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Sample records for copper arsenate cca-treated

  1. New Approach to Remove Metals from Chromated Copper Arsenate (CCA)-Treated Wood

    Science.gov (United States)

    Todd F. Shupe; Chung Y. Hse; Hui Pan

    2012-01-01

    Recovery of metals from chromated copper arsenate (CCA)-treated southern pine wood particles was investigated using binary acid solutions consisting of acetic, oxalic, and phosphoric acids in a microwave reactor. Formation of an insoluble copper oxalate complex in the binary solution containing oxalic acid was the major factor for low copper removal. Furthermore, the...

  2. Rapid microwave-assisted acid extraction of metals from chromated copper arsenate (CCA)-treated southern pine wood

    Science.gov (United States)

    Bin Yu; Chung Y. Hse; Todd F. Shupe

    2009-01-01

    The effects of acid concentration, reaction time, and temperature in a microwave reactor on recovery of CCA-treated wood were evaluated. Extraction of copper, chromium, and arsenic metals from chromated copper arsenate (CCA)-treated southern pine wood samples with three different acids (i.e., acetic acid, oxalic acid, and phosphoric acid) was investigated using in...

  3. ASSESSING CHILDREN'S EXPOSURES TO THE WOOD PRESERVATIVE CCA (CHROMATED COPPER ARSENATE) ON TREATED PLAYSETS AND DECKS

    Science.gov (United States)

    Concerns have been raised regarding the safety of young children contacting arsenic and chromium residues while playing on and around Chromated Copper Arsenate (CCA) treated wood playground structures and decks. Although CCA registrants voluntarily canceled treated wood for re...

  4. Fractionation of heavy metals in liquefied chromated copper arsenate (CCA)-treated wood sludge using a modified BCR-sequential extraction procedure

    Science.gov (United States)

    Hui Pan; Chung-Yun Hse; Robert Gambrell; Todd F. Shupe

    2009-01-01

    Chromated copper arsenate (CCA)-treated wood was liquefied with polyethylene glycol/glycerin and sulfuric acid. After liquefaction, most CCA metals (98% As, 92% Cr, and 83% Cu) were removed from liquefied CCA-treated wood by precipitation with calcium hydroxide. The original CCA-treated wood and liquefied CCA-treated wood sludge were fractionated by a modified...

  5. Effect of weathering on chromated copper arsenate (CCA) treated wood : leaching of metal salts and change in water repellency

    Science.gov (United States)

    R. Sam Williams; Stan Lebow; Patricia Lebow

    2003-01-01

    Wood pressure-treated with chromated copper arsenate (CCA) wood preservative is commonly used for outdoor construction. Oxides of arsenic, copper, and chromium are bound in the wood by a complex series of chemical reactions, but a small percentage of these compounds are gradually released by leaching and weathering. Recent studies suggest that the release of these...

  6. Leaching of chromated copper arsenate (CCA)-treated wood in a simulated monofill and its potential impacts to landfill leachate

    Energy Technology Data Exchange (ETDEWEB)

    Jambeck, Jenna R. [Department of Environmental Engineering Sciences, University of Florida, Gainesville, FL 32611-6450 (United States); Townsend, Timothy [Department of Environmental Engineering Sciences, University of Florida, Gainesville, FL 32611-6450 (United States)]. E-mail: ttown@ufl.edu; Solo-Gabriele, Helena [Department of Civil, Architectural, and Environmental Engineering, University of Miami, Coral Gables, FL 33146-0630 (United States)

    2006-07-31

    The proper end-of-life management of chromated copper arsenate (CCA)-treated wood, which contains arsenic, copper, and chromium, is a concern to the solid waste management community. Landfills are often the final repository of this waste stream, and the impacts of CCA preservative metals on leachate quality are not well understood. Monofills are a type of landfill designed and operated to dispose a single waste type, such as ash, tires, mining waste, or wood. The feasibility of managing CCA-treated wood in monofills was examined using a simulated landfill (a leaching lysimeter) that contained a mix of new and weathered CCA-treated wood. The liquid to solid ratio (LS) reached in the experiment was 0.63:1. Arsenic, chromium, and copper leached from the lysimeter at average concentrations of 42 mg/L for arsenic, 9.4 mg/L for chromium, and 2.4 mg/L for copper. Complementary batch leaching studies using deionized water were performed on similar CCA-treated wood samples at LS of 5:1 and 10:1. When results from the lysimeter were compared to the batch test results, copper and chromium leachability appeared to be reduced in the lysimeter disposal environment. Of the three metals, arsenic leached to the greatest extent and was found to have the best correlation between the batch and the lysimeter experiments.

  7. Impact of chromated copper arsenate (CCA) in wood mulch.

    Science.gov (United States)

    Townsend, Timothy G; Solo-Gabriele, Helena; Tolaymat, Thabet; Stook, Kristin

    2003-06-20

    The production of landscape mulch is a major market for the recycling of yard trash and waste wood. When wood recovered from construction and demolition (C&D) debris is used as mulch, it sometimes contains chromated copper arsenate (CCA)-treated wood. The presence of CCA-treated wood may cause some potential environmental problems as a result of the chromium, copper, and arsenic present. Research was performed to examine the leachability of the three metals from a variety of processed wood mixtures in Florida. The mixtures tested included mixed wood from C&D debris recycling facilities and mulch purchased from retail outlets. The synthetic precipitation leaching procedure (SPLP) was performed to examine the leaching of chromium, copper and arsenic. Results were compared to Florida's groundwater cleanup target levels (GWCTLs). Eighteen of the 22 samples collected from C&D debris processing facilities leached arsenic at concentrations greater than Florida's GWCTL of 50 microg/l. The mean leachable arsenic concentration for the C&D debris samples was 153 microg/l with a maximum of 558 microg/l. One of the colored mulch samples purchased from a retail outlet leached arsenic above 50 microg/l, while purchased mulch samples derived from virgin materials did not leach detectable arsenic (<5 microg/l). A mass balance approach was used to compute the potential metal concentrations (mg/kg) that would result from CCA-treated wood being present in wood mulch. Less than 0.1% CCA-treated wood would cause a mulch to exceed Florida's residential clean soil guideline for arsenic (0.8 mg/kg).

  8. Rapid microwave-assisted acid extraction of southern pine waste wood to remove metals from chromated copper arsenate (CCA) treatment

    Science.gov (United States)

    Chung-Yun Hse; Todd F. Shupe; Bin Yu

    2013-01-01

    Recovery of metals from chromated copper arsenate (CCA)-treated southern pine wood particles was investigated by extraction in a microwave reactor with binary combinations of acetic acid (AA), oxalic acid (OxA), and phosphoric acid (PhA). Use of OxA was not successful, as insoluble copper oxalate complexes impeded copper removal. The combination of OxA and AA also had...

  9. Application of a CCA-treated wood waste decontamination process to other copper-based preservative-treated wood after disposal

    Energy Technology Data Exchange (ETDEWEB)

    Janin, Amelie, E-mail: amelie.janin@ete.inrs.ca [University of Toronto, Faculty of Forestry, 33, Willcocks St., Toronto, ON, M5S 3B3 (Canada); Coudert, Lucie, E-mail: lucie.coudert@ete.inrs.ca [Institut national de la recherche scientifique (Centre Eau, Terre et Environnement), Universite du Quebec, 490 rue de la Couronne, Quebec, QC, G1K 9A9 (Canada); Riche, Pauline, E-mail: pauline.riche@ete.inrs.ca [Institut national de la recherche scientifique (Centre Eau, Terre et Environnement), Universite du Quebec, 490 rue de la Couronne, Quebec, QC, G1K 9A9 (Canada); Mercier, Guy, E-mail: guy_mercier@ete.inrs.ca [Institut national de la recherche scientifique (Centre Eau, Terre et Environnement), Universite du Quebec, 490 rue de la Couronne, Quebec, QC, G1K 9A9 (Canada); Cooper, Paul, E-mail: p.cooper@utoronto.ca [University of Toronto, Faculty of Forestry, 33, Willcocks St., Toronto, ON, M5S 3B3 (Canada); Blais, Jean-Francois, E-mail: blaisjf@ete.inrs.ca [Institut national de la recherche scientifique (Centre Eau, Terre et Environnement), Universite du Quebec, 490 rue de la Couronne, Quebec, QC, G1K 9A9 (Canada)

    2011-02-28

    Research highlights: {yields} This paper describes a process for the metal removal from treated (CA-, ACQ- or MCQ-) wood wastes. {yields} This sulfuric acid leaching process is simple and economic. {yields} The remediated wood could be recycled in the industry. - Abstract: Chromated copper arsenate (CCA)-treated wood was widely used until 2004 for residential and industrial applications. Since 2004, CCA was replaced by alternative copper preservatives such as alkaline copper quaternary (ACQ), copper azole (CA) and micronized copper quaternary (MCQ), for residential applications due to health concerns. Treated wood waste disposal is becoming an issue. Previous studies identified a chemical process for decontaminating CCA-treated wood waste based on sulfuric acid leaching. The potential application of this process to wood treated with the copper-based preservatives (alkaline copper quaternary (ACQ), copper azole (CA) and micronized copper quaternary (MCQ)) is investigated here. Three consecutive leaching steps with 0.1 M sulfuric acid at 75 deg, C for 2 h were successful for all the types of treated wood and achieved more than 98% copper solubilisation. The different acidic leachates produced were successively treated by coagulation using ferric chloride and precipitation (pH = 7) using sodium hydroxide. Between 94 and 99% of copper in leachates could be recovered by electrodeposition after 90 min using 2 A electrical current. Thus, the process previously developed for CCA-treated wood waste decontamination could be efficiently applied for CA-, ACQ- or MCQ-treated wood.

  10. Extant contents of chromium, copper and arsenic in waste CCA-treated timber

    International Nuclear Information System (INIS)

    Chiba, Keiko; Uchida, Shinpei; Honma, Yoshinori; Sera, Koichiro; Saitoh, Katsumi

    2009-01-01

    The segregation and disposal of chromated copper arsenate (CCA)-treated wood waste when recycling building waste materials is a serious issue. We examined the contents of CCA preserved cedar timber by PIXE analysis. CCA preserved timber contained large amounts of these metals both on the surface and core of the wood. The ratio of chromium, copper and arsenic contained on the surface was 1:2:1, and in contrast, the ratio in the core was 1:1:2. In other words, the arsenic content was highest in the core. Moreover, the chemical form of arsenic in both parts of the wood was only inorganic arsenic; the same form of arsenic in preservative components known as carcinogenic substances. These findings mean that the complete separation of waste CCA preserved timber from construction and demolition wood is needed. (author)

  11. Factors affecting sodium hypochlorite extraction of CCA from treated wood.

    Science.gov (United States)

    Gezer, E D; Cooper, P A

    2009-12-01

    Significant amounts of chromated copper arsenate (CCA) treated wood products, such as utility poles and residential construction wood, remain in service. There is increasing public concern about environmental contamination from CCA-treated wood when it is removed from service for reuse or recycling, placed in landfills or burned in commercial incinerators. In this paper, we investigated the effects of time, temperature and sodium hypochlorite concentration on chromium oxidation and extraction of chromated copper arsenate from CCA-treated wood (Type C) removed from service. Of the conditions evaluated, reaction of milled wood with sodium hypochlorite for one hour at room temperature followed by heating at 75 degrees C for two hours gave the highest extraction efficiency. An average of 95% Cr, 99% Cu and 96% As could be removed from CCA-treated, milled wood by this process. Most of the extracted chromium was oxidized to the hexavalent state and could therefore be recycled in a CCA treating solution. Sodium hypochlorite extracting solutions could be reused several times to extract CCA components from additional treated wood samples.

  12. Carcinogenic risk of chromium, copper and arsenic in CCA-treated wood

    International Nuclear Information System (INIS)

    Ohgami, Nobutaka; Yamanoshita, Osamu; Thang, Nguyen Dinh; Yajima, Ichiro; Nakano, Chihiro; Wenting, Wu; Ohnuma, Shoko

    2015-01-01

    We showed that 2.1% of 233 pieces of lumber debris after the Great East Japan Earthquake was chromated copper arsenate (CCA)-treated wood. Since hexavalent chromium (Cr), copper (Cu) and pentavalent arsenic (As) in the debris may be diffused in the air via incineration, we exposed human lung normal (BEAS-2B) and carcinoma (A549) cells to Cr, Cu and As at the molar ratio in a representative CCA-treated wood. Co-exposure to 0.10 μM Cr and 0.06 μM As, which solely had no effect on colony formation, synergistically promoted colony formation in BEAS-2B cells, but not A549 cells, with activation of the PI3K/AKT pathway. Sole exposure and co-exposure to Cu showed limited effects. Since previous reports showed Cr and As concentrations to which human lungs might be exposed, our results suggest the importance to avoid diffusion of Cr and As in the air via incineration of debris including CCA-treated wood after the disaster. - Highlights: • CCA-treated wood was found in debris after the Great East Japan Earthquake in 2011. • Carcinogenic risk of CCA-treated woods was evaluated with human lung cell lines. • Co-exposure to Cr and As synergistically promoted colony formation. • Co-exposure to Cr and As synergistically activated the PI3/AKT pathway. • Effects of sole exposure and co-exposure to Cu on colony formation were limited. - Co-exposure to Cr and As, but not Cu, in CCA-treated wood debris from the Great East Japan Earthquake showed carcinogenicity in vitro.

  13. Comparative study on liquefaction of creosote and chromated copper arsenate (CCA)-treated wood and untreated southern pine wood: effects of acid catalyst content, liquefaction time, temperature, and phenol to wood ratio

    Science.gov (United States)

    Hui Pan; Chung-Yun Hse; Todd F. Shupe

    2009-01-01

    Creosote- and chromated copper arsenate (CCA)-treated wood waste and untreated southern pine wood were liquefied with phenol and sulfuric acid. The effects of sulfuric acid content, liquefaction time, liquefaction temperature, and phenol to wood ratio on liquefaction rate (i.e., wood residue content) were investigated and analyzed by analysis of variance (...

  14. Mechanical and chemical properties of CCA-treated lumber removed from spent residential decks

    Science.gov (United States)

    Robert L. Smith; David Bailey; Philip A. Araman

    2007-01-01

    The amount of chromated copper arsenate (CCA)- treated wood being removed from spent residential decks is increasing at a tremendous rate. While most spent CCA-treated wood is being disposed in landfills, further useful and environmentally beneficial alternatives have to be met. If the volume of CCA-treated wood reaching landfills continues to rise, stricter disposal...

  15. Determination of chromated copper arsenate (CCA) in treated wood of Eucalyptus

    International Nuclear Information System (INIS)

    Parreira, Paulo S.; Vendrametto, Guilherme R.; Cunha, Magda E.T.

    2009-01-01

    This work deals with the possible application of a portable energy dispersive handmade system (PXRF-LFNA-02) for the determination of Chromium, Copper and Arsenic in the preservative solution used to protect commercial wood of Eucalyptus, which are employed as wood fence, posts, contention fences, railroad sleepers, etc. It was prepared five body-of-proof made of eucalyptus alburnum with different concentrations for each element varying from 0.0061 to 0.0180 (g/g) for CrO 3 , 0.0024 to 0.0070 (g/g) for CuO and 0.0044 to 0.0129 (g/g) for As 2 O 5 . Four of them were used for calibration curves and one used as reference sample. It was used a commercial CCA (Chromated Copper Arsenate ) solution to prepare the samples. The results show a good linear regression between concentrations and X-rays intensities, after applied the multiple linear regression methodology for interelemental corrections. The values obtained with this methodology were 3.01(kg/m 3 ), 1.18 (kg/m 3 ) e 2.21 (kg/m 3 ) for CrO 3 , CuO and As 2 O 5 , respectively, while the nominal values are 2.90 (kg/m 3 ) for CrO 3 , 1.13 (kg/m 3 ) for CuO and 2.07 (kg/m 3 ) for As 2 O 5 . The ED-XRF (Energy Dispersive X-Rays Fluorescence) is a well established technique with high-speed of analytical procedure and its portable configuration allowing a multielemental, simultaneous and non destructive analyses besides in situ application. (author)

  16. Determination of chromated copper arsenate (CCA) in treated wood of Eucalyptus

    Energy Technology Data Exchange (ETDEWEB)

    Parreira, Paulo S., E-mail: parreira@uel.b [Universidade Estadual de Londrina (UEL), PR (Brazil). Dept. de Fisica. Lab.de Fisica Nuclear Aplicada; Vendrametto, Guilherme R.; Cunha, Magda E.T., E-mail: grvendrametto@gmail.co [Universidade Norte do Parana, Arapongas, PR (Brazil). Centro de Ciencias Humanas, da Saude, Exatas e Tecnologicas-A

    2009-07-01

    This work deals with the possible application of a portable energy dispersive handmade system (PXRF-LFNA-02) for the determination of Chromium, Copper and Arsenic in the preservative solution used to protect commercial wood of Eucalyptus, which are employed as wood fence, posts, contention fences, railroad sleepers, etc. It was prepared five body-of-proof made of eucalyptus alburnum with different concentrations for each element varying from 0.0061 to 0.0180 (g/g) for CrO{sub 3}, 0.0024 to 0.0070 (g/g) for CuO and 0.0044 to 0.0129 (g/g) for As{sub 2}O{sub 5}. Four of them were used for calibration curves and one used as reference sample. It was used a commercial CCA (Chromated Copper Arsenate ) solution to prepare the samples. The results show a good linear regression between concentrations and X-rays intensities, after applied the multiple linear regression methodology for interelemental corrections. The values obtained with this methodology were 3.01(kg/m{sup 3}), 1.18 (kg/m{sup 3}) e 2.21 (kg/m{sup 3}) for CrO{sub 3}, CuO and As{sub 2}O{sub 5}, respectively, while the nominal values are 2.90 (kg/m{sup 3}) for CrO{sub 3}, 1.13 (kg/m{sup 3}) for CuO and 2.07 (kg/m{sup 3}) for As{sub 2}O{sub 5}. The ED-XRF (Energy Dispersive X-Rays Fluorescence) is a well established technique with high-speed of analytical procedure and its portable configuration allowing a multielemental, simultaneous and non destructive analyses besides in situ application. (author)

  17. Physical and mechanical properties of flakeboard produced from recycled CCA-treated wood

    Science.gov (United States)

    W. Li; T.F. Shupe; Chung-Yun Hse

    2004-01-01

    Chromated copper arsenate (CCA) treated wood has been most widely used in North America since the 1970s for many exterior applications such as decks, fences, playground equipment, utility poles, and others. A large volume of CCA-treated wood is currently coming out of service. Traditional disposal methods such as landfilling and incineration are not without adverse...

  18. Arsenic, chromium, and copper leaching from CCA-treated wood and their potential impacts on landfill leachate in a tropical country.

    Science.gov (United States)

    Kamchanawong, S; Veerakajohnsak, C

    2010-04-01

    This study looks into the potential risks of arsenic, chromium, and copper leaching from disposed hardwoods treated with chromated copper arsenate (CCA) in a tropical climate. The Toxicity Characteristic Leaching Procedure (TCLP) and the Waste Extraction Test (WET) were employed to examine new CCA-treated Burseraceae and Keruing woods, weathered CCA-treated teak wood, and ash from new CCA-treated Burseraceae wood. In addition, a total of six lysimeters, measuring 2 m high and 203 mm in diameter were prepared to compare the leachate generated from the wood monofills, construction and demolition (C&D) debris landfills and municipal solid waste (MSW) landfills, containing CCA-treated Burseraceae wood. The TCLP and WET results showed that the CCA-treated Burseraceae wood leached higher metal concentrations (i.e. 9.19-17.70 mg/L, 1.14-5.89 mg/L and 4.83-23.89 mg/L for arsenic, chromium, and copper, respectively) than the CCA-treated Keruing wood (i.e. 1.74-11.34 mg/L, 0.26-3.57 mg/L and 0.82-13.64 mg/L for arsenic, chromium and copper, respectively). Ash from the CCA-treated Burseraceae wood leached significantly higher metal concentrations (i.e. 108.5-116.9 mg/L, 1522-3862 mg/L and 84.03-114.4 mg/L for arsenic, chromium and copper, respectively), making this type of ash of high concern. The lysimeter study results showed that the MSW lysimeter exhibited higher reducing conditions, more biological activities and more dissolved ions in their leachates than the wood monofill and C&D debris lysimeters. All leachates generated from the lysimeters containing the CCA-treated Burseraceae wood contained significantly higher concentrations of arsenic in comparison to those of the untreated wood: in the range of 0.53-15.7 mg/L. It can be concluded that the disposal of CCA-treated Burseraceae wood in an unlined C&D landfill or a MSW landfill has the potential to contaminate groundwater.

  19. REMOVAL COPPER, CHROMIUM, ARSENIC FROM OUT-OF- SERVICE CCA-TREATED WOOD MATERIALS

    Directory of Open Access Journals (Sweden)

    Engin Derya Gezer

    2004-11-01

    Full Text Available Remediation can be defined as removing copper, chromium and arsenic from out-of-service CCA treated wood products. There are some various remediation methods that can be applied to remove copper, chromium and arsenic from out-of service CCA treated wood products in order to re-use that wooden materials and minimize adverse impacts of those out-of service CCA treated wood to environment, human health, animals and other living organisms. In this study, those applied various remediation methods to remove copper, chromium and arsenic were summarized.

  20. Electrodialytic remediation of CCA-treated waste wood in a 2 m3 pilot plant

    DEFF Research Database (Denmark)

    Christensen, Iben Vernegren; Pedersen, Anne Juul; Ottosen, Lisbeth M.

    2006-01-01

    Waste wood that has been treated with chromated-copper-arsenate (CCA) poses a potential environmental problem due to the content of copper, chromium and arsenic. A pilot plant for electrodialytic remediation of up to 2 m3 wood has been designed and tested and the results are presented here. Sever...

  1. Electrodialytic removal of Cu, Cr, and As from chromated copper arsenate-treated timber waste

    Energy Technology Data Exchange (ETDEWEB)

    Ribeiro, A.B.; Mateus, E.P.; Ottosen, L.M.; Bech-Nielsen, G.

    2000-03-01

    Waste of wood treated with chromated copper arsenate (CCA) is expected to increase in volume over the next decades. Alternative disposal options to landfilling are becoming more attractive to study, especially those that promote reuse. The authors have studied the electrodialytic removal of Cu, Cr, and As from CCA-treated timber wastes. The method uses a low-level direct current as the cleaning agent, combining the electrokinetic movement of ions in the matrix with the principle of electrodialysis. The technique was tested in four experiments using a laboratory cell on sawdust of an out-of-service CCA-treated Pinus pinaster Ait. pole. The duration of all the experiments was 30 days, and the current density was kept constant at 0.2 mA/cm{sup 2}. The experiments differ because in one the sawdust was saturated with water (experiment 1) and in the rest it was saturated with oxalic acid, 2.5, 5, and 7.5% (w/w), respectively, in experiments 2--4. The highest removal rates obtained were 93% of Cu, 95% of Cr, and 99% of As in experiment 2. Other experimental conditions might possibly optimize the removal rates.

  2. Effect of simulated rainfall and weathering on release of preservative elements from CCA treated wood

    Science.gov (United States)

    Stan Lebow; R. Sam Williams; Patricia Lebow

    2003-01-01

    The release of arsenic from wood pressure-treated with chromated copper arsenate (CCA) can be decreased by application of wood finishes, but little is known about the types of finishes that are best suited for this purpose. This study evaluated the effects of finish water repellent content and ultraviolet (UV) radiation on the release of arsenic, copper, and chromium...

  3. Long-term soil accumulation of chromium, copper, and arsenic adjacent to preservative-treated wood.

    Science.gov (United States)

    S. Lebow; D. Foster; J. Evans

    2004-01-01

    Chromated copper arsenate (CCA) treated wood has been used extensively in outdoor applications. The Environmental Protection Agency (EPA) and CCA producers recently reached an agreement to limit future use of CCA for some types of applications. One area of concern is the long-term accumulation of leached CCA in soil adjacent to treated wood structures. Interpreting...

  4. CCA retention and its effects on the bonding performance of decommissioned treated wood: a preliminary study

    Science.gov (United States)

    Cheng Piao; Todd F. Shupe; Mark Gibson; Chung Y. Hse

    2009-01-01

    Chromated copper arsenate (CCA) continues to be widely used as a wood preservative for industrial uses in the U.S. Disposal of treated wood is a potential long-term environmental liability. Current practices for disposing of decommissioned preservative-treated wood include landfilling and incineration, which are increasingly impractical due to environmental...

  5. Copper tolerance of brown-rot fungi : oxalic acid production in southern pine treated with arsenic-free preservatives

    Science.gov (United States)

    Frederick Green; Carol A. Clausen

    2005-01-01

    The voluntary withdrawal of chromated copper arsenate (CCA)-treated wood from most residential applications has increased the use of non-arsenical copper-based organic wood preservatives. Because the arsenic component of CCA controlled copper tolerant fungi, scientists have renewed interest in and concern about the decay capacity in the important copper-tolerant group...

  6. Improving the two-step remediation process for CCA-treated wood. Part I, Evaluating oxalic acid extraction

    Science.gov (United States)

    Carol Clausen

    2004-01-01

    In this study, three possible improvements to a remediation process for chromated-copper-arsenate (CCA) treated wood were evaluated. The process involves two steps: oxalic acid extraction of wood fiber followed by bacterial culture with Bacillus licheniformis CC01. The three potential improvements to the oxalic acid extraction step were (1) reusing oxalic acid for...

  7. Assessment of the environmental effects associated with wooden bridges preserved with creosote, pentachlorophenol, or chromated copper arsenate

    Science.gov (United States)

    Kenneth M. Brooks

    Timber bridges provide an economical alternative to concrete and steel structures, particularly in rural areas with light to moderate vehicle traffic. Wooden components of these bridges are treated with chromated copper arsenate type C (CCA), pentachlorophenol, or creosote to prolong the life of the structure from a few years to many decades. This results in reduced...

  8. Chemical yields from low-temperature pyrolysis of CCA-treated wood

    Science.gov (United States)

    Qirong Fu; Dimitris Argyropolous; Lucian Lucia; David Tilotta; Stan Lebow

    2009-01-01

    Low-temperature pyrolysis offers a feasible option for wood-waste management and the recovery of a variety of useful chemicals. The effect of chromated copper arsenate (CCA) wood preservative on the yield and composition of various pyrolysis products was investigated in the present research. A novel quantitative 31P nuclear magnetic resonance (...

  9. Leaching of CCA-treated wood: implications for waste disposal

    International Nuclear Information System (INIS)

    Townsend, Timothy; Tolaymat, Thabet; Solo-Gabriele, Helena; Dubey, Brajesh; Stook, Kristin; Wadanambi, Lakmini

    2004-01-01

    Leaching of arsenic, chromium, and copper from chromated copper arsenate (CCA)-treated wood poses possible environmental risk when disposed. Samples of un-weathered CCA-treated wood were tested using a variety of the US regulatory leaching procedures, including the toxicity characteristic leaching procedure (TCLP), synthetic precipitation leaching procedure (SPLP), extraction procedure toxicity method (EPTOX), waste extraction test (WET), multiple extraction procedure (MEP), and modifications of these procedures which utilized actual MSW landfill leachates, a construction and demolition (C and D) debris leachate, and a concrete enhanced leachate. Additional experiments were conducted to assess factors affecting leaching, such as particle size, pH, and leaching contact time. Results from the regulatory leaching tests provided similar results with the exception of the WET, which extracted greater quantities of metals. Experiments conducted using actual MSW leachate, C and D debris leachate, and concrete enhanced leachate provided results that were within the same order of magnitude as results obtained from TCLP, SPLP, and EPTOX. Eleven of 13 samples of CCA-treated dimensional lumber exceeded the US EPA's toxicity characteristic (TC) threshold for arsenic (5 mg/L). If un-weathered arsenic-treated wood were not otherwise excluded from the definition of hazardous waste, it frequently would require management as such. When extracted with simulated rainwater (SPLP), 9 of the 13 samples leached arsenic at concentrations above 5 mg/L. Metal leachability tended to increase with decreasing particle size and at pH extremes. All three metals leached above the drinking water standards thus possibly posing a potential risk to groundwater. Arsenic is a major concern from a disposal point of view with respect to ground water quality

  10. Effect of moisture content on strength of CCA-treated lumber

    Science.gov (United States)

    Jerrold E. Winandy

    1995-01-01

    Recent studies on the effects of chromated copper arsenate (CCA) treatment on lumber design properties have primarily evaluated the effects of such treatment at or near 12% moisture content and at failure times of 1 to 10 min. The influence of various moisture contents and faster loading rates is unknown. This report discusses the influence of moisture content and its...

  11. Elemental analysis of ash residue from combustion of CCA treated wood waste before and after electrodialytic extraction

    DEFF Research Database (Denmark)

    Pedersen, Anne Juul; Ottosen, Lisbeth M.

    2006-01-01

    Element distribution in a combined fly ash and bottom ash from combustion of copper chromate arsenate (CCA) treated wood waste was investigated by scanning electron microscopy (SEM/EDX) before and after electrodialytic extraction. The untreated ash contained various particles, including pieces...... of incompletely combusted wood rich in Cr and Ca, and irregular particles rich in Si, Al and K. Cr was also found incorporated in silica-based matrix particles. As was associated with Ca in porous (char) particles, indicating that Ca-arsenates had been formed during combustion. Cu was associated with Cr...... in the incompletely combusted wood pieces and was also found in almost pure form in a surface layer of some matrix particles – indicating surface condensation of volatile Cu species. In treated ash, Ca and As were no longer found together, indicating that Ca-arsenates had been dissolved due to the electrodialytic...

  12. Demonstration of the efficiency and robustness of an acid leaching process to remove metals from various CCA-treated wood samples.

    Science.gov (United States)

    Coudert, Lucie; Blais, Jean-François; Mercier, Guy; Cooper, Paul; Janin, Amélie; Gastonguay, Louis

    2014-01-01

    In recent years, an efficient and economically attractive leaching process has been developed to remove metals from copper-based treated wood wastes. This study explored the applicability of this leaching process using chromated copper arsenate (CCA) treated wood samples with different initial metal loading and elapsed time between wood preservation treatment and remediation. The sulfuric acid leaching process resulted in the solubilization of more than 87% of the As, 70% of the Cr, and 76% of the Cu from CCA-chips and in the solubilization of more than 96% of the As, 78% of the Cr and 91% of the Cu from CCA-sawdust. The results showed that the performance of this leaching process might be influenced by the initial metal loading of the treated wood wastes and the elapsed time between preservation treatment and remediation. The effluents generated during the leaching steps were treated by precipitation-coagulation to satisfy the regulations for effluent discharge in municipal sewers. Precipitation using ferric chloride and sodium hydroxide was highly efficient, removing more than 99% of the As, Cr, and Cu. It appears that this leaching process can be successfully applied to remove metals from different CCA-treated wood samples and then from the effluents. Copyright © 2013 Elsevier Ltd. All rights reserved.

  13. Oxalic acid as an assisting agent for the electrodialytic remediation of chromated copper arsenate treated timber waste

    DEFF Research Database (Denmark)

    Ribeiro, Alexandra B.; Mateus, Eduardo P.; Ottosen, Lisbeth M.

    1999-01-01

    The electrodialytic process is proposed as a technique for the remediation of chromated copper arsenate treated timber waste, using oxalic acid as assisting agent. The method prowed succesfull 93% Cu, 95% Cr and 99% As was removed from the timber.......The electrodialytic process is proposed as a technique for the remediation of chromated copper arsenate treated timber waste, using oxalic acid as assisting agent. The method prowed succesfull 93% Cu, 95% Cr and 99% As was removed from the timber....

  14. Determination of the distribution of copper and chromium in partly remediated CCA-treated pine wood using SEM and EDX analyses

    DEFF Research Database (Denmark)

    Christensen, Iben Vernegren; Ottosen, Lisbeth M.; Melcher, Eckhard

    2005-01-01

    . After soaking, a small amount of Cu and Cr was still present in the cell walls but larger particles were now found on wall surfaces. Most effective removal of Cu was obtained after soaking in phosphoric and oxalic acid followed by EDR; here numerous rice grain-shaped particles were observed containing...... large amounts of Cu and no Cr. Cr was most effectively removed after soaking in oxalic acid and subsequent EDR treatment or dual soaking in phosphoric acid and oxalic acid with and without subsequent EDR.......Soaking in different acids and electrodialytic remediation (EDR) were applied for removing copper and chromium from freshly Chromated Copper Arsenate (CCA) impregnated EN 113 pine wood samples. After remedial treatments, AAS analyses revealed that the concentration of copper (Cu) and chromium (Cr...

  15. Lead, arsenic, and copper content of crops grown on lead arsenate-treated and untreated soils

    Energy Technology Data Exchange (ETDEWEB)

    Chisholm, D

    1972-01-01

    Increased lead and arsenic concentrations in the surface soil (0-15 cm), resulting from applications of lead arsenate (PbHAs0/sub 1/), increased both lead and arsenic levels in crops grown on treated plots. The lead levels in some crops approached or exceeded the Canadian residue tolerance of 2.0 ppM. Lead arsenate soil treatments did not affect copper absorption by crops. On areas such as old orchard land contaminated with lead arsenate residues it may be advisable to ascertain crops, and also to determine the lead affinity and arsenic sensitivity of the plants to be grown.

  16. Soil and sediment concentrations of chromium, copper, and arsenic adjacent to a chromated copper arsenate-treated wetland boardwalk

    Science.gov (United States)

    Stan Lebow; Daniel Foster

    2010-01-01

    Environmental accumulation of preservative adjacent to a chromated copper arsenate (type C)–treated wetland boardwalk was evaluated. The site is considered a realistic ‘‘worst case’’ because of the large volume of treated wood, low current speeds, high annual rainfall, and environmental sensitivity. Soil and sediment samples were collected before construction and 0.5,...

  17. RETENTION AND PENETRATION OF CCA IN WOOD OF FIRST AND SECOND ROTATION OF Eucalyptus urophylla S.T. Blake

    Directory of Open Access Journals (Sweden)

    Mara Lúcia Agostini Valle

    2013-06-01

    Full Text Available http://dx.doi.org/10.5902/198050989292This study aimed to evaluate the retention and penetration of copper chrome arsenate (CCA type C as well as some wood properties of two rotations of two natural hybrid of Eucalyptus urophylla S. T. Blake, aiming their use as treated wood. The study was conducted with material from commercial plantations, with 63 months of age. For the wood characterization, the relationship sapwood-heartwood, the basic density and the size of fibers and vessels were evaluated. For the evaluation of treated wood, the penetration and retention of copper chrome arsenate (CCA type C were determined. Four trees per rotation and genetic material were used, which subsequently were split into three logs, in a total of 12 logs for each treatment. The preservative treatment was performed using the full cell process in autoclave using CCA solution with 2% concentration of active ingredients. The treatment process used was effective under the conditions required by the NBR 9480, with retention values ​​higher than the minimum required by the standard, which is 6.5 kg/m3 of CCA per treated wood, and in addition, provided deep penetration and regular condom in sapwood of all timber treated. There are no restrictions on the use of wood from the first and second rotation for preservative treatment, based on the properties evaluated. There was no correlation between the type C CCA retention and wood properties evaluated.

  18. Extractive decontamination of heavy metals from CCA contaminated ...

    African Journals Online (AJOL)

    In this paper, the mobilization and extraction of As, Cr and Cu from chromated copper arsenate (CCA) contaminated soil obtained from a wood treatment factory site by four organic acids are presented and discussed. The CCA contaminated soil (pH = 5.91, carbon = 0.32, CEC = 47.84 meq/100 g) was found to contain 39.55 ...

  19. Resistance of treated rubber wood ( Hevea brasiliensis ) to termite ...

    African Journals Online (AJOL)

    Spent rubber trees from a 25 year old plantation were cut, sawn and treated with Copper Chromium Arsenate (CCA) and Cashew Nut Shell Liquid (CNSL). Two sets of wood samples were treated with CCA and CNSL respectively while the third set was not treated to serve as control. The three sets were exposed to termite ...

  20. Classification of waste wood treated with chromated copper arsenate and boron/fluorine preservatives; Classificacao de residuos de madeira tratada com preservativos a base de arseniato de cobre cromatado e de boro/fluor

    Energy Technology Data Exchange (ETDEWEB)

    Ferrarini, Suzana Frighetto; Santos, Heldiane Souza dos; Miranda, Luciana Gampert; Azevedo, Carla M.N.; Pires, Marcal J.R., E-mail: suzana.ferrarini@gmail.com [Faculdade de Quimica, Pontificia Universidade Catolica do Rio Grande do Sul, Porto Alegre, RS (Brazil); Maia, Sandra Maria [Instituto de Quimica, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS (Brazil)

    2012-07-01

    Classification of waste wood treated with chromated copper arsenate (CCA) and boron/fluorine preservatives, according to NBR 10004, was investigated. The leaching test (ABNT NBR 10005) for As and Cr, and solubilization test (ABNT NBR 10006) for F, were applied to out-of-service wooden poles. Concentrations of As and Cr in leachates were determined by ICP-MS and of F by ESI. Values for As were higher than 1 mg L{sup -1} classifying the waste as hazardous material (Class I) whereas values for F (> 1.5 mg L{sup -1}) were non-hazardous but indicated non-inert material (Class IIA). (author)

  1. Comparative study of Nd:YAG laser-induced breakdown spectroscopy and transversely excited atmospheric CO2 laser-induced gas plasma spectroscopy on chromated copper arsenate preservative-treated wood.

    Science.gov (United States)

    Khumaeni, Ali; Lie, Zener Sukra; Niki, Hideaki; Lee, Yong Inn; Kurihara, Kazuyoshi; Wakasugi, Motoomi; Takahashi, Touru; Kagawa, Kiichiro

    2012-03-01

    Taking advantage of the specific characteristics of a transversely excited atmospheric (TEA) CO(2) laser, a sophisticated technique for the analysis of chromated copper arsenate (CCA) in wood samples has been developed. In this study, a CCA-treated wood sample with a dimension of 20 mm × 20 mm and a thickness of 2 mm was attached in contact to a nickel plate (20 mm × 20 mm × 0.15 mm), which functions as a subtarget. When the TEA CO(2) laser was successively irradiated onto the wood surface, a hole with a diameter of approximately 2.5 mm was produced inside the sample and the laser beam was directly impinged onto the metal subtarget. Strong and stable gas plasma with a very large diameter of approximately 10 mm was induced once the laser beam had directly struck the metal subtarget. This gas plasma then interacted with the fine particles of the sample inside the hole and finally the particles were effectively dissociated and excited in the gas plasma region. By using this technique, high precision and sensitive analysis of CCA-treated wood sample was realized. A linear calibration curve of Cr was successfully made using the CCA-treated wood sample. The detection limits of Cr, Cu, and As were estimated to be approximately 1, 2, and 15 mg/kg, respectively. In the case of standard LIBS using the Nd:YAG laser, the analytical intensities fluctuate and the detection limit was much lower at approximately one-tenth that of TEA CO(2) laser. © 2012 Optical Society of America

  2. Chemical-specific health consultation for chromated copper arsenate chemical mixture: port of Djibouti.

    Science.gov (United States)

    Chou, Selene; Colman, Joan; Tylenda, Carolyn; De Rosa, Christopher

    2007-05-01

    The Agency for Toxic Substances and Disease Registry (ATSDR) prepared this health consultation to provide support for assessing the public health implications of hazardous chemical exposure, primarily through drinking water, related to releases of chromated copper arsenate (CCA) in the port of Djibouti. CCA from a shipment, apparently intended for treating electric poles, is leaking into the soil in the port area. CCA is a pesticide used to protect wood against decay-causing organisms. This mixture commonly contains chromium(VI) (hexavalent chromium) as chromic acid, arsenic(V) (pentavalent arsenic) as arsenic pentoxide and copper (II) (divalent copper) as cupric oxide, often in an aqueous solution or concentrate. Experimental studies of the fate of CCA in soil and monitoring studies of wood-preserving sites where CCA was spilled on the soil indicate that the chromium(VI), arsenic and copper components of CCA can leach from soil into groundwater and surface water. In addition, at CCA wood-preserving sites, substantial concentrations of chromium(VI), arsenic and copper remained in the soil and were leachable into water four years after the use of CCA was discontinued, suggesting prolonged persistence in soil, with continued potential for leaching. The degree of leaching depended on soil composition and the extent of soil contamination with CCA. In general, leaching was highest for chromium(VI), intermediate for arsenic and lowest for copper. Thus, the potential for contamination of sources of drinking water exists. Although arsenic that is leached from CCA-contaminated soil into surface water may accumulate in the tissues of fish and shellfish, most of the arsenic in these animals will be in a form (often called fish arsenic) that is less harmful. Copper, which leaches less readily than the other components, can accumulate in tissues of mussels and oysters. Chromium is not likely to accumulate in the tissues of fish and shellfish. Limited studies of air

  3. Arsenic levels in wipe samples collected from play structures constructed with CCA-treated wood: Impact on exposure estimates

    Energy Technology Data Exchange (ETDEWEB)

    Barraj, Leila M. [Chemical Regulation and Food Safety, Exponent, Inc., Suite 1100, 1150 Connecticut Ave., NW, Washington, DC 20036 (United States)], E-mail: lbarraj@exponent.com; Scrafford, Carolyn G. [Chemical Regulation and Food Safety, Exponent, Inc., Suite 1100, 1150 Connecticut Ave., NW, Washington, DC 20036 (United States); Eaton, W. Cary [RTI International, 3040 Cornwallis Road, Research Triangle Park, NC 27709 (United States); Rogers, Robert E.; Jeng, Chwen-Jyh [Toxcon Health Sciences Research Centre Inc., 9607 - 41 Avenue, Edmonton, Alberta, T6E 5X7 (Canada)

    2009-04-01

    Lumber treated with chromated copper arsenate (CCA) has been used in residential outdoor wood structures and playgrounds. The U.S. EPA has conducted a probabilistic assessment of children's exposure to arsenic from CCA-treated structures using the Stochastic Human Exposure and Dose Simulation model for the wood preservative scenario (SHEDS-Wood). The EPA assessment relied on data from an experimental study using adult volunteers and designed to measure arsenic in maximum hand and wipe loadings. Analyses using arsenic handloading data from a study of children playing on CCA-treated play structures in Edmonton, Canada, indicate that the maximum handloading values significantly overestimate the exposure that occurs during actual play. The objective of our paper is to assess whether the dislodgeable arsenic residues from structures in the Edmonton study are comparable to those observed in other studies and whether they support the conclusion that the values derived by EPA using modeled maximum loading values overestimate hand exposures. We compared dislodgeable arsenic residue data from structures in the playgrounds in the Edmonton study to levels observed in studies used in EPA's assessment. Our analysis showed that the dislodgeable arsenic levels in the Edmonton playground structures are similar to those in the studies used by EPA. Hence, the exposure estimates derived using the handloading data from children playing on CCA-treated structures are more representative of children's actual exposures than the overestimates derived by EPA using modeled maximum values. Handloading data from children playing on CCA-treated structures should be used to reduce the uncertainty of modeled estimates derived using the SHEDS-Wood model.

  4. Landfill disposal of CCA-treated wood with construction and demolition (C&D) debris: arsenic, chromium, and copper concentrations in leachate.

    Science.gov (United States)

    Jambeck, Jenna R; Townsend, Timothy G; Solo-Gabriele, Helena M

    2008-08-01

    Although phased out of many residential uses in the United States, the disposal of CCA-treated wood remains a concern because significant quantities have yet to be taken out of service, and it is commonly disposed in landfills. Catastrophic events have also led to the concentrated disposal of CCA-treated wood, often in unlined landfills. The goal of this research was to simulate the complex chemical and biological activity of a construction and demolition (C&D) debris landfill containing a realistic quantity of CCA-treated wood (10% by mass), produce leachate, and then evaluate the arsenic, copper, and chromium concentrations in the leachate as an indication of what may occur in a landfill setting. Copper concentrations were not significantly elevated in the control or experimental simulated landfill setting (alpha = 0.05). However, the concentrations of arsenic and chromium were significantly higher in the experimental simulated landfill leachate compared to the control simulated landfill leachate (alpha = 0.05, p debris can impact leachate quality which, in turn could affect leachate management practices or aquifers below unlined landfills.

  5. Fixation effects on the release of copper, chromium and arsenic from CCA-C treated marine piles

    Science.gov (United States)

    Stan Lebow

    1999-01-01

    This study sought to determine the effect of fixation time and temperature on the release of copper, chromium and arsenic from treated marine piles immersed in seawater under "worst case" conditions. Sections of piles were CCA-C treated to a target retention of 2.5 lbs/ft3) (40 kg/m3) and then allowed to Condition at 36°F (2°C) for either 3, 7 or 20 days. As...

  6. FIELD-SCALE LEACHING OF ARSENIC, CHROMIUM AND COPPER FROM WEATHERED TREATED WOOD

    Science.gov (United States)

    Hasan, A. Rasem; Hu, Ligang; Solo-Gabriele, Helena M.; Fieber, Lynne; Cai, Yong; Townsend, Timothy G.

    2010-01-01

    Earlier studies documented the loss of wood preservatives from new wood. The objective of this study was to evaluate losses from weathered treated wood under field conditions by collecting rainfall leachate from 5 different wood types, all with a surface area of 0.21 m2. Wood samples included weathered chromate copper arsenate (CCA) treated wood at low (2.7 kg/m3), medium (4.8 kg/m3) and high (35.4 kg/m3) retention levels, new alkaline copper quat (ACQ) treated wood (1.1 kg/m3 as CuO) and new untreated wood. Arsenic was found to leach at a higher rate (100 mg in 1 year for low retention) than chromium and copper (leached at the highest rate from the ACQ sample (670 mg). Overall results suggest that metals’ leaching is a continuous process driven by rainfall, and that the mechanism of release from the wood matrix changes as wood weathers. PMID:20053493

  7. Formation of metal agglomerates during carbonisation of chromated copper arsenate (CCA) treated wood waste: Comparison between a lab scale and an industrial plant

    Energy Technology Data Exchange (ETDEWEB)

    Helsen, Lieve [Katholieke Universiteit Leuven, Department of Mechanical Engineering, Division of Applied Mechanics and Energy Conversion, Celestijnenlaan 300A, B-3001 Leuven (Heverlee) (Belgium)]. E-mail: lieve.helsen@mech.kuleuven.be; Hacala, Amelie [Company Thermya, 1 rue Nicolas Appert, 33140 Villenave d' Ornon (France)]. E-mail: hacala@thermya.com

    2006-10-11

    This paper compares the results obtained by scanning electron microscopy coupled to X-ray analysis (SEM-EDXA) of the solid product after carbonisation of treated wood waste in a lab scale and in an industrial installation. These setups (lab scale and industrial) are characterized by different operating conditions of the carbonisation process. Moreover, the wood waste input to the processes differs significantly. From this study, it is clear that some similarities but also some differences exist between the lab scale study and the study with the industrial Chartherm plant. In both reactors, a metal (and mineral) agglomeration process takes place, even in the case of untreated wood. The agglomerates initially present in the wood input may serve as a seed for the metal agglomeration process during 'chartherisation'. The industrial setup leads to a broader range of agglomerates' size (0.1-50 {mu}m) and composition (all possible combinations of Cu, Cr, As and wood minerals). Some agglomerates contain the three metals but the major part is a combination of wood minerals and one or two of the three preservative metals, while all agglomerates analysed in the lab scale product contain the three metals. The separate influence of wood input characteristics and process conditions cannot be derived from these experiments, but the observations suggest that the higher the CCA retention in the wood input is, the easier is the metal agglomeration process during chartherisation of CCA treated wood waste. From the analyses performed in this study it seems that copper behaves differently in the sense that it agglomerates easily, but the resulting particles are small (<1 {mu}m)

  8. Formation of metal agglomerates during carbonisation of chromated copper arsenate (CCA) treated wood waste: Comparison between a lab scale and an industrial plant

    International Nuclear Information System (INIS)

    Helsen, Lieve; Hacala, Amelie

    2006-01-01

    This paper compares the results obtained by scanning electron microscopy coupled to X-ray analysis (SEM-EDXA) of the solid product after carbonisation of treated wood waste in a lab scale and in an industrial installation. These setups (lab scale and industrial) are characterized by different operating conditions of the carbonisation process. Moreover, the wood waste input to the processes differs significantly. From this study, it is clear that some similarities but also some differences exist between the lab scale study and the study with the industrial Chartherm plant. In both reactors, a metal (and mineral) agglomeration process takes place, even in the case of untreated wood. The agglomerates initially present in the wood input may serve as a seed for the metal agglomeration process during 'chartherisation'. The industrial setup leads to a broader range of agglomerates' size (0.1-50 μm) and composition (all possible combinations of Cu, Cr, As and wood minerals). Some agglomerates contain the three metals but the major part is a combination of wood minerals and one or two of the three preservative metals, while all agglomerates analysed in the lab scale product contain the three metals. The separate influence of wood input characteristics and process conditions cannot be derived from these experiments, but the observations suggest that the higher the CCA retention in the wood input is, the easier is the metal agglomeration process during chartherisation of CCA treated wood waste. From the analyses performed in this study it seems that copper behaves differently in the sense that it agglomerates easily, but the resulting particles are small (<1 μm)

  9. Utility poles not affected by CCA decision

    Energy Technology Data Exchange (ETDEWEB)

    De Venzio, H. [Arch Wood Protection Canada, Mississauga, ON (Canada)

    2002-08-01

    A voluntary decision by industry to move non-industrial use of treated lumber products away from pressure-treated wood containing chromated copper arsenate (CCA) preservative was announced by the Environmental Protection Agency on February 12, 2002. Although new alternative wood preservatives would be used, this decision does not affect utility poles, which will continue to be sold and installed. The author provides a brief historical outline concerning the creation of CCA in 1933 and its subsequent uses. CCA has many advantages, including clean surface of the poles, ground line treatment that is not required thus eliminating the requirement to rotate the poles during extended storage periods. Conductivity is low, as is corrosivity without affecting the bending characteristics of the wood. The injection of a refined hydrocarbon oil emulsion in the outer layer of the pole after the treatment with CCA is offered by some pole producers to facilitate gaff penetration. Sawing, drilling and nailing are also made easier. Water repellents can be added to the treating solution to improve climbability, slowing down the absorption and release of moisture. Warranties, extending for 50-year periods, are offered by some companies against wood-destroying organisms. The North American Wood Pole Coalition (NAWPC) was formed in 1998 to promote the use of wood poles, and publishes brochures and technical bulletins to that effect.

  10. CCA-treated wood disposed in landfills and life-cycle trade-offs with waste-to-energy and MSW landfill disposal.

    Science.gov (United States)

    Jambeck, Jenna; Weitz, Keith; Solo-Gabriele, Helena; Townsend, Timothy; Thorneloe, Susan

    2007-01-01

    Chromated copper arsenate (CCA)-treated wood is a preservative treated wood construction product that grew in use in the 1970s for both residential and industrial applications. Although some countries have banned the use of the product for some applications, others have not, and the product continues to enter the waste stream from construction, demolition and remodeling projects. CCA-treated wood as a solid waste is managed in various ways throughout the world. In the US, CCA-treated wood is disposed primarily within landfills; however some of the wood is combusted in waste-to-energy (WTE) facilities. In other countries, the predominant disposal option for wood, sometimes including CCA-treated wood, is combustion for the production of energy. This paper presents an estimate of the quantity of CCA-treated wood entering the disposal stream in the US, as well as an examination of the trade-offs between landfilling and WTE combustion of CCA-treated wood through a life-cycle assessment and decision support tool (MSW DST). Based upon production statistics, the estimated life span and the phaseout of CCA-treated wood, recent disposal projections estimate the peak US disposal rate to occur in 2008, at 9.7 million m(3). CCA-treated wood, when disposed with construction and demolition (C&D) debris and municipal solid waste (MSW), has been found to increase arsenic and chromium concentrations in leachate. For this reason, and because MSW landfills are lined, MSW landfills have been recommended as a preferred disposal option over unlined C&D debris landfills. Between landfilling and WTE for the same mass of CCA-treated wood, WTE is more expensive (nearly twice the cost), but when operated in accordance with US Environmental Protection Agency (US EPA) regulations, it produces energy and does not emit fossil carbon emissions. If the wood is managed via WTE, less landfill area is required, which could be an influential trade-off in some countries. Although metals are concentrated

  11. A PROBABILISTIC EXPOSURE ASSESSMENT FOR CHILDREN WHO CONTACT CCA-TREATED PLAYSETS AND DECKS USING THE STOCHASTIC HUMAN EXPOSURE AND DOSE SIMULATION (SHEDS) MODEL FOR THE WOOD PRESERVATIVE EXPOSURE SCENARIO

    Science.gov (United States)

    The U.S. Environmental Protection Agency has conducted a probabilistic exposure and dose assessment on the arsenic (As) and chromium (Cr) components of Chromated Copper Arsenate (CCA) using the Stochastic Human Exposure and Dose Simulation model for wood preservatives (SHEDS-Wood...

  12. Performance of copper-based wood preservatives in soil bed exposures

    Science.gov (United States)

    Stan T. Lebow; Thomas Nilsson; Jeffrey J. Morrell

    Copper-based biocides are widely used to protect wood from biological attack in a variety of environments. Chromated copper arsenate (CCA) is the dominant copper-based preservative for wood protection (J. T. MICKLEWRIGHT, 1989). First developed in India in the 1930s, CCA contains a very effective combination of materials. Copper provides protection against most...

  13. Electrochemical removal of CU, CR and AS from CCA-treated waste wood

    Energy Technology Data Exchange (ETDEWEB)

    Kristensen, I.V.; Ottosen, L.M.; Villumsen, A. [Dept. of Geology and Geotechnical Engineering, The Technical Univ. of Denmark, Lyngby (Denmark); Ribeiro, A.B. [Dept. of Geology and Geotechnical Engineering, The Technical Univ. of Denmark, Lyngby (Denmark)]|[Dept. de Ciencias e Engenharia do Ambiente, Faculdade de Ciencias e Tecnologia, Univ. Nova de Lisboa, Caparica (Portugal)

    2001-07-01

    CCA-treated waste wood poses a potential environmental problem due to the content of copper, chromium and arsenic. This paper presents the results obtained by electrodialytic remediation of CCA-treated waste wood. It is found that more than 90% Cu, and approximately 85% Cr and As was removed from the wood during the remediation. Thereby the concentration of copper in the wood is reduced from app. 426 ppm to app. 25 ppm, chromium is reduced from app. 837 ppm to app. 135 ppm and the arsenic content decreases from app. 589 ppm to app. 151 ppm. After remediation the removed metals are collected into liquids. The use of ion exchange membranes to separate the wood from the electrolytes result in a distribution of the metals after remediation that makes the collection of the metals easier, and reuse of the metals, for e.g. new CCA, may be possible. (orig.)

  14. Enhanced Tools and Techniques to Support Debris Management in Disaster Response Missions (Flood and Coastal Storm Damage Reduction Research and Development Program)

    Science.gov (United States)

    2009-05-01

    used for advertising , publication, or promotional purposes. Citation of trade names does not constitute an official endorsement or approval of the...Acronyms ATSDR Agency for Toxic Substances and Disease Registry CAR Clean Air Report CCA Chromated copper arsenate treated wood CDC Center for...2005): 1. Vegetative materials 2. Clean lumber 3. Inert materials 4. Building materials 5. Chromate copper arsenate (CCA)-treated wood 6

  15. Evaluation of the wood CCA preservative treatment process of Eucalyptus (Eucaliptus ssp) by X-ray fluorescence technique

    International Nuclear Information System (INIS)

    Pereira Junior, Sergio Matias; Salvador, Vera Lucia Ribeiro; Sato, Ivone Mulako

    2013-01-01

    Brazil produces around 1,2 mi m 3 of treated wood to meet the annual demand of railway, electric, rural and construction sectors. The treated woods used for poles, sleepers, fence posts and plywoods should be according to Brazilian norms requirements. The most used wood species are eucalyptus (Eucaliptus ssp)and pine (Pinus ssp). The most wood preservative products used in Brazil are CCA (Chromated Copper Arsenate) and CCB (Copper Chromium and Boron Salt). The analytical methods, such as Flame Atomic Absorption Spectrometry (FAAS) and Plasma Inductively Coupled Optical Emission Spectrometry (ICPOES) have been used for the evaluation of those treatment processes. In this work, the sapwood sample was obtained from eucalyptus trees (Eucaliptus ssp) obtained from Minas Gerais State, Brazil, cut plantation areas. Sawdust sapwood sample was grounded and submitted to different additions of CCA solutions (0.2, 0.7, 1.3, 2.3, 3.6, 6.3, 11.7and17.9 kg m -3 ). Power and pressed pellets sapwood samples, analyzed by EDXRFS, showed a good linear relation (r 2 >0.99) between the characteristic intensity fluorescent lines (CuΚα, CrΚαand AsΚΒ) and their concentration, also, showed adequate sensitivity (LQ -1 ) for Cu, Cr and As determination in treated woods. Cu, Cr and As were determined in powdered sawdust samples by FAA spectrometry, using the AWPA A11-93 standard method; the relation between the CCA retention and their concentration showed a lower linear relation than EDXRFS; the FAAS spreading result could be attributed to laboratorial CCA addition process. (author)

  16. Effect of different extracting solutions on the electrodialytic remediation of CCA-treated wood waste Part I. - Behaviour of Cu and Cr

    DEFF Research Database (Denmark)

    Velizarova, E.; Ribeiro, A. B.; Mateus, E.

    2004-01-01

    Removal of Cu and Cr from chromated copper arsenate (CCA)-treated wood waste under batch electrodialytic conditions was studied. The effect of different types of extracting solutions, such as deionised water or aqueous solutions of NaCl, formic acid, oxalic acid, and EDTA, on the magnitude...... and direction of the fluxes of Cu- and Cr-containing species in the electrodialytic cell was investigated. Oxalic acid was found to have the best performance if simultaneous removal of the two elements is required (removal efficiencies of 80.5% for Cu and 87.4% for Cr, respectively). A mixture of oxalic acid...... and formic acid also led to similar removal efficiencies. In these experiments, the target elements were accumulated in both the anode and cathode compartments of the electrodialytic cell due to the formation of negatively charged complexes with the organic acids used besides the free cationic forms...

  17. Evaluation of commercial landscaping mulch for possible contamination from CCA.

    Science.gov (United States)

    Jacobi, Gary; Solo-Gabriele, Helena; Dubey, Brajesh; Townsend, Timothy; Shibata, Tomoyuki

    2007-01-01

    Wood treated with chromated copper arsenate (CCA) is found in construction and demolition (C&D) debris, and a common use for wood recycled from C&D debris is the production of mulch. Given the high metals concentrations in CCA-treated wood, a small fraction of CCA-treated wood can increase the metal concentrations in the mulch above regulatory thresholds. The objective of this study was to determine the extent of contamination of CCA-treated wood in consumer landscaping mulch and to determine whether visual methods or rapid X-ray fluorescence (XRF) technology can be used to identify suspect mulch. Samples were collected throughout the State of Florida (USA) and evaluated both visually and chemically. Visual analysis focused on documenting wood-chip size distribution, whether the samples were artificially colored, and whether they contained plywood chips which is an indication that the sample was, in part, made from recycled C&D wood. Chemical analysis included measurements of total recoverable metals, leachable metals as per the standardized synthetic precipitation leaching procedure (SPLP), and XRF analysis. Visual identification methods, such as colorant addition or presence of plywood, were found effective to preliminarily screen suspect mulch. XRF analysis was found to be effective for identifying mulch containing higher than 75 mg/kg arsenic. For mulch samples that were not colored and did not contain evidence of C&D wood, none exceeded leachable metal concentrations of 50 microg/L and only 3% exceeded 10 mg/kg for recoverable metals. The majority of the colored mulch made from recycled C&D wood contained from 1% to 5% CCA-treated wood (15% maximum fraction) resulting in leachable metals in excess of 50 microg/L and total recoverable metals in excess of 10 mg/kg. The maximum arsenic concentration measured in the mulch samples evaluated was 230 mg/kg, which was above the Florida residential direct exposure regulatory guideline of 2.1 mg/kg.

  18. PRESERVATIVE LEACHING FROM WEATHERED CCA-TREATED WOOD

    Science.gov (United States)

    Disposal of discarded CCA-treated wood in landfills raises concerns with respect to leaching of preservative compounds. When unweathered CCA-treated wood is leached using the toxicity characteristic leaching procedure (TCLP), arsenic concentrations exceed the toxicity characteris...

  19. Evaluation of the wood CCA preservative treatment process of Eucalyptus (Eucaliptus ssp) by X-ray fluorescence technique

    Energy Technology Data Exchange (ETDEWEB)

    Pereira Junior, Sergio Matias, E-mail: matias@ipt.br [Instituto de Pesquisas Tecnologicas (IPT), Sao Paulo, SP (Brazil); Salvador, Vera Lucia Ribeiro; Sato, Ivone Mulako, E-mail: imsato@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2013-07-01

    Brazil produces around 1,2 mi m{sup 3} of treated wood to meet the annual demand of railway, electric, rural and construction sectors. The treated woods used for poles, sleepers, fence posts and plywoods should be according to Brazilian norms requirements. The most used wood species are eucalyptus (Eucaliptus ssp)and pine (Pinus ssp). The most wood preservative products used in Brazil are CCA (Chromated Copper Arsenate) and CCB (Copper Chromium and Boron Salt). The analytical methods, such as Flame Atomic Absorption Spectrometry (FAAS) and Plasma Inductively Coupled Optical Emission Spectrometry (ICPOES) have been used for the evaluation of those treatment processes. In this work, the sapwood sample was obtained from eucalyptus trees (Eucaliptus ssp) obtained from Minas Gerais State, Brazil, cut plantation areas. Sawdust sapwood sample was grounded and submitted to different additions of CCA solutions (0.2, 0.7, 1.3, 2.3, 3.6, 6.3, 11.7and17.9 kg m{sup -3}). Power and pressed pellets sapwood samples, analyzed by EDXRFS, showed a good linear relation (r{sup 2}>0.99) between the characteristic intensity fluorescent lines (CuΚα, CrΚαand AsΚΒ) and their concentration, also, showed adequate sensitivity (LQ < 5mgkg{sup -1}) for Cu, Cr and As determination in treated woods. Cu, Cr and As were determined in powdered sawdust samples by FAA spectrometry, using the AWPA A11-93 standard method; the relation between the CCA retention and their concentration showed a lower linear relation than EDXRFS; the FAAS spreading result could be attributed to laboratorial CCA addition process. (author)

  20. STOCHASTIC HUMAN EXPOSURE AND DOSE SIMULATION MODEL FOR THE WOOD PRESERVATIVE SCENARIO (SHEDS-WOOD), VERSION 2 MODEL SAS CODE

    Science.gov (United States)

    Concerns have been raised regarding the safety of young children contacting arsenic and chromium residues while playing on and around Chromated Copper Arsenate (CCA) treated wood playground structures and decks. Although CCA registrants voluntarily canceled treated wood for resi...

  1. Online Sorting of Wood Treated with Chromated Copper Arsenate Using Laser Induced Breakdown Spectroscopy

    National Research Council Canada - National Science Library

    Moskal, Thomas

    2001-01-01

    .... While CCA treated wood has several benefits, with perhaps the most important being the saving of an estimated 225 million trees annually due to its longer service life, there are growing concerns...

  2. Reuse of poles treated with CCA; CCA-kyllaestettyjen puupylvaeiden uudelleenkaeyttoe

    Energy Technology Data Exchange (ETDEWEB)

    Lehmus, E. [Vtt Building and Transport, Espoo (Finland)

    2005-07-01

    This study investigated the feasibility of re-using utility poles or parts of poles for structural use in construction. There are more than 10 million poles in Finland and about 200 000 poles will be removed from service yearly during the next few years. The directive 2003/2/EY will restrict the use of poles treated with CCA. This will change the practice that the energy and telecommunication companies have given the removed poles to the land owners. The present study launched by the Technical Research Centre of Finland (VTT) was carried out to determine the technical condition of CCA impregnated poles removed from service and the concentration levels and leaching of remaining preservatives. To summarize the results of the tests, it is safe to say that re-use of recovered poles of 30 to 50 years of age is possible. Both the preservative concentrations and strength/load-bearing capacity are high enough to allow the use of the poles as load-bearing structures. (orig.)

  3. Metal loss from treated wood products in contact with municipal solid waste landfill leachate

    Energy Technology Data Exchange (ETDEWEB)

    Dubey, Brajesh [Department of Environmental Health, PO Box 70682, East Tennessee State University, Johnson City, TN 37614 (United States); Department of Environmental Engineering Sciences, University of Florida, Gainesville, FL 32611-6450 (United States); Townsend, Timothy, E-mail: ttown@ufl.edu [Department of Environmental Engineering Sciences, University of Florida, Gainesville, FL 32611-6450 (United States); Solo-Gabriele, Helena [Department of Civil, Architectural and Environmental Engineering, University of Miami, Coral Gables, FL 33124-0630 (United States)

    2010-03-15

    The research presented in this paper evaluates the potential impact of municipal solid waste (MSW) landfill leachate quality on the loss of metals from discarded treated wood during disposal. The loss of arsenic (As), chromium (Cr), copper (Cu), and boron (B) from several types of pressure-treated wood (CCA: chromated copper arsenate, ACQ: alkaline copper quaternary, CBA: copper boron azole, and DOT: disodium octaborate tetrahydrate) using leachate collected from 26 MSW landfills in Florida was examined. The toxicity characteristic leaching procedure (TCLP), the synthetic precipitation leaching procedure (SPLP), and California's waste extraction test (WET) were also performed. The results suggested that loss of preservative components was influenced by leachate chemistry. Copper loss from CCA-, ACQ- and CBA-treated wood was similar in magnitude when in contact with landfill leachates compared to synthetic TCLP and SPLP solutions. Ammonia was found as one of the major parameters influencing the leaching of Cu from treated wood when leached with MSW landfill leachates. The results suggest that disposal of ACQ- and CBA-treated wood in substantial quantity in MSW landfills may elevate the Cu concentration in the leachate; this could be of potential concern, especially for a bioreactor MSW landfill in which relatively higher ammonia concentrations in leachate have been reported in recent literature. For the As, Cr and B the concentrations observed with the landfill leachate as the leaching solutions were over a range from some sample showing the concentrations below and some showing above the observed value from corresponding SPLP and TCLP tests. In general the WET test showed the highest concentrations.

  4. Finishability of CCA pressure-treated wood

    Science.gov (United States)

    Alan Ross; Richard Carlson; William Feist; Steven Bussjaeger

    2000-01-01

    Thus, a need arose for the development of surface finishes for CCA-treated wood that could address the special requirements of this substrate and provide protection against the ravages of water, sunlight, mildew, and other aspects of weathering and wear. Initially, this need was not addressed, most wood preserving companies had little expertise in surface finishes and...

  5. Potential arsenic exposures in 25 species of zoo animals living in CCA-wood enclosures

    International Nuclear Information System (INIS)

    Gress, J.; Silva, E.B. da; Oliveira, L.M. de; Zhao, Di; Anderson, G.; Heard, D.; Stuchal, L.D.; Ma, L.Q.

    2016-01-01

    Animal enclosures are often constructed from wood treated with the pesticide chromated copper arsenate (CCA), which leaches arsenic (As) into adjacent soil during normal weathering. This study evaluated potential pathways of As exposure in 25 species of zoo animals living in CCA-wood enclosures. We analyzed As speciation in complete animal foods, dislodgeable As from CCA-wood, and As levels in enclosure soils, as well as As levels in biomarkers of 9 species of crocodilians (eggs), 4 species of birds (feathers), 1 primate species (hair), and 1 porcupine species (quills). Elevated soil As in samples from 17 enclosures was observed at 1.0–110 mg/kg, and enclosures housing threatened and endangered species had As levels higher than USEPA's risk-based Eco-SSL for birds and mammals of 43 and 46 mg/kg. Wipe samples of CCA-wood on which primates sit had dislodgeable As residues of 4.6–111 μg/100 cm 2 , typical of unsealed CCA-wood. Inorganic As doses from animal foods were estimated at 0.22–7.8 μg/kg bw/d. Some As levels in bird feathers and crocodilian eggs were higher than prior studies on wild species. However, hair from marmosets had 6.37 mg/kg As, 30-fold greater than the reference value, possibly due to their inability to methylate inorganic As. Our data suggested that elevated As in soils and dislodgeable As from CCA-wood could be important sources of As exposure for zoo animals. - Highlights: • Daily inorganic As dose from zoo animal foods was 0.22–7.8 μg/kg bw/day. • Total As concentrations in soils of zoo animal enclosures were 1.0–110 mg/kg. • Endangered zoo animals live in soils with As above USEPA Eco-SSLs for avian and mammal species. • Dislodgeable As on CCA-wood beams where primates sit was 4.6–111 μg/100 cm 2 . • Marmoset hair had 6.37 mg/kg As compared to a reference value of 0.21 mg/kg.

  6. Potential arsenic exposures in 25 species of zoo animals living in CCA-wood enclosures

    Energy Technology Data Exchange (ETDEWEB)

    Gress, J. [State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Jiangsu 201146 (China); Soil and Water Science Department, University of Florida, Gainesville, FL 32611 (United States); Silva, E.B. da; Oliveira, L.M. de [Soil and Water Science Department, University of Florida, Gainesville, FL 32611 (United States); Zhao, Di [State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Jiangsu 201146 (China); Anderson, G. [Virginia Polytechnic Institute and State University, Blacksburg, VA 24061 (United States); Heard, D. [Department of Small Animal Clinical Sciences, University of Florida, Gainesville, FL 32610 (United States); Stuchal, L.D. [Center for Environmental and Human Toxicology, University of Florida, Gainesville, FL 32611 (United States); Department of Environmental and Global Health, College of Public Health and Health Professions, University of Florida, Gainesville, FL 32611 (United States); Ma, L.Q., E-mail: lqma@ufl.edu [State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Jiangsu 201146 (China); Soil and Water Science Department, University of Florida, Gainesville, FL 32611 (United States)

    2016-05-01

    Animal enclosures are often constructed from wood treated with the pesticide chromated copper arsenate (CCA), which leaches arsenic (As) into adjacent soil during normal weathering. This study evaluated potential pathways of As exposure in 25 species of zoo animals living in CCA-wood enclosures. We analyzed As speciation in complete animal foods, dislodgeable As from CCA-wood, and As levels in enclosure soils, as well as As levels in biomarkers of 9 species of crocodilians (eggs), 4 species of birds (feathers), 1 primate species (hair), and 1 porcupine species (quills). Elevated soil As in samples from 17 enclosures was observed at 1.0–110 mg/kg, and enclosures housing threatened and endangered species had As levels higher than USEPA's risk-based Eco-SSL for birds and mammals of 43 and 46 mg/kg. Wipe samples of CCA-wood on which primates sit had dislodgeable As residues of 4.6–111 μg/100 cm{sup 2}, typical of unsealed CCA-wood. Inorganic As doses from animal foods were estimated at 0.22–7.8 μg/kg bw/d. Some As levels in bird feathers and crocodilian eggs were higher than prior studies on wild species. However, hair from marmosets had 6.37 mg/kg As, 30-fold greater than the reference value, possibly due to their inability to methylate inorganic As. Our data suggested that elevated As in soils and dislodgeable As from CCA-wood could be important sources of As exposure for zoo animals. - Highlights: • Daily inorganic As dose from zoo animal foods was 0.22–7.8 μg/kg bw/day. • Total As concentrations in soils of zoo animal enclosures were 1.0–110 mg/kg. • Endangered zoo animals live in soils with As above USEPA Eco-SSLs for avian and mammal species. • Dislodgeable As on CCA-wood beams where primates sit was 4.6–111 μg/100 cm{sup 2}. • Marmoset hair had 6.37 mg/kg As compared to a reference value of 0.21 mg/kg.

  7. Effects of compost and phosphate on plant arsenic accumulation from soils near pressure-treated wood

    International Nuclear Information System (INIS)

    Cao Xinde; Ma, Lena Q.

    2004-01-01

    Leaching of arsenic (As) from chromated copper arsenate (CCA)-treated wood may elevate soil arsenic levels. Thus, an environmental concern arises regarding accumulation of As in vegetables grown in these soils. In this study, a greenhouse experiment was conducted to evaluate As accumulation by vegetables from the soils adjacent to the CCA-treated utility poles and fences and examine the effects of soil amendments on plant As accumulation. Carrot (Daucus carota L.) and lettuce (Lactuca sativa L.) were grown for ten weeks in the soil with or without compost and phosphate amendments. As expected, elevated As concentrations were observed in the pole soil (43 mg kg -1 ) and in the fence soil (27 mg kg -1 ), resulting in enhanced As accumulation of 44 mg kg -1 in carrot and 32 mg kg -1 in lettuce. Addition of phosphate to soils increased As accumulation by 4.56-9.3 times for carrot and 2.45-10.1 for lettuce due to increased soil water-soluble As via replacement of arsenate by phosphate in soil. However, biosolid compost application significantly reduced plant As uptake by 79-86%, relative to the untreated soils. This suppression is possibly because of As adsorbed by biosolid organic mater, which reduced As phytoavailability. Fractionation analysis showed that biosolid decreased As in soil water-soluble, exchangeable, and carbonate fraction by 45%, whereas phosphate increased it up to 2.61 times, compared to the untreated soils. Our results indicate that growing vegetables in soils near CCA-treated wood may pose a risk of As exposure for humans. Compost amendment can reduce such a risk by reducing As accumulation by vegetables and can be an important strategy for remediating CCA-contaminated soils. Caution should be taken for phosphate application since it enhances As accumulation. - Capsule: Compost amendment can reduce As exposure risk for humans by reducing As accumulation by vegetables and can be an important strategy for remediating CCA-contaminated soils

  8. Effects of compost and phosphate on plant arsenic accumulation from soils near pressure-treated wood

    Energy Technology Data Exchange (ETDEWEB)

    Cao Xinde [Soil and Water Science Department, University of Florida, Gainesville, FL (United States)]. E-mail: xcao@stevens.edu; Ma, Lena Q. [Soil and Water Science Department, University of Florida, Gainesville, FL (United States)

    2004-12-01

    Leaching of arsenic (As) from chromated copper arsenate (CCA)-treated wood may elevate soil arsenic levels. Thus, an environmental concern arises regarding accumulation of As in vegetables grown in these soils. In this study, a greenhouse experiment was conducted to evaluate As accumulation by vegetables from the soils adjacent to the CCA-treated utility poles and fences and examine the effects of soil amendments on plant As accumulation. Carrot (Daucus carota L.) and lettuce (Lactuca sativa L.) were grown for ten weeks in the soil with or without compost and phosphate amendments. As expected, elevated As concentrations were observed in the pole soil (43 mg kg{sup -1}) and in the fence soil (27 mg kg{sup -1}), resulting in enhanced As accumulation of 44 mg kg{sup -1} in carrot and 32 mg kg{sup -1} in lettuce. Addition of phosphate to soils increased As accumulation by 4.56-9.3 times for carrot and 2.45-10.1 for lettuce due to increased soil water-soluble As via replacement of arsenate by phosphate in soil. However, biosolid compost application significantly reduced plant As uptake by 79-86%, relative to the untreated soils. This suppression is possibly because of As adsorbed by biosolid organic mater, which reduced As phytoavailability. Fractionation analysis showed that biosolid decreased As in soil water-soluble, exchangeable, and carbonate fraction by 45%, whereas phosphate increased it up to 2.61 times, compared to the untreated soils. Our results indicate that growing vegetables in soils near CCA-treated wood may pose a risk of As exposure for humans. Compost amendment can reduce such a risk by reducing As accumulation by vegetables and can be an important strategy for remediating CCA-contaminated soils. Caution should be taken for phosphate application since it enhances As accumulation. - Capsule: Compost amendment can reduce As exposure risk for humans by reducing As accumulation by vegetables and can be an important strategy for remediating CCA

  9. Mitigating Impacts Of Arsenic Contaminated Materials Via Two (2) Stabilization Methods Based On Polymeric And Cement Binders

    Science.gov (United States)

    The primary objective of this study was to evaluate the performance of two selected chemical stabilization and solidification (S/S) techniques to treat three types of arsenic-contaminated wastes 1) chromated copper arsenate (CCA) wood treater waste, 2) La Trinidad Mine tailings, ...

  10. Weight loss studies of fastener materials corrosion in contact with timbers treated with copper azole and alkaline copper quaternary compounds

    Energy Technology Data Exchange (ETDEWEB)

    Kear, Gareth [Building Research Association of New Zealand (BRANZ) Ltd., Science and Engineering Services, Private Bag 50 908, Porirua City 5240 (New Zealand)], E-mail: G.Kear@soton.ac.uk; Wu Haizhen; Jones, Mark S. [Building Research Association of New Zealand (BRANZ) Ltd., Science and Engineering Services, Private Bag 50 908, Porirua City 5240 (New Zealand)

    2009-02-15

    Corrosion rates of mild steel, AISI 316 stainless steel and hot-dipped galvanised steel in contact with preservative-treated Pinus radiata have been determined using four distinct accelerated (49 {+-} 1 deg. C) and non-accelerated (21 {+-} 2 deg. C) weight loss methodologies. The data were measured as a function of timber moisture content and copper concentration over periods of exposure ranging from 2 weeks to 14 months. The results show that the corrosion resistance of the stainless steel was not influenced by classification or magnitude of preservative loading. Corrosion rates of this material were multiple orders of magnitude lower than those of the mild and galvanised steels. In most instances, corrosion rates of hot-dipped galvanised layers in contact with alkaline copper quaternary-treated timbers were up to a factor of 10 times, or greater, than those measured for copper-chrome-arsenate treatments. A direct negative influence of copper ion concentration on the corrosion resistance of mild steel was also observed for each preservative type.

  11. Copper naphthenate: a proven solution for new wood preservative problems

    Energy Technology Data Exchange (ETDEWEB)

    McNair, W.S. [Merichem Chemicals and Refinery Services LLC, Houston, TX (United States); Loecner, P. [Pacific Gas and Electric, Davis, CA (United States)

    2002-08-01

    Today's engineers have the responsibility of considering cost, availability and climbability, as well as the environmental alternatives available to the traditional wood preservatives used in the production of utility poles: creosote, pentachlorophenol (PCP) and chromated copper arsenate (CCA). The leading alternative now emerging for utilities in this field is copper naphthenate. The authors present a case study that clearly demonstrates copper naphthenate as one of the most environmentally sensitive and effective wood preservative. When first introduced, copper naphthenate seemed to frequently result in early failure of the poles treated with this preservative. It was discovered that it was a phenomenon that had been largely exaggerated, and the failure rate was less than one per cent. A recent review has concluded that premature failures have basically disappeared. Several reasons can explain premature failures, such as pretreatment decay, improper sterilization/conditioning/drying, inadequate copper penetration and retention, and others. The long term effectiveness and performance of copper naphthenate has been documented in a number of field trials. The ultimate disposal of the product must be considered by the specifying engineer, and it is possible to dispose of copper naphthenate poles in a sanitary landfill. Due in part to recent manufacturing economies, the cost of copper naphthenate is similar to other oil-borne treatments. The case study of Pacific Gas and Electric was discussed. 7 refs., 2 figs.

  12. Ecological risks of an old wood impregnation mill: application of the triad approach.

    NARCIS (Netherlands)

    Karjalainen, A.-M.; Kilpi-Koski, J.; Väisänen, A.O.; Penttinen, S.; van Gestel, C.A.M.; Penttinen, O.-P.

    2009-01-01

    Although many studies deal with the distribution and mobility of chromated copper arsenate (CCA) metals in soil, the ecotoxicity of CCA-contaminated soils is rarely studied. The Triad approach was applied to determine the ecological risks posed by a CCA mixture at a decommissioned wood impregnation

  13. In vitro bioaccessibility of copper azole following simulated dermal transfer from pressure-treated wood

    Science.gov (United States)

    Micronized copper azole (MCA) and micronized copper quaternary are the latest wood preservatives to replace the liquid lkaline copper and chromated copper arsenate preservatives due to concerns over the toxicity or lack of effectiveness of the earlier formulations. Today, the use...

  14. Pilot-scale investigation of the robustness and efficiency of a copper-based treated wood wastes recycling process

    Energy Technology Data Exchange (ETDEWEB)

    Coudert, Lucie [INRS-ETE (Canada); Blais, Jean-François, E-mail: blaisjf@ete.inrs.ca [INRS-ETE (Canada); Mercier, Guy [INRS-ETE (Canada); Cooper, Paul [University of Toronto (Canada); Gastonguay, Louis [IREQ (Canada); Morris, Paul [FPInnovations (Canada); Janin, Amélie; Reynier, Nicolas [INRS-ETE (Canada)

    2013-10-15

    Highlights: • A leaching process was studied for metals removal from CCA-treated wood wastes. • This decontamination process was studied at pilot scale (130-L reactor). • Removals up to 98% of As, 88% of Cr, and 96% of Cu were obtained from wood wastes. • The produced leachates can be treated by chemical precipitation. -- Abstract: The disposal of metal-bearing treated wood wastes is becoming an environmental challenge. An efficient recycling process based on sulfuric acid leaching has been developed to remove metals from copper-based treated wood chips (0 < x < 12 mm). The present study explored the performance and the robustness of this technology in removing metals from copper-based treated wood wastes at a pilot plant scale (130-L reactor tank). After 3× 2 h leaching steps followed by 3× 7 min rinsing steps, up to 97.5% of As, 87.9% of Cr, and 96.1% of Cu were removed from CCA-treated wood wastes with different initial metal loading (>7.3 kg m{sup −3}) and more than 94.5% of Cu was removed from ACQ-, CA- and MCQ-treated wood. The treatment of effluents by precipitation–coagulation was highly efficient; allowing removals more than 93% for the As, Cr, and Cu contained in the effluent. The economic analysis included operating costs, indirect costs and revenues related to remediated wood sales. The economic analysis concluded that CCA-treated wood wastes remediation can lead to a benefit of 53.7 US$ t{sup −1} or a cost of 35.5 US$ t{sup −1} and that ACQ-, CA- and MCQ-treated wood wastes recycling led to benefits ranging from 9.3 to 21.2 US$ t{sup −1}.

  15. Electrodialytic remediation of CCA treated waste wood in pilot scale

    DEFF Research Database (Denmark)

    Pedersen, Anne Juul; Christensen, Iben Vernegren; Ottosen, Lisbeth M.

    2005-01-01

    study the utility of the method Electrodialytic Remediation was demonstrated for handling of CCA treated waste wood in pilot scale. The electrodialytic remediation method, which uses a low level DC current as the cleaning agent, combines elektrokinetic movement of ions in the wood matrix with the princi......-ples of electrodialysis. It has previously been shown that it is possible to remove Cu, Cr and As from CCA treated wood using electrodialytic remediation in laboratory scale (Ribeiro et al., 2000; Kristensen et al., 2003), but until now, the method had not been studied in larger scale. The pilot scale plant used...... in this study was designed to contain up to 2 m3 wood chips. Six remediation experiments were carried out. In these experiments, the process was up-scaled stepwise by increasing the distance between the electrodes from initially 60 cm to fi-nally 150 cm. The remediation time was varied between 11 and 21 days...

  16. Consumer willingness to pay for a naturally decay-resistant wood product.

    Science.gov (United States)

    Geoffrey Donovan; Hayley. Hesseln

    2004-01-01

    Chromated copper arsenate (CCA) is the most widely used chemical wood preservative in the United States. Concerns about the safety of CCA led to an agreement between the Environmental Protection Agency and the wood treatment industry to withdraw CCA for nonindustrial uses by the end of 2003. In light of the publicity surrounding the withdrawal of CCA, this article...

  17. A General Evaluation for Recycling Process of Impregnated Wood Removed From the Service

    Directory of Open Access Journals (Sweden)

    Cihat Taşçıoğlu

    2011-03-01

    Full Text Available Wood presevatives such as creosote, pentaclorophenol (PCP and chromated copper arsenate (CCA have been widely used over the years in order to extend wood products’ service life. CCA was known as most widely used wood preservative chemical in residendial and commercial applications world wide until 2004 volanteered phase out of the chemical from residential use bye the major manufacturers. Over the years CCA treated wood acuumulated in service reaching millions of cubic meters. But there is growing concern about the environmental impacts and increasing difficulty in disposing of treated wood products in many countries. Since disposal of CCA treated wood material poses greater problems than the other treated wood products due to heavy and toxic metal componets of CCA such as chromium and arsenic Traditional disposal methods like landfillig or incineration, both have negative environmental consequences. For that reason the increasing volume of CCA-treated wood products coming out of service requires alternative disposal methods and recycling techniques never tried before. The main purpose of this study, except for traditional methods like landfilling and incineration, is to evaluate the current alternative disposal and recycling methods for CCA treated wood removed from service.

  18. Towards a selective adsorbent for arsenate and selenite in the presence of phosphate: Assessment of adsorption efficiency, mechanism, and binary separation factors of the chitosan-copper complex.

    Science.gov (United States)

    Yamani, Jamila S; Lounsbury, Amanda W; Zimmerman, Julie B

    2016-01-01

    The potential for a chitosan-copper polymer complex to select for the target contaminants in the presence of their respective competitive ions was evaluated by synthesizing chitosan-copper beads (CCB) for the treatment of (arsenate:phosphate), (selenite:phosphate), and (selenate:sulfate). Based on work by Rhazi et al., copper (II) binds to the amine moiety on the chitosan backbone as a monodentate complex (Type I) and as a bidentate complex crosslinking two polymer chains (Type II), depending on pH and copper loading. In general, the Type I complex exists alone; however, beyond threshold conditions of pH 5.5 during synthesis and a copper loading of 0.25 mol Cu(II)/mol chitosan monomer, the Type I and Type II complexes coexist. Subsequent chelation of this chitosan-copper ligand to oxyanions results in enhanced and selective adsorption of the target contaminants in complex matrices with high background ion concentrations. With differing affinities for arsenate, selenite, and phosphate, the Type I complex favors phosphate chelation while the Type II complex favors arsenate chelation due to electrostatic considerations and selenite chelation due to steric effects. No trend was exhibited for the selenate:sulfate system possibly due to the high Ksp of the corresponding copper salts. Binary separation factors, α12, were calculated for the arsenate-phosphate and selenite-phosphate systems, supporting the mechanistic hypothesis. While, further research is needed to develop a synthesis method for the independent formation of the Type II complexes to select for target contaminants in complex matrices, this work can provide initial steps in the development of a selective adsorbent. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Enhanced extraction of heavy metals in the two-step process with the mixed culture of Lactobacillus bulgaricus and Streptococcus thermophilus.

    Science.gov (United States)

    Chang, Young-Cheol; Choi, DuBok; Kikuchi, Shintaro

    2012-01-01

    For biological extraction of heavy metals from chromated copper arsenate (CCA) treated wood, different bacteria were investigated. The extraction rates of heavy metals using Lactobacillusbulgaricus and Streptococcusthermophilus were highest. The chemical extraction rates were depended on the amounts of pyruvic acid and lactic acid. Especially, the extraction rates using mixed pyruvic acid and lactic acid were increased compared to those of sole one. They were also enhanced in the mixed culture of L. bulgaricus and S. thermophilus. To improve the extraction of CCA, a two-step processing procedure with the mixed culture of L. bulgaricus and S. thermophilus was conducted. A maximum of 93% of copper, 86.5% of chromium, and 97.8% of arsenic were extracted after 4 days. These results suggest that a two-step process with the mixed culture of L. bulgaricus and S. thermophilus is most effective to extract heavy metals from CCA treated wood. Copyright © 2011 Elsevier Ltd. All rights reserved.

  20. A comparative toxicity assessment of materials used in aquatic construction.

    Science.gov (United States)

    Lalonde, Benoit A; Ernst, William; Julien, Gary; Jackman, Paula; Doe, Ken; Schaefer, Rebecca

    2011-10-01

    Comparative toxicity testing was performed on selected materials that may be used in aquatic construction projects. The tests were conducted on the following materials: (1) untreated wood species (hemlock [Tsuga ssp], Western red cedar (Thuja plicata), red oak [Quercus rubra], Douglas fir [Pseudotsuga menziesii], red pine [Pinus resinosa], and tamarack [Larix ssp]); (2) plastic wood; (3) Ecothermo wood hemlock stakes treated with preservatives (e.g., chromated copper arsenate [CCA], creosote, alkaline copper quaternary [ACQ], zinc naphthenate, copper naphthenate, and Lifetime Wood Treatment); (4) epoxy-coated steel; (5) hot-rolled steel; (6) zinc-coated steel; and (7) concrete. Those materials were used in acute lethality tests with rainbow trout, Daphnia magna, Vibrio fischeri and threespine stickleback. The results indicated the following general ranking of the materials (from the lowest to highest LC(50) values); ACQ > creosote > zinc naphthenate > copper naphthenate > CCA (treated at 22.4 kg/m(3)) > concrete > red pine > western red cedar > red oak > zinc-coated steel > epoxy-coated steel > CCA (6.4 kg/m(3)). Furthermore, the toxicity results indicated that plastic wood, certain untreated wood species (hemlock, tamarack, Douglas fir, and red oak), hot-rolled steel, Ecothermo wood, and wood treated with Lifetime Wood Treatment were generally nontoxic to the test species. © Springer Science+Business Media, LLC 2011

  1. Evolution of copper arsenate resistance for enhanced enargite bioleaching using the extreme thermoacidophile Metallosphaera sedula.

    Science.gov (United States)

    Ai, Chenbing; McCarthy, Samuel; Liang, Yuting; Rudrappa, Deepak; Qiu, Guanzhou; Blum, Paul

    2017-12-01

    Adaptive laboratory evolution (ALE) was employed to isolate arsenate and copper cross-resistant strains, from the copper-resistant M. sedula CuR1. The evolved strains, M. sedula ARS50-1 and M. sedula ARS50-2, contained 12 and 13 additional mutations, respectively, relative to M. sedula CuR1. Bioleaching capacity of a defined consortium (consisting of a naturally occurring strain and a genetically engineered copper sensitive strain) was increased by introduction of M. sedula ARS50-2, with 5.31 and 26.29% more copper recovered from enargite at a pulp density (PD) of 1 and 3% (w/v), respectively. M. sedula ARS50-2 arose as the predominant species and modulated the proportions of the other two strains after it had been introduced. Collectively, the higher Cu 2+ resistance trait of M. sedula ARS50-2 resulted in a modulated microbial community structure, and consolidating enargite bioleaching especially at elevated PD.

  2. EVALUATING ACQ AS AN ALTERNATIVE WOOD PRESERVATIVE SYSTEM

    Science.gov (United States)

    This evaluation addresses the waste reduction/pollution prevention and economic issues involved in replacing chromated copper arsenate (CCA) with ammoniacal copper/quaternary ammonium (ACQ) as a way to preserve wood. The most obvious pollution prevention benefit gained by using A...

  3. Assessment of zerovalent iron for stabilization of chromium, copper, and arsenic in soil

    International Nuclear Information System (INIS)

    Kumpiene, Jurate; Ore, Solvita; Renella, Giancarlo; Mench, Michel; Lagerkvist, Anders; Maurice, Christian

    2006-01-01

    Stabilization of soil contaminated with trace elements is a remediation practice that does not reduce the total content of contaminants, but lowers the amounts of mobile and bioavailable fractions. This study evaluated the efficiency of Fe to reduce the mobility and bioavailability of Cr, Cu, As and Zn in a chromated copper arsenate (CCA)-contaminated soil using chemical, biochemical and biotoxicity tests. Contaminated soil was stabilized with 1% iron grit. This treatment decreased As and Cr concentrations in leachates (by 98% and 45%, respectively), in soil pore water (by 99% and 94%, respectively) and in plant shoots (by 84% and 95%, respectively). The stabilization technique also restored most of analyzed soil enzyme activities and reduced microbial toxicity, as evaluated by the BioTox TM test. After stabilization, exchangeable and bioaccessible fractions of Cu remained high, causing some residual toxicity in the treated soil. - Zerovalent iron effectively reduces mobility and bioavailability of As and Cr, but does not adequately stabilize Cu

  4. Evaluating the natural durability of native and tropical wood species against Reticulitermes flavipes

    Science.gov (United States)

    R.A. Arango; F. Green; K. Hintz; R.B. Miller

    2004-01-01

    Environmental pressures to eliminate arsenate from wood preservatives has resulted in voluntary removal of CCA for residential applications in the United States. A new generation of copper organic preservatives has been formulated to replace CCA for decking and in-ground applications but there is no guarantee that these preservatives represent a permanent solution to...

  5. Environmentally friendly wood preservatives formulated with enzymatic-hydrolyzed okara, copper and/or boron salts

    International Nuclear Information System (INIS)

    Ahn, Sye Hee; Oh, Sei Chang; Choi, In-gyu; Han, Gyu-seong; Jeong, Han-seob; Kim, Ki-woo; Yoon, Young-ho; Yang, In

    2010-01-01

    Novel biocides, such as copper azole (CuAz) and ammoniacal copper quaternary (ACQ), are extensively used as substitutes for chromate copper arsenate (CCA) in wood preservation. However, the expense of these biocides has necessitated the development of cost-effective and environmentally friendly wood preservatives. This study was conducted to investigate the effectiveness against decaying fungi of the preservatives formulated with enzymatic-hydrolyzed okara (OK), which is an organic waste produced from the manufacture of tofu, CuCl 2 (CC) and/or Na 2 B 4 O 7 .10H 2 O (B). With the addition of NH 4 OH as a dissociating agent, the addition of OK facilitated the target retention of most of the OK/CC and OK/CC/B preservative formulations in wood blocks. The OK-based wood preservatives (OK-WPs) were stable against hot-water leaching. When compared with control and CC-treated wood blocks, the leached wood blocks treated with OK/CC and OK/CC/B formulations showed excellent decay resistance against both Postia placenta and Gloeophyllum trabeum, especially when OK was hydrolyzed by Celluclast at a loading level of 0.1 ml/g. Scanning electron microscopy (SEM) and SEM-energy dispersive X-ray (SEM-EDX) spectrometry analyses demonstrated that preservative complexes, such as OK-CC and OK-CC-B, existed in the wood blocks treated with OK/CC and OK/CC/B formulations. This study results support the potential application of OK-WPs as environmentally friendly wood preservatives capable of replacing CuAz and ACQ.

  6. Environmentally friendly wood preservatives formulated with enzymatic-hydrolyzed okara, copper and/or boron salts

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, Sye Hee; Oh, Sei Chang [Department of Forest Resources, Daegu University, Gyeongsan 712-714 (Korea, Republic of); Choi, In-gyu [Department of Forest Sciences, Seoul National University, Seoul 151-921 (Korea, Republic of); Han, Gyu-seong [Department of Wood and Paper Sciences, Chungbuk National University, Cheongju 361-763 (Korea, Republic of); Jeong, Han-seob [Department of Forest Sciences, Seoul National University, Seoul 151-921 (Korea, Republic of); Kim, Ki-woo [National Instrumentation Center for Environmental Management, Seoul National University, Seoul 151-921 (Korea, Republic of); Yoon, Young-ho [KCI Co. Ltd., Seosan, Chungcheongnam-do 356-874 (Korea, Republic of); Yang, In, E-mail: dahadad2000@yahoo.com [Research Institute for Agriculture and Life Sciences, Seoul National University, San 56-1 Sillim-Dong, Kwanak-gu, Seoul 151-921 (Korea, Republic of)

    2010-06-15

    Novel biocides, such as copper azole (CuAz) and ammoniacal copper quaternary (ACQ), are extensively used as substitutes for chromate copper arsenate (CCA) in wood preservation. However, the expense of these biocides has necessitated the development of cost-effective and environmentally friendly wood preservatives. This study was conducted to investigate the effectiveness against decaying fungi of the preservatives formulated with enzymatic-hydrolyzed okara (OK), which is an organic waste produced from the manufacture of tofu, CuCl{sub 2} (CC) and/or Na{sub 2}B{sub 4}O{sub 7}.10H{sub 2}O (B). With the addition of NH{sub 4}OH as a dissociating agent, the addition of OK facilitated the target retention of most of the OK/CC and OK/CC/B preservative formulations in wood blocks. The OK-based wood preservatives (OK-WPs) were stable against hot-water leaching. When compared with control and CC-treated wood blocks, the leached wood blocks treated with OK/CC and OK/CC/B formulations showed excellent decay resistance against both Postia placenta and Gloeophyllum trabeum, especially when OK was hydrolyzed by Celluclast at a loading level of 0.1 ml/g. Scanning electron microscopy (SEM) and SEM-energy dispersive X-ray (SEM-EDX) spectrometry analyses demonstrated that preservative complexes, such as OK-CC and OK-CC-B, existed in the wood blocks treated with OK/CC and OK/CC/B formulations. This study results support the potential application of OK-WPs as environmentally friendly wood preservatives capable of replacing CuAz and ACQ.

  7. Cu,Cr and As determination in preserved woods (Eucalyptus ssp.) by X-ray fluorescence spectrometries; Determinacao de cobre, cromo e arsenio em madeira preservada (Eucalyptus sp.) pelas espectrometrias de fluorescencia de raios X

    Energy Technology Data Exchange (ETDEWEB)

    Pereira Junior, Sergio Matias

    2014-07-01

    Brazil produces around 2.2 millions of cubic meters of treated wood to meet the annual demand of railway, electric, rural and construction sectors. The most used wood species are eucalyptus (Eucalyptus ssp.) and pine (Pinus ssp.).The treated woods used for poles, sleepers, fence posts and plywoods should be according to Brazilian norms requirements. The most usual wood preservative products used in Brazil are CCA (chromated copper arsenate) and CCB (copper chromium and boron salt). The analytical methods, such as flame atomic absorption spectrometry (FAAS), plasma inductively coupled optical emission spectrometry (ICPOES) and X-ray fluorescence spectrometry (XRFS) have been used for the analytical control of those treatment processes. In this work, the eucalyptus trees (Eucalyptus ssp) samples was obtained from Minas Gerais State, Brazil, cut plantation areas. Under pressure, eucalyptus wood samples were submitted to different concentration of CCA solution reaching 3.9, 6.7, 9.1, 12.4 and 14.0 kg of CCA by m-³ sapwood retentions. Samples in cylinders and sawdust forms were obtained from treated wood samples. Copper, chromium and arsenic determination was performed using the energy dispersive X-ray fluorescence spectrometry (EDXRFS), portable X-ray fluorescence spectrometry (PXRFS), flame atomic absorption spectrometry (FAAS) and instrumental neutron activation analysis. In this work, the method of analysis, sensitivity, precision and accuracy performances of the related techniques were outlined. (author)

  8. Cu,Cr and As determination in preserved woods (Eucalyptus ssp.) by X-ray fluorescence spectrometries

    International Nuclear Information System (INIS)

    Pereira Junior, Sergio Matias

    2014-01-01

    Brazil produces around 2.2 millions of cubic meters of treated wood to meet the annual demand of railway, electric, rural and construction sectors. The most used wood species are eucalyptus (Eucalyptus ssp.) and pine (Pinus ssp.).The treated woods used for poles, sleepers, fence posts and plywoods should be according to Brazilian norms requirements. The most usual wood preservative products used in Brazil are CCA (chromated copper arsenate) and CCB (copper chromium and boron salt). The analytical methods, such as flame atomic absorption spectrometry (FAAS), plasma inductively coupled optical emission spectrometry (ICPOES) and X-ray fluorescence spectrometry (XRFS) have been used for the analytical control of those treatment processes. In this work, the eucalyptus trees (Eucalyptus ssp) samples was obtained from Minas Gerais State, Brazil, cut plantation areas. Under pressure, eucalyptus wood samples were submitted to different concentration of CCA solution reaching 3.9, 6.7, 9.1, 12.4 and 14.0 kg of CCA by m-³ sapwood retentions. Samples in cylinders and sawdust forms were obtained from treated wood samples. Copper, chromium and arsenic determination was performed using the energy dispersive X-ray fluorescence spectrometry (EDXRFS), portable X-ray fluorescence spectrometry (PXRFS), flame atomic absorption spectrometry (FAAS) and instrumental neutron activation analysis. In this work, the method of analysis, sensitivity, precision and accuracy performances of the related techniques were outlined. (author)

  9. Natural durability of tropical and native woods against termite damage by Reticulitermes flavipes (Kollar)

    Science.gov (United States)

    Rachel A. Arango; Frederick Green; Kristina Hintz; Patricia K. Lebow; Regis B. Miller

    2006-01-01

    Environmental pressure has resulted in voluntary removal of chromated copper arsenate (CCA) from wood preservatives in residential applications in the United States. A new generation of copper organic preservatives was formulated as replacements, but these preservatives may not provide a permanent solution to all related problems. Some of these issues include concern...

  10. Statistical analysis of influence of soil source on leaching of arsenic and copper from CCA-C treated wood

    Science.gov (United States)

    Patricia Lebow; Richard Ziobro; Linda Sites; Tor Schultz; David Pettry; Darrel Nicholas; Stan Lebow; Pascal Kamdem; Roger Fox; Douglas Crawford

    2006-01-01

    Leaching of wood preservatives affects the long-term efficacy and environmental impact of treated wood. Soil properties and wood characteristicscan affectleaching of woad preservatives, but these effects are not well understood. This paper reports a statistical analysis of the effects of soil and wood properties on leaching of arsenic (As) and copper (Cu) from southern...

  11. Removal of arsenate from groundwater by electrocoagulation method.

    Science.gov (United States)

    Ali, Imran; Khan, Tabrez A; Asim, Mohd

    2012-06-01

    Arsenic, a toxic metalloid in drinking water, has become a major threat for human beings and other organisms. In the present work, attempts have been made to remove arsenate from the synthetic as well as natural water of Ballia district, India by electrocoagulation method. Efforts have also been made to optimize the various parameters such as initial arsenate concentration, pH, applied voltage, processing time, and working temperature. Electrocoagulation is a fast, inexpensive, selective, accurate, reproducible, and eco-friendly method for arsenate removal from groundwater. The present paper describes an electrocoagulation method for arsenate removal from groundwater using iron and zinc as anode and cathode, respectively. The maximum removal of arsenate was 98.8% at 2.0 mg L(-1), 7.0, 3.0 V, 10.0 min, and 30°C as arsenate concentration, pH, applied voltage, processing time, and working temperature, respectively. Relative standard deviation, coefficient of determination (r (2)), and confidence limits were varied from 1.50% to 1.59%, 0.9996% to 0.9998%, and 96.0% to 99.0%, respectively. The treated water was clear, colorless, and odorless without any secondary contamination. The developed and validated method was applied for arsenate removal of two samples of groundwater of Ballia district, U.P., India, having 0.563 to 0.805 mg L(-1), arsenate concentrations. The reported method is capable for the removal of arsenate completely (100% removal) from groundwater of Ballia district. There was no change in the groundwater quality after the removal of arsenate. The treated water was safe for drinking, bathing, and recreation purposes. Therefore, this method may be the choice of arsenate removal from natural groundwater.

  12. Regressional modeling of electrodialytic removal of Cu, Cr and As from CCA treated timber waste

    DEFF Research Database (Denmark)

    Moreira, E.E.; Ribeiro, Alexandra B.; Mateus, Eduardo

    2005-01-01

    ) removal of Cu, Cr and As from CCA treated timber waste. The method uses a low-level direct current as the cleaning agent, combining the electrokinetic movement of ions in the matrix with the principle of electrodialysis. The technique was tested in eight experiments using a laboratory cell on sawdust...

  13. Treatability Study Report for In SITU Lead Immobilization Using Phosphate-Based Binders

    Science.gov (United States)

    2008-05-01

    advertisement . i EXECUTIVE SUMMARY Metal contamination in soil is found on 69 percent of identified Department of Defense (DoD) sites with...American Society of Testing and Materials ATC = U.S. Army Aberdeen Test Center bgs = below ground surface CBD = Commerce Business Daily CCA = chromated ...ppm chromated copper arsenate (CCA) - wood preservative EC50 = 3.95 percent and 10 percent Isopropanol EC50 = 12.55%), the untreated soil was

  14. Monitoring losses of copper based wood preservatives in the Thames estuary

    International Nuclear Information System (INIS)

    Hingston, J.A.; Murphy, R.J.; Lester, J.N.

    2006-01-01

    Field trials were conducted at two sites in the Thames estuary to monitor losses of copper, chromium and arsenic from wood preservative treated timbers of varying sizes and treatment regimes. Results indicated that leaching tests conducted under standard laboratory conditions might overestimate losses compared to losses resulting from real environmental exposures. Amine copper treated wood was noted to leach higher levels of copper compared to chromated copper arsenate treated wood, and was therefore considered an inappropriate replacement biocide for fresh and marine construction purposes on this basis. Increases in copper concentrations in the outer sections of amine copper treated posts may have represented re-distribution of this component in this timber. No accumulation of metals was found in sediments surrounding field trial posts. - Wood preservative field trials in the UK indicate that standard laboratory tests overestimate losses compared to those resulting from real environmental exposures

  15. Monitoring losses of copper based wood preservatives in the Thames estuary

    Energy Technology Data Exchange (ETDEWEB)

    Hingston, J.A. [Environmental Processes and Water Technology Research Group, Department of Environmental Science and Technology, Faculty of Life Sciences, Imperial College, London SW7 2AZ (United Kingdom)]. E-mail: james.hingston@psd.defra.gsi.gov.uk; Murphy, R.J. [Department of Biology, Imperial College, London SW7 2AZ (United Kingdom); Lester, J.N. [School of Water Sciences, Cranfield University, Cranfield, Bedfordshire, MK43 0AL (United Kingdom)

    2006-09-15

    Field trials were conducted at two sites in the Thames estuary to monitor losses of copper, chromium and arsenic from wood preservative treated timbers of varying sizes and treatment regimes. Results indicated that leaching tests conducted under standard laboratory conditions might overestimate losses compared to losses resulting from real environmental exposures. Amine copper treated wood was noted to leach higher levels of copper compared to chromated copper arsenate treated wood, and was therefore considered an inappropriate replacement biocide for fresh and marine construction purposes on this basis. Increases in copper concentrations in the outer sections of amine copper treated posts may have represented re-distribution of this component in this timber. No accumulation of metals was found in sediments surrounding field trial posts. - Wood preservative field trials in the UK indicate that standard laboratory tests overestimate losses compared to those resulting from real environmental exposures.

  16. Effect of moisture control and air venting on H2S production and leachate quality in mature C&D debris landfills.

    Science.gov (United States)

    Zhang, Jianye; Dubey, Brajesh; Townsend, Timothy

    2014-10-21

    The effect of air venting and moisture variation on H2S production and the leaching of metals/metalloids (arsenic, copper, chromium, and boron) from treated wood in aged mature construction and demolition (C&D) debris landfills were examined. Three simulated C&D debris landfill lysimeters were constructed and monitored, each containing as a major debris component either wooden pallets, chromated copper arsenate (CCA) treated wood, or alkaline copper quaternary (ACQ) treated wood. The lysimeters were operated with alternating periods of water addition (a total of 160 L in four equal amounts) and air venting (68.4 m(3)per day for 121 days in two phases). Moisture addition did not increase H2S levels in the long term, and a significant drop in H2S concentration was observed (up to 99%) when aerobic conditions were promoted through air venting. H2S concentrations increased after venting stopped up to values approximately two orders of magnitude lower than observed prior to venting. Venting had the immediate consequence of suppressing biological H2S production, and the longer-term effect of decreasing organic matter that could otherwise be utilized in this process. Under aerobic conditions, the levels of arsenic, chromium, and boron in leachate decreased up to 96%, 49%, and 68%, respectively, while copper was found to increase up to 200% in CCA and 445% in ACQ column leachates.

  17. Graphene oxide/ferric hydroxide composites for efficient arsenate removal from drinking water

    International Nuclear Information System (INIS)

    Zhang Kai; Dwivedi, Vineet; Chi Chunyan; Wu Jishan

    2010-01-01

    A series of novel composites based on graphene oxide (GO) cross-linked with ferric hydroxide was developed for effective removal of arsenate from contaminated drinking water. GO, which was used as a supporting matrix here, was firstly treated with ferrous sulfate. Then, the ferrous compound cross-linked with GO was in situ oxidized to ferric compound by hydrogen peroxide, followed by treating with ammonium hydroxide. The morphology and composition of the composites were analyzed by X-ray diffraction, scanning electron microscopy and transmission electron microscopy. The ferric hydroxide was found to be homogenously impregnated onto GO sheets in amorphous form. These composites were evaluated as absorbents for arsenate removal from contaminated drinking water. For the water with arsenate concentration at 51.14 ppm, more than 95% of arsenate was absorbed by composite GO-Fe-5 with an absorption capacity of 23.78 mg arsenate/g of composite. Effective arsenate removal occurred in a wide range of pH from 4 to 9. However, the efficiency of arsenate removal was decreased when pH was increased to higher than 8.

  18. Temperature development and sterilization of red pine poles during CCA treatment, elevated temperature fixation and drying

    Energy Technology Data Exchange (ETDEWEB)

    Cooper, P.; Albright, M.; Srinivasan, U.; Ung, A. [New Brunswick Univ., Fredericton, NB (Canada). Wood Science and Technology Centre

    2002-07-01

    The application of chromated copper arsenate (CCA) treatment and fixation and drying under the conditions of the study to large red pine poles left for an air seasoning period of 10 months in Quebec, Canada progressively reduced the number of micro-organisms present. A large number of microfungi isolations were effected before the treatment from the sapwood and heartwood of all poles and wood decay fungi on 8 selected poles from the 20 test poles. They originated from the sapwood zone. A reduction of approximately 50 per cent in the number of microfungi isolated from the sapwood was noted after the CCA treatment. In the case of 9 of 30 poles, basidiomycetes were isolated after treatment primarily from the untreated heartwood. There were a few instances where basidiomycetes were isolated from unpenetrated sapwood (wet pockets). Temperatures of 55 to 60 degrees Celsius were achieved under moderate temperature fixation schedules (20 hours) for approximately 5 hours at full sapwood depth. Only by the end of the schedule was a temperature of 55 degrees celsius achieved at the centre of the poles. Most of the microfungi were eliminated by this temperature regime. Trichoderma was eliminated, and only one isolation of basidiomycetes was left from the heartwood of one pole. Temperatures of 55 to 60 degrees Celsius were achieved in the wood core for 9 to 10 days during kiln drying. No basidiomycete isolations remained after this exposure. In several of the poles, there was evidence of Paecilomyces variotii, a thermo-tolerant species and a number of species of Penicillium moulds. It was concluded that there was a negligible probability of decay fungi surviving the sequence of processes as described, given the effectiveness of the fixation exposure and the higher wood temperatures sustained for longer periods. 16 refs., 5 tabs., 2 figs.

  19. Relationship between firewood usage and urinary Cr, Cu and As in informal areas of Cape Town.

    Science.gov (United States)

    Dalvie, Mohamed Aqiel; Africa, Algernon; Naidoo, Sivapregasen

    2013-09-03

    The study investigated whether wood usage by informal food vendors and household residents in Cape Town results in the absorption of arsenic (As), chromium (Cr) and copper (Cu) owing to release of these metals in the burning of chromated copper arsenate (CCA)-treated wood. The participants (N=78) selected included an equal number of food vendors and non-vendors from 2 informal settlements. All participants answered a questionnaire concerning exposure and were tested for urinary Cr, Cu and As, while the urine of 29 participants was also tested for toxic As (As(tox)). Multivariate analysis showed that the time spent in close proximity to the wood, as well as the quantity of wood used for cooking and for household use, was weakly positively associated with urinary levels of As, Cr and the sum of As, Cr and Cu. The study provides evidence that use of wood likely to contain CCA as a fuel for informal food outlets and household purposes may increase the absorption of inorganic As, Cu and Cr.

  20. "Artifactual" arsenate DNA

    DEFF Research Database (Denmark)

    Nielsen, Peter E

    2012-01-01

    The recent claim by Wolfe-Simon et al. that the Halomonas bacterial strain GFAJ-1 when grown in arsenate-containing medium with limiting phosphate is able to substitute phosphate with arsenate in biomolecules including nucleic acids and in particular DNA(1) arose much skepticism, primarily due...... to the very limited chemical stability of arsenate esters (see ref. 2 and references therein). A major part of the criticisms was concerned with the insufficient (bio)chemical evidence in the Wolfe-Simon study for the actual chemical incorporation of arsenate in DNA (and/or RNA). Redfield et al. now present...... evidence that the identification of arsenate DNA was artifactual....

  1. Equilibriums of sorption of impurities of 3 d - cations by inorganic sorbents from phosphate and arsenate solutions

    International Nuclear Information System (INIS)

    Filatova, L.N.; Kurdyumova, T.N.; Bagrov, V.M.; Blyum, G.Z.

    1986-01-01

    Present article is devoted to equilibriums of sorption of impurities of 3 d - cations by inorganic sorbents from phosphate and arsenate solutions. Equilibriums of sorption of microquantities of iron, scandium, zink, copper, cobalt and manganese by inorganic sorbents on the basis of titanium and aluminium oxides from phosphate and arsenate solutions are studied. The influence of structural and chemical properties of matrix on sorption properties of oxides in phosphate and arsenate solutions is studied as well. It is defined that in concentrated solutions the sorption value of trace contaminant depends on a character of cation of alkaline metal.

  2. A comparative study on Cu, Cr and As removal from CCA-treated wood waste by dialytic and electrodialytic processes

    DEFF Research Database (Denmark)

    Velizarova, Emiliya; Ribeiro, Alexandra B.; Ottosen, Lisbeth M.

    2002-01-01

    In this study, electrodialytic and dialytic techniques were used for Cu, Cr and As removal from 20-years out-of-service CCA-treated Pinus pinaster Ait. pole. The effect of applying direct current, as "cleaning agent", of up to 120mA was investigated. Focus was given to a parallel comparison...

  3. Dissolution of arsenic minerals mediated by dissimilatory arsenate reducing bacteria: estimation of the physiological potential for arsenic mobilization.

    Science.gov (United States)

    Lukasz, Drewniak; Liwia, Rajpert; Aleksandra, Mantur; Aleksandra, Sklodowska

    2014-01-01

    The aim of this study was characterization of the isolated dissimilatory arsenate reducing bacteria in the context of their potential for arsenic removal from primary arsenic minerals through reductive dissolution. Four strains, Shewanella sp. OM1, Pseudomonas sp. OM2, Aeromonas sp. OM4, and Serratia sp. OM17, capable of anaerobic growth with As (V) reduction, were isolated from microbial mats from an ancient gold mine. All of the isolated strains: (i) produced siderophores that promote dissolution of minerals, (ii) were resistant to dissolved arsenic compounds, (iii) were able to use the dissolved arsenates as the terminal electron acceptor, and (iii) were able to use copper minerals containing arsenic minerals (e.g., enargite) as a respiratory substrate. Based on the results obtained in this study, we postulate that arsenic can be released from some As-bearing polymetallic minerals (such as copper ore concentrates or middlings) under reductive conditions by dissimilatory arsenate reducers in indirect processes.

  4. Dissolution of Arsenic Minerals Mediated by Dissimilatory Arsenate Reducing Bacteria: Estimation of the Physiological Potential for Arsenic Mobilization

    Directory of Open Access Journals (Sweden)

    Drewniak Lukasz

    2014-01-01

    Full Text Available The aim of this study was characterization of the isolated dissimilatory arsenate reducing bacteria in the context of their potential for arsenic removal from primary arsenic minerals through reductive dissolution. Four strains, Shewanella sp. OM1, Pseudomonas sp. OM2, Aeromonas sp. OM4, and Serratia sp. OM17, capable of anaerobic growth with As (V reduction, were isolated from microbial mats from an ancient gold mine. All of the isolated strains: (i produced siderophores that promote dissolution of minerals, (ii were resistant to dissolved arsenic compounds, (iii were able to use the dissolved arsenates as the terminal electron acceptor, and (iii were able to use copper minerals containing arsenic minerals (e.g., enargite as a respiratory substrate. Based on the results obtained in this study, we postulate that arsenic can be released from some As-bearing polymetallic minerals (such as copper ore concentrates or middlings under reductive conditions by dissimilatory arsenate reducers in indirect processes.

  5. Arsenic uptake by lettuce from As-contaminated soil remediated with Pteris vittata and organic amendment.

    Science.gov (United States)

    de Oliveira, Letuzia M; Suchismita, Das; Gress, Julia; Rathinasabapathi, Bala; Chen, Yanshan; Ma, Lena Q

    2017-06-01

    Leaching of inorganic arsenic (As) from chromated copper arsenate (CCA)-treated wood may elevate soil As levels. Thus, an environmental concern arises regarding As accumulation in vegetables grown in these soils. In this study, a greenhouse experiment was conducted to investigate the ability of As-hyperaccumulator P. vittata and organic amendments in reducing As uptake by lettuce (Lactuca sativa) from a soil contaminated from CCA-treated wood (63.9 mg kg -1 As). P. vittata was grown for 150 d in a CCA-contaminated soil amended with biochar, activated carbon or coffee grounds at 1%, followed by lettuce for another 55 d. After harvest, plant biomass and As concentrations in plant and soil were determined. The presence of P. vittata reduced As content in lettuce by 21% from 27.3 to 21.5 mg kg -1 while amendment further reduced As in lettuce by 5.6-18%, with activated C being most effective. Our data showed that both P. vittata and organic amendments were effective in reducing As concentration in lettuce. Though no health-based standard for As in vegetables exists in USA, care should be taken when growing lettuce in contaminated soils. Our data showed that application of organic amendments with P. vittata reduced As hazards in CCA-contaminated soils. Published by Elsevier Ltd.

  6. Weathering properties of treated southern yellow pine wood examined by X-ray photoelectron spectroscopy, scanning electron microscopy and physical characterization

    Energy Technology Data Exchange (ETDEWEB)

    Salaita, Ghaleb N.; Ma, Frank M.S.; Parker, Trudy C. [Dow Chemical Company, Technical Center, 3200 Kanawha Turnpike, South Charleston, WV 25303 (United States); Hoflund, Gar B. [Department of Chemical Engineering, University of Florida, P.O. Box 116005, Gainesville, FL 32611 (United States)], E-mail: garho@hotmail.com

    2008-04-30

    In this study the weathering behavior of southern yellow pine (SYP) wood samples pretreated in different solutions has been examined using X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and various types of physical characterization regarding material loss and discoloration. The treatment solutions include water as a control, a commercially available water repellent (WR) wood treating additive and polyethylene glycol (PEG) products including PEG PLUS{sup TM}, PEG 8000 solutions and Compound 20M in varying concentrations. All contained the wood preservative chromated copper arsenate (CCA). One sample was treated with a CCA solution only. The treatments were carried out at 20 deg. C and 150 psig for 1/2 h after exposure to vacuum (28 mmHg) for 15 min. Simulated weathering was achieved in an Atlas 65-W Weather-Ometer for 2000 h with both light and dark periods and rain. The temperature ranged from 23 deg. C during the dark cycle to 35 deg. C during the light cycle. With weathering the XPS O/C ratios increase due to oxidation of the surface. Exposure to UV light results in bond breakage and reaction with oxygen in the presence of air to form organic functional groups such as , , C=O and/or O-C-O. These oxidized products can protect the underlying wood from deterioration if they are insoluble in water and remain on the surface as a protective coating. If soluble, rain washes the compounds away and assists in the degradation. Correlated changes are observed in the XPS O/C ratios, the high-resolution XPS C 1s spectra, the SEM micrographs and physical measurements including thickness alteration, weight loss, and discoloration by yellowing or whitening of the weathered wood. The PEG treatments are effective in protecting wood with the 2% PEG PLUS treatment providing the best weathering behavior similar to that of the CCA treatment. The WR and water treatments yield the poorest weathering properties.

  7. Weathering properties of treated southern yellow pine wood examined by X-ray photoelectron spectroscopy, scanning electron microscopy and physical characterization

    International Nuclear Information System (INIS)

    Salaita, Ghaleb N.; Ma, Frank M.S.; Parker, Trudy C.; Hoflund, Gar B.

    2008-01-01

    In this study the weathering behavior of southern yellow pine (SYP) wood samples pretreated in different solutions has been examined using X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and various types of physical characterization regarding material loss and discoloration. The treatment solutions include water as a control, a commercially available water repellent (WR) wood treating additive and polyethylene glycol (PEG) products including PEG PLUS TM , PEG 8000 solutions and Compound 20M in varying concentrations. All contained the wood preservative chromated copper arsenate (CCA). One sample was treated with a CCA solution only. The treatments were carried out at 20 deg. C and 150 psig for 1/2 h after exposure to vacuum (28 mmHg) for 15 min. Simulated weathering was achieved in an Atlas 65-W Weather-Ometer for 2000 h with both light and dark periods and rain. The temperature ranged from 23 deg. C during the dark cycle to 35 deg. C during the light cycle. With weathering the XPS O/C ratios increase due to oxidation of the surface. Exposure to UV light results in bond breakage and reaction with oxygen in the presence of air to form organic functional groups such as , , C=O and/or O-C-O. These oxidized products can protect the underlying wood from deterioration if they are insoluble in water and remain on the surface as a protective coating. If soluble, rain washes the compounds away and assists in the degradation. Correlated changes are observed in the XPS O/C ratios, the high-resolution XPS C 1s spectra, the SEM micrographs and physical measurements including thickness alteration, weight loss, and discoloration by yellowing or whitening of the weathered wood. The PEG treatments are effective in protecting wood with the 2% PEG PLUS treatment providing the best weathering behavior similar to that of the CCA treatment. The WR and water treatments yield the poorest weathering properties

  8. Application of Copper Cladding Aluminum Composites in UHV Portable Earthing and Short-circuiting Wires

    Directory of Open Access Journals (Sweden)

    Zhu Jianjun

    2018-01-01

    Full Text Available Aiming at the heavy weight and inconvenience when carrying and installing copper earthing wires on the UHV transmission lines, in this paper, we present the use of copper clad aluminum(CCA composite materials as a lightweight method for UHV earthing wire conductor. Theoretical calculations and tests of the fusing current in a short time for copper and CCA material are conducted. The results show that the theoretical value of the earthing wire conductor's fusing current corresponds with the test value on condition of the conductor cross section greater than 4mm2 as well as fusing time less than 1.5s. The CCA-10 earthing wires get 36.2% weight reduction compared with copper wires.

  9. Environmental Assessment for Construction of a 20-Slip Boat Dock Structure MacDill AFB, Florida

    Science.gov (United States)

    2008-01-01

    practice CAA Clean Air Act CCA chromated copper arsenate CEQ Council on Environmental Quality CES Civil Engineering Squadron CEV Environmental...newspaper advertisement in the April 10, 2007 edition of the Tampa Tribune announcing the availability of the Draft EA for public review at the John F...chlorine, freon, paints, thinners, oils, lubricants, compressed gases, pesticides, herbicides, nitrates, and chromates . A detailed tracking and accounting

  10. Thick-target Pixe analysis of chromium, copper and arsenic impregnated lumber

    International Nuclear Information System (INIS)

    Saarela, K-E.; Harju, L.; Lill, J-O.; Rajander, J.; Lindroos, A.; Heselius, S-J.

    1999-01-01

    Chromium, copper and arsenic (CCA) have for decades been used for wood preservation. Of these elements especially arsenic is very toxic. As CCA impregnated wood is still today used for many construction purposes, a monitoring of these metal ions is of great environmental importance. Thick-target PIXE is a powerful method for the determination of trace metals in wood. The TTPIXE method enabled study of variations of the elemental concentrations in lumber treated with CCA impregnation solution. Distribution patterns were obtained for both naturally occurring elements and elements introduced in the treatment process. During the impregnation process a desorption of e.g. alkali metal ions takes place from the wood. The sensitivity of the method is improved by dry ashing of the samples prior to PIXE analysis. The TTPIXE method was calibrated and validated using international certified reference materials (CRM) based on wood material

  11. Natural Arsenate DNA?

    DEFF Research Database (Denmark)

    Nielsen, Peter E

    2011-01-01

    The recent paper by Wolfe-Simon et al.1 reporting a bacterial strain, which is able to grow in high concentrations of arsenate, apparently in the absence of phosphate, and claims that in this strain arsenate is substituting for phosphate, e.g. in nucleic acids (Figure 1), was highly profiled, att...

  12. Soil arsenic surveys of New Orleans: localized hazards in children's play areas.

    Science.gov (United States)

    Mielke, Howard W; Gonzales, Chris R; Cahn, Elise; Brumfield, Jessica; Powell, Eric T; Mielke, Paul W

    2010-10-01

    Arsenic (As) ranks first on the 2005 and 2007 hazardous substances priority lists compiled for the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA). This study describes two New Orleans soil As surveys: (1) a survey of composite soil samples from 286 census tracts and (2) a field survey of soil As at 38 play areas associated with the presence of chromated-copper-arsenate (CCA)-treated wood on residential and public properties. The survey of metropolitan New Orleans soils revealed a median As content of 1.5 mg/kg (range New Orleans probably exists in play areas across the nation. These findings support a precautionary program for testing soils and wood for hazardous substances at all play areas intended for children.

  13. Evaluation of leachate quality from pentachlorophenol, creosote and ACA [ammoniacal chromium arsenate] preserved wood products

    International Nuclear Information System (INIS)

    Whiticar, D.M.; Letourneau, L.; Konasewich, D.

    1994-01-01

    A field study was conducted to evaluate the leachability characteristics of pentachlorophenol (PCP), creosote, and ammoniacal chromium arsenate (ACA) wood preservatives from freshly treated wood products. Test products included PCP-treated utility poles, creosote-treated timbers and marine pilings, and ACA-treated utility poles. Bundles of test products were placed over collection trays to collect the leachate generated by natural rainfall and by sprinkling with tap water. The sampling schedule was based on accumulated rainfall with samples taken at about every 15 mm from 15 mm to 150 mm. Analyses included pH, oil and grease, total organic carbon, ammonia, metals, polynuclear aromatic hydrocarbons (PAH), chlorinated and nonchlorinated phenols, resin acids, and fish toxicity. The study indicated that leachates from wood products freshly treated with ACA, creosote, and PCP have potential for aquatic toxicity if released to the environment. A decreasing trend was noted in both the arsenic and copper releases as cumulative precipitation increased. PCP releases remained constant over the course of the study while PAH releases showed no significant trend. Phenanthrene was found to be the main component in the releases. 28 refs., 18 figs., 7 tabs

  14. Copper Leaching from Copper-ethanolamine Treated Wood: Comparison of Field Test Studies and Laboratory Standard Procedures

    OpenAIRE

    Nejc Thaler; Miha Humar

    2014-01-01

    Copper-based compounds are some of the most important biocides for the protection of wood in heavy duty applications. In the past, copper was combined with chromium compounds to reduce copper leaching, but a recent generation of copper-based preservatives uses ethanolamine as a fixative. To elucidate the leaching of copper biocides from wood, Norway spruce (Picea abies) wood was treated with a commercial copper-ethanolamine solution with two different copper concentrations (cCu = 0.125% and 0...

  15. Arsenate uncoupling of oxidative phosphorylation in isolated plant mitochondria

    Energy Technology Data Exchange (ETDEWEB)

    Wickes, W A; Wiskich, J T

    1976-01-01

    The uncoupling by arsenate of beetroot and cauliflower bud mitochondria showed the following characteristics: arsenate stimulation of respiration above the rate found with phosphate; inhibition of arsenate-stimulated respiration by phosphate; enhancement of arsenate-stimulated respiration by ADP; only partial prevention of this ADP-enhanced respiration by atractyloside; inhibition by oligomycin of the arsenate-stimulated respiration back to the phosphate rate; and the absence of any stimulatory effect of ADP in the presence of oligomycin. These results are qualitatively analogous to those reported for arsenate uncoupling in rat liver mitochondria. Arsenate stimulated malate oxidation, presumably by stimulating malate entry, in both beetroot and cauliflower bud mitochondria; however, high rates of oxidation, and presumably entry, were only sustained with arsenate in beetroot mitochondria. NADH was oxidized rapidly in cauliflower bud mitochondria in the presence of arsenate, showing that arsenate did not inhibit electron transfer processes.

  16. Identification and characterization of Burkholderia multivorans CCA53.

    Science.gov (United States)

    Akita, Hironaga; Kimura, Zen-Ichiro; Yusoff, Mohd Zulkhairi Mohd; Nakashima, Nobutaka; Hoshino, Tamotsu

    2017-07-06

    A lignin-degrading bacterium, Burkholderia sp. CCA53, was previously isolated from leaf soil. The purpose of this study was to determine phenotypic and biochemical features of Burkholderia sp. CCA53. Multilocus sequence typing (MLST) analysis based on fragments of the atpD, gltD, gyrB, lepA, recA and trpB gene sequences was performed to identify Burkholderia sp. CCA53. The MLST analysis revealed that Burkholderia sp. CCA53 was tightly clustered with B. multivorans ATCC BAA-247 T . The quinone and cellular fatty acid profiles, carbon source utilization, growth temperature and pH were consistent with the characteristics of B. multivorans species. Burkholderia sp. CCA53 was therefore identified as B. multivorans CCA53.

  17. Microdistribution of copper-carbonate and iron oxide nanoparticles in treated wood

    Energy Technology Data Exchange (ETDEWEB)

    Matsunaga, Hiroshi, E-mail: mhiroshi@ffpri.affrc.go.jp; Kiguchi, Makoto [Forestry and Forest Products Research Institute (Japan); Evans, Philip D. [University of British Columbia, Centre for Advanced Wood Processing (Canada)

    2009-07-15

    Aqueous dispersions of copper-carbonate nanoparticles and microparticles have just begun to be exploited commercially for the preservative treatment of wood. The success of the new systems will depend, in part, on the uniform distribution of the preservative in wood and the ability of copper to penetrate cell walls. We examined the distribution of copper in wood treated with a nano-Cu preservative. Copper particles are not uniformly distributed in treated wood, but they accumulate in voids that act as the flow paths for liquids in wood. Particles are deposited on, but not within cell walls. Nevertheless, elemental copper is present within cell walls, but at a lower level than that in wood treated with a conventional wood preservative. These findings suggest that nano-Cu preservatives are able to deliver bioactive components into wood cell walls even though the majority of copper particles are too large to penetrate the cell wall's nanocapillary network.

  18. Arsenate and chromate incorporation in schwertmannite

    International Nuclear Information System (INIS)

    Regenspurg, Simona; Peiffer, Stefan

    2005-01-01

    High concentrations of Cr (up to 812 ppm) and As (up to 6740 ppm) were detected in precipitates of the mineral schwertmannite in areas influenced by acid mine drainage. Schwertmannite may act as well as a natural filter for these elements in water as well as their source by releasing the previously bound elements during its dissolution or mineral-transformation. The mechanisms of uptake and potential release for the species arsenate and chromate were investigated by performing synthesis and stability experiments with schwertmannite. Schwertmannite, synthesized in solutions containing arsenate in addition to sulphate, was enriched by up to 10.3 wt% arsenate without detectable structural changes as demonstrated by powder X-ray diffraction (XRD). In contrast to arsenate, a total substitution of sulphate by chromate was possible in sulphate-free solutions. Thereby, the chromate content in schwertmannite could reach 15.3 wt%. To determine the release of oxyanions from schwertmannite over time, synthetic schwertmannite samples containing varying amounts of sulphate, chromate and arsenate were kept at a stable pH of either 2 or 4 over 1 year in suspension. At several time intervals Fe and the oxyanions were measured in solution and alterations of the solid part were observed by XRD and Fourier-Transform infrared (FT-IR) spectroscopy. At pH 2 schwertmannite partly dissolved and the total release of arsenate (24%) was low in contrast to chromate (35.4-57.5%) and sulphate (67-76%). Accordingly, the ionic activity product (log IAP) of arsenated schwertmannite was lowest (13.5), followed by the log IAP for chromated schwertmannite (16.2-18.5) and the log IAP for regular (=non-substituted) schwertmannite (18). At pH 4 schwertmannite transformed to goethite, an effect which occurred at the fastest rate for regular schwertmannite (=arsenate- and chromate-free), followed by chromate and arsenate containing schwertmannite. Both chromate and more evidently arsenate have a

  19. Characterization and Low-Cost Remediation of Soils Contaminated by Timbers in Community Gardens.

    Science.gov (United States)

    Heiger-Bernays, W; Fraser, A; Burns, V; Diskin, K; Pierotti, D; Merchant-Borna, K; McClean, M; Brabander, D; Hynes, H P

    2009-01-01

    Urban community gardens worldwide provide significant health benefits to those gardening and consuming fresh produce from them. Urban gardens are most often placed in locations and on land in which soil contaminants reflect past practices and often contain elevated levels of metals and organic contaminants. Garden plot dividers made from either railroad ties or chromated copper arsenate (CCA) pressure treated lumber contribute to the soil contamination and provide a continuous source of contaminants. Elevated levels of polycyclic aromatic hydrocarbons (PAHs) derived from railroad ties and arsenic from CCA pressure treated lumber are present in the gardens studied. Using a representative garden, we 1) determined the nature and extent of urban community garden soil contaminated with PAHs and arsenic by garden timbers; 2) designed a remediation plan, based on our sampling results, with our community partner guided by public health criteria, local regulation, affordability, and replicability; 3) determined the safety and advisability of adding city compost to Boston community gardens as a soil amendment; and 4) made recommendations for community gardeners regarding healthful gardening practices. This is the first study of its kind that looks at contaminants other than lead in urban garden soil and that evaluates the effect on select soil contaminants of adding city compost to community garden soil.

  20. Response to arsenate treatment in Schizosaccharomyces pombe and the role of its arsenate reductase activity.

    Directory of Open Access Journals (Sweden)

    Alejandro Salgado

    Full Text Available Arsenic toxicity has been studied for a long time due to its effects in humans. Although epidemiological studies have demonstrated multiple effects in human physiology, there are many open questions about the cellular targets and the mechanisms of response to arsenic. Using the fission yeast Schizosaccharomyces pombe as model system, we have been able to demonstrate a strong activation of the MAPK Spc1/Sty1 in response to arsenate. This activation is dependent on Wis1 activation and Pyp2 phosphatase inactivation. Using arsenic speciation analysis we have also demonstrated the previously unknown capacity of S. pombe cells to reduce As (V to As (III. Genetic analysis of several fission yeast mutants point towards the cell cycle phosphatase Cdc25 as a possible candidate to carry out this arsenate reductase activity. We propose that arsenate reduction and intracellular accumulation of arsenite are the key mechanisms of arsenate tolerance in fission yeast.

  1. Analysis of preservative-treated wood by multivariate analysis of laser-induced breakdown spectroscopy spectra

    International Nuclear Information System (INIS)

    Martin, Madhavi Z.; Labbe, Nicole; Rials, Timothy G.; Wullschleger, Stan D.

    2005-01-01

    In this work, multivariate statistical analysis (MVA) techniques are coupled with laser-induced breakdown spectroscopy (LIBS) to identify preservative types (chromated copper arsenate, ammoniacal copper zinc or alkaline copper quat), and to predict elemental content in preservative-treated wood. The elemental composition of the samples was measured with a standard laboratory method of digestion followed by atomic absorption spectroscopy analysis. The elemental composition was then correlated with the LIBS spectra using projection to latent structures (PLS) models. The correlations for the different elements introduced by different treatments were very strong, with the correlation coefficients generally above 0.9. Additionally, principal component analysis (PCA) was used to differentiate the samples treated with different preservative formulations. The research has focused not only on demonstrating the application of LIBS as a tool for use in the forest products industry, but also considered sampling errors, limits of detection, reproducibility, and accuracy of measurements as they relate to multivariate analysis of this complex wood substrate

  2. Analysis of preservative-treated wood by multivariate analysis of laser-induced breakdown spectroscopy spectra

    Energy Technology Data Exchange (ETDEWEB)

    Martin, Madhavi Z. [Environmental Sciences Division Oak Ridge National Laboratory, P.O. Box 2008 MS 6422, Oak Ridge TN 37831-6422 (United States); Labbe, Nicole [Forest Products Center, University of Tennessee, 2506 Jacob Drive, Knoxville, TN 37996-4570 (United States)]. E-mail: nlabbe@utk.edu; Rials, Timothy G. [Forest Products Center, University of Tennessee, 2506 Jacob Drive, Knoxville, TN 37996-4570 (United States); Wullschleger, Stan D. [Environmental Sciences Division Oak Ridge National Laboratory, P.O. Box 2008 MS 6422, Oak Ridge TN 37831-6422 (United States)

    2005-08-31

    In this work, multivariate statistical analysis (MVA) techniques are coupled with laser-induced breakdown spectroscopy (LIBS) to identify preservative types (chromated copper arsenate, ammoniacal copper zinc or alkaline copper quat), and to predict elemental content in preservative-treated wood. The elemental composition of the samples was measured with a standard laboratory method of digestion followed by atomic absorption spectroscopy analysis. The elemental composition was then correlated with the LIBS spectra using projection to latent structures (PLS) models. The correlations for the different elements introduced by different treatments were very strong, with the correlation coefficients generally above 0.9. Additionally, principal component analysis (PCA) was used to differentiate the samples treated with different preservative formulations. The research has focused not only on demonstrating the application of LIBS as a tool for use in the forest products industry, but also considered sampling errors, limits of detection, reproducibility, and accuracy of measurements as they relate to multivariate analysis of this complex wood substrate.

  3. RESISTÊNCIA BIOLÓGICA DA MADEIRA TRATADA DE Eucalyptus grandis E Eucalyptus cloeziana A FUNGOS APODRECEDORES EM ENSAIOS DE LABORATÓRIO

    Directory of Open Access Journals (Sweden)

    Magnos Alan Vivian

    2015-01-01

    Full Text Available The present study aimed to evaluate the biological resistance of treated wood from Eucalyptus grandis and Eucalyptus cloeziana under the action of biodeteriorative organisms in laboratory testing. Thus, we used trees of Eucalyptus grandis and Eucalyptus cloeziana, both 16 years old, which was converted into planks and subjected to preservative treatment in an autoclave with chromate copper arsenate (CCA. Then, it was made the specimens for the conduct of accelerated decay test, as recommended by ASTM. From the results, it was observed for the fungus Trametes versicolor that the preservative treatment was effective in reducing the biological degradation of the wood of the two species, with reduced mass loss in 35.17 and 82.31% for wood Eucalyptus grandis and Eucalyptus cloeziana, respectively, as for the fungus Gloeophyllum trabeum mass loss was reduced by 6.79 and 96.65%, compared to the control. Based on the conditions of realization of the present study, it was observed that preservative treatment with CCA is effective in the increasing the biological resistance of the wood under the action of fungi Trametes versicolor and Gloeophyllum trabeum.

  4. Thermochemical investigations on uranyl phosphates and arsenates

    International Nuclear Information System (INIS)

    Barten, H.

    1986-11-01

    The results are described of a study of the thermochemical stability of anhydrous uranyl phosphates and arsenates. A number of aspects of chemical technological importance are indicated in detail. The synthesized anhydrous uranyl phosphates and arsenates were very hygroscopic, so that experiments on these compounds had to be carried out under moisture-free conditions. Further characterisation of these compounds are given, including a study of their thermal stabilities and phase relations. The uranyl phosphates reduced reversibly at temperatures of the order of 1100 to 1600 0 C. This makes it possible to express their relative stabilities quantitatively, in terms of the oxygen pressures of the reduction reactions. The thermal decomposition of uranyl arsenates did not occur by reduction, as for the phosphates, but by giving off arsenic oxide vapour. The results of measurements of enthalpies of solution led to the determination of the enthalpies of formation, heat capacity and the standard entropies of the uranyl arsenates. The thermochemical functions at high-temperatures could consequently be calculated. Attention is paid to the possible formation of uranium arsenates, whose uranium has a valency lower than six, hitherto not reported in literature. It was not possible to prepare arsenates of tetravalent uranium. However, three new compounds were observed, one of these, UAsO 5 , was studied in some detail. (Auth.)

  5. Respiration of arsenate and selenate by hyperthermophilic archaea.

    Science.gov (United States)

    Huber, R; Sacher, M; Vollmann, A; Huber, H; Rose, D

    2000-10-01

    A novel, strictly anaerobic, hyperthermophilic, facultative organotrophic archaeon was isolated from a hot spring at Pisciarelli Solfatara, Naples, Italy. The rod-shaped cells grew chemolithoautotrophically with carbon dioxide as carbon source, hydrogen as electron donor and arsenate, thiosulfate or elemental sulfur as electron acceptor. H2S was formed from sulfur or thiosulfate, arsenite from arsenate. Organotrophically, the new isolate grew optimally in the presence of an inorganic electron acceptor like sulfur, selenate or arsenate. Cultures, grown on arsenate and thiosulfate or arsenate and L-cysteine, precipitated realgar (As2S2). During growth on selenate, elemental selenium was produced. The G+C content of the DNA was 58.3 mol%. Due to 16S rRNA gene sequence analysis combined with physiological and morphological criteria, the new isolate belongs to the Thermoproteales order. It represents a new species within the genus Pyrobaculum, the type species of which we name Pyrobaculum arsenaticum (type strain PZ6*, DSM 13514, ATCC 700994). Comparative studies with different Pyrobaculum-species showed, that Pyrobaculum aerophilum was also able to grow organotrophically under anaerobic culture conditions in the presence of arsenate, selenate and selenite. During growth on selenite, elemental selenium was formed as final product. In contrast to P. arsenaticum, P. aerophilum could use selenate or arsenate for lithoautotrophic growth with carbon dioxide and hydrogen.

  6. LWD–TCP complex activates the morning gene CCA1 in Arabidopsis

    Science.gov (United States)

    Wu, Jing-Fen; Tsai, Huang-Lung; Joanito, Ignasius; Wu, Yi-Chen; Chang, Chin-Wen; Li, Yi-Hang; Wang, Ying; Hong, Jong Chan; Chu, Jhih-Wei; Hsu, Chao-Ping; Wu, Shu-Hsing

    2016-01-01

    A double-negative feedback loop formed by the morning genes CIRCADIAN CLOCK ASSOCIATED1 (CCA1)/LATE ELONGATED HYPOCOTYL (LHY) and the evening gene TIMING OF CAB EXPRESSION1 (TOC1) contributes to regulation of the circadian clock in Arabidopsis. A 24-h circadian cycle starts with the peak expression of CCA1 at dawn. Although CCA1 is targeted by multiple transcriptional repressors, including PSEUDO-RESPONSE REGULATOR9 (PRR9), PRR7, PRR5 and CCA1 HIKING EXPEDITION (CHE), activators of CCA1 remain elusive. Here we use mathematical modelling to infer a co-activator role for LIGHT-REGULATED WD1 (LWD1) in CCA1 expression. We show that the TEOSINTE BRANCHED 1-CYCLOIDEA-PCF20 (TCP20) and TCP22 proteins act as LWD-interacting transcriptional activators. The concomitant binding of LWD1 and TCP20/TCP22 to the TCP-binding site in the CCA1 promoter activates CCA1. Our study reveals activators of the morning gene CCA1 and provides an action mechanism that ensures elevated expression of CCA1 at dawn to sustain a robust clock. PMID:27734958

  7. LWD-TCP complex activates the morning gene CCA1 in Arabidopsis.

    Science.gov (United States)

    Wu, Jing-Fen; Tsai, Huang-Lung; Joanito, Ignasius; Wu, Yi-Chen; Chang, Chin-Wen; Li, Yi-Hang; Wang, Ying; Hong, Jong Chan; Chu, Jhih-Wei; Hsu, Chao-Ping; Wu, Shu-Hsing

    2016-10-13

    A double-negative feedback loop formed by the morning genes CIRCADIAN CLOCK ASSOCIATED1 (CCA1)/LATE ELONGATED HYPOCOTYL (LHY) and the evening gene TIMING OF CAB EXPRESSION1 (TOC1) contributes to regulation of the circadian clock in Arabidopsis. A 24-h circadian cycle starts with the peak expression of CCA1 at dawn. Although CCA1 is targeted by multiple transcriptional repressors, including PSEUDO-RESPONSE REGULATOR9 (PRR9), PRR7, PRR5 and CCA1 HIKING EXPEDITION (CHE), activators of CCA1 remain elusive. Here we use mathematical modelling to infer a co-activator role for LIGHT-REGULATED WD1 (LWD1) in CCA1 expression. We show that the TEOSINTE BRANCHED 1-CYCLOIDEA-PCF20 (TCP20) and TCP22 proteins act as LWD-interacting transcriptional activators. The concomitant binding of LWD1 and TCP20/TCP22 to the TCP-binding site in the CCA1 promoter activates CCA1. Our study reveals activators of the morning gene CCA1 and provides an action mechanism that ensures elevated expression of CCA1 at dawn to sustain a robust clock.

  8. Effect of co-existing copper and calcium on the removal of As(V) by reused aluminum oxides.

    Science.gov (United States)

    Yang, J K; Park, Y J; Kim, K H; Lee, H Y; Min, K C; Lee, S M

    2013-01-01

    Among the various heavy metals, arsenic is frequently found in abandoned mine drainage and the environmental fate of arsenic in real aqueous solutions can be highly dependent on the presence of co-existing ions. In this study, removal of arsenate through adsorption on the reused aluminum oxide or through precipitation was investigated in a single and in a binary system as a function of pH and concentration. Different removal behaviors of arsenate were observed in the presence of different cations as well as a variation of the molar ratios of arsenate to cations. Co-operative effects on arsenate removal by precipitation in solution occurred with an increase of copper concentration, while a decrease of arsenate removal resulted in increasing calcium concentration. It was observed that the arsenate removal in the presence of calcium would be highly dependent on the molar ratios of both elements.

  9. Chemical remediation of wood treated with micronised, nano or soluble copper preservatives

    Science.gov (United States)

    Saip Nami Kartal; Evren Terzi; Bessie Woodward; Carol A. Clausen; Stan T. Lebow

    2013-01-01

    The potential for extraction of copper from wood treated with micronised, nano or soluble forms of copper has been evaluated in view of chemical remediation. In focus were EDTA, oxalic acid, bioxalate, and D-gluconic acid for extraction of Cu from treated wood. Bioxalate extractions for 24 h resulted in Cu removal over 95% for all tested...

  10. Selective Removal of Toxic Metals like Copper and Arsenic from Drinking Water Using Phenol-Formaldehyde Type Chelating Resins

    Directory of Open Access Journals (Sweden)

    Debasis Mohanty

    2009-01-01

    Full Text Available The concentration of different toxic metals has increased beyond environmentally and ecologically permissible levels due to the increase in industrial activity. More than 100 million people of Bangladesh and West Bengal in India are affected by drinking ground water contaminated with arsenic and some parts of India is also affected by poisoning effect of copper, cadmium and fluoride. Different methods have been evolved to reduce the arsenic concentration in drinking water to a maximum permissible level of 10 μg/L where as various methods are also available to separate copper from drinking water. Of the proven methods available today, removal of arsenic by polymeric ion exchangers has been most effective. While chelating ion exchange resins having specific chelating groups attached to a polymer have found extensive use in sorption and pre concentration of Cu2+ ions. Both the methods are coupled here to separate and preconcentrate toxic metal cation Cu2+ and metal anion arsenate(AsO4– at the same time. We have prepared a series of low-cost polymeric resins, which are very efficient in removing copper ion from drinking water and after coordinating with copper ion they act as polymeric ligand exchanger, which are efficiently removing arsenate from drinking water. For this purpose Schiff bases were prepared by condensing o-phenylenediamine with o-, m-, and p-hydroxybenzaldehydes. Condensing these phenolic Schiff bases with formaldehyde afforded the chelating resins in high yields. These resins are loaded with Cu2+, Ni2+ 2+, and Fe3+ ions. The resins and the polychelates are highly insoluble in water. In powdered form the metal ion-loaded resins are found to very efficiently remove arsenate ion from water at neutral pH. Resins loaded with optimum amount of Cu2+ ion is more effective in removing arsenate ions compared to those with Fe3+ ion, apparently because Cu2+ is a stronger Lewis acid than Fe3+. Various parameters influencing the removal of the

  11. Effects of compost and phosphate amendments on arsenic mobility in soils and arsenic uptake by the hyperaccumulator, Pteris vittata L

    International Nuclear Information System (INIS)

    Cao Xinde; Ma, Lena Q.; Shiralipour, Aziz

    2003-01-01

    Chinese brake fern (Pteris vittata L.), an arsenic (As) hyperaccumulator, has shown the potential to remediate As-contaminated soils. This study investigated the effects of soil amendments on the leachability of As from soils and As uptake by Chinese brake fern. The ferns were grown for 12 weeks in a chromated-copper-arsenate (CCA) contaminated soil or in As spiked contaminated (ASC) soil. Soils were treated with phosphate rock, municipal solid waste, or biosolid compost. Phosphate amendments significantly enhanced plant As uptake from the two tested soils with frond As concentrations increasing up to 265% relative to the control. After 12 weeks, plants grown in phosphate-amended soil removed >8% of soil As. Replacement of As by P from the soil binding sites was responsible for the enhanced mobility of As and subsequent increased plant uptake. Compost additions facilitated As uptake from the CCA soil, but decreased As uptake from the ASC soil. Elevated As uptake in the compost-treated CCA soil was related to the increase of soil water-soluble As and As(V) transformation into As(III). Reduced As uptake in the ASC soil may be attributed to As adsorption to the compost. Chinese brake fern took up As mainly from the iron-bound fraction in the CCA soil and from the water-soluble/exchangeable As in the ASC soil. Without ferns for As adsorption, compost and phosphate amendments increased As leaching from the CCA soil, but had decreased leaching with ferns when compared to the control. For the ASC soil, treatments reduced As leaching regardless of fern presence. This study suggest that growing Chinese brake fern in conjunction with phosphate amendments increases the effectiveness of remediating As-contaminated soils, by increasing As uptake and decreasing As leaching. - Phosphate amendment increases the effectiveness of Chinese brake fern to remediate As-contaminated soils, by increasing As uptake and decreasing As leaching

  12. Hfq stimulates the activity of the CCA-adding enzyme

    Directory of Open Access Journals (Sweden)

    Betat Heike

    2007-10-01

    Full Text Available Abstract Background The bacterial Sm-like protein Hfq is known as an important regulator involved in many reactions of RNA metabolism. A prominent function of Hfq is the stimulation of RNA polyadenylation catalyzed by E. coli poly(A polymerase I (PAP. As a member of the nucleotidyltransferase superfamily, this enzyme shares a high sequence similarity with an other representative of this family, the tRNA nucleotidyltransferase that synthesizes the 3'-terminal sequence C-C-A to all tRNAs (CCA-adding enzyme. Therefore, it was assumed that Hfq might not only influence the poly(A polymerase in its specific activity, but also other, similar enzymes like the CCA-adding enzyme. Results Based on the close evolutionary relation of these two nucleotidyltransferases, it was tested whether Hfq is a specific modulator acting exclusively on PAP or whether it also influences the activity of the CCA-adding enzyme. The obtained data indicate that the reaction catalyzed by this enzyme is substantially accelerated in the presence of Hfq. Furthermore, Hfq binds specifically to tRNA transcripts, which seems to be the prerequisite for the observed effect on CCA-addition. Conclusion The increase of the CCA-addition in the presence of Hfq suggests that this protein acts as a stimulating factor not only for PAP, but also for the CCA-adding enzyme. In both cases, Hfq interacts with RNA substrates, while a direct binding to the corresponding enzymes was not demonstrated up to now (although experimental data indicate a possible interaction of PAP and Hfq. So far, the basic principle of these stimulatory effects is not clear yet. In case of the CCA-adding enzyme, however, the presented data indicate that the complex between Hfq and tRNA substrate might enhance the product release from the enzyme.

  13. Development of laboratory experiments serving as a basis for modeling the transport behaviour of arsenate, lead, cadmium and copper in water-saturated columns

    International Nuclear Information System (INIS)

    Hamer, K.

    1993-01-01

    The aim of the study was to work out laboratory experiments which might serve as a link between the bench and the application of CoTAM (Column Transport and Absorption Model) in real practice, thus thanking the development of this computer model which is to permit the simulation of the transport behaviour of heavy metals in porous aquilers. Efforts were made to find a process-oriented concept so as to provide a wide field of application. In developing the model and the laboratory experiments, this meant studying all the processes in groundwater separately as far as possible and avoiding case-specific sum parameters. The work centered on an examination of sorption processes during transport in groundwater, as this combination of processes is always found in natural porous aquifers. In water-saturated-column experiments on combinations of arenaceous quartz, feldspar, montmorillonite, goethite, peat and manganese oxide as the aquifer material, the transport of cadmium, copper, lead and arsenate was simulated on the bench scale. These case examples served to study sorption processes and their diverse kinetics as well as hydrodynamic processes. (orig./BBR) [de

  14. Counter-current acid leaching process for copper azole treated wood waste.

    Science.gov (United States)

    Janin, Amélie; Riche, Pauline; Blais, Jean-François; Mercier, Guy; Cooper, Paul; Morris, Paul

    2012-09-01

    This study explores the performance of a counter-current leaching process (CCLP) for copper extraction from copper azole treated wood waste for recycling of wood and copper. The leaching process uses three acid leaching steps with 0.1 M H2SO4 at 75degrees C and 15% slurry density followed by three rinses with water. Copper is recovered from the leachate using electrodeposition at 5 amperes (A) for 75 min. Ten counter-current remediation cycles were completed achieving > or = 94% copper extraction from the wood during the 10 cycles; 80-90% of the copper was recovered from the extract solution by electrodeposition. The counter-current leaching process reduced acid consumption by 86% and effluent discharge volume was 12 times lower compared with the same process without use of counter-current leaching. However, the reuse of leachates from one leaching step to another released dissolved organic carbon and caused its build-up in the early cycles.

  15. Recycling and reuse of waste from electricity distribution networks as reinforcement agents in polymeric composites.

    Science.gov (United States)

    Zimmermann, Matheus V G; Zattera, Ademir J

    2013-07-01

    Of the waste generated from electricity distribution networks, wooden posts treated with chromated copper arsenate (CCA) and ceramic insulators make up the majority of the materials for which no effective recycling scheme has been developed. This study aims to recycle and reuse this waste as reinforcement elements in polymer composites and hybrid composites, promoting an ecologically and economically viable alternative for the disposal of this waste. The CCA wooden posts were cut, crushed and recycled via acid leaching using 0.2 and 0.4N H2SO4 in triplicate at 70°C and then washed and dried. The ceramic insulators were fragmented in a hydraulic press and separated by particle size using a vibrating sieve. The composites were mixed in a twin-screw extruder and injected into the test specimens, which were subjected to physical, mechanical, thermal and morphological characterization. The results indicate that the acid treatment most effective for removing heavy metals in the wood utilizes 0.4NH2SO4. However, the composites made from wood treated with 0.2NH2SO4 exhibited the highest mechanical properties of the composites, whereas the use of a ceramic insulator produces composites with better thermal stability and impact strength. This study is part of the research and development project of ANEEL (Agência Nacional de Energia Elétrica) and funded by CPFL (Companhia Paulista de Força e Luz). Copyright © 2013 Elsevier Ltd. All rights reserved.

  16. Embryotoxicity of arsenite and arsenate

    International Nuclear Information System (INIS)

    Lindgren, A.; Danielsson, R.G.; Dencker, L.; Vahter, M.

    1984-01-01

    The distribution of 74 As-labelled and arsenite in pregnant mice and a monkey has been studied by autoradiography and gamma counting of isolated tissues, and their in vitro toxicity to a chondrogenic system has been investigated. With both arsenic forms, given as single intravenous injections to the mother, the 74 As-arsenic appeared to pass the mouse placenta relatively freely and approximately to the same extent. The retention time in material tissues including the placenta was, however, around three times longer with arsenite than with arsenate. In early gestation, high activity was registered in the embryonic neuroepithelium, which correlates well with reported CNS malformations in rodents. In late gestation, the distribution pattern was more like that in the adults. Accumulation in skin and squamous epithelia of the upper gastrointestinal tract (oral cavity, oesophagus and oesophageal region of stomach) dominated the distribution pucture, especially at a long survival interval. Arsenate, but not arsenite, showed affinity for the calcified areas of the skeleton. A marmoset monkey in late gestation receiving arsenite showed a somewhat lower rate of placental transfer than the mice. Skin and liver had the highest concentrations (at 8 hrs), both in mother and foetuses. This species is known not to methylate arsenic, resulting in stronger binding and longer retention times of arsenic as compared with other species. The stronger binding in maternal tissues may possibly explain the lower rate of placental transfer. Arsenite was shown to inhibit cartilage formation in a chick limb bud mesenchymal spot culture system (ED50 approximately 5-10μM) while arsenate seemed to be without effect at concentrations up to 200 μM (highest tested). Arsenate, however, showed a potential of the arsenite toxicity. (author)

  17. Comparison of arsenate and cadmium toxicity in a freshwater amphipod (Gammarus pulex)

    International Nuclear Information System (INIS)

    Vellinger, Céline; Parant, Marc; Rousselle, Philippe; Immel, Françoise

    2012-01-01

    Cadmium is largely documented on freshwater organisms while arsenic, especially arsenate, is rarely studied. The kinetic of the LC50s values for both metals was realized on Gammarus pulex. Physiological [i.e. metal concentration in body tissues, bioconcentration factor (BCF)] effects and behavioural responses (via pleopods beats) were investigated after 240-h exposure. Arsenate LC50 value was 100 fold higher than Cd-LC50 value after 240-h exposure, while concentrations in gammarids were similar for both metals at their respective LC50s. BCF decreased with increasing cadmium concentration while BCF remained stable with increasing arsenate concentration. Moreover, BCF was between 148 and 344 times lower for arsenate than cadmium. A significant hypoventilation was observed for cadmium concentrations exceeding or close to the 240h-LC50 Cd , while gammarids hyperventilated for the lowest arsenate concentrations and hypoventilated for the highest arsenate concentrations. We discussed the relationships between potential action mechanisms of these two metals and observed results. - Highlights: ► First study of arsenate toxicity in a Crustacean gammarid. ► Specific toxicological and behavioural responses to AsV and Cd contamination. ► Each metal led to specific-action mechanisms. ► Different energetic reallocation could explain specific behavioural responses. - This study brings to light the potential relationship between toxicological effects and behavioural responses of G. pulex exposed at both Cadmium and Arsenate.

  18. Caracterización de las cibercomunidades de aprendizaje (cCA

    Directory of Open Access Journals (Sweden)

    Iñaki Murua Anzola

    2015-01-01

    Full Text Available En este artículo se presentan los principales resultados de la investigación exploratoria llevada a cabo sobre las cibercomunidades de aprendizaje (cCA y la formación del profesorado aplicando , entre otros, el método Delphi; e l marco teórico y contextual de la misma se presentó en el número 43 de la revista RED. Los participantes de l panel de expertos han sido 31 encuestados online con el instrumento Delphi - cCA, y 19 respo nsables de comunidades que han contestado al cuestionario - cCA. Entre los principales resultados se destacan las condiciones para la creación y desarrollo de cCA, las herramientas y funcionalidades de las comunidades y las tipologías de participación ( perso nas implicadas, activas, pasivas y ausentes.

  19. Respiratory arsenate reductase as a bidirectional enzyme

    Science.gov (United States)

    Richey, C.; Chovanec, P.; Hoeft, S.E.; Oremland, R.S.; Basu, P.; Stolz, J.F.

    2009-01-01

    The haloalkaliphilic bacterium Alkalilimnicola ehrlichii is capable of anaerobic chemolithoautotrophic growth by coupling the oxidation of arsenite (As(III)) to the reduction of nitrate and carbon dioxide. Analysis of its complete genome indicates that it lacks a conventional arsenite oxidase (Aox), but instead possesses two operons that each encode a putative respiratory arsenate reductase (Arr). Here we show that one homolog is expressed under chemolithoautotrophic conditions and exhibits both arsenite oxidase and arsenate reductase activity. We also demonstrate that Arr from two arsenate respiring bacteria, Alkaliphilus oremlandii and Shewanella sp. strain ANA-3, is also biochemically reversible. Thus Arr can function as a reductase or oxidase. Its physiological role in a specific organism, however, may depend on the electron potentials of the molybdenum center and [Fe–S] clusters, additional subunits, or constitution of the electron transfer chain. This versatility further underscores the ubiquity and antiquity of microbial arsenic metabolism.

  20. Arsenate-induced maternal glucose intolerance and neural tube defects in a mouse model

    International Nuclear Information System (INIS)

    Hill, Denise S.; Wlodarczyk, Bogdan J.; Mitchell, Laura E.; Finnell, Richard H.

    2009-01-01

    Background: Epidemiological studies have linked environmental arsenic (As) exposure to increased type 2 diabetes risk. Periconceptional hyperglycemia is a significant risk factor for neural tube defects (NTDs), the second most common structural birth defect. A suspected teratogen, arsenic (As) induces NTDs in laboratory animals. Objectives: We investigated whether maternal glucose homeostasis disruption was responsible for arsenate-induced NTDs in a well-established dosing regimen used in studies of arsenic's teratogenicity in early neurodevelopment. Methods: We evaluated maternal intraperitoneal (IP) exposure to As 9.6 mg/kg (as sodium arsenate) in LM/Bc/Fnn mice for teratogenicity and disruption of maternal plasma glucose and insulin levels. Selected compounds (insulin pellet, sodium selenate (SS), N-acetyl cysteine (NAC), L-methionine (L-Met), N-tert-Butyl-α-phenylnitrone (PBN)) were investigated for their potential to mitigate arsenate's effects. Results: Arsenate caused significant glucose elevation during an IP glucose tolerance test (IPGTT). Insulin levels were not different between arsenate and control dams before (arsenate, 0.55 ng/dl; control, 0.48 ng/dl) or after glucose challenge (arsenate, 1.09 ng/dl; control, 0.81 ng/dl). HOMA-IR index was higher for arsenate (3.9) vs control (2.5) dams (p = 0.0260). Arsenate caused NTDs (100%, p < 0.0001). Insulin pellet and NAC were the most successful rescue agents, reducing NTD rates to 45% and 35%. Conclusions: IPGTT, insulin assay, and HOMA-IR results suggest a modest failure of glucose stimulated insulin secretion and insulin resistance characteristic of glucose intolerance. Insulin's success in preventing arsenate-induced NTDs provides evidence that these arsenate-induced NTDs are secondary to elevated maternal glucose. The NAC rescue, which did not restore maternal glucose or insulin levels, suggests oxidative disruption plays a role.

  1. Adsorption of arsenate from aqueous solution by rice husk-based adsorbent

    International Nuclear Information System (INIS)

    Khan, Taimur; Chaudhuri, Malay

    2013-01-01

    Rice husk-based adsorbent (RHBA) was prepared by burning rice husk in a muffle furnace at 400°C for 4 h and adsorption of arsenate by the RHBA from aqueous solution was examined. Batch adsorption test showed that extent of arsenate adsorption depended on contact time and pH. Equilibrium adsorption was attained in 60 min, with maximum adsorption occurring at pH 7. Equilibrium adsorption data were well described by the Freundlich isotherm model. Freundlich constants K f and 1/n were 3.62 and 2, respectively. The RHBA is effective in the adsorption of arsenate from water and is a potentially suitable filter medium for removing arsenate from groundwater at wells or in households.

  2. Metals determination in wood treated by synchrotron radiation X-ray fluorescence analysis

    International Nuclear Information System (INIS)

    Vives, Ana Elisa Sirito de; Medeiros, Jean Gabriel da Silva; Tomazello Filho, Mario

    2005-01-01

    The paper describes the use of X-Ray fluorescence analysis for distribution and quantification of metals in the hardwood (Eucalyptus sp) and softwood (Pinus sp) treated with CCA (copper-chromium-arsenic). The sapwood/heartwood for hardwood sample and the growth-rings for softwood sample were analyzed. The samples were scanned in 320 mm steps in the vertical direction. For excitation of the elements a white beam synchrotron radiation of ∼ 320 x 180 mm was employed and for the X-ray detection a Si(Li) semiconductor detector. The elements K, Ca, Cr, Mn, Cu, Zn and As were determined. Fundamental parameters were used to quantify the elements concentrations. (author)

  3. Metals determination in wood treated by synchrotron radiation X-ray fluorescence analysis

    Energy Technology Data Exchange (ETDEWEB)

    Vives, Ana Elisa Sirito de [Universidade Metodista de Piracicaba (UNIMEP), Santa Barbara D' Oeste, SP (Brazil). Faculdade de Engenharia, Arquitetura e Urbanismo]. E-mail: aesvives@unimep.br; Silva, Richard Maximiliano da Cunha [Centro de Energia Nuclear na Agricultura, Piracicaba, SP (Brazil)]. E-mail: maxcunha@cena.usp.br; Medeiros, Jean Gabriel da Silva; Tomazello Filho, Mario [Sao Paulo Univ., Piracicaba, SP (Brazil). Escola Superior de Agricultura Luiz de Queiroz]. E-mail: jeangm@esalq.usp.br; mtomazel@esalq.usp.br; Moreira, Silvana [Universidade Estadual de Campinas, SP (Brazil). Faculdade de Engenharia Civil, Arquitetura e Urbanismo]. E-mail: Silvana@fec.unicamp.br; Zucchi, Orgheda Luiza Araujo Domingues [Sao Paulo Univ., Ribeirao Preto, SP (Brazil). Faculdade de Ciencias Farmaceuticas]. E-mail: olzucchi@fcfrp.usp.br; Barroso, Regina Cely [Universidade do Estado, Rio de Janeiro, RJ (Brazil)]. E-mail: cely@uerj.br

    2005-07-01

    The paper describes the use of X-Ray fluorescence analysis for distribution and quantification of metals in the hardwood (Eucalyptus sp) and softwood (Pinus sp) treated with CCA (copper-chromium-arsenic). The sapwood/heartwood for hardwood sample and the growth-rings for softwood sample were analyzed. The samples were scanned in 320 mm steps in the vertical direction. For excitation of the elements a white beam synchrotron radiation of {approx} 320 x 180 mm was employed and for the X-ray detection a Si(Li) semiconductor detector. The elements K, Ca, Cr, Mn, Cu, Zn and As were determined. Fundamental parameters were used to quantify the elements concentrations. (author)

  4. Form and toxicity of copper released into marine systems from conventionally and nano-sized copper treated lumber

    Science.gov (United States)

    The fate and effects of pristine engineered nanomaterials (ENMs) in simplified systems have been widely studied; however, little is known about the potential release and impact of ENMs from consumer goods, especially lumber that has been treated with micronized copper. Micronized...

  5. Occupational exposure to chromium, copper and arsenic during work with impregnated wood in joinery shops.

    Science.gov (United States)

    Nygren, O; Nilsson, C A; Lindahl, R

    1992-10-01

    CCA-impregnated timber contains copper, chromium and arsenic (CCA), and occupational exposure to wood dust as well as the CCA compounds may occur in work with such timber. Dust from commercially available impregnated wood has been found to contain hexavalent chromium, which is regarded as a carcinogen. Apart from determinations of the total amounts of the CCA compounds, specific determination of hexavalent chromium is therefore essential. Selective methods have been applied for control of the work environment in six joinery shops. The mean exposure to wood dust was found to be below 1 mg m-3. The mean airborne concentration of arsenic around various types of joinery machines was in the range from 0.54 to 3.1 micrograms m-3. No hexavalent chromium was detected in any samples and no increased concentrations of arsenic were found in urine from the workers. The presence of arsenic in the work-room air must be considered for appropriate assessment of the occupational environment in joinery shops.

  6. Thermochemical investigations on uranyl phosphates and arsenates

    International Nuclear Information System (INIS)

    Barten, H.

    1986-01-01

    Results are described of a study of the thermochemical stability of anhydrous phosphates and arsenates. The results of phase studies deal with compound formation and characterization, coexisting phases and limiting physical or chemical properties. The uranyl phosphates evolve oxygen at higher temperatures and the arsenates lose arsenic oxide vapour. These phenomena give the possibility to describe their thermodynamic stabilities. Thus oxygen pressures of uranyl phosphates have been measured using a static, non-isothermal method. Having made available the pure anhydrous compounds in the course of this investigation, molar thermodynamic quantities have been measured as well. These include standard enthalpies of formation from solution calorimetry and high-temperature heat-capacity functions derived from enthalpy increments measured. Some attention is given to compounds with uranium in valencies lower than six which have been met during the investigation. An evaluation is made of the thermodynamics of the compounds studied, to result in tabulized high-temperature thermodynamic functions. Relative stabilities within the systems are discussed and comparisons of the uranyl phosphates and the arsenates are made. (Auth.)

  7. Pore-Water Carbonate and Phosphate As Predictors of Arsenate Toxicity in Soil.

    Science.gov (United States)

    Lamb, Dane T; Kader, Mohammed; Wang, Liang; Choppala, Girish; Rahman, Mohammad Mahmudur; Megharaj, Mallavarapu; Naidu, Ravi

    2016-12-06

    Phytotoxicity of inorganic contaminants is influenced by the presence of competing ions at the site of uptake. In this study, interaction of soil pore-water constituents with arsenate toxicity was investigated in cucumber (Cucumis sativa L) using 10 contrasting soils. Arsenate phytotoxicity was shown to be related to soluble carbonate and phosphate. The data indicated that dissolved phosphate and carbonate had an antagonistic impact on arsenate toxicity to cucumber. To predict arsenate phytotoxicity in soils with a diverse range of soil solution properties, both carbonate and phosphate were required. The relationship between arsenic and pore-water toxicity parameters was established initially using multiple regression. In addition, based on the relationship with carbonate and phosphate we successively applied a terrestrial biotic ligand-like model (BLM) including carbonate and phosphate. Estimated effective concentrations from the BLM-like parametrization were strongly correlated to measured arsenate values in pore-water (R 2 = 0.76, P soils.

  8. Characteristics of copper-clad aluminum rods prepared by horizontal continuous casting

    Science.gov (United States)

    Zhang, Yubo; Fu, Ying; Jie, Jinchuan; Wu, Li; Svynarenko, Kateryna; Guo, Qingtao; Li, Tingju; Wang, Tongmin

    2017-11-01

    An innovative horizontal continuous casting method was developed and successfully used to prepare copper-clad aluminum (CCA) rods with a diameter of 85 mm and a sheath thickness of 16 mm. The solidification structure and element distribution near the interface of the CCA ingots were investigated by means of a scanning electron microscope, an energy dispersive spectrometer, and an electron probe X-ray microanalyzer. The results showed that the proposed process can lead to a good metallurgical bond between Cu and Al. The interface between Cu and Al was a multilayered structure with a thickness of 200 μm, consisting of Cu9Al4, CuAl2, α-Al/CuAl2 eutectic, and α-Al + α-Al/CuAl2 eutectic layers from the Cu side to the Al side. The mean tensile-shear strength of the CCA sample was 45 MPa, which fulfills the requirements for the further extrusion process. The bonding and diffusion mechanisms are also discussed in this paper.

  9. Arsenates of rare-metals: electrometric investigations on praseodymium arsenates as a function of pH

    Energy Technology Data Exchange (ETDEWEB)

    Prasad, S [Paraiba Univ., Joao Pessoa (Brazil). Dept. de Engenharia Quimica

    1982-01-01

    The stoichiometry of the compounds formed by the interaction of praseodymium chloride and different alkali arsenates (meta, pyro and ortho) at specific pH levels - 7.2, 8.3 and 11.1 - was investigated by electrometric techniques involving pH measurements and potentiometric and conductometric titrations. The inflections and breaks in the titration curves provide evidence for the formation of three praseodymium arsenates having the molecular formulae Pr/sub 2/O/sub 3/.3 As/sub 2/O/sub 5/, 2Pr/sub 2/O/sub 3/.3As/sub 2/O/sub 5/ and Pr2O/sub 3/.As/sub 2/O/sub 5/ in the vicinity of pH 4.8, 5.8 and 7.0, respectively. Analysis of the compounds by conventional methods (gravimetric, as oxide, for praseodymium; iodometric for arsenic) substantiate the results of the electrometric study

  10. Simultaneous sequestration of uranyl and arsenate at the goethite/water interface

    International Nuclear Information System (INIS)

    Fang Yuan; Yawen Cai; Shitong Yang; Zhiyong Liu; Lanhua Chen; Yue Lang; Shuao Wang; Xiangke Wang; Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, Suzhou; North China Electric Power University, Beijing

    2017-01-01

    This study highlights the simultaneous sequestration of U(VI) and arsenate at the goethite/water interface. The uptake trends and speciation of these two components were related with molar arsenate/U(VI) ratio, solution pH, contact order and aging time. A metastable [UO_2(H_2AsO_4)_2·H_2O] was observed after 3 days and then this solid completely transformed into Na_2(UO_2AsO_4)_2·3H_2O after 7 days. The disodium ethylenediamine tetraacetate ligand gave rise to the complete dissolution of Na_2(UO_2AsO_4)_2·3H_2O phase and the release of U(VI) and arsenate back into the solution. The experimental findings facilitated us better comprehend the migration and fate of coexisting U(VI) and arsenate in the aquatic environment. (author)

  11. Crystal structure and vibrational spectra of melaminium arsenate

    Science.gov (United States)

    Anbalagan, G.; Marchewka, M. K.; Pawlus, K.; Kanagathara, N.

    2015-01-01

    The crystals of the new melaminium arsenate (MAS) [C3H7N6+ṡH2AsO4-] were obtained by the slow evaporation of an aqueous solution at room temperature. Single crystal X-ray diffraction analysis reveals that the crystal belongs to triclinic system with centro symmetric space group P-1. The crystals are built up from single protonated melaminium residues and single dissociated arsenate H2AsO4- anions. The protonated melaminium ring is almost planar. A combination of ionic and donor-acceptor hydrogen-bond interactions linking together the melaminium and arsenate residues forms a three-dimensional network. Vibrational spectroscopic analysis is reported on the basis of FT-IR and FT-Raman spectra recorded at room temperature. Hydrogen bonded network present in the crystal gives notable vibrational effect. DSC has also been performed for the crystal shows no phase transition in the studied temperature range (113-293 K).

  12. Effects of lead arsenate sprays on the fruit growth and sugar and acid contents in Natsudaidai (Citrus natsudaidai Hayata)

    Energy Technology Data Exchange (ETDEWEB)

    Kadoya, K; Kuraoka, T; Matsumoto, K

    1965-01-01

    The juice of the fruit of Citrus natsudaidai is characterized by high acidity. The acidity of the juice was most effectively reduced by treatment with lead arsenate spray at an early fruit growth stage when the acids were being most actively formed. The water-soluble organic acid content of leaves was not affected. The sugar content of the juice was increased by the treatment. The activity of phosphoenolpyruvate carboxylase was lowered in the vesicles of fruit sprayed with lead arsenate. It was also much depressed in the extracts from normal fruit when arsenic trioxide was added. Arsenic was detected in the vesicles of treated fruit. 15 references, 9 figures.

  13. Effects of Chronic Exposure to Sodium Arsenate on Kidney of Rats

    Directory of Open Access Journals (Sweden)

    Namdar Yousofvand

    2015-09-01

    Full Text Available Background: In the present study, histopathological effects of chronic exposure to sodium arsenate in drinkable water were studied on a quantity of organs of rat. Methods: Rats were divided into two groups, group I; served as control group, were main-tained on deionized drinkable water for 2 months, and group II; the study group were given 60 g/ml of sodium arsenate in deionized drinkable water for 2 months. Blood and urine samples from two groups of animals were collected under anesthesia and the animals were sacrificed under deep anesthesia (a-chloralose, 100 mg/kg, I.P. Their kidney, liver, aorta, and heart were dissected out and cleaned of surrounding connective tissue. The organs were kept in formaldehyde (10% for histopathologic examination. Serum and urine samples from two groups were collected and analyzed for arsenic level. Total quantity of arsenic in serum and urine of animal was measured through graphic furnace atomic absorption spectrometry (GF-AAS. Results:Examination with light microscopy did not show any visible structural changes in the aorta, myocardium, and liver of chronic arsenic treated animals.However, a significant effect was observed in the kidneys of chronic arsenic treated rats showing distinct changes in proxi-mal tubular cells. There was high concentration of arsenic in serum and urine of arsenic ex-posed animals (group II significantly (P<0.001. Conclusion:Swollen tubular cells in histopathologic study of kidney may suggest toxic effects of arsenic in the body.

  14. Evaluation of ferrolysis in arsenate adsorption on the paddy soil derived from an Oxisol.

    Science.gov (United States)

    Jiang, Jun; Dai, Zhaoxia; Sun, Rui; Zhao, Zhenjie; Dong, Ying; Hong, Zhineng; Xu, Renkou

    2017-07-01

    Iron oxides are dominant effective adsorbents for arsenate in iron oxide-rich variable charge soils. Oxisol-derived paddy soils undergo intensive ferrolysis, which results in high leaching and transformation of iron oxides. However, little information is available concerning the effect of ferrolysis on arsenate adsorption by paddy soil and parent Oxisol. In the present study, we examined the arsenate affinity of soils using arsenate adsorption/desorption isotherms, zeta potential, adsorption kinetics, pH effect and phosphate competition experiments. Results showed that ferrolysis in an alternating flooding-drying Oxisol-derived paddy soil resulted in a significant decrease of free iron oxides and increase of amorphous iron oxides in the surface and subsurface layers. There were more reactive sites exposed on amorphous than on crystalline iron oxides. Therefore, disproportionate ratios of arsenate adsorption capacities and contents of free iron oxides were observed in the studied Oxisols compared with paddy soils. The Gibbs free energy values corroborated that both electrostatic and non-electrostatic adsorption mechanisms contributed to the arsenate adsorption by bulk soils, and the kinetic adsorption data further suggested that the rate-limiting step was chemisorption. The zeta potential of soil colloids decreased after arsenate was adsorbed on the surfaces, forming inner-sphere complexes and thus transferring their negative charges to the soil particle surfaces. The adsorption/desorption isotherms showed that non-electrostatic adsorption was the main mechanism responsible for arsenate binding to the Oxisol and derived paddy soils, representing 91.42-94.65% of the adsorption capacities. Further studies revealed that arsenate adsorption was greatly inhibited by increasing suspension pH and incorporation of phosphate. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Rice-arsenate interactions in hydroponics: whole genome transcriptional analysis.

    Science.gov (United States)

    Norton, Gareth J; Lou-Hing, Daniel E; Meharg, Andrew A; Price, Adam H

    2008-01-01

    Rice (Oryza sativa) varieties that are arsenate-tolerant (Bala) and -sensitive (Azucena) were used to conduct a transcriptome analysis of the response of rice seedlings to sodium arsenate (AsV) in hydroponic solution. RNA extracted from the roots of three replicate experiments of plants grown for 1 week in phosphate-free nutrient with or without 13.3 muM AsV was used to challenge the Affymetrix (52K) GeneChip Rice Genome array. A total of 576 probe sets were significantly up-regulated at least 2-fold in both varieties, whereas 622 were down-regulated. Ontological classification is presented. As expected, a large number of transcription factors, stress proteins, and transporters demonstrated differential expression. Striking is the lack of response of classic oxidative stress-responsive genes or phytochelatin synthases/synthatases. However, the large number of responses from genes involved in glutathione synthesis, metabolism, and transport suggests that glutathione conjugation and arsenate methylation may be important biochemical responses to arsenate challenge. In this report, no attempt is made to dissect differences in the response of the tolerant and sensitive variety, but analysis in a companion article will link gene expression to the known tolerance loci available in the BalaxAzucena mapping population.

  16. Rice–arsenate interactions in hydroponics: whole genome transcriptional analysis

    Science.gov (United States)

    Norton, Gareth J.; Lou-Hing, Daniel E.; Meharg, Andrew A.; Price, Adam H.

    2008-01-01

    Rice (Oryza sativa) varieties that are arsenate-tolerant (Bala) and -sensitive (Azucena) were used to conduct a transcriptome analysis of the response of rice seedlings to sodium arsenate (AsV) in hydroponic solution. RNA extracted from the roots of three replicate experiments of plants grown for 1 week in phosphate-free nutrient with or without 13.3 μM AsV was used to challenge the Affymetrix (52K) GeneChip Rice Genome array. A total of 576 probe sets were significantly up-regulated at least 2-fold in both varieties, whereas 622 were down-regulated. Ontological classification is presented. As expected, a large number of transcription factors, stress proteins, and transporters demonstrated differential expression. Striking is the lack of response of classic oxidative stress-responsive genes or phytochelatin synthases/synthatases. However, the large number of responses from genes involved in glutathione synthesis, metabolism, and transport suggests that glutathione conjugation and arsenate methylation may be important biochemical responses to arsenate challenge. In this report, no attempt is made to dissect differences in the response of the tolerant and sensitive variety, but analysis in a companion article will link gene expression to the known tolerance loci available in the Bala×Azucena mapping population. PMID:18453530

  17. Efficient removal of chromate and arsenate from individual and mixed system by malachite nanoparticles

    International Nuclear Information System (INIS)

    Saikia, Jiban; Saha, Bedabrata; Das, Gopal

    2011-01-01

    Graphical abstract: Malachite nanoparticles of 100-150 nm, have been efficiently and for the first time used as an adsorbent for the removal of toxic arsenate and chromate in pH range 4-5. - Abstract: Malachite nanoparticles of 100-150 nm have been efficiently and for the first time used as an adsorbent for the removal of toxic arsenate and chromate. We report a high adsorption capacity for chromate and arsenate on malachite nanoparticle from both individual and mixed solution in pH ∼4-5. However, the adsorption efficiency decreases with the increase of solution pH. Batch studies revealed that initial pH, temperature, malachite nanoparticles dose and initial concentration of chromate and arsenate were important parameters for the adsorption process. Thermodynamic analysis showed that adsorption of chromate and arsenate on malachite nanoparticles is endothermic and spontaneous. The adsorption of these anions has also been investigated quantitatively with the help of adsorption kinetics, isotherm, and selectivity coefficient (K) analysis. The adsorption data for both chromate and arsenate were fitted well in Langmuir isotherm and preferentially followed the second order kinetics. The binding affinity of chromate is found to be slightly higher than arsenate in a competitive adsorption process which leads to the comparatively higher adsorption of chromate on malachite nanoparticles surface.

  18. Fate of Cu, Cr, and As during combustion of impregnated wood with and without peat additive

    Energy Technology Data Exchange (ETDEWEB)

    Karin Lundholm; Dan Bostroem; Anders Nordin; Andrei Shchukarev [Umeaa University, Umeaa (Sweden). Energy Technology and Thermal Process Chemistry

    2007-09-15

    The EU Directive on incineration of waste regulates the harmful emissions of particles and twelve toxic elements, including copper, chromium, and arsenic. Using a 15 kW pellets-fueled grate burner, experiments were performed to determine the fate of copper, chromium, and arsenic during combustion of chromate copper arsenate (CCA) preservative wood. The fate and speciation of copper, chromium, and arsenic were determined from analysis of the flue gas particles and the bottom ash using SEM-EDS, XRD, XPS, and ICP-AES. Chemical equilibrium model calculations were performed to interpret the experimental findings. The results revealed that about 5% copper, 15% chromium, and 60% arsenic were volatilized during combustion of pure CCA-wood, which is lower than predicted volatilization from the individual arsenic, chromium, and copper oxides. This is explained by the formation of more stable refractory complex oxide phases for which the stability trends and patterns are presented. When co-combusted with peat, an additional stabilization of these phases was obtained and thus a small but noteworthy decrease in volatilization of all three elements was observed. The major identified phases for all fuels were CuCrO{sub 2}(s), (Fe,Mg,Cu)(Cr,Fe,Al)O{sub 4}(s), Cr{sub 2}O{sub 3}(s), and Ca{sub 3}(AsO{sub 4}){sub 2}(s). Arsenic was also identified in the fine particles as KH{sub 2}AsO{sub 4}(s) and As{sub 2}O{sub 3}). A strong indication of hexavalent chromium in the form of K{sub 2}CrO{sub 4} or as a solid solution between K{sub 3}Na(CrO{sub 4}){sub 2} and K{sub 3}Na(SO{sub 4}){sub 2} was found in the fine particles. Good qualitative agreement was observed between experimental data and chemical equilibrium model calculations. 38 refs., 6 figs., 2 tabs.

  19. A Novel Multilayer Correlation Maximization Model for Improving CCA-Based Frequency Recognition in SSVEP Brain-Computer Interface.

    Science.gov (United States)

    Jiao, Yong; Zhang, Yu; Wang, Yu; Wang, Bei; Jin, Jing; Wang, Xingyu

    2018-05-01

    Multiset canonical correlation analysis (MsetCCA) has been successfully applied to optimize the reference signals by extracting common features from multiple sets of electroencephalogram (EEG) for steady-state visual evoked potential (SSVEP) recognition in brain-computer interface application. To avoid extracting the possible noise components as common features, this study proposes a sophisticated extension of MsetCCA, called multilayer correlation maximization (MCM) model for further improving SSVEP recognition accuracy. MCM combines advantages of both CCA and MsetCCA by carrying out three layers of correlation maximization processes. The first layer is to extract the stimulus frequency-related information in using CCA between EEG samples and sine-cosine reference signals. The second layer is to learn reference signals by extracting the common features with MsetCCA. The third layer is to re-optimize the reference signals set in using CCA with sine-cosine reference signals again. Experimental study is implemented to validate effectiveness of the proposed MCM model in comparison with the standard CCA and MsetCCA algorithms. Superior performance of MCM demonstrates its promising potential for the development of an improved SSVEP-based brain-computer interface.

  20. Coprecipitation of arsenate with metal oxides. 3. Nature, mineralogy, and reactivity of iron(III)-aluminum precipitates.

    Science.gov (United States)

    Violante, Antonio; Pigna, Massimo; Del Gaudio, Stefania; Cozzolino, Vincenza; Banerjee, Dipanjan

    2009-03-01

    Coprecipitation involving arsenic with aluminum or iron has been studied because this technique is considered particularly efficient for removal of this toxic element from polluted waters. Coprecipitation of arsenic with mixed iron-aluminum solutions has received scant attention. In this work we studied (i)the mineralogy, surface properties, and chemical composition of mixed iron-aluminum oxides formed at initial Fe/Al molar ratio of 1.0 in the absence or presence of arsenate [As/ Fe+Al molar ratio (R) of 0, 0.01, or 0.1] and at pH 4.0, 7.0, and 10.0 and aged for 30 and 210 days at 50 degrees C and (ii) the removal of arsenate from the coprecipitates after addition of phosphate. The amounts of short-range ordered precipitates (ferrihydrite, aluminous ferrihydrite and/or poorly crystalline boehmite) were greater than those found in iron and aluminum systems (studied in previous works), due to the capacity of both aluminum and arsenate to retard or inhibitthe transformation of the initially formed precipitates into well-crystallized oxides (gibbsite, bayerite, and hematite). As a consequence, the surface areas of the iron-aluminum oxides formed in the absence or presence of arsenate were usually much larger than those of aluminum or iron oxides formed under the same conditions. Arsenate was found to be associated mainly into short-range ordered materials. Chemical composition of all samples was affected by pH, initial R, and aging. Phosphate sorption was facilitated by the presence of short-range ordered materials, mainly those richer in aluminum, but was inhibited by arsenate present in the samples. The quantities of arsenate replaced by phosphate, expressed as percentages of its total amount present in the samples, were particularly low, ranging from 10% to 26%. A comparison of the desorption of arsenate by phosphate from aluminum-arsenate and iron-arsenate (studied in previous works) and iron-aluminum-arsenate coprecipitates evidenced that phosphate has a greater

  1. Studies on the lanthanum arsenate ion-exchanger: preparation, physicochemical properties and applications

    International Nuclear Information System (INIS)

    Mukherjee, A.K.; Mandal, S.K.

    1984-01-01

    The cation-exchange behaviour of lanthanum arsenate has been studied. This paper reports the preparation and physicochemical properties of the exchanger. Its analytical utility is compared with that of other arsenate exchangers. Some practical analytical applications are described. (author)

  2. Processing and Characterisation of the Copper Treated Polylactic Acid and Cotton Fabrics: Thermophysiological Comfort Properties

    Directory of Open Access Journals (Sweden)

    Muhammet UZUN

    2014-04-01

    Full Text Available The main objective of this study is to develop a novel copper treatment method and characterise the effect of treatment on the thermophysiological comfort properties of the treated fabrics. It is also aimed to analyse and evaluate the thermophysiological properties of the PLA fabrics. The study was conducted by using polylactic acid (PLA, cotton and their blend yarns. The knitted fabrics, single pique, were made from these yarns by using weft knitting machine. The fabrics were treated with two copper solution concentrations (5 % and 10 % at 20 minutes ultrasonic energy. The results show that the treatment has a critical effect on the tested fabrics in terms of thermal conductivity, thermal resistance, thermal absorbtivity, water vapour permeability, and heat loss. The results also clearly demonstrated that the PLA fabric was successfully treated with the copper solution, and the coated fabrics showed significant change as compared to their untreated counterparts in terms of tested parameters.DOI: http://dx.doi.org/10.5755/j01.ms.20.1.1853

  3. Efficient removal of chromate and arsenate from individual and mixed system by malachite nanoparticles.

    Science.gov (United States)

    Saikia, Jiban; Saha, Bedabrata; Das, Gopal

    2011-02-15

    Malachite nanoparticles of 100-150 nm have been efficiently and for the first time used as an adsorbent for the removal of toxic arsenate and chromate. We report a high adsorption capacity for chromate and arsenate on malachite nanoparticle from both individual and mixed solution in pH ∼4-5. However, the adsorption efficiency decreases with the increase of solution pH. Batch studies revealed that initial pH, temperature, malachite nanoparticles dose and initial concentration of chromate and arsenate were important parameters for the adsorption process. Thermodynamic analysis showed that adsorption of chromate and arsenate on malachite nanoparticles is endothermic and spontaneous. The adsorption of these anions has also been investigated quantitatively with the help of adsorption kinetics, isotherm, and selectivity coefficient (K) analysis. The adsorption data for both chromate and arsenate were fitted well in Langmuir isotherm and preferentially followed the second order kinetics. The binding affinity of chromate is found to be slightly higher than arsenate in a competitive adsorption process which leads to the comparatively higher adsorption of chromate on malachite nanoparticles surface. Copyright © 2010 Elsevier B.V. All rights reserved.

  4. Formation of iron (hydr)oxides during the abiotic oxidation of Fe(II) in the presence of arsenate.

    Science.gov (United States)

    Song, Jia; Jia, Shao-Yi; Yu, Bo; Wu, Song-Hai; Han, Xu

    2015-08-30

    Abiotic oxidation of Fe(II) is a common pathway in the formation of Fe (hydr)oxides under natural conditions, however, little is known regarding the presence of arsenate on this process. In hence, the effect of arsenate on the precipitation of Fe (hydr)oxides during the oxidation of Fe(II) is investigated. Formation of arsenic-containing Fe (hydr)oxides is constrained by pH and molar ratios of As:Fe during the oxidation Fe(II). At pH 6.0, arsenate inhibits the formation of lepidocrocite and goethite, while favors the formation of ferric arsenate with the increasing As:Fe ratio. At pH 7.0, arsenate promotes the formation of hollow-structured Fe (hydr)oxides containing arsenate, as the As:Fe ratio reaches 0.07. Arsenate effectively inhibits the formation of magnetite at pH 8.0 even at As:Fe ratio of 0.01, while favors the formation of lepidocrocite and green rust, which can be latterly degenerated and replaced by ferric arsenate with the increasing As:Fe ratio. This study indicates that arsenate and low pH value favor the slow growth of dense-structured Fe (hydr)oxides like spherical ferric arsenate. With the rapid oxidation rate of Fe(II) at high pH, ferric (hydr)oxides prefer to precipitate in the formation of loose-structured Fe (hydr)oxides like lepidocrocite and green rust. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. Simultaneous removal of perchlorate and arsenate by ion-exchange media modified with nanostructured iron (hydr)oxide

    Energy Technology Data Exchange (ETDEWEB)

    Hristovski, Kiril [Environmental Technology Laboratory, Arizona State University, 6075 S. WMS Campus Loop W, Mesa, AZ 85212 (United States)], E-mail: kiril.hristovski@asu.edu; Westerhoff, Paul [Department of Civil and Environmental Engineering, Arizona State University, Box 5306, Tempe, AZ 85287-5306 (United States)], E-mail: p.westerhoff@asu.edu; Moeller, Teresia [SolmeteX Inc., 50 Bearfoot Road, Northborough, MA 01532 (United States)], E-mail: tmoller@solmetex.com; Sylvester, Paul [SolmeteX Inc., 50 Bearfoot Road, Northborough, MA 01532 (United States)], E-mail: psylvester@solmetex.com; Condit, Wendy [Battelle, 505 King Avenue, Columbus, OH 43201 (United States)], E-mail: conditw@battelle.org; Mash, Heath [United States Environmental Protection Agency, 26W. Martin Luther King Dr., Cincinnati, OH 45268 (United States)], E-mail: mash.heath@epa.gov

    2008-03-21

    Hybrid ion-exchange (HIX) media for simultaneous removal of arsenate and perchlorate were prepared by impregnation of non-crystalline iron (hydr)oxide nanoparticles onto strong base ion-exchange (IX) resins using two different chemical treatment techniques. In situ precipitation of Fe(III) (M treatment) resulted in the formation of sphere-like clusters of nanomaterials with diameters of {approx}5 nm, while KMnO{sub 4}/Fe(II) treatments yielded rod-like nanomaterials with diameters of 10-50 nm inside the pores of the media. The iron content of most HIX media was >10% of dry weight. The HIX media prepared via the M treatment method consistently exhibited greater arsenate adsorption capacity. The fitted Freundlich adsorption intensity parameters (q=KxC{sub E}{sup 1/n}) for arsenate (1/n < 0.6) indicated favorable adsorption trends. The K values ranged between 2.5 and 34.7 mgAs/g dry resin and were generally higher for the M treated media in comparison to the permanganate treated media. The separation factors for perchlorate over chloride ({alpha}{sub Cl{sup -}}{sup ClO{sub 4}{sup -}}) for the HIX media were lower than its untreated counterparts. The HIX prepared via the M treatment, had higher {alpha}{sub Cl{sup -}}{sup ClO{sub 4}{sup -}} than the HIX obtained by the KMnO{sub 4}/Fe(II) treatments suggesting that permanganate may adversely impact the ion-exchange base media. Short bed adsorber (SBA) tests demonstrated that the mass transport kinetics for both ions are adequately rapid to permit simultaneous removal using HIX media in a fixed bed reactor.

  6. Adsorption of arsenate on Cu/Mg/Fe/La layered double hydroxide from aqueous solutions

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Yanwei [State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, Shanghai 200092 (China); Zhu, Zhiliang, E-mail: zzl@tongji.edu.cn [State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, Shanghai 200092 (China); Qiu, Yanling [Key Laboratory of Yangtze River Water Environment, Ministry of Education, Tongji University, Shanghai 200092 (China); Zhao, Jianfu [State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, Shanghai 200092 (China)

    2012-11-15

    Highlights: Black-Right-Pointing-Pointer A novel layered double hydroxide containing lanthanum (Cu/Mg/Fe/La-LDH) has been synthesized. Black-Right-Pointing-Pointer The average pore size of the materials with about 16 nm indicated that the mesoporous structures existed in the Cu/Mg/Fe/La-LDHs. Black-Right-Pointing-Pointer The adsorption capacity of As(V) increased with the increment of La{sup 3+} content in the LDH. Black-Right-Pointing-Pointer The maximum adsorption capacity of the synthesized Cu/Mg/Fe/La-LDH for arsenate was 43.5 mg/g. - Abstract: A novel layered double hydroxide containing lanthanum (Cu/Mg/Fe/La-LDH) has been synthesized and used for the removal of arsenate from aqueous solutions. The purpose of incorporation of La{sup 3+} into LDHs was tried to enhance the uptake efficiency of arsenate and broaden the application field of LDHs functional materials. Effects of various physico-chemical factors such as solution pH, adsorbent dosage, contact time and initial arsenate concentrations on the adsorption of arsenate onto Cu/Mg/Fe/La-LDH were investigated. Results showed that the removal efficiency of arsenate increased with the increment of the lanthanum content in Cu/Mg/Fe/La-LDH adsorbents, and the optimized lanthanum content was 20% of the total trivalent metals composition (Fe{sup 3+} and La{sup 3+}). The adsorption isotherms can be well described by Langmuir equation, and the adsorption kinetics of arsenate followed the pseudo-second-order kinetic model. Coexistent ions such as HPO{sub 4}{sup 2-}, CO{sub 3}{sup 2-}, SO{sub 4}{sup 2-}, Cl{sup -} and NO{sub 3}{sup -} exhibited obvious competition with arsenate for the adsorption on Cu/Mg/Fe/La-LDH. The solution pH significantly affected the removal efficiency, which was closely related to the change of arsenate species distribution under different pH conditions. The predominant adsorption mechanism can be mainly attributed to the processes including ion exchange and layer ligand exchange.

  7. Adsorption of arsenate on Cu/Mg/Fe/La layered double hydroxide from aqueous solutions

    International Nuclear Information System (INIS)

    Guo, Yanwei; Zhu, Zhiliang; Qiu, Yanling; Zhao, Jianfu

    2012-01-01

    Highlights: ► A novel layered double hydroxide containing lanthanum (Cu/Mg/Fe/La-LDH) has been synthesized. ► The average pore size of the materials with about 16 nm indicated that the mesoporous structures existed in the Cu/Mg/Fe/La-LDHs. ► The adsorption capacity of As(V) increased with the increment of La 3+ content in the LDH. ► The maximum adsorption capacity of the synthesized Cu/Mg/Fe/La-LDH for arsenate was 43.5 mg/g. - Abstract: A novel layered double hydroxide containing lanthanum (Cu/Mg/Fe/La-LDH) has been synthesized and used for the removal of arsenate from aqueous solutions. The purpose of incorporation of La 3+ into LDHs was tried to enhance the uptake efficiency of arsenate and broaden the application field of LDHs functional materials. Effects of various physico-chemical factors such as solution pH, adsorbent dosage, contact time and initial arsenate concentrations on the adsorption of arsenate onto Cu/Mg/Fe/La-LDH were investigated. Results showed that the removal efficiency of arsenate increased with the increment of the lanthanum content in Cu/Mg/Fe/La-LDH adsorbents, and the optimized lanthanum content was 20% of the total trivalent metals composition (Fe 3+ and La 3+ ). The adsorption isotherms can be well described by Langmuir equation, and the adsorption kinetics of arsenate followed the pseudo-second-order kinetic model. Coexistent ions such as HPO 4 2− , CO 3 2− , SO 4 2− , Cl − and NO 3 − exhibited obvious competition with arsenate for the adsorption on Cu/Mg/Fe/La-LDH. The solution pH significantly affected the removal efficiency, which was closely related to the change of arsenate species distribution under different pH conditions. The predominant adsorption mechanism can be mainly attributed to the processes including ion exchange and layer ligand exchange.

  8. Evaluation of Strength Characteristics of Laterized Concrete with Corn Cob Ash (CCA) Blended Cement

    Science.gov (United States)

    Ikponmwosa, E. E.; Salau, M. A.; Kaigama, W. B.

    2015-11-01

    Agricultural wastes are dumped in landfills or left on land in which they constitute nuisance. This study presents the results of investigation of strength characteristics of reinforced laterized concrete beams with cement partially replaced with corn cob (agricultural wastes) ash (CCA). Laterized concrete specimen of 25% laterite and 75% sharp sand were made by blending cement with corn cob ash at 0 to 40% in steps of 10%. A concrete mix ratio of 1:2:4 was used to cast 54 cubes of 150×150×150mm size and 54 beams of dimension 750×150×150mm. The results show that the consistency and setting time of cement increased as the percentage replacement of cement with CCA increased while the workability and density of concrete decreased as the percentage of CCA increased. There was a decrease in compressive strength when laterite was introduced to the concrete from 25.04 to 22.96N/mm2 after 28 days and a continual reduction in strength when CCA was further added from 10% to 40% at steps of 10%. Generally, the beam specimens exhibited majorly shear failure with visible diagonal cracks extending from support points to the load points. The corresponding central deflection in beams, due to two points loading, increased as the laterite was added to the concrete mix but reduced and almost approaching that of the control as 10% CCA was added. The deflection then increased as the CCA content further increased to 20%, 30% and 40% in the mix. It was also noted that the deflection of all percentage replacement including 40% CCA is less than the standard recommended maximum deflection of the beam. The optimal flexural strength occurred with 10% CCA content.

  9. Removal of Arsenic from Wastewaters by Airlift Electrocoagulation: Part 3: Copper Smelter Wastewater Treatment

    DEFF Research Database (Denmark)

    Hansen, H.K.; Ottosen, Lisbeth M.

    2010-01-01

    The arsenic content in wastewater is of major concern for copper smelters. A typical complex wastewater treatment is needed with a combination of chemical and physical processes. Electrocoagulation (EC) has shown its potential for arsenic removal due to the formation of ferric hydroxide-arsenate ...... threshold value for wastewater discharge could rapidly be reached when the conventional method did not clean the wastewater sufficiently....

  10. Amino-functionalized MCM-41 and MCM-48 for the removal of chromate and arsenate.

    Science.gov (United States)

    Benhamou, A; Basly, J P; Baudu, M; Derriche, Z; Hamacha, R

    2013-08-15

    The aim of the present work was to investigate the efficiency of three amino-functionalized (hexadecylamine, dodecylamine, and dimethyldodecylamine) mesoporous silicas (MCM-41 and MCM-48) toward the adsorption of arsenate and chromate. Hexadecylamine-functionalized materials were characterized; BET surface areas, pore volumes, and sizes decreased with the functionalization, whereas XRD patterns show that the hexagonal structure of MCM-41 and the cubic structure of MCM-48 were not modified. The zeta potential decreases with pH and the highest arsenate and chromate removal was observed at the lowest pHs. Adsorption of chromium and arsenate was significantly enhanced after functionalization and amino-functionalized MCM-41 adsorb larger amounts of arsenate when compared to expanded MCM-48 materials. Chromate sorption capacities increased with the chain length and the larger capacities were obtained with hexadecylamine-functionalized mesoporous silicas. Mesoporous silicas modified by dimethyldodecylamine exhibited the higher arsenate sorption capacities. Copyright © 2013 Elsevier Inc. All rights reserved.

  11. 2D-3D Face Recognition Method Basedon a Modified CCA-PCA Algorithm

    Directory of Open Access Journals (Sweden)

    Patrik Kamencay

    2014-03-01

    Full Text Available This paper presents a proposed methodology for face recognition based on an information theory approach to coding and decoding face images. In this paper, we propose a 2D-3D face-matching method based on a principal component analysis (PCA algorithm using canonical correlation analysis (CCA to learn the mapping between a 2D face image and 3D face data. This method makes it possible to match a 2D face image with enrolled 3D face data. Our proposed fusion algorithm is based on the PCA method, which is applied to extract base features. PCA feature-level fusion requires the extraction of different features from the source data before features are merged together. Experimental results on the TEXAS face image database have shown that the classification and recognition results based on the modified CCA-PCA method are superior to those based on the CCA method. Testing the 2D-3D face match results gave a recognition rate for the CCA method of a quite poor 55% while the modified CCA method based on PCA-level fusion achieved a very good recognition score of 85%.

  12. Efficient KDM-CCA Secure Public-Key Encryption via Auxiliary-Input Authenticated Encryption

    Directory of Open Access Journals (Sweden)

    Shuai Han

    2017-01-01

    Full Text Available KDM[F]-CCA security of public-key encryption (PKE ensures the privacy of key-dependent messages f(sk which are closely related to the secret key sk, where f∈F, even if the adversary is allowed to make decryption queries. In this paper, we study the design of KDM-CCA secure PKE. To this end, we develop a new primitive named Auxiliary-Input Authenticated Encryption (AIAE. For AIAE, we introduce two related-key attack (RKA security notions, including IND-RKA and weak-INT-RKA. We present a generic construction of AIAE from tag-based hash proof system (HPS and one-time secure authenticated encryption (AE and give an instantiation of AIAE under the Decisional Diffie-Hellman (DDH assumption. Using AIAE as an essential building block, we give two constructions of efficient KDM-CCA secure PKE based on the DDH and the Decisional Composite Residuosity (DCR assumptions. Specifically, (i our first PKE construction is the first one achieving KDM[Faff]-CCA security for the set of affine functions and compactness of ciphertexts simultaneously. (ii Our second PKE construction is the first one achieving KDM[Fpolyd]-CCA security for the set of polynomial functions and almost compactness of ciphertexts simultaneously. Our PKE constructions are very efficient; in particular, they are pairing-free and NIZK-free.

  13. Production of bio-oil with low contents of copper and chlorine by fast pyrolysis of alkaline copper quaternary-treated wood in a fluidized bed reactor

    International Nuclear Information System (INIS)

    Koo, Won-Mo; Jung, Su-Hwa; Kim, Joo-Sik

    2014-01-01

    Fast pyrolysis of ACQ (alkaline copper quaternary)-treated wood was carried out in a bench-scale pyrolysis plant equipped with a fluidized bed reactor and char separation system. This study focused on the production of a bio-oil with low copper and chlorine contents, especially by adopting the fractional condensation of bio-oil using water condensers, an impact separator and an electrostatic precipitator. In addition, various analytical tools were applied to investigate the physicochemical properties of the pyrolysis products and the behavior of the preservative during pyrolysis. The bio-oil yield was maximized at 63.7 wt% at a pyrolysis temperature of 411 °C. Highly water-soluble holocellulose-derived components such as acetic acid and hydroxyacetone were mainly collected by the condensers, while lignin-derived components and levoglucosan were mainly observed in the oils collected by the impact separator and electrostatic precipitator. All the bio-oils produced in the experiments were almost free of copper and chlorine. Most copper in ACQ was transferred into the char. - Highlights: • ACQ(alkaline copper quaternary)-treated wood was successfully pyrolyzed in a bench-scale fluidized bed. • Bio-oils separately collected were different in their characteristics. • Bio-oils were free of didecyldimethylammonium chloride. • Bio oils were almost free of copper and chlorine. • The concentration of levoglucosan in a bio-oil was 24–31 wt%

  14. In vitro bioaccessibility of copper azole following simulated dermal transfer from pressure-treated wood

    Data.gov (United States)

    U.S. Environmental Protection Agency — In vitro bioaccessibility of copper azole following simulated dermal transfer from pressure-treated wood. This dataset is associated with the following publication:...

  15. PRESERVAÇÃO DE MADEIRAS NO BRASIL: HISTÓRICO, CENÁRIO ATUAL E TENDÊNCIAS

    Directory of Open Access Journals (Sweden)

    Jackson Marcelo Vidal

    2015-01-01

    Full Text Available The objective of this paper was to show a comprehensive literature review about wood preservation in Brazil, since the earliest years until 2011. Brazil is rich in natural resources and wood has always occurred in abundance. With the industrial growing, there was the necessity of using wood with low natural durability but with chemical preservative treatment. Wood chemical treatment began in late XIX century, mainly to attend the big demand of sleepers to railroads. Only during the 60’s, wood preservation gained market with the increase of scientific researches, elaboration of technical standards and building industrial plants for wood preservation. From this point on, few advances have been reached. In 2011, Eucalyptus and Pinus, were the main species used in wood preservation plants that adopts the vacuum-pressure process. In small production scale, diffusion process is adopted. Copper chromium arsenate (CCA and Copper chromium borate (CCB are the most preservatives utilised with some creosote utilisation. The treatedwood production is concentrated in fence posts, poles and sleepers. As a trend, the wood preservation must reach new markets, such as building constructions, wood packages and crossarms, and also to intensify the traditional uses. Although there are a lot of researches about chemicals for wood preservation, CCA must keep by the years, once alternative products do not present the same efficacy or clear effects about human health and environment.

  16. Composition and solubility of precipitated copper(II) arsenates

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, Hanna; Shchukarev, Andrey; Sjoeberg, Staffan [Department of Chemistry, Umea University, SE-901 87 Umea (Sweden); Loevgren, Lars, E-mail: lars.lovgren@chem.umu.se [Department of Chemistry, Umea University, SE-901 87 Umea (Sweden)

    2011-05-15

    Research Highlights: > By mixing solutions of Cu{sup 2+} and HAsO{sub 4}{sup 2-} solid phases are formed in a wide pH range. > Five different stoichiometric compositions were found. > Two of the solid phases formed in 0.1 M NaCl contained Na{sup +}. > Stability constants for all solid phases have been determined. > Aqueous complexes containing Cu{sup 2+} and AsO{sub 4}{sup 3-} ions could not be detected. - Abstract: Equilibrium reactions involving Cu(II) and As(V) have been studied with respect to formation of complexes in aqueous solutions as well as formation of solid phases. Potentiometric titrations performed at 25 deg. C (I = 0.1 M Na(Cl)) and at different Cu to As ratios gave no evidence for the existence of Cu(II) arsenate complexes in solution below the pH of the precipitation boundaries (pH {approx} 4), irrespective of the Cu to As ratio and pH. Mixing of solutions of Cu(II) and As(V) at different proportions and adjusting pH to values ranging from 4 to 9 resulted in precipitation of five different solid phases. The elemental composition of the solids was determined using X-ray Photoelectron Spectroscopy, and Environmental Scanning Microscopy-Field Emission Gun equipped with an energy dispersive spectroscopy detector. The average Cu/As ratio was determined by dissolving the solids. Total soluble concentrations of the components Cu(II) and As(V), as well as the basicity of the solid phases were determined by analysis of aqueous solutions. Based upon these experimental data the stoichiometric composition of the solid phases and their stability were determined. The resulting equilibrium model includes the solid phases Cu{sub 3}(AsO{sub 4}){sub 2}, Cu{sub 3}(AsO{sub 4})(OH){sub 3}, Cu{sub 2}(AsO{sub 4})(OH), Cu{sub 5}Na(HAsO{sub 4})(AsO{sub 4}){sub 3} and Cu{sub 5}Na{sub 2}AsO{sub 4}){sub 4}, where Cu{sub 5}Na(HAsO{sub 4})(AsO{sub 4}){sub 3} and Cu{sub 5}Na{sub 2}(AsO{sub 4}){sub 4} have not been reported previously. In 0.1 M Na(Cl), Na{sup +} was found to be

  17. Adsorption of arsenate on soils. Part 1: Laboratory batch experiments using 16 Chinese soils with different physiochemical properties

    International Nuclear Information System (INIS)

    Jiang Wei; Zhang Shuzhen; Shan Xiaoquan; Feng Muhua; Zhu Yongguan; McLaren, Ron G.

    2005-01-01

    Laboratory batch experiments were carried out to study the adsorption of arsenate on 16 Chinese soils with different physicochemical properties. Wide differences in arsenate adsorption were observed, and the Jiangxi and Hubei soils were more effective sorbents for arsenate than other soils. The Langmuir one-surface and two-surface equations were used to model the arsenate adsorption data. Except for the Jiangxi and Hubei soils, the Langmuir one-surface equation gave reasonably good fits to the arsenate adsorption data. However, the Langmuir two-surface equation generally provided a better fit than the Langmuir one-surface equation. For soils with relative high organic matter (OM), dissolved organic carbon (DOC) or extractable phosphate, the Langmuir one-surface and two-surface equations described the adsorption isotherms similarly. In contrast, for soils with relatively low contents of OM, DOC or extractable phosphate, the Langmuir two-surface equation gave the better fit to the arsenate adsorption data. - The Langmuir two-surface equation fits arsenate adsorption onto soils

  18. Hepatoprotective effects of hexane root extract of Alchornea laxiflora in sodium arsenate toxicity in wistar albino rats

    Directory of Open Access Journals (Sweden)

    Esosa Samuel Uhunmwangho

    2018-01-01

    Full Text Available Background: Medicinal plants are have been used in the treatment of myriad disease conditions, Alchornea laxiflora is one of such medicinal plant. Aim: To investigate the hepatoprotective effect of hexane root extract of Alchornea laxiflora against sodium arsenate induced liver damage in wistar male rats. Setting and Design: Extraction and administration of bioactive extract. Materials and Methods: Extraction of air-dried ground root of Alchornea laxiflora was done by extracting 500 g with 500 cm of 95% hexane for 72 hrs.The animals (120-150 g were pre-treated with the extract at varying doses (0.1, 0.5, 1.0, 10, 50 and 100 mg/kg body weight for seven days orally prior to the intra-peritoneal administration of the toxicant (sodium arsenate at a dose of 2 mg/kg body weight at the eight day. Hepatoprotective activity of the extracts was evaluated by studying the Cytochrome b5content, Glutathione-S-transferase and 4- Nitroanisole-o-demethylase activities in the liver, Plasma levels of Alanine aminotransferase (AST, Alanine aminotransferase (ALT, Alkaline phosphatase (ALP and the levels of Total protein, Albumin, Globulin and Glutathione of the various groups. Statistical Analysis: The data were analysed with Microsoft excels (for windows 2007 and Student t-test and ANOVA. Result and Conclusion: The results suggest that pre-treatment of rats with hexane root extract of Alchornea laxiflora for seven days reduced the elevated levels of liver enzymes, reduced the levels of induced liver metabolizing enzymes and the levels of Total protein, Albumin, Globulin and Glutathione that was increased by the toxicity of sodium arsenate in rats and as such possess hepatoprotective effect against sodium arsenate.

  19. Arsenate tolerance in Silene paradoxa does not rely on phytochelatin-dependent sequestration

    International Nuclear Information System (INIS)

    Arnetoli, Miluscia; Vooijs, Riet; Bookum, Wilma ten; Galardi, Francesca; Gonnelli, Cristina; Gabbrielli, Roberto; Schat, Henk; Verkleij, Jos A.C.

    2008-01-01

    Arsenate tolerance, As accumulation and As-induced phytochelatin accumulation were compared in populations of Silene paradoxa, one from a mine site enriched in As, Cu and Zn, the other from an uncontaminated site. The mine population was significantly more arsenate-tolerant. Arsenate uptake and root-to-shoot transport were slightly but significantly higher in the non-mine plants. The difference in uptake was quantitatively insufficient to explain the difference in tolerance between the populations. As accumulation in the roots was similar in both populations, but the mine plants accumulated much less phytochelatins than the non-mine plants. The mean phytochelatin chain length, however, was higher in the mine population, possibly due to a constitutively lower cellular glutathione level. It is argued that the mine plants must possess an arsenic detoxification mechanism other than arsenate reduction and subsequent phytochelatin-based sequestration. This alternative mechanism might explain at least some part of the superior tolerance in the mine plants. - Neither decreased uptake nor phytochelatins seem to play a role in the As tolerance in Silene paradoxa

  20. Absorption and translocation of arsenate arsenic by coffee plants

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, J F; Yamaguchi, S

    1964-01-01

    Studies on arsenate arsenic absorption and translocation in coffee plants were carried out using arsenic-77 applied either to leaves or to roots through the nutrient solution. The youngest leaves were unable to export arsenic and only an acropetal movement in the transpiration stream was observed. From the second pair of leaves, it moved into the growing leaves. From the fourth pair it moved downward through the stem and into the roots. Roots absorbed high amounts of arsenate once absorbed it moved via the xylem of the transpiration stream into the leaves. 7 references, 2 figures.

  1. Modeling Banking, Sovereign, and Macro Risk in a CCA Global VAR

    OpenAIRE

    Dale F. Gray

    2013-01-01

    The purpose of this paper is to develop a model framework for the analysis of interactions between banking sector risk, sovereign risk, corporate sector risk, real economic activity, and credit growth for 15 European countries and the United States. It is an integrated macroeconomic systemic risk model framework that draws on the advantages of forward-looking contingent claims analysis (CCA) risk indicators for the banking systems in each country, forward-looking CCA risk indicators for sover...

  2. Transformation and Release of Micronized Cu Used as a Wood Preservative in Treated Wood in Wetland Soil.

    Science.gov (United States)

    Micronized Cu (µ-Cu) is used as a wood preservative, replacing toxic Chromated Copper Arsenates. Micronized Cu is Malachite [Cu2CO3(OH)2] that has been milled to micron/submicron particles, many with diameters less than 100 nm, and then mixed with quat or azol biocides. I...

  3. Developing multi-cellular tumor spheroid model (MCTS) in the chitosan/collagen/alginate (CCA) fibrous scaffold for anticancer drug screening

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jian-Zheng, E-mail: wppzheng@126.com [Laboratory of Biomedical Material Engineering, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023 (China); Affiliated General Hospital, Tianguan Group Co., Ltd, Nanyang 473000 (China); Testing Center of Henan Tianguan Group Co., Ltd, Nanyang 473000 (China); Zhu, Yu-Xia [Laboratory of Biomedical Material Engineering, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023 (China); Affiliated General Hospital, Tianguan Group Co., Ltd, Nanyang 473000 (China); Testing Center of Henan Tianguan Group Co., Ltd, Nanyang 473000 (China); Ma, Hui-Chao; Chen, Si-Nan; Chao, Ji-Ye; Ruan, Wen-Ding; Wang, Duo; Du, Feng-guang [Affiliated General Hospital, Tianguan Group Co., Ltd, Nanyang 473000 (China); Testing Center of Henan Tianguan Group Co., Ltd, Nanyang 473000 (China); Meng, Yue-Zhong [State Key Laboratory of Optoelectronic Materials and Technologies, Sun Yat-sen University, Guangzhou 510275 (China)

    2016-05-01

    In this work, a 3D MCTS-CCA system was constructed by culturing multi-cellular tumor spheroid (MCTS) in the chitosan/collagen/alginate (CCA) fibrous scaffold for anticancer drug screening. The CCA scaffolds were fabricated by spray-spinning. The interactions between the components of the spray-spun fibers were evidenced by methods of Coomassie Blue stain, X-ray diffraction (XRD) and Fourier transform-infrared spectroscopy (FTIR). Co-culture indicated that MCF-7 cells showed a spatial growth pattern of multi-cellular tumor spheroid (MCTS) in the CCA fibrous scaffold with increased proliferation rate and drug-resistance to MMC, ADM and 5-Aza comparing with the 2D culture cells. Significant increases of total viable cells were found in 3D MCTS groups after drug administration by method of apoptotic analysis. Glucose–lactate analysis indicated that the metabolism of MCTS in CCA scaffold was closer to the tumor issue in vivo than the monolayer cells. In addition, MCTS showed the characteristic of epithelial mesenchymal transition (EMT) which is subverted by carcinoma cells to facilitate metastatic spread. These results demonstrated that MCTS in CCA scaffold possessed a more conservative phenotype of tumor than monolayer cells, and anticancer drug screening in 3D MCTS-CCA system might be superior to the 2D culture system. - Highlights: • Chitosan/collagen/alginate (CCA) scaffolds were fabricated by spray-spinning. • MCF-7 cells presented a multi-cellular tumor spheroid model (MCTS) in CCA scaffold. • MCTS in CCA possessed a more conservative phenotype of tumor than monolayer cells. • Anticancer drug screening in MCTS-CCA system is superior to 2D culture system.

  4. Developing multi-cellular tumor spheroid model (MCTS) in the chitosan/collagen/alginate (CCA) fibrous scaffold for anticancer drug screening

    International Nuclear Information System (INIS)

    Wang, Jian-Zheng; Zhu, Yu-Xia; Ma, Hui-Chao; Chen, Si-Nan; Chao, Ji-Ye; Ruan, Wen-Ding; Wang, Duo; Du, Feng-guang; Meng, Yue-Zhong

    2016-01-01

    In this work, a 3D MCTS-CCA system was constructed by culturing multi-cellular tumor spheroid (MCTS) in the chitosan/collagen/alginate (CCA) fibrous scaffold for anticancer drug screening. The CCA scaffolds were fabricated by spray-spinning. The interactions between the components of the spray-spun fibers were evidenced by methods of Coomassie Blue stain, X-ray diffraction (XRD) and Fourier transform-infrared spectroscopy (FTIR). Co-culture indicated that MCF-7 cells showed a spatial growth pattern of multi-cellular tumor spheroid (MCTS) in the CCA fibrous scaffold with increased proliferation rate and drug-resistance to MMC, ADM and 5-Aza comparing with the 2D culture cells. Significant increases of total viable cells were found in 3D MCTS groups after drug administration by method of apoptotic analysis. Glucose–lactate analysis indicated that the metabolism of MCTS in CCA scaffold was closer to the tumor issue in vivo than the monolayer cells. In addition, MCTS showed the characteristic of epithelial mesenchymal transition (EMT) which is subverted by carcinoma cells to facilitate metastatic spread. These results demonstrated that MCTS in CCA scaffold possessed a more conservative phenotype of tumor than monolayer cells, and anticancer drug screening in 3D MCTS-CCA system might be superior to the 2D culture system. - Highlights: • Chitosan/collagen/alginate (CCA) scaffolds were fabricated by spray-spinning. • MCF-7 cells presented a multi-cellular tumor spheroid model (MCTS) in CCA scaffold. • MCTS in CCA possessed a more conservative phenotype of tumor than monolayer cells. • Anticancer drug screening in MCTS-CCA system is superior to 2D culture system.

  5. X-ray graphical and thermodynamical study of mercury arsenates

    International Nuclear Information System (INIS)

    Makitova, G. Zh.; Mustafin, E. S.; Kasenov, B. K.

    1999-01-01

    Purposes of the work are both determination of lattice parameters on the base of X-ray graphical data and experimental study of thermal conduction dependence of mercury arsenates Hg(AsO 3 ) 2 and Hg 3 (AsO 4 ) 2 . In this work for the first time the parameters of elementary cell thermal conduction in the range 298.15-625 K were determined. Formation of equilibrium contents of mercury arsenates was confirmed by X-ray phase analysis conducted on DRON-2,0 unit under Cu K - radiation. Curves of thermal-differential analysis show, that Hg(AsO 3 ) 2 and Hg 3 (AsO 4 ) 2 melting incongruently, relatively at 725 and 790 grad C. Displaying of X-ray- grammars of examined compounds have been conducted by homology method. On the base the displaying parameter of lattice crystallization were determined. Further arsenates were exposed to calorimetric research for determination of its thermal conduction. It is shown, that Hg 3 (AsO 4 ) 2 thermal conduction has maximum at 448 K and then it value is go down at 473 K and then smoothly increasing. It was supposed, such behavior is related with second kind phase transformation

  6. Transgenic plants expressing GLK1 and CCA1 having increased nitrogen assimilation capacity

    Science.gov (United States)

    Coruzzi, Gloria [New York, NY; Gutierrez, Rodrigo A [Santiago, CL; Nero, Damion C [Woodside, NY

    2012-04-10

    Provided herein are compositions and methods for producing transgenic plants. In specific embodiments, transgenic plants comprise a construct comprising a polynucleotide encoding CCA1, GLK1 or bZIP1, operably linked to a plant-specific promote, wherein the CCA1, GLK1 or bZIP1 is ectopically overexpressed in the transgenic plants, and wherein the promoter is optionally a constitutive or inducible promoter. In other embodiments, transgenic plants in which express a lower level of CCA1, GLK1 or bZIP1 are provided. Also provided herein are commercial products (e.g., pulp, paper, paper products, or lumber) derived from the transgenic plants (e.g., transgenic trees) produced using the methods provided herein.

  7. A creative therapy in treating cavernous hemangioma of penis with copper wire.

    Science.gov (United States)

    Zhang, Dong; Zhang, Haiyang; Sun, Peng; Li, Peng; Xue, Aibing; Jin, Xunbo

    2014-10-01

    Cavernous hemangiomas of penis are rare benign lesions infrequently described in the literature. No completely satisfactory treatment has been found to correct the cosmetic deformities especially the extensive hemangiomas of corpus penis. In light of the promising application of copper wire/needle in vascular malformations, we began a clinical study to investigate the safety, feasibility, and cosmetic effect of copper wire therapy in treating cavernous hemangioma of penis. Seven patients ranging in age from 12 to 32 years with penile cavernous hemangiomas entered our study from 2005 to 2011. All patients received treatments with percutaneous copper wires. Perioperative data including mean operation time, estimated blood loss, length of copper wire retention, and length of hospital stay were analyzed. All possible complications were noted, and cosmetic result was evaluated. Patients were followed up after discharge from the hospital. All operations were successful, and no obvious complications were observed. The patients were satisfied with the aesthetic results. Follow-up time ranged from 1 to 5 years. Recurrence was discovered in a patient with the largest lesion of corpus penis 2 months after the treatment. Secondary procedure was carried out with the same technique, and no lesions were found later. The shortage of studies on this topic prevented us from defining a therapeutic reference standard. The results of our study confirmed that copper wire therapy was a simple, safe, and useful option for penile cavernous hemangioma. © 2013 International Society for Sexual Medicine.

  8. RiArsB and RiMT-11: Two novel genes induced by arsenate in arbuscular mycorrhiza.

    Science.gov (United States)

    Maldonado-Mendoza, Ignacio E; Harrison, Maria J

    Plants associated with arbuscular mycorrhizal fungi (AMF) increase their tolerance to arsenic-polluted soils. This study aims to investigate the genes involved in the AMF molecular response to arsenic pollution. Genes encoding proteins involved in arsenic metabolism were identified and their expression assessed by PCR or RT-qPCR. The As-inducible gene GiArsA (R. irregularis ABC ATPase component of the ArsAB arsenite efflux pump) and two new genes, an arsenate/arsenite permease component of ArsAB (RiArsB) and a methyltransferase type 11 (RiMT-11) were induced when arsenate was added to two-compartment in vitro monoxenic cultures of R. irregularis-transformed carrot roots. RiArsB and RiMT-11 expression in extraradical hyphae in response to arsenate displayed maximum induction 4-6 h after addition of 350 μM arsenate. Their expression was also detected in colonized root tissues grown in pots, or in the root-fungus compartment of two-compartment in vitro systems. We used a Medicago truncatula double mutant (mtpt4/mtpt8) to demonstrate that RiMT-11 and RiArsB transcripts accumulate in response to the addition of arsenate but not in response to phosphate. These results suggest that these genes respond to arsenate addition regardless of non-functional Pi symbiotic transport, and that RiMT-11 may be involved in arsenate detoxification by methylation in AMF-colonized tissues. Copyright © 2017 British Mycological Society. All rights reserved.

  9. Focused Ion Beam Analysis of Banana Peel and Its Application for Arsenate Ion Removal

    Directory of Open Access Journals (Sweden)

    Jamil R. Memon

    2015-06-01

    Full Text Available Banana peel, a common fruit waste, has been investigated for its ability to remove arsenate ions from ground water as a function of pH, contact time, and initial metal ion concentration. Focused ion beam (FIB analysis revealed the internal morphology of the banana peels. Arsenate ions were entered into micropores of banana peel. pH was seen to have no effect on the sorption process. Retained species were eluted using 5 mL of 2 M H2SO4. The kinetics of sorption were observed to follow the pseudo first order rate equation. The sorption data followed Freundlich and D-R isotherms. The energy value obtained from the D-R isotherms indicated that the sorption was physical in nature for arsenate species. Our study has shown that banana peel has the ability to remove arsenate species from ground water samples.

  10. Focused ion beam analysis of banana peel and its application for arsenate ion removal

    International Nuclear Information System (INIS)

    Memon, J.R.

    2015-01-01

    Banana peel, a common fruit waste, has been investigated for its ability to remove arsenate ions from ground water as a function of pH, contact time, and initial metal ion concentration. Focused ion beam (FIB) analysis revealed the internal morphology of the banana peels. Arsenate ions were entered into micropores of banana peel. pH was seen to have no effect on the sorption process. Retained species were eluted using 5 mL of 2 M H/sub 2/SO/sub 4/. The kinetics of sorption were observed to follow the pseudo first order rate equation. The sorption data followed Freundlich and D-R isotherms. The energy value obtained from the D-R isotherms indicated that the sorption was physical in nature for arsenate species. Our study has shown that banana peel has the ability to remove arsenate species from ground water samples. (author)

  11. Competitive adsorption of arsenate and phosphate onto calcite; experimental results and modeling with CCM and CD-MUSIC

    DEFF Research Database (Denmark)

    Sø, Helle Ugilt; Postma, Dieke; Jakobsen, Rasmus

    2012-01-01

    The competitive adsorption of arsenate and phosphate onto calcite was studied in batch experiments using calcite-equilibrated solutions. The solutions had circum-neutral pH (7–8.3) and covered a wide span in the activity of Ca2+ and View the MathML source. The results show that the adsorption...... that adsorption of arsenate onto calcite is of minor importance in most groundwater aquifers, as phosphate is often present at concentration levels sufficient to significantly reduce arsenate adsorption. The CD-MUSIC model for calcite was used successfully to model adsorption of arsenate and phosphate separately...

  12. Accuracy of urine circulating cathodic antigen (CCA test for Schistosoma mansoni diagnosis in different settings of Côte d'Ivoire.

    Directory of Open Access Journals (Sweden)

    Jean T Coulibaly

    2011-11-01

    Full Text Available BACKGROUND: Promising results have been reported for a urine circulating cathodic antigen (CCA test for the diagnosis of Schistosoma mansoni. We assessed the accuracy of a commercially available CCA cassette test (designated CCA-A and an experimental formulation (CCA-B for S. mansoni diagnosis. METHODOLOGY: We conducted a cross-sectional survey in three settings of Côte d'Ivoire: settings A and B are endemic for S. mansoni, whereas S. haematobium co-exists in setting C. Overall, 446 children, aged 8-12 years, submitted multiple stool and urine samples. For S. mansoni diagnosis, stool samples were examined with triplicate Kato-Katz, whereas urine samples were tested with CCA-A. The first stool and urine samples were additionally subjected to an ether-concentration technique and CCA-B, respectively. Urine samples were examined for S. haematobium using a filtration method, and for microhematuria using Hemastix dipsticks. PRINCIPAL FINDINGS: Considering nine Kato-Katz as diagnostic 'gold' standard, the prevalence of S. mansoni in setting A, B and C was 32.9%, 53.1% and 91.8%, respectively. The sensitivity of triplicate Kato-Katz from the first stool and a single CCA-A test was 47.9% and 56.3% (setting A, 73.9% and 69.6% (setting B, and 94.2% and 89.6% (setting C. The respective sensitivity of a single CCA-B was 10.4%, 29.9% and 75.0%. The ether-concentration technique showed a low sensitivity for S. mansoni diagnosis (8.3-41.0%. The specificity of CCA-A was moderate (76.9-84.2%; CCA-B was high (96.7-100%. The likelihood of a CCA-A color reaction increased with higher S. mansoni fecal egg counts (odds ratio: 1.07, p<0.001. A concurrent S. haematobium infection or the presence of microhematuria did not influence the CCA-A test results for S. mansoni diagnosis. CONCLUSION/SIGNIFICANCE: CCA-A showed similar sensitivity than triplicate Kato-Katz for S. mansoni diagnosis with no cross-reactivity to S. haematobium and microhematuria. The low sensitivity

  13. Precursors for formation of copper selenide, indium selenide, copper indium diselenide, and/or copper indium gallium diselenide films

    Science.gov (United States)

    Curtis, Calvin J; Miedaner, Alexander; Van Hest, Maikel; Ginley, David S

    2014-11-04

    Liquid-based precursors for formation of Copper Selenide, Indium Selenide, Copper Indium Diselenide, and/or copper Indium Galium Diselenide include copper-organoselenides, particulate copper selenide suspensions, copper selenide ethylene diamine in liquid solvent, nanoparticulate indium selenide suspensions, and indium selenide ethylene diamine coordination compounds in solvent. These liquid-based precursors can be deposited in liquid form onto substrates and treated by rapid thermal processing to form crystalline copper selenide and indium selenide films.

  14. Systems approach identifies an organic nitrogen-responsive gene network that is regulated by the master clock control gene CCA1.

    Science.gov (United States)

    Gutiérrez, Rodrigo A; Stokes, Trevor L; Thum, Karen; Xu, Xiaodong; Obertello, Mariana; Katari, Manpreet S; Tanurdzic, Milos; Dean, Alexis; Nero, Damion C; McClung, C Robertson; Coruzzi, Gloria M

    2008-03-25

    Understanding how nutrients affect gene expression will help us to understand the mechanisms controlling plant growth and development as a function of nutrient availability. Nitrate has been shown to serve as a signal for the control of gene expression in Arabidopsis. There is also evidence, on a gene-by-gene basis, that downstream products of nitrogen (N) assimilation such as glutamate (Glu) or glutamine (Gln) might serve as signals of organic N status that in turn regulate gene expression. To identify genome-wide responses to such organic N signals, Arabidopsis seedlings were transiently treated with ammonium nitrate in the presence or absence of MSX, an inhibitor of glutamine synthetase, resulting in a block of Glu/Gln synthesis. Genes that responded to organic N were identified as those whose response to ammonium nitrate treatment was blocked in the presence of MSX. We showed that some genes previously identified to be regulated by nitrate are under the control of an organic N-metabolite. Using an integrated network model of molecular interactions, we uncovered a subnetwork regulated by organic N that included CCA1 and target genes involved in N-assimilation. We validated some of the predicted interactions and showed that regulation of the master clock control gene CCA1 by Glu or a Glu-derived metabolite in turn regulates the expression of key N-assimilatory genes. Phase response curve analysis shows that distinct N-metabolites can advance or delay the CCA1 phase. Regulation of CCA1 by organic N signals may represent a novel input mechanism for N-nutrients to affect plant circadian clock function.

  15. Fabrication and evolution of multilayer silver nanofilms for surface-enhanced Raman scattering sensing of arsenate

    Directory of Open Access Journals (Sweden)

    Li Jinwei

    2011-01-01

    Full Text Available Abstract Surface-enhanced Raman scattering (SERS has recently been investigated extensively for chemical and biomolecular sensing. Multilayer silver (Ag nanofilms deposited on glass slides by a simple electroless deposition process have been fabricated as active substrates (Ag/GL substrates for arsenate SERS sensing. The nanostructures and layer characteristics of the multilayer Ag films could be tuned by varying the concentrations of reactants (AgNO3/BuNH2 and reaction time. A Ag nanoparticles (AgNPs double-layer was formed by directly reducing Ag+ ions on the glass surfaces, while a top layer (3rd-layer of Ag dendrites was deposited on the double-layer by self-assembling AgNPs or AgNPs aggregates which had already formed in the suspension. The SERS spectra of arsenate showed that characteristic SERS bands of arsenate appear at approximately 780 and 420 cm-1, and the former possesses higher SERS intensity. By comparing the peak heights of the approximately 780 cm-1 band of the SERS spectra, the optimal Ag/GL substrate has been obtained for the most sensitive SERS sensing of arsenate. Using this optimal substrate, the limit of detection (LOD of arsenate was determined to be approximately 5 μg·l-1.

  16. Narrowing the Broader Autism Phenotype: A Study Using the Communication Checklist-Adult Version (CC-A)

    Science.gov (United States)

    Whitehouse, Andrew J. O.; Coon, Hilary; Miller, Judith; Salisbury, Bryanna; Bishop, Dorothy V. M.

    2010-01-01

    This study investigated whether the Communication Checklist-Adult (CC-A) could identify subtypes of social and communication dysfunction in autism probands and their parents. The CC-A is divided into subscales measuring linguistic ability as well as two aspects of social communication: the Pragmatic Skills subscale assesses the level of pragmatic…

  17. Role of the CCA bulge of prohead RNA of bacteriophage ø29 in DNA packaging.

    Science.gov (United States)

    Zhao, Wei; Morais, Marc C; Anderson, Dwight L; Jardine, Paul J; Grimes, Shelley

    2008-11-14

    The oligomeric ring of prohead RNA (pRNA) is an essential component of the ATP-driven DNA packaging motor of bacteriophage ø29. The A-helix of pRNA binds the DNA translocating ATPase gp16 (gene product 16) and the CCA bulge in this helix is essential for DNA packaging in vitro. Mutation of the bulge by base substitution or deletion showed that the size of the bulge, rather than its sequence, is primary in DNA packaging activity. Proheads reconstituted with CCA bulge mutant pRNAs bound the packaging ATPase gp16 and the packaging substrate DNA-gp3, although DNA translocation was not detected with several mutants. Prohead/bulge-mutant pRNA complexes with low packaging activity had a higher rate of ATP hydrolysis per base pair of DNA packaged than proheads with wild-type pRNA. Cryoelectron microscopy three-dimensional reconstruction of proheads reconstituted with a CCA deletion pRNA showed that the protruding pRNA spokes of the motor occupy a different position relative to the head when compared to particles with wild-type pRNA. Therefore, the CCA bulge seems to dictate the orientation of the pRNA spokes. The conformational changes observed for this mutant pRNA may affect gp16 conformation and/or subsequent ATPase-DNA interaction and, consequently, explain the decreased packaging activity observed for CCA mutants.

  18. kCCA Transformation-Based Radiometric Normalization of Multi-Temporal Satellite Images

    Directory of Open Access Journals (Sweden)

    Yang Bai

    2018-03-01

    Full Text Available Radiation normalization is an essential pre-processing step for generating high-quality satellite sequence images. However, most radiometric normalization methods are linear, and they cannot eliminate the regular nonlinear spectral differences. Here we introduce the well-established kernel canonical correlation analysis (kCCA into radiometric normalization for the first time to overcome this problem, which leads to a new kernel method. It can maximally reduce the image differences among multi-temporal images regardless of the imaging conditions and the reflectivity difference. It also perfectly eliminates the impact of nonlinear changes caused by seasonal variation of natural objects. Comparisons with the multivariate alteration detection (CCA-based normalization and the histogram matching, on Gaofen-1 (GF-1 data, indicate that the kCCA-based normalization can preserve more similarity and better correlation between an image-pair and effectively avoid the color error propagation. The proposed method not only builds the common scale or reference to make the radiometric consistency among GF-1 image sequences, but also highlights the interesting spectral changes while eliminates less interesting spectral changes. Our method enables the application of GF-1 data for change detection, land-use, land-cover change detection etc.

  19. Characterization of flue gas, fly ash, aerosol and deposit compositions as a function of waste composition and grate operation

    DEFF Research Database (Denmark)

    Pedersen, Anne Juul; Zeuthen, Frederik Jacob; Frandsen, Flemming

    2007-01-01

    The Danish strategy for waste management is still to increase recycling and on the same time to reduce the volume of land-filled waste, in order to avoid loss of resources, and waste incineration is an important part of this strategy. In 2004, 26 % of the total reported Danish waste production...... metals, was then mixed with the reference fuel in the individual test runs. The dedicated waste fractions comprised NaCl (road salt), batteries, automotive shredder waste, CCA (Copper-Chromate-Arsenate)-impregnated wood, PVC plastics, and (leather) shoes. Test runs with varying operational parameters, e...... times increase in concentration in fly ash compared to the reference experiments), and for Hg when firing batteries (10 times increase in concentration in fly ash). These observations were in consistence with an increased concentration of the respective elements in the specific waste fractions...

  20. Growth of copper-treated corn roots as affected by EDTA, IAA, succinic acid-2,2-dimethyl hydrazide, vitamins and potassium

    Energy Technology Data Exchange (ETDEWEB)

    Hunter, R; Welkie, G W

    1977-04-01

    Corn roots were treated for 1 hr in a modified Hoagland's solution containing 8 mg/l Cu/sup 2 +/ and either simultaneously or subsequently with various substances, in order to test theories of copper toxicity to roots. Post treatment with IAA, niacin amide, thiamin, or sucrose had no effect on subsequent growth. Addition of excess KCl and succinic acid-2,2-dimethyl hydrazide (an inhibitor of ethylene production) to the copper solution doubled average growth and increased recovery from 27 to 87%. A rinse with EDTA resulted in resumption of normal growth rates and 100% recovery if performed 1 hr after Cu treatment, but this effect was gradually lost in the following 6 to 12 hr. Copper toxicity was increasingly severe as pH of the Cu treating medium increased. Results are not consistent with any theory tested, but they do suggest there is an initial phase of copper-stress which lasts 3 to 6 hr, followed by plant reaction that results in irreversible cessation of growth.

  1. Developing multi-cellular tumor spheroid model (MCTS) in the chitosan/collagen/alginate (CCA) fibrous scaffold for anticancer drug screening.

    Science.gov (United States)

    Wang, Jian-Zheng; Zhu, Yu-Xia; Ma, Hui-Chao; Chen, Si-Nan; Chao, Ji-Ye; Ruan, Wen-Ding; Wang, Duo; Du, Feng-guang; Meng, Yue-Zhong

    2016-05-01

    In this work, a 3D MCTS-CCA system was constructed by culturing multi-cellular tumor spheroid (MCTS) in the chitosan/collagen/alginate (CCA) fibrous scaffold for anticancer drug screening. The CCA scaffolds were fabricated by spray-spinning. The interactions between the components of the spray-spun fibers were evidenced by methods of Coomassie Blue stain, X-ray diffraction (XRD) and Fourier transform-infrared spectroscopy (FTIR). Co-culture indicated that MCF-7 cells showed a spatial growth pattern of multi-cellular tumor spheroid (MCTS) in the CCA fibrous scaffold with increased proliferation rate and drug-resistance to MMC, ADM and 5-Aza comparing with the 2D culture cells. Significant increases of total viable cells were found in 3D MCTS groups after drug administration by method of apoptotic analysis. Glucose-lactate analysis indicated that the metabolism of MCTS in CCA scaffold was closer to the tumor issue in vivo than the monolayer cells. In addition, MCTS showed the characteristic of epithelial mesenchymal transition (EMT) which is subverted by carcinoma cells to facilitate metastatic spread. These results demonstrated that MCTS in CCA scaffold possessed a more conservative phenotype of tumor than monolayer cells, and anticancer drug screening in 3D MCTS-CCA system might be superior to the 2D culture system. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. Synchrotron based x-ray fluorescence microscopy confirms copper in the corrosion products of metals in contact with treated wood

    Science.gov (United States)

    Samuel L. Zelinka; Joseph E. Jakes; Grant T. Kirker; David Vine; Stefan Vogt

    2017-01-01

    Copper based waterborne wood preservatives are frequently used to extend the service life of wood products when subjected to frequent moisture exposure. While these copper based treatments protect the wood from fungal decay and insect attack, they increase the corrosion of metals embedded or in contact with the treated wood. Previous research has shown the most...

  3. CSMA/CCA: A Modified CSMA/CA Protocol Mitigating the Fairness Problem for IEEE 802.11 DCF

    Directory of Open Access Journals (Sweden)

    Wang Xin

    2006-01-01

    Full Text Available Carrier sense multiple access with collision avoidance (CSMA/CA has been adopted by the IEEE 802.11 standards for wireless local area networks (WLANs. Using a distributed coordination function (DCF, the CSMA/CA protocol reduces collisions and improves the overall throughput. To mitigate fairness issues arising with CSMA/CA, we develop a modified version that we term CSMA with copying collision avoidance (CSMA/CCA. A station in CSMA/CCA contends for the shared wireless medium by employing a binary exponential backoff similar to CSMA/CA. Different from CSMA/CA, CSMA/CCA copies the contention window (CW size piggybacked in the MAC header of an overheard data frame within its basic service set (BSS and updates its backoff counter according to the new CW size. Simulations carried out in several WLAN configurations illustrate that CSMA/CCA improves fairness relative to CSMA/CA and offers considerable advantages for deployment in the 802.11-standard-based WLANs.

  4. Arsenate removal by layered double hydroxides embedded into spherical polymer beads: Batch and column studies.

    Science.gov (United States)

    Nhat Ha, Ho Nguyen; Kim Phuong, Nguyen Thi; Boi An, Tran; Mai Tho, Nguyen Thi; Ngoc Thang, Tran; Quang Minh, Bui; Van Du, Cao

    2016-01-01

    In this study, the performance of poly(layered double hydroxides) [poly(LDHs)] beads as an adsorbent for arsenate removal from aqueous solution was investigated. The poly(LDHs) beads were prepared by immobilizing LDHs into spherical alginate/polyvinyl alcohol (PVA)-glutaraldehyde beads (spherical polymer beads). Batch adsorption studies were conducted to assess the effect of contact time, solution pH, initial arsenate concentrations and co-existing anions on arsenate removal performance. The potential reuse of these poly(LDHs) beads was also investigated. Approximately 79.1 to 91.2% of arsenic was removed from an arsenate solution (50 mg As L(-1)) by poly(LDHs). The adsorption data were well described by the pseudo-second-order kinetics model and the Langmuir isotherm model, and the adsorption capacities of these poly(LDHs) beads at pH 8 were from 1.64 to 1.73 mg As g(-1), as calculated from the Langmuir adsorption isotherm. The adsorption ability of the poly(LDHs) beads decreased by approximately 5-6% after 5 adsorption-desorption cycles. Phosphates markedly decreased arsenate removal. The effect of co-existing anions on the adsorption capacity declined in the following order: HPO4 (2-) > HCO3 (-) > SO4 (2-) > Cl(-). A fixed-bed column study was conducted with real-life arsenic-containing water. The breakthrough time was found to be from 7 to 10 h. Under optimized conditions, the poly(LDHs) removed more than 82% of total arsenic. The results obtained in this study will be useful for further extending the adsorbents to the field scale or for designing pilot plants in future studies. From the viewpoint of environmental friendliness, the poly(LDHs) beads are a potential cost-effective adsorbent for arsenate removal in water treatment.

  5. Adsorption of arsenate on soils. Part 2: Modeling the relationship between adsorption capacity and soil physiochemical properties using 16 Chinese soils

    International Nuclear Information System (INIS)

    Jiang Wei; Zhang, Shuzhen; Shan Xiaoquan; Feng Muhua; Zhu Yongguan; McLaren, Ron G.

    2005-01-01

    An attempt has been made to elucidate the effects of soil properties on arsenate adsorption by modeling the relationships between adsorption capacity and the properties of 16 Chinese soils. The model produced was validated against three Australian and three American soils. The results showed that nearly 93.8% of the variability in arsenate adsorption on the low-energy surface could be described by citrate-dithionite extractable Fe (Fe CD ), clay content, organic matter content (OM) and dissolved organic carbon (DOC); nearly 87.6% of the variability in arsenate adsorption on the high-energy surface could be described by Fe CD , DOC and total arsenic in soils. Fe CD exhibited the most important positive influence on arsenate adsorption. Oxalate extractable Al (Al OX ), citrate-dithionite extractable Al (Al CD ), extractable P and soil pH appeared relatively unimportant for adsorption of arsenate by soils. - Citrate-dithionite extractable Fe has the most important positive influence on arsenate adsorption on soils

  6. Protective role of vitamin C and E against sodium arsenate induced changes in developing kidney of albino mice

    International Nuclear Information System (INIS)

    Qureshi, F.; Tahir, M.; Sami, W.

    2009-01-01

    Background: Arsenic is a teratogenic agent present in the environment as oxides and arsenate and humans are exposed to it through contaminated drinking water, food, soil and air. This investigation was undertaken to evaluate protective role of Vitamin C and E against teratogenic injury produced by sodium arsenate in developing kidney of the mouse. Methods: Twenty-four pregnant albino mice of BALB/c strain, were randomly divided into 4 groups of 6 each: A1, A2, A3 and A4. Group A1 served as the control and received weight related distilled water by intra-peritoneal (I/P) injection, group A2 was given a single doses of 35 mg/kg on 8 GD whereas groups A3 and A4 were treated with Vitamin C and E by IP injection, 9 mg/kg/day and 15 mg/kg/day respectively, starting from 8 day and continued for the rest of the pregnancy period. The foetal kidneys were weighed and histological studies carried out including micrometry on different components of nephron. Results: Sodium arsenate toxicity manifested as an increase in weight of the kidneys, wider nephrogenic zone and significant reduction in the mean of number of mature renal corpuscles as compared to the control group (p<0.000). There were moderate to severe necrotic and degenerative changes in proximal and distal convoluted tubules; glomeruli were hyper cellular, the Bowman's spaces were obliterated. There was a statistically significant difference in mean diameter of renal corpuscles of group A2 when compared with groups A1, A3 and A4, (p<0.000). Conclusions: The findings implied that groups receiving Vitamin C and E along with sodium arsenate showed an overall improvement in all parameters, indicating the protective role of Vitamin C and E against arsenic induced teratogenicity in developing kidney and are safe to use during pregnancy without deleterious effect on human conspectuses in arsenic exposed areas. (author)

  7. Three-dimensional dynamic magnetic resonance angiography for the evaluation of radiosurgically treated cerebral arteriovenous malformations

    International Nuclear Information System (INIS)

    Gauvrit, Jean-Yves; Oppenheim, Catherine; Naggara, Olivier; Trystram, Denis; Fredy, Daniel; Meder, Jean-Francois; Nataf, Francois; Roux, Francois-Xavier; Munier, Thierry; Pruvo, Jean-Pierre; Leclerc, Xavier

    2006-01-01

    We assessed the value of three-dimensional (3D) dynamic magnetic resonance angiography (MRA) for the follow-up of patients with radiosurgically treated cerebral arteriovenous malformations (AVMs). Fifty-four patients with cerebral AVMs treated by radiosurgery (RS) were monitored using conventional catheter angiography (CCA) and 3D dynamic MRA with sensitivity encoding based on the parallel imaging. Cerebral AVM was qualitatively classified by two radiologists into one of five categories in terms of residual nidus size and persistence of early draining vein (I, >6 cm; II, 3-6 cm; III, <3 cm; IV, isolated early draining vein; V, complete obliteration). 3D MRA findings showed a good agreement with CCA in 40 cases (κ=0.62). Of 23 nidus detected on CCA, 3D dynamic MRA showed 14 residual nidus. Of 28 occluded nidus on 3D dynamic MRA, 22 nidus were occluded on CCA. The sensitivity and specificity of 3D dynamic MRA for the detection of residual AVM were 81% and 100%. 3D dynamic MRA after RS may therefore be useful in association with MRI and can be repeated as long as opacification of the nidus or early venous drainage persists, one CCA remaining indispensable to affirm the complete occlusion at the end of follow-up. (orig.)

  8. Arsenate impact on the metabolite profile, production and arsenic loading of xylem sap in cucumbers (Cucumis sativus L.

    Directory of Open Access Journals (Sweden)

    Kalle eUroic

    2012-04-01

    Full Text Available Arsenic uptake and translocation studies on xylem sap focus generally on the concentration and speciation of arsenic in the xylem. Arsenic impact on the xylem sap metabolite profile and its production during short term exposure has not been reported in detail. To investigate this, cucumbers were grown hydroponically and arsenate (AsV and DMA were used for plant treatment for 24 h. Total arsenic and arsenic speciation in xylem sap was analysed including a metabolite profiling under arsenate stress. Produced xylem sap was quantified and absolute arsenic transported was determined. AsV exposure has a significant impact on the metabolite profile of xylem sap. Four m/z values corresponding to four compounds were up regulated, one compound down regulated by arsenate exposure. The compound down regulated was identified to be isoleucine. Furthermore, arsenate has a significant influence on sap production, leading to a reduction of up to 96 % sap production when plants are exposed to 1000 μg kg-1 arsenate. No difference to control plants was observed when plants were exposed to 1000 μg kg-1 DMA. Absolute arsenic amount in xylem sap was the lowest at high arsenate exposure. These results show that AsV has a significant impact on the production and metabolite profile of xylem sap. The physiological importance of isoleucine needs further attention.

  9. Uptake and biotransformation of arsenate in the lichen Hypogymnia physodes (L.) Nyl

    Energy Technology Data Exchange (ETDEWEB)

    Mrak, Tanja [Department of Environmental Sciences, Jozef Stefan Institute, Jamova 39, 1000 Ljubljana (Slovenia); Slejkovec, Zdenka [Department of Environmental Sciences, Jozef Stefan Institute, Jamova 39, 1000 Ljubljana (Slovenia)], E-mail: zdenka.slejkovec@ijs.si; Jeran, Zvonka; Jacimovic, Radojko [Department of Environmental Sciences, Jozef Stefan Institute, Jamova 39, 1000 Ljubljana (Slovenia); Kastelec, Damijana [Agronomy Department, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, 1000 Ljubljana (Slovenia)

    2008-01-15

    The uptake and metabolism of arsenate, As(V), as a function of time and concentration were examined in the lichen Hypogymnia physodes (L.) Nyl. Lichen thalli were exposed to As(V) in the form of a solution. Exponential uptake of As(V) from 4 {mu}g mL{sup -1} As(V) solution was accompanied by constant arsenite, As(III), excretion back into the solution. Arsenate taken up into the lichens from 0, 0.1, 1, 10 {mu}g mL{sup -1} As(V) solutions was partially transformed into As(III), dimethylarsinic acid (DMA) and (mono)methylarsonic acid (MA). 48 h after exposure, the main arsenic compound in the lichens was DMA in 0.1, As(III) in 1 and As(V) in 10 {mu}g mL{sup -1} treatment. The proportion of methylated arsenic compounds decreased with increasing arsenate concentration in the exposure solution. These results suggest that at least two types of As(V) detoxification exist in lichens; arsenite excretion and methylation. - Lichens are able to metabolize the inorganic arsenic taken up.

  10. Exogenous proline enhances the sensitivity of Tobacco BY-2 cells to arsenate.

    Science.gov (United States)

    Nahar, Mst Nur-E-Nazmun; Islam, Mohammad Muzahidul; Hoque, Md Anamul; Yonezawa, Anna; Prodhan, Md Yeasin; Nakamura, Toshiyuki; Nakamura, Yoshimasa; Munemasa, Shintaro; Murata, Yoshiyuki

    2017-09-01

    Arsenic causes physiological and structural disorders in plants. Proline is accumulated as a compatible solute in plants under various stress conditions and mitigates stresses. Here, we investigated the effects of exogenous proline on tobacco Bright Yellow-2 (BY-2) cultured cells under [Formula: see text] stress. Arsenate did not inhibit BY-2 cell growth at 40 and 50 μM but did it at 60 μM. Proline at 0.5 to 10 mM did not affect the cell growth but delayed it at 20 mM. At 40 μM [Formula: see text], neither 0.5 mM nor 1 mM proline affected the cell growth but 10 mM proline inhibited it. In the presence of [Formula: see text], 10 mM proline increased the number of Evans Blue-stained (dead) cells and decreased the number of total cells. Together, our results suggest that exogenous proline does not alleviate arsenate toxicity but enhances the sensitivity of BY-2 cells to arsenate.

  11. Uptake and biotransformation of arsenate in the lichen Hypogymnia physodes (L.) Nyl

    International Nuclear Information System (INIS)

    Mrak, Tanja; Slejkovec, Zdenka; Jeran, Zvonka; Jacimovic, Radojko; Kastelec, Damijana

    2008-01-01

    The uptake and metabolism of arsenate, As(V), as a function of time and concentration were examined in the lichen Hypogymnia physodes (L.) Nyl. Lichen thalli were exposed to As(V) in the form of a solution. Exponential uptake of As(V) from 4 μg mL -1 As(V) solution was accompanied by constant arsenite, As(III), excretion back into the solution. Arsenate taken up into the lichens from 0, 0.1, 1, 10 μg mL -1 As(V) solutions was partially transformed into As(III), dimethylarsinic acid (DMA) and (mono)methylarsonic acid (MA). 48 h after exposure, the main arsenic compound in the lichens was DMA in 0.1, As(III) in 1 and As(V) in 10 μg mL -1 treatment. The proportion of methylated arsenic compounds decreased with increasing arsenate concentration in the exposure solution. These results suggest that at least two types of As(V) detoxification exist in lichens; arsenite excretion and methylation. - Lichens are able to metabolize the inorganic arsenic taken up

  12. Sodium meta-arsenate for pH-metric determination of rare earth elements

    Energy Technology Data Exchange (ETDEWEB)

    Prasad, S [Paraiba Univ. (Brazil). Centro de Ciencias e Tecnologia, Dept. de Engenharia Quimica

    1981-01-01

    An accurate and rapid electrometric method for the determination of praseodymium and thorium as their meta-arsenates has been investigated. It consists in titrating praseodymium chloride and thorium nitrate solutions pH-metrically against a standard solution of sodium meta-arsenate, using a wide range glass electrode in conjunction with S.C.E. A marked change in pH is observed at the end-point corresponding to the precipitation of Pr(AsO/sub 3/)/sub 3/ and Th/sub 3/(AsO/sub 3/)/sub 4/ in the neighbourhood of pH 4.8 and 4.2, respectively. The curves have a regular form and a pronounced maximum in dpH/dV occurs at the end-point. The accuracy and reproducibility of the results have been found to be excellent even at low concentrations (5x10sup(-4)M) of the reactants. pH titration offers a simple, rapid and accurate method for the determination of praseodymium and thorium as their meta-arsenates. Similar titrations were also performed for estimation of samarium but they failed to provide any dependable results.

  13. Pentachlorophenol (PCP) sludge recycling unit

    International Nuclear Information System (INIS)

    1994-08-01

    The Guelph Utility Pole Company treats utility poles by immersion in pentachlorophenol (PCP) or by pressure treatment with chromated copper arsenate (CCA). The PCP treatment process involves a number of steps, each producing a certain amount of sludge and other wastes. In a plant upgrading program to improve processing and treatment of poles and to reduce and recycle waste, a PCP recovery unit was developed, first as an experimental pilot-scale unit and then as a full-scale unit. The PCP recovery unit is modular in design and can be modified to suit different requirements. In a recycling operation, the sludge is pumped through a preheat system (preheated by waste heat) and suspended solids are removed by a strainer. The sludge is then heated in a tank and at a predetermined temperature it begins to separate into its component parts: oil, steam, and solids. The steam condenses to water containing low amounts of light oil, and this water is pumped through an oil/water separator. The recovered oil is reused in the wood treatment process and the water is used in the CCA plant. The oil remaining in the tank is reused in PCP treatment and the solid waste, which includes small stones and wood particles, is removed and stored. By the third quarter of operation, the recovery unit was operating as designed, processing ca 10,000 gal of sludge. This sludge yielded 6,500 gal of water, 3,500 gal of oil, and ca 30 gal of solids. Introduction of the PCP sludge recycling system has eliminated long-term storage of PCP sludge and minimized costs of hazardous waste disposal. 4 figs

  14. Oxalic acid overproduction by copper-tolerant brown-rot basidiomycetes on southern yellow pine treated with copper-based preservatives

    Science.gov (United States)

    Carol A. Clausen; Frederick Green

    2003-01-01

    Accumulation of oxalic acid (OA) by brown-rot fungi and precipitation of copper oxalate crystals in wood decayed by copper-tolerant decay fungi has implicated OA in the mechanism of copper tolerance. Understanding the role of OA in copper tolerance is important due to an increasing reliance on copper-based wood preservatives. In this study, four copper-tolerant brown-...

  15. Music recommendation according to human motion based on kernel CCA-based relationship

    Science.gov (United States)

    Ohkushi, Hiroyuki; Ogawa, Takahiro; Haseyama, Miki

    2011-12-01

    In this article, a method for recommendation of music pieces according to human motions based on their kernel canonical correlation analysis (CCA)-based relationship is proposed. In order to perform the recommendation between different types of multimedia data, i.e., recommendation of music pieces from human motions, the proposed method tries to estimate their relationship. Specifically, the correlation based on kernel CCA is calculated as the relationship in our method. Since human motions and music pieces have various time lengths, it is necessary to calculate the correlation between time series having different lengths. Therefore, new kernel functions for human motions and music pieces, which can provide similarities between data that have different time lengths, are introduced into the calculation of the kernel CCA-based correlation. This approach effectively provides a solution to the conventional problem of not being able to calculate the correlation from multimedia data that have various time lengths. Therefore, the proposed method can perform accurate recommendation of best matched music pieces according to a target human motion from the obtained correlation. Experimental results are shown to verify the performance of the proposed method.

  16. Advancing Coordination Between DRM and CCA in Integrated Flood Risk Management

    DEFF Research Database (Denmark)

    Jebens, Martin; Sørensen, Carlo Sass

    Flood hazards in coastal regions induce risks toward lives, property, economy and the environment. In need of sustainable and holistic actions to reduce risks, these should include innovative Disaster Risk Management (DRM) and Climate Change Adaptation (CCA) measures. While differing on important...... flood events to exert pressure on the national government, and in a top-down approach the government could identify the needs among the civil society to include these in the decision-making process.......-structural measures is hampered by lack in coordination that should be improved to agree e.g. on an acceptable risk definition and to avoid duplicating efforts. To advance awareness and coordination between DRM and CCA and to improve measures, a bottom-up approach could by initiated by civil society using recent...

  17. Evaluation of circulating cathodic antigen (CCA strip for diagnosis of urinary schistosomiasis in Hassoba school children, Afar, Ethiopia

    Directory of Open Access Journals (Sweden)

    Ayele B.

    2008-03-01

    Full Text Available A total of 206 urine samples collected from Hassoba Elementary schoolchildren, Afar, Ethiopia, a low Schistosoma haematobium endemic setting, was diagnosed to evaluate the performance of CCA strip using double references, urine filtration technique and urinalysis dipstick (Combur 10 Test® that detect schistosome eggs and blood in urine, respectively. The former was used as a gold standard reference method. Sensitivity, specificity, positive and negative predictive values for the CCA were 52%, 63.8%, 56.7% and 59% respectively, with reference to urine filtration technique whereas these parameters were 50.4%, 62.4%, 55.6% and 57.5% respectively, with reference to Combur 10 Test®. 47 S. haematobium egg-positive children were found negative by CCA strip while 38 egg-negative children were found positive by CCA strip. Moreover, among the pre-tests done in duplicate, inconsistent results were also recorded. Assays were also compared with regard to the cost of equipment and reagents, speed and simplicity of use. Though CCA strip was found to be rapid and could be performed with minimal training, it was found to be expensive (US $ 4.95 per test to use it for large-scale field use even if its diagnostic value would have been satisfactory. Further development and standardization of the CCA strip are required for its applicability for field use. It is also recommended that its cost per strip should be substantially cut down if it is to be used in poor schistosomiasis endemic countries.

  18. Sorption and desorption of arsenate and arsenite on calcite

    DEFF Research Database (Denmark)

    Sø, Helle Ugilt; Postma, Diederik Jan; Jakobsen, Rasmus

    2008-01-01

    The adsorption and desorption of arsenate (As(V)) and arsenite (As(111)) oil calcite was investigated in a series of batch experiments in calcite-equilibrated solutions. The solutions covered a broad range of pH, alkalinity, calcium concentration and ionic strength. The initial arsenic...

  19. Chinese adaptation of Emotion Regulation Questionnaire for Children and Adolescents (ERQ-CCA): A psychometric evaluation in Chinese children.

    Science.gov (United States)

    Liu, Wen; Chen, Liang; Tu, Xintian

    2017-10-01

    This study validated a Chinese adaptation of the Emotion Regulation Questionnaire for Children and Adolescents (ERQ-CCA), a self-report instrument that evaluates two emotion regulation (ER) strategies, based on the process model of ER. The ERQ-CCA was evaluated using a sample of 1381 Chinese children aged between 7 and 12 years. The internal consistencies of the two factors indicated adequate reliability. Confirmatory factor analysis (CFA) revealed good support as the structure proved to be identical with that of the original instrument. Multigroup CFA supported an invariant factor solution of the ERQ-CCA across several demographic variations (gender, age, registered permanent residence and migrant status) in different groups. Test-retest correlations over a 2-month period were calculated using a subsample of children (N = 70). Convergent validity was evaluated in relation to the model dimensions of the ERQ-CCA, Chinese version of the Children's Depression Inventory, and Chinese version of the Eysenck Personality Questionnaire for Children and Adolescents. Results indicated that the ERQ-CCA has generally satisfactory reliability and validity in investigating the use of two ER strategies during the middle childhood developmental period. © 2015 International Union of Psychological Science.

  20. Solution structure of an arsenate reductase-related protein, YffB, from Brucella melitensis, the etiological agent responsible for brucellosis

    International Nuclear Information System (INIS)

    Buchko, Garry W.; Hewitt, Stephen N.; Napuli, Alberto J.; Van Voorhis, Wesley C.; Myler, Peter J.

    2011-01-01

    B. melitensis is a NIAID Category B microorganism that is responsible for brucellosis and is a potential agent for biological warfare. Here, the solution structure of the 116-residue arsenate reductase-related protein Bm-YffB (BR0369) from this organism is reported. Brucella melitensis is the etiological agent responsible for brucellosis. Present in the B. melitensis genome is a 116-residue protein related to arsenate reductases (Bm-YffB; BR0369). Arsenate reductases (ArsC) convert arsenate ion (H 2 AsO 4 − ), a compound that is toxic to bacteria, to arsenite ion (AsO 2 − ), a product that may be efficiently exported out of the cell. Consequently, Bm-YffB is a potential drug target because if arsenate reduction is the protein’s major biological function then disabling the cell’s ability to reduce arsenate would make these cells more sensitive to the deleterious effects of arsenate. Size-exclusion chromatography and NMR spectroscopy indicate that Bm-YffB is a monomer in solution. The solution structure of Bm-YffB shows that the protein consists of two domains: a four-stranded mixed β-sheet flanked by two α-helices on one side and an α-helical bundle. The α/β domain is characteristic of the fold of thioredoxin-like proteins and the overall structure is generally similar to those of known arsenate reductases despite the marginal sequence similarity. Chemical shift perturbation studies with 15 N-labeled Bm-YffB show that the protein binds reduced glutathione at a site adjacent to a region similar to the HX 3 CX 3 R catalytic sequence motif that is important for arsenic detoxification activity in the classical arsenate-reductase family of proteins. The latter observation supports the hypothesis that the ArsC-YffB family of proteins may function as glutathione-dependent thiol reductases. However, comparison of the structure of Bm-YffB with the structures of proteins from the classical ArsC family suggest that the mechanism and possibly the function of Bm

  1. Arsenite-oxidizing and arsenate-reducing bacteria associated with arsenic-rich groundwater in Taiwan

    Science.gov (United States)

    Liao, Vivian Hsiu-Chuan; Chu, Yu-Ju; Su, Yu-Chen; Hsiao, Sung-Yun; Wei, Chia-Cheng; Liu, Chen-Wuing; Liao, Chung-Min; Shen, Wei-Chiang; Chang, Fi-John

    2011-04-01

    Drinking highly arsenic-contaminated groundwater is a likely cause of blackfoot disease in Taiwan, but microorganisms that potentially control arsenic mobility in the subsurface remain unstudied. The objective of this study was to investigate the relevant arsenite-oxidizing and arsenate-reducing microbial community that exists in highly arsenic-contaminated groundwater in Taiwan. We cultured and identified arsenic-transforming bacteria, analyzed arsenic resistance and transformation, and determined the presence of genetic markers for arsenic transformation. In total, 11 arsenic-transforming bacterial strains with different colony morphologies and varying arsenic transformation abilities were isolated, including 10 facultative anaerobic arsenate-reducing bacteria and one strictly aerobic arsenite-oxidizing bacterium. All of the isolates exhibited high levels of arsenic resistance with minimum inhibitory concentrations of arsenic ranging from 2 to 200 mM. Strain AR-11 was able to rapidly oxidize arsenite to arsenate at concentrations relevant to environmental groundwater samples without the addition of any electron donors or acceptors. We provide evidence that arsenic-reduction activity may be conferred by the ars operon(s) that were not amplified by the designed primers currently in use. The 16S rRNA sequence analysis grouped the isolates into the following genera: Pseudomonas, Bacillus, Psychrobacter, Vibrio, Citrobacter, Enterobacter, and Bosea. Among these genera, we present the first report of the genus Psychrobacter being involved in arsenic reduction. Our results further support the hypothesis that bacteria capable of either oxidizing arsenite or reducing arsenate coexist and are ubiquitous in arsenic-contaminated groundwater.

  2. Biosorption of copper(II) and lead(II) onto potassium hydroxide treated pine cone powder.

    Science.gov (United States)

    Ofomaja, A E; Naidoo, E B; Modise, S J

    2010-08-01

    Pine cone powder surface was treated with potassium hydroxide and applied for copper(II) and lead(II) removal from solution. Isotherm experiments and desorption tests were conducted and kinetic analysis was performed with increasing temperatures. As solution pH increased, the biosorption capacity and the change in hydrogen ion concentration in solution increased. The change in hydrogen ion concentration for lead(II) biosorption was slightly higher than for copper(II) biosorption. The results revealed that ion-exchange is the main mechanism for biosorption for both metal ions. The pseudo-first order kinetic model was unable to describe the biosorption process throughout the effective biosorption period while the modified pseudo-first order kinetics gave a better fit but could not predict the experimentally observed equilibrium capacities. The pseudo-second order kinetics gave a better fit to the experimental data over the temperature range from 291 to 347 K and the equilibrium capacity increased from 15.73 to 19.22 mg g(-1) for copper(II) and from 23.74 to 26.27 for lead(II). Activation energy was higher for lead(II) (22.40 kJ mol(-1)) than for copper(II) (20.36 kJ mol(-1)). The free energy of activation was higher for lead(II) than for copper(II) and the values of DeltaH* and DeltaS* indicate that the contribution of reorientation to the activation stage is higher for lead(II) than copper(II). This implies that lead(II) biosorption is more spontaneous than copper(II) biosorption. Equilibrium studies showed that the Langmuir isotherm gave a better fit for the equilibrium data indicating monolayer coverage of the biosorbent surface. There was only a small interaction between metal ions when simultaneously biosorbed and cation competition was higher for the Cu-Pb system than for the Pb-Cu system. Desorption studies and the Dubinin-Radushkevich isotherm and energy parameter, E, also support the ion-exchange mechanism. Copyright 2010 Elsevier Ltd. All rights reserved.

  3. Potential Remobilization of Toxic Anions during Reduction of Arsenated and Chromated Schwertmannite by the Dissimilatory Fe(III)-Reducing Bacterium Acidiphilium cryptum JF-5

    International Nuclear Information System (INIS)

    Regenspurg, Simona; Goessner, Anita; Peiffer, Stefan; Kuesel, Kirsten

    2002-01-01

    Schwertmannite, an iron(III)-oxyhydroxysulfate formed in acidic mining-impacted stream or lake waters often contaminated with toxic elements like arsenate or chromate, is able to incorporate high amounts of these oxyanions. Detoxification of the water might be achieved if precipitated arsenated or chromated schwertmannite is fixed in the sediment. However, under reduced conditions, reductive dissolution of iron oxides mediated by the activity of Fe(III)-reducing bacteria might mobilize arsenate and chromate again. In this study, the reduction of synthesized arsenated or chromated schwertmannite by the acidophilic Fe(III)-reducer Acidiphilium cryptum JF-5, isolated from an acidic mining-impacted sediment, was investigated. In TSB medium at pH 2.7 with glucose as electron donor, A. cryptum JF-5 reduced about 10% of the total Fe(III) present in pure synthetic schwertmannite but only 5% of Fe(III) present in arsenated schwertmannite. In contrast to sulfate that was released during the reductive dissolution of pure schwertmannite, arsenate was not released during the reduction of arsenated schwertmannite probably due to the high surface complexation constant of arsenate and Fe(III). In medium containing chromated schwertmannite, no Fe(II) was formed, and no glucose was consumed indicating that chromate might have been toxic to cells of A. cryptum JF-5. Both As(V) or Cr(VI) could not be utilized as electron acceptor by A. cryptum JF-5. A comparison between autoclaved (121 o C for 20 min) and non-autoclaved schwertmannite samples demonstrated that nearly 100%of the bound sulfate was released during heating, and FTIR spectra indicated a transformation of schwertmannite to goethite. This structural change was not observed with autoclaved arsenated or chromated schwertmannite. These results suggest that the mobility of arsenate and chromate is not enhanced by the activity of acidophilic Fe(III)-reducing bacteria in mining-impacted sediments. In contrast, the presence of

  4. Arsenate Removal: Comparison of FSM-16 with Low Cost Modified Rice Husk

    International Nuclear Information System (INIS)

    Daifullah, A.A.M.

    2004-01-01

    The recently discovered meso porous molecular sieve FSM-16 was tested as an absorbent for arsenic (V) sorption from aqueous solutions. Its adsorption behavior was evaluated and compared with a low cost sorbent prepared from available agroresidue, rice husk, (boiled with 5% KOH followed by 10 % HCl). Factors affecting sorption of arsenate ions by the two sorbents (e.g., porosity, surface area of the sorbent, equilibrium time, adsorption rate, ph and temperature) were studied using ICP-MS for analysis. The data of adsorption of the two systems were described according to the S-Langmuir type according to the initial slope. The monolayer coverage was 92 and 68 mg/g for FSM-16 and modified rice husk (MRH),respectively, due to the silica content of the former is higher than the latter. The thermodynamic parameters were evaluated and indicated that this adsorption is endothermic process.It was found that the adsorptive capacity for arsenate using MRH represents 75% of that FSM-16. Therefore, the MRH is useful in the removal of arsenate ions due to its low cost, availability, and its good efficiency in this application and no need to be regenerated

  5. Mechanical properties of wood from Pinus sylvestris L. treated with Light Organic Solvent Preservative and with waterborne Copper Azole

    Directory of Open Access Journals (Sweden)

    A.M. Villasante

    2013-12-01

    Full Text Available Aim of study: To determine the effect on wood from Pinus sylvestris of treatment with preservatives on mechanical properties and to establish the relation between the penetration and compression strength.Area of study: SpainMaterial and Methods: 40 samples of defect-free wood from Pinus sylvestris L. were treated with Light Organic Solvent Preservative (Vacsol Azure WR 2601 and 50 with waterborne Copper Azole (Tanalith E 3492. 40 control samples were not treated (water or preservative. Mechanical resistance to static bending, modulus of elasticity and compression strength parallel to the grain were compared with untreated wood. Regression analysis between the penetration and compression strength parallel was done with the samples treated with waterborne preservative.Main results: The results indicate that the treated wood (with either product presents a statistically significant increase in mechanical resistance in all three mechanical characteristics. The results obtained differ from earlier studies carried out by other authors.There was no correlation between parallel compression strength and the degree of impregnation of the wood with waterborne Copper Azole . The most probable explanation for these results concerns changes in pressure during treatment.The use of untreated control samples instead of samples treated only with water is more likely to produce significant results in the mechanical resistance studies.Research highlights: Treated wood presents a statistically significant increase in MOE, modulus of rupture to static bending  and parallel compression strength.There was no correlation between parallel compression strength and the degree of impregnation with waterborne preservative.Keywords: Light Organic Solvent Preservative; MOE; parallel compression; static bending; waterborne Copper Azole; wood technology.

  6. Narrowing the broader autism phenotype: A study using the Communication Checklist - Adult Version (CC-A)

    OpenAIRE

    Whitehouse, AJ; Coon, H; Miller, J; Salisbury, B; Bishop, DV

    2010-01-01

    This study investigated whether the Communication Checklist – Adult (CC-A) could identify subtypes of social and communication dysfunction in autism probands and their parents. The CC-A is divided into subscales measuring linguistic ability as well as two aspects of social communication: the Pragmatic Skills subscale assesses the level of pragmatic oddities (e.g., excessive talking), while the Social Engagement subscale picks up on those behaviours that reflect a more passive communication st...

  7. Copper-silver ionization at a US hospital: interaction of treated ...

    Science.gov (United States)

    Tap water sampling and surface analysis of copper pipe/bathroom porcelain were performed to explore the fate of copper and silver during the first nine months of copper-silver ionization (CSI) applied to cold and hot water at a hospital in Cincinnati, Ohio. Ions dosed by CSI into the water at its point of entry to the hospital were inadvertently removed from hot water by a cation-exchange softener in one building (average removal of 72% copper and 51% silver). Copper at the tap was replenished from corrosion of the building’s copper pipes but was typically unable to reach 200 µg/L in first-draw and flushed hot and cold water samples. Unlike copper, silver solubility was not restricted by the incoming water’s high pH of 8.5. Cold water lines had >20 µg/L silver at most of the taps that were sampled, which further increased after flushing. However, silver plating onto copper pipe surfaces (particularly in the hot water line) prevented reaching 20 µg/L silver in hot water of many taps. Aesthetically displeasing purple/grey stains in bathroom porcelain were attributed to chlorargyrite [AgCl(s)], an insoluble precipitate that formed when CSI-dosed Ag+ ions combined with Cl- ions that were present in the incoming water. Overall, CSI aims to control Legionella bacteria in drinking water, but plumbing material interactions, aesthetics and other implications also deserve consideration to holistically evaluate in-building drinking water disinfection. To inform the

  8. Photoinduced Oxidation of Arsenite to Arsenate on Ferrihydrite

    Energy Technology Data Exchange (ETDEWEB)

    N Bhandari; R Reeder; D Strongin

    2011-12-31

    The photochemistry of an aqueous suspension of the iron oxyhydroxide, ferrihydrite, in the presence of arsenite has been investigated using attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR), X-ray absorption near edge structure (XANES), and solution phase analysis. Both ATR-FTIR and XANES show that the exposure of ferrihydrite to arsenite in the dark leads to no change in the As oxidation state, but the exposure of this arsenite-bearing surface, which is in contact with pH 5 water, to light leads to the conversion of the majority of the adsorbed arsenite to the As(V) bearing species, arsenate. Analysis of the solution phase shows that ferrous iron is released into solution during the oxidation of arsenite. The photochemical reaction, however, shows the characteristics of a self-terminating reaction in that there is a significant suppression of this redox chemistry before 10% of the total iron making up the ferrihydrite partitions into solution as ferrous iron. The self-terminating behavior exhibited by this photochemical arsenite/ferrihydrite system is likely due to the passivation of the ferrihydrite surface by the strongly bound arsenate product.

  9. PIXE study on absorption of arsenate and arsenite by arsenic hyperaccumulating fern (Pteris vittata)

    International Nuclear Information System (INIS)

    Yamazaki, H.; Ishii, K.; Matsuyama, S.

    2008-01-01

    Pytoremediation using an arsenic hyperaccumulator, Petris vittata L., has generated an increasing interest worldwide due to both environmentally sound and cost effectiveness. However the mechanism of arsenic accumulation by this fern is not clear at this time. This study examined the uptake of arsenate (As(V)) and arsenite (As(III)) by a hydroponic culture of Pteris vittata using both in-air submilli-PIXE for different parts of the fern and in-air micro-PIXE for the tissue cells. These PIXE analysis systems used 3 MeV proton beams from a 4.5-MV single-ended Dynamitron accelerator at Tohoku University, Japan. The fern took up both arsenate and arsenite from hydroponic solutions which were spiked with 50 mg of arsenic per litter. Final amount of arsenic accumulation in the fern is 1,500 mg per kg (wet weight) of the plant biomass in arsenite treatment and 1,100 mg per kg in arsenate treatment. Arsenic accumulation was not observed at the root parts of the ferns. The in-vivo mapping of elements by submilli-PIXE analyses on the fern laminas showed the arsenic accumulation in the edges of a pinna. The micro-PIXE analyses revealed arsenic maps homogeneously distributed in cells of the lamina, stem and rhizome of the fern. These results indicate that arsenic, both arsenate and arsenite in a contaminated medium are translocated quickly from roots to fronds of Pteris vittata, and distributes homogeneously into tissue cells of the fern laminas. (author)

  10. Phosphate and arsenate removal efficiency by thermostable ferritin enzyme from Pyrococcus furiosus using radioisotopes

    KAUST Repository

    Sevcenco, Ana-Maria

    2015-03-13

    Oxo-anion binding properties of the thermostable enzyme ferritin from Pyrococcus furiosus were characterized with radiography. Radioisotopes 32P and 76As present as oxoanions were used to measure the extent and the rate of their absorption by the ferritin. Thermostable ferritin proved to be an excellent system for rapid phosphate and arsenate removal from aqueous solutions down to residual concentrations at the picomolar level. These very low concentrations make thermostable ferritin a potential tool to considerably mitigate industrial biofouling by phosphate limitation or to remove arsenate from drinking water.

  11. Behavior of Eucalyptus urophylla and Eucalyptus citriodora Seedlings Grown in Soil Contaminated by Arsenate

    Directory of Open Access Journals (Sweden)

    Roseli Freire Melo

    2016-01-01

    Full Text Available ABSTRACT Persistent areas of tailings and deposits from coal and gold mining may present high levels of arsenic (As, mainly in the arsenate form, endangering the environment and human health. The establishment of vegetation cover is a key step to reclaiming these environments. Thus, this study aimed to evaluate the potential of Eucalyptus urophylla and E. citriodora seedlings for use in phytoremediation programs of arsenate-contaminated areas. Soil samples were incubated at increasing rates (0, 50, 100, 200 and 400 mg dm-3 of arsenic (arsenate form, using Na2HAsO4 for 15 days. The seedlings were produced in a substrate (vermiculite + sawdust and were transplanted to the pots with soil three months after seed germination. The values of plant height and diameter were taken during transplanting and 30, 60 and 90 days after transplanting. In the last evaluation, the total leaf area and biomass of shoots and roots were also determined. The values of available As in soil which caused a 50 % dry matter reduction (TS50%, the As translocation index (TI from the roots to the shoot of the plants, and its bioconcentration factor (BF were also calculated. Higher levels of arsenate in the soil significantly reduced the dry matter production of roots and shoots and the height of both species, most notably in E. urophylla plants. The highest levels of As were found in the root, with higher values for E. citriodora (ranging from 253.86 to 400 mg dm-3. The TI and BF were also reduced with As doses, but the values found in E. citriodora were significantly higher than in E. urophylla. E. citriodora plants presented a higher capacity to tolerate As and translocate it to the shoot than E. urophylla. Although these species cannot be considered as hyperaccumulators of As, E. citriodora presented the potential to be used in phytoremediation programs in arsenate-contaminated areas due to the long-term growth period of this species.

  12. Differential Pair Distribution Function Study of the Structure of Arsenate Adsorbed on Nanocrystalline [gamma]-Alumina

    Energy Technology Data Exchange (ETDEWEB)

    Li, Wei; Harrington, Richard; Tang, Yuanzhi; Kubicki, James D.; Aryanpour, Masoud; Reeder, Richard J.; Parise, John B.; Phillips, Brian L. (SBU); (Penn)

    2012-03-15

    Structural information is important for understanding surface adsorption mechanisms of contaminants on metal (hydr)oxides. In this work, a novel technique was employed to study the interfacial structure of arsenate oxyanions adsorbed on {gamma}-alumina nanoparticles, namely, differential pair distribution function (d-PDF) analysis of synchrotron X-ray total scattering. The d-PDF is the difference of properly normalized PDFs obtained for samples with and without arsenate adsorbed, otherwise identically prepared. The real space pattern contains information on atomic pair correlations between adsorbed arsenate and the atoms on {gamma}-alumina surface (Al, O, etc.). PDF results on the arsenate adsorption sample on {gamma}-alumina prepared at 1 mM As concentration and pH 5 revealed two peaks at 1.66 {angstrom} and 3.09 {angstrom}, corresponding to As-O and As-Al atomic pair correlations. This observation is consistent with those measured by extended X-ray absorption fine structure (EXAFS) spectroscopy, which suggests a first shell of As-O at 1.69 {+-} 0.01 {angstrom} with a coordination number of 4 and a second shell of As-Al at 3.13 {+-} 0.04 {angstrom} with a coordination number of 2. These results are in agreement with a bidentate binuclear coordination environment to the octahedral Al of {gamma}-alumina as predicted by density functional theory (DFT) calculation.

  13. Differential pair distribution function study of the structure of arsenate adsorbed on nanocrystalline γ-alumina.

    Science.gov (United States)

    Li, Wei; Harrington, Richard; Tang, Yuanzhi; Kubicki, James D; Aryanpour, Masoud; Reeder, Richard J; Parise, John B; Phillips, Brian L

    2011-11-15

    Structural information is important for understanding surface adsorption mechanisms of contaminants on metal (hydr)oxides. In this work, a novel technique was employed to study the interfacial structure of arsenate oxyanions adsorbed on γ-alumina nanoparticles, namely, differential pair distribution function (d-PDF) analysis of synchrotron X-ray total scattering. The d-PDF is the difference of properly normalized PDFs obtained for samples with and without arsenate adsorbed, otherwise identically prepared. The real space pattern contains information on atomic pair correlations between adsorbed arsenate and the atoms on γ-alumina surface (Al, O, etc.). PDF results on the arsenate adsorption sample on γ-alumina prepared at 1 mM As concentration and pH 5 revealed two peaks at 1.66 Å and 3.09 Å, corresponding to As-O and As-Al atomic pair correlations. This observation is consistent with those measured by extended X-ray absorption fine structure (EXAFS) spectroscopy, which suggests a first shell of As-O at 1.69 ± 0.01 Å with a coordination number of ~4 and a second shell of As-Al at ~3.13 ± 0.04 Å with a coordination number of ~2. These results are in agreement with a bidentate binuclear coordination environment to the octahedral Al of γ-alumina as predicted by density functional theory (DFT) calculation.

  14. Advancing Coordination Between DRM and CCA in Integrated Flood Risk Management

    DEFF Research Database (Denmark)

    Flood hazards in coastal regions induce risks toward lives, property, economy and the environment. In need of sustainable and holistic actions to reduce risks, these should include innovative Disaster Risk Management (DRM) and Climate Change Adaptation (CCA) measures. While differing on important...

  15. A SAM-dependent methyltransferase cotranscribed with arsenate reductase alters resistance to peptidyl transferase center-binding antibiotics in Azospirillum brasilense Sp7.

    Science.gov (United States)

    Singh, Sudhir; Singh, Chhaya; Tripathi, Anil Kumar

    2014-05-01

    The genome of Azospirillum brasilense harbors a gene encoding S-adenosylmethionine-dependent methyltransferase, which is located downstream of an arsenate reductase gene. Both genes are cotranscribed and translationally coupled. When they were cloned and expressed individually in an arsenate-sensitive strain of Escherichia coli, arsenate reductase conferred tolerance to arsenate; however, methyltransferase failed to do so. Sequence analysis revealed that methyltransferase was more closely related to a PrmB-type N5-glutamine methyltransferase than to the arsenate detoxifying methyltransferase ArsM. Insertional inactivation of prmB gene in A. brasilense resulted in an increased sensitivity to chloramphenicol and resistance to tiamulin and clindamycin, which are known to bind at the peptidyl transferase center (PTC) in the ribosome. These observations suggested that the inability of prmB:km mutant to methylate L3 protein might alter hydrophobicity in the antibiotic-binding pocket of the PTC, which might affect the binding of chloramphenicol, clindamycin, and tiamulin differentially. This is the first report showing the role of PrmB-type N5-glutamine methyltransferases in conferring resistance to tiamulin and clindamycin in any bacterium.

  16. Facile synthesis of size-tunable gold nanoparticles by pomegranate (Punica granatum) leaf extract: Applications in arsenate sensing

    Energy Technology Data Exchange (ETDEWEB)

    Rao, Ashit; Mahajan, Ketakee; Bankar, Ashok [Institute of Bioinformatics and Biotechnology, University of Pune, Pune 411007 (India); Srikanth, Rapole [Proteomics Laboratory, National Centre for Cell Science, Pune 411007 (India); Kumar, Ameeta Ravi [Institute of Bioinformatics and Biotechnology, University of Pune, Pune 411007 (India); Gosavi, Suresh, E-mail: swg@physics.unipune.ac.in [Department of Physics, University of Pune, Pune 411007 (India); Centre for Sensor Studies, University of Pune, Pune 411007 (India); Zinjarde, Smita, E-mail: smita@unipune.ac.in [Institute of Bioinformatics and Biotechnology, University of Pune, Pune 411007 (India); Centre for Sensor Studies, University of Pune, Pune 411007 (India)

    2013-03-15

    Highlights: ► Pomegranate leaf extracts mediated rapid gold nanoparticle (AuNP) synthesis. ► The phyto-inspired AuNPs were size-tuned and characterized. ► The reducing and capping agents in the extract were identified. ► The nanoparticles reacted specifically with arsenate (V) ions. - Abstract: When pomegranate leaf extracts were incubated with chloroauric acid (HAuCl{sub 4}), gold nanoparticles (AuNPs) were synthesized. These were characterized by a variety of techniques. With an increasing content of the leaf extract, a gradual decrease in size and an increase in monodispersity were observed. Transmission electron microscope (TEM) images showed that the phyto-fabricated AuNPs were surrounded by an amorphous layer. Gallic acid in the extract mediated the reduction and a natural decapeptide capped the nanostructures. Blocking of thiol groups in the decapeptide cysteine residues caused the nanoparticles to aggregate. On interaction with arsenate (V) ions, the UV–vis spectra of the nanoparticles showed a decrease in intensity and a red-shift. Energy dispersive spectra confirmed the presence of arsenate associated with the AuNPs. Thus, by using these AuNPs, a method for sensing the toxic arsenate ions could be developed.

  17. Facile synthesis of size-tunable gold nanoparticles by pomegranate (Punica granatum) leaf extract: Applications in arsenate sensing

    International Nuclear Information System (INIS)

    Rao, Ashit; Mahajan, Ketakee; Bankar, Ashok; Srikanth, Rapole; Kumar, Ameeta Ravi; Gosavi, Suresh; Zinjarde, Smita

    2013-01-01

    Highlights: ► Pomegranate leaf extracts mediated rapid gold nanoparticle (AuNP) synthesis. ► The phyto-inspired AuNPs were size-tuned and characterized. ► The reducing and capping agents in the extract were identified. ► The nanoparticles reacted specifically with arsenate (V) ions. - Abstract: When pomegranate leaf extracts were incubated with chloroauric acid (HAuCl 4 ), gold nanoparticles (AuNPs) were synthesized. These were characterized by a variety of techniques. With an increasing content of the leaf extract, a gradual decrease in size and an increase in monodispersity were observed. Transmission electron microscope (TEM) images showed that the phyto-fabricated AuNPs were surrounded by an amorphous layer. Gallic acid in the extract mediated the reduction and a natural decapeptide capped the nanostructures. Blocking of thiol groups in the decapeptide cysteine residues caused the nanoparticles to aggregate. On interaction with arsenate (V) ions, the UV–vis spectra of the nanoparticles showed a decrease in intensity and a red-shift. Energy dispersive spectra confirmed the presence of arsenate associated with the AuNPs. Thus, by using these AuNPs, a method for sensing the toxic arsenate ions could be developed

  18. Removal of arsenate by ferrihydrite via surface complexation and surface precipitation

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Xiuli [Department of Environment Engineering, College of the Environment and Ecology, and The Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystem, Xiamen University, Xiamen (China); Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, and The Key Laboratory for Synthetic Biotechnology of Xiamen City, Xiamen University, Xiamen (China); Peng, Changjun; Fu, Dun; Chen, Zheng [Department of Environment Engineering, College of the Environment and Ecology, and The Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystem, Xiamen University, Xiamen (China); Shen, Liang [Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, and The Key Laboratory for Synthetic Biotechnology of Xiamen City, Xiamen University, Xiamen (China); Li, Qingbiao [Department of Environment Engineering, College of the Environment and Ecology, and The Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystem, Xiamen University, Xiamen (China); Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, and The Key Laboratory for Synthetic Biotechnology of Xiamen City, Xiamen University, Xiamen (China); Ouyang, Tong, E-mail: yz3t@xmu.edu.cn [Department of Environment Engineering, College of the Environment and Ecology, and The Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystem, Xiamen University, Xiamen (China); Wang, Yuanpeng, E-mail: wypp@xmu.edu.cn [Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, and The Key Laboratory for Synthetic Biotechnology of Xiamen City, Xiamen University, Xiamen (China)

    2015-10-30

    Graphical abstract: - Highlights: • Surface complexation and surface precipitation of As on ferrihydrite happen at pH 3–6. • The formation of surface precipitation enhanced As(V) adsorption. • The dissolved Fe{sup 3+} had a good linear relationship with the amount of arsenate re-adsorption. - Abstract: In this study, macroscopic and spectroscopic experimental methods accurately modeled the sorption process of arsenate on ferrihydrite. EXAFS, X-ray diffraction and infrared (IR) spectroscopy indicated that the behavior of As(V) adsorption onto ferrihydrite took place mainly via surface complexation and surface precipitation at acidic pH (3.0–6.0), while the surface precipitation was dominated at longer time intervals and higher Fe{sup 3+} concentration. The macroscopic competitive adsorption experiment between arsenate with phosphate indicated two types of adsorption sites existing on the surface of ferrihydrite, i.e., non-exchangeable sites, which are responsible for a rapid surface complex formation; and exchangeable sites for a slow build-up of surface precipitates. In the slow build-up precipitates, the As(V) surface coverage (mmol/g) exhibited a good linear relationship (R{sup 2} = 0.952) with the amount of dissolved Fe{sup 3+}. Three steps are involved during the process of surface precipitation, i.e., (1) an initial uptake of As(V) via surface complexation; (2) re-adsorption of Fe{sup 3+} leaching from ferrihydrite on the surface complex; and (3) As(V) adsorption via surface complexation again and finally forming the surface precipitate.

  19. Kinetics and thermodynamic for sorption of arsenate by Lanthanum-exchanged zeolite

    International Nuclear Information System (INIS)

    Mohd Jelas Haron; Saiful Adli Masdan; Mohd Zobir Hussein; Zulkarnain Zainal; Anuar Kassim

    2007-01-01

    Zeolites are crystalline, hydrated aluminosilicate containing exchangeable alkaline and alkaline earth cations in their structural frameworks. Since zeolites have permanent negative charges on their surfaces, they have no affinity for anions. However recent studies have shown that modification of zeolites with certain surfactants or metal cations yield sorbents with a strong affinity for many anions. In this paper, modification of zeolites (zeolite A, X and ZSM5) were performed by exchange of naturally occurring cations with lanthanum ion that forms low solubility arsenate salt. The exchanged zeolites were used to sorb arsenate from aqueous solution. Among parameters investigated were effect of pH, arsenate initial concentrations, contact time and temperature. The maximum exchanged capacity of La (III) ion was obtained when using solution with initial pH of 4. Zeolite X gives the highest La (III) exchanged capacity compared to other zeolites. The results showed that As (V) sorption by La-zeolites occurred at about pH 6.5 and increased as pH increased and reaching maximum at equilibrium pH about 7.8. On the other hand, almost no arsenate sorption occurred on un exchanged zeolites. This indicates that La (III) ion on the exchanged zeolites is taking part on the As(V) sorption via surface precipitation. The results also showed that the sorption capacities increased with increasing initial As (V) concentrations. The sorption followed Langmuir model with maximum sorption capacities of 0.41, 0.21 and 0.19 mmol/g at 25 degree Celsius for La exchanged zeolite X (La-ZX), La exchanged zeolite ZSM5 (La-ZSM) and La exchanged zeolite A (La-ZA), respectively. The amounts of sorption of As (V) by La exchanged zeolite increased as temperature increased from 25 to 70 degree Celsius indicating that the process is endothermic. The free energy changes ( ΔG degree) for the sorption at 25 degree Celsius were -10.25, -9.65 and -8.49 kJ/ mol for La-ZX, La-ZSM and La-ZA, respectively. The

  20. Release to the gas phase of metals, S and Cl during combustion of dedicated waste fractions

    DEFF Research Database (Denmark)

    Pedersen, Anne Juul; van Lith, Simone Cornelia; Frandsen, Flemming

    2010-01-01

    The release to the gas phase of inorganic elements such as alkali metals. Cl, S, and heavy metals in Waste-to-Energy (WtE) boilers is a challenge. Besides the risk of harmful emissions to the environment, inorganic elements released from the grate may cause severe ash deposition and corrosion...... and the link to the formation of fly ash and aerosols in full-scale waste incinerators. The release of metals, S and Cl from four dedicated waste fractions was quantified as a function of temperature in a lab-scale fixed-bed reactor. The waste fractions comprised chromated copper arsenate (CCA) impregnated....... The lab-scale release results were then compared with results from a related, full-scale partitioning study, in which test runs with the addition of similar, dedicated waste fractions to a base-load waste had been performed in a grate-fired WtE boiler. In general, the elements Al, Ca, Cr, Cu, Fe, Mg, Si...

  1. W342F Mutation in CCaMK Enhances Its Affinity to Calmodulin But Compromises Its Role in Supporting Root Nodule Symbiosis in Medicago truncatula

    Directory of Open Access Journals (Sweden)

    Edgard Jauregui

    2017-11-01

    Full Text Available The calcium/calmodulin-dependent protein kinase (CCaMK is regulated by free Ca2+ and Ca2+-loaded calmodulin. This dual binding is believed to be involved in its regulation and associated physiological functions, although direct experimental evidence for this is lacking. Here we document that site-directed mutations in the calmodulin-binding domain of CCaMK alters its binding capacity to calmodulin, providing an effective approach to study how calmodulin regulates CCaMK in terms of kinase activity and regulation of rhizobial symbiosis in Medicago truncatula. We observed that mutating the tryptophan at position 342 to phenylalanine (W342F markedly increased the calmodulin-binding capability of the mutant. The mutant CCaMK underwent autophosphorylation and catalyzed substrate phosphorylation in the absence of calcium and calmodulin. When the mutant W342F was expressed in ccamk-1 roots, the transgenic roots exhibited an altered nodulation phenotype. These results indicate that altering the calmodulin-binding domain of CCaMK could generate a constitutively activated kinase with a negative role in the physiological function of CCaMK.

  2. Effectiveness of Iron Filings in Arsenate and Arsenite Removal from Drinking Water

    Directory of Open Access Journals (Sweden)

    AliReza Asgari

    2009-09-01

    Full Text Available Groundwater contamination with arsenic (As has been recognized as a serious problem and there are various reports from different regions, especially from Kurdistan Providence, indicating the presence of As in the from of arsenate and arsenite in water recourses. Removal of these compounds can be accomplished by various methods but they are all expensive. In this study, three concentrations (0.5, 1, and 1 mg/L of iron filings (0.25, 0.5, 1 and 1.5 grams were used as a cheap and available material for adsorption of As and the effects of contact time and pH as well as chloride and sulfate ion concentrations on removal efficiency were determined. Description of adsorption isotherms (Ferundlich and Langmuir was accomplished. Finally, the data obtained were analyzed using the Excel softwere. The results indicate that iron filings show a high capability in adsorbing both arsenate and arsenic compounds from polluted water samples at pH 7 over a short contact time of 30 minutes. In fact, this cheap adsorbent shows good treatment when used at doses as low as 1g/L with no considerable interference by interfering anions (SO42- and Cl-. It appears that the absorbability of both arsenate and arsenite by iron filings can be expressed by Ferundlich isotherm with R2>0.96, whereas arsenate adsorption (with a R2 value of more than 0.96 can be better described by Langmuir isotherm than arsenite (with R2 value of more than 0.91. Results also indicate that the amount of iron added to water is much more than the standard value of 0.3mg/L set for dinking water. Nevertheless, this method has far greater advantages in terms of costs and availability than similar methods. Besides, as removal by this method is efficient without pH modification, iron filing treatment of drinking water may, therefore, be recomnended as a convenient solution to the problem of water resources polluted with As in Iran.

  3. Copper and trace element fractionation in electrokinetically treated methanogenic anaerobic granular sludge

    International Nuclear Information System (INIS)

    Virkutyte, Jurate; Hullebusch, Eric van; Sillanpaeae, Mika; Lens, Piet

    2005-01-01

    The effect of electrokinetic treatment (0.15 mA cm -2 ) on the metal fractionation in anaerobic granular sludge artificially contaminated with copper (initial copper concentration 1000 mg kg -1 wet sludge) was studied. Acidification of the sludge (final pH 4.2 in the sludge bed) with the intention to desorb the copper species bound to the organic/sulfides and residual fractions did not result in an increased mobility, despite the fact that a higher quantity of copper was measured in the more mobile (i.e. exchangeable/carbonate) fractions at final pH 4.2 compared to circum-neutral pH conditions. Also addition of the chelating agent EDTA (Cu 2+ :EDTA 4- ratio 1.2:1) did not enhance the mobility of copper from the organic/sulfides and residual fractions, despite the fact that it induced a reduction of the total copper content of the sludge. The presence of sulfide precipitates likely influences the copper mobilisation from these less mobile fractions, and thus makes EDTA addition ineffective to solubilise copper from the granules. - Electrokinetic treatment of copper contaminated anaerobic granular sludge at 0.15 mA cm -2 for 14 days induces copper and trace metal mobility as well as changes in their fractionation (i.e. bonding forms)

  4. A General Construction of IND-CCA2 Secure Public Key Encryption

    DEFF Research Database (Denmark)

    Kiltz, Eike; Malone-Lee, John

    2003-01-01

    We propose a general construction for public key encryption schemes that are IND-CCA2 secure in the random oracle model. We show that the scheme proposed in [1, 2] fits our general framework and moreover that our method of analysis leads to a more efficient security reduction....

  5. Soil organic matter reduces the sorption of arsenate and phosphate

    NARCIS (Netherlands)

    Verbeeck, M.; Hiemstra, T.; Thiry, Y.; Smolders, E.

    2017-01-01

    The arsenate (AsO4) and phosphate (PO4) mobility in aerobic soil is affected by soil organic matter (OM). This study was set up to quantify the interaction between OM and AsO4 with an observational, experimental and computational approach. The adsorption of

  6. Goethite surface reactivity: III. Unifying arsenate adsorption behavior through a variable crystal face - Site density model

    Science.gov (United States)

    Salazar-Camacho, Carlos; Villalobos, Mario

    2010-04-01

    We developed a model that describes quantitatively the arsenate adsorption behavior for any goethite preparation as a function of pH and ionic strength, by using one basic surface arsenate stoichiometry, with two affinity constants. The model combines a face distribution-crystallographic site density model for goethite with tenets of the Triple Layer and CD-MUSIC surface complexation models, and is self-consistent with its adsorption behavior towards protons, electrolytes, and other ions investigated previously. Five different systems of published arsenate adsorption data were used to calibrate the model spanning a wide range of chemical conditions, which included adsorption isotherms at different pH values, and adsorption pH-edges at different As(V) loadings, both at different ionic strengths and background electrolytes. Four additional goethite-arsenate systems reported with limited characterization and adsorption data were accurately described by the model developed. The adsorption reaction proposed is: lbond2 FeOH +lbond2 SOH +AsO43-+H→lbond2 FeOAsO3[2-]…SOH+HO where lbond2 SOH is an adjacent surface site to lbond2 FeOH; with log K = 21.6 ± 0.7 when lbond2 SOH is another lbond2 FeOH, and log K = 18.75 ± 0.9, when lbond2 SOH is lbond2 Fe 2OH. An additional small contribution of a protonated complex was required to describe data at low pH and very high arsenate loadings. The model considered goethites above 80 m 2/g as ideally composed of 70% face (1 0 1) and 30% face (0 0 1), resulting in a site density for lbond2 FeOH and for lbond2 Fe 3OH of 3.125/nm 2 each. Below 80 m 2/g surface capacity increases progressively with decreasing area, which was modeled by considering a progressively increasing proportion of faces (0 1 0)/(1 0 1), because face (0 1 0) shows a much higher site density of lbond2 FeOH groups. Computation of the specific proportion of faces, and thus of the site densities for the three types of crystallographic surface groups present in

  7. Minimizing corrosive action in timber bridges treated with waterborne preservatives

    Science.gov (United States)

    Samuel L. Zelinka; Douglas R. Rammer; James P. Wacker

    2007-01-01

    This work will briefly review published literature and current research activities on the corrosion of metals in contact with wood treated with waterborne alternatives to CCA. In addition, recommendations to minimize these corrosive effects in timber bridges will be discussed.

  8. Stabilization of As-, Pb-, and Cu-contaminated soil using calcined oyster shells and steel slag.

    Science.gov (United States)

    Moon, Deok Hyun; Wazne, Mahmoud; Cheong, Kyung Hoon; Chang, Yoon-Young; Baek, Kitae; Ok, Yong Sik; Park, Jeong-Hun

    2015-07-01

    In this study, As-, Pb-, and Cu-contaminated soil was stabilized using calcined oyster shells (COS) and steel slag (SS). The As-contaminated soil was obtained from a timber mill site where chromate copper arsenate (CCA) was used as a preservative. On the other hand, Pb- and Cu-contaminated soil was obtained from a firing range. These two soils were thoroughly mixed to represent As-, Pb-, and Cu-contaminated soil. Calcined oyster shells were obtained by treating waste oyster shells at a high temperature using the calcination process. The effectiveness of stabilization was evaluated by 1-N HCl extraction for As and 0.1-N HCl extraction for Pb and Cu. The treatment results showed that As, Pb, and Cu leachability were significantly reduced upon the combination treatment of COS and SS. The sole treatment of SS (10 wt%) did not show effective stabilization. However, the combination treatment of COS and SS showed a significant reduction in As, Pb, and Cu leachability. The best stabilization results were obtained from the combination treatment of 15 wt% COS and 10 wt% SS. The SEM-EDX results suggested that the effective stabilization of As was most probably achieved by the formation of Ca-As and Fe-As precipitates. In the case of Pb and Cu, stabilization was most probably associated with the formation of pozzolanic reaction products such as CSHs and CAHs.

  9. Neutralization of arsenic pollutants, contained in natural waters: The theoretical analysis of solubility of some arsenates and optimization of the processes

    Directory of Open Access Journals (Sweden)

    Marta Litynska

    2017-01-01

    Full Text Available Arsenic belongs to chemical elements, which are often found in natural waters and make it unsuitable for consumption without special treatment. Neutralization of arsenic pollutants of natural waters by converting them into insoluble form is one of the perspective methods of dearsenication. Precipitation (by iron or aluminium coagulants, lime and adsorption (by oxides and hydroxides of iron, aluminium or manganese are among the most popular dearsenication methods. The use of these chemicals entails the formation of poorly soluble arsenates. Since the possibility of the release of arsenic compounds into the water due to the dissolution of formed arsenates depends on its solubility under appropriate conditions, it is necessary to have information about the dependence of arsenates solubility on pH. According to the calculations the solubilities of arsenates of iron(III, aluminium, manganese(II and calcium are highly dependent on pH. At pH

  10. Mechanical properties of wood from Pinus sylvestris L. treated with Light Organic Solvent Preservative and with waterborne Copper Azole

    Energy Technology Data Exchange (ETDEWEB)

    Villasante, A.; Laina, R.; Rojas, J. A. M.; Rojas, I. M.; Vignote, S.

    2013-07-01

    Aim of study: To determine the effect on wood from Pinus sylvestris of treatment with preservatives on mechanical properties and to establish the relation between the penetration and compression strenght. Area of study: Spain. Material and methods: 40 samples of defect-free wood from Pinus sylvestris L. were treated with Light Organic Solvent Preservative (Vacsol Azure WR 2601) and 50 with waterborne Copper Azole (Tanalith E 3492). 40 control samples were not treated (water or preservative). Mechanical resistance to static bending, modulus of elasticity and compression strength parallel to the grain were compared with untreated wood. Regression analysis between the penetration and compression strength parallel was done with the samples treated with waterborne preservative. Main results: The results indicate that the treated wood (with either product) presents a statistically significant increase in mechanical resistance in all three mechanical characteristics. The results obtained differ from earlier studies carried out by other authors. There was no correlation between parallel compression strength and the degree of impregnation of the wood with waterborne Copper Azole. The most probable explanation for these results concerns changes in pressure during treatment. The use of untreated control samples instead of samples treated only with water is more likely to produce significant results in the mechanical resistance studies. Research highlights: Treated wood presents a statistically significant increase in MOE, modulus of rupture to static bending and parallel compression strength. There was no correlation between parallel compression strength and the degree of impregnation with waterborne preservative. (Author)

  11. Structural and magnetic characterization of copper sulfonated phthalocyanine grafted onto treated polyethylene

    Energy Technology Data Exchange (ETDEWEB)

    Reznickova, A., E-mail: alena.reznickova@vscht.cz [Department of Solid State Engineering, University of Chemistry and Technology, 166 28, Prague 6 (Czech Republic); Kolska, Z. [Department of Solid State Engineering, University of Chemistry and Technology, 166 28, Prague 6 (Czech Republic); Faculty of Science, J.E. Purkyne University, 400 96 Usti nad Labem (Czech Republic); Orendac, M.; Cizmar, E. [Faculty of Science, P.J. Safarik University, Park Angelinum 9, 04013 Kosice (Slovakia); Sajdl, P. [Department of Power Engineering, University of Chemistry and Technology, 166 28, Prague 6 (Czech Republic); Svorcik, V. [Department of Solid State Engineering, University of Chemistry and Technology, 166 28, Prague 6 (Czech Republic)

    2016-08-30

    Highlights: • Polyethylene (PE) surface was activated by argon plasma discharge. • Monolayer of copper phthalocyanine was achieved. • ESR proved that CuPc coated PE surface exhibits magnetic properties. • The studied structures may have potential application in spintronics and data storage. - Abstract: This study focuses on high density polyethylene (HDPE) activated by Ar plasma treatment, subsequently grafted with copper sulfonated phthalocyanine (CuPc) especially pointing out to the surface and magnetic properties of those composites. Properties of pristine PE and their plasma treated counterparts were studied by different experimental techniques: X-ray photoelectron spectroscopy (XPS), UV–vis spectroscopy, zeta potential and by electron spin resonance (ESR). XPS analysis confirmed the successful grafting of phthalocyanine. The highest absorption was found for the sample grafted with {sup b}CuPc for 1 h. Electrokinetic analysis also confirmed the plasma treatment and also subsequent CuPc grafting influence significantly the surface chemistry and charge. These results correspond well with XPS determination. ESR studies confirmed the presence of CuPc grafted on HDPE. It was found, that grafting is mediated by magnetically inactive functional groups, rather than radicals. Magnetic properties of CuPc do not seem to change significantly after grafting CuPc on polyethylene surface.

  12. Graphic-Card Cluster for Astrophysics (GraCCA) -- Performance Tests

    OpenAIRE

    Schive, Hsi-Yu; Chien, Chia-Hung; Wong, Shing-Kwong; Tsai, Yu-Chih; Chiueh, Tzihong

    2007-01-01

    In this paper, we describe the architecture and performance of the GraCCA system, a Graphic-Card Cluster for Astrophysics simulations. It consists of 16 nodes, with each node equipped with 2 modern graphic cards, the NVIDIA GeForce 8800 GTX. This computing cluster provides a theoretical performance of 16.2 TFLOPS. To demonstrate its performance in astrophysics computation, we have implemented a parallel direct N-body simulation program with shared time-step algorithm in this system. Our syste...

  13. Evaluation of circulating cathodic antigen (CCA) strip for diagnosis of urinary schistosomiasis in Hassoba school children, Afar, Ethiopia

    OpenAIRE

    Ayele B.; Erko B.; Legesse M.; Hailu A.; Medhin G.

    2008-01-01

    A total of 206 urine samples collected from Hassoba Elementary schoolchildren, Afar, Ethiopia, a low Schistosoma haematobium endemic setting, was diagnosed to evaluate the performance of CCA strip using double references, urine filtration technique and urinalysis dipstick (Combur 10 Test®) that detect schistosome eggs and blood in urine, respectively. The former was used as a gold standard reference method. Sensitivity, specificity, positive and negative predictive values for the CCA were 52%...

  14. Arsenic accumulation by the aquatic fern Azolla: Comparison of arsenate uptake, speciation and efflux by A. caroliniana and A. filiculoides

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Xin [State Key Lab of Urban and ONAL Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, 18 Shuangqing Road, Beijing 100085 (China); Lin Aijun [Department of Environmental Science and Engineering, Beijing University of Chemical Technology, Beijing 100029 (China); Zhao Fangjie [Soil Science Department, Rothamsted Research, Hertfordshire AL5 2JQ (United Kingdom); Xu Guozhong [Agricultural Ecology Institute, Fujian Academy of Agricultural Sciences, Fuzhou 350013 (China); Duan Guilan [State Key Lab of Urban and ONAL Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, 18 Shuangqing Road, Beijing 100085 (China); Zhu Yongguan [State Key Lab of Urban and ONAL Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, 18 Shuangqing Road, Beijing 100085 (China); Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361003 (China)], E-mail: ygzhu@rcees.ac.cn

    2008-12-15

    This study investigates As accumulation and tolerance of the aquatic fern Azolla. Fifty strains of Azolla showed a large variation in As accumulation. The highest- and lowest-accumulating ferns among the 50 strains were chosen for further investigations. Azolla caroliniana accumulated two times more As than Azolla filiculoides owing to a higher influx velocity for arsenate. A. filiculoides was more resistant to external arsenate due to a lower uptake. Both strains showed a similar degree of tolerance to internal As. Arsenate and arsenite were the dominant As species in both Azolla strains, with methlyated As species accounting for <5% of the total As. A. filiculoides had a higher proportion of arsenite than A. caroliniana. Both strains effluxed more arsenate than arsenite, and the amount of As efflux was proportional to the amount of As accumulation. The potential of growing Azolla in paddy fields to reduce As transfer from soil and water to rice should be further evaluated. - Arsenic accumulation and efflux differ between strains of the aquatic fern Azolla.

  15. Arsenic accumulation by the aquatic fern Azolla: Comparison of arsenate uptake, speciation and efflux by A. caroliniana and A. filiculoides

    International Nuclear Information System (INIS)

    Zhang Xin; Lin Aijun; Zhao Fangjie; Xu Guozhong; Duan Guilan; Zhu Yongguan

    2008-01-01

    This study investigates As accumulation and tolerance of the aquatic fern Azolla. Fifty strains of Azolla showed a large variation in As accumulation. The highest- and lowest-accumulating ferns among the 50 strains were chosen for further investigations. Azolla caroliniana accumulated two times more As than Azolla filiculoides owing to a higher influx velocity for arsenate. A. filiculoides was more resistant to external arsenate due to a lower uptake. Both strains showed a similar degree of tolerance to internal As. Arsenate and arsenite were the dominant As species in both Azolla strains, with methlyated As species accounting for <5% of the total As. A. filiculoides had a higher proportion of arsenite than A. caroliniana. Both strains effluxed more arsenate than arsenite, and the amount of As efflux was proportional to the amount of As accumulation. The potential of growing Azolla in paddy fields to reduce As transfer from soil and water to rice should be further evaluated. - Arsenic accumulation and efflux differ between strains of the aquatic fern Azolla

  16. Arsenic accumulation by the aquatic fern Azolla: comparison of arsenate uptake, speciation and efflux by A. caroliniana and A. filiculoides.

    Science.gov (United States)

    Zhang, Xin; Lin, Ai-Jun; Zhao, Fang-Jie; Xu, Guo-Zhong; Duan, Gui-Lan; Zhu, Yong-Guan

    2008-12-01

    This study investigates As accumulation and tolerance of the aquatic fern Azolla. Fifty strains of Azolla showed a large variation in As accumulation. The highest- and lowest-accumulating ferns among the 50 strains were chosen for further investigations. Azolla caroliniana accumulated two times more As than Azolla filiculoides owing to a higher influx velocity for arsenate. A. filiculoides was more resistant to external arsenate due to a lower uptake. Both strains showed a similar degree of tolerance to internal As. Arsenate and arsenite were the dominant As species in both Azolla strains, with methylated As species accounting for Azolla in paddy fields to reduce As transfer from soil and water to rice should be further evaluated.

  17. Co-adsorption of Trichloroethylene and Arsenate by Iron-Impregnated Granular Activated Carbon.

    Science.gov (United States)

    Deng, Baolin; Kim, Eun-Sik

    2016-05-01

    Co-adsorption of trichloroethylene (TCE) and arsenate [As(V)] was investigated using modified granular activated carbons (GAC): untreated, sodium hypochlorite-treated (NaClO-GAC), and NaClO with iron-treated GAC (NaClO/Fe-GAC). Batch experiments of single- [TCE or As(V)] and binary- [TCE and As(V)] components solutions are evaluated through Langmuir and Freundlich isotherm models and adsorption kinetic tests. In the single-component system, the adsorption capacity of As(V) was increased by the NaClO-GAC and the NaClO/Fe-GAC. The untreated GAC showed a low adsorption capacity for As(V). Adsorption of TCE by the NaClO/Fe-GAC was maximized, with an increased Freundlich constant. Removal of TCE in the binary-component system was decreased 15% by the untreated GAC, and NaClO- and NaClO/Fe-GAC showed similar efficiency to the single-component system because of the different chemical status of the GAC surfaces. Results of the adsorption isotherms of As(V) in the binary-component system were similar to adsorption isotherms of the single-component system. The adsorption affinities of single- and binary-component systems corresponded with electron transfer, competitive adsorption, and physicochemical properties.

  18. Determination of arsenate and organic arsenic via potentiometric titration of its heteropoly anions.

    Science.gov (United States)

    Metelka, R; Slavíková, S; Vytras, K

    2002-08-16

    Determination of arsenate based on its conversion to molybdoarsenate heteropoly anions followed by potentiometric titration is described. The titration is realized on the ion-pairing principle using cetylpyridinium chloride (or an analogous titrant containing a lipophilic cation), and is monitored by a carbon paste electrode, although other liquid-polymeric membrane-based electrodes can also be used. Calibration plots of the titrant end-point consumption versus concentration of arsenic were constructed and used to evaluate the content of arsenic in aqueous samples. The method could be applied in the analyses of samples with quite low arsenic content (amounts approximately 10 mug As in 50 cm(3) could be titrated). Organic arsenic was determined analogously after the Schöniger combustion of the sample and conversion of its arsenic to arsenate.

  19. Sumoylation of the Plant Clock Transcription Factor CCA1 Suppresses DNA Binding

    NARCIS (Netherlands)

    Hansen, L.L.; Imrie, L.; Le Bihan, T.; van den Burg, H.A.; van Ooijen, G.

    2017-01-01

    In plants, the circadian clock regulates the expression of one-third of all transcripts and is crucial to virtually every aspect of metabolism and growth. We now establish sumoylation, a posttranslational protein modification, as a novel regulator of the key clock protein CCA1 in the model plant

  20. Reparatory adaptation to copper-induced injury and occurrence of a copper-binding protein in the polycheate, Eudistylia vancouveri

    Energy Technology Data Exchange (ETDEWEB)

    Young, J.S.; Roesijadi, G.

    1983-01-01

    Chemically injured branchial pinnae of copper-treated polychaetes, Eudistylia vancouveri, regenerated while still exposed to copper. The first observations of pinna regeneration coincided with the apparent induction of a low molecular weight (approx.5000 daltons) copper-binding protein. This protein may play a role in the detoxification of copper and subsequent tissue regeneration. 7 references, 5 figures.

  1. Analysis of the Surface of Deposited Copper After Electroerosion Treatment

    Science.gov (United States)

    Ablyaz, T. R.; Simonov, M. Yu.; Shlykov, E. S.

    2018-03-01

    An electron microscope analysis of the surface of deposited copper is performed after a profiling-piercing electroerosion treatment. The deposited copper is treated with steel, duralumin, and copper electrode tools at different pulse energies. The treatment with the duralumin electrode produces on the treated surface a web-like structure and cubic-morphology polyhedral dimples about 10 μm in size. The main components of the surface treated with the steel electrode are developed polyhedral dimples with a size of 10 - 50 μm. After the treatment with the copper electrode the main components of the treated surface are large polyhedral dimples about 30 - 80 μm in size.

  2. The removal of sulphate from mine water by precipitation as ettringite and the utilisation of the precipitate as a sorbent for arsenate removal.

    Science.gov (United States)

    Tolonen, Emma-Tuulia; Hu, Tao; Rämö, Jaakko; Lassi, Ulla

    2016-10-01

    The aim of this research was to investigate sulphate removal from mine water by precipitation as ettringite (Ca6Al2(SO4)3(OH)12·26H2O) and the utilisation of the precipitate as a sorbent for arsenate removal. The mine water sulphate concentration was reduced by 85-90% from the initial 1400 mg/L during ettringite precipitation depending on the treatment method. The precipitation conditions were also simulated with MINEQL + software, and the computational results were compared with the experimental results. The precipitated solids were characterised with X-ray diffraction and a scanning electron microscope. The precipitated solids were tested as sorbents for arsenate removal from the model solution. The arsenic(V) model solution concentration reduced 86-96% from the initial 1.5 mg/L with a 1 g/L sorbent dosage. The effect of initial arsenate concentration on the sorption of arsenate on the precipitate was studied and Langmuir, Freundlich, and Langmuir-Freundlich sorption isotherm models were fitted to the experimental data. The maximum arsenate sorption capacity (qm = 11.2 ± 4.7 mg/g) of the precipitate was obtained from the Langmuir-Freundlich isotherm. The results indicate that the precipitate produced during sulphate removal from mine water by precipitation as ettringite could be further used as a sorbent for arsenate removal. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. ACCUMULATION AND METABOLISM OF ARSENIC IN MICE AFTER REPEATED ADMINISTRATION OF ARSENATE

    Science.gov (United States)

    Accumulation and metabolism of arsenic in mice after repeated oral administration of arsenate, Hughes, M. F., Kenyon, E. M., Edwards, B. C., Mitchell, C. T., Del Razo, L. M., and Thomas, D. J. The human carcinogen inorganic arsenic (iAs) is a pervasive environmental ...

  4. Embryotoxicity of arsenite and arsenate. Distribution in pregnant mice and monkeys and effects on embryonic cells in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Lindgren, A; Danielsson, R G; Dencker, L [Department of Toxicology, Biomedical Center, Uppsala University, Sweden; Vahter, M [National Institute of Environmental Medicine, Stockholm, Sweden

    1984-01-01

    The distribution of /sup 74/As-labelled arsenate and arsenite in pregnant mice and a monkey has been studied by autoradiography and gamma counting of isolated tissues, and their in vitro toxicity to a chondrogenic system has been investigated. With both arsenic forms, given as single intravenous injections to the mother, the /sup 74/As-arsenic appeared to pass the mouse placenta relatively freely and approximately to the same extent. The retention time in material tissues including the placenta was, however, around three times longer with arsenite than with arsenate. In early gestation, high activity was registered in the embryonic neuroepithelium, which correlates well with reported CNS malformations in rodents. In late gestation, the distribution pattern was more like that in the adults. Accumulation in skin and squamous epithelia of the upper gastrointestinal tract (oral cavity, oesophagus and oesophageal region of stomach) dominated the distribution pucture, especially at a long survival interval. Arsenate, but not arsenite, showed affinity for the calcified areas of the skeleton. A marmoset monkey in late gestation receiving arsenite showed a somewhat lower rate of placental transfer than the mice. Skin and liver had the highest concentrations (at 8 hrs), both in mother and foetuses. This species is known not to methylate arsenic, resulting in stronger binding and longer retention times of arsenic as compared with other species. The stronger binding in maternal tissues may possibly explain the lower rate of placental transfer. Arsenite was shown to inhibit cartilage formation in a chick limb bud mesenchymal spot culture system (ED50 approximately 5-10..mu..M) while arsenate seemed to be without effect at concentrations up to 200 ..mu..M (highest tested). Arsenate, however, showed a potential of the arsenite toxicity.

  5. Phylogenetic analysis of bacterial and archaeal arsC gene sequences suggests an ancient, common origin for arsenate reductase

    Directory of Open Access Journals (Sweden)

    Dugas Sandra L

    2003-07-01

    Full Text Available Abstract Background The ars gene system provides arsenic resistance for a variety of microorganisms and can be chromosomal or plasmid-borne. The arsC gene, which codes for an arsenate reductase is essential for arsenate resistance and transforms arsenate into arsenite, which is extruded from the cell. A survey of GenBank shows that arsC appears to be phylogenetically widespread both in organisms with known arsenic resistance and those organisms that have been sequenced as part of whole genome projects. Results Phylogenetic analysis of aligned arsC sequences shows broad similarities to the established 16S rRNA phylogeny, with separation of bacterial, archaeal, and subsequently eukaryotic arsC genes. However, inconsistencies between arsC and 16S rRNA are apparent for some taxa. Cyanobacteria and some of the γ-Proteobacteria appear to possess arsC genes that are similar to those of Low GC Gram-positive Bacteria, and other isolated taxa possess arsC genes that would not be expected based on known evolutionary relationships. There is no clear separation of plasmid-borne and chromosomal arsC genes, although a number of the Enterobacteriales (γ-Proteobacteria possess similar plasmid-encoded arsC sequences. Conclusion The overall phylogeny of the arsenate reductases suggests a single, early origin of the arsC gene and subsequent sequence divergence to give the distinct arsC classes that exist today. Discrepancies between 16S rRNA and arsC phylogenies support the role of horizontal gene transfer (HGT in the evolution of arsenate reductases, with a number of instances of HGT early in bacterial arsC evolution. Plasmid-borne arsC genes are not monophyletic suggesting multiple cases of chromosomal-plasmid exchange and subsequent HGT. Overall, arsC phylogeny is complex and is likely the result of a number of evolutionary mechanisms.

  6. Recovery of copper and water from copper-electroplating wastewater by the combination process of electrolysis and electrodialysis.

    Science.gov (United States)

    Peng, Changsheng; Liu, Yanyan; Bi, Jingjing; Xu, Huizhen; Ahmed, Abou-Shady

    2011-05-30

    In this paper, a laboratory-scale process which combined electrolysis (EL) and electrodialysis (ED) was developed to treat copper-containing wastewater. The feasibility of such process for copper recovery as well as water reuse was determined. Effects of three operating parameters, voltage, initial Cu(2+) concentration and water flux on the recovery of copper and water were investigated and optimized. The results showed that about 82% of copper could be recovered from high concentration wastewater (HCW, >400mg/L) by EL, at the optimal conditions of voltage 2.5 V/cm and water flux 4 L/h; while 50% of diluted water could be recycled from low concentration wastewater (LCW, water flux 4 L/h. However, because of the limitation of energy consumption (EC), LCW for EL and HCW for ED could not be treated effectively, and the effluent water of EL and concentrated water of ED should be further treated before discharged. Therefore, the combination process of EL and ED was developed to realize the recovery of copper and water simultaneously from both HCW and LCW. The results of the EL-ED process showed that almost 99.5% of copper and 100% of water could be recovered, with the energy consumption of EL ≈ 3 kW h/kg and ED ≈ 2 kW h/m(3). According to SEM and EDX analysis, the purity of recovered copper was as high as 97.9%. Copyright © 2011 Elsevier B.V. All rights reserved.

  7. Na₃Co₂(AsO₄)(As₂O₇): a new sodium cobalt arsenate.

    Science.gov (United States)

    Guesmi, Abderrahmen; Driss, Ahmed

    2012-07-01

    In the title compound, tris-odium dicobalt arsenate diarsenate, Na₃Co₂AsO₄As₂O₇, the two Co atoms, one of the two As and three of the seven O atoms lie on special positions, with site symmetries 2 and m for the Co, m for the As, and 2 and twice m for the O atoms. The two Na atoms are disordered over two general and special positions [occupancies 0.72 (3):0.28 (3) and 0.940 (6):0.060 (6), respectively]. The main structural feature is the association of the CoO₆ octa-hedra in the ab plane, forming Co₄O₂₀ units, which are corner- and edge-connected via AsO₄ and As₂O₇ arsenate groups, giving rise to a complex polyhedral connectivity with small tunnels, such as those running along the b- and c-axis directions, in which the Na⁺ ions reside. The structural model is validated by both bond-valence-sum and charge-distribution methods, and the distortion of the coordination polyhedra is analyzed by means of the effective coordination number.

  8. Nickel, copper and cobalt coalescence in copper cliff converter slag

    Directory of Open Access Journals (Sweden)

    Wolf A.

    2016-01-01

    Full Text Available The aim of this investigation is to assess the effect of various additives on coalescence of nickel, copper and cobalt from slags generated during nickel extraction. The analyzed fluxes were silica and lime while examined reductants were pig iron, ferrosilicon and copper-silicon compound. Slag was settled at the different holding temperatures for various times in conditions that simulated the industrial environment. The newly formed matte and slag were characterized by their chemical composition and morphology. Silica flux generated higher partition coefficients for nickel and copper than the addition of lime. Additives used as reducing agents had higher valuable metal recovery rates and corresponding partition coefficients than fluxes. Microstructural studies showed that slag formed after adding reductants consisted of primarily fayalite, with some minute traces of magnetite as the secondary phase. Addition of 5 wt% of pig iron, ferrosilicon and copper-silicon alloys favored the formation of a metallized matte which increased Cu, Ni and Co recoveries. Addition of copper-silicon alloys with low silicon content was efficient in copper recovery but coalescence of the other metals was low. Slag treated with the ferrosilicon facilitated the highest cobalt recovery while copper-silicon alloys with silicon content above 10 wt% resulted in high coalescence of nickel and copper, 87 % and 72 % respectively.

  9. Rainfall prediction of Cimanuk watershed regions with canonical correlation analysis (CCA)

    Science.gov (United States)

    Rustiana, Shailla; Nurani Ruchjana, Budi; Setiawan Abdullah, Atje; Hermawan, Eddy; Berliana Sipayung, Sinta; Gede Nyoman Mindra Jaya, I.; Krismianto

    2017-10-01

    Rainfall prediction in Indonesia is very influential on various development sectors, such as agriculture, fisheries, water resources, industry, and other sectors. The inaccurate predictions can lead to negative effects. Cimanuk watershed is one of the main pillar of water resources in West Java. This watersheds divided into three parts, which is a headwater of Cimanuk sub-watershed, Middle of Cimanuk sub-watershed and downstream of Cimanuk sub- watershed. The flow of this watershed will flow through the Jatigede reservoir and will supply water to the north-coast area in the next few years. So, the reliable model of rainfall prediction is very needed in this watershed. Rainfall prediction conducted with Canonical Correlation Analysis (CCA) method using Climate Predictability Tool (CPT) software. The prediction is every 3months on 2016 (after January) based on Climate Hazards group Infrared Precipitation with Stations (CHIRPS) data over West Java. Predictors used in CPT were the monthly data index of Nino3.4, Dipole Mode (DMI), and Monsoon Index (AUSMI-ISMI-WNPMI-WYMI) with initial condition January. The initial condition is chosen by the last data update. While, the predictant were monthly rainfall data CHIRPS region of West Java. The results of prediction rainfall showed by skill map from Pearson Correlation. High correlation of skill map are on MAM (Mar-Apr-May), AMJ (Apr-May-Jun), and JJA (Jun-Jul-Aug) which means the model is reliable to forecast rainfall distribution over Cimanuk watersheds region (over West Java) on those seasons. CCA score over those season prediction mostly over 0.7. The accuracy of the model CPT also indicated by the Relative Operating Characteristic (ROC) curve of the results of Pearson correlation 3 representative point of sub-watershed (Sumedang, Majalengka, and Cirebon), were mostly located in the top line of non-skill, and evidenced by the same of rainfall patterns between observation and forecast. So, the model of CPT with CCA method

  10. Mode of action of sodium arsenate on laboratory colonies of the pharaoh's ant Monomorium pharaonis L

    Energy Technology Data Exchange (ETDEWEB)

    Berndt, K P

    1974-01-01

    Arsenate compounds for pest control have been displayed on large scale by modern insecticides. In the control of the pharaoh's ant the arsenates however still remain an important means for eradication. The present study points out, that the mortality of workers and queens, respectively, are not the decisive factors of action as assumed until now. The causes for the extinction of the ant colonies after application of sodium arsenate are based on a combination of larval mortality and the induction of sterility in the queens, the sterility being the most important factor. A number of other factors moreover are working advantageously. First, the poison bait is not repellent and is well accepted by the workers, and is either stored in the nest or distributed trophalactically. Whereas with the workers there occurs a strongly delayed mortality, the larvae are being inhibited in their development after a few hours, shortly before pupation, or they are being paralyzed, whereby the further pupation would by cut off. The younger larvae normally do not come to pupation, but are being stunted and would be eliminated from the nest. The reproducing females, being the last members in the social chain, are protected in the polygynous society from the lethal action of the poison, although otherwise susceptible in the same way as workers. After a certain time sub-lethal doses of sodium arsenate lead to a decrease in fecundity. Egg production is suppressed dependent on the duration of the poison application up to permanent sterility. On the basis of these investigations some suggestions for practical control of the pharaoh's ant have been derived.

  11. Desulfohalophilus alkaliarsenatis gen. nov., sp. nov., an extremely halophilic sulfate- and arsenate-respiring bacterium from Searles Lake, California

    Science.gov (United States)

    Blum, Jodi Switzer; Kulp, Thomas R.; Han, Sukkyun; Lanoil, Brian; Saltikov, Chad W.; Stolz, John F.; Miller, Laurence G.; Oremland, Ronald S.

    2012-01-01

    A haloalkaliphilic sulfate-respiring bacterium, strain SLSR-1, was isolated from a lactate-fed stable enrichment culture originally obtained from the extreme environment of Searles Lake, California. The isolate proved capable of growth via sulfate-reduction over a broad range of salinities (125–330 g/L), although growth was slowest at salt-saturation. Strain SLSR-1 was also capable of growth via dissimilatory arsenate-reduction and displayed an even broader range of salinity tolerance (50–330 g/L) when grown under these conditions. Strain SLSR-1 could also grow via dissimilatory nitrate reduction to ammonia. Growth experiments in the presence of high borate concentrations indicated a greater sensitivity of sulfate-reduction than arsenate-respiration to this naturally abundant anion in Searles Lake. Strain SLSR-1 contained genes involved in both sulfate-reduction (dsrAB) and arsenate respiration (arrA). Amplicons of 16S rRNA gene sequences obtained from DNA extracted from Searles Lake sediment revealed the presence of close relatives of strain SLSR-1 as part of the flora of this ecosystem despite the fact that sulfate-reduction activity could not be detected in situ. We conclude that strain SLSR-1 can only achieve growth via arsenate-reduction under the current chemical conditions prevalent at Searles Lake. Strain SLSR-1 is a deltaproteobacterium in the family Desulfohalobiacea of anaerobic, haloalkaliphilic bacteria, for which we propose the name Desulfohalophilus alkaliarsenatis gen. nov., sp. nov.

  12. Different arsenate and phosphate incorporation effects on the nucleation and growth of iron(III) (Hydr)oxides on quartz.

    Science.gov (United States)

    Neil, Chelsea W; Lee, Byeongdu; Jun, Young-Shin

    2014-10-21

    Iron(III) (hydr)oxides play an important role in the geochemical cycling of contaminants in natural and engineered aquatic systems. The ability of iron(III) (hydr)oxides to immobilize contaminants can be related to whether the precipitates form heterogeneously (e.g., at mineral surfaces) or homogeneously in solution. Utilizing grazing incidence small-angle X-ray scattering (GISAXS), we studied heterogeneous iron(III) (hydr)oxide nucleation and growth on quartz substrates for systems containing arsenate and phosphate anions. For the iron(III) only system, the radius of gyration (Rg) of heterogeneously formed precipitates grew from 1.5 to 2.5 (± 1.0) nm within 1 h. For the system containing 10(-5) M arsenate, Rg grew from 3.6 to 6.1 (± 0.5) nm, and for the system containing 10(-5) M phosphate, Rg grew from 2.0 to 4.0 (± 0.2) nm. While the systems containing these oxyanions had more growth, the system containing only iron(III) had the most nucleation events on substrates. Ex situ analyses of homogeneously and heterogeneously formed precipitates indicated that precipitates in the arsenate system had the highest water content and that oxyanions may bridge iron(III) hydroxide polymeric embryos to form a structure similar to ferric arsenate or ferric phosphate. These new findings are important because differences in nucleation and growth rates and particle sizes will impact the number of available reactive sites and the reactivity of newly formed particles toward aqueous contaminants.

  13. Economic evaluation of zinc and copper use in treating acute diarrhea in children: A randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Dhande Leena A

    2003-08-01

    Full Text Available Abstract Background The therapeutic effects of zinc and copper in reducing diarrheal morbidity have important cost implications. This health services research study evaluated the cost of treating a child with acute diarrhea in the hospital, the impact of micronutrient supplementation on the mean predicted costs and its cost-effectiveness as compared to using only standard oral rehydration solution (ORS, from the patient's and government's (providers perspective. Methods Children aged 6 months to 59 months with acute diarrhea were randomly assigned to receive either the intervention or control. The intervention was a daily dose of 40 mg of zinc sulfate and 5 mg of copper sulfate powder dissolved in a liter of standard ORS (n = 102. The control was 50 mg of standard ORS powder dissolved in a liter of standard ORS (n = 98. The cost measures were the total mean cost of treating acute diarrhea, which included the direct medical, the direct non-medical and the indirect costs. The effectiveness measures were the probability of diarrhea lasting ≤ 4 days, the disability adjusted life years (DALYs and mortality. Results The mean total cost of treating a child with acute diarrhea was US $14 of which the government incurred an expenditure of 66%. The factors that increased the total were the number of stools before admission (p = 0.01, fever (p = 0.01, increasing grade of dehydration (p = 0.00, use of antibiotics (p = 0.00, use of intra-venous fluids (p = 0.00, hours taken to rehydrate a child (p = 0.00, the amount of oral rehydration fluid used (p = 0.00, presence of any complications (p = 0.00 and the hospital stay (p = 0.00. The supplemented group had a 8% lower cost of treating acute diarrhea, their cost per unit health (diarrhea lasting ≤ 4 days was 24% less and the incremental cost-effectiveness ratio indicated cost savings (in Rupees with the intervention [-452; 95%CI (-11306, 3410]. However these differences failed to reach conventional levels

  14. Mediator, SWI/SNF and SAGA complexes regulate Yap8-dependent transcriptional activation of ACR2 in response to arsenate.

    Science.gov (United States)

    Menezes, Regina Andrade; Pimentel, Catarina; Silva, Ana Rita Courelas; Amaral, Catarina; Merhej, Jawad; Devaux, Frédéric; Rodrigues-Pousada, Claudina

    2017-04-01

    Response to arsenic stress in Saccharomyces cerevisiae is orchestrated by the regulatory protein Yap8, which mediates transcriptional activation of ACR2 and ACR3. This study contributes to the state of art knowledge of the molecular mechanisms underlying yeast stress response to arsenate as it provides the genetic and biochemical evidences that Yap8, through cysteine residues 132, 137, and 274, is the sensor of presence of arsenate in the cytosol. Moreover, it is here reported for the first time the essential role of the Mediator complex in the transcriptional activation of ACR2 by Yap8. Based on our data, we propose an order-of-function map to recapitulate the sequence of events taking place in cells injured with arsenate. Modification of the sulfhydryl state of these cysteines converts Yap8 in its activated form, triggering the recruitment of the Mediator complex to the ACR2/ACR3 promoter, through the interaction with the tail subunit Med2. The Mediator complex then transfers the regulatory signals conveyed by Yap8 to the core transcriptional machinery, which culminates with TBP occupancy, ACR2 upregulation and cell adaptation to arsenate stress. Additional co-factors are required for the transcriptional activation of ACR2 by Yap8, particularly the nucleosome remodeling activity of SWI/SNF and SAGA complexes. Copyright © 2017. Published by Elsevier B.V.

  15. Antibacterial effect of silk treated with silver and copper nanoparticles synthesized by pulsed laser ablation in distilled water

    Science.gov (United States)

    Baruah, Prahlad K.; Raman, Moghe A.; Chakrabartty, Ishani; Rangan, Latha; Sharma, Ashwini K.; Khare, Alika

    2018-05-01

    The antibacterial activity of three kinds of silks viz. Eri, Pat and Muga treated with silver and copper nanoparticles is reported in this paper. The nanoparticles have been synthesized by pulsed laser ablation of the respective metal targets in distilled water. Treatment of the silk pellets with the synthesized nanoparticles exhibited definite antibacterial activity whereas no such activity is observed in the untreated silk pellets.

  16. Conversion of agricultural residues into activated carbons for water purification: Application to arsenate removal.

    Science.gov (United States)

    Torres-Perez, Jonatan; Gerente, Claire; Andres, Yves

    2012-01-01

    The conversion of two agricultural wastes, sugar beet pulp and peanut hulls, into sustainable activated carbons is presented and their potential application for the treatment of arsenate solution is investigated. A direct and physical activation is selected as well as a simple chemical treatment of the adsorbents. The material properties, such as BET surface areas, porous volumes, elemental analysis, ash contents and pH(PZC), of these alternative carbonaceous porous materials are determined and compared with a commercial granular activated carbon. An adsorption study based on experimental kinetic and equilibrium data is conducted in a batch reactor and completed by the use of different models (intraparticle diffusion, pseudo-second-order, Langmuir and Freundlich) and by isotherms carried out in natural waters. It is thus demonstrated that sugar beet pulp and peanut hulls are good precursors to obtain activated carbons for arsenate removal.

  17. Carotid stenosis measurement on colour Doppler ultrasound: Agreement of ECST, NASCET and CCA methods applied to ultrasound with intra-arterial angiographic stenosis measurement

    International Nuclear Information System (INIS)

    Wardlaw, Joanna M.; Lewis, Steff

    2005-01-01

    Purpose: Carotid stenosis is usually determined on Doppler ultrasound from velocity readings. We wondered if angiography-style stenosis measurements applied to ultrasound images improved accuracy over velocity readings alone, and if so, which measure correlated best with angiography. Materials and methods: We studied prospectively patients undergoing colour Doppler ultrasound (CDU) for TIA or minor stroke. Those with 50%+ symptomatic internal carotid artery (ICA) stenosis had intra-arterial angiography (IAA). We measured peak systolic ICA velocity, and from the ultrasound image, the minimal residual lumen, the original lumen (ECST), ICA diameter distal (NASCET) and CCA diameter proximal (CCA method) to the stenosis. The IAAs were measured by ECST, NASCET and CCA methods also, blind to CDU. Results: Amongst 164 patients (328 arteries), on CDU the ECST, NASCET and CCA stenosis measures were similarly related to each other (ECST = 0.54 NASCET + 46) as on IAA (ECST = 0.6 NASCET + 40). Agreement between CDU- and IAA-measured stenosis was similar for ECST (r = 0.51), and CCA (r = 0.48) methods, and slightly worse for NASCET (r = 0.41). Adding IAA-style stenosis to the peak systolic ICA velocity did not improve agreement with IAA over peak systolic velocity alone. Conclusion: Angiography-style stenosis measures have similar inter-relationships when applied to CDU, but do not improve accuracy of ultrasound over peak systolic ICA velocity alone

  18. A Case of Isolated Elevated Copper Levels during Pregnancy

    Directory of Open Access Journals (Sweden)

    LaToya R. Walker

    2011-01-01

    Full Text Available Introduction. Outside of Wilson's Disease, abnormal copper metabolism is a rare condition. In pregnancy, excess copper levels can be associated with intrauterine growth restriction, preeclampsia and neurological disease. Case Report. A 32 year old Gravida 4 para 2012 with an obstetrical history complicated by elevated copper levels presented for routine prenatal care. Her children had elevated copper levels at birth, with her firstborn child being diagnosed with autism and suffering three myocardial infarctions and being treated for elevated copper levels. During her prior pregnancies, she declined treatment for her elevated copper levels. During this pregnancy, she had declined chelation therapy and instead choose zinc therapy. She delivered a healthy infant with normal copper levels. Conclusion. Alterations in copper metabolism are rare, the consequences in pregnancy can be devastating. While isolated elevations of copper in pregnancy is exceedingly rare, it is treated the same as Wilson's disease. The goal is to prevent fetal growth restricting and neurological sequelae in the newborn and preeclampsia in the mother. Counseling, along with treatment options and timely delivery can greatly improve neonatal and maternal outcome.

  19. Presidential Green Chemistry Challenge: 2002 Designing Greener Chemicals Award

    Science.gov (United States)

    Presidential Green Chemistry Challenge 2002 award winner, Chemical Specialties, developed an alkaline copper quaternary wood preservative to replace chromated copper arsenate preservative phased out due to risk to children.

  20. The Effects of Natural Weathering on Color Stability of Impregnated and Varnished Wood Materials

    Directory of Open Access Journals (Sweden)

    Turkay Turkoglu

    2015-01-01

    Full Text Available The aim of this study was to investigate effects of natural weathering on color stability of Scots pine (Pinus sylvestris L. and Oriental beech (Fagus orientalis L. impregnated with some chemicals [tanalith-E (TN-E, adolit-KD5 (AD-KD5, and chromated copper arsenate (CCA] and then varnished [synthetic varnish (SV and polyurethane varnish (PV]. While applying varnish increased lightness, impregnation decreased lightness of the wood specimens before natural weathering. Natural weathering caused greenish, bluish, and dark color tones of the wood surface. Total color change was increased with increasing exposure times in natural weathering. Untreated (control wood specimens exhibited higher color changes than the other wood specimens in all the stages of natural weathering. The total color changes of untreated Oriental beech specimens were less than untreated Scots pine specimens. The color stability of impregnated and varnished wood specimens gave better results than untreated and solely varnished wood specimens after natural weathering. The best color stability was obtained from both Oriental beech and Scots pine wood impregnated with TN-E before PV coating.

  1. The removal of arsenate from water using iron-modified diatomite (D-Fe): isotherm and column experiments.

    Science.gov (United States)

    Pantoja, M L; Jones, H; Garelick, H; Mohamedbakr, H G; Burkitbayev, M

    2014-01-01

    Iron hydroxide supported onto porous diatomite (D-Fe) is a low-cost material with potential to remove arsenic from contaminated water due to its affinity for the arsenate ion. This affinity was tested under varying conditions of pH, contact time, iron content in D-Fe and the presence of competitive ions, silicate and phosphate. Batch and column experiments were conducted to derive adsorption isotherms and breakthrough behaviours (50 μg L(-1)) for an initial concentration of 1,000 μg L(-1). Maximum capacity at pH 4 and 17% iron was 18.12-40.82 mg of arsenic/g of D-Fe and at pH 4 and 10% iron was 18.48-29.07 mg of arsenic/g of D-Fe. Adsorption decreased in the presence of phosphate and silicate ions. The difference in column adsorption behaviour between 10% and 17% iron was very pronounced, outweighing the impact of all other measured parameters. There was insufficient evidence of a correlation between iron content and arsenic content in isotherm experiments, suggesting that ion exchange is a negligible process occurring in arsenate adsorption using D-Fe nor is there co-precipitation of arsenate by rising iron content of the solute above saturation.

  2. Arsenic leaching and speciation in C&D debris landfills and the relationship with gypsum drywall content.

    Science.gov (United States)

    Zhang, Jianye; Kim, Hwidong; Dubey, Brajesh; Townsend, Timothy

    2017-01-01

    The effects of sulfide levels on arsenic leaching and speciation were investigated using leachate generated from laboratory-scale construction and demolition (C&D) debris landfills, which were simulated lysimeters containing various percentages of gypsum drywall. The drywall percentages in lysimeters were 0, 1, 6, and 12.4wt% (weight percent) respectively. With the exception of a control lysimeter that contained 12.4wt% of drywall, each lysimeter contained chromated copper arsenate (CCA) treated wood, which accounts for 10wt% of the C&D waste. During the period of study, lysimeters were mostly under anaerobic conditions. Leachate analysis results showed that sulfide levels increased as the percentage of drywall increased in landfills, but arsenic concentrations in leachate were not linearly correlated with sulfide levels. Instead, the arsenic concentrations decreased as sulfide increased up to approximately 1000μg/L, but had an increase with further increase in sulfide levels, forming a V-shape on the arsenic vs. sulfide plot. The analysis of arsenic speciation in leachate showed different species distribution as sulfide levels changed; the fraction of arsenite (As(III)) increased as the sulfide level increased, and thioarsenate anions (As(V)) were detected when the sulfide level further increased (>10 4 μg/L). The formation of insoluble arsenic sulfide minerals at a lower range of sulfide and soluble thioarsenic anionic species at a higher range of sulfide likely contributed to the decreasing and increasing trend of arsenic leaching. Copyright © 2016. Published by Elsevier Ltd.

  3. Structural, optical, and redox properties of lamellar solids derived from copper(I) complexes and n-butylammonium uranyl phosphate and arsenate

    International Nuclear Information System (INIS)

    Jacob, A.T.; Ellis, A.B.

    1989-01-01

    A family of hydrated, layered solids has been prepared from intercalative ion-exchange reactions of n-butylammonium uranyl phosphate (BAUP) or arsenate (BAUAs), (n-C 4 H 9 NH 3 )UO 2 EO 4 ·3H 2 O (E = P, As), with Cu(LL) 2 + complexes (LL is dmp = 2,9-dimethyl-1,10-phenanthroline or bcp = 2,9-dimethyl-4,7-dipheyl-1,10-phenanthroline). The products obtained were analyzed as having compositions [Cu(LL) 2 ] x [BA] 1-x UO 2 EO 4 ·2H 2 O with x ∼ 0.2. X-ray powder diffraction data reveal that the compounds are single phases that can be indexed on the basis of a tetragonal unit cell. The solids exhibit absorption and photoluminescence (PL) properties characteristic of the Cu(LL) 2 + species; the Cu(I) complexes completely quench the uranyl PL. Once intercalated, the Cu(I) complexes can be oxidized by using Br 2 vapor and rereduced either by photochemical means or by N 2 H 4 vapor, as shown by changes in electronic and EPR spectra. 37 refs., 7 figs., 2 tabs

  4. Role of uniform pore structure and high positive charges in the arsenate adsorption performance of Al13-modified montmorillonite

    International Nuclear Information System (INIS)

    Zhao, Shou; Feng, Chenghong; Huang, Xiangning; Li, Baohua; Niu, Junfeng; Shen, Zhenyao

    2012-01-01

    Highlights: ► Al 13 modification changes As(V) sorption mechanism of montmorillonites. ► Intercalated ion charges mainly affects As(V) adsorption kinetics. ► Uniform pore structure exhibit more excellent As(V) adsorption performance. - Abstract: Four modified montmorillonite adsorbents with varied Al 13 contents (i.e., Na-Mont, AC-Mont, PAC 20 -Mont, and Al 13 -Mont) were synthesized and characterized by N 2 adsorption/desorption, X-ray diffraction, and Fourier-transform infrared analyses. The arsenate adsorption performance of the four adsorbents were also investigated to determine the role of intercalated Al 13 , especially its high purity, high positive charge (+7), and special Keggin structure. With increased Al 13 content, the physicochemical properties (e.g., surface area, structural uniformity, basal spacing, and pore volume) and adsorption performance of the modified montmorillonites were significantly but disproportionately improved. The adsorption data well fitted the Freundlich and Redlich–Peterson isotherm model, whereas the kinetic data better correlated with the pseudo-second-order kinetic model. The arsenate sorption mechanism of the montmorillonites changed from physical to chemisorption after intercalation with Al 13 . Increasing charges of the intercalated ions enhanced the arsenate adsorption kinetics, but had minimal effect on the structural changes of the montmorillonites. The uniform pore structure formed by intercalation with high-purity Al 13 greatly enhanced the pore diffusion and adsorption rate of arsenate, resulting in the high adsorption performance of Al 13 -Mont.

  5. A Pseudoproxy-Ensemble Study of Late-Holocene Climate Field Reconstructions Using CCA

    Science.gov (United States)

    Amrhein, D. E.; Smerdon, J. E.

    2009-12-01

    Recent evaluations of late-Holocene multi-proxy reconstruction methods have used pseudoproxy experiments derived from millennial General Circulation Model (GCM) integrations. These experiments assess the performance of a reconstruction technique by comparing pseudoproxy reconstructions, which use restricted subsets of model data, against complete GCM data fields. Most previous studies have tested methodologies using different pseudoproxy noise levels, but only with single realizations for each noise classification. A more robust evaluation of performance is to create an ensemble of pseudoproxy networks with distinct sets of noise realizations and a corresponding reconstruction ensemble that can be evaluated for consistency and sensitivity to random error. This work investigates canonical correlation analysis (CCA) as a late-Holocene climate field reconstruction (CFR) technique using ensembles of pseudoproxy experiments derived from the NCAR CSM 1.4 millennial integration. Three 200-member reconstruction ensembles are computed using pseudoproxies with signal-to-noise ratios (by standard deviation) of 1, 0.5, and 0.25 and locations that approximate the spatial distribution of real-world multiproxy networks. An important component of these ensemble calculations is the independent optimization of the three CCA truncation parameters for each ensemble member. This task is accomplished using an inexpensive discrete optimization algorithm that minimizes both RMS error in the calibration interval and the number of free parameters in the reconstruction model to avoid artificial skill. Within this framework, CCA is investigated for its sensitivity to the level of noise in the pseudoproxy network and the spatial distribution of the network. Warm biases, variance losses, and validation-interval error increase with noise level and vary spatially within the reconstructed fields. Reconstruction skill, measured as grid-point correlations during the validation interval, is lowest in

  6. Characterization of ferric arsenate-sulfate compounds: Implications for arsenic control in refractory gold processing residues

    Czech Academy of Sciences Publication Activity Database

    Paktunc, D.; Majzlan, J.; Palatinus, Lukáš; Dutrizac, J.; Klementová, Mariana; Poirier, G.

    2013-01-01

    Roč. 98, č. 4 (2013), s. 554-565 ISSN 0003-004X Institutional support: RVO:68378271 Keywords : arsenic * ferric arsenate sulfate * autoclave residue * hydrometallurgy Subject RIV: DB - Geology ; Mineralogy Impact factor: 2.059, year: 2013

  7. Estudio psicométrico del Cuestionario de Conducta Antisocial (CC-A en adolescentes tempranos de Tucumán, Argentina

    Directory of Open Access Journals (Sweden)

    Ana Betina Lacunza

    2016-01-01

    Full Text Available El comportamiento antisocial se refiere a una diversidad de actos que infringen las normas sociales y de convivencia. Su delimitación está dada tanto por la valoración social de la gravedad de los comportamientos como por su alejamiento a las pautas normativas de una sociedad. El objetivo de este trabajo fue analizar las propiedades psicométricas del cuestionario de Conducta Antisocial (CC-A en adolescentes de Tucumán, Argentina. Se aplicó el CC-A y la Batería de Socialización BAS-3 a quinientos once adolescentes escolarizados de once y doce años. Se encontró una solución de tres factores que explicaban el 35 % de la varianza, congruente con la propuesta original. Los coeficientes Alpha de Cronbach fueron adecuados en Agresividad (.735, Aislamiento (.769 y Ansiedad/Retraimiento (.681, y se establecieron relaciones entre CC-A y BAS-3. Así mismo, se observaron correlaciones negativas entre Agresividad, Consideración con los demás y Autocontrol mientras que fueron positivas entre Aislamiento y Retraimiento. Posteriormente, se determinaron las categorías percentilares de esta versión (CC-A de ventiocho ítems; 18% de los adolescentes presentaban percentiles de riesgo en Agresividad mientras que un 20.9% lo hacía en Aislamiento. El estudio aporta datos con respecto a las propiedades psicométricas del instrumento en población local, indicando su sensibilidad para la evaluación del comportamiento antisocial.

  8. A Study of Protection of Copper Alloys

    International Nuclear Information System (INIS)

    Kim, E. A.; Kim, S. H.; Kim, C. R.

    1974-01-01

    Volatile treatment of high capacity boiler water with hydrazine and ammonia is studied. Ammonia comes from the decomposition of excess hydrazine injected to treat dissolved oxygen. Ammonia is also injected for the control of pH. To find an effect of such ammonia on the copper alloy, the relations between pH and iron, and ammonia and copper are studied. Since the dependence of corrosion of iron on pH differs from that of copper, a range of pH was selected experimentally to minimize the corrosion rates of both copper and iron. Corrosion rates of various copper alloys are also compared

  9. Evaluation and optimization of the Circulating Cathodic Antigen (POC-CCA) cassette test for detecting Schistosoma mansoni infection by using image analysis in school children in Mwanza Region, Tanzania

    DEFF Research Database (Denmark)

    Partal, Miriam Casacuberta; Kinunghi, Safari; Vennervald, Birgitte J

    2016-01-01

    of Lake Victoria in Mwanza Region, Tanzania, and to optimize the reading of the POC-CCA test lines by using a computer software image analysis. Initially, a pilot study in 106 school children indicated that time of urine collection did not have an impact on CCA results as 84.9% (90) had identical scores...... POC-CCAs were compared to six Kato-Katz smears (75.0% vs. 42.6%; p reading of the POC-CCA, a Software...... tool (Image Studio Lite®) was used to read and quantify the colour (expressed as pixels) of the test line on all positive tests, showing a positive correlation between number of pixels and the visually scored intensities and between number of pixels and egg counts. In conclusion, the POC-CCA assay...

  10. Two Lactococcus lactis thioredoxin paralogues play different roles in responses to arsenate and oxidative stress

    DEFF Research Database (Denmark)

    Efler, Petr; Kilstrup, Mogens; Johnsen, Stig

    2015-01-01

    Thioredoxin (Trx) maintains intracellular thiol groups in a reduced state and is involved in a wide range of cellular processes, including ribonucleotide reduction, sulphur assimilation, oxidative stress responses and arsenate detoxification. The industrially important lactic acid bacterium...... Lactococcus lactis contains two Trxs. TrxA is similar to the well-characterized Trx homologue from Escherichia coli and contains the common WCGPC active site motif, while TrxD is atypical and contains an aspartate residue in the active site (WCGDC). To elucidate the physiological roles of the two Trx...... to the wild-type. The lack of TrxA also appears to impair methionine sulphoxide reduction. Both ΔtrxA and ΔtrxD strains displayed growth inhibition after treatment with sodium arsenate and tellurite as compared with the wild-type, suggesting partially overlapping functions of TrxA and TrxD. Overall...

  11. Crystal structures of CCa2CuO5 and CSr1.9Ca1.1Cu2O7 refined from single crystal data

    International Nuclear Information System (INIS)

    Kopnin, E.M.; Matveev, A.T.; Salamakha, P.S.; Sato, A.; Takayama-Muromachi, E.

    2003-01-01

    Single crystals were grown for new layered oxycarbonates CCa 2 CuO 5 and CSr 1.9 Ca 1.1 Cu 2 O 7 at 6 GPa using a belt-type apparatus. Their crystal structures were determined using single crystal X-ray diffraction data with R1(wR2)=0.0294(0.0659) and 0.0199(0.0457) for CCa 2 CuO 5 and CSr 1.9 Ca 1.1 Cu 2 O 7 , respectively. These phases crystallize in the space group P4/mmm (No. 123), Z=1 with a=3.8157(1) Angst, c=7.1426(3) Angst for CCa 2 CuO 5 and a=3.8753(1) Angst, c=10.6765(5) Angst for CSr 1.9 Ca 1.1 Cu 2 O 7 . In contrast to CSr 2 CuO 5 , no ordering in the orientation of the triangular CO 3 groups was revealed in CCa 2 CuO 5 and CSr 1.9 Ca 1.1 Cu 2 O 7

  12. Sulfidation treatment of copper-containing plating sludge towards copper resource recovery.

    Science.gov (United States)

    Kuchar, D; Fukuta, T; Onyango, M S; Matsuda, H

    2006-11-02

    The present study is concerned with the sulfidation treatment of copper-containing plating sludge towards copper resource recovery by flotation of copper sulfide from treated sludge. The sulfidation treatment was carried out by contacting simulated or real copper plating sludge with Na(2)S solution for a period of 5 min to 24 h. The initial molar ratio of S(2-) to Cu(2+) (S(2-) to Me(2+) in the case of real sludge) was adjusted to 1.00, 1.25 or 1.50, while the solid to liquid ratio was set at 1:50. As a result, it was found that copper compounds were converted to various copper sulfides within the first 5 min. In the case of simulated copper sludge, CuS was identified as the main sulfidation product at the molar ratio of S(2-) to Cu(2+) of 1.00, while Cu(7)S(4) (Roxbyite) was mainly found at the molar ratios of S(2-) to Cu(2+) of 1.50 and 1.25. Based on the measurements of oxidation-reduction potential, the formation of either CuS or Cu(7)S(4) at different S(2-) to Cu(2+) molar ratios was attributed to the changes in the oxidation-reduction potential. By contrast, in the case of sulfidation treatment of real copper sludge, CuS was predominantly formed, irrespective of S(2-) to Me(2+) molar ratio.

  13. Investigating the influence of heavy metals on macro-invertebrate assemblages using Partial Cononical Correspondence Analysis (pCCA)

    Science.gov (United States)

    Beasley, Gary; Kneale, Pauline E.

    This paper defines the spectrum of impairment to stream macroinvertebrates arising from urban runoff. Field sampling of stream sediments at 62 sites across Yorkshire, UK was used to investigate the influence of heavy metals and habitat on macroinvertebrate family distribution using partial Canonical Correspondence Analysis (pCCA). Increasing urbanization and trafficking was associated with increasing levels of metal pollution but, even when traffic is light, family numbers can be reduced by 50%. Industrial areas and motorway runoff depress macroinvertebrate numbers but drainage from streets with no off-road parking in residential areas can have similar impacts. The heavy metals in the sediment accounted for approximately 24% of the variation in macroinvertebrate community composition while the physical habitat variables used in RIVPACS (River InVertebrate Prediction And Classification System) (Wright, 2000) accounted for an additional 30%. Zinc and nickel were the main metal influences regardless of the time of sampling; at these sites copper is less than critical. Results agree with those reported in other studies in which families mainly from the orders Ephemeroptera (mayfly), Plecoptera (stonefly) and Tricoptera (caddisfly) displayed metal sensitivity in that they were absent from metal polluted streams. However, within each of these orders, a continuum of sensitivity is evident: this highlights the risks of generalising on orders rather than using family or indeed species data.

  14. [Influence of elevated homocystein level and selected lipid parameters in kidney transplant patients on the progression of atherosclerotic changes assessed by intima-media thickness index (CCA-IMT)].

    Science.gov (United States)

    Janda, Katarzyna; Aksamit, Dariusz; Drozdz, Maciej; Krzanowski, Marcin; Ignacak, Ewa; Kowalczyk-Michałek, Martyna; Tabor-Ciepiela, Barbara; Sułowicz, Władysław

    2012-01-01

    The aim of the study was to evaluate the influence of elevated homocystein (Hcy) level and selected lipid parameters on the progression of atherosclerotic changes in patients after kidney transplantation (KTx). The study included 51 pts (17 F, 34 M) aged 15-62 years (median 38.1) after cadaver KTx. The mean observation period equaled 21.2 months (6-24 months); while total observation period was 90 patients/ years. Hcy levels was measured using HPLC, Lp(a) and Apo-B levels using the nephelometric method and total cholesterol with its' HDL and LDL fractions, triglycerides and creatinine based on the Hitachi 917 analyzer. Patients' blood was drawn before renal transplantation and 3, 6, 9, 12, 15, 18, 21 and 24 months after KTx. Common carotid artery intima media thickness (CCA-IMT) was evaluated by ultrasound on 14 days, 12 and 24 months after KTx. CCA-IMT correlated significantly with Hcy levels after 12 months (R=0.53; p=0.0009) and 24 months (R=0.38; p=0.0356) after KTx. Significant differences were found 12 and 24 months after KTx in CCA-IMT between patients with normal (15 micromol/ l) mean Hcy concentrations: p=0.0035 and p= 0.015, respectively. Analyzing changes in CCA-IMT, significant differences were noted when comparing the CCA-IMT increment after 12 and 24 months post KTx in patients with normal (15 micromol/l) homocystein concentrations: p=0.049 and p=0.0039, respectively. Increment of CCA-IMT 12 months after KTx, significantly correlated with mean total cholesterol level (R=0.35; p=0.0333), whereas 24 months after procedure correlated significantly with 0.0315). Hcy level is an independent risk factor for atherosclerosis development in patients after KTx. Elevated Hcy level as well as increased cholesterol and Lp(a) levels enhance the progression of atherosclerotic changes evaluated by CCA-IMT in KTx patients.

  15. A new version of code Java for 3D simulation of the CCA model

    Science.gov (United States)

    Zhang, Kebo; Xiong, Hailing; Li, Chao

    2016-07-01

    In this paper we present a new version of the program of CCA model. In order to benefit from the advantages involved in the latest technologies, we migrated the running environment from JDK1.6 to JDK1.7. And the old program was optimized into a new framework, so promoted extendibility.

  16. Hydrothermally treated chitosan hydrogel loaded with copper and zinc particles as a potential micro-nutrient based antimicrobial feed additive

    Directory of Open Access Journals (Sweden)

    Parthiban eRajasekaran

    2015-11-01

    Full Text Available Large-scale use of antibiotics in food animal farms as growth promoters is considered as one of the driving factors behind increasing incidence of microbial resistance. Several alternatives are under investigation to reduce the amount of total antibiotics used in order to avoid any potential transmission of drug resistant microbes to humans through food chain. Copper sulfate and zinc oxide salts are used as feed supplement as they exhibit antimicrobial properties in addition to being micronutrients. However, higher dosage of copper and zinc (often needed for growth promoting effect to animals is not advisable because of potential environmental toxicity arising from excreta. Innovative strategies are needed to utilize the complete potential of trace minerals as growth promoting feed supplements. To this end, we describe here the development and preliminary characterization of hydrothermally treated chitosan as a delivery vehicle for copper and zinc nanoparticles that could act as a micronutrient based antimicrobial feed supplement. Material characterization studies showed that hydrothermal treatment makes a chitosan hydrogel that re-arranged to capture the copper and zinc metal particles. Systemic antimicrobial assays showed that this chitosan biopolymer matrix embedded with copper (57.6 μg/ml and zinc (800 μg/ml reduced the load of model gut-bacteria (target organisms of growth promoting antibiotics such as Escherichia coli, Enterococcus faecalis, Staphylococcus aureus and Lactobacillus fermentum under in vitro conditions. Particularly, the chitosan/copper/zinc hydrogel exhibited significantly higher antimicrobial effect against L. fermentum, one of the primary targets of antibiotic growth promoters. Additionally, the chitosan matrix ameliorated the cytotoxicity levels of metal supplements when screened against a murine macrophage cell line RAW 264.7 and in TE-71, a murine thymic epithelial cell line. In this proof of concept study, we show

  17. metaCCA: summary statistics-based multivariate meta-analysis of genome-wide association studies using canonical correlation analysis.

    Science.gov (United States)

    Cichonska, Anna; Rousu, Juho; Marttinen, Pekka; Kangas, Antti J; Soininen, Pasi; Lehtimäki, Terho; Raitakari, Olli T; Järvelin, Marjo-Riitta; Salomaa, Veikko; Ala-Korpela, Mika; Ripatti, Samuli; Pirinen, Matti

    2016-07-01

    A dominant approach to genetic association studies is to perform univariate tests between genotype-phenotype pairs. However, analyzing related traits together increases statistical power, and certain complex associations become detectable only when several variants are tested jointly. Currently, modest sample sizes of individual cohorts, and restricted availability of individual-level genotype-phenotype data across the cohorts limit conducting multivariate tests. We introduce metaCCA, a computational framework for summary statistics-based analysis of a single or multiple studies that allows multivariate representation of both genotype and phenotype. It extends the statistical technique of canonical correlation analysis to the setting where original individual-level records are not available, and employs a covariance shrinkage algorithm to achieve robustness.Multivariate meta-analysis of two Finnish studies of nuclear magnetic resonance metabolomics by metaCCA, using standard univariate output from the program SNPTEST, shows an excellent agreement with the pooled individual-level analysis of original data. Motivated by strong multivariate signals in the lipid genes tested, we envision that multivariate association testing using metaCCA has a great potential to provide novel insights from already published summary statistics from high-throughput phenotyping technologies. Code is available at https://github.com/aalto-ics-kepaco anna.cichonska@helsinki.fi or matti.pirinen@helsinki.fi Supplementary data are available at Bioinformatics online. © The Author 2016. Published by Oxford University Press.

  18. Micronized copper wood preservatives: An efficiency and potential health risk assessment for copper-based nanoparticles

    International Nuclear Information System (INIS)

    Civardi, Chiara; Schwarze, Francis W.M.R.; Wick, Peter

    2015-01-01

    Copper (Cu) is an essential biocide for wood protection, but fails to protect wood against Cu-tolerant wood-destroying fungi. Recently Cu particles (size range: 1 nm–25 μm) were introduced to the wood preservation market. The new generation of preservatives with Cu-based nanoparticles (Cu-based NPs) is reputedly more efficient against wood-destroying fungi than conventional formulations. Therefore, it has the potential to become one of the largest end uses for wood products worldwide. However, during decomposition of treated wood Cu-based NPs and/or their derivate may accumulate in the mycelium of Cu-tolerant fungi and end up in their spores that are dispersed into the environment. Inhaled Cu-loaded spores can cause harm and could become a potential risk for human health. We collected evidence and discuss the implications of the release of Cu-based NPs by wood-destroying fungi and highlight the exposure pathways and subsequent magnitude of health impact. - Highlights: • We compared copper particulate wood preservatives with conventional ones. • We assessed the fungicidal activity of particulate copper wood preservatives. • We reviewed the Cu-tolerance mechanisms of some wood-destroying fungi. • Fungi colonizing wood treated with particulate copper may release Cu-loaded spores. - We assess the fungicidal activity of particulate copper wood preservatives and their possible release in the air by Cu-tolerant wood-destroying fungi

  19. Removal of nano- and micronized-copper from treated wood by chelating agents

    Science.gov (United States)

    S. Nami Kartal; Evren Terzi; Bessie Woodward; Carol A. Clausen; Stan T. Lebow

    2013-01-01

    Micronized and nano-copper (Cu)-based and arsenic and chromium-free systems have received much attention for wood protection in recent years. Because they have different fixation, and micro-distribution properties, such copper systems may be more or less subject to release using known remediation methods than soluble forms of Cu. This study evaluated Cu recovery from...

  20. Embryotoxicity of arsenite and arsenate. Distribution in pregnant mice and monkeys and effects on embryonic cells in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Lindgren, A; Danielsson, R G; Dencker, L [Department of Toxicology, Biomedical Center, Uppsala University, Sweden; Vahter, M [National Institute of Environmental Medicine, Stockholm, Sweden

    1984-01-01

    The distribution of /sup 74/As-labelled and arsenite in pregnant mice and a monkey has been studied by autoradiography and gamma counting of isolated tissues, and their in vitro toxicity to a chondrogenic system has been investigated. With both arsenic forms, given as single intravenous injections to the mother, the /sup 74/As-arsenic appeared to pass the mouse placenta relatively freely and approximately to the same extent. The retention time in material tissues including the placenta was, however, around three times longer with arsenite than with arsenate. In early gestation, high activity was registered in the embryonic neuroepithelium, which correlates well with reported CNS malformations in rodents. In late gestation, the distribution pattern was more like that in the adults. Accumulation in skin and squamous epithelia of the upper gastrointestinal tract (oral cavity, oesophagus and oesophageal region of stomach) dominated the distribution picture, especially at a long survival interval. Arsenate, but not arsenite, showed affinity for the calcified areas of the skeleton. A marmoset monkey in late gestation receiving arsenite showed a somewhat lower rate of placental transfer than the mice. Skin and liver had the highest concentrations (at 8 hrs), both in mother and foetuses. This species is known not to methylate arsenic, resulting in stronger binding and longer retention times of arsenic as compared with other species. The stronger binding in maternal tissues may possibly explain the lower rate of placental transfer. Arsenite was shown to inhibit cartilage formation in a chick limb bud mesenchymal spot culture system (ED50 approximately 5-10..mu..M) while arsenate seemed to be without effect at concentrations up to 200 ..mu..M (highest tested). Arsenate, however, showed a potential of the arsenite toxicity.

  1. Improvement of POC-CCA Interpretation by Using Lyophilization of Urine from Patients with Schistosoma mansoni Low Worm Burden: Towards an Elimination of Doubts about the Concept of Trace.

    Directory of Open Access Journals (Sweden)

    Paulo Marcos Zech Coelho

    2016-06-01

    Full Text Available Accurate diagnostic techniques for schistosomiasis are essential for prevalence determination and identification of positive patients. A point-of-care test for detecting schistosome circulating cathodic antigen (POC-CCA has been evaluated for its accuracy in different endemic regions. This reagent strip/dipstick based assay has showed high sensitivity for individuals with high or moderate worm burden, but the interpretation of light infections is less clear, especially for trace readings.We introduced a urine lyophilization step to the POC-CCA assay to improve its sensitivity and clarify the interpretation of traces. We evaluated POC-CCA sensitivity and specificity within individuals with low parasite burdens in a Brazilian endemic area where a high number of traces were detected. Patients that were positive for other helminths were also evaluated for cross reactions. In all cases, a combined parasitological diagnosis using Kato-Katz (24 slides and Saline Gradient (1 g of feces were used as reference. At baseline, diagnosis by POC-CCA (1-2 cassettes showed 6% sensitivity, inaccurately predicting a low prevalence of Schistosoma mansoni infections (2 POC-CCA positives/32 egg positives. After urine lyophilization, the sensitivity was increased significantly (p < 0.05. Prevalence rates changed from 2% to 32% (27 POC-CCA positives/32 egg positives, equivalent to parasitological techniques. Most of the trace readings changed to positive after lyophilization while some negatives turned into traces. Cross reaction analysis confirmed the specificity of POC-CCA.Trace readings cannot be primarily defined as positive or negative cases. It is critical to verify case-by-case by concentrating urine 10 fold by lyophilization for the diagnosis. Following lyophilization, persistent trace readings should be read as negatives. No trained technician is needed and cost is restricted to the cost of a lyophilizer and the electricity to run it.

  2. CCA 3101/4101 Environmental Humanities: The History of a Unit through an Ecopedagogical Lens

    Science.gov (United States)

    Ryan, John Charles

    2012-01-01

    In 2011 the author taught, for the first time, the well-established unit CCA3101/4101 Environmental Humanities in the School of Communications and Arts at ECU (Edith Cowan University) in Western Australia. The unit has a 20-year history through associate professor Rod Giblett and parallels the development of the environmental humanities as a field…

  3. Expression profiling of Crambe abyssinica under arsenate stress identifies genes and gene networks involved in arsenic metabolism and detoxification

    Directory of Open Access Journals (Sweden)

    Kandasamy Suganthi

    2010-06-01

    Full Text Available Abstract Background Arsenic contamination is widespread throughout the world and this toxic metalloid is known to cause cancers of organs such as liver, kidney, skin, and lung in human. In spite of a recent surge in arsenic related studies, we are still far from a comprehensive understanding of arsenic uptake, detoxification, and sequestration in plants. Crambe abyssinica, commonly known as 'abyssinian mustard', is a non-food, high biomass oil seed crop that is naturally tolerant to heavy metals. Moreover, it accumulates significantly higher levels of arsenic as compared to other species of the Brassicaceae family. Thus, C. abyssinica has great potential to be utilized as an ideal inedible crop for phytoremediation of heavy metals and metalloids. However, the mechanism of arsenic metabolism in higher plants, including C. abyssinica, remains elusive. Results To identify the differentially expressed transcripts and the pathways involved in arsenic metabolism and detoxification, C. abyssinica plants were subjected to arsenate stress and a PCR-Select Suppression Subtraction Hybridization (SSH approach was employed. A total of 105 differentially expressed subtracted cDNAs were sequenced which were found to represent 38 genes. Those genes encode proteins functioning as antioxidants, metal transporters, reductases, enzymes involved in the protein degradation pathway, and several novel uncharacterized proteins. The transcripts corresponding to the subtracted cDNAs showed strong upregulation by arsenate stress as confirmed by the semi-quantitative RT-PCR. Conclusions Our study revealed novel insights into the plant defense mechanisms and the regulation of genes and gene networks in response to arsenate toxicity. The differential expression of transcripts encoding glutathione-S-transferases, antioxidants, sulfur metabolism, heat-shock proteins, metal transporters, and enzymes in the ubiquitination pathway of protein degradation as well as several unknown

  4. Expression profiling of Crambe abyssinica under arsenate stress identifies genes and gene networks involved in arsenic metabolism and detoxification

    Science.gov (United States)

    2010-01-01

    Background Arsenic contamination is widespread throughout the world and this toxic metalloid is known to cause cancers of organs such as liver, kidney, skin, and lung in human. In spite of a recent surge in arsenic related studies, we are still far from a comprehensive understanding of arsenic uptake, detoxification, and sequestration in plants. Crambe abyssinica, commonly known as 'abyssinian mustard', is a non-food, high biomass oil seed crop that is naturally tolerant to heavy metals. Moreover, it accumulates significantly higher levels of arsenic as compared to other species of the Brassicaceae family. Thus, C. abyssinica has great potential to be utilized as an ideal inedible crop for phytoremediation of heavy metals and metalloids. However, the mechanism of arsenic metabolism in higher plants, including C. abyssinica, remains elusive. Results To identify the differentially expressed transcripts and the pathways involved in arsenic metabolism and detoxification, C. abyssinica plants were subjected to arsenate stress and a PCR-Select Suppression Subtraction Hybridization (SSH) approach was employed. A total of 105 differentially expressed subtracted cDNAs were sequenced which were found to represent 38 genes. Those genes encode proteins functioning as antioxidants, metal transporters, reductases, enzymes involved in the protein degradation pathway, and several novel uncharacterized proteins. The transcripts corresponding to the subtracted cDNAs showed strong upregulation by arsenate stress as confirmed by the semi-quantitative RT-PCR. Conclusions Our study revealed novel insights into the plant defense mechanisms and the regulation of genes and gene networks in response to arsenate toxicity. The differential expression of transcripts encoding glutathione-S-transferases, antioxidants, sulfur metabolism, heat-shock proteins, metal transporters, and enzymes in the ubiquitination pathway of protein degradation as well as several unknown novel proteins serve as

  5. The functional interplay between protein kinase CK2 and CCA1 transcriptional activity is essential for clock temperature compensation in Arabidopsis.

    Directory of Open Access Journals (Sweden)

    Sergi Portolés

    2010-11-01

    Full Text Available Circadian rhythms are daily biological oscillations driven by an endogenous mechanism known as circadian clock. The protein kinase CK2 is one of the few clock components that is evolutionary conserved among different taxonomic groups. CK2 regulates the stability and nuclear localization of essential clock proteins in mammals, fungi, and insects. Two CK2 regulatory subunits, CKB3 and CKB4, have been also linked with the Arabidopsis thaliana circadian system. However, the biological relevance and the precise mechanisms of CK2 function within the plant clockwork are not known. By using ChIP and Double-ChIP experiments together with in vivo luminescence assays at different temperatures, we were able to identify a temperature-dependent function for CK2 modulating circadian period length. Our study uncovers a previously unpredicted mechanism for CK2 antagonizing the key clock regulator CIRCADIAN CLOCK-ASSOCIATED 1 (CCA1. CK2 activity does not alter protein accumulation or subcellular localization but interferes with CCA1 binding affinity to the promoters of the oscillator genes. High temperatures enhance the CCA1 binding activity, which is precisely counterbalanced by the CK2 opposing function. Altering this balance by over-expression, mutation, or pharmacological inhibition affects the temperature compensation profile, providing a mechanism by which plants regulate circadian period at changing temperatures. Therefore, our study establishes a new model demonstrating that two opposing and temperature-dependent activities (CCA1-CK2 are essential for clock temperature compensation in Arabidopsis.

  6. Correlation between oxalic acid production and copper tolerance in Wolfiporia cocos

    Science.gov (United States)

    C. A. Clausen; Frederick Green; B. M. Woodward; J. W. Evans; R. C. DeGroot

    2000-01-01

    The increased interest in copper-based wood preservatives has hastened the need for understanding why some fungi are able to attack copper-treated wood. Due in part to accumulation of oxalic acid by brown-rot fungi and visualization of copper oxalate crystals in wood decayed by known copper-tolerant decay fungi, oxalic acid has been implicated in copper tolerance by...

  7. Effect of ionophores on phosphate and arsenate transport in Micrococcus lysodeikticus

    Energy Technology Data Exchange (ETDEWEB)

    Friedberg, I

    1977-09-01

    The effects of ionophores on P/sub i/ and arsenate transport, at acid and alkaline environment, were investigated in whole cells of Micrococcus lysodeikticus, a Gram positive obligatory aerobic bacterium. The results suggest that both ..delta.. Psi and ..delta.. pH contribute to the driving force of P/sub i/ transport; ..delta.. Psi seems to be predominant at pH 7.8, whereas at pH 5.5, the transport is primarily driven by ..delta.. pH. 12 references, 1 figure.

  8. The arbuscular mycorrhizal fungus Glomus mosseae can enhance arsenic tolerance in Medicago truncatula by increasing plant phosphorus status and restricting arsenate uptake

    International Nuclear Information System (INIS)

    Xu Pengliang; Christie, Peter; Liu Yu; Zhang Junling; Li Xiaolin

    2008-01-01

    A pot experiment examined the biomass and As uptake of Medicago truncatula colonized by the arbuscular mycorrhizal (AM) fungus Glomus mosseae in low-P soil experimentally contaminated with different levels of arsenate. The biomass of G. mosseae external mycelium was unaffected by the highest addition level of As studied (200 mg kg -1 ) but shoot and root biomass declined in both mycorrhizal and non-mycorrhizal plants, indicating that the AM fungus was more tolerant than M. truncatula to arsenate. Mycorrhizal inoculation increased shoot and root dry weights by enhancing host plant P nutrition and lowering shoot and root As concentrations compared with uninoculated plants. The AM fungus may have been highly tolerant to As and conferred enhanced tolerance to arsenate on the host plant by enhancing P nutrition and restricting root As uptake. - G. mosseae was more tolerant than M. truncatula to As and may have conferred enhanced host tolerance by restricting root As uptake and enhancing P nutrition

  9. The arbuscular mycorrhizal fungus Glomus mosseae can enhance arsenic tolerance in Medicago truncatula by increasing plant phosphorus status and restricting arsenate uptake

    Energy Technology Data Exchange (ETDEWEB)

    Xu Pengliang [Key Laboratory of Plant-Soil Interactions, Ministry of Education, College of Resources and Environmental Sciences, China Agricultural University, Beijing 100094 (China); Christie, Peter [Key Laboratory of Plant-Soil Interactions, Ministry of Education, College of Resources and Environmental Sciences, China Agricultural University, Beijing 100094 (China); Agricultural and Environmental Science Department, Queen' s University Belfast, Belfast BT9 5PX (United Kingdom); Liu Yu [Key Laboratory of Plant-Soil Interactions, Ministry of Education, College of Resources and Environmental Sciences, China Agricultural University, Beijing 100094 (China); Zhang Junling [Key Laboratory of Plant-Soil Interactions, Ministry of Education, College of Resources and Environmental Sciences, China Agricultural University, Beijing 100094 (China)], E-mail: junlingz@cau.edu.cn; Li Xiaolin [Key Laboratory of Plant-Soil Interactions, Ministry of Education, College of Resources and Environmental Sciences, China Agricultural University, Beijing 100094 (China)

    2008-11-15

    A pot experiment examined the biomass and As uptake of Medicago truncatula colonized by the arbuscular mycorrhizal (AM) fungus Glomus mosseae in low-P soil experimentally contaminated with different levels of arsenate. The biomass of G. mosseae external mycelium was unaffected by the highest addition level of As studied (200 mg kg{sup -1}) but shoot and root biomass declined in both mycorrhizal and non-mycorrhizal plants, indicating that the AM fungus was more tolerant than M. truncatula to arsenate. Mycorrhizal inoculation increased shoot and root dry weights by enhancing host plant P nutrition and lowering shoot and root As concentrations compared with uninoculated plants. The AM fungus may have been highly tolerant to As and conferred enhanced tolerance to arsenate on the host plant by enhancing P nutrition and restricting root As uptake. - G. mosseae was more tolerant than M. truncatula to As and may have conferred enhanced host tolerance by restricting root As uptake and enhancing P nutrition.

  10. Highly Conductive and Reliable Copper-Filled Isotropically Conductive Adhesives Using Organic Acids for Oxidation Prevention

    Science.gov (United States)

    Chen, Wenjun; Deng, Dunying; Cheng, Yuanrong; Xiao, Fei

    2015-07-01

    The easy oxidation of copper is one critical obstacle to high-performance copper-filled isotropically conductive adhesives (ICAs). In this paper, a facile method to prepare highly reliable, highly conductive, and low-cost ICAs is reported. The copper fillers were treated by organic acids for oxidation prevention. Compared with ICA filled with untreated copper flakes, the ICA filled with copper flakes treated by different organic acids exhibited much lower bulk resistivity. The lowest bulk resistivity achieved was 4.5 × 10-5 Ω cm, which is comparable to that of commercially available Ag-filled ICA. After 500 h of 85°C/85% relative humidity (RH) aging, the treated ICAs showed quite stable bulk resistivity and relatively stable contact resistance. Through analyzing the results of x-ray diffraction, x-ray photoelectron spectroscopy, and thermogravimetric analysis, we found that, with the assistance of organic acids, the treated copper flakes exhibited resistance to oxidation, thus guaranteeing good performance.

  11. Immobilization of radium in uranium mine and mill tailings

    International Nuclear Information System (INIS)

    Lutwick, G.D.; Mosher, J.; Tizzard, R.

    1982-01-01

    Radium has been coprecipitated from solution as the arsenate in which ferric iron, barium, copper and lead are the macro ions. The order of efficiency of the macro ions in removing radium was found to be Ba > Fe > Pb > Cu at a pH of 6. It is expected that at higher pH's i.e., greater than 8, ferric iron will change positions. This change in position will be caused by the formation of ferrate ion hence increasing the solubility of ferric arsenate. The removal of radium from solution by ion exchangers consisting of the arsenates of ferric iron, barium, copper and lead was successful. As the pH is increased from 4 to 10 the efficiency of these exchangers in removing radium increases. The columns removed over 99 percent of the radium at pH's of 5.6 and higher. The order of efficiency of the exchangers in removing radium is not well defined. Thorium has been precipitated as the arsenate over the pH range of 2 to 9.6. This reaction suggests the possibility of using arsenate to remove thorium from uranium mill plant streams and as a reagent to keep thorium in the tailings ponds

  12. As(III) Removal from Drinking Water by Carbon Nanotube Membranes with Magnetron-Sputtered Copper: Performance and Mechanisms.

    Science.gov (United States)

    Luan, Hongyan; Zhang, Quan; Cheng, Guo-An; Huang, Haiou

    2018-06-07

    Current approaches for functionalizing carbon nanotubes (CNTs) often utilize harsh chemical conditions, and the resulting harmful wastes can cause various environmental and health concerns. In this study, magnetron sputtering technique is facilely employed to functionalize CNT membranes by depositing Cu onto premade CNT membranes without using any chemical treatment. A comparative evaluation of the substrate polymeric membrane (mixed cellulose ester (MCE)), MCE sputtered with copper (Cu/MCE), the pristine CNT membrane (CNT), and CNT membrane sputtered with Cu (Cu/CNT) shows that Cu/CNT possesses mechanically stable structures and similar membrane permeability as MCE. More importantly, Cu/CNT outperforms other membranes with high As(III) removal efficiency of above 90%, as compared to less than 10% by MCE and CNT, and 75% by Cu/MCE from water. The performance of Cu/CNT membranes for As(III) removal is also investigated as a function of ionic strength, sputtering time, co-existing ions, solution pH, and the reusability. Further characterizations of As speciation in the filtrate and on Cu/CNT reveal that arsenite removal by Cu/CNT possibly began with Cu-catalyzed oxidation of arsenite to arsenate, followed by adsorptive filtration of arsenate by the membrane. Overall, this study demonstrates that magnetron sputtering is a promising greener technology for the productions of metal-CNT composite membranes for environmental applications.

  13. Concentration and chemical status of arsenic in the blood of pregnant hamsters during critical embryogenesis. 1. Subchronic exposure to arsenate utilizing constant rate administration

    Energy Technology Data Exchange (ETDEWEB)

    Hanlon, D.P.; Ferm, V.H.

    1986-08-01

    The concentration, availability, and chemical status of radiolabeled arsenic has been determined in the blood of pregnant hamsters at the beginning (morning of Day 8) and the end (morning of Day 9) of the critical period of embryogenesis. Hamster dams were exposed to teratogenic doses of arsenate by means of osmotic minipumps implanted on the morning of Day 6 of the gestation period. Whole blood arsenic concentrations were the same for 48 and 72 hr postimplant. The arsenic concentration of plasma equaled that of red cells. Plasma arsenic was not bound to macromolecules and had the same chemical status 48 and 72 hr postimplant. Arsenate was the dominant form (67% of the total). However, the presence of dimethylarsinic acid and arsenite indicates that the pentavalent species was metabolized. Red cell arsenic was bound to macromolecules in the cell sap. Seventy percent of red cell sap arsenic was dialyzable 48 hr postimplant, but only 56% 72 hr postimplant. Arsenate was the dominant dialyzable red cell species on Day 8 and arsenite was the major dialyzable form on Day 9. The authors findings demonstrate a relationship between the maternal blood concentration and chemical status of arsenic and the presence of malformations resulting from a constant rate exposure of pregnant hamsters to arsenate via the osmotic minipump.

  14. Concentration and chemical status of arsenic in the blood of pregnant hamsters during critical embryogenesis. 1. Subchronic exposure to arsenate utilizing constant rate administration

    International Nuclear Information System (INIS)

    Hanlon, D.P.; Ferm, V.H.

    1986-01-01

    The concentration, availability, and chemical status of radiolabeled arsenic has been determined in the blood of pregnant hamsters at the beginning (morning of Day 8) and the end (morning of Day 9) of the critical period of embryogenesis. Hamster dams were exposed to teratogenic doses of arsenate by means of osmotic minipumps implanted on the morning of Day 6 of the gestation period. Whole blood arsenic concentrations were the same for 48 and 72 hr postimplant. The arsenic concentration of plasma equaled that of red cells. Plasma arsenic was not bound to macromolecules and had the same chemical status 48 and 72 hr postimplant. Arsenate was the dominant form (67% of the total). However, the presence of dimethylarsinic acid and arsenite indicates that the pentavalent species was metabolized. Red cell arsenic was bound to macromolecules in the cell sap. Seventy percent of red cell sap arsenic was dialyzable 48 hr postimplant, but only 56% 72 hr postimplant. Arsenate was the dominant dialyzable red cell species on Day 8 and arsenite was the major dialyzable form on Day 9. The authors findings demonstrate a relationship between the maternal blood concentration and chemical status of arsenic and the presence of malformations resulting from a constant rate exposure of pregnant hamsters to arsenate via the osmotic minipump

  15. A natural analogue for copper waste canisters: The copper-uranium mineralised concretions in the Permian mudrocks of south Devon, United Kingdom

    International Nuclear Information System (INIS)

    Milodowski, A.E.; Styles, M.T.; Hards, V.L.

    2000-08-01

    mineralisation and alteration that can be related to the burial and diagenetic history of the Permian strata. The native copper mineralisation exhibits close temporal association with the formation of uraniferous and vanadiferous concretions (known as 'fish-eyes') in the same rocks. Petrographical relationships indicate that both the copper and the 'fish-eye' concretions formed during burial diagenesis but before the maximum compaction of the host mudstone and siltstone. The regional burial history Wessex Basin, indicates that the maximum compaction of the Permian strata would have been achieved by at least the end of the Lower Jurassic (possibly even in the Triassic). Therefore, the native copper mineralisation is older than 176 Ma. The native copper sheets display a complex sequence of alteration and subsequent mineral growth of minerals on their surfaces. The earliest alteration was to copper oxides - principally cuprite with minor tenorite, indicating a change to more oxidising groundwater conditions. The dissolution of native silver and the growth of fringes of copper arsenides followed this. Nickel arsenides and chalcocite, associated with the precipitation of uranium silicates occurred in the later stages of alteration. This suggests a return to a more reducing pore water environment. Again, petrographical relationships indicate that this alteration and subsequent mineralisation is geologically old (i.e. Lower Jurassic or older). Secondary malachite, intimately intergrown copper sulphate and copper oxides, copper chloride, copper-uranium arsenate and uranium vanadates have formed as late-stage alteration products of the native copper and earlier diagenetic cuprite, chalcocite, copper-nickel arsenide and uranium silicate alteration and mineralisation. This latest stage alteration is most probably attributable to near-surface weathering processes. Although the native copper is affected by corrosion, the study has shown that a significant proportion (30-80% of the original

  16. A natural analogue for copper waste canisters: The copper-uranium mineralised concretions in the Permian mudrocks of south Devon, United Kingdom

    Energy Technology Data Exchange (ETDEWEB)

    Milodowski, A.E.; Styles, M.T.; Hards, V.L. [Natural Environment Research Council (United Kingdom). British Geological Survey

    2000-08-01

    mineralisation and alteration that can be related to the burial and diagenetic history of the Permian strata. The native copper mineralisation exhibits close temporal association with the formation of uraniferous and vanadiferous concretions (known as 'fish-eyes') in the same rocks. Petrographical relationships indicate that both the copper and the 'fish-eye' concretions formed during burial diagenesis but before the maximum compaction of the host mudstone and siltstone. The regional burial history Wessex Basin, indicates that the maximum compaction of the Permian strata would have been achieved by at least the end of the Lower Jurassic (possibly even in the Triassic). Therefore, the native copper mineralisation is older than 176 Ma. The native copper sheets display a complex sequence of alteration and subsequent mineral growth of minerals on their surfaces. The earliest alteration was to copper oxides - principally cuprite with minor tenorite, indicating a change to more oxidising groundwater conditions. The dissolution of native silver and the growth of fringes of copper arsenides followed this. Nickel arsenides and chalcocite, associated with the precipitation of uranium silicates occurred in the later stages of alteration. This suggests a return to a more reducing pore water environment. Again, petrographical relationships indicate that this alteration and subsequent mineralisation is geologically old (i.e. Lower Jurassic or older). Secondary malachite, intimately intergrown copper sulphate and copper oxides, copper chloride, copper-uranium arsenate and uranium vanadates have formed as late-stage alteration products of the native copper and earlier diagenetic cuprite, chalcocite, copper-nickel arsenide and uranium silicate alteration and mineralisation. This latest stage alteration is most probably attributable to near-surface weathering processes. Although the native copper is affected by corrosion, the study has shown that a significant proportion (30

  17. Enzyme phylogenies as markers for the oxidation state of the environment: the case of respiratory arsenate reductase and related enzymes.

    Science.gov (United States)

    Duval, Simon; Ducluzeau, Anne-Lise; Nitschke, Wolfgang; Schoepp-Cothenet, Barbara

    2008-07-16

    Phylogenies of certain bioenergetic enzymes have proved to be useful tools for deducing evolutionary ancestry of bioenergetic pathways and their relationship to geochemical parameters of the environment. Our previous phylogenetic analysis of arsenite oxidase, the molybdopterin enzyme responsible for the biological oxidation of arsenite to arsenate, indicated its probable emergence prior to the Archaea/Bacteria split more than 3 billion years ago, in line with the geochemical fact that arsenite was present in biological habitats on the early Earth. Respiratory arsenate reductase (Arr), another molybdopterin enzyme involved in microbial arsenic metabolism, serves as terminal oxidase, and is thus situated at the opposite end of bioenergetic electron transfer chains as compared to arsenite oxidase. The evolutionary history of the Arr-enzyme has not been studied in detail so far. We performed a genomic search of genes related to arrA coding for the molybdopterin subunit. The multiple alignment of the retrieved sequences served to reconstruct a neighbor-joining phylogeny of Arr and closely related enzymes. Our analysis confirmed the previously proposed proximity of Arr to the cluster of polysulfide/thiosulfate reductases but also unravels a hitherto unrecognized clade even more closely related to Arr. The obtained phylogeny strongly suggests that Arr originated after the Bacteria/Archaea divergence in the domain Bacteria, and was subsequently laterally distributed within this domain. It further more indicates that, as a result of accumulation of arsenate in the environment, an enzyme related to polysulfide reductase and not to arsenite oxidase has evolved into Arr. These findings are paleogeochemically rationalized by the fact that the accumulation of arsenate over arsenite required the increase in oxidation state of the environment brought about by oxygenic photosynthesis.

  18. Mechanical Properties of Longleaf Pine Treated with Waterborne Salt Preservatives.

    Science.gov (United States)

    1983-08-01

    were measured on small clear bending specimens of longleaf pine sapwood treated with three wateroorne salt preservative systems. Preservative...wood, but the results of past research in this area (appendix I: Literature) are inconsistent and inconclusive, particularly at high loadings of...pine sapwood either air or kiln dried after treatment to retentions from 0.25 to 2.5 lb/ft3. ACA has no effect on MOR. but CCA-type preservatives

  19. Automated radiofrequency-based US measurement of common carotid intima-media thickness in RA patients treated with synthetic vs synthetic and biologic DMARDs.

    Science.gov (United States)

    Naredo, Esperanza; Möller, Ingrid; Corrales, Alfonso; Bong, David A; Cobo-Ibáñez, Tatiana; Corominas, Hector; Garcia-Vivar, Ma Luz; Macarrón, Pilar; Navio, Teresa; Richi, Patricia; Iagnocco, Annamaria; Garrido, Jesús; Martínez-Hernández, David

    2013-02-01

    To compare the carotid intima-media thickness (IMT) assessed with automated radiofrequency-based US in RA patients treated with synthetic vs synthetic and biologic DMARDs and controls. Ninety-four RA patients and 94 sex- and age-matched controls were prospectively recruited at seven centres. Cardiovascular (CV) risk factors and co-morbidities, RA characteristics and therapy were recorded. Common carotid artery (CCA)-IMT was assessed in RA patients and controls with automated radiofrequency-based US by the same investigator at each centre. Forty-five (47.9%) RA patients had been treated with synthetic DMARDs and 49 (52.1%) with synthetic and biologic DMARDs. There were no significant differences between the RA patients and controls in demographics, CV co-morbidities and CV disease. There were significantly more smokers among RA patients treated with synthetic and biologic DMARDs (P = 0.036). Disease duration and duration of CS and synthetic DMARD therapy was significantly longer in RA patients treated with synthetic and biologic DMARDs (P radiofrequency-based measurement of CCA-IMT can discriminate between RA patients treated with synthetic DMARDs vs RA patients treated with synthetic and biologic DMARDs.

  20. Determination of Cu, Cr, and As in preserved wood (Eucalyptus sp.) using x-ray fluorescent spectrometry techniques

    International Nuclear Information System (INIS)

    Sergio Matias Pereira Junior; Vera Akiko Maihara; Edson Goncalves Moreira; Vera Lucia Ribeiro Salvador; Ivone Mulako Sato

    2016-01-01

    Energy dispersive (EDXRF) and Portable (PXRF) X-ray fluorescence techniques are proposed for wood treatment control process and wood waste assortment. In this study, different retentions of chromated copper arsenate preservative were applied to Eucalyptus sp. sapwood samples. Cu, Cr and As were determined by XRF techniques in treated sapwood massive blocks and treated sapwood sawdust samples were analyzed by FAAS spectrometry (Flame Atomic Absorption) and INAA (Instrumental Neutron Activation Analysis). Cu, Cr and As mean values, obtained by FAASS and INAA, showed to be statically equal; however, XRF analysis showed considerable deviations, presenting the absorption and the enhancement effects in analytical lines. (author)

  1. Identification of anaerobic arsenite-oxidizing and arsenate-reducing bacteria associated with an alkaline saline lake in Khovsgol, Mongolia.

    Science.gov (United States)

    Hamamura, Natsuko; Itai, Takaaki; Liu, Yitai; Reysenbach, Anna-Louise; Damdinsuren, Narantuya; Inskeep, William P

    2014-10-01

    Microbial arsenic transformation pathways associated with a saline lake located in northern Mongolia were examined using molecular biological and culturing approaches. Bacterial 16S rRNA gene sequences recovered from saline lake sediments and soils were affiliated with haloalkaliphiles, including Bacillus and Halomonas spp. Diverse sequences of arsenate respiratory reductase (arrA) and a new group of arsenite oxidase (arxA) genes were also identified. Pure cultures of arsenate-reducing Nitrincola strain and anaerobic arsenite-oxidizing Halomonas strain were isolated. The chemoorganotrophic Halomonas strain contains arxA gene similar to that of a chemoautotrophic arsenite-oxidizing Alkalilimnicola ehrlichii strain MLHE-1. These results revealed the diversity of arsenic transformation pathways associated with a geographically distinct saline system and the potential contribution of arx-dependent arsenite oxidation by heterotrophic bacteria.

  2. A CCA+ICA based model for multi-task brain imaging data fusion and its application to schizophrenia.

    Science.gov (United States)

    Sui, Jing; Adali, Tülay; Pearlson, Godfrey; Yang, Honghui; Sponheim, Scott R; White, Tonya; Calhoun, Vince D

    2010-05-15

    Collection of multiple-task brain imaging data from the same subject has now become common practice in medical imaging studies. In this paper, we propose a simple yet effective model, "CCA+ICA", as a powerful tool for multi-task data fusion. This joint blind source separation (BSS) model takes advantage of two multivariate methods: canonical correlation analysis and independent component analysis, to achieve both high estimation accuracy and to provide the correct connection between two datasets in which sources can have either common or distinct between-dataset correlation. In both simulated and real fMRI applications, we compare the proposed scheme with other joint BSS models and examine the different modeling assumptions. The contrast images of two tasks: sensorimotor (SM) and Sternberg working memory (SB), derived from a general linear model (GLM), were chosen to contribute real multi-task fMRI data, both of which were collected from 50 schizophrenia patients and 50 healthy controls. When examining the relationship with duration of illness, CCA+ICA revealed a significant negative correlation with temporal lobe activation. Furthermore, CCA+ICA located sensorimotor cortex as the group-discriminative regions for both tasks and identified the superior temporal gyrus in SM and prefrontal cortex in SB as task-specific group-discriminative brain networks. In summary, we compared the new approach to some competitive methods with different assumptions, and found consistent results regarding each of their hypotheses on connecting the two tasks. Such an approach fills a gap in existing multivariate methods for identifying biomarkers from brain imaging data.

  3. Is the effect of silicon on rice uptake of arsenate (AsV) related to internal silicon concentrations, iron plaque and phosphate nutrition?

    International Nuclear Information System (INIS)

    Guo, W.; Zhu, Y.-G.; Liu, W.-J.; Liang, Y.-C.; Geng, C.-N.; Wang, S.-G.

    2007-01-01

    Solution culture experiments were conducted to investigate the effects of silicon (Si) on arsenate (As V ) uptake by rice. The addition of Si to the pretreatment or uptake solution significantly decreased shoot and root As concentrations (P < 0.001 and P < 0.05). The presence of Si in the pretreatment or uptake solution also significantly decreased shoot P concentrations (P < 0.001). The data demonstrated that both internal and external Si inhibited the uptake of As and P. Results of As uptake kinetics showed that the mechanism of the effect of Si on arsenate uptake is not caused by direct competition for active sites of transporters with As. The effect of Si on As uptake was not entirely mediated through the effect of Si on P uptake. Although the addition of Si to pretreatment solutions still significantly decreased shoot and root As concentrations, the extent of reduction became smaller when rice roots were coated with iron plaque. - Arsenate uptake by rice seedlings is affected by both Si (internal and external) and iron plaque on root surface

  4. Evaluation in vitro of the infection times of engorged females of Rhipicephalus (Boophilus microplus by the entomopathogenic nematode Steinernema glaseri CCA strain Avaliação in vitro dos tempos de infecção de fêmeas ingurgitadas de Rhipicephalus (Boophilus microplus pelo nematoide entomopatogênico Steinernema glaseri estirpe CCA

    Directory of Open Access Journals (Sweden)

    Leandro Barbiéri de Carvalho

    2010-04-01

    Full Text Available Studies have shown that ticks are susceptible to infection by entomopathogenic nematodes. These studies indicate different susceptibilities of ticks to infection by these fungi, depending on the tick species, development phase, entomopathogenic nematodes species and strains and the time the ticks are exposed to them. Usually this period ranges from 24 to 72 hours. The aim of this study was to evaluate the infection times in vitro of engorged Rhipicephalus (Boophilus microplus females by the entomopathogenic nematodes Steinernema glaseri CCA strain, by analysis of the ticks' biological parameters. The results show that a 2-hour exposure time was sufficient for the engorged R. microplus females to be infected by S. glaseri CCA, but that a minimum exposure time of 24 hours was necessary to generate treatment efficacy above 90%.Os carrapatos são susceptíveis à infecção por nematoides entomopatogênicos. Essa susceptibilidade diverge quanto às espécies de carrapato estudadas, à fase evolutiva, às espécies e estirpes dos nematoides e ao tempo ao qual os carrapatos ficam expostos a estes. O presente trabalho teve como objetivo avaliar os tempos de infecção in vitro de fêmeas ingurgitadas de Rhipicephalus (Boophilus microplus pelo nematoide entomopatogênico Steinernema glaseri estirpe CCA, pela análise dos parâmetros biológicos do carrapato. Os resultados obtidos demonstraram que um período de duas horas de exposição foi suficiente para que fêmeas ingurgitadas de R. microplus fossem infectadas por S. glaseri CCA e que um período de exposição mínimo de 24h foi necessário para que houvesse infecção de fêmeas ingurgitadas de R. microplus por S. glaseri estirpe CCA, capaz de gerar, in vitro, eficácia no tratamento superior a 90%.

  5. Characterization of prealloyed copper powders treated in high energy ball mill

    International Nuclear Information System (INIS)

    Rajkovic, Viseslava; Bozic, Dusan; Jovanovic, Milan T.

    2006-01-01

    The inert gas atomised prealloyed copper powders containing 3.5 wt.% Al were milled up to 20 h in the planetary ball mill in order to oxidize aluminium in situ with oxygen from the air. In the next procedure compacts from milled powder were synthesized by hot-pressing in argon atmosphere. Compacts from as-received Cu-3.5 wt.% Al powder and electrolytic copper powder were also prepared under the same conditions. Microstructural and morphological changes of high energy milled powder as well as changes of thermal stability and electrical conductivity of compacts were studied as a function of milling time and high temperature exposure at 800 deg. C. Optical, scanning electron microscopy (SEM) and X-ray diffraction analysis were performed for microstructural characterization, whereas thermal stability and electrical conductivity were evaluated by microhardness measurements and conductometer Sigmatest, respectively. The prealloyed 5 h-milled and compacted powder showed a significant increase in microhardness reaching the value of 2600 MPa, about 4 times greater than that of compacts synthesized from as-received electrolytic copper powder (670 MPa). The electrical conductivity of compacts from 5 h-milled powder was 52% IACS. The results were discussed in terms of the effect of small grain size and finely distributed alumina dispersoids on hardening and thermal stability of compacts

  6. Photometric titration of arsenate with thorium nitrate on the microgram and milligram scale

    International Nuclear Information System (INIS)

    Harzdorf, C.; Fallah-Tafti, G.

    1976-01-01

    A method is decribed for the photometric titration of arsenate with thorium nitrate using pyrocatecholviolet as indicator. The method works at a low pH level and is therefore not subject to the most cationic interferences. Alkali salts do not affect the determination even at high concentrations if present as halides, nitrates or perchlorates. This makes the method particularly suitable for the analysis of arsenic in organic and inorganic compounds after decomposition. (orig.) [de

  7. Copper influence on bank vole's (Myodes glareolus) sexual behavior.

    Science.gov (United States)

    Miska-Schramm, Agata; Kapusta, Joanna; Kruczek, Małgorzata

    2018-04-01

    The impact of human activity on the environment has led to a steady increase of the amounts of copper in the ecosystems. This element accumulates in plants and water, potentially exposing rodents to its harmful effects. In industrial districts, a decrease in the density of small rodent populations has been observed. This decline may be caused by many factors, including mortality, decreased fertility, or impaired sexual behavior. The decline in the reproductive abilities of small rodents after copper exposure was demonstrated in our previous work (Miska-Schramm A, Kruczek M, Kapusta J, Ecotoxicology 23:1546-1554, 2014). The aim of the presented research was to determine how copper administered at concentrations similar to those recorded in industrial districts (Cu I-150 mg/kg, Cu II-600 mg/kg, C-control) affects the sexual behavior of small rodents. The model species was the bank vole (Myodes glareolus). The behavior and vocalizations of male-female pairs were recorded during open-field tests: ♂C vs. ♀C; ♂Cu I vs. ♀C; ♂Cu II vs. ♀C while in preference tests, female behavior was assessed in the following combinations: ♀C vs. ♂C & ♂Cu I; ♀C vs. ♂C & ♂Cu II. In the presented work, we show that copper decreased the males' sexual attractiveness. Females showed suppressed preference towards males treated with 600 mg/kg copper. The number of sniffs and a number of approaches towards Cu II males was significantly lower than towards control individuals. Also, in preference test with 150 mg/kg treated animals, total activity was lower towards copper treated animals. At the same time, copper did not influence intra-sexual interactions.

  8. Glutathione-S-transferase-omega [MMA(V) reductase] knockout mice: Enzyme and arsenic species concentrations in tissues after arsenate administration

    International Nuclear Information System (INIS)

    Chowdhury, Uttam K.; Zakharyan, Robert A.; Hernandez, Alba; Avram, Mihaela D.; Kopplin, Michael J.; Aposhian, H. Vasken

    2006-01-01

    Inorganic arsenic is a human carcinogen to which millions of people are exposed via their naturally contaminated drinking water. Its molecular mechanisms of carcinogenicity have remained an enigma, perhaps because arsenate is biochemically transformed to at least five other arsenic-containing metabolites. In the biotransformation of inorganic arsenic, GSTO1 catalyzes the reduction of arsenate, MMA(V), and DMA(V) to the more toxic + 3 arsenic species. MMA(V) reductase and human (hGSTO1-1) are identical proteins. The hypothesis that GST-Omega knockout mice biotransformed inorganic arsenic differently than wild-type mice has been tested. The livers of male knockout (KO) mice, in which 222 bp of Exon 3 of the GSTO1 gene were eliminated, were analyzed by PCR for mRNA. The level of transcripts of the GSTO1 gene in KO mice was 3.3-fold less than in DBA/1lacJ wild-type (WT) mice. The GSTO2 transcripts were about two-fold less in the KO mouse. When KO and WT mice were injected intramuscularly with Na arsenate (4.16 mg As/kg body weight); tissues removed at 0.5, 1, 2, 4, 8, and 12 h after arsenate injection; and the arsenic species measured by HPLC-ICP-MS, the results indicated that the highest concentration of the recently discovered and very toxic MMA(III), a key biotransformant, was in the kidneys of both KO and WT mice. The highest concentration of DMA(III) was in the urinary bladder tissue for both the KO and WT mice. The MMA(V) reducing activity of the liver cytosol of KO mice was only 20% of that found in wild-type mice. There appears to be another enzyme(s) other than GST-O able to reduce arsenic(V) species but to a lesser extent. This and other studies suggest that each step of the biotransformation of inorganic arsenic has an alternative enzyme to biotransform the arsenic substrate

  9. Thermally modified bentonite clay for copper removal

    International Nuclear Information System (INIS)

    Bertagnolli, C.; Kleinübing, S.J.; Silva, M.G.C.

    2011-01-01

    Bentonite clay coming from Pernambuco was thermally modified in order to increase its affinity and capacity in the copper removal in porous bed. The application of this procedure is justified by the low cost of clay, their abundance and affinity for various metal ions. Thermally treatment modifies the clay adsorption properties enables its use in porous bed system, with the increase in surface area and mechanical strength. The material was characterized by x-ray diffraction, thermogravimetric analysis and N_2 physisorption. Then tests were carried out for adsorption of copper in various experimental conditions and evaluated the mass transfer zone, useful and total adsorbed removal amounts and total copper removal percentage. The results showed that the clay treated at higher temperature showed higher copper removal. (author)

  10. Arsenate and Arsenite Sorption on Magnetite: Relations to Groundwater Arsenic Treatment Using Zerovalent Iron and Natural Attenuation

    Science.gov (United States)

    Magnetite (Fe3O4) is a zerovalent iron corrosion product; it is also formed in natural soil and sediment. Sorption of arsenate (As(V)) and arsenite (As(III)) on magnetite is an important process of arsenic removal from groundwater using zerovalent iron-based permeable reactive ba...

  11. Intelligent CAMAC crate controller with CC-A2 functionality and VICbus interface

    International Nuclear Information System (INIS)

    Erven, W.; Holzer, J.; Kopp, H.; Loevenich, H.W.; Meiling, W.; Zwoll, K.; Bovier, J.; Re, G.; Worm, F.

    1992-01-01

    This paper reports that for nuclear physics experiments at the Julich Cooler Synchrotron COSY a data acquisition system is under development. With this background, and in order to enhance existing CAMAC systems, an intelligent CAMAC crate controller with CC-A2 functionality was developed. The main enhancement is the replacement of the Branch Highway with a new standard of inter-crate connection: the VICbus. The other highlights are: optional use of a Motorola 68030 microprocessor as CAMAC list-processor and optimization of CAMAC blocktransfers, optional Ethernet or Cheapernet connection. This controller is commercially available from CES, Geneva and called VCC 2117

  12. Tolerance of Serpula lacrymans to copper-based wood preservatives

    DEFF Research Database (Denmark)

    Hastrup, Anne Christine Steenkjær; Green, Frederick; Clausen, Carol A.

    2005-01-01

    construction, but some decay fungi are known to be copper tolerant. In this study, soil-block tests were undertaken to clarify the effect of copper, copper citrate, and alkaline copper quaternary-type D (ACQ-D) on the decay capabilities of S. lacrymans compared with an alternative wood preservative......Serpula lacrymans, the dry rot fungus, is considered the most economically important wood decay fungus in certain temperate regions of the world, namely northern Europe, Japan, and Australia. Previously, copper-based wood preservatives were commonly used for pressure treatment of wood for building...... not containing copper. Twelve isolates of the dry rot fungus S. lacrymans and four other brown-rot species were evaluated for weight loss on wood treated with 1.2% copper citrate, 0.5% ACQ-D, and 0.5% naphthaloylhydroxylamine (NHA). Eleven out of 12 isolates of S. lacrymans were shown to be tolerant towards...

  13. Comparison of oxidation resistance of copper treated by beam-line ion implantation and plasma immersion ion implantation

    International Nuclear Information System (INIS)

    An Quanzhang; Li Liuhe; Hu Tao; Xin Yunchang; Fu, Ricky K.Y.; Kwok, D.T.K.; Cai Xun; Chu, Paul K.

    2009-01-01

    Copper which has many favorable properties such as low cost, high thermal and electrical conductivity, as well as easy fabrication and joining is one of the main materials in lead frames, interconnects, and foils in flexible circuits. Furthermore, copper is one of the best antibacterial materials. However, unlike aluminum oxide or chromium oxide, the surface copper oxide layer does not render sufficient protection against oxidation. In this work, in order to improve the surface oxidation resistance of Cu, Al and N were introduced into copper by plasma immersion ion implantation (PIII) and beam-line ion implantation (BII). The implantation fluences of Al and N were 2 x 10 17 ions cm -2 and 5 x 10 16 ions cm -2 , respectively. The implanted and untreated copper samples were oxidized in air at 260 deg. C for 1 h. The X-ray diffraction (XRD), scanning electron microscopy (SEM), as well as X-ray photoelectron spectroscopy (XPS) results indicate that both implantation methods can enhance the oxidation resistance of copper but to different extent. PIII is superior to BII in enhancing the oxidation resistance of copper. The effects and possible mechanisms are discussed.

  14. Evaluation of the AJCC 8th Edition Staging System for Pathologically Versus Clinically Staged Intrahepatic Cholangiocarcinoma (iCCA): a Time to Revisit a Dogma? A Surveillance, Epidemiology, and End Results (SEER) Analysis.

    Science.gov (United States)

    Kamarajah, Sivesh K

    2018-03-07

    Recently, the AJCC has released its 8th edition changes to the staging system for intrahepatic cholangiocarcinoma (iCCA). This study sought to validate the proposed changes to the 8th edition of AJCC system for T and N classification of iCCA using a population-based data set. Using the Surveillance, Epidemiology, and End Results (SEER) database (1998-2013), patients undergoing resection or non-surgical management for non-metastatic iCCA were identified. Overall survival was estimated using the Kaplan-Meier method and compared using log-rank tests. Concordance indices (c-indices) calculated from Cox proportional hazards models were calculated to evaluate discriminatory power. The study included 2630 patients resected (37%) or non-surgically managed (63%) for iCCA. Nodal staging was performed in 56%, of whom 31% had positive nodes. For all patients with iCCA, the median 5-year survival by AJCC T classification for T1a, T1b, T2, T3, and T4 was 32, 21, 14, 10, and 10 months, respectively (p < 0.001). The concordance index for the staging system was 0.57 for all patients, 0.62 for those who underwent resection, and 0.54 for patients who did not undergo resection. In summary, the new AJCC 8th edition staging system is comparable to the 7th edition and valid in stratifying patients with iCCA. However, the performance of the staging system is better in patients undergoing surgical resection than those undergoing non-surgical management. These findings further highlight the need for improved accuracy of radiological imaging in clinically staging patients to guide prognosis.

  15. Effects of chronic copper exposure during early life in rhesus monkeys.

    Science.gov (United States)

    Araya, Magdalena; Kelleher, Shannon L; Arredondo, Miguel A; Sierralta, Walter; Vial, María Teresa; Uauy, Ricardo; Lönnerdal, Bo

    2005-05-01

    Whether infants regulate copper absorption and the potential effects of excess copper in early life remain poorly defined. The objective of the study was to assess copper retention, liver copper content, and liver function in infant rhesus monkeys fed infant formula containing 6.6 mg Cu/L. From birth to 5 mo of age, infant rhesus monkeys were fed formula that was supplemented with copper (0.6 mg Cu/L; n = 5) or not supplemented (n = 4). In all animals, weight and crown-rump length (by anthropometry), hemoglobin, hematocrit, plasma ceruloplasmin activity, and zinc and copper concentrations were measured monthly (birth to 6 mo) and at 8 and 12 mo. When the animals were 1, 5, and 8 mo old, liver copper and metallothionein concentrations, liver histology (by light and electron microscopy), and the number of Kupffer cells were assessed, and 67Cu retention was measured. Liver function was assessed by measurement of plasma alanine aminotransferase, aspartate aminotransferase, gamma-glutamyl transferase, and alkaline phosphatase activities and protein, albumin, bilirubin, and blood urea nitrogen concentrations. 67Cu retention was 19.2% and 10.9% after 1 and 5 mo of copper treatment, respectively, compared with approximately 75% in controls at age 2 mo. At age 8 mo, 67Cu retention was 22.9% in copper-treated animals and 31.5% in controls. Liver histology remained normal by light microscopy, with mild ultrastructural signs of cell damage at 5 mo. Liver copper concentration was 4711, 1139, and 498 microg/g dry tissue at 1, 5, and 8 mo, respectively, in copper-treated animals and 250 microg/g at 2 mo in controls. Measurements could not be completed in all animals. No clinical evidence of copper toxicity was observed. Copper absorption was down-regulated; increases in liver copper content at ages 1 and 5 mo did not result in histologic damage. Ultrastructural changes at age 5 mo could signal early cellular damage.

  16. Interaction between copper and radiocesium in Indian mustard and sunflower grown in the hydroponic solution

    International Nuclear Information System (INIS)

    Shirong Tang; Xiaochang Wang

    2002-01-01

    Both Indian mustard and sunflower were grown in a hydroponic solution treated with different concentration activities of 134 Cs or with different amounts of copper or with both in order to investigate the interaction between copper and radiocesium. It was found that 134 Cs activity concentration applied in the nutrient solution exerted more influence on the uptake and translocation of copper by Indian mustard than by sunflower. Indian mustard grown in hydroponic solution containing certain levels of copper and being treated with higher 134 Cs activity concentration showed higher uptake of copper than sunflower. However, in the case of root copper concentrations, sunflower showed significantly higher copper immobilization by roots than Indian mustard. It was also found that the presence of copper the the hydroponic solution did modify radiocesium uptake by both species. The application of 1 mg/l in the growth medium could greatly increase the uptake of 134 Cs by both species. With 3 mg/l concentration of copper amended to the solution, the accumulation of 134 Cs by both species was decreased compared to the 1 mg/l copper treatment. These lines of evidence show that there is stronger interaction between copper and radiocesium in Indian mustard than in sunflower during the root uptake through nutrient solution. (author)

  17. Copper deficiency induced emphysema is associated with focal adhesion kinase inactivation.

    Directory of Open Access Journals (Sweden)

    Shiro Mizuno

    Full Text Available Copper is an important regulator of hypoxia inducible factor 1 alpha (HIF-1α dependent vascular endothelial growth factor (VEGF expression, and is also required for the activity of lysyl oxidase (LOX to effect matrix protein cross-linking. Cell detachment from the extracellular matrix can induce apoptosis (anoikis via inactivation of focal adhesion kinase (FAK.To examine the molecular mechanisms whereby copper depletion causes the destruction of the normal alveolar architecture via anoikis, Male Sprague-Dawley rats were fed a copper deficient diet for 6 weeks while being treated with the copper chelator, tetrathiomolybdate. Other groups of rats were treated with the inhibitor of auto-phosphorylation of FAK, 1,2,4,5-benzenetetraamine tetrahydrochloride (1,2,4,5-BT or FAK small interfering RNA (siRNA.Copper depletion caused emphysematous changes, decreased HIF-1α activity, and downregulated VEGF expression in the rat lungs. Cleaved caspase-3, caspase-8 and Bcl-2 interacting mediator of cell death (Bim expression was increased, and the phosphorylation of FAK was decreased in copper depleted rat lungs. Administration of 1,2,4,5-BT and FAK siRNA caused emphysematous lung destruction associated with increased expression of cleaved capase-3, caspase-8 and Bim.These data indicate that copper-dependent mechanisms contribute to the pathogenesis of emphysema, which may be associated with decreased HIF-1α and FAK activity in the lung.

  18. Na3Co2(AsO4(As2O7: a new sodium cobalt arsenate

    Directory of Open Access Journals (Sweden)

    Abderrahmen Guesmi

    2012-07-01

    Full Text Available In the title compound, trisodium dicobalt arsenate diarsenate, Na3Co2AsO4As2O7, the two Co atoms, one of the two As and three of the seven O atoms lie on special positions, with site symmetries 2 and m for the Co, m for the As, and 2 and twice m for the O atoms. The two Na atoms are disordered over two general and special positions [occupancies 0.72 (3:0.28 (3 and 0.940 (6:0.060 (6, respectively]. The main structural feature is the association of the CoO6 octahedra in the ab plane, forming Co4O20 units, which are corner- and edge-connected via AsO4 and As2O7 arsenate groups, giving rise to a complex polyhedral connectivity with small tunnels, such as those running along the b- and c-axis directions, in which the Na+ ions reside. The structural model is validated by both bond-valence-sum and charge-distribution methods, and the distortion of the coordination polyhedra is analyzed by means of the effective coordination number.

  19. Effect of copper on growth of an aquatic macrophyte, Elodea canadensis

    Energy Technology Data Exchange (ETDEWEB)

    Mal, T.K.; Adorjan, Peter; Corbett, A.L

    2002-12-01

    Elodea canadensis may be a good biomonitor for copper, but not a good bioaccumulator. - Elodea canadensis has been proposed as a potential biomonitor due to its wide distribution and apparent ability to accumulate pollutants in aquatic ecosystems. We investigated the effects of copper sulfate on growth in E. canadensis to determine its effectiveness as a biomonitor of copper pollution in aquatic systems and whether growth is a suitable index of sub-lethal stress. Copper sulfate significantly slowed or stopped growth at all concentrations (low: 1 ppm, medium: 5 ppm, high: 10 ppm of copper sulfate) used. Final plant drymass was significantly lower in medium and high copper treatments compared with controls. E. canadensis appears to be very sensitive to copper levels, and may be useful as a biomonitor of copper levels in aquatic systems. However, its utility as a bioaccumulator may be limited, because we observed senescence of most leaves in all copper-treated plants following 4 weeks of treatment.

  20. Effect of copper on growth of an aquatic macrophyte, Elodea canadensis

    International Nuclear Information System (INIS)

    Mal, T.K.; Adorjan, Peter; Corbett, A.L.

    2002-01-01

    Elodea canadensis may be a good biomonitor for copper, but not a good bioaccumulator. - Elodea canadensis has been proposed as a potential biomonitor due to its wide distribution and apparent ability to accumulate pollutants in aquatic ecosystems. We investigated the effects of copper sulfate on growth in E. canadensis to determine its effectiveness as a biomonitor of copper pollution in aquatic systems and whether growth is a suitable index of sub-lethal stress. Copper sulfate significantly slowed or stopped growth at all concentrations (low: 1 ppm, medium: 5 ppm, high: 10 ppm of copper sulfate) used. Final plant drymass was significantly lower in medium and high copper treatments compared with controls. E. canadensis appears to be very sensitive to copper levels, and may be useful as a biomonitor of copper levels in aquatic systems. However, its utility as a bioaccumulator may be limited, because we observed senescence of most leaves in all copper-treated plants following 4 weeks of treatment

  1. TISSUE DISTRIBUTION OF INORGANIC ARSENIC (AS) AND ITS METHYLATED METABOLITES IN MICE FOLLOWING ORAL ADMINISTRATION OF ARSENATE (ASV)

    Science.gov (United States)

    TISSUE DISTRIBUTION OF INORGANIC ARSENIC (iAs) AND ITS METHYLATED METABOLITES IN MICE FOLLOWING ORAL ADMINISTRATION OF ARSENATE (AsV). E M Kenyon1, L M Del Razo2, and M F Hughes1. 1NHEERL, ORD, US EPA, RTP, NC, USA; 2CINVESTAV-IPN, Mexico City, Mexico.The relationship o...

  2. Effect of copper on growth of an aquatic macrophyte, Elodea canadensis.

    Science.gov (United States)

    Mal, Tarun K; Adorjan, Peter; Corbett, Andrea L

    2002-01-01

    Elodea canadensis has been proposed as a potential biomonitor due to its wide distribution and apparent ability to accumulate pollutants in aquatic ecosystems. We investigated the effects of copper sulfate on growth in E. canadensis to determine its effectiveness as a biomonitor of copper pollution in aquatic systems and whether growth is a suitable index of sub-lethal stress. Copper sulfate significantly slowed or stopped growth at all concentrations (low: 1 ppm, medium: 5 ppm, high: 10 ppm of copper sulfate) used. Final plant drymass was significantly lower in medium and high copper treatments compared with controls. E. canadensis appears to be very sensitive to copper levels, and may be useful as a biomonitor of copper levels in aquatic systems. However, its utility as a bioaccumulator may be limited, because we observed senescence of most leaves in all copper-treated plants following 4 weeks of treatment.

  3. Beneficial behavior of nitric oxide in copper-treated medicinal plants

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Shiliang, E-mail: liushiliang9@163.com [College of Landscape Architecture, Sichuan Agricultural University, Chengdu, Sichuan 611130 (China); Yang, Rongjie; Pan, Yuanzhi [College of Landscape Architecture, Sichuan Agricultural University, Chengdu, Sichuan 611130 (China); Ren, Bo [Institute of Biotechnology & Breeding, Sichuan Academy of Forestry, Chengdu, Sichuan 610081 (China); Chen, Qibing; Li, Xi [College of Landscape Architecture, Sichuan Agricultural University, Chengdu, Sichuan 611130 (China); Xiong, Xi [College of Agriculture, Food & Natural Resources, University of Missouri, Columbia, MO 65211 (United States); Tao, Jianjun [College of Landscape Architecture, Sichuan Agricultural University, Chengdu, Sichuan 611130 (China); Cheng, Qingsu [Division of Life Sciences, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Department of Electrical & Biomedical Engineering, University of Nevada, Reno, NV 89557 (United States); Ma, Mingdong, E-mail: 610245498@qq.com [College of Landscape Architecture, Sichuan Agricultural University, Chengdu, Sichuan 611130 (China)

    2016-08-15

    Highlights: • Endogenous NO and ROS accumulation were inversely related. • Selected amino acids in the roots were increased by SNP. • NO induced regulation of phenolic metabolism for protection against Cu toxicity. • SNP improved the vincristine, vinblastine and total alkaloid contents in Cu-treated plants. - Abstract: Despite numerous reports implicating nitric oxide (NO) in the environmental-stress responses of plants, the specific metabolic and ionic mechanisms of NO-mediated adaptation to metal stress remain unclear. Here, the impacts of copper (Cu) and NO donor (SNP, 50 μM) alone or in combination on the well-known medicinal plant Catharanthus roseus L. were investigated. Our results showed that Cu markedly increased Cu{sup 2+} accumulation, decreased NO production, and disrupted mineral equilibrium and proton pumps, thereby stimulating a burst of ROS; in addition, SNP ameliorates the negative toxicity of Cu, and cPTIO reverses this action. Furthermore, the accumulations of ROS and NO resulted in reciprocal changes. Interestingly, nearly all of the investigated amino acids and the total phenolic content in the roots were promoted by the SNP treatment but were depleted by the Cu + SNP treatment, which is consistent with the self-evident increases in phenylalanine ammonia-lyase activity and total soluble phenol content induced by SNP. Unexpectedly, leaf vincristine and vinblastine as well as the total alkaloid content (ca. 1.5-fold) were decreased by Cu but markedly increased by SNP (+38% and +49% of the control levels). This study provides the first evidence of the beneficial behavior of NO, rather than other compounds, in depleting Cu toxicity by regulating mineral absorption, reestablishing ATPase activities, and stimulating secondary metabolites.

  4. Microneedle-Mediated Delivery of Copper Peptide Through Skin.

    Science.gov (United States)

    Li, Hairui; Low, Yong Sheng Jason; Chong, Hui Ping; Zin, Melvin T; Lee, Chi-Ying; Li, Bo; Leolukman, Melvina; Kang, Lifeng

    2015-08-01

    Copper peptide (GHK-Cu) plays an important role in skin regeneration and wound healing. However, its skin absorption remains challenging due to its hydrophilicity. Here we use polymeric microneedle array to pre-treat skin to enhance GHK-Cu skin penetration. Two in vitro skin models were used to assess the capability of microneedles in facilitating skin delivery of GHK-Cu. Histological assay and confocal laser scanning microscopy were performed to characterize and quantify the microconduits created by the microneedles inside skin. Cellular and porcine models were used to evaluate the safety of microneedle-assisted copper peptide delivery. The depth and percentage of microneedle penetration were correlated with application forces, which in turn influenced the extent of enhancement in the skin permeability of GHK-Cu. In 9 h, 134 ± 12 nanomoles of peptide and 705 ± 84 nanomoles of copper permeated though the microneedle treated human skin, while almost no peptide or copper permeated through intact human skin. No obvious signs of skin irritation were observed with the use of GHK-Cu after microneedle pretreatment. It is effective and safe to enhance the skin permeation of GHK-Cu by using microneedles. This approach may be useful to deliver similar peptides or minerals through skin.

  5. CONSIDERATIONS ON THE INFLUENCE OF COMPLEXATION IN THE COPPER UPTAKE AND TRANSLOCATION

    Directory of Open Access Journals (Sweden)

    SEMAGHIUL BIRGHILA

    2014-07-01

    Full Text Available The actual knowledge about food and the environment underlines the fact that agricultural and environmental sciences must solve various problems regarding copper uptake from soil to plants and its bioaccumulation, being important issues for copper concentration in crops and also for phytoremediation of polluted soils. We studied the relation between the form in which copper is applied to soil and the consequential copper bioavailability, uptake and translocation, using as examples simple and complex copper compounds. The copper concentration in basil plants harvested from soils treated with copper compounds and the calculated values of transfer coefficient, translocation factor, bioaccumulation factor, and uptake coefficient demonstrated that the ionic copper (from simple salts is not necessarily easier to uptake than complex ions, but is easier translocated in plants, while the copper given as complex ions is most likely to be retained by roots. The results indicated that the involvement of copper complexes in agricultural treatments is a solution for soils phytoremediation, concerning the phytostabilization technology.

  6. Gene Expression Analysis of Copper Tolerance and Wood Decay in the Brown Rot Fungus Fibroporia radiculosa

    Science.gov (United States)

    J. D. Tang; L. A. Parker; A. D. Perkins; T. S. Sonstegard; S. G. Schroeder; D. D. Nicholas; S. V. Diehl

    2013-01-01

    High-throughput transcriptomics was used to identify Fibroporia radiculosa genes that were differentially regulated during colonization of wood treated with a copper-based preservative. The transcriptome was profiled at two time points while the fungus was growing on wood treated with micronized copper quat (MCQ). A total of 917 transcripts were...

  7. Green synthesis and evaluation of an iron-based metal-organic framework MIL-88B for efficient decontamination of arsenate from water.

    Science.gov (United States)

    Hou, Shuliang; Wu, Yi-Nan; Feng, Lingyu; Chen, Wei; Wang, Ying; Morlay, Catherine; Li, Fengting

    2018-02-13

    Iron-containing metal-organic frameworks (MOFs) have gradually emerged as environmentally benign alternatives for reducing the levels of environmental contamination because of their advantages, such as readily obtained raw materials with low cost, nontoxic metal source with good biocompatibility, and distinguished physicochemical features e.g., high porosity, framework flexibility, and semiconductor properties. In this study, we reported an innovative strategy for synthesizing an iron-based MOF, MIL-88B, at room temperature. The novelty of this strategy was the use of ethanol as solvent and the pretreatment of dry milling with neither the bulk use of a toxic organic solvent nor the addition of extremely dangerous hydrofluoric acid or strong alkali. The synthesized MIL-88B(Fe) was evaluated as a sorbent for removing arsenate in water and it exhibited high adsorption capacity (156.7 mg g -1 ) at a low dosage. The removal capacity of trace arsenate on MIL-88B(Fe) was 32.3 mg g -1 at a low equilibrium concentration (6.4 μg L -1 ), which satisfied the arsenic threshold for drinking water. The results of Fourier transform infrared and X-ray photoelectron spectroscopy indicated that the As(v) molecules bonded with the oxygen molecules, which were coordinated with FeO clusters in the framework. This work presented the potential use of the up-scaled MIL-88B as an excellent sorbent for purifying arsenate-contaminated water.

  8. Electrokinetic copper and iron migration in anaerobic granular sludge

    NARCIS (Netherlands)

    Virkutyte, J.; Sillanpää, M.J.; Lens, P.N.L.

    2006-01-01

    The application of low-level direct electric current (0.15 mA cm¿2) as an electrokinetic technique to treat copper-contaminated mesophilic anaerobic granular sludge was investigated. The sludge was obtained from a full scale UASB reactor treating paper-mill wastewater and was artificially

  9. Copper-induced immunotoxicity involves cell cycle arrest and cell death in the spleen and thymus

    International Nuclear Information System (INIS)

    Mitra, Soham; Keswani, Tarun; Dey, Manali; Bhattacharya, Shaswati; Sarkar, Samrat; Goswami, Suranjana; Ghosh, Nabanita; Dutta, Anuradha; Bhattacharyya, Arindam

    2012-01-01

    Copper is an essential trace element for human physiological processes. To evaluate the potential adverse health impact/immunotoxicological effects of this metal in situ due to over exposure, Swiss albino mice were treated (via intraperitoneal injections) with copper (II) chloride (copper chloride) at doses of 0, 5, or 7.5 mg copper chloride/kg body weight (b.w.) twice a week for 4 wk; these values were derived from LD 50 studies using copper chloride doses that ranged from 0 to 40 mg/kg BW (2×/wk, for 4 wk). Copper treated mice evidenced immunotoxicity as indicated by dose-related decreases and increases, respectively, in thymic and splenic weights. Histomorphological changes evidenced in these organs were thymic atrophy, white pulp shrinkage in the spleen, and apoptosis of splenocytes and thymocytes; these observations were confirmed by microscopic analyses. Cell count analyses indicated that the proliferative functions of the splenocytes and thymocytes were also altered because of the copper exposures. Among both cell types from the copper treated hosts, flow cytometric analyses revealed a dose related increase in the percentages of cells in the Sub-G 0 /G 1 state, indicative of apoptosis which was further confirmed by Annexin V binding assay. In addition, the copper treatments altered the expression of selected cell death related genes such as EndoG and Bax in a dose related manner. Immunohistochemical analyses revealed that there was also increased ubiquitin expression in both the cell types. In conclusion, these studies show that sublethal exposure to copper (as copper chloride) induces toxicity in the thymus and spleen, and increased Sub G 0 /G 1 population among splenocytes and thymocytes that is mediated, in part, by the EndoG–Bax–ubiquitin pathway. This latter damage to these cells that reside in critical immune system organs are likely to be important contributing factors underlying the immunosuppression that has been documented by other

  10. Studies on the influence of surface pre-treatments on electroless copper coating of boron carbide particles

    International Nuclear Information System (INIS)

    Deepa, J.P.; Resmi, V.G.; Rajan, T.P.D.; Pavithran, C.; Pai, B.C.

    2011-01-01

    Boron carbide is one of the hard ceramic particles which find application as structural materials and neutron shielding material due to its high neutron capture cross section. Copper coating on boron carbide particle is essential for the synthesis of metal-ceramic composites with enhanced sinterability and dispersibility. Surface characteristics of the substrate and the coating parameters play a foremost role in the formation of effective electroless coating. The effect of surface pre-treatment conditions and pH on electroless copper coating of boron carbide particles has been studied. Surface pre-treatement of B 4 C when compared to acid treated and alkali treated particles were carried out. Uniform copper coating was observed at pH 12 in alkali treated particles when compared to others due to the effective removal of inevitable impurities during the production and processing of commercially available B 4 C. A threshold pH 11 was required for initiation of copper coating on boron carbide particles. The growth pattern of the copper coating also varies depending on the surface conditions from acicular to spherical morphology.

  11. Developmental consequences of in utero sodium arsenate exposure in mice with folate transport deficiencies

    International Nuclear Information System (INIS)

    Spiegelstein, Ofer; Gould, Amy; Wlodarczyk, Bogdan; Tsie, Marlene; Lu Xiufen; Le, Chris; Troen, Aron; Selhub, Jacob; Piedrahita, Jorge A.; Salbaum, J. Michael; Kappen, Claudia; Melnyk, Stepan; James, Jill; Finnell, Richard H.

    2005-01-01

    Previous studies have demonstrated that mice lacking a functional folate binding protein 2 gene (Folbp2 -/- ) were significantly more sensitive to in utero arsenic exposure than were the wild-type mice similarly exposed. When these mice were fed a folate-deficient diet, the embryotoxic effect of arsenate was further exacerbated. Contrary to expectations, studies on 24-h urinary speciation of sodium arsenate did not demonstrate any significant difference in arsenic biotransformation between Folbp2 -/- and Folbp2 +/+ mice. To better understand the influence of folate pathway genes on arsenic embryotoxicity, the present investigation utilized transgenic mice with disrupted folate binding protein 1 (Folbp1) and reduced folate carrier (RFC) genes. Because complete inactivation of Folbp1 and RFC genes results in embryonic lethality, we used heterozygous animals. Overall, no RFC genotype-related differences in embryonic susceptibility to arsenic exposure were observed. Embryonic lethality and neural tube defect (NTD) frequency in Folbp1 mice was dose-dependent and differed from the RFC mice; however, no genotype-related differences were observed. The RFC heterozygotes tended to have higher plasma levels of S-adenosylhomocysteine (SAH) than did the wild-type controls, although this effect was not robust. It is concluded that genetic modifications at the Folbp1 and RFC loci confers no particular sensitivity to arsenic toxicity compared to wild-type controls, thus disproving the working hypothesis that decreased methylating capacity of the genetically modified mice would put them at increased risk for arsenic-induced reproductive toxicity

  12. Copper imbalances in ruminants and humans: unexpected common ground.

    Science.gov (United States)

    Suttle, Neville F

    2012-09-01

    Ruminants are more vulnerable to copper deficiency than humans because rumen sulfide generation lowers copper availability from forage, increasing the risk of conditions such as swayback in lambs. Molybdenum-rich pastures promote thiomolybdate (TM) synthesis and formation of unabsorbable Cu-TM complexes, turning risk to clinical reality (hypocuprosis). Selection pressures created ruminant species with tolerance of deficiency but vulnerability to copper toxicity in alien environments, such as specific pathogen-free units. By contrast, cases of copper imbalance in humans seemed confined to rare genetic aberrations of copper metabolism. Recent descriptions of human swayback and the exploratory use of TM for the treatment of Wilson's disease, tumor growth, inflammatory diseases, and Alzheimer's disease have created unexpected common ground. The incidence of pre-hemolytic copper poisoning in specific pathogen-free lambs was reduced by an infection with Mycobacterium avium that left them more responsive to treatment with TM but vulnerable to long-term copper depletion. Copper requirements in ruminants and humans may need an extra allowance for the "copper cost" of immunity to infection. Residual cuproenzyme inhibition in TM-treated lambs and anomalies in plasma copper composition that appeared to depend on liver copper status raise this question "can chelating capacity be harnessed without inducing copper-deficiency in ruminants or humans?" A model of equilibria between exogenous (TM) and endogenous chelators (e.g., albumin, metallothionein) is used to predict risk of exposure and hypocuprosis; although risk of natural exposure in humans is remote, vulnerability to TM-induced copper deficiency may be high. Biomarkers of TM impact are needed, and copper chaperones for inhibited cuproenzymes are prime candidates.

  13. Analysis of Saprolegnia parasitica Transcriptome following Treatment with Copper Sulfate.

    Directory of Open Access Journals (Sweden)

    Kun Hu

    Full Text Available Massive infection caused by oomycete fungus Saprolegnia parasitica is detrimental to freshwater fish. Recently, we showed that copper sulfate demonstrated good efficacy for controlling S. parasitica infection in grass carp. In this study, we investigated the mechanism of inhibition of S. parasitica growth by copper sulfate by analyzing the transcriptome of copper sulfate-treated S. parasitica. To examine the mechanism of copper sulfate inhibiting S. parasitica, we utilized RNA-seq technology to compare differential gene expression in S. parasitica treated with or without copper sulfate.The total mapped rates of the reads with the reference genome were 90.50% in the control group and 73.50% in the experimental group. In the control group, annotated splice junctions, partial novel splice junctions and complete novel splice junctions were about 83%, 3% and 14%, respectively. In the treatment group, the corresponding values were about 75%, 6% and 19%. Following copper sulfate treatment, a total 310 genes were markedly upregulated and 556 genes were markedly downregulated in S. parasitica. Material metabolism related GO terms including cofactor binding (33 genes, 1,3-beta-D-glucan synthase complex (4 genes, carboxylic acid metabolic process (40 genes were the most significantly enriched. KEGG pathway analysis also determined that the metabolism-related biological pathways were significantly enriched, including the metabolic pathways (98 genes, biosynthesis of secondary metabolites pathways (42 genes, fatty acid metabolism (13 genes, phenylalanine metabolism (7 genes, starch and sucrose metabolism pathway (12 genes. The qRT-PCR results were largely consistent with the RNA-Seq results.Our results indicate that copper sulfate inhibits S. parasitica growth by affecting multiple biological functions, including protein synthesis, energy biogenesis, and metabolism.

  14. Copper and Copper Proteins in Parkinson's Disease

    Science.gov (United States)

    Rivera-Mancia, Susana; Diaz-Ruiz, Araceli; Tristan-Lopez, Luis; Rios, Camilo

    2014-01-01

    Copper is a transition metal that has been linked to pathological and beneficial effects in neurodegenerative diseases. In Parkinson's disease, free copper is related to increased oxidative stress, alpha-synuclein oligomerization, and Lewy body formation. Decreased copper along with increased iron has been found in substantia nigra and caudate nucleus of Parkinson's disease patients. Copper influences iron content in the brain through ferroxidase ceruloplasmin activity; therefore decreased protein-bound copper in brain may enhance iron accumulation and the associated oxidative stress. The function of other copper-binding proteins such as Cu/Zn-SOD and metallothioneins is also beneficial to prevent neurodegeneration. Copper may regulate neurotransmission since it is released after neuronal stimulus and the metal is able to modulate the function of NMDA and GABA A receptors. Some of the proteins involved in copper transport are the transporters CTR1, ATP7A, and ATP7B and the chaperone ATOX1. There is limited information about the role of those biomolecules in the pathophysiology of Parkinson's disease; for instance, it is known that CTR1 is decreased in substantia nigra pars compacta in Parkinson's disease and that a mutation in ATP7B could be associated with Parkinson's disease. Regarding copper-related therapies, copper supplementation can represent a plausible alternative, while copper chelation may even aggravate the pathology. PMID:24672633

  15. Diffuse emission and control of copper in urban surface runoff.

    Science.gov (United States)

    Boller, M A; Steiner, M

    2002-01-01

    Copper washed off from roofs and roads is considered to be a major contribution to diffuse copper pollution of urban environments. In order to guarantee sustainable protection of soils and water, the long-term strategy is to avoid or replace copper containing materials on roofs and fagades. Until achievement of this goal, a special adsorber system is suggested to control the diffuse copper fluxes by retention of copper by a mixture of granulated iron-hydroxide (GEH) and calcium carbonate. Since future stormwater runoff concepts are based on decentralised runoff infiltration into the underground, solutions are proposed which provide for copper retention in infiltration sites using GEH adsorption layers. The example of a large copper façade of which the runoff is treated in an adsorption trench reveals the first full-scale data on façade runoff and adsorber performance. During the first year of investigation average façade runoff concentrations in the range of 1-10 mg Cu/l are reduced by 96-99% in the adsorption ditch.

  16. Separation of copper-64 from copper phthalocyanine

    International Nuclear Information System (INIS)

    Battaglin, R.I.M.

    1979-01-01

    The separation of copper-64 from irradiated copper phthalocyanine by Szilard-Chalmers effect is studied. Two methods of separation are used: one of them is based on the dissolution of the irradiated dry compound in concentrated sulfuric acid following its precipitation in water. In the other one the compound is irradiated with water in paste form following treatment with water and hydrochloric acid. The influence of the crystal form of the copper phthalocyanine on the separation yield of copper-64 is shown. Preliminary tests using the ionic exchange technique for purification and changing of copper-64 sulfate to chloride form are carried out. The specific activity using the spectrophotometric technique, after the determination of the copper concentration in solution of copper-64, is calculated. (Author) [pt

  17. Active screen cage pulsed dc discharge for implanting copper in polytetrafluoroethylene (PTFE)

    Science.gov (United States)

    Zaka-ul-Islam, Mujahid; Naeem, Muhammad; Shafiq, Muhammad; Sitara; Jabbar Al-Rajab, Abdul; Zakaullah, Muhammad

    2017-07-01

    Polymers such as polytetrafluoroethylene (PTFE) are widely used in artificial organs where long-term anti-bacterial properties are required to avoid bacterial proliferation. Copper or silver ion implantation on the polymer surface is known as a viable method to generate long-term anti-bacterial properties. Here, we have tested pulsed DC plasma with copper cathodic cage for the PTFE surface treatment. The surface analysis of the treated specimens suggests that the surface, structural properties, crystallinity and chemical structure of the PTFE have been changed, after the plasma treatment. The copper release tests show that copper ions are released from the polymer at a slow rate and quantity of the released copper increases with the plasma treatment time.

  18. Method For Creating Corrosion Resistant Surface On An Aluminum Copper Alloy

    Science.gov (United States)

    Mansfeld, Florian B.; Wang, You; Lin, Simon H.

    1997-06-03

    A method for treating the surface of aluminum alloys hang a relatively high copper content is provided which includes the steps of removing substantially all of the copper from the surface, contacting the surface with a first solution containing cerium, electrically charging the surface while contacting the surface in an aqueous molybdate solution, and contacting the surface with a second solution containing cerium. The copper is substantially removed from the surface in the first step either by (i) contacting the surface with an acidic chromate solution or by (ii) contacting the surface with an acidic nitrate solution while subjecting the surface to an electric potential. The corrosion-resistant surface resulting from the invention is excellent, consistent and uniform throughout the surface. Surfaces treated by the invention may often be certified for use in salt-water services.

  19. Copper ions stimulate the proliferation of hepatic stellate cells via oxygen stress in vitro.

    Science.gov (United States)

    Xu, San-qing; Zhu, Hui-yun; Lin, Jian-guo; Su, Tang-feng; Liu, Yan; Luo, Xiao-ping

    2013-02-01

    This study examined the effect of copper ions on the proliferation of hepatic stellate cells (HSCs) and the role of oxidative stress in this process in order to gain insight into the mechanism of hepatic fibrosis in Wilson's disease. LX-2 cells, a cell line of human HSCs, were cultured in vitro and treated with different agents including copper sulfate, N-acetyl cysteine (NAC) and buthionine sulfoximine (BSO) for different time. The proliferation of LX-2 cells was measured by non-radioactive cell proliferation assay. Real-time PCR and Western blotting were used to detect the mRNA and protein expression of platelet-derived growth factor receptor β subunit (PDGFβR), ELISA to determine the level of glutathione (GSH) and oxidized glutathione (GSSG), dichlorofluorescein assay to measure the level of reactive oxygen species (ROS), and lipid hydroperoxide assay to quantify the level of lipid peroxide (LPO). The results showed that copper sulfate over a certain concentration range could promote the proliferation of LX-2 cells in a time- and dose-dependent manner. The effect was most manifest when LX-2 cells were treated with copper sulfate at a concentration of 100 μmol/L for 24 h. Additionally, copper sulfate could dose-dependently increase the levels of ROS and LPO, and decrease the ratio of GSH/GSSG in LX-2 cells. The copper-induced increase in mRNA and protein expression of PDGFβR was significantly inhibited in LX-2 cells pre-treated with NAC, a precursor of GSH, and this phenomenon could be reversed by the intervention of BSO, an inhibitor of NAC. It was concluded that copper ions may directly stimulate the proliferation of HSCs via oxidative stress. Anti-oxidative stress therapies may help suppress the copper-induced activation and proliferation of HSCs.

  20. Preparation of chitosan-collagen-alginate composite dressing and its promoting effects on wound healing.

    Science.gov (United States)

    Xie, Haixia; Chen, Xiuli; Shen, Xianrong; He, Ying; Chen, Wei; Luo, Qun; Ge, Weihong; Yuan, Weihong; Tang, Xue; Hou, Dengyong; Jiang, Dingwen; Wang, Qingrong; Liu, Yuming; Liu, Qiong; Li, Kexian

    2018-02-01

    The present study aimed to prepare a composite dressing composed of collagen, chitosan, and alginate, which may promote wound healing and prevent from seawater immersion. Chitosan-collagen-alginate (CCA) cushion was prepared by paintcoat and freeze-drying, and it was attached to a polyurethane to compose CCA composite dressing. The swelling, porosity, degradation, and mechanical properties of CCA cushion were evaluated. The effects on wound healing and seawater prevention of CCA composite dressing were tested by rat wound model. Preliminary biosecurity was tested by cytotoxicity and hemocompatibility. The results revealed that CCA cushion had good water absorption and mechanical properties. A higher wound healing ratio was observed in CCA composite dressing treated rats than in gauze or chitosan treated ones. On the fifth day, the healing rates of CCA composite dressing, gauze, and chitosan were 48.49%±1.07%, 28.02%±6.4%, and 38.97%±8.53%, respectively. More fibroblast and intact re-epithelialization were observed in histological images of CCA composite dressing treated rats, and the expressions of EGF, bFGF, TGF-β, and CD31 increased significantly. CCA composite dressing showed no significant cytotoxicity, and favorable hemocompatibility. These results suggested that CCA composite dressing could prevent against seawater immersion and promote wound healing while having a good biosecurity. Copyright © 2017. Published by Elsevier B.V.

  1. on bauxite in water

    African Journals Online (AJOL)

    DR OKE

    In comparison, the kinetics for As(III) adsorption was initially fast but then dropped ..... Handbook of elemental speciation ii: Species in the environment, food, medicine ... Leaching of chromated copper arsenate wood preservatives: A review.

  2. Copper-silver ionization at a US hospital: interaction of treated drinking water with plumbing materials, aesthetics and other considerations

    Science.gov (United States)

    Tap water sampling and surface analysis of copper pipe/bathroom porcelain were performed to explore the fate of copper and silver during the first nine months of copper-silver ionization (CSI) applied to cold and hot water at a hospital in Cincinnati, Ohio. Ions dosed by CSI into...

  3. Betacyanin accumulation and guaiacol peroxidase activity in Beta vulgaris L. leaves following copper stress

    Directory of Open Access Journals (Sweden)

    Janet M. León Morales

    2012-07-01

    Full Text Available The effect of copper stress on betacyanin accumulation and guaiacol peroxidase (GPOD activity in leaves of different age was evaluated in red beet (Beta vulgaris L. var. Crosby Egyptian plants. In hydroponic culture, plants were treated with 0.3 μM (control, 50 μM, 100 μM, and 250 μM of CuSO4 for 6 days. Copper was taken up and accumulated in old roots but was not translocated to leaves. However in young leaves, the increase of lipid peroxidation and reduction of growth were evident from day 3 of copper exposure; whereas in old leaves, the lipid peroxidation and growth were the same from either copper-treated or control plants. In response to copper exposure, the betacyanin accumulation was evident in young leaves by day 3, and continued to increase until day 6. Betacyanin only were accumulated in old leaves until day 6, but the contents were from 4 to 5 times lower than those observed in young leaves at the same copper concentrations. GPOD activity increased 3.3- and 1.4-fold in young and old leaves from day 3 of copper treatment respectively, but only in the young leaves was sustained at the same level until day 6. Old roots shown betacyanin in the control plants, but the betacyanin level and growth were reduced with the copper exposure. In contrast, young roots emerged by copper effect also accumulated copper and showed the highest betacyanin content of all plant parts assayed. These results indicate that betacyanin accumulation and GPOD activity are defense responses to copper stress in actively growing organs.

  4. Copper and copper-nickel alloys as zebra mussel antifoulants

    Energy Technology Data Exchange (ETDEWEB)

    Dormon, J.M.; Cottrell, C.M.; Allen, D.G.; Ackerman, J.D.; Spelt, J.K. [Univ. of Toronto, Ontario (Canada)

    1996-04-01

    Copper has been used in the marine environment for decades as cladding on ships and pipes to prevent biofouling by marine mussels (Mytilus edulis L.). This motivated the present investigation into the possibility of using copper to prevent biofouling in freshwater by both zebra mussels and quagga mussels (Dreissena polymorpha and D. bugensis collectively referred to as zebra mussels). Copper and copper alloy sheet proved to be highly effective in preventing biofouling by zebra mussels over a three-year period. Further studies were conducted with copper and copper-nickel mesh (lattice of expanded metal) and screen (woven wire with a smaller hole size), which reduced the amount of copper used. Copper screen was also found to be strongly biofouling-resistant with respect to zebra mussels, while copper mesh reduced zebra mussel biofouling in comparison to controls, but did not prevent it entirely. Preliminary investigations into the mechanism of copper antifouling, using galvanic couples, indicated that the release of copper ions from the surface of the exposed metal into the surrounding water is directly or indirectly responsible for the biofouling resistance of copper.

  5. Effects of blending of desalinated water with treated surface drinking water on copper and lead release.

    Science.gov (United States)

    Liu, Haizhou; Schonberger, Kenneth D; Korshin, Gregory V; Ferguson, John F; Meyerhofer, Paul; Desormeaux, Erik; Luckenbach, Heidi

    2010-07-01

    This study examined effects of desalinated water on the corrosion of and metal release from copper and lead-containing materials. A jar test protocol was employed to examine metal release from copper and lead-tin coupons exposed to water chemistries with varying blending ratios of desalinated water, alkalinities, pHs and orthophosphate levels. Increasing fractions of desalinated water in the blends resulted in non-monotonic changes of copper and lead release, with generally lower metal concentrations in the presence of desalinated water, especially when its contribution increased from 80% to 100%. SEM examination showed that the increased fractions of desalinated water were associated with pronounced changes of the morphology of the corrosion scales, likely due to the influence of natural organic matter. This hypothesis was corroborated by the existence of correlations between changes of the zeta-potential of representative minerals (malachite and hydrocerussite) and metal release. For practical applications, maintaining pH at 7.8 and adding 1 mg/L orthophosphate as PO(4) were concluded to be adequate to decrease copper and lead release. Lower alkalinity of desalinated water was beneficial for blends containing 50% or more desalinated water. Copyright 2010 Elsevier Ltd. All rights reserved.

  6. Copper and Copper Proteins in Parkinson’s Disease

    Directory of Open Access Journals (Sweden)

    Sergio Montes

    2014-01-01

    Full Text Available Copper is a transition metal that has been linked to pathological and beneficial effects in neurodegenerative diseases. In Parkinson’s disease, free copper is related to increased oxidative stress, alpha-synuclein oligomerization, and Lewy body formation. Decreased copper along with increased iron has been found in substantia nigra and caudate nucleus of Parkinson’s disease patients. Copper influences iron content in the brain through ferroxidase ceruloplasmin activity; therefore decreased protein-bound copper in brain may enhance iron accumulation and the associated oxidative stress. The function of other copper-binding proteins such as Cu/Zn-SOD and metallothioneins is also beneficial to prevent neurodegeneration. Copper may regulate neurotransmission since it is released after neuronal stimulus and the metal is able to modulate the function of NMDA and GABA A receptors. Some of the proteins involved in copper transport are the transporters CTR1, ATP7A, and ATP7B and the chaperone ATOX1. There is limited information about the role of those biomolecules in the pathophysiology of Parkinson’s disease; for instance, it is known that CTR1 is decreased in substantia nigra pars compacta in Parkinson’s disease and that a mutation in ATP7B could be associated with Parkinson’s disease. Regarding copper-related therapies, copper supplementation can represent a plausible alternative, while copper chelation may even aggravate the pathology.

  7. Separation/Preconcentration and Speciation Analysis of Trace Amounts of Arsenate and Arsenite in Water Samples Using Modified Magnetite Nanoparticles and Molybdenum Blue Method

    Directory of Open Access Journals (Sweden)

    Mohammad Ali Karimi

    2014-01-01

    Full Text Available A new, simple, and fast method for the separation/preconcentration and speciation analysis of arsenate and arsenite ions using cetyltrimethyl ammonium bromide immobilized on alumina-coated magnetite nanoparticles (CTAB@ACMNPs followed by molybdenum blue method is proposed. The method is based on the adsorption of arsenate on CTAB@ACMNPs. Total arsenic in different samples was determined as As(V after oxidation of As(III to As(V using potassium permanganate. The arsenic concentration has been determined by UV-Visible spectrometric technique based on molybdenum blue method and amount of As(III was calculated by subtracting the concentration of As(V from total arsenic concentration. MNPs and ACMNPs were characterized by VSM, XRD, SEM, and FT-IR spectroscopy. Under the optimal experimental conditions, the preconcentration factor, detection limit, linear range, and relative standard deviation (RSD of arsenate were 175 (for 350 mL of sample solution, 0.028 μg mL−1, 0.090–4.0 μg mL−1, and 2.8% (for 2.0 μg mL−1, n=7, respectively. This method avoided the time-consuming column-passing process of loading large volume samples in traditional SPE through the rapid isolation of CTAB@ACMNPs with an adscititious magnet. The proposed method was successfully applied to the determination and speciation of arsenic in different water samples and suitable recoveries were obtained.

  8. New Insight into the Local Structure of Hydrous Ferric Arsenate Using Full-Potential Multiple Scattering Analysis, Density Functional Theory Calculations, and Vibrational Spectroscopy.

    Science.gov (United States)

    Wang, Shaofeng; Ma, Xu; Zhang, Guoqing; Jia, Yongfeng; Hatada, Keisuke

    2016-11-15

    Hydrous ferric arsenate (HFA) is an important arsenic-bearing precipitate in the mining-impacted environment and hydrometallurgical tailings. However, there is no agreement on its local atomic structure. The local structure of HFA was reprobed by employing a full-potential multiple scattering (FPMS) analysis, density functional theory (DFT) calculations, and vibrational spectroscopy. The FPMS simulations indicated that the coordination number of the As-Fe, Fe-As, or both in HFA was approximately two. The DFT calculations constructed a structure of HFA with the formula of Fe(HAsO 4 ) x (H 2 AsO 4 ) 1-x (OH) y ·zH 2 O. The presence of protonated arsenate in HFA was also evidenced by vibrational spectroscopy. The As and Fe K-edge X-ray absorption near-edge structure spectra of HFA were accurately reproduced by FPMS simulations using the chain structure, which was also a reasonable model for extended X-Ray absorption fine structure fitting. The FPMS refinements indicated that the interatomic Fe-Fe distance was approximately 5.2 Å, consistent with that obtained by Mikutta et al. (Environ. Sci. Technol. 2013, 47 (7), 3122-3131) using wavelet analysis. All of the results suggested that HFA was more likely to occur as a chain with AsO 4 tetrahedra and FeO 6 octahedra connecting alternately in an isolated bidentate-type fashion. This finding is of significance for understanding the fate of arsenic and the formation of ferric arsenate minerals in an acidic environment.

  9. Copper chelators: chemical properties and bio-medical applications.

    Science.gov (United States)

    Tegoni, M; Valensin, D; Toso, L; Remelli, M

    2014-01-01

    Copper is present in different concentrations and chemical forms throughout the earth crust, surface and deep water and even, in trace amounts, in the atmosphere itself. Copper is one of the first metals used by humans, the first artifacts dating back 10,000 years ago. Currently, the world production of refined copper exceeds 16,000 tons/year. Copper is a micro-element essential to life, principally for its red-ox properties that make it a necessary cofactor for many enzymes, like cytochrome-c oxidase and superoxide dismutase. In some animal species (e.g. octopus, snails, spiders, oysters) copper-hemocyanins also act as carriers of oxygen instead of hemoglobin. However, these red-ox properties also make the pair Cu(+)/Cu(2+) a formidable catalyst for the formation of reactive oxygen species, when copper is present in excess in the body or in tissues. The treatment of choice in cases of copper overloading or intoxication is the chelation therapy. Different molecules are already in clinical use as chelators or under study or clinical trial. It is worth noting that chelation therapy has also been suggested to treat some neurodegenerative diseases or cardiovascular disorders. In this review, after a brief description of the homeostasis and some cases of dyshomeostasis of copper, the main (used or potential) chelators are described; their properties in solution, even in relation to the presence of metal or ligand competitors, under physiological conditions, are discussed. The legislation of the most important Western countries, regarding both the use of chelating agents and the limits of copper in foods, drugs and cosmetics, is also outlined.

  10. [Use of copper oxide wire particles (Copinox) for the prevention of congenital copper deficiency in a herd of German Improved Fawn breed of goat].

    Science.gov (United States)

    Winter, P; Hochsteiner, W; Chizzola, R

    2004-10-01

    In a herd of German Improved Fawn breed of goat in the year 2000 neonatal kid losses due to congenital copper deficiencies were observed. To clarify the problems and to prevent losses in the next breeding season serum copper levels of 10 dams and four control Boer goats were investigated at four time points during one year. Additionally ten kids of the following year were sampled and the serum copper levels were studied. Immediatly after parturition and 8 weeks later the dams showed low serum copper levels (10.4 +/- 11.1 micromol/l, 5.7 +/- 2.9 micromol/l resp.). At the end of the pasture season an increase of serum copper could be measured (19.3 +/- 16.0 micromol/l). To prevent enzootic ataxia due to congenital copper deficiency, the dams were treated with copper oxide wire particles in the next late gestation. At this time point serum copper concentrations started to decrease (18.5 +/- 8.4 micromol/l). The re-examination 3 month later demonstrated an increase of the serum mean copper concentrations up to 23.4 micromol/l in the dams and to 16.2 micromol/l in the kids. The serum copper levels were significantly higher compared to the levels the year before. Big variation of the serum copper levels in the control Boer goats occurred during the year, but no clinical symptoms of copper deficiency could be observed. The copper levels in the grass and soil samples were 6.8 mg/kg and 0.2 mg/kg dry substance, respectively. A secondary copper deficiency based on cadmium could be excluded through the low levels of soil samples. The contents of sulphur and molybdenum were not determined. The results indicate that the German Improved Fawn breed of goats suffered from a primary copper deficiency due to the inefficient mineral supplementation. The administration of Copinox in the last third of the gestation leads to a continious raising of the copper concentrations in the serum and is suited to prevent ataxia due to congential copper deficiency in neonatal kids.

  11. Hepatoprotective effects of hexane root extract of Alchornea laxiflora in sodium arsenate toxicity in wistar albino rats

    OpenAIRE

    Esosa Samuel Uhunmwangho; Nurudeen Olajide Rasaq; Iyanuoluwa Olubukola Osikoya

    2018-01-01

    Background: Medicinal plants are have been used in the treatment of myriad disease conditions, Alchornea laxiflora is one of such medicinal plant. Aim: To investigate the hepatoprotective effect of hexane root extract of Alchornea laxiflora against sodium arsenate induced liver damage in wistar male rats. Setting and Design: Extraction and administration of bioactive extract. Materials and Methods: Extraction of air-dried ground root of Alchornea laxiflora was done by extracting 500 g with 50...

  12. Accumulation and hyperaccumulation of copper in plants

    Science.gov (United States)

    Adam, V.; Trnkova, L.; Huska, D.; Babula, P.; Kizek, R.

    2009-04-01

    have adapted on such stress. The aim of this study is to investigate the behaviour of copper in plants and to assess its potential effect on the surrounding environment. To detect copper in biological samples electrochemical methods were employed particularly differential pulse voltammetry (DPV). Copper gave signals at 0.02 V measured by DPV. The obtained calibration dependence was linear (R2 = 0.995). Further, this method was utilized for determination of copper in real soil samples obtained from previously mentioned heavy-metal-polluted mining area. The content varied within range from tens to hundreds of mg of copper per kg of the soil. Moreover, we focused on investigation of copper influence on seedlings of Norway spruce. The seedlings were treated with copper (0, 0.1, 10 and 100 mM) for four weeks. We observed anatomical-morphological changes and other biochemical parameters in plants. We determined that seedlings synthesized more than 48 % protective thiols (glutathione and phytochelatins) compared to control ones. We investigated copper distribution in plant tissues by diphenylcarbazide staining. We found out that copper is highly accumulated in parenchymal stalk cells. In needles, change in auto-fluorescence of parenchymal cells of mesoderm similarly to endodermis cells. Besides, we analyzed samples of plants from the polluted area (spruce, pin, birch). The data obtained well correlated with previously mentioned. Acknowledgement The work on this experiment was supported by grant: INCHEMBIOL MSM0021622412.

  13. Silane pre-treatments on copper and aluminium

    International Nuclear Information System (INIS)

    Deflorian, F.; Rossi, S.; Fedrizzi, L.

    2006-01-01

    A large part of aluminium products are coated with an organic layer in order to improve the corrosion resistance. Copper surfaces are also sometimes protected with an organic coating to improve the durability or the aesthetic properties. Examples of industrial applications are household appliances and heat exchanger components. For these applications it is not rare to have the industrial need to treat at the same time components made of aluminium and copper. In order to extend the service life of the organic coated copper a specific surface pre-treatment is often required. Nevertheless, probably because of the limited market of this application, no specific pre-treatments for copper are industrially developed, with the exception of cleaning procedures, but simply extensions of existing pre-treatments optimised for other metals (aluminium, zinc) are used. The application of silane pre-treatments as adhesion promoters for organic coated metals is remarkably increasing in the last decade, because silanes offer very good performance together with high environmental compatibility. The idea is therefore to try to develop a specific silane based pre-treatment for copper. The starting point is the existing silane products for aluminium, optimising the composition and the application conditions (concentration, temperature, pH of the bath, etc.) in order to develop a high performance copper alloy pre-treatment increasing the protective properties and the adhesion of a successively applied organic coating. Moreover these pre-treatments could be used for aluminium alloys too and therefore could be suggested for multi-metals components. The deposits were analysed using FTIR spectroscopy and optical and electron microscopic observations. A careful electrochemical characterisation, mainly by electrochemical impedance spectroscopy measurements (EIS) was carried out to highlight the presence of silane and to evaluate the performance of the different deposits. In order to study an

  14. Copper carrier protein in copper toxic sheep liver

    Energy Technology Data Exchange (ETDEWEB)

    Harris, A L; Dean, P D.G.

    1973-01-01

    The livers of copper-toxic sheep have been analyzed by gel electrophoresis followed by staining the gels for copper with diethyldithiocarbamate and for protein with amido schwartz. These gels were compared with similar gels obtained from the livers of normal and copper-deficient animals. The copper-toxic livers contained an extra protein band which possessed relatively weakly bound copper. Possible origins of this protein are discussed. 8 references, 1 figure, 2 tables.

  15. Solid state de-wetting observed for vapor deposited copper films on carbon substrates

    International Nuclear Information System (INIS)

    Schrank, C.; Eisenmenger-Sittner, C.; Neubauer, E.; Bangert, H.; Bergauer, A.

    2004-01-01

    Copper-Carbon composites are a good example for novel materials consisting of components with extremely different physical and chemical properties. They have a high potential for an application as heat sinks for electronic components, but the joining of the two materials is a difficult task. To obtain reasonable mechanical and thermal contact between copper and carbon the following route was chosen. First glassy-carbon substrates were subjected to an RF-Nitrogen plasma treatment. Then 300 nm thick copper coatings were sputter-deposited on the plasma treated surface within the same vacuum chamber. Finally, the samples were removed from the deposition chamber and either investigated immediately or thermally annealed at 850 deg. C under high vacuum conditions (10 -4 Pa). While non-annealed copper-coatings were continuous and showed excellent adhesion values of approximately 700 N/cm 2 , the heat treated samples lose their continuity by a de-wetting process. At the beginning holes are formed, then a labyrinth-like morphology develops and finally the coating consists of isolated droplets. All these processes occur well below the melting temperature of copper and were observed by AFM and SEM. The mechanism of this solid-state de-wetting process is investigated in relation to the recent literature on de-wetting and its consequences on the manufacturing of copper-carbon composites are discussed

  16. STATISTICAL APPROACH FOR MULTI CRITERIA OPTIMIZATION OF CUTTING PARAMETERS OF TURNING ON HEAT TREATED BERYLLIUM COPPER ALLOY

    Directory of Open Access Journals (Sweden)

    K. DEVAKI DEVI

    2017-08-01

    Full Text Available In machining operations, achieving desired performance features of the machined product, is really a challenging job. Because, these quality features are highly correlated and are expected to be influenced directly or indirectly by the direct effect of process parameters or their interactive effects. This paper presents effective method and to determine optimal machining parameters in a turning operation on heat treated Beryllium copper alloy to minimize the surface roughness, cutting forces and work tool interface temperature along with the maximization of metal removal rate. The scope of this work is extended to Multi Objective Optimization. Response Surface Methodology is opted for preparing the design matrix, generating ANOVA, and optimization. A powerful model would be obtained with high accuracy to analyse the effect of each parameter on the output. The input parameters considered in this work are cutting speed, feed, depth of cut, work material (Annealed and Hardened and tool material (CBN and HSS.

  17. Regulatory Promotion of Waste Wood Reused as an Energy Source and the Environmental Concerns about Ash Residue in the Industrial Sector of Taiwan

    Directory of Open Access Journals (Sweden)

    Wen-Tien Tsai

    2012-11-01

    Full Text Available The objective of this paper was to provide a preliminary analysis of the utilization of energy derived from waste wood in Taiwan, a highly industrialized country with a high dependence (over 99% on imported energy. The discussion focuses on the status of waste wood generation and its management over the past decade. Findings show that the quantities of biomass waste collected for reuse purposes in the industrial sectors of Taiwan has exhibited an increasing trend, from about 4000 tons in 2001 to over 52,000 tons in 2010. Although waste wood can be reused as a fuel and raw material for a variety of applications based on regulatory promotion, the most commonly used end use is to directly utilize it as an auxiliary fuel in industrial utilities (e.g., boilers, heaters and furnaces for the purpose of co-firing with coal/fuel oil. The most progressive measure for promoting biomass-to-power is to introduce the feed-in tariff (FIT mechanism according to the Renewable Energy Development Act passed in June 2009. The financial support for biomass power generation has been increasing over the years from 0.070 US$/kWh in 2010 to 0.094 US$/kWh in 2012. On the other hand, the environmental regulations in Taiwan regarding the hazard identification of wood-combusted ash (especially in filter fly-ash and its options for disposal and utilization are further discussed in the paper, suggesting that waste wood impregnated with chromated copper arsenate (CCA and other copper-based preservatives should be excluded from the wood-to-energy system. Finally, some recommendations for promoting wood-to-energy in the near future of Taiwan are addressed.

  18. Integrated copper-containing wastewater treatment using xanthate process.

    Science.gov (United States)

    Chang, Yi-Kuo; Chang, Juu-En; Lin, Tzong-Tzeng; Hsu, Yu-Ming

    2002-09-02

    Although, the xanthate process has been shown to be an effective method for heavy metal removal from contaminated water, a heavy metal contaminated residual sludge is produced by the treatment process and the metal-xanthate sludge must be handled in accordance with the Taiwan EPA's waste disposal requirements. This work employed potassium ethyl xanthate (KEX) to remove copper ions from wastewater. The toxicity characteristic leaching procedure (TCLP) and semi-dynamic leaching test (SDLT) were used to determine the leaching potential and stability characteristics of the residual copper xanthate (Cu-EX) complexes. Results from metal removal experiments showed that KEX was suitable for the treatment of copper-containing wastewater over a wide copper concentration range (50, 100, 500, and 1000 mg/l) to the level that meets the Taiwan EPA's effluent regulations (3mg/l). The TCLP results of the residual Cu-EX complexes could meet the current regulations and thus the Cu-EX complexes could be treated as a non-hazardous material. Besides, the results of SDLT indicated that the complexes exhibited an excellent performance for stabilizing metals under acidic conditions, even slight chemical changes of the complexes occurred during extraction. The xanthate process, mixing KEX with copper-bearing solution to form Cu-EX precipitates, offered a comprehensive strategy for solving both copper-containing wastewater problems and subsequent sludge disposal requirements.

  19. Copper and copper-nickel-alloys - An overview

    Energy Technology Data Exchange (ETDEWEB)

    Klassert, Anton; Tikana, Ladji [Deutsches Kupferinstitut e.V. Am Bonneshof 5, 40474 Duesseldorf (Germany)

    2004-07-01

    With the increasing level of industrialization the demand for and the number of copper alloys rose in an uninterrupted way. Today, the copper alloys take an important position amongst metallic materials due to the large variety of their technological properties and applications. Nowadays there exist over 3.000 standardized alloys. Copper takes the third place of all metals with a worldwide consumption of over 15 millions tons per year, following only to steel and aluminum. In a modern industrial society we meet copper in all ranges of the life (electro-technology, building and construction industry, mechanical engineering, automotive, chemistry, offshore, marine engineering, medical applications and others.). Copper is the first metal customized by humanity. Its name is attributed to the island Cyprus, which supplied in the antiquity copper to Greece, Rome and the other Mediterranean countries. The Romans called it 'ore from Cyprus' (aes cyprium), later cuprum. Copper deposited occasionally also dapper and could be processed in the recent stone age simply by hammering. Already in early historical time copper alloys with 20 to 50 percent tin was used for the production of mirrors because of their high reflecting power. Although the elementary nickel is an element discovered only recently from a historical perspective, its application in alloys - without any knowledge of the alloy composition - occurred at least throughout the last 2.000 years. The oldest copper-nickel coin originates from the time around 235 B.C.. Only around 1800 AD nickel was isolated as a metallic element. In particular in the sea and offshore technology copper nickel alloys found a broad field of applications in piping systems and for valves and armatures. The excellent combination of characteristics like corrosion resistance, erosion stability and bio-fouling resistance with excellent mechanical strength are at the basis of this success. An experience of many decades supports the use

  20. Copper Tolerance and Biosorption of Saccharomyces cerevisiae during Alcoholic Fermentation

    Science.gov (United States)

    Liu, Ling-ling; Jia, Bo; Zhao, Fang; Huang, Wei-dong; Zhan, Ji-cheng

    2015-01-01

    At high levels, copper in grape mash can inhibit yeast activity and cause stuck fermentations. Wine yeast has limited tolerance of copper and can reduce copper levels in wine during fermentation. This study aimed to understand copper tolerance of wine yeast and establish the mechanism by which yeast decreases copper in the must during fermentation. Three strains of Saccharomyces cerevisiae (lab selected strain BH8 and industrial strains AWRI R2 and Freddo) and a simple model fermentation system containing 0 to 1.50 mM Cu2+ were used. ICP-AES determined Cu ion concentration in the must decreasing differently by strains and initial copper levels during fermentation. Fermentation performance was heavily inhibited under copper stress, paralleled a decrease in viable cell numbers. Strain BH8 showed higher copper-tolerance than strain AWRI R2 and higher adsorption than Freddo. Yeast cell surface depression and intracellular structure deformation after copper treatment were observed by scanning electron microscopy and transmission electron microscopy; electronic differential system detected higher surface Cu and no intracellular Cu on 1.50 mM copper treated yeast cells. It is most probably that surface adsorption dominated the biosorption process of Cu2+ for strain BH8, with saturation being accomplished in 24 h. This study demonstrated that Saccharomyces cerevisiae strain BH8 has good tolerance and adsorption of Cu, and reduces Cu2+ concentrations during fermentation in simple model system mainly through surface adsorption. The results indicate that the strain selected from China’s stress-tolerant wine grape is copper tolerant and can reduce copper in must when fermenting in a copper rich simple model system, and provided information for studies on mechanisms of heavy metal stress. PMID:26030864

  1. Copper Tolerance and Biosorption of Saccharomyces cerevisiae during Alcoholic Fermentation.

    Directory of Open Access Journals (Sweden)

    Xiang-Yu Sun

    Full Text Available At high levels, copper in grape mash can inhibit yeast activity and cause stuck fermentations. Wine yeast has limited tolerance of copper and can reduce copper levels in wine during fermentation. This study aimed to understand copper tolerance of wine yeast and establish the mechanism by which yeast decreases copper in the must during fermentation. Three strains of Saccharomyces cerevisiae (lab selected strain BH8 and industrial strains AWRI R2 and Freddo and a simple model fermentation system containing 0 to 1.50 mM Cu2+ were used. ICP-AES determined Cu ion concentration in the must decreasing differently by strains and initial copper levels during fermentation. Fermentation performance was heavily inhibited under copper stress, paralleled a decrease in viable cell numbers. Strain BH8 showed higher copper-tolerance than strain AWRI R2 and higher adsorption than Freddo. Yeast cell surface depression and intracellular structure deformation after copper treatment were observed by scanning electron microscopy and transmission electron microscopy; electronic differential system detected higher surface Cu and no intracellular Cu on 1.50 mM copper treated yeast cells. It is most probably that surface adsorption dominated the biosorption process of Cu2+ for strain BH8, with saturation being accomplished in 24 h. This study demonstrated that Saccharomyces cerevisiae strain BH8 has good tolerance and adsorption of Cu, and reduces Cu2+ concentrations during fermentation in simple model system mainly through surface adsorption. The results indicate that the strain selected from China's stress-tolerant wine grape is copper tolerant and can reduce copper in must when fermenting in a copper rich simple model system, and provided information for studies on mechanisms of heavy metal stress.

  2. Study on the Effect of Heat Treatment on Physical Properties of Poplar and Beech Woods Impregnated with Nano-Copper and Nano-Silver

    Directory of Open Access Journals (Sweden)

    Hassan Siahposht

    2012-06-01

    Full Text Available Present study conducted to review effects of heat treatment on weight loss, water adsorption, and thickness swelling of poplar (Populus nigra and beech (Fagus oreintalis woods impregnated with nano-copper and nano-silver. Specimens werepressur (2.5 bar impregnated with 400 PPM water-based solution of nano-copper and nano-silver particles in a pressure vessel. For heat treatment, nano-cupper,  nano-silver impregnated and control specimens, were heat treated at 145°C temperature for 24 hours. Water absorption and thickness swelling decreased in heat treated and nano-heat treated specimens and this decrease in specimens impregnated with nano-copper and nano-silver was more obvious than in heat treated control specimens. The reasons were the degradation in crystal sections of celluloses chains and the ink variation of wood polymers. On the other hand, a comparison between heat treated and nano- heat treated specimens has shown weight loss further in nano-heat treated specimens. This shows that retent nano-copper and nano-silver by impregnation facilitates heat transfer in wood; and it may increase the process of degradation and pyrolysis of wood structures in inner parts of specimens.

  3. Copper naphthenate: an update and status report on an effective wood pole and crossarm preservative for Canada

    Energy Technology Data Exchange (ETDEWEB)

    Freeman, M.

    2002-07-01

    The purpose of this PowerPoint presentation was three-fold: (1) tp provide information on copper naphthenate and treated wood, (2) to demonstrate that copper naphthenate is an excellent choice for wood poles, and (3) to provide an evaluation of copper naphthenate-treated poles in service. The author proceeded by describing the nature of naphthenic acid and copper naphthenate. Only those petroleum-based alicyclic carboxylic acids with acid numbers between 180-250 milligram KOH/gram. The author specified that two samples produced in Europe and Australia contain either naphthenic acid blends or 100 per cent synthetic acids, which could result in reduced preservatives performance. As for copper naphthenate, it is produced by the reaction of naphthenic acid and copper compounds. A drawing of the molecule was displayed. The toxicity for humans is low, minimal to avian, and moderate to high aquatic toxicity. Discovered in the late 1800s, copper naphthenate is used for pressure and non-pressure treatment, and the anticipated annual growth rate is 5 per cent. The regulatory status of copper naphthenate was described in both the United States and Canada. Results from field skate decay measurements were presented. The author concluded by stating that copper naphthenate is an excellent choice, recognized for its performance and efficacy. It is considered as an Environmental Protection Agency (EPA) unrestricted use pesticide, imposes minimal regulatory requirements on treaters and users, and there are no federal disposal restrictions. Copper naphthenate is a safe and effective wood preservative. refs., figs.

  4. Sorption of copper(II) from aqueous phase by waste biomass

    Energy Technology Data Exchange (ETDEWEB)

    Nagendra Rao, C.R. (Government Polytechnic, Anantapur (India)); Iyengar, L.; Venkobachar, C. (Indian Inst. of Tech., Kanpur (India))

    The objective of the present investigation is to compare three biomasses for copper uptake under different experimental conditions so as to choose the most suitable one for scaleup purposes. Ganoderma lucidum is a macrofungi, growing widely in tropical forests. Sorbent preparation requires its collection from the field. Asperigillus niger is obtained as a waste biomass from the fermentation industry. Activated sludge biomass is available from the biological waste treatment plants. The results of their potential to remove copper are presented. The copper uptake by biosorbents though, varied significantly, showed an increased trend in the range of pH 4 to 6. The increase in metal binding after alkali treatment was marginal for G. lucidum, significant for A. niger, and dramatic for sludge. Copper sorption capacities of M and M[sub c] were much higher than for other sorbents at pH 5.0. The effect of anionic ligands, like acetate and tartrate on copper uptake by raw and alkali treated biosorbents, was negligible as the predominant species in the presence of these ligands is divalent copper ion. Pyrophosphate, citrate, and EDTA had varying degrees of adverse effects on metal uptake. Thus, among the sorbents G. lucidum in its raw form is best suited for the practical application of copper removal from industrial effluents.

  5. Galvanic and stress corrosion of copper canisters in repository environment. A short review

    International Nuclear Information System (INIS)

    Hermansson, H.P.; Koenig, M.

    2001-02-01

    The Swedish Nuclear Power Inspectorate, SKI, has studied different aspects of canister and copper corrosion as part of the general improvement of the knowledge base within the area. General and local corrosion has earlier been treated by experiments as well as by thermodynamic calculations. For completeness also galvanic and stress corrosion should be treated. The present work is a short review, intended to indicate areas needing further focus. The work consists of two parts, the first of which contains a judgement of statements concerning risk of galvanic corrosion of copper in the repository. The second part concerns threshold values for the stress intensity factor of stress corrosion in copper. A suggestion is given on how such values possibly could be measured for copper at repository conditions. In early investigations by SKB, galvanic corrosion is not mentioned or at least not treated. In later works it is treated but often in a theoretical way without indications of any further treatment or investigation. Several pieces of work indicate that further investigations are required to ensure that different types of corrosion, like galvanic, cannot occur in the repository environment. There are for example effects of grain size, grain boundary conditions, impurities and other factors that could influence the appearance of galvanic corrosion that are not treated. Those factors have to be considered to be completely sure that galvanic corrosion and related effects does not occur for the actual canister in the specific environment of the repository. The circumstances are so specific, that a rather general discussion indicating that galvanic corrosion is not probable just is not enough. Experiments should also be performed for verification. It is concluded that the following specific areas, amongst others, could benefit from further consideration. Galvanic corrosion of unbreached copper by inhomogeneities in the environment and in the copper metal should be addressed

  6. Galvanic and stress corrosion of copper canisters in repository environment. A short review

    Energy Technology Data Exchange (ETDEWEB)

    Hermansson, H.P.; Koenig, M. [Studsvik Nuclear AB, Nykoeping (Sweden)

    2001-02-01

    The Swedish Nuclear Power Inspectorate, SKI, has studied different aspects of canister and copper corrosion as part of the general improvement of the knowledge base within the area. General and local corrosion has earlier been treated by experiments as well as by thermodynamic calculations. For completeness also galvanic and stress corrosion should be treated. The present work is a short review, intended to indicate areas needing further focus. The work consists of two parts, the first of which contains a judgement of statements concerning risk of galvanic corrosion of copper in the repository. The second part concerns threshold values for the stress intensity factor of stress corrosion in copper. A suggestion is given on how such values possibly could be measured for copper at repository conditions. In early investigations by SKB, galvanic corrosion is not mentioned or at least not treated. In later works it is treated but often in a theoretical way without indications of any further treatment or investigation. Several pieces of work indicate that further investigations are required to ensure that different types of corrosion, like galvanic, cannot occur in the repository environment. There are for example effects of grain size, grain boundary conditions, impurities and other factors that could influence the appearance of galvanic corrosion that are not treated. Those factors have to be considered to be completely sure that galvanic corrosion and related effects does not occur for the actual canister in the specific environment of the repository. The circumstances are so specific, that a rather general discussion indicating that galvanic corrosion is not probable just is not enough. Experiments should also be performed for verification. It is concluded that the following specific areas, amongst others, could benefit from further consideration. Galvanic corrosion of unbreached copper by inhomogeneities in the environment and in the copper metal should be addressed

  7. Advanced Copper Composites Against Copper-Tolerant Xanthomonas perforans and Tomato Bacterial Spot.

    Science.gov (United States)

    Strayer-Scherer, A; Liao, Y Y; Young, M; Ritchie, L; Vallad, G E; Santra, S; Freeman, J H; Clark, D; Jones, J B; Paret, M L

    2018-02-01

    Bacterial spot, caused by Xanthomonas spp., is a widespread and damaging bacterial disease of tomato (Solanum lycopersicum). For disease management, growers rely on copper bactericides, which are often ineffective due to the presence of copper-tolerant Xanthomonas strains. This study evaluated the antibacterial activity of the new copper composites core-shell copper (CS-Cu), multivalent copper (MV-Cu), and fixed quaternary ammonium copper (FQ-Cu) as potential alternatives to commercially available micron-sized copper bactericides for controlling copper-tolerant Xanthomonas perforans. In vitro, metallic copper from CS-Cu and FQ-Cu at 100 μg/ml killed the copper-tolerant X. perforans strain within 1 h of exposure. In contrast, none of the micron-sized copper rates (100 to 1,000 μg/ml) from Kocide 3000 significantly reduced copper-tolerant X. perforans populations after 48 h of exposure compared with the water control (P copper-based treatments killed the copper-sensitive X. perforans strain within 1 h. Greenhouse studies demonstrated that all copper composites significantly reduced bacterial spot disease severity when compared with copper-mancozeb and water controls (P copper composites significantly reduced disease severity when compared with water controls, using 80% less metallic copper in comparison with copper-mancozeb in field studies (P copper composites have the potential to manage copper-tolerant X. perforans and tomato bacterial spot.

  8. Stem cell recovering effect of copper-free GHK in skin.

    Science.gov (United States)

    Choi, Hye-Ryung; Kang, Youn-A; Ryoo, Sun-Jong; Shin, Jung-Won; Na, Jung-Im; Huh, Chang-Hun; Park, Kyoung-Chan

    2012-11-01

    The peptide Gly-His-Lys (GHK) is a naturally occurring copper(II)-chelating motifs in human serum and cerebrospinal fluid. In industry, GHK (with or without copper) is used to make hair and skin care products. Copper-GHK plays a physiological role in the process of wound healing and tissue repair by stimulating collagen synthesis in fibroblasts. We also reported that copper-GHK promotes the survival of basal stem cells in the skin. However, the effects of copper-free GHK (GHK) have not been investigated well. In this study, the effects of GHK were studied using cultured normal human keratinocytes and skin equivalent (SE) models. In monolayer cultured keratinocytes, GHK increased the proliferation of keratinocytes. When GHK was added during the culture of SE models, the basal cells became more cuboidal than control model. In addition, there was linear and intense staining of α6 and β1 integrin along the basement membrane. The number of p63 and proliferating cell nuclear antigen positive cells was also significantly increased in GHK-treated SEs than in control SEs. Western blot and slide culture experiment showed that GHK increased the expression of integrin by keratinocytes. All these results showed that GHK increased the stemness and proliferative potential of epidermal basal cells, which is associated with increased expression of integrin. In conclusion, copper-free GHK showed similar effects with copper-GHK. Thus, it can be said that copper-free GHK can be used in industry to obtain the effects of copper-GHK in vivo. Further study is necessary to explore the relationship between copper-free GHK and copper-GHK. Copyright © 2012 European Peptide Society and John Wiley & Sons, Ltd.

  9. Urinary arsenic speciation profiles in mice subchronically exposed to low concentrations of sodium arsenate in drinking water

    Directory of Open Access Journals (Sweden)

    Huijie Wu

    2011-09-01

    Full Text Available Arsenic is a proven human carcinogen. Although the mechanism of its carcinogenicity is still largely unknown, methylation is thought to have an important role to play in arsenic toxicity. In this study, urinary methylation profiles were investigated in female C57BL/6J black mice given drinking water containing 500 μg arsenate (AsV/L, 250 μg AsV/L, or 100 μg AsV/L as sodium arsenate for 2 months. The concentrations of arsenic chosen reflected those in the drinking water often encountered in arsenic-endemic areas. Urine samples were collected from the mice at the end of the exposure period, and the arsenic species were analyzed by high performance liquid chromatography-inductively coupled plasma-mass spectrometry. All detectable arsenic species showed strong linear correlation with the administered dosage. The methylation patterns were similar in all three groups with a slight decrease of dimethylarsinic acid/AsV ratio in the 500-μg/L group, which corresponded to the significantly higher arsenic retention in the tissue. The results indicate that urinary arsenic could be used as a good biomarker for internal dose and potential biological effects. Different doses of arsenic exposure could result in different degrees of methylation, excretion, and tissue retention, and this may contribute to the understanding of arsenic carcinogenicity.

  10. Leaching behavior and chemical stability of copper butyl xanthate complex under acidic conditions.

    Science.gov (United States)

    Chang, Yi Kuo; Chang, Juu En; Chiang, Li Choung

    2003-08-01

    Although xanthate addition can be used for treating copper-containing wastewater, a better understanding of the leaching toxicity and the stability characteristics of the copper xanthate complexes formed is essential. This work was undertaken to evaluate the leaching behavior of copper xanthate complex precipitates by means of toxicity characteristics leaching procedure (TCLP) and semi-dynamic leaching test (SDLT) using 1 N acetic acid solution as the leachant. Also, the chemical stability of the copper xanthate complex during extraction has been examined with the studying of variation of chemical structure using UV-vis, Fourier transform infrared and X-ray photoelectron spectroscopies (XPS). Both TCLP and SDLT results showed that a negligible amount of copper ion was leached out from the copper xanthate complex precipitate, indicating that the complex exhibited a high degree of copper leaching stability under acidic conditions. Nevertheless, chemical structure of the copper xanthate complex precipitate varied during the leaching tests. XPS data suggested that the copper xanthate complex initially contained both cupric and cuprous xanthate, but the unstable cupric xanthate change to the cuprous form after acid extraction, indicating the cuprous xanthate to be the final stabilizing structure. Despite that, the changes of chemical structure did not induce the rapid leaching of copper from the copper xanthate complex.

  11. Copper as a target for prostate cancer therapeutics: copper-ionophore pharmacology and altering systemic copper distribution

    Science.gov (United States)

    Denoyer, Delphine; Pearson, Helen B.; Clatworthy, Sharnel A.S.; Smith, Zoe M.; Francis, Paul S.; Llanos, Roxana M.; Volitakis, Irene; Phillips, Wayne A.; Meggyesy, Peter M.; Masaldan, Shashank; Cater, Michael A.

    2016-01-01

    Copper-ionophores that elevate intracellular bioavailable copper display significant therapeutic utility against prostate cancer cells in vitro and in TRAMP (Transgenic Adenocarcinoma of Mouse Prostate) mice. However, the pharmacological basis for their anticancer activity remains unclear, despite impending clinical trails. Herein we show that intracellular copper levels in prostate cancer, evaluated in vitro and across disease progression in TRAMP mice, were not correlative with copper-ionophore activity and mirrored the normal levels observed in patient prostatectomy tissues (Gleason Score 7 & 9). TRAMP adenocarcinoma cells harbored markedly elevated oxidative stress and diminished glutathione (GSH)-mediated antioxidant capacity, which together conferred selective sensitivity to prooxidant ionophoric copper. Copper-ionophore treatments [CuII(gtsm), disulfiram & clioquinol] generated toxic levels of reactive oxygen species (ROS) in TRAMP adenocarcinoma cells, but not in normal mouse prostate epithelial cells (PrECs). Our results provide a basis for the pharmacological activity of copper-ionophores and suggest they are amendable for treatment of patients with prostate cancer. Additionally, recent in vitro and mouse xenograft studies have suggested an increased copper requirement by prostate cancer cells. We demonstrated that prostate adenocarcinoma development in TRAMP mice requires a functional supply of copper and is significantly impeded by altered systemic copper distribution. The presence of a mutant copper-transporting Atp7b protein (tx mutation: A4066G/Met1356Val) in TRAMP mice changed copper-integration into serum and caused a remarkable reduction in prostate cancer burden (64% reduction) and disease severity (grade), abrogating adenocarcinoma development. Implications for current clinical trials are discussed. PMID:27175597

  12. Melatonin-induced CBF/DREB1s are essential for diurnal change of disease resistance and CCA1 expression in Arabidopsis.

    Science.gov (United States)

    Shi, Haitao; Wei, Yunxie; He, Chaozu

    2016-03-01

    Melatonin (N-acetyl-5-methoxytryptamine) is an important regulator of circadian rhythms and immunity in animals. However, the diurnal changes of endogenous melatonin and melatonin-mediated diurnal change of downstream responses remain unclear in Arabidopsis. Using the publicly available microarray data, we found that the transcript levels of two melatonin synthesis genes (serotonin N-acetyltransferase (SNAT) and caffeate O-methyltransferase (COMT)) and endogenous melatonin level were regulated by diurnal cycles, with different magnitudes of change. Moreover, the transcripts of C-repeat-binding factors (CBFs)/Drought response element Binding 1 factors (DREB1s) were co-regulated by exogenous melatonin and diurnal changes, indicating the possible correlation among clock, endogenous melatonin level and AtCBFs expressions. Interestingly, diurnal change of plant immunity against Pst DC3000 and CIRCADIANCLOCK ASSOCIATED 1 (CCA1) expression were largely lost in AtCBFs knockdown line-amiR-1. Taken together, this study identifies the molecular pathway underlying the diurnal changes of immunity in Arabidopsis. Notably, the diurnal changes of endogenous melatonin may regulate corresponding changes of AtCBF/DREB1s expression and their underlying diurnal cycle of plant immunity and AtCCA1. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  13. The fate of heavy metals during combustion and gasification of contaminated biomass—A brief review

    Energy Technology Data Exchange (ETDEWEB)

    Nzihou, Ange, E-mail: ange.nzihou@mines-albi.fr [Université de Toulouse, Mines Albi, CNRS, Centre RAPSODEE, Campus Jarlard, F-81013 Albi cedex 09 (France); Stanmore, Brian [Formerly of the University of Queensland, Brisbane, QLD 4072 (Australia)

    2013-07-15

    Highlights: ► A review on metal behaviour during the thermal treatment of contamined biomass. ► Wide range of biomass waste reported. ► Distribution of metals in the ash, and in the sub-micron particles discussed. -- Abstract: The literature on the presence of heavy metals in contaminated wastes is reviewed. Various categories of materials produced from domestic and industrial activities are included, but municipal solid waste, which is a more complex material, is excluded. This review considers among the most abundant the following materials – wood waste including demolition wood, phytoremediation scavengers and chromated copper arsenate (CCA) timber, sludges including de-inking sludge and sewage sludge, chicken litter and spent pot liner. The partitioning of the metals in the ashes after combustion or gasification follows conventional behaviour, with most metals retained, and higher concentrations in the finer sizes due to vaporisation and recondensation. The alkali metals have been shown to catalyse the biomass conversion, particularly lithium and potassium, although other metals are active to a lesser extent. The most prevalent in biomass is potassium, which is not only inherently active, but volatilises to become finely distributed throughout the char mass. Because the metals are predominantly found in the ash, the effectiveness of their removal depends on the efficiency of the collection of particulates. The potential for disposal into soil depends on the initial concentration in the feed material.

  14. The fate of heavy metals during combustion and gasification of contaminated biomass—A brief review

    International Nuclear Information System (INIS)

    Nzihou, Ange; Stanmore, Brian

    2013-01-01

    Highlights: ► A review on metal behaviour during the thermal treatment of contamined biomass. ► Wide range of biomass waste reported. ► Distribution of metals in the ash, and in the sub-micron particles discussed. -- Abstract: The literature on the presence of heavy metals in contaminated wastes is reviewed. Various categories of materials produced from domestic and industrial activities are included, but municipal solid waste, which is a more complex material, is excluded. This review considers among the most abundant the following materials – wood waste including demolition wood, phytoremediation scavengers and chromated copper arsenate (CCA) timber, sludges including de-inking sludge and sewage sludge, chicken litter and spent pot liner. The partitioning of the metals in the ashes after combustion or gasification follows conventional behaviour, with most metals retained, and higher concentrations in the finer sizes due to vaporisation and recondensation. The alkali metals have been shown to catalyse the biomass conversion, particularly lithium and potassium, although other metals are active to a lesser extent. The most prevalent in biomass is potassium, which is not only inherently active, but volatilises to become finely distributed throughout the char mass. Because the metals are predominantly found in the ash, the effectiveness of their removal depends on the efficiency of the collection of particulates. The potential for disposal into soil depends on the initial concentration in the feed material

  15. Effects of wood preservative leachates from docks

    Energy Technology Data Exchange (ETDEWEB)

    Wendt, P.H.; Van Dolah, R.F.; Bobo, M.Y.; Mathews, T.D. [South Carolina Marine Resources Research Inst., Charleston, SC (United States)

    1994-12-31

    Recent evidence indicates that the wood preservative commonly used in dock pilings (chromated copper arsenate or CCA) is highly toxic to several estuarine organisms in laboratory experiments. Increasing demand for residential docks prompted a field study intended to complement these earlier laboratory investigations. Objectives of the study were to: (1) examine concentrations of Cu, Cr, and As in sediments and oysters from intertidal locations in several creeks with and without high densities of docks; (2) examine the bioaccumulation of wood preservative leachates by laboratory-reared oysters transferred to field sites near and distant from newly constructed docks; and (3) investigate the acute toxicity of wood preservative leachates for several species of estuarine fishes and invertebrates exposed to these compounds in the field. Preliminary results indicate that sediment concentrations of all three metals were well below ER-L levels reported by Long and Morgan at all but one dock site. In an ancillary study, 24h LC{sub 50} bioassays were performed using rotifers (Brachionus plicatilis) which were exposed to pore water from sediments in creeks with and without docks. Toxicities of bulk sediments from the same sites were examined using Microtox which measures decreases in bioluminescence of marine bacteria (Photobacterium phosphoreum) as a function of sediment concentration. Neither the rotifer nor the Microtox bioassays showed any significant differences in toxicity between creeks with and without docks.

  16. Ultrasonic-assisted chemical reduction synthesis and structural characterization of copper nanoparticles

    Science.gov (United States)

    Anh-Nga, Nguyen T.; Tuan-Anh, Nguyen; Thanh-Quoc, Nguyen; Ha, Do Tuong

    2018-04-01

    Copper nanoparticles, due to their special properties, small dimensions and low-cost preparation, have many potential applications such as in optical, electronics, catalysis, sensors, antibacterial agents. In this study, copper nanoparticles were synthesized by chemical reduction method with different conditions in order to investigate the optimum conditions which gave the smallest (particle diameter) dimensions. The synthesis step used copper (II) acetate salt as precursor, ascorbic acid as reducing agent, glycerin and polyvinylpyrrolidone (PVP) as protector and stabilizer. The assistance of ultrasonic was were considered as the significant factor affecting the size of the synthesized particles. The results showed that the copper nanoparticles have been successfully synthesized with the diameter as small as 20-40 nm and the conditions of ultrasonic waves were 48 kHz of frequency, 20 minutes of treated time and 65-70 °C of temperature. The synthesized copper nanoparticles were characterized by optical absorption spectrum, scanning electron microscopy (SEM), and Fourier Transform Infrared Spectrometry.

  17. Micro-analytical evidence of origin and degradation of copper pigments found in Bohemian Gothic murals.

    Science.gov (United States)

    Svarcová, Silvie; Hradil, David; Hradilová, Janka; Kocí, Eva; Bezdicka, Petr

    2009-12-01

    Correct identification of pigments and all accompanying phases found in colour layers of historical paintings are relevant for searching their origin and pigment preparation pathways and for specification of their further degradation processes. We successfully applied the analytical route combining non-destructive in situ X-ray fluorescence analyses with subsequent laboratory investigation of micro-samples by optical microscopy, scanning electron microscopy/energy-dispersive spectroscopy and X-ray powder micro-diffraction (micro-XRD) to obtain efficiently all the data relevant for mineralogical interpretations of the copper pigments origin. Cu salts (carbonates, chlorides, sulphates, etc.) used as pigments exist in a range of polymorphs with similar or identical composition. The efficiency of the micro-XRD for direct identification of such crystal phases present in micro-samples of colour layers was demonstrated in the presented paper. A new, until now unpublished, type of copper pigment--cumengeite, Pb(21)Cu(20)Cl(42)(OH)(40)--used as a blue pigment on a sacral wall painting in the Czech Republic was found by means of micro-XRD. Furthermore, azurite, malachite, paratacamite, atacamite and posnjakite were identified in fragments of colour layers of selected Gothic wall paintings. We found Cu-Zn arsenates indicating the natural origin of azurite and malachite; artificial malachite was distinguishable according to its typical spherulitic crystals. The corrosion of blue azurite to green basic Cu chloride was clearly evidenced on some places exposed to the action of salts and moisture-in a good agreement with the results of laboratory experiments, which also show that oxalic acid accelerates the corrosion of Cu pigments.

  18. Rice-arsenate interactions in hydroponics: a three-gene model for tolerance.

    Science.gov (United States)

    Norton, Gareth J; Nigar, Meher; Williams, Paul N; Dasgupta, Tapash; Meharg, Andrew A; Price, Adam H

    2008-01-01

    In this study, the genetic mapping of the tolerance of root growth to 13.3 muM arsenate [As(V)] using the BalaxAzucena population is improved, and candidate genes for further study are identified. A remarkable three-gene model of tolerance is advanced, which appears to involve epistatic interaction between three major genes, two on chromosome 6 and one on chromosome 10. Any combination of two of these genes inherited from the tolerant parent leads to the plant having tolerance. Lists of potential positional candidate genes are presented. These are then refined using whole genome transcriptomics data and bioinformatics. Physiological evidence is also provided that genes related to phosphate transport are unlikely to be behind the genetic loci conferring tolerance. These results offer testable hypotheses for genes related to As(V) tolerance that might offer strategies for mitigating arsenic (As) accumulation in consumed rice.

  19. Rice–arsenate interactions in hydroponics: a three-gene model for tolerance

    Science.gov (United States)

    Norton, Gareth J.; Nigar, Meher; Dasgupta, Tapash; Meharg, Andrew A.; Price, Adam H.

    2008-01-01

    In this study, the genetic mapping of the tolerance of root growth to 13.3 μM arsenate [As(V)] using the Bala×Azucena population is improved, and candidate genes for further study are identified. A remarkable three-gene model of tolerance is advanced, which appears to involve epistatic interaction between three major genes, two on chromosome 6 and one on chromosome 10. Any combination of two of these genes inherited from the tolerant parent leads to the plant having tolerance. Lists of potential positional candidate genes are presented. These are then refined using whole genome transcriptomics data and bioinformatics. Physiological evidence is also provided that genes related to phosphate transport are unlikely to be behind the genetic loci conferring tolerance. These results offer testable hypotheses for genes related to As(V) tolerance that might offer strategies for mitigating arsenic (As) accumulation in consumed rice. PMID:18453529

  20. Native copper as a natural analogue for copper canisters

    International Nuclear Information System (INIS)

    Marcos, N.

    1989-12-01

    This paper discusses the occurrence of native copper as found in geological formations as a stability analogue of copper canisters that are planned to be used for the disposal of spent nuclear fuel in the Finnish bedrock. A summary of several publications on native copper occurrences is presented. The present geochemical and geohydrological conditions in which copper is met with in its metallic state show that metallic copper is stable in a wide range of temperatures. At low temperatures native copper is found to be stable where groundwater has moderate pH (about 7), low Eh (< +100 mV), and low total dissolved solids, especially chloride. Microscopical and microanalytical studies were carried out on a dozen of rock samples containing native copper. The results reveal that the metal shows no significant alteration. Only the surface of copper grains is locally coated. In the oldest samples there exist small corrosion cracks; the age of the oldest samples is over 1,000 million years. A review of several Finnish groundwater studies suggests that there are places in Finland where the geohydrological conditions are favourable for native copper stability. (orig.)

  1. Removal of muscle artifact from EEG data: comparison between stochastic (ICA and CCA) and deterministic (EMD and wavelet-based) approaches

    Science.gov (United States)

    Safieddine, Doha; Kachenoura, Amar; Albera, Laurent; Birot, Gwénaël; Karfoul, Ahmad; Pasnicu, Anca; Biraben, Arnaud; Wendling, Fabrice; Senhadji, Lotfi; Merlet, Isabelle

    2012-12-01

    Electroencephalographic (EEG) recordings are often contaminated with muscle artifacts. This disturbing myogenic activity not only strongly affects the visual analysis of EEG, but also most surely impairs the results of EEG signal processing tools such as source localization. This article focuses on the particular context of the contamination epileptic signals (interictal spikes) by muscle artifact, as EEG is a key diagnosis tool for this pathology. In this context, our aim was to compare the ability of two stochastic approaches of blind source separation, namely independent component analysis (ICA) and canonical correlation analysis (CCA), and of two deterministic approaches namely empirical mode decomposition (EMD) and wavelet transform (WT) to remove muscle artifacts from EEG signals. To quantitatively compare the performance of these four algorithms, epileptic spike-like EEG signals were simulated from two different source configurations and artificially contaminated with different levels of real EEG-recorded myogenic activity. The efficiency of CCA, ICA, EMD, and WT to correct the muscular artifact was evaluated both by calculating the normalized mean-squared error between denoised and original signals and by comparing the results of source localization obtained from artifact-free as well as noisy signals, before and after artifact correction. Tests on real data recorded in an epileptic patient are also presented. The results obtained in the context of simulations and real data show that EMD outperformed the three other algorithms for the denoising of data highly contaminated by muscular activity. For less noisy data, and when spikes arose from a single cortical source, the myogenic artifact was best corrected with CCA and ICA. Otherwise when spikes originated from two distinct sources, either EMD or ICA offered the most reliable denoising result for highly noisy data, while WT offered the better denoising result for less noisy data. These results suggest that

  2. Formation of copper-indium-selenide and/or copper-indium-gallium-selenide films from indium selenide and copper selenide precursors

    Science.gov (United States)

    Curtis, Calvin J [Lakewood, CO; Miedaner, Alexander [Boulder, CO; Van Hest, Maikel [Lakewood, CO; Ginley, David S [Evergreen, CO; Nekuda, Jennifer A [Lakewood, CO

    2011-11-15

    Liquid-based indium selenide and copper selenide precursors, including copper-organoselenides, particulate copper selenide suspensions, copper selenide ethylene diamine in liquid solvent, nanoparticulate indium selenide suspensions, and indium selenide ethylene diamine coordination compounds in solvent, are used to form crystalline copper-indium-selenide, and/or copper indium gallium selenide films (66) on substrates (52).

  3. COPPER AND COPPER-CONTAINING PESTICIDES: METABOLISM, TOXICITY AND OXIDATIVE STRESS

    Directory of Open Access Journals (Sweden)

    Viktor Husak

    2015-05-01

    Full Text Available The purpose of this paper is to provide a brief review of the current knowledge regarding metabolism and toxicity of copper and copper-based pesticides in living organisms. Copper is an essential trace element in all living organisms (bacteria, fungi, plants, and animals, because it participates in different metabolic processes and maintain functions of organisms. The transport and metabolism of copper in living organisms is currently the subject of many studies. Copper is absorbed, transported, distributed, stored, and excreted in the body via the complex of homeostatic processes, which provide organisms with a needed constant level of this micronutrient and avoid excessive amounts. Many aspects of copper homeostasis were studied at the molecular level. Copper based-pesticides, in particularly fungicides, bacteriocides and herbicides, are widely used in agricultural practice throughout the world. Copper is an integral part of antioxidant enzymes, particularly copper-zinc superoxide dismutase (Cu,Zn-SOD, and plays prominent roles in iron homeostasis. On the other hand, excess of copper in organism has deleterious effect, because it stimulates free radical production in the cell, induces lipid peroxidation, and disturbs the total antioxidant capacity of the body. The mechanisms of copper toxicity are discussed in this review also.

  4. Uptake and internalisation of copper by three marine microalgae: comparison of copper-sensitive and copper-tolerant species.

    Science.gov (United States)

    Levy, Jacqueline L; Angel, Brad M; Stauber, Jennifer L; Poon, Wing L; Simpson, Stuart L; Cheng, Shuk Han; Jolley, Dianne F

    2008-08-29

    Although it has been well established that different species of marine algae have different sensitivities to metals, our understanding of the physiological and biochemical basis for these differences is limited. This study investigated copper adsorption and internalisation in three algal species with differing sensitivities to copper. The diatom Phaeodactylum tricornutum was particularly sensitive to copper, with a 72-h IC50 (concentration of copper to inhibit growth rate by 50%) of 8.0 microg Cu L(-1), compared to the green algae Tetraselmis sp. (72-h IC50 47 microg Cu L(-1)) and Dunaliella tertiolecta (72-h IC50 530 microg Cu L(-1)). At these IC50 concentrations, Tetraselmis sp. had much higher intracellular copper (1.97+/-0.01 x 10(-13)g Cu cell(-1)) than P. tricornutum (0.23+/-0.19 x 10(-13)g Cu cell(-1)) and D. tertiolecta (0.59+/-0.05 x 10(-13)g Cu cell(-1)), suggesting that Tetraselmis sp. effectively detoxifies copper within the cell. By contrast, at the same external copper concentration (50 microg L(-1)), D. tertiolecta appears to better exclude copper than Tetraselmis sp. by having a slower copper internalisation rate and lower internal copper concentrations at equivalent extracellular concentrations. The results suggest that the use of internal copper concentrations and net uptake rates alone cannot explain differences in species-sensitivity for different algal species. Model prediction of copper toxicity to marine biota and understanding fundamental differences in species-sensitivity will require, not just an understanding of water quality parameters and copper-cell binding, but also further knowledge of cellular detoxification mechanisms.

  5. Transcriptome response to copper heavy metal stress in hard-shelled mussel (Mytilus coruscus

    Directory of Open Access Journals (Sweden)

    Meiying Xu

    2016-03-01

    Full Text Available The hard-shelled mussel (Mytilus coruscus has considerably one of the most economically important marine shellfish worldwide and considered as a good invertebrate model for ecotoxicity study for a long time. In the present study, we used Illumina sequencing technology (HiSeq2000 to sequence, assemble and annotate the transcriptome of the hard-shelled mussel which challenged with copper pollution. A total of 21,723,913 paired-end clean reads (NCBI SRA database SRX1411195 were generated from HiSeq2000 sequencer and 96,403 contigs (with N50 = 1118 bp were obtained after de novo assembling with Trinity software. Digital gene expression analysis reveals 1156 unigenes are upregulated and 1681 unigenes are downregulated when challenged with copper. By KEGG pathway enrichment analysis, we found that unigenes in four KEGG pathways (aminoacyl-tRNA biosynthesis, apoptosis, DNA replication and mismatch repair show significant differential expressed between control and copper treated groups. We hope that the gill transcriptome in copper treated hard-shelled mussel can give useful information to understand how mussel handles with heavy metal stress at molecular level. Keywords: Hard-shelled mussel, Heavy metal, Transcriptome, Ecotoxicity

  6. X-ray diffraction phase analysis of crystalline copper corrosion products after treatment in different chloride solutions

    International Nuclear Information System (INIS)

    Chmielova, M.; Seidlerova, J.; Weiss, Z.

    2003-01-01

    The corrosion products Cu 2 (OH) 3 Cl, Cu 2 O, and CuCl 2 were identified on the surface of copper plates after their four days treating in three different sodium chloride, sodium/magnesium, and sodium/calcium chloride solutions using X-ray diffraction powder analysis. However, the quantitative proportions of individual corrosion products differ and depend on the type of chloride solution used. Treating of copper plates only in the sodium chloride solution produced the mixture of corrosion products where Cu 2 O is prevailing over the Cu 2 (OH) 3 Cl and CuCl 2 was not identified. The sample developed after treating of the cooper surface in the sodium/magnesium chloride solution contains Cu 2 (OH) 3 Cl and CuCl 2 prevailing over the Cu 2 O, while the sample developed after treatment of copper in sodium/calcium chloride solution contains Cu 2 (OH) 3 Cl prevailing over CuCl 2 and Cu 2 O was not identified

  7. Influence of dietary selenium on the disposition of arsenate in the female B6C3F{sub 1} mouse

    Energy Technology Data Exchange (ETDEWEB)

    Kenyon, E.M.; Hughes, M.F. [Environmental Protection Agency, Research Triangle Park, NC (United States); Levander, O.A. [Nutrient Requirements and Functions Lab., Beltsville, MD (United States)

    1997-06-27

    Interactions between arsenic (As) and selenium (Se) at the metabolic level are multifaceted and complex. These interactions are of practical significance because populations in various parts of the world are simultaneously exposed to inorganic As in drinking water and Se mainly in the diet at varying levels. The primary goal of this study was to investigate whether differing dietary Se status would alter the profile of urinary metabolites or their time course for elimination after exposure to arsenate [As(V)]. Weanling female 86C3F, mice were maintained for 28 d on either a control diet of powdered rodent meal sufficient in Se (A 0.2 ppm) or Torula yeast-based (TYB) diets deficient (B, 0.02 ppm Se), sufficient (C, 0.2 ppm Se), or excessive (D, 2.0 ppm Se) in Se; mice then received by oral gavage 5 mg (As)/kg as sodium [{sup 73}As] arsenate. The time course for elimination of total arsenic and metabolites in urine was measured over a 48-h period, and total arsenic was determined in feces and tissues at 48 h. Mice on the Se excess diet excreted a significantly higher percentage of urinary As as inorganic As, with a significantly decreased ratio of organic to inorganic As compared to Se-sufficient mice, suggesting that As methylation was decreased. Mice on the Se-deficient diet appeared to eliminate As(V), arsenite, and dimethylarsinic acid (DMA) in urine more slowly than Se-sufficient mice; however, further studies are required to confirm this finding. Mice on the Se-sufficient meal diet (A) excreted significantly less (by percent) arsenate-derived radioactivity in urine and more in feces compared to mice on the Se-sufficient TYB diet (C), with total elimination being similar for both groups. This indicates that mice on the meal diet absorbed significantly less As(V) than mice on the TYB diet, and this may be due to more fiber or {open_quotes}bulk{close_quotes} in the meal diet. 35 refs., 6 figs., 6 tabs.

  8. Disruption of endocytic trafficking protein Rab7 impairs invasiveness of cholangiocarcinoma cells.

    Science.gov (United States)

    Suwandittakul, Nantana; Reamtong, Onrapak; Molee, Pattamaporn; Maneewatchararangsri, Santi; Sutherat, Maleerat; Chaisri, Urai; Wongkham, Sopit; Adisakwattana, Poom

    2017-09-07

    Alterations and mutations of endo-lysosomal trafficking proteins have been associated with cancer progression. Identification and characterization of endo-lysosomal trafficking proteins in invasive cholangiocarcinoma (CCA) cells may benefit prognosis and drug design for CCA. To identify and characterize endo-lysosomal trafficking proteins in invasive CCA. A lysosomal-enriched fraction was isolated from a TNF-α induced invasive CCA cell line (KKU-100) and uninduced control cells and protein identification was performed with nano-LC MS/MS. Novel lysosomal proteins that were upregulated in invasive CCA cells were validated by real-time RT-PCR. We selected Rab7 for further studies of protein level using western blotting and subcellular localization using immunofluorescence. The role of Rab7 in CCA invasion was determined by siRNA gene knockdown and matrigel transwell assay. Rab7 mRNA and protein were upregulated in invasive CCA cells compared with non-treated controls. Immunofluorescence studies demonstrated that Rab7 was expressed predominantly in invasive CCA cells and was localized in the cytoplasm and lysosomes. Suppression of Rab7 translation significantly inhibited TNF-α-induced cell invasion compared to non-treated control (p= 0.044). Overexpression of Rab7 in CCA cells was associated with cell invasion, supporting Rab7 as a novel candidate for the development of diagnostic and therapeutic strategies for CCA.

  9. Nano Copper Induces Apoptosis in PK-15 Cells via a Mitochondria-Mediated Pathway.

    Science.gov (United States)

    Zhang, Hui; Chang, Zhenyu; Mehmood, Khalid; Abbas, Rao Zahid; Nabi, Fazul; Rehman, Mujeeb Ur; Wu, Xiaoxing; Tian, Xinxin; Yuan, Xiaodan; Li, Zhaoyang; Zhou, Donghai

    2018-01-01

    Nano-sized copper particles are widely used in various chemical, physical, and biological fields. However, earlier studies have shown that nano copper particles (40-100 μg/mL) can induce cell toxicity and apoptosis. Therefore, this study was conducted to investigate the role of nano copper in mitochondrion-mediated apoptosis in PK-15 cells. The cells were treated with different doses of nano copper (20, 40, 60, and 80 μg/mL) to determine the effects of apoptosis using acridine orange/ethidium bromide (AO/EB) fluorescence staining and a flow cytometry assay. The levels of malondialdehyde (MDA) and superoxide dismutase (SOD) in the PK-15 cells were examined using commercially available kits. Moreover, the mRNA levels of the Bax, Bid, Caspase-3, and CYCS genes were assessed by real-time PCR. The results revealed that nano copper exposure induced apoptosis and changed the mitochondrial membrane potential. In addition, nano copper significantly altered the levels of the Bax, Bid, Caspase-3, and CYCS genes at a concentration of 40 μg/mL. To summarize, nano copper significantly (P nano copper can play an important role in inducing the apoptotic pathway in PK-15 cells, which may be the mechanism by which nano copper induces nephrotoxicity.

  10. Administration of high doses of copper to capuchin monkeys does not cause liver damage but induces transcriptional activation of hepatic proliferative responses.

    Science.gov (United States)

    Araya, Magdalena; Núñez, Héctor; Pavez, Leonardo; Arredondo, Miguel; Méndez, Marco; Cisternas, Felipe; Pizarro, Fernando; Sierralta, Walter; Uauy, Ricardo; González, Mauricio

    2012-02-01

    Liver cells respond to copper loading upregulating protective mechanisms. However, to date, except for liver content, there are no good indicators that identify individuals with excess liver copper. We hypothesized that administering high doses of copper to young (5.5 mg Cu · kg⁻¹ . d⁻¹) and adult (7.5 mg Cu · kg⁻¹ . d⁻¹) capuchin monkeys would induce detectable liver damage. Study groups included adult monkeys (2 females, 2 males) 3-3.5 y old at enrollment treated with copper for 36 mo (ACu); age-matched controls (1 female, 3 males) that did not receive additional copper (AC); young monkeys (2 female, 2 males) treated from birth with copper for 36 mo (YCu); and young age-matched controls (2 female, 2 males) that did not receive additional copper (YC). We periodically assessed clinical, blood biochemical, and liver histological indicators and at 36 mo the hepatic mRNA abundance of MT2a, APP, DMT1, CTR1, HGF, TGFβ, and NFκΒ only in adult monkeys. After 36 mo, the liver copper concentration was 4-5 times greater in treated monkeys relative to controls. All monkeys remained healthy with normal routine serum biochemical indices and there was no evidence of liver tissue damage. Relative mRNA abundance of HGF, TGFβ and NFκB was significantly greater in ACu than in AC monkeys. In conclusion, capuchin monkeys exposed to copper at doses up to 50 times the current upper level enhanced expression of genes related to inflammation and injury without clinical, blood biochemical, or histological evidence of liver damage.

  11. Electrical conduction in composites containing copper core-copper

    Indian Academy of Sciences (India)

    Composites of nanometre-sized copper core-copper oxide shell with diameters in the range 6.1 to 7.3 nm dispersed in a silica gel were synthesised by a technique comprising reduction followed by oxidation of a suitably chosen precursor gel. The hot pressed gel powders mixed with nanometre-sized copper particles ...

  12. The copper losses in the slags from the El Teniente process

    International Nuclear Information System (INIS)

    Imris, I.; Rebolledo, S.; Sanchez, M.; Castro, G.; Achurra, G.; Hernandez, F.

    2000-01-01

    The current El Teniente Pyrometallurgical Process for copper concentrate was commissioned at Caletones Smelter during the period 1988 - 1991 following an intensive research and development program that led to several improvements to the original process developed during the seventies. The Caletones Smelter production capacity is 370,000 tons of cast copper annually related to a concentrate smelting capacity of 1,250,000 tons per year. Several industrial applications of the process, in Chile and abroad, have shown its capability to treat copper concentrates in a wide range of chemical and mineralogical compositions. The main operational parameters that determine the performance of the process are oxygen enriched air flow rate, degree of oxygen enrichment, moisture content of the solid materials processed, molten material levels inside the vessel, frequency of molten materials tapping, bath temperature and copper losses in slags. The copper losses in the slags from the El Teniente Pyrometallurgical Process, predicted by calculation from thermodynamic data, have been compared with those determined by microscopic examination and quantitative electron microprobe analysis of the slag samples and by flotation tests of finely ground slag. (author)

  13. Reagent conditions of the flotation of copper, copper - molybdenum and copper -zinc ores in foreing countries

    International Nuclear Information System (INIS)

    Nevaeva, L.M.

    1983-01-01

    Reagents-collectors and frothers, used abroad in reagent regimes of flotation of copper, copper-molybdenum and copper zinc ores, have been considered. Xanthogenates, aerofloats, xanthogenformiates, thionocarbamates are mainly used as reagents-collectors. Methylizobutylcarbinol and Daufros are used as reagents-frothers

  14. Legacy lead arsenate soil contamination at childcare centers in the Yakima Valley, Central Washington, USA.

    Science.gov (United States)

    Durkee, Jenna; Bartrem, Casey; Möller, Gregory

    2017-02-01

    From the early 1900s to the 1950s, Yakima Valley orchards were commonly treated with lead arsenate (LA) insecticides. Lead (Pb) and arsenic (As) soil contamination has been identified on former orchard lands throughout Central Washington and pose a threat to human health and the environment. The levels of Pb and As in soil and interior dust at participating childcare centers in the Upper Yakima Valley (Yakima County), Washington were sampled to explore exposure potential for young children. Childcare center soils were collected from two soil depths, homogenized, and analyzed in bulk by a field-portable X-ray fluorescence spectrometer (XRF). Interior dust wipes samples were collected from at least two locations in each facility. All soil samples >250 mg/kg Pb and/or >20 As mg/kg were sieved to 250 μm, tested by XRF a second time, and analyzed via acid digestion and inductively coupled plasma mass spectrometry (ICP-MS) analysis. Bulk and sieved XRF results, as well as ICP-MS to XRF results were strongly correlated. Maximum Pb and As XRF results indicated that 4 (21%) and 8 (42%) of the 19 childcare centers surveyed exceeded the regulatory standard for Pb and As, respectively. Historic land use was significantly associated with elevated Pb and As levels. Interior dust loadings were below United States Environmental Protection Agency (EPA) guidelines. Childcare centers are areas of intensive use for children and when coupled with potential residential exposure in their homes, the total daily exposure is a potential hazard to children. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Zinc and copper distribution in swine wastewater treated by anaerobic digestion.

    Science.gov (United States)

    Cestonaro do Amaral, André; Kunz, Airton; Radis Steinmetz, Ricardo Luís; Justi, Karin Cristiane

    2014-08-01

    Swine wastewater contain high levels of metals, such as copper and zinc, which can cause a negative impact on the environment. Anaerobic digestion is a process commonly used to remove carbon, and can act on metal availability (e.g., solubility or oxidation state). The present study aimed to evaluate the influence of anaerobic digestion on total Zn and Cu contents, and their chemical fractioning due to the biodegradation of the effluent over different hydraulic retention times (HRTs). The sequential extraction protocol proposed by the Community Bureau of Reference (BCR), plus two additional fractions, was the method chosen for this study of Cu and Zn distribution evaluation in swine wastewater. The Zn and Cu concentrations in raw swine manure were 63.58 ± 27.72 mg L(-1) and 8.98 ± 3.99 mg L(-1), respectively. The metal retention capacity of the bioreactor decreased when the HRT was reduced from 17.86 d to 5.32 d. Anaerobic digestion had a direct influence on zinc and copper distribution when raw manure (RM) and digested manure (DM) were compared. The reducible fraction showed a reduction of between 3.17% and 7.84% for Zn and between 2.52% and 11.92% for Cu when DM was compared with RM. However, the metal concentration increased in the oxidizable fraction of DM, viz. from 3.01% to 10.64% for Zn and from 4.49% to 16.71% for Cu, thus demonstrating the effect of anaerobic conditions on metal availability. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. Improving Beneficiation of Copper and Iron from Copper Slag by Modifying the Molten Copper Slag

    Directory of Open Access Journals (Sweden)

    Zhengqi Guo

    2016-04-01

    Full Text Available In the paper, a new technology was developed to improve the beneficiation of copper and iron components from copper slag, by modifying the molten slag to promote the mineralization of valuable minerals and to induce the growth of mineral grains. Various parameters, including binary basicity, dosage of compound additive, modification temperature, cooling rate and the end point temperature of slow cooling were investigated. Meanwhile, optical microscope, scanning electron microscope and energy dispersive spectrometer (SEM-EDS was employed to determine the mineralogy of the modified and unmodified slag, as well as to reveal the mechanisms of enhancing beneficiation. The results show that under the proper conditions, the copper grade of rougher copper concentrate was increased from 6.43% to 11.04%, iron recovery of magnetic separation was increased significantly from 32.40% to 63.26%, and other evaluation indexes were changed slightly, in comparison with unmodified copper slag. Moreover, matte and magnetite grains in the modified slag aggregated together and grew obviously to the mean size of over 50 μm, resulting in an improvement of beneficiation of copper and iron.

  17. Development of a thermodynamic data base for selected heavy metals; Entwicklung einer thermodynamischen Datenbasis fuer ausgewaehlte Schwermetalle

    Energy Technology Data Exchange (ETDEWEB)

    Hageman, Sven; Scharge, Tina; Willms, Thomas

    2015-07-15

    The report on the development of a thermodynamic data base for selected heavy metals covers the description of experimental methods, the thermodynamic model for chromate, the thermodynamic model for dichromate, the thermodynamic model for manganese (II), the thermodynamic model for cobalt, the thermodynamic model for nickel, the thermodynamic model for copper (I), the thermodynamic model for copper(II), the thermodynamic model for mercury (0) and mercury (I), the thermodynamic model for mercury (III), the thermodynamic model for arsenate.

  18. Development of a thermodynamic data base for selected heavy metals

    International Nuclear Information System (INIS)

    Hageman, Sven; Scharge, Tina; Willms, Thomas

    2015-07-01

    The report on the development of a thermodynamic data base for selected heavy metals covers the description of experimental methods, the thermodynamic model for chromate, the thermodynamic model for dichromate, the thermodynamic model for manganese (II), the thermodynamic model for cobalt, the thermodynamic model for nickel, the thermodynamic model for copper (I), the thermodynamic model for copper(II), the thermodynamic model for mercury (0) and mercury (I), the thermodynamic model for mercury (III), the thermodynamic model for arsenate.

  19. Properties of CuS thin films treated in air plasma

    International Nuclear Information System (INIS)

    Rodriguez-Lazcano, Y.; Martinez, H.; Calixto-Rodriguez, M.; Nunez Rodriguez, A.

    2009-01-01

    Copper sulfide thin films were grown by chemical deposition and post treated in air plasma during 20 min. Air plasma was generated by alternating current discharge at a pressure of 4 x 10 2 Pa. The power discharge was maintained at an output of 220 V and a current of 0.2 A. Thermal annealing at 300 o C was performed for comparison. X-ray diffraction shows that plasma treatment results in phase transformation of Cu 39 S 28 (as grown) to CuS (treated by plasma). The copper lost is confirmed by X-ray fluorescence. No significant change in the optical band gap was observed due to plasma action. In addition, the electrical conductivity increases in one order of magnitude. On the other hand, the samples under plasma condition show a parallel growth to the substrate and an increase in the surface uniformity. The plasma etching removes copper due to its affinity with oxygen to form CuO, as is corroborated by optical emission spectroscopy.

  20. 21 CFR 73.1125 - Potassium sodium copper chloropyhllin (chlorophyllin-copper complex).

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Potassium sodium copper chloropyhllin (chlorophyllin-copper complex). 73.1125 Section 73.1125 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT....1125 Potassium sodium copper chloropyhllin (chlorophyllin-copper complex). (a) Identity. (1) The color...

  1. 21 CFR 73.2125 - Potassium sodium copper chlorophyllin (chlorophyllin-copper complex).

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Potassium sodium copper chlorophyllin (chlorophyllin-copper complex). 73.2125 Section 73.2125 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT... § 73.2125 Potassium sodium copper chlorophyllin (chlorophyllin-copper complex). (a) Identity and...

  2. Transformation of arsenic-rich copper smelter flue dust in contrasting soils: A 2-year field experiment.

    Science.gov (United States)

    Jarošíková, Alice; Ettler, Vojtěch; Mihaljevič, Martin; Penížek, Vít; Matoušek, Tomáš; Culka, Adam; Drahota, Petr

    2018-06-01

    Dust emissions from copper smelters processing arsenic-bearing ores represent a risk to soil environments due to the high levels of As and other inorganic contaminants. Using an in situ experiment in four different forest and grassland soils (pH 3.2-8.0) we studied the transformation of As-rich (>50 wt% As) copper smelter dust over 24 months. Double polyamide bags with 1 g of flue dust were buried at different depths in soil pits and in 6-month intervals; then those bags, surrounding soil columns, and soil pore waters were collected and analysed. Dust dissolution was relatively fast during the first 6 months (5-34%), and mass losses attained 52% after 24 months. The key driving forces affecting dust dissolution were not only pH, but also the water percolation/retention in individual soils. Primary arsenolite (As 2 O 3 ) dissolution was responsible for high As release from the dust (to 72%) and substantial increase of As in the soil (to a 56 × increase; to 1500 mg kg -1 ). Despite high arsenolite solubility, this phase persisted in the dust after 2 years of exposure. Mineralogical investigation indicated that mimetite [Pb 5 (AsO 4 ) 3 (Cl,OH)], unidentified complex Ca-Pb-Fe-Zn arsenates, and Fe oxyhydroxides partly controlled the mobility of As and other metal(loid)s. Compared to As, other less abundant contaminants (Bi, Cu, Pb, Sb, Zn) were released into the soil to a lesser extent (8-40% of total). The relatively high mobility of As in the soil can be seen from decreases of bulk As concentrations after spring snowmelt, high water-extractable fractions with up to ∼50% of As(III) in extracts, and high As concentrations in soil pore waters. Results indicate that efficient controls of emissions from copper smelters and flue dust disposal sites are needed to prevent extensive contamination of nearby soils by persistent As. Copyright © 2018 Elsevier Ltd. All rights reserved.

  3. Estimation of enthalpies and entropies of melting of arsenates from phase diagrams of MeAsO3-Me3AsO4 (Me=Na,K,Rb,Cs) and correlation of thermodynamic properties of alkali metal arsenates

    International Nuclear Information System (INIS)

    Kasenov, B.K.; Isabaev, S.M.; Buketov, E.A.

    1982-01-01

    Values of ΔHsub(melting)sup(0) and ΔSsub(melting)sup(0) for Na 3 AsO 4 , K 3 AsO 4 , Rb 3 AsO 4 and Cs 3 AsO 4 (65.3 kJ/mol and 44.4 J/molxK respectively) were calculated by the Shredder-Vant-Hoff equation in the approximation of ideal solutions from diagrams of the state of MeAsO 3 -He 3 AsO 4 (Me=Na, K, Rb, Cs) systems. ΔHsub(298)sup(0)-f(Tsub(melting)) and ΔHsub(melting)sup(0)-f(ΔHsub(298)sup(0)) dependences were found for arsenates

  4. Combined two-stage xanthate processes for the treatment of copper-containing wastewater

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Y.K. [Department of Safety Health and Environmental Engineering, Central Taiwan University of Sciences and Technology, Taichung (Taiwan); Leu, M.H. [Department of Environmental Engineering, Kun Shan University of Technology, Yung-Kang City (Taiwan); Chang, J.E.; Lin, T.F.; Chen, T.C. [Department of Environmental Engineering, National Cheng Kung University, Tainan City (Taiwan); Chiang, L.C.; Shih, P.H. [Department of Environmental Engineering and Science, Fooyin University, Kaohsiung County (Taiwan)

    2007-02-15

    Heavy metal removal is mainly conducted by adjusting the wastewater pH to form metal hydroxide precipitates. However, in recent years, the xanthate process with a high metal removal efficiency, attracted attention due to its use of sorption/desorption of heavy metals from aqueous solutions. In this study, two kinds of agricultural xanthates, insoluble peanut-shell xanthate (IPX) and insoluble starch xanthate (ISX), were used as sorbents to treat the copper-containing wastewater (Cu concentration from 50 to 1,000 mg/L). The experimental results showed that the maximum Cu removal efficiency by IPX was 93.5 % in the case of high Cu concentrations, whereby 81.1 % of copper could rapidly be removed within one minute. Moreover, copper-containing wastewater could also be treated by ISX over a wide range (50 to 1,000 mg/L) to a level that meets the Taiwan EPA's effluent regulations (3 mg/L) within 20 minutes. Whereas IPX had a maximum binding capacity for copper of 185 mg/g IPX, the capacity for ISX was 120 mg/g ISX. IPX is cheaper than ISX, and has the benefits of a rapid reaction and a high copper binding capacity, however, it exhibits a lower copper removal efficiency. A sequential IPX and ISX treatment (i.e., two-stage xanthate processes) could therefore be an excellent alternative. The results obtained using the two-stage xanthate process revealed an effective copper treatment. The effluent (C{sub e}) was below 0.6 mg/L, compared to the influent (C{sub 0}) of 1,001 mg/L at pH = 4 and a dilution rate of 0.6 h{sup -1}. Furthermore, the Cu-ISX complex formed could meet the Taiwan TCLP regulations, and be classified as non-hazardous waste. The xanthatilization of agricultural wastes offers a comprehensive strategy for solving both agricultural waste disposal and metal-containing wastewater treatment problems. (Abstract Copyright [2007], Wiley Periodicals, Inc.)

  5. Copper deficiency can limit nitrification in biological rapid sand filters for drinking water production

    DEFF Research Database (Denmark)

    Wagner, Florian Benedikt; Nielsen, Peter Borch; Boe-Hansen, Rasmus

    2016-01-01

    Incomplete nitrification in biological filters during drinking water treatment is problematic, as it compromises drinking water quality. Nitrification problems can be caused by a lack of nutrients for the nitrifying microorganisms. Since copper is an important element in one of the essential...... enzymes in nitrification, we investigated the effect of copper dosing on nitrification in different biological rapid sand filters treating groundwater. A lab-scale column assay with filter material from a water works demonstrated that addition of a trace metal mixture, including copper, increased ammonium...... to the bulk phase. Overall, copper dosing to poorly performing biological rapid sand filters increased ammonium removal rates significantly, achieving effluent concentrations of below 0.01 mg NH4-N L-1, and had a long-term effect on nitrification performance....

  6. Enhanced Mechanical Properties of Laser Treated Al-Cu Alloys : A Microstructural Analysis

    NARCIS (Netherlands)

    Mol van Otterloo, J.L.de; Bagnoli, D.; de Hosson, J.T.M.

    Both mechanical Vickers hardness and electron microscopic studies have been carried out on laser treated aluminium copper alloys with a copper concentration in the range 0-40 wt%. It is found that a Vickers hardness of 470 kgf/mm(2) can be attained, which is high compared to a value of 120 kgf/mm(2)

  7. Rhizosphere colonization and arsenic translocation in sunflower (Helianthus annuus L.) by arsenate reducing Alcaligenes sp. strain Dhal-L.

    Science.gov (United States)

    Cavalca, Lucia; Corsini, Anna; Bachate, Sachin Prabhakar; Andreoni, Vincenza

    2013-10-01

    In the present study, six arsenic-resistant strains previously isolated were tested for their plant growth promoting characteristics and heavy metal resistance, in order to choose one model strain as an inoculum for sunflower plants in pot experiments. The aim was to investigate the effect of arsenic-resistant strain on sunflower growth and on arsenic uptake from arsenic contaminated soil. Based on plant growth promoting characteristics and heavy metal resistance, Alcaligenes sp. strain Dhal-L was chosen as an inoculum. Beside the ability to reduce arsenate to arsenite via an Ars operon, the strain exhibited 1-amino-cyclopropane-1-carboxylic acid deaminase activity and it was also able to produce siderophore and indole acetic acid. Pot experiments were conducted with an agricultural soil contaminated with arsenic (214 mg kg⁻¹). A real time PCR method was set up based on the quantification of ACR3(2) type of arsenite efflux pump carried by Alcaligenes sp. strain Dhal-L, in order to monitor presence and colonisation of the strain in the bulk and rhizospheric soil. As a result of strain inoculation, arsenic uptake by plants was increased by 53 %, whereas ACR3(2) gene copy number in rhizospheric soil was 100 times higher in inoculated than in control pots, indicating the colonisation of strain. The results indicated that the presence of arsenate reducing strains in the rhizosphere of sunflower influences arsenic mobilization and promotes arsenic uptake by plant.

  8. Arsenic in industrial waste water from copper production technological process

    Directory of Open Access Journals (Sweden)

    Biljana Jovanović

    2013-12-01

    Full Text Available Investigation of arsenic in industrial waste water is of a great importance for environment. Discharge of untreated waste water from a copper production process results in serious pollution of surface water, which directly affects flora and fauna, as well as humans. There is a need for efficient and environmentally acceptable treament of waste waters containing heavy metals and arsenic. The paper presents an analyisis of the waste water from The Copper Smelter which is discharged into the Bor river. The expected arsenic content in treated waste water after using HDS procedure is also presented.

  9. Assessment of the Bioaccessibility of Micronized Copper Wood on Simulated Stomach Fluid

    Data.gov (United States)

    U.S. Environmental Protection Agency — The widespread use of copper-treated lumber has increased the potential for human exposure. Moreover, there is a lack of information on the fate and behavior of...

  10. Calcification rates of crustose coralline algae (CCA) derived from Calcification Accretion Units (CAUs) deployed at coral reef sites in Batangas, Philippines in 2012 and recovered in 2015 (NCEI Accession 0162831)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Laboratory experiments reveal calcification rates of crustose coralline algae (CCA) are strongly correlated to seawater aragonite saturation state. Predictions of...

  11. COMPARATIVE TISSUE DISTRIBUTION AND URINARY EXCRETION OF INORGANIC ARSENIC (IAS) AND ITS METHYLATED METABOLITES IN MICE FOLLOWING ORAL ADMINISTRATION OF ARSENATE (ASV) AND ARSENITE (ASIII)

    Science.gov (United States)

    COMPARATIVE TISSUE DISTRIBUTION AND URINARY EXCRETION OF INORGANIC ARSENIC (iAs) AND ITS METHYLATED METABOLITES IN MICE FOLLOWING ORAL ADMINISTRATION OF ARSENATE (AsV) AND ARSENITE (AsIII). E M Kenyon, L M Del Razo and M F Hughes. U.S. EPA, ORD, NHEERL, ETD, PKB, RTP, NC, USA; ...

  12. Antwerp Copper Plates

    DEFF Research Database (Denmark)

    Wadum, Jørgen

    1999-01-01

    In addition to presenting a short history of copper paintings, topics detail artists’ materials and techniques, as well as aspects of the copper industry, including mining, preparation and trade routes.......In addition to presenting a short history of copper paintings, topics detail artists’ materials and techniques, as well as aspects of the copper industry, including mining, preparation and trade routes....

  13. Electroless copper plating on 3-mercaptopropyltriethoxysilane modified PET fabric challenged by ultrasonic washing

    International Nuclear Information System (INIS)

    Lu Yinxiang

    2009-01-01

    Electroless deposition of Cu on poly(ethylene terephthalate) (PET) fabric modified with 3-mercaptopropyltriethoxysilane was investigated. Morphology, composition, structure, thermal decomposing behavior of copper coating PET fabric after ultrasonic washing in water for 1 h were characterized by scanning electron microscopy (SEM), energy dispersive X-ray (EDX) analysis, X-ray photoelectron spectroscopy (XPS), Raman spectrometer, X-ray diffraction (XRD), and thermogravimetric analysis (TG), respectively. Copper plating on modified fabric has good adherence stability and high electric conductivity before and after ultrasonic washing, while copper coating fabric without modification is easily destroyed during the washing process, which leads to the textile changing from conductor to dielectric. As the copper weight on the treated fabric is 28 g/m 2 , the shielding effectiveness (SE) is more than 54 dB at frequency ranging from 0.01 MHz to 18 GHz.

  14. Sorptive removal of arsenate using termite mound.

    Science.gov (United States)

    Fufa, Fekadu; Alemayehu, Esayas; Lennartz, Bernd

    2014-01-01

    Long-term consumption of arsenic results in severe and permanent health damages. The aim of the study was to investigate arsenate (As(V)) sorption capacity of termite mound (TM), containing mainly silicon, aluminum, iron and titanium oxides, under batch adsorption setup. The pattern of As(V) removal with varying contact time, solution pH, adsorbent dose, As(V) concentration and competing anions was investigated. Dissolution of the adsorbent was insignificant under the equilibrium conditions. Equilibrium was achieved within 40 min of agitation time. Kinetic data of As(V) adsorption followed well the pseudo-second order equation (R(2) > 0.99). High As(V) removal efficiency (∼ 99%) was observed over a pH range ∼ 3-∼ 10, which is of great importance in the practical application. The Freundlich and Dubinin-Radushkevich isotherms well described (R(2) > 0.99, χ(2) ∼ 0.05) the equilibrium As(V) adsorption, giving a coefficient of adsorption 1.48 mg(1-1/n)L(1/n)/g and a saturation capacity 13.50 mg/g respectively. The obtained value of mean sorption energy (EDR = 13.32 kJ/mol) suggested the chemisorption mechanism of As(V) adsorption on TM. The removal of As(V) was significantly decreased in the presence of phosphate ions. The As(V) loaded adsorbent was successfully regenerated using NaOH solution with insignificant loss of metals. Therefore, the results of the study demonstrated that TM could be considered as a promising adsorbent for the treatment of As(V) in drinking water. Copyright © 2013 Elsevier Ltd. All rights reserved.

  15. Speciation and leachability of copper in mine tailings from porphyry copper mining

    DEFF Research Database (Denmark)

    Hansen, Henrik K.; Yianatos, Juan B; Ottosen, Lisbeth M.

    2005-01-01

    Mine tailing from the El Teniente-Codelco copper mine situated in VI Region of Chile was analysed in order to evaluate the mobility and speciation of copper in the solid material. Mine tailing was sampled after the rougher flotation circuits, and the copper content was measured to 1150mgkg^-^1 dry...... matter. This tailing was segmented into fractions of different size intervals: 0-38, 38-45, 45-53, 53-75, 75-106, 106-150, 150-212, and >212@mm, respectively. Copper content determination, sequential chemical extraction, and desorption experiments were carried out for each size interval in order...... to evaluate the speciation of copper. It was found that the particles of smallest size contained 50-60% weak acid leachable copper, whereas only 32% of the copper found in largest particles could be leached in weak acid. Copper oxides and carbonates were the dominating species in the smaller particles...

  16. Tribological properties of copper-based composites with copper coated NbSe2 and CNT

    International Nuclear Information System (INIS)

    Chen, Beibei; Yang, Jin; Zhang, Qing; Huang, Hong; Li, Hongping; Tang, Hua; Li, Changsheng

    2015-01-01

    Graphical abstract: Morphology of copper coated NbSe 2 and CNT; friction coefficient and wear rate of copper-based composites. - Highlights: • NbSe 2 and CNT were coated with copper layers by the means of electroless plating. • The mechanical and tribological properties of copper composites were studied. • The enhancement mechanisms of copper coated NbSe 2 and CNT were proposed. • Copper–copper coated (12 wt.%NbSe 2 –3 wt.%CNT) composite had the best wear resistance. - Abstract: Copper-based composites with copper coated NbSe 2 and/or CNT were fabricated by the powder metallurgy technique. The morphology and phase composition of copper coated NbSe 2 and carbon nanotube (CNT) were observed using high solution transmission electronic microscope (HRTEM), scanning electronic microscope (SEM equipped with EDS) and X-ray diffraction (XRD). The density, hardness, and bending strength of as-prepared copper-based composites were measured, and their tribological properties were investigated using UMT-2 tester. Results indicated that all copper-based composites showed decreased density and bending strength, but increased hardness in comparison with copper matrix. Besides, the incorporation of copper coated NbSe 2 improved the friction-reducing and anti-wear properties of copper matrix. Addition of copper coated CNT greatly enhanced the mechanical and tribological properties. In particular, when the content of copper coated CNT was 3 wt.%, the corresponding composite exhibited the best tribological properties. This was because NbSe 2 was distributed chaotically in matrix, which greatly improved the friction-reducing property of copper, while CNT with superior mechanical strength enhanced the wear resistance by increasing the load-carrying capacity. More importantly, copper layers coated on NbSe 2 and CNT favored the good interfacial combination between fillers and copper matrix showing beneficial effect for the stresses transferring from matrix to fillers

  17. A study on the coprecipitation of arsenite and arsenate into calcite coupled with the determination of oxidation states of arsenic both in calcite and water

    International Nuclear Information System (INIS)

    Yokoyama, Yuka; Takahashi, Yoshio; Mitsunobu, Satoshi; Tanaka, Kazuya; Itai, Takaaki

    2009-01-01

    It was found that the amount of arsenite incorporated into calcite is much less than that of arsenate. The result suggests that the sequestration of arsenic by coprecipitation with calcite cannot be an important chemical process under reducing conditions such as in groundwater where arsenite is the dominant arsenic species. (author)

  18. Copper and Anesthesia: Clinical Relevance and Management of Copper Related Disorders

    OpenAIRE

    Langley, Adrian; Dameron, Charles T.

    2013-01-01

    Recent research has implicated abnormal copper homeostasis in the underlying pathophysiology of several clinically important disorders, some of which may be encountered by the anesthetist in daily clinical practice. The purpose of this narrative review is to summarize the physiology and pharmacology of copper, the clinical implications of abnormal copper metabolism, and the subsequent influence of altered copper homeostasis on anesthetic management.

  19. Industrial Tests to Modify Molten Copper Slag for Improvement of Copper Recovery

    Science.gov (United States)

    Guo, Zhengqi; Zhu, Deqing; Pan, Jian; Zhang, Feng; Yang, Congcong

    2018-04-01

    In this article, to improve the recovery of copper from copper slag by flotation process, industrial tests of the modification process involving addition of a composite additive into molten copper slag were conducted, and the modified slag was subjected to the flotation process to confirm the modification effect. The phase evolution of the slag in the modification process was revealed by thermodynamic calculations, x-ray diffraction, optical microscopy and scanning electron microscopy. The results show that more copper was transformed and enriched in copper sulfide phases. The magnetite content in the modified slag decreased, and that of "FeO" increased correspondingly, leading to a better fluidity of the molten slag, which improved the aggregation and growth of fine particles of the copper sulfide minerals. Closed-circuit flotation tests of the original and modified slags were conducted, and the results show that the copper recovery increased obviously from 69.15% to 73.38%, and the copper grade of concentrates was elevated slightly from 20.24% to 21.69%, further confirming that the industrial tests of the modification process were successful. Hence, the modification process has a bright future in industrial applications for enhancing the recovery of copper from the copper slag.

  20. Recovery of uranium mineral concentrate from copper tailings

    International Nuclear Information System (INIS)

    Chakravarty, S.; Tewari, U.K.; Beri, K.K.

    1991-01-01

    Based on the studies conducted on the samples of copper tailings from Surda Copper Concentrator plant, wet concentrating table (Diaster Diagonal Deck) was found most suitable for recovering uranium mineral concentrate. Based on this technique, uranium recovery plants were set up at Surda, Rakha and Mosabani. The recoveries obtained from Surda Uranium Recovery Plant and Rakha Uranium Recovery Plant were in the range of 40-50%. But in Mosaboni Uranium Recovery Plant which is treating copper tailings from Mosaboni Copper Concentrator Plant, the biggest concentrator plant processing nearly 2,700 MT/day of copper ore, the recovery by wet concentrating tables was found to be around 22%. Low recovery was mainly due to low concentration of uranium in ore and as well as more percentage of uranium distribution in fines which tables were unable to recover. Studies were done to recover uranium mineral concentrate from the fines with new set of equipment viz. Curved Static Screen/Bartles Mozley Separator/Cross Belt Concentrator. This gave an improvement of 14-16% only. Studies by low acid leaching in chemical process side have shown that an overall recovery of 68% can be achieved. Though the chemical process is best as far as recovery is concerned but there are several constraints. The major constraint is pertaining to environmental and pollution control. Depending on the results of studies to overcome the constraints decision for the process to be adopted will be taken up and executed. The test results and plant performance data have also been included in the paper. (author). 8 figs., 11 tabs., 1 appendix

  1. Copper nitrate redispersion to arrive at highly active silica-supported copper catalysts

    NARCIS (Netherlands)

    Munnik, P.|info:eu-repo/dai/nl/328228524; Wolters, M.|info:eu-repo/dai/nl/304829560; Gabrielsson, A.; Pollington, S.D.; Headdock, G.; Bitter, J.H.|info:eu-repo/dai/nl/160581435; de Jongh, P.E.|info:eu-repo/dai/nl/186125372; de Jong, K.P.|info:eu-repo/dai/nl/06885580X

    2011-01-01

    In order to obtain copper catalysts with high dispersions at high copper loadings, the gas flow rate and gas composition was varied during calcination of silica gel impregnated with copper nitrate to a loading of 18 wt % of copper. Analysis by X-ray diffraction (XRD), N2O chemisorption, and

  2. Herbicide and pesticide occurrence in the soils of children's playgrounds in Sarajevo, Bosnia and Herzegovina.

    Science.gov (United States)

    Sapcanin, Aida; Cakal, Mirsada; Imamovic, Belma; Salihovic, Mirsada; Pehlic, Ekrem; Jacimovic, Zeljko; Jancan, Gordan

    2016-08-01

    Pesticide pollution in Sarajevo public playgrounds is an important health and environmental issue, and the lack of information about it is causing concerns amongst the general population as well as researchers. Since children are in direct contact with surface soils on children's playgrounds, such soils should be much more carefully examined. Furthermore, herbicides and pesticides get transmitted from soil surfaces brought from outside the urban areas, or they get dispersed following their direct applications in urban areas. Infants' and children's health can be directly affected by polluted soils because of the inherent toxicity and widespread use of the different pesticides in urban environments such as playgrounds. In addition to that, the presence of chromated copper arsenate (CCA) wood preservative pesticide found as soil pollutant in playing equipment was also documented. Soil samples from playgrounds were collected and analyzed for triazines, carbamates, dithiocarbamates, phenolic herbicides and organochlorine pesticides. Samples for the determination of heavy metals Cu, Cr and As were prepared by microwave-assisted acid digestion, and the findings were determined by using an inductively coupled plasma optical emission spectrometer. Triazines, carbamates, dithiocarbamates, chlorphenoxy compounds, phenolic herbicides, organochlorine pesticides and organotin compounds were detected in playground soils and their determined concentrations (mg/kg) were respectively found as follows: herbicides and pesticides on human health, which strengthens the case for a more preventative and protective approach to the uncontrolled presence of herbicides and pesticides in Sarajevo's playground soils.

  3. Copper economy in Chlamydomonas: Prioritized allocation and reallocation of copper to respiration vs. photosynthesis

    Science.gov (United States)

    Kropat, Janette; Gallaher, Sean D.; Urzica, Eugen I.; Nakamoto, Stacie S.; Strenkert, Daniela; Tottey, Stephen; Mason, Andrew Z.; Merchant, Sabeeha S.

    2015-01-01

    Inorganic elements, although required only in trace amounts, permit life and primary productivity because of their functions in catalysis. Every organism has a minimal requirement of each metal based on the intracellular abundance of proteins that use inorganic cofactors, but elemental sparing mechanisms can reduce this quota. A well-studied copper-sparing mechanism that operates in microalgae faced with copper deficiency is the replacement of the abundant copper protein plastocyanin with a heme-containing substitute, cytochrome (Cyt) c6. This switch, which is dependent on a copper-sensing transcription factor, copper response regulator 1 (CRR1), dramatically reduces the copper quota. We show here that in a situation of marginal copper availability, copper is preferentially allocated from plastocyanin, whose function is dispensable, to other more critical copper-dependent enzymes like Cyt oxidase and a ferroxidase. In the absence of an extracellular source, copper allocation to Cyt oxidase includes CRR1-dependent proteolysis of plastocyanin and quantitative recycling of the copper cofactor from plastocyanin to Cyt oxidase. Transcriptome profiling identifies a gene encoding a Zn-metalloprotease, as a candidate effecting copper recycling. One reason for the retention of genes encoding both plastocyanin and Cyt c6 in algal and cyanobacterial genomes might be because plastocyanin provides a competitive advantage in copper-depleted environments as a ready source of copper. PMID:25646490

  4. Treating a natural outbreak of columnaris in channel catfish with copper sulfate and potassium permanganate

    Science.gov (United States)

    An F. Columnare-exclusive epizootic occurred in fingerling channel catfish (Ictalurus punctatus) during normal tank culture practices at SNARC. Fish were transferred to the ultra low-flow system and 2.1 mg/L copper sulfate or 3 mg/L potassium permanganate was administered; an untreated control was ...

  5. Canine Copper-Associated Hepatitis

    NARCIS (Netherlands)

    Dirksen, Karen; Fieten, Hille

    2017-01-01

    Copper-associated hepatitis is recognized with increasing frequency in dogs. The disease is characterized by centrolobular hepatic copper accumulation, leading to hepatitis and eventually cirrhosis. The only way to establish the diagnosis is by histologic assessment of copper distribution and copper

  6. Corrosion of metals in treated wood examined by synchrotron based xanes and XFM

    Science.gov (United States)

    Samuel L. Zelinka; Joseph E. Jakes; Grant T. Kirker; Leandro Passarini; Barry Lai

    2016-01-01

    Copper based waterborne wood preservatives are frequently used to extend the service life of wood products used in outdoor environments. While these copper based treatments protect the wood from fungal decay and insect attack, they increase the corrosion of metals embedded or in contact with the treated wood. Over the past ten years, several studies have looked at the...

  7. Earth's copper resources estimated from tectonic diffusion of porphyry copper deposits

    Science.gov (United States)

    Kesler, Stephen E.; Wilkinson, Bruce H.

    2008-03-01

    Improved estimates of global mineral endowments are relevantto issues ranging from strategic planning to global geochemicalcycling. We have used a time-space model for the tectonic migrationof porphyry copper deposits vertically through the crust tocalculate Earth's endowment of copper in mineral deposits. Themodel relies only on knowledge of numbers and ages of porphyrycopper deposits, Earth's most widespread and important sourceof copper, in order to estimate numbers of eroded and preserveddeposits in the crust. Model results indicate that 125,895 porphyrycopper deposits were formed during Phanerozoic time, that only47,789 of these remain at various crustal depths, and that thesecontain 1.7 x 1011 tonnes (t) of copper. Assuming that othertypes of copper deposits behave similarly in the crust and haveabundances proportional to their current global production yieldsan estimate of 3 x 1011 t for total global copper resourcesat all levels in Earth's crust. Thus, 0.25% of the copper inthe crust has been concentrated into deposits through Phanerozoictime, and about two-thirds of this has been recycled by upliftand erosion. The amount of copper in deposits above 3.3 km,a likely limit of future mining, could supply current worldmine production for 5500 yr, thus quantifying the highly unusualand nonrenewable nature of mineral deposits.

  8. Environmental Risks of Nano Zerovalent Iron for Arsenate Remediation: Impacts on Cytosolic Levels of Inorganic Phosphate and MgATP2- in Arabidopsis thaliana.

    Science.gov (United States)

    Zhang, Weilan; Lo, Irene M C; Hu, Liming; Voon, Chia Pao; Lim, Boon Leong; Versaw, Wayne K

    2018-04-03

    The use of nano zerovalent iron (nZVI) for arsenate (As(V)) remediation has proven effective, but full-scale injection of nZVI into the subsurface has aroused serious concerns for associated environmental risks. This study evaluated the efficacy of nZVI treatment for arsenate remediation and its potential hazards to plants using Arabidopsis thaliana grown in a hydroponic system. Biosensors for inorganic phosphate (Pi) and MgATP 2- were used to monitor in vivo Pi and MgATP 2- levels in plant cells. The results showed that nZVI could remove As(V) from growth media, decrease As uptake by plants, and mitigate As(V) toxicity to plants. However, excess nZVI could cause Pi starvation in plants leading to detrimental effects on plant growth. Due to the competitive adsorption of As(V) and Pi on nZVI, removing As(V) via nZVI treatment at an upstream site could relieve downstream plants from As(V) toxicity and Pi deprivation, in which case 100 mg/L of nZVI was the optimal dosage for remediation of As(V) at a concentration around 16.13 mg/L.

  9. Efficient removal of copper from wastewater by using mechanically activated calcium carbonate.

    Science.gov (United States)

    Hu, Huimin; Li, Xuewei; Huang, Pengwu; Zhang, Qiwu; Yuan, Wenyi

    2017-12-01

    Copper removal from aqueous solution is necessary from the stances of both environmental protection and copper resource recycling. It is important to develop a new chemical precipitation method suitable for removing copper particularly at low concentration as the case of waste mine water, with regards to the various problems related to the current precipitation methods by using strong alkalis or soluble sulfides. In this research, we studied a possible chemical precipitation of copper ions at concentration around 60 mg/L or lower by cogrinding copper sulfate in water with calcium carbonate (CaCO 3 ) using wet stirred ball milling. With the aid of ball milling, copper precipitation as a basic sulfate (posnjakite: Cu 4 (SO 4 ) (OH) 6 ·H 2 O) occurred at a very high copper removal rate of 99.76%, to reduce the residual copper concentration in the solution less than 0.5 mg/L, reaching the discharge limit, even with the addition amount of CaCO 3 as a stoichiometric ratio of CaCO 3 /Cu 2+ at 1:1. It is more interesting to notice that, at the same conditions, other heavy metals such as Ni, Mn, Zn and Cd do not precipitate obviously just with CaCO 3 addition at CaCO 3 /M 2+ at 1:1 so that the precipitate without the impurities can be processed as good source to recover copper. This newly proposed concept can be further developed to treat wastewaters with other metals to serve both purposes of environmental purification and resource recovery in a similar way. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Stage specific effects of soluble copper and copper oxide nanoparticles during sea urchin embryo development and their relation to intracellular copper uptake.

    Science.gov (United States)

    Torres-Duarte, Cristina; Ramos-Torres, Karla M; Rahimoff, René; Cherr, Gary N

    2017-08-01

    The effects of exposure to either soluble copper (copper sulfate) or copper oxide nanoparticles (nano-CuO) during specific early developmental stages of sea urchin embryos were analyzed. Soluble copper caused significant malformations in embryos (skeletal malformations, delayed development or gut malformations) when present at any given stage, while cleavage stage was the most sensitive to nano-CuO exposure causing skeletal malformations and decreased total antioxidant capacity. The stage specificity was linked to higher endocytic activity during the first hours of development that leads to higher accumulation of copper in specific cells critical for development. Results indicate that nano-CuO results in higher accumulation of copper inside of embryos and this intracellular copper is more persistent as compared to soluble copper. The possible implications later in development are discussed. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Genome Sequences of Two Copper-Resistant Escherichia coli Strains Isolated from Copper-Fed Pigs

    DEFF Research Database (Denmark)

    Lüthje, Freja L.; Hasman, Henrik; Aarestrup, Frank Møller

    2014-01-01

    The draft genome sequences of two copper-resistant Escherichia coli strains were determined. These had been isolated from copper-fed pigs and contained additional putative operons conferring copper and other metal and metalloid resistances.......The draft genome sequences of two copper-resistant Escherichia coli strains were determined. These had been isolated from copper-fed pigs and contained additional putative operons conferring copper and other metal and metalloid resistances....

  12. Cytogenetical and ultrastructural effects of copper on root meristem cells of Allium sativum L.

    Science.gov (United States)

    Liu, Donghua; Jiang, Wusheng; Meng, Qingmin; Zou, Jin; Gu, Jiegang; Zeng, Muai

    2009-04-01

    Different copper concentrations, as well as different exposure times, were applied to investigate both cytogenetical and ultrastructural alterations in garlic (Allium sativum L.) meristem cells. Results showed that the mitotic index decreased progressively when either copper concentration or exposure time increased. C-mitosis, anaphase bridges, chromosome stickiness and broken nuclei were observed in the copper treated root tip cells. Some particulates containing the argyrophilic NOR-associated proteins were distributed in the nucleus of the root-tip cells and the amount of this particulate material progressively increased with increasing exposure time. Finally, the nucleolar material was extruded from the nucleus into the cytoplasm. Also, increased dictyosome vesicles in number, formation of cytoplasmic vesicles containing electron dense granules, altered mitochondrial shape, disruption of nuclear membranes, condensation of chromatin material, disintegration of organelles were observed. The mechanisms of detoxification and tolerance of copper are briefly discussed.

  13. Copper uptake and retention in liver parenchymal cells isolated from nutritionally copper-deficient rats

    NARCIS (Netherlands)

    Berg, van den G.J.; de Goeij, J.J.M.; Bock, I.; Gijbels, M.J.J.; Brouwer, A.; Lei, K.Y.; Hendriks, H.F.J.

    1991-01-01

    Copper uptake and retention were studied in primary cultures of liver parenchymal cells isolated from copper-deficient rats. Male Sprague-Dawley rats were fed a copper-deficient diet (<1 mg Cu/kg) for 10 wk. Copper-deficient rats were characterized by low copper concentrations in plasma and liver,

  14. Copper uptake and retention in liver parenchymal cells isolated from nutritionally copper-deficient rats

    NARCIS (Netherlands)

    Berg, G.J. van den; Goeij, J.J.M. de; Bock, I.; Gijbels, M.J.J.; Brouwer, A.; Lei, K.Y.; Hendruiks, H.F.J.

    1991-01-01

    Copper uptake and retention were studied in primary cultures of liver parenchymal cells isolated from copper-deficient rats. Male Sprague-Dawley rats were fed a copper-deficient diet (< 1 mg Cu/kg) for 10 wk. Copper-deficient rats were characterized by low copper concentrations in plasma and liver,

  15. Annual Copper Mountain Conferences on Multigrid and Iterative Methods, Copper Mountain, Colorado

    International Nuclear Information System (INIS)

    McCormick, Stephen F.

    2016-01-01

    This project supported the Copper Mountain Conference on Multigrid and Iterative Methods, held from 2007 to 2015, at Copper Mountain, Colorado. The subject of the Copper Mountain Conference Series alternated between Multigrid Methods in odd-numbered years and Iterative Methods in even-numbered years. Begun in 1983, the Series represents an important forum for the exchange of ideas in these two closely related fields. This report describes the Copper Mountain Conference on Multigrid and Iterative Methods, 2007-2015. Information on the conference series is available at http://grandmaster.colorado.edu/~copper/

  16. Annual Copper Mountain Conferences on Multigrid and Iterative Methods, Copper Mountain, Colorado

    Energy Technology Data Exchange (ETDEWEB)

    McCormick, Stephen F. [Front Range Scientific, Inc., Lake City, CO (United States)

    2016-03-25

    This project supported the Copper Mountain Conference on Multigrid and Iterative Methods, held from 2007 to 2015, at Copper Mountain, Colorado. The subject of the Copper Mountain Conference Series alternated between Multigrid Methods in odd-numbered years and Iterative Methods in even-numbered years. Begun in 1983, the Series represents an important forum for the exchange of ideas in these two closely related fields. This report describes the Copper Mountain Conference on Multigrid and Iterative Methods, 2007-2015. Information on the conference series is available at http://grandmaster.colorado.edu/~copper/.

  17. Is a high serum copper concentration a risk factor for implantation failure?

    Science.gov (United States)

    Matsubayashi, Hidehiko; Kitaya, Kotaro; Yamaguchi, Kohei; Nishiyama, Rie; Takaya, Yukiko; Ishikawa, Tomomoto

    2017-08-10

    Copper-containing contraceptive devices may deposit copper ions in the endometrium, resulting in implantation failure. The deposition of copper ions in many organs has been reported in patients with untreated Wilson's disease. Since these patients sometimes exhibit subfertility and/or early pregnancy loss, copper ions were also considered to accumulate in the uterine endometrium. Wilson's disease patients treated with zinc successfully delivered babies because zinc interfered with the absorption of copper from the gastrointestinal tract. These findings led to the hypothesis that infertile patients with high serum copper concentrations may have implantation failure due to the excess accumulation of copper ions. The relationship between implantation (pregnancy) rates and serum copper concentrations has not yet been examined. The Japanese government recently stated that actual copper intake was higher among Japanese than needed. Therefore, the aim of the present study was to investigate whether serum copper concentrations are related to the implantation (pregnancy) rates of human embryos in vivo. We included 269 patients (age copper, and zinc concentrations were measured 16 days after the first date of progesterone replacement. We compared 96 women who were pregnant without miscarriage at 10 weeks of gestation (group P) and 173 women who were not pregnant (group NP). No significant differences were observed in age or BMI between the groups. Copper concentrations were significantly higher in group NP (average 193.2 μg/dL) than in group P (average 178.1 μg/dL). According to the area under the curve (AUC) on the receiver operating characteristic curve for the prediction of clinical pregnancy rates, the Cu/Zn ratio (AUC 0.64, 95% CI 0.54-0.71) was a better predictor than copper or zinc. When we set the cut-off as 1.59/1.60 for the Cu/Zn ratio, sensitivity, specificity, the positive predictive value, and negative predictive value were 0.98, 0.29, 0.71, and 0

  18. Copper wire bonding

    CERN Document Server

    Chauhan, Preeti S; Zhong, ZhaoWei; Pecht, Michael G

    2014-01-01

    This critical volume provides an in-depth presentation of copper wire bonding technologies, processes and equipment, along with the economic benefits and risks.  Due to the increasing cost of materials used to make electronic components, the electronics industry has been rapidly moving from high cost gold to significantly lower cost copper as a wire bonding material.  However, copper wire bonding has several process and reliability concerns due to its material properties.  Copper Wire Bonding book lays out the challenges involved in replacing gold with copper as a wire bond material, and includes the bonding process changes—bond force, electric flame off, current and ultrasonic energy optimization, and bonding tools and equipment changes for first and second bond formation.  In addition, the bond–pad metallurgies and the use of bare and palladium-coated copper wires on aluminum are presented, and gold, nickel and palladium surface finishes are discussed.  The book also discusses best practices and re...

  19. Effect of the background radiation of a copper vapor laser with an unstable resonator on dye lasing

    Energy Technology Data Exchange (ETDEWEB)

    Elaev, V F; Mirza, S M; Sukhanov, V B; Troitskii, V O; Soldatov, A N

    1986-05-01

    Results of an experimental study of the emission divergence of a copper vapor laser with an unstable resonator are reported. It is shown that a copper vapor laser beam can be conveniently treated as a pair of components with a divergence higher or lower than a certain optimal value; the percent ratio of the components varies with the pulse repetition frequency. In the case where a copper vapor laser is used to pump a dye laser, the contribution of the component with the higher divergence to dye lasing does not exceed 1 percent. 7 references.

  20. Nearly 60% Copper Rod & Wire Companies Neutral about Future Copper Price

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    <正>How about the trend of copper price recently? According to the survey result of Shanghai Metals Market, amongst 21 domestic copper rod & wire companies, 57% of the companies are neutral about the future copper price, while 14% and 19% of the companies consider that

  1. Permanence and diffusion of borax-copper hydroxide remedial preservative applied to unseasoned pine posts : 10 year update

    Science.gov (United States)

    Douglas Crawford; Stan Lebow; Mike West; Bill Abbott

    2005-01-01

    In 1993, unseasoned pine posts were treated with groundline remedial treatment containing 3.1% copper hydroxide and 40% sodium tetraborate decahydrate (borax). The soundness of the posts was periodically evaluated using a push test. After 3.5, 6.5, and 10 years, sections were taken from two posts to determine retention of borax and copper hydroxide below ground to 36...

  2. Immunotoxicity of copper nanoparticle and copper sulfate in a common Indian earthworm.

    Science.gov (United States)

    Gautam, Arunodaya; Ray, Abhishek; Mukherjee, Soumalya; Das, Santanu; Pal, Kunal; Das, Subhadeep; Karmakar, Parimal; Ray, Mitali; Ray, Sajal

    2018-02-01

    Copper oxide nanoparticles and copper sulfate are established contaminants of water and soil. Metaphire posthuma is a common variety of earthworm distributed in moist soil of Indian subcontinent. Comparative toxicity of copper nanoparticles and copper sulfate were investigated with reference to selected immune associated parameters of earthworm. Total count, phagocytic response, generation of cytotoxic molecules (superoxide anion, nitric oxide), activities of enzymes like phenoloxidase, superoxide dismutase, catalase, acid phosphatase, alkaline phosphatase and total protein of coelomocytes were estimated under the exposures of 100, 500, 1000mg of copper oxide nanoparticles and copper sulfate per kg of soil for 7 and 14 d. A significant decrease in the total coelomocyte count were recorded with maximum depletion as 15.45 ± 2.2 and 12.5 ± 2 × 10 4 cells/ml under the treatment of 1000mg/kg of copper nanoparticles and copper sulfate for 14 d respectively. A significant decrease in generation of nitric oxide and activity of phenoloxidase were recorded upon exposure of both toxins for 7 and 14 d indicating possible decline in cytotoxic status of the organism. A maximum inhibition of superoxide dismutase activity was recorded as 0.083 ± 0.0039 and 0.055 ± 0.0057 unit/mg protein/minute against 1000mg/kg of copper nanoparticles and copper sulfate treatment for 14 d respectively. Activities of catalase and alkaline phosphatase were inhibited by all experimental concentrations of both toxins in the coelomocytes of earthworm. These toxins were recorded to be modifiers of the major immune associated parameters of M. posthuma. Unrestricted contamination of soil by sulfate and oxide nanoparticles of copper may lead to an undesirable shift in the innate immunological status of earthworm leading to a condition of immune compromisation and shrinkage in population density of this species in its natural habitat. This article is the first time report of immunological toxicity of

  3. Focus on CSIR research in water resources: antimicrobial properties of copper and its effects on micro-organisms in drinking water distribution systems

    CSIR Research Space (South Africa)

    Genthe, Bettina

    2007-08-01

    Full Text Available understanding of the mechanisms involved in copper toxicity in bacteria to better understand the potential applications of copper in treating drinking water. Further research is needed to determine why the growth continues after initial inactivation and whether...

  4. Biliary copper excretion by hepatocyte lysosomes in the rat. Major excretory pathway in experimental copper overload

    International Nuclear Information System (INIS)

    Gross, J.B. Jr.; Myers, B.M.; Kost, L.J.; Kuntz, S.M.; LaRusso, N.F.

    1989-01-01

    We investigated the hypothesis that lysosomes are the main source of biliary copper in conditions of hepatic copper overload. We used a rat model of oral copper loading and studied the relationship between the biliary output of copper and lysosomal hydrolases. Male Sprague-Dawley rats were given tap water with or without 0.125% copper acetate for up to 36 wk. Copper loading produced a 23-fold increase in the hepatic copper concentration and a 30-65% increase in hepatic lysosomal enzyme activity. Acid phosphatase histochemistry showed that copper-loaded livers contained an increased number of hepatocyte lysosomes; increased copper concentration of these organelles was confirmed directly by both x ray microanalysis and tissue fractionation. The copper-loaded rats showed a 16-fold increase in biliary copper output and a 50-300% increase in biliary lysosomal enzyme output. In the basal state, excretory profiles over time were similar for biliary outputs of lysosomal enzymes and copper in the copper-loaded animals but not in controls. After pharmacologic stimulation of lysosomal exocytosis, biliary outputs of copper and lysosomal hydrolases in the copper-loaded animals remained coupled: injection of colchicine or vinblastine produced an acute rise in the biliary output of both lysosomal enzymes and copper to 150-250% of baseline rates. After these same drugs, control animals showed only the expected increase in lysosomal enzyme output without a corresponding increase in copper output. We conclude that the hepatocyte responds to an increased copper load by sequestering excess copper in an increased number of lysosomes that then empty their contents directly into bile. The results provide direct evidence that exocytosis of lysosomal contents into biliary canaliculi is the major mechanism for biliary copper excretion in hepatic copper overload

  5. Underwater explosive compaction-sintering of tungsten-copper coating on a copper surface

    Science.gov (United States)

    Chen, Xiang; Li, Xiaojie; Yan, Honghao; Wang, Xiaohong; Chen, Saiwei

    2018-01-01

    This study investigated underwater explosive compaction-sintering for coating a high-density tungsten-copper composite on a copper surface. First, 50% W-50% Cu tungsten-copper composite powder was prepared by mechanical alloying. The composite powder was pre-compacted and sintered by hydrogen. Underwater explosive compaction was carried out. Finally, a high-density tungsten-copper coating was obtained by diffusion sintering of the specimen after explosive compaction. A simulation of the underwater explosive compaction process showed that the peak value of the pressure in the coating was between 3.0 and 4.8 GPa. The hardness values of the tungsten-copper layer and the copper substrate were in the range of 87-133 and 49 HV, respectively. The bonding strength between the coating and the substrate was approximately 100-105 MPa.

  6. Copper induces hepatocyte injury due to the endoplasmic reticulum stress in cultured cells and patients with Wilson disease

    International Nuclear Information System (INIS)

    Oe, Shinji; Miyagawa, Koichiro; Honma, Yuichi; Harada, Masaru

    2016-01-01

    Copper is an essential trace element, however, excess copper is harmful to human health. Excess copper-derived oxidants contribute to the progression of Wilson disease, and oxidative stress induces accumulation of abnormal proteins. It is known that the endoplasmic reticulum (ER) plays an important role in proper protein folding, and that accumulation of misfolded proteins disturbs ER homeostasis resulting in ER stress. However, copper-induced ER homeostasis disturbance has not been fully clarified. We treated human hepatoma cell line (Huh7) and immortalized-human hepatocyte cell line (OUMS29) with copper and chemical chaperones, including 4-phenylbutyrate and ursodeoxycholic acid. We examined copper-induced oxidative stress, ER stress and apoptosis by immunofluorescence microscopy and immunoblot analyses. Furthermore, we examined the effects of copper on carcinogenesis. Excess copper induced not only oxidative stress but also ER stress. Furthermore, excess copper induced DNA damage and reduced cell proliferation. Chemical chaperones reduced this copper-induced hepatotoxicity. Excess copper induced hepatotoxicity via ER stress. We also confirmed the abnormality of ultra-structure of the ER of hepatocytes in patients with Wilson disease. These findings show that ER stress plays a pivotal role in Wilson disease, and suggests that chemical chaperones may have beneficial effects in the treatment of Wilson disease.

  7. Copper induces hepatocyte injury due to the endoplasmic reticulum stress in cultured cells and patients with Wilson disease

    Energy Technology Data Exchange (ETDEWEB)

    Oe, Shinji, E-mail: ooes@med.uoeh-u.ac.jp; Miyagawa, Koichiro, E-mail: koichiro@med.uoeh-u.ac.jp; Honma, Yuichi, E-mail: y-homma@med.uoeh-u.ac.jp; Harada, Masaru, E-mail: msrharada@med.uoeh-u.ac.jp

    2016-09-10

    Copper is an essential trace element, however, excess copper is harmful to human health. Excess copper-derived oxidants contribute to the progression of Wilson disease, and oxidative stress induces accumulation of abnormal proteins. It is known that the endoplasmic reticulum (ER) plays an important role in proper protein folding, and that accumulation of misfolded proteins disturbs ER homeostasis resulting in ER stress. However, copper-induced ER homeostasis disturbance has not been fully clarified. We treated human hepatoma cell line (Huh7) and immortalized-human hepatocyte cell line (OUMS29) with copper and chemical chaperones, including 4-phenylbutyrate and ursodeoxycholic acid. We examined copper-induced oxidative stress, ER stress and apoptosis by immunofluorescence microscopy and immunoblot analyses. Furthermore, we examined the effects of copper on carcinogenesis. Excess copper induced not only oxidative stress but also ER stress. Furthermore, excess copper induced DNA damage and reduced cell proliferation. Chemical chaperones reduced this copper-induced hepatotoxicity. Excess copper induced hepatotoxicity via ER stress. We also confirmed the abnormality of ultra-structure of the ER of hepatocytes in patients with Wilson disease. These findings show that ER stress plays a pivotal role in Wilson disease, and suggests that chemical chaperones may have beneficial effects in the treatment of Wilson disease.

  8. A Novel Multimodal Biometrics Recognition Model Based on Stacked ELM and CCA Methods

    Directory of Open Access Journals (Sweden)

    Jucheng Yang

    2018-04-01

    Full Text Available Multimodal biometrics combine a variety of biological features to have a significant impact on identification performance, which is a newly developed trend in biometrics identification technology. This study proposes a novel multimodal biometrics recognition model based on the stacked extreme learning machines (ELMs and canonical correlation analysis (CCA methods. The model, which has a symmetric structure, is found to have high potential for multimodal biometrics. The model works as follows. First, it learns the hidden-layer representation of biological images using extreme learning machines layer by layer. Second, the canonical correlation analysis method is applied to map the representation to a feature space, which is used to reconstruct the multimodal image feature representation. Third, the reconstructed features are used as the input of a classifier for supervised training and output. To verify the validity and efficiency of the method, we adopt it for new hybrid datasets obtained from typical face image datasets and finger-vein image datasets. Our experimental results demonstrate that our model performs better than traditional methods.

  9. Rheology of Prepreg and Properties of Silica/bismaleimide Matrix Copper Clad Laminate

    Directory of Open Access Journals (Sweden)

    DAI Shankai

    2017-08-01

    Full Text Available The effects of the silica surface treated by coupling agents KH550, KH560 and KH570 on the rheological properties of bismaleimide (BMI resin system were investigated. The rigidity, coefficient of thermal expansion (CTE and thermal stability of the copper clad laminate (CCL were studied by DMA, TMA and TGA. The resin system containing silica surface treated by KH-560, comparing to KH550, KH570 and without surface treatment resin system has better rheological properties and low melt viscosity. The comprehensive properties of the copper clad laminate can be effectively improved by the introduction of silica in the resin system, exhibiting higher storage modulus and lower CTE compare to no silica in the CCL. When the silica mass fraction is 50%, the storage modulus is increased by 83% at 50℃, and the CTE below the glass transition temperature is decreased by 153%.

  10. Effect of silane coupling agent on interfacial adhesion of copper/glass fabric/epoxy composites

    International Nuclear Information System (INIS)

    Langroudi, A. E.; Yousefi, A. A.; Kabiri, Kourosh

    2003-01-01

    The effect of silane coupling agent on the peel strength of copper/prep reg/copper composites was investigated. The composite consisted of one or two sheets of prepress covered by two copper plates. The prep reg was prepared by hand dry-lay-up technique using an epoxy resin and an electrical resistant glass fabric (e-glass style 2165). 4,4'-methylene dianiline. An aromatic amine, was used as curing agent. curing times for prep reg and composite at 120 d ig C and 170 d ig C were 15 min and 1 h, respectively. γ-aminopropyl trimethoxy silane was used as coupling agent. The effect of aminopropyl trimethoxy silane on the adhesion of epoxy/glass and epoxy/copper interfaces was investigated by two methods. In the first method, the surface of the glass fabric and/or the copper plates were treated by aminopropyl trimethoxy silane. In the second method, aminopropyl trimethoxy silane was directly added to epoxy resin. In addition, the effect of additional resin on the adhesion strength was also studied by the latter method

  11. A copper-mediated reverse aromatic Finkelstein reaction in ionic liquid

    Directory of Open Access Journals (Sweden)

    Anh T.H. Nguyen

    2018-03-01

    Full Text Available We have developed a general method for reverse aromatic Finkelstein reactions. Good reaction yields were obtained when aryl iodides or aryl bromides were treated with copper halide salts as promoters in a 1-butyl-3-methylimidazolium bromide ([BMIM]Br ionic liquid (IL solvent at 140 °C for 8 h. Preliminary investigation supported that the copper salts were also the halide sources in halogen exchange reactions. The optimized conditions are applicable to a variety of substrates and have excellent functional group tolerance. Additionally, the [BMIM]Br solvent showed good stability for at least 10 consecutive runs. Results indicated that the [BMIM]Br solvent was recyclable for reverse aromatic Finkelstein reactions.

  12. Critical review: Copper runoff from outdoor copper surfaces at atmospheric conditions.

    Science.gov (United States)

    Hedberg, Yolanda S; Hedberg, Jonas F; Herting, Gunilla; Goidanich, Sara; Odnevall Wallinder, Inger

    2014-01-01

    This review on copper runoff dispersed from unsheltered naturally patinated copper used for roofing and facades summarizes and discusses influencing factors, available literature, and predictive models, and the importance of fate and speciation for environmental risk assessment. Copper runoff from outdoor surfaces is predominantly governed by electrochemical and chemical reactions and is highly dependent on given exposure conditions (size, inclination, geometry, degree of sheltering, and orientation), surface parameters (age, patina composition, and thickness), and site-specific environmental conditions (gaseous pollutants, chlorides, rainfall characteristics (amount, intensity, pH), wind direction, temperature, time of wetness, season). The corrosion rate cannot be used to assess the runoff rate. The extent of released copper varies largely between different rain events and is related to dry and wet periods, dry deposition prior to the rain event and prevailing rain and patina characteristics. Interpretation and use of copper runoff data for environmental risk assessment and management need therefore to consider site-specific factors and focus on average data of long-term studies (several years). Risk assessments require furthermore that changes in copper speciation, bioavailability aspects, and potential irreversible retention on solid surfaces are considered, factors that determine the environmental fate of copper runoff from outdoor surfaces.

  13. Simulation of the effects of phosphate on adsorption of arsenite and arsenate on ferrihydrite matrix using a geochemical equilibrium model

    International Nuclear Information System (INIS)

    Kassenga, G.R.

    2005-01-01

    Arsenic is of environmental concern because of its toxicity to plants, animals, and human beings. Iron oxides, including the poorly crystalline (amorphous) iron oxides, e.g., ferrihydrite, have a strong affinity for both arsenite and arsenate (the most toxic species of arsenic). In view of this, adsorption on ferrihydrite matrix is the main process of immobilization of arsenic in groundwater. The presence of phosphate in groundwater may however limit adsorption of arsenic on iron oxides due to competition for adsorption sites, resulting in higher aqueous concentrations in some environments. This paper analyses the effects of phosphate on aqueous concentration of arsenic at different pH using a geochemical equilibrium simulation model. It specifically focuses on arsenite and arsenate, the most toxic forms of arsenic. A general description of the occurrence of arsenic in the environment, its toxicity, and health hazards is first given. The paper discusses sources and geochemical processes that control arsenic mobility in aquifers. Adsorption and desorption reactions of arsenic on ferrihydrite and the factors that affect them are described. Modeling of adsorption/desorption processes is then discussed. Finally, the effects of phosphate on adsorption and desorption processes of arsenic on ferrihydrite as a function of pH are analyzed using PHREEQC Version 2, a computer program for simulating chemical reactions and transport processes in natural and polluted water. The model is applied in a case study formulated on the basis of a realistic hydrogeochemical setting to demonstrate how the use of arsenical pesticides and phosphate fertilizers may pose potential public health problems in areas where groundwater is used for domestic purposes. The modeling results have shown that aqueous concentration of arsenic increases with increasing phosphate-phosphorus concentration for pH values less than 10 assuming that ferrihydrite concentration and other hydrogeochemical conditions

  14. Copper hypersensitivity

    DEFF Research Database (Denmark)

    Fage, Simon W; Faurschou, Annesofie; Thyssen, Jacob P

    2014-01-01

    hypersensitivity, a database search of PubMed was performed with the following terms: copper, dermatitis, allergic contact dermatitis, contact hypersensitivity, contact sensitization, contact allergy, patch test, dental, IUD, epidemiology, clinical, and experimental. Human exposure to copper is relatively common...

  15. A cytosolic copper storage protein provides a second level of copper tolerance in Streptomyces lividans.

    Science.gov (United States)

    Straw, Megan L; Chaplin, Amanda K; Hough, Michael A; Paps, Jordi; Bavro, Vassiliy N; Wilson, Michael T; Vijgenboom, Erik; Worrall, Jonathan A R

    2018-01-24

    Streptomyces lividans has a distinct dependence on the bioavailability of copper for its morphological development. A cytosolic copper resistance system is operative in S. lividans that serves to preclude deleterious copper levels. This system comprises of several CopZ-like copper chaperones and P 1 -type ATPases, predominantly under the transcriptional control of a metalloregulator from the copper sensitive operon repressor (CsoR) family. In the present study, we discover a new layer of cytosolic copper resistance in S. lividans that involves a protein belonging to the newly discovered family of copper storage proteins, which we have named Ccsp (cytosolic copper storage protein). From an evolutionary perspective, we find Ccsp homologues to be widespread in Bacteria and extend through into Archaea and Eukaryota. Under copper stress Ccsp is upregulated and consists of a homotetramer assembly capable of binding up to 80 cuprous ions (20 per protomer). X-ray crystallography reveals 18 cysteines, 3 histidines and 1 aspartate are involved in cuprous ion coordination. Loading of cuprous ions to Ccsp is a cooperative process with a Hill coefficient of 1.9 and a CopZ-like copper chaperone can transfer copper to Ccsp. A Δccsp mutant strain indicates that Ccsp is not required under initial copper stress in S. lividans, but as the CsoR/CopZ/ATPase efflux system becomes saturated, Ccsp facilitates a second level of copper tolerance.

  16. Fabricating Copper Nanotubes by Electrodeposition

    Science.gov (United States)

    Yang, E. H.; Ramsey, Christopher; Bae, Youngsam; Choi, Daniel

    2009-01-01

    Copper tubes having diameters between about 100 and about 200 nm have been fabricated by electrodeposition of copper into the pores of alumina nanopore membranes. Copper nanotubes are under consideration as alternatives to copper nanorods and nanowires for applications involving thermal and/or electrical contacts, wherein the greater specific areas of nanotubes could afford lower effective thermal and/or electrical resistivities. Heretofore, copper nanorods and nanowires have been fabricated by a combination of electrodeposition and a conventional expensive lithographic process. The present electrodeposition-based process for fabricating copper nanotubes costs less and enables production of copper nanotubes at greater rate.

  17. The CCA-end of P-tRNA Contacts Both the Human RPL36AL and the A-site Bound Translation Termination Factor eRF1 at the Peptidyl Transferase Center of the Human 80S Ribosome.

    Science.gov (United States)

    Hountondji, Codjo; Bulygin, Konstantin; Créchet, Jean-Bernard; Woisard, Anne; Tuffery, Pierre; Nakayama, Jun-Ichi; Frolova, Ludmila; Nierhaus, Knud H; Karpova, Galina; Baouz, Soria

    2014-01-01

    We have demonstrated previously that the E-site specific protein RPL36AL present in human ribosomes can be crosslinked with the CCA-end of a P-tRNA in situ. Here we report the following: (i) We modeled RPL36AL into the structure of the archaeal ortholog RPL44E extracted from the known X-ray structure of the 50S subunit of Haloarcula marismortui. Superimposing the obtained RPL36AL structure with that of P/E tRNA observed in eukaryotic 80S ribosomes suggested that RPL36AL might in addition to its CCA neighbourhood interact with the inner site of the tRNA elbow similar to an interaction pattern known from tRNA•synthetase pairs. (ii) Accordingly, we detected that the isolated recombinant protein RPL36AL can form a tight binary complex with deacylated tRNA, and even tRNA fragments truncated at their CCA end showed a high affinity in the nanomolar range supporting a strong interaction outside the CCA end. (iii) We constructed programmed 80S complexes containing the termination factor eRF1 (stop codon UAA at the A-site) and a 2',3'-dialdehyde tRNA (tRNAox) analog at the P-site. Surprisingly, we observed a crosslinked ternary complex containing the tRNA, eRF1 and RPL36AL crosslinked both to the aldehyde groups of tRNAox at the 2'- and 3'-positions of the ultimate A. We also demonstrated that, upon binding to the ribosomal A-site, eRF1 induces an alternative conformation of the ribosome and/or the tRNA, leading to a novel crosslink of tRNAox to another large-subunit ribosomal protein (namely L37) rather than to RPL36AL, both ribosomal proteins being labeled in a mutually exclusive fashion. Since the human 80S ribosome in complex with P-site bound tRNAox and A-site bound eRF1 corresponds to the post-termination state of the ribosome, the results represent the first biochemical evidence for the positioning of the CCA-arm of the P-tRNA in close proximity to both RPL36AL and eRF1 at the end of the translation process.

  18. Symbiotic Effect of Trichoderma atroviride on Growth Characteristics and Yield of two Cultivars of Rapeseed (Brassica napus L. in a Contaminated Soil Treated with Copper Nitrate

    Directory of Open Access Journals (Sweden)

    E TashakoriFard

    2017-06-01

    Full Text Available Introduction Accumulation of heavy metals in agricultural soils can be a threat to crop production due to plant toxicity. In the recent years, hyperaccumulator plants are cultivated to cleaning up the soils which contaminated with pollutants especially heavy metals. However, the biomass of these plants is low and metal specific. Many studies have shown that microorganisms can be used to significantly reduce the toxicity of heavy metals. Therefore, the present study aimed to determine the role of Trichoderma atroviride on the growth characteristics of tow cultivars of rapeseed in different levels on copper. Materials and Methods In this study, a pot experiment was conducted in factorial arrangement based completely randomized design with three replicates. Treatment were T. atroviride fungi at two levels of inoculated and non-inoculated plants, four levels of copper nitrate including 0, 50, 100 and 150 mg l-1 and two cultivars of rapeseed consist of Hayola 401 and Sarigol. Trichoderma atroviride was prepared from Mycology Lab of Sari Agricultural Science and Natural Resource University. PDA medium (potato extract, dextrose and agar was kept for a week at 25˚C to propagation of fungal strain. The used medium was previously sterilized in autoclave for 30 minutes. So, this fungus propagated in Wheat's bran for five days. Healthy and uniform seeds of rapeseeds were separated from rogues and infertile ones. Seeds disinfected in hypochlorite sodium 0.5% for five minute and then washed with distilled water three times. After preparing fungus spore suspension of 108 CFU per ml water, 50 g wheat' bran mixed to the soil of each pot. Twenty sterilized seeds sown in 2 cm of soil depth in 25×30 cm pot with 10 kg capacity. Copper nitrate was used to pollute treated soil. During this experiment did not used any pesticides and herbicides and all weed controlled manually. Some growth and yield related parameters such as plant height, number of secondary branches

  19. Possible Roles of Plant Sulfurtransferases in Detoxification of Cyanide, Reactive Oxygen Species, Selected Heavy Metals and Arsenate

    Directory of Open Access Journals (Sweden)

    Parvin Most

    2015-01-01

    Full Text Available Plants and animals have evolved various potential mechanisms to surmount the adverse effects of heavy metal toxicity. Plants possess low molecular weight compounds containing sulfhydryl groups (-SH that actively react with toxic metals. For instance, glutathione (γ-Glu-Cys-Gly is a sulfur-containing tripeptide thiol and a substrate of cysteine-rich phytochelatins (γ-Glu-Cys2–11-Gly (PCs. Phytochelatins react with heavy metal ions by glutathione S-transferase in the cytosol and afterwards they are sequestered into the vacuole for degradation. Furthermore, heavy metals induce reactive oxygen species (ROS, which directly or indirectly influence metabolic processes. Reduced glutathione (GSH attributes as an antioxidant and participates to control ROS during stress. Maintenance of the GSH/GSSG ratio is important for cellular redox balance, which is crucial for the survival of the plants. In this context, sulfurtransferases (Str, also called rhodaneses, comprise a group of enzymes widely distributed in all phyla, paving the way for the transfer of a sulfur atom from suitable sulfur donors to nucleophilic sulfur acceptors, at least in vitro. The best characterized in vitro reaction is the transfer of a sulfane sulfur atom from thiosulfate to cyanide, leading to the formation of sulfite and thiocyanate. Plants as well as other organisms have multi-protein families (MPF of Str. Despite the presence of Str activities in many living organisms, their physiological role has not been clarified unambiguously. In mammals, these proteins are involved in the elimination of cyanide released from cyanogenic compounds. However, their ubiquity suggests additional physiological functions. Furthermore, it is speculated that a member of the Str family acts as arsenate reductase (AR and is involved in arsenate detoxification. In summary, the role of Str in detoxification processes is still not well understood but seems to be a major function in the organism.

  20. Recirculation effect of Chilean copper smelting dust with high impurities contents on the impurity distributions during smelting process; Efecto de la recirculacion de polvo de fundicion de cobre de Chile con altos contenidos de impurezas en la distribucion de impurezas durante el proceso de fusion

    Energy Technology Data Exchange (ETDEWEB)

    Montenegro, V.; Sano, H.; Fujisawa, T.

    2010-07-01

    Usually, dust generated during the copper smelting process by the Teniente Converter and the Flash Smelting Furnaces in Chile, contains high concentrations of copper, zinc, arsenic, antimony and other metals. In general, the dust is recirculated to the smelting process or it is directed to hydrometallurgical process for recovery and stabilization. However, in recent years the generation of dust has increased because of the degradation of the quality of the concentrate. In addition, the environmental regulations have become stricter. It is therefore desirable to understand the behavior of those elements, when the smelting process operates with recirculation of dust. In this study, the effect of dust recirculation to smelting process on the distribution among the matte, slag and gas phases was evaluated, as a function of matte grade, amount of recirculated dust, oxygen enrichment and temperature. It was found that the concentration in the matte of the impurities such as arsenic, antimony and bismuth, increased slightly with recirculation of dust. On the other hand, the concentration of lead and zinc depend of the direct recirculation of dust to the process. Additionally, it was found that high concentrations of arsenic and antimony in the dust may lead to the formation and precipitation of copper arsenates and other metals (speiss), which may generates important operational problems. (Author) 15 refs.

  1. Surface characteristics, copper release, and toxicity of nano- and micrometer-sized copper and copper(II) oxide particles: a cross-disciplinary study.

    OpenAIRE

    Midander, Klara; Cronholm, Pontus; Karlsson, Hanna L.; Elihn, Karine; Moller, Lennart; Leygraf, Christofer; Wallinder, Inger Odnevall

    2009-01-01

    An interdisciplinary and multianalytical research effort is undertaken to assess the toxic aspects of thoroughly characterized nano- and micrometer-sized particles of oxidized metallic copper and copper(II) oxide in contact with cultivated lung cells, as well as copper release in relevant media. All particles, except micrometer-sized Cu, release more copper in serum-containing cell medium (supplemented Dulbecco's minimal essential medium) compared to identical exposures in phosphate-buffered ...

  2. Synthesis of calix[4]arene-grafted magnetite nanoparticles and Evaluation of their arsenate as well as dichromate removal efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Sayin, Serkan; Ozcan, Fatih; Yilmaz, Mustafa; Cengeloglu, Yunus [Department of Chemistry, Selcuk University, Konya (Turkey); Tor, Ali [Department of Environmental Engineering, Selcuk University, Konya (Turkey); Memon, Shahabuddin [National Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro (Pakistan)

    2010-07-15

    In this study, 5,17-bis-[(4-benzylpiperidine)methyl]-25,26,27,28-tetrahydroxy-calix[4]arene (3) has been prepared by the treatment of calix[4]arene with a secondary amine (4-benzylpiperidine) and formaldehyde by means of Mannich reaction. The prepared Mannich base (3) has been grafted onto [3-(2,3-epoxypropoxy)-propyl]-trimethoxysilane-modified Fe{sub 3}O{sub 4} magnetite nanoparticles (EPPTMS-MN) in order to obtain 5,17-bis-[(4-benzylpiperidine)methyl]-25,26,27,28-tetrahydroxy calix[4]arene-grafted EPPTMS-MN (BP-calix[4]arene-grafted Fe{sub 3}O{sub 4}). All new compounds were characterized by a combination of FTIR and {sup 1}H-NMR analyses. The morphology of the magnetic nanoparticles was examined by transmission electron microscopy. Moreover, the studies regarding the removal of arsenate and dichromate ions from the aqueous solutions were also carried out by using 5,17-bis-[(4-benzylpiperidine)methyl]-25,26,27,28-tetrahydroxy-calix[4]arene in liquid-liquid extraction and BP-calix[4]arene-grafted Fe{sub 3}O{sub 4} (4) in solid-liquid extraction experiments. The extraction results indicated that 3 is protonated at proton-switchable binding sites in acidic conditions. Hence, facilitating binding of arsenate and dichromate is resulted from both electrostatic interactions and hydrogen bonding. To understand the selectivity of 3, the retention of dichromate anions in the presence of Cl{sup -}, NO{sub 3}{sup -}, and SO{sub 4}{sup 2-} anions at pH 1.5 was also examined. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  3. Mechanochemical Effects on the Synthesis of Copper Orthophosphate and cyclo-Tetraphosphate Bulks by the Hydrothermal Hot Pressing Method

    Directory of Open Access Journals (Sweden)

    Isao Tanaka

    2009-01-01

    Full Text Available Copper orthophosphate, Cu3(PO42, and cyclo-tetraphosphates, Cu2P4O12, were synthesized using phosphoric acid and basic copper carbonate, and then treated with a planetary mill for up to 360 minutes. The un-milled and milled samples were characterized by X-ray diffraction (XRD and Fourier transform infrared (FT-IR spectroscopy. SEM images, particle size distribution, specific surface area, UV-Vis reflectance spectra were also used to evaluate the materials. The un-milled and milled materials were used to fabricate copper phosphate bulks by a hydrothermal hot pressing method. The influence of powder condition on the sintering behavior of the copper phosphates was studied.

  4. Electrochemical in-situ impregnation of wood using a copper nail as source for copper

    DEFF Research Database (Denmark)

    Ottosen, Lisbeth M.; Block, Thomas; Nymark, Morten

    2011-01-01

    A new method for copper impregnation of wood in structures was suggested and tested in laboratory scale with specimen of new pine sapwood. A copper nail and a steel screw were placed in the wood, and an electric direct current field was applied, so the copper nail was anode and the screw...... was cathode. At the anode, copper ions were generated. The copper ions were transported into the wood by electromigration (movement of ions in an applied electric field) towards the cathode, and a volume between the two electrodes was thereby impregnated. Copper also moved to a lesser degree in the opposite...

  5. Decolorization Treatment of Copper Phthalocyanine Textile Dye Wastewater by Electrochemical Methods

    Directory of Open Access Journals (Sweden)

    K. Dermentzis

    2013-01-01

    Full Text Available Electrochemical decolorization and degradation treatment of aqueous copper phthalocyanine reactive dye solutions was comparatively studied by electrocoagulation, electrooxidation and electro-Fenton processes. In the electrocoagulation process with aluminum electrodes the colored aqueous solutions of initial pH 6.4 containing 50 mg L-1 copper phthalocyanine and 6 g L-1 NaCl were treated at applied current densities of 2.5 and 5 mA cm-2. Fast and 100% decolorization was achieved in 4 and 2 minutes of electroprocessing respectively. The indirect electrooxidation process was conducted in acidic electrolyte solutions containing 50 mg L-1 copper phthalocyanine and 6 g L-1 NaCl with Ti/Pt and graphite plate electrodes at the applied current density of 10 mA cm-2. Even after 90 minutes of electrolysis time the dye remained by 23 and 18.8 % respectively undegradable. By the direct and indirect electrooxidation with the same amount of Na2SO4 electrolyte and added H2O2 respectively and using the same electrodes, the copper phthalocyanine dye was not or was only barely degraded respectively. In the electro-Fenton process with Fe electrodes and added amounts of H2O2 at pH 3 and an applied current density of 5 mA/cm2 complete degradation of copper phthalocyanine occurred in 15 minutes.

  6. Distribution of copper, silver and gold during thermal treatment with brominated flame retardants

    International Nuclear Information System (INIS)

    Oleszek, Sylwia; Grabda, Mariusz; Shibata, Etsuro; Nakamura, Takashi

    2013-01-01

    Highlights: • Copper, silver and gold during thermal treatment with brominated flame retardants. • Distribution of copper, silver and gold during thermal processing. • Thermodynamic considerations of the bromination reactions. - Abstract: The growing consumption of electric and electronic equipment results in creating an increasing amount of electronic waste. The most economically and environmentally advantageous methods for the treatment and recycling of waste electric and electronic equipment (WEEE) are the thermal techniques such as direct combustion, co-combustion with plastic wastes, pyrolysis and gasification. Nowadays, this kind of waste is mainly thermally treated in incinerators (e.g. rotary kilns) to decompose the plastics present, and to concentrate metals in bottom ash. The concentrated metals (e.g. copper, precious metals) can be supplied as a secondary raw material to metal smelters, while the pyrolysis of plastics allows the recovery of fuel gases, volatilising agents and, eventually, energy. Indeed, WEEE, such as a printed circuit boards (PCBs) usually contains brominated flame retardants (BFRs). From these materials, hydrobromic acid (HBr) is formed as a product of their thermal decomposition. In the present work, the bromination was studied of copper, silver and gold by HBr, originating from BFRs, such as Tetrabromobisphenol A (TBBPA) and Tetrabromobisphenol A-Tetrabromobisophenol A diglycidyl ether (TTDE) polymer; possible volatilization of the bromides formed was monitored using a thermo-gravimetric analyzer (TGA) and a laboratory-scale furnace for treating samples of metals and BFRs under an inert atmosphere and at a wide range of temperatures. The results obtained indicate that up to about 50% of copper and silver can evolve from sample residues in the form of volatile CuBr and AgBr above 600 and 1000 °C, respectively. The reactions occur in the molten resin phase simultaneously with the decomposition of the brominated resin. Gold is

  7. Copper metabolism: a multicompartmental model of copper kinetics in the rat

    International Nuclear Information System (INIS)

    Dunn, M.A.

    1985-01-01

    A qualitative multicompartmental model was developed that describes the whole-body kinetics of copper metabolism in the adult rat. The model was developed from radiocopper percent dose vs. time data measured over a three day period in plasma, liver, skin, skeletal muscle, bile and feces after the intravenous injection of 10 μg copper labeled with 64 Cu. Plasma radiocopper was separated into ceruloplasmin (Cp) and nonceruloplasmin (NCp) fractions. Liver cytosolic radiocopper was fractionated into void volume superoxide dismutase (SOD) containing and metallothionein fractions by gel filtration. Liver particulate fractions were isolated by differential centrifugation. The SAAM and CONSAM modeling programs were used to develop the model. The sizes of compartments, fractional rate constants and mass transfer rates between compartments were evaluated. The intracellular metabolism of copper was similar in hepatic and extrahepatic tissues being comprised of a faster turning over compartment (FTC) exchanging copper with NCp and a slower turning over compartment (STC) with input from Cp. Output from the STC was into the FTC. In the liver the STC was postulated to represent SOD copper which unlike the extrahepatic tissues received much of its input from the FTC. A small amount of biliary copper (9%) was postulated to return to plasma NCp by enterohepatic recycling. The model developed was contrasted and compared with two previous models of copper metabolism

  8. Potential phytoextraction and phytostabilization of perennial peanut on copper-contaminated vineyard soils and copper mining waste.

    Science.gov (United States)

    Andreazza, Robson; Bortolon, Leandro; Pieniz, Simone; Giacometti, Marcelo; Roehrs, Dione D; Lambais, Mácio R; Camargo, Flávio A O

    2011-12-01

    This study sought to evaluate the potential of perennial peanut (Arachis pintoi) for copper phytoremediation in vineyard soils (Inceptisol and Mollisol) contaminated with copper and copper mining waste. Our results showed high phytomass production of perennial peanut in both vineyard soils. Macronutrient uptakes were not negatively affected by perennial peanut cultivated in all contaminated soils. Plants cultivated in Mollisol showed high copper concentrations in the roots and shoots of 475 and 52 mg kg(-1), respectively. Perennial peanut plants showed low translocation factor values for Cu, although these plants showed high bioaccumulation factor (BCF) for both vineyard soils, Inceptisol and Mollisol, with BCF values of 3.83 and 3.24, respectively, being characterized as a copper hyperaccumulator plant in these soils. Copper phytoextraction from Inceptisol soil was the highest for both roots and entire plant biomass, with more than 800 mg kg(-1) of copper in whole plant. The highest potential copper phytoextraction by perennial peanut was in Inceptisol soil with copper removal of 2,500 g ha(-1). Also, perennial peanut showed high potential for copper phytoremoval in copper mining waste and Mollisol with 1,700 and 1,500 g of copper per hectare, respectively. In addition, perennial peanuts characterized high potential for phytoextraction and phytostabilization of copper in vineyard soils and copper mining waste.

  9. Renal cortex copper concentration in acute copper poisoning in calves

    Directory of Open Access Journals (Sweden)

    Luis E. Fazzio

    2012-01-01

    Full Text Available The aim of this study was to estimate the diagnostic value of renal cortex copper (Cu concentration in clinical cases of acute copper poisoning (ACP. A total of 97 calves that died due to subcutaneous copper administration were compiled in eleven farms. At least, one necropsy was conducted on each farm and samples for complementary analysis were taken. The degree of autolysis in each necropsy was evaluated. The cases appeared on extensive grazing calf breeding and intensive feedlot farms, in calves of 60 to 200 kg body weight. Mortality varied from 0.86 to 6.96 %, on the farms studied. The first succumbed calf was found on the farms between 6 and 72 hours after the susbcutaneous Cu administration. As discrepancies regarding the reference value arose, the local value (19.9 parts per million was used, confirming the diagnosis of acute copper poisoning in 93% of the analyzed kidney samples. These results confirm the value of analysis of the cortical kidney Cu concentration for the diagnosis of acute copper poisoning.

  10. Prenatal treatment of mosaic mice (Atp7a mo-ms) mouse model for Menkes disease, with copper combined by dimethyldithiocarbamate (DMDTC)

    DEFF Research Database (Denmark)

    Lenartowicz, Małgorzata; Krzeptowski, Wojciech; Koteja, Paweł

    2012-01-01

    Menkes disease is a fatal neurodegenerative disorder in infants caused by mutations in the gene ATP7A which encodes a copper (Cu) transporter. Defects in ATP7A lead to accumulated copper in the small intestine and kidneys and to copper deficiencies in the brain and the liver. The copper level...... and 18 with a combination of CuCl(2) (50 mg/kg) and dimethyldithiocarbamate (DMDTC) (280 mg/kg) leads to an increase in survival to about 76±25.3 days, whereas treatment with CuCl(2) alone (50 mg/kg) only leads to survival for about 21 days ±5 days. These copper-DMDTC treated mutants showed an improved...... locomotor activity performance and a gain in body mass. In contrast to treatment with CuCl(2) alone, a significant increase in the amount of copper was observed in the brain after prenatal copper-DMDTC treatment as well as a decrease in the amount of accumulated copper in the kidney, both leading towards...

  11. Short communication: Efficacy of copper sulfate hoof baths against digital dermatitis--Where is the evidence?

    Science.gov (United States)

    Thomsen, Peter T

    2015-04-01

    Digital dermatitis is a major problem in modern dairy production because of decreased animal welfare and financial losses. Individual cow treatments are often seen as too time consuming by farmers, and walk-through hoof baths have therefore been used extensively to control digital dermatitis. For decades, copper sulfate hoof baths have been used to treat and prevent digital dermatitis. Copper sulfate has been referred to as the industry gold standard when it comes to hoof-bath chemicals. In several scientific studies testing the efficacy of other hoof-care products, copper sulfate has been used as a positive control, thereby indicating that copper sulfate has a known positive effect. However, this may not be the case. A dilemma may exist between (1) copper sulfate generally being perceived as being effective against digital dermatitis and (2) a possible lack of well-documented scientific evidence of this effect. The objective of this study was to evaluate the existing scientific literature to determine whether the efficacy of copper sulfate used in hoof baths against digital dermatitis has in fact been demonstrated scientifically. A systematic literature search identified 7 peer-reviewed journal articles describing the efficacy of copper sulfate in hoof baths as treatment or prevention of bovine digital dermatitis. Only 2 of the 7 studies compared copper sulfate to a negative control; most studies were relatively small, and often no clear positive effect of copper sulfate was demonstrated. In conclusion, the frequent claim that copper sulfate is widely reported to be effective is supported by little scientific evidence. Well-designed clinical trials evaluating the effect of copper sulfate against digital dermatitis compared with a negative control are needed. Until such studies have been made, the efficacy of copper sulfate in hoof baths against digital dermatitis remains largely unproven. Copyright © 2015 American Dairy Science Association. Published by Elsevier

  12. Full densification of inkjet-printed copper conductive tracks on a flexible substrate utilizing a hydrogen plasma sintering

    Science.gov (United States)

    Kwon, Young-Tae; Lee, Young-In; Kim, Seil; Lee, Kun-Jae; Choa, Yong-Ho

    2017-02-01

    Low temperature sintering techniques are crucial in developing flexible printed electronics. In this work, we demonstrate a novel hydrogen plasma sintering method that achieves a full reduction and densification of inkjet-printed patterns using a copper complex ion ink. After inkjet printing on polyethylene terephthalate (PET) substrates, both hydrogen plasma and conventional hydrogen thermal treatment were employed to compare the resulting microstructures, electrical properties and anti-oxidation behavior. The plasma treated pattern shows a fully densified microstructure with a resistivity of 3.23 μΩ cm, while the thermally treated pattern shows a relatively poor microstructure and high resistivity. In addition, the hydrogen plasma-treated copper pattern retains its electrical resistivity for one month without any significant decrease. This novel hydrogen plasma sintering technique could be used to produce conductive patterns with excellent electrical properties, allowing for highly reliable flexible printed electronics.

  13. SORPTION OF ARSENATE AND ARSENITE ON RUO2 X H2O: ANALYSIS OF SORBED PHASE OXIDATION STATE BY XANES IN ADVANCED PHOTON SOURCE ACTIVITY REPORT 2002

    Science.gov (United States)

    The sorption reactions of arsenate (As(V)) and arsenite (As(III)) on RuO2 x H2O were examined by X-ray Absorption Near Edge Spectroscopy (XANES) to elucidate the solid state speciation of sorbed As. At all pH values studied (pH 4-8), RuO2 x H

  14. Preparation of copper and silicon/copper powders by a gas ...

    Indian Academy of Sciences (India)

    Administrator

    aCentre for Materials Research, Department of Imaging and Applied Physics, ... Copper powder; Si/Cu composite particle; gas evaporation–condensation method; characteriza- tion. .... from the liquid metal surface, the mixed vapour of copper.

  15. Posttranslational regulation of copper transporters

    NARCIS (Netherlands)

    van den Berghe, P.V.E.

    2009-01-01

    The transition metal copper is an essential cofactor for many redox-active enzymes, but excessive copper can generate toxic reactive oxygen species. Copper homeostasis is maintained by highly conserved proteins, to balance copper uptake, distribution and export on the systemic and cellular level.

  16. RECYCLING OF SCRAP AND WASTE OF COPPER AND COPPER ALLOYS IN BELARUS

    Directory of Open Access Journals (Sweden)

    S. L. Rovin

    2017-01-01

    Full Text Available The construction of a new casting and mechanical shop of unitary enterprise «Tsvetmet» in December 2015 has allowed to solve the complex problem of processing and utilization of scrap and wastes of copper and copper alloys in the Republic of Belarus. The technological processes of fire refinement of copper and manufacturing of copper rod from scrap and production of brass rod by hot pressing (extrusion of the continuously casted round billet have been mastered for the first time in the Republic of Belarus.

  17. Demystifying Controlling Copper Corrosion

    Science.gov (United States)

    The LCR systematically misses the highest health and corrosion risk sites for copper. Additionally, there are growing concerns for WWTP copper in sludges and discharge levels. There are many corrosion control differences between copper and lead. This talk explains the sometimes c...

  18. Copper Bioleaching in Chile

    OpenAIRE

    Juan Carlos Gentina; Fernando Acevedo

    2016-01-01

    Chile has a great tradition of producing and exporting copper. Over the last several decades, it has become the first producer on an international level. Its copper reserves are also the most important on the planet. However, after years of mineral exploitation, the ease of extracting copper oxides and ore copper content has diminished. To keep the production level high, the introduction of new technologies has become necessary. One that has been successful is bioleaching. Chile had the first...

  19. Hazard evaluation of inorganics, singly and in mixtures, to Flannelmouth Sucker Catostomus latipinnis in the San Juan River, New Mexico

    Science.gov (United States)

    Hamilton, S.J.; Buhl, K.J.

    1997-01-01

    Larval flannelmouth sucker (Catostomus latipinnis) were exposed to arsenate, boron, copper, molybdenum, selenate, selenite, uranium, vanadium, and zinc singly, and to five mixtures of five to nine inorganics. The exposures were conducted in reconstituted water representative of the San Juan River near Shiprock, New Mexico. The mixtures simulated environmental ratios reported for sites along the San Juan River (San Juan River backwater, Fruitland marsh, Hogback East Drain, Mancos River, and McElmo Creek). The rank order of the individual inorganics, from most to least toxic, was: copper > zinc > vanadium > selenite > selenate > arsenate > uranium > boron > molybdenum. All five mixtures exhibited additive toxicity to flannelmouth sucker. In a limited number of tests, 44-day-old and 13-day-old larvae exhibited no difference in sensitivity to three mixtures. Copper was the major toxic component in four mixtures (San Juan backwater, Hogback East Drain, Mancos River, and McElmo Creek), whereas zinc was the major toxic component in the Fruitland marsh mixture, which did not contain copper. The Hogback East Drain was the most toxic mixture tested. Comparison of 96-h LC50values with reported environmental water concentrations from the San Juan River revealed low hazard ratios for arsenic, boron, molybdenum, selenate, selenite, uranium, and vanadium, moderate hazard ratios for zinc and the Fruitland marsh mixture, and high hazard ratios for copper at three sites and four environmental mixtures representing a San Juan backwater, Hogback East Drain, Mancos River, and McElmo Creek. The high hazard ratios suggest that inorganic contaminants could adversely affect larval flannelmouth sucker in the San Juan River at four sites receiving elevated inorganics.

  20. The copper-transporting ATPase pump and its potential role in copper-tolerance

    Science.gov (United States)

    Katie Ohno; C.A. Clausen; Frederick Green; G. Stanosz

    2016-01-01

    Copper-tolerant brown-rot decay fungi exploit intricate mechanisms to neutralize the efficacy of copper-containing preservative formulations. The production and accumulation oxalate is the most widely recognized theory regarding the mechanism of copper-tolerance in these fungi. The role of oxalate, however, may be only one part of a series of necessary components...