WorldWideScience

Sample records for mercury perchlorates

  1. Mercury

    International Nuclear Information System (INIS)

    Vilas, F.; Chapman, C.R.; Matthews, M.S.

    1988-01-01

    Papers are presented on future observations of and missions to Mercury, the photometry and polarimetry of Mercury, the surface composition of Mercury from reflectance spectrophotometry, the Goldstone radar observations of Mercury, the radar observations of Mercury, the stratigraphy and geologic history of Mercury, the geomorphology of impact craters on Mercury, and the cratering record on Mercury and the origin of impacting objects. Consideration is also given to the tectonics of Mercury, the tectonic history of Mercury, Mercury's thermal history and the generation of its magnetic field, the rotational dynamics of Mercury and the state of its core, Mercury's magnetic field and interior, the magnetosphere of Mercury, and the Mercury atmosphere. Other papers are on the present bounds on the bulk composition of Mercury and the implications for planetary formation processes, the building stones of the planets, the origin and composition of Mercury, the formation of Mercury from planetesimals, and theoretical considerations on the strange density of Mercury

  2. Adeninium perchlorate

    Directory of Open Access Journals (Sweden)

    Hoong-Kun Fun

    2011-02-01

    Full Text Available In the title salt (systematic name: 6-amino-9H-purin-1-ium perchlorate, C5H6N5+·ClO4−, the adeninium cation is essentially planar, with a maximum deviation of 0.038 (1 Å. The whole of the perchlorate anion is disordered over two sets of sites with an occupancy ratio of 0.589 (13:0.411 (13. In the crystal, the adeninium cations are linked by pairs of N—H...N hydrogen bond into inversion dimers. The dimers and the anions are further interconnected into a three-dimensional supramolecular structure via intermolecular N—H...O, C—H...O and C—H...N hydrogen bonds.

  3. Mercury

    NARCIS (Netherlands)

    de Vries, Irma

    2017-01-01

    Mercury is a naturally occurring metal that exists in several physical and chemical forms. Inorganic mercury refers to compounds formed after the combining of mercury with elements such as chlorine, sulfur, or oxygen. After combining with carbon by covalent linkage, the compounds formed are called

  4. Mercury

    Science.gov (United States)

    ... build up in fish, shellfish, and animals that eat fish. The nervous system is sensitive to all forms of mercury. Exposure to high levels can damage the brain and kidneys. Pregnant women can pass the mercury in their bodies to their babies. It is important to protect your family from ...

  5. Mercury

    Science.gov (United States)

    ... has set a limit of 2 parts of mercury per billion parts of drinking water (2 ppb). The Food and Drug Administration (FDA) has set a maximum permissible level of 1 part of methylmercury in a million ... of 0.1 milligram of organic mercury per cubic meter of workplace air (0.1 ...

  6. Perchlorate isotope forensics

    Science.gov (United States)

    Böhlke, J.K.; Sturchio, N.C.; Gu, B.; Horita, J.; Brown, G.M.; Jackson, W.A.; Batista, J.; Hatzinger, P.B.

    2005-01-01

    Perchlorate has been detected recently in a variety of soils, waters, plants, and food products at levels that may be detrimental to human health. These discoveries have generated considerable interest in perchlorate source identification. In this study, comprehensive stable isotope analyses ( 37Cl/35Cl and 18O/17O/ 16O) of perchlorate from known synthetic and natural sources reveal systematic differences in isotopic characteristics that are related to the formation mechanisms. In addition, isotopic analyses of perchlorate extracted from groundwater and surface water demonstrate the feasibility of identifying perchlorate sources in contaminated environments on the basis of this technique. Both natural and synthetic sources of perchlorate have been identified in water samples from some perchlorate occurrences in the United States by the isotopic method. ?? 2005 American Chemical Society.

  7. Mercury

    CERN Document Server

    Balogh, André; Steiger, Rudolf

    2008-01-01

    Mercury, the planet closest to the Sun, is different in several respects from the other three terrestrial planets. In appearance, it resembles the heavily cratered surface of the Moon, but its density is high, it has a magnetic field and magnetosphere, but no atmosphere or ionosphere. This book reviews the progress made in Mercury studies since the flybys by Mariner 10 in 1974-75, based on the continued research using the Mariner 10 archive, on observations from Earth, and on increasingly realistic models of its interior evolution.

  8. Perchlorate in seawater

    International Nuclear Information System (INIS)

    Martinelango, P. Kalyani; Tian Kang; Dasgupta, Purnendu K.

    2006-01-01

    There has been no reliable published data on the presence of perchlorate in seawater. Seaweeds are among the most important plant life in the ocean and are good sources of iodine and have been widely used as food and nutritional supplement. Perchlorate is known to inhibit the transport of iodide by the sodium iodide symporter (NIS), present e.g., in the thyroid and mammary glands. With perchlorate being increasingly detected in drinking water, milk and various other foods, increasing the iodide intake through inexpensive natural supplements may be an attractive solution for maintaining iodine assimilation. We report here measurable concentrations of perchlorate in several samples of seawater (detectable in about half the samples analyzed). We also report the iodide and perchlorate concentrations of 11 different species of seaweed and the corresponding bioconcentration factors (BCF) for perchlorate and iodide, relative to the seawater from which they were harvested. All seaweed samples came from the same region, off the coast of Northeastern Maine. Concentrations of iodide and perchlorate in four seawater samples collected from the region near harvest time were 30 ± 11 and 0.16 ± 0.084 μg l -1 , respectively. Concentrations of both iodide and perchlorate varied over a wide range for different seaweed species; iodide ranging from 16 to 3134 mg kg -1 and perchlorate from 0.077 to 3.2 mg kg -1 . The Laminaria species had the highest iodide concentration; Laminaria digitata is the seaweed species most commonly used in the kelp tablets sold in health food stores. Our sample of L. digitata contained 3134 ± 15 mg iodide/kg dry weight. The BCF varied widely for different species, with Laminaria species concentrating iodide preferentially over perchlorate. The iodide BCF (BCF i ) to perchlorate BCF (BCF p ) quotient ranged from 0.66 to 53; L. digitata and L. saccarina having a BCF i /BCF p value of 45 and 53, respectively, far greater than a simple anion exchange process

  9. Widespread Occurrence of Plant Perchlorate

    Science.gov (United States)

    Harvey, G.; Orris, G.; Jackson, W. A.; Rajagopalan, S.; Andraski, B.; Stonestrom, D.

    2007-12-01

    Perchlorate is a water soluble oxyanion containing four oxygens bonded to a single chlorine atom. High concentration of perchlorate can competitively block the uptake of iodide by the sodium iodide symporter and disrupt thyroid function. Due to this ability to potentially impair thyroid function, perchlorate in environmental exposure pathways has been of concern for more than a decade. Our knowledge of the spatial and temporal aspects of environmental perchlorate has increased dramatically in the past few years. To date, perchlorate has been found in numerous different environmental media, including water, soils and sediments, and plants, from many parts of the world. Perchlorate can be found in marine alage, food and plant samples from Asia, Africa, Europe, North and South America. It is becoming increasingly apparent that perchlorate in low levels is ubiquitous. Perchlorate has been found in several different carbon age-dated water and midden samples that pre-date the industrial age and agricultural use of Chilean nitrate fertilizers by thousands of years. While anthropogenic sources of perchlorate exist, the accumulating spatial and temporal evidence suggests that perchlorate must have a significant natural source. This natural source of perchlorate under the appropriate geochemical and climatic conditions is contributing a natural background level of perchlorate. Concentrations of perchlorate in soils appears to be influenced by soil geochemistry. Soils with low organic content usually have higher levels of perchlorate then soils with abundant organic matter. High levels of perchlorate have been found in remotely located xerophytes growing in aridosols and in deciduous phreatophytes growing in humid densely populated areas. Often the amount of perchlorate in a plant cannot be explained by the amount of perchlorate in either the soil or precipitation. Investigations into the relative source contribution of lithogenic, atmospheric and other sources and mechanisms

  10. Perchlorate Questions and Answers

    Science.gov (United States)

    ... 280 types of foods, including 40 types of baby food, every year from different parts of the country. ... perchlorate at the levels present in water and foods. However, you should discuss ... for a baby's normal brain development, so it is particularly important ...

  11. Ammonium Perchlorate and Ammonium Perchlorate- Hydroxyl Terminated Polybutadiene Simulated Combustion

    Directory of Open Access Journals (Sweden)

    Rene Francisco Boschi Gonçalves

    2012-03-01

    Full Text Available The combustion simulation of ammonium perchlorate was carried out with the software Chemkin, in two steps: the burning behavior of pure ammonium perchlorate and the one of formulated ammonium perchlorate with hydroxyl terminated polybutadiene binder. In both cases, the room pressure varied in order to verify its influence in the system. The burning environment conditions were diverse. During the combustion process, the data obtained from the kinetic chemistry simulation software were compiled. The flame structure can be described by the molar fraction of the burning products and the temperature evolution from the surface of the material.

  12. The determination of perchlorates in ventilation systems

    Energy Technology Data Exchange (ETDEWEB)

    Stewart, Jr, J H; Mueller, T R; Moore, M L; Bader, M; Haskew, M W; Phillips, C C; Vick, D O; Jerome, B A

    1992-01-01

    A methylene blue test is described which provides a rapid screening test for a rough estimate of the amount of perchlorate in a sample. This test can detect perchlorate concentrations in excess of 750 ppm.

  13. Perchlorate Reduction by Yeast for Mars Exploration

    Science.gov (United States)

    Sharma, Alaisha

    2015-01-01

    Martian soil contains high levels (0.6 percentage by mass) of calcium perchlorate (Ca(ClO4)2), which readily dissociates into calcium and the perchlorate ion (ClO4-) in water. Even in trace amounts, perchlorates are toxic to humans and have been implicated in thyroid dysfunction. Devising methods to lessen perchlorate contamination is crucial to minimizing the health risks associated with human exploration and colonization of Mars. We designed a perchlorate reduction pathway, which sequentially reduces perchlorate to chloride (Cl-) and oxygen (O2), for implementation in the yeast Saccharomyces cerevisiae. Using genes obtained from perchlorate reducing bacteria Azospira oryzae and Dechloromonas aromatica, we plan to assemble this pathway directly within S. cerevisiae through recombinational cloning. A perchlorate reduction pathway would enable S. cerevisiae to lower perchlorate levels and produce oxygen, which may be harvested or used directly by S. cerevisiae for aerobic growth and compound synthesis. Moreover, using perchlorate as an external electron acceptor could improve the efficiency of redox-imbalanced production pathways in yeast. Although several perchlorate reducing bacteria have been identified and utilized in water treatment systems on Earth, the widespread use of S. cerevisiae as a synthetic biology platform justifies the development of a perchlorate reducing strain for implementation on Mars.

  14. Perchlorate: environmental occurrence, interactions and treatment

    National Research Council Canada - National Science Library

    Gu, Baohua, Ph. D; Coates, John D

    2006-01-01

    ..... ... . ... .. ... .. ... . ... ... .. . . . . , . , . , .. ... ... .. 14 Chapter 2. The Chemistry of Perchlorate in the Environment Gilbert M Brown and Baohua Gu Introduction ... 17 Redox Properties of Chlorine Compounds ... 18...

  15. Jarosite dissolution rates in perchlorate brine

    Science.gov (United States)

    Legett, Carey; Pritchett, Brittany N.; Elwood Madden, Andrew S.; Phillips-Lander, Charity M.; Elwood Madden, Megan E.

    2018-02-01

    Perchlorate salts and the ferric sulfate mineral jarosite have been detected at multiple locations on Mars by both landed instruments and orbiting spectrometers. Many perchlorate brines have eutectic temperatures <250 K, and may exist as metastable or stable liquids for extended time periods, even under current Mars surface conditions. Therefore, jarosite-bearing rocks and sediments may have been altered by perchlorate brines. Here we measured jarosite dissolution rates in 2 M sodium perchlorate brine as well as dilute water at 298 K to determine the effects of perchlorate anions on jarosite dissolution rates and potential reaction products. We developed a simple method for determining aqueous iron concentrations in high salinity perchlorate solutions using ultraviolet-visible spectrophotometry that eliminates the risk of rapid oxidation reactions during analyses. Jarosite dissolution rates in 2 M perchlorate brine determined by iron release rate (2.87 × 10-12 ±0.85 × 10-12 mol m-2 s-1) were slightly slower than the jarosite dissolution rate measured in ultrapure (18.2 MΩ cm-1) water (5.06 × 10-12 mol m-2 s-1) using identical methods. No additional secondary phases were observed in XRD analyses of the reaction products. The observed decrease in dissolution rate may be due to lower activity of water (ɑH2O = 0.9) in the 2 M NaClO4 brine compared with ultrapure water (ɑH2O = 1). This suggests that the perchlorate anion does not facilitate iron release, unlike chloride anions which accelerated Fe release rates in previously reported jarosite and hematite dissolution experiments. Since dissolution rates are slower in perchlorate-rich solutions, jarosite is expected to persist longer in perchlorate brines than in dilute waters or chloride-rich brines. Therefore, if perchlorate brines dominate aqueous fluids on the surface of Mars, jarosite may remain preserved over extended periods of time, despite active aqueous processes.

  16. Novel biomarkers of perchlorate exposure in zebrafish

    Science.gov (United States)

    Mukhi, S.; Carr, J.A.; Anderson, T.A.; Patino, R.

    2005-01-01

    Perchlorate inhibits iodide uptake by thyroid follicles and lowers thyroid hormone production. Although several effects of perchlorate on the thyroid system have been reported, the utility of these pathologies as markers of environmental perchlorate exposures has not been adequately assessed. The present study examined time-course and concentration-dependent effects of perchlorate on thyroid follicle hypertrophy, colloid depletion, and angiogenesis; alterations in whole-body thyroxine (T4) levels; and somatic growth and condition factor of subadult and adult zebrafish. Changes in the intensity of the colloidal T4 ring previously observed in zebrafish also were examined immunohistochemically. Three-month-old zebrafish were exposed to ammonium perchlorate at measured perchlorate concentrations of 0, 11, 90, 1,131, and 11,480 ppb for 12 weeks and allowed to recover in clean water for 12 weeks. At two weeks of exposure, the lowest-observed-effective concentrations (LOECs) of perchlorate that induced angiogenesis and depressed the intensity of colloidal T4 ring were 90 and 1,131 ppb, respectively; other parameters were not affected (whole-body T4 was not determined at this time). At 12 weeks of exposure, LOECs for colloid depletion, hypertrophy, angiogenesis, and colloidal T4 ring were 11,480, 1,131, 90, and 11 ppb, respectively. All changes were reversible, but residual effects on angiogenesis and colloidal T4 ring intensity were still present after 12 weeks of recovery (LOEC, 11,480 ppb). Whole-body T 4 concentration, body growth (length and weight), and condition factor were not affected by perchlorate. The sensitivity and longevity of changes in colloidal T4 ring intensity and angiogenesis suggest their usefulness as novel markers of perchlorate exposure. The 12-week LOEC for colloidal T4 ring is the lowest reported for any perchlorate biomarker in aquatic vertebrates. ?? 2005 SETAC.

  17. Background Perchlorate Source Identification Technical Guidance

    Science.gov (United States)

    2013-12-01

    descriptions of the state of the science assessment in Section 2, and also applied to a case study in Section 4. iv Benefit to the Navy While...component for some fertilizers for alfalfa and clover (Lefond, 1975). Atmospheric Formation While the exact mechanism for the creation of perchlorate is...chlorate or chlorine manufacture (GeoSyntec Consultants, 2005). Descriptions of these sources follow. Fireworks Perchlorate is a major component of

  18. The Microbiology of Perchlorate in the Environment

    Science.gov (United States)

    Coates, J. D.

    2007-12-01

    In the last decade perchlorate has been identified as an important groundwater component that poses potential health threat. Although primarily sourced anthropogenically, many recent studies have identified significant natural pools throughout the US and the natural mechanisms of its synthesis remain a mystery. As such, the true perchlorate concentrations naturally present in the environment are still unknown making its regulation problematic. Because of its solubility and non-reactivity the fate and transport of perchlorate in the environment is primarily a function of microbial activity. In the last seven years more than forty specialized perchlorate respiring organisms have been identified and characterized. These dissimilatory perchlorate reducing bacteria (DPRB) are metabolically diverse and environmental populations tend to be dominated by two primary genotypes, the Dechloromonas and the Azospira species. As such, the majority of our understanding of this metabolism is based on these organisms. These organisms are readily found in soil and sedimentary environments and often associate with the rhizosphere. Recent research has demonstrated an accumulation of these organisms along plant roots suggesting their catabolism of root exudates and molecular studies has demonstrated their existence as endophytic infections of the stem and leaves of actively growing Brachypodium grass plants although their exact role under these conditions is unknown. These microorganisms are generally not nutritionally fastidious and vitamin supplementation is unnecessary for growth although molybdenum is a required trace element for perchlorate reduction. The Dechloromonas and Azospira species generally grow optimally at pH values near neutrality in freshwater environments. Even so, recent field studies have shown that related deep-branching members of these genera often predominate in sites of adverse pH or salinity with some species being capable of growth and perchlorate respiration

  19. A Colorimetric Bioassay for Perchlorate

    Science.gov (United States)

    Heinnickel, M. L.; Smith, S.; Coates, J. D.

    2007-12-01

    Recognition of perchlorate (ClO4-) as a widespread contaminant across the United States and its potential adverse affects towards human health has motivated the EPA to place ClO4- on its contaminant candidate list for drinking water supplies. While a federal MCL has not yet been set, a recommended public health goal of 1 ppb (μg.L-1) was established by the US EPA in 2002. To date, methods of detection require use of sensitive ion chromatographic equipment that are expensive, time consuming, and require highly trained personnel for use. Our studies are focused on the development of a highly sensitive, simple, and robust colorimetric bioassay based on the primary enzyme involved in microbial ClO4- reduction, the perchlorate reductase (Pcr). A previously published assay used reduced methyl viologen (MV, the dye is reduced with sodium hydrosulfite) as an electron donor to demonstrate Pcr activity. The assay directly correlates the amount of MV oxidized with the amount of ClO4- reduced by assuming a transfer of four electrons. To test this assumption, we compared actual concentrations of MV oxidized to ClO4- reduced in this assay. ClO4- concentrations were determined using a Dionex ICS-500 ion chromatography system, while MV concentrations were determined using a standard curve generated at 578 nm. Comparisons between the two revealed that twelve molecules of MV were oxidized for each molecule of ClO4- reduced. The oxidation of these additional eight MV molecules is explained by the interaction of the dye with chlorite (the product of the Pcr reaction) and other contaminants that could be present in the enzyme prep. This unsettling result indicated this assay would be problematic for the detection of ClO4- in soil, which has many chemicals that could react with MV. To improve upon this assay, we have tried to reduce ClO4- using less reactive dyes and reductants. The reductants ascorbic acid, NADH, and dithiothreitol drive Pcr catalyzed ClO4- reduction, however, they

  20. Biodegradation of Perchlorate in Laboratory Reactors Under Different Environmental Conditions

    Science.gov (United States)

    2010-07-01

    Perchlorate Uptake in Lettuce Seedlings . Symposia Papers presented before the Division of Environmental Chemistry, American Chemical Society, New Orleans...CADHS) 2002), throughout Southern California (CADHS 2002), and Western Texas (Christen 2003). Researchers have found perchlorate in lettuce (Hogue 2003...Krieger (2004) revealed that accumulation of perchlorate takes place in some plants, mostly in leafy greens. Studies on lettuce have shown that

  1. Environmental biotechnology and microbiology of (per)chlorate reducing bacteria

    NARCIS (Netherlands)

    Mehboob, F.; Schraa, G.; Stams, A.J.M.

    2011-01-01

    Perchlorates are the salts derived from perchloric acid (HClO4). They occur both naturally and through manufacturing. They have been used as a medicine for more than 50 years to treat thyroid gland disorders and are used extensively within the pyrotechnics industry, and ammonium perchlorate is also

  2. Interaction of perchlorate and trichloroethene bioreductions in mixed anaerobic culture

    Energy Technology Data Exchange (ETDEWEB)

    Wen, Li-Lian [Department of Environmental Engineering, College of Environmental and Resource Science, Zhejiang University, Hangzhou (China); Zhejiang Prov Key Lab Water Pollut Control & Envi, Zhejiang University, Hangzhou, Zhejiang (China); Yang, Qiang [Hangzhou Institute of Environmental Protection Science, Hangzhou (China); Zhang, Zhao-Xin; Yi, Yang-Yi [Department of Environmental Engineering, College of Environmental and Resource Science, Zhejiang University, Hangzhou (China); Tang, Youneng [Department of Civil and Environmental Engineering, FAMU-FSU College of Engineering, Florida State University, Tallahassee, FL 32310-6046 (United States); Zhao, He-Ping, E-mail: zhaohp@zju.edu.cn [Department of Environmental Engineering, College of Environmental and Resource Science, Zhejiang University, Hangzhou (China); Zhejiang Prov Key Lab Water Pollut Control & Envi, Zhejiang University, Hangzhou, Zhejiang (China); Hangzhou Institute of Environmental Protection Science, Hangzhou (China)

    2016-11-15

    This work evaluated the interaction of perchlorate and trichloroethene (TCE), two common co-contaminants in groundwater, during bioreduction in serum bottles containing synthetic mineral salts media and microbial consortia. TCE at concentrations up to 0.3 mM did not significantly affect perchlorate reduction; however, perchlorate concentrations higher than 0.1 mM made the reduction of TCE significantly slower. Perchlorate primarily inhibited the reduction of vinyl chloride (VC, a daughter product of TCE) to ethene. Mechanistic analysis showed that the inhibition was mainly because perchlorate reduction is thermodynamically more favorable than reduction of TCE and its daughter products and not because of toxicity due to accumulation of dissolved oxygen produced during perchlorate reduction. As the initial perchlorate concentration increased from 0 to 600 mg/L in a set of serum bottles, the relative abundance of Rhodocyclaceae (a putatively perchlorate-reducing genus) increased from 6.3 to 80.6%, while the relative abundance of Dehalococcoides, the only known genus that is able to reduce TCE all the way to ethene, significantly decreased. Similarly, the relative abundance of Proteobacteria (a phylum to which most known perchlorate-reducing bacteria belong) increased from 22% to almost 80%. - Graphical abstract: Fig. A plots the interaction of TCE and perchlorate bio-reduction under different concentrations of perchlorate and suggests that initial ethene wasn't formed until the perchlorate was completely reduced. B shows the electron donor utilization and oxygen generated during the experiment and indicates that it is perchlorate reduction over-competed for electron donor rather than oxygen generated that inhibits TCE reductive dechlorination. - Highlight: • Perchlorate slowed but did not inhibit the complete dechlorination of TCE. • The inhibition was mainly due to the thermodynamic preference of perchlorate to TCE. • The generated oxygen was consumed and

  3. Electric conductivity of alkali metal perchlorates

    International Nuclear Information System (INIS)

    Ulikhin, A.S.; Uvarov, N.F.

    2007-01-01

    Ionic conductivity of high-temperature phases of alkali metal perchlorates, MClO 4 , where M stands for Li-Cs, is studied. It is found that the conductivity passes through a minimum with increasing radius of cation, and KClO 4 exhibits the lowest conductivity. This is explained by a decrease in the relative size of conduction channel, which hampers the cation transfer, and an increase in the relative free volume. The free-volume increase promotes the perchlorate anion reorientation and reduces the activation energy for ion transfer by the paddle-wheel mechanism; as a result, the conductivity increases [ru

  4. Mercury and Your Health

    Science.gov (United States)

    ... the Risk of Exposure to Mercury Learn About Mercury What is Mercury What is Metallic mercury? Toxicological Profile ToxFAQs Mercury Resources CDC’s National Biomonitoring Program Factsheet on Mercury ...

  5. Atmospheric origins of perchlorate on Mars and in the Atacama

    Science.gov (United States)

    Catling, D. C.; Claire, M. W.; Zahnle, K. J.; Quinn, R. C.; Clark, B. C.; Hecht, M. H.; Kounaves, S.

    2010-01-01

    Isotopic studies indicate that natural perchlorate is produced on Earth in arid environments by the oxidation of chlorine species through pathways involving ozone or its photochemical products. With this analogy, we propose that the arid environment on Mars may have given rise to perchlorate through the action of atmospheric oxidants. A variety of hypothetical pathways can be proposed including photochemical reactions, electrostatic discharge, and gas-solid reactions. Because perchlorate-rich deposits in the Atacama desert are closest in abundance to perchlorate measured at NASA's Phoenix Lander site, we made a preliminary study of the means to produce Atacama perchlorate to help shed light on the origin of Martian perchlorate. We investigated gas phase pathways using a 1-D photochemical model. We found that perchlorate can be produced in sufficient quantities to explain the abundance of perchlorate in the Atacama from a proposed gas phase oxidation of chlorine volatiles to perchloric acid. The feasibility of gas phase production for the Atacama provides justification for future investigations of gas phase photochemistry as a possible source for Martian perchlorate.

  6. Got Mercury?

    Science.gov (United States)

    Meyers, Valerie E.; McCoy, J. Torin; Garcia, Hector D.; James, John T.

    2009-01-01

    Many of the operational and payload lighting units used in various spacecraft contain elemental mercury. If these devices were damaged on-orbit, elemental mercury could be released into the cabin. Although there are plans to replace operational units with alternate light sources, such as LEDs, that do not contain mercury, mercury-containing lamps efficiently produce high quality illumination and may never be completely replaced on orbit. Therefore, exposure to elemental mercury during spaceflight will remain possible and represents a toxicological hazard. Elemental mercury is a liquid metal that vaporizes slowly at room temperature. However, it may be completely vaporized at the elevated operating temperatures of lamps. Although liquid mercury is not readily absorbed through the skin or digestive tract, mercury vapors are efficiently absorbed through the respiratory tract. Therefore, the amount of mercury in the vapor form must be estimated. For mercury releases from lamps that are not being operated, we utilized a study conducted by the New Jersey Department of Environmental Quality to calculate the amount of mercury vapor expected to form over a 2-week period. For longer missions and for mercury releases occurring when lamps are operating, we conservatively assumed complete volatilization of the available mercury. Because current spacecraft environmental control systems are unable to remove mercury vapors, both short-term and long-term exposures to mercury vapors are possible. Acute exposure to high concentrations of mercury vapors can cause irritation of the respiratory tract and behavioral symptoms, such as irritability and hyperactivity. Chronic exposure can result in damage to the nervous system (tremors, memory loss, insomnia, etc.) and kidneys (proteinurea). Therefore, the JSC Toxicology Group recommends that stringent safety controls and verifications (vibrational testing, etc.) be applied to any hardware that contains elemental mercury that could yield

  7. Perchlorate Exposure and Thyroid Function in Ammonium Perchlorate Workers in Yicheng, China

    Directory of Open Access Journals (Sweden)

    Hongxia Chen

    2014-05-01

    Full Text Available The impact of low level dust on the thyroid function of workers chronically exposed to ammonium perchlorate (AP is uncertain and controversial. The aim of this study was to examine whether workers in China with long-term (>3 years occupational exposure to low levels of AP dust had affected thyroid homeostasis. Mean occupational exposures to AP dust ranged from 0.43 to 1.17 mg/m3. Geometric means of post-shift urinary perchlorate levels were 20.5 µg/L for those exposed and 12.8 µg/L for the controls. No significant differences were found for thyroid function parameters of FT3, FT4, or log TSH or for TPO prevalence or thyroglobulin levels. Additionally, no differences in findings were observed for complete blood count (CBC, serum biochemical profile, or pulmonary function test. Median urinary iodine levels of 172 and 184 µg/L showed that the workers had sufficient iodine intake. This study found no effect on thyroid function from long term, low-level documented exposure to ammonium perchlorate. It is the first study to report both thyroid status parameters and urinary perchlorate, a biomarker of internal perchlorate exposure, in occupationally exposed workers in China.

  8. Basic Information about Mercury

    Science.gov (United States)

    ... Your Environment Contact Us Share Basic Information about Mercury On this page: What is mercury? Emissions of ... Consumer products that traditionally contain mercury What is Mercury? Mercury is a naturally-occurring chemical element found ...

  9. Atmospheric Production of Perchlorate on Earth and Mars

    Science.gov (United States)

    Claire, M.; Catling, D. C.; Zahnle, K. J.

    2009-12-01

    Natural production and preservation of perchlorate on Earth occurs only in arid environments. Isotopic evidence suggests a strong role for atmospheric oxidation of chlorine species via pathways including ozone or its photochemical derivatives. As the Martian atmosphere is both oxidizing and drier than the driest places on Earth, we propose an atmospheric origin for the Martian perchlorates measured by NASA's Phoenix Lander. A variety of hypothetical formation pathways can be proposed including atmospheric photochemical reactions, electrostatic discharge, and gas-solid reactions. Here, we investigate gas phase formation pathways using a 1-D photochemical model (Catling et al. 2009, accepted by JGR). Because perchlorate-rich deposits in the Atacama desert are closest in abundance to perchlorate measured at NASA's Phoenix Lander site, we start with a study of the means to produce Atacama perchlorate. We found that perchlorate can be produced in sufficient quantities to explain the abundance of perchlorate in the Atacama from a proposed gas phase oxidation of chlorine volatiles to perchloric acid. These results are sensitive to estimated reaction rates for ClO3 species. The feasibility of gas phase production for the Atacama provides justification for further investigations of gas phase photochemistry as a possible source for Martian perchlorate. In addition to the Atacama results, we will present a preliminary study incorporating chlorine chemistry into an existing Martian photochemical model (Zahnle et al. JGR 2008).

  10. Wet Deposition of Perchlorate Over the Continental United States

    Science.gov (United States)

    Rajagopalan, S.; Jackson, A. W.; Anderson, T. A.

    2007-12-01

    Natural perchlorate (ClO4-) has been detected in soil, vegetation, food products, and ground and drinking water supplies at various concentrations across the world. For almost a century natural perchlorate has been known to exist in Chilean nitrate deposits that are up to 16 million years old, and recent isotopic evidence has confirmed its source to be predominantly atmospheric. Although the source of natural perchlorate has been attributed to atmospheric deposition, there is almost no data available concerning the deposition rate of perchlorate from precipitation. This research effort, supported by SERDP, was designed to investigate the range of concentrations, and temporal and spatial variations in perchlorate deposition. Sub-samples of precipitation collected through the National Atmospheric Deposition program over a two year period were analyzed for perchlorate. Sample locations included 14 continental states, and Puerto Rico. Perchlorate has been detected (DL= 5 ng/L) in over 65 % of all samples tested with a mean value of 12.60 ± 13.60 ng/L and ranged from 0.5) between ClO4- and other ions (Cl-, NO3-, SO4-2, Na+, K+, Ca+2, Mg+2, and NH4+). Results from this study will have important implications to the national perchlorate issue and may aid in explaining the occurrence of non-anthropogenic perchlorate being reported in arid and semi-arid areas.

  11. Development of a drinking water regulation for perchlorate in California.

    Science.gov (United States)

    Tikkanen, Maria W

    2006-05-10

    Perchlorate is an environmental contaminant often associated with military installations and rocket propellant manufacture and testing facilities across the U.S. Highly water soluble, perchlorate has been found by federal and state agencies at almost 400 sites within the U.S. in groundwater, surface water, soil or public drinking water. There is no federal drinking water standard for perchlorate, but it is on the drinking water Contaminant Candidate List, and falls under the Unregulated Contaminant Monitoring Rule (UCMR) for which monitoring is required. The recent National Academy of Science (NAS) report on the potential health effects of perchlorate recommended a perchlorate reference dose of 0.0007 mg/kg of body weight which would be equivalent to a drinking water concentration of 24.5 microg/L. In California, approximately 395 wells in 96 water systems have been shown to contain perchlorate, and about 90% of these are located in Southern California. Water taken from the Colorado River, a major surface water supply to Southern California, has had reported detections of perchlorate ranging from non-detect to 9 microg/L. California has established a Public Health Goal (PHG) of 6 microg/L for perchlorate, and a proposed drinking water regulation is imminent. This review details the regulatory process involved with particular attention given to the occurrence of perchlorate in California drinking water sources and analytical methodology utilized.

  12. Environmental Screening Assessment of Perchlorate Replacements

    Science.gov (United States)

    2007-08-01

    macroinvertebrates (Table 12). Based on the toxicity values predicted by EPI Suite for the Daphnia species (i.e., LD50 and Lowest Observed Effect Concentrations...tetranitro-1,3,5,7-tetrazocine Koc Organic carbon soil sorption coefficient Kow Octanol water partitioning coefficient LOEC Lowest observed effect ...mobility, persistence, and potential toxicity issues related to perchlorate have high- lighted the importance of trying to anticipate the environmental

  13. Validation of Chlorine and Oxygen Isotope Ratio Analysis to Differentiate Perchlorate Sources and to Document Perchlorate Biodegradation

    Science.gov (United States)

    2011-12-01

    natural . Chlorine and oxygen isotopic analyses of perchlorate provide the primaty direct approach whereby different sources of perchlorate can be...REPORT NUMBER U.S. Geological Survey NA University of Illinois at Chicago 9 . SPONSORII\\IGI MONITORING AGENCY NAME(S) A ND ADDRESS( ESl 10 . SPONSOR...Unlimited 13. SUPPLEMENTARY NOTES None 14.ABSTRACT Perchlorate in the environment is derived from both synthetic and natural sources. Synthetic

  14. PERCHLORATE IDENTIFICATION IN FERTILIZERS AND ACCUMULATION IN LETTUCE SEEDLINGS

    Science.gov (United States)

    Perchlorate has contaminated groundwater, drinking water and soils at several locations in the U.S. The primary source of contamination at sites that have been investigated to date seems to be from industrial and military operations that use Perchlorate as an oxidizing agent. How...

  15. Microbial (per)chlorate reduction in hot subsurface environments

    NARCIS (Netherlands)

    Liebensteiner, M.

    2014-01-01

    The microbial reduction of chlorate and perchlorate has been known for long as a respiratory process of mesophilic bacteria that thrive in diverse environments such as soils, marine and freshwater sediments. Chlorate and perchlorate are found in nature deriving from anthropogenic and natural

  16. Microbial (per)chlorate reduction in hot subsurface environments

    NARCIS (Netherlands)

    Liebensteiner, M.

    2014-01-01

     

    The microbial reduction of chlorate and perchlorate has been known for long as a respiratory process of mesophilic bacteria that thrive in diverse environments such as soils, marine and freshwater sediments. Chlorate and perchlorate are found in nature deriving from anthropogenic and

  17. Development of an extraction method for perchlorate in soils.

    Science.gov (United States)

    Cañas, Jaclyn E; Patel, Rashila; Tian, Kang; Anderson, Todd A

    2006-03-01

    Perchlorate originates as a contaminant in the environment from its use in solid rocket fuels and munitions. The current US EPA methods for perchlorate determination via ion chromatography using conductivity detection do not include recommendations for the extraction of perchlorate from soil. This study evaluated and identified appropriate conditions for the extraction of perchlorate from clay loam, loamy sand, and sandy soils. Based on the results of this evaluation, soils should be extracted in a dry, ground (mortar and pestle) state with Milli-Q water in a 1 ratio 1 soil ratio water ratio and diluted no more than 5-fold before analysis. When sandy soils were extracted in this manner, the calculated method detection limit was 3.5 microg kg(-1). The findings of this study have aided in the establishment of a standardized extraction method for perchlorate in soil.

  18. Perchlorate Exposure Through Water and Milk in Istanbul.

    Science.gov (United States)

    Can, Ozge; Blount, Ben; Valentin-Blasini, Liza; Erdemgil, Yigit; Uzunoglu, Deniz; Aksoy, Murat; Coskun, Abdurrahman; Serteser, Mustafa; Unsal, Ibrahim; Ozpinar, Aysel

    2016-09-01

    Perchlorate is a chemical pollutant that inhibits iodide uptake and may possibly impair thyroid function. Our previous study found widespread perchlorate exposure in non-pregnant, non-lactating, healthy women residing in Istanbul. The aim of this study is to assess the relative amounts of perchlorate exposure attributable to consumption of municipal water, bottled water and boxed milk available in Istanbul. Only trace levels of perchlorate were found in treated municipal water (58 % detectable, mean = 0.13 µg/L, maximum = 0.75 µg/L) and bottled water (7.4 % detectable, mean = Istanbul. Therefore, additional studies are needed to identify the major sources of perchlorate exposure in Istanbul.

  19. Mercury and Pregnancy

    Science.gov (United States)

    ... Home > Pregnancy > Is it safe? > Mercury and pregnancy Mercury and pregnancy E-mail to a friend Please ... vision problems. How can you be exposed to mercury? Mercury has several forms: It can be a ...

  20. Perchlorate reduction by a novel chemolithoautotrophic, hydrogen-oxidizing bacterium.

    Science.gov (United States)

    Zhang, Husen; Bruns, Mary Ann; Logan, Bruce E

    2002-10-01

    Water treatment technologies are needed that can remove perchlorate from drinking water without introducing organic chemicals that stimulate bacterial growth in water distribution systems. Hydrogen is an ideal energy source for bacterial degradation of perchlorate as it leaves no organic residue and is sparingly soluble. We describe here the isolation of a perchlorate-respiring, hydrogen-oxidizing bacterium (Dechloromonas sp. strain HZ) that grows with carbon dioxide as sole carbon source. Strain HZ is a Gram-negative, rod-shaped facultative anaerobe that was isolated from a gas-phase anaerobic packed-bed biofilm reactor treating perchlorate-contaminated groundwater. The ability of strain HZ to grow autotrophically with carbon dioxide as the sole carbon source was confirmed by demonstrating that biomass carbon (100.9%) was derived from CO2. Chemolithotrophic growth with hydrogen was coupled with complete reduction of perchlorate (10 mM) to chloride with a maximum doubling time of 8.9 h. Strain HZ also grew using acetate as the electron donor and chlorate, nitrate, or oxygen (but not sulphate) as an electron acceptor. Phylogenetic analysis of the 16S rRNA sequence placed strain HZ in the genus Dechloromonas within the beta subgroup of the Proteobacteria. The study of this and other novel perchlorate-reducing bacteria may lead to new, safe technologies for removing perchlorate and other chemical pollutants from drinking water.

  1. Modeling In Situ Bioremediation of Perchlorate-Contaminated Groundwater

    National Research Council Canada - National Science Library

    Secody, Roland E

    2007-01-01

    .... An innovative technology was recently developed which uses dual-screened treatment wells to mix an electron donor into perchlorate-contaminated groundwater in order to effect in situ bioremediation...

  2. Stability and Concentration Verification of Ammonium Perchlorate Dosing Solutions

    National Research Council Canada - National Science Library

    Tsui, David

    1998-01-01

    Stability and concentration verification was performed for the ammonium perchlorate dosing solutions used in the on-going 90-Day Oral Toxicity Study conducted by Springborn Laboratories, Inc. (SLI Study No. 3433.1...

  3. Perchlorate Contamination of Drinking Water: Regulatory Issues and Legislative Actions

    National Research Council Canada - National Science Library

    Tiemann, Mary

    2007-01-01

    .... It also has been found in milk, fruits, and vegetables. Concern over the potential health risks of perchlorate exposure has increased, and some states and Members of Congress have urged the Environmental Protection Agency (EPA...

  4. Assembled cross-species perchlorate dose-response data

    Data.gov (United States)

    U.S. Environmental Protection Agency — This data set contains dose-response data for perchlorate exposure in multiple species. These data were assembled from peer-reviewed studies. Species included in...

  5. Isotopic tracing of perchlorate in the environment

    Science.gov (United States)

    Sturchio, Neil C.; Böhlke, John Karl; Gu, Baohua; Hatzinger, Paul B.; Jackson, W. Andrew; Baskaran, Mark

    2012-01-01

    Isotopic measurements can be used for tracing the sources and behavior of environmental contaminants. Perchlorate (ClO 4 − ) has been detected widely in groundwater, soils, fertilizers, plants, milk, and human urine since 1997, when improved analytical methods for analyzing ClO 4 −concentration became available for routine use. Perchlorate ingestion poses a risk to human health because of its interference with thyroidal hormone production. Consequently, methods for isotopic analysis of ClO 4 − have been developed and applied to assist evaluation of the origin and migration of this common contaminant. Isotopic data are now available for stable isotopes of oxygen and chlorine, as well as 36Cl isotopic abundances, in ClO 4 − samples from a variety of natural and synthetic sources. These isotopic data provide a basis for distinguishing sources of ClO 4 − found in the environment, and for understanding the origin of natural ClO 4 − . In addition, the isotope effects of microbial ClO 4 − reduction have been measured in laboratory and field experiments, providing a tool for assessing ClO 4 − attenuation in the environment. Isotopic data have been used successfully in some areas for identifying major sources of ClO 4 − contamination in drinking water supplies. Questions about the origin and global biogeochemical cycle of natural ClO 4 − remain to be addressed; such work would benefit from the development of methods for preparation and isotopic analysis of ClO 4 − in samples with low concentrations and complex matrices.

  6. Determination of Perchlorate in Bottled Water from Italy

    Directory of Open Access Journals (Sweden)

    Patrizia Iannece

    2013-06-01

    Full Text Available Perchlorate is regarded as an emerging persistent inorganic contaminant. It is widely known that perchlorate is an endocrine disruptor as it competitively inhibits iodide transport in the thyroid gland. As drinking water is the major source of human exposure to perchlorate, its occurrence in commercially available bottled waters purchased in different regions of Italy was investigated. Perchlorate was measured using the rapid, sensitive, and selective LC-ESI-MS/MS (liquid chromatography-electrospray tandem mass spectrometry method by multiple reaction monitoring (MRM of the transition 98.8→82.8, which corresponds to the loss of one oxygen atom in the perchlorate ion (ClO4−→ClO3−. The chlorine isotope ratio (35Cl/37Cl was used as a confirmation tool. The limit of quantification (LOQ for this method was 5 ng/L, and the recovery ranged from 94% to 108%. Perchlorate was detected in 44 of the 62 drinking waters tested, with concentrations ranging from <5 to 75 ng/L. These values are similar in magnitude to those reported in drinking water from the USA and do not pose an immediate health concern.

  7. Potentiometric perchlorate determination at nanomolar concentrations in vegetables.

    Science.gov (United States)

    Leoterio, Dilmo M S; Paim, Ana Paula S; Belian, Mônica F; Galembeck, André; Lavorante, André F; Pinto, Edgar; Amorim, Célia G; Araújo, Alberto N; Montenegro, Maria C B S M

    2017-07-15

    In this work, an expeditious method based on the multi-commutated flow-analysis concept with potentiometric detection is proposed to perform determinations of the emergent contaminant perchlorate in vegetable matrices down to nanomolar concentration. To accomplish the task, a tubular shaped potentiometric sensor selective to perchlorate ion was constructed with a PVC membrane containing 12mmol/kg of the polyamine bisnaphthalimidopropyl-4,4'-diaminodiphenylmethane and 2-nitrophenyl phenyl ether 68% (w/w) as plasticizer casted on a conductive epoxy resin. Under optimal flow conditions, the sensor responded linearly in the concentration range of 6.3×10 -7 -1.0×10 -3 mol/L perchlorate. In order to extend the determinations to lower concentrations (4.6(±1.3)×10 -10 mol/L perchlorate), a column packed with 70mg of sodium 2,5,8,11,14-pentaoxa-1-silacyclotetradecane-polymer was coupled to the flow-system thus enabling prior pre-concentration of the perchlorate. The proposed procedure provides a simpler alternative for the determination of perchlorate in foods, nowadays only allowed by sophisticated and expensive equipment and laborious methods. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Mercury's Messenger

    Science.gov (United States)

    Chapman, Clark R.

    2004-01-01

    Forty years after Mariner 2, planetary exploration has still only just begun, and many more missions are on drawing boards, nearing the launch pad, or even en route across interplanetary space to their targets. One of the most challenging missions that will be conducted this decade is sending the MESSENGER spacecraft to orbit the planet Mercury.…

  9. Mercury Report-Children's exposure to elemental mercury

    Science.gov (United States)

    ... gov . Mercury Background Mercury Report Additional Resources Mercury Report - Children's Exposure to Elemental Mercury Recommend on Facebook ... I limit exposure to mercury? Why was the report written? Children attending a daycare in New Jersey ...

  10. Perchlorate, iodine supplements, iodized salt and breast milk iodine content

    International Nuclear Information System (INIS)

    Kirk, Andrea B.; Kroll, Martina; Dyke, Jason V.; Ohira, Shin-Ichi; Dias, Rukshan A.; Dasgupta, Purnendu K.

    2012-01-01

    This study was undertaken to determine if increasing maternal iodine intake through single dose tablets will decrease breast milk concentrations of the iodine-uptake inhibitor, perchlorate, through competitive inhibition. We also sought to determine if the timing of supplementation influences the fraction of iodine excreted in milk versus urine and to compare the effectiveness of iodized salt as a means of providing iodine to breastfed infants. Thirteen women who did not use supplements, seven of whom used iodized salt and six of whom used non-iodized salt, submitted four milk samples and a 24-h urine collection daily for three days. Women repeated the sampling protocol for three more days during which ∼ 150 μg of iodine were taken in the evening and again for three days with morning supplementation. Samples were analyzed using isotope-dilution inductively-coupled plasma-mass spectrometry for iodine and isotope-dilution ion chromatography-tandem mass spectrometry for perchlorate. No statistically significant differences were observed in milk iodine or perchlorate concentrations during the two treatment periods. Estimated perchlorate intake was above the U.S. National Academy of Sciences suggested reference dose for most infants. Single daily dose iodine supplementation was not effective in decreasing milk perchlorate concentrations. Users of iodized salt had significantly higher iodine levels in milk than non-users. Iodized salt may be a more effective means of iodine supplementation than tablets. - Highlights: ► Estimated infant exposures to perchlorate were, on a μg/kg basis, ∼ 5 × higher than those of mothers. ► Daily supplements are less effective than iodized salt in providing iodine to lactating women. ► Low iodine and high perchlorate in milk may place infants at risk of iodine deficiency.

  11. Perchlorate, iodine supplements, iodized salt and breast milk iodine content

    Energy Technology Data Exchange (ETDEWEB)

    Kirk, Andrea B. [Department of Epidemiology, School of Public Health, University of North Texas Health Sciences Center, 3500 Camp Bowie Blvd., Fort Worth, TX 76107 (United States); Kroll, Martina; Dyke, Jason V.; Ohira, Shin-Ichi; Dias, Rukshan A.; Dasgupta, Purnendu K. [Department of Chemistry and Biochemistry, 700 Planetarium Place, University of Texas at Arlington, Arlington, TX 76019 (United States)

    2012-03-15

    This study was undertaken to determine if increasing maternal iodine intake through single dose tablets will decrease breast milk concentrations of the iodine-uptake inhibitor, perchlorate, through competitive inhibition. We also sought to determine if the timing of supplementation influences the fraction of iodine excreted in milk versus urine and to compare the effectiveness of iodized salt as a means of providing iodine to breastfed infants. Thirteen women who did not use supplements, seven of whom used iodized salt and six of whom used non-iodized salt, submitted four milk samples and a 24-h urine collection daily for three days. Women repeated the sampling protocol for three more days during which {approx} 150 {mu}g of iodine were taken in the evening and again for three days with morning supplementation. Samples were analyzed using isotope-dilution inductively-coupled plasma-mass spectrometry for iodine and isotope-dilution ion chromatography-tandem mass spectrometry for perchlorate. No statistically significant differences were observed in milk iodine or perchlorate concentrations during the two treatment periods. Estimated perchlorate intake was above the U.S. National Academy of Sciences suggested reference dose for most infants. Single daily dose iodine supplementation was not effective in decreasing milk perchlorate concentrations. Users of iodized salt had significantly higher iodine levels in milk than non-users. Iodized salt may be a more effective means of iodine supplementation than tablets. - Highlights: Black-Right-Pointing-Pointer Estimated infant exposures to perchlorate were, on a {mu}g/kg basis, {approx} 5 Multiplication-Sign higher than those of mothers. Black-Right-Pointing-Pointer Daily supplements are less effective than iodized salt in providing iodine to lactating women. Black-Right-Pointing-Pointer Low iodine and high perchlorate in milk may place infants at risk of iodine deficiency.

  12. Rate and extent of aqueous perchlorate removal by iron surfaces.

    Science.gov (United States)

    Moore, Angela M; De Leon, Corinne H; Young, Thomas M

    2003-07-15

    The rate and extent of perchlorate reduction on several types of iron metal was studied in batch and column reactors. Mass balances performed on the batch experiments indicate that perchlorate is initially sorbed to the iron surface, followed by a reduction to chloride. Perchlorate removal was proportional to the iron dosage in the batch reactors, with up to 66% removal in 336 h in the highest dosage system (1.25 g mL(-1)). Surface-normalized reaction rates among three commercial sources of iron filings were similar for acid-washed samples. The most significant perchlorate removal occurred in solutions with slightly acidic or near-neutral initial pH values. Surface mediation of the reaction is supported by the absence of reduction in batch experiments with soluble Fe2+ and also by the similarity in specific reaction rate constants (kSA) determined for three different iron types. Elevated soluble chloride concentrations significantly inhibited perchlorate reduction, and lower removal rates were observed for iron samples with higher amounts of background chloride contamination. Perchlorate reduction was not observed on electrolytic sources of iron or on a mixed-phase oxide (Fe3O4), suggesting that the reactive iron phase is neither pure zerovalent iron nor the mixed oxide alone. A mixed valence iron hydr(oxide) coating or a sorbed Fe2+ surface complex represent the most likely sites for the reaction. The observed reaction rates are too slow for immediate use in remediation system design, but the findings may provide a basis for future development of cost-effective abiotic perchlorate removal techniques.

  13. The thermal decomposition behavior of ammonium perchlorate and of an ammonium-perchlorate-based composite propellant

    Energy Technology Data Exchange (ETDEWEB)

    Behrens, R.; Minier, L.

    1998-03-24

    The thermal decomposition of ammonium perchlorate (AP) and ammonium-perchlorate-based composite propellants is studied using the simultaneous thermogravimetric modulated beam mass spectrometry (STMBMS) technique. The main objective of the present work is to evaluate whether the STMBMS can provide new data on these materials that will have sufficient detail on the reaction mechanisms and associated reaction kinetics to permit creation of a detailed model of the thermal decomposition process. Such a model is a necessary ingredient to engineering models of ignition and slow-cookoff for these AP-based composite propellants. Results show that the decomposition of pure AP is controlled by two processes. One occurs at lower temperatures (240 to 270 C), produces mainly H{sub 2}O, O{sub 2}, Cl{sub 2}, N{sub 2}O and HCl, and is shown to occur in the solid phase within the AP particles. 200{micro} diameter AP particles undergo 25% decomposition in the solid phase, whereas 20{micro} diameter AP particles undergo only 13% decomposition. The second process is dissociative sublimation of AP to NH{sub 3} + HClO{sub 4} followed by the decomposition of, and reaction between, these two products in the gas phase. The dissociative sublimation process occurs over the entire temperature range of AP decomposition, but only becomes dominant at temperatures above those for the solid-phase decomposition. AP-based composite propellants are used extensively in both small tactical rocket motors and large strategic rocket systems.

  14. Crystal structure of iron(III perchlorate nonahydrate

    Directory of Open Access Journals (Sweden)

    Erik Hennings

    2014-12-01

    Full Text Available Since the discovery of perchlorate salts on Mars and the known occurrence of ferric salts in the regolith, there is a distinct possibility that the title compound could form on the surface of Mars. [Fe(H2O6](ClO43·3H2O was crystallized from aqueous solutions at low temperatures according to the solid–liquid phase diagram. It consists of Fe(H2O6 octahedra (point group symmetry -3. and perchlorate anions (point group symmetry .2 as well as non-coordinating water molecules, as part of a second hydrogen-bonded coordination sphere around the cation. The perchlorate appears to be slightly disordered, with major–minor component occupancies of 0.773 (9:0.227 (9.

  15. Environmental mercury problem

    Energy Technology Data Exchange (ETDEWEB)

    D' Itri, F.M.

    1972-01-01

    The urgent need to eliminate or greatly reduce the discharge of mercury into the environment is paramount to the health and well being of man. That all forms of mercury are hazardous is widely recognized, but what is more devastating to our society is that all forms of mercury appear to have the potential to be converted in to highly toxic monomethylmercury, or dimethylmercury. This paper examined the historical uses of mercury, the background concentrations of mercury, the analytical methods for the determination of mercury, the contamination of the food chain by mercury, the biological methylation of mercury, the decontamination and restoration of mercury polluted areas, the epidemiology and toxicology of mercury, and the chronology of the world's mercury poisoning problem.

  16. In Situ Bioremediation of Perchlorate in Vadose Zone Source Areas

    Science.gov (United States)

    2011-01-01

    Perchlorate in Vadose Zone Source Areas 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER 5e. TASK NUMBER...laboratory and field research has demonstrated success with treatment of perchlorate-laden surface soils by addition of manure, composting , or in large...Pre11ped By Test Codl’S 184702-1 Collected: 19-FEB-08 00;00 By: Received: 04- MAR -08 By: B4 HOMOGENIZED 184702- 1 SW846 7471A 07- MAR -08 )3:58 1W 07- MAR

  17. μ-Peroxido-bis[acetonitrilebis(ethylenediaminecobalt(III] tetrakis(perchlorate

    Directory of Open Access Journals (Sweden)

    Valentina A. Kalibabchuk

    2010-12-01

    Full Text Available The title compound, [Co2(O2(CH3CN2(C2H8N24](ClO44, consists of centrosymmetric binuclear cations and perchlorate anions. Two CoIII atoms, which have a slightly distorted octahedral coordination, are connected through a peroxido bridge; the O—O distance is 1.476 (3 Å. Both acetonitrile ligands are situated in a trans position with respect to the O—O bridge. In the crystal, the complex cations are connected by N—H...O hydrogen bonds between ethylendiamine NH groups and O atoms from the perchlorate anions and peroxide O atoms.

  18. Perchlorate adsorption and desorption on activated carbon and anion exchange resin.

    Science.gov (United States)

    Yoon, In-Ho; Meng, Xiaoguang; Wang, Chao; Kim, Kyoung-Woong; Bang, Sunbaek; Choe, Eunyoung; Lippincott, Lee

    2009-05-15

    The mechanisms of perchlorate adsorption on activated carbon (AC) and anion exchange resin (SR-7 resin) were investigated using Raman, FTIR, and zeta potential analyses. Batch adsorption and desorption results demonstrated that the adsorption of perchlorate by AC and SR-7 resin was reversible. The reversibility of perchlorate adsorption by the resin was also proved by column regeneration test. Solution pH significantly affected perchlorate adsorption and the zeta potential of AC, while it did not influence perchlorate adsorption and the zeta potential of resin. Zeta potential measurements showed that perchlorate was adsorbed on the negatively charged AC surface. Raman spectra indicated the adsorption resulted in an obvious position shift of the perchlorate peak, suggesting that perchlorate was associated with functional groups on AC at neutral pH through interactions stronger than electrostatic interaction. The adsorbed perchlorate on the resin exhibited a Raman peak at similar position as the aqueous perchlorate, indicating that perchlorate was adsorbed on the resin through electrostatic attraction between the anion and positively charged surface sites.

  19. Aluminum-based drinking-water treatment residuals: a novel sorbent for perchlorate removal.

    Science.gov (United States)

    Makris, Konstantinos C; Sarkar, Dibyendu; Datta, Rupali

    2006-03-01

    Perchlorate contamination of aquifers and drinking-water supplies has led to stringent regulations in several states to reduce perchlorate concentrations in water at acceptable levels for human consumption. Several perchlorate treatment technologies exist, but there is significant cost associated with their use, and the majority of them are unable to degrade perchlorate to innocuous chloride. We propose the use of a novel sorbent for perchlorate, i.e. an aluminum-based drinking-water treatment residual (Al-WTR), which is a by-product of the drinking-water treatment process. Perchlorate sorption isotherms (23+/-1 degrees C) showed that the greatest amount (65%) of perchlorate removed by the Al-WTR was observed with the lowest initial perchlorate load (10 mg L(-1)) after only 2 h of contact time. Increasing the contact time to 24 h, perchlorate removal increased from 65 to 76%. A significant correlation was observed between the amounts of perchlorate removed with evolved chloride in solution, suggesting degradation of perchlorate to chloride.

  20. Mercury contamination extraction

    Science.gov (United States)

    Fuhrmann, Mark [Silver Spring, MD; Heiser, John [Bayport, NY; Kalb, Paul [Wading River, NY

    2009-09-15

    Mercury is removed from contaminated waste by firstly applying a sulfur reagent to the waste. Mercury in the waste is then permitted to migrate to the reagent and is stabilized in a mercury sulfide compound. The stable compound may then be removed from the waste which itself remains in situ following mercury removal therefrom.

  1. An upper-bound assessment of the benefits of reducing perchlorate in drinking water.

    Science.gov (United States)

    Lutter, Randall

    2014-10-01

    The Environmental Protection Agency plans to issue new federal regulations to limit drinking water concentrations of perchlorate, which occurs naturally and results from the combustion of rocket fuel. This article presents an upper-bound estimate of the potential benefits of alternative maximum contaminant levels for perchlorate in drinking water. The results suggest that the economic benefits of reducing perchlorate concentrations in drinking water are likely to be low, i.e., under $2.9 million per year nationally, for several reasons. First, the prevalence of detectable perchlorate in public drinking water systems is low. Second, the population especially sensitive to effects of perchlorate, pregnant women who are moderately iodide deficient, represents a minority of all pregnant women. Third, and perhaps most importantly, reducing exposure to perchlorate in drinking water is a relatively ineffective way of increasing iodide uptake, a crucial step linking perchlorate to health effects of concern. © 2014 Society for Risk Analysis.

  2. Perchlorate in fish from a contaminated site in east-central Texas.

    Science.gov (United States)

    Theodorakis, Christopher; Rinchard, Jacques; Anderson, Todd; Liu, Fujun; Park, June-Woo; Costa, Filipe; McDaniel, Leslie; Kendall, Ronald; Waters, Aaron

    2006-01-01

    Perchlorate, a known thyroid endocrine disruptor, contaminates surface waters near military instillations where solid fuel rocket motors are manufactured or assembled. To assess potential perchlorate exposure to fish and the human population which may feed on them, fish were collected around the Naval Weapons Industrial Reserve Plant in McLennan County, TX, and analyzed for the presence of the perchlorate anion. The sampling sites included Lake Waco and Belton Lake, and several streams and rivers within their watersheds. The general tendency was that perchlorate was only found in a few species sampled, and perchlorate was not detected in every individual within these species. When detected in the fish, perchlorate tissue concentrations were greater than that in the water. This may be due to highly variable perchlorate concentrations in the water coupled with individual-level variation in elimination from the body, or to routes of exposure other than water.

  3. The determination of residual perchlorate after the controlled ignition of selected fireworks compositions

    Energy Technology Data Exchange (ETDEWEB)

    Armstrong, K.; Ridley, W.; Guilbeault, R.; Duff, B.

    2008-04-15

    This study investigated perchlorate releases into the atmosphere caused by fireworks displays. Five perchlorate-based compositions were ignited in a sealed stainless steel vessel. The interior of the vessel and the exhaust filters were then washed with hot de-ionized water. Ion chromatography was then used to analyzed the water solutions. Amounts of perchlorate ion measured in the solution were then used to calculate the percentage of residual perchlorate based on the original mass of perchlorate contained within the samples. The study showed that 99.98 to 99.999 per cent of the initial mass of perchlorate in the samples was consumed during ignition. It was concluded that the incomplete combustion of fireworks caused by defective article construction will cause higher amounts of perchlorate releases into the environment. Stricter quality controls are needed to reduce the environmental impacts of fireworks. 14 refs., 4 tabs., 3 figs.

  4. Treatment of amiodarone-induced hypothyroidism with potassium perchlorate

    NARCIS (Netherlands)

    van Dam, E. W.; Prummel, M. F.; Wiersinga, W. M.; Nikkels, R. E.

    1993-01-01

    The antiarrhythmic drug, amiodarone, induces thyroid dysfunction, which is potentially dangerous in cardiac patients. After discontinuation of the drug it takes several months before euthyroidism is restored. The potent antithyroid drug, potassium perchlorate (KClO4), is used successfully to treat

  5. Mercury Quick Facts: Health Effects of Mercury Exposure

    Science.gov (United States)

    Mercury Quick Facts Health Effects of Mercury Exposure What is Elemental Mercury? Elemental (metallic) mercury is the shiny, silver-gray metal found in thermometers, barometers, and thermostats and other ...

  6. Sample processing method for the determination of perchlorate in milk

    International Nuclear Information System (INIS)

    Dyke, Jason V.; Kirk, Andrea B.; Kalyani Martinelango, P.; Dasgupta, Purnendu K.

    2006-01-01

    In recent years, many different water sources and foods have been reported to contain perchlorate. Studies indicate that significant levels of perchlorate are present in both human and dairy milk. The determination of perchlorate in milk is particularly important due to its potential health impact on infants and children. As for many other biological samples, sample preparation is more time consuming than the analysis itself. The concurrent presence of large amounts of fats, proteins, carbohydrates, etc., demands some initial cleanup; otherwise the separation column lifetime and the limit of detection are both greatly compromised. Reported milk processing methods require the addition of chemicals such as ethanol, acetic acid or acetonitrile. Reagent addition is undesirable in trace analysis. We report here an essentially reagent-free sample preparation method for the determination of perchlorate in milk. Milk samples are spiked with isotopically labeled perchlorate and centrifuged to remove lipids. The resulting liquid is placed in a disposable centrifugal ultrafilter device with a molecular weight cutoff of 10 kDa, and centrifuged. Approximately 5-10 ml of clear liquid, ready for analysis, is obtained from a 20 ml milk sample. Both bovine and human milk samples have been successfully processed and analyzed by ion chromatography-mass spectrometry (IC-MS). Standard addition experiments show good recoveries. The repeatability of the analytical result for the same sample in multiple sample cleanup runs ranged from 3 to 6% R.S.D. This processing technique has also been successfully applied for the determination of iodide and thiocyanate in milk

  7. Branched polymeric media: Perchlorate-selective resins from hyperbranched polyethyleneimine

    KAUST Repository

    Chen, Dennis P.

    2012-10-02

    Perchlorate (ClO4 -) is a persistent contaminant found in drinking groundwater sources in the United States. Ion exchange (IX) with selective and disposable resins based on cross-linked styrene divinylbenzene (STY-DVB) beads is currently the most commonly utilized process for removing low concentrations of ClO4 - (10-100 ppb) from contaminated drinking water sources. However, due to the low exchange capacity of perchlorate-selective STY-DVB resins (∼0.5-0.8 eq/L), the overall cost becomes prohibitive when treating groundwater with higher concentration of ClO4 - (e.g., 100-1000 ppb). In this article, we describe a new perchlorate-selective resin with high exchange capacity. This new resin was prepared by alkylation of branched polyethyleneimine (PEI) beads obtained from an inverse suspension polymerization process. Batch and column studies show that our new PEI resin with mixed hexyl/ethyl quaternary ammonium chloride exchange sites can selectively extract trace amounts of ClO4 - from a makeup groundwater (to below detection limit) in the presence of competing ions. In addition, this resin has a strong-base exchange capacity of 1.4 eq/L, which is 1.75-2.33 times larger than those of commercial perchlorate-selective STY-DVB resins. The overall results of our studies suggest that branched PEI beads provide versatile and promising building blocks for the preparation of perchlorate-selective resins with high exchange capacity. © 2012 American Chemical Society.

  8. [Perchlorate removal from underground water by anaerobic biological reduction with bark].

    Science.gov (United States)

    Wang, Rui; Liu, Fei; Chen, Nan; Chen, Hong-Han

    2013-07-01

    Batch experiments were conducted to check the feasibility of perchlorate removal from underground water with bark as a carbon source and reaction media, the effect of bark dosage, temperature and initial perchlorate concentrations on perchlorate reduction were also investigated. The results indicated that compared to corn cob, sweet potato and potato, bark in combination with perchlorate reducing microorganisms (PRMs) can efficiently achieve perchlorate removal from underground water, the concentrations of dissolved organic carbon (DOC) which was available to PRMs was the limiting factor that affected the perchlorate removal efficiency. Degradation of 10 mg perchlorate needed to consume 35-40 mg DOC when using bark as the solid carbon source. The removal rate of perchlorate was increased by about 3 fold when the bark dosage was increased from 1:500 to 3:500; however, further increase of solid-liquid ratio (over 5:500) provided no further benefit to the perchlorate reduction rate. The rate constant reached 1.365 mg x (L x d)(-1) at (38 +/- 1) degrees C which was the highest in the batch experiments. The activation energy was 31.08 kJ x mol(-1). Anaerobic biological reduction supported by bark had a good impact on the water quality; the high perchlorate concentration did not cause substrate inhibition.

  9. Perchlorate reduction by autotrophic bacteria in the presence of zero-valent iron.

    Science.gov (United States)

    Yu, Xueyuan; Amrhein, Christopher; Deshusses, Marc A; Matsumoto, Mark R

    2006-02-15

    A series of batch experiments were performed to study the combination of zero-valent iron (ZVI) with perchlorate-reducing microorganisms (PRMs) to remove perchlorate from groundwater. In this method, H2 produced during the process of iron corrosion by water is used by PRMs as an electron donor to reduce perchlorate to chloride. Perchlorate degradation rates followed Monod kinetics, with a normalized maximum utilization rate (rmax) of 9200 microg g(-1) (dry wt) h(-1) and a half-velocity constant (Ks) of 8900 microg L(-1). The overall rate of perchlorate reduction was affected by the biomass density within the system. An increase in the OD600 from 0.025 to 0.08 led to a corresponding 4-fold increase of perchlorate reduction rate. PRM adaptation to the local environment and initiation of perchlorate reduction was rapid under neutral pH conditions. At the initial OD600 of 0.015, perchlorate reduction followed pseudo-first-order reaction rates with constants of 0.059 and 0.033 h(-1) at initial pH 7 and 8, respectively. Once perchlorate reduction was established, the bioreductive process was insensitive to the increases of pH from near neutral to 9.0. In the presence of nitrate, perchlorate reduction rate was reduced, but not inhibited completely.

  10. Sensitivity and adaptability of methanogens to perchlorates: Implications for life on Mars

    Science.gov (United States)

    Kral, Timothy A.; Goodhart, Timothy H.; Harpool, Joshua D.; Hearnsberger, Christopher E.; McCracken, Graham L.; McSpadden, Stanley W.

    2016-01-01

    In 2008, the Mars Phoenix Lander discovered perchlorate at its landing site, and in 2012, the Curiosity rover confirmed the presence of perchlorate on Mars. The research reported here was designed to determine if certain methanogens could grow in the presence of three different perchlorate salt solutions. The methanogens tested were Methanothermobacter wolfeii, Methanosarcina barkeri, Methanobacterium formicicum and Methanococcus maripaludis. Media were prepared containing 0%, 0.5%, 1.0%, 2%, 5% and 10% wt/vol magnesium perchlorate, sodium perchlorate, or calcium perchlorate. Organisms were inoculated into their respective media followed by incubation at each organism's growth temperature. Methane production, commonly used to measure methanogen growth, was measured by gas chromatography of headspace gas samples. Methane concentrations varied with species and perchlorate salt tested. However, all four methanogens produced substantial levels of methane in the presence of up to 1.0% perchlorate, but not higher. The standard procedure for growing methanogens typically includes sodium sulfide, a reducing agent, to reduce residual molecular oxygen. However, the sodium sulfide may have been reducing the perchlorate, thus allowing for growth of the methanogens. To investigate this possibility, experiments were conducted where stainless steel nails were used instead of sodium sulfide as the reducing agent. Prior to the addition of perchlorate and inoculation, the nails were removed from the liquid medium. Just as in the prior experiments, the methanogens produced methane at comparable levels to those seen with sodium sulfide as the reductant, indicating that sodium sulfide did not reduce the perchlorate to any significant extent. Additionally, cells metabolizing in 1% perchlorate were transferred to 2%, cells metabolizing in 2% were transferred to 5%, and finally cells metabolizing in 5% were transferred to 10%. All four species produced methane at 2% and 5%, but not 10

  11. Relative source contributions for perchlorate exposures in a lactating human cohort

    Energy Technology Data Exchange (ETDEWEB)

    Kirk, Andrea B. [University of North Texas Health Sciences Center (United States); Dyke, Jason V. [University of Texas at Arlington (United States); Ohira, Shin-Ichi [Kumamoto University (Japan); Dasgupta, Purnendu K., E-mail: Dasgupta@uta.edu [University of Texas at Arlington (United States)

    2013-01-15

    Perchlorate is an iodine-uptake inhibitor and common contaminant of food and drinking water. Understanding the amount of perchlorate exposure occurring through non-water sources is essential for accurate estimates of human exposure levels, and establishment of drinking water limits for this pervasive contaminant. The study objective was to determine the amount of perchlorate intake derived from diet rather than water. Subjects provided drinking water samples, detailed fluid-intake records, 24 h urine collections and four milk samples for nine days. Samples were analyzed for perchlorate by isotope dilution ion chromatography–tandem mass spectrometry. Amounts of perchlorate derived from drinking water and dietary sources were calculated for each individual. Water of local origin was found to contribute a minor fraction of perchlorate intake. Estimated fraction intake from drinking water ranged from 0 to 36%. The mean and median dose of perchlorate derived from non-water sources by lactating women was 0.18 μg/kg/day (range: 0.06 to 0.36 μg/kg/day.) Lactating women consumed more fluid (mean 2.424 L/day) than has been assumed in recent risk assessments for perchlorate. The data reported here indicate that lactating women may be exposed to perchlorate through dietary sources at markedly higher levels than estimated previously. Exposures to perchlorate from non-water sources may be higher than recent estimates, including those used to develop drinking water standards. - Highlights: ► Residence in an area with perchlorate-contaminated water may be a poor predictor of exposure. ► Exposures to perchlorate from food are likely underestimated. ► The relative contributions for human perchlorate exposures should be weighted more heavily towards non-water sources.

  12. Efflorescence of Magnesium Perchlorate by Contact with Mineral Dust Particles

    Science.gov (United States)

    Ushijima, S.; Tolbert, M. A.; Gough, R. V.

    2017-12-01

    Liquid water was not uncommon on early Mars and it shaped geologic features on the surface that are still seen today. Due to the extremely cold and dry conditions of Mars currently, only water ice and water vapor have been observed and or detected. However, it has been suggested that liquid may form seasonally based on the observations of recurring slope lineae (RSL). The liquid may be a brine composed of hygroscopic salts such as perchlorates whose hydrated form has recently been detected in an RSL by the Mars Reconnaissance Orbiter. Through a process called deliquescence, the salts can absorb water from the surrounding environment and become a brine above a specific relative humidity (RH) known as the deliquescence relative humidity (DRH). The reverse process, recrystallization or efflorescence, often occurs at a much lower RH called the efflorescence relative humidity (ERH). The hysteresis effect caused by the distinctly different RH values allows for liquid brines to be metastable even under dry conditions. However, there is evidence that ERH can be raised when a mineral particle encounters the surface of the brine or it is immersed inside, effectively diminishing the metastability potential of liquid brines. If the brines are responsible for RSL formation, the brine will inevitably mix with the Martian soil. Thus, it is important to understand the effects that mineral particles can have on efflorescence. Here we use optical trapping to examine efflorescence of magnesium perchlorate in the presence of montmorillonite and halite. Studies on the efflorescence and deliquescence of magnesium perchlorate has shown that its brine could be stable in the subsurface of Mars during certain periods of time. Both montmorillonite and halite have been suggested to be a part of or similar to components of the Martian soil. Results at ambient conditions have shown that efflorescence of magnesium perchlorate is unaffected by the presence of either minerals. Whether the droplet

  13. Minamata Convention on Mercury

    Science.gov (United States)

    On November 6, 2013 the United States signed the Minamata Convention on Mercury, a new multilateral environmental agreement that addresses specific human activities which are contributing to widespread mercury pollution

  14. Effects of perchlorate on growth of four wetland plants and its accumulation in plant tissues.

    Science.gov (United States)

    He, Hongzhi; Gao, Haishuo; Chen, Guikui; Li, Huashou; Lin, Hai; Shu, Zhenzhen

    2013-10-01

    Perchlorate contamination in water is of concern because of uncertainties about toxicity and health effects, impact on ecosystems, and possible indirect exposure pathways to humans. Therefore, it is very important to investigate the ecotoxicology of perchlorate and to screen plant species for phytoremediation. Effects of perchlorate (20, 200, and 500 mg/L) on the growth of four wetland plants (Eichhornia crassipes, Acorus calamus L., Thalia dealbata, and Canna indica) as well as its accumulation in different plant tissues were investigated through water culture experiments. Twenty milligrams per liter of perchlorate had no significant effects on height, root length, aboveground part weight, root weight, and oxidizing power of roots of four plants, except A. calamus, and increasing concentrations of perchlorate showed that out of the four wetland plants, only A. calamus had a significant (pplants showed significant decline contrasted to control groups, except the root length of E. crassipes and C. indica. The order of inhibition rates of perchlorate on root length, aboveground part weight and root weight, and oxidizing power of roots was: A. calamus > C. indica > T. dealbata > E. crassipes and on chlorophyll content in the leaf it was: A. calamus > T. dealbata > C. indica > E. crassipes. The higher the concentration of perchlorate used, the higher the amount of perchlorate accumulation in plants. Perchlorate accumulation in aboveground tissues was much higher than that in underground tissues and leaf was the main tissue for perchlorate accumulation. The order of perchlorate accumulation content and the bioconcentration factor in leaf of four plants was: E. crassipes > C. indica > T. dealbata > A. calamus. Therefore, E. crassipes might be an ideal plant with high tolerance ability and accumulation ability for constructing wetland to remediate high levels of perchlorate polluted water.

  15. Bioelectroremediation of perchlorate and nitrate contaminated water: A review.

    Science.gov (United States)

    Sevda, Surajbhan; Sreekishnan, T R; Pous, Narcís; Puig, Sebastià; Pant, Deepak

    2018-05-01

    Fresh water is a fundamental source for humans, hence the recent shrinkage in freshwater and increase in water pollution are imperative problems that vigorously affect the people and the environment worldwide. The breakneck industrialization contributes to the procreation of substantial abundance of wastewater and its treatment becomes highly indispensable. Perchlorate and nitrate containing wastewaters poses a serious threat to human health and environment. Conventional biological treatment methods are expensive and also not effective for treating wastewater effectively and incapable of in situ bioremediation. Bioelectrochemical systems are emerging as a new technology platform for a sustainable removal of such contaminants from wastewater streams. This article reviews the state of art of bioelectroremediation of contaminated waters with perchlorate and nitrate. Different aspects of this technology such as configuration and design, mode of operation and type of substrate are considered in detail. Copyright © 2018 Elsevier Ltd. All rights reserved.

  16. The Effect of Gamma Radiation on Mars Mineral Matrices: Implications for Perchlorate Formation on Mars

    Science.gov (United States)

    Fox, A. C.; Eigenbrode, J. L.; Pavlov, A.; Lewis, J.

    2017-12-01

    Observations by the Phoenix Wet Chemistry Lab of the Martian surface indicate the presence of perchlorate in high concentrations. Additional observations by the Sample Analysis at Mars and the Viking Landers indirectly support the presence of perchlorate at other localities on Mars. The evidence for perchlorate at several localities on Mars coupled with its detection in Martian meteorite EETA79001 suggests that perchlorate is present globally on Mars. The presence of perchlorate on Mars further complicates the search for organic molecules indicative of past life. While perchlorate is kinetically limited in Martian conditions, the intermediate species associated with its formation or decomposition, such as chlorate or chlorite, could oxidize Martian organic species. As a result, it is vital to understand the mechanism of perchlorate formation on Mars in order to determine its role in the degradation of organics. Here, we explore an alternate mechanism of formation of perchlorate by bombarding Cl-salts and Mars-relevant mineral mixtures with gamma radiation both with and without the presence of liquid water, under vacuum. Previous work has shown that OClO can form from both UV radiation and energetic electrons bombardment of Cl-ices or Cl-salts, which then reacts with either OH- or O-radicals to produce perchlorate. Past research has suggested that liquid water or ice is the source of these hydroxyl and oxygen radicals, which limits the location of perchlorate formation on Mars. We demonstrate that trace amounts of perchlorate are potentially formed in samples containing silica dioxide or iron oxide and Cl-salts both with and without liquid water. Perchlorate was also detected in a portion of samples that were not irradiated, suggesting possible contamination. We did not detect perchlorate in samples that contained sulfate minerals. If perchlorate was formed without liquid water, it is possible that oxide minerals could be a potential source of oxygen radicals

  17. Highly-selective and Regenerable Ion Exchange for Perchlorate Remediation, Recovery, and Environmental Forensics

    Science.gov (United States)

    Gu, B.; Brown, G.

    2007-12-01

    Perchlorate (ClO4-) has recently emerged as a widespread contaminant found in drinking water and groundwater supplies in the United States and is known to disrupt thyroid function by inhibiting iodide uptake. Among various treatment technologies, the highly-selective and regenerable ion-exchange technology has recently been developed at ORNL for removing ClO4- from contaminated water. The selective ion exchange technology relies on a unique, highly specific resin to trap ClO4- from contaminated water. The treatment system is then regenerated and perchlorate is destroyed. The reaction that destroys ClO4- produces Cl- and Fe(III) that are used to regenerate the resin, resulting in practically zero secondary waste production. In comparison with conventional non-selective ion-exchange technology, this new treatment process is expected to result in not only a reduced O&M cost but also the elimination of the disposal of hazardous wastes containing perchlorate. Additionally, the selective and regenerable ion exchange technology has allowed the quantitative recovery of perchlorate from contaminated water for reuse, or from other environmental matrices such as sediment, groundwater, and salt deposits for perchlorate isotopic and source identification. Naturally-forming perchlorate has been found to contain distinct oxygen and chlorine isotope signatures or anomalies as compared with anthropogenic perchlorate and can thus provide unambiguous identification of the sources of perchlorate contamination as a powerful tool for the forensics of perchlorate in the environment.

  18. Perchlorate in fish from a contaminated site in east-central Texas

    International Nuclear Information System (INIS)

    Theodorakis, Christopher; Rinchard, Jacques; Anderson, Todd; Liu, Fujun; Park, June-Woo; Costa, Filipe; McDaniel, Leslie; Kendall, Ronald; Waters, Aaron

    2006-01-01

    Perchlorate, a known thyroid endocrine disruptor, contaminates surface waters near military instillations where solid fuel rocket motors are manufactured or assembled. To assess potential perchlorate exposure to fish and the human population which may feed on them, fish were collected around the Naval Weapons Industrial Reserve Plant in McLennan County, TX, and analyzed for the presence of the perchlorate anion. The sampling sites included Lake Waco and Belton Lake, and several streams and rivers within their watersheds. The general tendency was that perchlorate was only found in a few species sampled, and perchlorate was not detected in every individual within these species. When detected in the fish, perchlorate tissue concentrations were greater than that in the water. This may be due to highly variable perchlorate concentrations in the water coupled with individual-level variation in elimination from the body, or to routes of exposure other than water. - In perchlorate-contaminated lakes and streams, perchlorate is detected infrequently in fish heads, fillets, and whole bodies, but may be detected more often depending on species and seasonal trends, and always at concentrations higher in the fish than in the water

  19. Perchlorate in fish from a contaminated site in east-central Texas

    Energy Technology Data Exchange (ETDEWEB)

    Theodorakis, Christopher [Institute of Environmental and Human Health, Department of Environmental Toxicology, Texas Tech University, Lubbock, TX 79409-1163 (United States)]. E-mail: chris.theodorakis@tiehh.ttu.edu; Rinchard, Jacques [Institute of Environmental and Human Health, Department of Environmental Toxicology, Texas Tech University, Lubbock, TX 79409-1163 (United States); Anderson, Todd [Institute of Environmental and Human Health, Department of Environmental Toxicology, Texas Tech University, Lubbock, TX 79409-1163 (United States); Liu, Fujun [Institute of Environmental and Human Health, Department of Environmental Toxicology, Texas Tech University, Lubbock, TX 79409-1163 (United States); Park, June-Woo [Institute of Environmental and Human Health, Department of Environmental Toxicology, Texas Tech University, Lubbock, TX 79409-1163 (United States); Costa, Filipe [Institute of Environmental and Human Health, Department of Environmental Toxicology, Texas Tech University, Lubbock, TX 79409-1163 (United States); McDaniel, Leslie [Institute of Environmental and Human Health, Department of Environmental Toxicology, Texas Tech University, Lubbock, TX 79409-1163 (United States); Kendall, Ronald [Institute of Environmental and Human Health, Department of Environmental Toxicology, Texas Tech University, Lubbock, TX 79409-1163 (United States); Waters, Aaron [Institute of Environmental and Human Health, Department of Environmental Toxicology, Texas Tech University, Lubbock, TX 79409-1163 (United States)

    2006-01-15

    Perchlorate, a known thyroid endocrine disruptor, contaminates surface waters near military instillations where solid fuel rocket motors are manufactured or assembled. To assess potential perchlorate exposure to fish and the human population which may feed on them, fish were collected around the Naval Weapons Industrial Reserve Plant in McLennan County, TX, and analyzed for the presence of the perchlorate anion. The sampling sites included Lake Waco and Belton Lake, and several streams and rivers within their watersheds. The general tendency was that perchlorate was only found in a few species sampled, and perchlorate was not detected in every individual within these species. When detected in the fish, perchlorate tissue concentrations were greater than that in the water. This may be due to highly variable perchlorate concentrations in the water coupled with individual-level variation in elimination from the body, or to routes of exposure other than water. - In perchlorate-contaminated lakes and streams, perchlorate is detected infrequently in fish heads, fillets, and whole bodies, but may be detected more often depending on species and seasonal trends, and always at concentrations higher in the fish than in the water.

  20. Perchlorate in sewage sludge, rice, bottled water and milk collected from different areas in China.

    Science.gov (United States)

    Shi, Yali; Zhang, Ping; Wang, Yawei; Shi, Jianbo; Cai, Yaqi; Mou, Shifen; Jiang, Guibin

    2007-10-01

    As a new emerging environmental contaminant, perchlorate has prompted people to pay more attention. The presence of perchlorate in the human body can result in improper regulation of metabolism for adults. Furthermore, it also causes developmental and behavioral problems for infants and children because it can interfere with iodide uptake into the thyroid tissue. In this paper, perchlorate in sewage sludge, rice, bottled drinking water and milk was detected for investigating the perchlorate pollution status in China. The places, where the samples were collected, cover most regions of China. Therefore, the final data on perchlorate levels will give an indication of the perchlorate pollution status in China. The final determination of perchlorate was performed by ion chromatography-electrospray tandem mass spectrometry with negative mode. The concentration of perchlorate in sewage sludge, rice, bottled drinking water and milk was in the range of 0.56-379.9 microg/kg, 0.16-4.88 mug/kg, 0.037-2.013 microg/L and 0.30-9.1 microg/L, respectively. The results show that perchlorate has been widespread in China.

  1. Perchlorate and Halogen-Free High Energy Dense Oxidizers (HEDO)

    Science.gov (United States)

    2011-06-01

    The specific impulses have been compared to this of an ammonium perchlorate / aluminum mixture. Objective:   The objectives of this project are...catalytic amounts of iron trichloride (FeCl3). Compound 5 was fully characterized by single crystal X-ray diffraction, vibrational spectroscopy (IR and...obtained referring to [38] from oxalyl dichloride with 2,2,2-trinitroethanol dichloride and a catalytic amount of dry aluminum (III) chloride (Scheme 16

  2. Pseudoideal detonation of mechanoactivated mixtures of ammonium perchlorate with nanoaluminum

    Science.gov (United States)

    Shevchenko, A. A.; Dolgoborodov, A. Yu; Brazhnikov, M. A.; Kirilenko, V. G.

    2018-01-01

    Detonation properties of mechanochemical activated ammonium perchlorate with aluminum (AP–Al) mixtures with increased detonation velocity was studied. For compositions with nanoscale aluminum was obtained nonmonotonic dependence of the detonation velocity vs reciprocal diameter. The results generally showed that the combined usage of mechanical activation and nanoscale components of explosive mixtures can significantly increase the detonation ability and reduce the critical diameter to d cr = 7 mm.

  3. 4-(2-Azaniumylethylpiperazin-1-ium bis(perchlorate

    Directory of Open Access Journals (Sweden)

    Mohammad Reza Reisi

    2011-09-01

    Full Text Available In the title compound, C6H17N32+·2ClO4−, the piperazine ring adopts a chair conformation with the ethylammonium fragment occupying an equatorial position. In the crystal, the dications and perchlorate anions are linked through N—H...O hydrogen bonding and weak C—H...O hydrogen bonding into a three-dimensional supramolecular network.

  4. Identification and Characterization of Natural Sources of Perchlorate

    Science.gov (United States)

    2017-01-01

    chemoorganotrophic bacteria from permanently ice-covered Lake Hoare, McMurdo Dry Valleys, Antarctica. Applied and Environmental Microbiology 73, 3077-3083...chemolithotrophic, sulfur-oxidizing bacteria from perennially ice-covered Lake Fryxell, Antarctica. Applied and Environmental Microbiology 72, 5562-5568. Schauble...different letters differ at P < 0.05. Figure 2.7.2. There was no significant relationship between basal perchlorate content (at 4 ppb O3) and the change

  5. Mercury in Your Environment

    Science.gov (United States)

    Basic information about mercury, how it gets in the air, how people are exposed to it and health effects associated with exposure; what EPA and other organizations are doing to limit exposures; what citizens should know to minimize exposures and to reduce mercury in the environment; and information about products that contain mercury.

  6. Intentional intravenous mercury injection

    African Journals Online (AJOL)

    Three forms of mercury exist: elemental, inorganic and organic, all of which may be toxic with clinical consequences, depending on the type of exposure. Elemental mercury poisoning usually occurs via vapour inhalation, as mercury is well absorbed through the lungs. The central nervous system is then the major site of ...

  7. Kinetics analysis of a salt-tolerant perchlorate-reducing bacterium: effects of sodium, magnesium, and nitrate.

    Science.gov (United States)

    Xiao, Yeyuan; Roberts, Deborah J

    2013-08-06

    Salt-tolerant perchlorate-reducing bacteria can be used to regenerate ion-exchange brines or resins exhausted with perchlorate. A salt-tolerant perchlorate-reducing Marinobacter vinifirmus strain P4B1 was recently purified. This study determined the effects of Na(+) and Mg(2+) concentrations on the perchlorate reduction rate of P4B1. The results showed that strain P4B1 could utilize perchlorate and grow in the presence of 1.8% to 10.2% NaCl. Lower NaCl concentrations allowed faster perchlorate reduction. The addition of Mg(2+) to the culture showed significant effects on perchlorate reduction when perchlorate was the sole electron acceptor. A molar Mg(2+)/Na(+) ratio of ∼0.11 optimized perchlorate degradation and cell growth. When perchlorate and nitrate were both present, nitrate reduction did not start significantly until perchlorate was below 100 mg/L. Tests with washed cell suspensions indicated that strain P4B1 had both perchlorate and nitrate reduction enzymes. When the culture was exposed to both perchlorate and nitrate, the nitrate reduction enzyme activity was low. The maximum specific substrate utilization rate (Vm) and the half saturation coefficient (KS) for P4B1 (30 g/L NaCl) determined in this study were 0.049 ± 0.003 mg ClO4(-)/mg VSS-h and 18 ± 4 mg ClO4(-)/L, respectively.

  8. Perchlorate in the Hydrologic Cycle - An Overview of Sources and Occurrence

    Science.gov (United States)

    Stonestrom, D. A.; Jackson, W.; Mayer, K.; Orris, G. J.

    2007-12-01

    Perchlorate (ClO4-) in water and food is of concern due to deleterious health affects associated with hypothyroidism. The presence of widespread perchlorate in 0-to-28 ka-old pristine ground water of the Middle Rio Grande Basin (Plummer et al., 2006, ES&T, DOI:10.1021/es051739h), in ground water >1 mile from agricultural activities in the Southern High Plains (Rajagapolan et al., 2006, ES&T, DOI:10.1021/es052155i), and in unsaturated zones throughout the arid and semiarid southwestern United States (Rao et al., 2007, ES&T, DOI:10.1021/es062853i) clearly indicates that perchlorate is a non-exotic component of the hydrologic cycle, at least in dry environments. The natural system has been greatly perturbed in places by human activities. Most anthropogenic inputs are associated with the manufacture and use of explosives and rocket fuel, providing concentrated sources of excess perchlorate to the hydrologic cycle. Perchlorate-containing fertilizers and irrigation provide dispersed sources within and down-gradient from agricultural areas. Natural sources include photochemically mediated reactions involving ozone at the land surface and in the lower atmosphere. A growing body of work indicates that a small, but persistent, meteoric source acting over thousands of years can explain observed accumulations of unsaturated-zone perchlorate in arid regions. In addition to meteoric sources, oxyanions produced during volcanogenic processes can include appreciable amounts of natural perchlorate. Terrestrial plants take up perchlorate in soil water, with some species of xerophytic succulents concentrating the anion to high levels. Similarly, perchlorate in marine plants indicates that perchlorate is part of marine biochemical cycles. Perchlorate-bearing marine sediments of late Tertiary age suggest that perchlorate has been part of global geochemical cycles for millions of years and, furthermore, can be preserved in the subsurface despite the nearly ubiquitous presence of

  9. Individual activity coefficients of single ionic species of alkaline earth halogenides, alkaline earth perchlorates, and uranyl perchlorate at 25 0C in aqueous solutions

    International Nuclear Information System (INIS)

    Ferse, A.

    1981-01-01

    The individual activity coefficients of the single ionic species of alkaline-earth haloides, alkaline earth perchlorates and uranylic perchlorate, resp., at 25 0 C in aqueous solution are calculated and presented up to the concentration of about m = 4 mol/kg. The individual activity coefficients of the alkaline-earth ions pass mostly as a function of the concentration through a steep minimum and decrease from Mg 2+ to Ba 2+ . The individual activity coefficients of the anions pass generally as a function of the concentration through a marked flat minimum, but they increase - the complex perchlorate ions excepted - only a little above 1. (author)

  10. Fatty acid profile in milk from goats, Capra aegagrus hircus, exposed to perchlorate and its relationship with perchlorate residues in human milk.

    Science.gov (United States)

    Cheng, Qiuqiong; Smith, Ernest E; Kirk, Andrea B; Liu, Fujun; Boylan, Lee Mallory; McCarty, Michael E; Hart, Sybil; Dong, Linxia; Cobb, George P; Jackson, W Andrew; Anderson, Todd A

    2007-10-01

    Polyunsaturated fatty acids (PUFA) in milk are vital for normal growth and development of infant mammals. Changes in fatty acid composition were observed in milk fat from goats dosed with perchlorate (0.1 and 1 mg/kg body weight/day) for 31 days, but the effect was not persistent. Adaptation may be induced in these goats to compensate for the perchlorate effect. In an analysis of fatty acid composition in human milk samples, a weak negative correlation was observed between perchlorate concentrations and total PUFA in 38 human milk samples.

  11. PERCHLORATE UPTAKE BY SALT CEDAR (TAMARIX RAMOSISSIMA) IN THE LAS VEGAS WASH RIPARIAN ECOSYSTEM

    Science.gov (United States)

    Perchlorate ion (CIO4-) has been identified in samples of dormant salt cedar (Tamarix ramosissima) growing in the Las vegas Wash. Perchlorate is an oxidenat, but its reduction is kineticaly hindered. CXoncern over thyrpoid effects caused the Environmental Protection Agency (EPA...

  12. Perchlorate and halophilic prokaryotes: implications for possible halophilic life on Mars.

    Science.gov (United States)

    Oren, Aharon; Elevi Bardavid, Rahel; Mana, Lily

    2014-01-01

    In view of the finding of perchlorate among the salts detected by the Phoenix Lander on Mars, we investigated the relationships of halophilic heterotrophic microorganisms (archaea of the family Halobacteriaceae and the bacterium Halomonas elongata) toward perchlorate. All strains tested grew well in NaCl-based media containing 0.4 M perchlorate, but at the highest perchlorate concentrations, tested cells were swollen or distorted. Some species (Haloferax mediterranei, Haloferax denitrificans, Haloferax gibbonsii, Haloarcula marismortui, Haloarcula vallismortis) could use perchlorate as an electron acceptor for anaerobic growth. Although perchlorate is highly oxidizing, its presence at a concentration of 0.2 M for up to 2 weeks did not negatively affect the ability of a yeast extract-based medium to support growth of the archaeon Halobacterium salinarum. These findings show that presence of perchlorate among the salts on Mars does not preclude the possibility of halophilic life. If indeed the liquid brines that may exist on Mars are inhabited by salt-requiring or salt-tolerant microorganisms similar to the halophiles on Earth, presence of perchlorate may even be stimulatory when it can serve as an electron acceptor for respiratory activity in the anaerobic Martian environment.

  13. COMMENT ON "PERCHLORATE IDENTIFICATION IN FERTILIZERS" AND THE SUBSEQUENT ADDITION/CORRECTION [LETTER TO EDITOR

    Science.gov (United States)

    Perchlorate contamination has been reported in several fertilizer materials and not just in mined Chile saltpeter, where it is a welo-known natural impurity. To survey fertilizers for perchlorate, two analytical techniques have been applied to 45 products that span agricultural, ...

  14. Bifunctional lanthanum phosphate substrates as novel adsorbents and biocatalyst supports for perchlorate removal

    International Nuclear Information System (INIS)

    Sankar, Sasidharan; Prajeesh, Gangadharan Puthiya Veetil; Anupama, Vijaya Nadaraja; Krishnakumar, Bhaskaran; Hareesh, Padinhattayil; Nair, Balagopal N.; Warrier, Krishna Gopakumar; Hareesh, Unnikrishnan Nair Saraswathy

    2014-01-01

    Graphical abstract: Porous lanthanum phosphate substrates, obtained by an environmentally benign thermal gelation process, performed the role of dual functional sorbent facilitating perchlorate adsorption and bioremediation through the growth of perchlorate reducing microbial colonies. - Highlights: • Lanthanum phosphate monoliths as efficient perchlorate adsorbents. • And also as substrates for biofilm (perchlorate reducing bacteria) growth. • Environmentally benign thermal gelation process for substrate fabrication. • 98% adsorption efficiency for perchlorate concentrations up to 100 μg/L. • The regenerated monoliths show nearly 100% reusability. - Abstract: Porous lanthanum phosphate substrates, obtained by an environmentally benign colloidal forming process employing methyl cellulose, are reported here as excellent adsorbents of perchlorate with >98% efficiency and with 100% reusability. Additionally, the effectiveness of such substrates as biocatalyst supports that facilitate biofilm formation of perchlorate reducing microbes (Serratia marcescens NIIST 5) is also demonstrated for the first time. The adsorption of perchlorate ions is attributed to the pore structure of lanthanum phosphate substrate and the microbial attachment is primarily ascribed to its intrinsic hydrophobic property. Lanthanum phosphate thus emerges as a dual functional material that possesses an integrated adsorption/bioremediation property for the effective removal of ClO 4 − which is an increasingly important environmental contaminant

  15. The effects of sodium perchlorate on the liver of Molly Fish ( Poecilia ...

    African Journals Online (AJOL)

    Adult male molly fishes were reared up to ten days in control water or in water containing sodium perchlorate at concentrations of 1, 5, 25 and 125 ppm. Remarkable steatosis, fibrosis, hyperemia and necrosis were distinguished in parallel with increasing sodium perchlorate concentrations. The striking cellular damages ...

  16. Transport and degradation of perchlorate in deep vadose zone: implications from direct observations during bioremediation treatment

    Science.gov (United States)

    Dahan, Ofer; Katz, Idan; Avishai, Lior; Ronen, Zeev

    2017-08-01

    An in situ bioremediation experiment of a deep vadose zone ( ˜ 40 m) contaminated with a high concentration of perchlorate (> 25 000 mg L-1) was conducted through a full-scale field operation. Favourable environmental conditions for microbiological reduction of perchlorate were sought by infiltrating an electron donor-enriched water solution using drip irrigation underlying an airtight sealing liner. A vadose zone monitoring system (VMS) was used for real-time tracking of the percolation process, the penetration depth of dissolved organic carbon (DOC), and the variation in perchlorate concentration across the entire soil depth. The experimental conditions for each infiltration event were adjusted according to insight gained from data obtained by the VMS in previous stages. Continuous monitoring of the vadose zone indicated that in the top 13 m of the cross section, perchlorate concentration is dramatically reduced from thousands of milligrams per litre to near-detection limits with a concurrent increase in chloride concentration. Nevertheless, in the deeper parts of the vadose zone (consumable carbon and energy sources due to their enhanced biodegradation in the upper soil layers. Nevertheless, the increased DOC concentration with concurrent reduction in perchlorate and increase in the chloride-to-perchlorate ratio in the top 13 m indicate partial degradation of perchlorate in this zone. There was no evidence of improved degradation conditions in the deeper parts where the initial concentrations of perchlorate were significantly higher.

  17. Bifunctional lanthanum phosphate substrates as novel adsorbents and biocatalyst supports for perchlorate removal

    Energy Technology Data Exchange (ETDEWEB)

    Sankar, Sasidharan [Materials Science and Technology Division (India); Prajeesh, Gangadharan Puthiya Veetil; Anupama, Vijaya Nadaraja [Process Engineering and Environmental Technology Division, CSIR – National Institute for Interdisciplinary Science and Technology, Industrial Estate P.O., Thiruvananthapuram 695019 (India); Krishnakumar, Bhaskaran [Process Engineering and Environmental Technology Division, CSIR – National Institute for Interdisciplinary Science and Technology, Industrial Estate P.O., Thiruvananthapuram 695019 (India); Academy of Scientific and Industrial Research (AcSIR) (India); Hareesh, Padinhattayil [Materials Science and Technology Division (India); Nair, Balagopal N. [R and D Centre, Noritake Co. Ltd., Aichi (Japan); Warrier, Krishna Gopakumar [Materials Science and Technology Division (India); Academy of Scientific and Industrial Research (AcSIR) (India); Hareesh, Unnikrishnan Nair Saraswathy, E-mail: hareesh@niist.res.in [Materials Science and Technology Division (India); Academy of Scientific and Industrial Research (AcSIR) (India)

    2014-06-30

    Graphical abstract: Porous lanthanum phosphate substrates, obtained by an environmentally benign thermal gelation process, performed the role of dual functional sorbent facilitating perchlorate adsorption and bioremediation through the growth of perchlorate reducing microbial colonies. - Highlights: • Lanthanum phosphate monoliths as efficient perchlorate adsorbents. • And also as substrates for biofilm (perchlorate reducing bacteria) growth. • Environmentally benign thermal gelation process for substrate fabrication. • 98% adsorption efficiency for perchlorate concentrations up to 100 μg/L. • The regenerated monoliths show nearly 100% reusability. - Abstract: Porous lanthanum phosphate substrates, obtained by an environmentally benign colloidal forming process employing methyl cellulose, are reported here as excellent adsorbents of perchlorate with >98% efficiency and with 100% reusability. Additionally, the effectiveness of such substrates as biocatalyst supports that facilitate biofilm formation of perchlorate reducing microbes (Serratia marcescens NIIST 5) is also demonstrated for the first time. The adsorption of perchlorate ions is attributed to the pore structure of lanthanum phosphate substrate and the microbial attachment is primarily ascribed to its intrinsic hydrophobic property. Lanthanum phosphate thus emerges as a dual functional material that possesses an integrated adsorption/bioremediation property for the effective removal of ClO{sub 4}{sup −} which is an increasingly important environmental contaminant.

  18. A Novel System for the Separation and Destruction of Perchlorate from Contaminated Waters

    Science.gov (United States)

    Callahan, J.; Cumbal, N.; Fink, H.; Goergen, A.; Goldberg, D.; Merriam, K.; Caslake, L.; Kney, A. D.; Tavakoli, J.; Mylon, S. E.

    2007-12-01

    The remediation of perchlorate contaminated ground water through conventional ion-exchange technology requires frequent regeneration of the ion exchange resins and subsequent disposal of the regenerate solutions. The disposal of these wastes poses environmental challenges, and it is not an economically favorable option. This research focuses on the development of a two stage process for the separation and destruction of perchlorate from contaminated waters. The separation stage employs a transition metal-functionalized DOW3N- based ion exchangers which has shown promise as a remediation strategy for trace anionic contaminates such as perchlorate and can be successfully regenerated using mild solution conditions. Three transition metals (Fe(III), Ni(II), and Cu(II)) have been used to functionalize Dowex M4195 polymeric ligand exchangers. The resulting materials were compared with respect to their perchlorate selectivity, capacity, kinetics and regeneration efficiency through a series of batch and column experiments. In parallel studies, perchlorate reduction in batch laboratory cultures could indicate the potential to couple these two processes through the biological destruction of perchlorate in regenerant solutions. The destruction of perchlorate through functionalized zero-valent-iron (ZVI) nanoparticles may be an alternative or complimentary second stage to this process. Kinetic data from batch perchlorate reduction experiments in the presence of functionalized ZVI nanoparticles will be included.

  19. Mercury evaporation from amalgams with varied mercury contents.

    Science.gov (United States)

    Ohmoto, K; Nakajima, H; Ferracane, J L; Shintani, H; Okabe, T

    2000-09-01

    This study examined the relationship between mercury content and mercury evaporation from amalgams during setting. Two different types of commercial high-copper amalgams (single composition and admixed types) were used. Cylindrical specimens of each amalgam were prepared with five different mercury contents according to ADA Specification No.1. Specimens were also prepared by hand condensation. Mercury evaporation from amalgam specimens maintained at 37 degrees C was measured using a gold film mercury analyzer from 10 min after the end of trituration until the mercury concentration in air reached an undetectable level. The mercury content more clearly influenced the mercury evaporation from the admixed type amalgam specimens when the mercury content decreased below the manufacturers' recommended trituration conditions. Triturating with less mercury than the manufacturers' recommended amount cannot lower the evaporation of mercury from freshly made amalgam. Proper condensing procedures can minimize the mercury evaporation from the amalgam surface.

  20. Mercury balance analysis

    International Nuclear Information System (INIS)

    Maag, J.; Lassen, C.; Hansen, E.

    1996-01-01

    A detailed assessment of the consumption of mercury, divided into use areas, was carried out. Disposal and emissions to the environment were also qualified. The assessment is mainly based on data from 1992 - 1993. The most important source of emission of mercury to air is solid waste incineration which is assessed in particular to be due to the supply of mercury in batteries (most likely mercury oxide batteries from photo equipment) and to dental fillings. The second most important source of mercury emission to air is coal-fired power plants which are estimated to account for 200-500 kg of mercury emission p.a. Other mercury emissions are mainly related to waste treatment and disposal. The consumption of mercury is generally decreasing. During the period from 1982/83 - 1992-93, the total consumption of mercury in Denmark was about halved. This development is related to the fact that consumption with regard to several important use areas (batteries, dental fillings, thermometers etc.) has been significantly reduced, while for other purposes the use of mercury has completely, or almost disappeared, i.e. (fungicides for seed, tubes etc.). (EG)

  1. Process for low mercury coal

    Science.gov (United States)

    Merriam, Norman W.; Grimes, R. William; Tweed, Robert E.

    1995-01-01

    A process for producing low mercury coal during precombustion procedures by releasing mercury through discriminating mild heating that minimizes other burdensome constituents. Said mercury is recovered from the overhead gases by selective removal.

  2. Perchlorate uptake by salt cedar (Tamarix ramosissima) in the Las Vegas wash riparian ecosystem.

    Science.gov (United States)

    Urbansky, E T; Magnuson, M L; Kelty, C A; Brown, S K

    2000-07-10

    Perchlorate ion (ClO4-) has been identified in samples of dormant salt cedar (Tamarix ramosissima) growing in the Las Vegas Wash. Perchlorate is an oxidant, but its reduction is kinetically hindered. Concern over thyroid effects caused the Environmental Protection Agency (EPA) to add perchlorate to the drinking water Contaminant Candidate List (CCL). Beginning in 2001, utilities will look for perchlorate under the Unregulated Contaminants Monitoring Rule (UCMR). In wood samples acquired from the same plant growing in a contaminated stream, perchlorate concentrations were found as follows: 5-6 microg g(-1) in dry twigs extending above the water and 300 microg g(-1) in stalks immersed in the stream. Perchlorate was leached from samples of wood, and the resulting solutions were analyzed by ion chromatography after clean-up. The identification was confirmed by electrospray ionization mass spectrometry after complexation of perchlorate with decyltrimethylammonium cation. Because salt cedar is regarded as an invasive species, there are large scale programs aimed at eliminating it. However, this work suggests that salt cedar might play a role in the ecological distribution of perchlorate as an environmental contaminant. Consequently, a thorough investigation of the fate and transport of perchlorate in tamarisks is required to assess the effects that eradication might have on perchlorate-tainted riparian ecosystems, such as the Las Vegas Wash. This is especially important since water from the wash enters Lake Mead and the Colorado River and has the potential to affect the potable water source of tens of millions of people as well as irrigation water used on a variety of crops, including much of the lettuce produced in the USA.

  3. CRYSTALLIZATION KINETICS OF AMMONIUM PERCHLORATE IN AN AGITATED VESSEL

    Directory of Open Access Journals (Sweden)

    Nahidh Kaseer

    2013-05-01

    Full Text Available 31Overall crystal growth kinetics for ammonium perchlorate in laboratory scale batch  agitated vessel crystallizer have been determined from batch experiments performed in an integral mode. The effects of temperature between 30-60ºC, seed size 0.07, 0.120 and 0.275 mm and stirrer speed 160, 340, and 480 rpm, on the kinetics of crystal growth were investigated. Two different methods, viz. polynomial fitting and initial derivative were used to predict the kinetics expression. In general both methods gave comparable results for growth kinetics estimation. The order of growth process is not more than two. The activation energy for crystal growth of ammonium perchlorate was determined and found  to be equal to 5.8 kJ/ mole.            Finally, the influence of the affecting parameters on the crystal growth rate gives general expression that had an obvious dependence of the growth rate on each variables of concern (temperature, seed size, and stirrer speed .The general overall growth rate expression had shown that super saturation is the most significant variable. While the positive dependence of the stirrer speed demonstrates the importance of the diffusional step in the growth rate model. Moreover, the positive dependence of the seed size demonstrate the importance of the surface integration  step in the growth rate model. All the studied variables tend to suggest that the growth rate characteristics  of ammonium perchlorate from aqueous solution commenced in a batch crystallizer are diffusion kinetic controlled process.

  4. Discovery of Perchlorate at the Phoenix Landing Site

    Science.gov (United States)

    Hecht, M. H.; Kounaves, S. P.; Quinn, R. C.; West, S. J.; Young, S. M.; Clark, B. C.; Deflores, L. P.; Kapit, J. A.; Gospodinova, K.; Smith, P. H.; Team, T. P.

    2008-12-01

    One of several payload components on the Phoenix Lander, the Microscopy, Electrochemistry, and Conductivity Analyzer (MECA) is a suite of instruments that includes a microscopy station (optical and atomic force), four wet chemistry laboratories (WCL), and a soil probe. After the addition of up to 1 cm3 of martian soil into 25 ml of an aqueous calibration solution, the WCL measures solution cation and anion concentration, including pH, as well as total conductivity and cyclic voltammetry. With the exception of a redundant coulombic titration of halides, all cation and anion measurements are made with ion selective electrodes (ISE). Among the species not directly measured are sulfate and carbonate, which can be inferred indirectly by the response to acid and Ba additions, and soluble Fe, which can sometimes be detected with cyclic voltammetry. Responses from several cation and anion sensors were observed almost immediately upon addition of soil to the solution. Most striking was a three order-of-magnitude increase of the Hofmeister series sensor, which could only be explained by a large concentration of the perchlorate ion, ClO4-. Perchlorates are highly water soluble oxidants, often deliquescent, and some are powerful freezing-point depressors that can form aqueous brines at mean Martian temperatures appropriate to this region, as low as -70 deg C. This combination of properties has implications that span the disciplines of geochemistry, atmospheric sciences, astrobiology, and the potential for future human exploration. An important qualification of any such discussion, however, is uncertainty about how widespread the distribution of perchlorate may be. Other WCL findings, including alkaline pH and buffered response to purposeful addition of acid consistent with the presence of carbonates, will also be summarized.

  5. Mercury is Moon's brother

    International Nuclear Information System (INIS)

    Ksanfomalifi, L.V.

    1976-01-01

    The latest information on Mercury planet is presented obtained by studying the planet with the aid of radar and space vehicles. Rotation of Mercury about its axis has been discovered; within 2/3 of its year it executes a complete revolution about its axis. In images obtained by the ''Mariner-10'' Mercurys surface differs little from that of the Moon. The ''Mariner-10'' has also discovered the Mercurys atmosphere, which consists of extremely rarefied helium. The helium is continuously supplied to the planet by the solar wind. The Mercury's magnetic field has been discovered, whose strength is 35 x 10 -4 at the Equator and 70 x 10 -4 E at the poles. The inclination of the dipole axis to the Mercury's rotation axis is 7 deg

  6. In-Situ Bioreduction and Removal of Ammonium Perchlorate

    Science.gov (United States)

    2006-05-09

    ATCC 29543 (M26636), and Helicobacter pylori (M88157). 4.2.4 Mol% G+C analysis. Analyses of the mol% G+C of the chromosomal DNA was performed by... adhered to a value of 18 µg.L-1. In 1998 perchlorate was added to the US EPA Contaminant Candidate List for drinking water supplies (41) and in January...Dechloromonas and Dechlorosoma species. 5.2.3.1 Dechloromonas Dechloromonas. De.chlo.ro.mo´nas; L. pref. de from, Gr. adj. chloros green ("chlorine

  7. Peru Mercury Inventory 2006

    Science.gov (United States)

    Brooks, William E.; Sandoval, Esteban; Yepez, Miguel A.; Howard, Howell

    2007-01-01

    In 2004, a specific need for data on mercury use in South America was indicated by the United Nations Environmental Programme-Chemicals (UNEP-Chemicals) at a workshop on regional mercury pollution that took place in Buenos Aires, Argentina. Mercury has long been mined and used in South America for artisanal gold mining and imported for chlor-alkali production, dental amalgam, and other uses. The U.S. Geological Survey (USGS) provides information on domestic and international mercury production, trade, prices, sources, and recycling in its annual Minerals Yearbook mercury chapter. Therefore, in response to UNEP-Chemicals, the USGS, in collaboration with the Economic Section of the U.S. Embassy, Lima, has herein compiled data on Peru's exports, imports, and byproduct production of mercury. Peru was selected for this inventory because it has a 2000-year history of mercury production and use, and continues today as an important source of mercury for the global market, as a byproduct from its gold mines. Peru is a regional distributor of imported mercury and user of mercury for artisanal gold mining and chlor-alkali production. Peruvian customs data showed that 22 metric tons (t) of byproduct mercury was exported to the United States in 2006. Transshipped mercury was exported to Brazil (1 t), Colombia (1 t), and Guyana (1 t). Mercury was imported from the United States (54 t), Spain (19 t), and Kyrgyzstan (8 t) in 2006 and was used for artisanal gold mining, chlor-alkali production, dental amalgam, or transshipment to other countries in the region. Site visits and interviews provided information on the use and disposition of mercury for artisanal gold mining and other uses. Peru also imports mercury-containing batteries, electronics and computers, fluorescent lamps, and thermometers. In 2006, Peru imported approximately 1,900 t of a wide variety of fluorescent lamps; however, the mercury contained in these lamps, a minimum of approximately 76 kilograms (kg), and in

  8. Particle size distribution and perchlorate levels in settled dust from urban roads, parks, and roofs in Chengdu, China.

    Science.gov (United States)

    Li, Yiwen; Shen, Yang; Pi, Lu; Hu, Wenli; Chen, Mengqin; Luo, Yan; Li, Zhi; Su, Shijun; Ding, Sanglan; Gan, Zhiwei

    2016-01-01

    A total of 27 settled dust samples were collected from urban roads, parks, and roofs in Chengdu, China to investigate particle size distribution and perchlorate levels in different size fractions. Briefly, fine particle size fractions (dust samples, with mean percentages of 80.2%, 69.5%, and 77.2% for the urban roads, roofs, and the parks, respectively. Perchlorate was detected in all of the size-fractionated dust samples, with concentrations ranging from 73.0 to 6160 ng g(-1), and the median perchlorate levels increased with decreasing particle size. The perchlorate level in the finest fraction (dust intake is safe to both children and adults in Chengdu, China. However, due to perchlorate mainly existing in fine particles, there is a potential for perchlorate to transfer into surface water and the atmosphere by runoff and wind erosion or traffic emission, and this could act as an important perchlorate pollution source for the indoor environment, and merits further study.

  9. High-pressure structural study of Ammonium Perchlorate

    Science.gov (United States)

    Stavrou, Elissaios; Zaug, Joseph; Bastea, Sorin; Grivickas, Paulius; Greenberg, Eran; Kunz, Martin

    Ammonium perchlorate (AP) with the chemical formula NH4ClO4 is a powerful energetic oxidizer used as an ingredient in rocket propellants and explosive formulations. For this reason, its structural properties under extreme conditions have attracted considerable attention (M. Dunuwille et al., S. Hunter et al.). However, its structural properties under pressure are not completely understood. In addition to its importance as an energetic oxidizer, AP is one of the simplest supramolecular systems. Thus, a structural study of AP under pressure can provide crucial information in the context of the emerging field of high pressure supramolecular chemistry. Ammonium perchlorate has been studied using x-ray diffraction and Raman spectroscopy up to the record pressure of 40 GPa. The results reveal a pressure-induced first order phase transition at 4 GPa, in agreement with previous studies. However, preliminary analysis of our results contradicts with the previously proposed high-pressure phase, as determined by neutron diffraction. No further structural phase transitions have been observed up to the highest pressure of this study. Intermolecular bonding between NH4 and ClO4 ions will be discussed based on Raman spectroscopy measurements. This work was performed under the auspices of the U. S. Department of Energy by Lawrence Livermore National Security, LLC under Contract DE-AC52-07NA27344.

  10. The photochemistry of neptunium in aqueous perchloric acid solutions

    International Nuclear Information System (INIS)

    Friedman, H.A.; Toth, L.M.; Osborne, M.M.

    1979-01-01

    The photochemistry of neptunium ions in aqueous perchloric acid has been investigated using 254 and 300 nm UV radiation. In the absence of other reagents, Np(IV) and (V) oxidized to Np(VI), in a stepwise fashion, with individual quantum efficiencies for each step that vary from 0.02 to 0.004. Decreasing acid concentration favors the Np(IV) → Np(V) reaction whereas it hinders the Np(V) → Np(VI) photo-oxidation. When ethanol, acetaldehyde and other mild reducing agents are added to neptunium-perchloric acid solutions which are then photolyzed, the Np species are reduced to Np(III) in a stepwise fashion with individual quantum efficiencies that vary from 0.07 to 0.006. The overall photoredox reactions of neptunium are subject to competing secondary product reactions that become significant as the photolysis products accumulate. Absorption spectrophotometry was used to monitor the changes in Np oxidation states and reference spectra of the various Np oxidation states are given for 1.0 N HClO 4 . The Np species have absorption bands in the 300 to 1320 nm region that obey Beer's law only when they were properly resolved. (author)

  11. Modeling Mercury in Proteins

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Jeremy C [ORNL; Parks, Jerry M [ORNL

    2016-01-01

    Mercury (Hg) is a naturally occurring element that is released into the biosphere both by natural processes and anthropogenic activities. Although its reduced, elemental form Hg(0) is relatively non-toxic, other forms such as Hg2+ and, in particular, its methylated form, methylmercury, are toxic, with deleterious effects on both ecosystems and humans. Microorganisms play important roles in the transformation of mercury in the environment. Inorganic Hg2+ can be methylated by certain bacteria and archaea to form methylmercury. Conversely, bacteria also demethylate methylmercury and reduce Hg2+ to relatively inert Hg(0). Transformations and toxicity occur as a result of mercury interacting with various proteins. Clearly, then, understanding the toxic effects of mercury and its cycling in the environment requires characterization of these interactions. Computational approaches are ideally suited to studies of mercury in proteins because they can provide a detailed picture and circumvent issues associated with toxicity. Here we describe computational methods for investigating and characterizing how mercury binds to proteins, how inter- and intra-protein transfer of mercury is orchestrated in biological systems, and how chemical reactions in proteins transform the metal. We describe quantum chemical analyses of aqueous Hg(II), which reveal critical factors that determine ligand binding propensities. We then provide a perspective on how we used chemical reasoning to discover how microorganisms methylate mercury. We also highlight our combined computational and experimental studies of the proteins and enzymes of the mer operon, a suite of genes that confers mercury resistance in many bacteria. Lastly, we place work on mercury in proteins in the context of what is needed for a comprehensive multi-scale model of environmental mercury cycling.

  12. Exposure to perchlorate induces the formation of macrophage aggregates in the trunk kidney of zebrafish and mosquitofish

    Science.gov (United States)

    Capps, T.; Mukhi, S.; Rinchard, J.J.; Theodorakis, C.W.; Blazer, V.S.; Patino, R.

    2004-01-01

    Environmental contamination of ground and surface waters by perchlorate, derived from ammonium perchlorate (AP) and other perchlorate salts, is of increasing concern. Exposure to perchlorate can impair the thyroid endocrine system, which is thought to modulate renal and immune function in vertebrates. This study with zebrafish Danio rerio and eastern mosquitofish Gambusia holbrooki examined the histological effects of perchlorate on the trunk kidney, which in teleosts serves excretory and hemopoietic functions and therefore may be a target of perchlorate effects. Adult zebrafish of both sexes were exposed in the laboratory to waterborne, AP-derived perchlorate at measured concentrations of 18 mg/L for 8 weeks. Adult male mosquitofish were exposed to waterborne sodium perchlorate at measured perchlorate concentrations of 1-92 mg/L for 8 weeks. Control fish were kept in untreated water. The region of the body cavity containing the trunk kidney was processed from each fish for histological analysis. Macrophage aggregates (MAs), possible markers of contaminant exposure or immunotoxic effect, were present in the hemopoietic region of the kidney in both species exposed to perchlorate. The estimated percent area of kidney sections occupied by MAs was greater in zebrafish exposed to perchlorate at 18 mg/L (P < 0.05) than in controls. In male mosquitofish, the incidence of renal MAs increased proportionally with sodium perchlorate concentration and was significantly different from that of controls at 92 mg/L (P < 0.05). These observations confirm that in fish the kidney is affected by exposure to perchlorate. The concentrations of perchlorate at which the effects were noted are relatively high but within the range reported in some contaminated habitats.

  13. A review of perchlorate (ClO4-) occurrence in fruits and vegetables.

    Science.gov (United States)

    Calderón, R; Godoy, F; Escudey, M; Palma, P

    2017-02-01

    Since the 1990s, a large number of studies around the world have reported the presence of perchlorate in different types of environmental matrices. In view of their inherent characteristics, such as high solubility, mobility, persistence, and low affinity for the surface of soil, perchlorates are mobilized through the water-soil system and accumulate in edible plant species of high human consumption. However, the ingestion of food products containing perchlorate represents a potential health risk to people due to their adverse effects on thyroid, hormone, and neuronal development, mainly in infants and fetuses. At present, research has been centered on determining sources, fates, and remediation methods and not on its real extension in vegetables under farming conditions. This review presents a comprehensive overview and update of the frequent detection of perchlorate in fruits and vegetables produced and marketed around the world. Additionally, the impact of fertilizer on the potential addition of perchlorate to soil and its mobility in the water-soil-plant system is discussed. This review is organized into the following sections: sources of perchlorate, mobility in the water-soil system, presence in fruits and vegetables in different countries, international regulations, and toxicological studies. Finally, recommendations for future studies concerning perchlorate in fruits and vegetables are presented.

  14. Bacterial growth tolerance to concentrations of chlorate and perchlorate salts relevant to Mars

    Science.gov (United States)

    Al Soudi, Amer F.; Farhat, Omar; Chen, Fei; Clark, Benton C.; Schneegurt, Mark A.

    2017-07-01

    The Phoenix lander at Mars polar cap found appreciable levels of (per)chlorate salts, a mixture of perchlorate and chlorate salts of Ca, Fe, Mg and Na at levels of ~0.6% in regolith. These salts are highly hygroscopic and can form saturated brines through deliquescence, likely producing aqueous solutions with very low freezing points on Mars. To support planetary protection efforts, we have measured bacterial growth tolerance to (per)chlorate salts. Existing bacterial isolates from the Great Salt Plains of Oklahoma (NaCl-rich) and Hot Lake in Washington (MgSO4-rich) were tested in high concentrations of Mg, K and Na salts of chlorate and perchlorate. Strong growth was observed with nearly all of these salinotolerant isolates at 1% (~0.1 M) (per)chlorate salts, similar to concentrations observed in bulk soils on Mars. Growth in perchlorate salts was observed at concentrations of at least 10% (~1.0 M). Greater tolerance was observed for chlorate salts, where growth was observed to 2.75 M (>25%). Tolerance to K salts was greatest, followed by Mg salts and then Na salts. Tolerances varied among isolates, even among those within the same phylogenetic clade. Tolerant bacteria included genera that also are found in spacecraft assembly facilities. Substantial microbial tolerance to (per)chlorate salts is a concern for planetary protection since tolerant microbes contaminating spacecraft would have a greater chance for survival and proliferation, despite the harsh chemical conditions found near the surface of Mars.

  15. Effluent recirculation to improve perchlorate reduction in a fixed biofilm reactor.

    Science.gov (United States)

    Choi, Hyeoksun; Silverstein, Joann

    2007-09-01

    The effect of effluent recirculation on perchlorate reduction in a nominally plug-flow fixed biofilm reactor was studied in two cases: influent concentrations of 10 and 400 microg/L at low hydraulic loading rates (1.9 and 37.5 m(3)/m(2)/day without and with recirculation, respectively) and after a step increase in perchlorate concentration to 1,000 microg/L at the higher hydraulic loading rate (5 and 100 m(3)/m(2)/day without and with recirculation, respectively). Complete perchlorate reduction was sustained for influent concentrations of 400 and 10 microg/L in both flow regimes at the lower hydraulic loading rates. Reactor tracer profiles showed that biofilm diffusion had a more significant effect on mass transfer in the plug flow reactor compared with recirculation. The recirculation bioreactor acclimated more rapidly to increased hydraulic and perchlorate mass loading rates with significantly lower effluent perchlorate compared to the plug flow reactor: 16 microg/L versus 46 microg/L, respectively, although complete perchlorate removal was not achieved in either flow regime after 21 days acclimation to the higher loading. Total biofilm mass was more uniformly distributed in the recirculation reactor which may have contributed to better performance under increased perchlorate loading.

  16. The relationship between perchlorate in drinking water and cord blood thyroid hormones: First experience from Iran

    Directory of Open Access Journals (Sweden)

    Ashraf Javidi

    2015-01-01

    Full Text Available Background: Considering the controversial information regarding the effects of perchlorate on thyroid function of high risk population as neonates, and given the high prevalence rate of thyroid disorders specially congenital hypothyroidism in our region, this study aims to investigate for the first time in Iran, the relationship between drinking groundwater perchlorate and cord blood thyroid hormones level in an industrial region. Methods: In this cross-sectional study, drinking groundwater perchlorate level of rural areas of Zarinshahr, Isfahan was measured. Simultaneously, cord blood level of thyroid hormones of neonates born in the studied region was measured. Thyroid function test of neonates in regions with low and high perchlorate level were compared. Results: In this study, 25 tap water samples were obtained for perchlorate measurement. Level of cord blood thyroid stimulating hormone (TSH, T4 and T3 of 25 neonates were measured. Mean (standard deviation of perchlorate, TSH, T4 and T3 was 3.59 (5.10 μg/l, 7.81 (4.14 mIU/m, 6.06 (0.85 mg/dl, and 63.46 (17.53 mg/dl, respectively. Mean levels of thyroid function tests were not different in low ( 0.05. Conclusions: Perchlorate did not appear to be related to thyroid function of neonates in the studied industrial region. It seems that iodine status of the regions, as well as other environmental contaminants and genetic background, could impact on its relation with thyroid function of neonates.

  17. Perchlorate Exposure Reduces Primordial Germ Cell Number in Female Threespine Stickleback.

    Directory of Open Access Journals (Sweden)

    Ann M Petersen

    Full Text Available Perchlorate is a common aquatic contaminant that has long been known to affect thyroid function in vertebrates, including humans. More recently perchlorate has been shown to affect primordial sexual differentiation in the aquatic model fishes zebrafish and threespine stickleback, but the mechanism has been unclear. Stickleback exposed to perchlorate from fertilization have increased androgen levels in the embryo and disrupted reproductive morphologies as adults, suggesting that perchlorate could disrupt the earliest stages of primordial sexual differentiation when primordial germ cells (PGCs begin to form the gonad. Female stickleback have three to four times the number of PGCs as males during the first weeks of development. We hypothesized that perchlorate exposure affects primordial sexual differentiation by reducing the number of germ cells in the gonad during an important window of stickleback sex determination at 14-18 days post fertilization (dpf. We tested this hypothesis by quantifying the number of PGCs at 16 dpf in control and 100 mg/L perchlorate-treated male and female stickleback. Perchlorate exposure from the time of fertilization resulted in significantly reduced PGC number only in genotypic females, suggesting that the masculinizing effects of perchlorate observed in adult stickleback may result from early changes to the number of PGCs at a time critical for sex determination. To our knowledge, this is the first evidence of a connection between an endocrine disruptor and reduction in PGC number prior to the first meiosis during sex determination. These findings suggest that a mode of action of perchlorate on adult reproductive phenotypes in vertebrates, including humans, such as altered fecundity and sex reversal or intersex gonads, may stem from early changes to germ cell development.

  18. Transport and degradation of perchlorate in deep vadose zone: implications from direct observations during bioremediation treatment

    Directory of Open Access Journals (Sweden)

    O. Dahan

    2017-08-01

    Full Text Available An in situ bioremediation experiment of a deep vadose zone ( ∼  40 m contaminated with a high concentration of perchlorate (> 25 000 mg L−1 was conducted through a full-scale field operation. Favourable environmental conditions for microbiological reduction of perchlorate were sought by infiltrating an electron donor-enriched water solution using drip irrigation underlying an airtight sealing liner. A vadose zone monitoring system (VMS was used for real-time tracking of the percolation process, the penetration depth of dissolved organic carbon (DOC, and the variation in perchlorate concentration across the entire soil depth. The experimental conditions for each infiltration event were adjusted according to insight gained from data obtained by the VMS in previous stages. Continuous monitoring of the vadose zone indicated that in the top 13 m of the cross section, perchlorate concentration is dramatically reduced from thousands of milligrams per litre to near-detection limits with a concurrent increase in chloride concentration. Nevertheless, in the deeper parts of the vadose zone (< 17 m, perchlorate concentration increased, suggesting its mobilization down through the cross section. Breakthrough of DOC and bromide at different depths across the unsaturated zone showed limited migration capacity of biologically consumable carbon and energy sources due to their enhanced biodegradation in the upper soil layers. Nevertheless, the increased DOC concentration with concurrent reduction in perchlorate and increase in the chloride-to-perchlorate ratio in the top 13 m indicate partial degradation of perchlorate in this zone. There was no evidence of improved degradation conditions in the deeper parts where the initial concentrations of perchlorate were significantly higher.

  19. Perchlorate Exposure Reduces Primordial Germ Cell Number in Female Threespine Stickleback.

    Science.gov (United States)

    Petersen, Ann M; Earp, Nathanial C; Redmond, Mandy E; Postlethwait, John H; von Hippel, Frank A; Buck, C Loren; Cresko, William A

    2016-01-01

    Perchlorate is a common aquatic contaminant that has long been known to affect thyroid function in vertebrates, including humans. More recently perchlorate has been shown to affect primordial sexual differentiation in the aquatic model fishes zebrafish and threespine stickleback, but the mechanism has been unclear. Stickleback exposed to perchlorate from fertilization have increased androgen levels in the embryo and disrupted reproductive morphologies as adults, suggesting that perchlorate could disrupt the earliest stages of primordial sexual differentiation when primordial germ cells (PGCs) begin to form the gonad. Female stickleback have three to four times the number of PGCs as males during the first weeks of development. We hypothesized that perchlorate exposure affects primordial sexual differentiation by reducing the number of germ cells in the gonad during an important window of stickleback sex determination at 14-18 days post fertilization (dpf). We tested this hypothesis by quantifying the number of PGCs at 16 dpf in control and 100 mg/L perchlorate-treated male and female stickleback. Perchlorate exposure from the time of fertilization resulted in significantly reduced PGC number only in genotypic females, suggesting that the masculinizing effects of perchlorate observed in adult stickleback may result from early changes to the number of PGCs at a time critical for sex determination. To our knowledge, this is the first evidence of a connection between an endocrine disruptor and reduction in PGC number prior to the first meiosis during sex determination. These findings suggest that a mode of action of perchlorate on adult reproductive phenotypes in vertebrates, including humans, such as altered fecundity and sex reversal or intersex gonads, may stem from early changes to germ cell development.

  20. Intentional intravenous mercury injection

    African Journals Online (AJOL)

    In this case report, intravenous complications, treatment strategies and possible ... Mercury toxicity is commonly associated with vapour inhalation or oral ingestion, for which there exist definite treatment options. Intravenous mercury ... personality, anxiousness, irritability, insomnia, depression and drowsi- ness.[1] However ...

  1. International mercury conference

    CSIR Research Space (South Africa)

    Leaner, J

    2006-10-01

    Full Text Available Mercury (Hg) affects human health and the environment, it calls for immediate action. Action is needed at local, regional and international level to reduce the risk associated with mercury, which is a global international problem, as it is a...

  2. Mercury's shifting, rolling past

    OpenAIRE

    Trulove, Susan

    2008-01-01

    Patterns of scalloped-edged cliffs or lobate scarps on Mercury's surface are thrust faults that are consistent with the planet shrinking and cooling with time. However, compression occurred in the planet's early history and Mariner 10 images revealed decades ago that lobate scarps are among the youngest features on Mercury. Why don't we find more evidence of older compressive features?

  3. MESSENGER: Exploring Mercury's Magnetosphere

    Science.gov (United States)

    Slavin, James A.

    2008-01-01

    The MESSENGER mission to Mercury offers our first opportunity to explore this planet's miniature magnetosphere since Mariner 10's brief fly-bys in 1974-5. Mercury's magnetosphere is unique in many respects. The magnetosphere of Mercury is the smallest in the solar system with its magnetic field typically standing off the solar wind only - 1000 to 2000 km above the surface. For this reason there are no closed dri-fi paths for energetic particles and, hence, no radiation belts; the characteristic time scales for wave propagation and convective transport are short possibly coupling kinetic and fluid modes; magnetic reconnection at the dayside magnetopause may erode the subsolar magnetosphere allowing solar wind ions to directly impact the dayside regolith; inductive currents in Mercury's interior should act to modify the solar In addition, Mercury's magnetosphere is the only one with its defining magnetic flux tubes rooted in a planetary regolith as opposed to an atmosphere with a conductive ionosphere. This lack of an ionosphere is thought to be the underlying reason for the brevity of the very intense, but short lived, approx. 1-2 min, substorm-like energetic particle events observed by Mariner 10 in Mercury's magnetic tail. In this seminar, we review what we think we know about Mercury's magnetosphere and describe the MESSENGER science team's strategy for obtaining answers to the outstanding science questions surrounding the interaction of the solar wind with Mercury and its small, but dynamic magnetosphere.

  4. Global Mercury Assessment 2013

    International Development Research Centre (IDRC) Digital Library (Canada)

    mercury pollution. This summary report and the accompanying. Technical Background Report for the Global. Mercury Assessment 2013 are developed in response to Decision 25/5, paragraph ... The use of different pollution control technologies in different ...... vegetation, snow, freshwater, and seawater. One of the largest ...

  5. Municipal actions to reduce mercury

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-03-15

    This paper presented proper management practices for products containing mercury. The measures can help reduce mercury releases, occupational exposure and mercury spills, thereby preventing impacts on human health and the environment. Despite mercury's toxic nature, many common products that contain mercury are commercially available. These include thermostats, thermometers, fluorescent lamps, pressure measuring devices, electrical switches and relays, and dental amalgam. Mercury emissions are also associated with base metal smelting, waste incineration and coal-fired power generation. Mercury in the environment is a global issue, because it can travel in the atmosphere on wind currents. The actions taken by municipalities to address the issue include reducing or eliminating mercury releases from internal municipal operations and sources within the community. This document provided guidance on how to develop a Municipal Mercury Elimination Policy and Plan that will help reduce mercury releases. It presented information and case studies that will help municipalities manage mercury-containing products found in municipal buildings and street lighting. Information on sources of mercury from within the community was presented along with case studies that can help municipalities determine where community action is needed to reduce mercury releases. The 5 modules of this document were intended to help municipalities identify priorities, timelines and budget requirements for mercury initiatives. It was emphasized that municipalities that adopt a Municipal Mercury Elimination Policy and Plan formally commit to reducing and eliminating mercury from the environment. tabs., figs.

  6. Getting Mercury out of Schools.

    Science.gov (United States)

    1999

    This guide was prepared while working with many Massachusetts schools to remove items that contain mercury and to find suitable alternatives. It contains fact sheets on: mercury in science laboratories and classrooms, mercury in school buildings and maintenance areas, mercury in the medical office and in medical technology classrooms in vocational…

  7. Mercury's Dynamic Magnetic Tail

    Science.gov (United States)

    Slavin, James A.

    2010-01-01

    The Mariner 10 and MESSENGER flybys of Mercury have revealed a magnetosphere that is likely the most responsive to upstream interplanetary conditions of any in the solar system. The source of the great dynamic variability observed during these brief passages is due to Mercury's proximity to the Sun and the inverse proportionality between reconnection rate and solar wind Alfven Mach number. However, this planet's lack of an ionosphere and its small physical dimensions also contribute to Mercury's very brief Dungey cycle, approx. 2 min, which governs the time scale for internal plasma circulation. Current observations and understanding of the structure and dynamics of Mercury's magnetotail are summarized and discussed. Special emphasis will be placed upon such questions as: 1) How much access does the solar wind have to this small magnetosphere as a function of upstream conditions? 2) What roles do heavy planetary ions play? 3) Do Earth-like substorms take place at Mercury? 4) How does Mercury's tail respond to extreme solar wind events such coronal mass ejections? Prospects for progress due to advances in the global magnetohydrodynamic and hybrid simulation modeling and the measurements to be taken by MESSENGER after it enters Mercury orbit on March 18, 2011 will be discussed.

  8. Perchlorate: Health Effects and Technologies for Its Removal from Water Resources

    Directory of Open Access Journals (Sweden)

    Thiruvenkatachari Viraraghavan

    2009-04-01

    Full Text Available Perchlorate has been found in drinking water and surface waters in the United States and Canada. It is primarily associated with release from defense and military operations. Natural sources include certain fertilizers and potash ores. Although it is a strong oxidant, perchlorate is very persistent in the environment. At high concentrations perchlorate can affect the thyroid gland by inhibiting the uptake of iodine. A maximum contaminant level has not been set, while a guidance value of 6 ppb has been suggested by Health Canada. Perchlorate is measured in environmental samples primarily by ion chromatography. It can be removed from water by anion exchange or membrane filtration. Biological and chemical processes are also effective in removing this species from water.

  9. Applications of selective ion exchange for perchlorate removal, recovery, and environmental forensics

    Science.gov (United States)

    Gu, Baohua; Böhlke, John Karl; Sturchio, Neil C.; Hatzinger, Paul B.; Jackson, Andrew; Beloso, Abelardo D.; Heraty, Linnea J.; Bian, Yongrong; Jiang, Xin; Brown, Gilbert M.; SenGupta, Arup K.

    2011-01-01

    Perchlorate (ClO4-) is a widespread contaminant found in drinking water and groundwater that has caused far-reaching ramifications ranging from public health issues to potential liabilities arising from environmental clean-up requirements.

  10. Feasibility Study for the Reduction of Perchlorate, Iodide, and Other Aqueous Anions

    National Research Council Canada - National Science Library

    Clewell, Rebecca A; Tsui, David T; Mattie, David R

    1999-01-01

    Cyclic Voltammetry (CV) was used as a technique to determine the feasibility of the use of a coulometric detector in the determination of perchlorate, iodide, and various other anions commonly found in drinking water...

  11. ANALYSIS OF HYDROPONIC FERTILIZER MATRIXES FOR PERCHLORATE: COMPARISON OF ANALYTICAL TECHNIQUES

    Science.gov (United States)

    Seven retail hydroponic nitrate fertilizer products, two liquid and five solid, were comparatively analyzed for the perchlorate anion (ClO4-) by ion chromatography (IC) with suppressed conductivity detection, complexation electrospray ionization mass spectrometry (cESI-MS), norma...

  12. Theobrominium perchlorate dibenzo-18-crown-6 3.25-hydrate

    Directory of Open Access Journals (Sweden)

    Vladislav Kulikov

    2013-07-01

    Full Text Available The co-crystal, C7H9N4O2+·ClO4−·C20H24O6·3.25H2O, consists of theobrominium (3,7-dimethyl-2,6-dioxo-1H-purin-9-ium cations, perchlorate anions and dibenzo-18-crown-6 and water molecules. The crown ether is in a bent conformation, in which the planes of the aromatic rings subtend an angle of 63.7 (1°. Intermolecular O—H...O hydrogen bonding between the water molecules and the O atoms of the cyclic ether delimit an empty space reminiscent of a hollow cage. The water molecules are additionally linked to the cations by N—H...O hydrogen bonding. One of the positions of the water molecules is occupied only fractionally (25% and is located outside this framework.

  13. Luminescent Properties of Oxazine 170 Perchlorate Doped PMMA Fiber

    Directory of Open Access Journals (Sweden)

    Piotr Miluski

    2017-04-01

    Full Text Available The article presents fabrication and luminescent properties of poly(methyl methacrylate (PMMA fiber doped by Oxazine 170 perchlorate. The bright fluorescence of polymeric fiber (at molar fluorescent organic dye concentration 4.3 × 10−5 was characterized in terms of spectrum and signal attenuation vs. the fiber length. The significant changes in fluorescence spectrum (λmax red shift average slope 4.6 nm/cm and Full Width at Half Maximum (FWHM increasing slope 6.7 nm/cm have been noticed for the length of the fiber (0.02–0.08 m which corresponds to a high overlapping region of absorption and emission spectra of used dye. The red shift of λmax (c.a. 80 nm was presented in fabricated polymeric fiber at distance 0.85 m. The obtained characteristics can be used for luminescent properties optimization of fluorescent organic-dye-doped PMMA fiber.

  14. Inorganic: the other mercury.

    Science.gov (United States)

    Risher, John F; De Rosa, Christopher T

    2007-11-01

    There is a broad array of mercury species to which humans may be exposed. While exposure to methylmercury through fish consumption is widely recognized, the public is less aware of the sources and potential toxicity of inorganic forms of mercury. Some oral and laboratory thermometers, barometers, small batteries, thermostats, gas pressure regulators, light switches, dental amalgam fillings, cosmetic products, medications, cultural/religious practices, and gold mining all represent potential sources of exposure to inorganic forms of mercury. The route of exposure, the extent of absorption, the pharmacokinetics, and the effects all vary with the specific form of mercury and the magnitude and duration of exposure. If exposure is suspected, a number of tissue analyses can be conducted to confirm exposure or to determine whether an exposure might reasonably be expected to be biologically significant. By contrast with determination of exposure to methylmercury, for which hair and blood are credible indicators, urine is the preferred biological medium for the determination of exposure to inorganic mercury, including elemental mercury, with blood normally being of value only if exposure is ongoing. Although treatments are available to help rid the body of mercury in cases of extreme exposure, prevention of exposure will make such treatments unnecessary. Knowing the sources of mercury and avoiding unnecessary exposure are the prudent ways of preventing mercury intoxication. When exposure occurs, it should be kept in mind that not all unwanted exposures will result in adverse health consequences. In all cases, elimination of the source of exposure should be the first priority of public health officials.

  15. Solvent extraction studies on the mixed ligand complexes of lanthanides with antipyrine and perchlorate

    International Nuclear Information System (INIS)

    Murthy, M.V.K.; Satyanarayana, D.

    1981-01-01

    Lanthanide ions are found to form colourless mixed-ligand complexes with antipyrine in presence of perchlorate at pH 4.0, and these are quantitatively extractable into nitrobenzene. The composition of the extracted species is shown to be metal:antipyrine:perchlorate = 1:6:3. The variation of the extraction constants with atomic number of the lanthanides is attributed to the 'tetrad effect'. (author)

  16. Treatment of amiodarone induced hyperthyroidism with potassium perchlorate and methimazole during amiodarone treatment.

    OpenAIRE

    Reichert, L. J.; de Rooy, H. A.

    1989-01-01

    To exploit the antiarrhythmic effect of amiodarone when patients develop the side effect of thyrotoxicosis three patients with hyperthyroidism induced by amiodarone were given simultaneously 1 g potassium perchlorate a day for 40 days and a starting dose of 40 mg methimazole a day while they continued to take amiodarone. As hyperthyroidism might have recurred after potassium perchlorate treatment was stopped the dose of methimazole was not reduced until biochemical hypothyroidism (raised thyr...

  17. Validation of a Novel Bioassay for Low-level Perchlorate Determination

    Science.gov (United States)

    2014-04-01

    concentration would be observed. Both strains were cultivated on the same medium , and the procedure described in Section L-1.0 was used to prepare...RA and Achenbach LA. (2000) The diverse microbiology of (per)chlorate reduction. In: Urbansky ED. Perchlorate in the Environment. Kluwer Academic...phosphate medium containing 10 mM acetate and 10 mM chlorate. Cells in late exponential growth phase were harvested by centrifugation. The cell

  18. Effect of Hydration State of Martian Perchlorate Salts on Their Decomposition Temperatures During Thermal Extraction

    Science.gov (United States)

    Royle, Samuel H.; Montgomery, Wren; Kounaves, Samuel P.; Sephton, Mark A.

    2017-12-01

    Three Mars missions have analyzed the composition of surface samples using thermal extraction techniques. The temperatures of decomposition have been used as diagnostic information for the materials present. One compound of great current interest is perchlorate, a relatively recently discovered component of Mars' surface geochemistry that leads to deleterious effects on organic matter during thermal extraction. Knowledge of the thermal decomposition behavior of perchlorate salts is essential for mineral identification and possible avoidance of confounding interactions with organic matter. We have performed a series of experiments which reveal that the hydration state of magnesium perchlorate has a significant effect on decomposition temperature, with differing temperature releases of oxygen corresponding to different perchlorate hydration states (peak of O2 release shifts from 500 to 600°C as the proportion of the tetrahydrate form in the sample increases). Changes in crystallinity/crystal size may also have a secondary effect on the temperature of decomposition, and although these surface effects appear to be minor for our samples, further investigation may be warranted. A less than full appreciation of the hydration state of perchlorate salts during thermal extraction analyses could lead to misidentification of the number and the nature of perchlorate phases present.

  19. Numerical model for biological fluidized-bed reactor treatment of perchlorate contaminated groundwater.

    Science.gov (United States)

    McCarty, Perry L; Meyer, Travis E

    2005-02-01

    Biological fluidized-bed reactor (BFBR) treatment with 1.3 mm granular activated carbon as support medium is being used for removal of 2.6 mg/L perchlorate from contaminated groundwater in California. The California drinking-water action level of 4 microg/L for perchlorate requires 99.9% perchlorate removal. Sufficient ethanol, the electron donor, is added to remove oxygen and nitrate as well as perchlorate, as all three serve as electron acceptors, but with biological preference for oxygen and nitrate. A numerical BFBR model based upon basic physical, chemical, and biological processes including reaction stoichiometry, biofilm kinetics, and sequential electron acceptor usage was developed and evaluated with the full-scale treatment results. A key fitting parameter was bacterial detachment rate, which impacts reaction stoichiometry. For best model fit this was found to vary between 0.062 and 0.31 d(-1), with an average of 0.22 d(-1). The model indicates that GAC particle size, reactor diameter, and perchlorate concentration affect BFBR performance. While empty-bed detention time might be decreased somewhat below 10 min by an increase in either GAC particle size or reactor diameter, the current design provides a good factor of safety in operation. With a 10 min detention time, the effluent goal of 4 microg/L should be achievable even with influent perchlorate concentration as high as 10 mg/L.

  20. Perchlorate reduction by hydrogen autotrophic bacteria and microbial community analysis using high-throughput sequencing.

    Science.gov (United States)

    Wan, Dongjin; Liu, Yongde; Niu, Zhenhua; Xiao, Shuhu; Li, Daorong

    2016-02-01

    Hydrogen autotrophic reduction of perchlorate have advantages of high removal efficiency and harmless to drinking water. But so far the reported information about the microbial community structure was comparatively limited, changes in the biodiversity and the dominant bacteria during acclimation process required detailed study. In this study, perchlorate-reducing hydrogen autotrophic bacteria were acclimated by hydrogen aeration from activated sludge. For the first time, high-throughput sequencing was applied to analyze changes in biodiversity and the dominant bacteria during acclimation process. The Michaelis-Menten model described the perchlorate reduction kinetics well. Model parameters q(max) and K(s) were 2.521-3.245 (mg ClO4(-)/gVSS h) and 5.44-8.23 (mg/l), respectively. Microbial perchlorate reduction occurred across at pH range 5.0-11.0; removal was highest at pH 9.0. The enriched mixed bacteria could use perchlorate, nitrate and sulfate as electron accepter, and the sequence of preference was: NO3(-) > ClO4(-) > SO4(2-). Compared to the feed culture, biodiversity decreased greatly during acclimation process, the microbial community structure gradually stabilized after 9 acclimation cycles. The Thauera genus related to Rhodocyclales was the dominated perchlorate reducing bacteria (PRB) in the mixed culture.

  1. Perchlorate formation on Mars through surface radiolysis-initiated atmospheric chemistry: A potential mechanism

    Science.gov (United States)

    Wilson, Eric H.; Atreya, Sushil K.; Kaiser, Ralf I.; Mahaffy, Paul R.

    2016-08-01

    Recent observations of the Martian surface by the Phoenix lander and the Sample Analysis at Mars indicate the presence of perchlorate (ClO4-). The abundance and isotopic composition of these perchlorates suggest that the mechanisms responsible for their formation in the Martian environment may be unique in our solar system. With this in mind, we propose a potential mechanism for the production of Martian perchlorate: the radiolysis of the Martian surface by galactic cosmic rays, followed by the sublimation of chlorine oxides into the atmosphere and their subsequent synthesis to form perchloric acid (HClO4) in the atmosphere, and the surface deposition and subsequent mineralization of HClO4 in the regolith to form surface perchlorates. To evaluate the viability of this mechanism, we employ a one-dimensional chemical model, examining chlorine chemistry in the context of Martian atmospheric chemistry. Considering the chlorine oxide, OClO, we find that an OClO flux as low as 3.2 × 107 molecules cm-2 s-1 sublimated into the atmosphere from the surface could produce sufficient HClO4 to explain the perchlorate concentration on Mars, assuming an accumulation depth of 30 cm and integrated over the Amazonian period. Radiolysis provides an efficient pathway for the oxidation of chlorine, bypassing the efficient Cl/HCl recycling mechanism that characterizes HClO4 formation mechanisms proposed for the Earth but not Mars.

  2. Recovery of mercury from mercury compounds via electrolytic methods

    Science.gov (United States)

    Grossman, Mark W.; George, William A.

    1988-01-01

    A process for electrolytically recovering mercury from mercury compounds is provided. In one embodiment, Hg is recovered from Hg.sub.2 Cl.sub.2 employing as the electrolyte solution a mixture of HCl and H.sub.2 O. In another embodiment, Hg is electrolytically recovered from HgO wherein the electrolyte solution is comprised of glacial acetic acid and H.sub.2 O. Also provided is an apparatus for producing isotopically enriched mercury compounds in a reactor and then transporting the dissolved compounds into an electrolytic cell where mercury ions are electrolytically reduced and elemental mercury recovered from the mercury compounds.

  3. DDT performance of energetic cobalt coordination compounds. [Dozen of compounds similar to 2-(5-cyanotetrazolato)pentaaminecobalt perchlorate, trinitrotriamine cobalt, dinitrobis(ethylenediamine) cobalt perchlorate

    Energy Technology Data Exchange (ETDEWEB)

    Lieberman, M.L.; Fleming, W.

    1986-01-01

    The compound 2-(5-cyanotetrazolato)pentaamminecobalt(III) perchlorate (CP) has been utilized in low-voltage detonators because it reliably undergoes deflagration-to-detonation transition (DDT). In the present investigation, we have compared the performance of over a dozen similar compounds. These compounds all have cobalt as the coordinating metal, most are ammine complexes, and all except one incorporate the perchlorate anion as an oxidizer. Chemical factors such as fuel-to-oxidizer ratio, trigger group, and organic content have been varied. 18 refs., 7 figs., 2 tabs.

  4. Fabrication of ammonium perchlorate/copper-chromium oxides core-shell nanocomposites for catalytic thermal decomposition of ammonium perchlorate

    Energy Technology Data Exchange (ETDEWEB)

    Eslami, Abbas, E-mail: eslami@umz.ac.ir [Department of Inorganic Chemistry, Faculty of Chemistry, University of Mazandaran, P.O.Box 47416-95447, Babolsar (Iran, Islamic Republic of); Juibari, Nafise Modanlou [Department of Inorganic Chemistry, Faculty of Chemistry, University of Mazandaran, P.O.Box 47416-95447, Babolsar (Iran, Islamic Republic of); Hosseini, Seyed Ghorban [Department of Chemistry, Malek Ashtar University of Technology, P.O. Box 16765-3454, Tehran (Iran, Islamic Republic of)

    2016-09-15

    The ammonium perchlorate/Cu(II)-Cr(III)-oxides(AP/Cu-Cr-O) core-shell nanocomposites were in-situ prepared by deposition of copper and chromium oxides on suspended ammonium perchlorate particles in ethyl acetate as solvent. The results of differential scanning calorimetery (DSC) and thermal gravimetric analysis (TGA) experiments showed that the nanocomposites have excellent catalytic effect on the thermal decomposition of AP, so that the released heat increases up to about 3-fold over initial values, changing from 450 J/g for pure AP to 1510 J/g for most appropriate mixture. For better comparison, single metal oxide/AP core-shell nanocomposite have also been prepared and the results showed that they have less catalytic effect respect to mixed metal oxides system. Scanning electron microscopy (SEM) results revealed homogenous deposition of nanoparticles on the surface of AP and fabrication of core-shell structures. The kinetic parameters of thermal decomposition of both pure AP and AP/Cu-Cr-O samples have been calculated by Kissinger method and the results showed that the values of pre-exponential factor and activation energy are higher for AP/Cu-Cr-O nanocomposite. The better catalytic effect of Cu-Cr-O nanocomposites is probably attributed to the synergistic effect between Cu{sup 2+} and Cr{sup 3+} in the nanocomposites, smaller particle size and more crystal defect. - Highlights: • The Cu-Cr-O nanoparticles were synthesized by chemical liquid deposition method. • Then, the AP/Cu-Cr-O core-shell nanocomposites were prepared. • The core-shell samples showed high catalytic activity for AP decomposition. • Thermal decomposition of samples occurs at lower temperature range.

  5. Fabrication of ammonium perchlorate/copper-chromium oxides core-shell nanocomposites for catalytic thermal decomposition of ammonium perchlorate

    International Nuclear Information System (INIS)

    Eslami, Abbas; Juibari, Nafise Modanlou; Hosseini, Seyed Ghorban

    2016-01-01

    The ammonium perchlorate/Cu(II)-Cr(III)-oxides(AP/Cu-Cr-O) core-shell nanocomposites were in-situ prepared by deposition of copper and chromium oxides on suspended ammonium perchlorate particles in ethyl acetate as solvent. The results of differential scanning calorimetery (DSC) and thermal gravimetric analysis (TGA) experiments showed that the nanocomposites have excellent catalytic effect on the thermal decomposition of AP, so that the released heat increases up to about 3-fold over initial values, changing from 450 J/g for pure AP to 1510 J/g for most appropriate mixture. For better comparison, single metal oxide/AP core-shell nanocomposite have also been prepared and the results showed that they have less catalytic effect respect to mixed metal oxides system. Scanning electron microscopy (SEM) results revealed homogenous deposition of nanoparticles on the surface of AP and fabrication of core-shell structures. The kinetic parameters of thermal decomposition of both pure AP and AP/Cu-Cr-O samples have been calculated by Kissinger method and the results showed that the values of pre-exponential factor and activation energy are higher for AP/Cu-Cr-O nanocomposite. The better catalytic effect of Cu-Cr-O nanocomposites is probably attributed to the synergistic effect between Cu 2+ and Cr 3+ in the nanocomposites, smaller particle size and more crystal defect. - Highlights: • The Cu-Cr-O nanoparticles were synthesized by chemical liquid deposition method. • Then, the AP/Cu-Cr-O core-shell nanocomposites were prepared. • The core-shell samples showed high catalytic activity for AP decomposition. • Thermal decomposition of samples occurs at lower temperature range.

  6. The tectonics of Mercury

    International Nuclear Information System (INIS)

    Melosh, H.J.; Mckinnon, W.B.

    1988-01-01

    The probable tectonic history of Mercury and the relative sequence of events are discussed on the basis of data collected by the Mariner-10 spacecraft. Results indicate that Mercury's tectonic activity was confined to its early history; its endogenic activity was principally due to a small change in the shape of its lithosphere, caused by tidal despinning, and a small change in area caused by shrinkage due to cooling. Exogenic processes, in particular the impact activity, have produced more abundant tectonic features. Many features associated with the Caloris basin are due to loading of Mercury's thick lithosphere by extrusive lavas or subsidence due to magma withdrawal. It is emphasized that tectonic features observed on Mercury yield insight into the earliest tectonic events on planets like Mars and, perhaps, the earth, where subsequent events obscured or erased the most ancient tectonic records

  7. The presence of nitrate dramatically changed the predominant microbial community in perchlorate degrading cultures under saline conditions

    OpenAIRE

    Stepanov, Victor G; Xiao, Yeyuan; Tran, Quyen; Rojas, Mark; Willson, Richard C; Fofanov, Yuriy; Fox, George E; Roberts, Deborah J

    2014-01-01

    Background Perchlorate contamination has been detected in both ground water and drinking water. An attractive treatment option is the use of ion-exchange to remove and concentrate perchlorate in brine. Biological treatment can subsequently remove the perchlorate from the brine. When nitrate is present, it will also be concentrated in the brine and must also be removed by biological treatment. The primary objective was to obtain an in-depth characterization of the microbial populations of two ...

  8. Catalytic destruction of perchlorate in ferric chloride and hydrochloric acid solution with control of temperature, pressure and chemical reagents

    Science.gov (United States)

    Gu, Baohua; Cole, David R.; Brown, Gilbert M.

    2004-10-05

    A method is described to decompose perchlorate in a FeCl.sub.3 /HCl aqueous solution such as would be used to regenerate an anion exchange resin used to remove perchlorate. The solution is mixed with a reducing agent, preferably an organic alcohol and/or ferrous chloride, and can be heated to accelerate the decomposition of perchlorate. Lower temperatures may be employed if a catalyst is added.

  9. Mercury CEM Calibration

    Energy Technology Data Exchange (ETDEWEB)

    John F. Schabron; Joseph F. Rovani; Susan S. Sorini

    2007-03-31

    The Clean Air Mercury Rule (CAMR) which was published in the Federal Register on May 18, 2005, requires that calibration of mercury continuous emissions monitors (CEMs) be performed with NIST-traceable standards. Western Research Institute (WRI) is working closely with the Electric Power Research Institute (EPRI), the National Institute of Standards and Technology (NIST), and the Environmental Protection Agency (EPA) to facilitate the development of the experimental criteria for a NIST traceability protocol for dynamic elemental mercury vapor generators. The traceability protocol will be written by EPA. Traceability will be based on the actual analysis of the output of each calibration unit at several concentration levels ranging from about 2-40 ug/m{sup 3}, and this analysis will be directly traceable to analyses by NIST using isotope dilution inductively coupled plasma/mass spectrometry (ID ICP/MS) through a chain of analyses linking the calibration unit in the power plant to the NIST ID ICP/MS. Prior to this project, NIST did not provide a recommended mercury vapor pressure equation or list mercury vapor pressure in its vapor pressure database. The NIST Physical and Chemical Properties Division in Boulder, Colorado was subcontracted under this project to study the issue in detail and to recommend a mercury vapor pressure equation that the vendors of mercury vapor pressure calibration units can use to calculate the elemental mercury vapor concentration in an equilibrium chamber at a particular temperature. As part of this study, a preliminary evaluation of calibration units from five vendors was made. The work was performed by NIST in Gaithersburg, MD and Joe Rovani from WRI who traveled to NIST as a Visiting Scientist.

  10. Mercury in human hair

    International Nuclear Information System (INIS)

    Kapauan, P.A.; Cruz, C.C.; Verceluz, F.P.

    1980-10-01

    The analysis of mercury (Hg) in scalp hair obtained from individuals residing in five different localities in the Philippines - Metro Manila, Naga City in Bicol, Bataan, Oriental Mindoro, and Palawan is presented. An overall mean of 1.46 ug/g of hair was obtained for all samples excluding those from Palawan and represents a baseline value.'' In terms of the mercury levels found in hair, the Honda Bay area in Palawan is, relatively, a ''contaminated area.'' (author)

  11. On solubility of perchloric (periodic) acid and α-cyanacetanmide in aqueous solutions at 25 deg C

    International Nuclear Information System (INIS)

    Omarova, R.A.; Balysbekov, S.M.; Erkasov, R.Sh.; Nikolenko, O.N.

    1996-01-01

    Acid-base interaction within perchloric (periodic) acid-α-cyanacetamide-water systems in studied by method of solubility under isothermal conditions at 25 deg C. Solubility regularities of crystalline α-cyanacetamide in perchloric and periodic acid solutions are determined, the concentration limits of formation of a new solid phase-tris(α-cyanacetamide) perchlorate within perchloric acid-α-cyanacetamide-water system are determined. The compound is identified by means of chemical and X-ray phase analyses, its density and melting temperature are determined. Iodic acid and α-cyanacetamide water solution base system is shown to belong to a simple eutonic type. 2 refs., 3 figs., 2 tabs

  12. Integration of adsorption and direct bio-reduction of perchlorate on surface of cotton stalk based resin.

    Science.gov (United States)

    Ren, Zhongfei; Xu, Xing; Gao, Baoyu; Yue, Qinyan; Song, Wen

    2015-12-01

    In this work, perchlorate was first adsorbed by the cotton stalk based resin (CS-resin) and then the laden perchlorate was directly reduced by mixed perchlorate reduction bacteria (PRB) on surface of CS-resin. The characteristics of cotton stalk, clean CS-resin, perchlorate-laden CS-resin and bio-regenerated CS-resin were evaluated by XPS, FT-IR, SEM, zeta potential measurements. All characteristics showed clearly that (i) adsorption mechanism of perchlorate onto CS-resin was based on electrostatic attraction; (ii) biological destruction of laden perchlorate was effective for bio-regenerating the saturated CS-resin. The experimental adsorption capacities (Qexp) of perchlorate by CS-resin achieved at equilibrium condition was about 138.9 mg/g. Reduction rate of laden perchlorate on surface of CS-resin were about 2.12, 1.67, 0.032 and 0.009 mg/g(CS-resin)/d for initial redox potentials poised at -193, -70, +169, and +363 mV, respectively. This indicated that the rapid reduction of laden perchlorate may occur only when conditions were present to cause a low Eh. Copyright © 2015 Elsevier Inc. All rights reserved.

  13. The geochemical associations of nitrate and naturally formed perchlorate in the Mojave Desert, California, USA

    Science.gov (United States)

    Lybrand, Rebecca A.; Michalski, Greg; Graham, Robert C.; Parker, David R.

    2013-03-01

    Perchlorate is a widely studied environmental contaminant that may adversely affect human health, and whose natural occurrence has emerged as a subject of great interest. Naturally formed perchlorate has been found to co-occur with nitrate in arid environments worldwide, but the relationship is not fully understood in the desert soils of the southwestern United States. The main objective of this research was to explore the origin, pedogenic distribution, and possible preservation of perchlorate and nitrate in the Mojave Desert mud hill deposits of California and to determine if the co-occurrence of putatively natural perchlorate was significantly correlated with nitrate in these soils. We identified 39 soil horizons in the Mojave Desert, California that contained reportable levels of perchlorate (MRL >165 μg kg-1) with a maximum concentration of 23 mg kg-1. A weak yet significant correlation was observed between perchlorate and nitrate (r2 = 0.321∗∗∗), which could be indicative of similar mechanisms of accumulation. When compared to published data for the Atacama Desert, the Mojave Desert perchlorate concentrations were remarkably lower for a given nitrate concentration. Oxygen isotopes in the nitrate were examined to identify variation within the Mojave Desert field sites, and to compare with the available literature for the Atacama Desert. The Mojave Desert Δ17O values ranged from 7‰ to 13‰, indicating a mixture of biologically and atmospherically-derived nitrate. An investigation of the distribution of perchlorate among soil horizons revealed that over sixty percent of the samples containing perchlorate were from C horizons while only twenty percent of the samples were from B horizons and even fewer in the overlying A horizons. Soil chemical, morphologic, and geologic characteristics of the soils suggest that the perchlorate, nitrate and/or other soluble salts have moved in a "bottom-up" manner wherein the salts were deposited in strata through

  14. Method and apparatus for monitoring mercury emissions

    Science.gov (United States)

    Durham, Michael D.; Schlager, Richard J.; Sappey, Andrew D.; Sagan, Francis J.; Marmaro, Roger W.; Wilson, Kevin G.

    1997-01-01

    A mercury monitoring device that continuously monitors the total mercury concentration in a gas. The device uses the same chamber for converting speciated mercury into elemental mercury and for measurement of the mercury in the chamber by radiation absorption techniques. The interior of the chamber is resistant to the absorption of speciated and elemental mercury at the operating temperature of the chamber.

  15. Mercury pollution in Malaysia.

    Science.gov (United States)

    Hajeb, Parvaneh; Jinap, S; Ismail, Ahmad; Mahyudin, Nor Ainy

    2012-01-01

    Although several studies have been published on levels of mercury contamination of the environment, and of food and human tissues in Peninsular Malaysia, there is a serious dearth of research that has been performed in East Malaysia (Sabah and Sarawak). Industry is rapidly developing in East Malaysia, and, hence, there is a need for establishing baseline levels of mercury contamination in environmental media in that part of the country by performing monitoring studies. Residues of total mercury and inorganic in food samples have been determined in nearly all previous studies that have been conducted; however, few researchers have analyzed samples for the presence of methlymercury residues. Because methylmercury is the most toxic form of mercury, and because there is a growing public awareness of the risk posed by methylmercury exposure that is associated with fish and seafood consumption, further monitoring studies on methylmercury in food are also essential. From the results of previous studies, it is obvious that the economic development in Malaysia, in recent years, has affected the aquatic environment of the country. Primary areas of environmental concern are centered on the rivers of the west Peninsular Malaysian coast, and the coastal waters of the Straits of Malacca, wherein industrial activities are rapidly expanding. The sources of existing mercury input to both of these areas of Malaysia should be studied and identified. Considering the high levels of mercury that now exists in human tissues, efforts should be continued, and accelerated in the future, if possible, to monitor mercury contamination levels in the coastal states, and particularly along the west Peninsular Malaysian coast. Most studies that have been carried out on mercury residues in environmental samples are dated, having been conducted 20-30 years ago; therefore, the need to collect much more and more current data is urgent. Furthermore, establishing baseline levels of mercury exposure to

  16. Fabrication of mercury target vessel

    International Nuclear Information System (INIS)

    Wakui, Takashi; Kogawa, Hiroyuki; Haga, Katsuhiro; Futakawa, Masatoshi; Hayashi, Ryoichi; Uchiyama, Naoyoshi; Okamoto, Yoshinao; Nakamura, Koji

    2010-03-01

    The construction of materials and life science experimental facility in J-PARC (Japan Proton Accelerator Complex) project had been completed and accepted pulsed proton beams with low power. Since 2003, the detailed design, fabrication and examination for the mercury target vessel as a pulsed neutron source were carried out by the vender. The mercury target vessel consists of triple-walled structure in order to prevent the leak of mercury to outside at the failure of the mercury vessel and to remove the heat of the safety hull, which covers the mercury vessel, due to the injection of the pulsed proton beams. The high fabrication accuracy is required for the mercury target vessel assembled by the welding, because there are the relationships between the mercury target vessel and other components (target trolley, target storage container, flange of helium vessel, reflector and water-cooled shield). At each fabrication step, the examinations for the mercury target vessel with multi-walled structure were required. In this report, the required specification and basic structure of parts in the mercury target vessel are described and the fabrication procedure of the mercury target vessel by the vender is reported. In the fabrication of the mercury target vessel, there were many troubles such as large deformation due to the welding and then the vender repaired and brought the mercury target vessel to completion. Furthermore, improvements for the design and fabrication of the mercury target are reported. (author)

  17. CO-occurring exposure to perchlorate, nitrate and thiocyanate alters thyroid function in healthy pregnant women

    International Nuclear Information System (INIS)

    Horton, Megan K.; Blount, Benjamin C.; Valentin-Blasini, Liza; Wapner, Ronald; Whyatt, Robin; Gennings, Chris; Factor-Litvak, Pam

    2015-01-01

    Background: Adequate maternal thyroid function during pregnancy is necessary for normal fetal brain development, making pregnancy a critical window of vulnerability to thyroid disrupting insults. Sodium/iodide symporter (NIS) inhibitors, namely perchlorate, nitrate, and thiocyanate, have been shown individually to competitively inhibit uptake of iodine by the thyroid. Several epidemiologic studies examined the association between these individual exposures and thyroid function. Few studies have examined the effect of this chemical mixture on thyroid function during pregnancy Objectives: We examined the cross sectional association between urinary perchlorate, thiocyanate and nitrate concentrations and thyroid function among healthy pregnant women living in New York City using weighted quantile sum (WQS) regression. Methods: We measured thyroid stimulating hormone (TSH) and free thyroxine (FreeT4) in blood samples; perchlorate, thiocyanate, nitrate and iodide in urine samples collected from 284 pregnant women at 12 (±2.8) weeks gestation. We examined associations between urinary analyte concentrations and TSH or FreeT4 using linear regression or WQS adjusting for gestational age, urinary iodide and creatinine. Results: Individual analyte concentrations in urine were significantly correlated (Spearman's r 0.4–0.5, p<0.001). Linear regression analyses did not suggest associations between individual concentrations and thyroid function. The WQS revealed a significant positive association between the weighted sum of urinary concentrations of the three analytes and increased TSH. Perchlorate had the largest weight in the index, indicating the largest contribution to the WQS. Conclusions: Co-exposure to perchlorate, nitrate and thiocyanate may alter maternal thyroid function, specifically TSH, during pregnancy. - Highlights: • Perchlorate, nitrate, thiocyanate and iodide measured in maternal urine. • Thyroid function (TSH and Free T4) measured in maternal blood.

  18. Mercury Emissions: The Global Context

    Science.gov (United States)

    Mercury emissions are a global problem that knows no national or continental boundaries. Mercury that is emitted to the air can travel thousands of miles in the atmosphere before it is eventually deposited back to the earth.

  19. Mercury's magnetic field and interior

    International Nuclear Information System (INIS)

    Connerney, J.E.P.; Ness, N.F.

    1988-01-01

    The magnetic-field data collected on Mercury by the Mariner-10 spacecraft present substantial evidence for an intrinsic global magnetic field. However, studies of Mercury's thermal evolution show that it is most likely that the inner core region of Mercury solidified or froze early in the planet's history. Thus, the explanation of Mercury's magnetic field in the framework of the traditional planetary dynamo is less than certain

  20. Reference Atmosphere for Mercury

    Science.gov (United States)

    Killen, Rosemary M.

    2002-01-01

    We propose that Ar-40 measured in the lunar atmosphere and that in Mercury's atmosphere is due to current diffusion into connected pore space within the crust. Higher temperatures at Mercury, along with more rapid loss from the atmosphere will lead to a smaller column abundance of argon at Mercury than at the Moon, given the same crustal abundance of potassium. Because the noble gas abundance in the Hermean atmosphere represents current effusion, it is a direct measure of the crustal potassium abundance. Ar-40 in the atmospheres of the planets is a measure of potassium abundance in the interiors, since Ar-40 is a product of radiogenic decay of K-40 by electron capture with the subsequent emission of a 1.46 eV gamma-ray. Although the Ar-40 in the Earth's atmosphere is expected to have accumulated since the late bombardment, Ar-40 in the atmospheres of Mercury and the Moon is eroded quickly by photoionization and electron impact ionization. Thus, the argon content in the exospheres of the Moon and Mercury is representative of current effusion rather than accumulation over the lifetime of the planet.

  1. Mercury content of edible mushrooms

    Energy Technology Data Exchange (ETDEWEB)

    Woidich, H.; Pfannhauser, W.

    1975-05-01

    The mercury content of edible fungi is different. Relatively high burdened are Boletus and Agaricus campestris. A minimum of mercury is found in Russula, Agaricus bisporus and Cantharellus cibarius. The possibilities of mercury uptake and the potential cumulation mechanism is discussed. 8 references, 3 tables.

  2. Mercury (Environmental Health Student Portal)

    Science.gov (United States)

    ... Water Waterborne Diseases & Illnesses Water Cycle Water Treatment Mercury The Basics Mercury — sometimes called quicksilver — is a natural metal. It’s ... to breathe it in without knowing it. When mercury combines with other chemical elements, it creates compounds, ...

  3. Effect of perchlorate in fertilisers on lettuce and fruit vegetables : Uptake and distribution of perchlorate in greenhouse soil-grown butterhead lettuce and solless-grown cucumber, sweet pepper, round and cherry tomate

    NARCIS (Netherlands)

    Voogt, W.; Eveleens, B.A.; Steenhuizen, J.W.; Vandevelde, I.; Vis, de R.; Lommel, van J.

    2014-01-01

    In 2013 traces of perchlorate were detected in fruits and vegetable samples. Because perchlorate (ClO4 -) is part of a group of substances (goitrogens) that may inhibit the uptake of iodine by the thyroid, these findings caused commotion in the markets. Fertilizers were named as one of the sources

  4. Hydrogen oxidation on gold electrode in perchloric acid solution

    Energy Technology Data Exchange (ETDEWEB)

    Sustersic, M.G.; Almeida, N.V.; Von Mengershausen, A.E. [Facultad de Ingenieria y Ciencias Economico Sociales, Universidad Nacional de San Luis, 25 de Mayo N 384, 5730 Villa Mercedes, San Luis (Argentina)

    2010-06-15

    The aim of this research is to study the interface gold/perchloric acid solution in presence of hydrogen. The reactive is generated by H{sup +} ion reduction and by saturating the electrolyte with the gaseous H{sub 2}. No evidence of H{sub 2} dissociative adsorption is found. In special conditions, a strongly adsorbed layer is formed from the atoms diffusing from inside of the metal. The mass transport occurs in three ways: the diffusion of H atoms inwards, the diffusion of H atoms back to the surface and the dissolved H{sub 2} diffusion from the bulk electrolyte to the surface. When dissolved H{sub 2} reacts, the reaction is kinetically controlled when the H{sub 2} partial pressure is high, and it is diffusionally controlled when the reactive partial pressure is low. Above 0.7 V, (measured vs. RHE), the (100) plane surface reconstruction lifts, and the rate determining step is the H diffusion towards inside of the metal, and the current suddenly falls. The Hydrogen redox reaction on gold shows reversibility with respect to the potential when the reactives are the H diffusing outwards of the metal and the H{sup +} ion present in the electrolyte. However, the absolute current values of oxidation and reduction are different because the reactive sources are different. (author)

  5. Chlorine-36 abundance in natural and synthetic perchlorate

    Energy Technology Data Exchange (ETDEWEB)

    Heikoop, Jeffrey M [Los Alamos National Laboratory; Dale, M [NON LANL; Sturchio, Neil C [UNIV OF ILLIONOIS; Caffee, M [PURDUE UNIV; Belosa, A D [UNIV OF ILLINOIS; Heraty, Jr., L J [UNIV OF ILLINOIS; Bohike, J K [RESTON, VA; Hatzinger, P B [SHAW ENIVIORNMENTAL C0.; Jackson, W A [TEXAS TECH; Gu, B [ORNL

    2009-01-01

    Perchlorate (ClO{sub 4}{sup -}) is ubiquitous in the environment. It occurs naturally as a product of atmospheric photochemical reactions, and is synthesized for military, aerospace, and industrial applications. Nitrate-enriched soils of the Atacama Desert (Chile) contain high concentrations of natural ClO{sub 4}{sup -}; nitrate produced from these soils has been exported worldwide since the mid-1800's for use in agriculture. The widespread introduction of synthetic and agricultural ClO{sub 4}{sup -} into the environment has complicated attempts to understand the geochemical cycle of ClO{sub 4}{sup -}. Natural ClO{sub 4}{sup -} samples from the southwestern United States have relatively high {sup 36}Cl abundances ({sup 36}Cl/Cl = 3,100 x 10{sup -15} to 28,800 x 10{sup -15}), compared with samples of synthetic ({sup 36}Cl/Cl = 0.0 x 10{sup -15} to 40 x 10{sup -15}) and Atacama Desert ({sup 36}Cl/Cl = 0.9 x 10{sup -15} to 590 x 10{sup -15}) ClO{sub 4}{sup -}. These data give a lower limit for the initial {sup 36}Cl abundance of natural ClO{sub 4}{sup -} and provide temporal and other constraints on its geochemical cycle.

  6. Biological perchlorate reduction in packed bed reactors using elemental sulfur.

    Science.gov (United States)

    Sahu, Ashish K; Conneely, Teresa; Nüsslein, Klaus R; Ergas, Sarina J

    2009-06-15

    Sulfur-utilizing perchlorate (ClO4-)-reducing bacteria were enriched from a denitrifying wastewater seed with elemental sulfur (S0) as an electron donor. The enrichment was composed of a diverse microbial community, with the majority identified as members of the phylum Proteobacteria. Cultures were inoculated into bench-scale packed bed reactors (PBR) with S0 and crushed oyster shell packing media. High ClO4-concentrations (5-8 mg/L) were reduced to PBR performance decreased when effluent recirculation was applied or when smaller S0 particle sizes were used, indicating that mass transfer of ClO4- to the attached biofilm was not the limiting mechanism in this process, and that biofilm acclimation and growth were key factors in overall reactor performance. The presence of nitrate (6.5 mg N/L) inhibited ClO4- reduction. The microbial community composition was found to change with ClO4- availability from a majority of Beta-Proteobacteria near the influent end of the reactor to primarily sulfur-oxidizing bacteria near the effluent end of the reactor.

  7. Widespread occurrence of (per)chlorate in the Solar System

    Science.gov (United States)

    Jackson, W. Andrew; Davila, Alfonso F.; Sears, Derek W. G.; Coates, John D.; McKay, Christopher P.; Brundrett, Maeghan; Estrada, Nubia; Böhlke, J. K.

    2015-11-01

    Perchlorate (ClO4-) and chlorate (ClO3-) are ubiquitous on Earth and ClO4- has also been found on Mars. These species can play important roles in geochemical processes such as oxidation of organic matter and as biological electron acceptors, and are also indicators of important photochemical reactions involving oxyanions; on Mars they could be relevant for human habitability both in terms of in situ resource utilization and potential human health effects. For the first time, we extracted, detected and quantified ClO4- and ClO3- in extraterrestrial, non-planetary samples: regolith and rock samples from the Moon, and two chondrite meteorites (Murchison and Fayetteville). Lunar samples were collected by astronauts during the Apollo program, and meteorite samples were recovered immediately after their fall. This fact, together with the heterogeneous distribution of ClO4- and ClO3- within some of the samples, and their relative abundance with respect to other soluble species (e.g., NO3-) are consistent with an extraterrestrial origin of the oxychlorine species. Our results, combined with the previously reported widespread occurrence on Earth and Mars, indicate that ClO4- and ClO3- could be present throughout the Solar System.

  8. Widespread occurrence of (per)chlorate in the Solar System

    Science.gov (United States)

    Jackson, W. Andrew; Davila, Alfonso F; Sears, Derek W. G.; Coates, John D.; McKay, Christopher P.; Brundrett, Meaghan; Estrada, Nubia; Böhlke, John Karl

    2015-01-01

    Perchlorate (ClO− 4 ) and chlorate (ClO− 3 ) are ubiquitous on Earth and ClO− 4 has also been found on Mars. These species can play important roles in geochemical processes such as oxidation of organic matter and as biological electron acceptors, and are also indicators of important photochemical reactions involving oxyanions; on Mars they could be relevant for human habitability both in terms of in situ resource utilization and potential human health effects. For the first time, we extracted, detected and quantified ClO− 4 and ClO− 3 in extraterrestrial, non-planetary samples: regolith and rock samples from the Moon, and two chondrite meteorites (Murchison and Fayetteville). Lunar samples were collected by astronauts during the Apollo program, and meteorite samples were recovered immediately after their fall. This fact, together with the heterogeneous distribution of ClO− 4 and ClO− 3 within some of the samples, and their relative abundance with respect to other soluble species (e.g., NO− 3 ) are consistent with an extraterrestrial origin of the oxychlorine species. Our results, combined with the previously reported widespread occurrence on Earth and Mars, indicate that ClO− 4 and ClO− 3 could be present throughout the Solar System.

  9. Sensing Mercury for Biomedical and Environmental Monitoring

    Directory of Open Access Journals (Sweden)

    Julia Xiaojun Zhao

    2009-07-01

    Full Text Available Mercury is a very toxic element that is widely spread in the atmosphere, lithosphere, and surface water. Concentrated mercury poses serious problems to human health, as bioaccumulation of mercury within the brain and kidneys ultimately leads to neurological diseases. To control mercury pollution and reduce mercury damage to human health, sensitive determination of mercury is important. This article summarizes some current sensors for the determination of both abiotic and biotic mercury. A wide array of sensors for monitoring mercury is described, including biosensors and chemical sensors, while piezoelectric and microcantilever sensors are also described. Additionally, newly developed nanomaterials offer great potential for fabricating novel mercury sensors. Some of the functional fluorescent nanosensors for the determination of mercury are covered. Afterwards, the in vivo determination of mercury and the characterization of different forms of mercury are discussed. Finally, the future direction for mercury detection is outlined, suggesting that nanomaterials may provide revolutionary tools in biomedical and environmental monitoring of mercury.

  10. Stability of perchlorate hydrates and their liquid solutions at the Phoenix landing site, Mars

    Science.gov (United States)

    Chevrier, Vincent F.; Hanley, Jennifer; Altheide, Travis S.

    2009-05-01

    We studied the low-temperature properties of sodium and magnesium perchlorate solutions as potential liquid brines at the Phoenix landing site. We determined their theoretical eutectic values to be 236 ± 1 K for 52 wt% sodium perchlorate and 206 ± 1 K for 44.0 wt% magnesium perchlorate. Evaporation rates of solutions at various concentrations were measured under martian conditions, and range from 0.07 to 0.49 mm h-1 for NaClO4 and from 0.06 to 0.29 mm h-1 for Mg(ClO4)2. The extrapolation to Phoenix landing site conditions using our theoretical treatment shows that perchlorates are liquid during the summer for at least part of the day, and exhibit very low evaporation rates. Moreover, magnesium perchlorate eutectic solutions are thermodynamically stable over vapour and ice during a few hours a day. We conclude that liquid brines may be present and even stable for short periods of time at the Phoenix landing site.

  11. Bioreactor configurations for ex-situ treatment of perchlorate: a review.

    Science.gov (United States)

    Sutton, Paul M

    2006-12-01

    The perchlorate anion has been detected in the drinking water of millions of people living in the United States. At perchlorate levels equal to or greater than 1 mg/L and where the water is not immediately used for household purposes, ex-situ biotreatment has been widely applied. The principal objective of this paper was to compare the technical and economic advantages and disadvantages of various bioreactor configurations in the treatment of low- and medium-strength perchlorate-contaminated aqueous streams. The ideal bioreactor configuration for this application should be able to operate efficiently while achieving a long solids retention time, be designed to promote physical-chemical adsorption in addition to biodegradation, and operate under plug-flow hydraulic conditions. To date, the granular activated carbon (GAC) or sand-media-based fluidized bed reactors (FBRs) and GAC, sand-, or plastic-media-based packed bed reactors (PBRs) have been the reactor configurations most widely applied for perchlorate treatment. Only the FBR configuration has been applied commercially. Commercial-scale cost information presented implies no economic advantage for the PBR relative to the FBR configuration. Full-scale application information provides evidence that the FBR is a good choice for treating perchlorate-contaminated aqueous streams.

  12. Perchlorate adsorption onto orange peel modified by cross-linking amine groups from aqueous solutions.

    Science.gov (United States)

    Zhang, Lixiang; Yang, Zhiquan; Li, Ting; Zhou, Shaoqi; Wu, Zhenyi

    2015-01-01

    Orange peel was made into a highly efficient bio-sorbent by modification with cross-linking amine groups for perchlorate removal. Bench-scale experiments were performed to explore the factors affecting the perchlorate adsorption onto the modified orange peel (MOP). Perchlorate could be removed effectively at a wide range of pH (from 1.5 to 11). The maximum adsorption capacity of MOP for perchlorate was calculated as 154.1 mg/g within 15 min. The Redlich-Peterson model was fitted to the adsorption isotherm very well (R2>0.99). The adsorption process was spontaneous and exothermic, which was proved by thermodynamic parameters (Gibbs energy and enthalpy). The pseudo-second-order kinetic model could provide satisfactory fitting of the experimental data (R2>0.99). The scanning electron microscopy and energy-dispersive X-ray analysis indicated that the surface of MOP became smooth and the contents of N and Cl in MOP were increased during the modification process. Elemental analysis results showed that the nitrogen content in MOP was increased to 5.5%, while it was 1.06% in orange peel. The adsorption mechanism was also explored using zeta potential and Fourier transform infrared spectroscopy analysis. Ion exchange was the primary mechanism responsible for uptake of perchlorate onto MOP.

  13. Possible Calcite and Magnesium Perchlorate Interaction in the Mars Phoenix Thermal and Evolved Gas Analyzer (TEGA)

    Science.gov (United States)

    Cannon, K. M.; Sutter, B.; Ming, D. W.; Boynton, W. V.; Quinn, R. C.

    2012-01-01

    The Mars Phoenix Lander's TEGA instrument detected a calcium carbonate phase decomposing at high temperatures (approx.700 C) from the Wicked Witch soil sample [1]. TEGA also detected a lower temperature CO2 release between 400 C and 680 C [1]. Possible explanations given for this lower temperature CO2 release include thermal decomposition of Mg or Fe carbonates, a zeolitictype desorption reaction, or combustion of organic compounds in the soil [2]. The detection of 0.6 wt % soluble perchlorate by the Wet Chemistry Laboratory (WCL) on Phoenix [3] has implications for the possibility of organic molecules in the soil. Ming et al. [4] demonstrated that perchlorates could have oxidized organic compounds to CO2 in TEGA, preventing detection of their characteristic mass fragments. Here, we propose that a perchlorate salt and calcium carbonate present in martian soil reacted to produce the 400 C - 680 C TEGA CO2 release. The parent salts of the perchlorate on Mars are unknown, but geochemical models using WCL data support the possible dominance of Mg-perchlorate salts [5]. Mg(ClO4)2 6H2O is the stable phase at ambient martian conditions [6], and breaks down at lower temperatures than carbonates giving off Cl2 and HCl gas [7,8]. Devlin and Herley [7] report two exotherms at 410-478 C and 473-533 C which correspond to the decomposition of Mg(ClO4)2.

  14. Water displacement mercury pump

    Science.gov (United States)

    Nielsen, M.G.

    1984-04-20

    A water displacement mercury pump has a fluid inlet conduit and diffuser, a valve, a pressure cannister, and a fluid outlet conduit. The valve has a valve head which seats in an opening in the cannister. The entire assembly is readily insertable into a process vessel which produces mercury as a product. As the mercury settles, it flows into the opening in the cannister displacing lighter material. When the valve is in a closed position, the pressure cannister is sealed except for the fluid inlet conduit and the fluid outlet conduit. Introduction of a lighter fluid into the cannister will act to displace a heavier fluid from the cannister via the fluid outlet conduit. The entire pump assembly penetrates only a top wall of the process vessel, and not the sides or the bottom wall of the process vessel. This insures a leak-proof environment and is especially suitable for processing of hazardous materials.

  15. Effective adsorption/electrocatalytic degradation of perchlorate using Pd/Pt supported on N-doped activated carbon fiber cathode

    International Nuclear Information System (INIS)

    Yao, Fubing; Zhong, Yu; Yang, Qi; Wang, Dongbo; Chen, Fei; Zhao, Jianwei; Xie, Ting; Jiang, Chen; An, Hongxue; Zeng, Guangming; Li, Xiaoming

    2017-01-01

    Highlights: • Pd/Pt-NACF served as an adsorption/electrocatalysis electrode to reduce perchlorate. • The possible mechanisms involved in the reaction process were explained. • The reusability and stability of Pd/Pt-NACF bifunctional material was evaluated. - Abstract: In this work, Pd/Pt supported on N-doped activated carbon fiber (Pd/Pt-NACF) was employed as the electrode for electrocatalytic degradation of perchlorate through adsorption/electroreduction process. Perchlorate in solution was firstly adsorbed on Pd/Pt-NACF and then reduced to non-toxic chloride by the catalytic function of Pd/Pt at a constant current (20 mA). Compared with Pd/Pt-ACF, the adsorption capacity and electrocatalytic degradation efficiency of Pd/Pt-NACF for perchlorate increased 161% and 28%, respectively. Obviously, positively charged N-functional groups on NACF surface enhanced the adsorption capacity of Pd/Pt-NACF, and the dissociation of hydrogen to atomic H* by the Pd/Pt nanostructures on the cathode might drastically promote the electrocatalytic reduction of perchlorate. The role of atomic H* in the electroreduction process was identified by tertiary butanol inhibition test. Meanwhile, the perchlorate degradation performance was not substantially lower after three successive adsorption/electrocatalytic degradation experiments, demonstrating the electrochemical reusability and stability of the as-prepared electrode. These results showed that Pd/Pt-NACF was effective for electrocatalytic degradation of perchlorate and had great potential in perchlorate removal from water.

  16. Feasibility and kinetics study on the direct bio-regeneration of perchlorate laden anion-exchange resin.

    Science.gov (United States)

    Wang, Chao; Lippincott, Lee; Meng, Xiaoguang

    2008-11-01

    Anion exchange is one of the most promising treatment technologies for the removal of low levels of perchlorate. The spent anion-exchange resins, however, need to be disposed of or regenerated because they contain high contents of perchlorate. This study investigated the feasibility and kinetics of a direct bio-regeneration method. The method accomplished resin regeneration and biological perchlorate destruction concurrently, by directly contacting the spent resin with the perchlorate-reducing bacteria (PRB). The results indicated that the method was effective in regeneration of perchlorate and nitrate loaded resin and the resin could be repeatedly regenerated with the method. The regenerated resin was effective, stable, and durable in the filtration treatment of perchlorate in well water from the Saddle River area, NJ. Moreover, the method was also effective in regeneration of the spent A-530E resin, which had high perchlorate affinity and was yet very difficult for regeneration with the conventional brine desorption technique. Besides, the results further suggested that the perchlorate and nitrate desorption from the loaded resin coupling with their subsequent biological reduction could be the direct bio-regeneration mechanism. No biofilm was formed on the regenerated resin surface according to a scanning electron microscopy (SEM) analysis.

  17. Perchlorate exposure and association with iron homeostasis and other biological functions among NHANES 2005-2008 subjects

    Science.gov (United States)

    Perchlorate exposure and association with iron homeostasis and other biological functions among NHANES 2005-2008 subjects Schreinemachers DM, Ghio AJ, Cascio WE, Sobus JR. U.S. EPA, RTP, NC, USA Perchlorate (ClO4-), an environmental pollutant, is a known thyroid toxicant and...

  18. Mercury CEM Calibration

    Energy Technology Data Exchange (ETDEWEB)

    John Schabron; Joseph Rovani; Mark Sanderson

    2008-02-29

    Mercury continuous emissions monitoring systems (CEMS) are being implemented in over 800 coal-fired power plant stacks. The power industry desires to conduct at least a full year of monitoring before the formal monitoring and reporting requirement begins on January 1, 2009. It is important for the industry to have available reliable, turnkey equipment from CEM vendors. Western Research Institute (WRI) is working closely with the Electric Power Research Institute (EPRI), the National Institute of Standards and Technology (NIST), and the Environmental Protection Agency (EPA) to facilitate the development of the experimental criteria for a NIST traceability protocol for dynamic elemental mercury vapor generators. The generators are used to calibrate mercury CEMs at power plant sites. The Clean Air Mercury Rule (CAMR) which was published in the Federal Register on May 18, 2005 requires that calibration be performed with NIST-traceable standards (Federal Register 2007). Traceability procedures will be defined by EPA. An initial draft traceability protocol was issued by EPA in May 2007 for comment. In August 2007, EPA issued an interim traceability protocol for elemental mercury generators (EPA 2007). The protocol is based on the actual analysis of the output of each calibration unit at several concentration levels ranging initially from about 2-40 {micro}g/m{sup 3} elemental mercury, and in the future down to 0.2 {micro}g/m{sup 3}, and this analysis will be directly traceable to analyses by NIST. The document is divided into two separate sections. The first deals with the qualification of generators by the vendors for use in mercury CEM calibration. The second describes the procedure that the vendors must use to certify the generator models that meet the qualification specifications. The NIST traceable certification is performance based, traceable to analysis using isotope dilution inductively coupled plasma/mass spectrometry performed by NIST in Gaithersburg, MD. The

  19. Validation of chlorine and oxygen isotope ratio analysis to differentiate perchlorate sources and to document perchlorate biodegradation

    Science.gov (United States)

    Paul B. Hatzinger,; Böhlke, John Karl; Sturchio, Neil C.; Gu, Baohua

    2013-01-01

    Increased health concerns about perchlorate (ClO4-) during the past decade and subsequent regulatory considerations have generated appreciable interest in source identification. The key objective of the isotopic techniques described in this guidance manual is to provide evidence concerning the origin of ClO4- in soils and groundwater and, more specifically, whether that ClO4- is synthetic or natural. Chlorine and oxygen isotopic analyses of ClO4- provide the primary direct approach whereby different sources of ClO4- can be distinguished from each other. These techniques measure the relative abundances of the stable isotopes of chlorine (37Cl and 35Cl) and oxygen (18O, 17O, and 16O) in ClO4- using isotope-ratio mass spectrometry (IRMS). In addition, the relative abundance of the radioactive chlorine isotope 36Cl is measured using accelerator mass spectrometry (AMS). Taken together, these measurements provide four independent quantities that can be used to distinguish natural and synthetic ClO4- sources, to discriminate different types of natural ClO4-, and to detect ClO4- biodegradation in the environment. Other isotopic, chemical, and geochemical techniques that can be applied in conjunction with isotopic analyses of ClO4- to provide supporting data in forensic studies are also described.

  20. A simplified method for obtaining high-purity perchlorate from groundwater for isotope analyses.

    Energy Technology Data Exchange (ETDEWEB)

    vonKiparski, G; Hillegonds, D

    2011-04-04

    Investigations into the occurrence and origin of perchlorate (ClO{sub 4}{sup -}) found in groundwater from across North America have been sparse until recent years, and there is mounting evidence that natural formation mechanisms are important. New opportunities for identifying groundwater perchlorate and its origin have arisen with the utilization of improved detection methods and sampling techniques. Additionally, application of the forensic potential of isotopic measurements has begun to elucidate sources, potential formation mechanisms and natural attenuation processes. Procedures developed appear to be amenable to enable high precision stable isotopic analyses, as well as lower precision AMS analyses of {sup 36}Cl. Immediate work is in analyzing perchlorate isotope standards and developing full analytical accuracy and uncertainty expectations. Field samples have also been collected, and will be analyzed when final qa/qc samples are deemed acceptable.

  1. Perchlorate-selective membrane electrode based on a new complex of uranil.

    Science.gov (United States)

    Mazloum Ardakani, M; Jalayer, M; Naeimi, H; Zare, H R; Moradi, L

    2005-03-01

    A potentiometric ion-selective electrode based on new compound, as a carrier, has been successfully developed for detection of perchlorate anion in aqueous solution. Within the perchlorate ion concentration range 1.0x10(-6) to 1.0 mol L(-1) the electrode had a linear response with a Nernstian slope of 60.6+/-1.0 mV per decade . The limit of detection as determined from the intersection of the extrapolated linear segments of the calibration plot was 8.0x10(-7) mol L(-1). The proposed electrode has fairly a good discriminating ability towards ClO(4) (-) ion in comparison to other anions. The sensor has a response time of < or =10 s and can be used for at least 2 months without substantial divergence in potential. It was successfully applied to direct determination of perchlorate in urine and water.

  2. Effects of larval-juvenile treatment with perchlorate and co-treatment with thyroxine on zebrafish sex ratios

    Science.gov (United States)

    Mukhi, S.; Torres, L.; Patino, R.

    2007-01-01

    The objective of this study was to determine the effect of larval-juvenile exposure to perchlorate, a thyroid hormone synthesis inhibitor, on the establishment of gonadal sex ratios in zebrafish. Zebrafish were exposed to untreated water or water containing perchlorate at 100 or 250 ppm for a period of 30 days starting at 3 days postfertilization (dpf). Recovery treatments consisted of a combination of perchlorate and exogenous thyroxine (T4; 10 nM). Thyroid histology was assessed at the end of the treatment period (33 dpf), and gonadal histology and sex ratios were determined in fish that were allowed an additional 10-day period of growth in untreated water. As expected, exposure to perchlorate caused changes in thyroid histology consistent with hypothyroidism and these effects were reversed by co-treatment with exogenous T4. Perchlorate did not affect fish survival but co-treatment with T4 induced higher mortality. However, relative to the corresponding perchlorate concentration, co-treatment with T4 caused increased mortality only at a perchlorate concentration of 100 ppm. Perchlorate alone or in the presence of T4 suppressed body length at 43 dpf relative to control values. Perchlorate exposure skewed the sex ratio toward female in a concentration-dependent manner, and co-treatment with T4 not only blocked the feminizing effect of perchlorate but also overcompensated by skewing the sex ratio towards male. Moreover, co-treatment with T4 advanced the onset of spermatogenesis in males. There was no clear association between sex ratios and larval survival or growth. We conclude that endogenous thyroid hormone plays a role in the establishment of gonadal sex phenotype during early development in zebrafish. ?? 2006 Elsevier Inc. All rights reserved.

  3. Fractionation of stable isotopes in perchlorate and nitrate during in situ biodegradation in a sandy aquifer

    Science.gov (United States)

    Hatzinger, P.B.; Bohlke, John Karl; Sturchio, N.C.; Gu, B.; Heraty, L.J.; Borden, R.C.

    2009-01-01

    An in situ experiment was performed in a shallow alluvial aquifer in Maryland to quantify the fractionation of stable isotopes in perchlorate (Cl and O) and nitrate (N and O) during biodegradation. An emulsified soybean oil substrate that was previously injected into this aquifer provided the electron donor necessary for biological perchlorate reduction and denitrification. During the field experiment, groundwater extracted from an upgradient well was pumped into an injection well located within the in situ oil barrier, and then groundwater samples were withdrawn for the next 30 h. After correction for dilution (using Br– as a conservative tracer of the injectate), perchlorate concentrations decreased by 78% and nitrate concentrations decreased by 82% during the initial 8.6 h after the injection. The observed ratio of fractionation effects of O and Cl isotopes in perchlorate (e18O/e37Cl) was 2.6, which is similar to that observed in the laboratory using pure cultures (2.5). Denitrification by indigenous bacteria fractionated O and N isotopes in nitrate at a ratio of ~0.8 (e18O/e15N), which is within the range of values reported previously for denitrification. However, the magnitudes of the individual apparent in situ isotope fractionation effects for perchlorate and nitrate were appreciably smaller than those reported in homogeneous closed systems (0.2 to 0.6 times), even after adjustment for dilution. These results indicate that (1) isotope fractionation factor ratios (e18O/e37Cl, e18O/e15N) derived from homogeneous laboratory systems (e.g. pure culture studies) can be used qualitatively to confirm the occurrence of in situ biodegradation of both perchlorate and nitrate, but (2) the magnitudes of the individual apparent e values cannot be used quantitatively to estimate the in situ extent of biodegradation of either anion.

  4. Effects of prolonged exposure to perchlorate on thyroid and reproductive function in zebrafish

    Science.gov (United States)

    Mukhi, S.; Patino, R.

    2007-01-01

    The objectives of this study were to determine the effects of prolonged exposure to perchlorate on (1) thyroid status and reproductive performance of adult zebrafish (Danio rerio) and (2) F1 embryo survival and early larval development. Using a static-renewal procedure, mixed sex populations of adult zebrafish were exposed to 0, 10, and 100 mg/l nominal concentrations of waterborne perchlorate for 10 weeks. Thyroid histology was qualitatively assessed, and females and males were separated and further exposed to their respective treatments for six additional weeks. Eight females in each tank replicate (n = 3) were paired weekly with four males from the same respective treatment, and packed-egg (spawn) volume (PEV) was measured each of the last five weeks. At least once during weeks 14-16 of exposure, other end points measured included fertilization rate, fertilized egg diameter, hatching rate, standard length, and craniofacial development of 4-day-postfertilization larvae and thyroid hormone content of 3.5-h embryos and of exposed mothers. At 10 weeks of exposure, perchlorate at both concentrations caused thyroidal hypertrophy and colloid depletion. A marked reduction in PEV was observed toward the end of the 6-week spawning period, but fertilization and embryo hatching rates were unaffected. Fertilized egg diameter and larval length were increased by parental exposure to perchlorate. Larval head depth was unaffected but the forward protrusion of the lower jaw-associated cartilage complexes, Meckel's and ceratohyal, was decreased. Exposure to both concentrations of perchlorate inhibited whole-body thyroxine content in mothers and embryos, but triiodothyronine content was unchanged. In conclusion, prolonged exposure of adult zebrafish to perchlorate not only disrupts their thyroid endocrine system but also impairs reproduction and influences early F1 development. ?? 2007 Oxford University Press.

  5. Method and apparatus for sampling atmospheric mercury

    Science.gov (United States)

    Trujillo, Patricio E.; Campbell, Evan E.; Eutsler, Bernard C.

    1976-01-20

    A method of simultaneously sampling particulate mercury, organic mercurial vapors, and metallic mercury vapor in the working and occupational environment and determining the amount of mercury derived from each such source in the sampled air. A known volume of air is passed through a sampling tube containing a filter for particulate mercury collection, a first adsorber for the selective adsorption of organic mercurial vapors, and a second adsorber for the adsorption of metallic mercury vapor. Carbon black molecular sieves are particularly useful as the selective adsorber for organic mercurial vapors. The amount of mercury adsorbed or collected in each section of the sampling tube is readily quantitatively determined by flameless atomic absorption spectrophotometry.

  6. Possible Detection of Perchlorates by the Sample Analysis at Mars (SAM) Instrument: Comparison with Previous Missions

    Science.gov (United States)

    Navarro-Gonzalex, Rafael; Sutter, Brad; Archer, Doug; Ming, Doug; Eigenbrode, Jennifer; Franz, Heather; Glavin, Daniel; McAdam, Amy; Stern, Jennifer; McKay, Christopher; hide

    2013-01-01

    The first chemical analysis of soluble salts in the soil was carried out by the Phoenix Lander in the Martian Arctic [1]. Surprisingly, chlorine was present as magnesium or calcium perchlorate at 0.4 to 0.6 percent. Additional support for the identification of perchlorate came from the evolved gas analysis which detected the release of molecular oxygen at 350-550C [1]. When Mars-like soils from the Atacama Desert were spiked with magnesium perchlorate (1 percent) and heated using the Viking GC-MS protocol, nearly all the organics were combusted but a small amount was chlorinated, forming chloromethane and dichloromethane [2]. These chlorohydrocarbons were detected by the Viking GC-MS experiments when the Martian soil was analyzed but they were considered to be terrestrial contaminants [3]. Reinterpretation of the Viking results suggests detected compounds (CH3Cl and CH2Cl2) were carried from Earth [4]. Recently the Sample Analysis at Mars (SAM) instrument on board the Mars Science Laboratory (MSL) ran four samples from an aeolian bedform named Rocknest. The samples analyzed were portioned from the fifth scoop at this location. The samples were heated to 835C at 35C/min with a He flow. The SAM QMS detected a major oxygen release (300-500C) [5], coupled with the release of chlorinated hydrocarbons (chloromethane, dichloromethane, trichloromethane, and chloromethylpropene) detected both by SAM QMS and GC-MS derived from known Earth organic contaminants in the instrument [6]. Calcium perchlorate appears to be the best candidate for evolved O2 in the Rocknest samples at this time but other Cl species (e.g., chlorates) are possible and must be evaluated. The potential detection of perchlorates in Rocknest material adds weight to the argument that both Viking Landers measured signatures of perchlorates. Even if the source of the organic carbon detected is still unknown, the chlorine source was likely Martian. Two mechanisms have been hypothesized for the formation of soil

  7. Growth and optical characterizations on 3-aminophenol perchlorate (3-AMPP) crystal

    Energy Technology Data Exchange (ETDEWEB)

    Boopathi, K., E-mail: ramasamyp@ssn.edu.in; Ramasamy, P., E-mail: ramasamyp@ssn.edu.in [Centre for Crystal Growth, SSN College of Engineering, Kalavakkam-603110 (India)

    2014-04-24

    A single crystal of organic nonlinear optical material 3-aminophenol perchlorate (3-AMP) was successfully grown by the slow evaporation solution method. Single-crystal X-ray diffractrometer was utilized to measure unit cell parameters and to confirm lattice parameter. 3-aminophenol perchlorate belongs to monoclinic space group P2{sub 1}. The optical transparency window in the UV-vis-NIR region is found to be good for nonlinear optical applications second harmonic studies were carried out. The second harmonic output intensity was tested using the Kurtz and Perry powder method and was found to be 1.1 times that of potassium dihydrogen phosphate (KDP)

  8. Perchlorate in Lake Water from an Operating Diamond Mine.

    Science.gov (United States)

    Smith, Lianna J D; Ptacek, Carol J; Blowes, David W; Groza, Laura G; Moncur, Michael C

    2015-07-07

    Mining-related perchlorate [ClO4(-)] in the receiving environment was investigated at the operating open-pit and underground Diavik diamond mine, Northwest Territories, Canada. Samples were collected over four years and ClO4(-) was measured in various mine waters, the 560 km(2) ultraoligotrophic receiving lake, background lake water and snow distal from the mine. Groundwaters from the underground mine had variable ClO4(-) concentrations, up to 157 μg L(-1), and were typically an order of magnitude higher than concentrations in combined mine waters prior to treatment and discharge to the lake. Snow core samples had a mean ClO4(-) concentration of 0.021 μg L(-1) (n=16). Snow and lake water Cl(-)/ClO4(-) ratios suggest evapoconcentration was not an important process affecting lake ClO4(-) concentrations. The multiyear mean ClO4(-) concentrations in the lake were 0.30 μg L(-1) (n = 114) in open water and 0.24 μg L(-1) (n = 107) under ice, much below the Canadian drinking water guideline of 6 μg L(-1). Receiving lake concentrations of ClO4(-) generally decreased year over year and ClO4(-) was not likely [biogeo]chemically attenuated within the receiving lake. The discharge of treated mine water was shown to contribute mining-related ClO4(-) to the lake and the low concentrations after 12 years of mining were attributed to the large volume of the receiving lake.

  9. Mercury analysis in hair

    DEFF Research Database (Denmark)

    Esteban, Marta; Schindler, Birgit Karin; Jiménez, José Antonio

    2015-01-01

    laboratories. Training sessions were organized for field workers and four external quality-assessment exercises (ICI/EQUAS), followed by the corresponding web conferences, were organized between March 2011 and February 2012. ICI/EQUAS used native hair samples at two mercury concentration ranges (0...

  10. Mercury exposure in Ireland

    DEFF Research Database (Denmark)

    Cullen, Elizabeth; Evans, David S; Davidson, Fred

    2014-01-01

    of a study to Coordinate and Perform Human Biomonitoring on a European Scale (DEMOCOPHES) pilot biomonitoring study. METHODS: Hair mercury concentrations were determined from a convenience sample of 120 mother/child pairs. Mothers also completed a questionnaire. Rigorous quality assurance within DEMOCOPHES...

  11. Metabolic models for methyl and inorganic mercury

    Energy Technology Data Exchange (ETDEWEB)

    Bernard, S.R.; Purdue, P.

    1984-03-01

    Following the outbreak of mercury poisoning in Minimata, Japan (1953-60), much work has been done on the toxicology of mercury - in particular methyl mercury. In this paper, the authors derive two compartmental models for the metabolism of methyl mercury and inorganic mercury based upon the data which have been collected since 1960.

  12. [Mercury in vaccines].

    Science.gov (United States)

    Hessel, Luc

    2003-01-01

    Thiomersal, also called thimerosal, is an ethyl mercury derivative used as a preservative to prevent bacterial contamination of multidose vaccine vials after they have been opened. Exposure to low doses of thiomersal has essentially been associated with hypersensitivity reactions. Nevertheless there is no evidence that allergy to thiomersal could be induced by thiomersal-containing vaccines. Allergy to thiomersal is usually of delayed-hypersensitivity type, but its detection through cutaneous tests is not very reliable. Hypersensitivity to thiomersal is not considered as a contraindication to the use of thiomersal-containing vaccines. In 1999 in the USA, thiomersal was present in approximately 30 different childhood vaccines, whereas there were only 2 in France. Although there were no evidence of neurological toxicity in infants related to the use of thiomersal-containing vaccines, the FDA considered that the cumulative dose of mercury received by young infants following vaccination was high enough (although lower than the FDA threshold for methyl mercury) to request vaccine manufacturers to remove thiomersal from vaccine formulations. Since 2002, all childhood vaccines used in Europe and the USA are thiomersal-free or contain only minute amounts of thiomersal. Recently published studies have shown that the mercury levels in the blood, faeces and urine of children who had received thiomersal-containing vaccines were much lower than those accepted by the American Environmental Protection Agency. It has also been demonstrated that the elimination of mercury in children was much faster than what was expected on the basis of studies conducted with methyl mercury originating from food. Recently, the hypothesis that mercury contained in vaccines could be the cause of autism and other neurological developmental disorders created a new debate in the medical community and the general public. To date, none of the epidemiological studies conducted in Europe and elsewhere

  13. Mercury Information Clearinghouse

    Energy Technology Data Exchange (ETDEWEB)

    Chad A. Wocken; Michael J. Holmes; Dennis L. Laudal; Debra F. Pflughoeft-Hassett; Greg F. Weber; Nicholas V. C. Ralston; Stanley J. Miller; Grant E. Dunham; Edwin S. Olson; Laura J. Raymond; John H. Pavlish; Everett A. Sondreal; Steven A. Benson

    2006-03-31

    The Canadian Electricity Association (CEA) identified a need and contracted the Energy & Environmental Research Center (EERC) to create and maintain an information clearinghouse on global research and development activities related to mercury emissions from coal-fired electric utilities. With the support of CEA, the Center for Air Toxic Metals{reg_sign} (CATM{reg_sign}) Affiliates, and the U.S. Department of Energy (DOE), the EERC developed comprehensive quarterly information updates that provide a detailed assessment of developments in the various areas of mercury monitoring, control, policy, and research. A total of eight topical reports were completed and are summarized and updated in this final CEA quarterly report. The original quarterly reports can be viewed at the CEA Web site (www.ceamercuryprogram.ca). In addition to a comprehensive update of previous mercury-related topics, a review of results from the CEA Mercury Program is provided. Members of Canada's coal-fired electricity generation sector (ATCO Power, EPCOR, Manitoba Hydro, New Brunswick Power, Nova Scotia Power Inc., Ontario Power Generation, SaskPower, and TransAlta) and CEA, have compiled an extensive database of information from stack-, coal-, and ash-sampling activities. Data from this effort are also available at the CEA Web site and have provided critical information for establishing and reviewing a mercury standard for Canada that is protective of environment and public health and is cost-effective. Specific goals outlined for the CEA mercury program included the following: (1) Improve emission inventories and develop management options through an intensive 2-year coal-, ash-, and stack-sampling program; (2) Promote effective stack testing through the development of guidance material and the support of on-site training on the Ontario Hydro method for employees, government representatives, and contractors on an as-needed basis; (3) Strengthen laboratory analytical capabilities through

  14. Small Mercury Relativity Orbiter

    Science.gov (United States)

    Bender, Peter L.; Vincent, Mark A.

    1989-01-01

    The accuracy of solar system tests of gravitational theory could be very much improved by range and Doppler measurements to a Small Mercury Relativity Orbiter. A nearly circular orbit at roughly 2400 km altitude is assumed in order to minimize problems with orbit determination and thermal radiation from the surface. The spacecraft is spin-stabilized and has a 30 cm diameter de-spun antenna. With K-band and X-band ranging systems using a 50 MHz offset sidetone at K-band, a range accuracy of 3 cm appears to be realistically achievable. The estimated spacecraft mass is 50 kg. A consider-covariance analysis was performed to determine how well the Earth-Mercury distance as a function of time could be determined with such a Relativity Orbiter. The minimum data set is assumed to be 40 independent 8-hour arcs of tracking data at selected times during a two year period. The gravity field of Mercury up through degree and order 10 is solved for, along with the initial conditions for each arc and the Earth-Mercury distance at the center of each arc. The considered parameters include the gravity field parameters of degree 11 and 12 plus the tracking station coordinates, the tropospheric delay, and two parameters in a crude radiation pressure model. The conclusion is that the Earth-Mercury distance can be determined to 6 cm accuracy or better. From a modified worst-case analysis, this would lead to roughly 2 orders of magnitude improvement in the knowledge of the precession of perihelion, the relativistic time delay, and the possible change in the gravitational constant with time.

  15. Mercury Phase II Study - Mercury Behavior in Salt Processing Flowsheet

    Energy Technology Data Exchange (ETDEWEB)

    Jain, V. [Savannah River Remediation, LLC., Aiken, SC (United States); Shah, H. [Savannah River Remediation, LLC., Aiken, SC (United States). Sludge and Salt Planning; Bannochie, C. J. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Wilmarth, W. R. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-07-25

    Mercury (Hg) in the Savannah River Site Liquid Waste System (LWS) originated from decades of canyon processing where it was used as a catalyst for dissolving the aluminum cladding of reactor fuel. Approximately 60 metric tons of mercury is currently present throughout the LWS. Mercury has long been a consideration in the LWS, from both hazard and processing perspectives. In February 2015, a Mercury Program Team was established at the request of the Department of Energy to develop a comprehensive action plan for long-term management and removal of mercury. Evaluation was focused in two Phases. Phase I activities assessed the Liquid Waste inventory and chemical processing behavior using a system-by-system review methodology, and determined the speciation of the different mercury forms (Hg+, Hg++, elemental Hg, organomercury, and soluble versus insoluble mercury) within the LWS. Phase II activities are building on the Phase I activities, and results of the LWS flowsheet evaluations will be summarized in three reports: Mercury Behavior in the Salt Processing Flowsheet (i.e. this report); Mercury Behavior in the Defense Waste Processing Facility (DWPF) Flowsheet; and Mercury behavior in the Tank Farm Flowsheet (Evaporator Operations). The evaluation of the mercury behavior in the salt processing flowsheet indicates, inter alia, the following: (1) In the assembled Salt Batches 7, 8 and 9 in Tank 21, the total mercury is mostly soluble with methylmercury (MHg) contributing over 50% of the total mercury. Based on the analyses of samples from 2H Evaporator feed and drop tanks (Tanks 38/43), the source of MHg in Salt Batches 7, 8 and 9 can be attributed to the 2H evaporator concentrate used in assembling the salt batches. The 2H Evaporator is used to evaporate DWPF recycle water. (2) Comparison of data between Tank 21/49, Salt Solution Feed Tank (SSFT), Decontaminated Salt Solution Hold Tank (DSSHT), and Tank 50 samples suggests that the total mercury as well as speciated

  16. Mercury Phase II Study - Mercury Behavior in Salt Processing Flowsheet

    International Nuclear Information System (INIS)

    Jain, V.; Shah, H.; Wilmarth, W. R.

    2016-01-01

    Mercury (Hg) in the Savannah River Site Liquid Waste System (LWS) originated from decades of canyon processing where it was used as a catalyst for dissolving the aluminum cladding of reactor fuel. Approximately 60 metric tons of mercury is currently present throughout the LWS. Mercury has long been a consideration in the LWS, from both hazard and processing perspectives. In February 2015, a Mercury Program Team was established at the request of the Department of Energy to develop a comprehensive action plan for long-term management and removal of mercury. Evaluation was focused in two Phases. Phase I activities assessed the Liquid Waste inventory and chemical processing behavior using a system-by-system review methodology, and determined the speciation of the different mercury forms (Hg+, Hg++, elemental Hg, organomercury, and soluble versus insoluble mercury) within the LWS. Phase II activities are building on the Phase I activities, and results of the LWS flowsheet evaluations will be summarized in three reports: Mercury Behavior in the Salt Processing Flowsheet (i.e. this report); Mercury Behavior in the Defense Waste Processing Facility (DWPF) Flowsheet; and Mercury behavior in the Tank Farm Flowsheet (Evaporator Operations). The evaluation of the mercury behavior in the salt processing flowsheet indicates, inter alia, the following: (1) In the assembled Salt Batches 7, 8 and 9 in Tank 21, the total mercury is mostly soluble with methylmercury (MHg) contributing over 50% of the total mercury. Based on the analyses of samples from 2H Evaporator feed and drop tanks (Tanks 38/43), the source of MHg in Salt Batches 7, 8 and 9 can be attributed to the 2H evaporator concentrate used in assembling the salt batches. The 2H Evaporator is used to evaporate DWPF recycle water. (2) Comparison of data between Tank 21/49, Salt Solution Feed Tank (SSFT), Decontaminated Salt Solution Hold Tank (DSSHT), and Tank 50 samples suggests that the total mercury as well as speciated

  17. A mercury transport and fate model (LM2-mercury) for mass budget assessment of mercury cycling in Lake Michigan

    Science.gov (United States)

    LM2-Mercury, a mercury mass balance model, was developed to simulate and evaluate the transport, fate, and biogeochemical transformations of mercury in Lake Michigan. The model simulates total suspended solids (TSS), disolved organic carbon (DOC), and total, elemental, divalent, ...

  18. Development of a Reference Dose for Perchlorate: Current Issues and Status

    Science.gov (United States)

    Pleus, R. C.; Goodman, G.; Mattie, D. R.

    2000-01-01

    The perchlorate anion (ClO4) is typically manufactured as the ammonium salt. The most common use of ammonium perchlorate is in the aerospace program as a component of solid rocket fuel. The perchlorate anion is exceedingly stable under environmental conditions and has been found in ground and surface waters in CA, NV, UT, AZ, TX, AK, NY, MD, WV and FL. The National Center for Environmental Assessment (NCEA) of the U.S. Environmental Protection Agency (US EPA) is in the process of developing an oral reference dose (RfD) for perchlorate. An oral RfD is a body-weight-adjusted dose that can be consumed daily over an entire lifetime with the expectation of no adverse health effects. Once developed, the new RfD will be used by US EPA as the basis of a safe-drinking-water level (SDWL) guideline. US EPA and regional regulatory agencies will then jointly or separately propose clean-up action levels for ground and surface waters at contaminated sites. The toxicological database on CIO4- as of March 1997 was determined by an expert peer-review panel to be inadequate for the purpose of deriving an oral RfD. For example, little or no experimental data existed on the subchronic, reproductive, or developmental toxicity of perchlorate. To fill gaps in the toxicological database, eight animal studies were designed by a government-industry consortium that included US EPA and AFRL. These studies were performed in 1997-1998. It has been known for many years that in the thyroid, high doses of perchlorate block the function of iodide by competing for iodide binding sites. Perchlorate was used in the 1950s-60s as a treatment for Graves' disease (a hyperthyroid condition). Because of what was already known about the pharmacological mode of action of perchlorate, specific concerns addressed in the design of the recent animal studies included the potential for developmental toxicity, notably neurological development. Upon review of complete study reports from four of the studies and

  19. Mercury Exposure and Heart Diseases.

    Science.gov (United States)

    Genchi, Giuseppe; Sinicropi, Maria Stefania; Carocci, Alessia; Lauria, Graziantonio; Catalano, Alessia

    2017-01-12

    Environmental contamination has exposed humans to various metal agents, including mercury. It has been determined that mercury is not only harmful to the health of vulnerable populations such as pregnant women and children, but is also toxic to ordinary adults in various ways. For many years, mercury was used in a wide variety of human activities. Nowadays, the exposure to this metal from both natural and artificial sources is significantly increasing. Recent studies suggest that chronic exposure, even to low concentration levels of mercury, can cause cardiovascular, reproductive, and developmental toxicity, neurotoxicity, nephrotoxicity, immunotoxicity, and carcinogenicity. Possible biological effects of mercury, including the relationship between mercury toxicity and diseases of the cardiovascular system, such as hypertension, coronary heart disease, and myocardial infarction, are being studied. As heart rhythm and function are under autonomic nervous system control, it has been hypothesized that the neurotoxic effects of mercury might also impact cardiac autonomic function. Mercury exposure could have a long-lasting effect on cardiac parasympathetic activity and some evidence has shown that mercury exposure might affect heart rate variability, particularly early exposures in children. The mechanism by which mercury produces toxic effects on the cardiovascular system is not fully elucidated, but this mechanism is believed to involve an increase in oxidative stress. The exposure to mercury increases the production of free radicals, potentially because of the role of mercury in the Fenton reaction and a reduction in the activity of antioxidant enzymes, such as glutathione peroxidase. In this review we report an overview on the toxicity of mercury and focus our attention on the toxic effects on the cardiovascular system.

  20. Mercury Exposure and Heart Diseases

    Directory of Open Access Journals (Sweden)

    Giuseppe Genchi

    2017-01-01

    Full Text Available Environmental contamination has exposed humans to various metal agents, including mercury. It has been determined that mercury is not only harmful to the health of vulnerable populations such as pregnant women and children, but is also toxic to ordinary adults in various ways. For many years, mercury was used in a wide variety of human activities. Nowadays, the exposure to this metal from both natural and artificial sources is significantly increasing. Recent studies suggest that chronic exposure, even to low concentration levels of mercury, can cause cardiovascular, reproductive, and developmental toxicity, neurotoxicity, nephrotoxicity, immunotoxicity, and carcinogenicity. Possible biological effects of mercury, including the relationship between mercury toxicity and diseases of the cardiovascular system, such as hypertension, coronary heart disease, and myocardial infarction, are being studied. As heart rhythm and function are under autonomic nervous system control, it has been hypothesized that the neurotoxic effects of mercury might also impact cardiac autonomic function. Mercury exposure could have a long-lasting effect on cardiac parasympathetic activity and some evidence has shown that mercury exposure might affect heart rate variability, particularly early exposures in children. The mechanism by which mercury produces toxic effects on the cardiovascular system is not fully elucidated, but this mechanism is believed to involve an increase in oxidative stress. The exposure to mercury increases the production of free radicals, potentially because of the role of mercury in the Fenton reaction and a reduction in the activity of antioxidant enzymes, such as glutathione peroxidase. In this review we report an overview on the toxicity of mercury and focus our attention on the toxic effects on the cardiovascular system.

  1. Mercury's exosphere: observations during MESSENGER's First Mercury flyby.

    Science.gov (United States)

    McClintock, William E; Bradley, E Todd; Vervack, Ronald J; Killen, Rosemary M; Sprague, Ann L; Izenberg, Noam R; Solomon, Sean C

    2008-07-04

    During MESSENGER's first Mercury flyby, the Mercury Atmospheric and Surface Composition Spectrometer measured Mercury's exospheric emissions, including those from the antisunward sodium tail, calcium and sodium close to the planet, and hydrogen at high altitudes on the dayside. Spatial variations indicate that multiple source and loss processes generate and maintain the exosphere. Energetic processes connected to the solar wind and magnetospheric interaction with the planet likely played an important role in determining the distributions of exospheric species during the flyby.

  2. Evaluation and Determination of Heavy Metals (Mercury, Lead and Cadmium in Human Breast Milk

    Directory of Open Access Journals (Sweden)

    Abdollahi Atousa

    2014-07-01

    Full Text Available Mercury, Lead and Cadmium were determined in 100 samples of human breast milk samples from urban and rural mothers in Isfahan (IRAN. A questionnaire about area of residence, nutrition, smoking habits, and dental fillings was filled out by the lactating mothers. The combination of nitric acid, hydrogen peroxide and perchloric acid was found to be one of the most suitable acids in wet digestion of milk. Cold vapor atomic absorption was used to determine the mercury content in milk after wet digestion. The effect of concentration of nitric acid, influence of flow rate and tin(П chloride were investigated. The mean concentration of mercury in human breast milk samples was 0.96 ppb. Extraction of Pb and Cd were performed with ammonium pyrrolidine dithiocarbamate (APDC to methyl isobutyl ketone (MIBK and were determined by Flame Atomic Absorption Spectrometry. The factors influencing, the complex formation, pH, time and buffer were optimized. The mean concentration of Pb and Cd in human breast milk was 0.0147 and 0.0121 ppm, respectively. The maximum concentrations were found in breast milk of rural mothers.

  3. Recovery of mercury from acid waste residues

    Science.gov (United States)

    Greenhalgh, Wilbur O.

    1989-12-05

    Mercury can be recovered from nitric acid-containing fluids by reacting the fluid with aluminum metal to produce mercury metal, and then quenching the reactivity of the nitric acid prior to nitration of the mercury metal.

  4. Mercury Poisoning Linked to Skin Products

    Science.gov (United States)

    ... Products For Consumers Home For Consumers Consumer Updates Mercury Poisoning Linked to Skin Products Share Tweet Linkedin ... and, in some situations, criminal prosecution. Dangers of Mercury Exposure to mercury can have serious health consequences. ...

  5. Perchlorate-Coupled Carbon Monoxide (CO Oxidation: Evidence for a Plausible Microbe-Mediated Reaction in Martian Brines

    Directory of Open Access Journals (Sweden)

    Marisa R. Myers

    2017-12-01

    Full Text Available The presence of hydrated salts on Mars indicates that some regions of its surface might be habitable if suitable metabolizable substrates are available. However, several lines of evidence have shown that Mars’ regolith contains only trace levels of the organic matter needed to support heterotrophic microbes. Due to the scarcity of organic carbon, carbon monoxide (CO at a concentration of about 700 parts per million (about 0.4 Pa might be the single most abundant readily available substrate that could support near-surface bacterial activity. Although a variety of electron acceptors can be coupled to CO oxidation, perchlorate is likely the most abundant potential oxidant in Mars’ brines. Whether perchlorate, a potent chaotrope, can support microbial CO oxidation has not been previously documented. We report here the first evidence for perchlorate-coupled CO oxidation based on assays with two distinct euryarchaeal extreme halophiles. CO oxidation occurred readily in 3.8 M NaCl brines with perchlorate concentrations from 0.01 to 1 M. Both isolates were able to couple CO with perchlorate or chlorate under anaerobic conditions with or without nitrate as an inducer for nitrate reductase, which serves as a perchlorate reductase in extreme halophiles. In the presence of perchlorate, CO concentrations were reduced to levels well below those found in Mars’ atmosphere. This indicates that CO could contribute to the survival of microbial populations in hydrated salt formations or brines if water activities are suitably permissive.

  6. Systematics of Natural Perchlorate in Precipitation, Soils, and Plants at the Amargosa Desert Research Site, Nye County, Nevada

    Science.gov (United States)

    Andraski, B. J.; Stonestrom, D. A.; Jackson, W. A.; Rajagopalan, S.; Taylor, E. M.

    2007-12-01

    Naturally occurring perchlorate is known to be associated with nitrate deposits of the hyperarid Atacama Desert in Chile, and recent large-scale sampling has identified a substantial reservoir (up to 1 kg/ha) of natural perchlorate in diverse unsaturated zones of the arid and semiarid Southwestern United States (Rao et al., 2007, ES&T, DOI: 10.1021/es062853i). The objective of the Amargosa Desert work is to develop a better understanding of the deposition, accumulation, and biological cycling of perchlorate in arid environments. Occurrence of perchlorate was evaluated by sampling shallow soil profiles up to 3 m in depth at four different locations and at two different time periods, and by sampling dominant plant species growing near the subsurface profiles. Deposition of perchlorate was evaluated by analyzing both bulk deposition (precipitation plus dry fall, collected under oil) collected on site and wet deposition samples collected by the National Atmospheric Deposition program at a nearby site. Soil samples and atmospheric-deposition samples were tested for both perchlorate (ClO4- ) and major anions. Perchlorate concentrations (0.2-20 µg/kg) were variable with depth in soil profiles and generally correlated most highly with chloride (Cl-) and nitrate (NO3-), although the intensity of these relations differed among profiles. Plant concentrations were generally above 1 mg/kg, suggesting ClO4- accumulation. Concentrations of ClO4- were generally much greater in total deposition than wet deposition samples, indicating a substantial dryfall component of meteoric deposition. This presentation will present the mass distribution and variability of perchlorate in bulk deposition, soils, and plants. Reasons for observed relations between subsurface concentrations of perchlorate and other anions will be explored.

  7. Removal of Perchlorate from Water and Wastewater by Catalytic Hydrogen Gas Membrane Systems

    Science.gov (United States)

    2007-01-01

    Quimica , Serie A: Quimica Fisica e Ingenieria Quimica , 1984. 80(2): p. 219-25. Logan, B.E. and D. LaPoint, Treatment of Perchlorate- and Nitrate...ion at iridium electrodes. Ion concentration and solution pH effects. Anales de Quimica , Serie A: Quimica Fisica e Ingenieria Quimica (1985), 81(3

  8. Oxidation of some aliphatic and cyclic diols by cerium(4) in perchloric acid solutions

    International Nuclear Information System (INIS)

    Dehka, M; Dzegets, Yu.

    1998-01-01

    Oxidation velocities of 1,5-pentandiol and 1,8-octanediol by cerium(4) in water solutions of perchloric acid, as well as the dependence of Ce(4) quantity reduced by trans-1,2-cyclohexanol on the reduction time are studied. Stoichiometry of the process is determined, intermediate and final products of oxidation are identified. Possible reaction mechanisms are proposed [ru

  9. Uptake and Transformation of the Propellants 2,4-DNT, Perchlorate and Nitroglycerin by Grasses

    Science.gov (United States)

    2006-07-31

    applications, it is also used in the field of medicine for the treatment of blood pressure and heart diseases (Brodman et al., 1997). 19 The biodegradation...Lu Yu, Jaclyn E.Cafias, Cobb G.P., Jackson W.A. Anderson T.A. "Uptake of perchlorate in terrestrial plants." Ecotoxicology and Environmental Safety 58

  10. Radioiodine tracers as useful tools in studies of thyrotoxic effects of exogenous bromide and perchlorate ions

    Czech Academy of Sciences Publication Activity Database

    Pavelka, Stanislav

    2012-01-01

    Roč. 291, č. 2 (2012), s. 405-408 ISSN 0236-5731 R&D Projects: GA ČR(CZ) GA304/08/0256 Institutional research plan: CEZ:AV0Z50110509 Keywords : bromide * perchlorate * radioiodine tracer * thyroid hormone Subject RIV: ED - Physiology Impact factor: 1.467, year: 2012

  11. 77 FR 64335 - Notification of a Public Teleconference of the Science Advisory Board; Perchlorate Advisory Panel

    Science.gov (United States)

    2012-10-19

    ... Perchlorate Advisory Panel to discuss its revised draft report concerning EPA's draft white paper Life Stage... draft report regarding EPA's draft white paper Life Stage Considerations and Interpretation of Recent..., 2012 to discuss the EPA white paper and a public teleconference on September 25, 2012 to discuss its...

  12. Double-Polymer-Modified Pencil Lead for Stripping Voltammetry of Perchlorate in Drinking Water

    Science.gov (United States)

    Izadyar, Anahita; Kim, Yushin; Ward, Michelle M.; Amemiya, Shigeru

    2012-01-01

    The inexpensive and disposable electrode based on a double-polymer-modified pencil lead is proposed for upper-division undergraduate instrumental laboratories to enable the highly sensitive detection of perchlorate. Students fabricate and utilize their own electrodes in the 3-4 h laboratory session to learn important concepts and methods of…

  13. Trace determination of perchlorate using electromembrane extraction and capillary electrophoresis with capacitively coupled contactless conductivity detection

    Czech Academy of Sciences Publication Activity Database

    Kiplagat, I.K.; Doan, T.K.O.; Kubáň, Pavel; Boček, Petr

    2011-01-01

    Roč. 32, č. 21 (2011), s. 3008-3015 ISSN 0173-0835 R&D Projects: GA ČR GAP206/10/1219 Institutional research plan: CEZ:AV0Z40310501 Keywords : electromembrane extraction * perchlorate * capillary electrophoresis Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 3.303, year: 2011

  14. Suppression by perchlorate of technetium-99m and iodine-123 secretion in milk of lactating goats

    International Nuclear Information System (INIS)

    Mountford, P.J.; Heap, R.B.; Hamon, M.; Fleet, I.R.; Coakley, A.J.

    1987-01-01

    Lactating goats were infused with either technetium-99m (/sup 99m/Tc) or iodine-123 ( 123 I) together with chlorine-36 ( 36 Cl) through an indwelling catheter previously placed in an external pudic mammary artery. The radioisotope infusions were repeated together with 100 mg of sodium perchlorate. There was a rapid transfer of /sup 99m/Tc and 123 I into milk, reaching a peak concentration 30 min after a 15-min infusion. The fractional secretion of /sup 99m/Tc and 123 I in milk was reduced by 70%-80% and 60%-66%, respectively, by perchlorate. The fractional secretion of 36 Cl was not affected by perchlorate, and the shape of the 36 Cl secretion curve differed from those of /sup 99m/Tc and 123 I, which were similar. It is probable, therefore, that the latter nuclides were secreted by a transport route different from that of chloride. Available data describing the secretion of /sup 99m/Tc in human milk after pertechnetate administration was reviewed, and it was concluded that perchlorate pretreatment significantly reduced the secretion of /sup 99m/Tc in human breast milk

  15. (Per)chlorate reduction by an acetogenic bacterium, Sporomusa sp., isolated from an underground gas storage.

    KAUST Repository

    Balk, Melike

    2010-08-03

    A mesophilic bacterium, strain An4, was isolated from an underground gas storage reservoir with methanol as substrate and perchlorate as electron acceptor. Cells were Gram-negative, spore-forming, straight to curved rods, 0.5-0.8 microm in diameter, and 2-8 microm in length, growing as single cells or in pairs. The cells grew optimally at 37 degrees C, and the pH optimum was around 7. Strain An4 converted various alcohols, organic acids, fructose, acetoin, and H(2)/CO(2) to acetate, usually as the only product. Succinate was decarboxylated to propionate. The isolate was able to respire with (per)chlorate, nitrate, and CO(2). The G+C content of the DNA was 42.6 mol%. Based on the 16S rRNA gene sequence analysis, strain An4 was most closely related to Sporomusa ovata (98% similarity). The bacterium reduced perchlorate and chlorate completely to chloride. Key enzymes, perchlorate reductase and chlorite dismutase, were detected in cell-free extracts.

  16. PERCHLORATE LEVELS IN SAMPLES OF SODIUM NITRATE FERTILIZER DERIVED FROM CHILEAN CALICHE

    Science.gov (United States)

    Paleogeochemical deposits in northern Chile are a rich source of naturally occurring sodium nitrate. These caliche ores are mined and processed to isolate NaNO3 (16-0-0) for use in fertilizers. Coincidentally, these very same deposits are a natural soure of perchlorate anion (C...

  17. DISTRIBUTION OF PERCHLORATE IN SAMPLES OF SODIUM NITRATE (CHILE SALTPETER) FERTILIZER DERIVED FROM NATURAL CALICHE

    Science.gov (United States)

    Two lots of sodium nitrate fertilizer derived from Chilean caliche were analyzed to determine the distribution of perchlorate throughout the material. Although our samples represent a limited amount, we found that distribution was essentially homogeneous in any 100-g portion. Whe...

  18. Tailored Granular Activated Carbon Treatment of Perchlorate in Drinking Water. ESTCP Cost and Performance Report

    Science.gov (United States)

    2011-08-01

    carbon layer surfaces are generally uncharged ( hydrophobic ), and they thus repel water and charged inorganic species such as perchlorate. However...cationic surfactants onto graphite, cellulose, clay, quartz, titanium dioxide, zeolites , soils, and membranes. However, the project team is not aware

  19. A STUDY ON THE ACCUMULATION OF PERCHLORATE IN YOUNG HEAD LETTUCE

    Science.gov (United States)

    The overall objective of this study was to demonstrate in a greenhouse study the potential for incorporation of perchlorate from aqueous solutions of 10, 50, 100, 500, 1,000, 5,000, and 10,000 ppb into an agricultural food crop (lettuce; Lactuca sativa), which is typically grown ...

  20. Synthesis and characterization of solid complexes of thorium, uranyl perchlorates with bis-quinolylmethylene

    International Nuclear Information System (INIS)

    He Liangyou; Tang Ning; Gan Xinmin; Tan Minyu

    1990-01-01

    The solid complexes of thorium, uranyl perchlorates with bis-quinolylmethylene (Biqm) having the composition Th(Biqm) 5 (ClO 4 ) 4 , UO 2 (Biqm) 2 (ClO 4 ) 2 have been synthesized in nonaqueous solvents. These two complexes have been characterized by elemental analysis, IR and UV spectra, differential thermal analysis (DTA) and thermogravimetry (TG), fluorescence spectra and molar conductances

  1. Mercury, Vaccines, and Autism

    Science.gov (United States)

    Baker, Jeffrey P.

    2008-01-01

    The controversy regarding the once widely used mercury-containing preservative thimerosal in childhood vaccines has raised many historical questions that have not been adequately explored. Why was this preservative incorporated in the first place? Was there any real evidence that it caused harm? And how did thimerosal become linked in the public mind to the “autism epidemic”? I examine the origins of the thimerosal controversy and their legacy for the debate that has followed. More specifically, I explore the parallel histories of three factors that converged to create the crisis: vaccine preservatives, mercury poisoning, and autism. An understanding of this history provides important lessons for physicians and policymakers seeking to preserve the public’s trust in the nation’s vaccine system. PMID:18172138

  2. Large-Scale Demonstration of Perchlorate Removal Using Weak Base Anion Resin at Well No. 3 in Rialto, California

    Science.gov (United States)

    2012-12-01

    USEPA 324–Volatile Organics μg/L All were ND USEPA 608–Chlorinated Pesticides and/or PCBs μg/L All were ND Oil & Grease mg/L ND Sulfide, soluble mg...perchlorate. Wastewater produced during regeneration is treated to remove perchlorate. This is performed using a small volume of strong base anion (SBA...regeneration. Wastewater produced during regeneration is treated to remove perchlorate. This can be done by using a small volume of scavenger resin, or

  3. Mercury in Canadian crude oil

    International Nuclear Information System (INIS)

    Hollebone, B.P.

    2005-01-01

    Estimates for average mercury concentrations in crude oil range widely from 10 ng/g of oil to 3,500 ng/g of oil. With such a broad range of estimates, it is difficult to determine the contributions of the petroleum sector to the total budget of mercury emissions. In response to concerns that the combustion of petroleum products may be a major source of air-borne mercury pollution, Environment Canada and the Canadian Petroleum Products Institute has undertaken a survey of the average total mercury concentration in crude oil processed in Canadian refineries. In order to calculate the potential upper limit of total mercury in all refined products, samples of more than 30 different types of crude oil collected from refineries were measured for their concentration of mercury as it enters into a refinery before processing. High temperature combustion, cold vapour atomic absorption and cold vapour atomic fluorescence were the techniques used to quantify mercury in the samples. The results of the study provide information on the total mass of mercury present in crude oil processed in Canada each year. Results can be used to determine the impact of vehicle exhaust emissions to the overall Canadian mercury emission budget. 17 refs., 2 tabs., 2 figs

  4. Method for mercury refinement

    Science.gov (United States)

    Grossman, M.W.; Speer, R.; George, W.A.

    1991-04-09

    The effluent from mercury collected during the photochemical separation of the [sup 196]Hg isotope is often contaminated with particulate mercurous chloride, Hg[sub 2]Cl[sub 2]. The use of mechanical filtering via thin glass tubes, ultrasonic rinsing with acetone (dimethyl ketone) and a specially designed cold trap have been found effective in removing the particulate (i.e., solid) Hg[sub 2]Cl[sub 2] contaminant. The present invention is particularly directed to such filtering. 5 figures.

  5. Apparatus for mercury refinement

    Science.gov (United States)

    Grossman, M.W.; Speer, R.; George, W.A.

    1991-07-16

    The effluent from mercury collected during the photochemical separation of the [sup 196]Hg isotope is often contaminated with particulate mercurous chloride, Hg[sub 2]Cl[sub 2]. The use of mechanical filtering via thin glass tubes, ultrasonic rinsing with acetone (dimethyl ketone) and a specially designed cold trap have been found effective in removing the particulate (i.e., solid) Hg[sub 2]Cl[sub 2] contaminant. The present invention is particularly directed to such filtering. 5 figures.

  6. Apparatus for mercury refinement

    International Nuclear Information System (INIS)

    Grossman, M.W.; Speer, R.; George, W.A.

    1991-01-01

    The effluent from mercury collected during the photochemical separation of the 196 Hg isotope is often contaminated with particulate mercurous chloride, Hg 2 Cl 2 . The use of mechanical filtering via thin glass tubes, ultrasonic rinsing with acetone (dimethyl ketone) and a specially designed cold trap have been found effective in removing the particulate (i.e., solid) Hg 2 Cl 2 contaminant. The present invention is particularly directed to such filtering. 5 figures

  7. Method for scavenging mercury

    Science.gov (United States)

    Chang, Shih-ger [El Cerrito, CA; Liu, Shou-heng [Kaohsiung, TW; Liu, Zhao-rong [Beijing, CN; Yan, Naiqiang [Berkeley, CA

    2009-01-20

    Disclosed herein is a method for removing mercury from a gas stream comprising contacting the gas stream with a getter composition comprising bromine, bromochloride, sulphur bromide, sulphur dichloride or sulphur monochloride and mixtures thereof. In one preferred embodiment the getter composition is adsorbed onto a sorbent. The sorbent may be selected from the group consisting of flyash, limestone, lime, calcium sulphate, calcium sulfite, activated carbon, charcoal, silicate, alumina and mixtures thereof. Preferred is flyash, activated carbon and silica.

  8. Magnetic field of Mercury

    International Nuclear Information System (INIS)

    Jackson, D.J.; Beard, D.B.

    1977-01-01

    The geomagnetic field, suitably scaled down and parameterized, is shown to give a very good fit to the magnetic field measurements taken on the first and third passes of the Mariner 10 space probe past Mercury. The excellence of the fit to a reliable planetary magnetospheric model is good evidence that the Mercury magnetosphere is formed by a simple, permanent, intrinsic planetary magnetic field distorted by the effects of the solar wind. The parameters used for a best fit to all the data are (depending slightly on the choice of data) 2.44--2.55 for the ratio of Mercury's magnetic field strength at the subsolar point to that of the earth's subsolar point field (this results in a dipole moment of 170 γR/sub M/ 3 (R/sub M/ is Mercury Radius), i.e., 2.41 x 10 22 G cm 3 in the same direction as the earth's dipole), approx.-113 γR/sub M/ 4 for the planetary quadrupole moment parallel to the dipole moment, 10degree--17degree for the tilt of the planet dipole toward the sun, 4.5degree for the tilt of the dipole toward dawn, and 2.5degree--7.6degree aberration angle for the shift in the tail axis from the planet-sun direction because of the planet's orbital velocity. The rms deviation overall for the entire data set compared with the theoretical fitted model for the magnetic field strength was 17 γ (approx.4% of the maximum field measured). If the data from the first pass that show presumed strong time variations are excluded, the overall rms deviation for the field magnitude is only 10 γ

  9. The planet Mercury (1971)

    Science.gov (United States)

    1972-01-01

    The physical properties of the planet Mercury, its surface, and atmosphere are presented for space vehicle design criteria. The mass, dimensions, mean density, and orbital and rotational motions are described. The gravity field, magnetic field, electromagnetic radiation, and charged particles in the planet's orbit are discussed. Atmospheric pressure, temperature, and composition data are given along with the surface composition, soil mechanical properties, and topography, and the surface electromagnetic and temperature properties.

  10. Mercury removal sorbents

    Science.gov (United States)

    Alptekin, Gokhan

    2016-03-29

    Sorbents and methods of using them for removing mercury from flue gases over a wide range of temperatures are disclosed. Sorbent materials of this invention comprise oxy- or hydroxyl-halogen (chlorides and bromides) of manganese, copper and calcium as the active phase for Hg.sup.0 oxidation, and are dispersed on a high surface porous supports. In addition to the powder activated carbons (PACs), this support material can be comprised of commercial ceramic supports such as silica (SiO.sub.2), alumina (Al.sub.2O.sub.3), zeolites and clays. The support material may also comprise of oxides of various metals such as iron, manganese, and calcium. The non-carbon sorbents of the invention can be easily injected into the flue gas and recovered in the Particulate Control Device (PCD) along with the fly ash without altering the properties of the by-product fly ash enabling its use as a cement additive. Sorbent materials of this invention effectively remove both elemental and oxidized forms of mercury from flue gases and can be used at elevated temperatures. The sorbent combines an oxidation catalyst and a sorbent in the same particle to both oxidize the mercury and then immobilize it.

  11. Contribution of tap water to chlorate and perchlorate intake: a market basket study.

    Science.gov (United States)

    Asami, Mari; Yoshida, Nobue; Kosaka, Koji; Ohno, Koichi; Matsui, Yoshihiko

    2013-10-01

    The contributions of water to total levels of chlorate and perchlorate intake were determined using food and water samples from a market basket study from 10 locations in Japan between 2008 and 2009. Foods were categorized into 13 groups and analyzed along with tap water. The average total chlorate intake was 333 (min. 193-max. 486) μg/day for samples cooked with tap water. The contribution of tap water to total chlorate intake was as high as 47%-58%, although total chlorate intake was less than 32% of the tolerable daily intake, 1500 μg/day for body weight of 50 kg. For perchlorate, daily intake from water was 0.7 (0.1-4.4) μg/day, which is not high compared to the average total intake of 14 (2.5-84) μg/day, while the reference dose (RfD) is 35 μg/day and the provisional maximum tolerable daily intake (PMTDI) is 500 μg/day for body weight of 50 kg. The highest intake of perchlorate was 84 μg/day, where concentrations in foods were high, but not in water. The contribution of water to total perchlorate intake ranged from 0.5% to 22%, while the ratio of highest daily intake to RfD was 240% and that to PMTDI was 17%. Eight baby formulas were also tested--total chlorate and perchlorate intakes were 147 (42-332) μg/day and 1.11 (0.05-4.5) μg/day, respectively, for an ingestion volume of 1 L/day if prepared with tap water. Copyright © 2013 The Authors. Published by Elsevier B.V. All rights reserved.

  12. An Ion-selective Electrode for Anion Perchlorate in Thick-film Technology

    Directory of Open Access Journals (Sweden)

    Luís Gil

    2006-04-01

    Full Text Available The ionophore 1,4,7,10,13-penta(n-octyl-1,4,7,10,13-pentaazacyclopentadecane(L1 was used for the development of miniaturised perchlorate-selective electrodes in thick-film technology. Different PVC membranes containing L1 and the plasticizers o-nitrophenyloctyl ether (NPOE, dibutyl phthalate (DBP, bis(2-ethylhexylsebacate (DOS and dibutylsebacate (DBS were prepared and placed on a graphite working electrode manufactured byusing thick film serigraphic technology. The perchlorate selective electrode containing DBSas plasticizer showed a potentiometric Nernstian response of -57 mV per decade in a rangeof perchlorate concentration from 1 x 10-4 to 1 x 10-1 M with a detection limit of 5 x 10-5 M.The ion selective electrodes containing DBP and NPOE as plasticizers exhibit a workingrange from 6.3 x 10-5 to 1 x 10-1 M and 7.4 x 10-5 to 1 x 10-1 M for perchlorate, respectively,with a detection limit of ca. 2.2 x 10-5 M. For all three electrodes a response time of ca. 5 s was found. The prepared electrodes do not show appreciable decay of the slope for at least 25 days. Potentiometric selectivity coefficients (log KpotClO4-,X- with respect to the primaryanion perchlorate were evaluated using the fixed interference method. These coefficients areof the order of 10-1.7 or smaller, indicating the relatively poor interference of the differentanions studied.

  13. Mercury's Magnetic Field

    Science.gov (United States)

    Johnson, C. L.

    2014-12-01

    Mercury is the only inner solar system body other than Earth to possess an active core dynamo-driven magnetic field and the only planet with a small, highly dynamic magnetosphere. Measurements made by the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft have provided a wealth of data on Mercury's magnetic field environment. Mercury's weak magnetic field was discovered 40 years ago by the Mariner 10 spacecraft, but its large-scale geometry, strength and origin could not be definitively established. MESSENGER data have shown that the field is dynamo-generated and can be described as an offset axisymmetric dipole field (hereafter OAD): the magnetic equator lies ~0.2 RM (RM = 2440 km) north of the geographic equator and the dipole moment is 2.8 x1019 Am2 (~0.03% that of Earth's). The weak internal field and the high, but variable, solar wind ram pressure drive vigorous magnetospheric dynamics and result in an average distance from the planet center to the sub-solar magnetopause of only 1.42 RM. Magnetospheric models developed with MESSENGER data have allowed re-analysis of the Mariner 10 observations, establishing that there has been no measureable secular variation in the internal field over 40 years. Together with spatial power spectra for the OAD, this provides critical constraints for viable dynamo models. Time-varying magnetopause fields induce secondary core fields, the magnitudes of which confirm the core radius estimated from MESSENGER gravity and Earth-based radar data. After accounting for large-scale magnetospheric fields, residual signatures are dominated by additional external fields that are organized in the local time frame and that vary with magnetospheric activity. Birkeland currents have been identified, which likely close in the planetary interior at depths below the base of the crust. Near-periapsis magnetic field measurements at altitudes greater than 200 km have tantalizing hints of crustal fields, but crustal

  14. Perchlorate exposure is associated with oxidative stress and indicators of serum iron homeostasis among NHANES 2005-2008 subjects

    Science.gov (United States)

    ABSTRACT Perchlorate (ClO4-), an oxidizing agent, is a ubiquitous environmental pollutant. Several studies have investigated its thyroid hormone disrupting properties. Its associations with other biological measures are largely unknown. This study, combining 2005-2008 National H...

  15. Determination of nitrate, nitrite and perchlorate anions in meat, milk and their products consumed in Hatay region in Turkey.

    Science.gov (United States)

    Sungur, Şana; Atan, Muhammet Meriç

    2013-01-01

    Nitrates and nitrites added to food can cause formation of cancerous N-nitroso compounds, whereas exposure to perchlorate is especially emphasised as an important risk factor for newborns' health. In this study, nitrate, nitrite and perchlorate concentrations in meat and milk products consumed in the Hatay region of Turkey were determined. Nitrate and nitrite were analysed with a spectrophotometric method, and perchlorate analysed via ion chromatography. The detected sodium nitrate and nitrite amounts in meat consumed in the Hatay region are less than the maximum levels as declared in the Turkish Food Codex. The amount of perchlorate was considered not to pose a threat as well. However, in 50% of the cheese samples, sodium nitrate amounts were found to be more than the maximum acceptable level in the Turkish Food Codex.

  16. Mercury: Exploration of a Planet

    Science.gov (United States)

    1976-01-01

    The flight of the Mariner 10 spacecraft to Venus and Mercury is detailed in animation and photography. Views of Mercury are featured. Also included is animation on the origin of the solar system. Dr. Bruce C. Murray, director of the Jet Propulsion Laboratory, comments on the mission.

  17. Rotation of the planet mercury.

    Science.gov (United States)

    Jefferys, W H

    1966-04-08

    The equations of motion for the rotation of Mercury are solved for the general case by an asymptotic expansion. The findings of Liu and O'Keefe, obtained by numerical integration of a special case, that it is possible for Mercury's rotation to be locked into a 2:3 resonance with its revolution, are confirmed in detail. The general solution has further applications.

  18. 49 CFR 173.164 - Mercury (metallic and articles containing mercury).

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Mercury (metallic and articles containing mercury... Than Class 1 and Class 7 § 173.164 Mercury (metallic and articles containing mercury). (a) For transportation by aircraft, mercury must be packaged in packagings which meet the requirements of part 178 of...

  19. Mercury concentration in bivalve molluscs

    Directory of Open Access Journals (Sweden)

    Szkoda Józef

    2015-09-01

    Full Text Available A total of 85 mussel samples of eight species were examined. Analysis of mercury in the freeze-dried samples was carried out by atomic absorption spectrometry method using direct mercury analyser AMA 254. The analytical procedure for determination of mercury was covered by the quality assurance programme of research and participation in national and international proficiency tests. Concentrations of total mercury in all investigated samples were found to be generally low, in the range of 0.033-0.577 mg/kg of dry weight and of 0.003-0.045 mg/kg of wet weight. The results indicate that obtained levels of mercury in bivalve molluscs are not likely to pose a risk to the health of consumers.

  20. Mercury: Beethoven Quadrangle, H-7

    Science.gov (United States)

    2000-01-01

    Mercury: Computer Photomosaic of the Beethoven Quadrangle, H-7 The Beethoven Quadrangle, named for the 19th century classical German composer, lies in Mercury's Equatorial Mercator located between longitude 740 to 1440. The Mariner 10 spacecraft imaged the region during its initial flyby of the planet. The Image Processing Lab at NASA's Jet Propulsion Laboratory produced this photomosaic using computer software and techniques developed for use in processing planetary data. The images used to construct the Beethoven Quadrangle were taken as Mariner 10 flew passed Mercury. The Mariner 10 spacecraft was launched in 1974. The spacecraft took images of Venus in February 1974 on the way to three encounters with Mercury in March and September 1974 and March 1975. The spacecraft took more than 7,000 images of Mercury, Venus, the Earth and the Moon during its mission. The Mariner 10 Mission was managed by the Jet Propulsion Laboratory for NASA's Office of Space Science in Washington, D.C.

  1. Oxygen and chlorine isotopic fractionation during perchlorate biodegradation: laboratory results and implications for forensics and natural attenuation studies.

    Science.gov (United States)

    Sturchio, Neil C; Böhlke, John Karl; Beloso, Abelardo D; Streger, Sheryl H; Heraty, Linnea J; Hatzinger, Paul B

    2007-04-15

    Perchlorate is a widespread environmental contaminant having both anthropogenic and natural sources. Stable isotope ratios of O and Cl in a given sample of perchlorate may be used to distinguish its source(s). Isotopic ratios may also be useful for identifying the extent of biodegradation of perchlorate, which is critical for assessing natural attenuation of this contaminant in groundwater. For this approach to be useful, however, the kinetic isotopic fractionations of O and Cl during perchlorate biodegradation must first be determined as a function of environmental variables such as temperature and bacterial species. A laboratory study was performed in which the O and Cl isotope ratios of perchlorate were monitored as a function of degradation by two separate bacterial strains (Azospira suillum JPLRND and Dechlorospirillum sp. FBR2) at both 10 degrees C and 22 degrees C with acetate as the electron donor. Perchlorate was completely reduced by both strains within 280 h at 22 degrees C and 615 h at 10 degrees C. Measured values of isotopic fractionation factors were epsilon(18)O = -36.6 to -29.0% per hundred and epsilon(37)Cl = -14.5 to -11.5% per hundred, and these showed no apparent systematic variation with either temperature or bacterial strain. An experiment using (18)O-enriched water (delta(18)O = +198% per hundred) gave results indistinguishable from those observed in the isotopically normal water (delta(18)O = -8.1% per hundred) used in the other experiments, indicating negligible isotope exchange between perchlorate and water during biodegradation. The fractionation factor ratio epsilon(18)O/epsilon(37)Cl was nearly invariant in all experiments at 2.50 +/- 0.04. These data indicate that isotope ratio analysis will be useful for documenting perchlorate biodegradation in soils and groundwater. The establishment of a microbial fractionation factor ratio (epsilon(18)O/ epsilon(37)Cl) also has significant implications for forensic studies.

  2. Human Exposure and Health Effects of Inorganic and Elemental Mercury

    OpenAIRE

    Park, Jung-Duck; Zheng, Wei

    2012-01-01

    Mercury is a toxic and non-essential metal in the human body. Mercury is ubiquitously distributed in the environment, present in natural products, and exists extensively in items encountered in daily life. There are three forms of mercury, i.e., elemental (or metallic) mercury, inorganic mercury compounds, and organic mercury compounds. This review examines the toxicity of elemental mercury and inorganic mercury compounds. Inorganic mercury compounds are water soluble with a bioavailability o...

  3. The Nitrate/Perchlorate Ratio on Mars As an Indicator for Habitability

    Science.gov (United States)

    Stern, J. C.; Sutter, B.; McKay, C. P.; Navarro-Gonzalez, R.; Freissinet, C.; Conrad, P. G.; Mahaffy, P. R.; Archer, P. D., Jr.; Ming, D. W.; Martín-Torres, J.; Zorzano, M. P.

    2014-12-01

    Discovery of indigenous martian nitrogen in Mars surface materials has important implications for habitability and the potential development of a nitrogen cycle at some point in martian history. The Sample Analysis at Mars (SAM) instrument suite on the Mars Science Laboratory (MSL) Curiosity Rover detected evolved nitric oxide (NO) gas during pyrolysis of scooped aeolian sediments and drilled mudstone acquired in Gale Crater. The detection of NO suggests an indigenous source of fixed nitrogen, and may indicate a mineralogical sink for atmospheric N2 in the form of nitrate. The ratio of nitrate to oxychlorine species (e.g. perchlorate) may provide insight into the extent of development of a nitrogen cycle on Mars. Nitrate and perchlorate on Earth are geochemically related in arid environments such as the Atacama Desert and the Dry Valleys of Antarctica due to their similar mobilities and deposition mechanisms [1,2]. Here, low NO3-/ClO4- molar ratios (~1000) dominate, in comparison to other places on Earth, where the main nitrate source is biological fixation of N2 to NO3-, and there is no corresponding biological source of perchlorate, resulting in much higher NO3-/ClO4- molar ratios (~10,000). The NO3-/ClO4- molar ratio is estimated to be ~ 0.05 on Mars based on SAM measurements at Gale Crater [3]. The possibility exists that perchlorate brines could leach and increase nitrate concentrations at depth, increasing the martian NO3-/ClO4- ratio in the subsurface. However, it is unknown whether terrestrial NO3-/ClO4- molar ratios could be achieved by this mechanism. Nevertheless, the low NO3-/ClO4- the ratio detected by SAM suggests that N fixation to nitrate on Mars, whether biologically mediated or abiotic, was extremely limited compared to the potentially ongoing abiotic formation and deposition of oxychlorine species on the martian surface. [1] Kounaves, S.P. et al. "Discovery of natural perchlorate in the Antarctic dry valleys and its global implications." ES&T44

  4. Methods for dispensing mercury into devices

    Science.gov (United States)

    Grossman, Mark W.; George, William A.

    1987-04-28

    A process for dispensing mercury into devices which requires mercury. Mercury is first electrolytically separated from either HgO or Hg.sub.2 Cl.sub.2 and plated onto a cathode wire. The cathode wire is then placed into a device requiring mercury.

  5. 21 CFR 872.3700 - Dental mercury.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Dental mercury. 872.3700 Section 872.3700 Food and... DENTAL DEVICES Prosthetic Devices § 872.3700 Dental mercury. (a) Identification. Dental mercury is a device composed of mercury intended for use as a component of amalgam alloy in the restoration of a...

  6. Assessment of the feasibility of anaerobic composting for treatment of perchlorate - contaminated soils in a war zone

    Directory of Open Access Journals (Sweden)

    Mohammad Mehdi Amin

    2015-01-01

    Full Text Available Aims: The objectives of this study were to determine the perchlorate concentrations in surface soils and assess feasibility of anaerobic bioremediation in full-scale for perchlorate-contaminated soils in a war zone. Materials and Methods: Fifteen samples of surface soil were collected using a composite sampling method in the study area. The soil samples, after extraction and preparation, were analyzed by ion chromatography. Anaerobic composting technique (soil excavation, mixing with manure, transfer into treatment cell and cover with a 6-mil high-density polyethylene liner considered to cleanup perchlorate-contaminated soil in a war zone. Results: The concentration of perchlorate in the soil surface samples ranged from 3 to 107.9 mg/kg, which is more than State advisory levels for residential and protection of domestic groundwater use pathway. This study indicates that technologies, skills, experience, raw materials (manure, lands, and machinery needed for implementation of full-scale composting, are available in the study area. Conclusions: Based on the results, anaerobic composting technique could be considered as a feasible, viable and cost-effective alternative for perchlorate bioremediation in the study area. According to the available of techniques and skills, successful experiences of anaerobic composting in other countries, and potential of study area, The application of anaerobic composting is technically feasible and can be use for perchlorate contaminated soil cleanup in a zone war.

  7. Fluorescent sensor for mercury

    Science.gov (United States)

    Wang, Zidong [Urbana, IL; Lee, Jung Heon [Evanston, IL; Lu, Yi [Champaign, IL

    2011-11-22

    The present invention provides a sensor for detecting mercury, comprising: a first polynucleotide, comprising a first region, and a second region, a second polynucleotide, a third polynucleotide, a fluorophore, and a quencher, wherein the third polynucleotide is optionally linked to the second region; the fluorophore is linked to the first polynucleotide and the quencher is linked to the second polynucleotide, or the fluorophore is linked to the second polynucleotide and the quencher is linked to the first polynucleotide; the first region and the second region hybridize to the second polynucleotide; and the second region binds to the third polynucleotide in the presence of Hg.sup.2+ ions.

  8. The Investigation of Perchlorate/Iron Phase Mixtures as A Possible Source of Oxygen Detected by the Sample Analysis at Mars (SAM) Instrument in Gale Crater, Mars

    Science.gov (United States)

    Sutter, B.; Heil, E.; Morris, R. V.; Archer, P. D.; Ming, D. W.; Niles, P. B.; Eigenbrode, J. L.; Franz, H.; Freissinet C.; Glavin, D. P.; hide

    2015-01-01

    The Sample Analysis at Mars (SAM) instrument onboard the Curiosity rover detected O2 and HCl gas releases from the Rocknest (RN) eolian bedform and the John Klein (JK) and Cumberland (CB) drill hole materials in Gale Crater. Chlorinated hydrocarbons have also been detected by the SAM quadrupole mass spectrometer (QMS) and gas chromatography/mass spectrometer (GCMS). These detections along with the detection of perchlorate (ClO4-) by the Mars Phoenix Lander's Wet Chemistry Laboratory (WCL) suggesting perchlorate is a possible candidate for evolved O2 and chlorine species. Laboratory thermal analysis of individual per-chlorates has yet to provide an unequivocal temperature match to the SAM O2 and HCl release data. These detections along with the detection of perchlorate (ClO4-) by the Mars Phoenix Lander's Wet Chemistry Laboratory suggested perchlorate is a possible candidate for evolved O2 and chlorine species. Laboratory thermal analysis of pure perchlorates has yet to provide an unequivocal temperature match to the SAM O2 and HCl release data. Analog laboratory analysis of iron mineralogy detected in Gale materials that was physically mixed with Ca- and Mg-perchlorate has been shown to catalyze lower O2 release temperatures and approach some SAM O2 release data. Instead of physical mixtures used in previous work, the work presented here utilized perchlorate solutions added to Fe phases. This technique allowed for perchlorate to come in closer contact with the Fe-phase and may more closely mimic Mars conditions where humidity can increase enough to cause deliquescence of the highly hygroscopic perchlorate phases. The objective of this work is to: 1) Utilize a laboratory SAM analog instrument to evaluate the O2 release temperatures from Mg- and Ca-perchlorates solutions applied to Fephases detetected in Gale Crate; and 2) Determine if perchlorate solutions can provide improved matches with the SAM O2 temperature release profiles.

  9. Increased mercury emissions from modern dental amalgams

    OpenAIRE

    Bengtsson, Ulf G.; Hylander, Lars D.

    2017-01-01

    All types of dental amalgams contain mercury, which partly is emitted as mercury vapor. All types of dental amalgams corrode after being placed in the oral cavity. Modern high copper amalgams exhibit two new traits of increased instability. Firstly, when subjected to wear/polishing, droplets rich in mercury are formed on the surface, showing that mercury is not being strongly bonded to the base or alloy metals. Secondly, high copper amalgams emit substantially larger amounts of mercury vapor ...

  10. Mercury toxicity and neurodegenerative effects.

    Science.gov (United States)

    Carocci, Alessia; Rovito, Nicola; Sinicropi, Maria Stefania; Genchi, Giuseppe

    2014-01-01

    Mercury is among the most toxic heavy metals and has no known physiological role in humans. Three forms of mercury exist: elemental, inorganic and organic. Mercury has been used by man since ancient times. Among the earliest were the Chinese and Romans, who employed cinnabar (mercury sulfide) as a red dye in ink (Clarkson et al. 2007). Mercury has also been used to purify gold and silver minerals by forming amalgams. This is a hazardous practice, but is still widespread in Brazil's Amazon basin, in Laos and in Venezuela, where tens of thousands of miners are engaged in local mining activities to find and purify gold or silver. Mercury compounds were long used to treat syphilis and the element is still used as an antiseptic,as a medicinal preservative and as a fungicide. Dental amalgams, which contain about 50% mercury, have been used to repair dental caries in the U.S. since 1856.Mercury still exists in many common household products around the world.Examples are: thermometers, barometers, batteries, and light bulbs (Swain et al.2007). In small amounts, some organo mercury-compounds (e.g., ethylmercury tiosalicylate(thimerosal) and phenylmercury nitrate) are used as preservatives in some medicines and vaccines (Ballet al. 2001).Each mercury form has its own toxicity profile. Exposure to Hg0 vapor and MeHg produce symptoms in CNS, whereas, the kidney is the target organ when exposures to the mono- and di-valent salts of mercury (Hg+ and Hg++, respectively)occur. Chronic exposure to inorganic mercury produces stomatitis, erethism and tremors. Chronic MeHg exposure induced symptoms similar to those observed in ALS, such as the early onset of hind limb weakness (Johnson and Atchison 2009).Among the organic mercury compounds, MeHg is the most biologically available and toxic (Scheuhammer et a!. 2007). MeHg is neurotoxic, reaching high levels of accumulation in the CNS; it can impair physiological function by disrupting endocrine glands (Tan et a!. 2009).The most

  11. Removal of an acid fume system contaminated with perchlorates located within hot cell

    International Nuclear Information System (INIS)

    Rosenberg, K.E.; Henslee, S.P.; Vroman, W.R.; Krsul, J.R.; Michelbacher, J.A.; Knighton, G.C.

    1992-09-01

    An add scrubbing system located within the confines of a highly radioactive hot cell at Argonne National Laboratory-West (ANL-W) was remotely removed. The acid scrubbing system was routinely used for the dissolution of irradiated reactor fuel samples and structural materials. Perchloric acid was one of the acids used in the dissolution process and remained in the system with its inherent risks. Personnel could not enter the hot cell to perform the dismantling of the acid scabbing system due to the high radiation field and the explosion potential associated with the perchlorates. A robot was designed and built at ANL-W and used to dismantle the system without the need for personnel entry into the hot cell. The robot was also used for size reduction of removed components and loading of the removed components into waste containers

  12. [(6-Methyl-2-pyridylmethyl(2-pyridylmethylamine][(2-pyridylmethylamine]copper(II bis(perchlorate

    Directory of Open Access Journals (Sweden)

    Ray J. Butcher

    2008-01-01

    Full Text Available The title compound, [Cu(C6H8N2(C13H15N3](ClO42, is a mixed ligand complex with the CuII atom coordinated by (6-methyl-2-pyridylmethyl(2-pyridylmethylamine, acting as a tridentate ligand, and 2-(2-aminomethylpyridine, as a bidentate ligand, leading to an N5 square-pyramidal geometry. The amine H atoms are involved in hydrogen bonding to the perchlorate O atoms and there are extensive but weak intermolecular C—H...O interactions in the crystal structure. The perchlorate ions are each disordered over two positions, with site occupancies of 0.601 (8:0.399 (8 and 0.659 (11:0.341 (11.

  13. Mercury kinetics in marine zooplankton

    International Nuclear Information System (INIS)

    Fowler, S.W.; Heyraud, M.; LaRosa, J.

    1976-01-01

    Mercury, like many other heavy metals, is potentially available to marine animals by uptake directly from water and/or through the organisms food. Furthermore, bioavailability, assimilation and subsequent retention in biota may be affected by the chemical species of the element in sea water. While mercury is known to exist in the inorganic form in sea water, recent work has indicated that, in certain coastal areas, a good portion of the total mercury appears to be organically bound; however, the exact chemical nature of the organic fraction has yet to be determined. Methyl mercury may be one constituent of the natural organically bound fraction since microbial mechanisms for in situ methylation of mercury have been demonstrated in the aquatic environment. Despite the fact that naturally produced methyl mercury probably comprises only a small fraction of an aquatic ecosystem, the well-documented toxic effects of this organo-mercurial, caused by man-made introductions into marine food chains, make it an important compound to study

  14. Atmospheric mercury footprints of nations.

    Science.gov (United States)

    Liang, Sai; Wang, Yafei; Cinnirella, Sergio; Pirrone, Nicola

    2015-03-17

    The Minamata Convention was established to protect humans and the natural environment from the adverse effects of mercury emissions. A cogent assessment of mercury emissions is required to help implement the Minamata Convention. Here, we use an environmentally extended multi-regional input-output model to calculate atmospheric mercury footprints of nations based on upstream production (meaning direct emissions from the production activities of a nation), downstream production (meaning both direct and indirect emissions caused by the production activities of a nation), and consumption (meaning both direct and indirect emissions caused by final consumption of goods and services in a nation). Results show that nations function differently within global supply chains. Developed nations usually have larger consumption-based emissions than up- and downstream production-based emissions. India, South Korea, and Taiwan have larger downstream production-based emissions than their upstream production- and consumption-based emissions. Developed nations (e.g., United States, Japan, and Germany) are in part responsible for mercury emissions of developing nations (e.g., China, India, and Indonesia). Our findings indicate that global mercury abatement should focus on multiple stages of global supply chains. We propose three initiatives for global mercury abatement, comprising the establishment of mercury control technologies of upstream producers, productivity improvement of downstream producers, and behavior optimization of final consumers.

  15. Method for removal and stabilization of mercury in mercury-containing gas streams

    Science.gov (United States)

    Broderick, Thomas E.

    2005-09-13

    The present invention is directed to a process and apparatus for removing and stabilizing mercury from mercury-containing gas streams. A gas stream containing vapor phase elemental and/or speciated mercury is contacted with reagent, such as an oxygen-containing oxidant, in a liquid environment to form a mercury-containing precipitate. The mercury-containing precipitate is kept or placed in solution and reacts with one or more additional reagents to form a solid, stable mercury-containing compound.

  16. Ecological Risk Assessment of Perchlorate in Avian Species, Rodents, Amphibians and Fish

    Science.gov (United States)

    2003-04-01

    duck hens were captured with a net while incubating eggs and fitted with a radio-transmitter ( necklace attachment). Hens were then placed back into... GPS coordinates of all captures and radio-telemetry data, analytical data, embryonic growth and development, and hormone analysis data. Report content...contaminant ammonium perchlorate. Toxicol Sci 57:61-74. Smith PN, Cobb GP , Harper FD, Adair B, McMurry ST. 2002. Comparison of white-footed mice and

  17. Evaluation of Potential for Monitored Natural Attenuation of Perchlorate in Groundwater (Indian Head)

    Science.gov (United States)

    2010-07-01

    Hydrogeology ............................................................................................................. 37 4.2 Local Subsurface Conditions...in the Protocol, local regulators and the general public can gain confidence that MNA of perchlorate is protective of the public welfare, human...SGP-8S SGP-10D, SGP-21, SDG -23SW/S/D) and piezometers (TP-3, TP-4, RP-5, TP-6 and TP-7). 3.4.5 Determination of Aquifer Hydraulic Conductivity

  18. Nitrate and Perchlorate Destruction and Potable Water Production Using Membrane Biofilm Reduction

    Science.gov (United States)

    2014-01-01

    Polypropylene Membrane b. c. Figure 1. Schematic of hydrogen-fed MBfR (a) membrane cross section, (b) woven fibers and biofilm...MBfR effluent goal of 6 µg/L perchlorate and 0.5 mg-N/L nitrate • Tracer Testing Start-Up • Varied feed flow rates • Varied recycle ratios • Batch...parameters including flow rate, recycle flow rate, hydrogen pressure, gas sparge frequency, and the gas used for sparging were varied during optimization

  19. Exploring Mercury: The Iron Planet

    OpenAIRE

    Stevenson, David J.

    2004-01-01

    Planet Mercury is both difficult to observe and difficult to reach by spacecraft. Just one spacecraft, Mariner 10, flew by the planet 30 years ago. An upcoming NASA mission, MESSENGER, will be launched this year and will go into orbit around Mercury at the end of this decade. A European mission is planned for the following decade. It's worth going there because Mercury is a strange body and the history of planetary exploration has taught us that strangeness gives us insight into planetary ori...

  20. MESSENGER'S First Flyby of Mercury

    Science.gov (United States)

    Slavin, James A.

    2008-01-01

    The MESSENGER mission to Mercury offers our first opportunity to explore this planet's miniature magnetosphere since Mariner 10's brief fly-bys in 1974-5. The magnetosphere of Mercury is the smallest in the solar system with its magnetic field typically standing off the solar wind only - 1000 to 2000 km above the surface. An overview of the MESSENGER mission and its January 14th close flyby of Mercury will be provided. Primary science objectives and the science instrumentation will be described. Initial results from MESSENGER'S first flyby on January 14th, 2008 will be discussed with an emphasis on the magnetic field and charged particle measurements.

  1. Comparative assessment of the environmental sustainability of existing and emerging perchlorate treatment technologies for drinking water.

    Science.gov (United States)

    Choe, Jong Kwon; Mehnert, Michelle H; Guest, Jeremy S; Strathmann, Timothy J; Werth, Charles J

    2013-05-07

    Environmental impacts of conventional and emerging perchlorate drinking water treatment technologies were assessed using life cycle assessment (LCA). Comparison of two ion exchange (IX) technologies (i.e., nonselective IX with periodic regeneration using brines and perchlorate-selective IX without regeneration) at an existing plant shows that brine is the dominant contributor for nonselective IX, which shows higher impact than perchlorate-selective IX. Resource consumption during the operational phase comprises >80% of the total impacts. Having identified consumables as the driving force behind environmental impacts, the relative environmental sustainability of IX, biological treatment, and catalytic reduction technologies are compared more generally using consumable inputs. The analysis indicates that the environmental impacts of heterotrophic biological treatment are 2-5 times more sensitive to influent conditions (i.e., nitrate/oxygen concentration) and are 3-14 times higher compared to IX. However, autotrophic biological treatment is most environmentally beneficial among all. Catalytic treatment using carbon-supported Re-Pd has a higher (ca. 4600 times) impact than others, but is within 0.9-30 times the impact of IX with a newly developed ligand-complexed Re-Pd catalyst formulation. This suggests catalytic reduction can be competitive with increased activity. Our assessment shows that while IX is an environmentally competitive, emerging technologies also show great promise from an environmental sustainability perspective.

  2. Electrochemical reduction of CO2 to CO over Zn in propylene carbonate/tetrabutylammonium perchlorate

    Science.gov (United States)

    Shen, Feng-xia; Shi, Jin; Chen, Tian-you; Shi, Feng; Li, Qing-yuan; Zhen, Jian-zheng; Li, Yun-fei; Dai, Yong-nian; Yang, Bin; Qu, Tao

    2018-02-01

    Developing low cost and high efficient electrode for carbon dioxide (CO2) reduction in organic media is essential for practical application. Zn is a cheap metal and has high catalytic effects on CO2 reduction to carbon monoxide (CO) in aqueous solution. However, little attention has been given to investigate the performance of Zn in organic media for CO2 reduction. In present work, we have conducted CO2 reduction in propylene carbonate/tetrabutylammonium perchlorate on Zn due to that propylene carbonate is a widely used industrial absorber, and tetrabutylammonium perchlorate is a commonly used organic supporting electrolyte. In addition, because electrochemical reduction of CO2 to CO naturally produces H2O, we have discussed water effects on CO2 reduction in propylene carbonate/tetrabutylammonium perchlorate+6.8 wt % H2O. Our experiment results reveal that the faradaic efficiency for CO formation reaches to 83%, and the current density remains stable at 6.72 mA/cm2 at voltage -2.3 V for 4 h. Interestingly, Zn presents higher catalytic activity than Ag, and slightly lower than Au. X-ray photoelectron spectroscopy results confirm that no poisonous species is formed and absorbed on the cathode, which is an important advantage in practical application.

  3. Perchlorate contamination from the detonation of insensitive high-explosive rounds.

    Science.gov (United States)

    Walsh, Michael R; Walsh, Marianne E; Ramsey, Charles A; Brochu, Sylvie; Thiboutot, Sonia; Ampleman, Guy

    2013-11-15

    The insensitive high-explosive PAX-21 was the first of its kind fielded in an artillery munition by the United States military. This formulation contains three main components: RDX, dinitroanisole, and ammonium perchlorate (AP). In March 2012, detonation tests were conducted on PAX-21 60mm mortar rounds to determine the energetic residues resulting from high-order and blow-in-place (BIP) detonations. Post-detonation residues were sampled and analyzed for the three main PAX-21 components. Concentrations of RDX and dinitroanisole in the samples were quite low, less than 0.1% of the munitions' original organic explosive filler mass, indicating high order or near high order detonations. However, disproportionately high concentrations of AP occurred in all residues. The residues averaged 15% of the original AP following high-order detonations and 38% of the original AP mass following the BIP operations. There was no correlation between AP residues and the RDX and dinitroanisole. Perchlorate readily leached from the detonation residues, with over 99% contained in the aqueous portion of the samples. Use of these rounds will result in billions of liters of water contaminated above drinking water perchlorate limits. As a result of this research, PAX-21 mortar rounds are currently restricted from use on US training ranges. Published by Elsevier B.V.

  4. Treatment of amiodarone induced hyperthyroidism with potassium perchlorate and methimazole during amiodarone treatment.

    Science.gov (United States)

    Reichert, L. J.; de Rooy, H. A.

    1989-01-01

    To exploit the antiarrhythmic effect of amiodarone when patients develop the side effect of thyrotoxicosis three patients with hyperthyroidism induced by amiodarone were given simultaneously 1 g potassium perchlorate a day for 40 days and a starting dose of 40 mg methimazole a day while they continued to take amiodarone. As hyperthyroidism might have recurred after potassium perchlorate treatment was stopped the dose of methimazole was not reduced until biochemical hypothyroidism (raised thyroid stimulating hormone concentrations) was achieved. The patients became euthyroid (free triiodothyronine concentration returned to normal values) in two to five weeks and hypothyroid in 10 to 14 weeks. One patient became euthyroid while taking 5 mg methimazole a day and 600 mg amiodarone weekly; the two others required substitution treatment with thyroxine sodium while taking 5 mg methimazole or 50 mg propylthiouracil (because of an allergic reaction to methimazole) and 2100 or 1400 mg amiodarone weekly. Hyperthyroidism induced by amiodarone may be treated with potassium perchlorate and methimazole given simultaneously while treatment with amiodarone is continued. PMID:2547467

  5. Lanthanide iodide and perchlorate complexes of 4-N-(2'-hydroxybenzylidine)aminoantipyrine

    International Nuclear Information System (INIS)

    Radhakrishnan, P.K.

    1984-01-01

    Eighteen new complexes of lanthanide iodides and perchlorates with 4-N-(2'-hydroxybenzylidene)aminoantipyrine (HBAAP) have been prepared and characterized. They have the general formulae, [Ln(HBAAP) 5 I]I 2 , where Ln=La, Pr, Nd, Sm, Gd, Tb, Dy, Ho and Y, and [Ln(HBAAP) n ](ClO 4 ) 3 , where n=4 for La, Pr and Nd, and n=5 for Sm, Gd, Tb, Dy, Ho and Y. Conductance studies indicate 1:2 electrolytic behaviour for the iodide complexes and 1:3 electrolytic behaviour for the perchlorate complexes. The magnetic moments of all the complexes agree well with Van Vleck values. Their infrared spectra reveal that HBAAP acts as a bidentate neutral ligand, one of the iodides is coordinated and none of the perchlorates is coordinated. Electronic spectra of the Nd complexes show weak covalency in the lanthanide-ligand bond. Thermogravimetric studies of the complexes indicate that these complexes are stable upto 200deg and undergo complete decomposition in the range 200 - 620deg forming the respective stable lanthanide oxides. (author)

  6. Distribution and retention of organic and inorganic mercury in methyl mercury-treated neonatal rats

    International Nuclear Information System (INIS)

    Thomas, D.J.; Fisher, H.L.; Sumler, M.R.; Hall, L.L.; Mushak, P.

    1988-01-01

    Seven-day-old Long Evans rats received one mumol of 203 Hg-labeled methyl mercury/kg sc and whole body retention and tissue distribution of organic and inorganic mercury were examined for 32 days postdosing. Neonates cleared mercury slowly until 10 days postdosing when the clearance rate abruptly increased. During the interval when whole body clearance of mercury was extremely slow, methyl mercury was metabolized to inorganic mercury. Peak concentration of mercury in kidney occurred at 2 days postdosing. At 32 days postdosing, 8% of mercury in kidney was in an organic from. Liver mercury concentration peaked at 2 days postdosing and organic mercury accounted for 38% at 32 days postdosing. Brain concentrations of mercury peaked at 2 days postdosing. At 10 days postdosing, organic mercury accounted for 86% of the brain mercury burden, and, at 32 days postdosing, for 60%. The percentage of mercury body burden in pelt rose from 30 to 70% between 1 and 10 days postdosing. At 32 days postdosing pelt contained 85% of the body burden of mercury. At all time points, about 95% of mercury in pelt was in an organic form. Compartmental analysis of these data permitted development of a model to describe the distribution and excretion of organic and inorganic mercury in methyl mercury-treated neonatal rats

  7. Elimination of mercury in health care facilities.

    Science.gov (United States)

    2000-03-01

    Mercury is a persistent, bioaccumulative toxin that has been linked to numerous health effects in humans and wildlife. It is a potent neurotoxin that may also harm the brain, kidneys, and lungs. Unborn children and young infants are at particular risk for brain damage from mercury exposure. Hospitals' use of mercury in chemical solutions, thermometers, blood pressure gauges, batteries, and fluorescent lamps makes these facilities large contributors to the overall emission of mercury into the environment. Most hospitals recognize the dangers of mercury. In a recent survey, four out of five hospitals stated that they have policies in place to eliminate the use of mercury-containing products. Sixty-two percent of them require vendors to disclose the presence of mercury in chemicals that the hospitals purchase. Only 12 percent distribute mercury-containing thermometers to new parents. Ninety-two percent teach their employees about the health and environmental effects of mercury, and 46 percent teach all employees how to clean up mercury spills. However, the same study showed that many hospitals have not implemented their policies. Forty-two percent were not aware whether they still purchased items containing mercury. In addition, 49 percent still purchase mercury thermometers, 44 percent purchase mercury gastrointestinal diagnostic equipment, and 64 percent still purchase mercury lab thermometers.

  8. Mercury pollution: a transdisciplinary treatment

    National Research Council Canada - National Science Library

    Zuber, Sharon L; Newman, Michael C

    2012-01-01

    .... Also included are smaller case studies, such as the Minamata tragedy, fish consumption, and international treaties"-- "Mercury is the gravest chemical pollutant problem of our time, and this is...

  9. Origin and composition of Mercury

    International Nuclear Information System (INIS)

    Lewis, J.S.

    1988-01-01

    The predictions of the expected range of composition of Mercury at the time of its formation made on the basis of a suite of condensation-accretion models of Mercury spanning a range of condensation temperature and accretion sampling functions appropriate to Mercury are examined. It is concluded that these compositonal models can, if modified to take into account the nonselective loss of most of the silicate component of the planet during accretion, provide compositional predictions for the Weidenschilling (1978, 1980) mechanism for the accretion of a metal-rich Mercury. The silicate portion would, in this case, contain 3.6 to 4.5 percent alumina, roughly 1 percent of alkali oxides, and between 0.5 and 6 percent FeO

  10. Localized surface plasmon resonance mercury detection system and methods

    Science.gov (United States)

    James, Jay; Lucas, Donald; Crosby, Jeffrey Scott; Koshland, Catherine P.

    2016-03-22

    A mercury detection system that includes a flow cell having a mercury sensor, a light source and a light detector is provided. The mercury sensor includes a transparent substrate and a submonolayer of mercury absorbing nanoparticles, e.g., gold nanoparticles, on a surface of the substrate. Methods of determining whether mercury is present in a sample using the mercury sensors are also provided. The subject mercury detection systems and methods find use in a variety of different applications, including mercury detecting applications.

  11. Mercury Toolset for Spatiotemporal Metadata

    Science.gov (United States)

    Devarakonda, Ranjeet; Palanisamy, Giri; Green, James; Wilson, Bruce; Rhyne, B. Timothy; Lindsley, Chris

    2010-06-01

    Mercury (http://mercury.ornl.gov) is a set of tools for federated harvesting, searching, and retrieving metadata, particularly spatiotemporal metadata. Version 3.0 of the Mercury toolset provides orders of magnitude improvements in search speed, support for additional metadata formats, integration with Google Maps for spatial queries, facetted type search, support for RSS (Really Simple Syndication) delivery of search results, and enhanced customization to meet the needs of the multiple projects that use Mercury. It provides a single portal to very quickly search for data and information contained in disparate data management systems, each of which may use different metadata formats. Mercury harvests metadata and key data from contributing project servers distributed around the world and builds a centralized index. The search interfaces then allow the users to perform a variety of fielded, spatial, and temporal searches across these metadata sources. This centralized repository of metadata with distributed data sources provides extremely fast search results to the user, while allowing data providers to advertise the availability of their data and maintain complete control and ownership of that data. Mercury periodically (typically daily)harvests metadata sources through a collection of interfaces and re-indexes these metadata to provide extremely rapid search capabilities, even over collections with tens of millions of metadata records. A number of both graphical and application interfaces have been constructed within Mercury, to enable both human users and other computer programs to perform queries. Mercury was also designed to support multiple different projects, so that the particular fields that can be queried and used with search filters are easy to configure for each different project.

  12. Mercury Toolset for Spatiotemporal Metadata

    Science.gov (United States)

    Wilson, Bruce E.; Palanisamy, Giri; Devarakonda, Ranjeet; Rhyne, B. Timothy; Lindsley, Chris; Green, James

    2010-01-01

    Mercury (http://mercury.ornl.gov) is a set of tools for federated harvesting, searching, and retrieving metadata, particularly spatiotemporal metadata. Version 3.0 of the Mercury toolset provides orders of magnitude improvements in search speed, support for additional metadata formats, integration with Google Maps for spatial queries, facetted type search, support for RSS (Really Simple Syndication) delivery of search results, and enhanced customization to meet the needs of the multiple projects that use Mercury. It provides a single portal to very quickly search for data and information contained in disparate data management systems, each of which may use different metadata formats. Mercury harvests metadata and key data from contributing project servers distributed around the world and builds a centralized index. The search interfaces then allow the users to perform a variety of fielded, spatial, and temporal searches across these metadata sources. This centralized repository of metadata with distributed data sources provides extremely fast search results to the user, while allowing data providers to advertise the availability of their data and maintain complete control and ownership of that data. Mercury periodically (typically daily) harvests metadata sources through a collection of interfaces and re-indexes these metadata to provide extremely rapid search capabilities, even over collections with tens of millions of metadata records. A number of both graphical and application interfaces have been constructed within Mercury, to enable both human users and other computer programs to perform queries. Mercury was also designed to support multiple different projects, so that the particular fields that can be queried and used with search filters are easy to configure for each different project.

  13. Molecular assessment of inoculated and indigenous bacteria in biofilms from a pilot-scale perchlorate-reducing bioreactor.

    Science.gov (United States)

    Zhang, H; Logan, B E; Regan, J M; Achenbach, L A; Bruns, M A

    2005-04-01

    Bioremediation of perchlorate-contaminated groundwater can occur via bacterial reduction of perchlorate to chloride. Although perchlorate reduction has been demonstrated in bacterial pure cultures, little is known about the efficacy of using perchlorate-reducing bacteria as inoculants for bioremediation in the field. A pilot-scale, fixed-bed bioreactor containing plastic support medium was used to treat perchlorate-contaminated groundwater at a site in Southern California. The bioreactor was inoculated with a field-grown suspension of the perchlorate-respiring bacterium Dechlorosoma sp. strain KJ and fed groundwater containing indigenous bacteria and a carbon source amendment. Because the reactor was flushed weekly to remove accumulated biomass, only bacteria capable of growing in biofilms in the reactor were expected to survive. After 26 days of operation, perchlorate was not detected in bioreactor effluent. Perchlorate remained undetected by ion chromatography (detection limit 4 mug L(-1)) during 6 months of operation, after which the reactor was drained. Plastic medium was subsampled from top, middle, and bottom locations of the reactor for shipment on blue ice and storage at -80 degrees C prior to analysis. Microbial community DNA was extracted from successive washes of thawed biofilm material for PCR-based community profiling by 16S-23S ribosomal intergenic spacer analysis (RISA). No DNA sequences characteristic of strain KJ were recovered from any RISA bands. The most intense bands yielded DNA sequences with high similarities to Dechloromonas spp., a closely related but different genus of perchlorate-respiring bacteria. Additional sequences from RISA profiles indicated presence of representatives of the low G+C gram-positive bacteria and the Cytophaga-Flavobacterium-Bacteroides group. Confocal scanning laser microscopy and fluorescence in situ hybridization (FISH) were also used to examine biofilms using genus-specific 16S ribosomal RNA probes. FISH was more

  14. Determination of trace perchlorate concentrations by anion-selective membranes and total reflection X-ray fluorescence analysis.

    Science.gov (United States)

    Hatzistavros, Vasilios S; Kallithrakas-Kontos, Nikolaos G

    2011-05-01

    In the present work a method for the determination of perchlorate trace levels by total reflection X-ray fluorescence (TXRF) is introduced. Perchlorate anions were concentrated on anion-selective membranes that had been prepared on the surface of TXRF quartz reflectors. Various complexation substances were used in the membranes. The reflectors were immersed in water solutions containing nanogram per milliliter (ppb) concentrations of perchlorate. After this step, the reflectors were taken out of the solution and they were analyzed by TXRF, using a copper X-ray tube and helium flow on the target (to lower the argon peak which is present in the air). The effects of various experimental parameters were examined, and the possibility of discrimination between chloride and perchlorate anions was shown. Minimum detection limits lower than 1 ng/mL and good linearity at the concentration range of 1-50 ng/mL were achieved. The method is applicable for the analysis of perchlorate in drinking water samples.

  15. Phytoremediation of Ionic and Methyl Mercury Pollution

    Energy Technology Data Exchange (ETDEWEB)

    Meagher, Richard B.

    2005-06-01

    Phytoremediation is defined as the use of plants to extract, resist, detoxify, and/or sequester toxic environmental pollutants. The long-term goal of the proposed research is to develop and test highly productive, field-adapted plant species that have been engineered for the phytoremediation of mercury. A variety of different genes, which should enable plants to clean mercury polluted sites are being tested as tools for mercury phytoremediation, first in model laboratory plants and then in potential field species. Several of these genes have already been shown to enhance mercury phytoremediation. Mercury pollution is a serious, world-wide problem affecting the health of human and wildlife populations. Environmentally, the most serious mercury threat is the production of methylmercury (CH3Hg+) by native bacteria at mercury contaminated wetland sites. Methylmercury is inherently more toxic than metallic (Hg(0)) or ionic (Hg(II)) mercury, and because methylmercury is prolifically biomagnified up the food chain, it poses the most immediate danger to animal populations. We have successfully engineered two model plants, Arabidopsis and tobacco, to use the bacterial merB gene to convert methylmercury to less toxic ionic mercury and to use the bacterial merA gene to further detoxify ionic mercury to the least toxic form of mercury, metallic mercury. Plants expressing both MerA and MerB proteins detoxify methylmercury in two steps to the metallic form. These plants germinate, grow, and set seed at normal growth rates on levels of methylmercury or ionic mercury that are lethal to normal plants. Our newest efforts involve engineering plants with several additional bacterial and plant genes that allow for higher levels of mercury resistance and mercury hyperaccumulation. The potential for these plants to hyperaccumulate mercury was further advanced by developing constitutive, aboveground, and root-specific gene expression systems. Our current strategy is to engineer plants to

  16. Autometallographic tracing of mercury in frog liver

    International Nuclear Information System (INIS)

    Loumbourdis, N.S.; Danscher, G.

    2004-01-01

    The distribution of mercury in the liver of the frog Rana ridibunda with the autometallographic method was investigated. The mercury specific autometallographic (HgS/Se AMG ) technique is a sensitive histochemical approach for tracing mercury in tissues from mercury-exposed organisms. Mercury accumulates in vivo as mercury sulphur/mercury selenium nanocrystals that can be silver-enhanced. Thus, only a fraction of the Hg can be visualized. Six animals were exposed for one day and another group of six animals for 6 days in 1 ppm mercury (as HgCI 2 ) dissolved in fresh water. A third group of six animals, served as controls, were sacrificed the day of arrival at the laboratory. First, mercury appears in the blood plasma and erythrocytes. Next, mercury moves to hepatocytes and in the apical part of the cells, that facing bile canaliculi. In a next step, mercury appears in the endothelial and Kupffer cells. It seems likely that, the mercury of hepatocytes moves through bile canaliculi to the gut, most probably bound to glutathione and/or other similar ligands. Most probably, the endothelial and Kupffer cells comprise the first line of defense against metal toxicity. - Frogs can be good bioindicators of mercury

  17. Mercury: Aspects of its ecology and environmental toxicity. [physiological effects of mercury compound contamination of environment

    Science.gov (United States)

    Siegel, S. M.

    1973-01-01

    A study was conducted to determine the effects of mercury pollution on the environment. The possible sources of mercury contamination in sea water are identified. The effects of mercury on food sources, as represented by swordfish, are analyzed. The physiological effects of varying concentrations of mercury are reported. Emphasis is placed on the situation existing in the Hawaiian Islands.

  18. Groundwater Modeling Of Mercury Pollution At A Former Mercury Cell Chlor Alkali Facility In Pavoldar, Kazakhstan

    Science.gov (United States)

    In Kazakhstan, there is a serious case of mercury pollution near the city of Pavlodar from an old mercury cell chlor-alkali plant. The soil, sediment, and water is severly contaminated with mercury and mercury compounds as a result of the industrial activity of this chemical pla...

  19. Sorption of mercury on chemically synthesized polyaniline

    International Nuclear Information System (INIS)

    Remya Devi, P.S.; Verma, R.; Sudersanan, M.

    2006-01-01

    Sorption of inorganic mercury (Hg 2+ ) and methyl mercury, on chemically synthesized polyaniline, in 0.1-10N HCl solutions has been studied. Hg 2+ is strongly sorbed at low acidities and the extent of sorption decreases with increase in acidity. The sorption of methyl mercury is very low in the HCl concentration range studied. Sorption of Hg 2+ on polyaniline in 0.1-10N LiCl and H 2 SO 4 solutions has also been studied. The analysis of the data indicates that the sorption of Hg 2+ depends on the degree of protonation of polyaniline and the nature of mercury(II) chloride complexes in solution. X-ray photoelectron spectroscopy analysis (XPS) of polyaniline sorbed with mercury show that mercury is bound as Hg 2+ . Sorbed mercury is quantitatively eluted from polyaniline with 0.5N HNO 3 . Polyaniline can be used for separation and pre-concentration of inorganic mercury from aqueous samples. (author)

  20. EPA Leadership in the Global Mercury Partnership

    Science.gov (United States)

    The Global Mercury Partnership is a voluntary multi-stakeholder partnership initiated in 2005 to take immediate actions to protect human health and the environment from the releases of mercury and its compounds to the environment.

  1. Mercury-Containing Devices and Demolition

    Science.gov (United States)

    Some items inside residential buildings contain mercury, which poses a persistent and toxic human health and environmental threat. These materials should be carefully salvaged for proper recycling to prevent mercury contamination prior to demolition.

  2. Health Effects of Exposures to Mercury

    Science.gov (United States)

    ... Mercury in Your Environment Contact Us Share Health Effects of Exposures to Mercury Related Health Information for ... About PDF ; discussion starts on page 20) Methylmercury Effects Effects on People of All Ages Exposure to ...

  3. The effect of longterm exposure to mercury on the bacterial community in marine sediment

    DEFF Research Database (Denmark)

    Rasmussen, Lasse Dam; Sørensen, Søren Johannes

    1998-01-01

    Mercury pollution, bacteria, diversity, mercury resistance, antibiotic resistance, plasmid abundance......Mercury pollution, bacteria, diversity, mercury resistance, antibiotic resistance, plasmid abundance...

  4. Method for the removal and recovery of mercury

    Science.gov (United States)

    Easterly, Clay E.; Vass, Arpad A.; Tyndall, Richard L.

    1997-01-01

    The present invention is an enhanced method for the removal and recovery of mercury from mercury-contaminated matrices. The method involves contacting a mercury-contaminated matrix with an aqueous dispersant solution derived from specific intra-amoebic isolates to release the mercury from the mercury-contaminated matrix and emulsify the mercury; then, contacting the matrix with an amalgamating metal from a metal source to amalgamate the mercury to the amalgamating metal; removing the metallic source from the mercury-contaminated matrix; and heating the metallic source to vaporize the mercury in a closed system to capture the mercury vapors.

  5. Phytoremediation of Ionic and Methyl Mercury Pollution

    Energy Technology Data Exchange (ETDEWEB)

    Meagher, Richard B.

    2004-12-01

    Phytoremediation is defined as the use of plants to extract, resist, detoxify, and/or sequester toxic environmental pollutants. The long-term goal of the proposed research is to develop and test highly productive, field-adapted plant species that have been engineered for the phytoremediation of mercury. A variety of different genes, which should enable plants to clean mercury polluted sites are being tested as tools for mercury phytoremediation, first in model laboratory plants and then in potential field species. Several of these genes have already been shown to enhance mercury phytoremediation. Mercury pollution is a serious, world-wide problem affecting the health of human and wildlife populations. Environmentally, the most serious mercury threat is the production of methylmercury (CH3Hg+) by native bacteria at mercury contaminated wetland sites. Methylmercury is inherently more toxic than metallic (Hg(0)) or ionic (Hg(II)) mercury, and because methylmercury is prolifically biomagnified up the food chain, it poses the most immediate danger to animal populations. We have successfully engineered two model plants, Arabidopsis and tobacco, to use the bacterial merB gene to convert methylmercury to less toxic ionic mercury and to use the bacterial merA gene to further detoxify ionic mercury to the least toxic form of mercury, metallic mercury. Plants expressing both MerA and MerB proteins detoxify methylmercury in two steps to the metallic form. These plants germinate, grow, and set seed at normal growth rates on levels of methylmercury or ionic mercury that are lethal to normal plants. Our newest efforts involve engineering plants with several additional bacterial and plant genes that allow for higher levels of mercury resistance and mercury hyperaccumulation. The potential for these plants to hyperaccumulate mercury was further advanced by developing constitutive, aboveground, and root-specific gene expression systems.

  6. Mercury Continuous Emmission Monitor Calibration

    Energy Technology Data Exchange (ETDEWEB)

    John Schabron; Eric Kalberer; Ryan Boysen; William Schuster; Joseph Rovani

    2009-03-12

    Mercury continuous emissions monitoring systems (CEMs) are being implemented in over 800 coal-fired power plant stacks throughput the U.S. Western Research Institute (WRI) is working closely with the Electric Power Research Institute (EPRI), the National Institute of Standards and Technology (NIST), and the Environmental Protection Agency (EPA) to facilitate the development of the experimental criteria for a NIST traceability protocol for dynamic elemental mercury vapor calibrators/generators. These devices are used to calibrate mercury CEMs at power plant sites. The Clean Air Mercury Rule (CAMR) which was published in the Federal Register on May 18, 2005 and vacated by a Federal appeals court in early 2008 required that calibration be performed with NIST-traceable standards. Despite the vacature, mercury emissions regulations in the future will require NIST traceable calibration standards, and EPA does not want to interrupt the effort towards developing NIST traceability protocols. The traceability procedures will be defined by EPA. An initial draft traceability protocol was issued by EPA in May 2007 for comment. In August 2007, EPA issued a conceptual interim traceability protocol for elemental mercury calibrators. The protocol is based on the actual analysis of the output of each calibration unit at several concentration levels ranging initially from about 2-40 {micro}g/m{sup 3} elemental mercury, and in the future down to 0.2 {micro}g/m{sup 3}, and this analysis will be directly traceable to analyses by NIST. The EPA traceability protocol document is divided into two separate sections. The first deals with the qualification of calibrator models by the vendors for use in mercury CEM calibration. The second describes the procedure that the vendors must use to certify the calibrators that meet the qualification specifications. The NIST traceable certification is performance based, traceable to analysis using isotope dilution inductively coupled plasma

  7. Combined effects of perchlorate, thiocyanate, and iodine on thyroid function in the National Health and Nutrition Examination Survey 2007–08

    Energy Technology Data Exchange (ETDEWEB)

    Steinmaus, Craig, E-mail: craigs@berkeley.edu [Office of Environmental Health Hazard Assessment, California Environmental Protection Agency, 1515 Clay St. 16th Floor, Oakland, CA 94612 (United States); Miller, Mark D., E-mail: ucsfpehsumiller@gmail.com [Office of Environmental Health Hazard Assessment, California Environmental Protection Agency, 1515 Clay St. 16th Floor, Oakland, CA 94612 (United States); Cushing, Lara, E-mail: lara.cushing@berkeley.edu [Energy and Resources Group, 310 Barrows Hall, University of California, Berkeley, CA 93720-3050 (United States); Blount, Benjamin C., E-mail: bkb3@cdc.gov [Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention, 4770 Buford Highway, NE, Mail Stop F47, Atlanta, GA (United States); Smith, Allan H., E-mail: ahsmith@berkeley.edu [Arsenic Health Effects Research Group, 1950 Addison St., Suite 204, University of California, Berkeley, CA 94704 (United States)

    2013-05-15

    Perchlorate, thiocyanate, and low iodine intake can all decrease iodide intake into the thyroid gland. This can reduce thyroid hormone production since iodide is a key component of thyroid hormone. Previous research has suggested that each of these factors alone may decrease thyroid hormone levels, but effect sizes are small. We hypothesized that people who have all three factors at the same time have substantially lower thyroid hormone levels than people who do not, and the effect of this combined exposure is substantially larger than the effects seen in analyses focused on only one factor at a time. Using data from the 2007–2008 National Health and Nutrition Examination Survey, subjects were categorized into exposure groups based on their urinary perchlorate, iodine, and thiocyanate concentrations, and mean serum thyroxine concentrations were compared between groups. Subjects with high perchlorate (n=1939) had thyroxine concentrations that were 5.0% lower (mean difference=0.40 μg/dl, 95% confidence interval=0.14–0.65) than subjects with low perchlorate (n=2084). The individual effects of iodine and thiocyanate were even smaller. Subjects with high perchlorate, high thiocyanate, and low iodine combined (n=62) had thyroxine concentrations 12.9% lower (mean difference=1.07 μg/dl, 95% confidence interval=0.55–1.59) than subjects with low perchlorate, low thiocyanate, and adequate iodine (n=376). Potential confounders had little impact on results. Overall, these results suggest that concomitant exposure to perchlorate, thiocyanate, and low iodine markedly reduces thyroxine production. This highlights the potential importance of examining the combined effects of multiple agents when evaluating the toxicity of thyroid-disrupting agents. -- Highlights: ► Recent data suggest that essentially everyone in the US is exposed to perchlorate. ► Perchlorate exposure may be associated with lower thyroid hormone levels. ► Some groups may be more susceptible to

  8. Δ17O Isotopic Investigation of Nitrate Salts Found in Co-Occurrence with Naturally Formed Perchlorate in the Mojave Desert, California, USA and the Atacama Desert, Chile

    Science.gov (United States)

    Lybrand, R. A.; Parker, D.; Rech, J.; Prellwitz, J.; Michalski, G.

    2009-12-01

    Perchlorate is both a naturally occurring and manmade contaminant that has been identified in soil, groundwater and surface water. Perchlorate directly affects human health by interfering with iodide uptake in the thyroid gland, which may in turn lower the production of key hormones that are needed for proper growth and development. Until recently, the Atacama Desert, Chile was thought to be the only location where perchlorate salts formed naturally. Recent work has documented the occurrence of these salts in several semi-arid regions of the United States. This study identified putatively natural sources of perchlorate in the Mojave Desert of California. Soil samples were collected from six field sites varying in geologic age. The co-occurrence of perchlorate and nitrate in caliches from the Atacama Desert and soils from the Mojave Desert was also investigated. Although the former are richer in NO3-, near-ore-grade (~5%) deposits occur in the vicinity of Death Valley National Park. Weak but significant correlations exist between ClO4- and NO3- at both locations, but the perchlorate levels are much higher (up to 800 mg/kg) in the Chilean samples than in California (atmospheric origin for the Atacama nitrate salts, and a mixture between biological nitrate and atmospherically-derived nitrate for the Mojave samples. When corrected for the percentage of atmospheric nitrate measured in the Atacama samples, the Mojave samples still contain much lower perchlorate concentrations than would be expected if the occurrence of perchlorate correlated strictly with atmospherically derived nitrate. These results indicate that the variation in the origins of the nitrate salts is not the only factor influencing perchlorate distribution in these environments. These findings suggest that there are other geologic differences in landform age and stability that are crucial to understanding the co-occurrence of nitrate and perchlorate between the two locations.

  9. Effect of environmental perchlorate on thyroid function in pregnant women from Córdoba, Argentina, and Los Angeles, California.

    Science.gov (United States)

    Pearce, Elizabeth N; Spencer, Carole A; Mestman, Jorge H; Lee, Richard H; Bergoglio, Liliana M; Mereshian, Paula; He, Xuemei; Leung, Angela M; Braverman, Lewis E

    2011-01-01

    To determine whether environmental perchlorate exposure adversely affects thyroid function in women in the first trimester of pregnancy. First-trimester pregnant women were recruited from prenatal clinics in the Los Angeles County Hospital, Los Angeles, California, and in the Hospital Universitario de Maternidad dependent Universidad Nacional de Córdoba, Córdoba, Argentina, between 2004 and 2007. Spot urine and blood specimens were obtained during the clinic visit. Urinary perchlorate, iodine, and creatinine were measured, and thyroid function tests were performed. The study included 134 pregnant women from Los Angeles, California (mean gestational age ± SD = 9.1 ± 2.2 weeks), and 107 pregnant women from Córdoba, Argentina (mean gestational age = 10.0 ± 2.0 weeks). Median urinary iodine values were 144 μg/L in California and 130 μg/L in Argentina. Urinary perchlorate levels were detectable in all women (California: median, 7.8 μg/L [range, 0.4-284 μg/L] and Argentina: median, 13.5 μg/L [range, 1.1-676 μg/L]). Serum thyroperoxidase antibodies were detectable in 21 women from California (16%) and in 17 women from Argentina (16%). Using Spearman rank correlation analyses, there was no association between urinary perchlorate concentrations and serum thyrotropin, free thyroxine index, or total triiodothyronine values, including within the subset of women with urinary iodine values less than 100 μg/L. In multivariate analyses using the combined Argentina and California data sets and adjusting for urinary iodine concentrations, urinary creatinine, gestational age, and thyroperoxidase antibody status, urinary perchlorate was not a significant predictor of thyroid function. Low-level perchlorate exposure is ubiquitous, but is not associated with altered thyroid function among women in the first trimester of pregnancy.

  10. Mercury detection with thermal neutrons

    International Nuclear Information System (INIS)

    Bell, Z.W.

    1994-01-01

    This report describes the work performed to design a gauge to detect mercury concealed within walls, floors, pipes, and equipment inside a building. The project arose out of a desire to decontaminate and decommission (D ampersand D) a building in which mercury had been used as part of a chemical process. The building contains plumbing and equipment, some with residual mercury even after draining, sumps, and hollow walls. So that releases of mercury to the environment might be minimized during D ampersand D activities, it was considered advisable to locate pockets of mercury that may have collected in concealed spaces so that they might be drained in a controlled fashion prior to the application of the wrecking ball or sledge hammer. The detection of such pockets within a building presents some problems not ordinarily encountered in a laboratory environment. Often, only a single side of a wall or pipe is accessible. This condition disqualifies transmission gauges (such as conventional x radiography) in which a probe is sent through the volume under test (VUT) from one side and its passage or attenuation is detected on the opposite side. A robust, one-sided system was needed

  11. Mercury bioaccumulation in the Mediterranean

    Directory of Open Access Journals (Sweden)

    Cinnirella S.

    2013-04-01

    Full Text Available This study details mercury pollution within the food chain of the Mediterranean by analysing the most comprehensive mercury dataset available for biota and water measurements. In this study we computed a bioaccumulation factor (BAF for datasets in the existing mercury-related scientific literature, in on-going programs, and in past measurement campaigns. Preliminary results indicate a major lack of information, making the outcome of any assessment very uncertain. Importantly, not all marine eco-regions are (or have ever been covered by measurement campaigns. Most lacking is information associated with the South-Eastern part of the Mediterranean, and in several eco-regions it is still impossible to reconstruct a trophic net, as the required species were not accounted for when mercury measurements were taken. The datasets also have additional temporal sampling problems, as species were often not sampled systematically (but only sporadically during any given sampling period. Moreover, datasets composed of mercury concentrations in water also suffer from similar geographic limitations, as they are concentrated in the North-Western Mediterranean. Despite these concerns, we found a very clear bioaccumulation trend in 1999, the only year where comprehensive information on both methylmercury concentrations in water and biota was available.

  12. Mineral resource of the month: mercury

    Science.gov (United States)

    ,

    2012-01-01

    The article offers information on mercury, a mineral commodity used in industrial and small-scale gold mining applications. Mercury has been reported to be used for amalgamation with gold since the Roman times. Mercury from cinnabar from Almadén, Spain has been used by Romans and has been continued to be used through the Middle Ages and the Colonial era.

  13. 40 CFR 721.10068 - Elemental mercury.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Elemental mercury. 721.10068 Section... Substances § 721.10068 Elemental mercury. (a) Definitions. The definitions in § 721.3 apply to this section... elemental mercury (CAS. No. 7439-97-6) is subject to reporting under this section for the significant new...

  14. The Effects of Perchlorates on the Permafrost Methanogens: Implication for Autotrophic Life on Mars.

    Science.gov (United States)

    Shcherbakova, Viktoria; Oshurkova, Viktoria; Yoshimura, Yoshitaka

    2015-09-09

    The terrestrial permafrost represents a range of possible cryogenic extraterrestrial ecosystems on Earth-like planets without obvious surface ice, such as Mars. The autotrophic and chemolithotrophic psychrotolerant methanogens are more likely than aerobes to function as a model for life forms that may exist in frozen subsurface environments on Mars, which has no free oxygen, inaccessible organic matter, and extremely low amounts of unfrozen water. Our research on the genesis of methane, its content and distribution in permafrost horizons of different ages and origin demonstrated the presence of methane in permanently frozen fine-grained sediments. Earlier, we isolated and described four strains of methanogenic archaea of Methanobacterium and Methanosarcina genera from samples of Pliocene and Holocene permafrost from Eastern Siberia. In this paper we study the effect of sodium and magnesium perchlorates on growth of permafrost and nonpermafrost methanogens, and present evidence that permafrost hydogenotrophic methanogens are more resistant to the chaotropic agent found in Martian soil. In this paper we study the effect of sodium and magnesium perchlorates on the growth of permafrost and nonpermafrost methanogens, and present evidence that permafrost hydogenotrophic methanogens are more resistant to the chaotropic agent found in Martian soil. Furthermore, as shown in the studies strain M2(T) M. arcticum, probably can use perchlorate anion as an electron acceptor in anaerobic methane oxidation. Earth's subzero subsurface environments are the best approximation of environments on Mars, which is most likely to harbor methanogens; thus, a biochemical understanding of these pathways is expected to provide a basis for designing experiments to detect autotrophic methane-producing life forms on Mars.

  15. The Effects of Perchlorates on the Permafrost Methanogens: Implication for Autotrophic Life on Mars

    Directory of Open Access Journals (Sweden)

    Viktoria Shcherbakova

    2015-09-01

    Full Text Available The terrestrial permafrost represents a range of possible cryogenic extraterrestrial ecosystems on Earth-like planets without obvious surface ice, such as Mars. The autotrophic and chemolithotrophic psychrotolerant methanogens are more likely than aerobes to function as a model for life forms that may exist in frozen subsurface environments on Mars, which has no free oxygen, inaccessible organic matter, and extremely low amounts of unfrozen water. Our research on the genesis of methane, its content and distribution in permafrost horizons of different ages and origin demonstrated the presence of methane in permanently frozen fine-grained sediments. Earlier, we isolated and described four strains of methanogenic archaea of Methanobacterium and Methanosarcina genera from samples of Pliocene and Holocene permafrost from Eastern Siberia. In this paper we study the effect of sodium and magnesium perchlorates on growth of permafrost and nonpermafrost methanogens, and present evidence that permafrost hydogenotrophic methanogens are more resistant to the chaotropic agent found in Martian soil. In this paper we study the effect of sodium and magnesium perchlorates on the growth of permafrost and nonpermafrost methanogens, and present evidence that permafrost hydogenotrophic methanogens are more resistant to the chaotropic agent found in Martian soil. Furthermore, as shown in the studies strain M2T M. arcticum, probably can use perchlorate anion as an electron acceptor in anaerobic methane oxidation. Earth’s subzero subsurface environments are the best approximation of environments on Mars, which is most likely to harbor methanogens; thus, a biochemical understanding of these pathways is expected to provide a basis for designing experiments to detect autotrophic methane-producing life forms on Mars.

  16. The effect of wax coating, aluminum and ammonium perchlorate on impact sensitivity of HMX

    OpenAIRE

    Yu-bin LI; Li-ping PAN; Zhi-jian YANG; Fei-yan GONG; Xue ZHENG; Guan-song HE

    2017-01-01

    Interaction of 1,3,5,7-tetranitro-1,3,5,7-tetrazocane (HMX)/ammonium perchlorate (AP) and its effect on mechanical sensitivity may result in some restrictions for the application of AP/HMX system in high energetic weapon system. In this work, impact sensitivity test is used to study the effects of wax coating of HMX, AP and aluminum (Al) powder on sensitivity properties of HMX/AP/Al mixtures. Thermogravimetry-differential scanning calorimetry (TG-DSC) analysis has been developed to investigat...

  17. Oxidation of benzenesulphonic acid derivatives with cerium (IV) in perchloric acid solution

    OpenAIRE

    Ignaczak, Maksymilian; Deka, Mirosława

    1985-01-01

    The effact of several reagents on the oxidation rate of o- - and p-toluenesulphfonic acids and p-toluenesulphfonamide was ascertained by potentiometric determination of cerium ions concentration. It was shown that the transfer of the first electron is the step limiting the rate of these processes in the reaction mixtures where perchloric acid concentrations are of the order of l-4 mole/1 while in the case of concentrations of 8-10 mole/1 the decisive step is the transfer of ...

  18. Anaerobic Treatment of Wastewaters Containing Perchlorate from Munitions Handling and Production

    Science.gov (United States)

    2008-01-01

    2003. Brock Biology of Microorganisms . Prentice Hall, New Jersey, 576-587. Maloney, S. W., E. G. Engbert, M. T. Suidan, and R. F. Hickey. 1998...reactions for the two compounds are as follow: microorganisms 1.5 NaClO4- + C2H6O → 1.5...Cl- + 2 CO2 + 3 H2O + 1.5 Na (1) (perchlorate) (ethanol) microorganisms 2 C3H6N3(NO2)3 + C2H6O → 5 CO2 + 3 CH4 + 6 N2 + 3 H2O

  19. Magneto and spectral behaviour of lanthanide(III) perchlorate complexes of n-isonicotinamidoanisalaldimine

    International Nuclear Information System (INIS)

    Agarwal, R.K.; Agarwal, Himanshu; Sarin, R.K.

    1996-01-01

    A new series of lanthanide(III) perchlorate complexes of N-isonicotinamidoanisalaldimine (INH-SAL) with the general composition (Ln(INH-SAL) 4 )(ClO) 4 ) 3 (Ln=La, Pr, Nd, Sm, Gd, Tb or Dy) were synthesized and characterized by elemental analyses, conductance, molecular weight, infrared and electronic spectral data. INH-SAL acts as a bidentate (N, O) chelating agents. The tentative coordination number eight has been assigned. Thermal behaviour of some representative chelates has also been investigated. (author). 14 refs., 2 tabs

  20. 2-(2-Hydroxy-3-methoxyphenyl-1H-benzimidazol-3-ium perchlorate

    Directory of Open Access Journals (Sweden)

    Chuan Chen

    2012-06-01

    Full Text Available In the title molecular salt, C14H13N2O2+·ClO4−, the ring systems in the cation are almost coplanar [dihedral angle = 5.53 (13°]. Intramolecular N—H...O and O—H...O hydrogen bonds generate S(6 and S(5 rings, respectively. In the crystal, the two H atoms involved in the intramolecular hydrogen bonds also participate in intermolecular links to acceptor O atoms of the perchlorate anions. A simple intermolecular N—H...O bond also occurs. Together, these form a double-chain structure along [101].

  1. Perchlorate in indoor dust and human urine in China: contribution of indoor dust to total daily intake.

    Science.gov (United States)

    Zhang, Tao; Chen, Xiaojia; Wang, Dou; Li, Rudan; Ma, Yufang; Mo, Weiwen; Sun, Hongwen; Kannan, Kurunthachalam

    2015-02-17

    Perchlorate is used in fireworks and China is the largest fireworks producer and consumer in the world. Information regarding human exposure to perchlorate is scarce in China, and exposure via indoor dust ingestion (EDI indoor dust) has rarely been evaluated. In this study, perchlorate was found in indoor dust (detection rate: 100%, median: 47.4 μg/g), human urine (99%, 26.2 ng/mL), drinking water (100%, 3.99 ng/mL), and dairy milk (100%, 12.3 ng/mL) collected from cities that have fireworks manufacturing areas (Yueyang and Nanchang) and in cities that do not have fireworks manufacturing industries (Tianjin, Shijiazhuang, Yuxi and Guilin) in China. In comparison with perchlorate levels reported for other countries, perchlorate levels in urine samples from fireworks sites and nonfireworks sites in China were higher. Median indoor dust perchlorate concentrations were positively correlated (r = 0.964, p < 0.001) with outdoor dust perchlorate levels reported previously. The total daily intake (EDI total) of perchlorate, estimated based on urinary levels, ranged from 0.090 to 27.72 μg/kg body weight (bw)/day for all studied participants; the percentage of donors who had EDI total exceeding the reference dose (RfD) recommended by the United States Environmental Protection Agency (US EPA) was 79%, 48%, and 25% for toddlers (median: 1.829 μg/kg bw/day), adults (0.669 μg/kg bw/day), and children (median: 0.373 μg/kg bw/day), respectively. Toddlers (0.258 μg/kg bw/day) had the highest median EDI indoor dust, which was 2 to 5 times greater than the EDI indoor dust calculated for other age groups (the range of median values: 0.044 to 0.127 μg/kg bw/day). Contribution of indoor dust to EDItotal was 26%, 28%, and 7% for toddlers, children, and adults, respectively. Indoor dust contributed higher percentage to EDI total than that by dairy milk (0.5-5%).

  2. How Tiny Collisions Shape Mercury

    Science.gov (United States)

    Kohler, Susanna

    2017-07-01

    If space rocks are unpleasant to encounter, space dust isnt much better. Mercurys cratered surface tells of billions of years of meteoroid impacts but its thin atmosphere is what reveals its collisional history with smaller impactors. Now new research is providing a better understanding of what were seeing.Micrometeoroids Ho!The inner solar system is bombarded by micrometeoroids, tiny particles of dust (on the scale of a tenth of a millimeter) emitted by asteroids and comets as they make their closest approach to the Sun. This dust doesnt penetrateEarths layers of atmosphere, but the innermost planet of our solar system, Mercury, doesnt have this convenient cushioning.Just as Mercury is affected by the impacts of large meteoroids, its also shaped by the many smaller-scale impacts it experiences. These tiny collisions are thought to vaporize atoms and molecules from the planets surface, which quickly dissociate. This process adds metals to Mercurys exosphere, the planets extremely tenuous atmosphere.Modeling PopulationsDistribution of the directions from which meteoroids originate before impacting Mercurys surface, as averaged over its entire orbit. Local time of 12 hr corresponds to the Sun-facing side. A significant asymmetry is seen between the dawn (6 hrs) and dusk (18 hrs) rates. [Pokorn et al. 2017]The metal distribution in the exosphere provides a way for us to measure the effect of micrometeoroid impacts on Mercury but this only works if we have accurate models of the process. A team of scientists led by Petr Pokorn (The Catholic University of America and NASA Goddard SFC) has now worked to improve our picture of micrometeoroid impact vaporization on Mercury.Pokorn and collaborators argue that two meteoroid populations Jupiter-family comets (short-period) and Halley-type comets (long-period) contribute the dust for the majority of micrometeoroid impacts on Mercury. The authors model the dynamics and evolution of these two populations, reproducing the

  3. Control of mercury emissions: policies, technologies, and future trends

    OpenAIRE

    Rhee, Seung-Whee

    2015-01-01

    Seung-Whee Rhee Department of Environmental Engineering, Kyonggi University, Suwon, Republic of Korea Abstract: Owing to the Minamata Convention on Mercury and the Global Mercury Partnership, policies and regulations on mercury management in advanced countries were intensified by a mercury phaseout program in the mercury control strategy. In developing countries, the legislative or regulatory frameworks on mercury emissions are not established specifically, but mercury management is designed...

  4. Canadian mercury inventories: the missing pieces

    Energy Technology Data Exchange (ETDEWEB)

    Hagreen, L.A.; Lourie, B.A. [Summerhill Group, Toronto, ON (Canada)

    2004-07-01

    Research was conducted to determine the significance of the deliberate use of mercury in products in Canada and the associated releases from these sources. Through a combination of literature review and new calculations, the reservoir, flux, and releases of mercury from eight product sources were calculated, and these results compared to historical Canadian inventories. Mercury contributions from the waste sector were also assessed and compared to total Canadian mercury releases and to mercury releases from coal-fired generating stations. Results suggest the use and release of mercury associated with its use in products is 4.5 times what previous inventories indicate. Including dental amalgam and sewage sludge, the total releases of mercury to all environmental compartments in Canada totals 20 tonnes per year. This accounts for less than one-half of the 44 tonnes per year of mercury released from mercury waste disposal each year in Canada. Waste mercury contributions from hazardous waste imports, unknown product sources, and incomplete information on the use of mercury in known products may account for this discrepancy. Waste-related mercury releases and transfers for disposal and recycling are 11 times greater than that of electricity generation in Canada. Results indicate that Canadian inventories have underestimated the significance of mercury use and release associated with products, calling into question the current priorities for mercury management. This paper was developed as part of a panel session at the International Joint Commission 'Mercury in the Ecosystem' workshop, February 26-27, 2003, Windsor, ON, Canada, as a complement to the information on Canadian Inventories presented by Luke Trip (Senes Consulting, Ottawa, ON, Canada).

  5. Sodium Velocity Maps on Mercury

    Science.gov (United States)

    Potter, A. E.; Killen, R. M.

    2011-01-01

    The objective of the current work was to measure two-dimensional maps of sodium velocities on the Mercury surface and examine the maps for evidence of sources or sinks of sodium on the surface. The McMath-Pierce Solar Telescope and the Stellar Spectrograph were used to measure Mercury spectra that were sampled at 7 milliAngstrom intervals. Observations were made each day during the period October 5-9, 2010. The dawn terminator was in view during that time. The velocity shift of the centroid of the Mercury emission line was measured relative to the solar sodium Fraunhofer line corrected for radial velocity of the Earth. The difference between the observed and calculated velocity shift was taken to be the velocity vector of the sodium relative to Earth. For each position of the spectrograph slit, a line of velocities across the planet was measured. Then, the spectrograph slit was stepped over the surface of Mercury at 1 arc second intervals. The position of Mercury was stabilized by an adaptive optics system. The collection of lines were assembled into an images of surface reflection, sodium emission intensities, and Earthward velocities over the surface of Mercury. The velocity map shows patches of higher velocity in the southern hemisphere, suggesting the existence of sodium sources there. The peak earthward velocity occurs in the equatorial region, and extends to the terminator. Since this was a dawn terminator, this might be an indication of dawn evaporation of sodium. Leblanc et al. (2008) have published a velocity map that is similar.

  6. Apparatus for control of mercury

    Science.gov (United States)

    Downs, William; Bailey, Ralph T.

    2001-01-01

    A method and apparatus for reducing mercury in industrial gases such as the flue gas produced by the combustion of fossil fuels such as coal adds hydrogen sulfide to the flue gas in or just before a scrubber of the industrial process which contains the wet scrubber. The method and apparatus of the present invention is applicable to installations employing either wet or dry scrubber flue gas desulfurization systems. The present invention uses kraft green liquor as a source for hydrogen sulfide and/or the injection of mineral acids into the green liquor to release vaporous hydrogen sulfide in order to form mercury sulfide solids.

  7. Coal fired flue gas mercury emission controls

    CERN Document Server

    Wu, Jiang; Pan, Weiguo; Pan, Weiping

    2015-01-01

    Mercury (Hg) is one of the most toxic heavy metals, harmful to both the environment and human health. Hg is released into the atmosphere from natural and anthropogenic sources and its emission control has caused much concern. This book introduces readers to Hg pollution from natural and anthropogenic sources and systematically describes coal-fired flue gas mercury emission control in industry, especially from coal-fired power stations. Mercury emission control theory and experimental research are demonstrated, including how elemental mercury is oxidized into oxidized mercury and the effect of

  8. Marine biogeochemistry of mercury

    International Nuclear Information System (INIS)

    Gill, G.A.

    1986-01-01

    Noncontaminating sample collection and handling procedures and accurate and sensitive analysis methods were developed to measure sub-picomolar Hg concentrations in seawater. Reliable and diagnostic oceanographic Hg distributions were obtained, permitting major processes governing the marine biogeochemistry of Hg to be identified. Mercury concentrations in the northwest Atlantic, central Pacific, southeast Pacific, and Tasman Sea ranged from 0.5 to 12 pM. Vertical Hg distributions often exhibited a maximum within or near the main thermocline. At similar depths, Hg concentrations in the northwest Atlantic Ocean were elevated compared to the N. Pacific Ocean. This pattern appears to result from a combination of enhanced supply of Hg to the northwest Atlantic by rainfall and scavenging removal along deep water circulation pathways. These observations are supported by geochemical steady-state box modelling which predicts a relatively short mean residence time for Hg in the oceans; demonstrating the reactive nature of Hg in seawater and precluding significant involvement in nutrient-type recyclic. Evidence for the rapid removal of Hg from seawater was obtained at two locations. Surface seawater Hg measurements along 160 0 W (20 0 N to 20 0 S) showed a depression in the equatorial upwelling area which correlated well with the transect region exhibiting low 234 Th/ 238 U activity ratios. This relationship implies that Hg will be scavenged and removed from surface seawater in biologically productive oceanic zones. Further, a broad minimum in the vertical distribution of Hg was observed to coincide with the intense oxygen minimum zone in the water column in coastal waters off Peru

  9. Environmental contamination and risk assessment of mercury from a historic mercury mine located in southwestern China.

    Science.gov (United States)

    Li, Yonghua

    2013-02-01

    A field survey of mercury pollution in environmental media and human hair samples obtained from residents living in the area surrounding the Chatian mercury mine (CMM) of southwestern China was conducted to evaluate the health risks of mercury to local residents. The results showed that mine waste, and tailings in particular, contained high levels of mercury and that the maximum mercury concentration was 88.50 μg g(-1). Elevated mercury levels were also found in local surface water, paddy soil, and paddy grain, which may cause severe health problems. The mercury concentration of hair samples from the inhabitants of the CMM exceeded 1.0 μg g(-1), which is the limit recommended by the US EPA. Mercury concentrations in paddy soil were positively correlated with mercury concentrations in paddy roots, stalks, and paddy grains, which suggested that paddy soil was the major source of mercury in paddy plant tissue. The average daily dose (ADD) of mercury for local adults and preschool children via oral exposure reached 0.241 and 0.624 μg kg(-1) body weight per day, respectively, which is approaching or exceeds the provisional tolerable daily intake. Among the three oral exposure routes, the greatest contributor to the ADD of mercury was the ingestion of rice grain. Open-stacked mine tailings have resulted in heavy mercury contamination in the surrounding soil, and the depth of appreciable soil mercury concentrations exceeded 100 cm.

  10. Mercury accumulation plant Cyrtomium macrophyllum and its potential for phytoremediation of mercury polluted sites.

    Science.gov (United States)

    Xun, Yu; Feng, Liu; Li, Youdan; Dong, Haochen

    2017-12-01

    Cyrtomium macrophyllum naturally grown in 225.73 mg kg -1 of soil mercury in mining area was found to be a potential mercury accumulator plant with the translocation factor of 2.62 and the high mercury concentration of 36.44 mg kg -1 accumulated in its aerial parts. Pot experiments indicated that Cyrtomium macrophyllum could even grow in 500 mg kg -1 of soil mercury with observed inhibition on growth but no obvious toxic effects, and showed excellent mercury accumulation and translocation abilities with both translocation and bioconcentration factors greater than 1 when exposed to 200 mg kg -1 and lower soil mercury, indicating that it could be considered as a great mercury accumulating species. Furthermore, the leaf tissue of Cyrtomium macrophyllum showed high resistance to mercury stress because of both the increased superoxide dismutase activity and the accumulation of glutathione and proline induced by mercury stress, which favorited mercury translocation from the roots to the aerial parts, revealing the possible reason for Cyrtomium macrophyllum to tolerate high concentration of soil mercury. In sum, due to its excellent mercury accumulation and translocation abilities as well as its high resistance to mercury stress, the use of Cyrtomium macrophyllum should be a promising approach to remediating mercury polluted soils. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Mercury emission monitoring on municipal waste combustion

    International Nuclear Information System (INIS)

    Braun, H.; Gerig, A.

    1991-01-01

    In waste incineration, mercury is the only heavy metal to be released as a gas, mostly as mercury(II) chloride, because of its high volatility. Continuous emission monitoring is possible only when mercury occurs in its elemental form. This paper reports on various possibilities of converting Hg(II) into Hg(0) that has been studied and tested on a laboratory scale and in the TAMARA refuse incineration pilot facility. Continuous mercury emission measurement appears to be possible, provided mercury is converted in the flue gas condensate precipitated. The measuring results obtained on two municipal solid waste and on one sewage treatment sludge incineration plants show that the mercury monitor is a highly sensitive and selective continuously working instrument for mercury emission monitoring

  12. Fate of mercury in the Arctic (FOMA)

    DEFF Research Database (Denmark)

    Skov, H.; Christensen, J.; Asmund, G.

    This report is the final reporting of the project FONA, funded by the Danish Environmental Protection Agency with means from the MIKA/DANCEA funds for Environmental Support to the Arctic Region. The aim of the project is to study the intercompartment mercury transport chain in the arctic area. From...... atmospheric deposition of mercury on sea surfaces to uptake in marine organisms, bio-accumulation, and finally mercury levels in mammals. The studies in the project are focused on the behaviour of mercury during the spring period where special phenomena lead to an enhanced deposition of mercury in the Arctic...... environment, at a time where the marine ecosystem is particularly active. The studies also include a comprehensive time trend study of mercury in top carnivore species. Each of these studies contributes towards establishing the knowledge necessary to develop a general model for transport and uptake of mercury...

  13. Evaluating the Development of Biocatalytic Technology for the Targeted Removal of Perchlorate from Drinking Water.

    Science.gov (United States)

    Hutchison, Justin M; Guest, Jeremy S; Zilles, Julie L

    2017-06-20

    Removing micropollutants is challenging in part because of their toxicity at low concentrations. A biocatalytic approach could harness the high affinity of enzymes for their substrates to address this challenge. The potential of biocatalysis relative to mature (nonselective ion exchange, selective ion exchange, and whole-cell biological reduction) and emerging (catalysis) perchlorate-removal technologies was evaluated through a quantitative sustainable design framework, and research objectives were prioritized to advance economic and environmental sustainability. In its current undeveloped state, the biocatalytic technology was approximately 1 order of magnitude higher in cost and environmental impact than nonselective ion exchange. Biocatalyst production was highly correlated with cost and impact. Realistic improvement scenarios targeting biocatalyst yield, biocatalyst immobilization for reuse, and elimination of an electron shuttle could reduce total costs to $0.034 m -3 and global warming potential (GWP) to 0.051 kg CO 2 eq m -3 : roughly 6.5% of cost and 7.3% of GWP of the background from drinking water treatment and competitive with the best performing technology, selective ion exchange. With less stringent perchlorate regulatory limits, ion exchange technologies had increased cost and impact, in contrast to biocatalytic and catalytic technologies. Targeted advances in biocatalysis could provide affordable and sustainable treatment options to protect the public from micropollutants.

  14. Formation of color centers in ammonium perchlorate by x-ray irradiation at room temperature

    International Nuclear Information System (INIS)

    Levy, P.W.; Goldberg, M.; Herley, P.J.

    1978-01-01

    Radiation induced color center formation has been studied in single crystal ammonium perchlorate. Large, high purity, water clear single crystals were uniformly irradiated normal to the c or 001 face with filtered 60 kV x-rays at room temperature. The radiation induced coloring, measured through the c face, can be resolved into four Gaussian shaped absorption bands whose peak energies and full widths are 6.72, 1.62; 4.81, 0.88; 3.91, 1.12; and 2.47, 0.72 eV. The 6.72 band lies at the 'band-gap' or 'edge' and could represent either a shift in the edge or the superposition of one or more bands on the edge. The other bands are, most likely, defect related color centers or trapped molecular species. The coloring contains a small unstable component, at most 10%, consisting of these bands and an additional one at 5.78 eV, width 0.35 eV, which has a negligible effect on coloring kinetic determinations. The color-centers vs. dose curves for the bands at 6.72 and 2.47 eV are linear. The curves for the 4.81 and 3.91 eV bands contain a linear and one saturating exponential component. The linear components appear to be related to a linear dose induced process observed in the thermal decomposition of irradiated ammonium perchlorate. (author)

  15. The discrimination of 72 nitrate, chlorate and perchlorate salts using IR and Raman spectroscopy

    Science.gov (United States)

    Zapata, Félix; García-Ruiz, Carmen

    2018-01-01

    Inorganic oxidizing energetic salts including nitrates, chlorates and perchlorates are widely used in the manufacture of not only licit pyrotechnic compositions, but also illicit homemade explosive mixtures. Their identification in forensic laboratories is usually accomplished by either capillary electrophoresis or ion chromatography, with the disadvantage of dissociating the salt into its ions. On the contrary, vibrational spectroscopy, including IR and Raman, enables the non-invasive identification of the salt, i.e. avoiding its dissociation. This study focuses on the discrimination of all nitrate, chlorate and perchlorate salts that are commercially available, using both Raman and IR spectroscopy, with the aim of testing whether every salt can be unequivocally identified. Besides the visual spectra comparison by assigning every band with the corresponding molecular vibrational mode, a statistical analysis based on Pearson correlation was performed to ensure an objective identification, either using Raman, IR or both. Positively, 25 salts (out of 72) were unequivocally identified using Raman, 30 salts when using IR and 44 when combining both techniques. Negatively, some salts were undistinguishable even using both techniques demonstrating there are some salts that provide very similar Raman and IR spectra.

  16. Ionic, paramagnetic and photophysical properties of a new biohybrid material incorporating copper perchlorate

    International Nuclear Information System (INIS)

    Leones, R.; Donoso, J.P.; Magon, C.J.; Silva, I.D.A.; Camargo, A.S.S. de; Pawlicka, A.; Silva, M.M.

    2015-01-01

    Graphical abstract: Display Omitted -- Highlights: •Poly(ϵ-caprolactone)/siloxane biohybrids electrolytes were prepared by sol-gel method. •The polymer electrolytes were doped with copper perchlorate salt. •The ionic, paramagnetic and photophysical properties of the samples were evaluated. •The samples were analyzed by means of impedance spectroscopy, electron paramagnetic resonance (EPR) and photoluminescence spectroscopy. -- Abstract: The sol-gel method was employed in the synthesis of di-urethane cross-linked poly(ϵ-caprolactone) (d-PCL(530)/siloxane biohybrid ormolytes incorporating copper perchlorate (Cu(ClO 4 ) 2 ). The highest ionic conductivity of the d-PCL(530)/siloxane n Cu(ClO 4 ) 2 system is that with n = 10 (1.4 × 10 −7 and 1.4 × 10 −5 S cm −1 , at 25 and 100 °C, respectively). In an attempt to understand the ionic conductivity/ionic association relationship, we decided to inspect the chemical environment experienced by the Cu 2+ ions in the d-PCL(530)/siloxane medium. The observed EPR spectra are typical of isolated monomeric Cu 2+ ions in axially distorted sites. The molecular orbital coefficients obtained from the EPR spin Hamiltonian parameters and the optical absorption band suggests that bonding between the Cu 2+ and its ligand in the ormolytes are moderately ionic. Investigation by photoluminescence spectroscopy did not evidence or allow selective excitation of transitions corresponding to complexed Cu 2+ species

  17. Sol-gel preparation of a di-ureasil electrolyte doped with lithium perchlorate

    International Nuclear Information System (INIS)

    Silva, M.M.; Nunes, S.C.; Barbosa, P.C.; Evans, A.; Zea Bermudez, V. de; Smith, M.J.; Ostrovskii, D.

    2006-01-01

    Solid polymer electrolytes (SPEs) synthesized by the sol-gel process and designated as di-ureasils have been prepared through the incorporation of lithium perchlorate, LiClO 4 , into the d-U(2000) organic-inorganic hybrid network. Electrolytes with lithium salt compositions of n (where n indicates the number of oxyethylene units per Li + ion) between ∞ and 0.5 were characterized by conductivity measurements, cyclic voltammetry at a gold microelectrode, thermal analysis and Fourier transform Raman (FT-Raman) spectroscopy. The conductivity results obtained suggest that this system offers a quite significant improvement over previously characterized analogues doped with lithium triflate [S.C. Nunes, V. de Zea Bermudez, D. Ostrovskii, M.M. Silva, S. Barros, M.J. Smith, R.A. Sa Ferreira, L.D. Carlos, J. Rocha, E. Morales, J. Electrochem. Soc. 152 (2) (2005), A429]. 'Free' perchlorate ions, detected in all the samples examined, are identified as the main charge carriers in the sample that yields the highest room temperature conductivity (n = 20). In the di-ureasils with n ≤ 10 ionic association is favoured and the ionic conductivity drops

  18. Interfacial behavior of perchlorate versus chloride ions in saturated aqueous salt solutions

    Energy Technology Data Exchange (ETDEWEB)

    Ghosal, S; Kuo, I W; Baer, M D; Bluhm, H

    2009-04-14

    In recent years combination of theoretical and experimental work have presented a novel view of the aqueous interface wherein hard and/or multiply charged ions are excluded from the interface, but large polarizable anions show interfacial enhancement relative to the bulk. The observed trend in the propensity of anions to adsorb at the air/water interface appears to be reverse of the Hofmeister series for anions. This study focuses on experimental and theoretical examination of the partitioning behavior of perchlorate (ClO{sub 4}{sup -}) and chloride (Cl{sup -}) ions at the air/water interface. We have used ambient pressure X-ray photoelectron spectroscopy technique to directly probe the interfacial concentrations of ClO{sub 4}{sup -} and Cl{sup -} ions in sodium perchlorate and sodium chloride solutions, respectively. Experimental observations are compared with first principles molecular dynamics simulations. Both experimental and simulation results show enhancement of ClO{sub 4}{sup -} ion at the interface, compared with the absence of such enhancement in the case of Cl{sup -} ion. These observations are in agreement with the expected trend in the interfacial propensity of anions based on the Hofmeister series.

  19. Mercury in the environment : a review

    International Nuclear Information System (INIS)

    Goodarzi, F.

    2000-01-01

    Both geogenic and anthropogenic sources are responsible for the input of mercury into the environment. However, mercury comes mostly from geogenic sources and is found naturally in air, water and soil. Crustal degassing results in emission of mercury into the atmosphere. Mercury in water and soil is due mostly to input from sedimentary rocks. Mercury in lake sediments is related mainly to input by country rock and anthropogenic activities such as agriculture. The mercury content of coal is similar to or less than the amount found in the earths crust. Natural charcoal is also able to capture mercury at low temperature combustion. The amount of mercury emitted from the stack of coal-fired power plants is related to the nature of the milled coal and its mineralogical and elemental content. Mercury emissions originating from the combustion of coal from electric utility power plants are considered to be among the greatest contributors to global mercury air emissions. In order to quantify the impact the electric power industry has on the environment, information regarding mercury concentrations in coal and their speciation is needed. For this reason the author examined the behaviour of mercury in three coal samples ashed at increasing temperatures. Mercury removal from coal-fired power plants ranges from 10 to 50 per cent by fabric filters and 20 to 95 per cent by FGD systems. This data will help in regulating emissions of hazardous air pollutants from electric utility steam generating units and will potentially provide insight into the industry's contribution to the global mercury burden. 50 refs

  20. Mercury biogeochemistry: Paradigm shifts, outstanding issues and research needs

    Science.gov (United States)

    Sonke, Jeroen E.; Heimbürger, Lars-Eric; Dommergue, Aurélien

    2013-05-01

    Half a century of mercury research has provided scientists and policy makers with a detailed understanding of mercury toxicology, biogeochemical cycling and past and future impacts on human exposure. The complexity of the global biogeochemical mercury cycle has led to repeated and ongoing paradigm shifts in numerous mercury-related disciplines and outstanding questions remain. In this review, we highlight some of the paradigm shifts and questions on mercury toxicity, the risks and benefits of seafood consumption, the source of mercury in seafood, and the Arctic mercury cycle. We see a continued need for research on mercury toxicology and epidemiology, for marine mercury dynamics and ecology, and for a closer collaboration between observational mercury science and mercury modeling in general. As anthropogenic mercury emissions are closely tied to the energy cycle (in particular coal combustion), mercury exposure to humans and wildlife are likely to persist unless drastic emission reductions are put in place.

  1. Mercury erosion experiments for spallation target system

    International Nuclear Information System (INIS)

    Kinoshita, Hidetaka; Kaminaga, Masanori; Haga, Katsuhiro; Hino, Ryutaro

    2003-01-01

    The Japan Atomic Energy Research Institute (JAERI) and the High Energy Accelerator Research Organization (KEK) are promoting a plan to construct the spallation neutron source at the Tokai Research Establishment, JAERI, under the High-Intensity Proton Accelerator Project (J-PARC). A mercury circulation system has been designed so as to supply mercury to the target stably under the rated flow rate of 41 m 3 /hr. Then, it was necessary to confirm a mercury pump performance from the viewpoint of making the mercury circulation system feasible, and more, to investigate erosion rate under the mercury flow as well as an amount of mercury remained on the surface after drain from the viewpoints of mechanical strength relating to the lifetime and remote handling of mercury components. The mercury pump performance was tested under the mercury flow conditions by using an experimental gear pump, which had almost the same structure as a practical mercury pump to be expected in the mercury circulation system, and the erosion rates in a mercury pipeline as well as the amount of mercury remained on the surface were also investigated. The discharged flow rates of the experimental gear pump increased linearly with the rotation speed, so that the gear pump would work as the flow meter. Erosion rates obtained under the mercury velocity less than 1.6 m/s was found to be so small that decrease of pipeline wall thickness would be 390 μm after 30-year operation under the rated mercury velocity of 0.7 m/s. For the amount of remaining mercury on the pipeline, remaining rates of weight and volume were estimated at 50.7 g/m 2 and 3.74 Hg-cm 3 /m 2 , respectively. Applying these remaining rates of weight and volume to the mercury target, the remaining mercury was estimated at about 106.5 g and 7.9 cm 3 . Radioactivity of this remaining mercury volume was found to be three-order lower than that of the target casing. (author)

  2. Touchstones and mercury at Hedeby

    Czech Academy of Sciences Publication Activity Database

    Ježek, Martin; Holub, M.

    2014-01-01

    Roč. 89, č. 1 (2014), s. 193-204 ISSN 0079-4848 Institutional support: RVO:67985912 Keywords : Hedeby * Viking Age * grave goods * touchstone * precious metal * mercury * chemical microanalysis * archaeometallurgy Subject RIV: AC - Archeology, Anthropology, Ethnology Impact factor: 0.278, year: 2014

  3. PERCEPTION OF MERCURY RISK INFORMATION

    Science.gov (United States)

    Approximately 8% of American women have blood Mercury levels exceeding the EPA reference dose (a dose below which symptoms would be unlikely). The children of these women are at risk of neurological deficits (lower IQ scores) primarily because of the mother's consumption of conta...

  4. A downstream voyage with mercury

    Science.gov (United States)

    Heinz, Gary

    2016-01-01

    Retrospective essay for the Bulletin of Environmental Contamination and Toxicology.As I look back on my paper, “Effects of Low Dietary Levels of Methyl Mercury on Mallard Reproduction,” published in 1974 in the Bulletin of Environmental Contamination and Toxicology, a thought sticks in my mind. I realize just how much my mercury research was not unlike a leaf in a stream, carried this way and that, sometimes stalled in an eddy, restarted, and carried downstream at a pace and path that was not completely under my control. I was hired in 1969 by the Patuxent Wildlife Research Center to study the effects of environmental pollutants on the behavior of wildlife. A colleague was conducting a study on the reproductive effects of methylmercury on mallards (Anas platyrhynchos), and he offered to give me some of the ducklings. I conducted a pilot study, testing how readily ducklings approached a tape-recorded maternal call. Sample sizes were small, but the results suggested that ducklings from mercury-treated parents behaved differently than controls. That’s how I got into mercury research—pretty much by chance.

  5. Venus and Mercury as Planets

    Science.gov (United States)

    1974-01-01

    A general evolutionary history of the solar planetary system is given. The previously observed characteristics of Venus and Mercury (i.e. length of day, solar orbit, temperature) are discussed. The role of the Mariner 10 space probe in gathering scientific information on the two planets is briefly described.

  6. Venus and Mercury as planets

    International Nuclear Information System (INIS)

    1974-01-01

    A general evolutionary history of the solar planetary system is given. The previously observed characteristics of Venus and Mercury (i.e. length of day, solar orbit, temperature) are discussed. The role of the Mariner 10 space probe in gathering scientific information on the two planets is briefly described

  7. 76 FR 75446 - Amendment of Class E Airspace; Mercury, NV

    Science.gov (United States)

    2011-12-02

    ...-0894; Airspace Docket No. 11-AWP-14] Amendment of Class E Airspace; Mercury, NV AGENCY: Federal... Mercury, Desert Rock Airport, Mercury, NV. Decommissioning of the Mercury Non-Directional Beacon (NDB) at Mercury, Desert Rock Airport has made this action necessary for the safety and management of Instrument...

  8. Structure elucidation of cresylviolet perchlorate in polyvinylbutyral by the joint application of IR, FTIR, Raman, UV and visible spectroscopy.

    Science.gov (United States)

    Bayrakçeken, Fuat; Karaaslan, Ipek S; Erol, Berkant

    2007-09-01

    Infrared, Fourier transform infrared, Raman, UV absorption and emission spectra of cresylviolet perchlorate (CV) in polyvinylbutyral (PVB) were recorded in the region 1250-4000 cm(-1) at room temperature and assignments have been made for the observed absorption emission and Raman scattered lines.

  9. Chitosan Derivatives as Important Biorefinery Intermediates. Quaternary Tetraalkylammonium Chitosan Derivatives Utilized in Anion Exchange Chromatography for Perchlorate Removal

    Directory of Open Access Journals (Sweden)

    Shakeela Sayed

    2015-04-01

    Full Text Available There has recently been great interest in the valorization of biomass waste in the context of the biorefinery. The biopolymer chitosan, derived from chitin, is present in large quantities of crustacean waste. This biomass can be converted into value-added products with applications in energy, fuel, chemicals and materials manufacturing. The many reported applications of this polymer can be attributed to its unique properties, such as biocompatibility, chemical versatility, biodegradability and low toxicity. Cost effective water filters which decontaminate water by removal of specific impurities and microbes are in great demand. To address this need, the development of ion exchange resins using environmentally friendly, renewable materials such as biopolymers as solid supports was evaluated. The identification and remediation of perchlorate contaminated water using an easy, inexpensive method has come under the spotlight recently. Similarly, the use of a low cost perchlorate selective solid phase extraction (SPE cartridge that can be rapidly employed in the field is desirable. Chitosan based SPE coupled with colorimetric analytical methods showed promise as a renewable anion exchange support for perchlorate analysis or removal. The polymers displayed perchlorate retention comparable to the commercial standard whereby the quaternized iron loaded polymer TMC-Fe(III displayed the best activity.

  10. Chitosan derivatives as important biorefinery intermediates. Quaternary tetraalkylammonium chitosan derivatives utilized in anion exchange chromatography for perchlorate removal.

    Science.gov (United States)

    Sayed, Shakeela; Jardine, Anwar

    2015-04-23

    There has recently been great interest in the valorization of biomass waste in the context of the biorefinery. The biopolymer chitosan, derived from chitin, is present in large quantities of crustacean waste. This biomass can be converted into value-added products with applications in energy, fuel, chemicals and materials manufacturing. The many reported applications of this polymer can be attributed to its unique properties, such as biocompatibility, chemical versatility, biodegradability and low toxicity. Cost effective water filters which decontaminate water by removal of specific impurities and microbes are in great demand. To address this need, the development of ion exchange resins using environmentally friendly, renewable materials such as biopolymers as solid supports was evaluated. The identification and remediation of perchlorate contaminated water using an easy, inexpensive method has come under the spotlight recently. Similarly, the use of a low cost perchlorate selective solid phase extraction (SPE) cartridge that can be rapidly employed in the field is desirable. Chitosan based SPE coupled with colorimetric analytical methods showed promise as a renewable anion exchange support for perchlorate analysis or removal. The polymers displayed perchlorate retention comparable to the commercial standard whereby the quaternized iron loaded polymer TMC-Fe(III) displayed the best activity.

  11. The effect of water content on the electropolishing behavior of Inconel 718 alloy in perchloric-acetic acid mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Huang, C A [Department of Mechanical Engineering, Chang Gung University, Taoyuan 333, Taiwan (China)], E-mail: gfehu@mail.cgu.edu.tw; Chen, Y C [Department of Mechanical Engineering, Chang Gung University, Taoyuan 333, Taiwan (China)

    2009-09-15

    The electropolishing behavior of Inconel 718 alloy was studied in perchloric-acetic acid mixtures using a rotating disc electrode. The electropolishing behavior of an Inconel 718 weld, which was prepared with electron beam welding, was also investigated. A leveled but not brightened surface can be achieved when Inconel 718 alloy is potentiostatically polished in the acid mixture with 20 vol.% perchloric acid. Interestingly, a brightening effect could be obtained in this acid mixture by adding 10-50 ml l{sup -1} water or by being at rest at room temperature for several days. When electropolishing in acid mixture with 40 vol.% perchloric acid, leveling and brightening of the Inconel 718 surface can be detected. When electropolished in this acid mixture, the fusion zone of the Inconel 718 weld cannot be leveled together with its nearby base metal. Nevertheless, a good polished surface of the Inconel 718 weld can be achieved with the acid mixture with 20 vol.% perchloric acid by adding 40 ml l{sup -1} of water. Electropolishing was performed in the limiting diffusion current region where the transport of water to the anode seemed to be the rate-determining process.

  12. Analysis of perchlorate, thiocyanate, nitrate and iodide in human amniotic fluid using ion chromatography and electrospray tandem mass spectrometry

    International Nuclear Information System (INIS)

    Blount, Benjamin C.; Valentin-Blasini, Liza

    2006-01-01

    Because of health concerns surrounding in utero exposure to perchlorate, we developed a sensitive and selective method for quantifying iodide, as well as perchlorate and other sodium-iodide symporter (NIS) inhibitors in human amniotic fluid using ion chromatography coupled with electrospray ionization tandem mass spectrometry. Iodide and NIS inhibitors were quantified using a stable isotope-labeled internal standards (Cl 18 O 4 - , S 13 CN - and 15 NO 3 - with excellent assay accuracy of 100%, 98%, 99%, 95% for perchlorate, thiocyanate, nitrate and iodide, respectively, in triplicate analysis of spiked amniotic fluid sample). Excellent analytical precision (<5.2% RSD for all analytes) was found when amniotic fluid quality control pools were repetitively analyzed for iodide and NIS-inhibitors. Selective chromatography and tandem mass spectrometry reduced the need for sample cleanup, resulting in a rugged and rapid method capable of routinely analyzing 75 samples/day. Analytical response was linear across the physiologically relevant concentration range for the analytes. Analysis of a set of 48 amniotic fluid samples identified the range and median levels for perchlorate (0.057-0.71, 0.18 μg/L), thiocyanate (<10-5860, 89 μg/L), nitrate (650-8900, 1620 μg/L) and iodide (1.7-170, 8.1 μg/L). This selective, sensitive, and rapid method will help assess exposure of the developing fetus to low levels of NIS-inhibitors and their potential to inhibit thyroid function

  13. Perchlorate, Nitrate, and Iodine Uptake and Distribution in Lettuce (Lactuca sativa L.) and Potential Impact on Background Levels in Humans

    NARCIS (Netherlands)

    Voogt, W.; Jackson, A.

    2010-01-01

    Much focus has been placed on the impact of exposure to perchlorate (ClO4-) from drinking water. Recently, it has become more apparent that a significant percentage of the total ClO4- exposure may be due to ingestion of food. Most studies have only evaluated the uptake and distribution of ClO4- by

  14. The Plasma Environment at Mercury

    Science.gov (United States)

    Raines, James M.; Gershman, Daniel J.; Zurbuchen, Thomas H.; Gloeckler, George; Slavin, James A.; Anderson, Brian J.; Korth, Haje; Krimigis, Stamatios M.; Killen, Rosemary M.; Sarantos, Menalos; hide

    2011-01-01

    Mercury is the least explored terrestrial planet, and the one subjected to the highest flux of solar radiation in the heliosphere. Its highly dynamic, miniature magnetosphere contains ions from the exosphere and solar wind, and at times may allow solar wind ions to directly impact the planet's surface. Together these features create a plasma environment that shares many features with, but is nonetheless very different from, that of Earth. The first in situ measurements of plasma ions in the Mercury space environment were made only recently, by the Fast Imaging Plasma Spectrometer (FIPS) during the MESSENGER spacecraft's three flybys of the planet in 2008-2009 as the probe was en route to insertion into orbit about Mercury earlier this year. Here. we present analysis of flyby and early orbital mission data with novel techniques that address the particular challenges inherent in these measurements. First. spacecraft structures and sensor orientation limit the FIPS field of view and allow only partial sampling of velocity distribution functions. We use a software model of FIPS sampling in velocity space to explore these effects and recover bulk parameters under certain assumptions. Second, the low densities found in the Mercury magnetosphere result in a relatively low signal-to-noise ratio for many ions. To address this issue, we apply a kernel density spread function to guide removal of background counts according to a background-signature probability map. We then assign individual counts to particular ion species with a time-of-flight forward model, taking into account energy losses in the carbon foil and other physical behavior of ions within the instrument. Using these methods, we have derived bulk plasma properties and heavy ion composition and evaluated them in the context of the Mercury magnetosphere.

  15. Chemical form matters: differential accumulation of mercury following inorganic and organic mercury exposures in zebrafish larvae.

    Science.gov (United States)

    Korbas, Malgorzata; Macdonald, Tracy C; Pickering, Ingrid J; George, Graham N; Krone, Patrick H

    2012-02-17

    Mercury, one of the most toxic elements, exists in various chemical forms each with different toxicities and health implications. Some methylated mercury forms, one of which exists in fish and other seafood products, pose a potential threat, especially during embryonic and early postnatal development. Despite global concerns, little is known about the mechanisms underlying transport and toxicity of different mercury species. To investigate the impact of different mercury chemical forms on vertebrate development, we have successfully combined the zebrafish, a well-established developmental biology model system, with synchrotron-based X-ray fluorescence imaging. Our work revealed substantial differences in tissue-specific accumulation patterns of mercury in zebrafish larvae exposed to four different mercury formulations in water. Methylmercury species not only resulted in overall higher mercury burdens but also targeted different cells and tissues than their inorganic counterparts, thus revealing a significant role of speciation in cellular and molecular targeting and mercury sequestration. For methylmercury species, the highest mercury concentrations were in the eye lens epithelial cells, independent of the formulation ligand (chloride versusl-cysteine). For inorganic mercury species, in absence of l-cysteine, the olfactory epithelium and kidney accumulated the greatest amounts of mercury. However, with l-cysteine present in the treatment solution, mercuric bis-l-cysteineate species dominated the treatment, significantly decreasing uptake. Our results clearly demonstrate that the common differentiation between organic and inorganic mercury is not sufficient to determine the toxicity of various mercury species.

  16. Chemical Form Matters: Differential Accumulation of Mercury Following Inorganic and Organic Mercury Exposures in Zebrafish Larvae

    Energy Technology Data Exchange (ETDEWEB)

    Korbas, Malgorzata; MacDonald, Tracy C.; Pickering, Ingrid J.; George, Graham N.; Krone, Patrick H. (Saskatchewan)

    2013-04-08

    Mercury, one of the most toxic elements, exists in various chemical forms each with different toxicities and health implications. Some methylated mercury forms, one of which exists in fish and other seafood products, pose a potential threat, especially during embryonic and early postnatal development. Despite global concerns, little is known about the mechanisms underlying transport and toxicity of different mercury species. To investigate the impact of different mercury chemical forms on vertebrate development, we have successfully combined the zebrafish, a well-established developmental biology model system, with synchrotron-based X-ray fluorescence imaging. Our work revealed substantial differences in tissue-specific accumulation patterns of mercury in zebrafish larvae exposed to four different mercury formulations in water. Methylmercury species not only resulted in overall higher mercury burdens but also targeted different cells and tissues than their inorganic counterparts, thus revealing a significant role of speciation in cellular and molecular targeting and mercury sequestration. For methylmercury species, the highest mercury concentrations were in the eye lens epithelial cells, independent of the formulation ligand (chloride versus L-cysteine). For inorganic mercury species, in absence of L-cysteine, the olfactory epithelium and kidney accumulated the greatest amounts of mercury. However, with L-cysteine present in the treatment solution, mercuric bis-L-cysteineate species dominated the treatment, significantly decreasing uptake. Our results clearly demonstrate that the common differentiation between organic and inorganic mercury is not sufficient to determine the toxicity of various mercury species.

  17. Mercury emission from crematories in Japan

    Directory of Open Access Journals (Sweden)

    M. Takaoka

    2010-04-01

    Full Text Available Anthropogenic sources of mercury emissions have a significant impact on global pollution. Therefore, finding uncharacterised sources and assessing the emissions from these sources are important. However, limited data are available worldwide on mercury emissions from crematories. In Japan, 99.9% of dead bodies are cremated, which is the highest percentage in the world, and more than 1600 crematories are in operation. We thus focused on emissions from crematories in Japan. The number of targeted facilities was seven, and we used continuous emission monitoring to measure the mercury concentrations and investigate mercury behaviour. The total mercury concentrations in stack gases were a few μg/Nm3 (normal cubic meters. Considering the time profile of mercury and its species in cremations, the findings confirmed that the mercury in stack gas originated from dental amalgam. The amount of mercury emissions was calculated using the total concentration and gas flow rate. Furthermore, the annual amount of mercury emission from crematories in Japan was estimated by using the total number of corpses. The emission amount was considerably lower than that estimated in the United Kingdom. From statistical analyses on population demographics and measurements, future total emissions from crematories were also predicted. As a result, the amount of mercury emitted by crematories will likely increase by 2.6-fold from 2007 to 2037.

  18. Environmental Mercury and Its Toxic Effects

    Directory of Open Access Journals (Sweden)

    Kevin M. Rice

    2014-03-01

    Full Text Available Mercury exists naturally and as a man-made contaminant. The release of processed mercury can lead to a progressive increase in the amount of atmospheric mercury, which enters the atmospheric-soil-water distribution cycles where it can remain in circulation for years. Mercury poisoning is the result of exposure to mercury or mercury compounds resulting in various toxic effects depend on its chemical form and route of exposure. The major route of human exposure to methylmercury (MeHg is largely through eating contaminated fish, seafood, and wildlife which have been exposed to mercury through ingestion of contaminated lower organisms. MeHg toxicity is associated with nervous system damage in adults and impaired neurological development in infants and children. Ingested mercury may undergo bioaccumulation leading to progressive increases in body burdens. This review addresses the systemic pathophysiology of individual organ systems associated with mercury poisoning. Mercury has profound cellular, cardiovascular, hematological, pulmonary, renal, immunological, neurological, endocrine, reproductive, and embryonic toxicological effects.

  19. Mercury emissions from municipal solid waste combustors

    Energy Technology Data Exchange (ETDEWEB)

    1993-05-01

    This report examines emissions of mercury (Hg) from municipal solid waste (MSW) combustion in the United States (US). It is projected that total annual nationwide MSW combustor emissions of mercury could decrease from about 97 tonnes (1989 baseline uncontrolled emissions) to less than about 4 tonnes in the year 2000. This represents approximately a 95 percent reduction in the amount of mercury emitted from combusted MSW compared to the 1989 mercury emissions baseline. The likelihood that routinely achievable mercury emissions removal efficiencies of about 80 percent or more can be assured; it is estimated that MSW combustors in the US could prove to be a comparatively minor source of mercury emissions after about 1995. This forecast assumes that diligent measures to control mercury emissions, such as via use of supplemental control technologies (e.g., carbon adsorption), are generally employed at that time. However, no present consensus was found that such emissions control measures can be implemented industry-wide in the US within this time frame. Although the availability of technology is apparently not a limiting factor, practical implementation of necessary control technology may be limited by administrative constraints and other considerations (e.g., planning, budgeting, regulatory compliance requirements, etc.). These projections assume that: (a) about 80 percent mercury emissions reduction control efficiency is achieved with air pollution control equipment likely to be employed by that time; (b) most cylinder-shaped mercury-zinc (CSMZ) batteries used in hospital applications can be prevented from being disposed into the MSW stream or are replaced with alternative batteries that do not contain mercury; and (c) either the amount of mercury used in fluorescent lamps is decreased to an industry-wide average of about 27 milligrams of mercury per lamp or extensive diversion from the MSW stream of fluorescent lamps that contain mercury is accomplished.

  20. Mercury exposure from interior latex paint.

    Science.gov (United States)

    Agocs, M M; Etzel, R A; Parrish, R G; Paschal, D C; Campagna, P R; Cohen, D S; Kilbourne, E M; Hesse, J L

    1990-10-18

    Many paint companies have used phenylmercuric acetate as a preservative to prolong the shelf life of interior latex paint. In August 1989, acrodynia, a form of mercury poisoning, occurred in a child exposed to paint fumes in a home recently painted with a brand containing 4.7 mmol of mercury per liter (at that time the Environmental Protection Agency's recommended limit was 1.5 mmol or less per liter). To determine whether the recent use of that brand of paint containing phenylmercuric acetate was associated with elevated indoor-air and urinary mercury concentrations, we studied 74 "exposed" persons living in 19 homes recently painted with the brand and 28 "unexposed" persons living in 10 homes not recently painted with paint containing mercury. The paint samples from the homes of exposed persons contained a median of 3.8 mmol of mercury per liter, and air samples from the homes had a median mercury content of 10.0 nmol per cubic meter (range, less than 0.5 to 49.9). No mercury was detected in paint or air samples from the homes of unexposed persons. The median urinary mercury concentration was higher in the exposed persons (4.7 nmol of mercury per millimole of creatinine; range, 1.4 to 66.5) than in the unexposed persons (1.1 nmol per millimole; range, 0.02 to 3.9; P less than 0.001). Urinary mercury concentrations within the range that we found in exposed persons have been associated with symptomatic mercury poisoning. We found that potentially hazardous exposure to mercury had occurred among persons whose homes were painted with a brand of paint containing mercury at concentrations approximately 2 1/2 times the Environmental Protection Agency's recommended limit.

  1. RECOVERY OF MERCURY FROM CONTAMINATED LIQUID WASTES

    Energy Technology Data Exchange (ETDEWEB)

    Robin M. Stewart

    1999-09-29

    Mercury was widely used in U.S. Department of Energy (DOE) weapons facilities, resulting in a broad range of mercury-contaminated wastes and wastewaters. Some of the mercury contamination has escaped to the local environment, particularly at the Y-12 Plant in Oak Ridge, Tennessee, where approximately 330 metric tons of mercury were discharged to the environment between 1953 and 1963 (TN & Associates, 1998). Effective removal of mercury contamination from water is a complex and difficult problem. In particular, mercury treatment of natural waters is difficult because of the low regulatory standards. For example, the Environmental Protection Agency has established a national ambient water quality standard of 12 parts-per-trillion (ppt), whereas the standard is 1.8 ppt in the Great Lakes Region. In addition, mercury in the environment is typically present in several different forms, but sorption processes are rarely effective with more than one or two of these forms. To meet the low regulatory discharge limits, an effective sorption process must be able to address all forms of mercury present in the water. One approach is to apply different sorbents in series depending on the mercury speciation and the regulatory discharge limits. ADA Technologies, Inc. has developed four new sorbents to address the variety of mercury species present in industrial discharges and natural waters. Three of these sorbents have been field tested on contaminated creek water at the Y-12 Plant. Two of these sorbents have been successfully demonstrated very high removal efficiencies for soluble mercury species, reducing mercury concentrations at the outlet of a pilot-scale system to less than 12 ppt for as long as six months. The other sorbent tested at the Y-12 Plant targeted colloidal mercury not removed by standard sorption or filtration processes. At the Y-12 Plant, colloidal mercury appears to be associated with iron, so a sorbent that removes mercury-iron complexes in the presence of a

  2. An Epidemiological Study of Mercury Sensitization

    Directory of Open Access Journals (Sweden)

    Kazuhiro Sato

    1997-01-01

    Full Text Available Mercury sensitization has been historically in question and may be related to recent increases of type I allergic diseases. To clarify the epidemiological factors of mercury sensitization, we investigated factors relating to mercury sensitization in 215 medical students. Their allergic symptoms, family histories and lifestyles were studied by questionnaire. Patch tests were performed with HgCI2 (0.05% aq. and NiS04 (5% aq.. Anti- Dermatophagoides and anti-Crypfomeria pollen IgE antibodies in sera were also measured. Urinary mercury concentrations were measured in 25 mercury sensitized and 44 non-sensitized subjects (controls. Hair mercury concentrations were also measured in 19 sensitized and 22 non-sensitized subjects. While the positive rate of nickel was 6.0% (13/215, that of mercury was high (13.0%; 28/215. The subjects' individual histories of allergic rhinitis, eczema, urticaria and allergic conjunctivitis were significantly associated with family histories of these conditions (P<0.01, P<0.005 and P<0.005, respectively, as reported in the literature. However, no allergen- specific antibody positivity or past history of allergic disease was associated with mercury sensitization. Mercury sensitized subjects had experienced eczema caused by cosmetics, shampoos, soaps and haircreams significantly more frequently (P<0.05. The history of mercurochrome usage was not associated with mercury sensitization. The number of teeth treated with metals in mercury sensitized subjects was significantly higher than that in the control group (6.8±4.3 vs 4.8±1; P<0.05. There were significant differences in urinary mercury concentrations (specific gravity adjusted levels between mercury sensitized subjects and non-sensitized subjects (2.0±0.9 and 1.3±0.6 (xg/L, respectively; P<0.001. There were also significant differences in hair mercury concentrations between mercury sensitized and non-sensitized subjects (2.0±0.9 and 1.2±0.5 μg/g, respectively; P<0

  3. Mercury Phase II Study - Mercury Behavior across the High-Level Waste Evaporator System

    Energy Technology Data Exchange (ETDEWEB)

    Bannochie, C. J. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Crawford, C. L. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Jackson, D. G. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Shah, H. B. [Savannah River Remediation, LLC., Aiken, SC (United States); Jain, V. [Savannah River Remediation, LLC., Aiken, SC (United States); Occhipinti, J. E. [Savannah River Remediation, LLC., Aiken, SC (United States); Wilmarth, W. R. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-06-17

    The Mercury Program team’s effort continues to develop more fundamental information concerning mercury behavior across the liquid waste facilities and unit operations. Previously, the team examined the mercury chemistry across salt processing, including the Actinide Removal Process/Modular Caustic Side Solvent Extraction Unit (ARP/MCU), and the Defense Waste Processing Facility (DWPF) flowsheets. This report documents the data and understanding of mercury across the high level waste 2H and 3H evaporator systems.

  4. Assessing Mercury and Methylmercury Bioavailability in Sediment Pore Water Using Mercury-Specific Hydrogels

    Science.gov (United States)

    2015-06-01

    FINAL REPORT Assessing Mercury and Methylmercury Bioavailability in Sediment Pore Water Using Mercury -Specific Hydrogels SERDP Project ER-1771...From - To) 2010-2015 4. TITLE AND SUBTITLE Assessing Mercury and Methylmercury Bioavailability in 5a. CONTRACT NUMBER W912HQ-10-C-0069 Sediment...Using Mercury -Specific DGTs 5b. GRANT NUMBER ER-1771 5c. PROGRAM ELEMENT NUMBER NA 6. AUTHOR(S) Magar, Victor S.*, Steenhaut, Nicholas

  5. Mercury concentrations at a historically mercury-contaminated site in KwaZulu-Natal, South Africa

    CSIR Research Space (South Africa)

    Williams, CR

    2011-02-01

    Full Text Available . Biogeochem., 43:237?257 Barrat GJ, Combrink J (2002) An Assessment of the degree of mercury (Hg) bio-transformation in two river systems following discharges from a mercury recovery plant. Water SA Special Edition: WISA Proceedings 2002 Benoit JM... in mercury and methylmercury biogeochemical cycling and bioaccumulation within shallow estuaries. PhD thesis, University of Maryland, College Park Kim E-H, Mason RP, Porter ET, Soulen HL (2006) The impact of resuspension on sediment mercury dynamics...

  6. Amended Silicated for Mercury Control

    Energy Technology Data Exchange (ETDEWEB)

    James Butz; Thomas Broderick; Craig Turchi

    2006-12-31

    Amended Silicates{trademark}, a powdered, noncarbon mercury-control sorbent, was tested at Duke Energy's Miami Fort Station, Unit 6 during the first quarter of 2006. Unit 6 is a 175-MW boiler with a cold-side electrostatic precipitator (ESP). The plant burns run-of-the-river eastern bituminous coal with typical ash contents ranging from 8-15% and sulfur contents from 1.6-2.6% on an as-received basis. The performance of the Amended Silicates sorbent was compared with that for powdered activated carbon (PAC). The trial began with a period of baseline monitoring during which no sorbent was injected. Sampling during this and subsequent periods indicated mercury capture by the native fly ash was less than 10%. After the baseline period, Amended Silicates sorbent was injected at several different ratios, followed by a 30-day trial at a fixed injection ratio of 5-6 lb/MMACF. After this period, PAC was injected to provide a comparison. Approximately 40% mercury control was achieved for both the Amended Silicates sorbent and PAC at injection ratios of 5-6 lbs/MMACF. Higher injection ratios did not achieve significantly increased removal. Similar removal efficiencies have been reported for PAC injection trials at other plants with cold-side ESPs, most notably for plants using medium to high sulfur coal. Sorbent injection did not detrimentally impact plant operations and testing confirmed that the use of Amended Silicates sorbent does not degrade fly ash quality (unlike PAC). The cost for mercury control using either PAC or Amended Silicates sorbent was estimated to be equivalent if fly ash sales are not a consideration. However, if the plant did sell fly ash, the effective cost for mercury control could more than double if those sales were no longer possible, due to lost by-product sales and additional cost for waste disposal. Accordingly, the use of Amended Silicates sorbent could reduce the overall cost of mercury control by 50% or more versus PAC for locations where

  7. Percolation of cadmium across a mercury film

    International Nuclear Information System (INIS)

    Malek, K.; Gobal, F.

    2003-01-01

    Electrodeposition/dissolution of cadmium onto a film of mercury shows some deviations from the natural liquidity of mercury caused by the reduction of Cd onto it. Percolation and fractal analyzes were done on the surface and the bulk of the mercury film during diffusion of Cd species (atoms). These show that the fractal dimensions of the Cd-inserted mercury film are about 2.11 and 2.54 near the surface of the mercury film and at deeper points inside the film, respectively. The insertion process has a negligible effect on the surface morphology of the mercury film and there is a phase transition in the bulk, as well as a geometrical transition during the Cd-insertion (de-insertion) process. This corresponds to a percolation threshold of about 0.2 mol l -1 Cd content

  8. Mercury in dated Greenland marine sediments

    DEFF Research Database (Denmark)

    Asmund, G.; Nielsen, S.P.

    2000-01-01

    Twenty marine sediment cores from Greenland were analysed for mercury, and dated by the lead-210 method. In general the cores exhibit a mercury profile with higher mercury concentrations in the upper centimetres of the core. The cores were studied by linear regression of In Hg vs, age...... of the sediment for the youngest 100 years. As a rule the mercury decreased with depth in the sediment with various degrees of significance. The increase of the mercury flux during the last 100 years is roughly a doubling. The increase may be of anthropogenic origin as it is restricted to the last 100 years....... In four cores the concentration of manganese was found also to increase in the top layers indicating diagenesis. In the other cases the higher concentrations were not accompanied by higher manganese concentrations. The mercury flux to the sediment surface was generally proportional to the Pb-210 flux...

  9. Human accumulation of mercury in Greenland

    DEFF Research Database (Denmark)

    Johansen, P.; Mulvad, G.; Pedersen, H. S.

    2007-01-01

    In the Arctic, the traditional diet exposes its people to a high intake of mercury especially from marine mammals. To determine whether the mercury is accumulated in humans, we analyzed autopsy samples of liver, kidney and spleen from adult ethnic Greenlanders who died between 1990 and 1994 from...... a wide range of causes, natural and violent. Liver, kidney and spleen samples from between 33 and 71 case subjects were analyzed for total mercury and methylmercury, and liver samples also for selenium. Metal levels in men and women did not differ and were not related to age except in one case, i.......e. for total mercury in liver, where a significant declining concentration with age was observed. The highest total mercury levels were found in kidney followed by liver and spleen. Methylmercury followed the same pattern, but levels were much lower, constituting only 19% of the total mercury concentration...

  10. Acclimation of subsurface microbial communities to mercury

    DEFF Research Database (Denmark)

    de Lipthay, Julia R; Rasmussen, Lasse D; Øregaard, Gunnar

    2008-01-01

    We studied the acclimation to mercury of bacterial communities of different depths from contaminated and noncontaminated floodplain soils. The level of mercury tolerance of the bacterial communities from the contaminated site was higher than those of the reference site. Furthermore, the level...... of mercury tolerance and functional versatility of bacterial communities in contaminated soils initially were higher for surface soil, compared with the deeper soils. However, following new mercury exposure, no differences between bacterial communities were observed, which indicates a high adaptive potential...... of the subsurface communities, possibly due to differences in the availability of mercury. IncP-1 trfA genes were detected in extracted community DNA from all soil depths of the contaminated site, and this finding was correlated to the isolation of four different mercury-resistance plasmids, all belonging...

  11. Thiosulphate assisted phytoextraction of mercury contaminated soils at the Wanshan Mercury Mining District, Southwest China

    Directory of Open Access Journals (Sweden)

    J. Wang

    2013-10-01

    Full Text Available Wanshan, known as the “Mercury Capital” of China, is located in the Southwest of China. Due to the extensive mining and smelting works in the Wanshan area, the local ecosystem has been serious contaminated with mercury. In the present study, a number of soil samples were taken from the Wanshan mercury mining area and the mercury fractionations in soils were analyzed using sequential extraction procedure technique. The obtained results showed that the dominate mercury fractions (represent 95% of total mercury were residual and organic bound mercury. A field trial was conducted in a mercury polluted farmland at the Wanshan mercury mine. Four plant species Brassica juncea Czern. et Coss.var. ASKYC (ASKYC, Brassica juncea Czern. et Coss.var.DPDH (DPDH, Brassica juncea Czern. et Coss.var.CHBD(CHBD, Brassica juncea Czern. et Coss.var.LDZY (LDZY were tested their ability to extract mercury from soil with thiosulphate amendment. The results indicated that the mercury concentration in the roots and shoots of the four plants were significantly increased with thiosulphate treatment. The mercury phytoextraction yield of ASKYC, DPDH, CHBD and LDZY were 92, 526, 294 and 129 g/ha, respectively

  12. Blood Mercury Levels of Zebra Finches Are Heritable: Implications for the Evolution of Mercury Resistance.

    Directory of Open Access Journals (Sweden)

    Kenton A Buck

    Full Text Available Mercury is a ubiquitous metal contaminant that negatively impacts reproduction of wildlife and has many other sub-lethal effects. Songbirds are sensitive bioindicators of mercury toxicity and may suffer population declines as a result of mercury pollution. Current predictions of mercury accumulation and biomagnification often overlook possible genetic variation in mercury uptake and elimination within species and the potential for evolution in affected populations. We conducted a study of dietary mercury exposure in a model songbird species, maintaining a breeding population of zebra finches (Taeniopygia guttata on standardized diets ranging from 0.0-2.4 μg/g methylmercury. We applied a quantitative genetics approach to examine patterns of variation and heritability of mercury accumulation within dietary treatments using a method of mixed effects modeling known as the 'animal model'. Significant variation in blood mercury accumulation existed within each treatment for birds exposed at the same dietary level; moreover, this variation was highly repeatable for individuals. We observed substantial genetic variation in blood mercury accumulation for birds exposed at intermediate dietary concentrations. Taken together, this is evidence that genetic variation for factors affecting blood mercury accumulation could be acted on by selection. If similar heritability for mercury accumulation exists in wild populations, selection could result in genetic differentiation for populations in contaminated locations, with possible consequences for mercury biomagnification in food webs.

  13. Radioactive mercury distribution in biological fluids and excretion in human subjects after inhalation of mercury vapor

    International Nuclear Information System (INIS)

    Cherian, M.G.; Hursh, J.B.; Clarkson, T.W.; Allen, J.

    1978-01-01

    The distribution of mercury in red blood cells (RBCs) and plasma, and its excretion in urine and feces are described in five human subjects during the first 7 days following inhalation of radioactive mercury vapor. A major portion (98%) of radioactive mercury in whole blood is initially accumulated in the RBCs and is transferred partly to the plasma compartment until the ratio of mercury in RBCs to plasma is about 2 within 20 h. The cumulative urinary and fecal excretion of mercury for 7 days is about 11.6% of the retained dose, and is closely related to the percent decline in body burden of mercury. There is little correlation between either the urinary excretion and plasma radioactivity of mercury, or the specific activities of urine and plasma mercury, suggesting a mechanism other than a direct glomerular filtration involved in the urinary excretion of recently exposed mercury. These studies suggest that blood mercury levels can be used as an index of recent exposure, while urinary levels may be an index of renal concentration of mercury. However, there is no reliable index for mercury concentration in the brain

  14. Thiosulphate assisted phytoextraction of mercury contaminated soils at the Wanshan Mercury Mining District, Southwest China

    Directory of Open Access Journals (Sweden)

    J Wang

    2013-10-01

    Full Text Available Wanshan, known as the “Mercury Capital” of China, is located in the Southwest of China. Due to the extensive mining and smelting works in the Wanshan area, the local ecosystem has been serious contaminated with mercury. In the present study, a number of soil samples were taken from the Wanshan mercury mining area and the mercury fractionations in soils were analyzed using sequential extraction procedure technique. The obtained results showed that the dominate mercury fractions (represent 95% of total mercury were residual and organic bound mercury. A field trial was conducted in a mercury polluted farmland at the Wanshan mercury mine. Four plant species Brassica juncea Czern. et Coss.var. ASKYC (ASKYC, Brassica juncea Czern. et Coss.var.DPDH (DPDH, Brassica juncea Czern. et Coss.var.CHBD(CHBD, Brassica juncea Czern. et Coss.var.LDZY (LDZY were tested their ability to extract mercury from soil with thiosulphate amendment. The results indicated that the mercury concentration in the roots and shoots of the four plants were significantly increased with thiosulphate treatment. The mercury phytoextraction yield of ASKYC, DPDH, CHBD and LDZY were 92, 526, 294 and 129 g/ha, respectively.

  15. STRESS SENSITIVITY OF MERCURY INJECTION MEASUREMENTS

    OpenAIRE

    Guise, P; Grattoni, C; Allshorn, S; Fisher, QJ; Schiffer, A

    2017-01-01

    Many petrophysical properties (e.g. permeability, electrical resistivity etc.) of tight rocks are very stress sensitive. However, most mercury injection measurements are made using an instrument that does not apply a confining pressure to the samples. Here we further explore the implications of the use and analysis of data from mercury injection porosimetry or mercury capillary pressure measurements (MICP). Two particular aspects will be discussed. First, the effective stress acting on sample...

  16. Mercury in polar bears from Alaska

    Energy Technology Data Exchange (ETDEWEB)

    Lentfer, J.W.; Galster, W.A.

    1987-04-01

    Alaskan polar bear (Ursus maritimus) muscle and liver samples collected in 1972 were analyzed for total mercury. Bears north of Alaska had more mercury than bears west of Alaska. The only difference between young and adult animals was in the northern area where adults had more mercury in liver tissue than young animals. Levels were probably not high enough to be a serious threat to bears.

  17. Process for removing mercury from aqueous solutions

    Science.gov (United States)

    Googin, John M.; Napier, John M.; Makarewicz, Mark A.; Meredith, Paul F.

    1986-01-01

    A process for removing mercury from water to a level not greater than two parts per billion wherein an anion exchange material that is insoluble in water is contacted first with a sulfide containing compound and second with a compound containing a bivalent metal ion forming an insoluble metal sulfide. To this treated exchange material is contacted water containing mercury. The water containing not more than two parts per billion of mercury is separated from the exchange material.

  18. Surface composition of Mercury from reflectance spectrophotometry

    Science.gov (United States)

    Vilas, Faith

    1988-01-01

    The controversies surrounding the existing spectra of Mercury are discussed together with the various implications for interpretations of Mercury's surface composition. Special attention is given to the basic procedure used for reducing reflectance spectrophotometry data, the factors that must be accounted for in the reduction of these data, and the methodology for defining the portion of the surface contributing the greatest amount of light to an individual spectrum. The application of these methodologies to Mercury's spectra is presented.

  19. METHOD 332.0: DETERMINATION OF PERCHLORATE IN DRINKING WATER BY ION CHROMATOGRAPHY WITH SUPPRESSED CONDUCTIVITY AND ELECTROSPRAY IONIZATION MASS SPECTROMETRY

    Science.gov (United States)

    This method is applicable to the identification and quantitation of perchlorate in raw and finished drinking waters. The approach used is ion chromatography with suppressed conductivity and electrospray ionization mass spectrometry (IC-ESI/MS)

  20. Theoretical Investigation of Oxazine 170 Perchlorate Doped Polymeric Optical Fiber Amplifier

    Directory of Open Access Journals (Sweden)

    Piotr Miluski

    2017-01-01

    Full Text Available Optical signal amplification in the waveguiding structure of optical fibers can be used for optical telecommunication systems and new light sources constructions. Organic dyes doped materials are interesting for new applications in polymeric optical fibers technology due to their benefits (efficient fluorescence, high absorption cross section, and easy processing. This article presents a numerical simulation of gain in poly(methyl methacrylate optical fiber doped by Oxazine 170 Perchlorate. The calculated gain characteristic for the used dye molar concentration (0.2·10-6–1.4·10-6 and pump power (1–10 kW is presented. The fabricated fluorescent polymeric optical fiber is also shown. The presented analysis can be used for optical amplifier construction based on dye-doped polymeric optical fiber (POF.

  1. Complexes of Th(IV) perchlorates, nitrates and thiocyanates with some heterocyclic bases

    International Nuclear Information System (INIS)

    Agarwal, R.K.; Srivastava, A.K.; Srivastava, M.; Bhakru, N.; Srivastava, T.N.

    1980-01-01

    Some Th(IV) perchlorate complexes of heterocyclic bases have been reported previously. Adducts of Th(IV) nitrates and thiocyanates with some heterocyclic N-oxides have been prepared and physico-chemical properties investigated. Comparatively little is known about the complexes of Th(IV) ion with the ligands containing nitrogen atom acting as electron donating centres. In view of this, the adducts of Th(IV) ion with certain nitrogen heterocyclic bases such as pyridine (Py), α-picoline (Pic), 2-amino pyridine (NH 2 Py), 2:4-lutidine (2,4LN), 2:6-lutidine, (2,6LN), quinoline (Q), isoquinoline (Isoq), 2,2'-bipyridine (Bipy) and 1,10-phenanthroline (Phen) were synthesised and characterised by analysis and IR absorption spectra. The results are presented and discussed. (author)

  2. Ligand isotopic exchange of tris(acetylacetonato)germanium(IV) perchlorate in organic solvents

    International Nuclear Information System (INIS)

    Nagasawa, Akira; Saito, Kazuo

    1978-01-01

    The ligand isotopic exchange between tris(acetylacetonato)germanium(IV) perchlorate and acetylacetone[ 14 C] has been studied in 1,1,2,2-tetrachloroethane (TCE), nitromethane (NM), and acetonitrile (AN), at 100 - 120 0 C. In these solvents, the rate formula was R = k[H 2 O][complex]; the concentrations of the complex, free ligand, and water in solution were in the ranges from 0.01 to 0.1 mol dm -3 . The activation enthalpies and entropies for the k's are 105, 98, and 90 kJ mol -1 ; and -25, -53, and -69 JK -1 mol -1 , in TCE, NM, and AN, respectively. Influence of acid and base concentrations, and deuterium isotope effect on the rate in AN suggest that the rate controlling step of the exchange is governed by the ease of the proton transfer between the leaving and the incoming acac - in an intermediate. (auth.)

  3. Accumulation of mercury in selected plant species grown in soils contaminated with different mercury compounds

    International Nuclear Information System (INIS)

    Su, Yi; Han, Fengxiang; Shiyab, Safwan; Chen, Jian; Monts, David L.

    2007-01-01

    The objective of our research is to screen and search for suitable plant species for phyto-remediation of mercury-contaminated soil. Currently our effort is specifically focused on mercury removal from the U.S. Department of Energy (DOE) sites, where mercury contamination is a major concern. In order to cost effectively implement mercury remediation efforts, it is necessary now to obtain an improved understanding of biological means of removing mercury and mercury compounds.. Phyto-remediation is a technology that uses various plants to degrade, extract, contain, or immobilize contaminants from soil and water. In particular, phyto-extraction is the uptake of contaminants by plant roots and translocation within the plants to shoots or leaves. Contaminants are generally removed by harvesting the plants. We have investigated phyto-extraction of mercury from contaminated soil by using some of the known metal-accumulating plants since no natural plant species with mercury hyper-accumulating properties has yet been identified. Different natural plant species have been studied for mercury uptake, accumulation, toxicity and overall mercury removal efficiency. Various mercury compounds, such as HgS, HgCl 2 , and Hg(NO 3 ) 2 , were used as contaminant sources. Different types of soil were examined and chosen for phyto-remediation experiments. We have applied microscopy and diffuse reflectance spectrometry as well as conventional analytical chemistry to monitor the phyto-remediation processes of mercury uptake, translocation and accumulation, and the physiological impact of mercury contaminants on selected plant species. Our results indicate that certain plant species, such as beard grass (Polypogon monospeliensis), accumulated a very limited amount of mercury in the shoots ( 2 powder, respectively; no visual stress symptoms were observed. We also studied mercury phyto-remediation using aged soils that contained HgS, HgCl 2 , or Hg(NO 3 ) 2 . We have found that up to hundreds

  4. Collective Ion-Pair Single-Drop Microextraction Attenuated Total Reflectance Fourier Transform Infrared Spectroscopic Determination of Perchlorate in Bioenvironmental Samples.

    Science.gov (United States)

    Chandrawanshi, Swati; Verma, Santosh K; Deb, Manas K

    2017-09-28

    Perchlorate (ClO₄ - ) is an environmental pollutant that affects human health. Perchlorate acts as a competitive inhibitor of iodine uptake in the thyroid gland (sodium-iodide symporter inhibitor); thus, its determination is important for public health concerns. Water and milk constitute a significant portion of the human diet. Because regular intake leads to an increase in perchlorate concentration in the human body, the estimation of perchlorate is of great concern. In this work, ion-pair single-drop microextraction (SDME) combined with attenuated total reflectance (ATR)-FTIR spectroscopy has been developed for the determination of perchlorate in bioenvironmental (soil, water, dairy milk, breast milk, and urine) samples. Perchlorate was extracted in a single drop of methyl isobutyl ketone as an - with the cationic surfactant cetyltrimethylammonuim bromide under optimized conditions. The strongest IR peak (at 1076 cm -1 ) was selected for the quantification of perchlorate among three observed vibrational peaks. Eight calibration curves for different concentration ranges of perchlorate were prepared, and excellent linearity was observed for absorbance and peak area in the range of 0.03-100 ng/mL perchlorate, with r values of 0.977 and 0.976, respectively. The RSDs ( n = 8) for the perchlorate concentration ranges of 0.03-100, 0.03-0.5, 0.5-10, and 10-100 ng/mL were in the range of 1.9-2.7% for the above calibration curves. The LOD and LOQ in the present work were 0.003 and 0.02 ng/mL, respectively. The extracted microdrop was analyzed directly by ATR-FTIR spectroscopy. The parameters affecting SDME, i.e, effect of pH, stirring rate, reagent concentration, microdrop volume, and extraction time, were optimized, and the role of foreign species was also investigated. F - and t -tests were performed to check the analytical QA of the method. A noteworthy feature of the reported method is the noninterference of any of the associated ions. The results were compared with

  5. The Messenger Mission to Mercury

    CERN Document Server

    Domingue, D. L

    2007-01-01

    NASA’s MESSENGER mission, launched on 3 August, 2004 is the seventh mission in the Discovery series. MESSENGER encounters the planet Mercury four times, culminating with an insertion into orbit on 18 March 2011. It carries a comprehensive package of geophysical, geological, geochemical, and space environment experiments to complete the complex investigations of this solar-system end member, which begun with Mariner 10. The articles in this book, written by the experts in each area of the MESSENGER mission, describe the mission, spacecraft, scientific objectives, and payload. The book is of interest to all potential users of the data returned by the MESSENGER mission, to those studying the nature of the planet Mercury, and by all those interested in the design and implementation of planetary exploration missions.

  6. Augustus as Mercury at last

    Directory of Open Access Journals (Sweden)

    Paulo Martins

    2017-07-01

    Full Text Available My purpose in this paper is to investigate and to analyse the representation of Augustus as Mercury, and what this association may suggest and mean to the Romans from both the urbs and the prouinciae, focusing the epigraphy, the numismatic, and the literature. Furthermore, I review three researches that someway work this problem: Bandinelli, Zanker and Martins. Even though the associations between divinities and rulers were very common – Augustus represented as Apollo, Jupiter or Neptune; Tiberius as Apollo; Claudius as Jupiter; or Commodus as Hercules –, the discussion on the relationship between Augustus and Mercury is very rare in recent bibliography. The latest relevant research on this subject dates back to the first half of the twentieth century. Chittenden’s work on numismatic and Grether’s article on epigraphy are both very important. Thus, new evidences must be considered, so that we can further investigate these representations in the Roman world.

  7. Mercury dosing solutions for fluorescent lamps

    Energy Technology Data Exchange (ETDEWEB)

    Corazza, A; Boffito, C [SAES Getters S.p.A., Viale Italia 77, Lainate (MI) 20020 (Italy)], E-mail: alessio_corazza@saes-group.com

    2008-07-21

    A review of the different technologies used to dose mercury in fluorescent lamps is presented. Conventional liquid mercury dosing is gradually being replaced with more reliable and environmentally friendly solutions that enable a significant reduction of the amount of mercury introduced in the lamp, so as to cope with more stringent regulations issued to minimize the environmental impact of exhausted lamps. This paper will review the most advanced novel methods to assure an accurate and fine dosing of mercury in fluorescent lamps, especially focusing on solutions based on the use of solid alloys.

  8. Sorbents for mercury removal from flue gas

    Energy Technology Data Exchange (ETDEWEB)

    Granite, Evan J.; Hargis, Richard A.; Pennline, Henry W.

    1998-01-01

    A review of the various promoters and sorbents examined for the removal of mercury from flue gas is presented. Commercial sorbent processes are described along with the chemistry of the various sorbent-mercury interactions. Novel sorbents for removing mercury from flue gas are suggested. Since activated carbons are expensive, alternate sorbents and/or improved activated carbons are needed. Because of their lower cost, sorbent development work can focus on base metal oxides and halides. Additionally, the long-term sequestration of the mercury on the sorbent needs to be addressed. Contacting methods between the flue gas and the sorbent also merit investigation.

  9. Risk assessment of mercury contaminated sites

    International Nuclear Information System (INIS)

    Hempel, M.

    1993-01-01

    At two sites, highly contaminated with mercury, risk assessment was executed. Methods were developed to determine organomercury compounds in water, air and soil. Toxicity tests demonstrated the high toxicity of organomercury compounds compared to inorganic mercury. Besides highly toxic methylmercury, ethylmercury was found in soils close to a chemical plant in Marktredwitz. In ultrafiltration-experiments mercury showed great affinity to high molecular substances in water. Lysimeter-experiments proved, that organomercury compounds are adsorbed and transformed to inorganic and elemental mercury. (orig.) [de

  10. Alkaline sorbent injection for mercury control

    Science.gov (United States)

    Madden, Deborah A.; Holmes, Michael J.

    2002-01-01

    A mercury removal system for removing mercury from combustion flue gases is provided in which alkaline sorbents at generally extremely low stoichiometric molar ratios of alkaline earth or an alkali metal to sulfur of less than 1.0 are injected into a power plant system at one or more locations to remove at least between about 40% and 60% of the mercury content from combustion flue gases. Small amounts of alkaline sorbents are injected into the flue gas stream at a relatively low rate. A particulate filter is used to remove mercury-containing particles downstream of each injection point used in the power plant system.

  11. Apparatus for isotopic alteration of mercury vapor

    Science.gov (United States)

    Grossman, Mark W.; George, William A.; Marcucci, Rudolph V.

    1988-01-01

    An apparatus for enriching the isotopic Hg content of mercury is provided. The apparatus includes a reactor, a low pressure electric discharge lamp containing a fill including mercury and an inert gas. A filter is arranged concentrically around the lamp. In a preferred embodiment, constant mercury pressure is maintained in the filter by means of a water-cooled tube that depends from it, the tube having a drop of mercury disposed in it. The reactor is arranged around the filter, whereby radiation from said lamp passes through the filter and into said reactor. The lamp, the filter and the reactor are formed of a material which is transparent to ultraviolet light.

  12. Identification of elemental mercury in the subsurface

    Science.gov (United States)

    Jackson, Dennis G

    2015-01-06

    An apparatus and process is provided for detecting elemental mercury in soil. A sacrificial electrode of aluminum is inserted below ground to a desired location using direct-push/cone-penetrometer based equipment. The insertion process removes any oxides or previously found mercury from the electrode surface. Any mercury present adjacent the electrode can be detected using a voltmeter which indicates the presence or absence of mercury. Upon repositioning the electrode within the soil, a fresh surface of the aluminum electrode is created allowing additional new measurements.

  13. Coal fired flue gas mercury emission controls

    International Nuclear Information System (INIS)

    Wu, Jiang; Pan, Weiguo; Cao, Yan; Pan, Weiping

    2015-01-01

    Mercury (Hg) is one of the most toxic heavy metals, harmful to both the environment and human health. Hg is released into the atmosphere from natural and anthropogenic sources and its emission control has caused much concern. This book introduces readers to Hg pollution from natural and anthropogenic sources and systematically describes coal-fired flue gas mercury emission control in industry, especially from coal-fired power stations. Mercury emission control theory and experimental research are demonstrated, including how elemental mercury is oxidized into oxidized mercury and the effect of flue gas contents on the mercury speciation transformation process. Mercury emission control methods, such as existing APCDs (air pollution control devices) at power stations, sorbent injection, additives in coal combustion and photo-catalytic methods are introduced in detail. Lab-scale, pilot-scale and full-scale experimental studies of sorbent injection conducted by the authors are presented systematically, helping researchers and engineers to understand how this approach reduces the mercury emissions in flue gas and to apply the methods in mercury emission control at coal-fired power stations.

  14. Ocular disorders among workers exposed to mercury.

    Science.gov (United States)

    Gabal, M S; Raslan, O A

    1995-01-01

    Mercury vapor exposed workers may show ocular changes, as well as other systems affection. A sample of 84 workers in preparing mercury fulminate were examined for conjunctival corneal and lenticular manifestation of long duration exposure, together with mercury urinary output. Lens changes were found in 50% of the involved workers while keratopathy as recorded in 34.5% of them. No statistically significant association was found between the occurrence of eye lesions and levels of urinary elimination of mercury. These results suggest local absorption of this element is most probably the underlying cause of ocular affection.

  15. Increased mercury emissions from modern dental amalgams.

    Science.gov (United States)

    Bengtsson, Ulf G; Hylander, Lars D

    2017-04-01

    All types of dental amalgams contain mercury, which partly is emitted as mercury vapor. All types of dental amalgams corrode after being placed in the oral cavity. Modern high copper amalgams exhibit two new traits of increased instability. Firstly, when subjected to wear/polishing, droplets rich in mercury are formed on the surface, showing that mercury is not being strongly bonded to the base or alloy metals. Secondly, high copper amalgams emit substantially larger amounts of mercury vapor than the low copper amalgams used before the 1970s. High copper amalgams has been developed with focus on mechanical strength and corrosion resistance, but has been sub-optimized in other aspects, resulting in increased instability and higher emission of mercury vapor. This has not been presented to policy makers and scientists. Both low and high copper amalgams undergo a transformation process for several years after placement, resulting in a substantial reduction in mercury content, but there exist no limit for maximum allowed emission of mercury from dental amalgams. These modern high copper amalgams are nowadays totally dominating the European, US and other markets, resulting in significant emissions of mercury, not considered when judging their suitability for dental restoration.

  16. Side effects of mercury in dental amalgam

    Directory of Open Access Journals (Sweden)

    Titiek Berniyanti

    2008-03-01

    Full Text Available Dental amalgam is an alloy composed of mixture of approximately equal parts of elemental liquid mercury and an alloy powder. The popularity of amalgam arises from excellent long term performance, ease of use and low cost. Despite the popularity of dental amalgam as restorative material, there have been concerns regarding the potential adverse health and environmental effects arising from exposure to mercury in amalgam. They have long been believed to be of little significance as contributors to the overall body burden of mercury, because the elemental form of mercury is rapidly consumed in the setting reaction of the restoration. In 1997, 80% of dentist in Indonesia still using amalgam as an alternative material, and 60% of them treat the rest of unused amalgam carelessly. In recent years, the possible environmental and health impact caused by certain routines in dental practice has attracted attention among regulators. As part of point source reduction strategies, the discharge of mercury/amalgam-contaminated wastes has been regulated in a number of countries, even though it has been documented that by adopting appropriate mercury hygiene measures, the impact of amalgam use in dentistry is minimal. The purpose of this paper is to examine on studies that relate mercury levels in human to the presence of dental amalgams. It is concluded that even though mercury used in filling is hazardous, if normal occupational recommendations for proper mercury hygiene routines and source of reduction strategies are followed, no occupational health risk can be assumed.

  17. Observations of Mercury in 1988 and 1989

    International Nuclear Information System (INIS)

    Schmude, R.W. Jr.

    1990-01-01

    A visual study of the planet Mercury was carried out in May 1988 and in April and May 1989. Most of the observations were made with the 35.5-cm telescope at the Texas A ampersand M University Observatory. This report presents drawings and a map of Mercury that covers the longitude range of 195-285 deg. One important finding was that a polarizing filter combined with color filters gives a sharper view of the planet. It is also concluded that high-resolution images of Mercury's terminator, either as seen from the earth or with the Hubble Space Telescope, can provide information about Mercury's topography. 10 refs

  18. Phytoremediation of Ionic and Methyl Mercury Pollution

    Energy Technology Data Exchange (ETDEWEB)

    Meagher, Richard B.

    2005-06-01

    Phytoremediation is defined as the use of plants to extract, resist, detoxify, and/or sequester toxic environmental pollutants. The long-term goal of the proposed research is to develop and test highly productive, field-adapted plant species that have been engineered for the phytoremediation of mercury. A variety of different genes, which should enable plants to clean mercury polluted sites are being tested as tools for mercury phytoremediation, first in model laboratory plants and then in potential field species. Several of these genes have already been shown to enhance mercury phytoremediation. Mercury pollution is a serious, world-wide problem affecting the health of human and wildlife populations. Environmentally, the most serious mercury threat is the production of methylmercury (CH3Hg+) by native bacteria at mercury contaminated wetland sites. Methylmercury is inherently more toxic than metallic (Hg(0)) or ionic (Hg(II)) mercury, and because methylmercury is prolifically biomagnified up the food chain, it poses the most immediate danger to animal populations. We have successfully engineered two model plants, Arabidopsis and tobacco, to use the bacterial merB gene to convert methylmercury to less toxic ionic mercury and to use the bacterial merA gene to further detoxify ionic mercury to the least toxic form of mercury, metallic mercury. Plants expressing both MerA and MerB proteins detoxify methylmercury in two steps to the metallic form. These plants germinate, grow, and set seed at normal growth rates on levels of methylmercury or ionic mercury that are lethal to normal plants. Our newest efforts involve engineering plants with several additional bacterial and plant genes that allow for higher levels of mercury resistance and mercury hyperaccumulation. The potential for these plants to hyperaccumulate mercury was further advanced by developing constitutive, aboveground, and root-specific gene expression systems. Our current strategy is to engineer plants to

  19. EDITORIAL: Mercury-free discharges for lighting

    Science.gov (United States)

    Haverlag, M.

    2007-07-01

    This special Cluster of articles in Journal of Physics D: Applied Physics covers the subject of mercury-free discharges that are being investigated by different light source researchers, as an alternative to existing mercury-containing lamps. The main driving force to move away from mercury-containing discharge light sources is connected to the environmentally unfriendly nature of mercury. After inhalation or direct contact, severe mercury exposure can lead to damage to human brain cells, the kidneys, the liver and the nervous system. For this reason, the use of mercury in products is becoming more and more restricted by different governmental bodies. In the lighting industry, however, many products still make use of mercury, for different reasons. The main reason is that mercury-containing products are, in most cases, more efficient than mercury-free products. For a realistic comparison of the environmental impact, the mercury-contamination due to electricity production must be taken into account, which depends on the type of fuel being used. For an average European fuel-mix, the amount of mercury that is released into the environment is around 29 μg kWh-1. This means that a typical 30 W TL lamp during a lifetime of 20,000 hours will release a total of about 20 mg mercury due to electricity production, which exceeds the total mercury dose in the lamp (more and more of which is being recycled) by a factor of 5-10 for a modern TL lamp. This illustrates that, quite apart from other environmental arguments like increased CO2 production, mercury-free alternatives that use more energy can in fact be detrimental for the total mercury pollution over the lifetime of the lamp. For this reason, the lighting industry has concentrated on lowering the mercury content in lamps as long as no efficient alternatives exist. Nevertheless, new initiatives for HID lamps and fluorescent lamps with more or less equal efficiency are underway, and a number of them are described in this

  20. Rapid Monitoring of Mercury in Air from an Organic Chemical Factory in China Using a Portable Mercury Analyzer

    OpenAIRE

    Yasutake, Akira; Cheng, Jin Ping; Kiyono, Masako; Uraguchi, Shimpei; Liu, Xiaojie; Miura, Kyoko; Yasuda, Yoshiaki; Mashyanov, Nikolay

    2011-01-01

    A chemical factory, using a production technology of acetaldehyde with mercury catalysis, was located southeast of Qingzhen City in Guizhou Province, China. Previous research showed heavy mercury pollution through an extensive downstream area. A current investigation of the mercury distribution in ambient air, soils, and plants suggests that mobile mercury species in soils created elevated mercury concentrations in ambient air and vegetation. Mercury concentrations of up to 600 ng/m3 in air o...

  1. Multiscale geomorphometric modeling of Mercury

    Science.gov (United States)

    Florinsky, I. V.

    2018-02-01

    Topography is one of the key characteristics of a planetary body. Geomorphometry deals with quantitative modeling and analysis of the topographic surface and relationships between topography and other natural components of landscapes. The surface of Mercury is systematically studied by interpretation of images acquired during the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) mission. However, the Mercurian surface is still little explored by methods of geomorphometry. In this paper, we evaluate the Mercury MESSENGER Global DEM MSGR_DEM_USG_SC_I_V02 - a global digital elevation model (DEM) of Mercury with the resolution of 0.015625° - as a source for geomorphometric modeling of this planet. The study was performed at three spatial scales: the global, regional (the Caloris basin), and local (the Pantheon Fossae area) ones. As the initial data, we used three DEMs of these areas with resolutions of 0.25°, 0.0625°, and 0.015625°, correspondingly. The DEMs were extracted from the MESSENGER Global DEM. From the DEMs, we derived digital models of several fundamental morphometric variables, such as: slope gradient, horizontal curvature, vertical curvature, minimal curvature, maximal curvature, catchment area, and dispersive area. The morphometric maps obtained represent peculiarities of the Mercurian topography in different ways, according to the physical and mathematical sense of a particular variable. Geomorphometric models are a rich source of information on the Mercurian surface. These data can be utilized to study evolution and internal structure of the planet, for example, to visualize and quantify regional topographic differences as well as to refine geological boundaries.

  2. The Effect of Mars-relevant Minerals on the Water Uptake of Magnesium Perchlorate and Implications for the Near-surface of Mars

    Science.gov (United States)

    Primm, Katherine; Gough, Raina; Rivera-Valentin, Edgard G.; Tolbert, Margaret

    2017-10-01

    The water uptake and release by hygroscopic salts such as perchlorate has been well studied in the decade since they were first discovered on the surface of Mars. However, there have been few studies on the effect of the insoluble regolith minerals on this well documented interaction of perchlorate and water vapor. In this work, we investigate the effect that two insoluble Mars-relevant minerals, montmorillonite and Mojave Mars Simulant (MMS), have on the water uptake (deliquescence), ice formation, and recrystallization (efflorescence) of pure magnesium perchlorate. We studied mixtures of equal parts (by mass) magnesium perchlorate hexahydrate and either montmorillonite or MMS. Although montmorillonite and MMS are insoluble minerals that may serve as nuclei for either ice nucleation or salt efflorescence, we find that these minerals did not affect any of the phase transitions of magnesium perchlorate. The salt-mineral mixture behaved like pure magnesium perchlorate in all cases, with stable deliquescence as well as metastable brine supersaturation and supercooling observed. Experiments were performed in both N2 and CO2 atmospheres, with no detectable difference. We use data from the Rover Environmental Monitoring Station instrument on MSL and from the Thermal and Electrical Conductivity Probe instrument on Phoenix, as well as modeling of the shallow subsurface near the rover and lander, to determine the likelihood of liquid water and water ice at Gale Crater and the Phoenix landing site.

  3. Acute and chronic activity of perchlorate and hexavalent chromium contamination on the survival and development of Culex quinquefasciatus Say (Diptera: Culicidae)

    Energy Technology Data Exchange (ETDEWEB)

    Sorensen, Mary A. [Department of Entomology, University of California, Riverside, CA 92521 (United States)]. E-mail: mary.sorensen@email.ucr.edu; Jensen, Peter D. [Department of Entomology, University of California, Riverside, CA 92521 (United States); Walton, William E. [Department of Entomology, University of California, Riverside, CA 92521 (United States); Trumble, John T. [Department of Entomology, University of California, Riverside, CA 92521 (United States)

    2006-12-15

    Effects of water contamination with perchlorate and hexavalent chromium [Cr (VI)] on the mosquito Culex quinquefasciatus were assessed. The chronic (10-day) LC{sub 5}s values for perchlorate and chromium were 74 {+-} 8.0 mg/L and 0.41 {+-} 0.15 mg/L, respectively. Relative Growth Index, a measure of growth and mortality rates in a population, was significantly reduced within 5 days for levels of perchlorate as low as 25 mg/L and for levels of chromium as low as 0.16 mg/L. Neither compound altered wing length of surviving adults. In combination, contaminants were synergistic, causing 14% more mortality than predicted. Acute (24-h) LC{sub 5} values for perchlorate and Cr (VI) were 17,000 {+-} 3200 and 38 {+-} 1.3 mg/L, respectively. Effects on mosquito larvae in contaminated environments are likely to be observed for Cr (VI) but not for perchlorate, which generally does not occur at levels as high as those shown here to affect larval mosquitoes. - While pollution with hexavalent chromium may adversely affect Culex quinquefasciatus larvae, levels of perchlorate currently in the environment will not impact these insects.

  4. Crystal structure of aqua(perchloratobis[μ-(E-2-({[2-(pyridin-2-ylethyl]imino}methylphenolato-κ4N,N′,O:O]dicopper(II perchlorate

    Directory of Open Access Journals (Sweden)

    Ugochukwu Okeke

    2017-11-01

    Full Text Available The title compound, [Cu2(ClO4(C14H13N2O2(H2O]ClO4, crystallizes as an unsymmetrical dinuclear cation bridged by the phenoxy O atoms with one CuII atom coordinated by a water molecule and the other by a perchlorate anion, thus making both CuII atoms five-coordinate, and with a further perchlorate anion present for charge balance. A long interaction [2.9893 (5 Å] between one of the two CuII atoms and an O atom of the perchlorate counter-ion links the cations and anions into linear chains along the a-axis direction. In addition, the water H atoms link with the perchlorate counter-ion. These interactions, along with numerous C—H...O interactions between the tetrahedral perchlorate anions, link the ions into a complex three-dimensional array. One of the perchlorate anions is disordered over two conformations with occupancies of 0.586 (4 and 0.414 (4.

  5. Maternal transfer of mercury to songbird eggs.

    Science.gov (United States)

    Ackerman, Joshua T; Hartman, C Alex; Herzog, Mark P

    2017-11-01

    We evaluated the maternal transfer of mercury to eggs in songbirds, determined whether this relationship differed between songbird species, and developed equations for predicting mercury concentrations in eggs from maternal blood. We sampled blood and feathers from 44 house wren (Troglodytes aedon) and 34 tree swallow (Tachycineta bicolor) mothers and collected their full clutches (n = 476 eggs) within 3 days of clutch completion. Additionally, we sampled blood and feathers from 53 tree swallow mothers and randomly collected one egg from their clutches (n = 53 eggs) during mid to late incubation (6-10 days incubated) to evaluate whether the relationship varied with the timing of sampling the mother's blood. Mercury concentrations in eggs were positively correlated with mercury concentrations in maternal blood sampled at (1) the time of clutch completion for both house wrens (R 2  = 0.97) and tree swallows (R 2  = 0.97) and (2) during mid to late incubation for tree swallows (R 2  = 0.71). The relationship between mercury concentrations in eggs and maternal blood did not differ with the stage of incubation when maternal blood was sampled. Importantly, the proportion of mercury transferred from mothers to their eggs decreased substantially with increasing blood mercury concentrations in tree swallows, but increased slightly with increasing blood mercury concentrations in house wrens. Additionally, the proportion of mercury transferred to eggs at the same maternal blood mercury concentration differed between species. Specifically, tree swallow mothers transferred 17%-107% more mercury to their eggs than house wren mothers over the observed mercury concentrations in maternal blood (0.15-1.92 μg/g ww). In contrast, mercury concentrations in eggs were not correlated with those in maternal feathers and, likewise, mercury concentrations in maternal blood were not correlated with those in feathers (all R 2  mercury concentrations from maternal blood to eggs

  6. Recovery of Mercury From Contaminated Liquid Wastes

    International Nuclear Information System (INIS)

    1998-01-01

    The Base Contract program emphasized the manufacture and testing of superior sorbents for mercury removal, testing of the sorption process at a DOE site, and determination of the regeneration conditions in the laboratory. During this project, ADA Technologies, Inc. demonstrated the following key elements of a successful regenerable mercury sorption process: (1) sorbents that have a high capacity for dissolved, ionic mercury; (2) removal of ionic mercury at greater than 99% efficiency; and (3) thermal regeneration of the spent sorbent. ADA's process is based on the highly efficient and selective sorption of mercury by noble metals. Contaminated liquid flows through two packed columns that contain microporous sorbent particles on which a noble metal has been finely dispersed. A third column is held in reserve. When the sorbent is loaded with mercury to the point of breakthrough at the outlet of the second column, the first column is taken off-line and the flow of contaminated liquid is switched to the second and third columns. The spent column is regenerated by heating. A small flow of purge gas carries the desorbed mercury to a capture unit where the liquid mercury is recovered. Laboratory-scale tests with mercuric chloride solutions demonstrated the sorbents' ability to remove mercury from contaminated wastewater. Isotherms on surrogate wastes from DOE's Y-12 Plant in Oak Ridge, Tennessee showed greater than 99.9% mercury removal. Laboratory- and pilot-scale tests on actual Y-12 Plant wastes were also successful. Mercury concentrations were reduced to less than 1 ppt from a starting concentration of 1,000 ppt. The treatment objective was 50 ppt. The sorption unit showed 10 ppt discharge after six months. Laboratory-scale tests demonstrated the feasibility of sorbent regeneration. Results show that sorption behavior is not affected after four cycles

  7. Worldwide trend of atmospheric mercury since 1995

    Directory of Open Access Journals (Sweden)

    F. Slemr

    2011-05-01

    Full Text Available Concern about the adverse effects of mercury on human health and ecosystems has led to tightening emission controls since the mid 1980s. But the resulting mercury emissions reductions in many parts of the world are believed to be offset or even surpassed by the increasing emissions in rapidly industrializing countries. Consequently, concentrations of atmospheric mercury are expected to remain roughly constant. Here we show that the worldwide atmospheric mercury concentrations have decreased by about 20 to 38 % since 1996 as indicated by long-term monitoring at stations in the Southern and Northern Hemispheres combined with intermittent measurements of latitudinal distribution over the Atlantic Ocean. The total reduction of the atmospheric mercury burden of this magnitude within 14 years is unusually large among most atmospheric trace gases and is at odds with the current mercury emission inventories with nearly constant anthropogenic emissions over this period. This suggests a major shift in the biogeochemical cycle of mercury including oceans and soil reservoirs. Decreasing reemissions from the legacy of historical mercury emissions are the most likely explanation for this decline since the hypothesis of an accelerated oxidation rate of elemental mercury in the atmosphere is not supported by the observed trends of other trace gases. Acidification of oceans, climate change, excess nutrient input and pollution may also contribute by their impact on the biogeochemistry of ocean and soils. Consequently, models of the atmospheric mercury cycle have to include soil and ocean mercury pools and their dynamics to be able to make projections of future trends.

  8. Mercury Methylation and Detoxification by Novel Microorganisms in Mercury Enriched Mesothermal Springs

    Science.gov (United States)

    Gionfriddo, C. M.; Krabbenhoft, D. P.; Stott, M.; Wick, R. R.; Schultz, M. B.; Holt, K. E.; Moreau, J. W.

    2015-12-01

    Hot springs and fumaroles release significant quantities of aqueous and gaseous mercury into the environment. Yet few studies have looked at the microbial underpinnings of mercury transformations in geothermal settings. Recent advancements in culture-independent molecular techniques, such as ultra-high-throughput sequencing, allow us to delve deeply into the functional and phylogenetic make-up of these extreme environments. Here we present results from deep metagenomic sequencing of geothermal microbial communities cycling mercury, focussing on the connections between putative metabolisms and mercury methylation, and the evolution of the mer-operon. Presented are data from two adjacent, acidic (pHNew Zealand), extremely enriched in total mercury (>1000 ng L-1), and varying methylmercury concentrations (1-10 ng L-1). Microbial communities of both springs are dominated by mercury resistant acidophilic, sulfur- and iron-cycling microbes: Acidithiobacillus, Thiomonas, and Thermoplasma. Mercury methylation genes (hgcAB) were only detected in the cooler spring (ΔT~10 °C), with an order of magnitude greater methylmercury (10 ng L-1). The hgcAB genes have no known closest relatives (40°C), and methylmercury concentration. We conclude that the relative amount of mercury methylation in each hot spring is controlled by the presence of methylating bacteria and archaea, the release of bioavailable mercury species from sulfide minerals, counterbalanced by microbial mercury demethylation and reduction and mercury sulfide mineralization.

  9. Mercury rising : mercury emissions from Ontario Power Generation's coal-fired plants

    International Nuclear Information System (INIS)

    Rang, S.

    2004-09-01

    Ontario Power Generation (OPG) operates 5 coal-fired power plants which are the largest single source of mercury emissions in Ontario. Mercury is a persistent, bioaccumulative neurotoxin which is considered toxic under the Canadian Environmental Protection Act. This report examines the health and environmental impacts of mercury, and the trends for mercury emission in Ontario. In 2002, the 5 coal-fired plants emitted 527 kg of mercury into the atmosphere and contributed 39 per cent of the total amount of mercury emitted into the air. While many other sectors have reduced their mercury emissions since 1988, Ontario's coal-fired plants have lagged behind and have actually increased mercury emissions by 16 per cent since 1988. This paper suggests that phasing out OPG coal-fired plants by 2007 could lead to a 39 per cent reduction in airborne mercury emissions. It would also allow Ontario to achieve the Canada Wide Standard for mercury emissions 3 years early, and would help both Ontario and Canada meet air pollution reduction commitments under international agreements. It was noted that phasing out coal-fired power plants by one-third will help Ontario achieve its goal of a 90 per cent reduction in mercury emissions by 2010. It was suggested that alternative power sources can offer a wide range of environmental advantages. 16 refs., 3 tabs., 2 figs

  10. Mercury(II) and methyl mercury speciation on Streptococcus pyogenes loaded Dowex Optipore SD-2

    Energy Technology Data Exchange (ETDEWEB)

    Tuzen, Mustafa, E-mail: m.tuzen@gmail.com [Gaziosmanpasa University, Faculty of Science and Arts, Chemistry Department, 60250 Tokat (Turkey); Uluozlu, Ozgur Dogan [Gaziosmanpasa University, Faculty of Science and Arts, Chemistry Department, 60250 Tokat (Turkey); Karaman, Isa [Gaziosmanpasa University, Faculty of Science and Arts, Biology Department, 60250 Tokat (Turkey); Soylak, Mustafa [Erciyes University, Faculty of Science and Arts, Chemistry Department, 38039 Kayseri (Turkey)

    2009-09-30

    A solid phase extraction procedure based on speciation of mercury(II) and methyl mercury on Streptococcus pyogenes immobilized on Dowex Optipore SD-2 has been established. Selective and sequential elution with 0.1 mol L{sup -1} HCl for methyl mercury and 2 mol L{sup -1} HCl for mercury(II) were performed at pH 8. The determination of mercury levels was performed by cold vapour atomic absorption spectrometry (CVAAS). Optimal analytical conditions including pH, amounts of biosorbent, sample volumes, etc., were investigated. The influences of the some alkaline and earth alkaline ions and some transition metals on the recoveries were also investigated. The capacity of biosorbent for mercury(II) and methyl mercury was 4.8 and 3.4 mg g{sup -1}. The detection limit (3 sigma) of the reagent blank for mercury(II) and methyl mercury was 2.1 and 1.5 ng L{sup -1}. Preconcentration factor was calculated as 25. The relative standard deviations of the procedure were below 7%. The validation of the presented procedure is performed by the analysis of standard reference material (NRCC-DORM 2 Dogfish Muscle). The procedure was successfully applied to the speciation of mercury(II) and methyl mercury in natural water and environmental samples.

  11. Mercury(II) and methyl mercury speciation on Streptococcus pyogenes loaded Dowex Optipore SD-2

    International Nuclear Information System (INIS)

    Tuzen, Mustafa; Uluozlu, Ozgur Dogan; Karaman, Isa; Soylak, Mustafa

    2009-01-01

    A solid phase extraction procedure based on speciation of mercury(II) and methyl mercury on Streptococcus pyogenes immobilized on Dowex Optipore SD-2 has been established. Selective and sequential elution with 0.1 mol L -1 HCl for methyl mercury and 2 mol L -1 HCl for mercury(II) were performed at pH 8. The determination of mercury levels was performed by cold vapour atomic absorption spectrometry (CVAAS). Optimal analytical conditions including pH, amounts of biosorbent, sample volumes, etc., were investigated. The influences of the some alkaline and earth alkaline ions and some transition metals on the recoveries were also investigated. The capacity of biosorbent for mercury(II) and methyl mercury was 4.8 and 3.4 mg g -1 . The detection limit (3 sigma) of the reagent blank for mercury(II) and methyl mercury was 2.1 and 1.5 ng L -1 . Preconcentration factor was calculated as 25. The relative standard deviations of the procedure were below 7%. The validation of the presented procedure is performed by the analysis of standard reference material (NRCC-DORM 2 Dogfish Muscle). The procedure was successfully applied to the speciation of mercury(II) and methyl mercury in natural water and environmental samples.

  12. Human Exposure and Health Effects of Inorganic and Elemental Mercury

    Science.gov (United States)

    Zheng, Wei

    2012-01-01

    Mercury is a toxic and non-essential metal in the human body. Mercury is ubiquitously distributed in the environment, present in natural products, and exists extensively in items encountered in daily life. There are three forms of mercury, i.e., elemental (or metallic) mercury, inorganic mercury compounds, and organic mercury compounds. This review examines the toxicity of elemental mercury and inorganic mercury compounds. Inorganic mercury compounds are water soluble with a bioavailability of 7% to 15% after ingestion; they are also irritants and cause gastrointestinal symptoms. Upon entering the body, inorganic mercury compounds are accumulated mainly in the kidneys and produce kidney damage. In contrast, human exposure to elemental mercury is mainly by inhalation, followed by rapid absorption and distribution in all major organs. Elemental mercury from ingestion is poorly absorbed with a bioavailability of less than 0.01%. The primary target organs of elemental mercury are the brain and kidney. Elemental mercury is lipid soluble and can cross the blood-brain barrier, while inorganic mercury compounds are not lipid soluble, rendering them unable to cross the blood-brain barrier. Elemental mercury may also enter the brain from the nasal cavity through the olfactory pathway. The blood mercury is a useful biomarker after short-term and high-level exposure, whereas the urine mercury is the ideal biomarker for long-term exposure to both elemental and inorganic mercury, and also as a good indicator of body burden. This review discusses the common sources of mercury exposure, skin lightening products containing mercury and mercury release from dental amalgam filling, two issues that happen in daily life, bear significant public health importance, and yet undergo extensive debate on their safety. PMID:23230464

  13. Sexual differences in the excretion of organic and inorganic mercury by methyl mercury-treated rats

    International Nuclear Information System (INIS)

    Thomas, D.J.; Fisher, H.L.; Sumler, M.R.; Mushak, P.; Hall, L.L.

    1987-01-01

    Adult male and female Long Evans rats received 1 mumole of methyl ( 203 Hg) mercuric chloride per kilogram sc. Whole-body retention of mercury and excretion of organic and inorganic mercury in urine and feces were monitored for 98 days after dosing. Females cleared mercury from the body more rapidly than did males. The major route of mercury excretion was feces. By 98 days after dosing, cumulative mercury excretion in feces accounted for about 51% of the dose in males and about 54% of the dose in females. For both sexes, about 33% of the dose was excreted in feces as inorganic mercury. Cumulative excretion of organic mercury in feces accounted for about 18 and 21% of the dose in males and females, respectively. Urinary excretion of mercury was quantitatively a smaller route for mercury clearance but important sexual differences in loss by this route were found. Over the 98-day experimental period, males excreted in urine about 3.2% of the dose and females excreted 7.5%. Cumulative organic Hg excretion in urine accounted for 1.8% of the dose in males and 5.3% of the dose in females. These sexual differences in urinary and fecal excretion of organic and inorganic mercury following methyl mercury treatment were consistent with previous reports of sexual differences in mercury distribution and retention in methyl mercury-treated rats, particularly sexual differences in organic mercury uptake and retention in the kidney. Relationships between body burdens of organic or inorganic Hg and output of these forms of Hg in urine and feces were also found to be influenced by the interval after MeHg treatment and by sex. Relationship between concentration of Hg in liver and feces and in kidney and urine differed for organic and inorganic Hg and depended upon sexual status and interval after MeHg treatment

  14. Poly[[tetrakis(μ2-pyrazine N,N′-dioxide-κ2O:O′erbium(III] tris(perchlorate

    Directory of Open Access Journals (Sweden)

    James D. Buchner

    2010-09-01

    Full Text Available The title three-dimensional coordination network, {[Er(C4H4N2O24](ClO43}n, is isostructural to that of other lanthanides. The Er+3 cation lies on a fourfold roto-inversion axis. It is coordinated in a distorted square-antiprismatic fashion by eight O atoms from bridging pyrazine N,N′-dioxide ligands. There are two unique pyrazine N,N′-dioxide ligands. One ring is located around an inversion center, and there is a a twofold rotation axis at the center of the other ring. There are also two unique perchlorate anions. One is centered on a twofold rotation axis and the other on a fourfold roto-inversion axis. The perchlorate anions are located in channels that run perpendicular to (001 and (110 and interact with the coordination network through C—H...O hydrogen bonds.

  15. Bis(μ-bis{[4-(2-pyridylpyrimidin-2-yl]sulfanyl}methanedisilver(I bis(perchlorate

    Directory of Open Access Journals (Sweden)

    Hai-Bin Zhu

    2010-12-01

    Full Text Available In the macrocyclic centrosymmetric dinuclear complex, [Ag2(C19H14N6S22](ClO42, the AgI atom, bis{[4-(2-pyridylpyrimidin-2-yl]sulfanyl}methane (2-bppt ligand and perchlorate anion each lie on a twofold rotation axis. The 2-bppt ligand chelates two four-coordinated AgI atoms through its two bipyridine-like arms. The O atoms of the perchlorate anion are disordered each over two positions of equal occupancy. Adjacent complex molecules are linked by π–π interactions between the pyridine and pyrimidine rings [centroid–centroid distance = 3.663 (8 Å].

  16. Impedance of basis cadmium monocrystal facet free from screw dislocation in solution of cadmium sulfate and perchlorate

    International Nuclear Information System (INIS)

    Bostanov, B.; Naneva, R.; Andreev, L.; Maslij, A.I.

    1987-01-01

    To clarify the mechanism of cadmium electrocrystallization the frequency dependence of impedance of basic cadmium facet free from dislocations in concentrated solutions of cadmium sulfate and perchlorate was measured by bridge method. It is shown that over all studied frequency region (0.6-40 kHz) facet behaviour is described satisfactorily by equivalent Frumkin-Melik-Jaykazan scheme. Exchange current and equilibrium concentration of cadmium adatoms were determined: ≅ 1x10 -4 A/cm 2 , ≅ 1.5x10 -13 mol/cm 2 . It was revealed that capacitance of binary layer in perchlorate (≅ 35 μf/cm 2 ) was two times lower as compared to cadmium sulfate (70-75 μf/cm 2 )

  17. Increased Mercury Bioaccumulation Follows Water Quality Improvement

    Energy Technology Data Exchange (ETDEWEB)

    Bogle, M.A.; Peterson, M.J.; Smith, J.G.; Southworth, G.R.

    1999-09-15

    Changes in physical and chemical characteristics of aquatic habitats made to reduce or eliminate ecological risks can sometimes have unforeseen consequences. Environmental management activities on the U.S. Dept. of Energy reservation in Oak Ridge, Tennessee,have succeeded in improving water quality in streams impacted by discharges fi-om industrial facilities and waste disposal sites. The diversity and abundance of pollution-sensitive components of the benthic macroinvertebrate communities of three streams improved after new waste treatment systems or remedial actions reduced inputs of various toxic chemicals. Two of the streams were known to be mercury-contaminated from historical spills and waste disposal practices. Waterborne mercury concentrations in the third were typical of uncontaminated systems. In each case, concentrations of mercury in fish, or the apparent biological availability of mercury increased over the period during which ecological metrics indicated improved water quality. In the system where waterborne mercury concentrations were at background levels, increased mercury bioaccumulation was probably a result of reduced aqueous selenium concentrations; however, the mechanisms for increased mercury accumulation in the other two streams remain under investigation. In each of the three systems, reduced inputs of metals and inorganic anions was followed by improvements in the health of aquatic invertebrate communities. However, this reduction in risk to aquatic invertebrates was accompanied by increased risk to humans and piscivorous wildlife related to increased mercury concentrations in fish.

  18. Increased Mercury Bioaccumulation Follows Water Quality Improvement

    International Nuclear Information System (INIS)

    Bogle, M.A.; Peterson, M.J.; Smith, J.G.; Southworth, G.R.

    1999-01-01

    Changes in physical and chemical characteristics of aquatic habitats made to reduce or eliminate ecological risks can sometimes have unforeseen consequences. Environmental management activities on the U.S. Dept. of Energy reservation in Oak Ridge, Tennessee,have succeeded in improving water quality in streams impacted by discharges fi-om industrial facilities and waste disposal sites. The diversity and abundance of pollution-sensitive components of the benthic macroinvertebrate communities of three streams improved after new waste treatment systems or remedial actions reduced inputs of various toxic chemicals. Two of the streams were known to be mercury-contaminated from historical spills and waste disposal practices. Waterborne mercury concentrations in the third were typical of uncontaminated systems. In each case, concentrations of mercury in fish, or the apparent biological availability of mercury increased over the period during which ecological metrics indicated improved water quality. In the system where waterborne mercury concentrations were at background levels, increased mercury bioaccumulation was probably a result of reduced aqueous selenium concentrations; however, the mechanisms for increased mercury accumulation in the other two streams remain under investigation. In each of the three systems, reduced inputs of metals and inorganic anions was followed by improvements in the health of aquatic invertebrate communities. However, this reduction in risk to aquatic invertebrates was accompanied by increased risk to humans and piscivorous wildlife related to increased mercury concentrations in fish

  19. A Challenging Case of Acute Mercury Toxicity

    Directory of Open Access Journals (Sweden)

    Ali Nayfeh

    2018-01-01

    Full Text Available Background. Mercury exists in multiple forms: elemental, organic, and inorganic. Its toxic manifestations depend on the type and magnitude of exposure. The role of colonoscopic decompression in acute mercury toxicity is still unclear. We present a case of acute elemental mercury toxicity secondary to mercury ingestion, which markedly improved with colonoscopic decompression. Clinical Case. A 54-year-old male presented to the ED five days after ingesting five ounces (148 cubic centimeters of elemental mercury. Examination was only significant for a distended abdomen. Labs showed elevated serum and urine mercury levels. An abdominal radiograph showed radiopaque material throughout the colon. Succimer and laxatives were initiated. The patient had recurrent bowel movements, and serial radiographs showed interval decrease of mercury in the descending colon with interval increase in the cecum and ascending colon. Colonoscopic decompression was done successfully. The colon was evacuated, and a repeat radiograph showed decreased hyperdense material in the colon. Three months later, a repeat radiograph showed no hyperdense material in the colon. Conclusion. Ingested elemental mercury can be retained in the colon. Although there are no established guidelines for colonoscopic decompression, our patient showed significant improvement. We believe further studies on this subject are needed to guide management practices.

  20. The influence of floodplains on mercury availability

    Energy Technology Data Exchange (ETDEWEB)

    Wallschlaeger, D.; Wilken, R.D. [GKSS Research Center, Geesthacht (Germany). Inst. of Physical and Chemical Analytics

    1997-09-01

    The floodplains of the German river Elbe affect the mercury distribution in the river system in two different ways: they act both as a medium-term sink and as a long-term source. The large amounts of mercury deposited onto the floodplains during annual floodings are first effectively fixed in the soils, rendering them basically unavailable. Sequential extraction experiments reveal that only a small fraction of the mercury (< 3%) is present in available forms, whereas the vast majority is associated with humic substances or present in sulfidic binding forms. After deposition, a small fraction of the total mercury is gradually remobilized into the aqueous phase bound passively to water-soluble humic acids. The availability of mercury in these complexes is still low, since environmental influences such as changes in pH or redox potential and competition with other cations do not cause any mercury liberation. In the next step, reactions in the aqueous phase lead to the formation of the highly available volatile species Hg{sup 0} and dimethylmercury (DMM). Their evaporation gives rise to a strong mercury flux from the floodplains into the atmosphere. Preliminary mass balances indicate that the majority of the deposited mercury stays bound in the floodplain soils, while small amounts are emitted back into the river`s ecosystem. Atmospheric emission is more important as a remobilization pathway than aquatic export.

  1. OCCURENCE OF MERCURY IN PET FOOD

    Directory of Open Access Journals (Sweden)

    M.C. Abete

    2013-02-01

    Full Text Available Mercury levels in 61 complete pet feed containing fish were evaluated. In five samples a mercury content exceeding the maximum residues level (0.4 mg/kg was detected. The statistical evaluation didn’t show a significant correlation between the percentage of fish in feedingstuffs and the contamination level.

  2. Hair mercury measurement in Egyptian autistic children

    African Journals Online (AJOL)

    Farida El-baz

    Abstract Background: A review of medical literature has shown that exposure to mercury, whether organic or inorganic, can give rise to the symptoms and traits defining or commonly found in autism spectrum disorders (ASD). Mercury can cause impairments in social interaction, commu- nication difficulties, and repetitive ...

  3. Terahertz oscillations in mercury cuprate superconductors

    Indian Academy of Sciences (India)

    Abstract. It has been recently reported that the three-dimensional Bose–Einstein con- densation of the quasi-particles is valid for the mercury cuprates at liquid helium tem- perature. In this study, the validity of the interlayer theory in three dimensions has been investigated for optimally oxygen-doped mercury cuprates at the ...

  4. Mercury poisoning | Shamley | South African Medical Journal

    African Journals Online (AJOL)

    The diagnosis of mercury poisoning requires a high index of suspicion. Mercury poisoning in a patient involved in illicit gold extraction is reported and 6 other cases considered. Some of the clinical features and treatment of this condition are discussed. S Afr Med J 1989; 76: 114-116 ...

  5. Mercury soil surveys: a good reconnaissance tool

    Energy Technology Data Exchange (ETDEWEB)

    Stone, C.; Ruscetta, C.A.; Foley, D. (eds.)

    1981-05-01

    Three examples of mercury soil surveys are discussed, along with the gravity data. An excellent correlation was found in southern Arizona between buried structures revealed by gravity and mercury soil surveys. The advantages of the latter over the former as a reconnaissance tool are listed. (MHR)

  6. Intentional intravenous mercury injection | Yudelowitz | South African ...

    African Journals Online (AJOL)

    Intravenous mercury injection is rarely seen, with few documented cases. Treatment strategies are not clearly defined for such cases, although a few options do show benefit. This case report describes a 29-year-old man suffering from bipolar disorder, who presented following self-inflicted intravenous injection of mercury.

  7. Pneumonitis after Inhalation of Mercury Vapours

    Directory of Open Access Journals (Sweden)

    JD Glezos

    2006-01-01

    Full Text Available A 43-year-old man presented to hospital with pneumonia but only after discharge from hospital did he admit to deliberate prior inhalation of mercury. His pulmonary involvement appeared to resolve almost completely with antibiotics and supportive care. Nevertheless, persisting elevated urinary excretion of mercury required two courses of chelation therapy. No serious systemic sequelae were observed.

  8. Recent Advances in Atmospheric Chemistry of Mercury

    Directory of Open Access Journals (Sweden)

    Lin Si

    2018-02-01

    Full Text Available Mercury is one of the most toxic metals and has global importance due to the biomagnification and bioaccumulation of organomercury via the aquatic food web. The physical and chemical transformations of various mercury species in the atmosphere strongly influence their composition, phase, transport characteristics and deposition rate back to the ground. Modeling efforts to assess global cycling of mercury require an accurate understanding of atmospheric mercury chemistry. Yet, there are several key uncertainties precluding accurate modeling of physical and chemical transformations. We focus this article on recent studies (since 2015 on improving our understanding of the atmospheric chemistry of mercury. We discuss recent advances in determining the dominant atmospheric oxidant of elemental mercury (Hg0 and understanding the oxidation reactions of Hg0 by halogen atoms and by nitrate radical (NO3—in the aqueous reduction of oxidized mercury compounds (HgII as well as in the heterogeneous reactions of Hg on atmospheric-relevant surfaces. The need for future research to improve understanding of the fate and transformation of mercury in the atmosphere is also discussed.

  9. Urban artisanal gold shops and mercury emissions

    International Nuclear Information System (INIS)

    Cordy, P.; Veiga, M.; Carrasco, V.H.G.

    2008-01-01

    Artisanal miners in developing countries use mercury amalgamation processes to extract gold. The amalgams are then refined before being sold on to urban gold shops. The amalgams can often contain between 2 to 40 per cent mercury. Unburned amalgams are also often sold directly to gold shops. There are serious health risks for shop employees and nearby populations when the gold is melted and further purified. Studies have shown that mercury concentrations in the ambient air of gold shops often exceeds World Health Organization (WHO) limits by an order of magnitude or more. This study examined the practices and technologies used to refine gold in Latin America and Indonesia. The study compared and contrasted various refining methods and their resulting mercury emissions. Methods of reducing mercury emissions were also investigated, including a filtration system designed to capture 80 per cent of mercury emissions. Barriers to implementing mercury emissions reduction plans were also investigated. It was concluded that the design of urban gold shops must include condensers, fume hoods, and efficient mercury capture systems. 15 refs

  10. Mercury cycling in peatland watersheds. Chapter 11.

    Science.gov (United States)

    Randall K. Kolka; Carl P.J. Mitchell; Jeffrey D. Jeremiason; Neal A. Hines; David F. Grigal; Daniel R. Engstrom; Jill K. Coleman-Wasik; Edward A. Nater; Edward B. Swain; Bruce A. Monson; Jacob A. Fleck; Brian Johnson; James E. Almendinger; Brian A. Branfireun; Patrick L. Brezonik; James B. Cotner

    2011-01-01

    Mercury (Hg) is of great environmental concern due to its transformation into the toxic methylmercury (MeHg) form that bioaccumulates within the food chain and causes health concerns for both humans and wildlife (U.S. Environmental Protection Agency 2002). Mercury can affect neurological development in fetuses and young children. In adults, exposure to Hg can lead to...

  11. Mercury in tropical and subtropical coastal environments

    Science.gov (United States)

    Costa, Monica F.; Landing, William M.; Kehrig, Helena A.; Barletta, Mário; Holmes, Christopher D.; Barrocas, Paulo R. G.; Evers, David C.; Buck, David G.; Vasconcellos, Ana Claudia; Hacon, Sandra S.; Moreira, Josino C.; Malm, Olaf

    2012-01-01

    Anthropogenic activities influence the biogeochemical cycles of mercury, both qualitatively and quantitatively, on a global scale from sources to sinks. Anthropogenic processes that alter the temporal and spatial patterns of sources and cycling processes are changing the impacts of mercury contamination on aquatic biota and humans. Human exposure to mercury is dominated by the consumption of fish and products from aquaculture operations. The risk to society and to ecosystems from mercury contamination is growing, and it is important to monitor these expanding risks. However, the extent and manner to which anthropogenic activities will alter mercury sources and biogeochemical cycling in tropical and sub-tropical coastal environments is poorly understood. Factors as (1) lack of reliable local/regional data; (2) rapidly changing environmental conditions; (3) governmental priorities and; (4) technical actions from supra-national institutions, are some of the obstacles to overcome in mercury cycling research and policy formulation. In the tropics and sub-tropics, research on mercury in the environment is moving from an exploratory “inventory” phase towards more process-oriented studies. Addressing biodiversity conservation and human health issues related to mercury contamination of river basins and tropical coastal environments are an integral part of paragraph 221 paragraph of the United Nations document “The Future We Want” issued in Rio de Janeiro in June 2012. PMID:22901765

  12. Episodic bioavailability of environmental mercury: implications for ...

    African Journals Online (AJOL)

    Perennial wildfires in Africa and other continents contribute an estimated 8 x 105 kg of mercury to the global atmosphere with a residence time of approximately one year. This phenomenon changes the flux of biologically available mercury in natural microbial communities where enzymatic actions, including mercuric ...

  13. Terahertz oscillations in mercury cuprate superconductors

    Indian Academy of Sciences (India)

    It has been recently reported that the three-dimensional Bose–Einstein condensation of the quasi-particles is valid for the mercury cuprates at liquid helium temperature. In this study, the validity of the interlayer theory in three dimensions has been investigated for optimally oxygen-doped mercury cuprates at the temperature ...

  14. Mercury in Thana creek, Bombay harbour

    Digital Repository Service at National Institute of Oceanography (India)

    Zingde, M.D.; Desai, B.N.

    Mercury content of the water column estimated along Thana Creek/Bombay Harbour gave a standing stock of about 77 kg in excess of the expected background. Mercury concentration in sediment from 23 locations which varied from 0.17 to 8.21 ppm (dry...

  15. Urban artisanal gold shops and mercury emissions

    Energy Technology Data Exchange (ETDEWEB)

    Cordy, P.; Veiga, M.; Carrasco, V.H.G. [British Columbia Univ., Vancouver, BC (Canada). Dept. of Mining and Mineral Process Engineering

    2008-07-01

    Artisanal miners in developing countries use mercury amalgamation processes to extract gold. The amalgams are then refined before being sold on to urban gold shops. The amalgams can often contain between 2 to 40 per cent mercury. Unburned amalgams are also often sold directly to gold shops. There are serious health risks for shop employees and nearby populations when the gold is melted and further purified. Studies have shown that mercury concentrations in the ambient air of gold shops often exceeds World Health Organization (WHO) limits by an order of magnitude or more. This study examined the practices and technologies used to refine gold in Latin America and Indonesia. The study compared and contrasted various refining methods and their resulting mercury emissions. Methods of reducing mercury emissions were also investigated, including a filtration system designed to capture 80 per cent of mercury emissions. Barriers to implementing mercury emissions reduction plans were also investigated. It was concluded that the design of urban gold shops must include condensers, fume hoods, and efficient mercury capture systems. 15 refs.

  16. Mercury Sorption onto Malt Spent Rootlets

    Science.gov (United States)

    Manariotis, I. D.; Anagnostopoulos, V.; Karapanagioti, H. K.; Chrysikopoulos, C.

    2011-12-01

    Mercury is a metal of particular concern due to its toxicity even at relatively low concentrations. The maximum permissible level for mercury in drinking water set by the European Union is 0.001 mg/L. Mercury is released into the environment via four principal pathways: (1) natural processes; i.e. a volcanic eruption, (2) incidental to some other activity; i.e. coal burning power plants, (3) accidentally during the manufacture, breakage or disposal of products that have mercury put into them deliberately, and (4) direct use in industrial settings. The present study focuses on the removal of mercury (II) from aqueous solutions via sorption onto Malt Spent Rootlets (MSR). Batch experiments were conducted employing MSR with size ranging from 0.18 to 1 mm. The effects of pH, mercury concentration, contact time, and solid to liquid ratio on mercury sorption onto MSR were investigated. The highest mercury removal from the aqueous phase, of 41%, was observed at pH of 5.

  17. Reactions of oxidation of methyl derivatives of aniline and diaminodurene by Ce(4) in perchloric acid aqueous solutions

    International Nuclear Information System (INIS)

    Ignachak, M.; Dzegets, Yu.; Leshchinski, L.

    1988-01-01

    Method of potentiometric titration was used to study the effect of reagent concentration on oxidation rate of methyl derivatives of aniline and diaminodurene by cerium (4) in aqueous solutions of perchloric acid at 50 deg C. Approximate stoichiometry of the reaction was established and some intermediate products were isolated. It was shown that oxidation process included series-parallel reactions, differing considerably from one onother with respect to rates

  18. Demonstration of a Full-Scale Fluidized Bed Bioreactor for the Treatment of Perchlorate at Low Concentrations in Groundwater

    Science.gov (United States)

    2009-01-01

    Fluidized Bed Reactor Iron Granulated Activated Carbon Gallons per minute Health & Safety Plan Hydraulic Residence Time Investigation-Derived Waste...FINAL REPORT Demonstration of a Full-Scale Fluidized Bed Bioreactor for the Treatment of Perchlorate at Low Concentrations in Groundwater...area code) 20-01-2009 Final Report March 2006-March 2008; January 2009 DEMONSTRATION OF A FULL-SCALE FLUIDIZED BED BIOREACTOR FOR THE TREATMENT OF

  19. Evaluation of Perchlorate Sources in the Rialto-Colton and Chino California Subbasins using Chlorine and Oxygen Isotope Ratio Analysis

    Science.gov (United States)

    2015-03-01

    4) isotopic exchange between O2 and CO2 in the reaction tubes (both O2-DI-IRMS methods); and (5) analytical artifact of elevated CO2 in the ion...FINAL REPORT Evaluation of Perchlorate Sources in the Rialto-Colton and Chino California Subbasins using Chlorine and Oxygen Isotope Ratio...0061 RIALTO-COLTON AND CHINO CALIFORNIA SUBBASINS USING 5b. GRANT NUMBER CHLORINE AND OXYGEN ISOTOPE RATIO ANALYSIS NA 5c. PROGRAM ELEMENT NUMBER

  20. Low dose mercury toxicity and human health.

    Science.gov (United States)

    Zahir, Farhana; Rizwi, Shamim J; Haq, Soghra K; Khan, Rizwan H

    2005-09-01

    Post Minamata incident there has been awareness about mercury toxicity even among the general public. Previous researches contributed a vast amount of data regarding acute mercury exposure, but gradually information about the low dose [Ninomiya, T., Ohmori, H., Hashimoto, K., Tsuruta, K., Ekino, S., 1995. Expansion of methylmercury poisoning outside minamata: an epidemiological study on chronic methylmercury poisoninig outside of Minamata. Environ. Res. 70 (1) 47-50; Lebel, J., Mergler, D., Lucotte, M., Amorim, M., Dolbec, J., Miranda, D., Arantes, G., Rheault, I., Pichet, P., 1996. Evidence of early nervous system dysfunction in Amazonian populations exposed to low-levels of methylmercury. Neurotoxicology 17 (1) 157-167] of mercury toxicity has been trickling in. With mercury contaminating rain-, ground- and sea-water no one is safe. Polluted water leads to mercury laced fish, meat and vegetable. In aquatic environments, inorganic mercury is microbiologically transformed into lipophilic organic compound 'methylmercury'. This transformation makes mercury more prone to biomagnification in food chains. Consequently, populations with traditionally high dietary intake of food originating from fresh or marine environment have highest dietary exposure to mercury. Extensive research done on locals across the globe have already established this, persons who routinely consume fish or a particular species of fish are at an increased risk of methylmercury poisoning. The easy access of the toxicant to man through multiple pathways air, water, food, cosmetic products and even vaccines increase the exposure. Foetus and children are more susceptible towards mercury toxicity. Mothers consuming diet containing mercury pass the toxicant to foetus and to infants through breast milk. Decreased performance in areas of motor function and memory has been reported among children exposed to presumably safe mercury levels. Similarly, disruption of attention, fine motor function and verbal

  1. Effect of salinity on methylation of mercury

    Energy Technology Data Exchange (ETDEWEB)

    Blum, J.E.; Bartha, R.

    1980-09-01

    Monomethyl and dimethylmercury are potent neurotoxins subject to biomagnification in food webs. This fact was tragically demonstrated by the Minamata and Niigata poisoning incidents in Japan in which 168 persons who ate seafood from mercury polluted waters were poisoned, 52 fatally. Shortly after these two incidents, work conducted in freshwater environments demonstrated the microbial conversion of inorganic and phenylmercury compounds to mono- and di-methylmercury. Consideration of some fragmentary evidence from the literature, however, indicates that the rate and the significance of microbial methylation of mercury in freshwater and saltwater environments may not be the same. A demonstrated relationship between mercury methylation rates and water salinity would greatly influence our thinking about mercury pollution effects in marine versus freshwater environments. Since we were unable to locate published reports on this subject, we are investigating the influence of salinity on the rate of mercury methylation in an estuarine sediment.

  2. High activity carbon sorbents for mercury capture

    Directory of Open Access Journals (Sweden)

    Stavropoulos George G.

    2006-01-01

    Full Text Available High efficiency activated carbons have been prepared for removing mercury from gas streams. Starting materials used were petroleum coke, lignite, charcoal and olive seed waste, and were chemically activated with KOH. Produced adsorbents were primarily characterized for their porosity by N2 adsorption at 77 K. Their mercury retention capacity was characterized based on the breakthrough curves. Compared with typical commercial carbons, they have exhibited considerably enhanced mercury adsorption capacity. An attempt has been made to correlate mercury entrapment and pore structure. It has been shown that physical surface area is increased during activation in contrast to the mercury adsorption capacity that initially increases and tends to decrease at latter stages. Desorption of active sites may be responsible for this behavior.

  3. Human accumulation of mercury in Greenland

    DEFF Research Database (Denmark)

    Johansen, Poul; Mulvad, Gert; Pedersen, Henning Sloth

    2007-01-01

    In the Arctic, the traditional diet exposes its people to a high intake of mercury especially from marine mammals. To determine whether the mercury is accumulated in humans, we analyzed autopsy samples of liver, kidney and spleen from adult ethnic Greenlanders who died between 1990 and 1994 from...... a wide range of causes, natural and violent. Liver, kidney and spleen samples from between 33 and 71 case subjects were analyzed for total mercury and methylmercury, and liver samples also for selenium. Metal levels in men and women did not differ and were not related to age except in one case, i...... in liver and spleen and as little as 3% in kidney. In liver selenium was found in surplus to mercury on a molar basis. Mercury concentrations in the liver and kidneys of Greenlanders were elevated compared to levels in the general population in Japan, Korea and several European countries, except...

  4. Autism: a novel form of mercury poisoning.

    Science.gov (United States)

    Bernard, S; Enayati, A; Redwood, L; Roger, H; Binstock, T

    2001-04-01

    Autism is a syndrome characterized by impairments in social relatedness and communication, repetitive behaviors, abnormal movements, and sensory dysfunction. Recent epidemiological studies suggest that autism may affect 1 in 150 US children. Exposure to mercury can cause immune, sensory, neurological, motor, and behavioral dysfunctions similar to traits defining or associated with autism, and the similarities extend to neuroanatomy, neurotransmitters, and biochemistry. Thimerosal, a preservative added to many vaccines, has become a major source of mercury in children who, within their first two years, may have received a quantity of mercury that exceeds safety guidelines. A review of medical literature and US government data suggests that: (i) many cases of idiopathic autism are induced by early mercury exposure from thimerosal; (ii) this type of autism represents an unrecognized mercurial syndrome; and (iii) genetic and non-genetic factors establish a predisposition whereby thimerosal's adverse effects occur only in some children. Copyright 2001 Harcourt Publishers Ltd.

  5. Removal of mercury by adsorption: a review.

    Science.gov (United States)

    Yu, Jin-Gang; Yue, Bao-Yu; Wu, Xiong-Wei; Liu, Qi; Jiao, Fei-Peng; Jiang, Xin-Yu; Chen, Xiao-Qing

    2016-03-01

    Due to natural and production activities, mercury contamination has become one of the major environmental problems over the world. Mercury contamination is a serious threat to human health. Among the existing technologies available for mercury pollution control, the adsorption process can get excellent separation effects and has been further studied. This review is attempted to cover a wide range of adsorbents that were developed for the removal of mercury from the year 2011. Various adsorbents, including the latest adsorbents, are presented along with highlighting and discussing the key advancements on their preparation, modification technologies, and strategies. By comparing their adsorption capacities, it is evident from the literature survey that some adsorbents have shown excellent potential for the removal of mercury. However, there is still a need to develop novel, efficient adsorbents with low cost, high stability, and easy production and manufacture for practical utility.

  6. Column adsorption of perchlorate by amine-crosslinked biopolymer based resin and its biological, chemical regeneration properties.

    Science.gov (United States)

    Song, Wen; Xu, Xing; Tan, Xin; Wang, Yan; Ling, Jianya; Gao, Baoyu; Yue, Qinyan

    2015-01-22

    Column adsorption of perchlorate by amine-crosslinked biopolymer based resin was investigated by considering the bed depth, stream flow rate and influent pH. The empty bed contact time (EBCT) increased with the growth of bed depths, meanwhile rising flow rate at constant bed depth (3.4 cm) decreased the breakthrough time. It was observed that perchlorate adsorption capacity was optimum at neutral condition (pH: 6.0, 170.4 mg/g), and decreased at acidic (pH: 3.0, 96.4 mg/g) or alkalic (pH: 12.0, 72.8 mg/g) influents. The predominant strains of the acclimated sludge for resin biological regeneration were the β-subclass of Proteobacteria. Biological regeneration of the saturated amine-crosslinked biopolymer based resin with mixed bacteria have shown its merit with regeneration and biological perchlorate destruction simultaneously, although its regeneration efficiency was only 61.2-84.1% by contrast to chemical regeneration with efficiency more than 95%. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. Detection of trace organics in Mars analog samples containing perchlorate by laser desorption/ionization mass spectrometry.

    Science.gov (United States)

    Li, Xiang; Danell, Ryan M; Brinckerhoff, William B; Pinnick, Veronica T; van Amerom, Friso; Arevalo, Ricardo D; Getty, Stephanie A; Mahaffy, Paul R; Steininger, Harald; Goesmann, Fred

    2015-02-01

    Evidence from recent Mars missions indicates the presence of perchlorate salts up to 1 wt % level in the near-surface materials. Mixed perchlorates and other oxychlorine species may complicate the detection of organic molecules in bulk martian samples when using pyrolysis techniques. To address this analytical challenge, we report here results of laboratory measurements with laser desorption mass spectrometry, including analyses performed on both commercial and Mars Organic Molecule Analyzer (MOMA) breadboard instruments. We demonstrate that the detection of nonvolatile organics in selected spiked mineral-matrix materials by laser desorption/ionization (LDI) mass spectrometry is not inhibited by the presence of up to 1 wt % perchlorate salt. The organics in the sample are not significantly degraded or combusted in the LDI process, and the parent molecular ion is retained in the mass spectrum. The LDI technique provides distinct potential benefits for the detection of organics in situ on the martian surface and has the potential to aid in the search for signs of life on Mars.

  8. μ-Oxalato-bis[(2,2′-bipyridylcopper(II] bis(perchlorate dimethylformamide disolvate monohydrate

    Directory of Open Access Journals (Sweden)

    Alexander N. Boyko

    2010-09-01

    Full Text Available The title compound, [Cu2(C2O4(C10H8N24](ClO42·2C3H7NO·H2O, contains doubly charged centrosymmetric dinuclear oxalato-bridged copper(II complex cations, perchlorate anions, and DMF and water solvate molecules. In the complex cation, the oxalate ligand is coordinated in a bis-bidentate bridging mode to the Cu atoms. Each Cu atom has a distorted tetragonal-bipyramidal environment, being coordinated by two N atoms of the two chelating bipy ligands and two O atoms of the doubly deprotonated oxalate anion. Pairs of perchlorate anions and water molecules are linked into rectangles by O—H...O bonds in which the perchlorate O atoms act as acceptors and the water molecules as donors. Methyl groups of the DMF solvent molecule are disordered over two sites with occupancies of 0.453 (7:0.547 (7, and the water molecule is half-occupied.

  9. 21 CFR 862.3600 - Mercury test system.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Mercury test system. 862.3600 Section 862.3600....3600 Mercury test system. (a) Identification. A mercury test system is a device intended to measure mercury, a heavy metal, in human specimens. Measurements obtained by this device are used in the diagnosis...

  10. 21 CFR 880.2920 - Clinical mercury thermometer.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Clinical mercury thermometer. 880.2920 Section 880... Devices § 880.2920 Clinical mercury thermometer. (a) Identification. A clinical mercury thermometer is a... mercury. (b) Classification. Class II (special controls). The device is exempt from the premarket...

  11. Mercury flow experiments. 4th report: Measurements of erosion rate caused by mercury flow

    International Nuclear Information System (INIS)

    Kinoshita, Hidetaka; Kaminaga, Masanori; Haga, Katsuhiro; Hino, Ryutaro

    2002-06-01

    The Japan Atomic Energy Research Institute (JAERI) and the High Energy Accelerator Research Organization (KEK) are promoting a construction plan of the Material-Life Science Facility, which is consisted of a Muon Science Facility and a Neutron Scattering Facility, in order to open up the new science fields. The Neutron Scattering Facility will be utilized for advanced fields of Material and Life science using high intensity neutron generated by the spallation reaction of a 1 MW pulsed proton beam and mercury target. Design of the spallation mercury target system aims to obtain high neutron performance with high reliability and safety. Since the target system is using mercury as the target material and contains large amount of radioactive spallation products, it is necessary to estimate reliability for strength of instruments in a mercury flow system during lifetime of the facility. Piping and components in the mercury flow system would be damaged by erosion with mercury flow, since these components will be weak by thickness decreasing. This report presents experimental results of wall thickness change by erosion using a mercury experimental loop. In the experiments, an erosion test section and coupons were installed in the mercury experimental loop, and their wall thickness was measured with an ultra sonic thickness gage after every 1000 hours. As a result, under 0.7 m/s of mercury velocity condition which is slightly higher than the practical velocity in mercury pipelines, the erosion is about 3 μm in 1000 hours. The wall thickness decrease during facility lifetime of 30 years is estimated to be less than 0.5 mm. According to the experimental result, it is confirmed that the effect of erosion on component strength is extremely small. Moreover, a measurement of residual mercury on the piping surface was carried out. As a result, 19 g/m 2 was obtained as the residual mercury for the piping surface. According to this result, estimated amount of residual mercury for

  12. Biomolecular Aspects of Mercury Transformations

    Science.gov (United States)

    Johs, A.; Shi, L.; Miller, S. M.; Summers, A. O.; Liang, L.

    2008-12-01

    Bacteria participate significantly in mercury transformation in natural and industrial environments. Previous studies have shown that bacterial mercury resistance is mediated by the mer operon, typically located on transposons or plasmids. It encodes specific genes that facilitate uptake of mercury species, cleavage of organomercurials, and reduction of Hg(II) to Hg(0). Expression of mer operon genes is regulated by MerR, a metal-responsive regulator protein on the level of transcription. In vitro studies have shown that MerR forms a non-transcribing pre-initiation complex with RNA polymerase and the promoter DNA. Binding of Hg(II) induces conformational changes in MerR and other components of the complex resulting in the transcription of mer operon genes. As part of ongoing investigations on allosteric conformational changes induced by Hg(II) in dimeric MerR, and the implications on the binding of RNA polymerase to the promoter of the mer operon, we applied small angle scattering to study the regulatory mechanism of MerR in the presence and absence of Hg(II). Our results show that in the presence of Hg(II) the MerR dimer undergoes a significant reorientation from a compact state to a conformation revealing two distinct domains. Bacterial reduction of Hg(II) can also occur at concentrations too low to induce mer operon functions. Dissimilatory metal reducing bacteria, such as Shewanella and Geobacter are able to reduce Hg(II) in the presence of mineral oxides. This process has been linked to the activity of outer membrane multiheme cytochromes. We isolated and purified a decaheme outer membrane cytochrome OmcA from Shewanella oneidensis MR-1 and characterized its envelope shape in solution by small angle x-ray scattering. Structural features were identified and compared to homology models. These results show that OmcA is an elongated macromolecule consisting of separate modules, which may be connected by flexible linkers.

  13. Mercury in food items from the Idrija Mercury Mine area.

    Science.gov (United States)

    Miklavčič, Ana; Mazej, Darja; Jaćimović, Radojko; Dizdarevi, Tatjana; Horvat, Milena

    2013-08-01

    As a consequence of over 500 years of mining and smelting activities (1490-1995), and of its natural geological occurrence, the soil in the Idrija region is highly contaminated with Hg. In order to assess the present situation regarding the Hg levels in local food samples, concentrations of total mercury (THg) and monomethyl mercury (MeHg) were determined in selected vegetables, mushrooms and fish from the Idrija Hg mine area. Hg levels in the foodstuffs analysed were not very high but were elevated compared to the levels in food from non-contaminated areas. The study showed that THg accumulates in mushrooms (X=5680ng/g dry weight, Min=346ng/g dry weight, Max=17,100 dry weight) and chicory (X=1950ng/g dry weight, Min=86ng/g dry weight, Max=17,100ng/g dry weight). In addition, Se and Cd concentrations were determined by ICP-MS in those vegetable and mushroom species in which the highest Hg levels were found. The levels of Cd and Se were below the threshold levels. Based on data from previous studies, we can conclude that the levels of Hg in food have not diminished significantly during the past 15 years after closure of the Hg mine. Special attention should be given to vegetables such as chicory, representing a local seasonal vegetable eaten frequently. Copyright © 2013 Elsevier Inc. All rights reserved.

  14. Estimating mercury emissions from a zinc smelter in relation to China's mercury control policies

    International Nuclear Information System (INIS)

    Wang, S.X.; Song, J.X.; Li, G.H.; Wu, Y.; Zhang, L.; Wan, Q.; Streets, D.G.; Chin, Conrad K.; Hao, J.M.

    2010-01-01

    Mercury concentrations of flue gas at inlet/outlet of the flue gas cleaning, electrostatic demister, reclaiming tower, acid plant, and mercury contents in zinc concentrate and by-products were measured in a hydrometallurgical zinc smelter. The removal efficiency of flue gas cleaning, electrostatic demister, mercury reclaiming and acid plant was about 17.4%, 30.3%, 87.9% and 97.4% respectively. Flue gas cleaning and electrostatic demister captured 11.7% and 25.3% of the mercury in the zinc concentrate, respectively. The mercury reclaiming tower captured 58.3% of the mercury in the zinc concentrate. About 4.2% of the mercury in the zinc concentrate was captured by the acid plant. Consequently, only 0.8% of the mercury in the zinc concentrate was emitted to the atmosphere. The atmospheric mercury emission factor was 0.5 g t -1 of zinc produced for the tested smelter, indicating that this process offers the potential to effectively reduce mercury emissions from zinc smelting. - Modern scale production equipped with acid plant and Hg reclaiming tower will significantly reduce Hg emissions from zinc smelters in China.

  15. Treatment of mercury containing waste

    Science.gov (United States)

    Kalb, Paul D.; Melamed, Dan; Patel, Bhavesh R; Fuhrmann, Mark

    2002-01-01

    A process is provided for the treatment of mercury containing waste in a single reaction vessel which includes a) stabilizing the waste with sulfur polymer cement under an inert atmosphere to form a resulting mixture and b) encapsulating the resulting mixture by heating the mixture to form a molten product and casting the molten product as a monolithic final waste form. Additional sulfur polymer cement can be added in the encapsulation step if needed, and a stabilizing additive can be added in the process to improve the leaching properties of the waste form.

  16. Geodesy at Mercury with MESSENGER

    Science.gov (United States)

    Smith, David E.; Zuber, Maria t.; Peale, Stanley J.; Phillips, Roger J.; Solomon, Sean C.

    2006-01-01

    In 2011 the MESSENGER (MErcury Surface, Space ENvironment, GEochemistry, and Ranging) spacecraft will enter Mercury orbit and begin the mapping phase of the mission. As part of its science objectives the MESSENGER mission will determine the shape and gravity field of Mercury. These observations will enable the topography and the crustal thickness to be derived for the planet and will determine the small libration of the planet about its axis, the latter critical to constraining the state of the core. These measurements require very precise positioning of the MESSENGER spacecraft in its eccentric orbit, which has a periapsis altitude as low as 200 km, an apoapsis altitude near 15,000 km, and a closest approach to the surface varying from latitude 60 to about 70 N. The X-band tracking of MESSENGER and the laser altimetry are the primary data that will be used to measure the planetary shape and gravity field. The laser altimeter, which has an expected range of 1000 to 1200 km, is expected to provide significant data only over the northern hemisphere because of MESSENGER's eccentric orbit. For the southern hemisphere, radio occultation measurements obtained as the spacecraft passes behind the planet as seen from Earth and images obtained with the imaging system will be used to provide the long-wavelength shape of the planet. Gravity, derived from the tracking data, will also have greater resolution in the northern hemisphere, but full global models for both topography and gravity will be obtained at low harmonic order and degree. The limiting factor for both gravity and topography is expected to be knowledge of the spacecraft location. Present estimations are that in a combined tracking, altimetry, and occultation solution the spacecraft position uncertainty is likely to be of order 10 m. This accuracy should be adequate for establishing an initial geodetic coordinate system for Mercury that will enable positioning of imaged features on the surface, determination of

  17. Mercury migration into ground water, a literature study

    Energy Technology Data Exchange (ETDEWEB)

    Carlton, W.H.; Carden, J.L.; Kury, R.; Eichholz, G.G.

    1994-11-01

    This report presents a broad review of the technical literature dealing with mercury migration in the soil. The approach followed was to identify relevant articles by searching bibliographic data bases, obtaining the promising articles and searching these articles for any additional relevant citations. Eight catagories were used to organize the literature, with a review and summary of each paper. Catagories used were the following: chemical states of mercury under environmental conditions; diffusion of mercury vapor through soil; solubility and stability of mercury in environmental waters; transport of mercury on colloids; models for mercury migration through the environment; analytical techniques; retention of mercury by soil components; formation of organomecurials.

  18. Study of high levels indoor air mercury contamination from mercury amalgam use in dentistry

    International Nuclear Information System (INIS)

    Khwaja, M.A.; Abbasi, M.S.; Mehmood, F.; Jahangir, S.

    2014-01-01

    In 2005, United Nations Environment Programme (UNEP) estimated that 362 tonnes of dental mercury are consumed annually worldwide. Dental mercury amalgams also called silver fillings and amalgam fillings are widely done. These fillings gave off mercury vapours. Estimated average absorbed concentrations of mercury vapours from dental fillings vary from 3,000 to 17,000 ng Hg. Mercury (Hg) also known as quick silver is an essential constituent of dental amalgam. It is a toxic substance of global concern. A persistent pollutant, mercury is not limited to its source but it travels, on time thousands of kilometers away from the source. Scientific evidence, including, UNEP Global Mercury report, establishes mercury as an extremely toxic substance, which is a major threat to wildlife, ecosystem and human health, at a global scale. Children are more at risk from mercury poisoning which affects their neurological development and brain. Mercury poisoning diminishes memory, attention, thinking and sight. In the past, a number of studies at dental sites in many countries have been carried out and reported which have been reviewed and briefly described. This paper describes and discusses the recent investigations, regarding mercury vapours level in air, carried out at 18 dental sites in Pakistan and other countries. It is evident from the data of 42 dental sites in 17 countries, including, selected dental sites in five main cities of Pakistan, described and discussed in this paper that at most dental sites in many countries including Pakistan, the indoor mercury vapours levels exceed far above the permissible limit, recommended for safe physical and mental health. At these sites, public, in general, and the medical, paramedical staff and vulnerable population, in particular, are at most serious risk to health resulting from exposure to toxic and hazardous mercury. (author)

  19. Immunological detection of small organic molecules in the presence of perchlorates: relevance to the life marker chip and life detection on Mars.

    Science.gov (United States)

    Rix, Catherine S; Sims, Mark R; Cullen, David C

    2011-11-01

    The proposed ExoMars mission, due to launch in 2018, aims to look for evidence of extant and extinct life in martian rocks and regolith. Previous attempts to detect organic molecules of biological or abiotic origin on Mars have been unsuccessful, which may be attributable to destruction of these molecules by perchlorate salts during pyrolysis sample extraction techniques. Organic molecules can also be extracted and measured with solvent-based systems. The ExoMars payload includes the Life Marker Chip (LMC) instrument, capable of detecting biomarker molecules of extant and extinct Earth-like life in liquid extracts of martian samples with an antibody microarray assay. The aim of the work reported here was to investigate whether the presence of perchlorate salts, at levels similar to those at the NASA Phoenix landing site, would compromise the LMC extraction and detection method. To test this, we implemented an LMC-representative sample extraction process with an LMC-representative antibody assay and used these to extract and analyze a model sample that consisted of a Mars analog sample matrix (JSC Mars-1) spiked with a representative organic molecular target (pyrene, an example of abiotic meteoritic infall targets) in the presence of perchlorate salts. We found no significant change in immunoassay function when using pyrene standards with added perchlorate salts. When model samples spiked with perchlorate salts were subjected to an LMC-representative liquid extraction, immunoassays functioned in a liquid extract and detected extracted pyrene. For the same model sample matrix without perchlorate salts, we observed anomalous assay signals that coincided with yellow coloration of the extracts. This unexpected observation is being studied further. This initial study indicates that the presence of perchlorate salts, at levels similar to those detected at the NASA Phoenix landing site, is unlikely to prevent the LMC from extracting and detecting organic molecules from

  20. Occurrence of perchlorate and thiocyanate in human serum from e-waste recycling and reference sites in Vietnam: association with thyroid hormone and iodide levels.

    Science.gov (United States)

    Eguchi, Akifumi; Kunisue, Tatsuya; Wu, Qian; Trang, Pham Thi Kim; Viet, Pham Hung; Kannan, Kurunthachalam; Tanabe, Shinsuke

    2014-07-01

    Perchlorate (ClO4 (-)) and thiocyanate (SCN(-)) interfere with iodide (I(-)) uptake by the sodium/iodide symporter, and thereby these anions may affect the production of thyroid hormones (THs) in the thyroid gland. Although human exposure to perchlorate and thiocyanate has been studied in the United States and Europe, few investigations have been performed in Asian countries. In this study, we determined concentrations of perchlorate, thiocyanate, and iodide in 131 serum samples collected from 2 locations in Northern Vietnam, Bui Dau (BD; electrical and electronic waste [e-waste] recycling site) and Doung Quang (DQ; rural site) and examined the association between serum levels of these anions with levels of THs. The median concentrations of perchlorate, thiocyanate, and iodide detected in the serum of Vietnamese subjects were 0.104, 2020, and 3.11 ng mL(-1), respectively. Perchlorate levels were significantly greater in serum of the BD population (median 0.116 ng mL(-1)) than those in the DQ population (median 0.086 ng mL(-1)), which indicated greater exposure from e-waste recycling operations by the former. Serum concentrations of thiocyanate were not significantly different between the BD and DQ populations, but increased levels of this anion were observed among smokers. Iodide was a significant positive predictor of serum levels of FT3 and TT3 and a significant negative predictor of thyroid-stimulating hormone in males. When the association between serum levels of perchlorate or thiocyanate and THs was assessed using a stepwise multiple linear regression model, no significant correlations were found. In addition to greater concentrations of perchlorate detected in the e-waste recycling population, however, given that lower concentrations of iodide were observed in the serum of Vietnamese females, detailed risk assessments on TH homeostasis for females inhabiting e-waste recycling sites, especially for pregnant women and their neonates, are required.

  1. Substance Flow Analysis of Mercury in China

    Science.gov (United States)

    Hui, L. M.; Wang, S.; Zhang, L.; Wang, F. Y.; Wu, Q. R.

    2015-12-01

    In previous studies, the emission of anthropogenic atmospheric Hg in China as well as single sector have been examined a lot. However, there might have been more Hg released as solid wastes rather than air. Hg stored in solid wastes may be released to air again when the solid wastes experience high temperature process or cause local pollution if the solid wastes are stacked casually for a long time. To trace the fate of Hg in China, this study developed the substance flow of Hg in 2010 covering all the sectors summarized in table 1. Below showed in Figure 1, the total Hg input is 2825t. The unintentional input of Hg, mined Hg, and recycled Hg account for 57%, 32% and 11% respectively. Figure 2 provides the detail information of substance flow of Hg. Byproducts from one sector may be used as raw materials of another, causing cross Hg flow between sectors. The Hg input of cement production is 303 t, of which 34% comes from coal and limestone, 33% comes from non-ferrous smelting, 23% comes from coal combustion, 7% comes from iron and steel production and 3% comes from mercury mining. Hg flowing to recycledHg production is 639 t, mainly from Hg contained in waste active carbon and mercuric chloride catalyst from VCM production and acid sludge from non-ferrous smelting. There are 20 t mercury flowing from spent mercury adding products to incineration. Figure1 and Figure 2 also show that 46% of the output Hg belongs to "Lagged release", which means this part of mercury might be released later. The "Lagged release" Hg includes 809 t Hg contained in stacked byproducts form coal combustion, non-ferrous smelting, iron and steel production, Al production, cement production and mercury mining, 161t Hg stored in the pipeline of VCM producing, 10 t Hg in fluorescent lamps that are in use and 314 t mercury stored in materials waiting to be handled with in recycled mercury plants. There is 112 t Hg stored in landfill and 129 t Hg exported abroad with the export of mercury adding

  2. Mercury in the environment : a primer

    Energy Technology Data Exchange (ETDEWEB)

    Lourie, B.; Glenn, W. (ed.); Ogilvie, K.; Everhardus, E.; Friesen, K.; Rae, S.

    2003-06-01

    This report provides an overview of the occurrence and effects of mercury in the environment and its impacts on human health. Low levels of mercury occur naturally everywhere in the environment in plants, animals, rocks and air. Incidental emissions occur when natural mercury is released to the environment through human activity. In Canada, coal burning and metal processing are the two largest point sources of atmospheric mercury emissions. Energy facilities have the option to invest in expensive control technologies for coal plants, or they can generate electricity from alternative energy sources. Energy conservation, however, offers the greatest overall benefits for the environment and the public. Mercury can also be released when products containing mercury (such as electrical switches, thermostats, dental amalgam, and thermometers) are broken while in use, or when they are crushed in garbage trucks and dumped in landfills. Source separation is the best way to reduce waste-related emissions. Once mercury is released to the natural environment, it can be transported long distances through air or watercourses. It is volatile, therefore evaporates readily to the atmosphere where it may do one of three things: it may fall out near the point where it was emitted; it may be transported long distances to some point downwind; or, it may enter the global atmospheric mercury pool where it will circle the globe for a year or more within the Earth's major weather systems before being deposited. Data from Canada's National Pollutant Release Inventory indicates that mercury releases and transfers total 28,674 kg per year. The most critical component of the mercury cycle is the conversion of inorganic forms of mercury to the organic compound methylmercury which is more toxic to humans. Most concern about mercury focuses on lakes and other aquatic ecosystems. Fish in hydroelectric reservoirs have been found to contain elevated methylmercury levels because natural

  3. 40 CFR Appendix Xiii to Part 266 - Mercury Bearing Wastes That May Be Processed in Exempt Mercury Recovery Units

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 26 2010-07-01 2010-07-01 false Mercury Bearing Wastes That May Be Processed in Exempt Mercury Recovery Units XIII Appendix XIII to Part 266 Protection of Environment... XIII to Part 266—Mercury Bearing Wastes That May Be Processed in Exempt Mercury Recovery Units These...

  4. Groundwater Modeling of Mercury Pollution at a Former Mercury Cell Chlor Alkali Facility in Pavlodar City, Kazakhstan

    Science.gov (United States)

    In northern Kazakhstan, there is a serious case of mercury pollution near the city of Pavlodar from an old mercury cell chlor-alkali plant. The soil, sediment, and water is severely contaminated with mercury and mercury compounds as a result of the industrial activity of this ch...

  5. Removal of toxic ions (chromate, arsenate, and perchlorate) using reverse osmosis, nanofiltration, and ultrafiltration membranes

    KAUST Repository

    Yoon, Jaekyung

    2009-09-01

    Rejection characteristics of chromate, arsenate, and perchlorate were examined for one reverse osmosis (RO, LFC-1), two nanofiltration (NF, ESNA, and MX07), and one ultrafiltration (UF and GM) membranes that are commercially available. A bench-scale cross-flow flat-sheet filtration system was employed to determine the toxic ion rejection and the membrane flux. Both model and natural waters were used to prepare chromate, arsenate, and perchlorate solutions (approximately 100 μg L-1 for each anion) in mixtures in the presence of other salts (KCl, K2SO4, and CaCl2); and at varying pH conditions (4, 6, 8, and 10) and solution conductivities (30, 60, and 115 mS m-1). The rejection of target ions by the membranes increases with increasing solution pH due to the increasingly negative membrane charge with synthetic model waters. Cr(VI), As(V), and ClO4 - rejection follows the order LFC-1 (>90%) > MX07 (25-95%) ≅ ESNA (30-90%) > GM (3-47%) at all pH conditions. In contrast, the rejection of target ions by the membranes decreases with increasing solution conductivity due to the decreasingly negative membrane charge. Cr(VI), As(V), and ClO4 - rejection follows the order CaCl2 < KCl ≅ K2SO4 at constant pH and conductivity conditions for the NF and UF membranes tested. For natural waters the LFC-1 RO membrane with a small pore size (0.34 nm) had a significantly greater rejection for those target anions (>90%) excluding NO3 - (71-74%) than the ESNA NF membrane (11-56%) with a relatively large pore size (0.44 nm), indicating that size exclusion is at least partially responsible for the rejection. The ratio of solute radius (ri,s) to effective membrane pore radius (rp) was employed to compare ion rejection. For all of the ions, the rejection is higher than 70% when the ri,s/rp ratio is greater than 0.4 for the LFC-1 membrane, while for di-valent ions (CrO4 2 -, SO4 2 -, and HAsSO4 2 -) the rejection (38-56%) is fairly proportional to the ri,s/rp ratio (0.32-0.62) for the ESNA

  6. Thermodynamics of the complexation of ciprofloxacin with calcium and magnesium perchlorate

    Energy Technology Data Exchange (ETDEWEB)

    Al-Mustafa, Jamil, E-mail: malkawi@just.edu.jo [Department of Applied Chemistry, Faculty of Arts and Sciences, Jordan University of Science and Technology, P.O. Box 3030, Irbid (Jordan); Taha, Ziyad A. [Department of Applied Chemistry, Faculty of Arts and Sciences, Jordan University of Science and Technology, P.O. Box 3030, Irbid (Jordan)

    2011-07-10

    Highlights: {yields} The thermodynamics of the reactions of ciprofloxacin (CIP) with Ca(ClO{sub 4}){sub 2} and Mg(ClO{sub 4}){sub 2} were investigated by conductometric titration. {yields} The reactions of CIP with each ion produce two ionic complexes with the formulas M(CIP){sup 2+} and M(CIP){sub 2}{sup 2+}. {yields} The change in enthalpy and entropy were negative which indicate that the complexation is driven by the enthalpy change. - Abstract: The thermodynamics of the reactions of ciprofloxacin (CIP) with calcium perchlorate (Ca(ClO{sub 4}){sub 2}) and magnesium perchlorate (Mg(ClO{sub 4}){sub 2}) have been investigated in water-methanol solvent using conductometric titration. The reactions of CIP with each ion produce two ionic complexes with the general formulas M(CIP){sup 2+} and M(CIP){sub 2}{sup 2+}. The stability constants K{sub 1} and K{sub 2} at 25 {sup o}C for the complexes formed from the reaction with Ca(ClO{sub 4}){sub 2} were 8.84 x 10{sup 4} and 3.62 x 10{sup 4}, respectively. For the reaction with Mg(ClO{sub 4}){sub 2}K{sub 1} and K{sub 2} were 1.72 x 10{sup 5} and 2.50 x 10{sup 3}, respectively. The enthalpy ({Delta}H{sub 1}, {Delta}H{sub 2}, {Delta}H{sub 12}) and entropy ({Delta}S{sub 1}, {Delta}S{sub 2}, {Delta}S{sub 12}) of complexation reactions were determined from the temperature dependence of the complexation constants. The reactions of CIP with both ions are accompanied by a decrease in entropy ({Delta}S{sub 12} = -468.12 and -478.89 J/K mol for complexation with Ca(ClO{sub 4}){sub 2} and Mg(ClO{sub 4}){sub 2}, respectively) and enthalpy ({Delta}H{sub 12} = -193.09 and -192.01 kJ/mol for complexation with Ca(ClO{sub 4}){sub 2} and Mg(ClO{sub 4}){sub 2}, respectively), which indicate that the reactions are driven by the enthalpy change.

  7. Excitation of skinned muscle fibers by imposed ion gradients. IV. Effects of stretch and perchlorate ion.

    Science.gov (United States)

    Stephenson, E W

    1989-01-01

    Depolarizing ion gradients stimulate 45Ca release in skeletal muscle fibers skinned by microdissection. Several lines of indirect evidence suggest that sealed transverse (T) tubules rather than sarcoplasmic reticulum (SR) are the locus of such stimulatory depolarization. Two implications of this hypothesis were tested. (a) A requirement for signal transmission was evaluated from the stimulation of 45Ca efflux in fibers that had been highly stretched, an intervention that can impair the electrical stimulation of intact fibers. Length was increased over approximately 95-115 s, after loading with 45Ca and rinsing at normal length; prestimulus 45Ca loss due to stretch itself was very small. In the first study, stimulation of 45Ca release by KCl replacement of K propionate was inhibited completely in fibers stretched to twice slack length, compared with fibers at 1.05-1.1 times slack length. Identical protocols did not alter 45Ca release stimulated by caffeine or Mg2+ reduction, implying that SR Ca release per se was fully functional and inhibition was selective for a preceding step in ionic stimulation. In a second study, stimulation by choline Cl replacement of K methanesulfonate, at constant [K+] [Cl-] product, was inhibited strongly; total 45Ca release decreased 69%, and stimulation above control loss decreased 78%, in segments stretched to twice the length at which sarcomere spacing had been 2.2 micron, compared with paired controls from the same fibers kept at 2.3 micron. (b) Perchlorate potentiation of T tubule activation was evaluated in fibers stimulated at constant [K+] [Cl-] at normal length (2.3 micron); this anion shifts the voltage dependence of intramembrane charge movement and contractile activation in intact fibers. Perchlorate (8 mM) potentiated both submaximal stimulation of Ca2+-dependent 45Ca release by partial choline Cl replacement of K methanesulfonate and the small Ca2+-insensitive 45Ca efflux component stimulated by nearly full replacement in

  8. Action of perchlorate on the voltage dependent inactivation of excitation-contraction coupling in frog skeletal muscle fibres.

    Science.gov (United States)

    Píriz, Nazira; Pizarro, Gonzalo

    2007-01-01

    Perchlorate is an agonist of excitation-contraction coupling (ECC) in skeletal muscle displacing charge movement and release activation towards more negative voltages. Contradictory effects of this compound on the voltage dependent inactivation (VDI) of ECC ranging from no effect to a negative shift have been previously reported. In this study we report the effect of the extracellular application of 8 mM perchlorate to cut frog fibres on: (1) the charge movement that activates release (Q(1)), (2) the charge movement measured in fibres inactivated by depolarization (Q(2)) and (3) on the steady state VDI of Q(1) and Ca(2+) release. Our findings were: (1) The central voltage of Q(1) was negatively displaced by perchlorate from -29.0 +/- 1.6 to -38.4 +/- 1.7 mV (n = 4). The maximum Q(1) was not significantly affected while the slope of the Q(1) vs. V was increased by perchlorate. (2) The central voltage of Q(2) was shifted from -91.6 +/- 1.4 to -102.3 +/- 1.5 mV (n = 4). (3) The central voltage of the steady state inactivation curve of Q(1) went from -39.3 +/- 1.8 to -48.6 +/- 1.2 mV (mean +/- SEM, n = 6). Perchlorate had a paradoxical effect on Ca(2+) release, while potentiated the release flux in fibres held at -90 mV (peak release flux increased from 3.9 +/- 1.1 to 6.8 +/- 1.9 microM/ms, n = 5) it had an inhibitory effect when applied to fibres at a depolarized holding potential (peak release flux decreased from 3.9 +/- 0.9 to 2.0 +/- 0.5 microM/ms, n = 9). The above findings suggest that the effect on the steady state inactivation is a direct consequence of the negative shift in Q(1) activation. The negative shift in the steady state inactivation of Q(1) correlated well with the effect on Ca(2+) release.

  9. Dental amalgam and urinary mercury concentrations: a descriptive study

    OpenAIRE

    Nicolae, Alexandra; Ames, Harry; Qui?onez, Carlos

    2013-01-01

    Background Dental amalgam is a source of elemental and inorganic mercury. The safety of dental amalgam in individuals remains a controversial issue. Urinary mercury concentrations are used to assess chronic exposure to elemental mercury. At present, there are no indications of mercury-associated adverse effects at levels below 5??g Hg/g creatinine (Cr) or 7??g Hg/L (urine). The purpose of the present study is to determine the overall urinary mercury level in the Canadian general population in...

  10. Passive Biobarrier for Treating Co-mingled Perchlorate and RDX in Groundwater at an Active Range

    Science.gov (United States)

    2016-05-12

    emulsified vegetable oil Fe iron ft foot g grams GAC granular activated carbon GC-IRMS gas chromatography-isotope ratio mass spectrometry Hg mercury HMX...be associated with RDX degradation. Moreover, this organism is an anaerobe, with very different physiological characteristics from the...substrate added during biostimulation may be one means of driving the degradative processes in a favorable direction. Use of emulsified vegetable

  11. Mercury's magnetosphere and magnetotial revisited

    International Nuclear Information System (INIS)

    Bergan, S.; Engle, I.M.

    1981-01-01

    Magnetic observations which are not complicated by currents of trapped plasma are a good test of geomagnetopause and geomagnetotail predictions. Recent attempts to model the Hermean magnetospheric field based on a planet-centered magnetic multipole field with a quadrupole moment in addition to the planetary dipole field or a dipole field linearly displaced from planet center and no quadrupole moment have produced reasonably good fits to the Mercury magnetic field measurements. In this work we find a better fit for a dipole displacement from the planet center by making use of an improved representation of the magnetic field in the magnetotail, where many of the Mercury measurements were made. The rms deviation of the data was reduced from 10. or 11. γ to 9.3 γ by employing this new tail field representation. Also, by making use of this new tail field representation, we find a best fit for a dipole displacement of -0.0285 R/sub M/ (earlier, 0.026 R/sub M/) toward the dawn in the magnetic equatorial plane and 0.17 R/sub M/ (earlier, 0.189 R/sub M/ (earlier 0.189 R/sub M/) northward along the magnetic dipole axis, where R/sub M/ is the planet radius. Thus with only minor adjustments in the displacement vector of the dipole from the planet center we achieve a measurable improvement in the fit of the data by using the improved magnetotail field representation

  12. A thin, dense crust for Mercury

    Science.gov (United States)

    Sori, Michael M.

    2018-05-01

    Crustal thickness is a crucial geophysical parameter in understanding the geology and geochemistry of terrestrial planets. Recent development of mathematical techniques suggests that previous studies based on assumptions of isostasy overestimated crustal thickness on some of the solid bodies of the solar system, leading to a need to revisit those analyses. Here, I apply these techniques to Mercury. Using MESSENGER-derived elemental abundances, I calculate a map of grain density (average 2974 ± 89 kg/m3) which shows that Pratt isostasy is unlikely to be a major compensation mechanism of Mercury's topography. Assuming Airy isostasy, I find the best fit value for Mercury's mean crustal thickness is 26 ± 11 km, 25% lower than the most recently reported and previously thinnest number. Several geological implications follow from this relatively low value for crustal thickness, including showing that the largest impacts very likely excavated mantle material onto Mercury's surface. The new results also show that Mercury and the Moon have a similar proportion of their rocky silicates composing their crusts, and thus Mercury is not uniquely efficient at crustal production amongst terrestrial bodies. Higher resolution topography and gravity data, especially for the southern hemisphere, will be necessary to refine Mercury's crustal parameters further.

  13. Elimination of mercury from amalgam in rats

    Energy Technology Data Exchange (ETDEWEB)

    Galic, N. [Dept. of Dental Pathology, School of Dentistry, Zagreb (Croatia); Prpic-Mehicic, G.; Prester, Lj.; Blanusa, M. [Inst. for Medical Research and Occupational Health, Zagreb (Croatia); Krnic, Z.; Erceg, D. [Pliva Pharmaceutical Co., Biomedicine Research Inst. ' ' Pliva' ' , Zagreb (Croatia)

    2001-07-01

    The aim of this study was to measure the urinary mercury excretion in rats exposed to amalgam over a two months period. Animals were either exposed to mercury from 4 dental amalgams or fed the diet containing powdered amalgams. The results showed significantly higher mercury amount in urine of both exposed groups than in control. Even two months after the amalgam had been placed in rats teeth, the amount of mercury in the urine remained 4-5 times higher than in control, and 4 times higher than in rats exposed to diet containing powdered amalgam. The elevated urinary Hg amount was accompanied by an increased level of total protein in urine. In the same exposure period the excretion of total protein in urine of rats with amalgam fillings was 2 times higher than in control and 1.5 times higher than in rats exposed to amalgam through diet. Concentrations of mercury in the sera of all groups were below the detection limit of the method. The results show that amount of mercury and protein in the urine of rats were related to the mercury release from dental amalgam. (orig.)

  14. Mercury flow experiments. 4th report Measurements of erosion rate caused by mercury flow

    CERN Document Server

    Kinoshita, H; Hino, R; Kaminaga, M

    2002-01-01

    The Japan Atomic Energy Research Institute (JAERI) and the High Energy Accelerator Research Organization (KEK) are promoting a construction plan of the Material-Life Science Facility, which is consisted of a Muon Science Facility and a Neutron Scattering Facility, in order to open up the new science fields. The Neutron Scattering Facility will be utilized for advanced fields of Material and Life science using high intensity neutron generated by the spallation reaction of a 1 MW pulsed proton beam and mercury target. Design of the spallation mercury target system aims to obtain high neutron performance with high reliability and safety. Since the target system is using mercury as the target material and contains large amount of radioactive spallation products, it is necessary to estimate reliability for strength of instruments in a mercury flow system during lifetime of the facility. Piping and components in the mercury flow system would be damaged by erosion with mercury flow, since these components will be we...

  15. Concentration of mercury in wheat samples stored with mercury tablets as preservative

    International Nuclear Information System (INIS)

    Lalit, B.Y.; Ramachandran, T.V.

    1977-01-01

    Tablets consisting of mercury in the form of a dull grey powder made by triturating mercury with chalk and sugar are used in Indian household for storing food-grains. The contamination of wheat samples by mercury, when stored with mercury tablets for period of upto four years has been assessed by using non-destructive neutron activation analysis. The details of the analytical procedure used have also been briefly described. The concentration of mercury in wheat increases with storage period. Loss of weight of mercury tablet is proportional to the storage period to a first approximation. In the present experiment, the average weight loss at the and end of first year was 0.009716 g corresponding to 6 ppm in wheat. (T.G.)

  16. Hidden sources of mercury in clinical laboratories.

    Science.gov (United States)

    Alvarez-Chavez, C R; Federico-Perez, R A; Gomez-Alvarez, A; Velazquez-Contreras, L E; Perez-Rios, R

    2014-09-01

    The healthcare sector is an important contributor to mercury (Hg) pollution because of the potential presence of mercury in thermometers, blood pressure cuffs, amalgams, etc. There are also other potential sources of mercury in this sector which are used frequently and in high volumes where the presence of the metal is not obvious and which might be collectively contributing to pollution. For instance, some chemicals used for the clinical diagnosis of illness may contain mercury. The goal of this study was to investigate potential sources of mercury pollution, which originate from clinical laboratory discharges, using an exploratory approach. The focus was on the residue generated during automatic analysis of patients' bodily fluids at a medical center in Hermosillo, Sonora, Mexico. This study shows an overview of what might be happening in the region or the country related to non-obvious sources of mercury in the healthcare sector. The results showed measurable levels of mercury in the residues coming from urine sediment analysis. These amounts do not exceed the maximum allowed by Mexican environmental regulations; nevertheless, the frequency and cumulative volume of residues generated, combined with the potential for persistence and the bioaccumulation of mercury in the environment, warrant attention. The work carried out in this study is being taken as a model for future studies for pollution prevention in the healthcare sector with the goal of measuring mercury emissions to the environment from clinical laboratory wastewater, including identifying sources which--while not obvious--could be important given the frequency and volume of their use in the clinical diagnosis.

  17. The tropical African mercury anomaly: lower than expected mercury concentrations in fish and human hair.

    Science.gov (United States)

    Black, Frank J; Bokhutlo, Thethela; Somoxa, Aaron; Maethamako, Mothusi; Modisaemang, Ontlogetse; Kemosedile, Thebe; Cobb-Adams, Cristina; Mosepele, Ketlhatlogile; Chimbari, Moses

    2011-04-15

    Mercury is a neurotoxin and global pollutant, and wetlands and newly flooded areas are known to be sites of enhanced production of monomethylmercury, the form of mercury that is readily biomagnified in aquatic food chains to potentially toxic levels. The Okavango Delta in Botswana, Southern Africa, is the largest inland delta in the world and a wetland ecosystem that experiences dramatic annual flooding of large tracts of seasonal floodplains. The Delta was, therefore, expected to be home to high mercury levels in fish and to be an area where local subsistence fishing communities would be at substantial risk of mercury toxicity from fish consumption. Total mercury concentrations measured in 27 species of fish from the Okavango Delta averaged (mean±s.d., wet weight) 19±19ng g(-1) in non-piscivorous fish, and 59±53ng g(-1) in piscivorous fish. These mercury concentrations are similar to those reported for fish from lakes in other areas of tropical Africa, demonstrating that not all wetlands are sites of elevated mercury concentrations in biota. Even more intriguing is that concentrations of mercury in fish from across tropical Africa are systematically and substantially lower than those typically reported for fish from freshwater ecosystems elsewhere globally. The reasons for this apparent "African mercury anomaly" are unclear, but this finding poses a unique opportunity to improve our understanding of mercury's biogeochemical cycling in the environment. Mercury concentrations measured in human hair collected in subsistence fishing communities in the Okavango Delta were similarly low (0.21±0.22μg g(-1) dry weight) despite high levels of fish consumption, and reflect the low mercury concentrations in the fish here. Copyright © 2010 Elsevier B.V. All rights reserved.

  18. Methyl mercury, but not inorganic mercury, associated with higher blood pressure during pregnancy.

    Science.gov (United States)

    Wells, Ellen M; Herbstman, Julie B; Lin, Yu Hong; Hibbeln, Joseph R; Halden, Rolf U; Witter, Frank R; Goldman, Lynn R

    2017-04-01

    Prior studies addressing associations between mercury and blood pressure have produced inconsistent findings; some of this may result from measuring total instead of speciated mercury. This cross-sectional study of 263 pregnant women assessed total mercury, speciated mercury, selenium, and n-3 polyunsaturated fatty acids in umbilical cord blood and blood pressure during labor and delivery. Models with a) total mercury or b) methyl and inorganic mercury were evaluated. Regression models adjusted for maternal age, race/ethnicity, prepregnancy body mass index, neighborhood income, parity, smoking, n-3 fatty acids and selenium. Geometric mean total, methyl, and inorganic mercury concentrations were 1.40µg/L (95% confidence interval: 1.29, 1.52); 0.95µg/L (0.84, 1.07); and 0.13µg/L (0.10, 0.17), respectively. Elevated systolic BP, diastolic BP, and pulse pressure were found, respectively, in 11.4%, 6.8%, and 19.8% of mothers. In adjusted multivariable models, a one-tertile increase of methyl mercury was associated with 2.83mmHg (0.17, 5.50) higher systolic blood pressure and 2.99mmHg (0.91, 5.08) higher pulse pressure. In the same models, an increase of one tertile of inorganic mercury was associated with -1.18mmHg (-3.72, 1.35) lower systolic blood pressure and -2.51mmHg (-4.49, -0.53) lower pulse pressure. No associations were observed with diastolic pressure. There was a non-significant trend of higher total mercury with higher systolic blood pressure. We observed a significant association of higher methyl mercury with higher systolic and pulse pressure, yet higher inorganic mercury was significantly associated with lower pulse pressure. These results should be confirmed with larger, longitudinal studies. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. Isolation, screening and identification of mercury resistant bacteria from mercury contaminated soil

    OpenAIRE

    Kowalczyk Anna; Wilińska Magdalena; Chyc Marek; Bojko Monika; Latowski Dariusz

    2016-01-01

    New bacterial strains resistant to high concentration of mercury were obtained and character iz ed focusing on their potential application in bioremediation. The biological material was isolated from soil contaminated with mercury. The ability to removal of Hg from the liquid medium and the effect of the various pH and mercury concentrations in the environment on bacterial strains growth kinetics were tested. The selected strains were identified by analysis of the 16S ribosome subunit coding ...

  20. Mercury fluxes through the sediment water interface and bioavailability of mercury in southern Baltic Sea sediments

    Directory of Open Access Journals (Sweden)

    Jacek Bełdowski

    2009-06-01

    Full Text Available Sediment cores collected in several areas of the southern Baltic were analysed for total mercury (HgTOT and five operationally defined mercury fractions: HgA - contained in pore waters, HgF - bound to fulvic acids, HgH - bound to humic acids, HgS - bound to sulphide, and HgR - residual. An effort was made to quantify mercury fluxes at the sediment/water interface in the study area. Net mercury input, calculated on the basis of sedimentation rate and concentration in the uppermost sediments, ranged from 1 to 5.5 ng cm-2 year-1. Mercury remobilisation from sediments due to diffusion and resuspension was calculated from the proportion of labile mercury and the velocity of near-bottom currents. The results showed that the return soluble and particulate fluxes of mercury from the sediments to the water column constitute a substantial proportion of the input (20-50%, and are slightly higher than those found in pristine areas, although they are less than the values recorded in areas with a history of mercury contamination. In addition, an index was developed to assess the methylation potential of mercury in sediments. Mercury contained in pore waters, and mercury bound to fulvic and humic acids together with Loss on Ignition were used to calculate the semi-quantitative methylation potential (Pm. Despite the simplicity of this approach, Pm correlates well with methyl mercury in fish from the study area.full, complete article (PDF - compatibile with Acrobat 4.0, 291.3 kB

  1. Efficient decomposition of perchlorate to chloride ions in subcritical water by use of steel slag.

    Science.gov (United States)

    Hori, Hisao; Kamijo, Ayae; Inoue, Miki; Chino, Asako; Wu, Qian; Kannan, Kurunthachalam

    2018-03-01

    Decomposition of perchlorate (ClO 4 - ) in subcritical water in the presence of steel slag, a by-product of the steel industry, was investigated. Reactivity of ClO 4 - was low in pure subcritical water state up to 300 °C, whereas adding steel slag efficiently accelerated the decomposition of ClO 4 - to Cl - , with no leaching of heavy metals such as chromium and other environmentally undesirable elements (boron and fluorine). When the reaction was performed in subcritical water at a relatively low temperature (250 °C) for 6 h, virtually all ClO 4 - ions were removed from the reaction solution. The concentration of Cl - after the reaction was well accounted for by the sum of the amount of Cl - ascribed to the decomposition of ClO 4 - and the amount of Cl - leached from the slag. This method was successfully applied to decompose ClO 4 - in water samples collected from a man-made reflection pond following a fireworks display, even though these samples contained much higher concentrations of Cl - and SO 4 2- than ClO 4 - .

  2. The influence of VO2(B nanobelts on thermal decomposition of ammonium perchlorate

    Directory of Open Access Journals (Sweden)

    Zhang Yifu

    2015-09-01

    Full Text Available The influence of vanadium dioxide VO2(B on thermal decomposition of ammonium perchlorate (AP has not been reported before. In this contribution, the effect of VO2(B nanobelts on the thermal decomposition of AP was investigated by the Thermo- Gravimetric Analysis and Differential Thermal Analysis (TG/DTA. VO2(B nanobelts were hydrothermally prepared using peroxovanadium (V complexes, ethanol and water as starting materials. The thermal decomposition temperatures of AP in the presence of I wt.%, 3 wt.% and 6 wt.% of as-obtained VO2

  3. The effect of wax coating, aluminum and ammonium perchlorate on impact sensitivity of HMX

    Directory of Open Access Journals (Sweden)

    Yu-bin LI

    2017-12-01

    Full Text Available Interaction of 1,3,5,7-tetranitro-1,3,5,7-tetrazocane (HMX/ammonium perchlorate (AP and its effect on mechanical sensitivity may result in some restrictions for the application of AP/HMX system in high energetic weapon system. In this work, impact sensitivity test is used to study the effects of wax coating of HMX, AP and aluminum (Al powder on sensitivity properties of HMX/AP/Al mixtures. Thermogravimetry-differential scanning calorimetry (TG-DSC analysis has been developed to investigate the mechanism of interaction between HMX and AP during the course of thermal decomposition of HMX/AP/Al mixtures. The results show that severe interaction effect exists between AP and HMX, which causes the impact sensitivity (H50 to become smaller. The impact energy (E50 of mixture can be improved under the circumstances of effective separating HMX from AP by surface coating with Wax. AP may firstly engender low-temperature decomposition under the circumstance of external heat or mechanical impact, which causes the exothermic peak of HMX forward shift about 28 °C. The gaseous product releasing from thermal decomposition of HMX accelerates further decomposition of AP. For HMX/AP composite system, the interactive catalysis effect between AP and HMX can be eliminated mostly by adding a great deal of Al powder (i.e. above 30%.

  4. Carbon-coated copper nanoparticles prepared by detonation method and their thermocatalysis on ammonium perchlorate

    Directory of Open Access Journals (Sweden)

    Chongwei An

    2017-03-01

    Full Text Available Carbon-coated copper nanoparticles (CCNPs were prepared by initiating a high-density charge pressed with a mixture of microcrystalline wax, hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX, and copper nitrate hydrate (Cu(NO32·3H2O in an explosion vessel filled with nitrogen gas. The detonation products were characterized by transmission electron microcopy (TEM, high resolution transmission electron microcopy (HRTEM, energy dispersive X-ray spectroscopy (EDX, X-ray diffraction (XRD, and Raman spectroscopy. The effects of CCNPs on thermal decomposition of ammonium perchlorate (AP were also investigated by differential scanning calorimeter (DSC. Results indicated that the detonation products were spherical, 25-40 nm in size, and had an apparent core-shell structure. In this structure, the carbon shell was 3-5 nm thick and mainly composed of graphite, C8 (a kind of carbyne, and amorphous carbon. When 5 wt.% CCNPs was mixed with 95 wt.% AP, the high-temperature decomposition peak of AP decreased by 95.97, 96.99, and 96.69 °Cat heating rates of 5, 10, and 20 °C/min, respectively. Moreover, CCNPs decreased the activation energy of AP as calculated through Kissinger’s method by 25%, which indicated outstanding catalysis for the thermal decomposition of AP.

  5. Ferroelectric Polarization Switching Dynamics and Domain Growth of Triglycine Sulfate and Imidazolium Perchlorate

    KAUST Repository

    Ma, He

    2016-04-10

    The weak bond energy and large anisotropic domain wall energy induce many special characteristics of the domain nucleation, growth, and polarization switch in triglycine sulfate (TGS) and imidazolium perchlorate (IM), two typical molecular ferroelectrics. Their domain nucleation and polarization switch are rather slower than those of conventional oxide ferroelectrics, which may be due to the weaker bond energy of hydrogen bond or van der Waals bond than that of ionic bond. These chemical bonds dominate the elastic energy, with the latter being an important component of domain wall energy and playing an important role in domain nucleation and domain growth. The ratio of anisotropic domain wall energy to Gibbs free energy is large in TGS and IM, which allows a favorable domain shape and a special domain evolution under a certain electric field. Therefore, this study not only sheds light on the physical nature but also indicates the application direction for molecular ferroelectrics. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

  6. determination of mercury content in milk powder

    International Nuclear Information System (INIS)

    Jovchev, M.; Grigorov, T.; Apostolov, D.

    1985-01-01

    Four samples of humanized full cream cow milk powder of Bulgarian origin for new-born, sucklings, small children and soured milk powder were activated for 18-24 h in a neutron flux of 5.10 12 , resp. 2.10 13 n/cm 2 .sec in quartz ampules. The samples were activated without preliminary lyophilization, thus avoiding possible mistakes from mercury losses. Ag-110m, being eliminated in the amalgam, was not an obstacle to the mercury determination. The results obtained for the mercury content are in the same order as in other investigations and many times lower than the admissible norm for foodstuffs - 50 ppb

  7. Effect of mercury on algal growth rates

    Energy Technology Data Exchange (ETDEWEB)

    Hannan, P.J.; Patouillet, C.

    1972-01-01

    In experiments with one freshwater (Chlorella pyrenoidosa) and three marine organisms (Phaeodactylum tricornutum, Cyclotella nana, and Chaetoceras gavestonensis), mercury was more toxic than the other metals tested (silver, cadmium, lead, and copper); and its toxicity is comparatively irreversible. Growth was monitored by changes in fluorescence of the cultures over a 3-day test period. The toxicity of the mercury varied inversely with the concentrations of nutrients present. Preliminary experiments indicate that mercury in the form of mercuric chloride is more toxic than as dimethylmercury. 12 references, 3 figures, 1 table.

  8. Conditioning of spent mercury by amalgamation

    International Nuclear Information System (INIS)

    Yim, S. P.; Shon, J. S.; An, B. G.; Lee, H. J.; Lee, J. W.; Ji, C. G.; Kim, S. H.; Yoon, J. H.; Yang, M. S.

    2002-01-01

    Solidification by amalgamation was performed to immobilize and stabilize the liquid spent mercury. First, the appropriate metal and alloy which can convert liquid mercury into a solid form of amalgam were selected through initial tests. The amalgam form, formulated in optimum composition, was characterized and subjected to performance tests including compressive strength, water immersion, leachability and initial vaporization rate to evaluate mechanical integrity, durability and leaching properties. Finally, bench scale amalgamation trial was conducted with about 1 kg of spent mercury to verify the feasibility of amalgamation method

  9. A self-focusing mercury jet target

    CERN Document Server

    Johnson, C

    2002-01-01

    Mercury jet production targets have been studied in relation to antiproton production and, more recently, pion production for a neutrino factory. There has always been a temptation to include some self-focusing of the secondaries by passing a current through the mercury jet analogous to the already proven lithium lens. However, skin heating of the mercury causes fast vaporization leading to the development of a gliding discharge along the surface of the jet. This external discharge can, nevertheless, provide some useful focusing of the secondaries in the case of the neutrino factory. The technical complications must not be underestimated.

  10. Mercury Thermal Hydraulic Loop (MTHL) Summary Report

    Energy Technology Data Exchange (ETDEWEB)

    Felde, David K. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Crye, Jason Michael [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Wendel, Mark W. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Yoder, Jr, Graydon L. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Farquharson, George [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Jallouk, Philip A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); McFee, Marshall T. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Pointer, William David [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Ruggles, Art E. [Univ. of Tennessee, Knoxville, TN (United States); Carbajo, Juan J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2017-03-01

    The Spallation Neutron Source (SNS) is a high-power linear accelerator built at Oak Ridge National Laboratory (ORNL) which incorporates the use of a flowing liquid mercury target. The Mercury Thermal Hydraulic Loop (MTHL) was constructed to investigate and verify the heat transfer characteristics of liquid mercury in a rectangular channel. This report provides a compilation of previously reported results from the water-cooled and electrically heated straight and curved test sections that simulate the geometry of the window cooling channel in the target nose region.

  11. Physical properties of the planet Mercury

    Science.gov (United States)

    Clark, Pamela E.

    1988-01-01

    The global physical properties of Mercury are summarized with attention given to its figure and orbital parameters. The combination of properties suggests that Mercury has an extensive iron-rich core, possibly with a still-functioning dynamo, which is 42 percent of the interior by volume. Mercury's three major axes are comparable in size, indicating that the planet is a triaxial ellipsoid rather than an oblate spheroid. In terms of the domination of its surface by an intermediate plains terrane, it is more Venus- or Mars-like; however, due to the presence of a large metallic magnetic core, its interior may be more earth-like.

  12. MESSENGER'S First and Second Flybys of Mercury

    Science.gov (United States)

    Slavin, James A.

    2009-01-01

    The MESSENGER mission to Mercury offers our first opportunity to explore this planet's miniature magnetosphere since Mariner 10's brief fly-bys in 1974-5. The magnetosphere of Mercury is the smallest in the solar system with its magnetic field typically standing off the solar wind only approximately 1000 km above the surface. An overview of the MESSENGER mission and its January 14th and October 6th, 2008 close flybys of Mercury will be provided. Primary science objectives and the science instrumentation will be described. Initial results from MESSENGER will be discussed with an emphasis on the magnetic field and charged particle measurements.

  13. Injurious effect of mercury vapor from bichloride of mercury in soil of rose houses

    Energy Technology Data Exchange (ETDEWEB)

    Zimmerman, P.W.; Crocker, W.

    1933-01-01

    Addition of mercuric chloride, or corrosive sublimate, to Rose soil for killing earthworms may injure the Roses. The organic matter of the soil reduces the bichloride to metallic mercury and the vapors of the mercury rise into the air and kill the buds and peduncles. When the soil is rich in tankage or other organic matter, the rate of reduction of the bichloride is increased and thereby the severity of the injury intensified. If a container of metallic mercury is set in an enclosed chamber with Rose plants, severe injuries of the type mentioned below soon appear. The Briarcliff Rose is especially susceptible to mercury injury. 1 figure.

  14. Mercury Information Clearinghouse. Quarterly 3: advanced and developmental mercury control technologies

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-07-01

    Advanced mercury control technologies for coal-fired electric utilities are reviewed. The technologies evaluated are at various stages of development and most have been tested under limited operational conditions. The following technologies are described: K-Fuel and K-Fuel Plus pre-combustion technology, combustion modification and in situ generation of sorbents, new sorbent developments, direct bromine injection, MerCAP{sup {trademark}} (Mercury Control via Adsorption Process, Gore felt filter bag inserts, EnviroScrub Pahlman{sup {trademark}} process, combined oxidation of NO{sub x} and mercury, and mercury control with the Advanced Hybrid{trademark} filter. 36 refs., 1 fig.

  15. Solubility of helium in mercury for bubbling technology of the spallation neutron mercury target

    International Nuclear Information System (INIS)

    Hasegawa, S.; Naoe, T.; Futakawa, M.

    2010-01-01

    The pitting damage of mercury target container that originates in the pressure wave excited by the proton beam incidence becomes a large problem to reach the high-power neutron source in JSNS and SNS. The lifetime of mercury container is decreased remarkably by the pitting damage. As one of solutions, the pressure wave is mitigated by injecting the helium micro bubbles in mercury. In order to inject the helium micro bubbles into mercury, it is important to understand the characteristic of micro bubbles in mercury. The solubility of mercury-helium system is a key factor to decide bubbling conditions, because the disappearance behavior, i.e. the lifetime of micro bubbles, depends on the solubility. In addition, the bubble generation method is affected by it. Moreover, the experimental data related to the solubility of helium in mercury hardly exist. In this work, the solubility was obtained experimentally by measuring precisely the pressure drop of the gas that is facing to mercury surface. The pressure drop was attributed to the helium dissolution into mercury. Based on the measured solubility, the lifetime of micro bubbles and the method of the bubble generation is estimated using the solubility data.

  16. Inorganic mercury exposure, mercury-copper interaction, and DMPS treatment in rats.

    OpenAIRE

    Blanusa, M; Prester, L; Radić, S; Kargacin, B

    1994-01-01

    The aim of this study was to evaluate the efficiency of oral treatment with sodium 2,3-dimercaptopropane-1-sulfonate (DMPS) on reducing mercury deposits in rat kidney after chronic exposure to inorganic mercury. The effect on kidney copper levels was also evaluated. The results showed that after two months of exposure to 50 ppm of mercury (as mercuric chloride) the concentration of mercury in the kidney was 124 micrograms/g wet tissue. At the same time copper concentration rose from 11 to 77 ...

  17. Mercury nano-trap for effective and efficient removal of mercury(II) from aqueous solution

    Science.gov (United States)

    Li, Baiyan; Zhang, Yiming; Ma, Dingxuan; Shi, Zhan; Ma, Shengqian

    2014-11-01

    Highly effective and highly efficient decontamination of mercury from aqueous media remains a serious task for public health and ecosystem protection. Here we report that this task can be addressed by creating a mercury ‘nano-trap’ as illustrated by functionalizing a high surface area and robust porous organic polymer with a high density of strong mercury chelating groups. The resultant porous organic polymer-based mercury ‘nano-trap’ exhibits a record-high saturation mercury uptake capacity of over 1,000 mg g-1, and can effectively reduce the mercury(II) concentration from 10 p.p.m. to the extremely low level of smaller than 0.4 p.p.b. well below the acceptable limits in drinking water standards (2 p.p.b.), and can also efficiently remove >99.9% mercury(II) within a few minutes. Our work therefore presents a new benchmark for mercury adsorbent materials and provides a new perspective for removing mercury(II) and also other heavy metal ions from contaminated water for environmental remediation.

  18. Tundra uptake of atmospheric elemental mercury drives Arctic mercury pollution

    Science.gov (United States)

    Obrist, Daniel; Agnan, Yannick; Jiskra, Martin; Olson, Christine L.; Colegrove, Dominique P.; Hueber, Jacques; Moore, Christopher W.; Sonke, Jeroen E.; Helmig, Detlev

    2017-07-01

    Anthropogenic activities have led to large-scale mercury (Hg) pollution in the Arctic. It has been suggested that sea-salt-induced chemical cycling of Hg (through ‘atmospheric mercury depletion events’, or AMDEs) and wet deposition via precipitation are sources of Hg to the Arctic in its oxidized form (Hg(II)). However, there is little evidence for the occurrence of AMDEs outside of coastal regions, and their importance to net Hg deposition has been questioned. Furthermore, wet-deposition measurements in the Arctic showed some of the lowest levels of Hg deposition via precipitation worldwide, raising questions as to the sources of high Arctic Hg loading. Here we present a comprehensive Hg-deposition mass-balance study, and show that most of the Hg (about 70%) in the interior Arctic tundra is derived from gaseous elemental Hg (Hg(0)) deposition, with only minor contributions from the deposition of Hg(II) via precipitation or AMDEs. We find that deposition of Hg(0)—the form ubiquitously present in the global atmosphere—occurs throughout the year, and that it is enhanced in summer through the uptake of Hg(0) by vegetation. Tundra uptake of gaseous Hg(0) leads to high soil Hg concentrations, with Hg masses greatly exceeding the levels found in temperate soils. Our concurrent Hg stable isotope measurements in the atmosphere, snowpack, vegetation and soils support our finding that Hg(0) dominates as a source to the tundra. Hg concentration and stable isotope data from an inland-to-coastal transect show high soil Hg concentrations consistently derived from Hg(0), suggesting that the Arctic tundra might be a globally important Hg sink. We suggest that the high tundra soil Hg concentrations might also explain why Arctic rivers annually transport large amounts of Hg to the Arctic Ocean.

  19. Tundra uptake of atmospheric elemental mercury drives Arctic mercury pollution.

    Science.gov (United States)

    Obrist, Daniel; Agnan, Yannick; Jiskra, Martin; Olson, Christine L; Colegrove, Dominique P; Hueber, Jacques; Moore, Christopher W; Sonke, Jeroen E; Helmig, Detlev

    2017-07-12

    Anthropogenic activities have led to large-scale mercury (Hg) pollution in the Arctic. It has been suggested that sea-salt-induced chemical cycling of Hg (through 'atmospheric mercury depletion events', or AMDEs) and wet deposition via precipitation are sources of Hg to the Arctic in its oxidized form (Hg(ii)). However, there is little evidence for the occurrence of AMDEs outside of coastal regions, and their importance to net Hg deposition has been questioned. Furthermore, wet-deposition measurements in the Arctic showed some of the lowest levels of Hg deposition via precipitation worldwide, raising questions as to the sources of high Arctic Hg loading. Here we present a comprehensive Hg-deposition mass-balance study, and show that most of the Hg (about 70%) in the interior Arctic tundra is derived from gaseous elemental Hg (Hg(0)) deposition, with only minor contributions from the deposition of Hg(ii) via precipitation or AMDEs. We find that deposition of Hg(0)-the form ubiquitously present in the global atmosphere-occurs throughout the year, and that it is enhanced in summer through the uptake of Hg(0) by vegetation. Tundra uptake of gaseous Hg(0) leads to high soil Hg concentrations, with Hg masses greatly exceeding the levels found in temperate soils. Our concurrent Hg stable isotope measurements in the atmosphere, snowpack, vegetation and soils support our finding that Hg(0) dominates as a source to the tundra. Hg concentration and stable isotope data from an inland-to-coastal transect show high soil Hg concentrations consistently derived from Hg(0), suggesting that the Arctic tundra might be a globally important Hg sink. We suggest that the high tundra soil Hg concentrations might also explain why Arctic rivers annually transport large amounts of Hg to the Arctic Ocean.

  20. Rethinking mercury: the role of selenium in the pathophysiology of mercury toxicity.

    Science.gov (United States)

    Spiller, Henry A

    2018-05-01

    There is increasing evidence that the pathophysiological target of mercury is in fact selenium, rather than the covalent binding of mercury to sulfur in the body's ubiquitous sulfhydryl groups. The role of selenium in mercury poisoning is multifaceted, bidirectional, and central to understanding the target organ toxicity of mercury. An initial search was performed using Medline/PubMed, Toxline, Google Scholar, and Google for published work on mercury and selenium. These searches yielded 2018 citations. Publications that did not evaluate selenium status or evaluated environmental status (e.g., lake or ocean sediment) were excluded, leaving approximately 500 citations. This initial selection was scrutinized carefully and 117 of the most relevant and representative references were selected for use in this review. Binding of mercury to thiol/sulfhydryl groups: Mercury has a lower affinity for thiol groups and higher affinity for selenium containing groups by several orders of magnitude, allowing for binding in a multifaceted way. The established binding of mercury to thiol moieties appears to primarily involve the transport across membranes, tissue distribution, and enhanced excretion, but does not explain the oxidative stress, calcium dyshomeostasis, or specific organ injury seen with mercury. Effects of mercury on selenium and the role this plays in the pathophysiology of mercury toxicity: Mercury impairs control of intracellular redox homeostasis with subsequent increased intracellular oxidative stress. Recent work has provided convincing evidence that the primary cellular targets are the selenoproteins of the thioredoxin system (thioredoxin reductase 1 and thioredoxin reductase 2) and the glutathione-glutaredoxin system (glutathione peroxidase). Mercury binds to the selenium site on these proteins and permanently inhibits their function, disrupting the intracellular redox environment. A number of other important possible target selenoproteins have been identified

  1. Mercury pollution in Wuchuan mercury mining area, Guizhou, Southwestern China: the impacts from large scale and artisanal mercury mining.

    Science.gov (United States)

    Li, Ping; Feng, Xinbin; Qiu, Guangle; Shang, Lihai; Wang, Shaofeng

    2012-07-01

    To evaluate the environmental impacts from large scale mercury mining (LSMM) and artisanal mercury mining (AMM), total mercury (THg) and methyl mercury (MeHg) were determined in mine waste, ambient air, stream water and soil samples collected from Wuchuan mercury (Hg) mining area, Guizhou, Southwestern China. Mine wastes from both LSMM and AMM contained high THg concentrations, which are important Hg contamination sources to the local environment. Total gaseous mercury (TGM) concentrations in the ambient air near AMM furnaces were highly elevated, which indicated that AMM retorting is a major source of Hg emission. THg concentrations in the stream water varied from 43 to 2100 ng/L, where the elevated values were mainly found in the vicinity of AMM and mine waste heaps of LSMM. Surface soils were seriously contaminated with Hg, and land using types and organic matter played an important role in accumulation and transportation of Hg in soil. The results indicated heavy Hg contaminations in the study area, which were resulted from both LSMM and AMM. The areas impacted by LSMM were concentrated in the historical mining and smelting facilities, while Hg pollution resulted from AMM can be distributed anywhere in the Hg mining area. Copyright © 2011 Elsevier Ltd. All rights reserved.

  2. Mercury content in electrum from artisanal mining site of Mongolia

    Energy Technology Data Exchange (ETDEWEB)

    Murao, Satoshi [Geological Survey of Japan, AIST, Higashi 1-1-1, No. 7, Tsukuba 305-8567 (Japan)]. E-mail: s.murao@aist.go.jp; Naito, Kazuki [Geological Survey of Japan, AIST, Higashi 1-1-1, No. 7, Tsukuba 305-8567 (Japan); Dejidmaa, Gunchin [Geological Information Center, Mineral and Petroleum Resources Authority of Mongolia, State Building No. 5, Ulaanbaatar (Mongolia); Sie, Soey H. [CSIRO, P.O. Box 136, North Ryde, NSW 1670 (Australia)

    2006-08-15

    In Mongolia, artisanal gold mining, modern gold rush, in which people use mercury to extract gold, is being proliferated rapidly and the mercury contamination of mining site is becoming a serious social issue. For the risk assessment of mercury, it is necessary to understand how much mercury is introduced to the environment from what kind of materials during mining activity. It is already known that major contribution of the contamination comes from mercury that was bought at shops and brought to mining sites by miners. However, no information is available on how much mercury is removed from electrum (natural gold grain) to the environment. Since gold deposit is always accompanied by mercury anomaly, it is anticipated that electrum grains contain some amount of mercury of natural origin, and this mercury (primary mercury) contributes to some extent to the contamination. In order to clarify how much mercury is incorporated in electrum grains, micro-PIXE at CSIRO was used for grain-by-grain analysis. The result showed that electrum from study area contains mercury up to 8260 ppm. It is concluded that for the risk management of mercury contamination, release of natural mercury from electrum grains during smelting must not be ignored.

  3. Mercury content in electrum from artisanal mining site of Mongolia

    Science.gov (United States)

    Murao, Satoshi; Naito, Kazuki; Dejidmaa, Gunchin; Sie, Soey H.

    2006-08-01

    In Mongolia, artisanal gold mining, modern gold rush, in which people use mercury to extract gold, is being proliferated rapidly and the mercury contamination of mining site is becoming a serious social issue. For the risk assessment of mercury, it is necessary to understand how much mercury is introduced to the environment from what kind of materials during mining activity. It is already known that major contribution of the contamination comes from mercury that was bought at shops and brought to mining sites by miners. However, no information is available on how much mercury is removed from electrum (natural gold grain) to the environment. Since gold deposit is always accompanied by mercury anomaly, it is anticipated that electrum grains contain some amount of mercury of natural origin, and this mercury (primary mercury) contributes to some extent to the contamination. In order to clarify how much mercury is incorporated in electrum grains, micro-PIXE at CSIRO was used for grain-by-grain analysis. The result showed that electrum from study area contains mercury up to 8260 ppm. It is concluded that for the risk management of mercury contamination, release of natural mercury from electrum grains during smelting must not be ignored.

  4. Bioavailability and stability of mercury sulfide in Armuchee (USA) soil

    International Nuclear Information System (INIS)

    Han, Fengxiang; Shiyab, Safwan; Su, Yi; Monts, David L.; Waggoner, Charles A.; Matta, Frank B.

    2007-01-01

    Because of the adverse effects of elemental mercury and mercury compounds upon human health, the U.S. Department of Energy (DOE) is engaged in an on-going effort to monitor and remediate mercury-contaminated DOE sites. In order to more cost effectively implement those extensive remediation efforts, it is necessary to obtain an improved understanding of the role that mercury and mercury compounds play in the ecosystem. We have conducted pilot scale experiments to study the bioavailability of mercury sulfide in an Armuchee (eastern US ) soil. The effects of plants and incubation time on chemical stability and bioavailability of HgS under simulated conditions of the ecosystem have been examined, as has the dynamics of the dissolution of mercury sulfide by various extractants. The results show that mercury sulfide in contaminated Armuchee soil was still to some extent bioavailable to plants. After planting, soil mercury sulfide is more easily dissolved by both 4 M and 12 M nitric acid than pure mercury sulfide reagent. Dissolution kinetics of soil mercury sulfide and pure chemical reagent by nitric acid are different. Mercury release by EDTA from HgS-contaminated soil increased with time of reaction and soil mercury level. Chelating chemicals increase the solubility and bioavailability of mercury in HgS-contaminated soil. (authors)

  5. Mercury content in electrum from artisanal mining site of Mongolia

    International Nuclear Information System (INIS)

    Murao, Satoshi; Naito, Kazuki; Dejidmaa, Gunchin; Sie, Soey H.

    2006-01-01

    In Mongolia, artisanal gold mining, modern gold rush, in which people use mercury to extract gold, is being proliferated rapidly and the mercury contamination of mining site is becoming a serious social issue. For the risk assessment of mercury, it is necessary to understand how much mercury is introduced to the environment from what kind of materials during mining activity. It is already known that major contribution of the contamination comes from mercury that was bought at shops and brought to mining sites by miners. However, no information is available on how much mercury is removed from electrum (natural gold grain) to the environment. Since gold deposit is always accompanied by mercury anomaly, it is anticipated that electrum grains contain some amount of mercury of natural origin, and this mercury (primary mercury) contributes to some extent to the contamination. In order to clarify how much mercury is incorporated in electrum grains, micro-PIXE at CSIRO was used for grain-by-grain analysis. The result showed that electrum from study area contains mercury up to 8260 ppm. It is concluded that for the risk management of mercury contamination, release of natural mercury from electrum grains during smelting must not be ignored

  6. Environmental chemistry and toxicology of mercury

    National Research Council Canada - National Science Library

    Liu, Guangliang; Cai, Yong; O'Driscoll, Nelson J

    2012-01-01

    ... employed in recent studies. The coverage discusses the environmental behavior and toxicological effects of mercury on organisms, including humans, and provides case studies at the end of each chapter...

  7. Filter for isotopic alteration of mercury vapor

    Science.gov (United States)

    Grossman, Mark W.; George, William A.

    1989-01-01

    A filter for enriching the .sup.196 Hg content of mercury, including a reactor, a low pressure electric discharge lamp containing a fill of mercury and an inert gas. A filter is arranged concentrically around the lamp. The reactor is arranged around said filter, whereby radiation from said lamp passes through the filter and into said reactor. The lamp, the filter and the reactor are formed of quartz, and are transparent to ultraviolet light. The .sup.196 Hg concentration in the mercury fill is less than that which is present in naturally occurring mercury, that is less than about 0.146 atomic weight percent. Hydrogen is also included in the fill and serves as a quenching gas in the filter, the hydrogen also serving to prevent disposition of a dark coating on the interior of the filter.

  8. Chemistry of impact events on Mercury

    Science.gov (United States)

    Berezhnoy, Alexey A.

    2018-01-01

    Based on the equilibrium thermochemical approach and quenching theory, formation of molecules and dust grains in impact-produced clouds formed after collisions between meteoroids and Mercury is considered. Based on observations of Al, Fe, and Mn atoms in the exosphere of Mercury and new results of studies of the elemental composition of the surface of Mercury, quenching temperatures and pressures of main chemical reactions and condensation of dust particles were estimated. The behavior of the main Na-, K-, Ca-, Fe-, Al-, Mn-, Mg-, Si-, Ti, Ni-, Cr-, Co, Zn-, O-, H-, S-, C-, Cl-, N-, and P-containing species delivered to the Hermean exosphere during meteoroid impacts was studied. The importance of meteoroid bombardment as a source of Na, K, Ca, Fe, Al, Mn, Mg, and O atoms in the exosphere of Mercury is discussed.

  9. Mercury in the South African environment

    CSIR Research Space (South Africa)

    Matooane, M

    2009-11-01

    Full Text Available ? Mercury, also known as quick silver, is ubiquitous in the environment ? Uses - Medical: medicines, thermometers, dental amalgam, etc. - Manufacturing industry: batteries, gold mining, chlorine production, cement production, etc. - Personal care...

  10. Mercury sorbent delivery system for flue gas

    Science.gov (United States)

    Klunder,; Edgar, B [Bethel Park, PA

    2009-02-24

    The invention presents a device for the removal of elemental mercury from flue gas streams utilizing a layer of activated carbon particles contained within the filter fabric of a filter bag for use in a flue gas scrubbing system.

  11. Environmental chemistry and toxicology of mercury

    National Research Council Canada - National Science Library

    Liu, Guangliang; Cai, Yong; O'Driscoll, Nelson J

    2012-01-01

    .... Bringing together information normally spread across several books, this text is unique in covering the entire mercury cycle and providing a baseline for what is known and what uncertainties remain...

  12. Mercury and halogens in coal--Their role in determining mercury emissions from coal combustion

    Science.gov (United States)

    Kolker, Allan; Quick, Jeffrey C.; Senior, Connie L.; Belkin, Harvey E.

    2012-01-01

    Mercury is a toxic pollutant. In its elemental form, gaseous mercury has a long residence time in the atmosphere, up to a year, allowing it to be transported long distances from emission sources. Mercury can be emitted from natural sources such as volcanoes, or from anthropogenic sources, such as coal-fired powerplants. In addition, all sources of mercury on the Earth's surface can re-emit it from land and sea back to the atmosphere, from which it is then redeposited. Mercury in the atmosphere is present in such low concentrations that it is not considered harmful. Once mercury enters the aquatic environment, however, it can undergo a series of biochemical transformations that convert a portion of the mercury originally present to methylmercury, a highly toxic organic form of mercury that accumulates in fish and birds. Many factors contribute to creation of methylmercury in aquatic ecosystems, including mercury availability, sediment and nutrient load, bacterial influence, and chemical conditions. In the United States, consumption of fish with high levels of methylmercury is the most common pathway for human exposure to mercury, leading the U.S. Environmental Protection Agency (EPA) to issue fish consumption advisories in every State. The EPA estimates that 50 percent of the mercury entering the atmosphere in the United States is emitted from coal-burning utility powerplants. An EPA rule, known as MATS (for Mercury and Air Toxics Standards), to reduce emissions of mercury and other toxic pollutants from powerplants, was signed in December 2011. The rule, which is currently under review, specifies limits for mercury and other toxic elements, such as arsenic, chromium, and nickel. MATS also places limits on emission of harmful acid gases, such as hydrochloric acid and hydrofluoric acid. These standards are the result of a 2010 detailed nationwide program by the EPA to sample stack emissions and thousands of shipments of coal to coal-burning powerplants. The United

  13. Gamma radiation stability studies of mercury fulminate

    International Nuclear Information System (INIS)

    Fondeur, F.F.

    2000-01-01

    Mercury fulminate completely decomposed in a gamma source (0.86 Mrad/h) after a dose of 208 Mrad. This exposure equates to approximately 2.4 years in Tank 15H and 4 years in Tank 12H, one of the vessels of concern. Since the tanks lost the supernatant cover layer more than a decade ago, this study suggests that any mercury fulminate or closely related energetic species decomposed long ago if ever formed

  14. Gamma radiation stability studies of mercury fulminate

    Energy Technology Data Exchange (ETDEWEB)

    Fondeur, F.F.

    2000-02-17

    Mercury fulminate completely decomposed in a gamma source (0.86 Mrad/h) after a dose of 208 Mrad. This exposure equates to approximately 2.4 years in Tank 15H and 4 years in Tank 12H, one of the vessels of concern. Since the tanks lost the supernatant cover layer more than a decade ago, this study suggests that any mercury fulminate or closely related energetic species decomposed long ago if ever formed.

  15. Stratigraphy and geologic history of Mercury

    International Nuclear Information System (INIS)

    Spudis, P.D.; Guest, J.E.

    1988-01-01

    The geologic evolution of Mercury based on the Mariner-10 mission data is discussed. As reconstructed through photogeological analysis of global geologic relations of rock-stratigraphic units, Mercury's geologic history is shown to involve intensive early impact bombardment and widespread resurfacing by volcanic lavas. Evidence is presented to indicate that this volcanic activity essentially ended as much as 3 Gyr ago, with most of the major geologic events being completed within the first 1 to 1.5 Gyr of Mercurian history

  16. Mercury's global evolution: New views from MESSENGER

    Science.gov (United States)

    Hauck, S. A., II; Byrne, P. K.; Denevi, B. W.; Grott, M.; McCoy, T.; Stanley, S.

    2015-12-01

    MESSENGER's exploration of Mercury has revealed the planet's rich and dynamic history and provided new constraints on the processes that control its internal evolution. Mercury's surface records evidence of an extensive geological history. This evidence includes resurfacing by impacts and volcanism prior to the end of the late heavy bombardment (LHB) and a subsequent rapid waning of effusive volcanism. Volcanism is an important indicator of the history of melt production. Thousands of globally distributed, contractional tectonic landforms collectively have accommodated a decrease in Mercury's radius of 5-7 km since the end of the LHB. Such contraction results from planetary cooling and crystallization within Mercury's metallic core. Measurements of surface chemistry have provided constraints on internal radiogenic heat production necessary to understand more fully Mercury's thermal evolution. Elemental abundances also reveal that Mercury is strongly chemically reduced, suggesting that the core's iron is alloyed with silicon as well as sulfur, which constrains the dynamics and crystallization of the metallic core. Magnetometer observations show that Mercury's dynamo-generated, dominantly dipolar field is displaced ~500 km northward along the rotation axis. Low-altitude magnetic field observations late in the mission led to the discovery of crustal magnetization in Mercury's ancient crust, dating to at least 3.7 Ga, which places a new constraint on the timing of the dynamo. Monte Carlo parameterized mantle convection models, constrained by these observations, indicate that for global contraction of 7 km or less, mantle convection persists to the present ~40% of the time, with the likelihood of modern convection decreasing with less global contraction. Slow present cooling in these models indicates that dynamo generation is strongly influenced by both a static layer at the top of the core and convective motions within the core driven by compositional buoyancy.

  17. Thermal elastic deformations of the planet Mercury.

    Science.gov (United States)

    Liu, H.-S.

    1972-01-01

    The variation in solar heating due to the resonance rotation of Mercury produces periodic elastic deformations on the surface of the planet. The thermal stress and strain fields under Mercury's surface are calculated after certain simplifications. It is found that deformations penetrate to a greater depth than the variation of solar heating, and that the thermal strain on the surface of the planet pulsates with an amplitude of .004 and a period of 176 days.

  18. Environmental costs of mercury pollution.

    Science.gov (United States)

    Hylander, Lars D; Goodsite, Michael E

    2006-09-01

    Mercury (Hg) has been used for millennia in many applications, primarily in artisanal mining and as an electrode in the chlor-alkali industry. It is anthropogenically emitted as a pollutant from coal fired power plants and naturally emitted, primarily from volcanoes. Its unique chemical characteristics enable global atmospheric transport and it is deposited after various processes, ultimately ending up in one of its final sinks, such as incorporated into deep sediment or bioaccumulated, primarily in the marine environment. All forms of Hg have been established as toxic, and there have been no noted biological benefits from the metal. Throughout time, there have been notable incidents of Hg intoxication documented, and the negative health effects have been documented to those chronically or acutely exposed. Today, exposure to Hg is largely diet or occupationally dependent, however, many are exposed to Hg from their amalgam fillings. This paper puts a tentative monetary value on Hg polluted food sources in the Arctic, where local, significant pollution sources are limited, and relates this to costs for strategies avoiding Hg pollution and to remediation costs of contaminated sites in Sweden and Japan. The case studies are compiled to help policy makers and the public to evaluate whether the benefits to the global environment from banning Hg and limiting its initial emission outweigh the benefits from its continued use or lack of control of Hg emissions. The cases we studied are relevant for point pollution sources globally and their remediation costs ranged between 2,500 and 1.1 million US dollars kg(-1) Hg isolated from the biosphere. Therefore, regulations discontinuing mercury uses combined with extensive flue gas cleaning for all power plants and waste incinerators is cost effective.

  19. Mercury

    Science.gov (United States)

    ... people never recover, but there has been some success in people who receive chelation treatment. References Sue ... ADAM Health Solutions. About MedlinePlus Site Map FAQs Customer Support Get email updates Subscribe to RSS Follow ...

  20. Detection of concealed mercury with thermal neutrons

    International Nuclear Information System (INIS)

    Bell, Z.W.

    1994-01-01

    In the United States today, governments at all levels and the citizenry are paying increasing attention to the effects, both real and hypothetical, of industrial activity on the environment. Responsible modem industries, reflecting this heightened public and regulatory awareness, are either substituting benign materials for hazardous ones, or using hazardous materials only under carefully controlled conditions. In addition, present-day environmental consciousness dictates that we deal responsibly with legacy wastes. The decontamination and decommissioning (D ampersand D) of facilities at which mercury was used or processed presents a variety of challenges. Elemental mercury is a liquid at room temperature and readily evaporates in air. In large mercury-laden buildings, droplets may evaporate from one area only to recondense in other cooler areas. The rate of evaporation is a function of humidity and temperature; consequently, different parts of a building may be sources or sinks of mercury at different times of the day or even the year. Additionally, although mercury oxidizes in air, the oxides decompose upon heating. Hence, oxides contained within pipes or equipment, may be decomposed when those pipes and equipment are cut with saws or torches. Furthermore, mercury seeps through the pores and cracks in concrete blocks and pads, and collects as puddles and blobs in void spaces within and under them