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Sample records for copper perchlorates

  1. A screened hybrid density functional study on energetic complexes: cobalt, nickel and copper carbohydrazide perchlorates.

    PubMed

    Huang, Huisheng; Zhang, Tonglai; Zhang, Jianguo; Wang, Liqiong

    2010-07-15

    The molecular geometry, electronic structure, infrared spectra and thermochemical properties of cobalt and nickel tris(carbohydrazide) perchlorates (CoCP and NiCP) as well as copper bis(carbohydrazide) perchlorate (CuCP) were investigated using the Heyd-Scuseria-Ernzerhof (HSE) screened hybrid density functional. The results show that both perchlorate ions coordinate with the copper atom, and the interactions between copper and perchlorate are ionic, whereas all the metal-carbohydrazide interactions are covalent. Due to the delocalization from the sigma(N-H) bond orbital to the n*(M) antibond orbital, the amino stretching vibrations of these complexes show considerable red-shift compared with those of free carbohydrazide ligand. The calculated heats of reaction and formation indicate that the formations of these complexes are exothermic, and the order of their thermal stability is NiCP>CoCP>CuCP. These agree well with the experimental results. Finally, we find that there is a relationship between the energy gap and impact sensitivity.

  2. Uncommon isonicotinamide supramolecular synthons in copper(II) complexes directed by nitrate and perchlorate anions.

    PubMed

    Daković, Marijana; Popović, Zora

    2009-09-01

    The title compounds, trans-diaquabis(nitrato-kappaO)bis(pyridine-4-carboxamide-kappaN(1))copper(II), [Cu(NO(3))(2)(C(6)H(6)N(2)O)(2)(H(2)O)(2)], (I), and trans-diaquatetrakis(pyridine-4-carboxamide-kappaN(1))copper(II) bis(perchlorate), [Cu(C(6)H(6)N(2)O)(4)(H(2)O)(2)](ClO(4))(2), (II), are composed of mononuclear coordination entities involving Cu(II) ions and isonicotinamide. In (I), the centrosymmetric tetragonally distorted octahedral copper(II) environment contains trans-related isonicotinamide and water molecules in the equatorial plane and two nitrate ions occupying the axial sites. In (II), the equatorial plane of the C(2)-symmetric distorted octahedron is built up of four isonicotinamide ligands, while water molecules occupy the axial positions. The complex molecules of (I) and (II) are linked into three-dimensional supramolecular frameworks by O-H...O and N-H...O hydrogen bonds. The nitrate and perchlorate ions are building blocks that disturb the robust R(2)(2)(8) amide supramolecular motif commonly found in crystal structures of copper-isonicotinamide complexes.

  3. Crystal structures of copper(II) nitrate, copper(II) chloride, and copper(II) perchlorate complexes with 2-formylpyridine semicarbazone

    SciTech Connect

    Chumakov, Yu. M.; Tsapkov, V. I.; Antosyak, B. Ya.; Bairac, N. N.; Simonov, Yu. A.; Bocelli, G.; Pahontu, E.; Gulea, A. P.

    2009-05-15

    Compounds dinitrato(2-formylpyridinesemicarbazone)copper (I), dichloro(2-formylpyridinesemicarbazone) copper hemihydrate (II), and bis(2-formylpyridinesemicarbazone)copper(2+) perchlorate hydrate (III) are synthesized and their crystal structures are determined. In compounds I-III, the neutral 2-formylpyridine semicarbazone molecule (L) is tridentately attached to the copper atom via the N,N,O set of donor atoms. In compounds I and II, the Cu: L ratio is equal to 1: 1, whereas, in III, it is 1: 2. In complex I, the coordination sphere of the copper atom includes two nitrate ions with different structural functions in addition to the L ligand. The structure is built as a one-dimensional polymer in which the NO{sub 3} bidentate group fulfills a bridging function. The coordination polyhedron of the copper(2+) atom can be considered a distorted tetragonal bipyramid (4 + 1 + 1). Compound II has an ionic structure in which the main element is the [CuLCl{sub 2} . Cu(H{sub 2}O)LCl]{sup +} dimer. In the dimer, the copper atoms are linked via one of the {mu}{sub 2}-bridging chlorine atoms. The coordination polyhedra of the central atoms of the Cu(H{sub 2})LCl and CuLCl{sub 2} complex fragments are tetragonal bipyramid and tetragonal pyramid, respectively. In compound III, the copper atom is octahedrally surrounded by two L ligands in the mer configuration.

  4. Carbon-coated copper nanoparticles prepared by detonation method and their thermocatalysis on ammonium perchlorate

    NASA Astrophysics Data System (ADS)

    An, Chongwei; Ding, Penghui; Ye, Baoyun; Geng, Xiaoheng; Wang, Jingyu

    2017-03-01

    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(NO3)2.3H2O) 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. Boron nitride encapsulated copper nanoparticles: a facile one-step synthesis and their effect on thermal decomposition of ammonium perchlorate

    PubMed Central

    Huang, Caijin; liu, Qiuwen; Fan, Wenjie; Qiu, Xiaoqing

    2015-01-01

    Reactivity is of great importance for metal nanoparticles used as catalysts, biomaterials and advanced sensors, but seeking for high reactivity seems to be conflict with high chemical stability required for metal nanoparticles. There is a subtle balance between reactivity and stability. This could be reached for colloidal metal nanoparticles using organic capping reagents, whereas it is challenging for powder metal nanoparticles. Here, we developed an alternative approach to encapsulate copper nanoparticles with a chemical inertness material—hexagonal boron nitride. The wrapped copper nanoparticles not only exhibit high oxidation resistance under air atmosphere, but also keep excellent promoting effect on thermal decomposition of ammonium perchlorate. This approach opens the way to design metal nanoparticles with both high stability and reactivity for nanocatalysts and their technological application. PMID:26567862

  6. Boron nitride encapsulated copper nanoparticles: a facile one-step synthesis and their effect on thermal decomposition of ammonium perchlorate

    NASA Astrophysics Data System (ADS)

    Huang, Caijin; Liu, Qiuwen; Fan, Wenjie; Qiu, Xiaoqing

    2015-11-01

    Reactivity is of great importance for metal nanoparticles used as catalysts, biomaterials and advanced sensors, but seeking for high reactivity seems to be conflict with high chemical stability required for metal nanoparticles. There is a subtle balance between reactivity and stability. This could be reached for colloidal metal nanoparticles using organic capping reagents, whereas it is challenging for powder metal nanoparticles. Here, we developed an alternative approach to encapsulate copper nanoparticles with a chemical inertness material—hexagonal boron nitride. The wrapped copper nanoparticles not only exhibit high oxidation resistance under air atmosphere, but also keep excellent promoting effect on thermal decomposition of ammonium perchlorate. This approach opens the way to design metal nanoparticles with both high stability and reactivity for nanocatalysts and their technological application.

  7. A fluorophore-labelled copper complex: crystal structure, hybrid cyclic water-perchlorate cluster and biological properties.

    PubMed

    Bhat, Satish S; Revankar, Vidyanand K; Shivalingegowda, Naveen; Lokanath, N K

    2017-09-01

    A fluorophore-labelled copper(II) complex, aquabis(dimethylformamide-κO)(perchlorato-κO)[2-(quinolin-2-yl)-1,3-oxazolo[4,5-f][1,10]phenanthroline]copper(II) perchlorate monohydrate, [Cu(ClO4)(C22H12N4O)(C3H7NO)2(H2O)]ClO4·H2O, has been synthesized and characterized. A cyclic hydrogen-bonded water-perchlorate anionic cluster, i.e. [(ClO4)2(H2O)2](2-), has been identified within the structure. Each cyclic anionic cluster unit is interconnected by hydrogen bonding to the cation. The cations join into an infinite hydrogen-bonded chain running in the [010] direction. Furthermore, interaction of the complex with calf-thymus DNA (CT-DNA) and cellular localization within the cells was explored. Spectroscopic studies indicate that the compound has a good affinity for DNA and stains the nucleus of the cells.

  8. Effectiveness of removal of aqueous perchlorate by Cuprilig, a copper(II) derivative of Octolig.

    PubMed

    Martin, Dean F; Kondis, Nicholas P; Alldredge, Robert L

    2009-02-01

    The present study describes the effectiveness of removal of perchlorate ion by Octolig a commercially available immobilized ligand, IMLIG, and by Cuprilig, the cupric ion derivative of this material. Octolig consists of polyethylenediamine moieties covalently bound to a high-surface area silica gel (CAS Registry number = 404899-06-5). Perchlorate in drinking water is a nuisance anion that escapes from firms that produce rocket fuel, batteries, and fireworks and becomes a contaminant of groundwater. It may also be a natural component of the environment. Perchlorate ion can interfere with thyroid function and may also cause birth defects. Perchlorate contamination of water supplies is serious because of the difficulty in removing it, especially in the western United States where a combination of drought and water shortages exacerbate the problems of supplying safe drinking water to an increasing population. In this study, aqueous solutions were passed over a chromatography column containing samples of Cuprilig. Test water contained 70 microg perchlorate/L and effluent was below detection level (< 1 microg/L. Equally good results were obtained for Octolig in deionized water and in well water. Analyses were performed by a commercial laboratory. Mechanisms of interaction are proposed.

  9. A copper(II) perchlorate-promoted tandem reaction of internal alkynol and salicyl N-tosylhydrazone: direct access to isochromeno[3,4-b]chromene.

    PubMed

    Siyang, Hai Xiao; Wu, Xu Rui; Ji, Xiao Yue; Wu, Xin Yan; Liu, Pei Nian

    2014-08-11

    A copper(ii) perchlorate-promoted tandem reaction of internal alkynol and salicyl N-tosylhydrazone provides a novel, concise method for constructing isochromeno[3,4-b]chromene in 35-94% yields. The tandem reaction involves cycloisomerization, formal [4+2] cycloaddition and an elimination process.

  10. Functionalized white graphene - Copper oxide nanocomposite: Synthesis, characterization and application as catalyst for thermal decomposition of ammonium perchlorate.

    PubMed

    Paulose, Sanoop; Raghavan, Rajeev; George, Benny K

    2017-05-15

    Reactivity is of great importance for metal oxide nanoparticles (MONP) used as catalysts and advanced materials, but seeking for higher reactivity seems to be conflict with high chemical stability required for MONP. There is direct balance between reactivity and stability of these MONP. This could be acheived for metal oxide by dispersing them in a substrate. Here, we report a simple, efficient and high-yield process for the production of copper oxide (CuO) nanoparticles dispersed on a chemically inert material, few-layer hexagonal boron nitride (h-BN) with a thickness around 1.7nm and lateral dimensions mostly below 200nm. The mechano-chemical reaction which take place at atmospheric pressure and room temperature involves a urea assisted exfoliation of pristine boron nitride. Copper oxide nanoparticles dispersed on the surface of these few layered h-BN reduced its tendency for aggregation. The optimum concentration of CuO:h-BN was found to be 2:1 which shows highest catalytic activity for the thermal decomposition of ammonium perchlorate. The high catalytic activity of the in situ synthesized CuO-h-BN composite may be attributed to uniform distribution of CuO nanoparticles on the few layered h-BN which in turn provide a number of active sites on the surface due to non aggregation.

  11. Copper(II) bromide, nitrate and perchlorate complexes with sterically demanding N-(6-methylpyridin-2-yl)acetamide ligands.

    PubMed

    Smolentsev, Anton I

    2017-08-01

    Functionalized acid amides are widely used in biology, medicine, environmental chemistry and many other areas. Among them, pyridine-substituted amides, in particular N-(pyridin-2-yl)acetamide and its derivatives, play an important role due to their excellent chelating properties. The donor properties of these ligands can be effectively modified by introducing electron-donating substituents (e.g. alkyl groups) into the heterocycle. On the other hand, substituents in the α-position of the pyridine ring can create steric hindrance, which significantly influences the coordination number and geometry. To achieve a better understanding of these effects, copper(II) complexes with sterically demanding N-(6-methylpyridin-2-yl)acetamide ligands (L) and monoanions of different size, shape and coordination ability have been chosen as model compounds. The crystal structures of three new compounds, bromidobis[N-(6-methylpyridin-2-yl-κN)acetamide-κO]copper(II) bromide, [CuBr(C8H10N2O)]Br, (I), aquabis[N-(6-methylpyridin-2-yl-κN)acetamide-κO]copper(II) dinitrate, [Cu(C8H10N2O)(H2O)](NO3)2, (II), and aquabis[N-(6-methylpyridin-2-yl-κN)acetamide-κO]copper(II) bis(perchlorate), [Cu(C8H10N2O)(H2O)](ClO4)2, (III), have been determined by single-crystal X-ray diffraction analysis. It has been shown that the presence of the 6-methyl group results in either a distorted square-pyramidal or a distorted trigonal-bipyramidal coordination geometry around the Cu(II) centres instead of the typical octahedral geometry observed when the methyl substituent is absent or occupies any other position on the pyridine ring. Moreover, due to the steric hindrance provided by the L ligands, only the bromide ligand, the smallest of the series, enters into the first coordination sphere of the Cu(II) ion in (I). In (II) and (III), the vacant coordination site of the Cu(II) ion is occupied by a water molecule, while the nitrate and perchlorate anions are not involved in coordination to the metal centre

  12. Field dependent ordering temperature in copper pyrazine perchlorate, Cu(pz)2(ClO4)2

    NASA Astrophysics Data System (ADS)

    Landee, Christopher; Xiao, Fan; Turnbull, Mark; Tsyrulin, N.; Kenzelmann, Michel; van Tol, Hans

    2007-03-01

    Copper pyrazine perchlorate is a molecular-based 2D S=1/2 Heisenberg antiferromagnet (QHAF) with a moderate exchange constant (J/k = 17.5 K) and a saturation field of 60 T. The zero-field ordering temperature, as recently determined by muon spin relaxation experiments [1], is 4.3 K corresponding to excellent isolation (J'/J 8x10-4) between magnetic layers [2]. Recent studies of Cu(pz)2(ClO4)2 in applied fields (specific heat and ESR) show the ordering transition to increase with field by as much as 30% in a field of nine tesla. This effect will be discussed in terms of a field-induced anisotropy crossover model [3]. 1. T. Lancaster, S. J. Blundell et al, submitted for publication. 2. P. Sengupta, A. W. Sandvik, and R. R. P. Singh, Phys. Rev. B 68, 094423 (2003). 3. A. Cuccoli et al, Phys. Rev. B 68, 060402 (2003).

  13. PERCHLORATE FACTS

    EPA Science Inventory

    Perchlorate is an anion (negative ion) with the formula C1O 4-. Perchlorate salts are famous in inorganic chemistry on account of their high solubilities. As a result, they are very difficult to remove. Although hot and concentrated perchloric acid is a strong oxidizing agent,...

  14. PERCHLORATE FACTS

    EPA Science Inventory

    Perchlorate is an anion (negative ion) with the formula C1O 4-. Perchlorate salts are famous in inorganic chemistry on account of their high solubilities. As a result, they are very difficult to remove. Although hot and concentrated perchloric acid is a strong oxidizing agent,...

  15. Di-mu-hydroxido-bis{[bis(6-methyl-2-pyridylmethyl)(2-phenylethyl)amine-kappa(3)N',N'',N''']copper(II)} bis(perchlorate).

    PubMed

    García, Ana María; Manzur, Jorge; Vega, Andrés

    2007-07-01

    The title compund, [Cu(2)(OH)(2)(C(22)H(25)N(3))(2)](ClO(4))(2), is a copper(II) dimer, with two [CuL](2+) units [L is bis(6-methyl-2-pyridylmethyl)(2-phenylethyl)amine] bridged by hydroxide groups to define the {[CuL](mu-OH)(2)[CuL]}(2+) cation. Charge balance is provided by perchlorate counter-anions. The cation has a crystallographic inversion centre halfway between the Cu(II) ions, which are separated by 3.0161 (8) Angstrom. The central core of the cation is an almost regular Cu(2)O(2) parallelogram of sides 1.931 (2) and 1.935 (2) Angstrom, with a Cu-O-Cu angle of 102.55 (11) degrees . The coordination geometry around each Cu(II) centre can be best described as a square-based pyramid, with three N atoms from L ligands and two hydroxide O atoms completing the coordination environment. Each cationic unit is hydrogen bonded to two perchlorate anions by means of hydroxide-perchlorate O-H...O interactions.

  16. Poly[[bis­(μ-4,4′-bipyridine-κ2 N:N′)copper(I)] perchlorate 0.24-hydrate

    PubMed Central

    Zhang, Chun-Yan; Yao, Xue-Jun; Wang, Run-Ling; Xie, Cheng-Zhi

    2012-01-01

    The title copper(I) polymeric compound, {[Cu(C10H8N2)2]ClO4·0.24H2O}n, obtained by the reaction of Cu(ClO4)2 and 4,4′-bipyridine (4,4′-bpy) under hydro­thermal conditions, features a fourfold-inter­penetrated diamondoid coordination framework. The asymmetric unit consists of two CuI atoms, three 4,4′-bpy ligands in general positions and two halves of two centrosymmetric 4,4′-bpy ligands, two ClO4 − anions and water mol­ecule with a site-occupancy factor of 0.480 (17). The CuI atoms are in a distorted tetra­hedral coordination environment and are bridged by 4,4′-bpy ligands, forming a diamondoid cationic polymeric framework that encloses two symmetry-independent channels along [100], which accommodate perchlorate anions and water mol­ecules. PMID:22590146

  17. Perchlorate mixed-ligand copper(II) complexes of beta-diketone and ethylene diamine derivatives: thermal, spectroscopic and biochemical studies.

    PubMed

    El-Ayaan, Usama; El-Metwally, Nashwa M; Youssef, Magdy M; El Bialy, Serry A A

    2007-12-31

    The present work carried out a study on perchlorate mixed-ligand copper(II) complexes which have been synthesized from ethylenediamine derivatives (3a-c) and beta-diketones. These complexes, namely [Cu(DA-Cl)(acac)H(2)O]ClO(4)4, [Cu(DA-Cl)(bzac)H(2)O]H(2)O.ClO(4)5, [Cu(DA-OMe)(acac)H(2)O]ClO(4)6, [Cu(DA-OMe)(bzac)H(2)O]ClO(4)7, [Cu(DA-H)(acac)H(2)O]2H(2)O.ClO(4)8 and [Cu(DA-H)(bzac)H(2)O]ClO(4)9 (where acac, acetylacetonate and bzac, benzoylacetonate) were characterized by elemental analysis, spectral (IR and UV-vis) and magnetic moment measurements. Thermal properties and decomposition kinetics of all complexes are investigated. The interpretation, mathematical analysis and evaluation of kinetic parameters (E, A, DeltaH, DeltaS and DeltaG) of all thermal decomposition stages have been evaluated using Coats-Redfern equation. The biochemical studies showed that, the diamines 3a-c have powerful effects on degradation of DNA and protein. The antibacterial screening demonstrated that, the diamine (DA-Cl), 3b has the maximum and broad activities against Gram +ve and Gram -ve bacterial strains.

  18. Perchlorate mixed-ligand copper(II) complexes of β-diketone and ethylene diamine derivatives: Thermal, spectroscopic and biochemical studies

    NASA Astrophysics Data System (ADS)

    El-Ayaan, Usama; El-Metwally, Nashwa M.; Youssef, Magdy M.; El Bialy, Serry A. A.

    2007-12-01

    The present work carried out a study on perchlorate mixed-ligand copper(II) complexes which have been synthesized from ethylenediamine derivatives ( 3a- c) and β-diketones. These complexes, namely [Cu(DA-Cl)(acac)H 2O]ClO 44, [Cu(DA-Cl)(bzac)H 2O]H 2O.ClO 45, [Cu(DA-OMe)(acac)H 2O]ClO 46, [Cu(DA-OMe)(bzac)H 2O]ClO 47, [Cu(DA-H)(acac)H 2O]2H 2O.ClO 48 and [Cu(DA-H)(bzac)H 2O]ClO 49 (where acac, acetylacetonate and bzac, benzoylacetonate) were characterized by elemental analysis, spectral (IR and UV-vis) and magnetic moment measurements. Thermal properties and decomposition kinetics of all complexes are investigated. The interpretation, mathematical analysis and evaluation of kinetic parameters ( E, A, Δ H, Δ S and Δ G) of all thermal decomposition stages have been evaluated using Coats-Redfern equation. The biochemical studies showed that, the diamines 3a- c have powerful effects on degradation of DNA and protein. The antibacterial screening demonstrated that, the diamine (DA-Cl), 3b has the maximum and broad activities against Gram +ve and Gram -ve bacterial strains.

  19. Perchlorate (ClO4) and Perchlorate Salts

    Integrated Risk Information System (IRIS)

    Perchlorate ( ClO4 - ) and Perchlorate Salts CASRN 7790 - 98 - 9 Ammonium perchlorate CASRN 7791 - 03 - 9 Lithium perchlorate CASRN 7778 - 74 - 7 Potassium perchlorate CASRN 7601 - 89 - 0 Sodium perchlorate This U.S . EPA IRIS Summary is based on the U.S . Government - sponsored technical review of

  20. Crystal structure of (perchlorato-κO)(1,4,7,10-tetra-aza-cyclo-dodecane-κ(4)N)copper(II) perchlorate.

    PubMed

    Gray, Jessica L; Gerlach, Deidra L; Papish, Elizabeth T

    2017-01-01

    The crystal structure of the title salt, [Cu(ClO4)(C8H20N4)]ClO4, is reported. The Cu(II) ion exhibits a square-pyramidal geometry and is coordinated by the four N atoms of the neutral 1,4,7,10-tetra-aza-cyclo-dodecane (cyclen) ligand and an O atom from one perchlorate anion, with the second perchlorate ion hydrogen-bonded to one of the amine N atoms of the cyclen ligand. Additional N-H⋯O hydrogen bonds between the amine H atoms and the coordinating and non-coordinating perchlorate groups create a three-dimensional network structure. Crystals were grown from a concentrated methanol solution at ambient temperature, resulting in no co-crystallization of solvent.

  1. Crystal structure of (perchlorato-κO)(1,4,7,10-tetra­aza­cyclo­dodecane-κ4 N)copper(II) perchlorate

    PubMed Central

    Gray, Jessica L.; Gerlach, Deidra L.; Papish, Elizabeth T.

    2017-01-01

    The crystal structure of the title salt, [Cu(ClO4)(C8H20N4)]ClO4, is reported. The CuII ion exhibits a square-pyramidal geometry and is coordinated by the four N atoms of the neutral 1,4,7,10-tetra­aza­cyclo­dodecane (cyclen) ligand and an O atom from one perchlorate anion, with the second perchlorate ion hydrogen-bonded to one of the amine N atoms of the cyclen ligand. Additional N—H⋯O hydrogen bonds between the amine H atoms and the coordinating and non-coordinating perchlorate groups create a three-dimensional network structure. Crystals were grown from a concentrated methanol solution at ambient temperature, resulting in no co-crystallization of solvent. PMID:28083129

  2. Perchlorate Isotope Forensics

    SciTech Connect

    Bohlke, J. K.; Sturchio, N. C.; Gu, Baohua; Horita, Juske; Brown, Gilbert M; Jackson, W. Andrew; Batista, Jacimaria

    2006-01-01

    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 ({sup 37}Cl/{sup 35}Cl and {sup 18}O/{sup 17}O/{sup 16}O) 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.

  3. Perchlorate isotope forensics

    USGS Publications Warehouse

    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.

  4. Modified Activated Carbon Perchlorate Sorbents

    DTIC Science & Technology

    2007-01-25

    and Accomplishments .................................................................................................. 13 Synthesis of Modified...The most promising technology for perchlorate remediation is bioremediation by perchlorate reducing bacteria to destroy perchlorate under...perchlorate reducing bacteria . This is a “SEED-like” proposal aimed specifically at synthesizing GMACs and determining their suitability as perchlorate

  5. {1,1'-Bis[(pyridin-2-yl)meth-yl]-2,2'-bipiperid-yl}(perchlorato)copper(II) perchlorate.

    PubMed

    Yang, Guang; Rybak-Akimova, Elena V; Campana, Charles

    2017-07-01

    The title complex, [Cu(II)(ClO4)(mesoPYBP)](ClO4) {PYBP = 1,1'-bis-[(pyridin-2-yl)meth-yl]-2,2'-bipiperidyl, C22H30N4}, was prepared and found to crystallize with two crystallographically independent complex salt moieties. The metal atoms of the cations adopt a pseudo-square-pyramidal coordination geometry, where the tetra-dentate amino-pyridine ligands (PYBP) are wrapped around the Cu atoms in the equatorial plane. The Cu-O bonds involving an O atom of the coordinating perchlorate anion are approximately perpendicular to the plane. The two remaining non-coordinating perchlorate anions are involved in several C-H⋯O hydrogen bonds with the PYBP ligand and balance the total charge of the complex salt. The two crystallographically independent moieties are related to each other via a pseudo-translation along the a-axis direction. Exact translational symmetry is broken by (i) a difference in the conformation of one of the piperidine rings, featuring a chair conformation in one of the cations, and a sterically disfavored boat conformation in the other; and (ii) by modulation of the non-coordinating perchlorate anions.

  6. {1,1′-Bis[(pyridin-2-yl)meth­yl]-2,2′-bipiperid­yl}(perchlorato)copper(II) perchlorate

    PubMed Central

    Yang, Guang; Rybak-Akimova, Elena V.

    2017-01-01

    The title complex, [CuII(ClO4)(mesoPYBP)](ClO4) {PYBP = 1,1′-bis­[(pyridin-2-yl)meth­yl]-2,2′-bipiperidyl, C22H30N4}, was prepared and found to crystallize with two crystallographically independent complex salt moieties. The metal atoms of the cations adopt a pseudo-square-pyramidal coordination geometry, where the tetra­dentate amino­pyridine ligands (PYBP) are wrapped around the Cu atoms in the equatorial plane. The Cu—O bonds involving an O atom of the coordinating perchlorate anion are approximately perpendicular to the plane. The two remaining non-coordinating perchlorate anions are involved in several C—H⋯O hydrogen bonds with the PYBP ligand and balance the total charge of the complex salt. The two crystallographically independent moieties are related to each other via a pseudo-translation along the a-axis direction. Exact translational symmetry is broken by (i) a difference in the conformation of one of the piperidine rings, featuring a chair conformation in one of the cations, and a sterically disfavored boat conformation in the other; and (ii) by modulation of the non-coordinating perchlorate anions. PMID:28775888

  7. Crystal structure of tin(II) perchlorate trihydrate

    PubMed Central

    Hennings, Erik; Schmidt, Horst; Köhler, Martin; Voigt, Wolfgang

    2014-01-01

    The title compound, [Sn(H2O)3](ClO4)2, was synthesized by the redox reaction of copper(II) perchlorate hexa­hydrate and metallic tin in perchloric acid. Both the trigonal–pyramidal [Sn(H2O)3]2+ cations and tetra­hedral perchlorate anions lie on crystallographic threefold axes. In the crystal, the cations are linked to the anions by O—H⋯O hydrogen bonds, generating (001) sheets. PMID:25552969

  8. Los Alamos National Laboratory Perchlorate Issues.

    SciTech Connect

    Hjeresen, Denny; Rae, Steve; Beers, Bob; Saladen, Mike; Barr, Alice; Pope, Alicia; Dziewinski, Lacek; Scott, Jim; Holcomb, Robert; Hollis, Diana; Leslie Dale,; Williams, Laurie; Strietelmeier, Betty; Carlson, Bryan; Alexander, Rick; Worland, Pete; Hanson, Steve; Stine, Jim; Hiskey, Mike; Archuleta, Jose; Kinkead, Scott; Sherrard, Ann; Longmire, Pat; Witkowski, Marc; Gard, Marvin

    2003-08-04

    This document reviews the chemical structure of the perchlorate anion and the uses of perchlorates, related health issues, applicable drinking water regulations, water supply system monitoring, current laboratory perchlorate use, management of perchlorate compound risks, potential perchlorate sites and sources, the search for a lower perchlorate detection limit, and treatment of perchlorate contamination.

  9. PERCHLORATE IDENTIFICATION IN FERTILIZERS

    EPA Science Inventory

    Perchlorate has contaminated groundwater, drinking water, and soils at several locations in the United States. 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...

  10. Crystal structure of trans-aqua­(perchlorato-κO)bis­(propane-1,3-di­amine-κ2 N,N′)copper(II) perchlorate

    PubMed Central

    Govindaraj, J.; Rajkumar, K.; Ganeshraja, A. S.; Anbalagan, K.; SubbiahPandi, A.

    2014-01-01

    In the title compound, [Cu(ClO4)(C3H10N2)2(H2O)]ClO4, the CuII atom has a distorted octa­hedral coordination sphere and is coordinated by the N atoms of two propane-1,3-di­amine ligands in the equatorial plane. The axial positions are occupied by a water O atom and an O atom of a disordered perchlorate anion [occupancy ratio 0.631 (9):0.369 (9)]. In the crystal, the various components are linked via O—H⋯O, N—H⋯O and C—H⋯O hydrogen bonds, forming sheets lying parallel to (001). PMID:25484768

  11. Perchlorate Treatment Technology Update

    EPA Pesticide Factsheets

    This issue paper has been prepared by EPA's Federal Facilities Forum to provide information about technologies available for treatment of perchlorate contamination in environmental media, including technologies that have been used to date and others that..

  12. Widespread Occurrence of Plant Perchlorate

    NASA Astrophysics Data System (ADS)

    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

  13. Perchlorate in Fertilizers

    DTIC Science & Technology

    1999-09-01

    to the National Technical Information Service (NTIS). At NTIS, it will be available to the generat" public, including foreign nations. This technical...States Environmental Protection Agency National Exposure Research Laboratory, Ecosystems Research Division (EPA/NERJERD). Laboratories who participated in...laboratories TDS total dissolve:solids UV ultra violet V volts Vi PERCHLORATE IN FERTILIZERS 1.0 INTRODUCTION Perchlorate is a powerful oxidizer used in

  14. PERCHLORATE AS AN ENVIRONMENTAL CONTAMINANT

    EPA Science Inventory

    Perchlorate anion (C104) has been found in drinking water supplies throughout the southwestern United States. I t is primarily associated with releases of ammonium perdhlorate by defense contractors, military operations, and aerospace programs. Ammonium perchlorate is used as ...

  15. PERCHLORATE AS AN ENVIRONMENTAL CONTAMINANT

    EPA Science Inventory

    Perchlorate anion (C104) has been found in drinking water supplies throughout the southwestern United States. I t is primarily associated with releases of ammonium perdhlorate by defense contractors, military operations, and aerospace programs. Ammonium perchlorate is used as ...

  16. Di-u-hydroxo-bis{(acetonitrile)dibenzyl(6-methyl-2-pyridylmethyl)-amine-kappa2N,N]copper(II)} bis(perchlorate).

    PubMed

    Rojas, Dario; García, Ana María; Manzur, Jorge; Vega, Andrés

    2005-02-01

    The title compound corresponds to a copper(II) dimer, [Cu2(OH)2(C2H3N)2(C21H22N2)2](ClO4)2, where the metal centres are mu2-bridged by hydroxo groups. The coordination of each copper(II) centre is a slightly distorted square-based pyramid, with two N atoms from dibenzyl(6-methyl-2-pyridylmethyl)amine (BiBzMePMA) and two hydroxo O atoms occupying the basal positions, and the acetonitrile N atom at the apical position. The dimer is centrosymmetric, with a crystallographic inversion centre midway between the two Cu atoms [Cu...Cu = 2.9522 (9) A].

  17. Bioelectrical Perchlorate Remediation

    NASA Astrophysics Data System (ADS)

    Thrash, C.; Achenbach, L. A.; Coates, J. D.

    2007-12-01

    Several bioreactor designs are currently available for the ex-situ biological attenuation of perchlorate- contaminated waters and recently, some of these reactor designs were conditionally approved by the California Department of Health Services for application in the treatment of perchlorate contaminated drinking water. However, all of these systems are dependent on the continual addition of a chemical electron donor to sustain microbial activity and are always subject to biofouling and downstream water quality issues. In addition, residual labile electron donor in the reactor effluent can stimulate microbial growth in water distribution systems and contribute to the formation of potentially toxic trihalomethanes during disinfection by chlorination. As part of our ongoing studies into microbial perchlorate reduction we investigated the ability of dissimilatory perchlorate reducing bacteria (DPRB) to metabolize perchlorate using a negatively charged electrode (cathode) in the working chamber of a bioelectrical reactor (BER) as the primary electron donor. In this instance the DPRB use the electrons on the electrode surface either directly or indirectly in the form of electrolytically produced H2 as a source of reducing equivalents for nitrate and perchlorate reduction. As part of this investigation our fed-batch studies showed that DPRB could use electrons from a graphite cathode poised at -500mV (vs. Ag/AgCl) for the reduction of perchlorate and nitrate. We isolated a novel organism, Dechlorospirillum strain VDY, from the cathode surface after 70 days operation which readily reduced 100 mg.L-1 perchlorate in a mediatorless batch bioelectrical reactor (BER) in 6 days. Continuous up-flow BERs (UFBERs) seeded with active cultures of strain VDY continuously treated waters containing 100 mg.L-1 perchlorate with almost 100% efficiency throughout their operation achieving a non-optimized volumetric loading of 60 mg.L-1 reactor volume.day-1. The same UFBERs also treated

  18. Synthesis and crystal structure of [2,7,12-trimethyl-3,7,11,17-tetra­aza­bicyclo­[11.3.1]hepta­deca-1(17),13,15-triene-κ4 N]copper(II) bis­(perchlorate)

    PubMed Central

    Hilvano, Edward Gabrielle V.; Yang, Guang; Emnacen, Inno A.; Rybak-Akimova, Elena V.; Billones, Junie B.; Carrillo, Maria Constancia O.; Noll, Bruce C.; Organo, Voltaire G.

    2016-01-01

    The title copper(II) complex of a pyridine-containing macrocycle (PyMAC), [Cu(C16H28N4)](ClO4)2, has been prepared. The crystal structure reveals the CuII atom to be octahedrally coordinated by a tetradentate aminopyridine macrocyclic ligand surrounding the metal cation in a square-planar geometry. Two weakly bound perchlorate counter-ions occupy the axial sites above and below the macrocyclic plane. The crystal studied was refined as a two-component pseudo-merohedral twin; the refined fractional contribution of the minor component is 38.77 (8)% PMID:27555952

  19. Synthesis and crystal structure of [2,7,12-trimethyl-3,7,11,17-tetra-aza-bicyclo-[11.3.1]hepta-deca-1(17),13,15-triene-κ(4) N]copper(II) bis-(perchlorate).

    PubMed

    Hilvano, Edward Gabrielle V; Yang, Guang; Emnacen, Inno A; Rybak-Akimova, Elena V; Billones, Junie B; Carrillo, Maria Constancia O; Noll, Bruce C; Organo, Voltaire G

    2016-07-01

    The title copper(II) complex of a pyridine-containing macrocycle (PyMAC), [Cu(C16H28N4)](ClO4)2, has been prepared. The crystal structure reveals the Cu(II) atom to be octahedrally coordinated by a tetradentate aminopyridine macrocyclic ligand surrounding the metal cation in a square-planar geometry. Two weakly bound perchlorate counter-ions occupy the axial sites above and below the macrocyclic plane. The crystal studied was refined as a two-component pseudo-merohedral twin; the refined fractional contribution of the minor component is 38.77 (8).

  20. Perchlorate Regulatory Determination Fact Sheets

    EPA Pesticide Factsheets

    Fact sheets have been developed for the perchlorate regulatory determination corresponding to the following stages published in the Federal Register: Final, Supplemental request for comments, and Preliminary.

  1. Isotopic mapping of groundwater perchlorate plumes.

    PubMed

    Sturchio, Neil C; Hoaglund, John R; Marroquin, Roy J; Beloso, Abelardo D; Heraty, Linnea J; Bortz, Sarah E; Patterson, Thomas L

    2012-01-01

    Analyses of stable isotope ratios of chlorine and oxygen in perchlorate can, in some cases, be used for mapping and source identification of groundwater perchlorate plumes. This is demonstrated here for large, intersecting perchlorate plumes in groundwater from a region having extensive groundwater perchlorate contamination and a large population dependent on groundwater resources. The region contains both synthetic perchlorate derived from rocket fuel manufacturing and testing activities and agricultural perchlorate derived predominantly from imported Chilean (Atacama) nitrate fertilizer, along with a likely component of indigenous natural background perchlorate from local wet and dry atmospheric deposition. Most samples within each plume reflect either a predominantly synthetic or a predominantly agricultural perchlorate source and there is apparently a minor contribution from the indigenous natural background perchlorate. The existence of isotopically distinct perchlorate plumes in this area is consistent with other lines of evidence, including groundwater levels and flow paths as well as the historical land use and areal distribution of potential perchlorate sources.

  2. Copper

    Integrated Risk Information System (IRIS)

    Copper ; CASRN 7440 - 50 - 8 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Effects )

  3. Perchlorate as an environmental contaminant.

    PubMed

    Urbansky, Edward Todd

    2002-01-01

    Perchlorate anion (ClO4-) has been found in drinking water supplies throughout the southwestern United States. It is primarily associated with releases of ammonium perchlorate by defense contractors, military operations, and aerospace programs. Ammonium perchlorate is used as a solid oxidant in missile and rocket propulsion systems. Traces of perchlorate are found in Chile saltpeter, but the use of such fertilizer has not been associated with large scale contamination. Although it is a strong oxidant, perchlorate anion is very persistent in the environment due to the high activation energy associated with its reduction. At high enough concentrations, perchlorate can affect thyroid gland functions, where it is mistakenly taken up in place of iodide. A safe daily exposure has not yet been set, but is expected to be released in 2002. Perchlorate is measured in environmental samples primarily by ion chromatography. It can be removed by anion exchange or membrane filtration. It is destroyed by some biological and chemical processes. The environmental occurrence, toxicity, analytical chemistry, and remediative approaches are discussed.

  4. Perchlorate, iodine and the thyroid

    PubMed Central

    Leung, Angela M.; Pearce, Elizabeth N.; Braverman, Lewis E.

    2014-01-01

    In pharmacologic doses, perchlorate inhibits thyroidal iodine uptake and subsequently decreases thyroid hormone production. Although pharmacologic doses may be used in the treatment of hyperthyroidism, recent literature has focussed on the detection of low levels of perchlorate in the environment, groundwater and foodstuffs and their potential adverse effects on human thyroid function. This is of particular concern to the developing foetus and infant, whose normal neurodevelopment depends on adequate iodine intake for the production of thyroid hormones. Further research is needed to clarify the potential health effects of low-level chronic environmental perchlorate exposure. The health impact of environmental perchlorate may be dependent upon adequate iodine intake and should be interpreted in combination with other environmental exposures that are also potential thyroidal endocrine disruptors. PMID:20172477

  5. Perchlorate Peer Review Frequent Questions

    EPA Pesticide Factsheets

    EPA believes that peer review is an important component of the scientific process. EPA will ask peer reviewers to comment on products that the agency will use to derive a Maximum Contaminant Level Goal (MCLG) for perchlorate.

  6. Effect of nitrate on microbial perchlorate reduction

    NASA Astrophysics Data System (ADS)

    Sun, Y.; Coates, J. D.

    2007-12-01

    Over the last decade perchlorate has been recognized as an important emerging water contaminant that poses a significant public health threat. Because of its chemical stability, low ionic charge density, and significant water solubility microbial remediation has been identified as the most feasible method for its in situ attenuation. Our previous studies have demonstrated that dissimilatory perchlorate reducing bacteria (DPRB) capable of the respiratory reduction of perchlorate into innocuous chloride are ubiquitous in soil and sedimentary environments. As part of their metabolism these organisms reduce perchlorate to chlorite which is subsequently dismutated into chloride and molecular oxygen. These initial steps are mediated by the perchlorate reductase and chlorite dismutase enzymes respectively. Previously we found that the activity of these organisms is dependent on the presence of molybdenum and is inhibited by the presence of oxygen and to different extents nitrate. However, to date, there is little understanding of the mechanisms involved in the regulation of perchlorate reduction by oxygen and nitrate. As a continuation of our studies into the factors that control DPRB activity we investigated these regulatory mechanisms in more detail as a model organism, Dechloromonas aromatica strain RCB, transitions from aerobic metabolism through nitrate reduction to perchlorate reduction. In series of growth transition studies where both nitrate and perchlorate were present, preference for nitrate to perchlorate was observed regardless of the nitrate to perchlorate ratio. Even when the organism was pre-grown anaerobically in perchlorate, nitrate was reduced prior to perchlorate. Using non-growth washed cell suspension, perchlorate- grown D. aromatica was capable of reducing both perchlorate and nitrate concomitantly suggesting the preferentially utilization of nitrate was not a result of enzyme functionality. To elucidate the mechanism for preferential utilization of

  7. Perchlorate uptake in spinach as related to perchlorate, nitrate and chloride concentrations in irrigation water

    USDA-ARS?s Scientific Manuscript database

    Several studies have reported on the detection of perchlorate in edible leafy vegetables irrigated with Colorado River water. However, there is no information on spinach as related to perchlorate in irrigation water nor on the effect of other anions on perchlorate uptake. A greenhouse perchlorate up...

  8. Perchlorate Reduction by Yeast for Mars Exploration

    NASA Technical Reports Server (NTRS)

    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.

  9. PERCHLORATE CROP INTERACTIONS VIA CONTAMINATED IRRIGATION WATER

    EPA Science Inventory

    Perchlorate has contaminated water and sods at several locations in the United States. Perchlorate is water soluble, exceedingly mobile in aqueous systems, and can persist for many decades under typical ground- and surface water conditions. Perchlorate is of concern because of un...

  10. PERCHLORATE CROP INTERACTIONS VIA CONTAMINATED IRRIGATION WATER

    EPA Science Inventory

    Perchlorate has contaminated water and sods at several locations in the United States. Perchlorate is water soluble, exceedingly mobile in aqueous systems, and can persist for many decades under typical ground- and surface water conditions. Perchlorate is of concern because of un...

  11. catena-Poly[[[di­aqua­bis­[1,2-bis­(pyridin-4-yl)diazene]copper(II)]-μ-1,2-bis­(pyridin-4-yl)diazene] bis­(perchlorate)

    PubMed Central

    Ballestero-Martínez, Ernesto; Campos-Fernández, Cristian Saul; Soto-Tellini, Victor Hugo; Gonzalez-Montiel, Simplicio; Martínez-Otero, Diego

    2013-01-01

    In the title compound, {[Cu(C10H8N4)3(H2O)2](ClO4)2}n, the coordination environment of the cationic CuII atom is distorted octa­hedral, formed by pairs of symmetry-equivalent 1,2-bis­(pyridin-4-yl)diazene ligands, bridging 1,2-bis­(pyridin-4-yl)diazene ligands and two non-equivalent water mol­ecules. The 1,2-bis­(pyridin-4-yl)diazene mol­ecules form polymeric chains parallel to [-101] via azo bonds which are situated about inversion centres. Since the CuII atom is situated on a twofold rotation axis, the monomeric unit has point symmetry 2. The perchlorate anions are disordered in a 0.536 (9):0.464 (9) ratio and are acceptors of water H atoms in medium–strong O—H⋯O hydrogen bonds with graph set R 4 4(12). The water mol­ecules, which are coordinated to the CuII atom and are hydrogen-bonded to the perchlorate anions, form columns parallel to [010]. A π–π inter­action [centroid–centroid distance = 3.913 (2) Å] occurs between pyridine rings, and weak C—H⋯O inter­actions also occur. PMID:23794983

  12. catena-Poly[[[di-aqua-bis-[1,2-bis-(pyridin-4-yl)diazene]copper(II)]-μ-1,2-bis-(pyridin-4-yl)diazene] bis-(perchlorate)].

    PubMed

    Ballestero-Martínez, Ernesto; Campos-Fernández, Cristian Saul; Soto-Tellini, Victor Hugo; Gonzalez-Montiel, Simplicio; Martínez-Otero, Diego

    2013-06-01

    In the title compound, {[Cu(C10H8N4)3(H2O)2](ClO4)2} n , the coordination environment of the cationic Cu(II) atom is distorted octa-hedral, formed by pairs of symmetry-equivalent 1,2-bis-(pyridin-4-yl)diazene ligands, bridging 1,2-bis-(pyridin-4-yl)diazene ligands and two non-equivalent water mol-ecules. The 1,2-bis-(pyridin-4-yl)diazene mol-ecules form polymeric chains parallel to [-101] via azo bonds which are situated about inversion centres. Since the Cu(II) atom is situated on a twofold rotation axis, the monomeric unit has point symmetry 2. The perchlorate anions are disordered in a 0.536 (9):0.464 (9) ratio and are acceptors of water H atoms in medium-strong O-H⋯O hydrogen bonds with graph set R 4 (4)(12). The water mol-ecules, which are coordinated to the Cu(II) atom and are hydrogen-bonded to the perchlorate anions, form columns parallel to [010]. A π-π inter-action [centroid-centroid distance = 3.913 (2) Å] occurs between pyridine rings, and weak C-H⋯O inter-actions also occur.

  13. Environmental Perchlorate Exposure: Potential Adverse Thyroid Effects

    PubMed Central

    Leung, Angela M.; Pearce, Elizabeth N.; Braverman, Lewis E.

    2014-01-01

    Purpose of review This review will present a general overview of the sources, human studies, and proposed regulatory action regarding environmental perchlorate exposure. Recent findings Some recent studies have reported significant associations between urinary perchlorate concentrations, thyroid dysfunction, and decreased infant IQ in groups who would be particularly susceptible to perchlorate effects. An update regarding the recent proposed regulatory actions and potential costs surrounding amelioration of perchlorate contamination is provided. Summary The potential adverse thyroidal effects of environmental perchlorate exposure remain controversial, and further research is needed to further define its relationship to human health among pregnant and lactating women and their infants. PMID:25106002

  14. Environmental perchlorate exposure: potential adverse thyroid effects.

    PubMed

    Leung, Angela M; Pearce, Elizabeth N; Braverman, Lewis E

    2014-10-01

    This review will present a general overview of the sources, human studies, and proposed regulatory action regarding environmental perchlorate exposure. Some recent studies have reported significant associations between urinary perchlorate concentrations, thyroid dysfunction, and decreased infant intelligence quotient in groups who would be particularly susceptible to perchlorate effects. An update regarding the recently proposed regulatory actions and potential costs surrounding amelioration of perchlorate contamination is provided. The potential adverse thyroidal effects of environmental perchlorate exposure remain controversial, and further research is needed to further define its relationship to human health among pregnant and lactating women and their infants.

  15. Perchlorate natural attenuation in a riparian zone.

    PubMed

    Borden, Robert C; Knox, Sheri L; Lieberman, M Tony; Ogles, Dora

    2014-01-01

    Multiple lines of evidence were used to document the natural attenuation of perchlorate in a shallow alluvial aquifer. In the upgradient, aerobic portion of the aquifer, perchlorate did not biodegrade. However, natural flushing by groundwater flow is reducing perchlorate concentrations in the aquifer over time. Perchlorate concentrations in the source area are expected to meet cleanup criteria in 11 to 27 years without active remedial measures. At the distal end of the plume, perchlorate is rapidly degraded as it migrates upward through organic rich littoral zone sediments. Apparent first-order degradation rates in groundwater were about 0.20 d(-1) and are consistent with laboratory macrocosm rates (0.12 d(-1)). qPCR results show a distinct region of the littoral zone where perchlorate degraders are elevated. The Eh within this zone varies from +0.1 to +0.3 V indicating perchlorate degraders can thrive in moderately oxidizing conditions. The study has shown that (i) there was no apparent perchlorate biodegradation in aerobic aquifer; (ii) perchlorate declines over time in aerobic aquifer due to flushing; (iii) there was a rapid perchlorate attenuation in organic rich littoral zone; and, (iv) qPCR results show large increases in perchlorate degraders in the littoral zone.

  16. ASSESSMENT OF PERCHLORATE IN FERTILIZERS

    EPA Science Inventory

    Perchlorate has been positively detected only in those materials known to be derived from Chilean caliche, which constitute less than 0.2% of U.S. fertilizer application. The data obtained in the preponderance of investigations suggest that fertilizers do not contribute to envir...

  17. ASSESSMENT OF PERCHLORATE IN FERTILIZERS

    EPA Science Inventory

    Perchlorate has been positively detected only in those materials known to be derived from Chilean caliche, which constitute less than 0.2% of U.S. fertilizer application. The data obtained in the preponderance of investigations suggest that fertilizers do not contribute to envir...

  18. PERCHLORATE BEHAVIOR IN A MUNICIPAL LAKE FOLLOWING FIREWORKS DISPLAYS

    EPA Science Inventory

    Perchlorate salts of potassium and ammonium are the primary oxidants in pyrotechnic mixtures, yet insufficient information is available regarding the relationship between fireworks displays and the environmental occurrence of perchlorate. Here we document changes in perchlorate ...

  19. PERCHLORATE BEHAVIOR IN A MUNICIPAL LAKE FOLLOWING FIREWORKS DISPLAYS

    EPA Science Inventory

    Perchlorate salts of potassium and ammonium are the primary oxidants in pyrotechnic mixtures, yet insufficient information is available regarding the relationship between fireworks displays and the environmental occurrence of perchlorate. Here we document changes in perchlorate ...

  20. The Chemistry of Perchlorate in the Environment

    SciTech Connect

    Brown, Gilbert M; Gu, Baohua

    2006-01-01

    The persistence of perchlorate in groundwater can be understood from its chemical and physical properties and its chemical reactivity. Although perchlorate is a powerful oxidizing agent, its notorious lack of reactivity can be understood from the requirement that reduction involves oxygen atom transfer. Because perchlorate is relatively unreactive, remediation schemes involving direct chemical or electrochemical reduction are not effective. The low hydration energy of perchlorate anions favors sorption on organic anion exchange resins. Remediation methods involving collection on such resins prior to reduction or some other means of disposal are feasible. Biological systems that naturally reduce and degrade perchlorate are also a potentially practical means of remediating perchlorate-contaminated groundwater in a cost-effective manner.

  1. Microbial isotopic fractionation of perchlorate chlorine.

    PubMed

    Coleman, Max L; Ader, Magali; Chaudhuri, Swades; Coates, John D

    2003-08-01

    Perchlorate contamination can be microbially respired to innocuous chloride and thus can be treated effectively. However, monitoring a bioremediative strategy is often difficult due to the complexities of environmental samples. Here we demonstrate that microbial respiration of perchlorate results in a significant fractionation ( approximately -15 per thousand ) of the chlorine stable isotope composition of perchlorate. This can be used to quantify the extent of biotic degradation and to separate biotic from abiotic attenuation of this contaminant.

  2. Ammonium Perchlorate Biodegradation for Industrial Wastewater Treatment

    DTIC Science & Technology

    2000-06-01

    Treatment Plant KCl Potassium Chloride KP Potassium Perchlorate NPDES National Pollutant Discharge Elimination System OB/OD Open Burning/Open...biodegradation treatment plant at Thiokol destroyed 15,400 pounds of perchlorate. Conversion from the yeast-whey nutrient blend to CBP took place in May 1999...a full-scale plant to treat up to 4 gpm of diluted perchlorate brine at the productivity of the Thiokol prototype was $225 million. Estimated

  3. Preparation and Properties of Methylammonium, Perchlorate.

    DTIC Science & Technology

    1978-05-01

    perchloric acid in ethanol and methylamine gas ( produced by heating methylamine solution) was bubbled into 71% perchloric acid. The use of bottled... produced . 2.4 Ammonium As methylamine solution contains a small amount of ammonia as an impurity the amount of AP present in the MAP was determined...principally by a proton transfer reaction to methylamine and perchloric acid, This dissociation reaction , any evaporation of the dissociation products

  4. Microbial Isotopic Fractionation of Perchlorate Chlorine

    PubMed Central

    Coleman, Max L.; Ader, Magali; Chaudhuri, Swades; Coates, John D.

    2003-01-01

    Perchlorate contamination can be microbially respired to innocuous chloride and thus can be treated effectively. However, monitoring a bioremediative strategy is often difficult due to the complexities of environmental samples. Here we demonstrate that microbial respiration of perchlorate results in a significant fractionation (∼−15‰) of the chlorine stable isotope composition of perchlorate. This can be used to quantify the extent of biotic degradation and to separate biotic from abiotic attenuation of this contaminant. PMID:12902300

  5. Aripiprazole salts. II. Aripiprazole perchlorate.

    PubMed

    Freire, Eleonora; Polla, Griselda; Baggio, Ricardo

    2012-06-01

    The molecular structure of aripiprazole perchlorate (systematic name: 4-(2,3-dichlorophenyl)-1-{4-[(2-oxo-1,2,3,4-tetrahydroquinolin-7-yl)oxy]butyl}piperazin-1-ium perchlorate), C(23)H(28)Cl(2)N(3)O(2)(+)·ClO(4)(-), does not differ substantially from the recently published structure of aripiprazole nitrate [Freire, Polla & Baggio (2012). Acta Cryst. C68, o170-o173]. Both compounds have almost identical bond distances, bond angles and torsion angles. The two different counter-ions occupy equivalent places in the two structures, giving rise to very similar first-order `packing motifs'. However, these elemental arrangements interact with each other in different ways in the two structures, leading to two-dimensional arrays with quite different organizations.

  6. Fire-assay collection of gold and silver by copper.

    PubMed

    Diamantatos, A

    1987-08-01

    Gold and silver are very effectively collected in copper after fire-assay fusion at 1200 degrees . The resultant copper button is dissolved in perchloric acid and the parting solution is diluted with an equal volume of water. Both gold and silver are precipitated in the copper perchlorate medium by reduction with formic acid or hydroquinone. The two noble metals are collected, dissolved in acids, and determined by atomic-absorption spectrometry. The proposed procedure is simple, relatively rapid, and has been successfully applied to ores, concentrates, furnace products, and copper alloys. Recoveries compare favourably with those obtained by the classical lead cupellation method.

  7. PHYTOTRANSFORMATION OF PERCHLORATE USING PARROT-FEATHER

    EPA Science Inventory

    Perchlorate is an oxvanion that has been extensively is a strong oxidizing
    agent in solid rocket fuel. Contamination of groundwater has occurred as the result of Perchlorate use. Standard disposal practices during the 1950s through the 1970s did not reflect the current knowled...

  8. ACCUMULATION AND FATE OF PERCHLORATE IN PLANTS

    EPA Science Inventory

    Perchlorate, a component of solid rocket fuels, has emerged as a potential threat to surface water and groundwater at several locations in the U.S. Perchlorate levels up to 16 ug/L were detected in Lake Mead and 5-9 ug/L in the lower Colorado River. The water from the Colorado Ri...

  9. ADSORPTION CHARACTERISTICS OF PERCHLORATE IN SOILS

    EPA Science Inventory

    Perchlorate(CI04) is an oxyanion that originates as a contaminant in ground and surface waters from the dissolution of ammonium, potassium, magnesium or sodium salts. Perchlorate is mainly used in solid rocket fuels, explosives, and military batteries. Because of its potential ha...

  10. PHYTOREMEDIATION OF PERCHLORATE BY TOBACCO PLANTS

    EPA Science Inventory

    Previous studies have shown that tobacco plants are tolerant of perchlorate and will accumulate perchlorate in the plant tissues. The objective of this research was to determine the effectiveness of tobacco plants in phytoremediation, a technology that employs plants to degrade,...

  11. Biodegradation of rocket propellant waste, ammonium perchlorate

    NASA Technical Reports Server (NTRS)

    Naqvi, S. M. Z.; Latif, A.

    1975-01-01

    The short term effects of ammonium perchlorate on selected organisms were studied. A long term experiment was also designed to assess the changes incurred by ammonium perchlorate on the nitrogen and chloride contents of soil within a period of 3 years. In addition, an attempt was made to produce methane gas from anaerobic fermentation of the aquatic weed, Alternanthera philoxeroides.

  12. PHYTOREMEDIATION OF PERCHLORATE BY TOBACCO PLANTS

    EPA Science Inventory

    Previous studies have shown that tobacco plants are tolerant of perchlorate and will accumulate perchlorate in the plant tissues. The objective of this research was to determine the effectiveness of tobacco plants in phytoremediation, a technology that employs plants to degrade,...

  13. PERCHLORATE IN FERTILIZERS?: ANALYSIS BY RAMAN SPECTROSCOPY

    EPA Science Inventory

    Recently, we and others found perchlorate at high levels (approximately 500 - 8000 mg/kg) in 90+% of 25+ fertilizers (primarily lawn-and-garden products) that are not identified as containing components derived from mined Chile saltpeter, which is known to contain perchlorate as ...

  14. MARGINAL IODINE DEFICIENCY EXACERBATES PERCHLORATE THYROID TOXICITY.

    EPA Science Inventory

    The environmental contaminant perchlorate disrupts thyroid homeostasis via inhibition of iodine uptake into the thyroid. This work tested whether iodine deficiency exacerbates the effects of perchlorate. Female 27 day-old LE rats were fed a custom iodine deficient diet with 0, 50...

  15. PERCHLORATE ACCUMULATION FROM FERTILIZER IN LEAFY VEGETATION

    EPA Science Inventory

    Perchlorate contaminated water and soil has been identified in many areas of the United States. Previous studies indicated that the primary source of contamination was from industry and military operations that use perchlorate as an oxidzing agent. However, recent studies have fo...

  16. ACCUMULATION AND FATE OF PERCHLORATE IN PLANTS

    EPA Science Inventory

    Perchlorate, a component of solid rocket fuels, has emerged as a potential threat to surface water and groundwater at several locations in the U.S. Perchlorate levels up to 16 ug/L were detected in Lake Mead and 5-9 ug/L in the lower Colorado River. The water from the Colorado Ri...

  17. PERCHLORATE IN FERTILIZERS?: ANALYSIS BY RAMAN SPECTROSCOPY

    EPA Science Inventory

    Recently, we and others found perchlorate at high levels (approximately 500 - 8000 mg/kg) in 90+% of 25+ fertilizers (primarily lawn-and-garden products) that are not identified as containing components derived from mined Chile saltpeter, which is known to contain perchlorate as ...

  18. MARGINAL IODINE DEFICIENCY EXACERBATES PERCHLORATE THYROID TOXICITY.

    EPA Science Inventory

    The environmental contaminant perchlorate disrupts thyroid homeostasis via inhibition of iodine uptake into the thyroid. This work tested whether iodine deficiency exacerbates the effects of perchlorate. Female 27 day-old LE rats were fed a custom iodine deficient diet with 0, 50...

  19. ADSORPTION CHARACTERISTICS OF PERCHLORATE IN SOILS

    EPA Science Inventory

    Perchlorate(CI04) is an oxyanion that originates as a contaminant in ground and surface waters from the dissolution of ammonium, potassium, magnesium or sodium salts. Perchlorate is mainly used in solid rocket fuels, explosives, and military batteries. Because of its potential ha...

  20. PHYTOTRANSFORMATION OF PERCHLORATE USING PARROT-FEATHER

    EPA Science Inventory

    Perchlorate is an oxvanion that has been extensively is a strong oxidizing
    agent in solid rocket fuel. Contamination of groundwater has occurred as the result of Perchlorate use. Standard disposal practices during the 1950s through the 1970s did not reflect the current knowled...

  1. PERCHLORATE ACCUMULATION FROM FERTILIZER IN LEAFY VEGETATION

    EPA Science Inventory

    Perchlorate contaminated water and soil has been identified in many areas of the United States. Previous studies indicated that the primary source of contamination was from industry and military operations that use perchlorate as an oxidzing agent. However, recent studies have fo...

  2. Novel biomarkers of perchlorate exposure in zebrafish

    USGS Publications Warehouse

    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.

  3. Perchlorate exposure and dose estimates in infants

    PubMed Central

    Valentín-Blasini, Liza; Blount, Benjamin C.; Otero-Santos, Samaret; Cao, Yang; Bernbaum, Judy C.; Rogan, Walter J.

    2011-01-01

    Perchlorate is a naturally occurring inorganic anion used as a component of solid rocket fuel, explosives, and pyrotechnics. Sufficiently high perchlorate intakes can modify thyroid function by competitively inhibiting iodide uptake in adults; however little is known about perchlorate exposure and health effects in infants. Food intake models predict that infants have higher perchlorate exposure doses than adults. For this reason, we measured perchlorate and related anions (nitrate, thiocyanate, and iodide) in 206 urine samples from 92 infants ages 1–377 days and calculated perchlorate intake dose for this population of infants. The median estimated exposure dose for this population of infants was 0.160 μg/kg/day. Of the 205 individual dose estimates, 9% exceeded the reference dose of 0.7 μg/kg/day; 6% of infants providing multiple samples had multiple perchlorate dose estimates above the reference dose. Estimated exposure dose differed by feeding method: breast-fed infants had a higher perchlorate exposure dose (geometric mean 0.220 μg/kg/day) than infants consuming cow milk-based formula (geometric mean 0.103 μg/kg/day, p<0.0001) or soy-based formula (geometric mean 0.027 μg/kg/day, p<0.0001), consistent with dose estimates based on dietary intake data. The ability of perchlorate to block adequate iodide uptake by the thyroid may have been reduced by the iodine-sufficient status of the infants studied (median urinary iodide 125 μg/L). Further research is needed to see whether these perchlorate intake doses lead to any health effects. PMID:21449579

  4. Perchlorate exposure and dose estimates in infants.

    PubMed

    Valentín-Blasini, Liza; Blount, Benjamin C; Otero-Santos, Samaret; Cao, Yang; Bernbaum, Judy C; Rogan, Walter J

    2011-05-01

    Perchlorate is a naturally occurring inorganic anion used as a component of solid rocket fuel, explosives, and pyrotechnics. Sufficiently high perchlorate intakes can modify thyroid function by competitively inhibiting iodide uptake in adults; however, little is known about perchlorate exposure and health effects in infants. Food intake models predict that infants have higher perchlorate exposure doses than adults. For this reason, we measured perchlorate and related anions (nitrate, thiocyanate, and iodide) in 206 urine samples from 92 infants ages 1-377 days and calculated perchlorate intake dose for this sample of infants. The median estimated exposure dose for this sample of infants was 0.160 μg/kg/day. Of the 205 individual dose estimates, 9% exceeded the reference dose of 0.7 μg/kg/day; 6% of infants providing multiple samples had multiple perchlorate dose estimates above the reference dose. Estimated exposure dose differed by feeding method: breast-fed infants had a higher perchlorate exposure dose (geometric mean 0.220 μg/kg/day) than infants consuming cow milk-based formula (geometric mean 0.103 μg/kg/day, p < 0.0001) or soy-based formula (geometric mean 0.027 μg/kg/day, p < 0.0001), consistent with dose estimates based on dietary intake data. The ability of perchlorate to block adequate iodide uptake by the thyroid may have been reduced by the iodine-sufficient status of the infants studied (median urinary iodide 125 μg/L). Further research is needed to see whether these perchlorate intake doses lead to any health effects.

  5. Atmospheric Formation of Perchlorate on Mars

    NASA Astrophysics Data System (ADS)

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

    2011-12-01

    In 2008, NASA's Mars Phoenix Lander measured perchlorate (salts containing ClO4-) concentrations of 0.6 wt%; an amount that is larger than the highest natural concentrations found on Earth [1,2]. However, the origin of Martian perchlorate is unknown. Perchlorates are interesting because some forms are highly deliquescent with very low eutectic temperatures, allowing the possibility of liquids on Mars today. Also, if perchlorates formed via photochemistry (as on Earth), potentially they can be used as a tracer of the past chemistry of the Martian atmosphere. On Earth, naturally-occurring perchlorate is found only in extremely arid areas, such as deserts or within stratospheric aerosols. Recently, [2] modeled the formation of perchlorate over the driest place on Earth, the Atacama Desert. In this mechanism, natural emissions of chlorine-containing volatiles (e.g. HCl) react with photochemically-produced oxidants to make perchloric acid, HClO4. The acid is then dry deposited onto the surface where it forms perchlorate salts. A similar process could have occurred on Mars when the planet was volcanically active. Here, we add halogen and sulfur chemistry to a Martian photochemical model [3] in order to study an analogous formation mechanism for perchlorate on Mars. The model applies for the period over which Mars was volcanically active and dry, as was the case during much of the Hesperian and Amazonian eras. The model boundary conditions include the deposition velocities of halogen species onto the surface, the odd-nitrogen flux from the ionosphere, and the composition of volcanic gases. Varying the boundary conditions tests the model sensitivity. Surface depositional fluxes for perchlorates, and also nitrates and sulfates, are calculated. Model results are then compared to observations of salts on the surface, providing insight into Martian surface mineralogy.

  6. Energetic co-ordination compounds: synthesis, characterization and thermolysis studies on bis-(5-nitro-2H-tetrazolato-N2)tetraammine cobalt(III) perchlorate (BNCP) and its new transition metal (Ni/Cu/Zn) perchlorate analogues.

    PubMed

    Talawar, M B; Agrawal, A P; Asthana, S N

    2005-04-11

    Bis-(5-nitro-2H-tetrazolato-N2)tetraammine[cobalt(III)/nickel(III)] perchlorates (BNCP/BNNP) and mono-(5-nitro-H-tetrazolato-N)triammine [copper(II)/zinc(II)] perchlorates (MNCuP/MNZnP) have been synthesized during this work. The synthesis was carried out by addition of carbonato tetraammine metal [Co/Ni/Cu/Zn] nitrate [CTCN/CTNN/CTCuN/CTZnN] to the aqueous solution of sodium salt of 5-nitrotetrazole followed by reaction with perchloric acid. The precursors were synthesized by the reaction of aqueous solution of their respective nitrates with ammonium carbonate at 70 degrees C. The complexes and their precursors were characterized by determining metal and perchlorate content as well as infrared (IR), electron spectra for chemical analysis (ESCA) and X-ray diffraction (XRD) techniques. The TG profiles indicated that BNCP, BNNP and MNCuP are thermally stable up to the temperature of 260-278 degrees C unlike MNZnP (150 degrees C). Sudden exothermic decomposition was observed in case of bis-(5-nitro-2H-tetrazolato-N2)tetraammine cobalt(III) perchlorate, bis-(5-nitro-2H-tetrazolato-N2)tetraammine nickel(III) perchlorate and mono-(5-nitro-H-tetrazolato-N)triammine zinc(II) perchlorate resulting in the severe damage of the sample cup. Sensitivity data indicated that the Co/Ni/Cu complexes are more friction sensitive (3-4.8 kg) than mono-(5-nitro-H-tetrazolato-N)triammine zinc(II) perchlorate (14 kg). The impact sensitivity results of the complexes corresponded to h50% of 30-36 cm.

  7. Electrochemical stimulation of microbial perchlorate reduction.

    PubMed

    Thrash, J Cameron; Van Trump, J Ian; Weber, Karrie A; Miller, Elisabeth; Achenbach, Laurie A; Coates, John D

    2007-03-01

    As part of our studies into the diversity of dissimilatory perchlorate reducing bacteria (DPRB) we investigated the reduction of perchlorate in the cathodic chamber of a bioelectrical reactor (BER). Our results demonstrated that washed cells of Dechloromonas and Azospira species readily reduced 90 mg L(-1) perchlorate in the BER with 2,6-anthraquinone disulfonate (AQDS) as a mediator. No perchlorate was reduced in the absence of cells or AQDS, or in an open-circuit control. Similar results were observed when a natural microbial community was inoculated into a fed-batch BER. After 70 days of operation, a novel DPRB, strain VDY, was isolated which readily reduced perchlorate in a mediatorless BER. Continuous up-flow BERs (UFBERs) were seeded with active cultures of strain VDY, and perchlorate at a volumetric loading of 60 mg L(-1) day(-1) was successfully removed. Gas phase analysis indicated that low levels of H2 produced at the cathode surface through electrolysis may mediate this metabolism. The results of these studies demonstrate that biological perchlorate remediation can be facilitated through the use of a cathode as the primary electron donor, and that continuous treatment in such a system approaches current industry standards. This has important implications for the continuous treatment of this critical contaminant in industrial waste streams and drinking water.

  8. Phytoremediation of perchlorate by free floating macrophytes.

    PubMed

    Bhaskaran, Krishnakumar; Vijaya Nadaraja, Anupama; Tumbath, Soumya; Babu Shah, Liji; Gangadharan Puthiya Veetil, Prajeesh

    2013-09-15

    Phytoremediation of perchlorate by free floating macrophytes (Eichornia, Pistia, Salvinia and Lemna) was evaluated in this study. Among the plants tested, Pistia showed 63.8 ± 4% (w/v) removal of 5 mg/L level perchlorate in 7 days, whereas the removal was absent in other plants. Phyto-accumulation (18.2%) and rhizo-degradation (45.68%) were identified as the mechanisms involved in perchlorate removal in Pistia. Whole plant extraction yielded 45.4 μg perchlorate/g dry weight biomass in 7 days period. High intensity of light and presence of nitrate negatively affected perchlorate removal by Pistia. An enrichment of Pistia root homogenate exhibited faster reduction of perchlorate where 100mg/L of the compound was reduced completely in 48 h under anoxic condition. A novel perchlorate reducing bacterium, isolated from Pistia root homogenate enrichment was identified as Acinetobacter sp. NIIST (Genbank JX467695). Copyright © 2013 Elsevier B.V. All rights reserved.

  9. Perchlorate Formation by Radiolysis on Mars

    NASA Astrophysics Data System (ADS)

    Wilson, E. H.; Atreya, S. K.; Kaiser, R. I.; Mahaffy, P. R.

    2015-12-01

    With recent observations indicating the presence of perchlorate (ClO4-) in the Martian surface by the Phoenix lander and the Sample Analysis at Mars (SAM) on the Mars Science Laboratory (MSL) rover, we employ a one-dimensional chemical model to investigate the viability of perchlorate formation in the atmosphere of Mars, instigated by the radiolysis of the Martian surface by galactic cosmic rays. The surface-atmosphere interaction to produce Martian perchlorate involves the injection of chlorine oxides into the atmosphere through surface radiolysis and the subsequent chemical conversion to perchloric acid (HClO4), followed by surface deposition and mineralization to perchlorate. Considering the chlorine oxide, OClO, we find an effective mechanism for forming perchloric acid, bypassing the efficient Cl/HCl recycling mechanism that characterizes HClO4 formation mechanisms proposed for the Earth. Through this mechanism, an OClO surface flux as low as 3.2*107 molecules cm-2 s-1 could produce enough HClO4 to explain the perchlorate concentration observed on Mars. These results could have wide-ranging implications in our understanding of chlorine chemistry on both Earth and Mars.

  10. Perchlorate reduction by microbes inhabiting oil reservoirs

    NASA Astrophysics Data System (ADS)

    Liebensteiner, Martin; Stams, Alfons; Lomans, Bart

    2014-05-01

    Microbial perchlorate and chlorate reduction is a unique type of anaerobic respiration as during reduction of (per)chlorate chlorite is formed, which is then split into chloride and molecular oxygen. In recent years it was demonstrated that (per)chlorate-reducing bacteria may employ oxygenase-dependent pathways for the degradation of aromatic and aliphatic hydrocarbons. These findings suggested that (per)chlorate may be used as oxygen-releasing compound in anoxic environments that contain hydrocarbons, such as polluted soil sites and oil reservoirs. We started to study perchlorate reduction by microbes possibly inhabiting oil reservoirs. One of the organisms studied was Archaeoglobus fulgidus. This extremely thermophilic archaeon is known as a major contributor to souring in hot oil reservoirs. A. fulgidus turned out to be able to use perchlorate as terminal electron acceptor for growth with lactate (Liebensteiner et al 2013). Genome based physiological experiments indicated that A. fulgidus possesses a novel perchlorate reduction pathway. Perchlorate is first reduced to chlorite, but chlorite is not split into chloride and molecular oxygen as occurs in bacteria. Rather, chlorite reacts chemically with sulfide, forming oxidized sulfur compounds, which are reduced to sulfide in the electron transport chain by the archaeon. The dependence of perchlorate reduction on sulfur compounds could be shown. The implications of our findings as novel strategy for microbiological enhanced oil recovery and for souring mitigation are discussed. Liebensteiner MG, Pinkse MWH, Schaap PJ, Stams AJM and Lomans BP (2013) Archaeal (per)chlorate reduction at high temperature, a matter of abiotic-biotic reactions. Science 340: 85-87

  11. (Dipyrido[3,2-a:2',3'-c]phenazine)(glycinato)copper(II) perchlorate: a novel DNA-intercalator with anti-proliferative activity against thyroid cancer cell lines.

    PubMed

    Terenzi, Alessio; Tomasello, Laura; Spinello, Angelo; Bruno, Giuseppe; Giordano, Carla; Barone, Giampaolo

    2012-12-01

    A novel copper(II) heteroleptic complex of dipyrido[3,2-a:2',3'-c]phenazine (dppz) and glycinato (gly) as chelating ancillary ligand, [Cu(dppz)(gly)]ClO(4) (1), was synthesized and characterized. X-ray crystallography revealed that the coordination geometry of the cationic [Cu(dppz)(gly)](+) unit is hexacoordinated and shows a distorted octahedral coordination geometry in the solid state, with the N,N and N,O chelating atoms of dppz and glycinato, respectively, in the square plane and in which the planar units are connected in a monodimensional polymeric array by the apical copper coordination of the second carboxylic oxygen atom. Biological assays showed that 1 exhibits a remarkable anti-proliferative activity against the two human anaplastic thyroid cancer cell lines 8505c (BrafV600E/V600E) and SW1736 (BrafWT/V600E), in a dose- and time-dependent manner. In details, the IC(50) after 48 h of drug exposure was 2.86 ± 0.54 μM for SW1736 and 1.05 ± 0.48 μM for 8505c. On the other hand, the IC(50) shown by cis-diamminedichloroplatinum(II) (cisplatin) against the same cell lines was 2.50 ± 0.40 μM and 6.03 ± 0.78 μM, respectively. Optical microscopy observations, after 48 h of treatment, showed morphological cell changes typical of apoptosis, confirmed by DNA ladder assays. DNA interaction studies, performed by UV absorption spectrophotometry, circular dichroism and viscosimetry, clearly showed that [Cu(dppz)(gly)]ClO(4) is a DNA-intercalator, with a DNA-binding constant, K(b), of 2.1 × 10(6) M(-1), suggesting that the mechanism of the cytotoxic activity can be related to its DNA-binding. Copyright © 2012 Elsevier Inc. All rights reserved.

  12. Biodegradation of rocket propellent waste, ammonium perchlorate

    NASA Technical Reports Server (NTRS)

    Naqui, S. M. Z.

    1975-01-01

    The impact of the biodegradation rate of ammonium perchlorate on the environment was studied in terms of growth, metabolic rate, and total biomass of selected animal and plant species. Brief methodology and detailed results are presented.

  13. Perchlorate Removal, Destruction, and Field Monitoring Demonstration

    DTIC Science & Technology

    2006-10-02

    operational pH (3 to 5), bicarbonate will be converted rapidly to carbonic acid and achieve equilibrium. A backpressure regulator will maintain constant...Groundwater Composition Perchlorate, mg/L 1.5 0.05 Bicarbonate Alkalinity, mg/L 150 150 Treated water composition Perchlorate, mg/L...0.004 ɘ.004 Bicarbonate alkalinity, mg/L N/A - 5 30 WBA resin treatment capacity, BV 6500 15,500 Regeneration solution Biodegrade and

  14. Natural Attenuation of Perchlorate in Groundwater: Processes, Tools and Monitoring Techniques

    DTIC Science & Technology

    2008-04-01

    dissolved solids TOC total organic carbon USEPA United States Environmental Protection Agency VOA volatile organic analysis VOC volatile organic...the western Unites States , more than 15 million people consume water with some level of perchlorate. The human health concern from perchlorate is...perchlorate, sodium perchlorate, potassium perchlorate, and perchloric acid. Of these, in the United States , approximately 90% of the production

  15. Direct enrichment of perchlorate-reducing microbial community for efficient electroactive perchlorate reduction in biocathodes.

    PubMed

    Mieseler, Maren; Atiyeh, Mays N; Hernandez, Hector H; Ahmad, Farrukh

    2013-11-01

    Biological reduction of perchlorate (ClO₄⁻) has emerged as a promising solution for the removal of perchlorate in contaminated water and soils. In this work, we demonstrate a simple process to enrich perchlorate-reducing microbial communities separately using acetate as electron donor and the municipal aerobic membrane bioreactor sludge as inoculum. Inoculation of cathodes in microbial fuel cells (MFCs) with these enrichments, and further electrochemical enrichment at constant resistance operation of the MFCs, led to perchlorate-reducing biocathodes with peak reduction rates of 0.095 mM/day (2 mg/m²/day). Analysis of the microbial diversity of perchlorate-reducing biocathodes using PCR-DGGE revealed unique community profiles when compared to the denitrifying biocathode communities. More importantly, the total time taken for enrichment of the electroactive communities was reduced from several months reported previously in literature to less than a month in this work.

  16. Stable Isotope Systematics of Martian Perchlorate

    NASA Astrophysics Data System (ADS)

    Martin, P.; Farley, K. A.; Archer, D., Jr.; Atreya, S. K.; Conrad, P. G.; Eigenbrode, J. L.; Fairen, A.; Franz, H. B.; Freissinet, C.; Glavin, D. P.; Mahaffy, P. R.; Malespin, C.; Ming, D. W.; Navarro-Gonzalez, R.; Sutter, B.

    2015-12-01

    Chlorine isotopic compositions in HCl released during evolved gas analysis (EGA) runs have been detected by the Sample Analysis at Mars (SAM) instrument on the Curiosity rover ranging from approximately -9‰ to -50‰ δ37Cl, with two spatially and isotopically separated groups of samples averaging -15‰ and -45‰. These extremely low values are the first such detection of any known natural material; common terrestrial values very rarely exceed ±5‰, and the most extreme isotopic signature yet detected elsewhere in the solar system are values of around +24‰ on the Moon. The only other known location in the solar system with large negative chlorine isotopes is the Atacama Desert, where perchlorate with -14‰ δ37Cl has been detected. The Atacama perchlorate has unusual Δ17O signatures associated with it, indicating a formation mechanism involving O3, which suggests an atmospheric origin of the perchlorate and associated large isotopic anomalies. Identification of non-zero positive Δ17O signatures in the O2 released during EGA runs would allow definitive evidence for a similar process having occurred on Mars. Perchlorate is thought to be the most likely source of HCl in EGA runs due to the simultaneous onset of O2 release. If perchlorate is indeed the HCl source, atmospheric chemistry could be responsible for the observed isotopic anomalies, with variable extents of perchlorate production producing the isotopic variability. However, chloride salts have also been observed to release HCl upon heating; if the timing of O2 release is merely coincidental, observed HCl could be coming from chlorides. At thermodynamic equilibrium, the fractionation factor of perchlorate reduction is 0.93, meaning that differing amounts of post-deposition reduction of isotopically normal perchlorate to chloride could account for the highly variable Cl isotopes. Additionally, post-deposition reduction could account for the difference between the two Cl isotopic groups if perchlorate

  17. The Microbiology of Perchlorate in the Environment

    NASA Astrophysics Data System (ADS)

    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

  18. Dose-Response Relationship Between Orally Administered Ammonium Perchlorate and Urine Perchlorate Concentrations in Rats: Possible Biomarker to Quantify Environmental Ammonium Perchlorate Exposure on Thyroid Homeostasis.

    PubMed

    Chen, Hong Xia; Ding, Miao Hong; Li, Yong Gan; Liu, Qin; Peng, Kai Liang

    2015-01-01

    To evaluate the feasibility of urine perchlorate as a biomarker of ammonium perchlorate (AP) exposure and to explore the correlation between the thyroid function indicators and the perchlorate concentrations, a sensitive and selective ultra-high-performance liquid chromatography-mass spectrometry (UHPLC-MS) method was developed to detect perchlorate in urine samples. Rats were orally administrated with different doses of perchlorate. Serum free thyroxine (FT4), free triiodothyronine (FT3), and thyroid-stimulating hormone (TSH) were determined by radioimmunoassays. The results showed that a dose of AP up to 520 mg kg(-1) body weight induced a significant increase of TSH, with a decrease of FT4. Particularly, the levels of urine perchlorate increased dose-dependently on AP exposure from drinking water. The findings highlighted that urine perchlorate may be a useful biomarker for AP environmental exposure.

  19. A Colorimetric Bioassay for Perchlorate

    NASA Astrophysics Data System (ADS)

    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. Perchlorate and nitrate in situ bioremediation of ground water

    SciTech Connect

    Strietelmeier, E. A.; Nuttall, H. Eric; Hatzinger, Paul; Goltz, Mark

    2002-01-01

    Nitrate and perchlorate are growing worldwide problems as mobile anionic groundwater contaminants. Biological rduction of nitrate and perchlorate in groundwater is under development as a technology to address these problems.

  1. SURVEY OF FERTILIZERS AND RELATED MATERIALS FOR PERCHLORATE

    EPA Science Inventory

    The most comprehensive survey of fertilizers and other raw materials for perchlorate to date has been conducted to determine whether these could be significant contributors to environmental perchlorate contamination. Although the data span a large range of commercial products, th...

  2. INVESTIGATION OF AGRICULTURAL FERTILIZERS AND RELATED MATERIALS FOR PERCHLORATE

    EPA Science Inventory

    The most comprehensive survey of fertilizers and other raw materials for perchlorate to date has been conducted to determine whether these could be significant contributors to environmental perchlorate contamination. Although the data span a large range of commercial products, th...

  3. SURVEY OF FERTILIZERS AND RELATED MATERIALS FOR PERCHLORATE

    EPA Science Inventory

    The most comprehensive survey of fertilizers and other raw materials for perchlorate to date has been conducted to determine whether these could be significant contributors to environmental perchlorate contamination. Although the data span a large range of commercial products, th...

  4. INVESTIGATION OF AGRICULTURAL FERTILIZERS AND RELATED MATERIALS FOR PERCHLORATE

    EPA Science Inventory

    The most comprehensive survey of fertilizers and other raw materials for perchlorate to date has been conducted to determine whether these could be significant contributors to environmental perchlorate contamination. Although the data span a large range of commercial products, th...

  5. The Effects of Perchlorate on Methane Production of Methanogens

    NASA Astrophysics Data System (ADS)

    Goodhart, T.; Kral, T. A.

    2010-04-01

    In May 2008, the Phoenix space craft analyzed the martian soil, detecting perchlorate, which is a highly oxidizing compound and potentially harmful to organic matter. This presentation discusses the effects that perchlorate has on methanogen growth.

  6. Methane Production by Methanogens in Perchlorate-supplemented Media

    NASA Astrophysics Data System (ADS)

    Howe, K. L.; Gavin, P.; Goodhart, T.; Kral, T. A.

    2009-03-01

    Perchlorates, found on the martian surface, create a harsh environment. Methanogens are familiar with harsh environments and their growth was tested in perchlorate salt media. All four species of methanogens produced methane at all concentrations of each salt tested.

  7. Perchlorate exposure from infant formula and comparisons with the perchlorate reference dose.

    PubMed

    Schier, Joshua G; Wolkin, Amy F; Valentin-Blasini, Lisa; Belson, Martin G; Kieszak, Stephanie M; Rubin, Carol S; Blount, Benjamin C

    2010-05-01

    Perchlorate exposure may be higher in infants compared with older persons, due to diet (infant formula) and body weight versus intake considerations. Our primary objective was to quantitatively assess perchlorate concentrations in commercially available powdered infant formulas (PIFs). Secondary objectives were: (1) to estimate exposure in infants under different dosing scenarios and compare them with the perchlorate reference dose (RfD); (2) estimate the perchlorate concentration in water used for preparing PIFs that would result in a dose exceeding the RfD; and (3) estimate iodine intakes from PIFs. We quantified perchlorate levels in three samples (different lot numbers) of reconstituted PIF (using perchlorate-free water) from commercial brands of PIF in each of the following categories: bovine milk-based with lactose, soy-based, bovine milk-based but lactose-free, and elemental (typically consisting of synthetic amino acids). Exposure modeling was conducted to determine whether the RfD might be exceeded in 48 dosing scenarios that were dependent on age, centile energy intake per unit of body weight, body weight percentile, and PIF perchlorate concentration. We obtained three different samples in each of the five brands of bovine- and soy-based PIF, three different samples in each of the three brands of lactose-free PIF, and three different samples in two brands of elemental PIF. The results were as follows: bovine milk-based with lactose (1.72 microg/l, range: 0.68-5.05); soy-based (0.21 microg/l, range: 0.10-0.44); lactose-free (0.27 microg/l, range: 0.03-0.93); and elemental (0.18 microg/l, range: 0.08-0.4). Bovine milk-based PIFs with lactose had a significantly higher concentration of perchlorate (P<0.05) compared with all. Perchlorate was a contaminant of all commercially available PIFs tested. Bovine milk-based PIFs with lactose had a significantly higher perchlorate concentration perchlorate than soy, lactose-free, and elemental PIFs. The perchlorate Rf

  8. PERCHLORATE INDUCES HERMAPHRODITISM IN THREESPINE STICKLEBACKS

    PubMed Central

    Bernhardt, Richard R.; von Hippel, Frank A.; Cresko, William A.

    2011-01-01

    Recently, concern regarding perchlorate contamination has arisen in many contexts. Perchlorate has many military, commercial, and domestic applications, and it has been found in milk, drinking and irrigation water, and produce. Perchlorate is harmful at low levels, yet it remains unregulated in the United States while the U.S. Environmental Protection Agency attempts to establish acceptable exposure levels. The present study investigated potential reproductive effects on vertebrates using a model fish species, the threespine stickleback (Gasterosteus aculeatus). Sticklebacks were raised from syngamy through sexual maturity in untreated water and in three target concentrations of sodium perchlorate–treated water. Perchlorate was found to interfere with the expression of nuptial coloration, courtship behavior, and normal sexual development. Genetic testing revealed that some females were masculinized to the extent that they produced both sperm and eggs, and histological analysis showed that these individuals had intersexual gonads (ovotestes) containing both oocytes and cells undergoing spermatogenesis. In vitro fertilizations revealed that those gametes were capable of self- and cross-fertilization. However, crosses using sperm derived from genetic females died either during the blastula phase or near the onset of organogenesis. Sperm derived from genetic males produced viable fry when crossed with eggs derived from genetic females from all treatments. To our knowledge, the present study provides the first evidence that perchlorate produces androgenic effects and is capable of inducing functional hermaphroditism in a nonhermaphroditic vertebrate. PMID:16916028

  9. PERCHLORATE PHYTOREMEDIATION USING HARDWOOD TREES AND VASCULAR PLANTS

    EPA Science Inventory

    Perchlorate has contaminated water and soils at several locations in the United States. Perchlorate is
    water soluble, exceedingly mobile in aqueous systems, and can persist for many decades under typical ground and surface water conditions. Perchlorate is of concern because of...

  10. ACCUMULATION OF PERCHLORATE IN TOBACCO PLANTS AND TOBACCO PRODUCTS

    EPA Science Inventory

    Previous field and laboratory studies with vascular plants have shown that perchlorate is transported from perchlorate fortified soils and is accumulated in the plant tissues and organs. This paper reports results of initial investigations on the accumulation of perchlorate in t...

  11. DETERMINATION OF PERCHLORATE IN TOBACCO PLANTS AND TOBACCO PRODUCTS

    EPA Science Inventory

    Previous field and laboratory studies with vascular plants have shown that perchlorate is transported from perchlorate fortified soils and is accumulated in the plant tissues and organs. This paper reports results of initial investigations on the accumulation of perchlorate in t...

  12. DETERMINATION OF PERCHLORATE IN TOBACCO PLANTS AND TOBACCO PRODUCTS

    EPA Science Inventory

    Previous field and laboratory studies with vascular plants have shown that perchlorate is transported from perchlorate fortified soils and is accumulated in the plant tissues and organs. This paper reports results of initial investigations on the accumulation of perchlorate in t...

  13. ACCUMULATION OF PERCHLORATE IN TOBACCO PLANTS AND TOBACCO PRODUCTS

    EPA Science Inventory

    Previous field and laboratory studies with vascular plants have shown that perchlorate is transported from perchlorate fortified soils and is accumulated in the plant tissues and organs. This paper reports results of initial investigations on the accumulation of perchlorate in t...

  14. Kinetics of a hydrogen-oxidizing, perchlorate-reducing bacterium.

    PubMed

    Nerenberg, Robert; Kawagoshi, Yasunori; Rittmann, Bruce E

    2006-10-01

    This paper provides the first kinetic parameters for a hydrogen-oxidizing perchlorate-reducing bacterium (PCRB), Dechloromonas sp. PC1. The qmax for perchlorate and chlorate were 3.1 and 6.3 mg/mgDW-day, respectively. The K for perchlorate was 0.14 mg/L, an order of magnitude lower than reported for other PCRB. The yields Y on perchlorate and chlorate were 0.23 and 0.22 mgDW/mg, respectively, and the decay constant b was 0.055/day. The growth-threshold, Smin, for perchlorate was 14 microg/L, suggesting that perchlorate cannot be reduced below this level when perchlorate is the primary electron-acceptor, although it may be possible when oxygen or nitrate is the primary acceptor. Chlorate accumulated at maximum concentrations of 0.6-4.3 mg/L in batch tests with initial perchlorate concentrations ranging from 100 to 600 mg/L. Furthermore, 50 mg/L chlorate inhibited perchlorate reduction with perchlorate at 100 mg/L. This is the first report of chlorate accumulation and inhibition for a pure culture of PCRB. These Chlorate effects are consistent with competitive inhibition between perchlorate and chlorate for the (per)chlorate reductase enzyme.

  15. PERCHLORATE PHYTOREMEDIATION USING HARDWOOD TREES AND VASCULAR PLANTS

    EPA Science Inventory

    Perchlorate has contaminated water and soils at several locations in the United States. Perchlorate is
    water soluble, exceedingly mobile in aqueous systems, and can persist for many decades under typical ground and surface water conditions. Perchlorate is of concern because of...

  16. Peptide Biomarkers as Evidence of Perchlorate Biodegradation▿ †

    PubMed Central

    Bansal, Reema; Crawford, Ronald L.; Paszczynski, Andrzej J.

    2011-01-01

    Perchlorate is a known health hazard for humans, fish, and other species. Therefore, it is important to assess the response of an ecosystem exposed to perchlorate contamination. The data reported here show that a liquid chromatography-mass spectrometry-based proteomics approach for the detection of perchlorate-reducing enzymes can be used to measure the ability of microorganisms to degrade perchlorate, including determining the current perchlorate degradation status. Signature peptides derived from chlorite dismutase (CD) and perchlorate reductase can be used as biomarkers of perchlorate presence and biodegradation. Four peptides each derived from CD and perchlorate reductase subunit A (PcrA) and seven peptides derived from perchlorate reductase subunit B (PcrB) were identified as signature biomarkers for perchlorate degradation, as these sequences are conserved in the majority of the pure and mixed perchlorate-degrading microbial cultures examined. However, chlorite dismutase signature biomarker peptides from Dechloromonas agitata CKB were found to be different from those in other cultures used and should also be included with selected CD biomarkers. The combination of these peptides derived from the two enzymes represents a promising perchlorate presence/biodegradation biomarker system. The biomarker peptides were detected at perchlorate concentrations as low as 0.1 mM and at different time points both in pure cultures and within perchlorate-reducing environmental enrichment consortia. The peptide biomarkers were also detected in the simultaneous presence of perchlorate and an alternate electron acceptor, nitrate. We believe that this technique can be useful for monitoring bioremediation processes for other anthropogenic environmental contaminants with known metabolic pathways. PMID:21115710

  17. Measuring supernova neutrino temperatures using lead perchlorate

    SciTech Connect

    Elliott, S. R.

    2000-12-01

    Neutrino interactions with lead produce neutrons in numbers that depend on neutrino energy and type. A detector based on lead perchlorate, for example, would be able to measure the energy deposited by electrons and gammas in coincidence with the number of neutrons produced. Sorting the electron energy spectra by the number of coincident neutrons permits the identification of the neutrino type that induced the reaction. This separation allows an analysis which can determine the temperatures of {nu}{sub e} and {bar {nu}}{sub e} from a supernova in one experiment. The neutrino reaction signatures of lead perchlorate, and the fundamentals of using this material as a neutrino detector, are described.

  18. Measuring supernova neutrino temperatures using lead perchlorate

    NASA Astrophysics Data System (ADS)

    Elliott, S. R.

    2000-12-01

    Neutrino interactions with lead produce neutrons in numbers that depend on neutrino energy and type. A detector based on lead perchlorate, for example, would be able to measure the energy deposited by electrons and gammas in coincidence with the number of neutrons produced. Sorting the electron energy spectra by the number of coincident neutrons permits the identification of the neutrino type that induced the reaction. This separation allows an analysis which can determine the temperatures of νe and ν¯e from a supernova in one experiment. The neutrino reaction signatures of lead perchlorate, and the fundamentals of using this material as a neutrino detector, are described.

  19. Perchlorate behavior in a municipal lake following fireworks displays.

    PubMed

    Wilkin, Richard T; Fine, Dennis D; Burnett, Nicole G

    2007-06-01

    Perchlorate salts of potassium and ammonium are the primary oxidants in pyrotechnic mixtures, yet insufficient information is available regarding the relationship between fireworks displays and the environmental occurrence of perchlorate. Here we document changes in perchlorate concentrations in surface water adjacent to a site of fireworks displays from 2004 to 2006. Preceding fireworks displays, perchlorate concentrations in surface water ranged from 0.005 to 0.081 microg/L, with a mean value of 0.043 microg/L. Within 14 h after the fireworks, perchlorate concentrations spiked to values ranging from 24 to 1028x the mean baseline value. A maximum perchlorate concentration of 44.2 microg/L was determined following the July 4th event in 2006. After the fireworks displays, perchlorate concentrations decreased toward the background level within 20 to 80 days, with the rate of attenuation correlating to surface water temperature. Adsorption tests indicate that sediments underlying the water column have limited (< 100 nmol/g) capacity to remove perchlorate via chemical adsorption. Microcosms showed comparatively rapid intrinsic perchlorate degradation in the absence of nitrate consistent with the observed disappearance of perchlorate from the study site. This suggests that at sites with appropriate biogeochemical conditions, natural attenuation may be an important factor affecting the fate of perchlorate following fireworks displays.

  20. Perchlorate levels in soil and waters from the Atacama Desert.

    PubMed

    Calderón, R; Palma, P; Parker, D; Molina, M; Godoy, F A; Escudey, M

    2014-02-01

    Perchlorate is an anion that originates as a contaminant in ground and surface waters. The presence of perchlorate in soil and water samples from northern Chile (Atacama Desert) was investigated by ion chromatography-electrospray mass spectrometry. Results indicated that perchlorate was found in five of seven soils (cultivated and uncultivated) ranging from 290 ± 1 to 2,565 ± 2 μg/kg. The greatest concentration of perchlorate was detected in Humberstone soil (2,565 ± 2 μg/kg) associated with nitrate deposits. Perchlorate levels in Chilean soils are greater than those reported for uncultivated soils in the United States. Perchlorate was also found in superficial running water ranging from 744 ± 0.01 to 1,480 ± 0.02 μg/L. Perchlorate water concentration is 30-60 times greater than levels established by the United States Environmental Protection Agency (24.5 μg/L) for drinking.

  1. Perchlorate in Water Supplies: Sources, Exposures, and Health Effects

    PubMed Central

    Steinmaus, Craig M.

    2016-01-01

    Perchlorate exposure occurs from ingestion of natural or manmade perchlorate in food or water. Perchlorate is used in a variety of industrial products including missile fuel, fireworks, and fertilizers, and industrial contamination of drinking water supplies has occurred in a number of areas. Perchlorate blocks iodide uptake into the thyroid, and decreases the production of thyroid hormone, a critical hormone for metabolism, neurodevelopment, and other physiologic functions. Occupational and clinical dosing studies have not identified clear adverse effects, but may be limited by small sample sizes, short study durations, and the inclusion of mostly healthy adults. Expanding evidence suggests that young children, pregnant women, fetuses, and people co-exposed to similarly acting agents may be especially susceptible to perchlorate. Given the ubiquitous nature of perchlorate exposure, and the importance of thyroid hormone for brain development, studying the impact of perchlorate on human health could have far-reaching public health implications. PMID:27026358

  2. Perchlorate in Water Supplies: Sources, Exposures, and Health Effects.

    PubMed

    Steinmaus, Craig M

    2016-06-01

    Perchlorate exposure occurs from ingestion of natural or man-made perchlorate in food or water. Perchlorate is used in a variety of industrial products including missile fuel, fireworks, and fertilizers, and industrial contamination of drinking water supplies has occurred in a number of areas. Perchlorate blocks iodide uptake into the thyroid and decreases the production of thyroid hormone, a critical hormone for metabolism, neurodevelopment, and other physiologic functions. Occupational and clinical dosing studies have not identified clear adverse effects, but may be limited by small sample sizes, short study durations, and the inclusion of mostly healthy adults. Expanding evidence suggests that young children, pregnant women, fetuses, and people co-exposed to similarly acting agents may be especially susceptible to perchlorate. Given the ubiquitous nature of perchlorate exposure, and the importance of thyroid hormone for brain development, studying the impact of perchlorate on human health could have far-reaching public health implications.

  3. Fate and Transport of Perchlorate at California's Stringfellow Superfund Site

    NASA Astrophysics Data System (ADS)

    Kenoyer, G. J.; Nuttall, H. E.; Paulson, R.; Wolfenden, A.; Aldern, J.

    2007-12-01

    Geologic conditions exert primary control over the fate and transport of perchlorate at the Stringfellow Superfund site. A buried valley filled with alluvium has been defined that extends from Pyrite Canyon, location of the former Stringfellow acid pits, down to near the Santa Ana River. The buried valley is cut into the underlying granitic bedrock, and appears to be a paleo-channel of the ancestral Pyrite Creek. The groundwater hydraulic gradient aligns closely with the buried valley, as does the perchlorate plume. The buried valley appears to be a preferential pathway for contaminant migration. Perchlorate concentrations in the downgradient portion of the plume have been slowly decreasing over time, suggesting that the groundwater extraction wells are effective at cutting off the source. Perchlorate degradation, however, appears to be minimal over most of the sandy aerobic aquifer, as concentrations of perchlorate persist over a 5-mile long plume. Scattered concentrations of perchlorate in the 1 to 12 ug/L range are widespread over a broad area adjacent to the plume and appear to be unrelated to the plume. Hydrogeologic analysis and perchlorate isotope analysis are being used to investigate whether these outlying concentrations may be related to the historic use of perchlorate- bearing mineral nitrate fertilizer. At the distal end of the plume, a marked change in the fate of perchlorate occurs beneath the Santa Ana River. Sampling of mini-piezometers installed into the river sediments shows that the perchlorate and nitrate concentrations fall to below detection as the aquifer environment changes from oxidizing to reducing conditions. In this local environment, it appears that anaerobic biodegradation reduces the perchlorate and nitrate. As a result of degradation of perchlorate, and possibly mixing of infiltrating river water beneath the losing portions of the river, perchlorate concentrations decrease to below 6 ug/L downgradient of the river. This presentation

  4. PERCHLORATE UPTAKE AND TRANSFORMATION IN AQUATIC PLANTS

    EPA Science Inventory

    Ammonium Perchlorate (AP) is produced on a large scale by the chemical industry, for a wide range of applications for example, as a strong oxidizing agent in solid rocket fuel. AP must be washed out of the inventory periodically due to its limited shelf-life,and replaced with a f...

  5. Astrobiological implications for Perchlorates on Mars

    NASA Astrophysics Data System (ADS)

    Mancinelli, R. L.

    2017-07-01

    Astrobiology is the study of the past, current and future potential for life in the Universe and has been fascinated with the possibility of life on Mars since the late 1800s. Because of the potential for life on Mars it is vital to understand the role perchlorates may play in that potential.

  6. PERCHLORATE CHEMISTRY: IMPLICATIONS FOR ANALYSIS AND REMEDIATION

    EPA Science Inventory

    Since the discovery of perchlorate in the ground and surface waters of several western states, there has been increasing interest in the health effects resulting from chronic exposure to low (ppb) levels. With this concern has come a need to investigate technologies that might be...

  7. PERCHLORATE UPTAKE AND TRANSFORMATION IN AQUATIC PLANTS

    EPA Science Inventory

    Ammonium Perchlorate (AP) is produced on a large scale by the chemical industry, for a wide range of applications for example, as a strong oxidizing agent in solid rocket fuel. AP must be washed out of the inventory periodically due to its limited shelf-life,and replaced with a f...

  8. PERCHLORATE CHEMISTRY: IMPLICATIONS FOR ANALYSIS AND REMEDIATION

    EPA Science Inventory

    Since the discovery of perchlorate in the ground and surface waters of several western states, there has been increasing interest in the health effects resulting from chronic exposure to low (ppb) levels. With this concern has come a need to investigate technologies that might be...

  9. Perchlorate in Drinking Water Frequent Questions

    EPA Pesticide Factsheets

    Perchlorate occurs naturally in arid states in the Southwest United States, in nitrate fertilizer deposits in Chile, and in potash ore in the United States and Canada. It has also been found in some public drinking water systems and in food.

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

    NASA Astrophysics Data System (ADS)

    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.

  11. Plant-mediated transformation of perchlorate into chloride

    SciTech Connect

    Nzengung, V.A.; Wang, C.; Harvey, G.

    1999-05-01

    The decontamination of perchlorate-contaminated water by woody plants was investigated in sand and hydroponic bioreactors. Willow trees were found to be the most favorable woody plants with phraetophytic characteristics in comparative screen tests with eastern cottonwoods and Eucalyptus cineria. Willows decontaminated aqueous solutions dosed with 10--100 mg/.L of perchlorate to below the method detection limit of 2 {micro}g/L. Two phytoprocesses were identified as important in the remediation of perchlorate-contaminated water: (1) uptake and phytodegradation of perchlorate in the tree branches and leaves and (2) rhizodegradation. Exposure of rooted willow trees to perchlorate-dosed media stimulated rhizodegradation. Homogeneous degradation studies using media from the root zone of dosed willow trees confirmed that rhizosphere-associated microorganisms mediated the degradation of perchlorate to chloride. Experiments conducted with varying ranges of nitrate concentrations clearly indicated that high nitrate concentrations interfered with rhizodegradation of perchlorate. This study provides evidence that the efficacy of phytoremediation of perchlorate-contaminated environments may depend on the concentration of competing terminal electron acceptors, such as nitrate, and the nitrogen source of the nutrient solution., Since perchlorate does not volatilize from water readily, a perchlorate remediation scheme may involve an intensively cultivated plantation of trees with phraetophytic characteristics and irrigation with the contaminated water.

  12. ACCUMULATION OF PERCHLORATE IN TOBACCO PLANTS: DEVELOPMENT OF A PLANT KINETIC MODEL

    EPA Science Inventory

    Previous studies have shown that tobacco plants are tolerant of perchlorate and will accumulate perchlorate in plant tissues. This research determined the uptake, translocation, and accumulation of perchlorate in tobacco plants. Three hydroponics growth studies were completed u...

  13. ACCUMULATION OF PERCHLORATE IN TOBACCO PLANTS: DEVELOPMENT OF A PLANT KINETIC MODEL

    EPA Science Inventory

    Previous studies have shown that tobacco plants are tolerant of perchlorate and will accumulate perchlorate in plant tissues. This research determined the uptake, translocation, and accumulation of perchlorate in tobacco plants. Three hydroponics growth studies were completed u...

  14. DEVELOPMENT AND VALIDATION OF AN ION CHROMATOGRAPHIC METHOD FOR DETERMINING PERCHLORATE IN FERTILIZERS

    EPA Science Inventory

    A method has been developed for the determination of perchlorate in fertilizers. Materials are leached with deionized water to dissolve any soluble perchlorate compounds. Ion chromatographic separation is followed by suppressed conductivity for detection. Perchlorate is retained ...

  15. DEVELOPMENT AND VALIDATION OF AN ION CHROMATOGRAPHIC METHOD FOR DETERMINING PERCHLORATE IN FERTILIZERS

    EPA Science Inventory

    A method has been developed for the determination of perchlorate in fertilizers. Materials are leached with deionized water to dissolve any soluble perchlorate compounds. Ion chromatographic separation is followed by suppressed conductivity for detection. Perchlorate is retained ...

  16. Maximizing microbial perchlorate degradation using a genetic algorithm: consortia optimization.

    PubMed

    Kucharzyk, Katarzyna H; Soule, Terence; Hess, Thomas F

    2013-09-01

    Microorganisms in consortia perform many tasks more effectively than individual organisms and in addition grow more rapidly and in greater abundance. In this work, experimental datasets were assembled consisting of all possible selected combinations of perchlorate reducing strains of microorganisms and their perchlorate degradation rates were evaluated. A genetic algorithm (GA) methodology was successfully applied to define sets of microbial strains to achieve maximum rates of perchlorate degradation. Over the course of twenty generations of optimization using a GA, we saw a statistically significant 2.06 and 4.08-fold increase in average perchlorate degradation rates by consortia constructed using solely the perchlorate reducing bacteria (PRB) and by consortia consisting of PRB and accompanying organisms that did not degrade perchlorate, respectively. The comparison of kinetic rates constant in two types of microbial consortia additionally showed marked increases.

  17. Perchlorate and Diet: Human Exposures, Risks, and Mitigation Strategies.

    PubMed

    Maffini, Maricel V; Trasande, Leonardo; Neltner, Thomas G

    2016-06-01

    Perchlorate is an endocrine-disrupting chemical that interferes with the normal functioning of the thyroid gland. Maternal thyroid dysfunction during gestation may alter fetal brain development. Perchlorate contamination is widespread: it is present in the body of all Americans tested and the majority of foods tested. The main sources of food contamination appear to be hypochlorite bleach, a disinfectant and sanitizer, that when poorly managed quickly degrades to perchlorate and perchlorate-laden plastic food packaging for dry food or localized contamination from manufacturing or processing of the chemical. Eliminating perchlorate from food packaging and improving bleach management, such as reducing concentration and storage time and temperature, would result in reduced perchlorate contamination of food and water.

  18. Aquifer susceptibility to perchlorate contamination in a highly urbanized environment

    USGS Publications Warehouse

    Woolfenden, Linda R.; Trefly, Michael G.

    2007-01-01

    Perchlorate contamination from anthropogenic sources has been released into the Rialto-Colton, California, USA, groundwater flow system since the 1940s during its production, distribution, storage, and use. Preliminary analysis of lithological, geophysical, and water-chemistry data provided new understanding of the pathways of perchlorate migration that aid in assessing the susceptibility of drinking-water supplies to contamination within the Rialto-Colton basin. Vertical migration of perchlorate into the main water-producing aquifers is restricted by an areally extensive old soil surface; however, perchlorate data indicate contamination below this soil surface. Possible pathways for the downward migration of the contaminated water include wellbore flow and discontinuities in the old soil surface. Horizontal migration of perchlorate is influenced by lithology and faults within the basin. The basin fill is a heterogeneous mixture of boulders, gravel, sand, silt, and clay, and internal faults may restrict perchlorate migration in some areas.

  19. The NAS perchlorate review: questions remain about the perchlorate RfD.

    PubMed

    Ginsberg, Gary; Rice, Deborah

    2005-09-01

    Human exposure to perchlorate is commonplace because it is a contaminant of drinking water, certain foods, and breast milk. The U.S. Environmental Protection Agency (EPA) conducted a perchlorate risk assessment in 2002 that yielded a reference dose (RfD) based on both the animal and human toxicology data. This assessment has been superceded by a recent National Academy of Science (NAS) review that derived a perchlorate RfD that is 20-fold greater (less stringent) than that derived by the U.S. EPA in 2002. The NAS-derived RfD was put on the U.S. EPA's Integrated Risk Information System (IRIS) database very quickly and with no further public review. In this commentary we raise concerns about the NAS approach to RfD development in three areas of toxicity assessment: the dose that the NAS described as a no observable adverse-effect level is actually associated with perchlorate-induced effects; consideration of uncertainties was insufficient; and the NAS considered the inhibition of iodine uptake to be a nonadverse effect. We conclude that risk assessors should carefully evaluate whether the IRIS RfD is the most appropriate value for assessing perchlorate risk.

  20. Novel Electrochemical Process for Treatment of Perchlorate in Waste Water

    DTIC Science & Technology

    2011-03-06

    exchange (ESIX) system based on a conducting polymer/carbon nanotube nanocomposite for removing perchlorate from drinking water and wastewater. The ESIX...nanotube nanocomposite for removing perchlorate from drinking water and wastewater. The ESIX technology combines ion exchange and electrochemistry to...potential for perchlorate occurrence in drinking water and food supplies is a human health concern because it can interfere with iodide uptake by the

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

    DTIC Science & Technology

    2005-02-23

    perchlorate exposure at low levels, and because of the need for more research on water treatment technologies. Related issues involve water treatment ... treatment technologies and is funding several more demonstration projects during FY2005. Perchlorate cleanup is proceeding at several sites; however...SDWA). The agency listed perchlorate as a priority for further research on health effects and treatment technologies, and as a priority for collecting

  2. Maternal perchlorate exposure in pregnancy and altered birth outcomes.

    PubMed

    Rubin, Rainbow; Pearl, Michelle; Kharrazi, Martin; Blount, Benjamin C; Miller, Mark D; Pearce, Elizabeth N; Valentin-Blasini, Liza; DeLorenze, Gerald; Liaw, Jane; Hoofnagle, Andrew N; Steinmaus, Craig

    2017-10-01

    At high medicinal doses perchlorate is known to decrease the production of thyroid hormone, a critical factor for fetal development. In a large and uniquely exposed cohort of pregnant women, we recently identified associations between environmental perchlorate exposures and decreased maternal thyroid hormone during pregnancy. Here, we investigate whether perchlorate might be associated with birthweight or preterm birth in the offspring of these women. Maternal urinary perchlorate, serum thyroid hormone concentrations, birthweight, gestational age, and urinary nitrate, thiocyanate, and iodide were collected in 1957 mother-infant pairs from San Diego County during 2000-2003, a period when the county's water supply was contaminated with perchlorate. Associations between perchlorate exposure and birth outcomes were examined using linear and logistic regression analyses adjusted for maternal age, weight, race/ethnicity, and other factors. Perchlorate was not associated with birth outcomes in the overall population. However, in analyses confined to male infants, log10 maternal perchlorate concentrations were associated with increasing birthweight (β=143.1gm, p=0.01), especially among preterm births (β=829.1g, p<0.001). Perchlorate was associated with male preterm births ≥2500g (odds ratio=3.03, 95% confidence interval=1.09-8.40, p-trend=0.03). Similar associations were not seen in females. This is the first study to identify associations between perchlorate and increasing birthweight. Further research is needed to explore the differences we identified related to infant sex, preterm birth, and other factors. Given that perchlorate exposure is ubiquitous, and that long-term impacts can follow altered birth outcomes, future research on perchlorate could have widespread public health importance. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. Kinetics of a chlorate-accumulating, perchlorate-reducing bacterium.

    PubMed

    Dudley, Margaret; Salamone, Anna; Nerenberg, Robert

    2008-05-01

    Kinetics parameters for perchlorate and chlorate reduction were determined for Dechlorosoma sp. HCAP-C, also known as Dechlorosoma sp. PCC, a novel perchlorate-reducing bacterium (PCRB) that accumulates significant amounts of chlorate during perchlorate reduction. This is the first report of such behavior, and we hypothesized the perchlorate reduction kinetics would be markedly different from other PCRB. In batch tests with initial perchlorate concentrations ranging from 200 to around 1400 mg/L, maximum chlorate accumulation ranged from 41 to 279 mg/L, and were consistently around 20% of the initial perchlorate concentration. For perchlorate, parameters were determined using a competitive inhibition model. The maximum specific substrate degradation rate qmaxP was 11.5mgClO4-/mgdry weight (DW)-d, and the half-maximum rate constant KP was 193 mgClO4-/L. For chlorate, the qmaxC was 8.3 mgClO3-/mgDW-d and the KC was 58.3 mgClO3-/L. The high KP values relative to conventional PCRB, values suggests that HCAP-C does not play a significant role at low perchlorate concentrations. However, the relatively high qmaxP, and the potential for syntrophic relationships with chlorate-reducing bacteria that relieve the effects of chlorate inhibition, suggest that HCAP-C could play a significant role at high perchlorate concentrations.

  4. Evidence for the distribution of perchlorates on Mars

    NASA Astrophysics Data System (ADS)

    Clark, Benton C.; Kounaves, Samuel P.

    2016-10-01

    Various Mars missions have detected Cl atoms, chlorides and perchlorates in martian surface materials. The global soils, in particular, always contain significant levels of observable Cl. Direct evidence points to this Cl being in the form of both chlorides and perchlorates, and possibly also chlorates and other oxychlorines. The most widespread measurements have been of Cl atoms, and cannot discern the chemical form. However, from separate evidence of perchlorate obtained at high latitudes (Phoenix lander) and low latitudes (Curiosity rover), it is likely that perchlorates are widespread, albeit in varying proportions relative to the total amount of ubiquitous Cl.

  5. Perchlorate as an emerging contaminant in soil, water and food.

    PubMed

    Kumarathilaka, Prasanna; Oze, Christopher; Indraratne, S P; Vithanage, Meththika

    2016-05-01

    Perchlorate ( [Formula: see text] ) is a strong oxidizer and has gained significant attention due to its reactivity, occurrence, and persistence in surface water, groundwater, soil and food. Stable isotope techniques (i.e., ((18)O/(16)O and (17)O/(16)O) and (37)Cl/(35)Cl) facilitate the differentiation of naturally occurring perchlorate from anthropogenic perchlorate. At high enough concentrations, perchlorate can inhibit proper function of the thyroid gland. Dietary reference dose (RfD) for perchlorate exposure from both food and water is set at 0.7 μg kg(-1) body weight/day which translates to a drinking water level of 24.5 μg L(-1). Chromatographic techniques (i.e., ion chromatography and liquid chromatography mass spectrometry) can be successfully used to detect trace level of perchlorate in environmental samples. Perchlorate can be effectively removed by wide variety of remediation techniques such as bio-reduction, chemical reduction, adsorption, membrane filtration, ion exchange and electro-reduction. Bio-reduction is appropriate for large scale treatment plants whereas ion exchange is suitable for removing trace level of perchlorate in aqueous medium. The environmental occurrence of perchlorate, toxicity, analytical techniques, removal technologies are presented. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Atmospheric Production of Perchlorate on Earth and Mars

    NASA Astrophysics Data System (ADS)

    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).

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

    PubMed

    Wen, Li-Lian; Yang, Qiang; Zhang, Zhao-Xin; Yi, Yang-Yi; Tang, Youneng; Zhao, He-Ping

    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 0.3mM did not significantly affect perchlorate reduction; however, perchlorate concentrations higher than 0.1mM 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 600mg/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%. Copyright © 2016 Elsevier B.V. All rights reserved.

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

    PubMed

    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.

  9. Extraction of Perchlorate Using Porous Organosilicate Materials

    PubMed Central

    Johnson, Brandy J.; Leska, Iwona A.; Melde, Brian J.; Siefert, Ronald L.; Malanoski, Anthony P.; Moore, Martin H.; Taft, Jenna R.; Deschamps, Jeffrey R.

    2013-01-01

    Sorbent materials were developed utilizing two morphological structures, comprising either hexagonally packed pores (HX) or a disordered pore arrangement (CF). The sorbents were functionalized with combinations of two types of alkylammonium groups. When capture of perchlorate by the sorbents was compared, widely varying performance was noted as a result of differing morphology and/or functional group loading. A material providing improved selectivity for perchlorate over perrhenate was synthesized with a CF material using N-trimethoxysilylpropyl-N,N,N-trimethylammonium chloride. Materials were applied in batch and column formats. Binding isotherms followed the behavior expected for a system in which univalent ligands of varying affinity compete for immobilized sites. Performance of the sorbents was also compared to that of commercial Purolite materials. PMID:28809217

  10. Bacterial reduction of perchlorate and nitrate in water

    SciTech Connect

    Herman, D.C.; Frankenberger, W.T. Jr.

    1999-05-01

    A bacterial isolate, strain perc1ace, was shown to reduce the ground water contaminant perchlorate (ClO{sub 4}{sup {minus}}) to levels < 0.005 mg L{sup {minus}1} when grown on acetate under anaerobic conditions. The ability of perc1ace to simultaneously reduce perchlorate and another ground water pollutant, nitrate (NO{sub 3}{sup {minus}}), was examined in batch studies and in a sand packed column under saturated flow conditions. Nitrate removal was monitored using ion chromatography, and perchlorate removal was monitored using a perchlorate specific electrode or ion chromatography, depending on the study. In batch studies, the reduction of 0.089, 0.92, 12.0, and 122 mg L{sup {minus}1} perchlorate was examined in the presence and absence of 62 mg L{sup {minus}1} NO{sub 3}{sup {minus}}. Perchlorate was reduced more rapidly in the absence of NO{sub 3}{sup {minus}} than in its presence. However, both perchlorate and NO{sub 3}{sup {minus}} were reduced by more than 10-fold within 48 h. A sand-packed column inoculated with perc1ace simulated a flow-through biotreatment system for water contaminated with a low level of perchlorate and a much higher level of NO{sub 3}{sup {minus}}. Biotreatment could reduce perchlorate to < 0.005 mg L{sup {minus}1} in a 3 h residence time. The addition of NO{sub 3}{sup {minus}} initially decreased the efficiency of perchlorate removal, however within 1 d the biotreatment system had adjusted such that there was complete removal of perchlorate and the reduction of NO{sub 3}{sup {minus}} to < 1 mg L{sup {minus}1}.

  11. Perchlorate Clinical Pharmacology and Human Health: A Review

    PubMed Central

    Soldin, Offie Porat; Braverman, Lewis E.; Lamm, Steven H.

    2013-01-01

    Summary Potassium perchlorate has been used at various times during the last 50 years to treat hyperthyroidism. Since World War II ammonium perchlorate has been used as a propellant for rockets. In 1997, the assay sensitivity for perchlorate in water was improved from 0.4 mg/L (ppm) to 4 µg/L (ppb). As a result, public water supplies in Southern California were found to contain perchlorate ions in the range of 5 to 8 ppb, and those in Southern Nevada were found to contain 5 to 24 ppb. Research programs have been developed to assess the safety or risk from these exposures and to assist state and regulatory agencies in setting a reasonable safe level for perchlorate in drinking water. This report reviews the evidence on the human health effects of perchlorate exposure. Perchlorate is a competitive inhibitor of iodine uptake. All of its pharmacologic effects at current therapeutic levels or lower are associated with inhibition of the sodium-iodide symporter (NIS) on the thyroid follicular cell membrane. A review of the medical and occupational studies has been undertaken to identify perchlorate exposure levels at which thyroid hormone levels may be reduced or thyrotropin levels increased. This exposure level may begin in the 35 to 100 mg/d range. Volunteer studies have been designed to determine the exposure levels at which perchlorate begins to affect iodine uptake in humans. Such effects may begin at levels of approximately 1 mg/d. Environmental studies have assessed the thyroidal health of newborns and adults at current environmental exposures to perchlorate and have concluded that the present levels appear to be safe. Whereas additional studies are underway both in laboratory animals and in the field, it appears that a safe level can be established for perchlorate in water and that regulatory agencies and others are now trying to determine that level. PMID:11477312

  12. Perchlorate in the Great Lakes: isotopic composition and origin.

    PubMed

    Poghosyan, Armen; Sturchio, Neil C; Morrison, Candice G; Beloso, Abelardo D; Guan, Yunbin; Eiler, John M; Jackson, W Andrew; Hatzinger, Paul B

    2014-10-07

    Perchlorate is a persistent and mobile contaminant in the environment with both natural and anthropogenic sources. Stable isotope ratios of oxygen (δ(18)O, Δ(17)O) and chlorine (δ(37)Cl) along with the abundance of the radioactive isotope (36)Cl were used to trace perchlorate sources and behavior in the Laurentian Great Lakes. These lakes were selected for study as a likely repository of recent atmospheric perchlorate deposition. Perchlorate concentrations in the Great Lakes range from 0.05 to 0.13 μg per liter. δ(37)Cl values of perchlorate from the Great Lakes range from +3.0‰ (Lake Ontario) to +4.0‰ (Lake Superior), whereas δ(18)O values range from -4.1‰ (Lake Superior) to +4.0‰ (Lake Erie). Great Lakes perchlorate has mass-independent oxygen isotopic variations with positive Δ(17)O values (+1.6‰ to +2.7‰) divided into two distinct groups: Lake Superior (+2.7‰) and the other four lakes (∼+1.7‰). The stable isotopic results indicate that perchlorate in the Great Lakes is dominantly of natural origin, having isotopic composition resembling that measured for indigenous perchlorate from preindustrial groundwaters of the western USA. The (36)Cl/Cl ratio of perchlorate varies widely from 7.4 × 10(-12) (Lake Ontario) to 6.7 × 10(-11) (Lake Superior). These (36)ClO4(-) abundances are consistent with an atmospheric origin of perchlorate in the Great Lakes. The relatively high (36)ClO4(-) abundances in the larger lakes (Lakes Superior and Michigan) could be explained by the presence of (36)Cl-enriched perchlorate deposited during the period of elevated atmospheric (36)Cl activity following thermonuclear bomb tests in the Pacific Ocean.

  13. Thyroid-stimulating hormone increases active transport of perchlorate into thyroid cells.

    PubMed

    Tran, Neil; Valentín-Blasini, Liza; Blount, Benjamin C; McCuistion, Caroline Gibbs; Fenton, Mike S; Gin, Eric; Salem, Andrew; Hershman, Jerome M

    2008-04-01

    Perchlorate blocks thyroidal iodide transport in a dose-dependent manner. The human sodium/iodide symporter (NIS) has a 30-fold higher affinity for perchlorate than for iodide. However, active transport of perchlorate into thyroid cells has not previously been demonstrated by direct measurement techniques. To demonstrate intracellular perchlorate accumulation, we incubated NIS-expressing FRTL-5 rat thyroid cells in various concentrations of perchlorate, and we used a sensitive ion chromatography tandem mass spectrometry method to measure perchlorate accumulation in the cells. Perchlorate caused a dose-related inhibition of 125-iodide uptake at 1-10 microM. The perchlorate content from cell lysate was analyzed, showing a higher amount of perchlorate in cells that were incubated in medium with higher perchlorate concentration. Thyroid-stimulating hormone increased perchlorate uptake in a dose-related manner, thus supporting the hypothesis that perchlorate is actively transported into thyroid cells. Incubation with nonradiolabeled iodide led to a dose-related reduction of intracellular accumulation of perchlorate. To determine potential toxicity of perchlorate, the cells were incubated in 1 nM to 100 microM perchlorate and cell proliferation was measured. Even the highest concentration of perchlorate (100 microM) did not inhibit cell proliferation after 72 h of incubation. In conclusion, perchlorate is actively transported into thyroid cells and does not inhibit cell proliferation.

  14. Perchlorate Exposure Through Water and Milk in Istanbul.

    PubMed

    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 = perchlorate (mean = 4.53 µg/L; maximum = 6.21 µg/L). Median perchlorate exposure attributable to water and milk (0.007 µg/kg/day) is small compared both to the reference dose (0.7 µg/kg/day) and to total perchlorate exposure (0.13 µg/kg/day) in Istanbul. Therefore, additional studies are needed to identify the major sources of perchlorate exposure in Istanbul.

  15. Edible Oil Barriers for Treatment of Perchlorate Contaminated Groundwater

    DTIC Science & Technology

    2006-02-16

    that the pathway proceeds via the following sequence (Logan et al., 2000): ClO4 - (perchlorate) ClO3 - (chlorate) ClO2 - (chlorite) Cl...biomass: ClO4 → ClO3 → ClO2 → Cl + O2 Perchlorate is known to occur naturally in only a very few locations (nitrate deposits). However, bacteria

  16. Microbial-mediated reduction of perchlorate in groundwater

    SciTech Connect

    Herman, D.C.; Frankenberger, W.T. Jr.

    1998-07-01

    Perchlorate has been widely used as a propellant in solid rocket fuel, and has recently been identified as a contaminant in both groundwater and surface waters. Perchlorate is recognized by the US Environmental Protection Agency (USEPA) as a potential health risk, and the State of California has set a drinking water action level of 18 {micro}g L{sup {minus}1}. Incidents of groundwater contamination have been associated with industrial sites in California and Nevada that have been involved in the manufacturing or testing of solid rocket propellants. Microorganisms have been shown to be capable of reducing perchlorate (ClO{sub 4}{sup {minus}}) to chloride (Cl{sup {minus}}) and oxygen, thus transforming perchlorate into innocuous end-products. Bioreactor processes for the remediation of perchlorate contaminated wastewater have previously been established. However, these systems were optimized for perchlorate concentrations in the grams per liter range, while groundwater contamination can be a million-fold lower but still exceed the water quality action level. This literature review will focus on microbial-mediated perchlorate reduction, and discuss issues of importance to the remediation of perchlorate-contaminated groundwater.

  17. Engineered Intrinsic Bioremediation of Ammonium Perchlorate in Groundwater

    DTIC Science & Technology

    2010-12-01

    German Collection of Microorganisms and Cell Cultures) GA Genetic Algorithms GA-ANN Genetic Algorithm Artificial Neural Network GMO genetically...for in situ treatment of perchlorate in groundwater. This is accomplished without the addition of genetically engineered microorganisms ( GMOs ) to the...perchlorate, even in the presence of oxygen and without the addition of genetically engineered microorganisms ( GMOs ) to the environment. This approach

  18. Kinetics of biological perchlorate reduction and pH effect.

    PubMed

    Wang, Chao; Lippincott, Lee; Meng, Xiaoguang

    2008-05-01

    Batch experiments were conducted to investigate the kinetics of perchlorate reduction by heterotrophic and mixed perchlorate-reducing bacteria. Substrate-utilizing and cellular maintenance models were employed to fit the experimental data for microbial perchlorate reduction. The half saturation constant, K(s), obtained in this study was below 0.1mg/L, which indicated that perchlorate-reducing bacteria are effective at utilizing low concentrations of perchlorate. The effect of pH on the kinetics of microbial perchlorate reduction was also studied. Perchlorate reduction occurred throughout the pH range from 5.0 to 9.0. Nevertheless, the rates of perchlorate removal by a unit mass of bacteria were significantly different at various pHs with a maximum rate at pH 7.0. The variation of q(max) with pH was described well with a Gaussian peak equation. This equation is expected to be applicable for practical purposes when pH effects need to be considered.

  19. PERCHLORATE IDENTIFICATION IN FERTILIZERS AND ACCUMULATION IN LETTUCE SEEDLINGS

    EPA Science Inventory

    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...

  20. PERCHLORATE IDENTIFICATION IN FERTILIZERS AND ACCUMULATION IN LETTUCE SEEDLINGS

    EPA Science Inventory

    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...

  1. Predicting perchlorate uptake in greenhouse lettuce from perchlorate, nitrate and chloride irrigation water concentrations

    USDA-ARS?s Scientific Manuscript database

    Perchlorate (ClO4-) has been detected in edible leafy vegetables irrigated with Colorado River water. The primary concern has been the ClO4- concentration in lettuce. There has been a limited number of studies on ClO4- uptake but the interactive effect of other anions on ClO4- uptake is not known in...

  2. High ozone increases soil perchlorate but does not affect foliar perchlorate content

    USDA-ARS?s Scientific Manuscript database

    Ozone (O3) is implicated in the natural source inventory of perchlorate (ClO4-), a hydrophilic salt that migrates to ground water and interferes with uptake of iodide in mammals, including humans. Tropospheric O3 is elevated in many areas. We previously showed (Grantz et al., 2013; Environmental Pol...

  3. Bioremediation Potential of Perchlorate Contaminated Deep Vadose Zone

    NASA Astrophysics Data System (ADS)

    Gal, H.; Ronen, Z.; Weisbrod, N.; Dahan, O.; Nativ, R.

    2007-12-01

    Widespread perchlorate contamination was found in the vadose zone near a plant that manufactures ammonium perchlorate above the coastal aquifer of Israel in Ramat Hasharon. As part of the plant's operations, untreated industrial wastewater was disposed of for over 30 years in unlined wastewater ponds and nearby washes, causing contamination of the unsaturated zone (up to 2200 mg kg-1 sediment at a depth of 20 m) and the groundwater below it (up to 300 mg L-1). In this study, we examined the potential for microbial metabolism of perchlorate reduction in the contaminated deep vadose zone profile by native microbial communities. Microbial reduction of perchlorate was found in three of the four sediment samples taken from different depths. The sediments taken from 1 m (shallowest) and 35 m (deepest- close to the water table) showed the fastest degradation rates, while the sediment taken from 15 m showed the slowest rate. No perchlorate reduction was observed in the sediment taken from 20 m, where perchlorate concentrations were highest. These results were correlated to the viable microorganism counts in the profile. In experiments in which the effect of nitrate was examined, the lag time for perchlorate degradation was found to be inversely correlated to the initial nitrate concentration, while the perchlorate-reduction rates were faster in treatments with higher initial nitrate concentrations. We found no perchlorate degradation as long as nitrate was present in the system: perchlorate reduction was initiated only after all of the nitrate had been reduced. Nitrate-reduction rates were correlated to the initial nitrate concentrations and no lag period was observed. Nitrite was temporarily accumulated during nitrate reduction and was totally reduced, like nitrate, after 4 days. Count of viable microbial communities as well as PCR analysis of the chlorite dismutase gene in the native microbial population exposed to high concentrations of perchlorate (10,000-20,000 mg L-1

  4. Proteomic detection of proteins involved in perchlorate and chlorate metabolism.

    PubMed

    Bansal, Reema; Deobald, Lee A; Crawford, Ronald L; Paszczynski, Andrzej J

    2009-09-01

    Mass spectrometry and a time-course cell lysis method were used to study proteins involved in perchlorate and chlorate metabolism in pure bacterial cultures and environmental samples. The bacterial cultures used included Dechlorosoma sp. KJ, Dechloromonas hortensis, Pseudomonas chloritidismutans ASK-1, and Pseudomonas stutzeri. The environmental samples included an anaerobic sludge enrichment culture from a sewage treatment plant, a sample of a biomass-covered activated carbon matrix from a bioreactor used for treating perchlorate-contaminated drinking water, and a waste water effluent sample from a paper mill. The approach focused on detection of perchlorate (and chlorate) reductase and chlorite dismutase proteins, which are the two central enzymes in the perchlorate (or chlorate) reduction pathways. In addition, acetate-metabolizing enzymes in pure bacterial samples and housekeeping proteins from perchlorate (or chlorate)-reducing microorganisms in environmental samples were also identified.

  5. CHRONIC PERCHLORATE EXPOSURE CAUSES MORPHOLOGICAL ABNORMALITIES IN DEVELOPING STICKLEBACK

    PubMed Central

    Bernhardt, Richard R.; Von Hippel, Frank A.; O’Hara, Todd M.

    2011-01-01

    Few studies have examined the effects of chronic perchlorate exposure during growth and development, and fewer still have analyzed the effects of perchlorate over multiple generations. We describe morphological and developmental characteristics for threespine stickleback (Gasterosteus aculeatus) that were spawned and raised to sexual maturity in perchlorate-treated water (G1,2003) and for their offspring (G2,2004) that were not directly treated with perchlorate. The G1,2003 displayed a variety of abnormalities, including impaired formation of calcified traits, slower growth rates, aberrant sexual development, poor survivorship, and reduced pigmentation that allowed internal organs to be visible. Yet these conditions were absent when the offspring of contaminated fish (G2,2004) were raised in untreated water, suggesting a lack of transgenerational effects and that surviving populations may be able to recover following remediation of perchlorate-contaminated sites PMID:21465539

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

    PubMed

    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.

  7. Chlorine isotopic composition of perchlorate in human urine as a means of distinguishing among exposure sources.

    PubMed

    Poghosyan, Armen; Morel-Espinosa, Maria; Valentin-Blasini, Liza; Blount, Benjamin C; Ferreccio, Catterina; Steinmaus, Craig M; Sturchio, Neil C

    2016-01-01

    Perchlorate (ClO4(-)) is a ubiquitous environmental contaminant with high human exposure potential. Natural perchlorate forms in the atmosphere from where it deposits onto the surface of Earth, whereas synthetic perchlorate is manufactured as an oxidant for industrial, aerospace, and military applications. Perchlorate exposure can potentially cause adverse health effects in humans by interfering with the production of thyroid hormones through competitively blocking iodide uptake. To control and reduce perchlorate exposure, the contributions of different sources of perchlorate exposure need to be quantified. Thus, we demonstrate a novel approach for determining the contribution of different perchlorate exposure sources by quantifying stable and radioactive chlorine isotopes of perchlorate extracted from composite urine samples from two distinct populations: one in Atlanta, USA and one in Taltal, Chile (Atacama region). Urinary perchlorate from the Atlanta region resembles indigenous natural perchlorate from the western USA (δ(37)Cl=+4.1±1.0‰; (36)Cl/Cl=1 811 (±136) × 10(-15)), and urinary perchlorate from the Taltal, Chile region is similar to natural perchlorate in nitrate salt deposits from the Atacama Desert of northern Chile (δ(37)Cl=-11.0±1.0‰; (36)Cl/Cl=254 (±40) × 10(-15)). Neither urinary perchlorate resembled the isotopic pattern found in synthetic perchlorate. These results indicate that natural perchlorate of regional provenance is the dominant exposure source for the two sample populations, and that chlorine isotope ratios provide a robust tool for elucidating perchlorate exposure pathways.

  8. Ecological Risk Assessment of Ammonium Perchlorate on Fish, Amphibians, and Small Mammals

    DTIC Science & Technology

    2003-02-01

    The Effects of Contaminated and Reference Surface Waters on Metamorphosis in Xenopus Laevis ...; 4) Lethal Concentration Determination of Sodium...Perchlorate and Ammonium Chloride on Xenopus Laevis Eggs ... ; 5) Sublethal Effects of Ammonium Chloride, Ammonium Perchlorate, and Sodium Perchlorate on the...Development and Metamorphosis of Xenopus Laevis ; 6) Protocol Development for Determination of Effects of Perchlorate on Growth and Reproduction of

  9. Placental transfer of and infantile exposure to perchlorate.

    PubMed

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

    2016-02-01

    Fetuses and infants are vulnerable to perchlorate toxicity. We assessed fetal and infantile exposure to perchlorate in two Chinese cities (Nanchang and Tianjin). Perchlorate was widely found (82%-100%) in breast milk, dissolved infant formula, infants' urine, maternal and cord blood samples. Perchlorate levels in infants' urine (mean ± standard deviation: 22.4 ± 35.6 ng mL(-1)), breast milk (36.6 ± 48.1 ng mL(-1)), and cord blood (3.18 ± 3.83 ng mL(-1)) samples collected from Nanchang and Tianjin were approximately an order of magnitude higher than those reported for the U.S. Perchlorate concentrations in cord blood were comparable to that in maternal blood, indicating that perchlorate is transferred from mother to fetus through placenta. Among all infants providing urine samples, the average daily intake of perchlorate (DOSEU) was estimated to be 1.17 ± 1.57 μg kg(-1) bw d(-1), and 40% of these infants had DOSEU exceeding the RfD (0.7 μg kg(-1) bw d(-1)) recommended by U.S. EPA. However, approximately 70% of exclusively breast-fed infants had perchlorate exposure dose via breast milk exceeding the RfD. For breast-fed infants, breast milk was the overwhelmingly predominant exposure pathway; while infant formula and indoor dust ingestion were major perchlorate exposure sources for formula-fed infants. To our knowledge, this is the first report to assess the fetal and infantile exposure to perchlorate in China. Copyright © 2015. Published by Elsevier Ltd.

  10. Perchlorate isotope forensics with naturally produced 36Cl

    NASA Astrophysics Data System (ADS)

    Hillegonds, D.; Parker, D.; Singleton, M.; Buchholz, B.; Esser, B.; Moran, J.; Rood, D.; Finkel, R.

    2008-12-01

    The source of perchlorate (ClO4-) in many surface and groundwaters is not known. Recent studies (Parker et al., 2008) suggest that natural production is widespread and common, and may involve atmospheric processes. The isotopic composition of perchlorate chlorine and oxygen has proven useful for identifying anthropogenic/natural perchlorate sources (Bohlke et al, 2005) and for exploring biodegradation in environmental samples (Sturchio et al, 2007). The stable isotope approach, however, requires processing very large volumes of water to obtain milligrams of rigorously separated perchlorate for analysis, limiting its widespread application. Chlorine-36 (36Cl) is a long-lived and rare radionuclide produced cosmogenically in the upper atmosphere. The measurement of 36Cl/Cl by accelerator mass spectrometry (AMS) only requires micrograms of sample chlorine enabling lower volume extractions (less than 1/10th that required for stable isotope techniques), and potentially less rigorous perchlorate chemistry. The primary technical goal of our work is to determine the utility of 36Cl in distinguishing perchlorate source and in constraining mechanisms of natural perchlorate formation. We expect that synthetic perchlorate compounds produced using chloride brines from ancient sources and concentrated modern deposits will have low 36Cl/Cl ratios that will be distinct from natural perchlorate produced in the atmosphere. High levels of 36Cl in groundwater or rainwater perchlorate would then be an unambiguous indication of a natural atmospheric production, and the distribution of 36Cl/Cl in precipitation and groundwater (in conjunction with stable isotope compositions) would constrain the mechanism for natural perchlorate production in the atmosphere. Using accelerator mass spectrometry (AMS), we have measured 36Cl/Cl in a number of synthetic perchlorate salts (including potassium, sodium, magnesium, and ammonium salts). Synthetic salt 36Cl/Cl atom ratios range from 1 to 35 e-15

  11. Electron donors and co-contaminants affect microbial community composition and activity in perchlorate degradation.

    PubMed

    Guan, Xiangyu; Xie, Yuxuan; Wang, Jinfeng; Wang, Jing; Liu, Fei

    2015-04-01

    Although microbial reduction of perchlorate (ClO4(-)) is a promising and effective method, our knowledge on the changes in microbial communities during ClO4(-) degradation is limited, especially when different electron donors are supplied and/or other contaminants are present. Here, we examined the effects of acetate and hydrogen as electron donors and nitrate and ammonium as co-contaminants on ClO4(-) degradation by anaerobic microcosms using six treatments. The process of degradation was divided into the lag stage (SI) and the accelerated stage (SII). Quantitative PCR was used to quantify four genes: pcrA (encoding perchlorate reductase), cld (encoding chlorite dismutase), nirS (encoding copper and cytochrome cd1 nitrite reductase), and 16S rRNA. While the degradation of ClO4(-) with acetate, nitrate, and ammonia system (PNA) was the fastest with the highest abundance of the four genes, it was the slowest in the autotrophic system (HYP). The pcrA gene accumulated in SI and played a key role in initiating the accelerated degradation of ClO4(-) when its abundance reached a peak. Degradation in SII was primarily maintained by the cld gene. Acetate inhibited the growth of perchlorate-reducing bacteria (PRB), but its effect was weakened by nitrate (NO3(-)), which promoted the growth of PRB in SI, and therefore, accelerated the ClO4(-) degradation rate. In addition, ammonia (NH4(+)), as nitrogen sources, accelerated the growth of PRB. The bacterial communities' structure and diversity were significantly affected by electron donors and co-contaminants. Under heterotrophic conditions, both ammonia and nitrate promoted Azospira as the most dominant genera, a fact that might significantly influence the rate of ClO4(-) natural attenuation by degradation.

  12. Perchlorate reduction by hydrogen autotrophic bacteria in a bioelectrochemical reactor.

    PubMed

    Wang, Zichao; Gao, Mengchun; Zhang, You; She, Zonglian; Ren, Yun; Wang, Zhe; Zhao, Congcong

    2014-09-01

    The autotrophic hydrogen reduction of perchlorate was investigated in batch modes in a proton-exchange membrane bioelectrochemical reactor. The phylogenic characterization of hydrogen-autotrophic perchlorate-reducing cultures in the cathode cell mainly included the genera Aureibacter tunicatorum, Fulvivirga kasyanovii, Thermotalea metallivorans (T), bacterium WHC2-6, and Thauera sp. Q20-C. The suitable H2SO4 supplement concentration was identified to be between 0.04 and 0.05 mol L(-1) in the anode cell. The perchlorate reduction was affected by the sludge concentration in the cathode cell, current intensity, and initial perchlorate concentration. The removal efficiency of perchlorate positively correlated with the current intensity, and the current intensity of 20, 40, 50, and 60 mA corresponded to removal efficiencies of 95.03, 96.29, 97.56 and 98.99%, respectively. When the current intensity was sufficient for hydrogen production, the kinetics of the perchlorate reduction conformed to a zero-order kinetics model, and the maximum specific substrate utilization rates for perchlorate (Vmax) ranged from 5.52 to 14.34 mg ClO4(-) g(-1) volatile suspended solid (VSS) h(-1). Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. Weakening of ice by magnesium perchlorate hydrate

    USGS Publications Warehouse

    Lenferinka, Hendrick J.; Durhama, William B.; Sternb, Laura A.; Patharec, Asmin V.

    2013-01-01

    We show that perchlorate hydrates, which have been detected at high circumpolar martian latitudes, have a dramatic effect upon the rheological behavior of polycrystalline water ice under conditions applicable to the North Polar Layered Deposits (NPLD). We conducted subsolidus creep tests on mixtures of ice and magnesium perchlorate hydrate, Mg(ClO4)2·6H2O (MP6), of 0.02, 0.05, 0.10, and 0.47 volume fraction MP6. We found these mixtures to be increasingly weak with increasing MP6 content. For mixtures with ⩽0.10 volume fraction MP6, we resolved a stress exponent of n ≈ 2 at low stresses transitioning to n ≈ 4 above 10 MPa. Scanning electron microscopy of deformed specimens revealed MP6 to be distributed as an interconnected film between ice grains. These results suggest that grain boundary sliding (GBS) may be enhanced with respect to pure ice. As the enhancement of GBS is expected in polycrystalline aggregates containing a few percent melt or otherwise weak material distributed along grain boundaries, the observed n ≈ 2 is consistent with the mutual accommodation of basal slip and GBS. If ice containing trace concentrations of MP6 is also much weaker than pure ice at low stresses, flow in the NPLD could be significantly enhanced, particularly at the warmer basal temperatures associated with higher martian obliquities.

  14. Weakening of ice by magnesium perchlorate hydrate

    NASA Astrophysics Data System (ADS)

    Lenferink, Hendrik J.; Durham, William B.; Stern, Laura A.; Pathare, Asmin V.

    2013-08-01

    We show that perchlorate hydrates, which have been detected at high circumpolar martian latitudes, have a dramatic effect upon the rheological behavior of polycrystalline water ice under conditions applicable to the North Polar Layered Deposits (NPLD). We conducted subsolidus creep tests on mixtures of ice and magnesium perchlorate hydrate, Mg(ClO4)2·6H2O (MP6), of 0.02, 0.05, 0.10, and 0.47 volume fraction MP6. We found these mixtures to be increasingly weak with increasing MP6 content. For mixtures with ⩽0.10 volume fraction MP6, we resolved a stress exponent of n ≈ 2 at low stresses transitioning to n ≈ 4 above 10 MPa. Scanning electron microscopy of deformed specimens revealed MP6 to be distributed as an interconnected film between ice grains. These results suggest that grain boundary sliding (GBS) may be enhanced with respect to pure ice. As the enhancement of GBS is expected in polycrystalline aggregates containing a few percent melt or otherwise weak material distributed along grain boundaries, the observed n ≈ 2 is consistent with the mutual accommodation of basal slip and GBS. If ice containing trace concentrations of MP6 is also much weaker than pure ice at low stresses, flow in the NPLD could be significantly enhanced, particularly at the warmer basal temperatures associated with higher martian obliquities.

  15. Wet Deposition of Perchlorate Over the Continental United States

    NASA Astrophysics Data System (ADS)

    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 < 5 ng/L to 75 ng/L with higher concentrations predominantly in summer months and inland regions. The Cl- /ClO4- molar ratio varied over three orders of magnitude with few thousands inland to few millions near coastal regions. There were no significant correlations (r > 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.

  16. Effects of Perchlorate on Organic Molecules under Simulated Mars Conditions

    NASA Astrophysics Data System (ADS)

    Carrier, B. L.; Kounaves, S. P.

    2014-12-01

    Perchlorate (ClO4-) was discovered in the northern polar region of Mars by the Mars Phoenix Lander in 2008 and has also been recently detected by the Curiosity Rover in Gale Crater [1,2]. Perchlorate has also been shown to be formed under current Mars conditions via the oxidation of mineral chlorides, further supporting the theory that perchlorate is present globally on Mars [3]. The discovery of perchlorate on Mars has raised important questions about the effects of perchlorate on the survival and detection of organic molecules. Although it has been shown that pyrolysis in the presence of perchlorate results in the alteration or destruction of organic molecules [4], few studies have been conducted on the potential effects of perchlorate on organic molecules under martian surface conditions. Although perchlorate is typically inert under Mars-typical temperatures [5], perchlorate does absorb high energy UV radiation, and has been shown to decompose to form reactive oxychlorine species such as chlorite (ClO2-) when exposed to martian conditions including UV or ionizing radiation [6,7]. Here we investigate the effects of perchlorate on the organic molecules tryptophan, benzoic acid and mellitic acid in order to determine how perchlorate may alter these compounds under Mars conditions. Experiments are performed in a Mars Simulation Chamber (MSC) capable of reproducing the temperature, pressure, atmospheric composition and UV flux found on Mars. Soil simulants are prepared consisting of SiO2 and each organic, as well as varying concentrations of perchlorate salts, and exposed in the MSC. Subsequent to exposure in the MSC samples are leached and the leachate analyzed by HPLC and LC-MS to determine the degree of degradation of the original organic and the identity of any potential decomposition products formed by oxidation or chlorination. References: [1] Kounaves et al., J. Geophys. Res. Planets, Vol. 115, p. E00E10, 2010 [2] Glavin et al., J. Geophys. Res. Planets, Vol

  17. Simultaneous removal of perchlorate and energetic compounds in munitions wastewater by zero-valent iron and perchlorate-respiring bacteria.

    PubMed

    Ahn, Se Chang; Hubbard, Brian; Cha, Daniel K; Kim, Byung J

    2014-01-01

    Ammonium perchlorate is one of the main constituents in Army's insensitive melt-pour explosive, PAX-21 in addition to RDX and 2,4-dinitroanisole (DNAN). The objective of this study is to develop an innovative treatment process to remove both perchlorate and energetic compounds simultaneously from PAX-21 production wastewater. It was hypothesized that the pretreatment of PAX-21 wastewater with zero-valent iron (ZVI) would convert energetic compounds to products that are more amenable for biological oxidation and that these products serve as electron donors for perchlorate-reducing bacteria. Results of batch ZVI reduction experiments showed that DNAN was completely reduced to 2,4-diaminoanisole and RDX was completely reduced to formaldehyde. Anaerobic batch biodegradation experiments showed that perchlorate (30 mg L(-1)) in ZVI-treated PAX-21 wastewater was decreased to an undetectable level after 5 days. Batch biodegradation experiments also confirmed that formaldehyde in ZVI-treated wastewater was the primary electron donor for perchlorate-respiring bacteria. The integrated iron-anaerobic bioreactor system was effective in completely removing energetic compounds and perchlorate from the PAX-21 wastewater without adding an exogenous electron donor. This study demonstrated that ZVI pretreatment not only removed energetic compounds, but also transformed energetic compounds to products that can serve as the source of electrons for perchlorate-respiring bacteria.

  18. Novel miniaturized sensors for potentiometric batch and flow-injection analysis (FIA) of perchlorate in fireworks and propellants.

    PubMed

    Almeer, Saeed H M A; Zogby, Ibrahim A; Hassan, Saad S M

    2014-11-01

    Three planar miniaturized perchlorate membrane sensors (3×5 mm(2)) are prepared using a flexible Kaptan substrate coated with nitron-perchlorate (NT-ClO4) [sensor 1], methylene blue-perchlorate (MB-ClO4) [sensor II] and indium-porphyrin (In-Por) [sensor III] as electroactive materials in PVC membranes plasticized with 2-NPPE. Sensors I, II and III display near-Nernstian response for 1.0×10(-5)-1.0×10(-2), 3.1×10(-5)-1.0×10(-2) and 3.1×10(-6)-1.0×10(-2) mol L(-1) ClO4(-) with lower detection limits of 6.1×10(-6), 6.9×10(-6) and 1.2×10(-6) mol L(-1), and anionic calibration slopes of 50.9±0.4, 48.4±0.4 and 57.7±0.3 mV decade(-1), respectively. Methods for determining perchlorate using these sensors offer many attractive advantages including simplicity, flexibility, cost effectiveness, wide linear dynamic response range (0.1-1000 ppm), low detection limit (<1.2×10(-6) mol L(-1)≡0.1 ppm), small sample test volume (100 μL), safety, short response time (<20 s), long life span (~8 weeks), and extended wide working pH range (4.5-8.0). The sensors show high selectivity in the presence of some inorganic ions (e.g., PO4(3-), SO4(2-), S2O3(2-), NO2(-), NO3(-), N3(-), CN(-), Cl(-), Br(-), I(-)) and automation feasibility. Indium-porphyrin based membrane sensor (sensor III) is used as a detector in a wall-jet flow injection set-up to enable accurate flow injection analysis (FIA) of perchlorate in some fireworks without interferences from the associated reducing agents (sulfur and charcoal), binders (dextrin, lactose), coloring agents (calcium, strontium, copper, iron, sodium), color brighten (linseed oil) and regulators (aluminum flakes) which are commonly used in the formulations. The sensor is also used for perchlorate assessment in some propellant powders. The results fairly agree with data obtained by ion-chromatography.

  19. Behavioral response of dissimilatory perchlorate-reducing bacteria to different electron acceptors.

    PubMed

    Sun, Yvonne; Gustavson, Ruth L; Ali, Nadia; Weber, Karrie A; Westphal, Lacey L; Coates, John D

    2009-10-01

    The response behavior of three dissimilatory perchlorate-reducing bacteria to different electron acceptors (nitrate, chlorate, and perchlorate) was investigated with two different assays. The observed response was species-specific, dependent on the prior growth conditions, and was inhibited by oxygen. We observed attraction toward nitrate when Dechloromonas aromatica strain RCB and Azospira suillum strain PS were grown with nitrate. When D. aromatica and Dechloromonas agitata strain CKB were grown with perchlorate, both responded to nitrate, chlorate, and perchlorate. When A. suillum was grown with perchlorate, the organism responded to chlorate and perchlorate but not nitrate. A gene replacement mutant in the perchlorate reductase subunit (pcrA) of D. aromatica resulted in a loss of the attraction response toward perchlorate but had no impact on the nitrate response. Washed-cell suspension studies revealed that the perchlorate grown cells of D. aromatica reduced both perchlorate and nitrate, while A. suillum cells reduced perchlorate only. Based on these observations, energy taxis was proposed as the underlying mechanism for the responses to (per)chlorate by D. aromatica. To the best of our knowledge, this study represents the first investigation of the response behavior of perchlorate-reducing bacteria to environmental stimuli. It clearly demonstrates attraction toward chlorine oxyanions and the unique ability of these organisms to distinguish structurally analogous compounds, nitrate, chlorate, and perchlorate and respond accordingly.

  20. Re: Request for Correction: Drinking Water: Determination on Perchlorate

    EPA Pesticide Factsheets

    Request for correction (RFC) of information developed and relied upon by the Environmental Protection Agency (EPA or Agency) to support its determination to regulate perchlorate under the Safe Drinking Water Act (SDWA).

  1. Perchlorate and thyroid function: what are the environmental issues?

    PubMed

    Hershman, Jerome M

    2005-05-01

    Ammonium perchlorate, used in the solid-propellant of rocket engines, has contaminated some water supplies and represents a potential public health hazard. Its toxicity is the result of the inhibition of the sodium iodide symporter resulting in reduced iodide uptake, possibly leading to reduced production of thyroid hormone. The fetus is the most vulnerable subject. Studies of newborn screening for thyroid function have yielded conflicting results and have not measured perchlorate or iodine intake. Based on short-term clinical studies in adults, less than 0.5 mg perchlorate per 70-kg adult will not lower thyroid uptake of radioiodine, while 1.6 mg/kg per day will lower thyroid uptake by 20%. To avoid interference with thyroid function, the California Office of Environmental Health Hazard Assessment recommended a public health goal of 6 microg perchlorate per liter of drinking water, but approximately three times that concentration is likely to be safe.

  2. National Cost Implications of a Potentional Perchlorate Regulation

    EPA Pesticide Factsheets

    In this study, a screening level cost assessment was conducted to evaluate the national cost implications of five potential regulatory levels for perchlorate in drinking water 4, 6, 12, 18, and 24 ?g/L.

  3. Organic functionalisation of graphene catalysed by ferric perchlorate.

    PubMed

    Yang, Lei; He, Junpo

    2014-12-25

    We have developed a method to prepare covalently functionalised graphene using ferric perchlorate as the catalyst. The resulting functionalised graphene was characterised by Raman spectroscopy, TGA, XPS, AFM, and dispersibility tests in organic or aqueous media.

  4. DISTRIBUTION SYSTEM AND WATER QUALITY IMPACTS OF PERCHLORATE REMOVAL TECHNOLOGIES

    EPA Science Inventory

    This paper will discuss the characteristics of perchlorate and the resulting treatment processes that hold promise for current or near-term use: ion exchange, anaerobic biological treatment, reverse osmosis, and tailored adsorbents. These treatment technologies are capable of cau...

  5. POLISHING THE EFFLUENT FROM AN ANAEROBIC BIOLOGICAL PERCHLORATE TREATMENT PROCESS

    EPA Science Inventory

    Anaerobic biological processes effectively reduce perchlorate to chloride. However, the effluent can be biologically unstable, high in particulates and high in disinfection by-product precursor compounds. Such an effluent would be unsuitable for transmission into a drinking water...

  6. POLISHING THE EFFLUENT FROM AN ANAEROBIC BIOLOGICAL PERCHLORATE TREATMENT PROCESS

    EPA Science Inventory

    Anaerobic biological processes effectively reduce perchlorate to chloride. However, the effluent can be biologically unstable, high in particulates and high in disinfection by-product precursor compounds. Such an effluent would be unsuitable for transmission into a drinking water...

  7. High pressure studies of potassium perchlorate

    DOE PAGES

    Pravica, Michael; Wang, Yonggang; Sneed, Daniel; ...

    2016-07-29

    Two experiments are reported on KClO4 at extreme conditions. A static high pressure Raman study was first conducted to 18.9 GPa. Evidence for at least two new phases was observed: one between 2.4 and 7.7 GPa (possibly sluggish), and the second near 11.7 GPa. Then, the X-ray induced decomposition rate of potassium perchlorate (KClO4 hv→ KCl + 2O2) was studied up to 15.2 GPa. The time-dependent growth of KCl and O2 was monitored. The decomposition rate slowed at higher pressures. As a result, we present the first direct evidence for O2 crystallization at higher pressures, demonstrating that O2 molecules aggregatemore » at high pressure.« less

  8. High pressure studies of potassium perchlorate

    SciTech Connect

    Pravica, Michael; Wang, Yonggang; Sneed, Daniel; Reiser, Sharissa; White, Melanie

    2016-07-29

    Two experiments are reported on KClO4 at extreme conditions. A static high pressure Raman study was first conducted to 18.9 GPa. Evidence for at least two new phases was observed: one between 2.4 and 7.7 GPa (possibly sluggish), and the second near 11.7 GPa. Then, the X-ray induced decomposition rate of potassium perchlorate (KClO4 hv→ KCl + 2O2) was studied up to 15.2 GPa. The time-dependent growth of KCl and O2 was monitored. The decomposition rate slowed at higher pressures. As a result, we present the first direct evidence for O2 crystallization at higher pressures, demonstrating that O2 molecules aggregate at high pressure.

  9. [Metabolism peculiarities of bacteria restoring chlorates and perchlorates].

    PubMed

    Smirnova, G F

    2010-01-01

    Bacteria facultative anaerobes capable to restore chlorine oxygen compounds - chlorates and perchlorates, using them as terminal acceptors of electrons, have been isolated from various natural sources. Chloride is the end product of this process. Besides chlorates and perchlorates the isolated bacteria also restored other electron acceptors: chromates, sulfates, nitrates, vanadates, manganates. The studied restored bacteria use awhole number of organic compounds as electron donors. The paper is presented in Russian.

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

    DTIC Science & Technology

    2007-04-04

    whether to regulate perchlorate and has cited the need for more research on health effects, water treatment techniques, and occurrence. Related issues...have involved environmental cleanup and water treatment costs, which will be driven by federal and state standards. Interagency disagreements over...effects and treatment technologies and for collecting occurrence data. In 1999, the EPA required water systems to monitor for perchlorate under the

  11. Elimination of Perchlorate Oxidizers from Yellow Pyrotechnic Flare Compositions

    DTIC Science & Technology

    2015-03-11

    from Yellow Pyrotechnic Flare Compositions POC: Dr. Eric Miklaszewski, eric.miklaszewski@navy.mil Prepared for: EuroPyro May 5 , 2015, Toulouse...Conference Presentation 3. DATES COVERED (From - To) 2002-2015 4. TITLE AND SUBTITLE Elimination of Perchlorate Oxidizers from Yellow Pyrotechnic...increasing government regulations to limit ground water contamination. A perchlorate-free yellow flare composition for future implementation into the Mk 144

  12. Tailored Granular Activated Carbon Treatment of Perchlorate in Drinking Water

    DTIC Science & Technology

    2010-10-01

    both the sample containers were reprepared and reanalyzed in October, with dissimilar results: container “2/16/07” ( 3710 ng/ mL ) and container “10/10...2.5 ml /min At PSU using water from Fontana Well 17B/17C Perchlorate elustion cuve during challenge with various influent ammendments at...approximately 3, 4, and 5 gram samples of carbon. Record weight. 3. Transfer carbon to 500 ml polyethylene sample bottles. 4. Add 300 ml perchlorate

  13. Dealing With Perchlorate in the Santa Clarita Valley, CA

    NASA Astrophysics Data System (ADS)

    Boulos, L.; Min, J.; Juby, G.; McLean, S.; Prasifka, D.; Brown, J.

    2004-05-01

    Castaic Lake Water Agency was faced with a dilemma: how to support the increasing water needs of a growing population in the Santa Clarita Valley with three to five wells in the area shut-down due to the presence of perchlorate. Carollo Engineers was hired to design a treatment program for the removal of perchlorate from Saugus Aquifer. Several unknowns challenged the project including an uncertainty in a regulatory MCL for perchlorate, lack of brine line in the area, and low chloride limits in LACSD sewer lines. The preliminary phase of the project was to identify and recommend perchlorate treatment processes for further bench and/or pilot-scale testing. Two alternatives were selected: 1) Three NSF certified perchlorate-selective ion exchange resins and 2) Two types of biological treatment systems. Selection criteria included: cost, minimal formation of wastes and full-scale demonstration of the processes. This paper will focus on the basis, design, and findings from three perchlorate-selective ion-exchange resins. Bench-scale testing of the ion-exchange resins was conducted over a period of 3 months. NDMA formation following chlorination and chloramination was investigated. The spent resins were further characterized for metals and uranium. Results: Adsorption cycles of two of the resins lasted more than 70,000 bed volumes before perchlorate was detected in the effluent of the columns (approximately 200,000- 550,000 gal/cu-ft resin). No NDMA was formed as a result of post-chlorination with free and combined chlorine, or as a result of prechlorination with free chlorine. The metals measured in the spent results were well below the TTLC and STLC limits, despite the long run times. Ion-exchange is therefore a feasible technology for treatment perchlorate in the Santa Clarita Valley.

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

    DTIC Science & Technology

    2010-07-01

    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...accumulation occurs mostly in outer leaves and not in consumable portions, such as the head. Studies reported that, when lettuce was irrigated with

  15. Isotopic tracing of perchlorate in the environment

    USGS Publications Warehouse

    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.

  16. The NAS Perchlorate Review: Adverse Effects?

    SciTech Connect

    Johnston, Richard B.; Corley, Richard; Cowan, Linda; Utiger, Robert D.

    2005-11-01

    To the editor: Drs. Ginsberg and Rice argue that the reference dose for perchlorate of 0.0007 mg/kg per day recommended by the National Academies’ Committee to Assess the Health Implications of Perchlorate Ingestion is not adequately protective. As members of the committee, we disagree. Ginsberg and Rice base their conclusion on three points. The first involves the designation of the point of departure as a NOEL (no-observed-effect level) versus a LOAEL (lowest-observed-adverse- effect level). The committee chose as its point of departure a dose of perchlorate (0.007 mg/kg per day) that when given for 14 days to 7 normal subjects did not cause a significant decrease in the group mean thyroid iodide uptake (Greer et al. 2002). Accordingly, the committee considered it a NOEL. Ginsberg and Rice focus on the fact that only 7 subjects were given that dose, and they 1seem to say that attention should be paid only to the results in those subjects in whom there was a 1fall in thyroid iodide uptake, and that the results in those in whom there was no fall or an increase should be ignored. They consider the dose to be a LOAEL because of the fall in uptake in those few subjects. It is important to note that a statistically significant decrease of, for example, 5% or even 10%, would not be biologically important and, more important, would not be sustained. For example, in another study (Braverman et al. 2004), administration of 0.04 mg/kg per day to normal subjects for 6 months had no effect on thyroid iodide uptake when measured at 3 and 6 months, and no effect on serum thyroid hormone or thyrotropin concentrations measured monthly (inspection of Figure 5A in the paper by Greer et al. suggests that this dose would inhibit thyroid iodide uptake by about 25% if measured at 2 weeks). The second issue involves database uncertainty. In clinical studies, perchlorate has been administered prospectively to 68 normal subjects for 2 weeks to 6 months. In one study (Brabant et al. 1992

  17. (Per)chlorate in Biology on Earth and Beyond.

    PubMed

    Youngblut, Matthew D; Wang, Ouwei; Barnum, Tyler P; Coates, John D

    2016-09-08

    Respiration of perchlorate and chlorate [collectively, (per)chlorate] was only recognized in the last 20 years, yet substantial advances have been made in our understanding of the underlying metabolisms. Although it was once considered solely anthropogenic, pervasive natural sources, both terrestrial and extraterrestrial, indicate an ancient (per)chlorate presence across our solar system. These discoveries stimulated interest in (per)chlorate microbiology, and the application of advanced approaches highlights exciting new facets. Forward and reverse genetics revealed new information regarding underlying molecular biology and associated regulatory mechanisms. Structural and functional analysis characterized core enzymes and identified novel reaction sequences. Comparative genomics elucidated evolutionary aspects, and stress analysis identified novel response mechanisms to reactive chlorine species. Finally, systems biology identified unique metabolic versatility and novel mechanisms of (per)chlorate respiration, including symbiosis and a hybrid enzymatic-abiotic metabolism. While many published studies focus on (per)chlorate and their basic metabolism, this review highlights seminal advances made over the last decade and identifies new directions and potential novel applications.

  18. Thermodynamic targeting of microbial perchlorate reduction by selective electron donors.

    PubMed

    Van Trump, James Ian; Coates, John D

    2009-04-01

    Here we describe 2,6-anthrahydroquinone disulfonate (AH(2)DS) as a model thermodynamically 'targeting' electron donor capable of selectively stimulating respiratory processes relevant to the bioremediation of perchlorate. Pure cultures of Dechloromonas aromatica, Dechloromonas agitata and Azospira suillum, as well as uncharacterized microbial consortia, were capable of stoichiometrically reducing perchlorate to chloride upon oxidation of AH(2)DS to the corresponding quinone 2,6-anthraquinone disulfonate (AQDS). No degradation of the anthraquinone structure was observed, and no organism tested grew by this metabolism. Thermodynamic calculations suggest that AH(2)DS oxidation should support nitrate and perchlorate reduction, whereas sulfate reduction and methanogenesis are predicted to be unfavorable. Mixed community microcosms oxidizing AH(2)DS reduced nitrate and perchlorate, whereas sulfate reduction never occurred. In contrast, microcosms amended with acetate respired nitrate, perchlorate and sulfate, as would be predicted by thermodynamic calculation. Our results suggest that the thermodynamic properties of hydroquinones allow for targeted stimulation of only a subset of potential respiratory processes. This observation could help improve enhanced in situ bioremediation of perchlorate by negating many of the detrimental aspects of biofouling.

  19. Perchlorate Reductase Is Distinguished by Active Site Aromatic Gate Residues*

    PubMed Central

    Youngblut, Matthew D.; Tsai, Chi-Lin; Clark, Iain C.; Carlson, Hans K.; Maglaqui, Adrian P.; Gau-Pan, Phonchien S.; Redford, Steven A.; Wong, Alan; Tainer, John A.; Coates, John D.

    2016-01-01

    Perchlorate is an important ion on both Earth and Mars. Perchlorate reductase (PcrAB), a specialized member of the dimethylsulfoxide reductase superfamily, catalyzes the first step of microbial perchlorate respiration, but little is known about the biochemistry, specificity, structure, and mechanism of PcrAB. Here we characterize the biophysics and phylogeny of this enzyme and report the 1.86-Å resolution PcrAB complex crystal structure. Biochemical analysis revealed a relatively high perchlorate affinity (Km = 6 μm) and a characteristic substrate inhibition compared with the highly similar respiratory nitrate reductase NarGHI, which has a relatively much lower affinity for perchlorate (Km = 1.1 mm) and no substrate inhibition. Structural analysis of oxidized and reduced PcrAB with and without the substrate analog SeO32− bound to the active site identified key residues in the positively charged and funnel-shaped substrate access tunnel that gated substrate entrance and product release while trapping transiently produced chlorate. The structures suggest gating was associated with shifts of a Phe residue between open and closed conformations plus an Asp residue carboxylate shift between monodentate and bidentate coordination to the active site molybdenum atom. Taken together, structural and mutational analyses of gate residues suggest key roles of these gate residues for substrate entrance and product release. Our combined results provide the first detailed structural insight into the mechanism of biological perchlorate reduction, a critical component of the chlorine redox cycle on Earth. PMID:26940877

  20. Potentiometric perchlorate determination at nanomolar concentrations in vegetables.

    PubMed

    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.

  1. Thermal and Evolved Gas Analysis of Magnesium Perchlorate: Implications for Perchlorates in Soils at the Mars Phoenix Landing Site

    NASA Technical Reports Server (NTRS)

    Ming, Douglas W.; Morris, R.V.; Lauer, H. V.; Sutter, B.; Golden, D.C.; Boynton, W.V.

    2009-01-01

    Perchlorate salts were discovered in the soils around the Phoenix landing site on the northern plains of Mars [1]. Perchlorate was detected by an ion selective electrode that is part of the MECA Wet Chemistry Laboratory (WCL). The discovery of a mass 32 fragment (likely 02) by the Thermal and Evolved-Gas Analyzer (TEGA) provided additional confirmation of a strong oxidizer in the soils around the landing site. The purpose of this paper is to evaluate the thermal and evolved gas behavior of perchlorate salts using TEGA-like laboratory testbed instruments. TEGA ovens were fabricated from high purity Ni. Hence, an additional objective of this paper is to determine the effects that Ni might have on the evolved gas behavior of perchlorate salts.

  2. Perchlorate Formation on Mineral Surfaces under Ambient Mars Conditions

    NASA Astrophysics Data System (ADS)

    Carrier, B. L.; Kounaves, S. P.

    2013-12-01

    Perchlorate(ClO4-) was first discovered in the northern polar region of mars by the Mars Phoenix Lander in 2008 and was also recently detected by the Mars Science Laboratory in Gale crater, indicating a possible planet-wide distribution [1,2]. The discovery of perchlorate on mars has led to numerous questions regarding its formation pathways, intermediate oxychlorine species that may be present, and their capacity to oxidize organics that may be present in the surface and sub-surface. If perchlorate is formed photochemically in the atmosphere as on earth, it would be expected that the large amount of perchlorate on mars (~0.6% by weight detected by Phoenix) would have been formed mainly in the distant past when volcanic activity on mars was more prevalent and more chlorine was available in the atmosphere, however recent research shows that perchlorate is broken down over time by gamma rays, suggesting an ongoing source of perchlorate production [3]. This suggests an ongoing mechanism for perchlorate formation. Our current research is aimed at understanding different mechanisms for perchlorate formation on mineral surfaces under ambient mars conditions. Experiments are performed in a Mars Simulation Chamber (MSC) capable of reproducing the temperature, pressure, atmospheric composition and UV fluence found on mars. Soil simulants are prepared consisting of SiO2 and various minerals that are known to be present on mars, as well as Cl-, OCl-, ClO2- or ClO3- and exposed in the MSC for varying lengths of time. Samples are subsequently analyzed for perchlorate formation using ion chromatography. To date, perchlorate has been shown to be formed relatively easily under simulated martian conditions from both ClO2- and ClO3- starting materials without invoking an atmospheric source of chlorine. References: [1] Hecht et al, Science, Vol. 325, p. 64-67, 2009 [2] Kerr, Science, Vol. 340, p. 138, 2013 [3] Quinn et al, Astrobiology, Vol. 13(6) p. 515-20, 2013

  3. Environmental Perchlorate and Thiocyanate Exposures and Infant Serum Thyroid Function

    PubMed Central

    Braverman, Lewis E.; He, Xuemei; Schuller, Kristin E.; Roussilhes, Alexandra; Jahreis, Katherine A.; Pearce, Elizabeth N.

    2012-01-01

    Background Breastfed infants rely on maternal iodine for thyroid hormone production required for neurodevelopment. Dietary iodine among women of childbearing age in the United States may be insufficient. Perchlorate (competitive inhibitor of the sodium/iodide symporter [NIS]) exposure is ubiquitous. Thiocyanate, from cigarettes and diet, is a weaker NIS inhibitor. Environmental perchlorate and thiocyanate exposures could decrease breast milk iodine by competitively inhibiting NIS in lactating breasts (thus impairing infants' iodine availability), and/or infants' thyroidal NIS to directly decrease infant thyroid function. The current study assessed the relationships between environmental perchlorate and thiocyanate exposures and infant serum thyroid function. Methods Iodine, perchlorate, and thiocyanate in breast milk, maternal and infant urine, and infant serum thyroid function tests were cross-sectionally measured in Boston-area women and their 1–3 month-old breastfed infants. Univariate and multivariable analyses assessed relationships between iodine, perchlorate, thiocyanate, thyroid-stimulating hormone (TSH), and free thyroxine (FT4) levels. Results In 64 mothers and infants, median (range) iodine levels were 45.6 μg/L (4.3–1080) in breast milk, 101.9 μg/L (27–570) in maternal urine, and 197.5 μg/L (40–785) in infant urine. Median perchlorate concentrations were 4.4 μg/L (0.5–29.5) in breast milk, 3.1 μg/L (0.2–22.4) in maternal urine, and 4.7 μg/L (0.3–25.3) in infant urine. There were no correlations between infant TSH or FT4 and iodine, perchlorate, and thiocyanate levels in breast milk, maternal urine, and infant urine. In multivariable analyses, perchlorate and thiocyanate levels in breast milk, maternal urine, and infant urine were not significant predictors of infant TSH or FT4. Conclusions Boston-area mothers and their breastfed infants are generally iodine sufficient. Although environmental perchlorate and thiocyanate

  4. Perchlorate in The Great Lakes: Distribution, Isotopic Composition and Origin

    NASA Astrophysics Data System (ADS)

    Poghosyan, A.; Sturchio, N. C.; Jackson, W. A.; Guan, Y.; Eiler, J. M.; Hatzinger, P. B.

    2013-12-01

    Concentrations, stable chlorine and oxygen isotopic compositions, and 36Cl abundances of perchlorate were investigated in the five Laurentian Great Lakes. Samples were collected during monitoring cruises in 2007 and 2008 of the U.S. EPA's RV Lake Guardian and in 2010 at the water supply intake of Marquette, MI on the southern shore of Lake Superior. Concentrations of perchlorate were measured by IC/MS/MS at 24 locations, including one or two depth profiles in each lake. Mean concentrations (μg/L) are: Superior, 0.06 × 0.01; Michigan, 0.10 × 0.01; Huron, 0.11 × 0.01; Erie, 0.08 × 0.01, and Ontario, 0.09 × 0.01. Concentration vs. depth is nearly constant in each lake, indicating well-mixed conditions. Perchlorate was extracted from near-surface water by passing 15,000 to 80,000 L of water through 1-L cartridges containing Purolite A530E bifunctional anion-exchange resin. In the laboratory, perchlorate was eluted from the resin, purified, and precipitated as a >99% pure crystalline phase. Milligram amounts were recovered from each lake. Chlorine and oxygen isotopic analyses were performed at Caltech using the Cameca 7f-GEO SIMS instrument, following validation of the SIMS method with analyses of USGS-37 and USGS-38 isotopic reference materials. Results indicate a relatively narrow range in δ37Cl values (+2.9 to +3.9 ‰) and a wider range in δ18O values (-4.0 to +4.1 ‰), with a general geographic trend of increasing δ18O from west to east. Oxygen-17 was measured at UIC using dual-inlet IRMS of O2 produced by decomposition of KClO4. Great Lakes perchlorate has mass-independent oxygen isotopic variations with positive Δ17O values (+1.6 ‰ to +2.7 ‰) divided into two distinct groups: Lake Superior (+2.7 ‰) and the other four lakes (~ +1.7 ‰). The isotopic data indicate that perchlorate is dominantly of natural origin, having stable isotopic compositions resembling those of perchlorate from pre-industrial groundwaters in the western USA. The 36Cl

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

    PubMed

    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.

  6. ASSOCIATION OF URINARY PERCHLORATE WITH INDIRECT MEASURES OFTHYROID DYSFUNCTION BASED ON NHANES 2001-2002

    EPA Science Inventory

    Background/Aims: Perchlorate is a widespread environmental pollutant. Previous population studies based on the National Health and Nutrition Examination Survey (NHANES) 2001-2002, showed that urinary perchlorate concentrations were associated with increased levels of thyroid stim...

  7. ALTERNATIVE TECHNIQUES FOR MEASUREMENT OF PERCHLORATE IN FERTILIZER AND ENVIRONMENTAL SAMPLES

    EPA Science Inventory

    The Perchlorate anion has been implicated as a potentially serious environmental pollutant, being found in drinking water and irrigated crops. Commercial fertilizers have recently been shown to contain high levels of Perchlorate impurities and thus be potentially important source...

  8. ASSOCIATION OF URINARY PERCHLORATE WITH INDIRECT MEASURES OFTHYROID DYSFUNCTION BASED ON NHANES 2001-2002

    EPA Science Inventory

    Background/Aims: Perchlorate is a widespread environmental pollutant. Previous population studies based on the National Health and Nutrition Examination Survey (NHANES) 2001-2002, showed that urinary perchlorate concentrations were associated with increased levels of thyroid stim...

  9. DEVELOPMENT OF AN ELECTROSPRAY MASS SPECTROMETRIC METHOD FOR DETERMINING PERCHLORATE IN FERTILIZERS

    EPA Science Inventory

    An electrospray mass spectrometric method has been developed for application to agricultural and horticultural fertilizers to determine perchlorate. After fertilizers are leached or dissolved in water, the method relies on the formation of stable ion pair complex of the perchlor...

  10. Developmental exposure to perchlorate alters synaptic transmission in hippocampus of the adult rat: in vivo studies.

    EPA Science Inventory

    Perchlorate, a contaminant found in food and water supplies throughout the USA, blocks iodine uptake into the thyroid gland to reduce circulating levels of thyroid hormone. Neurological function accompanying developmental exposure to perchlorate was evaluated in the present study...

  11. Developmental exposure to perchlorate alters synaptic transmission in hippocampus of the adult rat: in vivo studies.

    EPA Science Inventory

    Perchlorate, a contaminant found in food and water supplies throughout the USA, blocks iodine uptake into the thyroid gland to reduce circulating levels of thyroid hormone. Neurological function accompanying developmental exposure to perchlorate was evaluated in the present study...

  12. ALTERNATIVE TECHNIQUES FOR MEASUREMENT OF PERCHLORATE IN FERTILIZER AND ENVIRONMENTAL SAMPLES

    EPA Science Inventory

    The Perchlorate anion has been implicated as a potentially serious environmental pollutant, being found in drinking water and irrigated crops. Commercial fertilizers have recently been shown to contain high levels of Perchlorate impurities and thus be potentially important source...

  13. DEVELOPMENT OF AN ELECTROSPRAY MASS SPECTROMETRIC METHOD FOR DETERMINING PERCHLORATE IN FERTILIZERS

    EPA Science Inventory

    An electrospray mass spectrometric method has been developed for application to agricultural and horticultural fertilizers to determine perchlorate. After fertilizers are leached or dissolved in water, the method relies on the formation of stable ion pair complex of the perchlor...

  14. Removal of Perchlorate and Chlorate in Aquatic SystemsUsing Integrated Technologies

    EPA Science Inventory

    Because of its extremely low concentrations and strong resistance to most treatment technologies, perchlorate has become one of the biggest challenges currently being faced by the drinking water industry. Few studies have looked at electrochemical reduction of aqueous perchlorate...

  15. Removal of Perchlorate and Chlorate in Aquatic SystemsUsing Integrated Technologies

    EPA Science Inventory

    Because of its extremely low concentrations and strong resistance to most treatment technologies, perchlorate has become one of the biggest challenges currently being faced by the drinking water industry. Few studies have looked at electrochemical reduction of aqueous perchlorate...

  16. Stable Cl And O Isotope Ratios Of Anthropogenic And Natural Perchlorates

    NASA Astrophysics Data System (ADS)

    Beloso, A.; Sturchio, N. C.; Böhlke, J.; Gu, B.; Horita, J.; Brown, G.; Hatzinger, P.

    2004-12-01

    Perchlorate (ClO4-) in aqueous systems, even in low concentrations, is recognized to have potential human health risks. The drinking and irrigation water supplies of millions of people in the U.S. have recently been found to be contaminated with perchlorate, and this problem continues to become even more widespread. Perchlorate, as a highly soluble and relatively inert anion, tends to persist over long time periods and its removal by conventional water treatment technologies is difficult and expensive. Many known sources of perchlorate contamination are anthropogenic, resulting from its extensive use as an oxidizer component in solid propellants for missiles, rockets, and fireworks. However, certain fertilizers derived from Chilean nitrate evaporate deposits are known to contain a low percentage of perchlorate (<0.5%) that may contaminate groundwater. New isotopic evidence provides insights on the possible natural sources of perchlorate in surface and ground waters. Stable isotope ratios of Cl and O can now be used to determine whether the source of perchlorates in a given area is natural or anthropogenic. Microbial perchlorate reduction has a large (˜15 per mil) kinetic isotope effect, and this may be used to identify whether natural attenuation of perchlorate is occurring. Anthropogenic perchlorate salts in milligram amounts are readily analyzed for 37Cl and 18O isotopes. Extracting an isotopically measurable amount of perchlorate from natural waters, which are usually within ppb range of concentrations, is a challenge. But with the use of a new class of highly-selective bifunctional anion exchange resins, recovery of trace amounts of perchlorate for accurate isotopic analysis has been demonstrated. Isotopic characterization is being conducted on anthropogenic perchlorate reagents, natural perchlorate-bearing salt deposits, and perchlorate-bearing groundwaters. Significant and consistent isotopic differences in both the Cl and O isotope ratios between

  17. Chronic perchlorate exposure impairs stickleback reproductive behaviour and swimming performance

    PubMed Central

    Bernhardt, Richard R.; von Hippel, Frank A.

    2011-01-01

    Summary We describe behavioural changes in two generations of threespine stickleback (Gasterosteus aculeatus) exposed to environmentally relevant concentrations of perchlorate. The first generation (G0,2002) was exposed as two-year-old adults to perchlorate in experimental groups ranging in concentration from less than the method detection limit (<1.1 ppb) to 18.6 ppm for up to 22 days during their courtship, spawning, egg guarding, and first five days of fry guarding. No differences were noted in the behaviour or reproductive output of these fish that were exposed as adults. However, perchlorate exposure throughout development caused widespread effects in the second generation (G1,2003), which was spawned and raised through sexual maturity in one of four nominal experimental groups (0, 30 and 100 ppm, and a ‘variable’ treatment that progressively increased from <1.1 ppb to approximately 60 ppm perchlorate). Dose-dependent effects were found during the G1,2003’s swimming and behavioural evaluations, including higher mortality rates among treated fish following stressful events. Perchlorate-exposed fish had higher failure rates during swimming trials and failed at lower flow rates than control fish. A number of treated fish exhibited seizures. Progressively fewer males completed benchmark metrics, such as nest building, spawning, nursery formation, or fry production, in a dose-dependent manner. Fewer males from higher treatments courted females, and those that did initiated courtship later and had a reduced behavioural repertoire compared to fish from lower treatments. The lowest observed adverse effect level (LOAEL) for swimming performance, reproductive behaviour, survivorship and recruitment was 30 ppm perchlorate (our lowest G1,2003 treatment), and near complete inhibition of reproductive activity was noted among males raised in 100 ppm perchlorate. A small number of treated G1,2003 females were isolated in aquaria, and some performed reproductive

  18. Modeling Perchlorate Contamination In Coastal Aquifer of Israel

    NASA Astrophysics Data System (ADS)

    Yakirevich, A.; Kuznetsov, M.; Adar, E.; Nativ, R.

    2010-12-01

    The mathematical model of water flow and contaminant transport was developed and applied for simulating the perchlorate migration in soil and groundwater, in the Israeli Coastal Aquifer. The three-dimensional mathematical model of groundwater flow is presented by set of two-dimensional flow equations for the multilayered system, considering the interflow between layers (based on the MODFLOW code). Perchlorate transport simulations were carried out using the MT3DMS model, which solves the 3-D advection-dispersion equation. Perchlorate was considered as a conservative contaminant: neither sorption nor degradation reactions were taken into account. The GMS 5.1 (Groundwater Modeling System) was adjusted and used as a major platform for the simulations. The hydraulic parameters of four major materials (sandstone, sand, loam and clay) composing the sub-aquifers of the coastal alluvial aquifer and the annual groundwater recharge were assessed by a combination of trial-and-error and least square optimization (the PEST code) using observed groundwater levels during 1978-2004. The location of the contaminant source was assigned to the effluents storage ponds, represented by a strip of 200x50m. The concentration of perchlorate in the percolated water was calculated as a function of time, using measured distribution of perchlorate along the vadose zone and transient simulations of one-dimensional water flow and contaminant transport in the unsaturated layered soil profile. Simulations results indicate that the estimated total mass of approximately 280 ton of perchlorate in the unsaturated zone will be washed out into the groundwater reservoir during the coming 25 years. Simulations of perchlorate migration in groundwater were carried out for the period of 2006-2030. The predicted average advection velocity of the plume was 15-20 m/year. The model allows forecast of the plume migration and assessment of water volume and perchlorate mass being extracted for different water

  19. Oxygen and Chlorine Isotopic Fractionation During Microbial Reduction of Perchlorate

    NASA Astrophysics Data System (ADS)

    Beloso, A. D.; Sturchio, N. C.; Böhlke, J. K.; Streger, S. H.; Heraty, L. J.; Hatzinger, P. B.

    2006-12-01

    Perchlorate is a widespread environmental contaminant that has both anthropogenic and natural sources. Stable isotope ratios of O and Cl in perchlorate have been used recently to distinguish perchlorate of different origins. Isotopic ratios may also be useful for identifying the occurrence and extent of biodegradation of perchlorate in natural environments, information that is critical for assessing natural attenuation of this contaminant. For this approach to be useful, however, the extent of isotopic fractionation of both Cl and O by bacteria must be determined, and the influence of environmental variables on this process must be defined. During this laboratory study, the O and Cl isotope ratios of perchlorate were monitored as a function of degradation by two separate bacterial species (Azospira suillum JPLRND and Dechlorospirillum sp. FBR2) at both 10 °C and 22 °C with acetate as the electron donor. Perchlorate was completely degraded by both strains within 280 hr at 22 °C and 615 hr at 10 °C. Measured values of isotopic fractionation factors were ɛ18O = -36.6 to -29.0 ‰ and ɛ37Cl = -14.5 to - 11.5 ‰, and these showed no apparent systematic variation with either temperature or bacterial strain. One experiment using 18O-enriched water (δ18O = 200‰) gave results indistinguishable from those observed in isotopically normal water, indicating little or no isotopic exchange between perchlorate and water during biodegradation. The fractionation factor ratio ɛ18O/ɛ37Cl was nearly invariant in all experiments at 2.50 ± 0.04. These data indicate that isotopic analysis will be useful for documenting perchlorate biodegradation in soils and groundwater. The establishment of a microbial fractionation factor ratio (ɛ18O/ɛ37Cl) also has significance for forensic studies, as these data indicate that fractionation via biodegradation will not cause the reported mass-dependent Cl and O isotopic signatures of synthetic and natural perchlorate to overlap.

  20. [Should we fear the perchlorate ion in the environment?].

    PubMed

    Desailloud, Rachel; Wemeau, Jean-Louis

    2016-01-01

    Perchlorate ions (ClO4(-)) are present in groundwater and are then present in distribution networks of drinking water destined for human consumption. The perchlorate ion comes mainly from ammonium salt manufactured for industrial activities or from arms of the First World War. Perchlorate ion is a competitive inhibitor of the sodium-iodide symporter and inhibits the synthesis of thyroid hormones. Values of toxicity have been published by the French agency ANSES and are used by authorities to limit the consumption of drinking water of some distribution networks by children and pregnant women especially in Nord-Pas-de-Calais and Picardie. Epidemiological data in other countries show no or little clinical effect in areas with similar contamination; it is therefore a precautionary principle. An effective substitution with iodine would limit the effects of the iodine deficiency itself but also would counteract the potential effects of an excess of perchlorate ions and also of other symporter inhibitors (thiocyanate, nitrate). Further studies are nevertheless needed to determine possible extra-thyroid effects of perchlorate ions. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  1. Developmental timing of perchlorate exposure alters threespine stickleback dermal bone

    PubMed Central

    Furin, Christoff G.; von Hippel, Frank A.; Postlethwait, John; Buck, C. Loren; Cresko, William A.; O’Hara, Todd M.

    2015-01-01

    Adequate levels of thyroid hormone are critical during development and metamorphosis, and for maintaining metabolic homeostasis. Perchlorate, a common contaminant of water sources, inhibits thyroid function in vertebrates. We utilized threespine stickleback (Gasterosteus aculeatus) to determine if timing of perchlorate exposure during development impacts adult dermal skeletal phenotypes. Fish were exposed to water contaminated with perchlorate (30 mg/L or 100 mg/L) beginning at 0, 3, 7, 14, 21, 42, 154 or 305 days post fertilization until sexual maturity at one year of age. A reciprocal treatment moved stickleback from contaminated to clean water on the same schedule providing for different stages of initial exposure and different treatment durations. Perchlorate exposure caused concentration-dependent significant differences in growth for some bony traits. Continuous exposure initiated within the first 21 days post fertilization had the greatest effects on skeletal traits. Exposure to perchlorate at this early stage can result in small traits or abnormal skeletal morphology of adult fish which could affect predator avoidance and survival. PMID:25753171

  2. Developmental timing of perchlorate exposure alters threespine stickleback dermal bone.

    PubMed

    Furin, Christoff G; von Hippel, Frank A; Postlethwait, John; Buck, C Loren; Cresko, William A; O'Hara, Todd M

    2015-08-01

    Adequate levels of thyroid hormone are critical during development and metamorphosis, and for maintaining metabolic homeostasis. Perchlorate, a common contaminant of water sources, inhibits thyroid function in vertebrates. We utilized threespine stickleback (Gasterosteus aculeatus) to determine if timing of perchlorate exposure during development impacts adult dermal skeletal phenotypes. Fish were exposed to water contaminated with perchlorate (30mg/L or 100mg/L) beginning at 0, 3, 7, 14, 21, 42, 154 or 305days post fertilization until sexual maturity at 1year of age. A reciprocal treatment moved stickleback from contaminated to clean water on the same schedule providing for different stages of initial exposure and different treatment durations. Perchlorate exposure caused concentration-dependent significant differences in growth for some bony traits. Continuous exposure initiated within the first 21days post fertilization had the greatest effects on skeletal traits. Exposure to perchlorate at this early stage can result in small traits or abnormal skeletal morphology of adult fish which could affect predator avoidance and survival. Copyright © 2015 Elsevier Inc. All rights reserved.

  3. Neonatal thyroxine level and perchlorate in drinking water.

    PubMed

    Li, Z; Li, F X; Byrd, D; Deyhle, G M; Sesser, D E; Skeels, M R; Lamm, S H

    2000-02-01

    Environmental contamination of drinking water has been observed for perchlorate, a chemical able to affect thyroid function. This study examines whether that exposure affected the thyroid function of newborns. Neonatal blood thyroxine (T4) levels for days 1 to 4 of life were compared for newborns from the city of Las Vegas, Nevada, which has perchlorate in its drinking water, and those from the city of Reno, Nevada, which does not (detection limit, 4 micrograms/L [ppb]). This study is based on blood T4 analyses from more than 23,000 newborns in these two cities during the period April 1998 through June 1999. No difference was found in the mean blood T4 levels of the newborns from these two cities. Drinking water perchlorate levels measured monthly for Las Vegas ranged during this study period from non-detectable for 8 months to levels of 9 to 15 ppb for 7 months. Temporal differences in mean T4 level were noted in both cities but were unrelated to the perchlorate exposure. This study was sufficiently sensitive to detect the effects of gender, birth weight, and the day of life on which the blood sample was taken on the neonatal T4 level, but it detected no effect from environmental exposures to perchlorate that ranged up to 15 micrograms/L (ppb).

  4. Development of freshwater water-quality criteria for perchlorate.

    PubMed

    Dean, Kirk E; Palachek, Randy M; Noel, Jill M; Warbritton, Ryan; Aufderheide, John; Wireman, Jody

    2004-06-01

    The anion perchlorate (ClO4-) is an oxidizing component commonly used in solid propellants for rockets and missiles; in explosives, flares, fireworks, chemical processes, and automobile air-bag inflators; and for other assorted uses. With recent advances in analytical detection capability, perchlorate has been found in a variety of ground and surface waters throughout the United States. Because perchlorate has been associated with thyroid problems in humans and may have similar effects on wildlife, it is desirable to develop a water-quality criterion to assist in identifying concentrations of perchlorate in water likely to pose an ecological health risk. In the present study, we compiled all available data regarding the effects of perchlorate to aquatic organisms, and we performed additional toxicity and bioconcentration tests as required by the U.S. Environmental Protection Agency (U.S. EPA) for the development of water-quality criteria for aquatic life. A criterion maximum concentration of 20 mg/L and a criterion continuous concentration of 9.3 mg/L were calculated based on the test results. Although these are not formal Clean Water Act Section 304(a) criteria, which must be published by the U.S. EPA, these criteria may be useful in the determination of remedial action levels for contaminated sites, for National Pollutant Discharge Elimination System permit limits, and other water-quality management practices.

  5. THE REDUCTIVE TRANSFORMATION OF PERCHLORATE IN A FRESH WATER SEDIMENT: LABORATORY BATCH STUDIES

    EPA Science Inventory

    Perchlorate is widely used as a propellant in solid rocket fuel, and has recently been found in ground, surface, and drinking water, in many cases above the interim action level of 18 ppb. Perchlorate is recalcitrant to chemical reduction, however, studies of perchlorate in pure ...

  6. THE REDUCTIVE TRANSFORMATION OF PERCHLORATE IN A FRESH WATER SEDIMENT: LABORATORY BATCH STUDIES.

    EPA Science Inventory

    Perchlorate is widely used as a propellant in solid rocket fuel, and has recently been found in ground, surface, and drinking water, in many cases above the interim action level of 18 ppb. Perchlorate is recalcitrant to chemical reduction, however, studies of perchlorate in pure ...

  7. Using a physiologically based pharmacokinetic model to link urinary biomarker concentrations to dietary exposure of perchlorate

    EPA Science Inventory

    Exposure to perchlorate is widespread in the United States and many studies have attempted to character the perchlorate exposure by estimating the average daily intakes of perchlorate. These approaches provided population-based estimates, but did not provide individual-level exp...

  8. Photooxidation of chloride by oxide minerals: implications for perchlorate on Mars.

    PubMed

    Schuttlefield, Jennifer D; Sambur, Justin B; Gelwicks, Melissa; Eggleston, Carrick M; Parkinson, B A

    2011-11-09

    We show that highly oxidizing valence band holes, produced by ultraviolet (UV) illumination of naturally occurring semiconducting minerals, are capable of oxidizing chloride ion to perchlorate in aqueous solutions at higher rates than other known natural perchlorate production processes. Our results support an alternative to atmospheric reactions leading to the formation of high concentrations of perchlorate on Mars.

  9. THE REDUCTIVE TRANSFORMATION OF PERCHLORATE IN A FRESH WATER SEDIMENT: LABORATORY BATCH STUDIES

    EPA Science Inventory

    Perchlorate is widely used as a propellant in solid rocket fuel, and has recently been found in ground, surface, and drinking water, in many cases above the interim action level of 18 ppb. Perchlorate is recalcitrant to chemical reduction, however, studies of perchlorate in pure ...

  10. THE REDUCTIVE TRANSFORMATION OF PERCHLORATE IN A FRESH WATER SEDIMENT: LABORATORY BATCH STUDIES.

    EPA Science Inventory

    Perchlorate is widely used as a propellant in solid rocket fuel, and has recently been found in ground, surface, and drinking water, in many cases above the interim action level of 18 ppb. Perchlorate is recalcitrant to chemical reduction, however, studies of perchlorate in pure ...

  11. Using a physiologically based pharmacokinetic model to link urinary biomarker concentrations to dietary exposure of perchlorate

    EPA Science Inventory

    Exposure to perchlorate is widespread in the United States and many studies have attempted to character the perchlorate exposure by estimating the average daily intakes of perchlorate. These approaches provided population-based estimates, but did not provide individual-level exp...

  12. qPCR assays to quantify genes and gene expression associated with microbial perchlorate reduction.

    PubMed

    De Long, Susan K; Kinney, Kerry A; Kirisits, Mary Jo

    2010-11-01

    Quantitative PCR (qPCR) assays targeting cld (developed in this work) and pcrA (previously described) were used to quantify these perchlorate-related genes in a perchlorate-reducing enrichment culture. Transcript copies were quantified in perchlorate-reducing Rhodocyclaceae strain JDS4. Oxygen and nitrate inhibited expression of cld and pcrA.

  13. PERCHLORATE-CROP INTERACTIONS FROM CONTAMINATED IRRIGATION WATER AND FERTILIZER APPLICATIONS

    EPA Science Inventory

    Perchlorate has contaminated water and soils at several locations in the United States. Perchlorate is water soluble, exceedingly mobile in aqueous systems, and can persist for many decades under typical ground and surface water conditions. Perchlorate is of concern because of un...

  14. PERCHLORATE-CROP INTERACTIONS FROM CONTAMINATED IRRIGATION WATER AND FERTILIZER APPLICATIONS

    EPA Science Inventory

    Perchlorate has contaminated water and soils at several locations in the United States. Perchlorate is water soluble, exceedingly mobile in aqueous systems, and can persist for many decades under typical ground and surface water conditions. Perchlorate is of concern because of un...

  15. The Effects of Ammonium Perchlorate on Reproduction and Development of Amphibians

    DTIC Science & Technology

    2008-01-01

    Mitigating Ammonium Perchlorate (AP) Exposure........................................................................18 Table 5-1. Funding History and...amphibian species were reared on perchlorate-laden food (e.g., hydroponically grown lettuce ) and their growth and development monitored. Thyroid...of Perchlorate Derived from Food Sources on Amphibian Development 8 Table 3.1 (Continued) 3.1 Initiate Lettuce Growth 3.2 Tests with Native

  16. Natural attenuation of perchlorate in denitrified groundwater.

    PubMed

    Robertson, William D; Roy, James W; Brown, Susan J; Van Stempvoort, Dale R; Bickerton, Greg

    2014-01-01

    Monitoring of a well-defined septic system groundwater plume and groundwater discharging to two urban streams located in southern Ontario, Canada, provided evidence of natural attenuation of background low level (ng/L) perchlorate (ClO4⁻) under denitrifying conditions in the field. The septic system site at Long Point contains ClO4⁻ from a mix of waste water, atmospheric deposition, and periodic use of fireworks, while the nitrate plume indicates active denitrification. Plume nitrate (NO3⁻ -N) concentrations of up to 103 mg/L declined with depth and downgradient of the tile bed due to denitrification and anammox activity, and the plume was almost completely denitrified beyond 35 m from the tile bed. The ClO4⁻ natural attenuation occurs at the site only when NO3⁻ -N concentrations are <0.3 mg/L, after which ClO4⁻ concentrations decline abruptly from 187 ± 202 to 11 ± 15 ng/L. A similar pattern between NO3⁻ -N and ClO4⁻ was found in groundwater discharging to the two urban streams. These findings suggest that natural attenuation (i.e., biodegradation) of ClO4⁻ may be commonplace in denitrified aquifers with appropriate electron donors present, and thus, should be considered as a remediation option for ClO4⁻ contaminated groundwater.

  17. Thermal Decomposition Behavior of Ammonium Perchlorate and of an Ammonium-Perchlorate-Based Composite Propellant

    NASA Technical Reports Server (NTRS)

    Behrens, R.; Minier, L.

    1998-01-01

    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 H2O, O2, Cl2, N2O 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 NH3 + HClO4 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.

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

    SciTech Connect

    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.

  19. EPR evidence for magnetic exchange through a four-carbon aliphatic bridge in a binuclear copper(II) complex. Single crystal x-ray structure of 7,7'-(1,4-butanediyl)-bis(2,12-dimethyl-3,7,11,17-tetraazabicyclo(11. 3. 1)heptadeca-1(17),2,11,13,15-pentaene)nickel(II)) perchlorate monohydrate

    SciTech Connect

    Foster, K.A.; Brown, D.R.; Timken, M.D.; Van Derveer, D.G.; Belford, R.L.; Barefield, E.K.

    1988-12-01

    The single crystal x-ray structure of the title, binuclear nickel(II) complex has been determined and the compound used as a host for EPR investigations of the analogous copper(II) complex. The impetus for this work was an earlier suggestion that magnetic exchange interactions detected by EPR spectroscopy on frozen solutions of the biscopper(II) complex were a result of a direct copper-copper interaction in a closed conformation of the binuclear species. Results reported here suggest that the complex exists in the open conformation where the distance between metal centres is maximized and that the magnetic exchange occurs by a super-exchange mechanism through the aliphatic chain. The /vert bar/J/vert bar/ value for the exchange interaction is greater than 0.018 cm/sup /minus/1/. Crystal data for (Ni/sub 2/C/sub 34/H/sub 50/N/sub 8/)(ClO/sub 4/)/sub 4/ /center dot/ H/sub 2/O (298 K): monoclinic, space group P2/sub 1//n, a = 13.560(3), b = 11.678(2), c = 15.377(3) /angstrom/, /beta/ = = 108.48(2)/degree/, /rho//sub calcd/ = 1.588 g cm/sup /minus/3/ for Z = 2 and M/sub r/ = 1104.1, R = 0.068, R/sub w/ = 0.76. The intramolecular Ni-Ni distance is 9.13 /angstrom/. The analogous copper complex is isomorphorus with the nickel complex.

  20. Perchlorate reduction in microbial electrolysis cell with polyaniline modified cathode.

    PubMed

    Li, Jia-Jia; Gao, Ming-Ming; Zhang, Gang; Wang, Xin-Hua; Wang, Shu-Guang; Song, Chao; Xu, Yan-Yan

    2015-02-01

    Excellent perchlorate reduction was obtained under various initial concentrations in a non-membrane microbial electrolysis cell with polyaniline (PANI) modified graphite cathode as sole electron donor. PANI modification is conducive to the formation of biofilm due to its porous structure and good electrocatalytic performance. Compared with cathode without biofilm, over 12% higher reduction rates were acquired in the presence of biocathode. The study demonstrates that, instead of perchlorate reduction, the main contribution of biofilm is involved in facilitate electron transfer from cathode to electrolyte. Interestingly, hairlike structure, referred as to pili-like, was observed in the biofilm as well as in the electrolyte. Additionally, the results show that pili were prone to formation under the condition of external electron field as sole electron donor. Analysis of microbial community suggests that perchlorate reduction bacteria community was most consistent with Azospiraoryzae strain DSM 13638 in the subdivision of the class Proteobacteria.

  1. Crystal structure of iron(III) perchlorate nona-hydrate.

    PubMed

    Hennings, Erik; Schmidt, Horst; Voigt, Wolfgang

    2014-12-01

    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(H2O)6](ClO4)3·3H2O was crystallized from aqueous solutions at low temperatures according to the solid-liquid phase diagram. It consists of Fe(H2O)6 octa-hedra (point group symmetry -3.) and perchlorate anions (point group symmetry .2) as well as non-coordinating water mol-ecules, 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).

  2. Direct Measurement of Perchlorate Exposure Biomarkers in a Highly Exposed Population: A Pilot Study

    PubMed Central

    Wong, Michelle; Copan, Lori; Olmedo, Luis; Patton, Sharyle; Haas, Robert; Atencio, Ryan; Xu, Juhua; Valentin-Blasini, Liza

    2011-01-01

    Exposure to perchlorate is ubiquitous in the United States and has been found to be widespread in food and drinking water. People living in the lower Colorado River region may have perchlorate exposure because of perchlorate in ground water and locally-grown produce. Relatively high doses of perchlorate can inhibit iodine uptake and impair thyroid function, and thus could impair neurological development in utero. We examined human exposures to perchlorate in the Imperial Valley among individuals consuming locally grown produce and compared perchlorate exposure doses to state and federal reference doses. We collected 24-hour urine specimen from a convenience sample of 31 individuals and measured urinary excretion rates of perchlorate, thiocyanate, nitrate, and iodide. In addition, drinking water and local produce were also sampled for perchlorate. All but two of the water samples tested negative for perchlorate. Perchlorate levels in 79 produce samples ranged from non-detect to 1816 ppb. Estimated perchlorate doses ranged from 0.02 to 0.51 µg/kg of body weight/day. Perchlorate dose increased with the number of servings of dairy products consumed and with estimated perchlorate levels in produce consumed. The geometric mean perchlorate dose was 70% higher than for the NHANES reference population. Our sample of 31 Imperial Valley residents had higher perchlorate dose levels compared with national reference ranges. Although none of our exposure estimates exceeded the U. S. EPA reference dose, three participants exceeded the acceptable daily dose as defined by bench mark dose methods used by the California Office of Environmental Health Hazard Assessment. PMID:21394205

  3. Perchlorate Reductase Is Distinguished by Active Site Aromatic Gate Residues.

    PubMed

    Youngblut, Matthew D; Tsai, Chi-Lin; Clark, Iain C; Carlson, Hans K; Maglaqui, Adrian P; Gau-Pan, Phonchien S; Redford, Steven A; Wong, Alan; Tainer, John A; Coates, John D

    2016-04-22

    Perchlorate is an important ion on both Earth and Mars. Perchlorate reductase (PcrAB), a specialized member of the dimethylsulfoxide reductase superfamily, catalyzes the first step of microbial perchlorate respiration, but little is known about the biochemistry, specificity, structure, and mechanism of PcrAB. Here we characterize the biophysics and phylogeny of this enzyme and report the 1.86-Å resolution PcrAB complex crystal structure. Biochemical analysis revealed a relatively high perchlorate affinity (Km = 6 μm) and a characteristic substrate inhibition compared with the highly similar respiratory nitrate reductase NarGHI, which has a relatively much lower affinity for perchlorate (Km = 1.1 mm) and no substrate inhibition. Structural analysis of oxidized and reduced PcrAB with and without the substrate analog SeO3 (2-) bound to the active site identified key residues in the positively charged and funnel-shaped substrate access tunnel that gated substrate entrance and product release while trapping transiently produced chlorate. The structures suggest gating was associated with shifts of a Phe residue between open and closed conformations plus an Asp residue carboxylate shift between monodentate and bidentate coordination to the active site molybdenum atom. Taken together, structural and mutational analyses of gate residues suggest key roles of these gate residues for substrate entrance and product release. Our combined results provide the first detailed structural insight into the mechanism of biological perchlorate reduction, a critical component of the chlorine redox cycle on Earth. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  4. A bioinspired iron catalyst for nitrate and perchlorate reduction.

    PubMed

    Ford, Courtney L; Park, Yun Ji; Matson, Ellen M; Gordon, Zachary; Fout, Alison R

    2016-11-11

    Nitrate and perchlorate have considerable use in technology, synthetic materials, and agriculture; as a result, they have become pervasive water pollutants. Industrial strategies to chemically reduce these oxyanions often require the use of harsh conditions, but microorganisms can efficiently reduce them enzymatically. We developed an iron catalyst inspired by the active sites of nitrate reductase and (per)chlorate reductase enzymes. The catalyst features a secondary coordination sphere that aids in oxyanion deoxygenation. Upon reduction of the oxyanions, an iron(III)-oxo is formed, which in the presence of protons and electrons regenerates the catalyst and releases water. Copyright © 2016, American Association for the Advancement of Science.

  5. Copper hypersensitivity.

    PubMed

    Fage, Simon W; Faurschou, Annesofie; Thyssen, Jacob P

    2014-10-01

    The world production of copper is steadily increasing. Although humans are widely exposed to copper-containing items on the skin and mucosa, allergic reactions to copper are only infrequently reported. To review the chemistry, biology and accessible data to clarify the implications of copper hypersensitivity, a database search of PubMed was performed with the following terms: copper, dermatitis, allergic contact dermatitis, contact hypersensitivity, contact sensitization, contact allergy, patch test, dental, IUD, epidemiology, clinical, and experimental. Human exposure to copper is relatively common. As a metal, it possesses many of the same qualities as nickel, which is a known strong sensitizer. Cumulative data on subjects with presumed related symptoms and/or suspected exposure showed that a weighted average of 3.8% had a positive patch test reaction to copper. We conclude that copper is a very weak sensitizer as compared with other metal compounds. However, in a few and selected cases, copper can result in clinically relevant allergic reactions.

  6. Combined bio-regeneration and ion-exchange system for perchlorate removal.

    PubMed

    Bae, B U

    2014-01-01

    In order to prove that perchlorate-laden resins could be bio-regenerated through direct contact with perchlorate-reducing bacteria (PRB), a combined bio-regeneration and ion-exchange (IX) system was operated. Two kinds of perchlorate-laden resins, nitrate-selective A520E and perchlorate-selective A530E, were successfully regenerated by PRB cultivated under anaerobic conditions. The bio-regeneration efficiency of perchlorate-laden resins increased with the amount of flow passed through the IX column. When the fully exhausted resin was bio-regenerated for 10 days at the flow rate of 2 BV (bed volume)/min and mixed liquor suspended solids concentration of 80 mg/L, almost 100% of IX capacity was recovered. A520E resin had higher bio-regeneration efficiency than A530E under all conditions, probably due to the fact that the perchlorate ion is more strongly bonded to the functional group of perchlorate-selective A530E resin. Measurement of perchlorate concentrations in the column effluents also revealed that the amount of perchlorate eluted from A520E resin was higher than that from A530E resin. Since only 10-20% of perchlorate was eluted from the resin during 10 days of bio-regeneration, the main mechanism of bio-regeneration appears to be the direct reduction of perchlorate by PRB on the resin.

  7. Seasonal variation and factors influencing perchlorate in water, snow, soil and corns in Northeastern China.

    PubMed

    Ye, Long; You, Hong; Yao, Jie; Kang, Xi; Tang, Lu

    2013-03-01

    Seasonal variation and influencing factors of perchlorate in snow, surface soil, rain, surface water, groundwater and corn were studied. Seven hundreds and seventy samples were collected in different periods in Harbin and its vicinity, China. Perchlorate concentrations were analyzed by ion chromatography-electrospray mass spectrometry. Results indicate that fireworks and firecrackers display from the Spring Festival to the Lantern Festival (February 2, 2011-February 17, 2011) can result in the occurrence of perchlorate in surface soil and snow. Perchlorate distribution is affected by wind direction in winter. Melting snow which contained perchlorate can dissolve perchlorate in surface soil, and then perchlorate can percolate into groundwater so that perchlorate concentrations in groundwater increased in spring. Perchlorate concentrations in groundwater and surface water decrease after rainy season in summer. Groundwater samples collected in the floodplain areas of the Songhua River and the Ashi River contained higher perchlorate concentrations than that far away with the rivers. The corns have the ability to accumulate perchlorate. Crown Copyright © 2012. Published by Elsevier Ltd. All rights reserved.

  8. Preliminary assessment of perchlorate in ecological receptors at the Longhorn Army Ammunition Plant (LHAAP), Karnack, Texas.

    PubMed

    Smith, P N; Theodorakis, C W; Anderson, T A; Kendall, R J

    2001-10-01

    There have been increasing human health and ecological concerns about ionic perchlorate (ClO4-) since it was detected in drinking water sources in 1997. Perchlorate is known to affect thyroid function, causing subsequent hormone disruption and potential perturbations of metabolic activities. According to current estimates, perchlorate is found in the surface of groundwater of 14 states, including Texas. Longhorn Army Ammunition Plant, located in east central Texas, was a facility historically associated with perchlorate-containing propellants and rocket motors. Subsequently, perchlorate contamination in ground and surface waters at the facility has been reported. Soil, sediment, water, vegetation, and animal tissue samples were collected from several locations within the plant for a preliminary site assessment of perchlorate contamination. Perchlorate concentrations ranged from 555-5,557,000 ppb in vegetation, 811-2038 ppb in aquatic insects, below detection limits (ND) to 207 ppb in fish, ND-580 ppb in frogs, and ND-2328 ppb in mammals. Consistent with our hypothesis, aquatic organisms inhabiting perchlorate-contaminated surface water bodies contained detectable concentrations of perchlorate. Additionally, terrestrial organisms were exposed through pathways not necessarily related to contaminated surface waters. Therefore, these data demonstrate that aquatic and terrestrial species are exposed to perchlorate in the environment. To our knowledge, this represents the first incidence of perchlorate exposure among wild animals reported in the scientific literature.

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

    PubMed

    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.

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

    PubMed

    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.

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

    PubMed

    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.

  12. Discovery of natural perchlorate in the Antarctic Dry Valleys and its global implications.

    PubMed

    Kounaves, Samuel P; Stroble, Shannon T; Anderson, Rachel M; Moore, Quincy; Catling, David C; Douglas, Susanne; McKay, Christopher P; Ming, Douglas W; Smith, Peter H; Tamppari, Leslie K; Zent, Aaron P

    2010-04-01

    In the past few years, it has become increasingly apparent that perchlorate (ClO(4)(-)) is present on all continents, except the polar regions where it had not yet been assessed, and that it may have a significant natural source. Here, we report on the discovery of perchlorate in soil and ice from several Antarctic Dry Valleys (ADVs) where concentrations reach up to 1100 microg/kg. In the driest ADV, perchlorate correlates with atmospherically deposited nitrate. Far from anthropogenic activity, ADV perchlorate provides unambiguous evidence that natural perchlorate is ubiquitous on Earth. The discovery has significant implications for the origin of perchlorate, its global biogeochemical interactions, and possible interactions with the polar ice sheets. The results support the hypotheses that perchlorate is produced globally and continuously in the Earth's atmosphere, that it typically accumulates in hyperarid areas, and that it does not build up in oceans or other wet environments most likely because of microbial reduction on a global scale.

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

    PubMed

    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.

  14. Simultaneous detection of perchlorate and bromate using rapid high-performance ion exchange chromatography-tandem mass spectrometry and perchlorate removal in drinking water.

    PubMed

    West, Danielle M; Mu, Ruipu; Gamagedara, Sanjeewa; Ma, Yinfa; Adams, Craig; Eichholz, Todd; Burken, Joel G; Shi, Honglan

    2015-06-01

    Perchlorate and bromate occurrence in drinking water causes health concerns due to their effects on thyroid function and carcinogenicity, respectively. The purpose of this study was threefold: (1) to advance a sensitive method for simultaneous rapid detection of perchlorate and bromate in drinking water system, (2) to systematically study the occurrence of these two contaminants in Missouri drinking water treatment systems, and (3) to examine effective sorbents for minimizing perchlorate in drinking water. A rapid high-performance ion exchange chromatography-tandem mass spectrometry (HPIC-MS/MS) method was advanced for simultaneous detection of perchlorate and bromate in drinking water. The HPIC-MS/MS method was rapid, required no preconcentration of the water samples, and had detection limits for perchlorate and bromate of 0.04 and 0.01 μg/L, respectively. The method was applied to determine perchlorate and bromate concentrations in total of 23 selected Missouri drinking water treatment systems during differing seasons. The water systems selected include different source waters: groundwater, lake water, river water, and groundwater influenced by surface water. The concentrations of perchlorate and bromate were lower than or near to method detection limits in most of the drinking water samples monitored. The removal of perchlorate by various adsorbents was studied. A cationic organoclay (TC-99) exhibited effective removal of perchlorate from drinking water matrices.

  15. Perchlorate uptake in spinach as related to perchlorate, nitrate, and chloride concentrations in irrigation water.

    PubMed

    Ha, Wonsook; Suarez, Donald L; Lesch, Scott M

    2011-11-01

    Several studies have reported on the detection of perchlorate (ClO(4)(-)) in edible leafy vegetables irrigated with Colorado River water. However, there is no information on spinach as related to ClO(4)(-) in irrigation water nor on the effect of other anions on ClO(4)(-) uptake. A greenhouse ClO(4)(-) uptake experiment using spinach was conducted to investigate the impact of presence of chloride (Cl(-)) and nitrate (NO(3)(-)) on ClO(4)(-) uptake under controlled conditions. We examined three concentrations of ClO(4)(-), 40, 220, and 400 nmol(c)/L (nanomoles of charge per liter of solution), three concentrations of Cl(-), 2.5, 13.75, and 25 mmol(c)/L, and NO(3)(-) at 2, 11, and 20 mmol(c)/L. The results revealed that ClO(4)(-) was taken up the most when NO(3)(-) and Cl(-) were lowest in concentration in irrigation water. More ClO(4)(-) was detected in spinach leaves than that in the root tissue. Relative to lettuces, spinach accumulated more ClO(4)(-) in the plant tissue. Perchlorate was accumulated in spinach leaves more than reported for outer leaves of lettuce at 40 nmol(c)/L of ClO(4)(-) in irrigation water. The results also provided evidence that spinach selectively took up ClO(4)(-) relative to Cl(-). We developed a predictive model to describe the ClO(4)(-) concentration in spinach as related to the Cl(-), NO(3)(-), and ClO(4)(-) concentration in irrigation water.

  16. Perinatal exposure to perchlorate, thiocyanate, and nitrate in New Jersey mothers and newborns

    PubMed Central

    Blount, Benjamin C.; Rich, David Q.; Valentin-Blasini, Liza; Lashley, Susan; Ananth, Cande V.; Murphy, Eileen; Smulian, John C.; Spain, Betty J.; Barr, Dana B.; Ledoux, Thomas; Hore, Paromita; Robson, Mark

    2009-01-01

    Perchlorate is a commonly occurring environmental toxicant that may be transported across the placental barrier by the sodium-iodide symporter (NIS), possibly resulting in both increased perchlorate exposure and decreased iodide uptake by the fetus. Therefore, we measured levels of three physiologically relevant NIS-inhibitors (perchlorate, nitrate and thiocyanate) and iodide in maternal and fetal fluids collected during cesarean-section surgeries on 150 U.S. women. Geometric means of perchlorate, thiocyanate and nitrate levels in maternal urine (2.90, 947 and 47900 µg/L, respectively) were similar to previously published results, while urinary iodide levels (1420 µg/L) were significantly higher (p<0.0001), likely because of prevalent prenatal vitamin use in the study population (74%). Thiocyanate levels were higher in the maternal serum, cord serum, and amniotic fluid of smokers compared to women with environmental tobacco smoke exposure and non-smokers (p-values of 0.0006, p=0.0011, and 0.0026, respectively). Perchlorate was detected in most samples: urine (100%), maternal serum (94%), cord serum (67%), and amniotic fluid (97%). Maternal urinary perchlorate levels were positively correlated with perchlorate levels in amniotic fluid (r=0.57), indicating that maternal urine perchlorate is an effective biomarker of fetal perchlorate exposure. Maternal serum perchlorate was generally higher than cord serum perchlorate (median ratio 2.4:1 for paired samples), and maternal urine perchlorate was always higher than fetal amniotic fluid perchlorate levels (mean ratio 22:1); conversely, iodide levels were typically higher in fetal fluids compared to maternal fluids. We found no evidence of either disproportionate perchlorate accumulation or lack of iodide in the fetal compartment. In this panel of healthy infants, we found no association between cord blood levels of these anions and newborn weight, length and head circumference. PMID:19848174

  17. Perchlorate, nitrate, thiocyanate, and iodide levels in chicken feed, water, and eggs from three farms.

    PubMed

    Blount, Benjamin C; Ozpinar, Aysel; Alwis, K Udeni; Caudill, Samuel P; Gillespie, Jerry R

    2008-11-26

    Perchlorate is an inhibitor of iodide uptake that is found widely in the environment. Given the potential for perchlorate accumulation during egg formation and the widespread consumption of eggs, it is important to examine eggs as a source of exposure to perchlorate and other potential inhibitors of iodide uptake (nitrate and thiocyanate). This study was conducted to determine potential human exposure to perchlorate from eggs produced by chicken flocks consuming differing amounts of perchlorate. The mean concentrations of perchlorate (7.16 ( 1.99 microg/kg of dry weight), nitrate (2820 ( 2100 microg/kg of dry weight), thiocyanate (574 +/- 433 microg/kg of dry weight), and iodide (2980 ( 1490 microg/kg of dry weight) in eggs (n = 180) from 15 chicken houses on 3 U.S. farms were determined. Chickens secreted into eggs an average of 23% of the perchlorate ingested from feed and water. Perchlorate levels in eggs were positively correlated with perchlorate intake (p < 0.001). Increased intake of perchlorate, nitrate, and thiocyanate was associated with decreased iodide levels in eggs, possibly indicating a competitive transport mechanism, such as sodium-iodide symporter. It was estimated that egg consumption contributes minimal perchlorate (approximately 0.040 microg) compared to the average total intake of approximately 10.5 microg for U.S. adults. Additionally, it was found that egg consumption was not associated with increased perchlorate exposure in 2820 individuals from the National Health and Nutrition Examination Survey (p value for the difference of least-squares means, pDiff = 0.225). From these findings it was concluded that, although chickens secrete perchlorate in eggs, eggs do not appear to be a significant source of perchlorate exposure for adults in the United States.

  18. Copper transport.

    PubMed

    Linder, M C; Wooten, L; Cerveza, P; Cotton, S; Shulze, R; Lomeli, N

    1998-05-01

    In adult humans, the net absorption of dietary copper is approximately 1 mg/d. Dietary copper joins some 4-5 mg of endogenous copper flowing into the gastrointestinal tract through various digestive juices. Most of this copper returns to the circulation and to the tissues (including liver) that formed them. Much lower amounts of copper flow into and out of other major parts of the body (including heart, skeletal muscle, and brain). Newly absorbed copper is transported to body tissues in two phases, borne primarily by plasma protein carriers (albumin, transcuprein, and ceruloplasmin). In the first phase, copper goes from the intestine to the liver and kidney; in the second phase, copper usually goes from the liver (and perhaps also the kidney) to other organs. Ceruloplasmin plays a role in this second phase. Alternatively, liver copper can also exit via the bile, and in a form that is less easily reabsorbed. Copper is also present in and transported by other body fluids, including those bathing the brain and central nervous system and surrounding the fetus in the amniotic sac. Ceruloplasmin is present in these fluids and may also be involved in copper transport there. The concentrations of copper and ceruloplasmin in milk vary with lactational stage. Parallel changes occur in ceruloplasmin messenger RNA expression in the mammary gland (as determined in pigs). Copper in milk ceruloplasmin appears to be particularly available for absorption, at least in rats.

  19. 76 FR 7762 - Drinking Water: Regulatory Determination on Perchlorate

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-11

    ...--microgram (one-millionth of a gram) U.S.--United States I. General Information Does this action impose any... with positive detections for perchlorate was 9.85 g/L and the median concentration was 6.40 g/L. Table... a positive influence in reducing the iodide uptake inhibition effects associated with exposure...

  20. The Impact of Temperature on Anaerobic Biological Perchlorate Treatment

    EPA Science Inventory

    A 20-month pilot-scale study was conducted to examine the impact of temperature on the performance of an anaerobic biological contactor used to treat perchlorate-contaminated water. The contactor was successfully acclimated with indigenous micro-organisms. Influent temperatures...

  1. Potential Influence of Perchlorate on Organic Carbon in Martian Regolith

    NASA Astrophysics Data System (ADS)

    Oze, C.; Vithanage, M. S.; Kumarathilaka, P. R.; Indraratne, S.; Horton, T. W.

    2014-12-01

    Perchlorate is a strong oxidizer present at elevated concentrations in surface martian regolith. Chemical and isotopic modification of potential organic carbon with perchlorate in martian regolith during H2O(l) interactions is unknown. Here we assess the relationship between martian levels of perchlorate and organic carbon present in life harbouring geologic material from Earth. These materials represent chemical (i.e., processed serpentine soils from Sri Lanka) and temperature (i.e., hydrothermal jarosite/goethite deposit from White Island, New Zealand) extremes to where life exists on Earth. Preliminary evidence demonstrates that organic carbon decreases and δ13C values are modified for ultramafic sediment in both perchlorate kinetic and incubation experiments. In hydrothermal jarosite/goethite with microbial communities present, total and organic carbon is maintained and little modification in δ13C values is apparent. These preliminary results suggest that surface hydrothermal deposits with mineralogically 'protected' organic carbon are preferable sites to assess the potential of life on Mars.

  2. Iodine supplementation and drinking-water perchlorate mitigation.

    PubMed

    Lewandowski, Thomas A; Peterson, Michael K; Charnley, Gail

    2015-06-01

    Ensuring adequate iodine intake is important, particularly among women of reproductive age, because iodine is necessary for early life development. Biologically based dose-response modeling of the relationships among iodide status, perchlorate dose, and thyroid hormone production in pregnant women has indicated that iodide intake has a profound effect on the likelihood that exposure to goitrogens will produce hypothyroxinemia. We evaluated the possibility of increasing iodine intake to offset potential risks from perchlorate exposure. We also explored the effect of dietary exposures to nitrate and thiocyanate on iodine uptake and thyroid hormone production. Our modeling indicates that the level of thyroid hormone perturbation associated with perchlorate exposures in the range of current regulatory limits is extremely small and would be overwhelmed by other goitrogen exposures. Our analysis also shows that microgram levels of iodine supplementation would be sufficient to prevent the goitrogenic effects of perchlorate exposure at current regulatory limits among at risk individuals. The human health risks from supplementing drinking water with iodine are negligible; therefore, this approach is worthy of regulatory consideration.

  3. RAMAN SPECTROSCOPIC ANALYSIS OF FERTILIZERS AND PLANT TISSUE FOR PERCHLORATE

    EPA Science Inventory

    Raman spectroscopy, without the need for prior chromatographic separation, was used for qualitative and quantitative analysis of 59 samples of fertilizers for perchlorate (ClO4-). These primarily lawn and garden products had no known link to Chile saltpeter, which is known to con...

  4. POLISHING EFFLUENT FROM A PERCHLORATE-REDUCING ANAEROBIC BIOLOGICAL CONTACTOR

    EPA Science Inventory

    The U.S. Environmental Protection Agency undertook at 3 ½ year pilot-scale biological perchlorate treatment study that included two long (311 and 340 days) examinations of anaerobic effluent polishing. The polishing system consisted of hydrogen peroxide addition and aeration, fo...

  5. RAMAN SPECTROSCOPIC ANALYSIS OF FERTILIZERS AND PLANT TISSUE FOR PERCHLORATE

    EPA Science Inventory

    Raman spectroscopy, without the need for prior chromatographic separation, was used for qualitative and quantitative analysis of 59 samples of fertilizers for perchlorate (ClO4-). These primarily lawn and garden products had no known link to Chile saltpeter, which is known to con...

  6. Alternative for Perchlorates in Incendiary and Pyrotechnic Formulations for Projectiles

    DTIC Science & Technology

    2009-08-01

    gland and their level in drinking water is controlled. Research has been undertaken to find alternative perchlorate-free pyrotechnic incendiary... non -ignition conditions 15 Bullet firing trials 15 Results and discussion 17 Ingredient environmental screening study 17 Pyrotechnic fuels 17...measurements 38 Thermal analysis studies 39 Thermal studies on the ingredients 39 Magnesium/aluminum alloy 39 Oxidants 39 DSC experiments 40 Non

  7. POLISHING EFFLUENT FROM A PERCHLORATE-REDUCING ANAEROBIC BIOLOGICAL CONTACTOR

    EPA Science Inventory

    The U.S. Environmental Protection Agency undertook at 3 ½ year pilot-scale biological perchlorate treatment study that included two long (311 and 340 days) examinations of anaerobic effluent polishing. The polishing system consisted of hydrogen peroxide addition and aeration, fo...

  8. Structure of aqueous sodium perchlorate solutions.

    PubMed

    General, Ignacio J; Asciutto, Eliana K; Madura, Jeffry D

    2008-12-04

    Salt solutions have been the object of study of many scientists through history, but one of the most important findings came along when the Hofmeister series were discovered. Their importance arises from the fact that they influence the relative solubility of proteins, and solubility is directly related to one of today's holy grails: protein folding. In this work we characterize one of the more-destabilizing salts in the series, sodium perchlorate, by studying it as an aqueous solution at various concentrations ranging from 0.08 to 1.60 mol/L. Molecular dynamics simulations at room temperature permitted a detailed study of the organization of solvent and cosolvent, in terms of its radial distribution functions, along with the study of the structure of hydrogen bonds in the ions' solvation shells. We found that the distribution functions have some variations in their shape as concentration changes, but the position of their peaks is mostly unaffected. Regarding water, the most salient fact is the noticeable (although small) change in the second hydration shell and even beyond, especially for g(O(w)***O(w)), showing that the locality of salt effects should not be restricted to considerations of only the first solvation shell. The perturbation of the second shell also appears in the study of the HB network, where the difference between the number of HBs around a water molecule and around the Na(+) cation gets much smaller as one goes from the first to the second solvation shell, yet the difference is not negligible. Nevertheless, the effect of the ions past their first hydration shell is not enough to make a noticeable change in the global HB network. The Kirkwood-Buff theory of liquids was applied to our system, in order to calculate the activity derivative of the cosolvent. This coefficient, along with a previously calculated preferential binding, allowed us to establish that if a folded AP peptide is immersed in the studied solution, becoming the solute, then

  9. Nitrate and Perchlorate removal from groundwater by ion exchange

    SciTech Connect

    Burge, S; Halden, R

    1999-09-15

    This study was conducted to evaluate the performance of a small scale ion exchange unit (Krudico, Inc of Auborn, IA) for removal of nitrate and perchlorate from groundwater at Lawrence Livermore National Laboratory's Site 300. The unit was able to treat 3,600 gallons of Site 300 groundwater, at an average influent concentration of 100 mg/L NO{sub 3}{sup -} before breakthrough occurred. The unit contained 2.5 ft{sup 3} of Sybron SR-7 resin. Seventy gallons of regeneration waste were generated (water treated to waste ratio of 51:1). The effluent concentration was about 20 mg/L NO{sub 3}{sup -}, which is equivalent to a treatment efficiency of at least 80%. There are several options for implementing this technology at Site 300. A target well, in the 817 area, has been selected. It has a 3 to 4 gpm flow rate, and concentrations of 90 mg/L NO{sub 3}{sup -} and 40 {micro}g/L perchlorate. The different treatment options include ion exchange treatment of nitrate only, nitrate and perchlorate, or perchlorate only. Option 1: For the treatment of nitrate only, this unit will be able to treat 3,700 gallons of water before regeneration is required. If both columns of the ion exchange unit are used, 7,400 gallons could be treated before the columns will need to be regenerated (producing 140 gallons of waste, per cycle or every 1.5 days). The effluent nitrate concentration is expected to be about 17 mg/L. Annual operation and maintenance costs are estimated to be $0.14 per gallon of water treated. Option 2: If only perchlorate is to be removed with ion exchange at the 817 area, a smaller unit should be considered. A 55 gallon canister filled with ion exchange resin should be able to reduce perchlorate concentrations in the groundwater from 40 {micro}g/L to non-detect levels for three years before the resin would need to be replaced. The contaminant-laden resin would be disposed of as hazardous waste. It is not practical to regenerate the resin because of the extreme difficulty of

  10. Tissue distribution, elimination, and metabolism of sodium [36Cl]perchlorate in lactating goats.

    PubMed

    Smith, David J; Hakk, Heldur; Larsen, Gerald L

    2006-11-15

    Perchlorate has contaminated water sources throughout the United States but particularly in the arid Southwest, an area containing large numbers of people and few water sources. Recent studies have demonstrated that perchlorate is present in alfalfa and that perchlorate is secreted into the milk of cows. Studies in lactating cows have indicated that only a small portion of a perchlorate dose could be accounted for by elimination in milk, feces, or urine. It was hypothesized that the remainder of the perchlorate dose was excreted as chloride ion. The purpose of this study was to determine the fate and disposition of (36)Cl-perchlorate in lactating dairy goats. Two goats (60 kg) were each orally administered 3.5 mg (16.5 muCi) of (36)Cl-perchlorate, a dose selected to approximate environmental perchlorate exposure but that would allow for adequate detection of radioactive residues after a 72 h withdrawal period. Blood, milk, urine, and feces were collected incrementally until slaughter at 72 h. Total radioactive residue (TRR) and perchlorate concentrations were measured using radiochemical techniques and liquid chromatography mass spectrometry (LC-MS-MS). Peak blood levels of TRR occurred at 12 h ( approximately 195 ppb) postdose; peak levels of parent perchlorate, however, occurred after only 2 h, suggesting that perchlorate metabolism occurred rapidly in the rumen. The serum half-life of perchlorate was estimated to be 2.3 h. After 24 h, perchlorate was not detectable in blood serum but TRR remained elevated (160 ppb) through 72 h. Milk perchlorate levels peaked at 12 h (155 ppb) and were no longer detectable by 36 h, even though TRRs were readily detected through 72 h. Perchlorate was not detectable in skeletal muscle or liver at slaughter (72 h). Chlorite and chlorate were not detected in any matrix. The only radioactive residues observed were perchlorate and chloride ion. Bioavailability of perchlorate was poor in lactating goats, but the perchlorate that was

  11. Thyroid function and reproductive success in rodents exposed to perchlorate via food and water.

    PubMed

    Smith, Philip N; Severt, Scott A; Jackson, J W Andrew; Anderson, Todd A

    2006-04-01

    The purpose of the present study was to determine if exposure to perchlorate via food items would have effects on mammals similar to those caused by exposure through drinking water at approximately equivalent doses. Prairie voles (Microtus ochrogaster) and deer mice (Peromyscus maniculatus) were used to assess the potential toxicity of perchlorate-contaminated food items. Voles and mice were divided randomly into three treatment groups--perchlorate-contaminated food (PCF), perchlorate-contaminated water (PCW), and control groups--such that each treatment group contained equal numbers of males and females. Rodents in PCF treatment groups were fed chow formulated with soybean plant matter that had been grown with perchlorate-contaminated irrigation water. Individuals in the control and PCF groups were provided distilled/deionized drinking water, whereas the PCW group received drinking water containing sodium perchlorate. Only slight differences among treatment groups were observed in a variety of endpoints, including reproductive success, tissue perchlorate concentrations, thyroid hormone concentrations, and thyroid histology. However, trends observed in the present study suggest that perchlorate exposure via water may result in slightly greater effects than exposure to perchlorate via food. These data and recent reports of perchlorate in a wide variety of food items indicate that exposure via food intake is an important consideration when examining cumulative risk among humans, livestock, and wildlife.

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

    PubMed

    Kirk, Andrea B; Dyke, Jason V; Ohira, Shin-Ichi; Dasgupta, Purnendu K

    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, 24h 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.

  13. The origin of naturally occurring perchlorate: the role of atmospheric processes.

    PubMed

    Dasgupta, Purnendu K; Martinelango, P Kalyani; Jackson, W Andrew; Anderson, Todd A; Tian, Kang; Tock, Richard W; Rajagopalan, Srinath

    2005-03-15

    Perchlorate, an iodide uptake inhibitor, is increasingly being detected in new places and new matrices. Perchlorate contamination has been attributed largelyto the manufacture and use of ammonium perchlorate (the oxidizer in solid fuel rockets) and/or the earlier use of Chilean nitrate as fertilizer (approximately 0.1% perchlorate). However, there are regions such as the southern high plains (Texas Panhandle) where there is no clear historical or current evidence of the extensive presence of rocket fuel or Chilean fertilizer sources. The occurrence of easily measurable concentrations of perchlorate in such places is difficult to understand. In the southern high plains groundwater, perchlorate is better correlated with iodate, known to be of atmospheric origin, compared to any other species. We show that perchlorate is readily formed by a variety of simulated atmospheric processes. For example, it is formed from chloride aerosol by electrical discharge and by exposing aqueous chloride to high concentrations of ozone. We report that perchlorate is present in many rain and snow samples. This strongly suggests that some perchlorate is formed in the atmosphere and a natural perchlorate background of atmospheric origin should exist.

  14. Exogenous iodide ameliorates perchlorate-induced thyroid phenotypes in threespine stickleback.

    PubMed

    Gardell, Alison M; von Hippel, Frank A; Adams, Elise M; Dillon, Danielle M; Petersen, Ann M; Postlethwait, John H; Cresko, William A; Buck, C Loren

    2017-03-01

    Perchlorate is a ubiquitous environmental contaminant that has widespread endocrine disrupting effects in vertebrates, including threespine stickleback (Gasterosteus aculeatus). The target of perchlorate is thyroid tissue where it induces changes in the organization, activation, and morphology of thyroid follicles and surrounding tissues. To test the hypothesis that some phenotypes of perchlorate toxicity are not mediated by thyroid hormone, we chronically exposed stickleback beginning at fertilization to perchlorate (10, 30, 100ppm) or control water with and without supplementation of either iodide or thyroxine (T4). Stickleback were sampled across a one-year timespan to identify potential differences in responses to treatment combinations before and after sexual maturation. We found that most thyroid histomorphological phenotypes induced by perchlorate (follicle proliferation, reduced follicle area (adults only), colloid depletion, thyrocyte hypertrophy (subadults only)) were significantly ameliorated by exogenous iodide supplementation. In contrast, treatment with exogenous T4 did not correct any of the thyroid-specific histopathologies induced by perchlorate. Whole-body thyroid hormone concentrations were not significantly affected by perchlorate exposure; however, supplementation with iodide and T4 significantly increased T4 concentrations. This study also revealed an increased erythrocyte area in the thyroid region of perchlorate-exposed adults, while lipid droplet number increased in perchlorate-exposed subadults. Increased erythrocyte area was ameliorated by both iodide and T4, while neither supplement was able to correct lipid droplet number. Our finding on lipid droplets indicates that exposure to perchlorate in early development may have obesogenic effects. Copyright © 2016 Elsevier Inc. All rights reserved.

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

    PubMed

    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.

  16. Characteristics of electron transport chain and affecting factors for thiosulfate-driven perchlorate reduction.

    PubMed

    Zhang, Chao; Guo, Jianbo; Lian, Jing; Lu, Caicai; Ngo, Huu Hao; Guo, Wenshan; Song, Yuanyuan; Guo, Yankai

    2017-10-01

    The mechanism for perchlorate reduction was investigated using thiosulfate-driven (T-driven) perchlorate reduction bacteria. The influences of various environmental conditions on perchlorate reduction, including pH, temperature and electron acceptors were examined. The maximum perchlorate removal rate was observed at pH 7.5 and 40 °C. Perchlorate reduction was delayed due to the coexistence of perchlorate-chlorate and perchlorate-nitrate. The mechanism of the T-driven perchlorate reduction electron transport chain (ETC) was also investigated by utilizing different inhibitors. The results were as follows: firstly, the NADH dehydrogenase was not involved in the ETC; secondly, the FAD dehydrogenase and quinone loop participated in the ETC; and thirdly, cytochrome oxidase was the main pathway in the ETC. Meanwhile, microbial consortium structure analysis indicated that Sulfurovum which can oxidize sulfur compounds coupled to the reduction of nitrate or perchlorate was the primary bacterium in the T-driven and sulfur-driven consortium. This study generates a better understanding of the mechanism of T-driven perchlorate reduction. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Reduction of Perchlorate and Nitrate by Microbial Communities in Vadose Soil

    PubMed Central

    Nozawa-Inoue, Mamie; Scow, Kate M.; Rolston, Dennis E.

    2005-01-01

    Perchlorate contamination is a concern because of the increasing frequency of its detection in soils and groundwater and its presumed inhibitory effect on human thyroid hormone production. Although significant perchlorate contamination occurs in the vadose (unsaturated) zone, little is known about perchlorate biodegradation potential by indigenous microorganisms in these soils. We measured the effects of electron donor (acetate and hydrogen) and nitrate addition on perchlorate reduction rates and microbial community composition in microcosm incubations of vadose soil. Acetate and hydrogen addition enhanced perchlorate reduction, and a longer lag period was observed for hydrogen (41 days) than for acetate (14 days). Initially, nitrate suppressed perchlorate reduction, but once perchlorate started to be degraded, the process was stimulated by nitrate. Changes in the bacterial community composition were observed in microcosms enriched with perchlorate and either acetate or hydrogen. Denaturing gradient gel electrophoresis analysis and partial sequencing of 16S rRNA genes recovered from these microcosms indicated that formerly reported perchlorate-reducing bacteria were present in the soil and that microbial community compositions were different between acetate- and hydrogen-amended microcosms. These results indicate that there is potential for perchlorate bioremediation by native microbial communities in vadose soil. PMID:16000806

  18. Characterization of perchlorate in a new frozen human urine standard reference material.

    PubMed

    Yu, Lee L; Jarrett, Jeffery M; Davis, W Clay; Kilpatrick, Eric L; Oflaz, Rabia; Turk, Gregory C; Leber, Dennis D; Valentin, Liza; Morel-Espinosa, Maria; Blount, Benjamin C

    2012-10-01

    Perchlorate, an inorganic anion, has recently been recognized as an environmental contaminant by the US Environmental Protection Agency. Urine is the preferred matrix for assessment of human exposure to perchlorate. Although the measurement technique for perchlorate in urine was developed in 2005, the calibration and quality assurance aspects of the metrology infrastructure for perchlorate are still lacking in that there is no certified reference material (CRM) traceable to the International System of Units. To meet the quality assurance needs in biomonitoring measurements of perchlorate and the related anions that affect thyroid health, the National Institute of Standards and Technology (NIST), in collaboration with the Centers for Disease Control and Prevention (CDC), developed Standard Reference Material (SRM) 3668 Mercury, Perchlorate, and Iodide in Frozen Human Urine. SRM 3668 consists of perchlorate, nitrate, thiocyanate, iodine, and mercury in urine at two levels that represent the 50th and 95th percentiles, respectively, of the concentrations (with some adjustments) in the US population. It is the first CRM being certified for perchlorate. Measurements leading to the certification of perchlorate were made collaboratively at NIST and CDC using three methods based on liquid or ion chromatography tandem mass spectrometry. Potential sources of bias were analyzed, and results were compared for the three methods. Perchlorate in SRM 3668 Level I urine was certified to be 2.70 ± 0.21 μg L(-1), and for SRM 3668 Level II urine, the certified value is 13.47 ± 0.96 μg L(-1).

  19. Spatial Variability of Perchlorate along a Traverse Route from Zhongshan Station to Dome A, East Antarctica

    NASA Astrophysics Data System (ADS)

    Jiang, S.; Cole-Dai, J.; Li, Y.; An, C.

    2016-12-01

    Snow deposition and accumulation on the Antarctic ice sheet preserve records of climatic change, as well as those of chemical characteristics of the environment. Chemical composition of snow and ice cores can be used to track the sources of important substances including pollutants and to investigate relationships between atmospheric chemistry and climatic conditions. Recent development in analytical methodology has enabled the determination of ultra-trace levels of perchlorate in polar snow. We have measured perchlorate concentrations in surface snow samples collected along a traverse route from Zhongshan Station to Dome A in East Antarctica to determine the level of atmospheric perchlorate in East Antarctica and to assess the spatial variability of perchlorate along the traverse route. Results show that the perchlorate concentrations vary between 32 and 200 ng kg-1, with an average of 104.3 ng kg-1. And perchlorate concentration profile presents regional variation patterns along the traverse route. In the coastal region, perchlorate concentration displays an apparent decreasing relationship with increasing distance inland; it exhibits no apparent trend in the intermediate region from 200 to 1000 km. The inland region from 1000 to 1244 km presents a generally increasing trend of perchlorate concentration approaching the dome. Different rates of atmospheric production, dilution by snow accumulation and re-deposition of snow-emitted perchlorate (post-depositional change) are the three possible factors influencing the spatial variability of perchlorate over Antarctica.

  20. Environmentally relevant concentrations of ammonium perchlorate inhibit development and metamorphosis in Xenopus laevis.

    PubMed

    Goleman, Wanda L; Urquidi, Lina J; Anderson, Todd A; Smith, Ernest E; Kendall, Ronald J; Carr, James A

    2002-02-01

    We determined whether environmentally relevant concentrations of ammonium perchlorate alter development and metamorphosis in Xenopus laevis. Eggs and larvae were exposed to varying concentrations of ammonium perchlorate or control medium for 70 d. Most treatment-related mortality was observed within 5 d after exposure and was due in large part to reduced hatching success. The 5- and 70-d median lethal concentrations (LC50s) were 510 +/- 36 mg ammonium perchlorate/L and 223 +/- 13 mg ammonium perchlorate/L, respectively. Ammonium perchlorate did not cause any concentration-related developmental abnormalities at concentrations below the 70-d LC50. Ammonium perchlorate inhibited metamorphosis in a concentration-dependent manner as evident from effects on forelimb emergence, tail resorption, and hindlimb growth. These effects were observed after exposure to ammonium perchlorate concentrations in the parts-per-billion range, at or below concentrations reported in surface waters contaminated with ammonium perchlorate. Ammonium perchlorate significantly inhibited tail resorption after a 14-d exposure in the U.S. Environmental Protection Agency (U.S. EPA) Endocrine Disruptor Screening and Testing Committee (EDSTAC) Tier I frog metamorphosis assay for thyroid disruption in amphibians. We believe that ammonium perchlorate may pose a threat to normal development and growth in natural amphibian populations.

  1. Influence of soil type and extraction conditions on perchlorate analysis by ion chromatography.

    PubMed

    MacMillan, Denise K; Dalton, Shana R; Bednar, Anthony J; Waisner, Scott A; Arora, Prem N

    2007-02-01

    Perchlorate is a stable anion that has been introduced into the environment through activities related to its production and use as a solid rocket propellant. Perchlorate is thought to transport through soils without being adsorbed; thus, for determination of perchlorate in soil, samples are typically extracted with water prior to analysis. The completeness of extraction depends on perchlorate existing as a free ion within the soil matrix. In this study, perchlorate extraction efficiency was evaluated with five soil types under two different oxygen states. For each soil, 30% (w/w) slurries were prepared and equilibrated under either oxic or anoxic conditions prior to spiking with a stock solution of sodium perchlorate, and the slurries were then maintained for 1-week or 1-month. At the end of the exposure, slurries were centrifuged and separated into aqueous and soil phases. After phase separation, the soil was washed first with deionized water and then with 50mM NaOH, producing second and third aqueous phases, respectively. Perchlorate concentrations in the three aqueous phases were determined using ion chromatography. The results obtained from this study suggest that matrix interference and signal suppression due to high conductivity have greater effects upon observed perchlorate concentrations by ion chromatography than does perchlorate interaction with soil. Thus, a single water extraction is sufficient for quantitative determination of perchlorate in soil.

  2. Perchlorate reduction during electrochemically induced pitting corrosion of zero-valent titanium (ZVT).

    PubMed

    Lee, Chunwoo; Batchelor, Bill; Park, Sung Hyuk; Han, Dong Suk; Abdel-Wahab, Ahmed; Kramer, Timothy A

    2011-12-15

    Zero-valent metals and ionic metal species are a popular reagent for the abatement of contaminants in drinking water and groundwater and perchlorate is a contaminant of increasing concern. However, perchlorate degradation using commonly used reductants such as zero-valent metals and soluble reduced metal species is kinetically limited. Titanium in the zero-valent and soluble states has a high thermodynamic potential to reduce perchlorate. Here we show that perchlorate is effectively reduced to chloride by soluble titanium species in a system where the surface oxide film is removed from ZVT and ZVT is oxidized during electrochemically induced pitting corrosion to produce reactive soluble species. The pitting potential of ZVT was measured as 12.77±0.04 V (SHE) for a 100 mM solution of perchlorate. The rate of perchlorate reduction was independent of the imposed potential as long as the potential was maintained above the pitting potential, but it was proportional to the applied current. Solution pH and surface area of ZVT electrodes showed negligible effects on rates of perchlorate reduction. Although perchlorate is effectively reduced during electrochemically induced corrosion of ZVT, this process may not be immediately applicable to perchlorate treatment due to the high potentials needed to produce active reductants, the amount of titanium consumed, the inhibition of perchlorate removal by chloride, and oxidation of chloride to chlorine.

  3. Perchlorate reduction from a highly concentrated aqueous solution by bacterium Rhodococcus sp. YSPW03.

    PubMed

    Lee, Sang-Hoon; Hwang, Jae-Hoon; Kabra, Akhil N; Abou-Shanab, Reda A I; Kurade, Mayur B; Min, Booki; Jeon, Byong-Hun

    2015-12-01

    A novel isolated bacterium Rhodococcus sp. YSPW03 was able to reduce high concentrations (up to 700 mg L(-1)) of perchlorate using acetate as electron donor. Perchlorate reduction rate increased from 2.90 to 11.23 mg L(-1) h(-1) with increasing initial acetate concentration from 100 to 2000 mg L(-1), leading to complete removal of perchlorate (100 mg L(-1)) within 9 h. The bacterium also promoted complete reduction of high perchlorate concentrations (500 and 700 mg L(-1)) at 2000 mg L(-1) of acetate within 48 and 96 h, respectively. Under semi-continuous reactor operation, efficient reduction on varied perchlorate concentrations (80-700 mg L(-1)) was performed by the bacterium in presence of acetate (600-6000 mg L(-1)) over 140 days. The highest perchlorate reduction rate of 280 mg L(-1) day(-1) was observed with an initial perchlorate concentration of 570 mg L(-1) at day 34. Dissolved chloride ions of 1000 mg L(-1) in the semi-continuous reactor (SCR) completely inhibited the biological perchlorate reduction. The findings of this study will help improve the perchlorate bioreactor design and determine the optimal conditions to maximize the perchlorate reduction efficiency.

  4. Interaction between perchlorate and iodine in the metamorphosis of Hyla versicolor

    USGS Publications Warehouse

    Sparling, D.W.; Harvey, G.; Nzengung, V.; Linder, Gregory L.; Krest, Sherry K.; Sparling, Donald W.; Little, Edward E.

    2003-01-01

    Perchlorate (ClO4-) is a water-soluble, inorganic anion that is often combined with ammonium, potassium or other cations for use in industry and agriculture. Ammonium perchlorate, for example, is a potent oxidizer and is used in various military applications including rocket fuel. It has also been found in an historically widely used fertilizer, Chilean nitrate and in other fertilizers. It has been found in ground and surface waters of over 30 states and is considered a human health risk. Because of its similar atomic radius and volume, perchlorate competes with iodide for thyroid uptake and storage and thereby inhibits production of thyroid hormones. Amphibians may be particularly affected by perchlorate because they rely on the thyroid for metamorphosis. This study exposed early larval Hyla versicolor to concentrations of perchlorate ranging from 2.2 to 50 ppm to determine the effects of perchlorate on a native amphibian. In addition, three controls, 0 perchlorate, 0 perchlorate with 0.10 ppm iodide (C + I) and 50 ppm perchlorate + 0.10 ppm iodide (50 + I) were tested. Mortality (<11% with all treatments) and growth appeared to be unaffected by perchlorate. Inhibition of development started with 2.2 ppm perchlorate and little or no development occurred at 22.9 ppm and above. This inhibition was particularly apparent at the latter stages of development including hindlimb formation and metamorphosis. The estimated EC50 for total inhibition of metamorphosis at 70 days of treatment was 3.63 ppm. There was no evidence of inhibition of development with the 50 + I, C + I, or controls, indicating that the presence of small concentrations of iodide could counter the effects of perchlorate. When tadpoles that had been inhibited by perchlorate were subsequently treated with iodide, development through prometamorphosis progressed but mortality was very high.

  5. Interaction between perchlorate and iodine in the metamorphosis of Hyla versicolor

    USGS Publications Warehouse

    Sparling, D.; Harvey, G.; Nzengung, V.; ,

    2003-01-01

    Perchlorate (ClO4-) is a water-soluble, inorganic anion that is often combined with ammonium, potassium or other cations for use in industry and agriculture. Ammonium perchlorate, for example, is a potent oxidizer and is used in various military applications including rocket fuel. It has also been found in an historically widely used fertilizer, Chilean nitrate and in other fertilizers. It has been found in ground and surface waters of over 30 states and is considered a human health risk. Because of its similar atomic radius and volume, perchlorate competes with iodide for thyroid uptake and storage and thereby inhibits production of thyroid hormones. Amphibians may be particularly affected by perchlorate because they rely on the thyroid for metamorphosis. This study exposed early larval Hyla versicolor to concentrations of perchlorate ranging from 2.2 to 50 ppm to determine the effects of perchlorate on a native amphibian. In addition, three controls, 0 perchlorate, 0 perchlorate with 0.10 ppm iodide (C + I) and 50 ppm perchlorate + 0.10 ppm iodide (50 + I) were tested. Mortality (< 11% with all treatments) and growth appeared to be unaffected by perchlorate. Inhibition of development started with 2.2 ppm perchlorate and little or no development occurred at 22.9 ppm and above. This inhibition was particularly apparent at the latter stages of development including hindlimb formation and metamorphosis. The estimated EC50 for total inhibition of metamorphosis at 70 days of treatment was 3.63 ppm. There was no evidence of inhibition of development with the 50 + I, C + I, or controls, indicating that the presence of small concentrations of iodide could counter the effects of perchlorate. When tadpoles that had been inhibited by perchlorate were subsequently treated with iodide, development through prometamorphosis progressed but mortality was very high.

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

    PubMed

    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 (p<0.05) dose-dependent decrease in these parameters. When treated with 500 mg/L perchlorate, these parameters and chlorophyll content in the leaf of plants 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

  7. Detection of Perchlorate Anion on Functionalized Silver Colloids Using Surface-Enhanced Raman Scattering

    SciTech Connect

    Tio, J.; Wang, W.; Gu, B.

    2005-01-01

    Perchlorate anion interferes with the uptake of iodide by the human thyroid gland and consequently disrupts the regulation of metabolism. Chronic exposure to high levels of perchlorate may lead to the formation of thyroid gland tumors. Although the Environmental Protection Agency (EPA) has not set a maximum contaminant level (MCL) for perchlorate, a draft drinking water range of 4-18 ppb based on 2 liter daily consumption of water has been established. The current EPA approved method for detecting perchlorate uses ion chromatography which has a detection limit of ~1ppb and involves lengthy analytical time in the laboratory. A unique combination of the surface-enhanced Raman scattering (SERS) effect and the bifunctional anion exchange resin’s high selectivity may provide an alternative way to detect perchlorate at such low concentrations and with high specificity. SERS, which uses laser excitation of adsorbed perchlorate anions on silver nanoparticles, has been shown to detect perchlorate anions at concentrations as low as 50 ppb. Normal micro-Raman analysis of perchlorate sorbed onto the resin beads has detected an even lower concentration of 10 ppb. In an effort to integrate these two effects, silver nanoparticles were coated with N-trimethoxysilylpropyl-N,N,N-trimethylammonium chloride, a functional group similar to that found on the resin bead, and subsequently inserted into different perchlorate concentration environments. This method has resulted in perchlorate detection down to ~10 ppb and a more consistent detection of perchlorate anion at ~50 ppb than that of earlier methods. As suggested by the direct insertion of functionalized silver colloids into perchlorate samples, this technique may potentially allow for the development of a probe using on-site Raman spectrometry to detect significantly low concentrations of perchlorate in situ rather than in the laboratory.

  8. Perchlorate reduction by autotrophic bacteria attached to zerovalent iron in a flow-through reactor.

    PubMed

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

    2007-02-01

    Biological reduction of perchlorate by autotrophic microorganisms attached to zerovalent iron (ZVI) was studied in flow-through columns. The effects of pH, flow rate, and influent perchlorate and nitrate concentrations on perchlorate reduction were investigated. Excellent perchlorate removal performance (> or = 99%) was achieved at empty bed residence times (EBRTs) ranging from 0.3 to 63 h and an influent perchlorate concentration of 40-600 microg L(-1). At the longest liquid residence times, when the influent pH was above 7.5, a significant increase of the effluent pH was observed (pH > 10.0), which led to a decrease of perchlorate removal. Experiments at short residence times revealed that the ZVI column inoculated with local soil (Colton, CA) containing a mixed culture of denitrifiers exhibited much better performance than the columns inoculated with Dechloromonas sp. HZ for reduction of both perchlorate and nitrate. As the flow rate was varied between 2 and 50 mL min(-1), corresponding to empty bed contact times of 0.15-3.8 h, a maximum perchlorate elimination capacity of 3.0 +/- 0.7 g m(-3) h(-1) was obtained in a soil-inoculated column. At an EBRT of 0.3 h and an influent perchlorate concentration of 30 microg L(-1), breakthrough (> 6 ppb) of perchlorate in the effluent did not occur until the nitrate concentration in the influent was 1500 times (molar) greater than that of perchlorate. The mass of microorganisms attached on the solid ZVI/sand was found to be 3 orders of magnitude greater than that in the pore liquid, indicating that perchlorate was primarily reduced by bacteria attached to ZVI. Overall, the process appears to be a promising alternative for perchlorate remediation.

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

    NASA Astrophysics Data System (ADS)

    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

  10. Comparative Demonstration of Active and Semi-Passive In Situ Bioremediation Approaches for Perchlorate Impacted Groundwater: Active In Situ Bioremediation Demonstration

    DTIC Science & Technology

    2013-04-01

    approach for the treatment of perchlorate-affected groundwater under many different site conditions. Perchlorate biodegradation results from microbially ...37 5.6.6.2 Dissolved Hydrocarbon Gases ................................................ 39 5.6.6.3...35 Figure 5. Perchlorate biodegradation results

  11. Perchlorate and Superfund Response to Uncertainty and the Geochemical Cycle

    NASA Astrophysics Data System (ADS)

    Mayer, K. P.

    2007-12-01

    Perchlorate, a chemical that had been known both in nature and through synthesis since the nineteenth century, only emerged into the limelight as an environmental contaminant in 1997. US EPA's Superfund Program became involved in perchlorate issues in the late 1980s and early 1990s due to the chemical's presence mixed with other contaminants at cleanup sites. Relying largely on pharmaceutical studies primarily from the 1950s and 1960s, EPA scientists in 1992 made a provisional estimate of toxicity and estimated that about 4 micrograms per liter (parts per billion or ppb) in drinking water would be protective. "Uncertainty factors" were incorporated to address for several identified information gaps. Results of new animal and human studies funded by the Defense Department and industry in the late 1990s shifted the concern from affects on adults with unhealthy thyroids to the potential developmental health risks to infants and children. EPA's January, 2002, draft toxicity assessment was referred to a committee of the National Research Council. In January, 2005, this committee recommended a "reference dose" based primarily on human clinical data. Many decisions remain on interpretation of the scientific recommendations for regulatory applications. After California's 1997 development of an analytical method to detect perchlorate in water to 4 ppb, EPA and state officials quickly discovered this chemical at 10 Superfund sites in the Pacific Southwest Region and at more than 30 other locations in California, Arizona and Nevada. Even before current research on the potential for natural sources of this anion, reported detections of perchlorate were investigated with reasonable care and appropriate skepticism. A brief overview of the search for likely sources of perchlorate detected in California water supplies is presented from a regional Superfund perspective. Some are clearly anthropogenic and others may be unrelated to industrial or disposal practices. Currently, there

  12. Archaeal (Per)Chlorate Reduction at High Temperature: An Interplay of Biotic and Abiotic Reactions

    NASA Astrophysics Data System (ADS)

    Liebensteiner, Martin G.; Pinkse, Martijn W. H.; Schaap, Peter J.; Stams, Alfons J. M.; Lomans, Bart P.

    2013-04-01

    Perchlorate and chlorate anions [(per)chlorate] exist in the environment from natural and anthropogenic sources, where they can serve as electron acceptors for bacteria. We performed growth experiments combined with genomic and proteomic analyses of the hyperthermophile Archaeoglobus fulgidus that show (per)chlorate reduction also extends into the archaeal domain of life. The (per)chlorate reduction pathway in A. fulgidus relies on molybdo-enzymes that have similarity with bacterial enzymes; however, chlorite is not enzymatically split into chloride and oxygen. Evidence suggests that it is eliminated by an interplay of abiotic and biotic redox reactions involving sulfur compounds. Biological (per)chlorate reduction by ancient archaea at high temperature may have prevented accumulation of perchlorate in early terrestrial environments and consequently given rise to oxidizing conditions on Earth before the rise of oxygenic photosynthesis.

  13. Biodegradation of nitroglycerin and perchlorate in propellant wastewater. Report for March 1993--July 1994

    SciTech Connect

    Attaway, H.

    1994-09-01

    This report describes studies on the degradation of nitroglycerin and nitroglycerin/perchlorate mixtures by an anaerobic mixed culture containing the perchlorate reducing bacterium HAP1. The final goal was to demonstrate the feasibility of biotreating a model hazard class 1.1 propellant (CYH) wastewater containing these compounds. The results showed that nitroglycerin rapidly disappeared under culture growth conditions. The disappearance appeared to be due to non-enzymatic chemical denitration resulting from the strong reducing potential generated in the medium. Nitroglycerin and nitrite were shown to inhibit perchlorate reduction. Both glycering and perchlorate were degraded in 10% CYH propellant wastewater. Perchlorate reduction in 25% and 50% CYH wastewater occurred only after nitroglycerin and nitrite were predegraded and the mixture culture was reinoculated. The other major components of the CYH wastewater, trice tin and resorcinol, were not inhibitory to perchlorate reduction.

  14. Trends of perchlorate in Antarctic snow: Implications for atmospheric production and preservation in snow

    NASA Astrophysics Data System (ADS)

    Jiang, Su; Cox, Thomas S.; Cole-Dai, Jihong; Peterson, Kari M.; Shi, Guitao

    2016-09-01

    Perchlorate concentration ranges from a few to a few hundred ng kg-1 in surface and shallow-depth snow at three Antarctic locations (South Pole, Dome A, and central West Antarctica), with significant spatial variations dependent on snow accumulation rate and/or atmospheric production rate. An obvious trend of increasing perchlorate since the 1970s is seen in South Pole snow. The trend is possibly the result of stratospheric chlorine levels elevated by anthropogenic chlorine emissions; this is supported by the timing of a similar trend at Dome A. Alternatively, the trend may stem from postdepositional loss of snowpack perchlorate or a combination of both. The possible impact of stratospheric chlorine is consistent with evidence of perchlorate production in the stratosphere. Additionally, perchlorate concentration appears to be directly affected by the springtime Antarctic ozone hole. Therefore, perchlorate variations in Antarctic snow are likely linked to stratospheric chemistry and ozone over the Antarctic.

  15. Environmental impacts of perchlorate with special reference to fireworks--a review.

    PubMed

    Sijimol, M R; Mohan, Mahesh

    2014-11-01

    Perchlorate is an inorganic anion that is used in solid rocket propellants, fireworks, munitions, signal flares, etc. The use of fireworks is identified as one of the main contributors in the increasing environmental perchlorate contamination. Although fireworks are displayed for entertainment, its environmental costs are dire. Perchlorates are also emerging as potent thyroid disruptors, and they have an impact on the ecology too. Many studies have shown that perchlorate contaminates the groundwater and the surface water, especially in the vicinity of fireworks manufacturing sites and fireworks display sites. The health and ecological impacts of perchlorate released in fireworks are yet to be fully assessed. This paper reviews fireworks as a source of perchlorate contamination and its expected adverse impacts.

  16. A novel perchlorate- and nitrate-reducing bacterium, Azospira sp. PMJ.

    PubMed

    Nam, Ji-Hyun; Ventura, Jey-R S; Yeom, Ick Tae; Lee, Yongwoo; Jahng, Deokjin

    2016-07-01

    A novel perchlorate-reducing bacterium (PCRB), PMJ, was isolated from the mixed liquor suspended solids in the aerobic tank of a wastewater treatment plant. The 16S ribosomal RNA (rRNA), perchlorate reductase, and chlorite dismutase gene sequences revealed that PMJ belonged to the genus Azospira. PMJ was removed high-strength (700 mg/L) perchlorate and also removed low-strength (≤50 mg/L) perchlorate below the detection limit (2 μg/L) when acetate was used as a sole and carbon source. The maximum specific perchlorate utilization rate, q max, was 0.96 mg ClO4 (-)/mg dry cell weight day, and the half-saturation constant, K S , was lower than 0.002 mg ClO4 (-)/L. PMJ also utilized inorganic electron donors [(H2, S(0), and Fe(II)] with perchlorate as an electron acceptor. Perchlorate reduction by PMJ was completely inhibited by oxygen and chlorate but was not inhibited by nitrate. In the presence of similar concentrations (100∼140 mg/L) of nitrate and perchlorate, PMJ simultaneously removed both electron acceptors. Therefore, it was concluded that the strains PMJ might possess separate pathways for perchlorate and nitrate reduction. These results indicated that Azospira sp. PMJ could be efficiently used for treating perchlorate-contaminated groundwater and wastewater because many of these water bodies are known to contain both perchlorate and nitrate. In addition, low K S value and autotrophic perchlorate reduction of PMJ might be useful to design the biological treatment systems.

  17. Basis of the Massachusetts reference dose and drinking water standard for perchlorate.

    PubMed

    Zewdie, Tsedash; Smith, C Mark; Hutcheson, Michael; West, Carol Rowan

    2010-01-01

    Perchlorate inhibits the uptake of iodide in the thyroid. Iodide is required to synthesize hormones critical to fetal and neonatal development. Many water supplies and foods are contaminated with perchlorate. Exposure standards are needed but controversial. Here we summarize the basis of the Massachusetts (MA) perchlorate reference dose (RfD) and drinking water standard (DWS), which are considerably lower and more health protective than related values derived by several other agencies. We also review information regarding perchlorate risk assessment and policy. MA Department of Environmental Protection (DEP) scientists, with input from a science advisory committee, assessed a wide range of perchlorate risk and exposure information. Health outcomes associated with iodine insufficiency were considered, as were data on perchlorate in drinking water disinfectants. We used a weight-of-the-evidence approach to evaluate perchlorate risks, paying particular attention to sensitive life stages. A health protective RfD (0.07 microg/kg/day) was derived using an uncertainty factor approach with perchlorate-induced iodide uptake inhibition as the point of departure. The MA DWS (2 microg/L) was based on risk management decisions weighing information on perchlorate health risks and its presence in certain disinfectant solutions used to treat drinking water for pathogens. Current data indicate that perchlorate exposures attributable to drinking water in individuals at sensitive life stages should be minimized and support the MA DEP perchlorate RfD and DWS. Widespread exposure to perchlorate and other thyroid toxicants in drinking water and foods suggests that more comprehensive policies to reduce overall exposures and enhance iodine nutrition are needed.

  18. Evaluation of Potential for Monitored Natural Attenuation of Perchlorate in Groundwater

    DTIC Science & Technology

    2010-09-01

    Perchlorate-Impacted Groundwater for Base Case 8-4 Cost Components for Extraction and Treatment of Perchlorate-Impacted Groundwater for Base Case 8-5...consumed, increasing the likelihood of perchlorate biodegradation in the natural environment (Coates and Jackson, 2009). Trace amounts of molybdenum are...chlorinated solvents (USEPA, 1998) have been in use for many years. These documents describe systematic steps for delineating contaminant plumes

  19. Changes in cross-fostered Sprague-Dawley rat litters exposed to perchlorate.

    PubMed

    Mahle, Deirdre A; Yu, Kyung O; Narayanan, Latha; Mattie, David R; Fisher, Jeffrey W

    2003-01-01

    Ammonium perchlorate is used as an oxidizer in rocket fuel. It has become a groundwater contaminant, dissociating to ammonium cation and perchlorate anion. The perchlorate ion competes with iodide for uptake into the thyroid, reducing thyroid hormone production. Pregnant Sprague-Dawley rats were given either untreated or perchlorate (1 mg/kg-day) treated drinking water beginning on gestation day 2. One set of control and exposed dams was sacrificed on gestation day 20. The litters from the second set of control and exposed dams were crossed immediately after parturition and were sacrificed at postnatal day 10. Dam serum and thyroid, pooled fetal sera, and male and female pup sera were collected and analyzed for perchlorate, thyroid-stimulating hormone (TSH), triiodothyronine (T(3)), and thyroxine (T(4)). Control pups receiving perchlorate through lactation had serum levels at postnatal day 10 of 0.54 microg/ml and 0.56 microg/ml for male and female pups, respectively, whereas exposed fetuses had serum perchlorate levels of 0.38 +/- 0.04 microg/ml. Female pups receiving perchlorate lactationally had significantly lower levels of serum T(4) than control pups and prenatally exposed pups. Serum T(4) levels in male pups were not affected by perchlorate. Serum thyroid hormone levels from gestational perchlorate exposure were restored to control values by postnatal day 10. In utero perchlorate-exposure decreased serum T(4) levels in the fetus. Gestational studies in conjunction with a cross-fostering study design helped discern thyroid hormonal changes caused by perchlorate exposure during the perinatal period.

  20. Analysis and Exposure Assessment of Perchlorate in Korean Dairy Products with LC-MS/MS

    PubMed Central

    Oh, Sung-Hee; Lee, Ji-Woo; Mandy, Pawlas

    2011-01-01

    Objectives Perchlorate is an emerging contaminant that is found everywhere, including various foods. Perchlorate is known to disturb the production of thyroid hormones and leads to mental disorders in fetuses and infants, as well as metabolic problems in adults. In this study, we attempted to establish an LC-MS/MS method for measuring perchlorate in dairy products and used this developed method to investigate perchlorate levels in Korean milk and yogurt samples. Methods The developed method of perchlorate analysis requires a shaker and 1% acetic acid/acetonitrile as the extracting solvent. Briefly, the samples were extracted and then centrifuged (4000 rpm, 1hour), and the supernatant was then passed through a Envi™ Carb SPE cartridge that had been prewashed sequentially with 6 mL of acetonitrile and 6 mL of 1% acetic acid in water. The final volume of the sample extract was adjusted to 40 mL with reagent water and the final sample was filtered through a 0.20-µm pore size PTFE (Polytetrafluoroethylene) syringe filter prior to LC-MS/MS. Results The average levels of perchlorate in milk and yogurt samples were 5.63 ± 3.49 µg/L and 3.65 ± 2.42 µg/L, respectively. The perchlorate levels observed in milk samples in this study were similar to those reported from China, Japan, and the United States. Conclusions The exposure of Koreans to perchlorate through the consumption of dairy products was calculated based on the results of this study. For all age groups, the calculated exposure to perchlorate was below the reference of dose (0.7 µg/kg-day) proposed by the National Academy of Science, USA, but the perchlorate exposure of children was higher than that of adults. Therefore, further investigation of perchlorate in other food samples is needed to enable a more exact assessment of exposure of children to perchlorate. PMID:22125772

  1. Occurrence and exposure evaluation of perchlorate in outdoor dust and soil in mainland China.

    PubMed

    Gan, Zhiwei; Sun, Hongwen; Wang, Ruonan; Deng, Yuanyuan

    2014-02-01

    A total of 98 paired soil and outdoor dust samples were collected across mainland China for survey of perchlorate. Perchlorate was detected in all of the soil and outdoor dust samples. High levels of perchlorate were found in soil, ranging from 0.001 to 216 mg/kg in Northern China and from 0.001 to 25.8 mg/kg in Southern China. Even higher perchlorate concentrations were detected in dust samples, with concentrations ranging from 0.132 to 5,300 mg/kg in Northern China, and from 0.270 to 3,700 mg/kg in Southern China. This is the first known report of perchlorate in dust samples. The high perchlorate levels in soil and dust may raise concern on the potential risk for organisms and human. The daily perchlorate intakes were evaluated based on our measured perchlorate concentrations via inhalation, ingestion, and dermal contact of soil and dust for both children and adults, respectively. In general, the exposure from soil does not appear to lead to perchlorate intakes exceeding the US EPA reference for both children and adults. However, children can be at risk from exposure to perchlorate via dust, and it needs considerable concern for both children and adults at the sites with high dust perchlorate concentrations. After comparison with other possible exposure pathways, such as from drinking water, we suggested that dust may be an important potential source of perchlorate exposure in China, and further study is needed, especially for indoor dust. © 2013.

  2. A Potential Mechanism for Perchlorate Formation on Mars: Surface-Radiolysis-Initiated Atmospheric Chemistry

    NASA Astrophysics Data System (ADS)

    Wilson, Eric; Atreya, Sushil K.; Kaiser, Ralf-Ingo; Mahaffy, Paul

    2016-10-01

    Perchlorate (ClO4-) is prevalent on Earth, and with observations of perchlorate on lunar samples and chondrite meteorites, along with recent observations indicating the presence of perchlorate (ClO4-) in the Martian surface by the Phoenix lander and the Sample Analysis at Mars (SAM) on the Mars Science Laboratory (MSL) rover, it appears that the existence of perchlorate is widespread throughout the solar system. However, the abundance and isotopic composition of Martian perchlorate suggest that the perchlorate formation mechanism on Mars may involve a different path than perchlorate found elsewhere in the solar system. Motivated by this, we employ a one-dimensional chemical model to investigate the viability of perchlorate formation in the atmosphere of Mars, instigated by the radiolysis of the Martian surface by galactic cosmic rays. The surface-atmosphere interaction to produce Martian perchlorate involves the sublimation of chlorine oxides into the atmosphere, through surface radiolysis, and their subsequent synthesis to form perchloric acid (HClO4), followed by surface deposition and mineralization to form surface perchlorates. Considering the chlorine oxide, OClO, we find an OClO surface flux as low as 3.2x107 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.

  3. Microbial ecology of a perchlorate-reducing, hydrogen-based membrane biofilm reactor.

    PubMed

    Nerenberg, Robert; Kawagoshi, Yasunori; Rittmann, Bruce E

    2008-02-01

    The hydrogen-based membrane biofilm reactor (MBfR) has been shown to reduce perchlorate to below 4 microg/L, but little is known about the microbial ecology of this or other hydrogen-based reactors, especially when influent perchlorate concentrations are much lower than the influent oxygen and nitrate concentrations. Dissimilatory (per)chlorate-reducing bacteria (PCRB) can use oxygen as an electron acceptor, and most can also use nitrate. Since oxygen and nitrate can be reduced concurrently with perchlorate, they may serve as primary electron acceptors, sustaining PCRB when the perchlorate concentrations are very low. We studied five identical MBfRs, all seeded with the same inoculum and initially supplied with oxygen, or oxygen plus nitrate, in the influent. After 20 days, perchlorate was added to four MBfRs at influent concentrations of 100-10,000 microg/L, while the fifth was maintained as a control. One day after perchlorate addition, the MBfRs displayed limited perchlorate reduction, suggesting a low initial abundance of PCRB. However, perchlorate reduction improved significantly over time, and denaturing gradient gel electrophoresis (DGGE) analyses suggested an increasing abundance of a single Dechloromonas species. Fluorescence in-situ hybridization (FISH) tests showed that the Dechloromonas species accounted for 14% of the bacterial count in the control MBfR, and 22%, 31%, and 49% in the MBfRs receiving nitrate plus 100, 1000, and 10,000 microg/L perchlorate, respectively. The abundance was 34% in the MBfR receiving oxygen plus 1000 microg/L perchlorate. These results suggest that oxygen is more favorable than nitrate as a primary electron acceptor for PCRB, that PCRB are present at low levels even without perchlorate, and that the presence of perchlorate, even at low levels relative to nitrate or oxygen, significantly enhances selection for PCRB.

  4. Basis of the Massachusetts Reference Dose and Drinking Water Standard for Perchlorate

    PubMed Central

    Zewdie, Tsedash; Smith, C. Mark; Hutcheson, Michael; West, Carol Rowan

    2010-01-01

    Objective Perchlorate inhibits the uptake of iodide in the thyroid. Iodide is required to synthesize hormones critical to fetal and neonatal development. Many water supplies and foods are contaminated with perchlorate. Exposure standards are needed but controversial. Here we summarize the basis of the Massachusetts (MA) perchlorate reference dose (RfD) and drinking water standard (DWS), which are considerably lower and more health protective than related values derived by several other agencies. We also review information regarding perchlorate risk assessment and policy. Data sources MA Department of Environmental Protection (DEP) scientists, with input from a science advisory committee, assessed a wide range of perchlorate risk and exposure information. Health outcomes associated with iodine insufficiency were considered, as were data on perchlorate in drinking water disinfectants. Data synthesis We used a weight-of-the-evidence approach to evaluate perchlorate risks, paying particular attention to sensitive life stages. A health protective RfD (0.07 μg/kg/day) was derived using an uncertainty factor approach with perchlorate-induced iodide uptake inhibition as the point of departure. The MA DWS (2 μg/L) was based on risk management decisions weighing information on perchlorate health risks and its presence in certain disinfectant solutions used to treat drinking water for pathogens. Conclusions Current data indicate that perchlorate exposures attributable to drinking water in individuals at sensitive life stages should be minimized and support the MA DEP perchlorate RfD and DWS. Widespread exposure to perchlorate and other thyroid toxicants in drinking water and foods suggests that more comprehensive policies to reduce overall exposures and enhance iodine nutrition are needed. PMID:20056583

  5. Transposon and Deletion Mutagenesis of Genes Involved in Perchlorate Reduction in Azospira suillum PS

    PubMed Central

    Melnyk, Ryan A.; Clark, Iain C.; Liao, Annette; Coates, John D.

    2013-01-01

    ABSTRACT Although much work on the biochemistry of the key enzymes of bacterial perchlorate reduction, chlorite dismutase, and perchlorate reductase has been published, understanding of the molecular mechanisms of this metabolism has been somewhat hampered by the lack of a clear model system amenable to genetic manipulation. Using transposon mutagenesis and clean deletions, genes important for perchlorate reduction in Azospira suillum PS have been identified both inside and outside the previously described perchlorate reduction genomic island (PRI). Transposon mutagenesis identified 18 insertions in 11 genes that completely abrogate growth via reduction of perchlorate but have no phenotype during denitrification. Of the mutants deficient in perchlorate reduction, 14 had insertions that were mapped to eight different genes within the PRI, highlighting its importance in this metabolism. To further explore the role of these genes, we also developed systems for constructing unmarked deletions and for complementing these deletions. Using these tools, every core gene in the PRI was systematically deleted; 8 of the 17 genes conserved in the PRI are essential for perchlorate respiration, including 3 genes that comprise a unique histidine kinase system. Interestingly, the other 9 genes in the PRI are not essential for perchlorate reduction and may thus have unknown functions during this metabolism. We present a model detailing our current understanding of perchlorate reduction that incorporates new concepts about this metabolism. PMID:24381299

  6. Perchlorate exposure in lactating women in an urban community in New Jersey.

    PubMed

    Borjan, Marija; Marcella, Stephen; Blount, Benjamin; Greenberg, Michael; Zhang, Junfeng Jim; Murphy, Eileen; Valentin-Blasini, Liza; Robson, Mark

    2011-01-01

    Perchlorate is most widely known as a solid oxidant for missile and rocket propulsion systems although it is also present as a trace contaminant in some fertilizers. It has been detected in drinking water, fruits, and vegetables throughout New Jersey and most of the United States. At sufficiently high doses, perchlorate interferes with the uptake of iodine into the thyroid and may interfere with the development of the skeletal system and the central nervous system of infants. Therefore, it is important to quantify perchlorate in breast milk to understand potential perchlorate exposure in infants. In this study we measured perchlorate in breast milk, urine, and drinking water collected from 106 lactating mothers from Central New Jersey. Each subject was asked to provide three sets of samples over a 3-month period. The average±SD perchlorate level in drinking water, breast milk, and urine was 0.168±0.132 ng/mL (n=253), 6.80±8.76 ng/mL (n=276), and 3.19±3.64 ng/mL (3.51±6.79 μg/g creatinine) (n=273), respectively. Urinary perchlorate levels were lower than reference range values for women of reproductive age (5.16±11.33 μg/g creatinine, p=0.03), likely because of perchlorate secretion in breast milk. Drinking water perchlorate levels were ≤1.05 ng/mL and were not positively correlated with either breast milk or urine perchlorate levels. These findings together suggest that drinking water was not the most important perchlorate exposure source for these women. Creatinine-adjusted urine perchlorate levels were strongly correlated with breast milk perchlorate levels (r=0.626, p=<0.0005). Breast milk perchlorate levels in this study are consistent with widespread perchlorate exposure in lactating women and thus infants. This suggests that breast milk may be a source of exposure to perchlorate in infants.

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

    NASA Astrophysics Data System (ADS)

    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.

  8. Hypochlorite treatments are not a significant source of perchlorate exposure in lettuce.

    PubMed

    Sanchez, C A; Fonseca, J M; Blount, B C; Krieger, R I

    2009-03-25

    Leafy vegetables, such as lettuce ( Lactuca sativa L), have been identified as a potential source of perchlorate exposure to humans. Perchlorate is of concern because excessive amounts may impair thyroid function by inhibiting iodide uptake by the sodium iodide symporter. Perchlorate has been identified as an oxidation product in sodium hypochlorite. Dilute hypochlorite solutions are widely used on lettuce as a preservative and as a treatment to reduce microbial food risks. However, the potential of hypochlorite to be a source of human perchlorate exposure from lettuce had not been evaluated. Studies were conducted with lettuce collected in the San Luis Valley of southern Colorado and in the lower Colorado River Valley of southwestern Arizona to represent conditions under which hypochlorite is applied to lettuce in the field and in salad processing facilities. We used spray and dipping solutions that were dilutions of concentrated sodium hypochlorite that would contain from 12000 and 120000 microg/L perchlorate. The perchlorate content of iceberg and romaine lettuce averaged 6.2 and 7.2 microg/kg fw in southern Colorado and 14.0 and 56.7 microg/kg fw in southwestern Arizona and there were no significant (P > 0.05) increases in the perchlorate content of lettuce due to hypochlorite treatments. Because of the relatively low concentrations of perchlorate present after dilution and the low volumes applied to lettuce, hypochlorite solutions do not appear to be a significant source of the perchlorate levels found in lettuce.

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

    PubMed

    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.

  10. Spectroscopic and Visual Evidence of Perchlorate Deliquescence Under Martian Conditions

    NASA Astrophysics Data System (ADS)

    Nikolakakos, George; Whiteway, James

    2015-04-01

    One of the key findings during the Phoenix and Mars Science Laboratory landed Mars missions has been the detection of perchlorate, a highly deliquescent salt. Perchlorates are of great interest on Mars due to their high affinity for water vapour as well as their ability to greatly depress the freezing point of water when in solution. This has intriguing biological implications as resulting brines could potentially provide a habitable environment for living organisms. Additionally, it has been speculated that these salts may play a significant role in influencing the hydrological cycle on Mars. In order to experimentally study water exchange processes between the surface and atmosphere on Mars and assess the feasibility of a future landed detection tool, a stand-off Raman spectroscopy instrument and environmental simulation chamber have been developed at York University. A sample of magnesium perchlorate consistent with the size of patches found at the Phoenix site has been subjected to the low water vapour pressure and temperatures found at polar Martian latitudes. Results indicate that at a water vapour pressure of ~2 Pa (-54°C frost point temperature), Raman spectroscopy is able to detect the onset of brine formation and provide a relative estimate of the quantity of water taken up by the sample until complete deliquescence is reached. Significant uptake of water from the atmosphere is observed to occur prior to the frost point temperature being reached and on time scales relevant to the Martian diurnal cycle. This result suggests that perchlorates in the Martian regolith can contribute to the hydrological cycle, pre-emptively reducing the water vapour pressure before saturation is reached.

  11. Integrated Ion Exchange Regeneration Process for Perchlorate in Drinking Water

    DTIC Science & Technology

    2010-08-01

    or below notification level, 10 nanograms per liter (ng/L), for nitrosamines . The performance of IIX was evaluated through several cycles to...facility construction. IIX was not found to increase nitrosamines or other semivolatile organic compounds in treated water. Perchlorate-loaded resin...reducing operating costs. Re-use of resin also reduces nitrosamine and nitrosamine precursor residuals associated with installation of virgin resin

  12. In-Situ Bioreduction and Removal of Ammonium Perchlorate

    DTIC Science & Technology

    2006-05-09

    recently, it was demonstrated that solid fertilizers not derived from the Chilean deposits and commonly used for the hydroponic growth of various fruit...owing to the increasing use of hydroponic farming techniques for the production of a wide variety of plants for human consumption throughout the...sedimentary environments. Appl. Environ. Microbiol. 62:1531-1536. 35. Collette, T. W. 2003. Analysis of hydroponic fertilizer matrixes for perchlorate

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

    DTIC Science & Technology

    2008-10-16

    Hypothyroidism , Newborn Thyroid Function, and Environmental Perchlorate Exposure Among Residents of a Southern California Community,” Journal of Occupational...thyroid hormone as biochemical events that might precede adverse effects, and identified hypothyroidism as the first adverse effect. Because of research...women who might have hypothyroidism or iodide deficiency) and noted that the RfD was supported by clinical studies, occupational and environmental

  14. Lithium perchlorate-nitromethane-promoted alkylation of anilines with arylmethanols.

    PubMed

    Zhou, Jun; Mao, Hai-Feng; Wang, Lu; Zou, Jian-Ping; Zhang, Wei

    2011-11-01

    A new application of lithium perchlorate-nitromethane (LPNM) for the formation of aromatic C-N and C-C bonds is introduced. LPNM-promoted reactions of anilines with diarylmethanols selectively generate N-alkylated anilines or mono and double Friedel-Crafts alkylation products under different conditions by changing the reaction time, reaction temperature, and the ratio of the reactants. This method does not require the use of transition metal catalysts to prepare alkylated aniline derivatives.

  15. Parameters for the Pyrolysis of Organic Material - Perchlorate Mixtures

    NASA Astrophysics Data System (ADS)

    Steininger, Harald; Goesmann, Fred; Goetz, Walter

    2013-04-01

    The ESA-lead Mars rover ExoMars (launch in 2018) will carry a suit of instruments, one of the in-struments is the Mars Organic Molecule Analyzer MOMA. Organic material in the Martian soil will be either pyrolyzed at temperatures of up to 1000°C and separated by gas chromatography or volatilized with the help of an UV-laser. A mass spectrometer will be the detector for both methods. Chlorinated organics have been detected in pyroly-sis GC-MS experiments on Mars two times. The first time during the Viking mission in 1976 and a second time with the Sample Analysis on Mars (SAM) in-strument onboard the Curiosity rover in 2012. [1] [2] The presence of perchlorates found by the Phoenix mission in 2008 [3] lead to the discovery that organic molecules not only get oxidized during pyrolysis, but also chlorinated organic compounds can be pro-duced. [4] The parameters used for pyrolysis and the sample composition especially the distribution of organics and perchlorates within the sample and the concentrations of organics and perchlorate have a huge influence on the products created. It is possible to change the condi-tions of the pyrolysis by spatially separating the organ-ics from the perchlorates that the chloromethanes get the major product of the pyrolysis. This might help to understand the results of the (SAM) instrument yield-ing mono-, di- and trichloromethane and a chlorinated 4-hydrocarbon molecule. References: [1] Biemann K et al. (1977) JGR, 82, 4641-4658. [2] Grotzinger J. P et al. (2011) AGU Fall Meeting U13A-01 [3] Hecht M. H., et al. (2009) Science, 325 64-67. [4] Steininger H., Goesmann F., Goetz W. (2011) Planet. & Space Sci., 71, 9-17. Acknowledgments: This work was funded by DLR (FKZ 50QX1001)

  16. Dispersion strengthened copper

    DOEpatents

    Sheinberg, Haskell; Meek, Thomas T.; Blake, Rodger D.

    1990-01-01

    A composition of matter comprised of copper and particles which are dispersed throughout the copper, where the particles are comprised of copper oxide and copper having a coating of copper oxide, and a method for making this composition of matter.

  17. Dispersion strengthened copper

    DOEpatents

    Sheinberg, Haskell; Meek, Thomas T.; Blake, Rodger D.

    1989-01-01

    A composition of matter comprised of copper and particles which are dispersed throughout the copper, where the particles are comprised of copper oxide and copper having a coating of copper oxide, and a method for making this composition of matter.

  18. Formation Of Perchlorate By Ozonation Of Aqueous Oxy-chlorine Anions: An Insight To Natural Perchlorate Formation

    NASA Astrophysics Data System (ADS)

    Rao, B.; Jackson, A.; Kang, N.; Redder, A.

    2007-12-01

    Perchlorate (ClO4-) is a natural and anthropogenic contaminant of increasing concern. Natural perchlorate was first identified in Chilean nitrates from the Atacama dessert over 100 years ago. However, only in the last two years has the occurrence of natural perchlorate been seriously considered as a potential exposure source. Although there has been considerable research effort in understanding the occurrence, remediation, and impact of ClO4- in the environment, relatively little information is available regarding the mechanism(s) responsible for ClO4- formation. Perchlorate productions from ozone oxidation of chlorine and oxy- chlorine anions (Cl-, OCl-, ClO2-and ClO3-) were conducted in continuous flow reactors at constant ozone concentrations (approximately 6 mg L-1) and at varying concentrations of chlorine materials (ranging from 10 to 1000 mg L-1). Sub samples from both the main reaction flask and alkaline trapping flasks were taken over varying time intervals and the concentrations of oxy-chlorine anions including ClO4- were measured using various ion chromatographic methods whereas OCl- was determined iodometrically using the spectrophotometer. The experiment time ranged from 6 hrs to 7 days depending on the rate of decomposition of the reactants. Results indicate that ClO4- is readily formed during the ozonation of ClO2- and OCl- solutions (maximum conversion of 2.7 %) whereas the Cl- and ClO3- solutions produced relatively lower quantities of ClO4- ( maximum conversion of 0.02 %) . Further the presence of ClO2- in the initial OCl- solution is suspected to significantly contribute the total ClO4- generated augmenting the role of ClO2- in ClO4- formation as mentioned in recent study on the photochemical reactions of oxy-chlorine anions.

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

    NASA Astrophysics Data System (ADS)

    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

  20. Perchlorate exposure from food crops produced in the lower Colorado River region.

    PubMed

    Sanchez, Charles A; Barraj, Leila M; Blount, Benjamin C; Scrafford, Carolyn G; Valentin-Blasini, Liza; Smith, Kimberly M; Krieger, Robert I

    2009-05-01

    The Colorado River shows low levels of perchlorate derived from aerospace- and defense-related fuel industries once located near the Las Vegas Wash. At sufficiently high dosages perchlorate can disrupt thyroid function by inhibiting uptake of iodide. The Colorado River is the primary source of irrigation water for most food crops grown in Southern California and Southwestern Arizona. The objective of this study was to evaluate potential perchlorate exposure from food crops produced in the lower Colorado River region (LCRR). The major food commodities produced in the region were sampled and perchlorate levels were determined by ion chromatography followed by detection using either conductivity or tandem mass spectrometry, depending on analyte levels. The Monte Carlo module of the Dietary Exposure Evaluation Model (DEEM) was used to derive an estimate of the 2-day average perchlorate intakes. Data were derived assuming that individuals residing in the LCRR get their fruits and vegetables from within the LCRR as well as from other areas in the United States, or assuming individuals living in the LCRR get their fruits and vegetables from the LCRR only. Perchlorate exposure estimates derived in this study are comparable to exploratory estimates by the US Food and Drug Administration. For infants and children, over 50% of the estimated perchlorate exposure was from milk. The relative impact of vegetables and fruit toward perchlorate exposure increased by age through adulthood. Cumulative perchlorate exposure estimates based on this hypothetical analysis could approach or exceed the NAS reference dose (RfD) for some population groups as drinking water levels exceeded 6 microg/l. However, few individuals are exposed to perchlorate in drinking water at levels above 4 microg/l in the United States and very few would be exposed to perchlorate levels exceeding the RfD, whether consuming food crops from within or outside the LCRR.

  1. Investigating the Deliquescence Relative Humidity of Perchlorate Salts as a Function of Temperature: Implications for Mars

    NASA Astrophysics Data System (ADS)

    Gough, R. V.; Baustian, K. J.; Wise, M. E.; Tolbert, M. A.

    2009-12-01

    Recent observations suggest perchlorate salts are present in the regolith at the polar regions of Mars. Perchlorates are deliquescent, meaning they absorb significant water from the atmosphere and become an aqueous solution. Deliquescence of perchlorate salts is a possible explanation for the appearance and growth of droplet-like spheroids on a strut of the Phoenix lander. The relative humidity at which this deliquescence occurs (DRH) is often temperature-dependent, and the only value reported thus far is DRH = 44% for sodium perchlorate at room temperature. However, the deliquescence of perchlorate salts at Martian temperatures has not been studied, and the temperature dependence of this process is important for predicting the ability of liquid water to be stable on the Martian surface and in the shallow subsurface. To study the deliquescence of perchlorate at Martian temperatures, we are using a Raman microscope paired with an environmental cell. Deliquescence can be detected both spectrally and by visual inspection. We have determined that the DRH of pure perchlorate salts is independent of temperature. However, the DRH of pure perchlorate may be affected by the presence of minerals known to exist on Mars, such as phyllosilicates. Some clay minerals have unique water adsorption properties, and these competing water adsorption mechanisms may inhibit the ability of perchlorate salts to deliquesce, effectively shrinking the proposed window of aqueous perchlorate solution stability. For this reason, we also report DRH values for perchlorate mixed with analog minerals. These studies will help determine the likelihood of liquid water on present-day Mars and constrain the latitudes, seasons, and times of day in which it could exist.

  2. Containerized Wetland Bioreactor Evaluated for Perchlorate and Nitrate Degradation

    SciTech Connect

    Dibley, V R; Krauter, P W

    2004-12-02

    The U.S. Department of Energy (DOE) and Lawrence Livermore Laboratory (LLNL) designed and constructed an innovative containerized wetlands (bioreactor) system that began operation in November 2000 to biologically degrade perchlorate and nitrate under relatively low-flow conditions at a remote location at Site 300 known as Building 854. Since initial start-up, the system has processed over 3,463,000 liters of ground water and treated over 38 grams of perchlorate and 148 kilograms of nitrate. Site 300 is operated by the University of California as a high-explosives and materials testing facility supporting nuclear weapons research. The 11-square mile site located in northern California was added to the NPL in 1990 primarily due to the presence of elevated concentrations of volatile organic compounds (VOCs) in ground water. At the urging of the regulatory agencies, perchlorate was looked for and detected in the ground water in 1999. VOCs, nitrate and perchlorate were released into the soil and ground water in the Building 854 area as the result of accidental leaks during stability testing of weapons or from waste discharge practices that are no longer permitted at Site 300. Design of the wetland bioreactors was based on earlier studies showing that indigenous chlorate-respiring bacteria could effectively degrade perchlorate into nontoxic concentrations of chlorate, chlorite, oxygen, and chloride. Studies also showed that the addition of organic carbon would enhance microbial denitrification. Early onsite testing showed acetic acid to be a more effective carbon source than dried leaf matter, dried algae, or milk replacement starter; a nutrient and carbon source used in a Department of Defense phytoremediation demonstration. No inocula were added to the system. Groundwater was allowed to circulate through the bioreactor for three weeks to acclimate the wetland plants and to build a biofilm from indigenous flora. Using solar energy, ground water is pumped into granular

  3. Modeling aqueous perchlorate chemistries with applications to Mars

    NASA Astrophysics Data System (ADS)

    Marion, G. M.; Catling, D. C.; Zahnle, K. J.; Claire, M. W.

    2010-06-01

    NASA's Phoenix lander identified perchlorate and carbonate salts on Mars. Perchlorates are rare on Earth, and carbonates have largely been ignored on Mars following the discovery by NASA's Mars Exploration Rovers of acidic precipitated minerals such as jarosite. In light of the Phoenix results, we updated the aqueous thermodynamic model FREZCHEM to include perchlorate chemistry. FREZCHEM models the Na-K-Mg-Ca-Fe(II)-Fe(III)-Al-H-Cl-Br-SO 4-NO 3-OH-HCO 3-CO 3-CO 2-O 2-CH 4-Si-H 2O system, with 95 solid phases. We added six perchlorate salts: NaClO 4·H 2O, NaClO 4·2H 2O, KClO 4, Mg(ClO 4) 2·6H 2O, Mg(ClO 4) 2·8H 2O, and Ca(ClO 4) 2·6H 2O. Modeled eutectic temperatures for Na, Mg, and Ca perchlorates ranged from 199 K (-74 °C) to 239 K (-34 °C) in agreement with experimental data. We applied FREZCHEM to the average solution chemistry measured by the Wet Chemistry Laboratory (WCL) experiment at the Phoenix site when soil was added to water. FREZCHEM was used to estimate SO42- and alkalinity concentrations that were missing from the WCL data. The amount of SO42- is low compared to estimates from elemental abundance made by other studies on Mars. In the charge-balanced solution, the dominant cations were Mg 2+ and Na + and the dominant anions were ClO4-,SO42-, and alkalinity. The abundance of calcite measured at the Phoenix site has been used to infer that the soil may have been subject to liquid water in the past, albeit not necessarily locally; so we used FREZCHEM to evaporate (at 280.65 K) and freeze (from 280.65 to 213.15 K) the WCL-measured solution to provide insight into salts that may have been in the soil. Salts that precipitated under both evaporation and freezing were calcite, hydromagnesite, gypsum, KClO 4, and Mg(ClO 4) 2·8H 2O. Epsomite (MgSO 4·7H 2O) and NaClO 4·H 2O were favored by evaporation at temperatures >0 °C, while meridianite (MgSO 4·11H 2O), MgCl 2·12H 2O, and NaClO 4·2H 2O were favored at subzero temperatures. Incongruent melting

  4. High-nitrogen-based pyrotechnics: development of perchlorate-free green-light illuminants for military and civilian applications.

    PubMed

    Sabatini, Jesse J; Raab, James M; Hann, Ronald K; Damavarapu, Reddy; Klapötke, Thomas M

    2012-06-01

    The development of perchlorate-free hand-held signal illuminants for the US Army's M195 green star parachute is described. Compared with the perchlorate-containing control, the optimized perchlorate-free illuminants were less sensitive toward various ignition stimuli while offering comparable burn times and visible-light outputs. The results were also important from the perspective of civilian fireworks because the development of perchlorate-free illuminants remains an important objective of the commercial fireworks industry.

  5. Chlorine Isotopic Composition of Perchlorate in Human Urine as a Means of Distinguishing Among Natural and Synthetic Exposure Sources

    PubMed Central

    Poghosyan, Armen; Morel-Espinosa, Maria; Valentín-Blasini, Liza; Blount, Benjamin C.; Ferreccio, Catterina; Steinmaus, Craig M.; Sturchio, Neil C.

    2015-01-01

    Perchlorate (ClO4−) is a ubiquitous environmental contaminant with high human exposure potential; it has both natural and man-made sources in the environment. Natural perchlorate forms in the atmosphere from where it deposits onto the surface of Earth, whereas synthetic perchlorate is manufactured as an oxidant for industrial, aerospace, and military applications. Perchlorate exposure can potentially cause adverse health effects in humans by interfering with the production of thyroid hormones through competitively blocking iodide uptake. To control and reduce perchlorate exposure, the contributions of different sources of perchlorate exposure need to be quantified. Thus, we demonstrate a novel approach for determining the contribution of different perchlorate exposure sources by quantifying stable and radioactive chlorine isotopes of perchlorate extracted from composite urine samples from two distinct populations: one in Atlanta, USA and one in Taltal, Chile (Atacama region). Urinary perchlorate from the Atlanta region resembles indigenous natural perchlorate from the southwestern USA [δ37Cl = +4.1 ± 1.0 ‰; 36Cl/Cl = 1811 (± 136) × 10−15], and urinary perchlorate from the Taltal, Chile region is similar to natural perchlorate in nitrate salt deposits from the Atacama Desert of northern Chile [δ37Cl = −11.0 ± 1.0 ‰; 36Cl/Cl = 254 (± 40) × 10−15]. Neither urinary perchlorate resembled the isotopic pattern found in synthetic perchlorate. These results indicate that natural perchlorate of regional provenance is the dominant exposure source for the two sample populations, and that chlorine isotope ratios provide a robust tool for elucidating perchlorate exposure pathways. PMID:25805252

  6. Copper Metallochaperones

    PubMed Central

    Robinson, Nigel J.; Winge, Dennis R.

    2014-01-01

    The current state of knowledge on how copper metallochaperones support the maturation of cuproproteins is reviewed. Copper is needed within mitochondria to supply the CuA and intramembrane CuB sites of cytochrome oxidase, within the trans-Golgi network to supply secreted cuproproteins and within the cytosol to supply superoxide dismutase 1 (Sod1). Subpopulations of copper-zinc superoxide dismutase also localize to mitochondria, the secretory system, the nucleus and, in plants, the chloroplast, which also requires copper for plastocyanin. Prokaryotic cuproproteins are found in the cell membrane and in the periplasm of gram-negative bacteria. Cu(I) and Cu(II) form tight complexes with organic molecules and drive redox chemistry, which unrestrained would be destructive. Copper metallochaperones assist copper in reaching vital destinations without inflicting damage or becoming trapped in adventitious binding sites. Copper ions are specifically released from copper metallochaperones upon contact with their cognate cuproproteins and metal transfer is thought to proceed by ligand substitution. PMID:20205585

  7. Perchlorate content of plant foliage reflects a wide range of species-dependent accumulation but not ozone-induced biosynthesis

    USDA-ARS?s Scientific Manuscript database

    Perchlorate interferes with uptake of iodide in humans. Emission inventories do not explain observed distributions. Ozone is implicated in the natural origin of perchlorate, and has increased since pre-industrial times. Ozone produces perchlorate in vitro from chloride, and plant tissues contain chl...

  8. FATE OF DIETARY PERCHLORATE IN LACTATING DAIRY COWS: RELEVANCE TO ANIMAL HEALTH AND LEVELS IN THE MILK SUPPLY.

    USDA-ARS?s Scientific Manuscript database

    Perchlorate is a goitrogenic anion that competitively inhibits the sodium iodide transporter and has been detected in forages and in commercial milk throughout the U.S. The fate of perchlorate and its effect on animal health were studied in lactating cows, ruminally infused with perchlorate for fiv...

  9. REMOTE SENSING OF PERCHLORATE EFFECTS ON SALT CEDAR PRELIMINARY RESULTS FROM THE LAS VEGAS WASH

    EPA Science Inventory



    Sodium Perchlorate and ammonium Perchlorate, major components of solid rocket fuel, have been manufactured in the Las Vegas Valley immediately up gradient from the Las Vegas Wash, since 1945 and 1956, respectively. Measurements of emerging ground water quality in the vici...

  10. MICROSCALE EXTRACTION OF PERCHLORATE IN DRINKING WATER WITH LOW LEVEL DETECTION BY ELECTROSPRAY-MASS SPECTROMETRY.

    EPA Science Inventory

    Improper treatment and disposal of perchlorate can be an environmental hazard in regions where solid rocket motors are used, tested, or stored. The solubility and mobility of perchlorate lends itself to ground water contamination, and some of these sources are used for drinking ...

  11. Uptake, elimination, and relative distribution of perchlorate in various tissues of channel catfish

    USGS Publications Warehouse

    Park, J.-W.; Bradford, C.M.; Rinchard, J.; Liu, F.; Wages, M.; Waters, A.; Kendall, R.J.; Anderson, T.A.; Theodorakis, C.W.

    2007-01-01

    This study was undertaken to determine the kinetics of uptake and elimination of perchlorate in channel catfish, Ictalurus punctatus. Perchlorate - an oxidizer used in solid fuel rockets, fireworks, and illuminating munitions - has been shown to effect thyroid function, causing hormone disruption and potential perturbations of metabolic activities. For the uptake study, catfish were exposed to 100 mg/L sodium perchlorate for 12 h to 5 d in the laboratory. Perchlorate in tissues was analyzed using ion chromatography. The highest perchlorate concentrations were found in the head and fillet, indicating that these tissues are the most important tissues to analyze when determining perchlorate uptake into large fish. To calculate uptake and elimination rate constants for fillet, gills, G-I tract, liver, and head, fish were exposed to 100 ppm sodium perchlorate for 5 days, and allowed to depurate in clean water for up to 20 days. The animals rapidly eliminated the perchlorate accumulated showing the highest elimination in fillet (Ke = 1.67 day -1) and lowest elimination in liver (Ke = 0.79 day -1). ?? 2007 American Chemical Society.

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

    PubMed

    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

    EPA Science Inventory

    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. Treatment of Perchlorate-Contaminated Groundwater Using Highly Selective, Regenerable Ion-Exchange Technologies

    SciTech Connect

    Gu, Baohua; Brown, Gilbert M

    2007-01-01

    Treatment of perchlorate-contaminated water using highly selective, regenerable ion-exchange and perchlorate-destruction technologies was demonstrated at a field site in California. Four treatment and four regeneration cycles were carried out, and no significant deterioration of resin performance was noted in two years. The bifunctional resin (Purolite A-530E) treated about 37,000 empty bed volumes (BVs) of groundwater before a significant breakthrough of perchlorate occurred at an average flow rate of 150 gpm (or 1 BV/min) and a feed perchlorate concentration of about 860 g/L. Sorbed perchlorate (~20 kg) was quantitatively recovered by eluting with as little as 1 BV of the FeCl3-HCl regenerant solution. The eluted ClO4- was highly concentrated in the third quarter of the first BV of the regenerant solution with a concentration up to 100,000 mg/L. This concentrated effluent greatly facilitated subsequent perchlorate destruction or recovery by precipitation as KClO4 salts. High perchlorate destruction efficiency (92 V97%) was observed by reduction with FeCl2 in a thermo-reactor, which enabled recycling of the FeCl3-HCl regenerant solution, thereby minimizing the need to dispose of secondary wastes containing ClO4-. This study demonstrates that a combination of novel selective, regenerable ion-exchange and perchlorate-destruction and/or recovery technologies could potentially lead to enhanced treatment efficiency and minimized secondary waste production.

  15. Perchlorate trophic transfer increases tissue concentrations above ambient water exposure alone in a predatory fish.

    PubMed

    Furin, Christoff G; von Hippel, Frank A; Hagedorn, Birgit; O'Hara, Todd M

    2013-01-01

    This study examined effects of varying concentrations of the environmental contaminant perchlorate in northern pike (Esox lucius) based on exposure in water and/or from prey (threespine stickleback, Gasterosteus aculeatus). Routes of exposure to pike were through contaminated water at 0, 10, or 100 mg/L perchlorate for 49 d and/or through feeding, 1 per day over 14 d, sticklebacks that were previously maintained in water at 0, 10, or 100 mg/L perchlorate. Both water and food significantly contributed to pike tissue concentrations of perchlorate as compared to controls, but, as expected for a water-soluble contaminant, perchlorate did not biomagnify from prey to predatory fish. Pike gastrointestinal tissue retained significantly more perchlorate than other tissues combined. Route of exposure and concentration of perchlorate in various media are important to consider in risk assessment when evaluating uptake and tissue concentration of perchlorate because significantly higher tissue concentrations may result from combined prey and water exposures than from prey or water exposures alone in a concentration-dependent manner.

  16. Occurrence and exposure evaluation of perchlorate in indoor dust and diverse food from Chengdu, China.

    PubMed

    Gan, Zhiwei; Pi, Lu; Li, Yiwen; Hu, Wenli; Su, Shijun; Qin, Xiaolei; Ding, Sanglan; Sun, Hongwen

    2015-12-01

    A total of 688 samples, including 520 food samples belonging to 29 food types in 10 groups, 63 drinking water, and 105 indoor dust samples were collected during May to November in 2014 in Chengdu and Tianjin (only dust samples in Tianjin), China to investigate the perchlorate levels in these samples and to estimate the related exposure to Chinese people. Significant difference in indoor dust perchlorate levels was found between Chengdu and Tianjin, with the concentrations ranging from 0.11 to 38.8 mg/kg in Chengdu, and from 0.72 to 119 mg/kg in Tianjin. The mean perchlorate levels in 10 groups of food samples were in the order of vegetables>wheaten flour≈egg, and wheaten flour>milk>sea food>livestock meats≈poultry≈freshwater fish>fruits>steamed rice, while no statistical difference in perchlorate levels was found between egg and milk. Exposure evaluation indicated that indoor dust contributed little (less than 5%) to the total daily perchlorate intake, and food consumption was the primary perchlorate exposure route for Chengdu people, followed by drinking water. Based on the median perchlorate levels obtained in this study, the daily perchlorate intake was below the reference does suggested by the US EPA. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. Study of microbial perchlorate reduction: considering of multiple pH, electron acceptors and donors.

    PubMed

    Xu, Xing; Gao, Baoyu; Jin, Bo; Zhen, Hu; Wang, Xiaoyi; Dai, Ming

    2015-03-21

    Bioremediation of perchlorate-cotaminated water by a heterotrophic perchlorate reducing bacterium creates a multiple electron acceptor-donor system. We experimentally determined the perchlorate reduction by Azospira sp. KJ at multiple pH, electron acceptors and donors systems; this was the aim of this study. Perchlorate reduction was drastically inhibited at the pH 6.0, and the maximum reduction of perchlorate by Azospira sp. KJ was observed at pH value of 8.0. Perchlorate reduction was retarded in ClO4(-)-ClO3(-), ClO4(-)-ClO3(-)-NO3(-),and ClO4(-)-NO3(-) acceptor systems, while being completely inhibited by the additional O2 in the ClO4(-)-O2 acceptor system. The reduction proceeded as an order of ClO3(-), ClO4(-), and NO3(-) in the ClO4(-)-ClO3(-)-NO3(-) system. K(S), v(max), and q(max) obtained at different e(-) acceptor and donor conditions are calculated as 140.5-190.6 mg/L, 8.7-13.2 mg-perchlorate/L-h, and 0.094-0.16 mg-perchlorate/mg-DW-h, respectively. Copyright © 2014 Elsevier B.V. All rights reserved.

  18. PERCHLORATE TROPHIC TRANSFER INCREASES TISSUE CONCENTRATIONS ABOVE AMBIENT WATER EXPOSURE ALONE IN A PREDATORY FISH

    PubMed Central

    Furin, Christoff G.; von Hippel, Frank A.; Hagedorn, Birgit; O’Hara, Todd M.

    2013-01-01

    This study examined effects of varying concentrations of the environmental contaminant perchlorate in northern pike (Esox lucius) based on exposure in water and/or from prey (threespine stickleback, Gasterosteus aculeatus). Routes of exposure to pike were through contaminated water at 0, 10 or 100 mg/L perchlorate for 49 days and/or through feeding one stickleback per day over 14 days that were previously maintained in water at 0, 10 or 100 mg/L perchlorate. Both water and food significantly contributed to pike tissue concentrations of perchlorate as compared to controls, but, as expected for a water-soluble contaminant, perchlorate did not biomagnify from prey to predatory fish. Pike gastrointestinal tissue retained significantly more perchlorate than other tissues combined. Route of exposure and concentration of perchlorate in various media are important to consider in risk assessment when evaluating uptake and tissue concentration of perchlorate because significantly higher tissue concentrations may result from combined prey and water exposures than from prey or water exposures alone in a concentration dependent manner. PMID:24188192

  19. Thyroid Hormones and Thyroid Disease in Relation to Perchlorate Dose and Residence Near a Superfund Site

    PubMed Central

    Gold, Ellen B.; Blount, Benjamin C.; Rasor, Marianne O’Neill; Lee, Jennifer S.; Alwis, Udeni; Srivastav, Anup; Kim, Kyoungmi

    2013-01-01

    Background Perchlorate is a widely occurring contaminant, which can competitively inhibit iodide uptake and thus thyroid hormone production. The health effects of chronic low dose perchlorate exposure are largely unknown. Objectives In a community-based study, we compared thyroid function and disease in women with differing likelihoods of prior and current perchlorate exposure. Methods Residential blocks were randomly selected from areas: 1) with potential perchlorate exposure via drinking water; 2) with potential exposure to environmental contaminants; and 3) neighboring but without such exposures. Eligibility included having lived in the area for ≥6 months and aged 20–50 years during 1988–1996 (during documented drinking water well contamination). We interviewed 814 women and collected blood samples (assayed for thyroid stimulating hormone [TSH] and free thyroxine [fT4]) from 431 interviewed women. Daily urine samples were assayed for perchlorate and iodide for 178 premenopausal women with blood samples. We performed multivariable regression analyses comparing thyroid function and disease by residential area and by urinary perchlorate dose adjusted for urinary iodide levels. Results Residential location and current perchlorate dose were not associated with thyroid function or disease. Conclusions No persistent effect of perchlorate on thyroid function or disease was found several years after contaminated wells were capped. PMID:22968349

  20. Perchlorate and chlorate reduction by the Crenarchaeon Aeropyrum pernix and two thermophilic Firmicutes.

    PubMed

    Liebensteiner, Martin G; Pinkse, Martijn W H; Nijsse, Bart; Verhaert, Peter D E M; Tsesmetzis, Nicolas; Stams, Alfons J M; Lomans, Bart P

    2015-12-01

    This study reports the ability of one hyperthermophilic and two thermophilic microorganisms to grow anaerobically by the reduction of chlorate and perchlorate. Physiological, genomic and proteome analyses suggest that the Crenarchaeon Aeropyrum pernix reduces perchlorate with a periplasmic enzyme related to nitrate reductases, but that it lacks a functional chlorite-disproportionating enzyme (Cld) to complete the pathway. Aeropyrum pernix, previously described as a strictly aerobic microorganism, seems to rely on the chemical reactivity of reduced sulfur compounds with chlorite, a mechanism previously reported for perchlorate-reducing Archaeoglobus fulgidus. The chemical oxidation of thiosulfate (in excessive amounts present in the medium) and the reduction of chlorite result in the release of sulfate and chloride, which are the products of a biotic-abiotic perchlorate reduction pathway in Ae. pernix. The apparent absence of Cld in two other perchlorate-reducing microorganisms, Carboxydothermus hydrogenoformans and Moorella glycerini strain NMP, and their dependence on sulfide for perchlorate reduction is consistent with the observations made on Ar. fulgidus. Our findings suggest that microbial perchlorate reduction at high temperature differs notably from the physiology of perchlorate- and chlorate-reducing mesophiles and that it is characterized by the lack of a chlorite dismutase and is enabled by a combination of biotic and abiotic reactions. © 2015 Society for Applied Microbiology and John Wiley & Sons Ltd.

  1. Microscale extraction of perchlorate in drinking water with low level detection by electrospray-mass spectrometry.

    PubMed

    Magnuson, M L; Urbansky, E T; Kelty, C A

    2000-06-21

    Improper treatment and disposal of perchlorate can be an environmental hazard in regions where solid rocket motors are used, tested, or stored. The solubility and mobility of perchlorate lends itself to ground water contamination, and some of these sources are used for drinking water. Perchlorate in drinking water has been determined at sub-mug l(-1) levels by extraction of the ion-pair formed between the perchlorate ion and a cationic surfactant with electrospray-mass spectrometry detection. Confidence in the selective quantification of the perchlorate ion is increased through both the use of the mass based detection as well as the selectivity of the ion pair. This study investigates several extraction solvents and experimental work-up procedures in order to achieve high sample throughput. The method detection limit for perchlorate based on 3.14sigma(n-1) of seven replicate injections was 300 ng l(-1) (parts-per-trillion) for methylene chloride extraction and 270 ng l(-1) for methyl isobutyl ketone extraction. Extraction with methylene chloride produces linear calibration curves, enabling standard addition to be used to quantify perchlorate in drinking water. Perchlorate determination of a contaminated water compared favorably with results determined by ion chromatography.

  2. Thyroid hormones and thyroid disease in relation to perchlorate dose and residence near a superfund site.

    PubMed

    Gold, Ellen B; Blount, Benjamin C; O'Neill Rasor, Marianne; Lee, Jennifer S; Alwis, Udeni; Srivastav, Anup; Kim, Kyoungmi

    2013-07-01

    Perchlorate is a widely occurring contaminant, which can competitively inhibit iodide uptake and thus thyroid hormone production. The health effects of chronic low dose perchlorate exposure are largely unknown. In a community-based study, we compared thyroid function and disease in women with differing likelihoods of prior and current perchlorate exposure. Residential blocks were randomly selected from areas: (1) with potential perchlorate exposure via drinking water; (2) with potential exposure to environmental contaminants; and (3) neighboring but without such exposures. Eligibility included having lived in the area for ≥6 months and aged 20-50 years during 1988-1996 (during documented drinking water well contamination). We interviewed 814 women and collected blood samples (assayed for thyroid stimulating hormone and free thyroxine) from 431 interviewed women. Daily urine samples were assayed for perchlorate and iodide for 178 premenopausal women with blood samples. We performed multivariable regression analyses comparing thyroid function and disease by residential area and by urinary perchlorate dose adjusted for urinary iodide levels. Residential location and current perchlorate dose were not associated with thyroid function or disease. No persistent effect of perchlorate on thyroid function or disease was found several years after contaminated wells were capped.

  3. 77 FR 52633 - Notice of a Public Meeting: Stakeholder Meeting Concerning EPA's Intent To Regulate Perchlorate...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-30

    ... To Regulate Perchlorate Levels in Drinking Water AGENCY: Environmental Protection Agency (EPA... Drinking Water Regulation for Perchlorate. DATES: The public meeting and webcast will be held on September... Crystal Drive, Arlington, VA 22202. A government issued photo ID is required to obtain access to...

  4. Surveillance of perchlorate in ground water, surface water and bottled water in Kerala, India.

    PubMed

    Nadaraja, Anupama Vijaya; Puthiyaveettil, Prajeesh Gangadharan; Bhaskaran, Krishnakumar

    2015-01-01

    Perchlorate is an emerging water contaminant that disrupts normal functioning of human thyroid gland and poses serious threat to health, especially for pregnant women, fetus and children. High level of perchlorate contamination in fresh water sources at places nearby ammonium perchlorate (rocket fuel) handled in bulk is reported in this study. Of 160 ground water samples analyzed from 27 locations in the State Kerala, 58 % had perchlorate above detection limit (2 μg/L) and the highest concentration observed was 7270 μg/L at Ernakulam district, this value is ~480 times higher than USEPA drinking water equivalent level (15 μg/L). Perchlorate was detected in all surface water samples analyzed (n = 10) and the highest value observed was 355 μg/L in Periyar river (a major river in the State). The bottled drinking water (n = 5) tested were free of perchlorate. The present study underlines the need for frequent screening of water sources for perchlorate contamination around places the chemical is handled in bulk. It will help to avoid human exposure to high levels of perchlorate.

  5. Aerobic reduction of perchlorate by bacteria isolated in Kerala, South India.

    PubMed

    Shete, Anita; Mukhopadhyaya, Pratap N; Acharya, Arpan; Aich, Bikash A; Joshi, Suresh; Ghole, Vikram S

    2008-01-01

    Possibility of perchlorate reduction by microbes raises hope for an eco-friendly mode of degradation of this toxic rocket fuel. This study reports 3 isolates (A1, A2 and A3) capable of molybdenum-independent degradation of perchlorate under aerobic conditions. The rate of degradation was the highest when perchlorate concentration was 17 mM, and then 3.2 mM, 4.7 mM and 4.1 mM of perchlorate was reduced by isolates A1, A2 and A3 (respectively) after 72 h at 28 degrees C under aerobic conditions. Presence of perchlorate at a concentration higher than 17 mM resulted in some inhibition of perchlorate reduction. 16S ribosomal RNA gene analysis revealed isolate A1 to be Pseudomonas stutzeri (Proteobacteria) while isolates A2 ad A3 where found to belong to the genus Arthrobacter (Actinobacteria). The study, apart from demonstrating ribotyping as a rapid method of identification of economically important soil microbes, also raised prospects for using artificial consortia for environmental degradation of perchlorate, without apparent domination of Dechloromonas spp. (a group of microbes known for perchlorate remediation in the environment).

  6. DEVELOPMENT OF A BETTER METHOD TO IDENTIFY AND MEASURE PERCHLORATE IN DRINKING WATER

    EPA Science Inventory

    Perchlorate (ClO4 -) is an oxidant used primarily in solid propellant for rockets, missiles, pyrotechnics, as a component in air bag inflators, and in highway safety flares. Perchlorate tainted water has been found throughout the southwestern United States where its source has o...

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

    DTIC Science & Technology

    2013-05-01

    investigator PMS phenazine methosulfate PMSH reduced phenazine methosulfate ppb parts per billion PR plate reader QA quality assurance QC... phenazine methosulfate (PMS) as an electron shuttle. Hence the amount of perchlorate in an aqueous sample can be determined enzymatically by monitoring the...201019, which is based on perchlorate reductase (PCR) activity coupled to reduced nicotinamide adenine dinucleotide (NADH) oxidation, with phenazine

  8. Hybrid Adsorption-Membrane Biological Reactors for Improved Performance and Reliability of Perchlorate Removal Processes

    DTIC Science & Technology

    2008-12-01

    carbon supply for the autotrophic perchlorate reducing bacteria. The membrane used in the reactor is a hollow-fiber microfiltration membrane made from...1 HYBRID ADSORPTION- MEMBRANE BIOLOGICAL REACTORS FOR IMPROVED PERFORMANCE AND RELIABILITY OF PERCHLORATE REMOVAL PROCESSES L.C. Schideman...Center Champaign, IL 61826, USA ABSTRACT This study introduces the novel HAMBgR process (Hybrid Adsorption Membrane Biological Reactor) and

  9. REMOTE SENSING OF PERCHLORATE EFFECTS ON SALT CEDAR PRELIMINARY RESULTS FROM THE LAS VEGAS WASH

    EPA Science Inventory



    Sodium Perchlorate and ammonium Perchlorate, major components of solid rocket fuel, have been manufactured in the Las Vegas Valley immediately up gradient from the Las Vegas Wash, since 1945 and 1956, respectively. Measurements of emerging ground water quality in the vici...

  10. RAMAN SPECTRAL ANALYSIS OF PERCHLORATE CONTAMINATION IN COMMONLY-USED FERTILIZERS

    EPA Science Inventory

    Raman spectroscopy (RS) was used for qualitative and quantitative analysis of perchlorate (ClO4-1) in 30+ commonly-used fertilizers. Perchlorate contamination is emerging as an important environmental issue since its discovery in water resources that are widely used for drinking...

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

    EPA Science Inventory

    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. RAMAN SPECTRAL ANALYSIS OF PERCHLORATE CONTAMINATION IN COMMONLY-USED FERTILIZERS

    EPA Science Inventory

    Raman spectroscopy (RS) was used for qualitative and quantitative analysis of perchlorate (ClO4-1) in 30+ commonly-used fertilizers. Perchlorate contamination is emerging as an important environmental issue since its discovery in water resources that are widely used for drinking...

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

    EPA Science Inventory

    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. Optimization of Perchlorate Biodegradation: Performance and Cost Assessment for the Thiokol Prototype

    DTIC Science & Technology

    2000-03-01

    Biodegradation Prototype In the early 1990s, Thiokol Corporation, constructed an industrial wastewater treatment plant (IWTP) at its production facility near...for perchlorate biodegradation. Perchlorate has been successfully reduced using many alternate nutrients. These include cheese whey, marshmallow ...waste, fruit juice wastes, sugars, starches, and acetate. The marshmallow waste was evaluated because it is a very abundant and very inexpensive

  15. DEVELOPMENT OF A BETTER METHOD TO IDENTIFY AND MEASURE PERCHLORATE IN DRINKING WATER

    EPA Science Inventory

    Perchlorate (ClO4 -) is an oxidant used primarily in solid propellant for rockets, missiles, pyrotechnics, as a component in air bag inflators, and in highway safety flares. Perchlorate tainted water has been found throughout the southwestern United States where its source has o...

  16. PERFORMANCE OF POLYVINYL ALCOHOL GEL COLUMNS ON THE ION CHROMATOGRAPHIC DETERMINATION OF PERCHLORATE IN FERTILIZERS

    EPA Science Inventory

    Interest in possible sources of perchlorate (ClO4-) that could lead to environmental release has been heightened since the EPA placed this anion on its Contaminant Candidate List (CCL) for drinking water. Besides its association with defense and aerospace activities, perchlorate ...

  17. Monitoring of perchlorate in diverse foods and its estimated dietary exposure for Korea populations.

    PubMed

    Lee, Ji-Woo; Oh, Sung-Hee; Oh, Jeong-Eun

    2012-12-01

    The perchlorate concentrations in various Korean food samples were monitored, and 663 samples belonging to 39 kinds of food were analyzed. The analysis results revealed that dairy products contain the highest average concentration of 6.34 μg/kg and high detection frequency of over 85%. Fruit and vegetables showed the next highest perchlorate concentration with an average of 6.17 μg/kg. Especially, with its average concentration of 39.9 μg/kg, spinach showed the highest perchlorate level among all target food samples studied. Tomato was followed by spinach, which showed a high perchlorate average concentration of 19.8 μg/kg, and over 7 μg/kg was detected in ham and sausage (avg. 7.31 μg/kg) and in instant noodles (avg. 7.58 μg/kg). Less than 2 μg/kg was detected in fishes, meats and beverages. The exposure dose of perchlorate in Korean by food intake was calculated on the basis of the analyzed perchlorate levels in this study. The daily perchlorate dose to which Korean adults are exposed is 0.04 μg/kg bw/day, which is lower than the RfD (0.7 μg/kg bw/day) value suggested by US NAS. This result indicates that Korean people's current exposure to perchlorate from domestic food consumption is evaluated as safe. Copyright © 2012 Elsevier B.V. All rights reserved.

  18. Supercooling and Ice Formation of Perchlorate Brines under Mars-relevant Conditions

    NASA Astrophysics Data System (ADS)

    Primm, K.; Gough, R. V.; Tolbert, M. A.

    2015-12-01

    Perchlorate salts, discovered in the Martian regolith at multiple landing sites, may provide pathways for liquid water stability on current Mars. It has previously been assumed that if perchlorate brines form in the Martian regolith via melting or deliquescence, they would be present only briefly because efflorescence into a crystal or freezing to ice would soon occur. Here, we used a Raman microscope to study the temperature and relative humidity (RH) conditions at which magnesium perchlorate brine will form ice. Although ice is thermodynamically predicted to form whenever the saturation with respect to ice (Sice) is greater than or equal to 1, ice formation by perchlorate brines did not occur until elevated Sice values were reached: Sice= 1.17, 1.29, and 1.25 at temperatures of 218 K, 230.5 K, and 244 K, respectively. If a magnesium perchlorate particle was allowed to deliquesce completely prior to experiencing ice supersaturation, the extent of supercooling was increased even further. These high supersaturation values imply perchlorate brines can exist over a wider range of conditions than previously believed. From these experiments it has been found that magnesium perchlorate exhibits supercooling well into the previous theoretical ice region of the stability diagram and that liquid brines on Mars could potentially exist for up to two additional hours per sol. This supercooling of magnesium perchlorate will help with the exploration of Mars by the Mars 2020 spacecraft by helping to understand the phase and duration of water existing in the Martian subsurface.

  19. MICROSCALE EXTRACTION OF PERCHLORATE IN DRINKING WATER WITH LOW LEVEL DETECTION BY ELECTROSPRAY-MASS SPECTROMETRY.

    EPA Science Inventory

    Improper treatment and disposal of perchlorate can be an environmental hazard in regions where solid rocket motors are used, tested, or stored. The solubility and mobility of perchlorate lends itself to ground water contamination, and some of these sources are used for drinking ...

  20. PERFORMANCE OF POLYVINYL ALCOHOL GEL COLUMNS ON THE ION CHROMATOGRAPHIC DETERMINATION OF PERCHLORATE IN FERTILIZERS

    EPA Science Inventory

    Interest in possible sources of perchlorate (ClO4-) that could lead to environmental release has been heightened since the EPA placed this anion on its Contaminant Candidate List (CCL) for drinking water. Besides its association with defense and aerospace activities, perchlorate ...

  1. Occurrence of perchlorate in groundwater, paired farmland soil, lettuce, and rhizosphere soil from Chengdu, China.

    PubMed

    Tang, Yulu; Zhong, Bifeng; Qu, Bing; Feng, Shujin; Ding, Sanglan; Su, Shijun; Li, Zhi; Gan, Zhiwei

    2017-05-24

    A total of 28 groundwater, paired farmland soil, lettuce, and its rhizosphere soil samples were collected from Chengdu, China to detect perchlorate levels and to evaluate the relationships of perchlorate concentrations among these matrices. The perchlorate concentrations in the groundwater, farmland soil, lettuce, and rhizosphere soil samples ranged from below detection limit to 60.2 μg L(-1), from below detection limit to 249 μg kg(-1) dry weight (dw), from 2.07 to 1010 μg kg(-1) wet weight, and from below detection limit to 314 μg kg(-1) dw, respectively. Significant correlation was found in the perchlorate levels among the farmland soil, lettuce, and rhizosphere soil, suggesting that they have common pollution sources, or perchlorate might transfer from farmland soil-rhizosphere soil-plant. However, there is no significant correlation between groundwater and the other three matrices, indicating that infiltration from perchlorate contaminated farmland soil was not the predominant source for groundwater pollution in Chengdu. The perchlorate concentrations in the farmland soil and lettuce samples were significantly higher than those in the rhizosphere soil, primarily due to uptake of perchlorate through the rhizosphere micro-environment by lettuce, or accelerated degradation by rhizospheric microorganisms, which contributed more needs further investigation.

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

    EPA Science Inventory

    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...

  3. Transposon and deletion mutagenesis of genes involved in perchlorate reduction in Azospira suillum PS.

    PubMed

    Melnyk, Ryan A; Clark, Iain C; Liao, Annette; Coates, John D

    2013-12-31

    Although much work on the biochemistry of the key enzymes of bacterial perchlorate reduction, chlorite dismutase, and perchlorate reductase has been published, understanding of the molecular mechanisms of this metabolism has been somewhat hampered by the lack of a clear model system amenable to genetic manipulation. Using transposon mutagenesis and clean deletions, genes important for perchlorate reduction in Azospira suillum PS have been identified both inside and outside the previously described perchlorate reduction genomic island (PRI). Transposon mutagenesis identified 18 insertions in 11 genes that completely abrogate growth via reduction of perchlorate but have no phenotype during denitrification. Of the mutants deficient in perchlorate reduction, 14 had insertions that were mapped to eight different genes within the PRI, highlighting its importance in this metabolism. To further explore the role of these genes, we also developed systems for constructing unmarked deletions and for complementing these deletions. Using these tools, every core gene in the PRI was systematically deleted; 8 of the 17 genes conserved in the PRI are essential for perchlorate respiration, including 3 genes that comprise a unique histidine kinase system. Interestingly, the other 9 genes in the PRI are not essential for perchlorate reduction and may thus have unknown functions during this metabolism. We present a model detailing our current understanding of perchlorate reduction that incorporates new concepts about this metabolism. Although perchlorate is generated naturally in the environment, groundwater contamination is largely a result of industrial activity. Bacteria capable of respiring perchlorate and remediating contaminated water have been isolated, but relatively little is known about the biochemistry and genetics of this process. Here we used two complementary approaches to identify genes involved in perchlorate reduction. Most of these genes are located on a genomic island

  4. Quantification of genes and gene transcripts for microbial perchlorate reduction in fixed-bed bioreactors.

    PubMed

    De Long, S K; Li, X; Bae, S; Brown, J C; Raskin, L; Kinney, K A; Kirisits, M J

    2012-03-01

    Optimization of full-scale, biological perchlorate treatment processes for drinking water would benefit from knowledge of the location and quantity of perchlorate-reducing bacteria (PRB) and expression of perchlorate-related genes in bioreactors. The aim of this study was to quantify perchlorate removal and perchlorate-related genes (pcrA and cld) and their transcripts in bioreactors and to determine whether these genes or transcripts could serve as useful biomarkers for perchlorate treatment processes. Quantitative PCR (qPCR) assays targeting pcrA and cld were applied to two pilot-scale, fixed-bed bioreactors treating perchlorate-contaminated groundwater. pcrA and cld genes per microgram of DNA were two- to threefold higher and three- to fourfold higher, respectively, in the bioreactor showing superior perchlorate-removal performance. In a laboratory-scale bioreactor, quantities of pcrA and cld genes and transcripts were compared under two distinct performance conditions (c.60 and 20% perchlorate removal) for a 5-min empty bed contact time. cld genes per microgram of DNA were approximately threefold higher and cld transcripts per microgram of RNA were approximately sixfold higher under the higher perchlorate-removal condition. No differences in pcrA genes or transcripts per microgram of DNA or RNA, respectively, were detected between the c.60 and 20% perchlorate-removal conditions, possibly because these assays did not accurately quantify pcrA genes and transcripts in the mixed culture present. Quantities of cld genes and transcripts per microgram of DNA and RNA, respectively, were found to be higher when perchlorate removal was higher. However, quantities of pcrA and cld genes or transcripts were not found to directly correlate with perchlorate-removal rates. To our knowledge, this study represents the first application of qPCR assays to quantify perchlorate-related genes and transcripts in continuous-flow bioreactors. The results indicate that cld gene and

  5. Effects of intense alpha irradiation on the behavior of americium in perchlorate solutions

    SciTech Connect

    Kornilov, A.S.; Frolov, A.A.; Vasil'ev, V.Ya.

    1987-05-01

    Studies have been made on the radiation chemistry of americium(VI) and americium(V) in solutions of perchloric acid and sodium perchlorate. The reduction rate is related to the dose rate and perchlorate concentration. The radiolysis products in perchlorate solutions are vigorous reducing agents for americium(VI). There is a correlation between the yield in the reduction of americium(VI) and the yield of radiolysis products. Prolonged storage of saturated weakly acid solutions of sodium perchlorate containing americium(III) and curium(III) causes the deposition of the actinoid hydroxides as well as sodium chlorate and chloride. The americium in the precipitate is partially oxidized to the pentavalent state.

  6. Removal of perchlorate in water by calcined MgAl-CO3 layered double hydroxides.

    PubMed

    Yang, Yiqiong; Gao, Naiyun; Deng, Yang; Yu, Guoping

    2013-04-01

    Perchlorate is widely known as an inorganic endocrine disruptor. In this study, MgAl-CO3 layered double hydroxides with different Mg/Al molar ratios were prepared using a coprecipitation method and followed by a calcination process at a temperature range of 300 to 700 degrees C. Results showed that the best synthesis conditions were a calcination temperature of 550 degrees C and Mg/Al molar ratio of 3. Further, the adsorbent and its adsorption product were characterized by x-ray diffraction, Fourier transform-infrared spectroscopy, and thermogravimetric-differential thermal analysis. The layered double hydroxides structures in the adsorbent were lost during calcination at 550 degrees C but were reconstructed subsequent to adsorption of perchlorate, indicating that the "memory effect" appeared to play an important role in perchlorate adsorption. The perchlorate adsorption pattern was best described by the pseudo-second-order kinetics model, while the Freundlich isotherms appropriately explained perchlorate adsorption data.

  7. Detection of perchlorate using Ag/DMAH(+) SERS-active capture matrices.

    PubMed

    Mosier-Boss, P A; Putnam, M D

    2014-12-10

    In this communication, the fabrication of SERS-active capture matrices for the detection of perchlorate is described. The amine groups of amine-modified magnetic microparticles were used to immobilize silver colloidal particles. Once immobilized, the silver was reacted with dimethylaminoethanethiol hydrochloride (DMAH(+)Cl(-)) to form a self-assembled monolayer (SAM). The DMAH(+) SAM exhibits reasonably good selectivity for perchlorate. It was shown that calibration curves could be generated by ratioing the perchlorate peak with a DMAH(+) peak that did not change upon interaction with the perchlorate ion. Flow experiments, using Ag/DMAH(+) capture matrices held in place by a magnet, showed instantaneous response to changes in perchlorate concentration. The use of solid phase extraction (SPE) to eliminate chloride ion interference was explored. Published by Elsevier B.V.

  8. The impact of temperature on the performance of anaerobic biological treatment of perchlorate in drinking water.

    PubMed

    Dugan, Nicholas R; Williams, Daniel J; Meyer, Maria; Schneider, Ross R; Speth, Thomas F; Metz, Deborah H

    2009-04-01

    A 20-month pilot-scale study was conducted to examine the impact of temperature on the performance of an anaerobic biological contractor used to treat perchlorate-contaminated water. The contractor was successfully acclimated with indigenous microorganisms. Influent temperatures varied from 1.4 to 30 degrees C. The objectives of the study were to investigate the effects of temperature on perchlorate removal, nitrate removal, nitrite formation, dissolved oxygen consumption, sulfide production, and nutrient acetate consumption. The results confirmed that consistent biological perchlorate removal to 2 microg /L is feasible at temperatures above 10 degrees C. Effluent concentrations of perchlorate, nitrate, and dissolved oxygen varied inversely with temperature, while sulfide varied positively with temperature. Under the conditions that prevailed during this study, 10 degrees C was a threshold temperature below which microbial activity, including perchlorate reduction, decreased dramatically.

  9. Widespread natural perchlorate in unsaturated zones of the southwest United States

    USGS Publications Warehouse

    Rao, B.; Anderson, T.A.; Orris, G.J.; Rainwater, K.A.; Rajagopalan, S.; Sandvig, R.M.; Scanlon, B.R.; Stonestrom, D.A.; Walvoord, M.A.; Jackson, W.A.

    2007-01-01

    A substantial reservoir (up to 1 kg ha-1) of natural perchlorate is present in diverse unsaturated zones of the arid and semi-arid southwestern United States. The perchlorate co-occurs with meteoric chloride that has accumulated in these soils throughout the Holocene [0 to 10-15 ka (thousand years ago)] and possibly longer periods. Previously, natural perchlorate widely believed to be limited to the Atacama Desert, now appears widespread in steppe-to-desert ecoregions. The perchlorate reservoir becomes sufficiently large to affect groundwater when recharge from irrigation or climate change flushes accumulated salts from the unsaturated zone. This new source may help explain increasing reports of perchlorate in dry region agricultural products and should be considered when evaluating overall source contributions. ?? 2007 American Chemical Society.

  10. A method for assaying perchlorate concentration in microbial cultures using the fluorescent dye resazurin.

    PubMed

    Kucharzyk, Katarzyna H; Crawford, Ronald L; Paszczynski, Andrzej J; Hess, Thomas F

    2010-04-01

    Low concentrations (microg/L) of the perchlorate anion, ClO(4)(-), have been measured in surface and ground water supplies in many locations throughout the United States. Perchlorate is known to affect the function of the thyroid gland in mammals and its toxicity primarily results from its inhibition of thyroid hormone output. The major sources of perchlorate contamination in surface and ground waters are defense contractors, military installations, propellant manufacturers and agriculture. The currently accepted method of perchlorate analysis, recommended by the US EPA, is neither fast nor easy to use and requires purchase of an expensive high performance ion chromatograph (IC). The novel method described here uses dye resazurin to measure perchlorate reduction by bacterial cultures and bacterial consortia in a high-throughput, multi-well, culture plate format. The method is based on the observation that perchlorate reduction and the decrease of resazurin fluorescence occur simultaneously in perchlorate degrading cultures. The bioassays were performed in anaerobic serum bottles or 96-well plates with constant shaking, using a minimal ATCC medium with 10 mM acetate as electron donor/carbon source and 200 ppm perchlorate as an electron acceptor. Fluorescence measurements with excitation at 570 nm and emission at 590 nm were taken in 20 min intervals. Changes in perchlorate concentration were confirmed using IC. Based on the experimental data, a simple model showing the correlation between perchlorate concentration in microbial culture and resazurin fluorescence level was proposed. Other dyes including redox indicators, reactive azo dyes and electron shuttle chemicals were also tested for comparison and were found less useful. Copyright 2010 Elsevier B.V. All rights reserved.

  11. Specific adsorption of perchlorate anions on Pt{hkl} single crystal electrodes.

    PubMed

    Attard, Gary A; Brew, Ashley; Hunter, Katherine; Sharman, Jonathan; Wright, Edward

    2014-07-21

    The voltammetry of Pt{111}, Pt{100}, Pt{110} and Pt{311} single crystal electrodes as a function of perchloric acid concentration (0.05-2.00 M) has been studied in order to test the assertion made in recent reports by Watanabe et al. that perchlorate anions specifically adsorb on polycrystalline platinum. Such an assertion would have significant ramifications for our understanding of electrocatalytic processes at platinum surfaces since perchlorate anions at low pH have classically been assumed not to specifically adsorb. For Pt{111}, it is found that OHad and electrochemical oxide states are both perturbed significantly as perchloric acid concentration is increased. We suggest that this is due to specific adsorption of perchlorate anions competing with OHad for adsorption sites. The hydrogen underpotential deposition (H UPD) region of Pt{111} however remains unchanged although evidence for perchlorate anion decomposition to chloride on Pt{111} is reported. In contrast, for Pt{100} no variation in the onset of electrochemical oxide formation is found nor any shift in the potential of the OHad state which normally results from the action of specifically adsorbing anions. This suggests that perchlorate anions are non-specifically adsorbed on this plane although strong changes in all H UPD states are observed as perchloric acid concentration is increased. This manifests itself as a redistribution of charge from the H UPD state situated at more positive potential to the one at more negative potential. For Pt{110} and Pt{311}, marginal changes in the onset of electrochemical oxide formation are recorded, associated with specific adsorption of perchlorate. Specific adsorption of perchlorate anions on Pt{111} is deleterious to electrocatalytic activity in relation to the oxygen reduction reaction (ORR) as measured using a rotating disc electrode (RDE) in a hanging meniscus configuration. This study supports previous work suggesting that a large component of the ORR

  12. Perchlorate levels found in tap water collected from several cities in Turkey.

    PubMed

    Erdemgil, Yiğit; Gözet, Tuba; Can, Özge; Ünsal, İbrahim; Özpınar, Aysel

    2016-03-01

    Perchlorate is an inorganic anion that inhibits iodide transport to the thyroid by sodium-iodide transporters. Because perchlorate is highly soluble, stable, and mobile in water, drinking water is a potential source of perchlorate exposure. When exposed to perchlorate, thyroid dysfunction can be observed in sensitive populations (pregnant woman, infants, and children), especially those with iodide deficiency. The aim of this study was to determine the perchlorate levels in tap water from five cities in Turkey. Perchlorate concentrations of 145 tap water samples collected from Ankara, Isparta, Istanbul, Kayseri, and Sakarya were determined by liquid chromatography-tandem mass spectrometry. Mean and median values were found to be 0.15 and 0.07 μg/L, respectively. The median values (25-75 % percentile) of Istanbul, Ankara, Sakarya, Isparta, and Kayseri were 0.08 μg/L (0.04-0.09 μg/L), 0.07 μg/L (0.07-0.21 μg/L), 0.04 μg/L (0.04-0.04 μg/L), 0.03 μg/L (0.02-0.07 μg/L), and 0.25 μg/L (0.23-0.31 μg/L), respectively. The median perchlorate level observed in Kayseri was significantly higher than those found at other cities (p < 0.05). Perchlorate concentrations in water samples were lower than the interim drinking water health advisory level (15 μg/L) determined by the US Environmental Protection Agency. This study showed that perchlorate in drinking water is not the main source of exposure in these cities. Future studies should be performed to determine perchlorate levels in other potential sources, such as food products.

  13. Removal of perchlorate in ground water with a flow-through bioreactor

    SciTech Connect

    Giblin, T.; Herman, D.; Deshusses, M.A.; Frankenberger, W.T. Jr.

    2000-04-01

    The bacterium, perclace, has been shown to reduce perchlorate to less than the detection limit of 0.004 mg L{sup {minus}1} when grown on acetate under anaerobic conditions. In batch studies, the presence of nitrate does not significantly hinder the reduction of perchlorate. The ability of perclace to remove nitrate and perchlorate from ground water in a flow-through system is described in this study. Celite-packed columns of 300 ml were used to demonstrate the removal of perchlorate from ground water. At a flow rate of 1 ml min{sup {minus}1}, perchlorate was removed from 0.738 mg L{sup {minus}1} to less than detectable levels and when the flow rate was 2 ml min{sup {minus}1} 92 to 95% of the perchlorate was removed. Analysis of bacterial biomass at the completion of the study revealed that most of the bacterial growth was concentrated in the inlet area of the column. A circulating pump was added, with the idea that passing the ground water multiple times through the bacterially active zone might increase the efficiency of the column. In this experiment, perchlorate in ground water was reduced from 0.550 mg L{sup {minus}1} to nondetectable levels at a flow rate of 1 ml min{sup {minus}1}. When the flow rate was increased to 2 ml min{sup {minus}1}, 98% of perchlorate was removed and when the flow rate was 3 ml min{sup {minus}1} 95% of perchlorate was removed. Rapid removal of perchlorate by perclace immobilized in a bioreactor may provide an efficient, cost-effective technology for ground water remediation.

  14. Occurrence of perchlorate in drinking water, groundwater, surface water and human saliva from India.

    PubMed

    Kannan, Kurunthachalam; Praamsma, Meredith L; Oldi, John F; Kunisue, Tatsuya; Sinha, Ravindra K

    2009-06-01

    Perchlorate (ClO(4)(-)), which is used as an oxidizer in jet and rocket fuels, pyrotechnic devices and explosives, is a widespread contaminant in surface waters and groundwater of many countries. Perchlorate is known to affect thyroid function. Despite the compound's widespread occurrence and potential health effects, perchlorate levels in drinking water in India are not known. In this study, water samples collected from 13 locations in six states (n=66), and saliva samples collected from four locations in three states (n=74) in India, were analyzed for perchlorate using high performance liquid chromatography interfaced with tandem mass spectrometry (HPLC-MS/MS). Perchlorate was detected in most (76%) of the water samples analyzed at concentrations above the quantitation limit of 0.02 microg L(-1); concentrations ranged from <0.02 to 6.9 microg L(-1) (mean: 0.42+/-1.1 microg L(-1); median: 0.07 microg L(-1)). Mean concentrations of perchlorate in drinking water, groundwater, bottled water, surface water and rain water were 0.1, 1.0, <0.02, 0.05 and <0.02 microg L(-1), respectively. From a total of 66 water samples analyzed, only three samples contained perchlorate levels above 1 microg L(-1); all three were groundwater samples. Perchlorate was found in the saliva samples analyzed at concentrations above 0.2 microg L(-1) and up to 4.7 microg L(-1) (mean: 1.3+/-1.3 microg L(-1); median: 0.91 microug L(-1)). No remarkable differences in perchlorate concentrations were found among the sampling locations of water or saliva or in subgroups stratified by gender or age. Perchlorate concentrations in water samples from India are one to two orders of magnitude lower than the concentrations reported for the United States.

  15. Characterization of Perchlorate in a New Frozen Human Urine Standard Reference Material

    PubMed Central

    Yu, Lee L.; Jarrett, Jeffery M.; Davis, W. Clay; Kilpatrick, Eric L.; Oflaz, Rabia; Turk, Gregory C.; Leber, Dennis D.; Valentin, Liza; Morel-Espinosa, Maria; Blount, Benjamin C.

    2015-01-01

    Perchlorate, an inorganic anion, has recently been recognized as an environmental contaminant by the U.S. Environmental Protection Agency (EPA). Urine is the preferred matrix for assessment of human exposure to perchlorate. Although the measurement technique for perchlorate in urine was developed in 2005, the calibration and quality assurance aspects of the metrology infrastructure for perchlorate are still lacking in that there is no certified reference material (CRM) traceable to the International System of Units (SI). To meet the quality assurance needs in biomonitoring measurements of perchlorate and the related anions that affect thyroid health, the National Institute of Standards and Technology (NIST) in collaboration with the Centers for Disease Control and Prevention (CDC) developed Standard Reference Material (SRM) 3668 Mercury, Perchlorate, and Iodide in Frozen Human Urine. SRM 3668 consists of perchlorate, nitrate, thiocyanate, iodine, and mercury in urine at two levels that represent the 50th and 95th percentiles, respectively, of the concentrations (with some adjustments) in the U.S. population. It is the first CRM being certified for perchlorate. Measurements leading to the certification of perchlorate were made collaboratively at NIST and CDC using three methods based on liquid or ion chromatography tandem mass spectrometry (LC-MS/MS or IC-MS/MS). Potential sources of bias were analyzed and results were compared for the three methods. Perchlorate in SRM 3668 Level I urine was certified to be 2.70 μg L−1 ± 0.21 μg L−1, and for SRM 3668 Level II urine, the certified value is 13.47 μg L−1 ± 0.96 μg L−1. PMID:22850897

  16. Detoxification of PAX-21 ammunitions wastewater by zero-valent iron for microbial reduction of perchlorate.

    PubMed

    Ahn, Se Chang; Cha, Daniel K; Kim, Byung J; Oh, Seok-Young

    2011-08-30

    US Army and the Department of Defense (DoD) facilities generate perchlorate (ClO(4)(-)) from munitions manufacturing and demilitarization processes. Ammonium perchlorate is one of the main constituents in Army's new main charge melt-pour energetic, PAX-21. In addition to ammonium perchlorate, hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) and 2,4-dinitroanisole (DNAN) are the major constituents of PAX-21. In order to evaluate microbial perchlorate reduction as a practical option for the treatment of perchlorate in PAX-21 wastewater, we conducted biodegradation experiments using glucose as the primary sources of electrons and carbon. Batch experiments showed that negligible perchlorate was removed in microbial reactors containing PAX-21 wastewater while control bottles containing seed bacteria and glucose rapidly and completely removed perchlorate. These results suggested that the constituents in PAX-21 wastewater may be toxic to perchlorate reducing bacteria. A series of batch toxicity test was conducted to identify the toxic constituents in PAX-21 and DNAN was identified as the primary toxicant responsible for inhibiting the activity of perchlorate reducing bacteria. It was hypothesized that pretreatment of PAX-21 by zero-valent iron granules will transform toxic constituents in PAX-21 wastewater to non-toxic products. We observed complete reduction of DNAN to 2,4-diaminoanisole (DAAN) and RDX to formaldehyde in abiotic iron reduction study. After a 3-day acclimation period, perchlorate in iron-treated PAX-21 wastewater was rapidly decreased to an undetectable level in 2 days. This result demonstrated that iron treatment not only removed energetic compounds but also eliminated the toxic constituents that inhibited the subsequent microbial process. Copyright © 2011 Elsevier B.V. All rights reserved.

  17. Discovery of Perchlorate at the Phoenix Landing Site

    NASA Astrophysics Data System (ADS)

    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.

  18. Perchlorate, thiocyanate, and nitrate in edible cole crops (Brassica sp.) produced in the lower Colorado River region.

    PubMed

    Sanchez, C A; Blount, B C; Valentin-Blasini, L; Krieger, R I

    2007-12-01

    The Colorado River is contaminated with low levels of perchlorate. Perchlorate has the potential to disrupt thyroid function by inhibiting the uptake of iodide. Brassica are rich sources of thiocyanate and nitrate, also inhibitors of iodide uptake. This study was conducted to estimate potential human exposure to perchlorate, thiocyanate, and nitrate from Brassica sp. irrigated with Colorado River water. Results indicate that Brassica sp. irrigated with Colorado River water do accumulate trace levels of perchlorate. However, the levels of perchlorate observed are low relative to the nitrate and thiocyanate naturally present in these species and low relative to the reference dose recommended by the NAS and the USEPA.

  19. Elimination of Perchlorate Oxidizers from Pyrotechnic Flare Compositions

    DTIC Science & Technology

    2007-03-09

    expensive than the in-service flare composition, the new perchlorate-free compositions were still reasonably priced in terms of their true "cradle to...are perfected, batch sizes are scaled up, and customer demand for the new products increases, the general trend is for the price per pound to decrease...Ratio Scale- up B/KClO4/(Baseline) 2.21 BL BL BL - B/ KNO3 ~BL >BL <<BL No B/ALNC/ KNO3 6.49 >BL >>BL <<BL No B/Al0.5Mg0.5/ KNO3 3.55 >>BL

  20. The dissolution of an anthracite coal with perchloric acid

    SciTech Connect

    Hood, G.E.; Hyatt, A.G.; McGowan, C.W.

    1996-10-01

    Lignite coal, bituminous coal and several oil shales have previously been dissolved using perchloric acid of varying boiling point and subsequent oxidizing ability. These organic deposits generally dissolved between 150 and 160{degrees}C. This indicated that the aliphatic ether oxygen bond was being broken during the dissolution process. This dissolution process was performed on an anthracite coal because of the coal`s low oxygen content. The anthracite coal dissolved between 180 and 190{degrees}C making it similar to high-vol bituminous coal from New Zealand. Earlier work has indicated that carbon-carbon double bonds are being attacked during the dissolution process at the higher temperatures.

  1. Reflectance spectra of hydrated sulfates, phosphates and perchlorates

    NASA Astrophysics Data System (ADS)

    Bishop, J. L.; Lane, M. D.; Dyar, M. D.

    2012-12-01

    Reflectance spectra of hydrated sulfates, phosphates, and perchlorates have multiple strong absorptions in the VNIR region. These bands are important for identification of hydrated salt minerals on Mars using CRISM and OMEGA data. Detecting specific minerals or mineral classes in this group provides constraints on the geochemical environments during their formation. Orbital detections of hydrated salt minerals by CRISM on Mars can support characterization of minerals on the surface by the MER and MSL rovers and the Phoenix lander. VNIR SPECTRAL CHARACTER OF HYDRATED SALTS Many spectral features are diagnostic of specific minerals, but others are common to all of these hydrated salts. Monohydrated sulfate spectra have strong bands near 2.1 and 2.4 μm, while polyhydrated sulfate spectra generally exhibit a band near 1.92-1.98 μm and a drop in reflectance near 2.4 μm. Phosphates appear to exhibit spectral properties similar to sulfates with features near 1.4-1.5 and 1.92-1.98 μm for hydrated samples. Several OH-bearing minerals exhibit features near 2.2 μm that could be confused with the band near 2.2 μm that is commonly attributed to Al/Si-OH bearing clays/silica on Mars. Perchlorate spectra have three dominant bands near 1.43-1.47, 1.93-2.0, and 2.41-2.44 μm depending on the type of cation present. Spectra are shown from 0.4-2.65 μm for selected sulfates (Figure 1) and phosphates/perchlorates (Figure 2) as this region is predominantly used by CRISM for identification of minerals. Figure 1. Spectra of selected hydrated sulfates: coquimbite, (Fe3+)2(SO4)3●9H2O, butlerite, Fe3+SO4(OH)●2H2O, rozenite, Fe2+SO4●4H2O, and szomolnokite, Fe2+SO4●H2O. Figure 2. Spectra of selected perchlorates and phosphates: wavellite, Al3(PO4)2(OH,F)3●5H2O, and baricite, (Mg,Fe2+)3(PO4)2●H2O.

  2. Long-Range Transport of Perchlorate Observed in the Atmospheric Aerosols Collected at Okinawa Island, Japan

    NASA Astrophysics Data System (ADS)

    Handa, D.; Okada, K.; Kuroki, Y.; Nakama, Y.; Nakajima, H.; Arakaki, T.; Tanahara, A.; Oomori, T.; Miyagi, T.; Kadena, H.; Ishizaki, T.; Nakama, F.

    2007-12-01

    The study of perchlorate has become quite active in the U.S. in the last several years. Perchlorate has been recognized as a new environmental pollutant and it attracted much attention quickly in the world. The health concern about perchlorate stems from the fact that it displaces iodide in the thyroid gland, while iodine-containing thyroid hormones are essential for proper neural development from the fetal stage through the first years of life. In this study, we determined the concentrations of perchlorate ion present in the atmospheric aerosols collected in Okinawa Island, Japan. We then examined the relationships between the perchlorate concentrations and the environmental parameters and the climatic conditions peculiar to Okinawa. Bulk aerosol samples were collected on quartz filters by using a high volume air sampler at Cape Hedo Atmosphere and Aerosol Monitoring Station (CHAAMS). Each sampling duration was one week. The quartz filters with aerosols were stirred with Milli-Q pure water for three hours before perchlorate ion was extracted. The extracted perchlorate ion concentrations were determined by ion chromatography (ICS-2000, DIONEX). The mean perchlorate concentration for the samples collected at CHAAMS was 1.83 ng/m3, and the minimum was 0.18 ng/m3. The samples collected during November 21-27, 2005, January 23-30, 2006 and April 24-01, 2006 had highest perchlorate concentrations. For these three samples, we performed back trajectory analysis, and found that the air mass for the three samples arrived from the Asian continent. A relatively strong correlation (r2 = 0.55) was found between perchlorate and nss-sulfate concentrations for the CHAAMS samples. Furthermore, we analyzed perchlorate in the soils and the fertilizers used for sugar cane farming around the CHAAMS area. The Milli-Q extract of the soil and the fertilizers did not contain any detectable levels of perchlorate ions. Therefore, it was suggested that perchlorate found in the atmospheric

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

    PubMed

    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 (<250 μm) were the dominant composition in the settled 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 (<63 μm) was significantly higher than those in the coarser fractions. To our knowledge, this is the first report on perchlorate concentrations in different particle size fractions. The calculated perchlorate loadings revealed that perchlorate was mainly associated with finer particles (<125 μm). An exposure assessment indicated that exposure to perchlorate via settled road 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.

  4. The rapid adsorption-microbial reduction of perchlorate from aqueous solution by novel amine-crosslinked magnetic biopolymer resin.

    PubMed

    Song, Wen; Gao, Baoyu; Wang, Hailan; Xu, Xing; Xue, Moxi; Zha, Minchao; Gong, Bo

    2017-09-01

    The aim of this work was to study the adsorption characters of resin, microbial reduction of perchlorate and combined process of perchlorate removal in aqueous solution. Study demonstrated the adsorption equilibrium was achieved in 120min, which based on ion exchange reaction. Dissolved perchlorate (100mg/L) can be completely removed by acclimated anaerobic sludge in 15h, and the concentrated perchlorate (∼200mg/g) on the surface of resin would be effectively microbial reduced after 3days. Neutral environment (pH=7.4), higher biomass and additional electron donor can apparently improve the biological reduction efficiency of concentrated perchlorate. Addition of many co-anions showed the competition adsorption towards perchlorate, especially in the presence of NO3(-). This study provides an effective method for perchlorate reduction by the adsorption-microbial process. Copyright © 2017 Elsevier Ltd. All rights reserved.

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

    USGS Publications Warehouse

    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.

  6. Nitrate and (per)chlorate reduction pathways in (per)chlorate-reducing bacteria.

    PubMed

    Oosterkamp, Margreet J; Mehboob, Farrakh; Schraa, Gosse; Plugge, Caroline M; Stams, Alfons J M

    2011-01-01

    The reduction of (per)chlorate and nitrate in (per)chlorate-reducing bacteria shows similarities and differences. (Per)chlorate reductase and nitrate reductase both belong to the type II DMSO family of enzymes and have a common bis(molybdopterin guanine dinucleotide)molybdenum cofactor. There are two types of dissimilatory nitrate reductases. With respect to their localization, (per)chlorate reductase is more similar to the dissimilatory periplasmic nitrate reductase. However, the periplasmic, unlike the membrane-bound, respiratory nitrate reductase, is not able to use chlorate. Structurally, (per)chlorate reductase is more similar to respiratory nitrate reductase, since these reductases have analogous subunits encoded by analogous genes. Both periplasmic (per)chlorate reductase and membrane-bound nitrate reductase activities are induced under anoxic conditions in the presence of (per)chlorate and nitrate respectively. During microbial (per)chlorate reduction, molecular oxygen is generated. This is not the case for nitrate reduction, although an atypical reaction in nitrite reduction linked to oxygen formation has been described recently. Microbial oxygen production during reduction of oxyanions may enhance biodegradation of pollutants under anoxic conditions.

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

    NASA Astrophysics Data System (ADS)

    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.

  8. Determination of perchlorate in infant formula by isotope dilution ion chromatography/tandem mass spectrometry

    PubMed Central

    Wang, Z.; Lau, B.P.-Y.; Tague, B.; Sparling, M.; Forsyth, D.

    2011-01-01

    A sensitive and selective isotope dilution ion chromatography/tandem mass spectrometry (ID IC-MS/MS) method was developed and validated for the determination of perchlorate in infant formula. The perchlorate was extracted from infant formula by using 20 ml of methanol and 5 ml of 1% acetic acid. All samples were spiked with 18O4 isotope-labelled perchlorate internal standard prior to extraction. After purification on a graphitised carbon solid-phase extraction column, the extracts were injected into an ion chromatography system equipped with an Ionpac AS20 column for separation of perchlorate from other anions. The presence of perchlorate in samples was quantified by isotope dilution mass spectrometry. Analysis of both perchlorate and its isotope-labelled internal standard was carried out on a Waters Quattro Ultima triple quadrupole mass spectrometer operating in a multiple reaction monitoring (MRM) negative ionisation mode. The method was validated for linearity and range, accuracy, precision, sensitivity, and matrix effects. The limit of quantification (LOQ) was 0.4 μg 1−1 for liquid infant formula and 0.95 μg kg−1 for powdered infant formula. The recovery ranged from 94% to 110% with an average of 98%. This method was used to analyse 39 infant formula, and perchlorate concentrations ranging from

  9. Diversity of bacteria, archaea and protozoa in a perchlorate treating bioreactor.

    PubMed

    Anupama, V N; Prajeesh, P V G; Anju, S; Priya, P; Krishnakumar, B

    2015-08-01

    A microbial consortium reducing high level of perchlorate was developed and in a fed batch bioreactor using acetate as substrate perchlorate was reduced at 0.25 g/g vss. day. Under stable performance, the microbial community structure of the reactor was analyzed through molecular and phenotypic methods. The diversity of bacteria and archaea were analyzed through whole cell Fluorescence In-Situ Hybridization (FISH) and PCR-Denaturing Gradient Gel Electrophoresis (DGGE), whereas higher trophic community was analyzed phenotypically. FISH analysis revealed the presence of alpha, beta, gamma and delta proteobacteria in the sludge, dominated by beta proteobacteria (68.7%). DGGE analysis of bacteria revealed the presence of a single known perchlorate reducing bacterium-Dechloromonas, nitrate reducers like Thaeura and Azoarcus and a number of other genera so far not reported as perchlorate or nitrate reducing. The archaea community was represented by an acetoclastic methanogen, Methanosaeta harundinacea. We have also observed the presence of an acetate consuming flagellate, Polytomella sp. in significant number in the reactor. Archaea and protozoa community in perchlorate treating bioreactor is reported first time in this study and point out further the significance of non perchlorate reducing but acetate scavenging microbial groups in acetate fed perchlorate treating reactors. Copyright © 2015 Elsevier GmbH. All rights reserved.

  10. Potential mechanisms for bioregeneration of perchlorate-containing ion-exchange resin.

    PubMed

    Sharbatmaleki, Mohamadali; Unz, Richard F; Batista, Jacimaria R

    2015-05-15

    Ion-exchange (IX) is the most feasible technology for perchlorate removal from drinking water. Reuse of resins present challenges, however. Selective resins are non-regenerable, and are incinerated after one time use, while non-selective resins, when regenerable, produce a waste stream that contains high concentration of perchlorate that must be disposed of. A process to bioregenerate spent resin containing perchlorate with perchlorate-reducing bacteria (PRB) has been recently developed. In this research, potential mechanisms for bioregeneration of resin-attached perchlorate (RAP) were investigated. Batch bioregeneration experiments were performed using gel-type and macroporous-type resins. Various initial chloride concentrations and various resin bead sizes were used. The results of the bioregeneration experiments suggested that chloride, i.e. the product of perchlorate biodegradation, is more likely the desorbing agent of RAP; and increasing the concentration of chloride enhances the bioregeneration process. Both film and pore diffusion were found to be relevant with respect to the rate of perchlorate mass-transfer to the bulk liquid. Bioregeneration was found to be more effective for macroporous than for gel-type resins, especially in the case of macroporous resins with relatively small bead size in the presence of higher chloride concentration. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. [Surveillance of perchlorate level in wine, seafood, polished rice, milk, powdered milk and yogurt].

    PubMed

    Takatsuki, Satoshi; Watanabe, Takahiro; Matsuda, Rieko

    2011-01-01

    Perchlorate, which may be naturally occurring or artificial in origin, inhibits iodide uptake into the thyroid gland and disturbs thyroid function. In order to investigate perchlorate contamination in foods in Japan, perchlorate levels in 28 wine samples, 20 seafood samples, 10 polished rice samples, 30 milk (include whole milk, composition modified milk, low fat milk, processed milk, milk drink) samples, 10 powdered milk samples and 10 yogurt samples were measured. Perchlorate was found in all wine, milk, powdered milk and yogurt samples tested. Perchlorate levels ranged from 0.2 ng/g to 103 ng/g in wine samples, from 2 ng/g to 11 ng/g in milk samples, from 3 ng/g to 35 ng/g in powdered milk samples, and from 2 ng/g to 11 ng/g in yogurt samples. Perchlorate levels in the seafood samples were under the LOQ (0.8 ng/g) in 8 samples and ranged from 0.8 ng/g to 72 ng/g in 12 samples. In all polished rice samples, perchlorate level was under the LOQ (1.0 ng/g).

  12. Contribution of ammonium ions to the lethality and antimetamorphic effects of ammonium perchlorate.

    PubMed

    Goleman, Wanda L; Carr, James A

    2006-04-01

    Ammonium perchlorate (AP) is a widespread military waste product in the United States and is a potent thyroid function disruptor in all vertebrates tested thus far. To determine the relative contribution of ammonium ions to the toxicity of AP, we exposed embryonic and larval Xenopus laevis to various concentrations of sodium perchlorate (SP) or ammonium chloride (AC). Ammonium perchlorate was significantly more lethal than SP; 5-d LC50s were 83 and 2,780 mg/L, respectively. To determine whether ammonium ions contribute to the antithyroid effects of AP, we exposed embryonic and larval X. laevis to two sublethal, environmentally relevant concentrations of AP or identical concentrations of AC or SP. At the smaller concentration, only AP delayed metamorphosis and reduced hindlimb growth. Sodium perchlorate and AP, but not AC, prevented metamorphosis and reduced hindlimb growth at the greater concentration. Although AP was slightly more effective in reducing outward manifestations of thyroid disruption, both perchlorate salts, unlike AC, caused profound histopathologic changes in the thyroid. Exposure to the higher concentration of either perchlorate salt produced a feminizing effect, resulting in a skewed sex ratio. We conclude that ammonium ions contribute significantly to the toxicity of AP but not to the direct antithyroid effects of perchlorate.

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

    PubMed

    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. Measurement of chlorite dismutase activities in perchlorate respiring bacteria.

    PubMed

    Xu, Jianlin; Logan, Bruce E

    2003-08-01

    Chlorite dismutase (CD) catalyzes the disproportionation of chlorite to chloride (ClO(2)(-)-->Cl(-)+O(2)) and is present in bacteria capable of cell respiration using perchlorate or chlorate. The activity of this enzyme has previously been measured by monitoring oxygen evolution using a Clark-type dissolved oxygen (DO) probe. We demonstrate here, using two other methods to measure CD activity (a chloride-specific electrode and ion chromatography (IC)) via chloride production, that the DO probe method underestimates dismutation rates. Of the three methods, the chloride probe was the easiest to use and did not require extensive sample handling or post-experimental analysis. Using the chloride electrode method, we determined whole cell rate constants (V(max)=64 U/mg DW, K(m)=0.17 mM) for the chlorate-grown suspensions of Dechlorosoma sp. strain KJ. We compared the CD activities of strain KJ at a fixed chlorite concentration (0.6 mM) to four other perchlorate respiring bacteria (PRB), and to one non-PRB (Pseudomonas aeruginosa). Chlorate-grown cultures of the five PRB strains had CD activities ranging from 25 to 50 U/mg of cell dry weight (DW), while aerobically grown cultures of the PRB had much lower CD activities (0.5-4 U/mg DW). To our knowledge, this is the first systematic comparison of the different methods to measure CD activities, and the first comparison of CD activities of different PRBs.

  15. Bacterial reduction of highly concentrated perchlorate: Kinetics and influence of co-existing electron acceptors, temperature, pH and electron donors.

    PubMed

    Zhu, Yanping; Gao, Naiyun; Chu, Wenhai; Wang, Shuaifeng; Xu, Jianhong

    2016-04-01

    Perchlorate reduction kinetics and effects of various environmental conditions on removal of perchlorate from synthetic water were investigated to seek high-strength perchlorate removal using mixed perchlorate reducing bacteria. Results demonstrated that perchlorate (50-1500 mg L(-1)) could be degraded rapidly within 28 h under the optimal conditions. The maximum specific perchlorate reduction rate (qmax) and half saturation constant (Ks) were 0.92 mg-perchlorate (mg-dry weight)(-1) h(-1) and 157.7 mg L(-1), respectively. In the ClO4(-)-NO3(-) systems obvious but recoverable lags were caused in perchlorate reduction and the lag time increased with the ratio of nitrate to perchlorate concentration increasing from 0.5 to 3. While in the ClO4(-)-SO4(2-) systems inhibitions didn't occur until the ratio of sulfate to perchlorate concentration exceeded 10. The optimum temperature and pH value were 35 °C and 6.85, respectively. The optimal acetate-to-perchlorate ratio that could consume all perchlorate and acetate simultaneously was about 2. Dechloromonas, one of the most prominent perchlorate reducing bacteria, was identified as the dominant bacterium in the acclimated culture (69.33% of the whole clones). The study demonstrated that the perchlorate-acclimated mixed microorganisms can readily and efficiently realize reduction of highly concentrated perchlorate in wastewater. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Kinetics of nitrate and perchlorate removal and biofilm stratification in an ion exchange membrane bioreactor.

    PubMed

    Ricardo, Ana R; Carvalho, Gilda; Velizarov, Svetlozar; Crespo, João G; Reis, Maria A M

    2012-09-15

    The biological degradation of nitrate and perchlorate was investigated in an ion exchange membrane bioreactor (IEMB) using a mixed anoxic microbial culture and ethanol as the carbon source. In this process, a membrane-supported biofilm reduces nitrate and perchlorate delivered through an anion exchange membrane from a polluted water stream, containing 60 mg/L of NO₃⁻ and 100 μg/L of ClO₄⁻. Under ammonia limiting conditions, the perchlorate reduction rate decreased by 10%, whereas the nitrate reduction rate was unaffected. Though nitrate and perchlorate accumulated in the bioreactor, their concentrations in the treated water (2.8 ± 0.5 mg/L of NO₃⁻ and 7.0 ± 0.8 μg/L of ClO₄⁻, respectively) were always below the drinking water regulatory levels, due to Donnan dialysis control of the ionic transport in the system. Kinetic parameters determined for the mixed microbial culture in suspension showed that the nitrate reduction rate was 35 times higher than the maximum perchlorate reduction rate. It was found that perchlorate reduction was inhibited by nitrate, since after nitrate depletion perchlorate reduction rate increased by 77%. The biofilm developed in the IEMB was cryosectioned and the microbial population was analyzed by fluorescence in situ hybridization (FISH). The results obtained seem to indicate that the kinetic advantage of nitrate reduction favored accumulation of denitrifiers near the membrane, whereas per(chlorate) reducing bacteria were mainly positioned at the biofilm outer surface, contacting the biomedium. As a consequence of the biofilm stratification, the reduction of perchlorate and nitrate occur sequentially in space allowing for the removal of both ions in the IEMB. Copyright © 2012 Elsevier Ltd. All rights reserved.

  17. Effects of ammonium perchlorate on the reproductive performance and thyroid follicle histology of zebrafish

    USGS Publications Warehouse

    Patino, R.; Wainscott, M.R.; Cruz-Li, E. I.; Balakrishnan, S.; McMurry, C.; Blazer, V.S.; Anderson, T.A.

    2003-01-01

    Adult zebrafish were reared up to eight weeks in control water or in water containing ammonium perchlorate (AP) at measured perchlorate concentrations of 18 (environmentally relevant, high) and 677 ppm. Groups of eight females were paired with four males on a weekly basis to assess AP effects on spawned egg volume, an index of reproductive performance. All treatments were applied to four to five spawning replicates. At 677 ppm, spawn volume was reduced within one week and became negligible after four weeks. At 18 ppm, spawn volume was unaffected even after eight weeks. Also, perchlorate at 18 ppm did not affect percentage egg fertilization. Fish were collected at the end of the exposures (677 ppm, four weeks; control and 18 ppm, eight weeks) for whole-body perchlorate content and thyroid histopathological analysis. Fish perchlorate levels were about one-hundredth of those of treatment water levels, indicating that waterborne perchlorate does not accumulate in whole fish. At 677 ppm for four weeks, perchlorate caused thyroid follicle cell (nuclear) hypertrophy and angiogenesis, whereas at 18 ppm for eight weeks, its effects were more pronounced and included hypertrophy, angiogenesis, hyperplasia, and colloid depletion. In conclusion, an eight-week exposure of adult zebrafish to 18 ppm perchlorate (high environmentally relevant concentrations) affected the histological condition of their thyroid follicles but not their reproductive performance. The effect of 677 ppm perchlorate on reproduction may be due to extrathyroidal toxicity. Further research is needed to determine if AP at lower environmentally relevant concentrations also affects the thyroid follicles of zebrafish.

  18. Stability of low levels of perchlorate in drinking water and natural water samples

    USGS Publications Warehouse

    Stetson, S.J.; Wanty, R.B.; Helsel, D.R.; Kalkhoff, S.J.; Macalady, D.L.

    2006-01-01

    Perchlorate ion (ClO4-) is an environmental contaminant of growing concern due to its potential human health effects, impact on aquatic and land animals, and widespread occurrence throughout the United States. The determination of perchlorate cannot normally be carried out in the field. As such, water samples for perchlorate analysis are often shipped to a central laboratory, where they may be stored for a significant period before analysis. The stability of perchlorate ion in various types of commonly encountered water samples has not been generally examined-the effect of such storage is thus not known. In the present study, the long-term stability of perchlorate ion in deionized water, tap water, ground water, and surface water was examined. Sample sets containing approximately 1000, 100, 1.0, and 0.5 ??g l-1 perchlorate ion in deionized water and also in local tap water were formulated. These samples were analyzed by ion chromatography for perchlorate ion concentration against freshly prepared standards every 24 h for the first 7 days, biweekly for the next 4 weeks, and periodically after that for a total of 400 or 610 days for the two lowest concentrations and a total of 428 or 638 days for the high concentrations. Ground and surface water samples containing perchlorate were collected, held and analyzed for perchlorate concentration periodically over at least 360 days. All samples except for the surface water samples were found to be stable for the duration of the study, allowing for holding times of at least 300 days for ground water samples and at least 90 days for surface water samples. ?? 2006 Elsevier B.V. All rights reserved.

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

    PubMed Central

    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. PMID:27383240

  20. Genetic Factors That Might Lead to Different Responses in Individuals Exposed to Perchlorate

    PubMed Central

    Scinicariello, Franco; Murray, H. Edward; Smith, Lester; Wilbur, Sharon; Fowler, Bruce A.

    2005-01-01

    Perchlorate has been detected in groundwater in many parts of the United States, and recent detection in vegetable and dairy food products indicates that contamination by perchlorate is more widespread than previously thought. Perchlorate is a competitive inhibitor of the sodium iodide symporter, the thyroid cell–surface protein responsible for transporting iodide from the plasma into the thyroid. An estimated 4.3% of the U.S. population is subclinically hypothyroid, and 6.9% of pregnant women may have low iodine intake. Congenital hypothyroidism affects 1 in 3,000 to 1 in 4,000 infants, and 15% of these cases have been attributed to genetic defects. Our objective in this review is to identify genetic biomarkers that would help define subpopulations sensitive to environmental perchlorate exposure. We review the literature to identify genetic defects involved in the iodination process of the thyroid hormone synthesis, particularly defects in iodide transport from circulation into the thyroid cell, defects in iodide transport from the thyroid cell to the follicular lumen (Pendred syndrome), and defects of iodide organification. Furthermore, we summarize relevant studies of perchlorate in humans. Because of perchlorate inhibition of iodide uptake, it is biologically plausible that chronic ingestion of perchlorate through contaminated sources may cause some degree of iodine discharge in populations that are genetically susceptible to defects in the iodination process of the thyroid hormone synthesis, thus deteriorating their conditions. We conclude that future studies linking human disease and environmental perchlorate exposure should consider the genetic makeup of the participants, actual perchlorate exposure levels, and individual iodine intake/excretion levels. PMID:16263499

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

    PubMed

    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.

  2. Genetic factors that might lead to different responses in individuals exposed to perchlorate.

    PubMed

    Scinicariello, Franco; Murray, H Edward; Smith, Lester; Wilbur, Sharon; Fowler, Bruce A

    2005-11-01

    Perchlorate has been detected in groundwater in many parts of the United States, and recent detection in vegetable and dairy food products indicates that contamination by perchlorate is more widespread than previously thought. Perchlorate is a competitive inhibitor of the sodium iodide symporter, the thyroid cell-surface protein responsible for transporting iodide from the plasma into the thyroid. An estimated 4.3% of the U.S. population is subclinically hypothyroid, and 6.9% of pregnant women may have low iodine intake. Congenital hypothyroidism affects 1 in 3,000 to 1 in 4,000 infants, and 15% of these cases have been attributed to genetic defects. Our objective in this review is to identify genetic biomarkers that would help define subpopulations sensitive to environmental perchlorate exposure. We review the literature to identify genetic defects involved in the iodination process of the thyroid hormone synthesis, particularly defects in iodide transport from circulation into the thyroid cell, defects in iodide transport from the thyroid cell to the follicular lumen (Pendred syndrome), and defects of iodide organification. Furthermore, we summarize relevant studies of perchlorate in humans. Because of perchlorate inhibition of iodide uptake, it is biologically plausible that chronic ingestion of perchlorate through contaminated sources may cause some degree of iodine discharge in populations that are genetically susceptible to defects in the iodination process of the thyroid hormone synthesis, thus deteriorating their conditions. We conclude that future studies linking human disease and environmental perchlorate exposure should consider the genetic makeup of the participants, actual perchlorate exposure levels, and individual iodine intake/excretion levels.

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

    NASA Astrophysics Data System (ADS)

    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 (< 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.

  4. Reactions of atomic oxygen with the chlorate ion and the perchlorate ion

    NASA Astrophysics Data System (ADS)

    Anan'ev, Vladimir; Miklin, Mikhail; Kriger, Ludmila

    2014-06-01

    The reactions of the chlorate ion with atomic oxygen formed under photolysis of the nitrate ion introduced to potassium chlorate crystal by co-crystallization were studied by optical and infrared absorption spectroscopy. The perchlorate ion was found to form in solids as product of addition reaction of singlet atomic oxygen, formed under dissociation of the peroxynitrite ion - the product of isomerization of the excited nitrate ion. Triplet atomic oxygen does not react with the chlorate ion. The atomic oxygen formed under photolysis of the nitrate ion introduced to potassium perchlorate crystal by co-crystallization does not react with the perchlorate ion.

  5. Perchlorate on Mars: a chemical hazard and a resource for humans

    NASA Astrophysics Data System (ADS)

    Davila, Alfonso F.; Willson, David; Coates, John D.; McKay, Christopher P.

    2013-10-01

    Perchlorate (ClO4 -) is widespread in Martian soils at concentrations between 0.5 and 1%. At such concentrations, perchlorate could be an important source of oxygen, but it could also become a critical chemical hazard to astronauts. In this paper, we review the dual implications of ClO4 - on Mars, and propose a biochemical approach for removal of perchlorate from Martian soil that would be energetically cheap, environmentally friendly and could be used to obtain oxygen both for human consumption and to fuel surface operations.

  6. Effect of nitrate, acetate and hydrogen on native perchlorate-reducing microbial communities and their activity in vadose soil

    PubMed Central

    Nozawa-Inoue, Mamie; Jien, Mercy; Yang, Kun; Rolston, Dennis E.; Hristova, Krassimira R.; Scow, Kate M.

    2011-01-01

    Effect of nitrate, acetate and hydrogen on native perchlorate-reducing bacteria (PRB) was examined by conducting microcosm tests using vadose soil collected from a perchlorate-contaminated site. The rate of perchlorate reduction was enhanced by hydrogen amendment and inhibited by acetate amendment, compared to unamendment. Nitrate was reduced before perchlorate in all amendments. In hydrogen-amended and unamended soils, nitrate delayed perchlorate reduction, suggesting the PRB preferentially use nitrate as an electron acceptor. In contrast, nitrate eliminated the inhibitory effect of acetate amendment on perchlorate reduction and increased the rate and the extent, possibly because the preceding nitrate reduction/denitrification decreased the acetate concentration which was inhibitory to the native PRB. In hydrogen-amended and unamended soils, perchlorate reductase gene (pcrA) copies, representing PRB densities, increased with either perchlorate or nitrate reduction, suggesting either perchlorate or nitrate stimulates growth of the PRB. In contrast, in acetate-amended soil pcrA increased only when perchlorate was depleted: a large portion of the PRB may have not utilized nitrate in this amendment. Nitrate addition did not alter the distribution of the dominant pcrA clones in hydrogen-amended soil, likely because of the functional redundancy of PRB as nitrate-reducers/denitrifiers, whereas acetate selected different pcrA clones from those with hydrogen amendment. PMID:21284679

  7. Perchlorate disrupts embryonic androgen synthesis and reproductive development in threespine stickleback without changing whole-body levels of thyroid hormone

    PubMed Central

    Petersen, Ann M.; Dillon, Danielle; Bernhardt, Richard A.; Torunsky, Roberta; Postlethwait, John H.; von Hippel, Frank A.; Buck, C. Loren; Cresko, William A.

    2014-01-01

    Perchlorate, an environmental contaminant, disrupts normal functioning of the thyroid. We previously showed that perchlorate disrupts behavior and gonad development, and induces external morphological changes in a vertebrate model organism, the threespine stickleback. Whether perchlorate alters these phenotypes via a thyroid-mediated mechanism, and the extent to which the effects depend on dose, are unknown. To address these questions, we chronically exposed stickleback to control conditions and to three concentrations of perchlorate (10, 30 and 100 ppm) at various developmental stages from fertilization to reproductive maturity. Adults chronically exposed to perchlorate had increased numbers of thyroid follicles and decreased numbers of thyrocytes. Surprisingly, T4 and T3 levels in larval, juvenile, and adult whole fish chronically exposed to perchlorate did not differ from controls, except at the lowest perchlorate dose, suggesting a non-monotonic dose response curve. We found no detectable abnormalities in external phenotype at any dose of perchlorate, indicating that the increased number of thyroid follicles compensated for the disruptive effects of these doses. In contrast to external morphology, gonadal development was altered substantially, with the highest dose of perchlorate causing the largest effects. Perchlorate increased the number both of early stage ovarian follicles in females and of advanced spermatogenic stages in males. Perchlorate also disrupted embryonic androgen levels. We conclude that chronic perchlorate exposure may not result in lasting adult gross morphological changes but can produce lasting modifications to gonads when compensation of T3 and T4 levels occurs by thyroid follicle hyperplasia. Perchlorate may therefore affect vertebrate development via both thyroidal and non-thyroidal mechanisms. PMID:25448260

  8. Perchlorate disrupts embryonic androgen synthesis and reproductive development in threespine stickleback without changing whole-body levels of thyroid hormone.

    PubMed

    Petersen, Ann M; Dillon, Danielle; Bernhardt, Richard R; Torunsky, Roberta; Postlethwait, John H; von Hippel, Frank A; Loren Buck, C; Cresko, William A

    2015-01-01

    Perchlorate, an environmental contaminant, disrupts normal functioning of the thyroid. We previously showed that perchlorate disrupts behavior and gonad development, and induces external morphological changes in a vertebrate model organism, the threespine stickleback. Whether perchlorate alters these phenotypes via a thyroid-mediated mechanism, and the extent to which the effects depend on dose, are unknown. To address these questions, we chronically exposed stickleback to control conditions and to three concentrations of perchlorate (10, 30 and 100ppm) at various developmental stages from fertilization to reproductive maturity. Adults chronically exposed to perchlorate had increased numbers of thyroid follicles and decreased numbers of thyrocytes. Surprisingly, T4 and T3 levels in larval, juvenile, and adult whole fish chronically exposed to perchlorate did not differ from controls, except at the lowest perchlorate dose, suggesting a non-monotonic dose response curve. We found no detectable abnormalities in external phenotype at any dose of perchlorate, indicating that the increased number of thyroid follicles compensated for the disruptive effects of these doses. In contrast to external morphology, gonadal development was altered substantially, with the highest dose of perchlorate causing the largest effects. Perchlorate increased the number both of early stage ovarian follicles in females and of advanced spermatogenic stages in males. Perchlorate also disrupted embryonic androgen levels. We conclude that chronic perchlorate exposure may not result in lasting adult gross morphological changes but can produce lasting modifications to gonads when compensation of T3 and T4 levels occurs by thyroid follicle hyperplasia. Perchlorate may therefore affect vertebrate development via both thyroidal and non-thyroidal mechanisms. Copyright © 2014 Elsevier Inc. All rights reserved.

  9. Perchlorate Selectivity of Anion Exchange Resins as Evaluated Using Ion-Selective Electrodes.

    PubMed

    Yamamoto, Kenji; Mitsuda, Shin'ya; Ohtake, Naomi; Murashige, Natsuki; Ohmuro, Satoshi; Yuchi, Akio

    2017-01-01

    The selectivity coefficients reported for perchlorate of the high selectivity on anion exchange resins (AXRs) have not been consistent with one another. Possible errors by the unique use of four parameters (concentrations of two anions in two phases) were experimentally verified. The concentrations of perchlorate buffered at low levels (10(-6) - 10(-4) mol L(-1)) by two forms of AXRs were successfully determined by potentiometry with a perchlorate ion-selective electrode. This gave reasonable coefficients. The coefficients for perchlorate on several AXRs were independent of the relative exchange (RE), in contrast to the previous reports. On the other hand, the coefficients for fluoride of the low selectivity that were examined for comparison decreased with an increase in RE, and the dependency was more remarkable for the resins of large exchange capacity.

  10. Perchlorate: health effects and technologies for its removal from water resources.

    PubMed

    Srinivasan, Asha; Viraraghavan, Thiruvenkatachari

    2009-04-01

    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.

  11. Multi-Objective Optimization of an In situ Bioremediation Technology to Treat Perchlorate-Contaminated Groundwater

    EPA Science Inventory

    The presentation shows how a multi-objective optimization method is integrated into a transport simulator (MT3D) for estimating parameters and cost of in-situ bioremediation technology to treat perchlorate-contaminated groundwater.

  12. The Impact of Temperature on the Performance of Anaerobic Biological Treatment of Perchlorate in Drinking Water

    EPA Science Inventory

    A 20 month pilot-scale study was conducted to examine the impact of temperature on the performance of an anaerobic biological contactor used to treat perchlorate-contaminated water. The contactor was successfully acclimated with indigenous microorganisms. Influent temperatures ...

  13. Electrically Controlled Anion Exchange Based on Polypyrrole and Carbon Nanotubes Nanocomposite for Perchlorate Removal

    SciTech Connect

    Lin, Yuehe; Cui, Xiaoli; Bontha, Jagannadha R.

    2006-06-01

    A novel and stable carbon nanotube/polypyrrole nanocomposite film has been electrosynthesized and the feasibility for removing perchlorate ion through an electrically controlled anion exchange has been evaluated.

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

    EPA Science Inventory

    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...

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

    PubMed Central

    Srinivasan, Asha; Viraraghavan, Thiruvenkatachari

    2009-01-01

    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. PMID:19440526

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

    DTIC Science & Technology

    2014-04-01

    PD percent difference PI principal investigator PMS phenazine methosulfate PMSH reduced phenazine methosulfate PR plate reader QA...based on coupling perchlorate reduction to NADH oxidation using phenazine methosulfate (PMS) as an electron shuttle to transfer electrons from NADH

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

    EPA Science Inventory

    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...

  18. Multi-Objective Optimization of an In situ Bioremediation Technology to Treat Perchlorate-Contaminated Groundwater

    EPA Science Inventory

    The presentation shows how a multi-objective optimization method is integrated into a transport simulator (MT3D) for estimating parameters and cost of in-situ bioremediation technology to treat perchlorate-contaminated groundwater.

  19. Development of drinking water standards for perchlorate in the United States.

    PubMed

    Kucharzyk, Katarzyna H; Crawford, Ronald L; Cosens, Barbara; Hess, Thomas F

    2009-01-01

    Perchlorate, an anion that originates as a contaminant in ground and surface waters, is both naturally occurring and manmade. Because of its toxicity, there has been increased interest in setting drinking water safety standards and in health effects when perchlorate is present at low (parts per billion (ppb)) levels. In January 2009, the EPA issued a heath advisory to assist state and local officials in addressing local contamination of perchlorate in drinking water. The interim health advisory level of 15 micrograms per liter (microg/L), or ppb, is based on the reference dose recommended by the National Research Council (NRC) of the National Academy of Sciences (NAS). This paper describes scope and extent of contaminant issues and a legal process of setting standards for perchlorate concentration in drinking water in the United States of America.

  20. POLISHING THE EFFLUENT FROM AN ANAEROBIC BIOLOGICAL PERCHLORATE TREATMENT PROCESS - SLIDES

    EPA Science Inventory

    Anaerobic biological processes effectively reduce perchlorate to chloride. However, the effluent can be biologically unstable, high in particulates and high in disinfection by-product precursor compounds. Such an effluent would be unsuitable for transmission into a drinking water...

  1. POLISHING THE EFFLUENT FROM AN ANAEROBIC BIOLOGICAL PERCHLORATE TREATMENT PROCESS - SLIDES

    EPA Science Inventory

    Anaerobic biological processes effectively reduce perchlorate to chloride. However, the effluent can be biologically unstable, high in particulates and high in disinfection by-product precursor compounds. Such an effluent would be unsuitable for transmission into a drinking water...

  2. Influence of magnesium perchlorate on the pyrolysis of organic compounds in Mars analogue soils

    NASA Astrophysics Data System (ADS)

    Steininger, H.; Goesmann, F.; Goetz, W.

    2012-10-01

    The Mars Organic Molecule Analyzer (MOMA) onboard the ExoMars-2018 rover shall apply thermal volatilization (TV), gas chromatography (GC) and mass spectrometry (MS) in order to search for organic compounds in the Martian soil. Here we describe a series of TV-GC-MS experiments on powdered basalt containing known organic compounds (benzoic acid or mellitic acid) at different concentrations (500 and 0.5 ppm). With reference to the discovery of perchlorate in Martian soils by the Phoenix Wet Chemistry Laboratory (WCL) all pyrolysis experiments were performed both in presence of 0.6 wt% magnesium perchlorate and in absence of perchlorate. We find that benzoic acid (BA) is detectable at both concentrations, while mellitic acid (MA) is only detectable at high concentration (500 ppm). In both cases perchlorate strongly affects type and number of organic fragments generated during pyrolysis.

  3. Validation data for the determination of perchlorate in water using ion chromatography with suppressed conductivity detection.

    PubMed

    Seiler, Maike A; Jensen, Detlef; Neist, Udo; Deister, Ursula K; Schmitz, Franz

    2016-01-01

    Perchlorate salts are relatively stable, soluble in water, and migrate into groundwater sources. Groundwater is an essential source for drinking water suppliers. Perchlorate bears health risks as it is identified to impair normal thyroid function by interfering with iodine uptake by the thyroid gland. The development of a sensitive analytical method for the determination of perchlorate is therefore of the highest interest or public health. Ion chromatography is a sensitive method suitable for perchlorate determinations. This manuscript describes the validation of an ion chromatographic method. Perchlorate is determined by ion chromatography (IC) with conductivity detection after suppression (CD) applying isocratic elution. In this study, the suitability of IC-CD was tested for synthetic samples, selected environmental water, drinking water, and swimming pool water in order to evaluate potential matrix effects on the perchlorate signal even after sample preparation. A sample injection volume of 750 μL was applied to the selected 2-mm-IC column. In untreated samples, the perchlorate peak can be interfered by neighbouring signals from matrix ions like chloride, nitrate, carbonate, and sulphate. Depending on the concentration of the matrix ions, the perchlorate peak can show asymmetric shape in particular when the perchlorate concentration is low. Recovery is reduced with increasing matrix ion concentrations. Dedicated matrix elimination was applied to minimize such effects. A reporting limit of 1.5 μg/L perchlorate and an expanded measurement uncertainty of 13.2 % were achieved. The extended method validation proves the applicability of IC based on the EPA 314.0 method for the determination of trace amounts of perchlorate in water samples of different origin. The results support the development of a respective international standard pursued by ISO. The approach evidenced its working robustness and ease of use in terms of eluent preparation, chromatographic

  4. Thyroid Hormones and Moderate Exposure to Perchlorate during Pregnancy in Women in Southern California.

    PubMed

    Steinmaus, Craig; Pearl, Michelle; Kharrazi, Martin; Blount, Benjamin C; Miller, Mark D; Pearce, Elizabeth N; Valentin-Blasini, Liza; DeLorenze, Gerald; Hoofnagle, Andrew N; Liaw, Jane

    2016-06-01

    Findings from national surveys suggest that everyone in the United States is exposed to perchlorate. At high doses, perchlorate, thiocyanate, and nitrate inhibit iodide uptake into the thyroid and decrease thyroid hormone production. Small changes in thyroid hormones during pregnancy, including changes within normal reference ranges, have been linked to cognitive function declines in the offspring. We evaluated the potential effects of low environmental exposures to perchlorate on thyroid function. Serum thyroid hormones and anti-thyroid antibodies and urinary perchlorate, thiocyanate, nitrate, and iodide concentrations were measured in 1,880 pregnant women from San Diego County, California, during 2000-2003, a period when much of the area's water supply was contaminated from an industrial plant with perchlorate at levels near the 2007 California regulatory standard of 6 μg/L. Linear regression was used to evaluate associations between urinary perchlorate and serum thyroid hormone concentrations in models adjusted for urinary creatinine and thiocyanate, maternal age and education, ethnicity, and gestational age at serum collection. The median urinary perchlorate concentration was 6.5 μg/L, about two times higher than in the general U.S. Adjusted associations were identified between increasing log10 perchlorate and decreasing total thyroxine (T4) [regression coefficient (β) = -0.70; 95% CI: -1.06, -0.34], decreasing free thyroxine (fT4) (β = -0.053; 95% CI: -0.092, -0.013), and increasing log10 thyroid-stimulating hormone (β = 0.071; 95% CI: 0.008, 0.133). These results suggest that environmental perchlorate exposures may affect thyroid hormone production during pregnancy. This could have implications for public health given widespread perchlorate exposure and the importance of thyroid hormone in fetal neurodevelopment. Steinmaus C, Pearl M, Kharrazi M, Blount BC, Miller MD, Pearce EN, Valentin-Blasini L, DeLorenze G, Hoofnagle AN, Liaw J. 2016. Thyroid

  5. Thyroid Hormones and Moderate Exposure to Perchlorate during Pregnancy in Women in Southern California

    PubMed Central

    Steinmaus, Craig; Pearl, Michelle; Kharrazi, Martin; Blount, Benjamin C.; Miller, Mark D.; Pearce, Elizabeth N.; Valentin-Blasini, Liza; DeLorenze, Gerald; Hoofnagle, Andrew N.; Liaw, Jane

    2015-01-01

    Background: Findings from national surveys suggest that everyone in the United States is exposed to perchlorate. At high doses, perchlorate, thiocyanate, and nitrate inhibit iodide uptake into the thyroid and decrease thyroid hormone production. Small changes in thyroid hormones during pregnancy, including changes within normal reference ranges, have been linked to cognitive function declines in the offspring. Objectives: We evaluated the potential effects of low environmental exposures to perchlorate on thyroid function. Methods: Serum thyroid hormones and anti-thyroid antibodies and urinary perchlorate, thiocyanate, nitrate, and iodide concentrations were measured in 1,880 pregnant women from San Diego County, California, during 2000–2003, a period when much of the area’s water supply was contaminated from an industrial plant with perchlorate at levels near the 2007 California regulatory standard of 6 μg/L. Linear regression was used to evaluate associations between urinary perchlorate and serum thyroid hormone concentrations in models adjusted for urinary creatinine and thiocyanate, maternal age and education, ethnicity, and gestational age at serum collection. Results: The median urinary perchlorate concentration was 6.5 μg/L, about two times higher than in the general U.S. population. Adjusted associations were identified between increasing log10 perchlorate and decreasing total thyroxine (T4) [regression coefficient (β) = –0.70; 95% CI: –1.06, –0.34], decreasing free thyroxine (fT4) (β = –0.053; 95% CI: –0.092, –0.013), and increasing log10 thyroid-stimulating hormone (β = 0.071; 95% CI: 0.008, 0.133). Conclusions: These results suggest that environmental perchlorate exposures may affect thyroid hormone production during pregnancy. This could have implications for public health given widespread perchlorate exposure and the importance of thyroid hormone in fetal neurodevelopment. Citation: Steinmaus C, Pearl M, Kharrazi M, Blount BC

  6. Deliquescence of calcium perchlorate: A route to liquid water on Mars and other possibly habitable planets

    NASA Astrophysics Data System (ADS)

    Tolbert, M.; Nuding, D.; Gough, R. V.

    2013-05-01

    The Wet Chemistry Laboratory (WCL) aboard the Phoenix Mars Lander identified the presence of 0.5% perchlorate (ClO4-). Reanalysis of the Viking gas chromatography-mass spectrometry results also suggests perchlorate was present in the soil and the Mars Science Laboratory (MSL) rover has potentially found perchlorate as well. Perchlorate salts are known to readily absorb water vapor from the atmosphere and deliquesce into an aqueous solution. We have previously performed laboratory studies to better understand the deliquescence (crystalline solid to aqueous salt) and also efflorescence (aqueous salt to crystalline solid) of several perchlorate salts at low temperatures. We found that NaClO4 and Mg(ClO4)2 are highly deliquescent, forming aqueous solutions at humidity values as low as 40% RH and at temperatures as low as 223 K. We also observed a significant hysteresis that occurs during efflorescence of these salt solutions, expected due to the kinetic inhibition of crystal nucleation. The efflorescence relative humidity values of sodium and magnesium perchlorate solutions are 13% RH and 19% RH, respectively, indicating that perchlorate salts could exist as stable or metastable aqueous solutions over a wide range of Martian RH and temperature conditions. Although the low temperature deliquescence of several perchlorate salts is now well characterized, instruments onboard Phoenix and MSL have identified calcium perchlorate (Ca(ClO4)2) as the likely parent salt. Calcium perchlorate is known for its highly deliquescent properties and low eutectic point; however, the deliquescence and efflorescence of this salt have not yet been quantified as a function of temperature. We have used Raman microscopy to examine the deliquescence and efflorescence of Ca(ClO4)2 under relevant Martian temperatures. A extremely low DRH of ~1% for the anhydrous Ca(ClO4)2 at 273 K was observed, which could allow for formation of aqueous solutions under very low RH environmental conditions

  7. Copper cyanide

    Integrated Risk Information System (IRIS)

    Copper cyanide ; CASRN 544 - 92 - 3 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Ef

  8. (Ferrocenylmeth­yl)trimethyl­ammonium perchlorate

    PubMed Central

    Wang, Ying-Chun

    2012-01-01

    The asymmetric unit of the title complex, [Fe(C5H5)(C9H15N)]ClO4, contains one discrete (ferrocenylmeth­yl)trimethyl­ammonium cation and one perchlorate anion. The anion is disordered over two sets of sites, with refined occupancies of 0.776 (8) and 0.224 (8). The distances from the Fe atom to the centroids of the unsubstituted and substituted cyclo­penta­dienyl (Cp) rings are 1.650 (1) and 1.640 (1) Å, respectively. The Cp rings form a dihedral angle of 2.66 (3)°. PMID:22346865

  9. Effects of Perchlorate on Thyroidal Uptake of Iodide with Corresponding Hormonal Changes

    DTIC Science & Technology

    2000-07-01

    AFRL-HE-WP-TR-2000-0076 UNITED STATES AIR FORCE RESEARCH LABORATORY EFFECTS OF PERCHLORATE ON THYROIDAL UPTAKE OF IODIDE WITH CORRESPONDING HORMONAL ...on Thyroidal Uptake of Iodide with Corresponding Hormonal Contract F41624-96-C-9010 Changes PE 62202F PR 1710 6. AUTHOR(S) TA 1710D K.O. Yu, L...in reduced thyroidal hormone synthesis. The objective of this project was to conduct a series of experiments to investigate the role of perchlorate on

  10. The Relationship between Perchlorate in Drinking Water and Cord Blood Thyroid Hormones: First Experience from Iran.

    PubMed

    Javidi, Ashraf; Rafiei, Nasim; Amin, Mohammad Mehdi; Hovsepian, Silva; Hashemipour, Mahin; Kelishadi, Roya; Taghian, Zahra; Mofateh, Samaneh; Poursafa, Parinaz

    2015-01-01

    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. 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. 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 (<5 μg/l) and high level of drinking ground water perchlorate (P > 0.05). 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.

  11. Autotrophic perchlorate reduction kinetics of a microbial consortium using elemental sulfur as an electron donor.

    PubMed

    Gao, Mengchun; Wang, Sen; Jin, Chunji; She, Zonglian; Zhao, Congcong; Zhao, Yangguo; Zhang, Jian; Ren, Yun

    2015-07-01

    The perchlorate reduction kinetic parameters of a microbial consortium using elemental sulfur (S(0)) as an electron donor were investigated in batch experiments. Standard Monod substrate utilization and biomass accumulation models were employed to fit the experimental data for microbial perchlorate reduction. The maximum observed yield coefficient for the microbial consortium was 0.19 mg dry weight (DW) mg(-1) ClO4 (-), suggesting that the microbial consortium had a slow growth rate using S(0) as the electron donor. The maximum specific substrate utilization rate (q max) and half saturation constant (K s) for microbial perchlorate reduction were 0.14 mg ClO4 (-) mg(-1) DW day(-1) and 5.71 mg L(-1), respectively, which indicated that the microbial consortium could effectively utilize perchlorate as an electron acceptor. The variation of q max with pH was described well by using a Gaussian peak equation, and the maximal value of q max was obtained at pH 6.7. The presence of nitrate in perchlorate-contaminated water delayed the onset of sulfur autotrophic perchlorate reduction. The modified Gompertz equation could adequately describe the formation of Cl(-) and SO4(2-) during the process of sulfur autotrophic perchlorate reduction. The SO4(2-) production exceeded the theoretical SO4(2-) production due to S(0) disproportionation. The kinetic parameters for microbial perchlorate reduction are essential to design biological treatment systems, as well as to predict and evaluate their performance.

  12. 1-Benzyl-piperazine-1,4-diium bis-(perchlorate) monohydrate.

    PubMed

    Kaabi, Kamel; El Glaoui, Meher; Jeanneau, Erwann; Rzaigui, Mohamed; Ben Nasr, Cherif

    2010-06-23

    In the title compound, C(11)H(18)N(2) (2+)·2ClO(4) (-)·H(2)O, one perchlor-ate anion is disordered over two orientations in a 0.66 (3):0.34 (3) ratio. Inter-molecular O-H⋯O, N-H⋯O and C-H⋯O hydrogen bonds link the cations, anions and water mol-ecules into ribbons extending along [100].

  13. Effects of Ammonium Perchlorate on Thyroid Function in Developing Fathead Minnows, Pimephales promelas

    PubMed Central

    Crane, Helen M.; Pickford, Daniel B.; Hutchinson, Thomas H.; Brown, J. Anne

    2005-01-01

    Perchlorate is a known environmental contaminant, largely due to widespread military use as a propellant. Perchlorate acts pharmacologically as a competitive inhibitor of thyroidal iodide uptake in mammals, but the impacts of perchlorate contamination in aquatic ecosystems and, in particular, the effects on fish are unclear. Our studies aimed to investigate the effects of concentrations of ammonium perchlorate that can occur in the environment (1, 10, and 100 mg/L) on the development of fathead minnows, Pimephales promelas. For these studies, exposures started with embryos of < 24-hr postfertilization and were terminated after 28 days. Serial sectioning of thyroid follicles showed thyroid hyperplasia with increased follicular epithelial cell height and reduced colloid in all groups of fish that had been exposed to perchlorate for 28 days, compared with control fish. Whole-body thyroxine (T4) content (a measure of total circulating T4) in fish exposed to 100 mg/L perchlorate was elevated compared with the T4 content of control fish, but 3,5,3′-triiodothyronine (T3) content was not significantly affected in any exposure group. Despite the apparent regulation of T3, after 28 days of exposure to ammonium perchlorate, fish exposed to the two higher levels (10 and 100 mg/L) were developmentally retarded, with a lack of scales and poor pigmentation, and significantly lower wet weight and standard length than were control fish. Our study indicates that environmental levels of ammonium perchlorate affect thyroid function in fish and that in the early life stages these effects may be associated with developmental retardation. PMID:15811828

  14. The Relationship between Perchlorate in Drinking Water and Cord Blood Thyroid Hormones: First Experience from Iran

    PubMed Central

    Javidi, Ashraf; Rafiei, Nasim; Amin, Mohammad Mehdi; Hovsepian, Silva; Hashemipour, Mahin; Kelishadi, Roya; Taghian, Zahra; Mofateh, Samaneh; Poursafa, Parinaz

    2015-01-01

    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 (<5 μg/l) and high level of drinking ground water perchlorate (P > 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. PMID:25789149

  15. Perchlorate versus other environmental sodium/iodide symporter inhibitors: potential thyroid-related health effects.

    PubMed

    De Groef, Bert; Decallonne, Brigitte R; Van der Geyten, Serge; Darras, Veerle M; Bouillon, Roger

    2006-07-01

    Perchlorate is a known competitive inhibitor of the sodium/iodide symporter (NIS). Possible thyroid-related effects of environmental perchlorate have created great health concerns, especially in the US, resulting in a debated reference dose (RfD) of 0.0007 mg/kg per day in drinking water recommended by the National Academy of Sciences (NAS). However, the impact of other environmental NIS inhibitors and the role of iodine seem to have received little attention in the whole debate. We performed a PubMed search for articles published up to February 2006, using the key terms perchlorate, nitrate, thiocyanate, iodine, NIS, RfD, thyroid (alone or in combinations), with particular attention for human studies. In parallel, we critically analysed the January 2005 NAS' report, entitled 'Health implications of perchlorate ingestion'. The relative potencies of prevalent environmental NIS inhibitors (nitrate, thiocyanate and perchlorate) to inhibit iodine uptake have been estimated repeatedly with robust results. Our calculations show that nitrate and thiocyanate, acquired through drinking water or food, account for a much larger proportion of iodine uptake inhibition than perchlorate. Furthermore, the iodine uptake inhibitory effects of nitrate and thiocyanate - as defined by their legally accepted maximal contaminant levels in drinking water - exceed the potential effect of the proposed RfD for perchlorate by far. Iodine uptake inhibition and any potential downstream effect by perchlorate are highly dependent on the presence of other environmental NIS inhibitors and iodine intake itself. These potential confounders should therefore be considered in future studies and calculations for risk assessment.

  16. An Investigation into Palladium-Catalyzed Reduction of Perchlorate in Water

    DTIC Science & Technology

    2005-03-01

    depth beyond the plant root zone, phytoremediation would be not affect the transport of perchlorate. Also, once perchlorate is dispersed in a large...Agrawal provided essential guidance on experimental procedures and helped me to focus my research efforts. Without his assistance and expertise...which has been contaminated by discharges from manufacturing plants near Henderson, Nevada (Hogue, 2003). Lake Mead feeds into the lower Colorado

  17. Microbial Perchlorate Reduction in the Unsaturated Zone of an Israeli Mars Analog Site

    NASA Astrophysics Data System (ADS)

    Coleman, M. L.; Gal, H.; Ronen, Z.; Weisbrod, N.

    2010-12-01

    The identification of perchlorate on Mars by the Phoenix mission (Hecht et al. 2009 Science vol 325, 64) encouraged those who favored the Atacama Desert as an analog. However, in the Atacama, nitrate predominates wherever perchlorate is found and the extreme aridity is unlike the Phoenix landing site, where there is ice. In Israel, the site of a former ammonium perchlorate factory was investigated because of environmental concerns about perchlorate in both groundwater and the unsaturated zone but it is also a valuable Mars analog. The unsaturated zone comprises 40 m of sands with sandy clay and clay-rich layers in which bacteria with perchlorate reducing capability had been detected. Microbial perchlorate reduction occurs under anaerobic conditions, not those expected in the unsaturated zone, and the process needs water and an electron donor (e.g. trace organic matter). Chlorine stable isotope analyses quantitatively characterize both partially reduced perchlorate and the resultant chloride product. Our analyses show varying extents of perchlorate reduction in the unsaturated zone, up to 10%, but not correlated with depth, clay content, or water content. We assume that the reduction is occurring in microenvironments in a generally aerobic system but the precise source of the electron donor is still enigmatic; organic coatings on clays would be one possibility. This site, despite having been modified by human activity, is a valuable analog for possible microbial processes on Mars. The microbial activity has given another example of the persistence of life in an extreme environment where nutrients are extremely limited. Although not analogous in terms of Mars temperatures, this site offers the potential for new understanding of life processes (and new challenges for Mars exploration).

  18. Perchlorate in dust fall and indoor dust in Malta: An effect of fireworks.

    PubMed

    Vella, Alfred J; Chircop, Cynthia; Micallef, Tamara; Pace, Colette

    2015-07-15

    We report on the presence of perchlorate in the settleable dust of Malta, a small central Mediterranean island. Both dust fall collected directly as it precipitated from atmosphere over a period of one month and deposited indoor dust from domestic residences were studied. Perchlorate was determined by ion chromatography of water extracts of the collected dusts. Dust fall was collected from 43 towns during 2011 to 2013 and indoor dust was sampled from homes in the same localities. Perchlorate was detected in 108 of 153 samples of dust fall (71%) and in 28 of 37 indoor dust samples (76%). Detectable perchlorate in dust fall ranged from 0.52μgg(-1) to 561μgg(-1) with a median value of 6.2μgg(-1); in indoor dust, levels were from 0.79μgg(-1) to 53μgg(-1) with a median value of 7.8μgg(-1), the highest recorded anywhere to date. Statistical analysis suggested that there was no significant difference in perchlorate content of indoor dust and dust fall. Perchlorate levels in dust fall escalate during the summer in response to numerous religious feasts celebrated with fireworks and perchlorate persists at low μgg(-1) concentrations for several months beyond the summer festive period. In Malta, perchlorate derives exclusively from KClO4, imported for fireworks manufacture. Its residue in dust presents an exposure risk to the population, especially via ingestion by hand to mouth transfer. Our results suggest that wherever intensive burning of fireworks takes place, the environmental impact may be much longer lived than realised, mainly due to re-suspension and deposition of contaminated settled dust in the urban environment.

  19. Alternative Causes of Wide-Spread, Low Concentration Perchlorate Impacts to Groundwater

    DTIC Science & Technology

    2007-11-02

    heavy ANFO.” Their benefits include reduced mining costs, increased water resistance and increased density/strength (ISEE, 1998). MSDS sheets for...frequency of detection of perchlorate in groundwater and drinking water supplies has been steadily increasing since its initial identification as a chemical...of concern in 1997. It is currently estimated that perchlorate is present in groundwater in at least 30 states and affects the drinking water

  20. Oral (drinking water) developmental toxicity study of ammonium perchlorate in New Zealand White rabbits.

    PubMed

    York, R G; Brown, W R; Girard, M F; Dollarhide, J S

    2001-01-01

    This developmental toxicity study was conducted to evaluate the embryo-fetal toxicity and teratogenic potential of ammonium perchlorate in New Zealand White [Hra:(NZW)SPF] rabbits. Pregnant rabbits were given continual access to ammonium perchlorate in drinking water at target doses of 0, 0.1, 1.0, 10.0, 30.0, and 100.0 mg/kg-day on gestation days 6 through 28. The actual consumed doses in the study were 0, 0.1, 0.9, 10.4, 30.3, and 102.3 mg/kg-day. The rabbits were sacrificed on gestation day 29, and fetuses were examined for developmental alterations. In addition, blood was collected from does for determination of serum thyroid stimulating hormone (TSH), triiodothyronine (T3), and thyroxine (T4) levels and the thyroid was subjected to histopathologic examination. No maternal deaths were attributed to perchlorate exposure. Ammonium perchlorate as high as 100.0 mg/kg-day did not affect caesarean sectioning or litter parameters studied, and all values were found to be within the historical ranges of the laboratory. The litter averages for corpora lutea, implantations, litter sizes, live and dead fetuses, percent dead or resorbed conceptuses, and fetal body weights were comparable and also did not differ significantly in the six dose groups. All placentae appeared normal and no dam had a litter consisting of only resorbed conceptuses. The maternal thyroid was the target organ for ammonium perchlorate in this study. Increased incidence of thyroid follicular hypertrophy was observed in does treated with > or =10 mg/kg-day perchlorate and significantly decreased T4 was observed in does treated with > or =30 mg/kg-day. Based on these data, the maternal no-observable-adverse-effect level (NOAEL) for ammonium perchlorate was 1.0 mg/kg-day. The developmental NOAEL for ammonium perchlorate was found to be 100.0 mg/kg-day for rabbits.

  1. Preliminary analyses for perchlorate in selected natural materials and their derivative products

    USGS Publications Warehouse

    Orris, G.J.; Harvey, G.J.; Tsui, D.T.; Eldrige, J.E.

    2003-01-01

    Increasing concern about sources of perchlorate contamination in ground and surface waters has led to interest in identifying potential sources of natural perchlorate and products derived from these natural sources. To date, most perchlorate found in ground and surface waters has been attributed to its major uses as an oxidizer in solid propellants for rockets, in fireworks and other explosives, and a variety of other uses of man-made perchlorate salts. However, perchlorate found in the soils, surface water, and ground water of some locations cannot be linked to an anthropogenic source. This paper contains preliminary data on the detection and non-detection of perchlorate in a variety of natural materials and their products, including some fertilizer materials. These data were previously presented at two conferences; once in poster session and once orally (Harvey and others, 1999; Orris and others, 2000). Although the results presented here are included in a journal article awaiting publication, the lack of public information on this topic has led to repeated requests for the data used as the basis for our presentations in 1999 and 2000.

  2. Anaerobic treatment of army ammunition production wastewater containing perchlorate and RDX.

    PubMed

    Atikovic, Emina; Suidan, Makram T; Maloney, Stephen W

    2008-08-01

    Perchlorate is an oxidizer that has been routinely used in solid rocket motors by the Department of Defense and National Aeronautics and Space Administration. Royal Demolition Explosive (RDX) is a major component of military high explosives and is used in a wide variety of munitions. Perchlorate bearing wastewater typically results from production of solid rocket motors, while RDX is transferred to Army industrial wastewaters during load, assemble and pack operations for new munitions, and hot water or steam washout for disposal and deactivation of old munitions (commonly referred to as demilitarization, or simply demil). Biological degradation in Anaerobic Fluidized Bed Reactors (AFBR), has been shown to be an effective method for the removal of both perchlorate and RDX in contaminated wastewater. The focus of this study was to determine the effectiveness of removal of perchlorate and RDX, individually and when co-mingled, using ethanol as an electron donor under steady state conditions. Three AFBRs were used to assess the effectiveness of this process in treating the wastewater. The performance of the bioreactors was monitored relative to perchlorate, RDX, and chemical oxygen demand removal effectiveness. The experimental results demonstrated that the biodegradation of perchlorate and RDX was more effective in bioreactors receiving the single contaminant than in the bioreactor where both contaminants were fed.

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

    PubMed

    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.

  4. Impacts of natural organic matter on perchlorate removal by an advanced reduction process.

    PubMed

    Duan, Yuhang; Batchelor, Bill

    2014-01-01

    Perchlorate can be destroyed by Advanced Reduction Processes (ARPs) that combine chemical reductants (e.g., sulfite) with activating methods (e.g., UV light) in order to produce highly reactive reducing free radicals that are capable of rapid and effective perchlorate reduction. However, natural organic matter (NOM) exists widely in the environment and has the potential to influence perchlorate reduction by ARPs that use UV light as the activating method. Batch experiments were conducted to obtain data on the impacts of NOM and wavelength of light on destruction of perchlorate by the ARPs that use sulfite activated by UV light produced by low-pressure mercury lamps (UV-L) or by KrCl excimer lamps (UV-KrCl). The results indicate that NOM strongly inhibits perchlorate removal by both ARP, because it competes with sulfite for UV light. Even though the absorbance of sulfite is much higher at 222 nm than that at 254 nm, the results indicate that a smaller amount of perchlorate was removed with the UV-KrCl lamp (222 nm) than with the UV-L lamp (254 nm). The results of this study will help to develop the proper way to apply the ARPs as practical water treatment processes.

  5. Mechanistic Studies on the Radiolytic Decomposition of Perchlorates on the Martian Surface

    NASA Astrophysics Data System (ADS)

    Turner, Andrew M.; Abplanalp, Matthew J.; Kaiser, Ralf I.

    2016-04-01

    Perchlorates—inorganic compounds carrying the perchlorate ion ({{ClO}}4{}-)—were discovered at the north polar landing site of the Phoenix spacecraft and at the southern equatorial landing site of the Curiosity Rover within the Martian soil at levels of 0.4-0.6 wt%. This study explores in laboratory experiments the temperature-dependent decomposition mechanisms of hydrated perchlorates—namely magnesium perchlorate hexahydrate (Mg(ClO4)2·6H2O)—and provides yields of the oxygen-bearing species formed in these processes at Mars-relevant surface temperatures from 165 to 310 K in the presence of galactic cosmic-ray particles (GCRs). Our experiments reveal that the response of the perchlorates to the energetic electrons is dictated by the destruction of the perchlorate ion ({{ClO}}4{}-) and the inherent formation of chlorates ({{ClO}}3{}-) plus atomic oxygen (O). Isotopic substitution experiments reveal that the oxygen is released solely from the perchlorate ion and not from the water of hydration (H2O). As the mass spectrometer detects only molecular oxygen (O2) and no atomic oxygen (O), atomic oxygen recombines to molecular oxygen within the perchlorates, with the overall yield of molecular oxygen increasing as the temperature drops from 260 to 160 K. Absolute destruction rates and formation yields of oxygen are provided for the planetary modeling community.

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

    PubMed

    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 × 10(7) 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.

  7. Accumulation and perchlorate exposure potential of lettuce produced in the Lower Colorado River region.

    PubMed

    Sanchez, C A; Krieger, R I; Khandaker, N; Moore, R C; Holts, K C; Neidel, L L

    2005-06-29

    The Colorado River is contaminated with perchlorate concentrations of 1.5-8 microg/L, an anion linked to thyroid dysfunction. Over 90% of the lettuce (Lactuca sativa L.) consumed during the winter months in the United States is produced in the Lower Colorado River region. Studies were conducted in this region to survey the potential for lettuce perchlorate accumulation and estimate potential human exposure to perchlorate from lettuce. Total uptake of perchlorate in the above-ground plant of iceberg lettuce was approximately 5 g/ha. Exposure estimates ranged from 0.45 to 1.8 microg/day depending on lettuce types and trimming. For all lettuce types, hypothetical exposures were less than 4% of the reference dose recommended by the National Academy of Sciences. Results show the relative iodide uptake inhibition potential because of lettuce nitrate was 2 orders of magnitude greater than that associated with the corresponding trace levels of perchlorate. These data support the conclusion that potential perchlorate exposures from lettuce irrigated with Colorado River water are negligible relative to acute or long-term harmful amounts.

  8. Perchlorate Formation on Mars Through Surface Radiolysis-Initiated Atmospheric Chemistry: A Potential Mechanism

    NASA Technical Reports Server (NTRS)

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

    2016-01-01

    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 x 10(exp 7) molecules/sq cm/s 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.

  9. Perchlorate contamination of groundwater from fireworks manufacturing area in South India.

    PubMed

    Isobe, Tomohiko; Ogawa, Shohei P; Sugimoto, Rina; Ramu, Karri; Sudaryanto, Agus; Malarvannan, Govindan; Devanathan, Gnanasekaran; Ramaswamy, Babu Rajendran; Munuswamy, Natesan; Ganesh, Deavaraj Sankar; Sivakumar, Jeyaraj; Sethuraman, A; Parthasarathy, V; Subramanian, Annamalai; Field, Jennifer; Tanabe, Shinsuke

    2013-07-01

    Perchlorate contamination was investigated in groundwater and surface water from Sivakasi and Madurai in the Tamil Nadu State of South India. Sensitive determination of perchlorate (LOQ = 0.005 μg/L) was achieved by large-volume (500 μL) injection ion chromatography coupled with tandem mass spectrometry. Concentrations of perchlorate were <0.005-7,690 μg/L in groundwater (n = 60), <0.005-30.2 μg/L in surface water (n = 11), and 0.063-0.393 μg/L in tap water (n = 3). Levels in groundwater were significantly higher in the fireworks factory area than in the other locations, indicating that the fireworks and safety match industries are principal sources of perchlorate pollution. This is the first study that reports the contamination status of perchlorate in this area and reveals firework manufacture to be the pollution source. Since perchlorate levels in 17 out of 57 groundwater samples from Sivakasi, and none from Madurai, exceeded the drinking water guideline level proposed by USEPA (15 μg/L), further investigation on human health is warranted.

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

    NASA Astrophysics Data System (ADS)

    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.

  11. Purification and Characterization of (Per)Chlorate Reductase from the Chlorate-Respiring Strain GR-1

    PubMed Central

    Kengen, Servé W. M.; Rikken, Geoffrey B.; Hagen, Wilfred R.; van Ginkel, Cees G.; Stams, Alfons J. M.

    1999-01-01

    Strain GR-1 is one of several recently isolated bacterial species that are able to respire by using chlorate or perchlorate as the terminal electron acceptor. The organism performs a complete reduction of chlorate or perchlorate to chloride and oxygen, with the intermediate formation of chlorite. This study describes the purification and characterization of the key enzyme of the reductive pathway, the chlorate and perchlorate reductase. A single enzyme was found to catalyze both the chlorate- and perchlorate-reducing activity. The oxygen-sensitive enzyme was located in the periplasm and had an apparent molecular mass of 420 kDa, with subunits of 95 and 40 kDa in an α3β3 composition. Metal analysis showed the presence of 11 mol of iron, 1 mol of molybdenum, and 1 mol of selenium per mol of heterodimer. In accordance, quantitative electron paramagnetic resonance spectroscopy showed the presence of one [3Fe-4S] cluster and two [4Fe-4S] clusters. Furthermore, two different signals were ascribed to Mo(V). The Kmvalues for perchlorate and chlorate were 27 and <5 μM, respectively. Besides perchlorate and chlorate, nitrate, iodate, and bromate were also reduced at considerable rates. The resemblance of the enzyme to nitrate reductases, formate dehydrogenases, and selenate reductase is discussed. PMID:10542172

  12. Rapid analysis of perchlorate in drinking water at parts per billion levels using microchip electrophoresis.

    PubMed

    Gertsch, Jana C; Noblitt, Scott D; Cropek, Donald M; Henry, Charles S

    2010-05-01

    A microchip capillary electrophoresis (MCE) system has been developed for the determination of perchlorate in drinking water. The United States Environmental Protection Agency (USEPA) recently proposed a health advisory limit for perchlorate in drinking water of 15 parts per billion (ppb), a level requiring large, sophisticated instrumentation, such as ion chromatography coupled with mass spectrometry (IC-MS), for detection. An inexpensive, portable system is desired for routine online monitoring applications of perchlorate in drinking water. Here, we present an MCE method using contact conductivity detection for perchlorate determination. The method has several advantages, including reduced analysis times relative to IC, inherent portability, high selectivity, and minimal sample pretreatment. Resolution of perchlorate from more abundant ions was achieved using zwitterionic, sulfobetaine surfactants, N-hexadecyl-N,N-dimethyl-3-ammonio-1-propane sulfonate (HDAPS) and N-tetradecyl-N,N-dimethyl-3-ammonio-1-propane sulfonate (TDAPS). The system performance and the optimization of the separation chemistry, including the use of these surfactants to resolve perchlorate from other anions, are discussed in this work. The system is capable of detection limits of 3.4 +/- 1.8 ppb (n = 6) in standards and 5.6 +/- 1.7 ppb (n = 6) in drinking water.

  13. Enzymes responsible for chlorate reduction by Pseudomonas sp. are different from those used for perchlorate reduction by Azospira sp.

    PubMed

    Steinberg, Lisa M; Trimble, John J; Logan, Bruce E

    2005-06-15

    Pseudomonas sp. PDA is an unusual bacterium due to its ability to respire using chlorate under aerobic conditions. The chlorate reductase produced by PDA was shown to be intrinsically different from the enzyme responsible for chlorate and perchlorate [(per)chlorate] reduction produced by Azospira sp. KJ based on subunit composition and other enzyme properties. The perchlorate reductase from strain KJ appeared to have two subunits (100 and 40 kDa) while the chlorate reductase from PDA had three subunits (60, 48, and 27 kDa). N-terminal amino acid sequencing of the 100 kDa protein from strain KJ showed a 77% similarity with the perchlorate reductase alpha subunit from another perchlorate-respiring bacterium, Dechloromonas agitata, while the N-terminus amino acid sequence of the 60 kDa protein from strain PDA did not show a similarity to previously isolated chlorate or perchlorate reductases.

  14. High-nitrogen-based pyrotechnics: perchlorate-free red- and green-light illuminants based on 5-aminotetrazole.

    PubMed

    Sabatini, Jesse J; Moretti, Jared D

    2013-09-16

    Prototype testing of perchlorate-free hand-held signal illuminants for the US Army's M126 A1 red-star and M195 green-star parachute illuminants are described. Although previous perchlorate-free variants for these items have been developed based on high-nitrogen compounds that are not readily available, the new formulations consist of anhydrous 5-aminotetrazole as the suitable perchlorate replacement. Compared to the perchlorate-containing control, the disclosed illuminants exhibited excellent stabilities toward various ignition stimuli and had excellent pyrotechnic performance. The illuminants are important from both military and civil fireworks perspectives, as the perchlorate-free nature of the illuminants adequately address environmental concerns associated with perchlorate-containing red- and green-light-emitting illuminants.

  15. Development of a Screening Tool to Facilitate Technology Transfer of an Innovative Technology to Treat Perchlorate-Contaminated Water

    DTIC Science & Technology

    2008-03-01

    foods such as fruits, vegetables, and beverages (U.S. FDA, 2004). If the U.S. EPA ultimately establishes a drinking water standard for perchlorate...TREAT PERCHLORATE-CONTAMINATED WATER THESIS Daniel A. Craig, Captain, USAF AFIT/GEM/ENV/08-M06 DEPARTMENT OF THE AIR FORCE AIR UNIVERSITY...OF AN INNOVATIVE TECHNOLOGY TO TREAT PERCHLORATE- CONTAMINATED WATER THESIS Presented to the Faculty Department of Systems and Engineering

  16. High-performing red-light-emitting pyrotechnic illuminants through the use of perchlorate-free materials.

    PubMed

    Moretti, Jared D; Sabatini, Jesse J; Poret, Jay C

    2014-07-07

    The development of perchlorate-free M662 40 mm illuminating pyrotechnic compositions is described. On the bases of cost, performance, and sensitivity, potassium periodate was determined to be most effective potassium perchlorate replacement in the compositions tested. The optimal periodate-based composition exceeded the performance of the perchlorate-containing control, exhibited low sensitivity values to impact, friction, and electrostatic discharge, and had high thermal onset temperatures.

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

    DOEpatents

    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.

  18. The sensitivity of fixed-bed biological perchlorate removal to changes in operating conditions and water quality characteristics.

    PubMed

    Brown, Jess C; Snoeyink, Vernon L; Raskin, Lutgarde; Lin, Richard

    2003-01-01

    Flow rate, electron donor addition, and biomass control were evaluated in order to optimize perchlorate (ClO4-) removal from drinking water using biologically active carbon (BAC) filtration. Influent dissolved oxygen (DO) was lowered from ambient conditions to approximately 2.5 mg/L for all experiments using a nitrogen sparge. When influent nitrate concentration was 0-2.0 mg/L, 1.6-2.8 mg/L as carbon of acetate or ethanol was required to achieve and sustain the complete removal of 50 microg/L perchlorate in a BAC filter. Most or all of the exogenous acetate and ethanol was removed during biofiltration. When a 72-h electron donor feed failure was simulated, a maximum perchlorate breakthrough of 18 microg/L was observed and, once electron donor was reapplied, 9 days were required to reestablish complete perchlorate removal. During a 24-h electron donor feed failure simulation, the maximum effluent perchlorate concentration detected was 6.7 microg/L. Within 24 h of reactivating the electron donor, the filter regained its capacity to consistently remove 50 microg/L perchlorate to below detection. Although biomass growth diminished the filter's ability to consistently remove perchlorate, a cleaning procedure immediately restored stable, complete perchlorate removal. This cleaning procedure was required approximately every 50 days (4800 bed volumes) when influent DO concentration was 2.5 mg/L. Empty-bed contact time (EBCT) experiments showed that 80% perchlorate removal was achieved using a 5-min EBCT, and complete perchlorate removal was observed for an EBCT of 9 min. It was also demonstrated that BAC filtration consistently removed perchlorate to below detection for influent perchlorate concentrations ranging from 10 to 300 microg/L, influent sulfate concentrations between 0 and 220 mg/L, influent pH values of 6.5-9.0, and operating temperatures of 5-22 degrees C.

  19. Dispersion strengthened copper

    DOEpatents

    Sheinberg, H.; Meek, T.T.; Blake, R.D.

    1990-01-09

    A composition of matter is described which is comprised of copper and particles which are dispersed throughout the copper, where the particles are comprised of copper oxide and copper having a coating of copper oxide. A method for making this composition of matter is also described. This invention relates to the art of powder metallurgy and, more particularly, it relates to dispersion strengthened metals.

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

    PubMed

    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.

  1. Fate of perchlorate in a man-made reflecting pond following a fireworks display in Albany, New York, USA.

    PubMed

    Wu, Qian; Oldi, John F; Kannan, Kurunthachalam

    2011-11-01

    Perchlorate is a widespread contaminant in aquatic environments. Despite this, the aquatic environmental fate of perchlorate released from fireworks displays is not well known. In the present study, we examined the fate of perchlorate in man-made reflecting ponds, from 2008 to 2010, following three fireworks displays in Albany, New York, USA. Immediately after the fireworks display, perchlorate in pond waters increased significantly, with concentrations from 30 to 1,480 times higher than the baseline values. Perchlorate concentrations in pond water increased from 0.11 µg/L to up to 519 µg/L, following the fireworks display in 2008. Perchlorate concentrations in pond water decreased at a first-order kinetic degradation rate, with a mean k(obs) value of 0.026 d⁻¹ and an average half-life of 29 d. The rate of perchlorate deposition into water bodies following fireworks displays was estimated to range from 670 to 2,620 g/ha. We also estimated the perchlorate ingestion rate by the inhalation of aerosols of pond water by people frequently near the ponds. The estimated daily intake of perchlorate through the ingestion of aerosols was 32% (226 ng/kg body wt), 13% (92 ng/kg body wt), and 6% (42 ng/kg body wt) of the U.S. Environmental Protection Agency's reference dose for infants, children, and adults, respectively.

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

    NASA Technical Reports Server (NTRS)

    Navarro-Gonzalex, Rafael; Sutter, Brad; Archer, Doug; Ming, Doug; Eigenbrode, Jennifer; Franz, Heather; Glavin, Daniel; McAdam, Amy; Stern, Jennifer; McKay, Christopher; Coll, Patrice; Cabane, Michel; Mahaffy, Paul; Conrad, Pamela; Martin-Torres, Francisco; Zorzano-Mier, Maria; Grotzinger, John

    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 <0.1 percent perchlorate and ppm levels of organic carbon at landing site 1 and 2 [2]. The suggestion of perchlorate in the Viking sites [2] has been challenged on the grounds that the 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

  3. The Effects of Perchlorate and its Precursors on Organic Molecules under Simulated Mars Conditions

    NASA Astrophysics Data System (ADS)

    Carrier, B. L.; Beegle, L. W.; Bhartia, R.; Abbey, W. J.

    2016-12-01

    Perchlorate (ClO4-) was first detected on Mars by the Phoenix Lander in 2008 [1] and has subsequently been detected by Curiosity in Gale Crater [2], in Mars meteorite EETA79001 [3], and has been proposed as a possible explanation for results obtained by Viking [4]. Perchlorate has also been shown to be formed under current Mars conditions via the oxidation of mineral chlorides, further supporting the theory that perchlorate is present globally on Mars [5]. The discovery of perchlorate on Mars has raised important questions about its effects on the survival and detection of organic molecules. Although it has been shown that pyrolysis in the presence of perchlorate results in the alteration or destruction of organic molecules [2, 4], few studies have been conducted on the potential effects of perchlorate and its precursors on organic molecules prior to analysis. Perchlorate is typically inert under Mars temperatures and pressures, but it has been shown to decompose to form reactive oxychlorine species such as chlorite (ClO2-), hypochlorite (ClO-) and chlorine dioxide (ClO2) when exposed to Mars conditions including ionizing radiation [6]. The oxidation of chloride to perchlorate also results in the formation of reactive oxychlorine species such as chlorate (ClO3-) [5]. Here we investigate the effects of perchlorate and its oxychlorine precursors on organic molecules. Experiments are performed in a Mars Simulation Chamber (MSC) capable of reproducing the temperature, pressure, atmospheric composition and UV flux found on Mars. Soil simulants are prepared consisting of Mojave Mars Simulant (MMS) [7] and each organic, as well as varying concentrations of perchlorate and/or chloride salts, and exposed in the MSC. Subsequent to exposure in the MSC samples are leached and the leachate analyzed by HPLC and LC-MS to determine the degree of degradation of the original organic and the identity of any potential decomposition products formed by oxidation or chlorination

  4. Concurrent microbial reduction of high concentrations of nitrate and perchlorate in an ion exchange membrane bioreactor.

    PubMed

    Fox, Shalom; Bruner, Tali; Oren, Yoram; Gilron, Jack; Ronen, Zeev

    2016-09-01

    We investigated effective simultaneous removal of high loads of nitrate and perchlorate from synthetic groundwater using an ion exchange membrane bioreactor (IEMB). The aim of this research was to characterize both transport aspects and biodegradation mechanisms involved in the treatment process of high loads of the two anions. Biodegradation process was proven to be efficient with over 99% efficiency of both perchlorate and nitrate, regardless of their load. The maximum biodegradation rates were 18.3 (mmol m(-2)  h(-1) ) and 5.5 (mmol m(-2)  h(-1) ) for nitrate and perchlorate, respectively. The presence of a biofilm on the bio-side of the membrane only slightly increased the nitrate and perchlorate transmembrane flux as compared to the measured flux during a Donnan dialysis experiment where there is no biodegradation of perchlorate and nitrate in the bio-compartment. The nitrate flux in presence of a biofilm was 18.3 (±1.9) (mmole m(-2)  h(-1) ), while without the biofilm, the flux was 16.9 (±1.5) (mmole m(-2)  h(-1) ) for the same feed inlet nitrate concentration of 4 mM. The perchlorate transmembrane flux increased similarly by an average of 5%. Samples of membrane biofilm and suspended bacteria from the bio-reactor were analyzed for diversity and abundance of the perchlorate and nitrate reducing bacteria. Klebsiella oxytoca, known as a glycerol fermenter, accounted for 70% of the suspended bacteria. In contrast, perchlorate and nitrate reducing bacteria predominated in the biofilm present on the membrane. These results are consistent with our proposed two stage biodegradation mechanism where glycerol is first fermented in the suspended phase of the bio-reactor and the fermentation products drive perchlorate and nitrate bio-reduction in the biofilm attached to the membrane. These results suggest that the niche exclusion of microbial populations in between the reactor and membrane is controlled by the fluxes of the electron donors and

  5. Perchlorate in the San Antonio Segment of the Edwards Aquifer, Texas

    NASA Astrophysics Data System (ADS)

    Fahlquist, L.; Rajagapolan, S.; Jackson, W. A.

    2007-12-01

    Perchlorate has been detected in drinking-water supplies and can have adverse health effects on humans by disrupting thyroid function. Perchlorate and other constituents were analyzed from ground-water samples that were collected in 2004-06 from 99 wells completed in the San Antonio segment of the Edwards aquifer as part of the U.S. Geological Survey National Water-Quality Assessment Program. The fractured karstic carbonate Edwards aquifer, declared a sole-source aquifer by the U.S. Environmental Protection Agency, supplies nearly one-half million acre-feet per year for drinking water and other uses. Wells were located in a variety of land-use settings that included rangeland, agriculture, and urban; well types included domestic, public, and observation. Perchlorate was detected in 98 percent of the samples, and concentrations ranged from less than 0.05 to 3 micrograms per liter (μg/L). Five samples contained concentrations greater than 1 μg/L and were from wells in the urban northern San Antonio area. The results from three samples that contained perchlorate at concentrations greater than 2 μg/L are anomalous. Chloride concentration ranged from 5.6 to 69 milligrams per liter, typical for freshwater in the Edwards aquifer. No significant (r2 greater than 0.7) correlations were observed when perchlorate concentrations were correlated with depth to water, total depth of well, or concentrations of bicarbonate, nitrate, phosphate, sulfate, bromide, chloride, fluoride, calcium, magnesium, potassium, sodium, strontium, and dissolved solids. Tritium concentrations ranged from 1.2 to 2.9 tritium units in 31 of the 99 samples and indicate at least some fraction of modern water (post-atmospheric nuclear tests). No correlation between apparent tritium age and perchlorate concentration was observed, a possible indication that anthropogenic influences are not affecting observed perchlorate concentrations. The molar ratio of chloride to perchlorate ranged from 17,000 to 320

  6. The Radar Effects of Perchlorate-Doped Ice in the Martian Polar Layered Deposits

    NASA Astrophysics Data System (ADS)

    Stillman, D.; Winebrenner, D. P.; Grimm, R. E.; Pathare, A.

    2010-12-01

    The presence of perchlorate in soil at near-polar latitudes on Mars suggests that dust in the ice of the North Polar Layered Deposits (NPLD) may introduce perchlorate impurities to that ice. Because eutectic temperatures of perchlorate salts range as low as 206 K (for magnesium perchlorate), perchlorate doping of NPLD ice may result in grain-scale liquid veins and softening of ice rheology at temperatures comparable to those computed for the base of the NPLD in the present climate. Any such softening would be important for understanding how processes including ice flow have shaped the NPLD. Observable consequences of such softening, or of the combination of perchlorate doping and temperatures that could cause softening, are thus similarly important. In particular, the dielectric properties of perchlorate-laden ice in a temperature gradient will change relatively rapidly at the point in the gradient near the eutectic temperature. Here we investigate the radar reflectivity of such a eutectic transition in ice with a model in which perchlorate concentration is constant and temperature varies linearly with depth in the ice. We have conducted measurements of the complex permittivity of Mg and Na perchlorate-doped ice over a range of temperatures (183 - 273 K) and concentrations. Below the eutectic temperature, the perchlorate-doped ice has electrical properties similar to that of choride-doped ice. However, above the eutectic temperature, some of the ice melts forming liquid at triple junctions. At concentrations above 3 mM, the liquid at triple junctions become connected forming brine channels, which greatly increase the dc conductivity and radar attenuation. At concentrations below 3 mM, the liquid at triple junctions are not connected and do not affect the dc conductivity. However, the liquid H2O molecules are able to rotate their permanent dipole at radar frequencies, thus causing an increase in radar attenuation. The MARSIS and SHARAD attenuation rates increase

  7. Copper peroxide

    NASA Technical Reports Server (NTRS)

    Moser, L.

    1988-01-01

    A number of oxidizing agents, including chlorine, bromine, ozone and other peroxides, were allowed to act on copper solutions with the intention of forming copper peroxide. The only successful agent appears to be hydrogen peroxide. It must be used in a neutral 50 to 30 percent solution at a temperature near zero. Other methods described in the literature apparently do not work. The excess of hydrogen must be quickly sucked out of the brown precipitate, which it is best to wash with alcohol and ether. The product, crystalline under a microscope, can be analyzed only approximately. It approaches the formula CuO2H2O. In alkaline solution it appears to act catalytically in causing the decomposition of other peroxides, so that Na2O2 cannot be used to prepare it. On the addition of acids the H2O2 is regenerated. The dry substance decomposes much more slowly than the moist but is not very stable.

  8. Copper metallothioneins.

    PubMed

    Calvo, Jenifer; Jung, Hunmin; Meloni, Gabriele

    2017-04-01

    Metallothioneins (MTs) are a class of low molecular weight and cysteine-rich metal binding proteins present in all the branches of the tree of life. MTs efficiently bind with high affinity several essential and toxic divalent and monovalent transition metals by forming characteristic polynuclear metal-thiolate clusters within their structure. MTs fulfil multiple biological functions related to their metal binding properties, with essential roles in both Zn(II) and Cu(I) homeostasis as well as metal detoxification. Depending on the organism considered, the primary sequence, and the specific physiological and metabolic status, Cu(I)-bound MT isoforms have been isolated, and their chemistry and biology characterized. Besides the recognized role in the biochemistry of divalent metals, it is becoming evident that unique biological functions in selectively controlling copper levels, its reactivity as well as copper-mediated biochemical processes have evolved in some members of the MT superfamily. Selected examples are reviewed to highlight the peculiar chemical properties and biological functions of copper MTs. © 2016 IUBMB Life, 69(4):236-245, 2017. © 2017 International Union of Biochemistry and Molecular Biology.

  9. Analysis of hydroponic fertilizer matrixes for perchlorate: comparison of analytical techniques.

    PubMed

    Collette, Timothy W; Williams, Ted L; Urbansky, Edward T; Magnuson, Matthew L; Hebert, Gretchen N; Strauss, Steven H

    2003-01-01

    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), normal Raman spectroscopy, and infrared spectroscopy using an attenuated total reflectance crystal (ATR-FTIR) coated with a thin film of an organometallic ion-exchange compound. Three of the five solid products were found by all techniques to contain perchlorate at the level of approximately 100-350 mg kg(-1). The remaining products did not contain perchlorate above the detection level of any of the techniques. Comparative analysis using several analytical techniques that depend on different properties of perchlorate allow for a high degree of certainty in both the qualitative and quantitative determinations. This proved particularly useful for these samples, due to the complexity of the matrix. Analyses of this type, including multiple spectroscopic confirmations, may also be useful for other complicated matrixes (e.g., biological samples) or in forensic/regulatory frameworks where data are likely to be challenged. While the source of perchlorate in these hydroponic products is not known, the perchlorate-to-nitrate concentration ratio (w/w) in the aqueous extracts is generally consistent with the historical weight percent of water soluble components in caliche, a nitrate-bearing ore found predominantly in Chile. This ore, which is the only well-established natural source of perchlorate, is mined and used, albeit minimally, as a nitrogen source in some fertilizer products.

  10. The Perchlorate Reduction Genomic Island: Mechanisms and Pathways of Evolution by Horizontal Gene Transfer.

    PubMed

    Melnyk, Ryan A; Coates, John D

    2015-10-26

    Perchlorate is a widely distributed anion that is toxic to humans, but serves as a valuable electron acceptor for several lineages of bacteria. The ability to utilize perchlorate is conferred by a horizontally transferred piece of DNA called the perchlorate reduction genomic island (PRI). We compared genomes of perchlorate reducers using phylogenomics, SNP mapping, and differences in genomic architecture to interrogate the evolutionary history of perchlorate respiration. Here we report on the PRI of 13 genomes of perchlorate-reducing bacteria from four different classes of Phylum Proteobacteria (the Alpha-, Beta-, Gamma- and Epsilonproteobacteria). Among the different phylogenetic classes, the island varies considerably in genetic content as well as in its putative mechanism and location of integration. However, the islands of the densely sampled genera Azospira and Magnetospirillum have striking nucleotide identity despite divergent genomes, implying horizontal transfer and positive selection within narrow phylogenetic taxa. We also assess the phylogenetic origin of accessory genes in the various incarnations of the island, which can be traced to chromosomal paralogs from phylogenetically similar organisms. These observations suggest a complex phylogenetic history where the island is rarely transferred at the class level but undergoes frequent and continuous transfer within narrow phylogenetic groups. This restricted transfer is seen directly by the independent integration of near-identical islands within a genus and indirectly due to the acquisition of lineage-specific accessory genes. The genomic reversibility of perchlorate reduction may present a unique equilibrium for a metabolism that confers a competitive advantage only in the presence of an electron acceptor, which although widely distributed, is generally present at low concentrations in nature.

  11. Developmental Exposure to Perchlorate Alters Synaptic Transmission in Hippocampus of the Adult Rat

    PubMed Central

    Gilbert, Mary E.; Sui, Li

    2008-01-01

    Background Perchlorate is an environmental contaminant that blocks iodine uptake into the thyroid gland and reduces thyroid hormones. This action of perchlorate raises significant concern over its effects on brain development. Objectives The purpose of this study was to evaluate neurologic function in rats after developmental exposure to perchlorate. Methods Pregnant rats were exposed to 0, 30, 300, or 1,000 ppm perchlorate in drinking water from gestational day 6 until weaning. Adult male offspring were evaluated on a series of behavioral tasks and neurophysiologic measures of synaptic function in the hippocampus. Results At the highest perchlorate dose, triiodothyronine (T3) and thyroxine (T4) were reduced in pups on postnatal day 21. T4 in dams was reduced relative to controls by 16%, 28%, and 60% in the 30-, 300-, and 1,000-ppm dose groups, respectively. Reductions in T4 were associated with increases in thyroid-stimulating hormone in the high-dose group. No changes were seen in serum T3. Perchlorate did not impair motor activity, spatial learning, or fear conditioning. However, significant reductions in baseline synaptic transmission were observed in hippocampal field potentials at all dose levels. Reductions in inhibitory function were evident at 300 and 1,000 ppm, and augmentations in long-term potentiation were observed in the population spike measure at the highest dose. Conclusions Dose-dependent deficits in hippocampal synaptic function were detectable with relatively minor perturbations of the thyroid axis, indicative of an irreversible impairment in synaptic transmission in response to developmental exposure to perchlorate. PMID:18560531

  12. Effect of fireworks display on perchlorate in air aerosols during the Spring Festival

    NASA Astrophysics Data System (ADS)

    Shi, Yali; Zhang, Ning; Gao, Jianmin; Li, Xin; Cai, Yaqi

    2011-02-01

    Perchlorate is regarded as a new emerging persistent inorganic environmental contaminant. It can result in important neurodevelopmental deficits and goiter in infants and children because of its inhibition of iodine uptake into the thyroid tissue. Furthermore, its presence in the human body can cause improper regulation of metabolism for adults. It is often used as ingredient in the production of fireworks. So fireworks display may influence the perchlorate levels in atmospheric particulate matter (PM). In this paper perchlorate was determined in air aerosol samples (Inhalable particulate matter (PM10) and larger particulate matter (PM10-100)) collected from two locations (Lanzhou City and Yuzhong County) in Gansu province over a month period (February 1rst to March 4th) during the Spring Festival (February 18th) in 2007 in order to study the effect of fireworks display on perchlorate in air aerosol. The results showed that different concentrations of perchlorate were detected in almost all samples, ranging from perchlorate were 91% (100%) and 50% (59%) for PM10-100 (PM10) in Lanzhou City and Yuzhong County, respectively. The highest concentrations were all found in the samples from two sites on New Year's Eve, which was 39.16 ng m -3 (PM10-100) and 9.89 ng m -3 (PM10) for Lanzhou city, 3.43 ng m -3 (PM10-100) and 4.97 ng m -3 (PM10) for Yuzhong County, 6.8-26.2 times as the mean concentrations during the period of no or limited fireworks display. This indicated that the fireworks display during the Spring Festival can result in the levels of perchlorate increase.

  13. Gestational exposure to high perchlorate concentrations in drinking water and neonatal thyroxine levels.

    PubMed

    Amitai, Yona; Winston, Gary; Sack, Joseph; Wasser, Janice; Lewis, Matthew; Blount, Benjamin C; Valentin-Blasini, Liza; Fisher, Nirah; Israeli, Avi; Leventhal, Alex

    2007-09-01

    To assess the effect of gestational perchlorate exposure through drinking water on neonatal thyroxine (T(4)). T(4) values were compared among newborns in Ramat Hasharon, Israel, whose mothers resided in suburbs where drinking water contained perchlorate < or = 340 microg/L (very high exposure, n = 97), 42-94 microg/L (high exposure, n = 216), and < 3 microg/L (low exposure, n = 843). In the very high and high exposure areas, T(4) values in newborns whose mothers drank tap water exclusively (as determined by a telephone interview) were analyzed as a subset. Serum perchlorate levels in blood from donors residing in the area were used as proxy indicators of exposure. Neonatal T(4) values (mean +/- SD) in the very high, high, and low exposure groups were 13.9 +/- 3.8, 13.9 +/- 3.4, and 14.0 +/- 3.5 microg/dL, respectively (p = NS). Serum perchlorate concentrations in blood from donors residing in areas corresponding to these groups were 5.99 +/- 3.89, 1.19 +/- 1.37, and 0.44 +/- 0.55 microg/L, respectively. T(4) levels of neonates with putative gestational exposure to perchlorate in drinking water were not statistically different from controls. This study finds no change in neonatal T(4) levels despite maternal consumption of drinking water that contains perchlorate at levels in excess of the Environmental Protection Agency (EPA) drinking water equivalent level (24.5 microg/L) based on the National Research Council reference dose (RfD) [0.7 microg/(kg.day)]. Therefore the perchlorate RfD is likely to be protective of thyroid function in neonates of mothers with adequate iodide intake.

  14. NOVEL ASSOCIATIONS BETWEEN URINARY PERCHLORATE AND POTENTIALLY RELEVANT EFFECTS ON RISK FACTORS FOR HEART DISEASE BASED ON NHANES 2001-2002

    EPA Science Inventory

    Perchlorate is a widespread environmental pollutant, and is a thyroid hormone disruptor. A previous population study based on the National Health and Nutrition Examination Survey (NHANES) 2001-2002 database showed that urinary perchlorate concentrations were associated with signi...

  15. Microbial Community Structure during Nitrate and Perchlorate Reduction in Ion-exchange Brine Using the Hydrogen-based membrane Biofilm Reactor (MBIR)

    EPA Science Inventory

    Detoxification of perchlorate by microbial communities under denitrifying conditions has been recently reported, although the identity of the mixed populations involved in perchlorate reduction is not well understood. In order to address this, the bacterial diversity of membrane ...

  16. Association between Perchlorate and indirect indicators of thyroid dysfunction in NHANES 2001-2002, a Cross-Sectional, Hypothesis-Generating Study

    EPA Science Inventory

    Background: A previous study observed associations of urinary perchlorate with thyroid hormones based on the National Health and Nutrition Examination Survey (NHANES) 2001-2002. Increased levels of urinary perchlorate were associated with increased levels of thyroid stimulating h...

  17. NOVEL ASSOCIATIONS BETWEEN URINARY PERCHLORATE AND POTENTIALLY RELEVANT EFFECTS ON RISK FACTORS FOR HEART DISEASE BASED ON NHANES 2001-2002

    EPA Science Inventory

    Perchlorate is a widespread environmental pollutant, and is a thyroid hormone disruptor. A previous population study based on the National Health and Nutrition Examination Survey (NHANES) 2001-2002 database showed that urinary perchlorate concentrations were associated with signi...

  18. Association between Perchlorate and indirect indicators of thyroid dysfunction in NHANES 2001-2002, a Cross-Sectional, Hypothesis-Generating Study

    EPA Science Inventory

    Background: A previous study observed associations of urinary perchlorate with thyroid hormones based on the National Health and Nutrition Examination Survey (NHANES) 2001-2002. Increased levels of urinary perchlorate were associated with increased levels of thyroid stimulating h...

  19. Microbial Community Structure during Nitrate and Perchlorate Reduction in Ion-exchange Brine Using the Hydrogen-based membrane Biofilm Reactor (MBIR)

    EPA Science Inventory

    Detoxification of perchlorate by microbial communities under denitrifying conditions has been recently reported, although the identity of the mixed populations involved in perchlorate reduction is not well understood. In order to address this, the bacterial diversity of membrane ...

  20. Trace Perchlorate in Background Ground Water and Local Precipitation, Northern Rio Grande Basin, New Mexico

    NASA Astrophysics Data System (ADS)

    Dale, M.; Longmire, P.; Granzow, K. P.; Englert, D.; Yanicak, S.; Larson, T.; Rearick, M.; Heikoop, J.; Perkins, G.

    2007-12-01

    Perchlorate occurs at detectable concentrations of 0.07 to 0.45 parts per billion (ppb) in ground water of background quality within the northern Rio Grande basin, New Mexico. Ground-water samples were collected from 47 wells and springs near Los Alamos, Santa Fe, and Taos, New Mexico. Analytical methods consisted of liquid and ion chromatography-mass spectrometry mass spectrometry (LC/MS/MS and IC/MS/MS). An upper tolerance limit (mean plus two standard deviations) of 0.40 ppb was calculated from 184 analytical results for the background samples. Six distinguishable ground-water zones were sampled based on location, age, and hydrochemistry. In the Los Alamos area, ground water within the mountain-front and mountain-block region is mostly young or modern (less than 50 years). The regional aquifer including the White Rock Canyon springs are of sub-modern age (greater than 50 years). Tritium data from springs north of Taos indicate ground water of modern and sub-modern ages. Background perchlorate concentrations within the Los Alamos area were consistently higher than those measured in the Taos area. Ground water from the Taos area contains less perchlorate and has lower δ18O and δ2H values than ground water from the Los Alamos area. The elevation at which precipitation occurs with respect to recharge and/or the amount of evapotranspiration may play a role in perchlorate concentration in ground water. Natural variability, hydrogeology, and atmospheric inputs may also affect perchlorate concentration in ground water. A linear regression through perchlorate and chloride concentrations for all stations resulted in an r2 = 0. However, the r2 value of the Los Alamos regional aquifer for perchlorate versus chloride was 0.66. Thirteen precipitation samples were collected in the Los Alamos area. Results from eleven of these samples showed no perchlorate greater than 0.05 and 0.009 ppb, the method detection limit (MDL). Two precipitation samples analyzed using the IC

  1. [Effects of perchlorate on growth and chlorophyll fluorescence parameters of Alternanthera philoxeroides].

    PubMed

    Xie, Yin-feng; Cai, Xian-lei; Liu, Wei-long; Deng, Wei

    2009-08-15

    Perchlorate is a new emerging persistent pollutant, while no studies about its effects on plants have been reported both home and abroad. In order to explore the effects of perchlorate on growth and physiology of aquatic plant, Alternanthera philoxeroides were treated by 1/20 Hoagland nutrient solution with different concentrations (0, 1, 5, 20, 100, 500 mg/L) of ClO4- under the controlled conditions. The results showed as follow. (1) Under perchlorate treatment, relative growth yield,dry weight of root,shoot and leaves were inhibited at different degrees, in which root biomass under different treatments showed significant difference to the control. After treatment for 40 d, relative growth yield of different treatments at concentration from 1 mg/L to 500 mg/L were about 61.6%, 60.8%, 53.1%, 20.4% and 3.3% separately of the control. And the order of variation coefficients of biomass in different organ were as follows: leaf > root biomass > stem; the relationship of biomass allocation in different organs of Alternanthera philoxeroides under perchlorate treatment changed, and the proportion of stem biomass increased,while leaf decreased, in which 100 and 500 mg/L ClO4- treatment showed significant difference to the control. (2) Under perchlorate treatment, young leaves of Alternanthera philoxeroides presented injury symptoms (such as parietal roiling reversely, leaf edge getting black and withered etc), and the damaged degree of Alternanthera philoxeroides increased with the increase of treatment concentration and time. (3) Under perchlorate treatment, the relative chlorophyll content (SPAD value), primary maximal PSII efficiency(Fv/Fm), efficiency of excitation capture by open PSII centre (F'v,/F'm), actual photochemical efficiency of PSII (phi(PS II)), electron transport rate (ETR), maximal electron transport rate(ETR ,) and other indexes were inhibited at different degrees. SPAD and chlorophyll fluorescence parameters (phi(PS II)) etc. could be used as sensitive

  2. Adaptive evolution of Desulfovibrio alaskensis G20 for developing resistance to perchlorate

    NASA Astrophysics Data System (ADS)

    Mehta-Kolte, M. G.; Youngblut, M.; Redford, S.; Gregoire, P.; Carlson, H. K.; Coates, J. D.

    2015-12-01

    Due to its toxic, explosive, and corrosive nature, inadvertent biological H2S production by sulfate reducing microorganisms (SRM) poses significant health and industrial operational risks. Anthropogenic sources are dominated by the oil industry where H2S in reservoir gases and fluids has an associated annual cost estimated at $90 billion globally. Our previous studies have identified perchlorate (ClO4-) as a selective and potent inhibitor of SRM in pure culture and complex microbial ecosystems. However, constant addition of inhibitors like perchlorate to natural ecosystems may result in a new adaptive selective pressure on SRM populations. With this in mind we investigated the ability of Desulfovibrio alaskensis G20, a model oil reservoir SRM, to adapt to perchlorate and develop a resistance. Serial transfers of three parallel cultures with increasing concentrations of perchlorate up to 100 mM were generated and compared to wild-type strains that were transferred for same number of generations in absence of perchlorate. Genome sequencing revealed that all three adapted strains had single non-synonymous single-nucleotide polymorphisms in the same gene, Dde_2265, the sulfate adenylytransferase (ATP sulfurylase (ATPS)) (EC 2.7.7.4). ATPS catalyzes the first committed step in sulfate reduction and is essential in all SRM. IC50s against growth for these evolved strains demonstrated a three-fold increased resistance to perchlorate compared to wild-type controls. These evolved strains also had 5x higher transcriptional abundance of Dde_2265 compared to the wild-type strain. Biochemical characterization of the purified ATPS enzyme from both wild-type and the evolved strain showed that the mutant ATPS from the evolved strain was resistant to perchlorate inhibition of ATP turnover with a KI for perchlorate that was 3x greater relative to the wild-type ATPS. These results demonstrate that a single-base pair mutation in ATPS can have a significant impact on developing

  3. A survey on the temporal and spatial distribution of perchlorate in the Potomac River.

    PubMed

    Impellitteri, Christopher A; Saxe, Jennie P; Schmitt, Ellen C; Young, K R

    2011-08-01

    Samples of river water and treated drinking water were obtained from eight sites along the Potomac River between western Maryland and Washington DC. Samples were collected each month from October 2007 to September 2008 and analyzed for perchlorate by ion chromatography/mass spectrometry. Data on anions were also collected for seven of the twelve months. Data were analyzed to identify spatial and temporal patterns for the occurrence of perchlorate in the Potomac. Over the year of sampling, the largest monthly increase occurred from June to July, with levels then decreasing from July to September. Samples from the period between December and May had lower perchlorate concentrations, relative to the remainder of the study year. Spatially, higher levels of perchlorate were found at sites located in west-central Maryland, the eastern panhandle of West Virginia, and central northern Virginia, with levels decreasing slightly as the Potomac approaches Washington DC. Within the sampling boundaries, river (untreated) water perchlorate concentrations ranged from 0.03 μg L(-1) to 7.63 μg L(-1), averaged 0.67 ± 0.97 μg L(-1) over the year-long period and had a median value of 0.37 μg L(-1). There was no evidence that any of the existing drinking water treatment technologies at the sampling sites were effective in removing perchlorate. There were no correlations found between the presence of perchlorate and any of the anions or water quality parameters examined in the source water with the exception of a weak positive correlation with water temperature. Results from the summer (June-August) and fall (September-November) months sampled in this study were generally higher than from the winter and spring months (December-May). All but one of the locations had annual average perchlorate levels below 1 μg L(-1); however, 7 of the 8 sites sampled had river water perchlorate detections over 1 μg L(-1) and 5 of the 8 sites had treated water detections over this level.

  4. Perchlorate and nitrate remediation efficiency and microbial diversity in a containerized wetland bioreactor.

    PubMed

    Krauter, Paula; Daily, Bill; Dibley, Valerie; Pinkart, Holly; Legler, Tina

    2005-01-01

    We have developed a method to remove perchlorate (14-27 microg/L) and nitrate (48 mg/L) from contaminated groundwater using a wetland bioreactor. The bioreactor has operated continuously in a remote field location for more than 2 yr with a stable ecosystem of indigenous organisms. This study assesses the bioreactorfor long-term perchlorate and nitrate remediation by evaluating influent and effluent groundwater for oxidation-reduction conditions and nitrate and perchlorate concentrations. Total community DNA was extracted and purified from 10-g sediment samples retrieved from vertical coring of the bioreactor during winter. Analysis by denaturing gradient gel electrophoresis of short, 16S rDNA, polymerase-chainreaction products was used to identify dominant microorganisms. Bacteria genera identified were closely affiliated with bacteria widely distributed in soils, mud layers, and fresh water. Of the 17 dominant bands sequenced, most were gram negative and capable of aerobic or anaerobic respiration with nitrate as the terminal electron acceptor (Pseudomonas, Acinetobacter, Halomonas, and Nitrospira). Several identified genera (Rhizobium, Acinetobactor, and Xanthomonas) are capable of fixing atmospheric nitrogen into a combined form (ammonia) usable by host plants. Isolates were identified from the Proteobacteria class, known for the ability to reduce perchlorate. Initial bacterial assessments of sediments confirm the prevalence of facultative anaerobic bacteria capable of reducing perchlorate and nitrate in situ.

  5. Surface modification of silver nanofilms for improved perchlorate detection by surface-enhanced Raman scattering.

    PubMed

    Hao, Jumin; Han, Mei-Juan; Li, Jinwei; Meng, Xiaoguang

    2012-07-01

    Surface-enhanced Raman scattering (SERS), as one of the most sensitive spectroscopic analysis methods, has been investigated extensively for the detection of environmental contaminants in recent years. In this work, we reported the new development of robust SERS substrates for rapid and sensitive sensing of aqueous perchlorate, a widespread environmental contaminant. The fabrication of the substrates consisted of two simple steps: (a) formation of Ag nanofilms on Cu and surface-roughened Cu foils (Ag/Cu and Ag/rCu nanofilms) using a controllable and inexpensive one-step electroless plating process, and (b) surface modification of the Ag nanofilms with cysteamine (Cys) self-assembly monolayer (SAM) (Cys-Ag/Cu and Cys-Ag/rCu substrates). Due to the strong affinity of -NH(3)(+) groups of the Cys molecules for perchlorate ions, the rapid SERS detection of perchlorate has been realized with a limit of detection (LOD) down to 5 μg L(-1) (ppb) for aqueous samples without need for drying. Various calibration curves with good linear relationships were obtained, indicating the quantification potential of SERS analysis of perchlorate using these new substrates. It was found that the neutral pH yielded the maximum SERS signals, and 85% of original sensitivity was remained in 5 days of storage time in the air, indicating the substrates are fairly stable. Within 10 regeneration-reuse cycles, the SERS signals of perchlorate kept in the range of 85-105% of the original value, verifying its reusability.

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

    NASA Technical Reports Server (NTRS)

    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.

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

    PubMed

    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.

  8. In Situ Perchlorate Determination on Purolite A850 Ion Exchange Resin via Raman Spectroscopy

    SciTech Connect

    Levitskaia, Tatiana G.; Sinkov, Sergei I.; Bryan, Samuel A.

    2007-07-17

    The reported investigation represents a first step toward development of a sensor methodology for in-situ determination of ionic species retained on ion exchange column. Raman spectroscopy was demonstrated as a detection method for determining perchlorate loading on a non-selective ion exchange resin, Purolite A850 acrylic gel. This method has been established using laboratory water (DIW) samples and actual California ground water (CAGW) samples with the complexities of competing ions, dissolved organics, and other potential interfering agents. The detection limit for this method of monitoring perchlorate on resin was measured to be 0.014 meq g-1 for both DIW and CAGW systems. The anion selectivity of the A850 resin was determined via batch contact experiments using CAGW. Linear correlation between resin loading with perchlorate and the intensity of the Raman perchlorate signal was observed and quantitatively described. The obtained relationship was applied for the determination of the perchlorate retained on the A850 resin in the column elution experiments.

  9. Simultaneous removal of perchlorate and nitrate from drinking water using the ion exchange membrane bioreactor concept.

    PubMed

    Matos, Cristina T; Velizarov, Svetlozar; Crespo, João G; Reis, Maria A M

    2006-01-01

    This work evaluates the feasibility of the ion exchange membrane bioreactor (IEMB) concept for the simultaneous removal of perchlorate and nitrate from drinking water, when nitrate is present in the ppm range and perchlorate in the ppb range. The IEMB concept combines Donnan dialysis and simultaneous biological degradation of both pollutants. Membrane transport studies showed that Donnan dialysis is suitable for obtaining water with concentrations of perchlorate and nitrate below the recommended levels. However, the pollutants were accumulated in a receiving stream, thus requiring additional treatment before disposal. On the other hand, the IEMB process operated with hydraulic retention times ranging from 1.4 to 8.3h in the water compartment, proved to remove effectively perchlorate and nitrate while preserving the water composition with respect to other ions, thus avoiding secondary contamination of the treated water. For a polluted water stream containing 100 ppb of ClO(4)(-) and 60 ppm of NO(3)(-), the concentrations of both ions in the treated stream were kept below the recommended levels of 4 ppb for ClO(4)(-) and 25 ppm for NO(3)(-). The IEMB system was operated under ethanol limitation, but even under these conditions, an increase of the perchlorate and nitrate concentrations in the treated water was not observed for up to 6 days.

  10. Ion exchange membrane bioreactor for treating groundwater contaminated with high perchlorate concentrations.

    PubMed

    Fox, Shalom; Oren, Yoram; Ronen, Zeev; Gilron, Jack

    2014-01-15

    Perchlorate contamination of groundwater is a worldwide concern. The most cost efficient treatment for high concentrations is biological treatment. In order to improve and increase the acceptance of this treatment, there is a need to reduce the contact between micro organisms in the treatment unit and the final effluent. An ion exchange membrane bioreactor (IEMB), in which treated water is separated from the bioreactor, was suggested for this purpose. In this study, the IEMB's performance was studied at a concentration as high as 250mgL(-1) that were never studied before. In the bioreactor, glycerol was used as a low cost and nontoxic carbon and energy source for the reduction of perchlorate to chloride. We found that high perchlorate concentrations in the feed rendered the anion exchange membrane significantly less permeable to perchlorate. However, the presence of bacteria in the bio-compartment significantly increased the flux through the membrane by more than 25% in comparison to pure Donnan dialysis. In addition, the results suggested minimal secondary contamination (<3mgCL(-1)) of the treated water with the optimum feed of carbon substrate. Our results show that IEMB can efficiently treat groundwater contaminated with perchlorate as high as 250mgL(-1).

  11. [Determination of iodide, thiocyanate and perchlorate ions in environmental water by two-dimensional ion chromatography].

    PubMed

    Lin, Li; Wang, Haibo; Shi, Yali

    2013-03-01

    A procedure for the determination of iodide, thiocyanate and perchlorate ions in environmental water by two-dimensional ion chromatography has been developed. At first the iodide, thiocyanate and perchlorate ions were separated from interfering ions by a column (IonPac AS16, 250 mm x 4 mm). The iodide ion, thiocyanate and perchlorate ions were then enriched with an enrichment column (MAC-200, 80 mm x 0.75 mm). In the 2nd-dimensional chromatography, iodide thiocyanate and perchlorate ions were separated and quantified by a capillary column (IonPac AS20 Capillary, 250 mm x 0.4 mm). The linear ranges were 0.05 -100 pg/L with correlation coefficients of 0. 999 9, and the detection limits were 0. 02 - 0.05 micro gg/L. The spiked recoveries of iodide, thiocyanate and perchlorate ions were in the range of 85.1% to 100.1%. The relative standard deviations of the recoveries were 1.7% to 4.9%.

  12. Developmental timing of sodium perchlorate exposure alters angiogenesis, thyroid follicle proliferation and sexual maturation in stickleback

    PubMed Central

    Furin, Christoff G.; von Hippel, Frank A.; Postlethwait, John H.; Buck, C. Loren; Cresko, William A.; O’Hara, Todd M.

    2015-01-01

    Perchlorate, a common aquatic contaminant, is well known to disrupt homeostasis of the hypothalamus-pituitary-thyroid axis. This study utilizes the threespine stickleback (Gasterosteus aculeatus) fish to determine if perchlorate exposure during certain windows of development has morphological effects on thyroid and gonads. Fish were moved from untreated water to perchlorate-contaminated water (30 and 100 mg/L) starting at 0, 3, 7, 14, 21, 42, 154 and 305 days post fertilization until approximately one year old. A reciprocal treatment (fish in contaminated water switched to untreated water) was conducted on the same schedule. Perchlorate exposure increased angiogenesis and follicle proliferation in thyroid tissue, delayed gonadal maturity, and skewed sex ratios towards males; effects depended on concentration and timing of exposure. This study demonstrates that perchlorate exposure beginning during the first 42 days of development has profound effects on stickleback reproductive and thyroid tissues, and by implication can impact population dynamics. Long-term exposure studies that assess contaminant effects at various stages of development provide novel information to characterize risk to aquatic organisms, to facilitate management of resources, and to determine sensitive developmental windows for further study of underlying mechanisms. PMID:25865142

  13. Perchlorate and Nitrate Remediation Efficiency and Microbial Diversity in a Containerized Wetland Bioreactor

    SciTech Connect

    Jr., B D; Dibley, V; Pinkart, H; Legler, T

    2004-06-09

    We have developed a method to remove perchlorate (14 to 27 {micro}g/L) and nitrate (48 mg/L) from contaminated groundwater using a wetland bioreactor. The bioreactor has operated continuously in a remote field location for more than two years with a stable ecosystem of indigenous organisms. This study assesses the bioreactor for long-term perchlorate and nitrate remediation by evaluating influent and effluent groundwater for reduction-oxidation conditions and nitrate and perchlorate concentrations. Total community DNA was extracted and purified from 10-g sediment samples retrieved from vertical coring of the bioreactor during winter. Analysis by denaturing gradient gel electrophoresis of short, 16S rDNA, polymerase-chain-reaction products was used to identify dominant microorganisms. Bacteria genera identified were closely affiliated with bacteria widely distributed in soils, mud layers, and fresh water. Of the 17 dominant bands sequenced, most were gram negative and capable of aerobic or anaerobic respiration with nitrate as the terminal electron acceptor (Pseudomonas, Acinetobacter, Halomonas, and Nitrospira). Several identified genera (Rhizobium, Acinetobactor, and Xanthomonas) are capable of fixing atmospheric nitrogen into a combined form (ammonia) usable by host plants. Isolates were identified from the Proteobacteria class, known for the ability to reduce perchlorate. Initial bacterial assessments of sediments confirm the prevalence of facultative anaerobic bacteria capable of reducing perchlorate and nitrate in situ.

  14. Martian Chlorine Chemistry: A Study of Perchlorate on the Martian Surface, Evidence of an Ongoing Formation Mechanism and Implications of a Complex Chlorine Cycle

    NASA Astrophysics Data System (ADS)

    Carrier, Brandi L.

    2015-10-01

    The research presented herein addresses the detection of perchlorate on Mars, evidence of perchlorate in Mars meteorite EETA 79001, determination of the perchlorate parent salts at the Phoenix landing site, and the ongoing formation of perchlorate from chloride minerals as well as from other oxychlorine species. The detection of perchlorate in three samples by the Phoenix Wet Chemistry Laboratory and the implication of these results are discussed. The further detection of perchlorate in Mars meteorite EETA 79001 by ion chromatography and the determination of the parent salts of the perchlorate detected at the Phoenix landing site by electrochemical analyses and ion chromatography are detailed and the implications of the identity of the parent salts are discussed. The possible formation pathways for martian perchlorate are then explored and a possible mechanism for ongoing perchlorate formation on the martian surface is detailed. Perchlorate is shown to be formed upon exposure of chloride minerals, as well as of chlorite and chlorate salts, to current Mars relevant conditions including temperature, pressure, ultraviolet radiation and atmospheric composition. The implications of this ongoing perchlorate formation for the survival and detection of organics, the oxidizing nature of the soil, formation of liquid brines and recurring slope lineae are discussed. Further preliminary experiments have been conducted to investigate the effects of perchlorate formation on the survival and degradation of organic compounds.

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

    NASA Astrophysics Data System (ADS)

    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.

  16. Chlorine-36 abundance in natural and synthetic perchlorate

    SciTech Connect

    Heikoop, Jeffrey M; Dale, M; Sturchio, Neil C; Caffee, M; Belosa, A D; Heraty, Jr., L J; Bohike, J K; Hatzinger, P B; Jackson, W A; Gu, B

    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.

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

    USGS Publications Warehouse

    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.

  18. Molecular and crystal structure of anhydrous zirconium perchlorate

    SciTech Connect

    Genkina, E.A.; Babaeva, V.P.; Rosolovskii, V.Ya.

    1985-08-01

    An x-ray diffraction investigation (diffractometer, Mo K..cap alpha.., graphite monochromator, omega scan technique, Theta less than or equal to 30/sup 0/, 1060 reflections, least-squares method in the anisotropic approximation to R = 0.058) of anhydrous zirconium perchlorate has been carried out. The crystals of Zr(Cl0/sub 4/)/sub 4/ are monoclinic: ..cap alpha.. = 12.899(3), b = 13.188(7), c = 7.937(3) A, ..gamma.. = 107.91/sup 0/, Z = 4, space group Bb. The structure has an island character and is built up from isolated Zr(ClO/sub 4/)/sub 4/ molecules. The Zr atom is surrounded by eight O atoms in four bidentate perchlorato groups. The Zr-O distances lie in the range from 2.13 to 2.23 A, averaging 2.19 A. The eight-vertex polyhedron around Zr is the mmmm steroisomer of a dodecahedron. The centers of the perchlorato groups are located at the vertices of flattened tetrahedron. The ClO/sub 4/ groups have a distorted tetrahedral structure, and the mean length of the Cl-O/sub b/ bonds (1.50 A) is 0.11 A greater than the mean length of the Cl-O/sub t/ bonds, pointing out the essentially covalent character of the bonds of the perchlorato groups with the central Zr atom.

  19. Iodine-deficient vegetarians: a hypothetical perchlorate-susceptible population?

    PubMed

    Fields, Cheryl; Dourson, Michael; Borak, Jonathan

    2005-06-01

    Recent risk assessments of environmental perchlorate have been subject to much debate. A particular concern is whether appropriate susceptible sub-populations have been identified. Iodine-deficient pregnant women, especially vegetarians, have been proposed as such a potential susceptible sub-population, but there is no evidence of iodine deficiency in the US population and the adequacy of iodine nutrition has not been studied in US vegetarians. To understand the possibility that US vegetarians might be iodine deficient, we reviewed the prevalence, demography, and lifestyle characteristics of US vegetarians as well as the world literature on iodine nutrition in vegetarians. Our findings indicate that strict vegetarians and vegans, who comprise probably less than 0.1% of the US population, have higher education, higher incomes, and healthier lifestyles than the general population. Field studies indicate that vegetarian diets need not lead to iodine deficiency and vegans may suffer excess iodine intake. It is remains uncertain whether there are iodine-deficient vegans or pregnant women in the US. Of more general concern is whether the 10-fold default uncertainty factor is needed for intraspecies (i.e., within human) variability to protect such hypothetical susceptible sub-populations.

  20. Chlorine-36 as a tracer of perchlorate origin

    USGS Publications Warehouse

    Sturchio, N.C.; Caffee, M.; Beloso, A.D.; Heraty, L.J.; Böhlke, J.K.; Hatzinger, P.B.; Jackson, W.A.; Gu, B.; Heikoop, J.M.; Dale, M.

    2009-01-01

    Perchlorate (ClO4-) is ubiquitous in the environment. It is produced naturally by atmospheric photochemical reactions, and also is synthesized in large quantities for military, aerospace, and industrial applications. Nitrate-enriched salt deposits of the Atacama Desert (Chile) contain high concentrations of natural ClO4-, and have been exported worldwide since the mid-1800s for use in agriculture. The widespread introduction of synthetic and agricultural ClO4- into the environment has contaminated numerous municipal water supplies. Stable isotope ratio measurements of Cl and O have been applied for discrimination of different ClO4- sources in the environment. This study explores the potential of 36Cl measurements for further improving the discrimination of ClO4- sources. Groundwater and desert soil samples from the southwestern United States (U.S.) contain ClO4- having high 36Cl abundances (36Cl/Cl = 3100 ?? 10-15 to 28,800 ?? 10 -15), compared with those from the Atacama Desert (36Cl/Cl = 0.9 ?? 10-15 to 590 ?? 10-15) and synthetic ClO4- reagents and products (36Cl/Cl = 0.0 ?? 10-15 to 40 ?? 1015). In conjunction with stable Cl and O isotope ratios, 36Cl data provide a clear distinction among three principal. ClO4- source types in the environment of the southwestern U.S. ?? 2009 American Chemical Society.