned archaeological caves of the Iberian Peninsula spanning the last million years of human evolution. Heavy metal contents reached high values due to natural (guano deposition) and anthropogenic factors (e.g. combustion) in restricted cave environments. The earliest anthropogenic pollution evidence is related to Neanderthal hearths from Gorham's Cave (Gibraltar), being one of the first milestones in the so-called “Anthropocene”. According to its heavy metal concentration, these sediments meet the present-day standards of “contaminated soil”. Together with the former, the Gibraltar Vanguard Cave, shows Zn and Cu pollution ubiquitous across highly anthropic levels pointing to these elements as potential proxies for human activities. Pb concentrations in Magdalenian and Bronze age levels at El Pirulejo site can be similarly interpreted. Despite these high pollution levels, the contaminated soils might not have posed a major threat to Homo populations. Altogether, the data presented here indicate a long-term exposure of Homo to these elements, via fires, fumes and their ashes, which could have played certain role in environmental-pollution tolerance, a hitherto neglected influence. PMID:26388184

  6. Smart responsive microcapsules capable of recognizing heavy metal ions.

    PubMed

    Pi, Shuo-Wei; Ju, Xiao-Jie; Wu, Han-Guang; Xie, Rui; Chu, Liang-Yin

    2010-09-15

    Smart responsive microcapsules capable of recognizing heavy metal ions are successfully prepared with oil-in-water-in-oil double emulsions as templates for polymerization in this study. The microcapsules are featured with thin poly(N-isopropylacrylamide-co-benzo-18-crown-6-acrylamide) (P(NIPAM-co-BCAm)) membranes, and they can selectively recognize special heavy metal ions such as barium(II) or lead(II) ions very well due to the "host-guest" complexation between the BCAm receptors and barium(II) or lead(II) ions. The stable BCAm/Ba(2+) or BCAm/Pb(2+) complexes in the P(NIPAM-co-BCAm) membrane cause a positive shift of the volume phase transition temperature of the crosslinked P(NIPAM-co-BCAm) hydrogel to a higher temperature, and the repulsion among the charged BCAm/Ba(2+) or BCAm/Pb(2+) complexes and the osmotic pressure within the P(NIPAM-co-BCAm) membranes result in the swelling of microcapsules. Induced by recognizing barium(II) or lead(II) ions, the prepared microcapsules with P(NIPAM-co-BCAm) membranes exhibit isothermal and significant swelling not only in outer and inner diameters but also in the membrane thickness. The proposed microcapsules in this study are highly attractive for developing smart sensors and/or carriers for detection and/or elimination of heavy metal ions. PMID:20656104

  7. Heavy metal analysis in commercial Spirulina products for human consumption

    PubMed Central

    Al-Dhabi, Naif Abdullah

    2013-01-01

    For consumption of health foods of Spirulina, by the general public, health food stores are increasingly offering more exotic products. Though Spirulina consumption is growing worldwide, relatively few studies have reported on the quantities of heavy metals/minerals they contain and/or their potential effects on the population’s health. This study reveals the concentrations of six typical heavy metals/minerals (Ni, Zn, Hg, Pt, Mg, and Mn) in 25 Spirulina products commercialized worldwide for direct human consumption. Samples were ground, digested and quantified by Coupled Plasma Mass Spectroscopy (ICP–MS). The concentrations (mg/kg d.w.) were range from 0.001 to 0.012 (Pt) followed by 0.002–0.028 (Hg), 0.002–0.042 (Mg), 0.005–2.248 (Mn), 0.211–4.672 (Ni) and 0.533–6.225 (Zn). The inorganic elements of the present study were significantly lower than the recommended daily intake (RDI) level of heavy metal elements (mg/daily) Ni (0.4), Zn (13), Hg (0.01), Pt (0.002), Mg (400) and Mn (4). Based on this study the concentration of inorganic elements was not found to exceed the present regulation levels, and they can be considered as safe food. PMID:24235875

  8. Role of soil rhizobacteria in phytoremediation of heavy metal contaminated soils*

    PubMed Central

    Jing, Yan-de; He, Zhen-li; Yang, Xiao-e

    2007-01-01

    Heavy metal pollution of soil is a significant environmental problem and has its negative impact on human health and agriculture. Rhizosphere, as an important interface of soil and plant, plays a significant role in phytoremediation of contaminated soil by heavy metals, in which, microbial populations are known to affect heavy metal mobility and availability to the plant through release of chelating agents, acidification, phosphate solubilization and redox changes, and therefore, have potential to enhance phytoremediation processes. Phytoremediation strategies with appropriate heavy metal-adapted rhizobacteria have received more and more attention. This article paper reviews some recent advances in effect and significance of rhizobacteria in phytoremediation of heavy metal contaminated soils. There is also a need to improve our understanding of the mechanisms involved in the transfer and mobilization of heavy metals by rhizobacteria and to conduct research on the selection of microbial isolates from rhizosphere of plants growing on heavy metal contaminated soils for specific restoration programmes. PMID:17323432

  9. Heavy metals in commercial fish in New Jersey

    SciTech Connect

    Burger, Joanna . E-mail: burger@biology.rutgers.edu; Gochfeld, Michael

    2005-11-15

    Levels of contaminants in fish are of particular interest because of the potential risk to humans who consume them. While attention has focused on self-caught fish, most of the fish eaten by the American public comes from commercial sources. We sampled 11 types of fish and shellfish obtained from supermarkets and specialty fish markets in New Jersey and analyzed them for arsenic, cadmium, chromium, lead, manganese, mercury, and selenium. We test the null hypothesis that metal levels do not vary among fish types, and we consider whether the levels of any metals could harm the fish themselves or their predators or pose a health risk for human consumers. There were significant interspecific differences for all metals, and no fish types had the highest levels of more than two metals. There were few significant correlations (Kendall tau) among metals for the three most numerous fish (yellowfin tuna, bluefish, and flounder), the correlations were generally low (below 0.40), and many correlations were negative. Only manganese and lead positively were correlated for tuna, bluefish, and flounder. The levels of most metals were below those known to cause adverse effects in the fish themselves. However, the levels of arsenic, lead, mercury, and selenium in some fish were in the range known to cause some sublethal effects in sensitive predatory birds and mammals and in some fish exceeded health-based standards. The greatest risk from different metals resided in different fish; the species of fish with the highest levels of a given metal sometimes exceeded the human health guidance or standards for that metal. Thus, the risk information given to the public (mainly about mercury) does not present a complete picture. The potential of harm from other metals suggests that people not only should eat smaller quantities of fish known to accumulate mercury but also should eat a diversity of fish to avoid consuming unhealthy quantities of other heavy metals. However, consumers should

  10. 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.

  11. Bioaccumulation of heavy metals in macroinvertebrates living in stormwater wetlands

    SciTech Connect

    Karouna, N.K.; Sparling, D.W.

    1995-12-31

    The design of stormwater wetlands and ponds as wildlife habitats has prompted concern over the potential uptake of runoff contaminants by aquatic fauna. Stormwater wetlands provide a diverse array of habitat for aquatic macroinvertebrates. The importance of macroinvertebrates in aquatic communities has been well documented. Aquatic macroinvertebrates also serve as a major food source of many aquatic vertebrates, including fish and birds. The objectives of the study were to: (1) examine the responses of the macroinvertebrate community to water and sediment concentrations of heavy metals, and other water quality parameters; (2) determine whether macroinvertebrates living in stormwater wetlands bioaccumulate significant concentrations of heavy metals; (3) relate the concentrations of heavy metals in sediment, water and macroinvertebrates to land use in the surrounding watershed; (4) determine sediment and water toxicity to macroinvertebrates. Twenty stormwater wetlands, representing four land uses commercial, residential, highway and control, were monitored in this study. Water quality parameters, including pH, DO, turbidity, conductivity, hardness and metal concentrations were monitored bi-weekly for six months. Sediment samples were collected three times during the same period. Macroinvertebrate communities were sampled during alternate weeks after water collections. Ten-day sediment bioassays were conducted using the amphipod Hyalella azteca. Preliminary data analyses have indicated no significant difference in sediment and water metal concentrations between land uses. However, Zn concentrations in macroinvertebrates were significantly higher (p < 0.05) in wetlands serving commercial watersheds than in those serving the remaining three land uses. No differences have been detected in composition of invertebrate communities due to land use category.

  12. Concentration and transportation of heavy metals in vegetables and risk assessment of human exposure to bioaccessible heavy metals in soil near a waste-incinerator site, South China.

    PubMed

    Li, Ning; Kang, Yuan; Pan, Weijian; Zeng, Lixuan; Zhang, Qiuyun; Luo, Jiwen

    2015-07-15

    There is limited study focusing on the bioaccumulation of heavy metals in vegetables and human exposure to bioaccessible heavy metals in soil. In the present study, heavy metal concentrations (Cr, Ni, Cu, Pb and Cd) were measured in five types of vegetables, soil, root, and settled air particle samples from two sites (at a domestic waste incinerator and at 20km away from the incinerator) in Guangzhou, South China. Heavy metal concentrations in soil were greater than those in aerial parts of vegetables and roots, which indicated that vegetables bioaccumulated low amount of heavy metals from soil. The similar pattern of heavy metal (Cr, Cd) was found in the settled air particle samples and aerial parts of vegetables from two sites, which may suggest that foliar uptake may be an important pathway of heavy metal from the environment to vegetables. The highest levels of heavy metals were found in leaf lettuce (125.52μg/g, dry weight) and bitter lettuce (71.2μg/g) for sites A and B, respectively, followed by bitter lettuce and leaf lettuce for sites A and B, respectively. Swamp morning glory accumulated the lowest amount of heavy metals (81.02μg/g for site A and 53.2μg/g for site B) at both sites. The bioaccessibility of heavy metals in soil ranged from Cr (2%) to Cu (71.78%). Risk assessment showed that Cd and Pb in soil samples resulted in the highest non-cancer risk and Cd would result in unacceptable cancer risk for children and risk. The non-dietary intake of soil was the most important exposure pathway, when the bioaccessibility of heavy metals was taken into account.

  13. Concentration and transportation of heavy metals in vegetables and risk assessment of human exposure to bioaccessible heavy metals in soil near a waste-incinerator site, South China.

    PubMed

    Li, Ning; Kang, Yuan; Pan, Weijian; Zeng, Lixuan; Zhang, Qiuyun; Luo, Jiwen

    2015-07-15

    There is limited study focusing on the bioaccumulation of heavy metals in vegetables and human exposure to bioaccessible heavy metals in soil. In the present study, heavy metal concentrations (Cr, Ni, Cu, Pb and Cd) were measured in five types of vegetables, soil, root, and settled air particle samples from two sites (at a domestic waste incinerator and at 20km away from the incinerator) in Guangzhou, South China. Heavy metal concentrations in soil were greater than those in aerial parts of vegetables and roots, which indicated that vegetables bioaccumulated low amount of heavy metals from soil. The similar pattern of heavy metal (Cr, Cd) was found in the settled air particle samples and aerial parts of vegetables from two sites, which may suggest that foliar uptake may be an important pathway of heavy metal from the environment to vegetables. The highest levels of heavy metals were found in leaf lettuce (125.52μg/g, dry weight) and bitter lettuce (71.2μg/g) for sites A and B, respectively, followed by bitter lettuce and leaf lettuce for sites A and B, respectively. Swamp morning glory accumulated the lowest amount of heavy metals (81.02μg/g for site A and 53.2μg/g for site B) at both sites. The bioaccessibility of heavy metals in soil ranged from Cr (2%) to Cu (71.78%). Risk assessment showed that Cd and Pb in soil samples resulted in the highest non-cancer risk and Cd would result in unacceptable cancer risk for children and risk. The non-dietary intake of soil was the most important exposure pathway, when the bioaccessibility of heavy metals was taken into account. PMID:25829292

  14. Some Case Studies on Metal-Microbe Interactions to Remediate Heavy Metals- Contaminated Soils in Korea

    NASA Astrophysics Data System (ADS)

    Chon, Hyo-Taek

    2015-04-01

    Conventional physicochemical technologies to remediate heavy metals-contaminated soil have many problems such as low efficiency, high cost and occurrence of byproducts. Recently bioremediation technology is getting more and more attention. Bioremediation is defined as the use of biological methods to remediate and/or restore the contaminated land. The objectives of bioremediation are to degrade hazardous organic contaminants and to convert hazardous inorganic contaminants to less toxic compounds of safe levels. The use of bioremediation in the treatment of heavy metals in soils is a relatively new concept. Bioremediation using microbes has been developed to remove toxic heavy metals from contaminated soils in laboratory scale to the contaminated field sites. Recently the application of cost-effective and environment-friendly bioremediation technology to the heavy metals-contaminated sites has been gradually realized in Korea. The merits of bioremediation include low cost, natural process, minimal exposure to the contaminants, and minimum amount of equipment. The limitations of bioremediation are length of remediation, long monitoring time, and, sometimes, toxicity of byproducts for especially organic contaminants. From now on, it is necessary to prove applicability of the technologies to contaminated sites and to establish highly effective, low-cost and easy bioremediation technology. Four categories of metal-microbe interactions are generally biosorption, bioreduction, biomineralization and bioleaching. In this paper, some case studies of the above metal-microbe interactions in author's lab which were published recently in domestic and international journals will be introduced and summarized.

  15. Heavy metal and organochlorine compound concentrations in tissues of raccoons from east-central Michigan

    SciTech Connect

    Herbert, G.B.; Peterle, T.J. )

    1990-02-01

    Organochlorine (OC) pesticides and related compounds and heavy metals are persistent contaminants in the environment. Bioconcentration and biomagnification are well reported for organochlorine compounds. These compounds have a great potential for causing wildlife mortality or serious behavioral, reproductive, carcinogenic, teratogenic, and mutagenic effects, along with specific organ toxicity. The pervasive nature of toxic substances in the environment necessitates some knowledge for potential exposure of wildlife species. Without baseline values of contaminant loads for selected indicator species it is impossible to determine when abnormal or pathological conditions exist in wild populations. The purpose of this study was to provide baseline values for selected environmental contaminants in the raccoon (Procyon lotor), a potential indicator species for wildlife and to see if heavy metal accumulation was related to age or sex.

  16. Soil metatranscriptomics for mining eukaryotic heavy metal resistance genes.

    PubMed

    Lehembre, Frédéric; Doillon, Didier; David, Elise; Perrotto, Sandrine; Baude, Jessica; Foulon, Julie; Harfouche, Lamia; Vallon, Laurent; Poulain, Julie; Da Silva, Corinne; Wincker, Patrick; Oger-Desfeux, Christine; Richaud, Pierre; Colpaert, Jan V; Chalot, Michel; Fraissinet-Tachet, Laurence; Blaudez, Damien; Marmeisse, Roland

    2013-10-01

    Heavy metals are pollutants which affect all organisms. Since a small number of eukaryotes have been investigated with respect to metal resistance, we hypothesize that many genes that control this phenomenon remain to be identified. This was tested by screening soil eukaryotic metatranscriptomes which encompass RNA from organisms belonging to the main eukaryotic phyla. Soil-extracted polyadenylated mRNAs were converted into cDNAs and 35 of them were selected for their ability to rescue the metal (Cd or Zn) sensitive phenotype of yeast mutants. Few of the genes belonged to families known to confer metal resistance when overexpressed in yeast. Several of them were homologous to genes that had not been studied in the context of metal resistance. For instance, the BOLA ones, which conferred cross metal (Zn, Co, Cd, Mn) resistance may act by interfering with Fe homeostasis. Other genes, such as those encoding 110- to 130-amino-acid-long, cysteine-rich polypeptides, had no homologues in databases. This study confirms that functional metatranscriptomics represents a powerful approach to address basic biological processes in eukaryotes. The selected genes can be used to probe new pathways involved in metal homeostasis and to manipulate the resistance level of selected organisms.

  17. Heavy fermion behavior explained by bosons

    NASA Technical Reports Server (NTRS)

    Kallio, A.; Poykko, S.; Apaja, V.

    1995-01-01

    Conventional heavy fermion (HF) theories require existence of massive fermions. We show that heavy fermion phenomena can also be simply explained by existence of bosons with moderate mass but temperature dependent concentration below the formation temperature T(sub B), which in turn is close to room temperature. The bosons B(++) are proposed to be in chemical equilibrium with a system of holes h(+): B(++) = h(+) + h(+). This equilibrium is governed by a boson breaking function f(T), which determines the decreasing boson density and the increasing fermion density with increasing temperature. Since HF-compounds are hybridized from minimum two elements, we assume in addition existence of another fermion component h(sub s)(+) with temperature independent density. This spectator component is thought to be the main agent in binding the bosons in analogy with electronic or muonic molecules. Using a linear boson breaking function we can explain temperature dependence of the giant linear specific heat coefficient gamma(T) coming essentially from bosons. The maxima in resistivity, Hall coefficient, and susceptibility are explained by boson localization effects due to the Wigner crystallization. The antiferromagnetic transitions in turn are explained by similar localization of the pairing fermion system when their density n(sub h)(T(sub FL)) becomes lower than n(sub WC), the critical density of Wigner crystallization. The model applies irrespective whether a compound is superconducting or not. The same model explains the occurrence of low temperature antiferromagnetism also in high-T(sub c) superconductors. The double transition in UPt3 is proposed to be due to the transition of the pairing fermion liquid from spin polarized to unpolarized state.

  18. Differential accumulation of heavy metals by web spiders and ground spiders in an old-field

    SciTech Connect

    Larsen, K.J.; Brewer, S.R.; Taylor, D.H. . Dept. of Zoology)

    1994-03-01

    Accumulation of the heavy metals Cd, Cu, Pb, and Zn by web spiders (orb weavers: Araneidae) and ground spiders was examined in an old-field that had been subjected to 11 years of nutrient enrichment. The study area consistent of six 0.1-ha plots treated from 1978 to 1988 with municipal sewage sludge containing heavy-metal contaminants, urea-phosphate fertilizer, or left as untreated controls. In 1991 and 1992, heavy-metal concentrations in the soil, ground spiders, and web spiders were measured with a flame AA spectrophotometer. Spiders accumulated Cd, Cu, and Zn to concentrations greater than those present in the soil but did not accumulate Pb. Ground spiders contained significantly higher levels of Cd and Cu than web spiders, whereas web spiders contained slightly greater levels of Pb than ground spiders. No trend between spider guilds was apparent for Zn accumulation. To understand the impact of the application of metal-contaminated municipal sludge on ecosystem, the toxicological effects on the biology and behavior of major biotic components in terrestrial food webs must be known.

  19. Stabilized chitosan/Fe(0)-nanoparticle beads to remove heavy metals from polluted sediments.

    PubMed

    Liu, T; Sun, Y; Wang, Z L

    2016-01-01

    Sediment contamination by heavy metals has become a widespread problem that can affect the normal behaviors of rivers and lakes. After chitosan/Fe(0)-nanoparticles (CS-NZVI) beads were cross-linked with glutaraldehyde (GLA), their mechanical strength, stability and separation efficiency from the sediment were obviously improved. Moreover, the average aperture size of GLA-CS-NZVI beads was 20.6 μm and NZVI particles were nearly spherical in shape with a mean diameter of 40.2 nm. In addition, the pH showed an insignificant effect on the removal rates from the sediment. Due to the dissolution of metals species into aqueous solutions as an introduction of the salt, the removal rates of all heavy metals from the sediment were increased with an increase of the salinity. The competitive adsorption of heavy metals between the sediment particles and GLA-CS-NZVI beads became stronger as the sediment particles became smaller, leading to decreased removal rates. Therefore, the removal efficiency could be enhanced by optimizing experimental conditions and choosing appropriate materials for the target contaminants.

  20. Remediation of a heavy metal-contaminated soil by means of agglomeration.

    PubMed

    Polettini, Alessandra; Pomi, Raffaella; Valente, Mattia

    2004-01-01

    The feasibility of treating a heavy metal-contaminated soil by means of a solidification/stabilization treatment consisting of a granulation process is discussed in the present article. The aim of the study was to attain contaminant immobilization within the agglomerated solid matrix. The soil under concern was characterized by varying levels of heavy metal contamination, ranging from 50 to 500 mg kg(-1) dry soil for chromium. from 300 to 2000 mg kg(-1) dry soil for lead and from 270 to 5000 mg kg(-1) dry soil for copper. An artificially contaminated soil with contaminant concentrations corresponding to the upper level of the mentioned ranges was prepared from a sample of uncontaminated soil by means of spiking experiments. Pure soluble species of chromium, copper and lead. namely CrCl3.6H2O, CuCl2.2H2O and Pb(NO3)2, were selected for the spiking experiments, which were arranged according to a 2(3) full factorial design. The solidification/stabilization treatment was based on an agglomeration process making use of hydraulic binders including Portland cement, hydrated lime and sodium methasilicate, which were selected on the basis of preliminary test runs. It was found that after 7 days of curing the applied treatment was able to efficiently immobilize the investigated heavy metals within the hydrated matrix. Good acid neutralization behavior was also observed, indicating improved matrix resistance to acid attack and decreased potential for metal leaching. PMID:15137715

  1. Removal of heavy metal ions from aqueous solution using red loess as an adsorbent.

    PubMed

    Xing, Shengtao; Zhao, Meiqing; Ma, Zichuan

    2011-01-01

    The adsorption behaviors of heavy metals onto novel low-cost adsorbent, red loess, were investigated. Red loess was characterized by X-ray diffraction, scanning electron microscopy and Fourier transform infrared spectra. The results indicated that red loess mainly consisted of silicate, ferric and aluminum oxides. Solution pH, adsorbent dosage, initial metal concentration, contact time and temperature significantly influenced the efficiency of heavy metals removal. The adsorption reached equilibrium at 4 hr, and the experimental equilibrium data were fitted to Langmuir monolayer adsorption model. The adsorption of Cu(II) and Zn(II) onto red loess was endothermic, while the adsorption of Pb(II) was exothermic. The maximum adsorption capacities of red loess for Pb(II), Cu(II) and Zn(II) were estimated to be 113.6, 34.2 and 17.5 mg/g, respectively at 25 degrees C and pH 6. The maximum removal efficiencies were 100% for Pb(II) at pH 7, 100% for Cu(II) at pH 8, and 80% for Zn(II) at pH 8. The used adsorbents were readily regenerated using dilute HCl solution, indicating that red loess has a high reusability. All the above results demonstrated that red loess could be used as a possible alternative low-cost adsorbent for the removal of heavy metals from aqueous solution.

  2. Binding of heavy metal ions in aggregates of microbial cells, EPS and biogenic iron minerals measured in-situ using metal- and glycoconjugates-specific fluorophores

    NASA Astrophysics Data System (ADS)

    Hao, Likai; Guo, Yuan; Byrne, James M.; Zeitvogel, Fabian; Schmid, Gregor; Ingino, Pablo; Li, Jianli; Neu, Thomas R.; Swanner, Elizabeth D.; Kappler, Andreas; Obst, Martin

    2016-05-01

    Aggregates consisting of bacterial cells, extracellular polymeric substances (EPS) and Fe(III) minerals formed by Fe(II)-oxidizing bacteria are common at bulk or microscale chemical interfaces where Fe cycling occurs. The high sorption capacity and binding capacity of cells, EPS, and minerals controls the mobility and fate of heavy metals. However, it remains unclear to which of these component(s) the metals will bind in complex aggregates. To clarify this question, the present study focuses on 3D mapping of heavy metals sorbed to cells, glycoconjugates that comprise the majority of EPS constituents, and Fe(III) mineral aggregates formed by the phototrophic Fe(II)-oxidizing bacteria Rhodobacter ferrooxidans SW2 using confocal laser scanning microscopy (CLSM) in combination with metal- and glycoconjugates-specific fluorophores. The present study evaluated the influence of glycoconjugates, microbial cell surfaces, and (biogenic) Fe(III) minerals, and the availability of ferrous and ferric iron on heavy metal sorption. Analyses in this study provide detailed knowledge on the spatial distribution of metal ions in the aggregates at the sub-μm scale, which is essential to understand the underlying mechanisms of microbe-mineral-metal interactions. The heavy metals (Au3+, Cd2+, Cr3+, CrO42-, Cu2+, Hg2+, Ni2+, Pd2+, tributyltin (TBT) and Zn2+) were found mainly sorbed to cell surfaces, present within the glycoconjugates matrix, and bound to the mineral surfaces, but not incorporated into the biogenic Fe(III) minerals. Statistical analysis revealed that all ten heavy metals tested showed relatively similar sorption behavior that was affected by the presence of sorbed ferrous and ferric iron. Results in this study showed that in addition to the mineral surfaces, both bacterial cell surfaces and the glycoconjugates provided most of sorption sites for heavy metals. Simultaneously, ferrous and ferric iron ions competed with the heavy metals for sorption sites on the organic

  3. Broom fibre PRB for heavy metals groundwater remediation

    NASA Astrophysics Data System (ADS)

    Molinari, A.; Troisi, S.; Fallico, C.; Paparella, A.; Straface, S.

    2009-04-01

    Soil contamination by heavy metal and, though it, of groundwater represent a serious alteration of original geochemical levels owing to various human activities as: particular industrial processes and their non-correct treatment emission, urban traffic, use of phytosanitary product and mineral fertilizer. Heavy metals are genotoxic contaminants who can be found by environmental matrix analysis or by examination of the genetic damage inducted, after exposition, to sentry organism. In this last case we use a relative quantitation of the gene expression monitoring the mitochondrial oxidative metabolism hepatopancreas's gene of the organism used by bioindicator. This test is based on consideration that the hepatopancreas is the first internal organ affected by heavy metals or any other pollutant that the organism is exposed. In this work, the organism used by bioindicator to evalutate the pollutant contamination of waste water is Danio rerio (Zebrafish) that is a little tropical fish of 2-3 cm, native on asiatic south-east rivers. This organism has a large use in scientific field because its genoma is almost completely mapped and, above all, because the congenital gene cause in human, if it was mutated in zebrafish, similar damage or almost similar mutation that happens in human being so you can develop a dose - response curve. To do this, after prepared a cadmium solution with a concentration 10 times the Italian normative limit, the organisms have been put in the aquarium to recreate the optimal condition to survival of zebrafish observed by continuous monitoring by web-cam. After one month exposition, that we took little by little sample fish to analyzing, for different exposition time, the hepatopancreas's fish. First results shows considerable variation of the gene expression by interested gene in mitochondrial oxidative metabolism compared to control, highlighting the mutagenity caused by heavy metals on Danio rerio's hepatopancreas and, mutatis mutandis, also in

  4. Heavy metals and neurodegenerative diseases: an observational study.

    PubMed

    Giacoppo, Sabrina; Galuppo, Maria; Calabrò, Rocco Salvatore; D'Aleo, Giangaetano; Marra, Angela; Sessa, Edoardo; Bua, Daniel Giuseppe; Potortì, Angela Giorgia; Dugo, Giacomo; Bramanti, Placido; Mazzon, Emanuela

    2014-11-01

    In this study, we evaluated the levels of some of the most investigated metals (Cu, Se, Zn, Pb, and Hg) in the blood of patients affected by the most common chronic neurodegenerative diseases like Alzheimer's disease (AD) and multiple sclerosis (MS), in order to better clarify their involvement. For the first time, we investigated a Sicilian population living in an area exposed to a potentially contaminated environment from dust and fumes of volcano Etna and consumer of a considerable quantity of fish in their diet, so that this represents a good cohort to demonstrate a possible link between metals levels and development of neurodegenerative disorders. More specifically, 15 patients affected by AD, 41 patients affected by MS, 23 healthy controls, and 10 healthy elderly controls were recruited and subjected to a venous blood sampling. Quantification of heavy metals was performed by Inductively Coupled Plasma-Mass Spectrometry (ICP-MS). This technique has allowed us to establish that there is a concomitance of heavy metal unbalance associated with AD more than in other neurodegenerative pathologies, such as MS. Also, we can assess that the concentration of these elements is independent from the diet, especially from occasional or habitual consumption of fruits and vegetables, prevalence in the diet of meat or fish, possible exposure to contaminated environment due both to the occupation and place of residence.

  5. Improving the sensitivity of bacterial bioreporters for heavy metals.

    PubMed

    Hynninen, Anu; Tönismann, Karmen; Virta, Marko

    2010-01-01

    Whole-cell bacterial bioreporters represent a convenient testing method for quantifying the bioavailability of contaminants in environmental samples. Despite the fact that several bioreporters have been constructed for measuring heavy metals, their application to environmental samples has remained minimal. The major drawbacks of the available bioreporters include a lack of sensitivity and specificity. Here, we report an improvement in the limit of detection of bacterial bioreporters by interfering with the natural metal homeostasis system of the host bacterium. The limit of detection of a Pseudomonas putida KT2440-based Zn/Cd/Pb-biosensor was improved by a factor of up to 45 by disrupting four main efflux transporters for Zn/Cd/Pb and thereby causing the metals to accumulate in the cell. The specificity of the bioreporter could be modified by changing the sensor element. A Zn-specific bioreporter was achieved by using the promoter of the cadA1 gene from P. putida as a sensor element. The constructed transporter-deficient P. putida reporter strain detected Zn(2+) concentrations about 50 times lower than that possible with other available Zn-bioreporters. The achieved detection limits were significantly below the permitted limit values for Zn and Pb in water and in soil, allowing for reliable detection of heavy metals in the environment.

  6. Accumulation of heavy metals in the mole in Finland.

    PubMed

    Pankakoski, E; Hyvärinen, H; Jalkanen, M; Koivisto, I

    1993-01-01

    Metal concentrations (Cu, Ni, Zn, Cd, Cr, Hg, Pb and Mo) were analysed from the liver and kidneys of moles, Talpa europaea L. (Insectivora), trapped in southern Finland on both contaminated and rural areas. In rural areas the concentrations of Cd, Cu, Zn, Pb and Mo were lower in juveniles (individuals in their first summer), except for Zn in the liver, which was lower in adults. When the animals were divided into annual classes (0-6 years), Cd and Mo concentrations in the liver increased significantly with age, while concentrations of Cu, Zn and Cr tended to decrease. Female moles had higher Pb concentrations than males, especially adult females, which also had lower levels of Cu in the liver than adult males. Moles in the metropolitan area of Helsinki clearly differed from those in rural areas in that the concentrations of heavy metals in these moles were higher (especially for the most toxic metals: Cd, Pb and Hg), and their body weight was lower. The renal concentrations of Cd in most of the moles in Helsinki exceeded the threshold that has been shown to have a nephrotoxic effect in mammals. In one subsample from Helsinki, Pb and Zn concentrations in the mole liver decreased as the distance from the highway increased. Concentrations of Pb in earthworms and several heavy metals in soil also decreased similarly in the same area. Our data indicate that Pb accumulates in moles through their diet of earthworms. PMID:15091866

  7. Improving the sensitivity of bacterial bioreporters for heavy metals.

    PubMed

    Hynninen, Anu; Tönismann, Karmen; Virta, Marko

    2010-01-01

    Whole-cell bacterial bioreporters represent a convenient testing method for quantifying the bioavailability of contaminants in environmental samples. Despite the fact that several bioreporters have been constructed for measuring heavy metals, their application to environmental samples has remained minimal. The major drawbacks of the available bioreporters include a lack of sensitivity and specificity. Here, we report an improvement in the limit of detection of bacterial bioreporters by interfering with the natural metal homeostasis system of the host bacterium. The limit of detection of a Pseudomonas putida KT2440-based Zn/Cd/Pb-biosensor was improved by a factor of up to 45 by disrupting four main efflux transporters for Zn/Cd/Pb and thereby causing the metals to accumulate in the cell. The specificity of the bioreporter could be modified by changing the sensor element. A Zn-specific bioreporter was achieved by using the promoter of the cadA1 gene from P. putida as a sensor element. The constructed transporter-deficient P. putida reporter strain detected Zn(2+) concentrations about 50 times lower than that possible with other available Zn-bioreporters. The achieved detection limits were significantly below the permitted limit values for Zn and Pb in water and in soil, allowing for reliable detection of heavy metals in the environment. PMID:21326938

  8. EXAFS of heavy metal coordination in acid mine drainage sediments

    SciTech Connect

    Carroll, S.; O`Day, P.; Waychunas, G.; Phillips, B.

    1995-12-01

    We use extended x-ray adsorption fine structure (EXAFS) spectroscopy to examine the chemical environment of zinc (1-2 wt. %), lead (300-600 ppm) and cadmium (50-200 ppm) in complex acid mine drainage sediments from the Tri-State Mining District (KS, MO, OK). The sediments in streams draining tailings piles and open mine shafts are dominated by quartz or amorphous iron hydroxides; accessory minerals include calcite. The bulk water chemistry is buffered by the limestone geology and is undersaturated with respect to pure heavy metal carbonates and hydroxides. EXAFS spectra of the sediment samples were taken at SSRL with a fluorescence detector at low temperature ({approximately}10 K). Heavy metals do not form pure carbonate or hydroxide phases, nor do they appear to sorb to quartz surfaces. In sediments near the mine source, the metals are present primarily as sulfides, the original host mineral. With increasing distance from the source, second-neighbor backscattering from Fe indicates that the metals leached from the sulfides are taken up with amorphous iron hydroxides.

  9. Monitoring of heavy metal burden in mute swan (Cygnus olor).

    PubMed

    Grúz, Adrienn; Szemerédy, Géza; Kormos, Éva; Budai, Péter; Majoros, Szilvia; Tompai, Eleonóra; Lehel, József

    2015-10-01

    Concentrations of heavy metals (especially arsenic, cadmium, chromium, copper, mercury and lead) were measured in the contour (body) feathers of mute swans (Cygnus olor) and in its nutrients (fragile stonewort [Chara globularis], clasping leaf pondweed [Potamogeton perfoliatus], Eurasian watermilfoil [Myriophyllum spicatum], fennel pondweed [Potamogeton pectinatus]) to investigate the accumulation of metals during the food chain. The samples (17 feathers, 8 plants) were collected at Keszthely Bay of Lake Balaton, Hungary. Dry ashing procedure was used for preparing of sample and the heavy metal concentrations were analysed by inductively coupled plasma optical emission spectroscopy (ICP-OES). Copper (10.24 ± 2.25 mg/kg) and lead (1.11 ± 1.23 mg/kg) were detected the highest level in feathers, generally, the other metals were mostly under the detection limit (0.5 mg/kg). However, the concentrations of the arsenic (3.17 ± 1.87 mg/kg), cadmium (2.41 ± 0.66 mg/kg) and lead (2.42 ± 0.89 mg/kg) in the plants were low but the chromium (198.27 ± 102.21 mg/kg) was detected in high concentration. PMID:26044143

  10. Snails from heavy-metal polluted environments have reduced sensitivity to carbon dioxide-induced acidity.

    PubMed

    Lefcort, Hugh; Cleary, David A; Marble, Aaron M; Phillips, Morgan V; Stoddard, Timothy J; Tuthill, Lara M; Winslow, James R

    2015-01-01

    Anthropogenic atmospheric CO2 reacts with water to form carbonic acid (H2CO3) which increases water acidity. While marine acidification has received recent consideration, less attention has been paid to the effects of atmospheric carbon dioxide on freshwater systems-systems that often have low buffering potential. Since many aquatic systems are already impacted by pollutants such as heavy metals, we wondered about the added effect of rising atmospheric CO2 on freshwater organisms. We studied aquatic pulmonate snails (Physella columbiana) from both a heavy-metal polluted watershed and snails from a reference watershed that has not experienced mining pollution. We used gaseous CO2 to increase water acidity and we then measured changes in antipredatory behavior and also survival. We predicted a simple negative additive effect of low pH. We hypothesized that snails from metal-polluted environments would be physiologically stressed and impaired due to defense responses against heavy metals. Instead, snails from populations that acclimated or evolved in the presence of heavy metal mining pollution were more robust to acidic conditions than were snails from reference habitats. Snails from mining polluted sites seemed to be preadapted to a low pH environment. Their short-term survival in acidic conditions was better than snails from reference sites that lacked metal pollution. In fact, the 48 h survival of snails from polluted sites was so high that it did not significantly differ from the 24 h survival of snails from control sites. This suggests that the response of organisms to a world with rising anthropogenic carbon dioxide levels may be complex and difficult to predict. Snails had a weaker behavioral response to stressful stimuli if kept for 1 month at a pH that differed from their lake of origin. We found that snails raised at a pH of 5.5 had a weaker response (less of a decrease in activity) to concentrated heavy metals than did snails raised at their natal pH of

  11. Snails from heavy-metal polluted environments have reduced sensitivity to carbon dioxide-induced acidity.

    PubMed

    Lefcort, Hugh; Cleary, David A; Marble, Aaron M; Phillips, Morgan V; Stoddard, Timothy J; Tuthill, Lara M; Winslow, James R

    2015-01-01

    Anthropogenic atmospheric CO2 reacts with water to form carbonic acid (H2CO3) which increases water acidity. While marine acidification has received recent consideration, less attention has been paid to the effects of atmospheric carbon dioxide on freshwater systems-systems that often have low buffering potential. Since many aquatic systems are already impacted by pollutants such as heavy metals, we wondered about the added effect of rising atmospheric CO2 on freshwater organisms. We studied aquatic pulmonate snails (Physella columbiana) from both a heavy-metal polluted watershed and snails from a reference watershed that has not experienced mining pollution. We used gaseous CO2 to increase water acidity and we then measured changes in antipredatory behavior and also survival. We predicted a simple negative additive effect of low pH. We hypothesized that snails from metal-polluted environments would be physiologically stressed and impaired due to defense responses against heavy metals. Instead, snails from populations that acclimated or evolved in the presence of heavy metal mining pollution were more robust to acidic conditions than were snails from reference habitats. Snails from mining polluted sites seemed to be preadapted to a low pH environment. Their short-term survival in acidic conditions was better than snails from reference sites that lacked metal pollution. In fact, the 48 h survival of snails from polluted sites was so high that it did not significantly differ from the 24 h survival of snails from control sites. This suggests that the response of organisms to a world with rising anthropogenic carbon dioxide levels may be complex and difficult to predict. Snails had a weaker behavioral response to stressful stimuli if kept for 1 month at a pH that differed from their lake of origin. We found that snails raised at a pH of 5.5 had a weaker response (less of a decrease in activity) to concentrated heavy metals than did snails raised at their natal pH of

  12. Ecotoxic heavy metals transformation by bacteria and fungi in aquatic ecosystem.

    PubMed

    Chaturvedi, Amiy Dutt; Pal, Dharm; Penta, Santhosh; Kumar, Awanish

    2015-10-01

    Water is the most important and vital molecule of our planet and covers 75% of earth surface. But it is getting polluted due to high industrial growth. The heavy metals produced by industrial activities are recurrently added to it and considered as dangerous pollutants. Increasing concentration of toxic heavy metals (Pb(2+), Cd(2+), Hg(2+), Ni(2+)) in water is a severe threat for human. Heavy metal contaminated water is highly carcinogenic and poisonous at even relatively low concentrations. When they discharged in water bodies, they dissolve in the water and are distributed in the food chain. Bacteria and fungi are efficient microbes that frequently transform heavy metals and remove toxicity. The application of bacteria and fungi may offer cost benefit in water treatment plants for heavy metal transformation and directly related to public health and environmental safety issues. The heavy metals transformation rate in water is also dependent on the enzymatic capability of microorganisms. By transforming toxic heavy metals microbes sustain aquatic and terrestrial life. Therefore the application of microbiological biomass for heavy metal transformation and removal from aquatic ecosystem is highly significant and striking. This paper reviews the microbial transformation of heavy metal, microbe metal interaction and different approaches for microbial heavy metal remediation from water bodies.

  13. Chelant extraction of heavy metals from contaminated soils.

    PubMed

    Peters, R W

    1999-04-23

    The current state of the art regarding the use of chelating agents to extract heavy metal contaminants has been addressed. Results are presented for treatability studies conducted as worst-case and representative soils from Aberdeen Proving Ground's J-Field for extraction of copper (Cu), lead (Pb), and zinc (Zn). The particle size distribution characteristics of the soils determined from hydrometer tests are approximately 60% sand, 30% silt, and 10% clay. Sequential extractions were performed on the 'as-received' soils (worst case and representative) to determine the speciation of the metal forms. The technique speciates the heavy metal distribution into an easily extractable (exchangeable) form, carbonates, reducible oxides, organically-bound, and residual forms. The results indicated that most of the metals are in forms that are amenable to soil washing (i.e. exchangeable+carbonate+reducible oxides). The metals Cu, Pb, Zn, and Cr have greater than 70% of their distribution in forms amenable to soil washing techniques, while Cd, Mn, and Fe are somewhat less amenable to soil washing using chelant extraction. However, the concentrations of Cd and Mn are low in the contaminated soil. From the batch chelant extraction studies, ethylenediaminetetraacetic acid (EDTA), citric acid, and nitrilotriacetic acid (NTA) were all effective in removing copper, lead, and zinc from the J-Field soils. Due to NTA being a Class II carcinogen, it is not recommended for use in remediating contaminated soils. EDTA and citric acid appear to offer the greatest potential as chelating agents to use in soil washing the Aberdeen Proving Ground soils. The other chelating agents studied (gluconate, oxalate, Citranox, ammonium acetate, and phosphoric acid, along with pH-adjusted water) were generally ineffective in mobilizing the heavy metals from the soils. The chelant solution removes the heavy metals (Cd, Cu, Pb, Zn, Fe, Cr, As, and Hg) simultaneously. Using a multiple-stage batch extraction

  14. Chelant extraction of heavy metals from contaminated soils.

    PubMed

    Peters, R W

    1999-04-23

    The current state of the art regarding the use of chelating agents to extract heavy metal contaminants has been addressed. Results are presented for treatability studies conducted as worst-case and representative soils from Aberdeen Proving Ground's J-Field for extraction of copper (Cu), lead (Pb), and zinc (Zn). The particle size distribution characteristics of the soils determined from hydrometer tests are approximately 60% sand, 30% silt, and 10% clay. Sequential extractions were performed on the 'as-received' soils (worst case and representative) to determine the speciation of the metal forms. The technique speciates the heavy metal distribution into an easily extractable (exchangeable) form, carbonates, reducible oxides, organically-bound, and residual forms. The results indicated that most of the metals are in forms that are amenable to soil washing (i.e. exchangeable+carbonate+reducible oxides). The metals Cu, Pb, Zn, and Cr have greater than 70% of their distribution in forms amenable to soil washing techniques, while Cd, Mn, and Fe are somewhat less amenable to soil washing using chelant extraction. However, the concentrations of Cd and Mn are low in the contaminated soil. From the batch chelant extraction studies, ethylenediaminetetraacetic acid (EDTA), citric acid, and nitrilotriacetic acid (NTA) were all effective in removing copper, lead, and zinc from the J-Field soils. Due to NTA being a Class II carcinogen, it is not recommended for use in remediating contaminated soils. EDTA and citric acid appear to offer the greatest potential as chelating agents to use in soil washing the Aberdeen Proving Ground soils. The other chelating agents studied (gluconate, oxalate, Citranox, ammonium acetate, and phosphoric acid, along with pH-adjusted water) were generally ineffective in mobilizing the heavy metals from the soils. The chelant solution removes the heavy metals (Cd, Cu, Pb, Zn, Fe, Cr, As, and Hg) simultaneously. Using a multiple-stage batch extraction

  15. Amperometric biosensors for the determination of heavy metals

    NASA Astrophysics Data System (ADS)

    Compagnone, Dario; Palleschi, Giuseppe; Varallo, Giuseppe; Imperiali, PierLuigi

    1995-10-01

    A bioelectrochemical method for the determination of heavy metal ions has been developed. This method is based on the inhibition effect of metal ions on the enzymatic activity of oxidase enzymes. The enzymatic activity was determined with an amperometric hydrogen peroxide probe. The inhibition effect on enzymes in solution and covalently immobilized on polymeric supports has been evaluated. Hg(II) was the metal ion that inhibited almost all the enzymes, particularly glycerol-3-P oxidase. Hg(II) was detected in the 0.05/0.5 ppm range with the enzyme in solution. Calibration curves for Hg(II) were also obtained with the other oxidase enzymes in the 0.5/10 ppm range. The other metal ions tested inhibited the enzymes more specifically. The metal ion/enzyme systems which gave the best inhibition were Se(IV)/glutathione oxidase, Ni(II)/sarcosine oxidase, V(V)/glutathione oxidase, Cu(II)/alcohol oxidase from Pichia Pastoris and Cd(II)/D-aminoacid oxidase. All these metal ions were detected in the 0.1/10 ppm range using the enzymes in solution or covalently immobilized.

  16. Amperometric biosensors for the determination of heavy metals

    SciTech Connect

    Compagnone, D.; Palleschi, G.; Varallo, G.; Imperiali, P.L.

    1995-12-31

    A bioelectrochemical method for the determination of heavy metal ions has been developed. This method is based on the inhibition effect of metal ions on the enzymatic activity of oxidase enzymes. The enzymatic activity was determined with an amperometric hydrogen peroxide probe. The inhibition effect on enzymes in solution and covalently immobilized on polymeric supports has been evaluated. Hg(II) was the metal ion that inhibited almost all the enzymes, particularly glycerol-3-P oxidase. Hg(II) was detected in the 0.05/0.5 ppm range with the enzyme in solution. Calibration curves for Hg(II) were also obtained with the other oxidase enzymes in the 0.5/10 ppm range. The other metal ions tested inhibited the enzymes more specifically. The metal ion/enzyme systems which gave the best inhibition were Se(IV)/glutathione oxidase, Ni(II)/sarcosine oxidase, V(V)/glutathione oxidase, Cu(II)/alcohol oxidase from Pichia Pastoris and Cd(II)/D-amino acid oxidase. All these metal ions were detected in the 0.1/10 ppm range using the enzymes in solution or covalently immobilized.

  17. Heavy metal concentrations in edible barnacles exposed to natural contamination.

    PubMed

    Dionísio, M; Costa, A; Rodrigues, A

    2013-04-01

    The giant barnacle Megabalanus azoricus is a popular seafood in the Azores. It is mainly caught in coastal environments and sold for domestic human consumption. This species is a filter feeder and can be used as a biomonitor of trace metal bioavailabilities. To investigate consumption safety, the concentrations of 10 trace metals - As, Cd, Cr, Cu, Mn, Pb, Rb, Se, Sr and Zn - were evaluated in 3 body tissues of M. azoricus from 3 sites on 2 islands. There were no significant differences between the metal loads of the barnacles from the different sites. However, the concentrations of the total trace metal loads revealed significant differences among the tissues (cirrus, muscles and ovaries). The concentrations of some metals in the body were not within the safety levels for consumers, based on the allowable standard levels for crustaceans issued by the European Union and of legislations in several countries. Alarming levels of As and Cd were found. Considering the absence of heavy industry in the region, a non-anthropogenic volcanic source was assumed to be the reason for the observed metal levels. Barnacles, in particular M. azoricus, seem to be useful as bioindicators in this peculiar environment.

  18. Effect of heavy metal-solubilizing microorganisms on zinc and cadmium extractions from heavy metal contaminated soil with Tricholoma lobynsis.

    PubMed

    Ji, Ling-yun; Zhang, Wei-wei; Yu, Dong; Cao, Yan-ru; Xu, Heng

    2012-01-01

    The macrofungus, Tricholoma lobynsis, was chosen to remedy Zn-Cd-Pb contaminated soil. To enhance its metal-extracting efficiency, two heavy metal resistant microbes M6 and K1 were applied owing to their excellent abilities to solubilize heavy metal salts. The two isolated microbial strains could also produce indole acetic acid (IAA), siderophore and solubilize inorganic phosphate, but neither of them showed 1-aminocyclopropane-1-carboxylate deaminase activity. The strains M6 and K1 were identified as Serratia marcescens and Rhodotorula mucilaginosa based on 16S rDNA and ITS sequence analysis respectively. Pot experiment showed that spraying to T. lobynsis-inoculated soil with M6 and K1 respectively could increase total Cd accumulations of this mushroom by 216 and 61%, and Zn by 153 and 49% compared to the uninoculated control. Pb accumulation however, was too low (<1 mg kg(-1)) to be determined. The results illustrated that special microbes and macrofungi can work together to remedy polluted soil as plant and plant growth promoting microbes do, probably because of excellent metal-accumulating abilities of macrofungi and IAA-siderophore production, phosphate solubilization abilities of the assisted-microbes. This kind of macrofungi-microbe interaction can be developed into a novel bioremediation strategy.

  19. Estimation of Heavy Metal Contamination in Groundwater and Development of a Heavy Metal Pollution Index by Using GIS Technique.

    PubMed

    Tiwari, Ashwani Kumar; Singh, Prasoon Kumar; Singh, Abhay Kumar; De Maio, Marina

    2016-04-01

    Heavy metal (Al, As, Ba, Cr, Cu, Fe, Mn, Ni, Se and Zn) concentration in sixty-six groundwater samples of the West Bokaro coalfield were analyzed using inductively coupled plasma-mass spectroscopy for determination of seasonal fluctuation, source apportionment and heavy metal pollution index (HPI). Metal concentrations were found higher in the pre-monsoon season as compared to the post-monsoon season. Geographic information system (GIS) tool was attributed to study the metals risk in groundwater of the West Bokaro coalfield. The results show that 94 % of water samples were found as low class and 6 % of water samples were in medium class in the post-monsoon season. However, 79 % of water samples were found in low class, 18 % in medium class and 3 % in high class in the pre-monsoon season. The HPI values were below the critical pollution index value of 100. The concentrations of Al, Fe, Mn, and Ni are exceeding the desirable limits in many groundwater samples in both seasons. PMID:26886427

  20. Estimation of Heavy Metal Contamination in Groundwater and Development of a Heavy Metal Pollution Index by Using GIS Technique.

    PubMed

    Tiwari, Ashwani Kumar; Singh, Prasoon Kumar; Singh, Abhay Kumar; De Maio, Marina

    2016-04-01

    Heavy metal (Al, As, Ba, Cr, Cu, Fe, Mn, Ni, Se and Zn) concentration in sixty-six groundwater samples of the West Bokaro coalfield were analyzed using inductively coupled plasma-mass spectroscopy for determination of seasonal fluctuation, source apportionment and heavy metal pollution index (HPI). Metal concentrations were found higher in the pre-monsoon season as compared to the post-monsoon season. Geographic information system (GIS) tool was attributed to study the metals risk in groundwater of the West Bokaro coalfield. The results show that 94 % of water samples were found as low class and 6 % of water samples were in medium class in the post-monsoon season. However, 79 % of water samples were found in low class, 18 % in medium class and 3 % in high class in the pre-monsoon season. The HPI values were below the critical pollution index value of 100. The concentrations of Al, Fe, Mn, and Ni are exceeding the desirable limits in many groundwater samples in both seasons.

  1. Speciation of selected heavy metals geochemistry in surface sediments from Tirumalairajan river estuary, east coast of India.

    PubMed

    Venkatramanan, S; Ramkumar, T; Anithamary, I; Jonathan, M P

    2013-08-01

    Surface sediment samples from the Tirumalairajan river estuary were studied for grain size pattern, organic matter, and heavy metals (Fe, Mn, Zn, and Pb) using the sequential and bulk metal extraction methods to evaluate metal behavior. Ten surface sediment samples were collected during the monsoon and summer seasons of the year 2009. The observed orders of concentrations of heavy metals in the sediments were as follows: Fe > Mn > Zn > Pb. The results obtained from sequential extraction showed that, among the metals studied, a larger portion of the metals were associated with the residual phase, although they are available in other fractions. The low concentration of metals available in bioavailable phases indicated that the sediments of Tirumalairajan river estuary were relatively unpolluted. Correlation analysis was also carried out to understand the associations of metals in different phases with sand, silt, clay, and organic matter. To understand the risk of heavy metals to sediment-dwelling organisms, the data were compared with risk assessment code and sediment quality values using the screening quick reference table. The main source of metals to the estuary is from the irrigation field and its associated activities in the study area.

  2. Metal-organic framework templated inorganic sorbents for rapid and efficient extraction of heavy metals.

    PubMed

    Abney, C W; Gilhula, J C; Lu, K; Lin, W

    2014-12-17

    An innovative wet-treatment with Na2 S transforms two indium metal-organic frameworks (MOFs) into a series of porous inorganic sorbents. These MOF-templated materials display remarkable affinity for heavy metals with saturation occurring in less than 1 h. The saturation capacity for Hg(II) exceeds 2 g g(-1) , more than doubling the best thiol-functionalized sorbents in the literature.

  3. Heavy metals in urban soils of the Granada city (Spain)

    NASA Astrophysics Data System (ADS)

    Delgado, Gabriel; Sánchez-Marañón, Manuel; Bech, Jaume; Sartini, Alessandra; Martín-García, Juan Manuel; Delgado, Rafael

    2013-04-01

    Urban soils (Anthrosols, Technosols, and the remaining natural patches) are essential components of the city ecosystems influencing the quality of life for people. Unfortunately, because of the high concentration of matter and energy that occurs in any city, these soils might accumulate potentially toxic pollutants such as heavy metals, organic compounds, pathogens, pharmaceuticals, and soluble salts. Contamination by heavy metals has been considered especially dangerous because they can affect human health via inhalation of dust, ingestion, or skin contact with soils. Children are the more exposed citizens in gardens and parks. Accordingly, our objective was to analyze the content of heavy metals in soils of the two most emblematic, extensive, and visited landscaped areas of the Granada city (Salón Garden, which dates back to 1612, and Federico García Lorca Park, opened since 1993) for assessing the health hazard. Using a composite sampling of 20-30 points chosen at random, we collected the upper soil (10 cm) of five representative plots for each landscaped area. We determined soil characteristics by routine procedures and metal elements using ICP-mass. From high to low concentration we found Mn, Ba, Pb, Zn, V, Sn, Cr, Cu, Ni, Sb, Y, As, Sc, Co, Th, Au, U, Mo, Be, Bi, Tl, Cd, and In; the first 10 metals ranging between 478 and 22 ppm. Mn, Ba, and other trace elements were strongly correlated with soil properties suggesting the inheritance as a possible source of metal variation, especially in the soils of younger Park, where the materials used to build gardens in the five sampled plots seemed to be more variable (carbonates: 10-40%, clay: 18-26%, pH: 7.6-7.9, organic matter: 3-7%, free iron 0.5-1.1%). The content of many other metals measured in the sampled plots, however, were independent of soil material and management. On the other hand, compared to agricultural and native soils of the surroundings, our urban soils had obviously greater content in organic

  4. [Gastric non-Hodgkin lymphoma associated with heavy metal exposures].

    PubMed

    Garavito Rentería, Jorge; Araujo Banchón, William Javier; Quesada Ríos, María Pía; Ponce de León, Diego

    2012-01-01

    Primary extranodal Non-Hodgkin lymphoma (NHL) is a non epithelial tumours that accounts for 40% of cases of NHL. Spread of nodal lymphomas to the gastrointestinal tract (GIT) is the most common location. Within the GIT is the stomach the most affected organ (60%). We report the case of 52-year- old man , mining company worker for over 10 years, which is derived to the Service of Gastroenterology with history of epigastric pain, nausea, vomiting and weight loss. Upper gastrointestinal endoscopic examination revealed an ulcerated lesion on greater curve of stomach and histopathological examination and subsequent immunohistochemical analysis showed diffuse large B cell gastric NHL. Also, the patient had multiple organ involvement in relation to chronic exposure to heavy metals, which was found in the mineralograma, with the highest concentration of uranium, thallium, arsenic, lead and mercury. The literature has described the association of chronic occupational exposure to uranium and arsenic with NHL presenting gastrointestinal involvement. Therefore, gastric commitment can not be considered as an isolated injury, but rather part of systemic involvement associated with elevated concentrations of metals. Mining is a key driver of income for Peru; however, there are no reports to date of the association of gastrointestinal NHL commitment regarding occupational exposure to heavy metals. PMID:23307094

  5. Agriculturally Induced Heavy Metal Accumulation in Seyfe Lake, Turkey.

    PubMed

    Bölükbaşı, Vildan; Akın, Beril Salman

    2016-03-01

    The aim of the present 1-year study was to investigate the effect of heavy metals in synthetic fertilizers on water and sediment quality in the Seyfe Lake, where agricultural activity was the only anthropogenic source. Metal concentrations of five different types of synthetic fertilizers used in agricultural fields within the Seyfe Lake closed basin were as follows: Zn > Pb > Cu > Cr > Cd > As > Ni > Co. The annual average of heavy metal concentrations in the sediment samples were as follows: Zn > Pb > As > Cr > Ni > Cu > Cd > Co. Seyfe Lake sediment was classified as anthropogenically "highly polluted" in terms of the As and Zn concentrations at each sample station based on the sediment quality guidelines. Furthermore, the sediment could be classified as "moderately to highly polluted" in terms of the As concentration, based on the geo-accumulation index. PMID:26744023

  6. Acute toxicity of heavy metals towards freshwater ciliated protists.

    PubMed

    Madoni, Paolo; Romeo, Maria Giuseppa

    2006-05-01

    The acute toxicity of five heavy metals to four species of freshwater ciliates (Colpidium colpoda, Dexiotricha granulosa, Euplotes aediculatus, and Halteria grandinella) was examined in laboratory tests. After exposing the ciliates to soluble compound of cadmium, copper, chromium, lead, and nickel at several selected concentrations, the mortality rate was registered and the LC50 values (with 95% confidence intervals) were calculated. Large differences appeared in sensitivities of the four species to the metals. H. grandinella showed the highest sensitivity for cadmium (0.07 mg l(-1), LC50) and lead (0.12 mg l(-1), LC50), whilst E. aediculatus showed the highest sensitivity for nickel (0.03 mg l(-1), LC50). The comparison with data obtained with other species indicate that Halteria grandinella and Euplotes aediculatus are excellent and convenient bioindicator for evaluating the toxicity of waters and wastewaters polluted by heavy metals. The short time (24 h) and simplicity of the test procedure enable this test to be used in laboratory studies.

  7. 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).

  8. 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.

  9. Magnetic mineralogy of heavy metals-contaminated soils

    NASA Astrophysics Data System (ADS)

    Shenggao, L.

    2012-04-01

    Soils around mine and in urban areas are often contaminated by heavy metals derived from industrial and human activities [1, 2]. These contaminated soils are often characterized by a magnetic enhancement on topsoils. Many studies demonstrated that there are significant correlations between heavy metals and various magnetic parameters in contaminated soils, indicating a strong affinity of heavy metals to magnetic minerals. The magnetic particles in contaminated soils were separated by a magnetic separation technique. The rock magnetism, XRD, field emission scanning electron microscopy equiped with an energy-dispersive X-ray analyzer (FESEM/EDX) were used to characterize their magnetic mineralogy. Results of XRD analysis indicated that the magnetic particles separated from heavy metal-contaminated soils are composed of quartz, magnetite, and hematite. Based on the X-ray diffraction peak intensity, the Fe3O4 was identified as the predominant magnetic mineral phase. The high-temperature magnetization (Ms-T) curves of magnetic particles extracted from contaminated soils show a sharp Ms decrease at about 580C (the Curie temperature of magnetite), suggesting that magnetite is the dominant magnetic carrier. The hysteresis loops of contaminated soils are closed at about 100-200 mT which is consistent with the presence of a dominant ferrimagnetic mineral phase. The FESEM analysis showed a great variety of shapes of magnetic particles in contaminated soils. The most common morphology are observed in the form of spherules, with the sizes ranging from 20 to 100 um. The chemical composition of magnetic particles consist mainly of Fe, Si, Al, and Ca with minor heavy metal elements (Cu, Zn, Hg, and Cr). The semi-quantitative Fe content identified by FESEM/EDX ranged from 40 to 90%. Combined studies of rock magnetism, XRD, and FESEM/EDX indicated that magnetic mineral phases responsible for the magnetic enhancement of contaminated soils are anthropogenic origin which are coarse

  10. Assessment of heavy metal pollution in vegetables and relationships with soil heavy metal distribution in Zhejiang province, China.

    PubMed

    Ye, Xuezhu; Xiao, Wendan; Zhang, Yongzhi; Zhao, Shouping; Wang, Gangjun; Zhang, Qi; Wang, Qiang

    2015-06-01

    There are increasing concerns on heavy metal contaminant in soils and vegetables. In this study, we investigated heavy metal pollution in vegetables and the corresponding soils in the main vegetable production regions of Zhejiang province, China. A total of 97 vegetable samples and 202 agricultural soil samples were analyzed for the concentrations of Cd, Pb, As, Hg, and Cr. The average levels of Cd, Pb, and Cr in vegetable samples [Chinese cabbage (Brassica campestris spp. Pekinensis), pakchoi (Brassica chinensis L.), celery (Apium graveolens), tomato (Lycopersicon esculentum), cucumber (Colletotrichum lagenarium), cowpea (Vigna unguiculata), pumpkin (Cucurbita pepo L.), and eggplant (Solanum melongena)] were 0.020, 0.048, and 0.043 mg kg(-1), respectively. The Pb and Cr concentrations in all vegetable samples were below the threshold levels of the Food Quality Standard (0.3 and 0.5 mg kg(-1), respectively), except that two eggplant samples exceeded the threshold levels for Cd concentrations (0.05 mg kg(-1)). As and Hg contents in vegetables were below the detection level (0.005 and 0.002 mg kg(-1), respectively). Soil pollution conditions were assessed in accordance with the Chinese Soil Quality Criterion (GB15618-1995, Grade II); 50 and 68 soil samples from the investigated area exceeded the maximum allowable contents for Cd and Hg, respectively. Simple correlation analysis revealed that there were significantly positive correlations between the metal concentrations in vegetables and the corresponding soils, especially for the leafy and stem vegetables such as pakchoi, cabbage, and celery. Bio-concentration factor values for Cd are higher than those for Pb and Cr, which indicates that Cd is more readily absorbed by vegetables than Pb and Cr. Therefore, more attention should be paid to the possible pollution of heavy metals in vegetables, especially Cd.

  11. Assessment of heavy metal pollution in vegetables and relationships with soil heavy metal distribution in Zhejiang province, China.

    PubMed

    Ye, Xuezhu; Xiao, Wendan; Zhang, Yongzhi; Zhao, Shouping; Wang, Gangjun; Zhang, Qi; Wang, Qiang

    2015-06-01

    There are increasing concerns on heavy metal contaminant in soils and vegetables. In this study, we investigated heavy metal pollution in vegetables and the corresponding soils in the main vegetable production regions of Zhejiang province, China. A total of 97 vegetable samples and 202 agricultural soil samples were analyzed for the concentrations of Cd, Pb, As, Hg, and Cr. The average levels of Cd, Pb, and Cr in vegetable samples [Chinese cabbage (Brassica campestris spp. Pekinensis), pakchoi (Brassica chinensis L.), celery (Apium graveolens), tomato (Lycopersicon esculentum), cucumber (Colletotrichum lagenarium), cowpea (Vigna unguiculata), pumpkin (Cucurbita pepo L.), and eggplant (Solanum melongena)] were 0.020, 0.048, and 0.043 mg kg(-1), respectively. The Pb and Cr concentrations in all vegetable samples were below the threshold levels of the Food Quality Standard (0.3 and 0.5 mg kg(-1), respectively), except that two eggplant samples exceeded the threshold levels for Cd concentrations (0.05 mg kg(-1)). As and Hg contents in vegetables were below the detection level (0.005 and 0.002 mg kg(-1), respectively). Soil pollution conditions were assessed in accordance with the Chinese Soil Quality Criterion (GB15618-1995, Grade II); 50 and 68 soil samples from the investigated area exceeded the maximum allowable contents for Cd and Hg, respectively. Simple correlation analysis revealed that there were significantly positive correlations between the metal concentrations in vegetables and the corresponding soils, especially for the leafy and stem vegetables such as pakchoi, cabbage, and celery. Bio-concentration factor values for Cd are higher than those for Pb and Cr, which indicates that Cd is more readily absorbed by vegetables than Pb and Cr. Therefore, more attention should be paid to the possible pollution of heavy metals in vegetables, especially Cd. PMID:26013654

  12. Heavy metal-activated synthesis of peptides in Chlamydomonas reinhardtii

    SciTech Connect

    Howe, G.; Merchant, S. )

    1992-01-01

    In this study, the authors have addressed the capacity of the green alga Chlamydomonas reinhardtii to produce metal-binding peptides in response to stress induced by the heavy metals Cd{sup 2+}, Hg{sup 2+}, and Ag{sup +}. Cells cultured in the presence of sublethal concentrations of Cd{sup 2+} synthesized and accumulated oligopeptides consisting solely of glutamic acid, cysteine, and glycine in an average ratio of 3:3:1. Cadmium-induced peptides were isolated in their native form as higher molecular weight peptide-metal complexes with an apparent molecular weight of approximately 6.5 {times} 10{sup 3}. The isolated complex bound cadmium (as evidenced by absorption spectroscopy) and sequestered (with a stoichiometry of 0.7 moles of cadmium per mole of cysteine) up to 70% of the total cadmium found in extracts of cadmium-treated cells. In Hg{sup 2+}-treated cells, the principal thiol-containing compound induced by Hg{sup 2+} ion was glutathione. It is possible that glutathione functions in plant cells (as it does in animal cells) to detoxify heavy metals. Cells treated with Ag{sup +} ions also synthesized a sulfur-containing component with a charge to mass ratio similar to Cd{sup 2+}-induced peptides. But, in contrast to the results obtained using Cd{sup 2+} as an inducer, these molecules did not accumulate to significant levels in Ag{sup +}-treated cells. The presence of physiological concentrations of Cu{sup 2+} in the growth medium blocked the synthesis of the Ag{sup +}-inducible component(s) and rendered cells resistant to the toxic effects of Ag{sup +}, suggesting competition between Cu{sup 2+} and Ag{sup +} ions, possibly at the level of metal uptake.

  13. The Chemophytostabilisation Process of Heavy Metal Polluted Soil.

    PubMed

    Grobelak, Anna; Napora, Anna

    2015-01-01

    Industrial areas are characterised by soil degradation processes that are related primarily to the deposition of heavy metals. Areas contaminated with metals are a serious source of risk due to secondary pollutant emissions and metal leaching and migration in the soil profile and into the groundwater. Consequently, the optimal solution for these areas is to apply methods of remediation that create conditions for the restoration of plant cover and ensure the protection of groundwater against pollution. Remediation activities that are applied to large-scale areas contaminated with heavy metals should mainly focus on decreasing the degree of metal mobility in the soil profile and metal bioavailability to levels that are not phytotoxic. Chemophytostabilisation is a process in which soil amendments and plants are used to immobilise metals. The main objective of this research was to investigate the effects of different doses of organic amendments (after aerobic sewage sludge digestion in the food industry) and inorganic amendments (lime, superphosphate, and potassium phosphate) on changes in the metals fractions in soils contaminated with Cd, Pb and Zn during phytostabilisation. In this study, the contaminated soil was amended with sewage sludge and inorganic amendments and seeded with grass (tall fescue) to increase the degree of immobilisation of the studied metals. The contaminated soil was collected from the area surrounding a zinc smelter in the Silesia region of Poland (pH 5.5, Cd 12 mg kg-1, Pb 1100 mg kg-1, Zn 700 mg kg-1). A plant growth experiment was conducted in a growth chamber for 5 months. Before and after plant growth, soil subsamples were subjected to chemical and physical analyses. To determine the fractions of the elements, a sequential extraction method was used according to Zeien and Brümmer. Research confirmed that the most important impacts on the Zn, Cd and Pb fractions included the combined application of sewage sludge from the food industry and

  14. The Chemophytostabilisation Process of Heavy Metal Polluted Soil

    PubMed Central

    Grobelak, Anna; Napora, Anna

    2015-01-01

    Industrial areas are characterised by soil degradation processes that are related primarily to the deposition of heavy metals. Areas contaminated with metals are a serious source of risk due to secondary pollutant emissions and metal leaching and migration in the soil profile and into the groundwater. Consequently, the optimal solution for these areas is to apply methods of remediation that create conditions for the restoration of plant cover and ensure the protection of groundwater against pollution. Remediation activities that are applied to large-scale areas contaminated with heavy metals should mainly focus on decreasing the degree of metal mobility in the soil profile and metal bioavailability to levels that are not phytotoxic. Chemophytostabilisation is a process in which soil amendments and plants are used to immobilise metals. The main objective of this research was to investigate the effects of different doses of organic amendments (after aerobic sewage sludge digestion in the food industry) and inorganic amendments (lime, superphosphate, and potassium phosphate) on changes in the metals fractions in soils contaminated with Cd, Pb and Zn during phytostabilisation. In this study, the contaminated soil was amended with sewage sludge and inorganic amendments and seeded with grass (tall fescue) to increase the degree of immobilisation of the studied metals. The contaminated soil was collected from the area surrounding a zinc smelter in the Silesia region of Poland (pH 5.5, Cd 12 mg kg-1, Pb 1100 mg kg-1, Zn 700 mg kg-1). A plant growth experiment was conducted in a growth chamber for 5 months. Before and after plant growth, soil subsamples were subjected to chemical and physical analyses. To determine the fractions of the elements, a sequential extraction method was used according to Zeien and Brümmer. Research confirmed that the most important impacts on the Zn, Cd and Pb fractions included the combined application of sewage sludge from the food industry and

  15. The Chemophytostabilisation Process of Heavy Metal Polluted Soil.

    PubMed

    Grobelak, Anna; Napora, Anna

    2015-01-01

    Industrial areas are characterised by soil degradation processes that are related primarily to the deposition of heavy metals. Areas contaminated with metals are a serious source of risk due to secondary pollutant emissions and metal leaching and migration in the soil profile and into the groundwater. Consequently, the optimal solution for these areas is to apply methods of remediation that create conditions for the restoration of plant cover and ensure the protection of groundwater against pollution. Remediation activities that are applied to large-scale areas contaminated with heavy metals should mainly focus on decreasing the degree of metal mobility in the soil profile and metal bioavailability to levels that are not phytotoxic. Chemophytostabilisation is a process in which soil amendments and plants are used to immobilise metals. The main objective of this research was to investigate the effects of different doses of organic amendments (after aerobic sewage sludge digestion in the food industry) and inorganic amendments (lime, superphosphate, and potassium phosphate) on changes in the metals fractions in soils contaminated with Cd, Pb and Zn during phytostabilisation. In this study, the contaminated soil was amended with sewage sludge and inorganic amendments and seeded with grass (tall fescue) to increase the degree of immobilisation of the studied metals. The contaminated soil was collected from the area surrounding a zinc smelter in the Silesia region of Poland (pH 5.5, Cd 12 mg kg-1, Pb 1100 mg kg-1, Zn 700 mg kg-1). A plant growth experiment was conducted in a growth chamber for 5 months. Before and after plant growth, soil subsamples were subjected to chemical and physical analyses. To determine the fractions of the elements, a sequential extraction method was used according to Zeien and Brümmer. Research confirmed that the most important impacts on the Zn, Cd and Pb fractions included the combined application of sewage sludge from the food industry and

  16. Heavy Metal Distribution in Street Dust from Traditional Markets and the Human Health Implications

    PubMed Central

    Kim, Jin Ah; Park, Jin Hee; Hwang, Won Ju

    2016-01-01

    Street dust is a hazard for workers in traditional markets. Exposure time is longer than for other people, making them vulnerable to heavy metals in street dust. This study investigated heavy metal concentrations in street dust samples collected from different types of markets. It compared the results with heavy metal concentrations in heavy traffic and rural areas. Street dust was significantly enriched with most heavy metals in a heavy traffic area while street dust from a fish market was contaminated with cupper (Cu), lead (Pb) and zinc (Zn). Street dust from medicinal herb and fruit markets, and rural areas were not contaminated. Principal component and cluster analyses indicated heavy metals in heavy traffic road and fish market dust had different sources. Relatively high heavy metal concentration in street dust from the fish market may negatively affect worker’s mental health, as depression levels were higher compared with workers in other markets. Therefore, intensive investigation of the relationship between heavy metal concentrations in street dust and worker’s health in traditional marketplaces should be conducted to elucidate the effect of heavy metals on psychological health in humans. PMID:27529268

  17. Heavy Metal Distribution in Street Dust from Traditional Markets and the Human Health Implications.

    PubMed

    Kim, Jin Ah; Park, Jin Hee; Hwang, Won Ju

    2016-08-13

    Street dust is a hazard for workers in traditional markets. Exposure time is longer than for other people, making them vulnerable to heavy metals in street dust. This study investigated heavy metal concentrations in street dust samples collected from different types of markets. It compared the results with heavy metal concentrations in heavy traffic and rural areas. Street dust was significantly enriched with most heavy metals in a heavy traffic area while street dust from a fish market was contaminated with cupper (Cu), lead (Pb) and zinc (Zn). Street dust from medicinal herb and fruit markets, and rural areas were not contaminated. Principal component and cluster analyses indicated heavy metals in heavy traffic road and fish market dust had different sources. Relatively high heavy metal concentration in street dust from the fish market may negatively affect worker's mental health, as depression levels were higher compared with workers in other markets. Therefore, intensive investigation of the relationship between heavy metal concentrations in street dust and worker's health in traditional marketplaces should be conducted to elucidate the effect of heavy metals on psychological health in humans.

  18. Current state of heavy metal contents in Vienna soils.

    PubMed

    Pfleiderer, Sebastian; Englisch, Michael; Reiter, Rainer

    2012-12-01

    This study presents the current state of heavy metal contents in both urban and forest soils within the city area of Vienna, Austria. Based on a systematic survey of urban soils and on targeted sampling in forest areas, local and regional anomaly thresholds are derived using statistical methods and considering regional distribution patterns. For urban soils, local anomaly thresholds of elements Cu (60 mg/kg), Hg (0.5 mg/kg), Pb (100 mg/kg) and Zn (200 mg/kg) exceed national guideline values for uncontaminated urban soils and according to Austrian legislation fall into the category "anthropogenic contamination present but no damage to plants, animals or humans detectable". In forest soils within the city, thresholds are very similar to reference values for similar geological settings outside the city, apart from higher concentrations of elements Cr and Ni (threshold values of 107 and 64 mg/kg, respectively). Grouping urban soils according to land use reveals that Cd contents are 25 % higher, Pb contents 36 % higher, in traffic and industrial areas than in parks and like Cu, Hg and Zn, these elements can be shown to be at least partly caused by anthropogenic contamination. A dependency between heavy metal concentrations in soils and underlying geological units is shown within the flysch zone at the western city margin where the contents of elements Co, Cr, Cu, Ni and V are controlled by geology and reveal distinct differences between geological units. In built-up areas, no clear dependency between heavy metal contents in soils and geology is evident as urban soils represent accumulations by anthropogenic activity rather than in situ weathering products of underlying sediments.

  19. Heavy metal partitioning in a municipal solid waste incinerator

    SciTech Connect

    Sorum, L.; Fossum, M.; Hustad, J.E.; Evensen, E.

    1997-12-01

    Norway has the following priorities for management of municipal solid waste (MSW) (1) Reduce waste generation and toxic components in waste, (2) Encourage re-use, recycling and energy recovery, and (3) Secure an environmentally safe management of residues. MSW consists of household waste and waste from the service and trade industry delivered to municipal waste treatment plants or recycling schemes. In 1995, a total of 2.7 million tons of MSW (1.26 million tons of household waste and 1.44 million tons of waste from service and trade industry) was handled as follows: 68% was deposited on landfills, 18% was combusted, 13% recycled and 1% composted. Combustion of MSW is handled in five larger plants with energy recovery located in different cities in Norway. In addition, a new incinerator for MSW is planned. This incinerator will have to meet the new emission regulations given by the European Union which are more stringent than the present regulations. Hence, Norway is moving towards more stringent regulations, leading to an increased interest in the environmental aspects of MSW incinerators. During 1995 Trondheim Energy Company carried out an investigation program to examine the residues from the incinerator. Primary attention was on the heavy metals in the bottom ash, fly ash and the landfill leacate. The program was conducted in order to establish more information about characteristics of the residues and thus be able to undertake a sounder evaluation of the environmental aspects of the final treatment of these products. This program was supplementary to the emission analysis done periodically for the flue gas and drain water. The objective of this work has been to establish knowledge about the partitioning of heavy metals through the incinerator and calculate the concentrations of heavy metal in the input MSW.

  20. Hybrid process for heavy metal removal from wastewater sludge.

    PubMed

    Drogui, Patrick; Blais, Jean-François; Mercier, Guy

    2005-01-01

    Bioleaching processes have been demonstrated to be effective technologies in removing heavy metals from wastewater sludge, but long hydraulic retention times are typically required to operate these bioprocesses. A hybrid process (coupling biological and chemical processes) has been explored in laboratory pilot-scale experiments for heavy metals (cadmium [Cd], copper [Cu], chromium [Cr], and zinc [Zn]) removal from three types of sludge (primary sludge, secondary activated sludge, and a mixture of primary and secondary sludge). The hybrid process consisted of producing a concentrate ferric ion solution followed by chemical treatment of sludges. Ferric iron solution was produced biologically via oxidation of ferrous iron by A. ferrooxidans in a continuous-flow stirred tank (5.2 L) reactor (CSTR). Wastewater sludge filtrate (WSF) containing nutrients (phosphorus and nitrogen) has been used as culture media to support the growth and activity of indigenous iron-oxidizing bacteria. Results showed that total organic carbon (TOC) concentrations of the culture media in excess of 235 mg/L were found to be inhibitory to bacterial growth. The oxidation rate increased as ferrous iron concentrations ranged from 10 to 40 g Fe2+/L. The percentage of ferrous iron (Fe2+) oxidized to ferric iron (Fe3+) increased as the hydraulic retention time (HRT) increased from 12 to 48 h. Successful and complete Fe2+ oxidation was recorded at a HRT of 48 h using 10 g Fe2+/L. Subsequently, ferric ion solution produced by A. ferrooxidans in sludge filtrate was used to solubilize heavy metals contained in wastewater sludge. The best solubilization was obtained with a mixture of primary and secondary sludge, demonstrating a removal efficiency of 63, 71, 49, and 80% for Cd, Cu, Cr, and Zn, respectively. PMID:16121505

  1. Heavy metals in wild rice from northern Wisconsin

    USGS Publications Warehouse

    Bennett, J.P.; Chiriboga, E.; Coleman, J.; Waller, D.M.

    2000-01-01

    Wild rice grain samples from various parts of the world have been found to have elevated concentrations of heavy metals, raising concern for potential effects on human health. It was hypothesized that wild rice from north-central Wisconsin could potentially have elevated concentrations of some heavy metals because of possible exposure to these elements from the atmosphere or from water and sediments. In addition, no studies of heavy metals in wild rice from Wisconsin had been performed, and a baseline study was needed for future comparisons. Wild rice plants were collected from four areas in Bayfield, Forest, Langlade, Oneida, Sawyer and Wood Counties in September, 1997 and 1998 and divided into four plant parts for elemental analyses: roots, stems, leaves and seeds. A total of 194 samples from 51 plants were analyzed across the localities, with an average of 49 samples per part depending on the element. Samples were cleaned of soil, wet digested, and analyzed by ICP for Ag, As, Cd, Cr, Cu, Hg, Mg, Pb, Se and Zn. Roots contained the highest concentrations of Ag, As, Cd, Cr, Hg, Pb, and Se. Copper was highest in both roots and seeds, while Zn was highest just in seeds. Magnesium was highest in leaves. Seed baseline ranges for the 10 elements were established using the 95% confidence intervals of the medians. Wild rice plants from northern Wisconsin had normal levels of the nutritional elements Cu, Mg and Zn in the seeds. Silver, Cd, Hg, Cr, and Se were very low in concentration or within normal limits for food plants. Arsenic and Pb, however, were elevated and could pose a problem for human health. The pathway for As, Hg and Pb to the plants could be atmospheric.

  2. [Heavy metal concentrations in mosses from Qiyi Glacier region].

    PubMed

    Ma, Juan-Juan; Li, Zhen

    2014-06-01

    Heavy metal (Cr, Fe, Cu, Zn, As, Cd and Pb) concentrations were measured in 17 moss samples which were collected at Qiyi Glacier Region in July, August and September, 2009 in a preliminary investigation of heavy metal pollution situation in this area. The results indicated that heavy metal concentrations in mosses were relatively high and concentrations of Fe were at the highest level (varied between 15 160.00 and 34 960.00 microg x g(-1)), followed by Zn, Cu, Cr, Pb, As, with average concentrations of 169.56, 134.81, 34.52, 26.16, 9.15 microg x g(-1). Enrichment factor analysis and correlation analysis indicated that Fe and Cr in mosses mainly stemmed from crustal dust, and concentrations of Cu, Pb, Zn and Cd were influenced by human activities; As was moderately enriched which means As in mosses was mainly originated from anthropogenic pollution. According to the Global Data Assimilation System (GDAS) meteorological data from the National Center for Environmental Prediction (NCEP) of 2009 and the simulation of the HYSPLIT v4.9 Model on 3-dimension back trajectories of air mass at Qiyi glacier district, several trajectories reflecting the main characteristics of air flow were obtained based on the classification of cluster analysis on the hundreds of back trajectories. The back trajectories revealed that atmospheric transport characteristics in the study area changed obviously by season. Compared to Spring and Autumn, atmospheric transmission sources were relatively more in Winter and Summer. The main sources of atmospheric pollutants in Qiyi Glacier region were transported from Jiuquan and Jiayuguan regions.

  3. Phytomining of heavy metals from soil by Croton bonplandianum using phytoremediation technology

    NASA Astrophysics Data System (ADS)

    Panchal, K. J.; Dave, B. R.; Parmar, P. P.; Subramanian, R. B.

    2015-12-01

    Metal ions are not only valuable intermediates in metal extraction, but also important raw materials for technical applications. They possess some unique but, identical physical and chemical properties, which make them useful probes of low temperature geochemical reactions. Heavy metals are natural constituents of the earth's crust, but indiscriminate human activities have drastically altered their geochemical cycles and biochemical balance. Metal concentration in soil typically ranges from less than one to as high as 100,000 mg/kg. Heavy metal contaminations of land resources continue to be the focus of numerous environmental studies and attract a great deal of attention worldwide. This is attributed to no--biodegradability and persistence of heavy metals in soils. Prolonged exposure to heavy metals such as cadmium, copper, lead, nickel, and zinc can cause deleterious health effects in humans. Complexation, separation, and removal of metal ions have become increasingly attractive areas of research and have led to new technical developments like phytoremediation that has numerous biotechnological implications of understanding of plant metal accumulation. Croton bonplandianum is newly identified as a potential heavy metal hypreaccumulator. In this study Croton bonplandianum was subjected for in vitro heavy metal accumulation, to explore the accumulation pattern of four heavy metals viz Cadmium, Lead, Nickel and Zinc in various parts of Croton bonplandianum plant parts. It was found that the efficiency of Croton bonplandianum to accumulate heavy metals is Cd>Pb>Zn>Ni. The absorption of these heavy metals in plant parts revealed that the highest translocation of metals from ground to root was ground to be in the order of Pb (1.12) > Zn (0.26) > Ni (0.18) > Cd (0.15). The distribution of Cd in Croton bonplandianum followed the trend Root>Stem>Leaf; with Ni it was Root>Leaf>Stem, while Pb showed leaf>stem>root. Translocation of metals in Croton bonplandianum plant parts

  4. Accumulation rates of airborne heavy metals in wetlands

    USGS Publications Warehouse

    Souch, C.J.; Filippelli, G.M.; Dollar, N.; Perkins, S.; Mastalerz, Maria

    2002-01-01

    Accumulation rates of heavy metals (Cd, Cr, Cu, Mn, Pb, and Zn) retained in wetland sediments in northwest Indiana-downwind of the Chicago-Gary-Hammond industrial area-are quantified to assess anthropogenic influences on atmospheric fluxes. Metal concentrations for 22 sediment cores are determined by ICP-AES after ashing and strong acid extraction. Relations between organic content and metal concentrations at depth are used to separate natural and anthropogenic sources. Accumulation rates over the lifetime of the wetlands (???4500 years) have averaged 0.2 (Cd), 1.4 (Cu), 1.7 (Cr), 13.4 (Mn), 4.8 (Pb), and 18.7 (Zn) mg m-2 y-1. Rates for the last 100 years have increased on average by factors of 6 (Cd), 8 (Cu), 10 (Mn), 15 (Pb), and 30 (Zn), remaining effectively constant for Cr. Where the wetlands have been drained, metals have been lost from the sediments, owing to changes in organic content and local hydrochemistry (exposure to acidic rainfall). Sediment-based accumulation rates at the undrained sites are higher, though generally consistent, with measured and modeled atmospheric fluxes documented by short-term studies conducted over the last three decades. The fraction of the total metals in the wetlands estimated to be of anthropogenic origin ranges from approximately 3% for Cr, up to approximately 35% for Pb, and 70% for Zn. This historic legacy of contamination must be considered in land management decisions, particularly when wetlands are drained.

  5. Hydrate-based heavy metal separation from aqueous solution

    NASA Astrophysics Data System (ADS)

    Song, Yongchen; Dong, Hongsheng; Yang, Lei; Yang, Mingjun; Li, Yanghui; Ling, Zheng; Zhao, Jiafei

    2016-02-01

    A novel hydrate-based method is proposed for separating heavy metal ions from aqueous solution. We report the first batch of experiments and removal characteristics in this paper, the effectiveness and feasibility of which are verified by Raman spectroscopy analysis and cross-experiment. 88.01-90.82% of removal efficiencies for Cr3+, Cu2+, Ni2+, and Zn2+ were obtained. Further study showed that higher R141b-effluent volume ratio contributed to higher enrichment factor and yield of dissociated water, while lower R141b-effluent volume ratio resulted in higher removal efficiency. This study provides insights into low-energy, intensive treatment of wastewater.

  6. Occurrence and toxicology of heavy metals in Chesapeake Bay waterfowl

    SciTech Connect

    Di Giulio, R.T.

    1982-01-01

    The goals of this study were to elucidate relationships between food habits and tissue accumulations of heavy metals in Chesapeake Bay waterfowl and to determine effects of chronic cadmium and lead ingestion on energy metabolism in waterfowl. In combination with an imposed food restriction, cadmium ingestion appeared to alter some indices of energy metabolism, such as plasma concentrations of free fatty acids and triiodothyronine, at dietary cadmium levels far below those eliciting similar responses in the absence of a food restriction. Those results suggest the importance of considering interactions with other stressors when examining potential effects of environmental contaminants on wild animals.

  7. Using semivariogram scaled to the sample design of heavy metals

    NASA Astrophysics Data System (ADS)

    Medeiros Bezerra, Joel; Machado Siqueira, Glécio; Dafonte Dafonte, Jorge; Vidal Vazquez, Eva; Paz González, Antonio

    2013-04-01

    The "sampling intensity" issue is of important application to precision agriculture. About 80%-85 % of the total error in precision in agriculture results from the field sampling preceding the application of fertilizers and corrective practices. The spatial sampling design used to characterize the spatial variability of soil attributes is crucial to science studies. The sample planning for interpolation of a regionalized variable may use several criteria, which could be best selected from the estimated semivariogram from a previously established grid. The objective of this study was to evaluate the use of the semivariogram scaled to improve the sample design of heavy metals in an experimental plot. The study area surface is 6 ha and is located at Castro Ribeiras de Lea, Lugo, Spain. The geographical coordinates of the study area are: latitude 43° 09 '49''N and longitude 7° 29' 47''W, with average elevation of 410 m and average slope of 2 %. The mean annual temperature is 11.2 °C and mean annual rainfall is 930 mm (data 1961-1990). The soil is classified with Cambisol and the parent material are sediments from tertiary and quaternary. Heavy metals were initially sampled at 40 points randomly distributed in the study area. The heavy metals analyzed in this study were: Pb, Cd, Cu and Ni. Data were initially analyzed using descriptive statistics and geostatistical tools. The scaled semivariogram was built with the aim of setting a single theoretical semivariogram all elements studied. Subsequently, the software SANOS was used to determine the sampling optimization of new sampling points of the heavy metals. The spatial variability analysis of the studied elements using the scaled semivariogram showed the existence of a relationship between the spatial variability of these elements. The gaussian model was adjusted for Pb, Cd and Ni, and spherical models for the Cu element. The semivariogram scaled theoretical adjusted to elements in four study was Gaussian, with a

  8. Accumulation, availability, and uptake of heavy metals in a red soil after 22-year fertilization and cropping.

    PubMed

    Zhou, Shiwei; Liu, Jing; Xu, Minggang; Lv, Jialong; Sun, Nan

    2015-10-01

    Fertilization is important to increase crop yields, but long-term application of fertilizers probably aggravated the risk of heavy metals in acidic soils. In this study, the effect of 22-year fertilization and cropping on accumulation, availability, and uptake of heavy metals in red soil was investigated. The results showed that pig manure promoted significantly cadmium (Cd) accumulation (average 1.1 mg kg(-1)), nearly three times higher than national soil standards and, thus, increased metal availability. But the enrichment of heavy metals decreased remarkably by 50.5 % under manure fertilization, compared with CK (control without fertilization). On the contrary, chemical fertilizers increased greatly lead (Pb) availability and Cd activity; in particular, exceeding 85 % of soil Cd became available to plant under N (nitrogen) treatment during 9-16 years of fertilization, which correspondingly increased their enrichment by 29.5 %. Long-term application of chemical fertilizers caused soil acidification and manure fertilization led to the increase in soil pH, soil organic matter (SOM), and available phosphorus (Olsen P), which influenced strongly metal behavior in red soil, and their effect had extended to deeper soil layer (20∼40 cm). It is advisable to increase application of manure alone with low content of heavy metals or in combination with chemical fertilizers to acidic soils in order to reduce toxic metal risk. PMID:26004564

  9. Accumulation, availability, and uptake of heavy metals in a red soil after 22-year fertilization and cropping.

    PubMed

    Zhou, Shiwei; Liu, Jing; Xu, Minggang; Lv, Jialong; Sun, Nan

    2015-10-01

    Fertilization is important to increase crop yields, but long-term application of fertilizers probably aggravated the risk of heavy metals in acidic soils. In this study, the effect of 22-year fertilization and cropping on accumulation, availability, and uptake of heavy metals in red soil was investigated. The results showed that pig manure promoted significantly cadmium (Cd) accumulation (average 1.1 mg kg(-1)), nearly three times higher than national soil standards and, thus, increased metal availability. But the enrichment of heavy metals decreased remarkably by 50.5 % under manure fertilization, compared with CK (control without fertilization). On the contrary, chemical fertilizers increased greatly lead (Pb) availability and Cd activity; in particular, exceeding 85 % of soil Cd became available to plant under N (nitrogen) treatment during 9-16 years of fertilization, which correspondingly increased their enrichment by 29.5 %. Long-term application of chemical fertilizers caused soil acidification and manure fertilization led to the increase in soil pH, soil organic matter (SOM), and available phosphorus (Olsen P), which influenced strongly metal behavior in red soil, and their effect had extended to deeper soil layer (20∼40 cm). It is advisable to increase application of manure alone with low content of heavy metals or in combination with chemical fertilizers to acidic soils in order to reduce toxic metal risk.

  10. The study of partitioning of heavy metals during fluidized bed combustion of sewage sludge and coal

    SciTech Connect

    Gulyurtlu, I.; Lopes, M.H.; Abelha, P.; Cabrita, I.; Oliveira, J.F.S.

    2006-06-15

    The behavior of Cd, Cr, Cu, Co, Mn, Ni, Pb, Zn, and Hg during the combustion tests of a dry granular sewage sludge on a fluidized bed combustor pilot (FBC) of about 0.3 MW was evaluated. The emissions of these heavy metals from mono-combustion were compared with those of co-combustion of the sludge with a bituminous coal. The effect of the addition of limestone was also studied in order to retain sulphur compounds and to verify its influence on the retention of heavy metals (HM). Heavy metals were collected and analyzed from different locations of the installation, which included the stack, the two cyclones, and the material removed from the bed. The results showed that the volatility of metals was rather low, resulting in emissions below the legal limits of the new directive on incineration, with the exception of Hg during the mono-combustion tests. The partitioning of metals, except for Hg, appeared to follow that of ashes, amounting to levels above 90% in the bed streams in the mono-combustion case. For co-combustion, there was a lower fixation of HM in the bed ashes, mostly originating essentially from the sewage sludge, ranging between 40% and 80%. It is believed that in this latter case, a slightly higher temperature could have enhanced the volatilization, especially of Cd and Pb. However these metals were then retained in fly ashes captured in the cyclones. In the case of Hg, the volatilisation was complete. The bed ashes were free of Hg and part of Hg was retained in the cyclones and the rest was emitted either with fine ash particles or in gaseous forms. In mono-combustion the Hg emissions from the stack (particles and gas) accounted, for about 50%. This appeared to have significantly decreased in the case of co-combustion, as only about 75% has been emitted, due to the retention effect of cyclone ashes.

  11. Heavy metal contamination of river Yamuna, Haryana, India: Assessment by Metal Enrichment Factor of the Sediments.

    PubMed

    Kaushik, A; Kansal, Ankur; Santosh; Meena; Kumari, Shiv; Kaushik, C P

    2009-05-15

    Concentration of Heavy Metals (Cd, Cr, Fe, Ni) in water, plants and sediments of river Yamuna flowing in Haryana through Delhi are reported here selecting 14 stations covering the upstream and downstream sites of major industrial complexes of the State. Some important characteristics of river water and sediments (pH, EC, Cl(-), SO(3)(2-), and PO(4)(3-) in water and sediments, COD of water and organic matter content of sediments) were also analysed and inter-relationships of all these parameters with heavy metal concentration in different compartments were examined. The sediments of the river show significant enrichment with Cd and Ni indicating inputs from industrial sources. Concentrations of Cr are moderate and show high enrichment values only at a few sites. Enrichment factor for Fe is found to be <1, showing insignificant effect of anthropogenic flux. Concentrations of these metals in river water are generally high exceeding the standard maximum permissible limits prescribed for drinking water, particularly in the downstream sites. The aquatic plants show maximum accumulation of Fe. The other heavy metals Cd, Cr and Ni, though less in concentration, show some accumulation in the plants growing in contaminated sites. Interrelationships of metal concentration with important characteristics of water and sediment have been analysed. Analysis of heavy metals in water, sediments and littoral flora in the stretch of river Yamuna is first study of itself and interrelationship of metal concentration and other important characteristics make the study significant and interesting in analysing the pollution load at different points of the river body. PMID:18809251

  12. Heavy metal contamination of river Yamuna, Haryana, India: Assessment by Metal Enrichment Factor of the Sediments.

    PubMed

    Kaushik, A; Kansal, Ankur; Santosh; Meena; Kumari, Shiv; Kaushik, C P

    2009-05-15

    Concentration of Heavy Metals (Cd, Cr, Fe, Ni) in water, plants and sediments of river Yamuna flowing in Haryana through Delhi are reported here selecting 14 stations covering the upstream and downstream sites of major industrial complexes of the State. Some important characteristics of river water and sediments (pH, EC, Cl(-), SO(3)(2-), and PO(4)(3-) in water and sediments, COD of water and organic matter content of sediments) were also analysed and inter-relationships of all these parameters with heavy metal concentration in different compartments were examined. The sediments of the river show significant enrichment with Cd and Ni indicating inputs from industrial sources. Concentrations of Cr are moderate and show high enrichment values only at a few sites. Enrichment factor for Fe is found to be <1, showing insignificant effect of anthropogenic flux. Concentrations of these metals in river water are generally high exceeding the standard maximum permissible limits prescribed for drinking water, particularly in the downstream sites. The aquatic plants show maximum accumulation of Fe. The other heavy metals Cd, Cr and Ni, though less in concentration, show some accumulation in the plants growing in contaminated sites. Interrelationships of metal concentration with important characteristics of water and sediment have been analysed. Analysis of heavy metals in water, sediments and littoral flora in the stretch of river Yamuna is first study of itself and interrelationship of metal concentration and other important characteristics make the study significant and interesting in analysing the pollution load at different points of the river body.

  13. Carbon based secondary compounds do not provide protection against heavy metal road pollutants in epiphytic macrolichens.

    PubMed

    Gauslaa, Yngvar; Yemets, Olena A; Asplund, Johan; Solhaug, Knut Asbjørn

    2016-01-15

    Lichens are useful monitoring organisms for heavy metal pollution. They are high in carbon based secondary compounds (CBSCs) among which some may chelate heavy metals and thus increase metal accumulation. This study quantifies CBSCs in four epiphytic lichens transplanted for 6months on stands along transects from a highway in southern Norway to search for relationships between concentrations of heavy metals and CBSCs along a gradient in heavy metal pollutants. Viability parameters and concentrations of 21 elements including nutrients and heavy metals in these lichen samples were reported in a separate paper. Medullary CBSCs in fruticose lichens (Ramalina farinacea, Usnea dasypoga) were reduced in the most polluted sites, but not in foliose ones (Parmelia sulcata, Lobaria pulmonaria), whereas cortical CBSC did not change with distance from the road in any species. Strong positive correlations only occurred between the major medullary compound stictic acid present in L. pulmonaria and most heavy metals, consistent with a chelating role of stictic acid, but not of other studied CBSCs or in other species. However, heavy metal chelating did not protect L. pulmonaria against damage because this species experienced the strongest reduction in viability in the polluted sites. CBSCs with an accumulation potential for heavy metals should be quantified in lichen biomonitoring studies of heavy metals because they, like stictic acid, could overshadow pollutant inputs in some species rendering biomonitoring data less useful. In the two fruticose lichen species, CBSCs decreased with increasing heavy metal concentration, probably because heavy metal exposure impaired secondary metabolism. Thus, we found no support for a heavy metal protection role of any CBSCs in studied epiphytic lichens. No intraspecific relationships occurred between CBSCs versus N or C/N-ratio. Interspecifically, medullary CBSCs decreased and cortical CBSCs increased with increasing C/N-ratio.

  14. Heavy metal accumulation by recombinant mammalian metallothionein within Escherichia coli protects against elevated metal exposure.

    PubMed

    Sauge-Merle, Sandrine; Lecomte-Pradines, Catherine; Carrier, Patrick; Cuiné, Stéphan; Dubow, Michael

    2012-08-01

    Metallothioneins (MTs) are ubiquitous metal-binding, cysteine-rich, small proteins known to provide protection against toxic heavy metals such as cadmium. In an attempt to increase the ability of bacterial cells to accumulate heavy metals, sheep MTII was produced in fusion with the maltose binding protein (MBP) and localized to the cytoplasmic or periplasmic compartments of Escherichia coli. For all metals tested, higher levels of bioaccumulation were measured with strains over-expressing MBP-MT in comparison with control strains. A marked bioaccumulation of Cd, As, Hg and Zn was observed in the strain over-expressing MBP-MT in the cytoplasm, whereas Cu was accumulated to higher levels when MBP-MT was over-expressed in the periplasm. Metal export systems may also play a role in this bioaccumulation. To illustrate this, we over-expressed MBP-MT in the cytoplasm of two mutant strains of E. coli affected in metal export. The first, deficient in the transporter ZntA described to export numerous divalent metal ions, showed increasing quantities of Zn, Cd, Hg and Pb being bioaccumulated. The second, strain LF20012, deficient in As export, showed that As was bioaccumulated in the form of arsenite. Furthermore, high quantities of accumulated metals, chelated by MBP-MT in the cytoplasm, conferred greater metal resistance levels to the cells in the presence of added toxic metals, such as Cd or Hg, while other metals showed toxic effects when the export systems were deficient. The strain over-expressing MBP-MT in the cytoplasm, in combination, with disruption of metal export systems, could be used to develop strategies for bioremediation.

  15. Heavy metals in drinking water: Occurrences, implications, and future needs in developing countries.

    PubMed

    Chowdhury, Shakhawat; Mazumder, M A Jafar; Al-Attas, Omar; Husain, Tahir

    2016-11-01

    Heavy metals in drinking water pose a threat to human health. Populations are exposed to heavy metals primarily through water consumption, but few heavy metals can bioaccumulate in the human body (e.g., in lipids and the gastrointestinal system) and may induce cancer and other risks. To date, few thousand publications have reported various aspects of heavy metals in drinking water, including the types and quantities of metals in drinking water, their sources, factors affecting their concentrations at exposure points, human exposure, potential risks, and their removal from drinking water. Many developing countries are faced with the challenge of reducing human exposure to heavy metals, mainly due to their limited economic capacities to use advanced technologies for heavy metal removal. This paper aims to review the state of research on heavy metals in drinking water in developing countries; understand their types and variability, sources, exposure, possible health effects, and removal; and analyze the factors contributing to heavy metals in drinking water. This study identifies the current challenges in developing countries, and future research needs to reduce the levels of heavy metals in drinking water.

  16. Facet-dependent electrochemical properties of Co3O4 nanocrystals toward heavy metal ions

    PubMed Central

    Yu, Xin-Yao; Meng, Qiang-Qiang; Luo, Tao; Jia, Yong; Sun, Bai; Li, Qun-Xiang; Liu, Jin-Huai; Huang, Xing-Jiu

    2013-01-01

    We revealed an interesting facet-dependent electrochemical behavior toward heavy metal ions (HMIs) based on their adsorption behaviors. The (111) facet of Co3O4 nanoplates has better electrochemical sensing performance than that of the (001) facet of Co3O4 nanocubes. Adsorption measurements and density-functional theory (DFT) calculations reveals that adsorption of HMIs is responsible for the difference of electrochemical properties. Our combined experimental and theoretical studies provide a solid hint to explain the mechanism of electrochemical detection of HMIs using nanoscale metal oxides. Furthermore, this study not only suggests a promising new strategy for designing high performance electrochemical sensing interface through the selective synthesis of nanoscale materials exposed with different well-defined facets, but also provides a deep understanding for a more sensitive and selective electroanalysis at nanomaterials modified electrodes. PMID:24097175

  17. Mosh pits and Circle pits: Collective motion at heavy metal concerts

    NASA Astrophysics Data System (ADS)

    Bierbaum, Matthew; Silverberg, Jesse L.; Sethna, James P.; Cohen, Itai

    2013-03-01

    Heavy metal concerts present an extreme environment in which large crowds (~102 -105) of humans experience very loud music (~ 130 dB) in sync with bright, flashing lights, often while intoxicated. In this setting, we find two types of collective motion: mosh pits, in which participants collide with each other randomly in a manner resembling an ideal gas, and circle pits, in which participants run collectively in a circle forming a vortex of people. We model these two collective behaviors using a flocking model and find qualitative and quantitative agreement with the behaviors found in videos of metal concerts. Futhermore, we find a phase diagram showing the transition from a mosh pit to a circle pit as well as a predicted third phase, lane formation.

  18. Heavy metals in vegetables and respective soils irrigated by canal, municipal waste and tube well waters.

    PubMed

    Ismail, Amir; Riaz, Muhammad; Akhtar, Saeed; Ismail, Tariq; Amir, Mamoona; Zafar-ul-Hye, Muhammad

    2014-01-01

    Heavy metal contamination in the food chain is of serious concern due to the potential risks involved. The results of this study revealed the presence of maximum concentration of heavy metals in the canal followed by sewerage and tube well water. Similarly, the vegetables and respective soils irrigated with canal water were found to have higher heavy metal contamination followed by sewerage- and tube-well-watered samples. However, the heavy metal content of vegetables under study was below the limits as set by FAO/WHO, except for lead in canal-water-irrigated spinach (0.59 mg kg(-1)), radish pods (0.44 mg kg(-1)) and bitter gourd (0.33 mg kg(-1)). Estimated daily intakes of heavy metals by the consumption of selected vegetables were found to be well below the maximum limits. However, a complete estimation of daily intake requires the inclusion of other dietary and non-dietary exposure sources of heavy metals.

  19. Heavy metal content in rubbish bags used for separate collection of biowaste.

    PubMed

    Huerta-Pujol, Oscar; Soliva, Montserrat; Giró, Francesc; López, Marga

    2010-01-01

    The heavy metal content of several rubbish bags used to collect the organic fraction of municipal solid waste (OFMSW) is shown in this paper. Nowadays, several public awareness campaigns carried out by municipalities have promoted rubbish bags based mainly on their appearance, without concern for their heavy metal content. A high amount of heavy metals was detected in some polyethylene bags promoted in different campaigns for OFMSW source-sorted collection, while compostable bags presented low quantities of heavy metals. Some other rubbish bags, as well as commercial bags, were also analysed for comparison. These results should be taken into account before promoting the use of one or other type of bag. Moreover, the rubbish bag manufacturers should reduce the heavy metal content in order to avoid heavy metal scattering in the environment, and also to reduce the consumption of raw materials.

  20. An equation characterizing multi-heavy-metal sorption onto bentonite, forest soil and spruce bark.

    PubMed

    Li, F; Li, L Y

    2003-12-01

    An empirical equation was developed to quantitatively describe heavy metal sorption in ternary systems of lead (Pb), copper (Cu) and cadmium (Cd). The three sorbants investigated were bentonite, forest soil and spruce bark. This multi-sorption equation is based on three assumptions: the relationship between sorption and initial heavy metal concentration fits a power curve; the presence of one heavy metal proportionately reduces the sorption curve of another heavy metal; and the competition between two heavy metals is independent of the presence of other heavy metals. The multi-sorption equation modeled sorption in ternary systems to a regression fit greater than 0.96. The data required for the equation were generated from a technically straightforward and quick laboratory program involving batch adsorption tests. PMID:14977144

  1. [Application of ICP-MS to the detection of heavy metals in transgenic corn].

    PubMed

    Rui, Yu-Kui; Guo, Jing; Huang, Kun-Lun; Jin, Yin-Hua; Luo, Yun-Bo

    2007-04-01

    With the rapid development of the transgenic food, more and more transgenic food has been pouring into the market attracting much attention to the transgenic food's edible safety. Transgenic corns and its parents were studied by ICP-MS to detect the heavy metals. The results showed that the transgenic corn accumulated less heavy metals (Ni, Cu, Cd, As, Cr, Zn and Hg) than their own parents; and the contents of some heavy metals (V, Co and Pb) in transgenic corns were similar to their parents. All the data showed that the insertion of foreign gene (Bt) might change the absorbing dynamics of most heavy metals, especially some important heavy metals, which are disadvantageous to human health. The present paper indicated that the change in heavy metals absorption could harm the edible safety of transgenic plant. The cause of this change should be studied further.

  2. Assessment of interference in biosorption of a heavy metal

    SciTech Connect

    Figueira, M.M. |; Volesky, B.; Ciminelli, V.S.T.

    1997-05-20

    Biosorption of heavy metals by various biological materials has been studied extensively in the last decade due to its potential particularly in wastewater treatment. The presence of a large number of metals in industrial metal-bearing solutions makes it necessary to investigate their effect on the final metal uptake by individual biosorbent materials. Nonliving biomass of Sargassum, a brown marine alga, is capable of binding more than 10% of its dry weight in toxic cadmium ions. Although ubiquitous iron interferes with Cd uptake, only approximately 4.5% of it is sequestered (biomass dry weight). Biosorption of both metals at pH 4.5 could be described by Langmuir-type isotherms with b, the affinity-related coefficient (Cd: b = 0.015; Fe: b = 0.027). The interference of Fe with Cd uptake, and vice versa, was assessed by deriving three-dimensional equilibrium two-metal sorption isotherm surfaces, smoothed and cut to reveal the inhibition effect of Fe on biosorption of Cd: at the equilibrium concentration Cf[Cd] = 1.5 mM, the presence of Fe at 1.5 mM equilibrium concentration suppressed the Cd uptake to only 76% of the original value. For 50% Cd uptake reduction, a very high equilibrium Fe presence of 4.5 mM was required. The Cd presence affected the uptake of Fe very strongly. To obtain equal values of uptake for each metal in the biosorbent, the ratio of equilibrium concentrations of 0.42 Cd to 1 Fe is necessary in the liquid phase.

  3. Use of dried aquatic plant roots to adsorb heavy metals

    SciTech Connect

    Robichaud, K.D.

    1996-12-31

    The removal of heavy metal ions by dried aquatic macrophytes was investigated. The ability of the biomass, Eichhornia crassipes (water hyacinth), Typha latifolia (cattail), Sparganium minimum (burr reed) and Menyanthes trifoliata to abstract lead and mercury ions is presented here, along with a conceptual filter design. This paper examines an alternative to both the traditional and recent systems designed for metal removal. It involves the use of dried aquatic macrophytes. There are numerous advantages for the use of dried macrophytes in the treatment of industrial wastewater. First, it is cost-effective. There are also funding opportunities through a variety of Environmental Protection Agency`s (EPA) programs. It is more environmentally conscious because a wetland, the harvesting pond, has been created. And, it creates public goodwill by providing a more appealing, less hardware-intensive, natural system.

  4. Heavy metals contamination of soils surrounding waste deposits in Romania

    NASA Astrophysics Data System (ADS)

    Matache, M.; Rozylowicz, L.; Ropota, M.; Patroescu, C.

    2003-05-01

    Soils contamination with heavy metals is one of the most severe aspects of environmental pollution in Romania, independently of the origin sources (domestic or industrial activities) or type of disposal (organised landfill or hazardous deposits)[l-2]. This fact is the consequence of the poor state of the existing waste deposits in Romania and of the significant costs involved by the establishing of a new landfill according with the international regulations. The present study is trying to emphasise the contamination of soils surrounding different categories of waste deposits (sewage sludge ponds, domestic and industrial waste landfills, hillocks, sterile deposits) from various regions of Romania. Some case studies show a special interest being localise in a protected area (Iron Gates Natural Park). In order to quantify the concentration of metals like Cd, Cr, Cu, Pb, Zn, Ni, Mo in soil samples, analysis were performed using Inductively Coupled Plasma - Optical Emission Spectrometry (ICP-OES). Romanian standards were used as reference values[3].

  5. Natural and technogenic compounds of heavy metals in soils

    NASA Astrophysics Data System (ADS)

    Vodyanitskii, Yu. N.

    2014-04-01

    The existing geological classification of heavy metals (HMs) is not suitable for their characterization in soils. The carriers of HMs in soils differ from those in the lithosphere. These are clay minerals; iron oxides, whose composition varies between the background and urban soils; various manganese oxides; and different groups of organic substances. The mineral composition of HM carriers can vary significantly. The main iron oxides are ferrihydrite, goethite, feroxyhyte, and lepidocrocite in the background soils and technogenic magnetite in the urban soils. The different structures of manganese oxides determine their affinity for specific HMs. Metallic iron and green rust are very efficient in artificial geochemical barriers, although they act as strong reducers there. HM compounds strongly vary in soils because of the unstable conditions.

  6. Genetic manipulation of a cyanobacterium for heavy metal detoxivication

    SciTech Connect

    McCormick, P.; Cannon, G.; Heinhorst, S.

    1995-12-31

    Increasing heavy metal contamination of soil and water has produced a need for economical and effective methods to reduce toxic buildup of these materials. Biological systems use metallothionein proteins to sequester such metals as Cu, Cd, and Zn. Studies are underway to genetically engineer a cyanobacteria strain with increased ability for metallothionein production and increased sequestration capacity. Cyanobacteria require only sunlight and CO{sub 2}. Vector constructs are being developed in a naturally competent, unicellular cyanobacterium Anacystis nidulans R2. Closed copies of a yeast copper metallothionein gene have been inserted into a cyanobacterial shuttle vector as well as a vector designed for genomic integration. Transformation studies have produced recombinant cyanobacteria from both of these systems, and work is currently underway to assess the organism`s ability to withstand increasing Cu, Cd, and Zn concentrations.

  7. Heavy metals in commercial fish in New Jersey.

    PubMed

    Burger, Joanna; Gochfeld, Michael

    2005-11-01

    Levels of contaminants in fish are of particular interest because of the potential risk to humans who consume them. While attention has focused on self-caught fish, most of the fish eaten by the American public comes from commercial sources. We sampled 11 types of fish and shellfish obtained from supermarkets and specialty fish markets in New Jersey and analyzed them for arsenic, cadmium, chromium, lead, manganese, mercury, and selenium. We test the null hypothesis that metal levels do not vary among fish types, and we consider whether the levels of any metals could harm the fish themselves or their predators or pose a health risk for human consumers. There were significant interspecific differences for all metals, and no fish types had the highest levels of more than two metals. There were few significant correlations (Kendall tau) among metals for the three most numerous fish (yellowfin tuna, bluefish, and flounder), the correlations were generally low (below 0.40), and many correlations were negative. Only manganese and lead positively were correlated for tuna, bluefish, and flounder. The levels of most metals were below those known to cause adverse effects in the fish themselves. However, the levels of arsenic, lead, mercury, and selenium in some fish were in the range known to cause some sublethal effects in sensitive predatory birds and mammals and in some fish exceeded health-based standards. The greatest risk from different metals resided in different fish; the species of fish with the highest levels of a given metal sometimes exceeded the human health guidance or standards for that metal. Thus, the risk information given to the public (mainly about mercury) does not present a complete picture. The potential of harm from other metals suggests that people not only should eat smaller quantities of fish known to accumulate mercury but also should eat a diversity of fish to avoid consuming unhealthy quantities of other heavy metals. However, consumers should

  8. Heavy metal bioaccumulation by wild edible saprophytic and ectomycorrhizal mushrooms.

    PubMed

    Širić, Ivan; Humar, Miha; Kasap, Ante; Kos, Ivica; Mioč, Boro; Pohleven, Franc

    2016-09-01

    Heavy metals cause serious problems in the environment, and they can be accumulated in organisms, especially in the higher fungi. The concentration of Ni, Cr, Pb, Cd, and Hg in 10 species of edible mushrooms in Medvednica Nature Park, Croatia was therefore determined. In addition, the similarity between the studied species was determined by cluster analysis based on concentrations of the aforementioned metals in the fruiting bodies. The contents of nickel, chromium, lead, cadmium, and mercury in the fruiting bodies of mushrooms were obtained by X-ray fluorescence spectrometry. The highest concentrations of Ni (3.62 mg kg(-1)), Cr (3.01 mg kg(-1)), and Cd (2.67 mg kg(-1)) were determined in Agaricus campestris. The highest concentration of Pb (1.67 mg kg(-1)) was determined in Macrolepiota procera, and the highest concentration of Hg (2.39 mg kg(-1)) was determined in Boletus edulis. The concentration of all heavy metals significantly differed (p < 0.001) between examined saprophytic and ectomycorrhizal mushrooms. Considering anatomical part of the fruiting body (cap-stipe), a considerably higher concentration of the analyzed elements was found in the cap for all mushroom species. According to calculated bioconcentration factors, all the examined species were found to be bioexclusors of Ni, Cr, and Pb and bioaccumulators of Cd and Hg. Cluster analysis performed on the basis of the accumulation of the studied metals revealed great phenotypic similarity of mushroom species belonging to the same genus and partial similarity of species of the same ecological affiliation. PMID:27272918

  9. Heavy metals processing near-net-forming summary progress report

    SciTech Connect

    Watson, L.D.; Thompson, J.E.

    1994-09-01

    This study utilized a converging-diverging nozzle to spray-form an alloy having a weight percent composition of 49.6% iron, 49.6% tungsten, and 0.8% carbon into samples for analysis. The alloy was a surrogate that displayed metallurgical characteristics similar to the alloys used in the heavy metals processing industry. US DOE facilities are evaluating advanced technologies which can simplify component fabrication, reduce handling steps, and minimize final machining. The goal of producing net-shaped components can be approached from several directions. In spray forming, molten metal is converted by a nozzle into a plume of fine droplets which quickly cool in flight and solidify against a substrate. The near-final dimension product that is formed receives additional benefits from rapid solidification. This single-step processing approach would aid the heavy metals industry by streamlining fabrication, improving production yields, and minimizing the generation of processing wastes. This Program effort provided a large selection of as-sprayed specimens. These samples were sprayed with gas-to-metal mass ratios ranging from 0.8:1 to 4:1. Samples targeted for analysis were produced from different spray conditions. Metallography on some samples revealed areas that were fully dense and homogeneous at 5,000X. These areas averaged grain sizes of 1 micron diameter. Other samples when viewed at 2,000X were highly segregated in the 10 micron diameter range. Deposit efficiencies of greater than 90% were demonstrated using the untailored spray system. Discharge gases were analyzed and two categories of particles were identified. One category of particle had a chemical composition characteristic of the alloy being sprayed and the second type of particle had a chemical composition characteristic of the ceramics used in the spray system component fabrication. Particles ranged in size from 0.07 to 3 microns in diameter. 8 refs., 67 figs., 20 tabs.

  10. Triboelectrification-Enabled Self-Powered Detection and Removal of Heavy Metal Ions in Wastewater.

    PubMed

    Li, Zhaoling; Chen, Jun; Guo, Hengyu; Fan, Xing; Wen, Zhen; Yeh, Min-Hsin; Yu, Chongwen; Cao, Xia; Wang, Zhong Lin

    2016-04-20

    A fundamentally new working principle into the field of self-powered heavy-metal-ion detection and removal using the triboelectrification effect is introduced. The as-developed tribo-nanosensors can selectively detect common heavy metal ions. The water-driven triboelectric nanogenerator is taken as a sustainable power source for heavy-metal-ion removal by recycling the kinetic energy from flowing wastewater.

  11. [Effect of arbuscular mycorrhizae on growth, heavy metal uptake and accumulation of Zenia insignis Chun seedlings].

    PubMed

    Li, Xia; Peng, Xia-Wei; Wu, Song-Lin; Li, Zhi-Ru; Feng, Hong-Mei; Jiang, Ze-Ping

    2014-08-01

    To solve the trace metal pollution of a Pd/Zn mine in Hunan province, a greenhouse pot experiment was conducted to investigate the effect of two arbuscular mycorrhizal fungi, Glomus mosseae (Gm) and Glomus intraradices (Gi), on the growth, heavy metal uptake and accumulation of Zenia insignis Chun, the pioneer plant there. The results showed that symbiotic associations were successfully established between the two isolates and Z. insignis in heavy metal contaminated soil. AM fungi improved P absorption, biomass and changed heavy metal uptake and distribution of Z. insignis. AM fungi-inoculated plants had significantly lower Fe, Cu, Zn, Pd concentrations and higher Fe, Cu, Zn, Pd accumulation than non-inoculated plants. However, Gm and Gi showed different mycorrhizal effects on the distribution of heavy metal in hosts, depending on the species of heavy metal. Gi-inoculated Z. insignis showed significantly lower TF values of Fe, Zn, Pd than Gm and non-inoculated plants, while both strains had no effect on TF value of Cu, which indicated that Gi enhanced trace metal accumulation in root system, playing a filtering/sequestering role in the presence of trace metals. The overall results demonstrated that AM fungi had positive effect on Z. insignis in enhancing the ability to adapt the heavy metal contaminated soil and played potential role in the revegetation of heavy metal contaminated soil. But in practical application, the combination of AM, hosts and heavy metal should be considered. PMID:25338391

  12. Heavy metal contamination in a vulnerable mangrove swamp in South China.

    PubMed

    Wang, Yutao; Qiu, Qiu; Xin, Guorong; Yang, Zhongyi; Zheng, Jing; Ye, Zhihong; Li, Shaoshan

    2013-07-01

    Concentrations of six heavy metals (Cu, Ni, Zn, Cd, Cr, and Pb) in sediments and fine roots, thick roots, branches, and leaves of six mangrove plant species collected from the Futian mangrove forest, South China were measured. The results show that both the sediments and plants in Futian mangrove ecosystem are moderately contaminated by heavy metals, with the main contaminants being Zn and Cu. All investigated metals showed very similar distribution patterns in the sediments, implying that they had the same anthropogenic source(s). High accumulations of the heavy metals were observed in the root tissues, especially the fine roots, and much lower concentrations in the other organs. This indicates that the roots strongly immobilize the heavy metals and (hence) that mangrove plants possess mechanisms that limit the upward transport of heavy metals and exclude them from sensitive tissues. The growth performance of propagules and 6-month-old seedlings of Bruguiera gymnorhiza in the presence of contaminating Cu and Cd was also examined. The results show that this plant is not sufficiently sensitive to heavy metals after its propagule stage for its regeneration and growth to be significantly affected by heavy metal contamination in the Futian mangrove ecosystem. However, older mangrove seedlings appeared to be more metal-tolerant than the younger seedlings due to their more efficient exclusion mechanism. Thus, the effects of metal contamination on young seedlings should be assessed when evaluating the risks posed by heavy metals in an ecosystem. PMID:23203819

  13. [Effect of arbuscular mycorrhizae on growth, heavy metal uptake and accumulation of Zenia insignis Chun seedlings].

    PubMed

    Li, Xia; Peng, Xia-Wei; Wu, Song-Lin; Li, Zhi-Ru; Feng, Hong-Mei; Jiang, Ze-Ping

    2014-08-01

    To solve the trace metal pollution of a Pd/Zn mine in Hunan province, a greenhouse pot experiment was conducted to investigate the effect of two arbuscular mycorrhizal fungi, Glomus mosseae (Gm) and Glomus intraradices (Gi), on the growth, heavy metal uptake and accumulation of Zenia insignis Chun, the pioneer plant there. The results showed that symbiotic associations were successfully established between the two isolates and Z. insignis in heavy metal contaminated soil. AM fungi improved P absorption, biomass and changed heavy metal uptake and distribution of Z. insignis. AM fungi-inoculated plants had significantly lower Fe, Cu, Zn, Pd concentrations and higher Fe, Cu, Zn, Pd accumulation than non-inoculated plants. However, Gm and Gi showed different mycorrhizal effects on the distribution of heavy metal in hosts, depending on the species of heavy metal. Gi-inoculated Z. insignis showed significantly lower TF values of Fe, Zn, Pd than Gm and non-inoculated plants, while both strains had no effect on TF value of Cu, which indicated that Gi enhanced trace metal accumulation in root system, playing a filtering/sequestering role in the presence of trace metals. The overall results demonstrated that AM fungi had positive effect on Z. insignis in enhancing the ability to adapt the heavy metal contaminated soil and played potential role in the revegetation of heavy metal contaminated soil. But in practical application, the combination of AM, hosts and heavy metal should be considered.

  14. Mussel Shell Evaluation as Bioindicator For Heavy Metals

    NASA Astrophysics Data System (ADS)

    Andrello, Avacir Casanova; Lopes, Fábio; Galvão, Tiago Dutra

    2010-05-01

    Recently, in Brazil, it has appeared a new and unusual "plague" in lazer and commercial fishing. It is caused by the parasitic larval phase of certain native bivalve mollusks of fresh water known as "Naiades" and its involves the presence of big bivalve of fresh water, mainly Anodontites trapesialis, in the tanks and dams of the fish creation. These bivalve mollusks belong to the Unionoida Order, Mycetopodidae Family. The objective of the present work was to analyze the shells of these mollusks to verify the possibility of use as bioindicators for heavy metals in freshwater. The mollusks shells were collected in a commercial fishing at Londrina-PR. A qualitative analysis was made to determine the chemical composition of the shells and verify a possible correlation with existent heavy metals in the aquatic environment. In the inner part of the shells were identified the elements Ca, P, Fe, Mn and Sr and in the outer part were identified Ca, P, Fe, Mn, Sr and Cu. The Ca ratio of the outer part by inner part of the analyzed shells is around of 1, as expected, because Ca is the main compound of mollusks shells. The ratio of P, Fe, Mn, and Sr to the Ca were constant in all analyzed shells, being close to 0.015. The ratio Cu/Ca varied among the shells, showing that this mollusk is sensitive to concentration of this element in the aquatic environment.

  15. Adaptive Engineering of Phytochelatin-based Heavy Metal Tolerance*

    PubMed Central

    Cahoon, Rebecca E.; Lutke, W. Kevin; Cameron, Jeffrey C.; Chen, Sixue; Lee, Soon Goo; Rivard, Rebecca S.; Rea, Philip A.; Jez, Joseph M.

    2015-01-01

    Metabolic engineering approaches are increasingly employed for environmental applications. Because phytochelatins (PC) protect plants from heavy metal toxicity, strategies directed at manipulating the biosynthesis of these peptides hold promise for the remediation of soils and groundwaters contaminated with heavy metals. Directed evolution of Arabidopsis thaliana phytochelatin synthase (AtPCS1) yields mutants that confer levels of cadmium tolerance and accumulation greater than expression of the wild-type enzyme in Saccharomyces cerevisiae, Arabidopsis, or Brassica juncea. Surprisingly, the AtPCS1 mutants that enhance cadmium tolerance and accumulation are catalytically less efficient than wild-type enzyme. Metabolite analyses indicate that transformation with AtPCS1, but not with the mutant variants, decreases the levels of the PC precursors, glutathione and γ-glutamylcysteine, upon exposure to cadmium. Selection of AtPCS1 variants with diminished catalytic activity alleviates depletion of these metabolites, which maintains redox homeostasis while supporting PC synthesis during cadmium exposure. These results emphasize the importance of metabolic context for pathway engineering and broaden the range of tools available for environmental remediation. PMID:26018077

  16. [Immobilization of heavy metal Pb2+ with geopolymer].

    PubMed

    Jin, Man-tong; Jin, Zan-fang; Huang, Cai-ju

    2011-05-01

    A series of geopolymers were synthesized by mixing metakaolinite, water glass, sodium hydroxide and water, and the lead ion solidification experiments were performed with the geopolymer. Then, the immobilization efficiency was characterized by monitoring the leaching concentration and compressive strength of solidified products. Additionally, the structure and properties of the solidified products were studied by X-ray diffraction (XRD), scan electron microscopy (SEM) and Fourier transform infrared (FTIR) spectroscopy. Furthermore, based on the analysis of immobilization efficiency, microstructure and mineral structure, the difference between geopolymer and cement on the performance of immobilizing heavy metals was discussed. The results of lead ion immobilization experiments showed that over 99.7% of heavy metal was captured by the geopolymer as the doping concentration of lead ion was less than 3%. Meanwhile, the compressive strength of the solidified product ranged from 40 MPa to 50 MPa. Furthermore, by using the same Pb2+ concentration, the geopolymer showed higher compressive strength and lower leaching concentration compared to the cement. Because lead ion participated in constitution of structure of geopolymer, or Pb2+ was adsorbed by the aluminium ions on the geopolymeric skeleton and held in geopolymer. However, cement mainly solidified lead ion by physical encapsulation and adsorption mechanism. Therefore, both from the compressive strength and leaching concentration and from the microstructure characterization as well as the mechanism of the geopolymerization reaction, the geopolymer has more advantages in immobilizing Pb2+ than the cement.

  17. Joint toxicity of heavy metals and chlorobenzenes to pyriformis Tetrahymena.

    PubMed

    Zhang, Tian; Li, Xi; Lu, Yang; Liu, Peng; Zhang, Chaocan; Luo, Hui

    2014-06-01

    Chlorobenzens and heavy metals are frequently detected in the environment, but few studies have assessed the joint toxicity of organic and inorganic contaminants. The joint toxicity of heavy metals and chlorobenzenes was evaluated in the present study. Growth metabolism of the joint toxicity was studied by microcalorimetry at 28°C, the growth constant (k) and inhibitory ratio (I) were calculated. Toxic unit (TU) and additional index (AI) were introduced to determine the outcome in combined tests, and the coexistence of Cu, Cd, Cr(III) and p-chlorobenzene was antagonism, and the effect of Cu, Cd, Cr(III) and o-chlorobenzene, Cu and 1,2,4-trichlorobenzene were synergism. In addition, micro-situation of the cell membrane surface of pyriformis Tetrahymena was observed by SEM. The cells suffered serious damage after sufficient acting time. ATR-FTIR spectra revealed that amide groups and PO2(-) of the phospholipid phospho-diester, both in the hydrophobic end exposed to the outer layer, were the easiest to be damaged.

  18. Effective Removal of Heavy Metals from Wastewater Using Modified Clay.

    PubMed

    Song, Mun-Seon; Vijayarangamuthu, K; Han, EunJi; Jeon, Ki-Joon

    2016-05-01

    We report an economical and eco-friendly way to remove the heavy metal pollutant using modified clay. The modification of clay was done by calcining the natural clay from Kyushu region in Japan. Further, the removal efficiency for various pH and contact time was evaluated. The morphology of the clays was studied using the scanning electron microscopy (SEM). The structural and chemical analyses of modified clay were done by using X-ray diffraction (XRD), Raman spectroscopy, and Energy dispersion analysis (EDAX) to understand the properties related to the removal of heavy metal pollutant. Further, we studied the absorption efficiency of clay for various pH and contacting time using Ni polluted water. The modified clays show better removal efficiency for all pH with different saturation time. The adsorption follows pseudo-second order kinetics and the adsorption capacity of modified clay is 1.5 times larger than that of natural clay. The increase in the adsorption efficiency of modified clay was correlated to the increase in hematite phase along with increase in surface area due to surface morphological changes.

  19. Adaptive Engineering of Phytochelatin-based Heavy Metal Tolerance.

    PubMed

    Cahoon, Rebecca E; Lutke, W Kevin; Cameron, Jeffrey C; Chen, Sixue; Lee, Soon Goo; Rivard, Rebecca S; Rea, Philip A; Jez, Joseph M

    2015-07-10

    Metabolic engineering approaches are increasingly employed for environmental applications. Because phytochelatins (PC) protect plants from heavy metal toxicity, strategies directed at manipulating the biosynthesis of these peptides hold promise for the remediation of soils and groundwaters contaminated with heavy me